JP2006016370A - Silane compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a silane compound that provides an adhesive composition with sufficiently strong interfacial bond strength even after long-term preservation by adding the compound to the adhesive composition. <P>SOLUTION: The silane compound is represented by general formula (1) and the silane compound is represented by general formula (2) (R<SP>1</SP>is a 2-12C straight-chain or branched-chain alkyl group, a cycloalkyl group, a phenyl group or a substituted phenyl group; R<SP>2</SP>, R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP>and R<SP>6</SP>are each independently a 1-12C straight-chain or branched-chain alkyl group, a cycloalkyl group, a phenyl group or a substituted phenyl group; n is an integer of 1-6). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel silane compound.

  Silane compounds are used as potting agents for electronic materials, coating agents, and interfacial adhesion improvers for adhesives. Among them, when a silane compound containing a nitrogen atom in the molecule is added to the adhesive composition, it is effective for improving the interfacial adhesive force, but on the other hand, it tends to lower the storage stability of the adhesive composition. .

Under such circumstances, when N-trimethylsilyl-γ-aminopropyltriethoxysilane, which is a silane compound containing a nitrogen atom in the molecule, is contained in a polyorganosiloxane composition used for an elastic adhesive or the like, It has been disclosed that not only the interfacial adhesive strength is improved but also storage stability is improved (see, for example, Patent Documents 1 and 2). This is based on the fact that N-trimethylsilyl-γ-aminopropyltriethoxysilane has a property of trapping alcohol generated when a polyorganosiloxane composition is produced or stored in a sealed state.
JP-A-62-62863 Japanese Patent Laid-Open No. 08-41345

  However, the present inventors have examined in detail conventional silane compounds including N-trimethylsilyl-γ-aminopropyltriethoxysilane described in Patent Documents 1 and 2, and in particular, disclosed in Patent Document 1 or 2. It has been found that N-trimethylsilyl-γ-aminopropyltriethoxysilane is an easily decomposable compound. Therefore, it was revealed that when N-trimethylsilyl-γ-aminopropyltriethoxysilane described in Patent Document 1 or 2 was added to the adhesive composition, the storage stability of the composition was not sufficient.

  In particular, when this silane compound is added to a one-component epoxy adhesive or acrylate adhesive, N-trimethylsilyl-γ-aminopropyltriethoxysilane is decomposed when these adhesives are used after long-term storage. It has been found that since the alcohol that has progressed and is not trapped remains, sufficient interfacial adhesive strength tends not to be obtained.

  Therefore, an object of the present invention is to provide a silane compound that can give a sufficiently strong interfacial adhesive strength even after long-term storage to the adhesive composition by adding to the adhesive composition.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the adhesive composition contains a silane compound having a substituent having a molecular size larger than that of the conventional silane compound. It has been found that the interfacial adhesive strength and storage stability tend to be improved. At the same time, it has been found that if the molecular size of the substituent of the silane compound is increased too much, the interfacial adhesive strength tends to decrease. Based on such findings, the present inventors have examined in more detail. In a silane compound having a substituted silyl group bonded to a nitrogen atom, the substituent of the substituted silyl group is not stored after long-term storage of the adhesive composition. The present invention has been completed by finding that it has a great influence on the interfacial adhesive strength.

That is, the novel silane compound of the present invention is represented by the following general formula (1) or (2).

In the formulas (1) and (2), R ¹ represents a linear or branched alkyl group having 2 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represents a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group, and n represents an integer of 1 to 6. Show.

In the silane compound having such a structure, R ¹ which is a substituent of a silicon atom bonded to a nitrogen atom is a linear or branched alkyl group having 2 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituent. R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or substituted phenyl. Since it is a group, by adding this silane compound to the adhesive composition, a sufficiently strong interfacial adhesive strength can be obtained for the adhesive composition even after long-term storage.

  The reason for this is not clear, but it is considered that the structure and polarity of the substituent of the silicon atom bonded to the nitrogen atom influence the characteristics of the silane compound containing the nitrogen atom. However, the factor is not limited to this.

In the above silane compound, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each have 4 to 8 carbon atoms in the cycloalkyl group, and the substituent of the substituted phenyl group is a monovalent organic group Or it is preferably a halogen atom.

In the silane compound, R ¹ is a linear or branched alkyl group having 2 to 5 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or a phenyl group, and R ² and R ³ are each independently More preferably, it is an alkyl group or phenyl group having 1 to 5 carbon atoms, and R ⁴ , R ⁵ and R ⁶ are each independently a methyl group or an ethyl group, and R ¹ is an isopropyl group, a t-butyl group or a phenyl group. More preferably, R ⁴ , R ⁵ and R ⁶ are ethyl groups.

If R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ^{6 in the} general formula (1) or (2) are these substituents, the adhesive composition when added to the adhesive composition It is possible to obtain stronger interfacial adhesive strength after storage for a long time.

  According to the present invention, by adding to an adhesive composition, it is possible to provide a silane compound that can impart sufficiently strong interfacial adhesive strength to the adhesive composition even after long-term storage.

  Hereinafter, preferred embodiments of the present invention will be shown and described in further detail.

The silane compound of the present invention may be any compound as long as it has a structure represented by the following general formulas (1) and (2).

In the formulas (1) and (2), R ¹ represents a linear or branched alkyl group having 2 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group, and n represents an integer of 1 to 6. .

  With such a structure, the adhesive composition is excellent in interfacial adhesive strength and storage stability after long-term storage.

That is, in the above general formulas (1) and (2), the silane compound is added to the adhesive composition as the bulkiness of R ¹ , R ² and R ³ which are substituents of the silicon atom bonded to the nitrogen atom increases. When contained, the storage stability of the adhesive composition is improved. On the other hand, when R ¹ , R ² and R ³ are all methyl groups having a low bulkiness, the storage stability of the adhesive composition is reduced when the silane compound is contained in the adhesive composition. Tend to.

Therefore, in the present embodiment, from the viewpoint of improving the storage stability, among R ¹ , R ² and R ³ , R ¹ is an alkyl group having 2 or more carbon atoms, a cycloalkyl group having 4 or more carbon atoms, or a phenyl group. A silane compound is employed.

Further, when R ¹ , R ² and R ³ which are substituents of silicon atoms bonded to nitrogen atoms contain a silane compound in the adhesive composition as the bulkiness decreases, the interfacial adhesion of the adhesive composition Strength tends to improve. On the other hand, when the bulkiness of R ¹ , R ² and R ³ increases, the interfacial adhesive strength of the adhesive composition tends to decrease when the silane compound is contained in the adhesive composition.

Therefore, in the present embodiment, from the viewpoint of improving the interfacial bond strength, among R ¹ , R ² and R ³ , R ¹ is an alkyl group having 12 or less carbon atoms, a cycloalkyl group having 8 or less carbon atoms, or a phenyl group. R ² and R ³ each independently adopts a silane compound having an alkyl group having 12 or less carbon atoms, a cycloalkyl group having 8 or less carbon atoms, or a phenyl group.

  Considering these comprehensively, as a silane compound that can achieve both high interfacial adhesive strength and storage stability when added to an adhesive composition, a compound having the structure of the above general formulas (1) and (2) Become.

Here, in the above R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , the cycloalkyl group preferably has 4 to 8 carbon atoms, and the substituent of the substituted phenyl group Is preferably a monovalent organic group or a halogen atom.

In the formulas (1) and (2), R ¹ is a linear or branched alkyl group having 2 to 5 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or a phenyl group, and the R ² and R ³ are each independently a linear or branched alkyl group having 1 to 5 carbon atoms or a phenyl group, and the above R ⁴ , R ⁵ and R ⁶ are each independently a methyl group or an ethyl group. Is more preferable.

Further, in the above formulas (1) and (2), it is particularly preferable that R ¹ is an isopropyl group, a t-butyl group or a phenyl group, and that R ⁴ , R ⁵ and R ⁶ are each independently an ethyl group. preferable.

If R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ^{6 in the} above general formula (1) or (2) are these substituents, the adhesive when added to the adhesive composition A stronger interfacial adhesive strength can be obtained for the composition even after long-term storage.

  As specific structures of the silane compounds represented by the above formula (1) or (2), the following general formulas (1-1) to (1-50) and (2-1) shown in the following Tables 1 to 8 are used. ) To (2-50) are preferred examples. In formulas (1-1) to (1-50) and (2-1) to (2-50), Me is a methyl group, Et is an ethyl group, Pro is an n-propyl group, and Bu is n-butyl. The group Ph means a phenyl group.

  Next, a preferred embodiment according to the synthesis method of the novel silane compound according to the present invention will be described.

  The method for synthesizing the silane compound according to the present invention is not particularly limited, and generally known organic chemical reactions can be preferably used. Specific examples of the synthesis method that can be preferably used in the present invention include a coupling reaction (hereinafter simply referred to as “reaction”) between a silyl ether compound having a primary amino group and an alkyl (phenyl) silyl halide. The By this synthesis method, dehydrohalogenation occurs, and a silane compound in which the hydrogen atom of the amino group in the silyl ether compound having an amino group is substituted with an alkyl (phenyl) silyl group can be obtained.

Examples of the silyl ether compound having a primary amino group include those having the structures shown in the following general formulas (3) and (4).

In formulas (3) and (4), R ⁴ , R ⁵ and R ⁶ are each independently a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group. N represents an integer of 1 to 6.

In the above R ⁴ , R ⁵ and R ⁶ , the cycloalkyl group preferably has 4 to 8 carbon atoms, and the substituent of the substituted phenyl group is a monovalent organic group or a halogen atom. Preferably there is.

In the above formulas (3) and (4), it is more preferable that R ⁴ , R ⁵ and R ⁶ are each independently a methyl group or an ethyl group, and it is particularly preferable that all are ethyl groups.

Examples of the alkyl (phenyl) silyl halide include those having a structure represented by the following general formula (5).

In Formula (5), R ¹ represents a linear or branched alkyl group having 2 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group, and R ² and R ³ each independently represent a carbon number. 1 to 12 linear alkyl groups or branched alkyl groups, cycloalkyl groups, phenyl groups, or substituted phenyl groups are represented, and X represents a halogen atom (fluorine, chlorine, bromine, iodine).

In R ¹ , R ² and R ³ , the cycloalkyl group preferably has 4 to 8 carbon atoms, and the substituent of the substituted phenyl group is a monovalent organic group or a halogen atom. It is preferable.

In the above formula (5), R ¹ is a linear or branched alkyl group having 2 to 5 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or a phenyl group, and the above R ² and R ³ Are each independently a linear or branched alkyl group having 1 to 5 carbon atoms or a phenyl group, and R ¹ is more preferably an isopropyl group, a t-butyl group or a phenyl group.

  In consideration of the cost of raw materials and availability, it is preferable to use alkyl (phenyl) silyl chloride in which X is chlorine in the above formula (5). The above silyl ether compounds and alkyl (phenyl) silyl halides can be used singly or in combination of two or more.

  The reaction ratio of the silyl ether compound having a primary amino group and the alkyl (phenyl) silyl halide used in this reaction is alkyl (phenyl) relative to 1 molar equivalent of the amino group of the silyl ether compound having a primary amino group. ) The range of the halogen atom of silyl halide is preferably from 0.1 to 10 molar equivalents, more preferably from 0.7 to 1.5 molar equivalents, still more preferably from 0.8 to 1.3 molar equivalents. When the halogen atom of the alkyl (phenyl) silyl halide is less than 0.1 molar equivalent or exceeds 10 molar equivalent, synthesis of the silane compound itself is possible, but the amount of raw material recovered unreacted increases. The reaction efficiency is not sufficient.

  Moreover, it is preferable to add a basic compound to this reaction. As a result, the acid generated during this reaction can be captured, and therefore the reaction can be promoted under relatively mild conditions. The basic compound is not particularly limited, and generally known compounds can be used. Specifically, pyridine, dialkylamine, trialkylamine, 1,8-diazabicyclo [5.4.0] undeca-7. -Amine bases such as ene, lithium diisopropylamide, sodium amide, metal hydrides such as lithium hydride, sodium hydride, potassium hydride, metal hydroxides such as caustic potassium, caustic soda, sodium carbonate, potassium carbonate, carbonate Carbonates such as sodium hydrogen and potassium hydrogen carbonate, metal alkoxides such as sodium methoxide and sodium ethoxide, organometallic compounds such as methyl lithium, butyl lithium and phenyl lithium, and grinal reaction such as methyl magnesium bromide and ethyl magnesium bromide Agents and the like.

  When a basic compound is used in the present invention, the amount of the basic compound is preferably in the range of 0.1 to 1000 molar equivalents relative to 1 molar equivalent of the amino group of the silyl ether compound having a primary amino group. The range of 0.5-5 molar equivalent is more preferable, and the range of 0.7-2 molar equivalent is still more preferable. When the basic compound is less than 0.1 molar equivalent, there is a tendency that a substantial addition effect does not appear. Even when the basic compound exceeds 1000 molar equivalent, synthesis of the silane compound itself is possible. The amount increases and the reaction efficiency is not sufficient. However, the basic compound is liquid at the reaction temperature, and when used as a solvent, there is no problem even if it is used in excess of 1000 molar equivalents.

  Although this reaction can be performed without using a solvent, it can also be performed using a solvent in order to maintain the fluidity of the reaction solution. In the case of using a solvent, any solvent other than a solvent that inhibits the reaction or causes a side reaction to proceed can be used without particular limitation. For example, N, N-dimethylformamide, N, N-dimethylacetamide, diethyl ether, tetrahydrofuran, 1,4-dioxane, pentane, hexane, heptane, benzene, toluene, dichloromethane, dichloroethane, chloroform and the like are preferably used. These solvents can be used alone or in admixture of two or more.

  These solvents are preferably dehydrated in advance. A solvent containing a large amount of water tends to cause side reactions.

  When a solvent is used in this reaction, the amount of the solvent added is preferably 5 to 10000 parts by mass with respect to 100 parts by mass in total of the silyl ether compound having an amino group and the alkyl (phenyl) silyl halide, and 20 to 10,000. It is more preferable to set it as a mass part, and it is still more preferable to set it as 50-5000 mass parts. If the blending amount is less than 5 parts by mass, a substantial solvent addition effect tends not to be observed, and if it exceeds 10,000 parts by mass, the reaction rate tends to be slow and the reaction efficiency tends to decrease.

  Although this reaction can be carried out under pressure, reduced pressure or atmospheric pressure, it is preferably carried out in an atmospheric pressure atmosphere for the convenience of operation. Moreover, since alkyl (phenyl) silyl halide is excellent in the reactivity, it is preferable to dripping little by little in a silyl ether compound, stirring a silyl ether compound.

  Further, when dropping the alkyl (phenyl) silyl halide, it is preferable to carry out under dry gas filling or in a dry air flow because moisture-induced side reactions are suppressed, and dried nitrogen, helium, neon, argon, krypton are preferable. It is more preferable to carry out in an inert gas atmosphere such as xenon, and it is more preferred to carry out in a dry nitrogen or dry argon atmosphere. When moisture or oxygen is mixed during this reaction, highly reactive silyl ether compounds, alkyl (phenyl) silyl chlorides, etc. tend to cause side reactions, and the yield of the desired silane compound tends to decrease. is there.

  The reaction temperature can be from -100 ° C to the solvent reflux temperature or 200 ° C, preferably -30 ° C to 150 ° C, particularly preferably 0 ° C to 100 ° C. When the reaction temperature is lower than −100 ° C., the reaction rate becomes slow and the yield of the desired silane compound tends to decrease. In addition, by-products are generated at 200 ° C. or higher, and the yield of the desired silane compound tends to decrease. If the reaction temperature is in the range of 0 ° C. to 100 ° C., heating or cooling with water is possible, there is little danger, synthesis can be performed with general-purpose equipment, and energy consumption tends to be reduced.

  Furthermore, the reaction time is preferably 5 minutes to 7 days, more preferably 1 hour to 6 days, and even more preferably 1 hour to 5 days. If this reaction time is less than 5 minutes, the reaction does not proceed sufficiently and the yield of the desired silane compound tends to decrease. Moreover, even if it exceeds 7 days, the yield of a desired silane compound tends not to improve.

  Moreover, you may add catalysts, such as a quaternary ammonium salt and a quaternary phosphonium salt, in this reaction system. By adding a catalyst, the reaction rate can be increased or the yield of the desired silane compound can be increased.

  The progress of the reaction in this reaction and the end point of the reaction can be confirmed by gas chromatography, high performance liquid chromatography, thin phase chromatography, nuclear magnetic resonance spectrum, infrared absorption spectrum and the like.

  After completion of the reaction, the reaction solution is filtered and purified to obtain the desired silane compound.

  The method for purifying the silane compound obtained by the coupling reaction of the present invention is not particularly limited. For example, it may be appropriately performed by a method suitable for physical properties such as distillation, recrystallization, reprecipitation, reduced pressure distillation, liquid chromatography, gas chromatography, etc. Can do.

  Among these, it is preferable to perform distillation and recrystallization. By-product acidic compounds, salts when basic compounds are used, and solvents used as necessary can be removed, and desired silane compounds can be obtained with high purity.

  Analytical means for identifying the silane compound obtained by this reaction is not particularly limited. For example, infrared absorption spectrum (IR), nuclear magnetic resonance spectrum (NMR), mass spectrum (MS), elemental analysis, X-ray crystal analysis By such means, the bonding position, molecular weight, chemical composition, etc. of the functional group or hydrogen atom can be confirmed.

  The silane compound thus obtained has the following characteristics. For example, for stability, it is desirable to store it in a cool and dark place with a tight stopper. Moreover, since it is excellent in compatibility with other silicon-based compounds, it can be used as a silane coupling agent, and because it is also compatible with alcohol, it is also used as an alcohol scavenger. be able to.

  Specifically, the silane compound of the present invention can be suitably used as a constituent material of a one-component adhesive composition. Moreover, it can apply as a reactive compound which comprises a thermosetting composition or a photocurable composition. Furthermore, it can be applied to a wide variety of applications such as paints, electrical / electronic materials, semiconductor materials, optical materials, optical fibers, optical waveguides, single-layer and multilayer wiring board materials, resists, dry film resists, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail according to an Example, this invention is not limited to these Examples.

[Example 1: Synthesis example of N-tri (isopropyl) silyl-γ-aminopropyltriethoxysilane]
A 30 mL glass reaction vessel is filled with dry nitrogen, and 1.00 g of γ-aminopropyltriethoxysilane (product name: Silaace S330, manufactured by Chisso Corporation), which is a silyl ether compound having an amino group, and a basic compound 0.492 g (manufactured by Wako Pure Chemical Industries, Ltd.) and 10 mL of dehydrated hexane (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent were added and stirred until uniform to obtain a mixed solution. Next, 0.824 g (manufactured by Chisso Corporation) of triisopropylsilyl chloride, which is an alkyl (phenyl) silyl halide, was added dropwise to the obtained mixture over 10 minutes, and the reaction was terminated by stirring at 25 ° C. for 48 hours. . Thereafter, the precipitated triethylamine hydrochloride was filtered off with a glass filter, and hexane was distilled off. Next, vacuum distillation was performed to obtain 0.99 g of N-tri (isopropyl) silyl-γ-aminopropyltriethoxysilane (boiling point: 180 ° C./67 Pa) represented by the following formula (6). (Yield 55%)

  The infrared absorption spectrum of the obtained N-tri (isopropyl) silyl-γ-aminopropyltriethoxysilane is shown in FIG. 1, and the NMR spectrum is shown in FIG.

[Example 2: Synthesis example of N- (diphenylisopropyl) silyl-γ-aminopropyltriethoxysilane]
Synthesis example except that 1.23 g of diphenylisopropylsilyl chloride (a synthetic product from isopropylmagnesium chloride and dichlorodiphenylsilane: 4th edition, Experimental Chemistry Course 24, Organic Synthesis VI, page 145) was used in place of triisopropylsilyl chloride. 1 and reacting with N- (diphenylisopropyl) silyl-γ-aminopropyltriethoxysilane (boiling point: 250 ° C./80 Pa) (silane compound B) (1.12 g) represented by the following formula (7) Obtained. (Yield 53%)

  The infrared absorption spectrum of the obtained N- (diphenylisopropyl) silyl-γ-aminopropyltriethoxysilane is shown in FIG. 3, and the NMR spectrum is shown in FIG.

It is a figure which shows the infrared absorption spectrum of N-tri (isopropyl) silyl-gamma-aminopropyl triethoxysilane. It is a diagram showing the ¹ H-NMR spectrum of N- tri (isopropyl) silyl -γ- aminopropyltriethoxysilane. It is a figure which shows the infrared absorption spectrum of N- (diphenyl isopropyl) silyl-gamma-aminopropyl triethoxysilane. It is a diagram showing the ¹ H-NMR spectrum of N- (diphenyl-isopropyl) silyl -γ- aminopropyltriethoxysilane.

Claims (4)

A silane compound represented by the following general formula (1) or (2):

[In the formulas (1) and (2), R ¹ represents a linear or branched alkyl group having 2 to 12 carbon atoms, a cycloalkyl group, a phenyl group, or a substituted phenyl group, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a phenyl group or a substituted phenyl group, and n is an integer of 1 to 6 Indicates. ] In R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , the cycloalkyl group has 4 to 8 carbon atoms, and the substituent of the substituted phenyl group is a monovalent organic group or a halogen atom The silane compound according to claim 1, wherein R ¹ is a linear or branched alkyl group having 2 to 5 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or a phenyl group, and R ² and R ³ are each independently 1 The silane compound according to claim 2, wherein the silane compound is an alkyl group or a phenyl group of ˜5, and the R ⁴ , R ^5, and R ⁶ are each independently a methyl group or an ethyl group. The silane compound according to claim 3, wherein R ¹ is an isopropyl group, a t-butyl group, or a phenyl group, and R ⁴ , R ^5, and R ⁶ are ethyl groups.

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