JP2013184945A - Iminophosphorane compound, process for producing the same, and method of modifying surface of base material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel silane coupling agent, an efficient process for producing the same, and a method of modifying the surface of a base material at high efficiency.SOLUTION: An iminophosphorane compound of formula (1) which is useful as a novel silane coupling agent and is obtained by reacting an azidoalkylalkoxysilane having an azido group at the end as a starting material with a tertiary phosphine to introduce an iminophosphorane skeleton into the silane compound can provide an amino group on the surface of a base material by stably protecting the amino group and, at the same time, easily performing the deprotection in contact with water in a step of modifying the surface of a base material.

Description

  The present invention relates to an iminophosphorane compound which is a novel primary aminoalkylalkoxysilane precursor, a production method thereof, and a surface modification method of a substrate using the same.

  An aminoalkylalkoxysilane compound containing an alkoxysilyl group at the terminal of an aminoalkyl group is a treatment agent that modifies the surface of a substrate such as glass or a silicon substrate as a silane coupling agent, a curing agent such as an epoxy resin, silica gel It is widely used industrially as a templating agent for synthesizing inorganic silicon compounds such as the above.

For example, 3-aminopropyltriethoxysilane represented by H ₂ NC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ is known as a primary aminoalkylalkoxysilane compound used as a silane coupling agent. However, when 3-aminopropyltriethoxysilane is used for surface modification for introducing an amino group on the surface of a substrate such as a glass substrate, a highly reactive amino group and a polar group (such as a glass substrate or In the case of a silicon substrate, a side reaction such as a reaction with a surface silanol group) or a self-condensation reaction (oligomerization or polymerization) due to an autocatalytic action of an amino group occurs, which causes a disadvantage that the surface treatment efficiency is lowered. (Nonpatent literature 1-3).

  In order to solve this problem, an aminosilane obtained by converting (protecting) a highly reactive free amino group of 3-aminopropylalkoxysilane into a ketimine group (generated by a condensation reaction of an amino group and a carbonyl group) has also been synthesized. However, reconversion (deprotection, hydrolysis) from ketimine group to amino group requires a long reaction time. Moreover, since strong acid such as hydrochloric acid is used as a catalyst, it is not suitable for an acid-labile substance. There is a disadvantage of being (Patent Document 1). A bistrimethylsilylaminosilane compound in which an amino group is protected with a trimethylsilyl group instead of a ketimine group has also been synthesized. When such a silazane skeleton is present, the trimethylsilyl group introduced as a protective group acts as a modifier. The trimethylsilyl group is introduced into the substrate surface (Patent Documents 2-3).

JP-A-7-247295 JP 10-17579 A JP2007-191355

Chemistry of Materials, vol.18, pp5022, 2006. Langmuir, vol.22, pp2676, 2006. Chemistry of Materials, vol.15, pp1132, 2003.

  The present invention relates to an organosilicon compound containing an amino group and an alkoxysilyl group that can be widely used as a treatment agent for modifying a substrate surface such as glass or a silicon substrate as a silane coupling agent. A novel silane coupling agent capable of easily deprotecting and regenerating an amino group at the time of use while efficiently protecting it, an efficient production method thereof, and a high efficiency of the substrate surface using the same The object is to provide a modification method.

As a result of intensive studies to achieve the above object, the present inventors have made an azidoalkylalkoxysilane having an azido group at the terminal as a starting material and reacted with this tertiary phosphine to iminophosphorane on the silane compound. It was found that by introducing a skeleton, an iminophosphorane compound useful as a novel silane coupling agent can be obtained.
The iminophosphorane compound thus obtained stably protects the amino group in the surface modification process of the base material, and is easily deprotected by contact with moisture, and the amino group on the surface of the base material. Can be provided.

（式中、Ｒ¹、Ｒ²およびＲ³は、それぞれ独立して、炭素原子数１〜１５のアルキル基、アルケニル基、アリール基であり、ｎは１〜３０の整数であり、ｘは０〜２の整数である）で示されるイミノホスホラン化合物。
〈２〉一般式（２）：

（式中、Ｒ²およびＲ³は、それぞれ独立して、炭素原子数１〜１５のアルキル基、アルケニル基、アリール基であり、ｎは１〜３０の整数であり、ｘは０〜２の整数である）で示されるアジドアルキルアルコキシシランを出発原料とし、これを一般式（３）：

（式中、Ｒ¹は、炭素原子数１〜１５のアルキル基、アルケニル基、アリール基である）で示される３級ホスフィンと反応させることを特徴とする、〈１〉に記載のイミノホスホラン化合物の製造方法。
〈３〉〈１〉に記載のイミノホスホラン化合物により基材を修飾した後、水分により迅速かつ容易に基材表面のイミノホスホラン骨格をアミノ基に変換することにより、アミノ修飾表面を形成することを特徴とする、基材の表面修飾方法。 The present invention has been completed based on these findings, and provides an iminophosphorane compound and a method for producing the same, and a method for modifying the surface of a substrate using the same as described below.
<1> General formula (1):

Wherein R ¹ , R ² and R ³ are each independently an alkyl group, alkenyl group or aryl group having 1 to 15 carbon atoms, n is an integer of 1 to 30 and x is 0 Is an integer of ˜2).
<2> General formula (2):

Wherein R ² and R ³ are each independently an alkyl group, alkenyl group or aryl group having 1 to 15 carbon atoms, n is an integer of 1 to 30, and x is 0 to 2. An azidoalkylalkoxysilane represented by the general formula (3):

(Wherein R ¹ is an alkyl group having 1 to 15 carbon atoms, an alkenyl group, or an aryl group) and is reacted with a tertiary phosphine according to <1>. Compound production method.
<3> After modifying the substrate with the iminophosphorane compound according to <1>, the amino-modified surface is formed by quickly and easily converting the iminophosphorane skeleton of the substrate surface to an amino group with moisture. A method for modifying a surface of a substrate,

  The iminophosphorane compound of the present invention is a novel compound and is extremely useful as a surface treatment agent, a primer and the like. The iminophosphorane compound of the present invention is an aminosilane known as a conventional surface modifier since the iminophosphorane skeleton is converted to an amino group by a small amount of moisture and moisture after the surface modification of the substrate. In this case, it is a useful substance that does not cause a side reaction such as a reaction between an amino group and a substrate surface, a self-condensation reaction, etc. And according to the manufacturing method of this invention, these iminophosphorane compounds can be manufactured efficiently. Furthermore, when the iminophosphorane compound according to the present invention is used, amino groups can be efficiently introduced onto the surface of a substrate such as a glass substrate or silica particles.

It is the figure which showed the infrared absorption spectrum of the 3-azidopropyl triethoxysilane compound obtained by the reference example. 1 is a diagram showing an infrared absorption spectrum of a 3-triphenylphosphoryliminopropyltriethoxysilane compound obtained in Example 1. FIG. FIG. 4 is an infrared absorption spectrum of the 6-triphenylphosphoryliminohexyltriethoxysilane compound obtained in Example 2. 6 is a graph plotting zeta potentials of aminopropyl surface-modified silica particles and unmodified raw silica particles obtained in Example 5 and Comparative Example 2. FIG.

The iminophosphorane compound of the present invention is a compound represented by the above general formula (1).
In the above formula, each of R ¹ , R ² and R ³ may be the same or different and is an alkyl group, alkenyl group or aryl group having 1 to 15 carbon atoms. Examples thereof include alkyl groups such as methyl group, ethyl group and propyl group; alkenyl groups such as vinyl group and allyl group; and aryl groups such as phenyl group, tolyl group and xylyl group.
Furthermore, n is an integer of 1 to 30 and x is an integer of 0 to 2. However, n is preferably 3 to 10 because of easy availability of raw materials, and x is used as a surface modifier such as a silane coupling agent. In some cases, 0 to 2 are preferred due to their reactivity.

以下に、本発明を実施するための形態について、詳述する。 Examples of the iminophosphorane compound represented by the general formula (1) of the present invention include an iminophosphorane compound represented by the following formula.

Below, the form for implementing this invention is explained in full detail.

（式中、Ｘは、塩素基、臭素基、ヨウ素基、ｐ−トルエンスルホニルオキシ基、メタンスルホニルオキシ基であり、Ｒ¹は炭素原子数１〜１５のアルキル基、アルケニル基、アリール基であり、ｎは１〜３０の整数である。） In the present invention, the iminophosphorylsilane compound represented by the general formula (1) has an industrially available one end having a halogen group such as chlorine or bromine or an equivalent mesyloxy group or tosyloxy group. It is produced from an azidoalkylalkoxysilane obtained by hydrosilylating a double bond of an alkyl compound having a double bond at the other end and then azidating a halogen group or an equivalent group and a commercially available tertiary phosphine. The
An example of the synthesis reaction is shown below.

(In the formula, X is a chlorine group, bromine group, iodine group, p-toluenesulfonyloxy group, methanesulfonyloxy group, R ¹ is an alkyl group, alkenyl group, or aryl group having 1 to 15 carbon atoms. , N is an integer from 1 to 30.)

  The iminophosphorane compound of the present invention is rapidly hydrolyzed by addition of a small amount of water in the compound itself or in a solution dissolved in a general-purpose organic solvent such as toluene, acetone, tetrahydrofuran, alcohol, etc. to produce an amino group. To do. In addition, after surface modification of a substrate such as a glass substrate or a silicon substrate with the iminophosphorane compound, the iminophosphorane skeleton is hydrolyzed only by washing with the organic solvent containing water or water. Further, it has an advantage that the surface of a base material such as a glass substrate or a silicon substrate can be amino-modified. As described above, the iminophosphorane compound of the present invention can easily deprotect an amino group protected by forming an iminophosphorane skeleton when necessary, so that surface treatment agents, primers, and organic resins can be modified. It is useful as a silane coupling agent used for a quality agent.

The iminophosphorane compound of the present invention may be diluted with an organic solvent when used for applications such as surface treatment. As the organic solvent used, toluene, methanol, ethanol, tetrahydrofuran and the like can be used.
Examples of the substrate surface-treated with the iminophosphorane compound of the present invention include, for example, fumed silica, wet silica, calcined silica, fumed titanium dioxide, pulverized quartz, diatomaceous earth, aluminum oxide, magnesium oxide, aluminum silicate, and oxidation. Inorganic fine particles such as iron, zinc oxide, zinc carbonate, mica; fiber base materials such as glass fiber, nylon fiber, carbon fiber; glass plates, and metal plates such as steel plates, iron plates, stainless steel plates, aluminum plates, etc. .
Examples of the organic resin modified by blending the iminophosphorane compound of the present invention include, for example, epoxy resins, phenol resins, urethane resins, melamine resins, polycarbonate resins, polyethylene resins, polyvinyl chloride resins, polyamide resins. Is mentioned.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not restrict | limited at all to description of these Examples.
The experimental devices, reaction raw materials, catalysts and the like used in the following examples and comparative examples are as shown below.
1. Experimental apparatus A commercially available glass flask, a reflux condenser, a stirrer coated with Teflon (registered trademark), an oil bath, and a magnetic stirrer were used.
2. Raw materials, catalysts, etc. (1) Raw materials, solvent Chloropropyltriethoxysilane (Tokyo Chemical Industry Co., Ltd., purity 97% or more)
5-hexen-1-ol (manufactured by Tokyo Chemical Industry Co., Ltd., purity 95% or more)
Pyridine (manufactured by Wako Pure Chemical Industries, Ltd., purity 99.5% (GC))
Triethoxysilane, methyldiethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
Sodium azide (Wako Pure Chemical Industries, Ltd., purity 98%)
Triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd., purity 95% or more)
N, N-dimethylformamide (manufactured by Tokyo Chemical Industry Co., Ltd., purity 99.5% or more)
Toluene (Wako Pure Chemical Industries, Ltd., purity 99.5% (GC)
Methanol (Wako Pure Chemical Industries, Ltd., purity 99.5% (GC)
Ketimine type silane coupling agent (Shin-Etsu Silicone X-12817H)
6-Toluenesulfonyloxyhexane-1-ene (synthesized according to the method described in the literature (European Journal of Organic Chemistry, 2005, Vol. 10, pages 2040-2044))
Silica particles (made by Nippon Shokubai, particle size 1.62 microns)
(2) Catalyst
Karstedt catalyst (Gelest, platinum divinyltetramethyldisiloxane xylene solution, 2.1-2.4% platinum concentration)
(3) Analytical instrument Gas chromatography (Shimadzu GC2014, FID detector)
Infrared spectrum (JASCO IR4100)
Zeta potential (manufactured by Microtech Nichion)

Reference example. Synthesis of azidoalkylalkoxysilane (synthesis of 3-azidopropyltriethoxysilane)
In a 200 ml two-necked round bottom flask equipped with a dropping funnel and magnetic stir bar, under nitrogen atmosphere, 5.0 g (20.8 mmol) chloropropyltriethoxysilane, 2.6 g (40 mmol) sodium azide and 20 mL dimethylformamide. And stirred at 60 ° C. for 12 hours. The precipitated white solid was filtered, and the dimethylformamide solution was vacuum distilled to obtain 3-azidopropyltriethoxysilane in a yield of 92% from a fraction of 57-58 ° C./2.0 mmHg. The infrared absorption spectrum of this substance is shown in FIG.
(Synthesis of 6-azidohexyltriethoxysilane)
In a 200 ml two-necked round bottom flask equipped with a dropping funnel and a magnetic stirrer, under a nitrogen atmosphere, 10.0 g (78 mmol) of 6-toluenesulfonyloxyhexane-1-ene in 100 mL tetrahydrofuran solution was added 1. After adding 0 mL, 19 g (117 mmol) of triethoxysilane was added dropwise over about 20 minutes using a syringe. The reaction solution was heated and stirred at 40 ° C. for about 4 hours and then concentrated to obtain a light brown oil. 80 ml of dry DMF was added to this oil, the inside of the flask was purged with nitrogen, 10 g of sodium azide was added, and the mixture was heated and stirred at 60 ° C. for 3 hours. The precipitated white solid was filtered, and then the dimethylformamide solution was distilled in vacuo. From the distillate at 98 ° C./3.0 mmHg, 14.71 g, 6-azidohexyltriethoxysilane was obtained with a yield of 63%.

Example 1. (Synthesis of 3-triphenylphosphoryliminopropyltriethoxysilane)
In a 30 ml flask equipped with a magnetic stir bar under a nitrogen atmosphere, dry toluene (15 mL), 1.0 g (about 4.0 mmol) of 3-azidopropyltriethoxysilane, 1.0 g (about 4.0 mmol) of triphenylphosphine And stirred at 60 ° C. for 3 hours. From the gas chromatographic analysis of the reaction mixture, it was confirmed that the peak of 3-azidopropyltriethoxysilane used as a raw material almost disappeared and a new peak of 3-triphenylphosphoryliminopropyltriethoxysilane was generated. After distilling off the solvent, the pale yellow resulting liquid product the infrared absorption spectrum was measured, strong absorption disappeared in the vicinity 2130 cm ^-1 attributed to an azide groups in the starting materials, new 3000 cm ^-1 vicinity of The product was confirmed by the absorption attributed to aromatic CH stretching vibration. The infrared spectrum of the obtained product is shown in FIG.

Example 2 (Synthesis of 6-triphenylphosphoryliminohexyltriethoxysilane)
The same operation as in Example 1 was carried out except that 6-azidohexyltriethoxysilane was used instead of 3-azidopropyltriethoxysilane to obtain 6-triphenylphosphoryliminohexyltriethoxysilane.
The infrared absorption spectrum of the obtained product is shown in FIG.

Example 3 (Hydrolysis reaction of 3-triphenylphosphoryliminopropyltriethoxysilane)
A solution of 3-triphenylphosphoryliminopropyltriethoxysilane: water = 5/1 was prepared and analyzed by gas chromatography after 5 minutes. The peak of the raw material disappeared, and 3-aminopropyltriethoxysilane was newly added. A peak was observed.

Example 4 (Hydrolysis reaction of 6-triphenylphosphoryliminohexyltriethoxysilane)
The same procedure as in Example 3 was performed, except that 6-triphenylphosphoryliminohexyltriethoxysilane was used instead of 3-iminophosphorylpropyltriethoxysilane, and 6-aminophenyltriethoxysilane was converted to 6-amino. It was confirmed that hexyltriethoxysilane was produced.

Comparative Example 1
The same operation as in Example 4 was performed except that a ketimine type silane coupling agent (X-12-817H) was used instead of 3-triphenylphosphoryliminopropyltriethoxysilane, and gas chromatography analysis after 5 minutes was performed. It was confirmed that 90% of the raw material remained.

Example 5 FIG. (Silica particle surface modification)
To a dry toluene solution (5 mL) of 0.001 mol / L 3-iminophosphorylpropyltriethoxysilane, 50 mg of silica particles were added, stirred at room temperature for 2 hours, centrifuged, and the supernatant was removed. Washed. The obtained surface-modified silica particles were dried at 120 ° C. for 12 hours, and then an ethanol: water (= 5: 5) solution was added and stirred in order to remove hydrolysis and by-product triphenylphosphine oxide. Centrifugation and toluene washing were repeated to obtain aminopropyl-modified silica particles. The obtained aminopropyl-modified silica particles were suspended in 10 ⁻² , 10 ⁻³ , 10 ⁻⁴ , 10 ⁻⁵ mol / L sodium chloride aqueous solution, and the zeta potential was measured by electrophoresis. As shown in the graph of FIG. 4, the zeta potential is consistently negative in unmodified silica particles, whereas the amino group is converted by hydrolysis after surface modification with 3-iminophosphorylpropyltriethoxysilane. When generated, the obtained zeta potential consistently showed a positive value, and it was confirmed that the silica particle surface was sufficiently modified with aminopropyl groups.

Comparative Example 2
Similar to Example 5 except that 3-aminopropyltriethoxysilane was used instead of 3-triphenylphosphoryliminopropyltriethoxysilane and the treatment with the ethanol: water (= 5: 5) solution after surface modification was not performed. The zeta potential was measured by electrophoresis. As shown in the graph of FIG. 4, when 3-aminopropyltriethoxysilane is used for surface modification, the obtained zeta potential moves in the positive direction as compared with unmodified silica particles, but the same negative polarity is obtained. It was shown that the modification of the silica gel particle surface was insufficient.

Claims (3)

General formula (1):

Wherein R ¹ , R ² and R ³ are each independently an alkyl group, alkenyl group or aryl group having 1 to 15 carbon atoms, n is an integer of 1 to 30 and x is 0 Is an integer of ˜2). General formula (2):

Wherein R ² and R ³ are each independently an alkyl group, alkenyl group or aryl group having 1 to 15 carbon atoms, n is an integer of 1 to 30, and x is 0 to 2. An azidoalkylalkoxysilane represented by the general formula (3):

The iminophosphorane according to claim 1, which is reacted with a tertiary phosphine represented by the formula (wherein R ¹ is an alkyl group, alkenyl group or aryl group having 1 to 15 carbon atoms). Compound production method.   The substrate is modified with the iminophosphorane compound according to claim 1, and then the amino-modified surface is formed by quickly and easily converting the iminophosphorane skeleton of the substrate surface to an amino group with moisture. A surface modification method for a substrate.

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