JP2006282725A - Silicon-containing new optically active compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silicon-containing new optically active compound which has one or more optically active groups as substituents and has excellent characteristics such as transparency and polymerizability. <P>SOLUTION: This silicon-containing new optically active compound is characterized by comprising a polysilsesquioxane derivative represented by general formula (1) and having one or more optically active groups and one or more polymerizable substituents. Therein, R comprises the following three substituent groups. R certainly contains at least one substituent of the first group and at least one substituent of the second group, and does not sometimes contain the third group. The first group: asymmetric source-having organic or organometallic substituents. The second group: vinyl-containing groups, methacryloyloxy-containing groups, acryloyloxy-containing groups and epoxy-containing groups. The third group: H, 1 to 20C straight chain, branched or cyclic alkyl groups, and aromatic-containing groups. (n)/(m) is 0.0 to 1.0. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel group of silicon-containing optically active compounds having a structure in which an organic substituent containing a chiral center is directly bonded to a silicon atom, which is polymerizable and excellent in transparency.

  Conventionally, organic silicon compounds have properties that organic compounds do not have, such as high heat resistance and electrical properties, so polymers containing silicon as part of the skeleton are heat resistant materials, weather resistant materials, water repellent materials, It has been put to practical use in various fields such as insulating materials, electronic materials, heat media, and precursors of ceramic materials. Most of the silicon-containing compounds reported so far are a group of organic oil-inorganic hybrid materials called silicone oils and silicone resins in which organic functional groups are bonded to the siloxane main skeleton (for example, Non-Patent Document 1, p. .299-318). There have also been many reports on polysilane polymers whose main chain is composed only of silicon-silicon bonds (see Non-Patent Document 2, for example).

  On the other hand, a trihalosilane represented by the following general formula (2) or a trialkoxysilane represented by the following general formula (3) is used as a raw material, and a series of so-called polysilsesquioxanes are obtained by hydrolysis-polycondensation reaction. It is known that a compound can be synthesized (see, for example, Non-Patent Document 3, p34 to 44).

As R in the general formulas (2) and (3), it is known that various functional groups such as a hydrogen atom, an alkyl group, an aromatic substituent, and a polymerizable substituent can be introduced (for example, non-patent Reference 1).

  In particular, polysilsesquioxanes that have a cage structure (a cage structure) or an incomplete cage structure (a partial cage structure) in which a part of the cage structure is opened are Since it has no or few silanol groups which impede storage stability, it has good storage stability and is easy to handle. It is possible to have compatibility and copolymerization with other organic monomers, and the molecular structure can be discussed to some extent. As a result, research on polysilsesquioxanes that have a cage structure or an incomplete cage structure in which a part of the cage structure is opened has increased significantly in recent years. (For example, refer nonpatent literature 3, p34-44.).

  On the other hand, a compound containing an optically active group in a silicon compound has also been synthesized. Among these, as a polymer or a raw material thereof, for example, a chlorosilane having an optically active group as a substituent represented by the following general formula (4) (for example, see Patent Document 1) can be used as a raw material, and the reduction of this It has been reported that a polysilane polymer having helical or optical activity represented by the following general formula (5) can be synthesized by the selective dechlorination polycondensation (for example, see Patent Document 2).

Moreover, the report regarding the cyclic polysiloxane compound which has an optically active group shown by following General formula (6) is also reported (patent document 3).

JP-A-6-306087 (Chemical Formula 4) JP-A-10-226727 (Chemical Formula 5) JP2003-321383A (Chemical formula 6) Catalog of Chisso Corporation and Azumatec Corporation "Special Silicon Reagent / Special Silicone / Special Organometallic Reagent", November 3, 1998 Miller, R. D .; Michl, J. Chem. Rev., 1989, 89, 1359. K. Ogura, Network Polymer, 2004, 25, (4), 34.

However, there have been no reports on polysilsesquioxane compounds having optically active groups.
By introducing an optically active group into polysilsesquioxane, it can be expected to have a wide range of applications such as transparent optical materials. In addition, since different substituents can be introduced onto the polysilsesquioxane molecule, the optical activity of the molecule can be changed by changing the ratio of the optically active groups contained in the polysilsesquioxane. We can expect to be able to control.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a novel silicon-containing optically active compound having excellent properties such as having an optically active group as a substituent and being transparent and polymerizable. It is to provide.

  The inventors of the present invention use a trialkoxysilane having an optically active group as a substituent on silicon as a raw material and co-hydrolyze this with another trialkoxysilane having a polymerizable substituent or the like as a substituent on silicon. By decomposing-copolymerizing, it was found that a novel silicon-containing optically active compound having excellent properties such as having an optically active group as a substituent and being transparent and polymerizable can be synthesized, and the present invention has been completed. It was.

In order to solve the above problems, the silicon compound according to claim 1 is represented by the following general formula (1) and is a polysilsesquioxane derivative.
With the above configuration, a novel silicon-containing optically active compound having controlled optical activity can be obtained.

R in the formula is composed of the following three substituent groups. R always includes at least one substituent of the first group and at least one substituent of the second group, and may not be included for the third group.
First group: Organic or organometallic substituent having an asymmetric source Second group: Vinyl-containing group, methacryl-containing group, acrylic group, epoxy-containing group Third group: hydrogen atom, straight chain having 1 to 20 carbon atoms A branched or cyclic alkyl group, an aromatic-containing substituent, and the n / m ratio is 0.0 or more and 1.0 or less.

The novel silicon-containing optically active compound according to claim 2 is characterized by having a cage structure or a partially cage structure.

  If it is set as said structure, regularity can be provided to the structure of a silicon-containing novel optically active compound.

  As described above, the novel silicon-containing optically active compound of the present invention is a polysilsesquioxane having an optically active group and a polymerizable substituent, and further has a cage structure or a partial cage structure. Therefore, it is possible to provide a silicon-containing novel optically active compound having both controlled optical activity and moldability.

The silicon-containing novel optically active compound of the present invention has a structure represented by the following general formula (1).

R in the formula is composed of the following three substituent groups. R always includes at least one substituent of the first group and at least one substituent of the second group, and may not be included for the third group.

The first group is an organic or organometallic substituent having an asymmetric source. The organic or organometallic substituent having an asymmetric source is not particularly limited as long as it can be chemically introduced onto silicon, and specific examples thereof include the substituents shown below.

The second group is a polymerizable substituent. Specific examples include compounds having the following structure.

Of these polymerizable substituents, considering the availability of silicon monomers as raw materials, vinyl group, alkylene group, styryl group, 3-acryloylpropyl group, 3-methacryloylpropyl group, 3 glycidoxypropyl The group, 2- (3,4-epoxycyclohexyl) ethyl group, is preferred.

The third group is a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, or an aromatic substituent. Examples of the linear, branched or cyclic alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, and cyclopentyl group. Cyclohexyl group, 2-ethylhexyl group, n-octyl group and the like, and those having 1 to 12 carbon atoms, particularly those having 1 to 10 carbon atoms are preferable. The fluorinated alkyl group is one in which part or all of the hydrogen atoms of the above alkyl group are substituted with fluorine atoms, such as a trifluoromethyl group, a 2,2,2-trifluoroethyl group, 3, 3 , 3-trifluoropropyl group, 1,1,2,2,3,3,3-heptafluoropropyl group and the like. Examples of the aromatic substituent include a phenylalkyl group and derivatives thereof, a phenyl group and derivatives thereof, a biphenyl group and derivatives thereof, a naphthyl group and derivatives thereof, and in particular, phenylalkyl groups and derivatives thereof and phenyl groups and derivatives thereof. Derivatives are preferred, especially phenyl groups and derivatives thereof.

The value of the n / m ratio is preferably 0 to 1/2, and more preferably 0 to 1/3, which can be estimated that the polysilsesquioxane has a cage structure. The polysilsesquioxane derivative preferably has 6 to 100 silicon atoms, that is, (m + n) is 6 to 100. More preferably, it is 8-50. Here, when n / m ratio is 0.0, it is a cage structure, and when n / m ratio exceeds 0.0, it is a partial cage structure.

Next, a method for synthesizing the novel silicon-containing optically active compound of the present invention will be described.

The synthesis can be performed by a hydrolysis-polycondensation reaction of the following general formula (7).

R in the formula is composed of the following three substituent groups. R always includes at least one substituent of the first group and at least one substituent of the second group, and may not be included for the third group.
First group: Organic or organometallic substituent having an asymmetric source Second group: Vinyl-containing group, methacryl-containing group, acrylic group, epoxy-containing group Third group: hydrogen atom, straight chain having 1 to 20 carbon atoms A branched or cyclic alkyl group, an aromatic substituent, and X ′ in the formula is not particularly limited as long as it is a hydrolyzable group, and is not limited to a halogen atom, an alkoxy group, a cycloalkoxy group, or an aryloxy group. It can be a group or the like. In addition, three X ′ are contained in one molecule of the compound, but they may all be the same group or two or more different groups. Of these, X ′ in the present invention is preferably an alkoxy group. The reason is that when is a halogen atom, in addition to the generation of highly corrosive acid due to hydrolysis, the concentration of hydrogen ions in the reaction system, which greatly affects this synthesis reaction, is greatly changed. Therefore, it is difficult to control the reaction.

  Examples of the “alkoxy group” include methoxy group, ethoxy group, n- and i-propoxy group, n-, i- and t-butoxy group and the like. Examples of the “cycloalkoxy group” include a cyclohexyloxy group, and examples of the “aryloxy group” include a phenyloxy group. Among these, X ′ is preferably an alkoxy group having 1 to 3 carbon atoms because the raw material procurement cost is low and the hydrolyzability of the alkoxy group is good.

  In particular, a methoxy group is more preferable in terms of the highest hydrolyzability, and an ethoxy group is more preferable in terms of the highest safety.

Subsequently, the hydrolysis-polycondensation reaction which is a synthesis method in the present invention will be described. The above-mentioned trialkoxysilane is reacted with water in the presence of a basic or acidic catalyst in a solvent to cause a hydrolysis-polycondensation reaction, thereby obtaining a target product.
The hydrolysis is performed under acidic conditions when an alkoxysilane having a functional group that may react with water under basic conditions, such as a hydrosilyl group, is used for the reaction.
As the acidic catalyst, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, carbonic acid, phosphoric acid and zirconium sulfate, and organic acids such as paratoluenesulfonic acid, acetic acid and carboxylic acids can be used. Hydrochloric acid or nitric acid is preferred because of its high activity and easy removal during post-treatment.
As the basic catalyst, inorganic compounds such as sodium hydroxide and potassium hydroxide, and organic compounds such as ammonia, quaternary ammonium salts, tetraalkylammonium hydroxide, and organic amines can be used. Sodium hydroxide, potassium hydroxide, and tetraalkylammonium hydroxide, which are high and easily removed during post-treatment, are preferred.
Each catalyst can be added in advance as an aqueous solution, and the hydrogen ion concentration of the aqueous solution is preferably 1 to 0.0001 N.
As the equivalent of water used for hydrolysis, 1.5 to 30 equivalents can be used for all alkoxy groups. However, since the remaining alkoxy groups in the product can be reduced and the reaction system can be made uniform, 3 10 equivalents are preferred.

Although it does not specifically limit about other reaction conditions, The preferable reaction temperature is 10-80 degreeC (more preferably 40-60 degreeC), and suitable reaction time is 1 to 30 hours (more preferably 1 to 6 hours). is there. If the reaction temperature is too low or the reaction time is too short, the polycondensation may not be completed. Conversely, if the reaction temperature is too high or the reaction time is too long, the polymerizable substituent in the system will react. In addition, there is a risk of causing polymerization inactivation or gelation during the reaction.
The organic solvent used in this reaction is not particularly limited, and examples thereof include alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran, toluene, 1,4-dioxane, hexane, ligroin, Acetonitrile or the like can be used. Of these, polar solvents such as lower alcohols and tetrahydrofuran are preferred as the solvent capable of uniformly dissolving the reaction system. Particularly, since a residual alkoxy group in the product can be reduced, an aprotic solvent such as tetrahydrofuran is used. preferable.

After the reaction, the acid or base added as a reaction catalyst is neutralized with a saturated aqueous sodium hydrogencarbonate solution or a saturated aqueous ammonium chloride solution, respectively. Next, a low boiling point portion such as a solvent is distilled off, followed by liquid separation / extraction using a solvent such as diethyl ether, and the organic phase is washed with water and then with a saturated aqueous sodium chloride solution. The organic phase is separated, an inorganic anhydrous salt such as anhydrous magnesium hydroxide is added and left at room temperature for 3 hours or more, followed by dehydration and drying.
For the final purification, reprecipitation may be used when there is a solvent that is hardly soluble in the product, but when there is no solvent that is hardly soluble, the insoluble matter such as salt is removed by filtration and then reduced in pressure. The low boiling point portion is distilled off for purification.

  Examples of the use of the silicon-containing novel optically active compound of the present invention include various optical materials such as liquid crystal alignment films and materials as column fillers for enantiomer recognition.

Measuring instrument optical rotation: Union Giken's highly sensitive automatic polarimeter PM-101 (Automatic Digital Polarimeter PM-101)
NMR spectrum; Varian Unity 400 Spectrometer molecular weight; GPC (gel filtration chromatography) ("High performance liquid chromatography system manufactured by JASCO Corporation" with "SEC column (KF-805L) manufactured by Showa Denko KK") It was measured.)
EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples.

Reference example (synthesis of trialkoxysilane having optically active group)
A 50 mL two-necked eggplant-shaped flask equipped with a reflux tube, a three-way cock, a 20 mL dropping funnel (with a septum cap), and a magnetic stirrer was degassed and dried under an argon stream. To this was added β-pinene (manufactured by Tokyo Chemical Industry Co., Ltd.) 10.0 g (73.4 mmol), 100 μL of a 10 wt% chloroplatinic acid 2-propanol solution, and the mixture was stirred while heating to 80 ° C. Next, 12.1 g (73.4 mmol) of triethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was dropped over 5 minutes, and then reacted at 80 ° C. for 8 hours. The product was isolated and purified by distillation under reduced pressure to obtain the target β-pinenyl triethoxysilane. Colorless liquid. Boiling point: 50 ° C./20 mmHg) Yield: 6.60 g (22.0 mmol, 29.9%).

Example 1
The optically active three-dimensional organosilicon polymer was synthesized by the following method. In a 100 mL eggplant-shaped flask equipped with a reflux tube, 5.40 g of 1M sodium hydroxide aqueous solution, 75 mL of tetrahydrofuran, 0.451 g (1.50 mmol) of β-pinenyl triethoxysilane, 2.24 g of 3-methacryloyltrimethoxysilane ( 9.00 mmol), 1.80 g (12.0 mmol) of ethyltrimethoxysilane, 1.34 g (7.50 mmol) of isobutyltrimethoxysilane, heated to 60 ° C. while stirring with a magnetic stir bar, and allowed to react for 6 hours. It was. After the reaction, 5.40 g of 1M hydrochloric acid was added for neutralization, and then the low boiling point portion was distilled off by a rotary evaporator. Next, after extraction with diethyl ether, the organic phase was washed with saturated brine and dehydrated with anhydrous magnesium sulfate. Insoluble matter such as salt was removed by filtration, and the low boiling point portion was distilled off by purification under reduced pressure to purify. The product is a colorless transparent viscous liquid. Yield: 2.3 g. Yield: 63%.

Example 2
The starting trialkoxysilane was 0.902 g (3.00 mmol) of β-pinenyl triethoxysilane, 2.24 g (9.00 mmol) of 3-methacryloyltrimethoxysilane, and 1.80 g (12.0 mmol) of ethyltrimethoxysilane. This was synthesized in the same manner as in Example 1 except that 1.07 g (6.00 mmol) of isobutyltrimethoxysilane was used. The product is a colorless transparent viscous liquid. Yield: 2.6g. Yield: 68%.

Example 3
The starting trialkoxysilane was 2.70 g (9.00 mmol) of β-pinenyl triethoxysilane, 2.24 g (9.00 mmol) of 3-methacryloyltrimethoxysilane, 1.80 g (12.0 mmol) of ethyltrimethoxysilane. The synthesis was performed in the same manner as in Example 1. The product is a colorless transparent viscous liquid. Yield: 2.8g. Yield: 65%.

  Table 1 summarizes the molecular weights and structures of the compounds synthesized by Examples 1-3. T2 in the table means that two of the three alkoxy groups of trialkoxysilane react to form a siloxane bond, and T3 means that all three alkoxy groups of trialkoxysilane react. A siloxane bond is formed. These ratios can be calculated by 29Si-NMR measurement. If T3 is 100%, the structure is considered to be a completely closed cage structure, and the cage structure becomes more imperfect as the ratio of T2 increases. It can be estimated that T1 in which one of the three alkoxy groups of trialkoxysilane reacted to form a siloxane bond and unreacted monomer were not detected.

According to Table 1, the molecular weight distribution is narrow, and the silicon nuclear magnetic resonance spectrum shows that the T2 / T3 ratio is low at about 10/90 for all products. Further, from each average molecular weight, it can be presumed that each molecule is composed of 16 to 17 silicon units, and has an incomplete cage structure in which a part of the ring is opened on average. In addition, from the hydrogen nuclear magnetic resonance spectrum, the ratio of the substituents on silicon contained in the synthesized compound shows a good agreement with the charge ratio, and the synthesis method used this time shows the ratio of substituents according to the charge ratio. It was confirmed to give to the product.

Example 4
Next, the optical rotation of the synthesized silicon-containing novel optically active compound was measured. The results are summarized in Table 2.

It can be seen that the optical rotation increases linearly in proportion to the introduction rate of the optically active group with the same sign. From this result, it is clear that the optical activity of the product is maintained through these series of synthesis reactions, and that the optical rotation of the synthesized resin can be controlled by changing the ratio of the optically active monomer at the time of synthesis preparation. became.

Application Example 0.10 g of the resin synthesized in Examples 1 to 3 was taken, and 0.15 g of 2 wt% Irgacure 651 (manufactured by Ciba Geigy) propylene glycol monomethyl ether acetate solution was mixed and coated on a slide glass by a casting method. . This was heated to 130 ° C. to remove the solvent, and then irradiated with light in the air for 2 minutes using a metal hydrate lamp, and then heated at 200 ° C. for 1 hour to be cured. A colorless and transparent coating film having no tack could be formed, and the pencil hardness was 5B.

As described above, according to the present invention, it is possible to provide a novel silicon-containing optically active compound. The optical activity represented by the optical rotation of these silicon-containing novel optically active compounds can be controlled by the raw material charge ratio at the time of synthesis. These novel silicon-containing optically active compounds also have polymerizability and are easily cured by ultraviolet irradiation and heat treatment to form a transparent coating film. In addition, by having excellent characteristics unique to organic-inorganic hybrid materials such as durability, it can be used as various optical materials such as liquid crystal alignment films and materials as column fillers for enantiomer recognition.

Claims (2)

A novel silicon-containing optically active compound represented by the following general formula (1) and characterized by being a polysilsesquioxane derivative.
R in the formula is composed of the following three substituent groups. R necessarily contains at least one type of substituent of the first group and at least one type of substituent of the second group, and may not contain the third group.
First group: Organic or organometallic substituent having an asymmetric source Second group: Vinyl-containing group, methacryl-containing group, acrylic-containing group, epoxy-containing group Third group: hydrogen atom, straight chain having 1 to 20 carbon atoms A branched or cyclic alkyl group, an aromatic-containing substituent, and the n / m ratio is 0.0 or more and 1.0 or less. The silicon-containing novel optically active compound according to claim 1, wherein the polysilsesquioxane derivative has a cage structure or a partial cage structure.