JP2008184553A - Material for liquid crystal, liquid crystal elastomer, method for producing material for liquid crystal and method for producing liquid crystal elastomer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for a liquid crystal capable of forming a stable liquid crystal having a large enthalpy change when changing from the liquid crystal to a liquid, without impairment of the elasticity of a liquid crystal elastomer, and a liquid crystal elastomer including the material for liquid crystal. <P>SOLUTION: The material for a liquid crystal has two biphenol group in which the terminals are substituted with vinyl groups (carbon-carbon double bonds) and becomes a stable liquid crystalline state because of large enthalpy change when changing from a liquid crystal to a liquid and exhibits clear liquid crystalline properties in both of the temperature-raising process and the temperature-lowering process and has a wide liquid crystal temperature range. When the material for liquid crystal is mixed with a polybutadiene and the mixture is dissolved in an organic solvent and then, the organic solvent is evaporated and residual solid is heated from 180°C to 250°C, the material for liquid crystal is bound as side chains to polybutadiene chains and crosslinking is formed between polybutadienes to produce the liquid crystal elastomer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal material, a liquid crystal elastomer, a method for producing a liquid crystal material, and a method for producing a liquid crystal elastomer, and particularly relates to a technique suitable for use in artificial muscles, soft actuators, and the like.

  Liquid crystal molecules having a double bond at the terminal are important as liquid crystal monomers for synthesizing liquid crystal polymers. As a method of synthesizing a liquid crystal polymer using liquid crystal molecules having a double bond at the terminal, a method of vinyl polymerization of a double bond is generally used, but a polymer having a double bond and a double bond at the terminal are used. There are also known methods based on radical reaction or photoreaction in which a liquid crystal moiety is linked to a polymer from a liquid crystal molecule using a radical initiator.

  Polymerization of a compound having one liquid crystal moiety (mesogen) and having a double bond at the terminal, and bonding to a polymer having a double bond by a reaction using a photoreaction or a radical initiator are already known. For example, as shown in Chemical formula 1, many patents and research papers relating to the synthesis of a liquid crystal moiety (mesogen) having one biphenyl group and having a double bond at the terminal and a liquid crystal polymer obtained by polymerizing them are disclosed. In particular, the compound shown in Chemical Formula 2 is commercially available from Aldrich.

（式中、ＲがＨで、Ａが（ＣＨ₂）_mであるか、
ＲがＨ又はＭｅで、ＡがＣＯＯ（ＣＨ₂）_mであり、
ｍは２〜１２、ｎは３〜１２である。）

Wherein R is H and A is (CH ₂ ) _m
R is H or Me, A is COO (CH ₂ ) _m ,
m is 2 to 12, and n is 3 to 12. )

  However, a compound with one liquid crystal moiety (mesogen) and a double bond at the end generally has a small enthalpy change when changing from liquid crystal to liquid, and the liquid crystal is linked to a polymer having polymerization or a double bond. There is a surface in which liquid crystallinity is difficult to be expressed at a site (mesogen). On the other hand, it is disclosed that an oligomer liquid crystal having a plurality of liquid crystal sites (mesogens) has a large enthalpy change when changing from a liquid crystal to a liquid and becomes a stable liquid crystal (for example, see Patent Document 1).

  The liquid crystal elastomer including the oligomer liquid crystal has rubber elasticity because a polymer having elastomer characteristics has a crosslinked structure. Furthermore, since there is anisotropy due to the alignment of the liquid crystal molecules, it can expand and contract only in a specific direction. There are liquid crystal elastomers such as collagen in the living body, and the liquid crystal elastomers having anisotropic rubber elasticity can be used for various in vivo valves and artificial organ materials such as artificial hearts as artificial muscles that can substitute for the living body muscles. Expected.

  Many studies have been made on liquid crystal elastomer as a material having elastomer elasticity in which a side chain type polymer liquid crystal in which a liquid crystal portion is bonded to a side chain of a polymer is crosslinked (for example, see Non-Patent Document 1). However, synthesizing a liquid crystal polymer having an elastomeric property and cross-linking the liquid crystal polymer complicates the steps in the production method, which is disadvantageous in terms of cost. Therefore, it is efficient in practical use to obtain a liquid crystal elastomer by bonding a liquid crystal to a diene polymer (typical example: polybutadiene) well known as an elastomer. For example, in Patent Document 3, a diene polymer is terminated with a terminal. Discloses a method for preparing a liquid crystal elastomer in which liquid crystal molecules having a double bond are bonded as side chains.

  However, crosslinking is necessary to prepare a practical liquid crystal elastomer. Currently, crosslinking is performed by vulcanization (heating by adding sulfur) or by using various crosslinking agents. In a liquid crystal elastomer that has been cross-linked, it can be prevented from shifting due to cross-linking between polymer main chains when it stretches or shrinks to its original shape, and it returns to its original shape without loss of shape during expansion and contraction. Can do.

  In the case of a liquid crystal elastomer in which polymer chains are not cross-linked, each polymer chain is unwound and easily dissolved in an organic solvent. However, in the case of a liquid crystal elastomer in which polymer chains are cross-linked, each polymer chain is not unwound, so that it is difficult to dissolve in an organic solvent, and the organic solvent is sucked into a gel.

JP 2004-75623 A JP 2003-2904 A Liquid Crystal Elastomers, Oxford University Press, Oxford, 2003

  Development of liquid crystal elastomers in which stable liquid crystal molecules are bonded as side chains to the diene polymer and the main chains are cross-linked to prepare gels that swell upon absorption of organic solvents and liquid crystals. is required. However, as described above, when there is only one liquid crystal moiety (mesogen), the enthalpy change when changing from liquid crystal to liquid is small, and liquid crystal properties are manifested unless a large amount of liquid crystal molecules are bonded as side chains to the diene polymer. There is a problem that it is difficult to do.

  On the other hand, when a large amount of liquid crystal molecules is used, the elasticity of the liquid crystal elastomer is impaired. Therefore, in order to be able to exhibit liquid crystallinity only by bonding a small amount of liquid crystal molecules as a side chain, it is a stable liquid crystal with a large enthalpy change when changing from liquid crystal to liquid, and a diene type at the end. Development of liquid crystal molecules with vinyl groups (carbon / carbon double bonds) that can be linked to polymers is necessary.

  In view of the above-mentioned problems, the present invention includes a liquid crystal material capable of exhibiting a stable liquid crystal having a large enthalpy change when changing from liquid crystal to liquid, and that does not impair elastomer elasticity and the liquid crystal material. The object is to provide a liquid crystal elastomer.

（式中、ＲがＨで、Ａが（ＣＨ₂）_mであるか、
ＲがＨ又はＭｅで、ＡがＣＯＯ（ＣＨ₂）_mであり、
ｍは２以上、ｎは３以上である。） The liquid crystal material of the present invention is characterized by including a compound having a structure represented by Chemical Formula 3.

Wherein R is H and A is (CH ₂ ) _m
R is H or Me, A is COO (CH ₂ ) _m ,
m is 2 or more, and n is 3 or more. )

  The liquid crystal elastomer of the present invention is characterized by having a plurality of polybutadiene chains cross-linked to each other and a compound represented by Chemical Formula 3 bonded to at least a part of the plurality of polybutadiene chains.

（式中、ｎ＝３以上、Ｘはハロゲン原子）

（式中、ｎ＝３以上、Ｘはハロゲン原子）

（式中、ｎ＝３以上）

（式中、ｍ＝２以上、Ｘはハロゲン原子）

（式中、ｍ＝２以上、ｎ＝３以上）
また、本発明の液晶用材料の製造方法の他の特徴とするところは、４−シアノ−４'−ヒドロキシビフェニルと、化４に示す化合物とを反応させて、化５に示す化合物を生成する工程と、前記化５に示す化合物と、４'−ヒドロキシ−４−ビフェニルカルボン酸とを反応させて、化６に示す化合物を生成する工程と、前記化６に示す化合物と、化９に示す化合物とを反応させて、化１０に示す化合物を生成する工程と、前記化１０に示す化合物と、アクリル酸またはメタクリル酸と反応させて、化１１に示す化合物を生成する工程とを有する。

（式中、ｍ＝２以上、Ｘはハロゲン原子）

（式中、ｍ＝２以上、ｎ＝３以上、Ｘはハロゲン原子）

（式中、ｍ＝２以上、ｎ＝３以上、Ｒ＝Ｈ or Ｍｅ） The method for producing a liquid crystal material of the present invention includes a step of reacting 4-cyano-4′-hydroxybiphenyl with a compound represented by Chemical Formula 4 to produce a compound represented by Chemical Formula 5, and a compound represented by Chemical Formula 5 above: Is reacted with 4′-hydroxy-4-biphenylcarboxylic acid to produce the compound shown in Chemical Formula 6, the compound shown in Chemical Formula 6 is reacted with the compound shown in Chemical Formula 7, and Chemical Formula 8 And a step of producing a compound shown in the above.

(Where n = 3 or more, X is a halogen atom)

(Where n = 3 or more, X is a halogen atom)

(Where n = 3 or more)

(In the formula, m = 2 or more, X is a halogen atom)

(Where m = 2 or more, n = 3 or more)
Another feature of the method for producing a liquid crystal material of the present invention is that 4-cyano-4′-hydroxybiphenyl is reacted with a compound represented by Chemical Formula 4 to produce a compound represented by Chemical Formula 5. A step of reacting a compound represented by the chemical formula 5 with 4′-hydroxy-4-biphenylcarboxylic acid to produce a compound represented by the chemical formula 6, a compound represented by the chemical formula 6; It has the process of making a compound react, and producing | generating the compound shown to Chemical formula 10, The compound shown to the said Chemical formula 10, and making it react with acrylic acid or methacrylic acid, and producing | generating the compound shown to Chemical formula 11.

(In the formula, m = 2 or more, X is a halogen atom)

(In the formula, m = 2 or more, n = 3 or more, X is a halogen atom)

(Where, m = 2 or more, n = 3 or more, R = H or Me)

  The method for producing a liquid crystal elastomer of the present invention is characterized in that polybutadiene and the compound shown in Chemical formula 3 are mixed and heated within a range of 180 ° C to 250 ° C.

  According to the invention, the compound contains two biphenyl groups. As a result, a stable liquid crystal state having a large enthalpy change when changing from liquid crystal to liquid can be obtained, and clear liquid crystallinity can be exhibited in both the temperature rising process and the temperature falling process. Crosslinking occurs and can have elastomer elasticity.

  As described above, Patent Document 1 shows that a stable liquid crystal state is obtained when a plurality of liquid crystal sites (mesogens) are provided. Therefore, the present inventor has invented a liquid crystal molecule having two biphenyl groups as liquid crystal moieties and a vinyl group (carbon / carbon double bond) that can be bonded to a diene polymer at the terminal. If this liquid crystal molecule is used, stable liquid crystallinity can be exhibited by bonding two liquid crystal molecules having two liquid crystal molecules (mesogens) as side chains to the diene-based polymer. It is possible to prevent the liquid crystal elastomers from being out of shape by preventing them from being displaced due to cross-linking between chains.

  The novel compound represented by Chemical Formula 3 in the present invention has two biphenyl groups substituted with vinyl groups (carbon / carbon double bonds) at its ends, and its preferred embodiment is a large and stable enthalpy change when changing from liquid crystal to liquid. The liquid crystal state becomes clear and shows clear liquid crystallinity in both the temperature rising process and the temperature lowering process, and the liquid crystal temperature range is wide, and the melting point can be easily lowered by mixing them. Further, the compound shown in Chemical formula 3 can be bonded to the polybutadiene chain as a side chain by heating the compound shown in Chemical formula 3 and polybutadiene having a molecular weight of 2 million to 3 million at 180 ° C. to 250 ° C.

  Further, when the compound shown in Chemical formula 3 and polybutadiene having a molecular weight of 2 million to 3 million are dissolved in an organic solvent, the organic solvent is evaporated, and the remaining solid is heated from 180 ° C. to 250 ° C. to form a polybutadiene chain. While the compound is bonded as a side chain, cross-linking occurs between the polybutadienes to become an elastomer, and the compound shown in Chemical Formula 3 is included in the elastomer by being bonded to the polybutadiene chain. In addition, when the heating temperature is less than 180 ° C., the compound shown in Chemical Formula 3 is not bonded as a side chain to the polybutadiene chain, and when heated above 250 ° C., the compound shown in Chemical Formula 3 or an organic compound such as polybutadiene is easily decomposed. End up. Therefore, the heating temperature needs to be 180 ° C to 250 ° C. The reaction in which the compound shown in Chemical Formula 3 is bonded as a side chain and the cross-linking between polybutadienes are almost completed up to 230 ° C., but it is generally known that organic compounds begin to decompose when the temperature exceeds 300 ° C.

  In the case of m <2, the liquid crystal temperature becomes too high and cannot be used for a living body. When n> 12, it takes a lot of time to synthesize the compound shown in Chemical formula 3. Accordingly, m is 2 or more and preferably 12 or less.

  In the case of n <3, the liquid crystal temperature becomes too high and cannot be used for a living body. When n> 12, it takes a lot of time to synthesize the compound shown in Chemical formula 3. Accordingly, n is 3 or more and preferably 12 or less.

  Next, a method for synthesizing the compound represented by Chemical Formula 3 carried out in this example and the characteristics of the physical properties will be described.

  4-Cyano-4′-hydroxybiphenyl and α, ω-dibromoalkane (n = 3 to 12) are mixed at a molar ratio of 1: 1, dissolved in N, N-dimethylformamide, and potassium carbonate is added in the same number of moles. In addition, the mixture was stirred at room temperature for 12 to 24 hours. And the reaction liquid was filtered, the solvent of the filtrate was distilled, the residue was dissolved in chloroform, and separated using a silica gel column chromatograph (developing solvent: mixed solvent of chloroform and hexane). As a result, the compound (α-bromo-ω- (4-cyanobiphenyl-4′-yloxy) alkane) represented by Chemical formula 12 was obtained. In this example, N, N-dimethylformamide was used, but DMSO (dimethyl sulfoxide) may be used instead of N, N-dimethylformamide.

（式中、ｎ＝３以上）

(Where n = 3 or more)

  Next, the compound shown in Chemical Formula 12 and 4′-hydroxy-4-biphenylcarboxylic acid are mixed at a molar ratio of 1: 1, dissolved in N, N-dimethylformamide, and added with the same number of moles of potassium carbonate for 15 hours at room temperature. And stirred. And the reaction liquid was filtered, the solvent of the filtrate was distilled, the residue was dissolved in chloroform, and separated using silica gel chromatography (developing solvent: mixed solvent of chloroform and methanol). As a result, the compound shown in Chemical formula 6 was obtained. In this example, a mixed solvent of chloroform and methanol was used, but instead of the mixed solvent, only chloroform may be used.

  Next, the compound shown in Chemical formula 6 and the compound shown in Chemical formula 13 were mixed at a molar ratio of 1: 1, dissolved in N, N-dimethylformamide, added with the same number of moles of potassium carbonate, and stirred at room temperature for 15 hours. And the reaction liquid was filtered, the solvent of the filtrate was distilled, the residue was dissolved in chloroform, and separated using silica gel chromatography (developing solvent: mixed solvent of chloroform and hexane). As a result, the compound shown in Chemical Formula 8 was obtained. In this example, a mixed solvent of chloroform and hexane was used, but instead of the mixed solvent, only chloroform may be used.

（式中、ｍ＝２以上）

(Where m = 2 or more)

  In the present embodiment, a total of 20 combinations (m = 3, 6, n = 3 to 12), (m = 4, n = 5), and (m = 8, n = 5). The compounds shown in Chemical formula 8 were prepared in the same procedure for 22 types.

  Separately, the compound shown in Chemical Formula 6 and α, ω-dibromoalkane (m = 2 to 12) are mixed at a molar ratio of 1: 1, dissolved in N, N-dimethylformamide, and potassium carbonate is added. The same number of moles was added and the mixture was stirred at room temperature for 12 to 24 hours. And the reaction liquid was filtered, the solvent of the filtrate was distilled, the residue was dissolved in chloroform, and separated using a silica gel column chromatograph (developing solvent: mixed solvent of chloroform and hexane). As a result, the compound shown in Chemical formula 14 was obtained. In this example, N, N-dimethylformamide was used, but DMSO may be used instead of N, N-dimethylformamide.

（式中、ｍ＝２以上、ｎ＝３以上）

(Where m = 2 or more, n = 3 or more)

  Next, the compound shown in Chemical formula 14 and the compound shown in Chemical formula 15 were mixed at a molar ratio of 1: 1, dissolved in N, N-dimethylformamide, added with the same number of moles of potassium carbonate, and stirred at room temperature for 15 hours. And the reaction liquid was filtered, the solvent of the filtrate was distilled, the residue was dissolved in chloroform, and separated using silica gel chromatography (developing solvent: mixed solvent of chloroform and hexane). As a result, the compound shown in Chemical Formula 11 was obtained. In this example, a mixed solvent of chloroform and hexane was used, but instead of the mixed solvent, only chloroform may be used.

（式中、Ｒ＝ＨまたはＭｅ）

(Where R = H or Me)

  In this embodiment, a combination of (m = 3, n = 3, R = H), a combination of (m = 3, n = 3, R = Me), (m = 5, n = 5, R = H) A combination of (m = 10, n = 12, R = H), a combination of (m = 10, n = 12, R = Me), a combination of (m = 11, n = 11, R = Me) , (M = 12, n = 12, R = H) and (m = 12, n = 12, R = Me) in total for 8 types of compounds, the compound shown in Chemical formula 11 was prepared in the same procedure. .

  Next, the compound shown in Chemical formula 8 was identified by elemental analysis, hydrogen nuclear magnetic resonance spectrum, infrared absorption spectrum and the like. Table 1 shows the results of elemental analysis of the compound represented by Chemical Formula 8 (m = 3). In addition, Table 2 shows the results of elemental analysis of the compound represented by Chemical Formula 8 (m = 6). From the results of elemental analysis shown in Tables 1 and 2, it was confirmed that the compound shown in Chemical Formula 8 was pure.

  Table 3 shows the result of the hydrogen nuclear magnetic resonance spectrum of the compound represented by Chemical formula 8 (m = 3). The results of the hydrogen nuclear magnetic resonance spectrum shown in Table 3 showed a similar spectrum, and it was confirmed that the compound shown in Chemical Formula 3 had a similar structure in which only the length of the methylene chain (n number) was different depending on the value of n. .

  Next, Table 4 shows the result of the hydrogen nuclear magnetic resonance spectrum of the compound represented by Chemical formula 11. In the compound bonded with acrylic acid (R = H), δ6.4 (dd, 1H, J = 16.0.Hz, J = 1.5Hz), 6.1 (dd, 1H, due to vinyl group (double bond) J = 16.0Hz, J = 10.0Hz), 5.8 (dd, 1H, J = 10.0Hz, J = 1.5Hz), characteristic spectra were observed. In addition, in the compound bonded with methacrylic acid (R = Me), δ6.1 (s, 1H), 5.5 (s, 1H) and δ1.95 (Me of methacrylic acid) due to the vinyl group (double bond). ) A characteristic spectrum in the vicinity was observed. From these results, it was confirmed that acrylic acid or methacrylic acid was bound.

  The change of the phase structure due to the thermal change of the compound shown in Chemical Formula 3 was observed using a polarizing microscope while being placed on the hot plate. 1 to 11 show liquid crystal states of the compounds represented by Chemical Formula 8 (m = 3, n = 3, 5 to 12). Of the compounds shown in Chemical formula 8, those with n = 4 did not show liquid crystallinity or had a very narrow liquid crystal range. As shown in FIGS. 1 to 11, liquid crystallinity was confirmed in any compound.

  Next, FIG. 12 shows a nematic liquid crystal at 171 ° C. in the temperature lowering process of the compound (m = 4, n = 5) represented by Chemical Formula 8 having different m. As shown in FIG. 12, it was confirmed that the phase structures were similar even when m was different.

  13 to 16, the compounds shown in Chemical formula 11 (m = 3, n = 3, R = Me), (m = 11, n = 11, R = Me), (m = 12, n = 12, R = H), (m = 12, n = 12, R = Me). As shown in FIGS. 13 to 16, liquid crystallinity was confirmed in any compound.

  Furthermore, as a liquid crystal mixed system, a mixture in which the compound shown in FIG. 17 (m = 3, n = 5) and the compound shown in FIG. 8 (m = 6, n = 5) are mixed at a molar ratio of 1: 1. 2 shows a nematic liquid crystal at 172 ° C. in the temperature lowering process of the liquid crystal state. Further, the compound shown in Chemical formula 8 (m = 3, n = 5), the compound shown in Chemical formula 8 (m = 4, n = 5), and the compound shown in Chemical formula 8 (m = 6, n = 5) are shown in FIG. And a nematic liquid crystal at 84 ° C. in the temperature rising process of the liquid crystal state of a mixture in which four kinds of compounds represented by Chemical Formula 8 (m = 8, n = 5) are mixed at a molar ratio of 1: 1: 1: 1. Show. As shown in FIGS. 17 and 18, liquid crystallinity was confirmed in any compound.

  Next, Table 5 and FIG. 19 show the phase transition temperatures of the compound (m = 3) shown in Chemical Formula 8 confirmed by a differential scanning calorimeter (DSC) and a polarizing microscope. The temperature increase and decrease in DSC were measured at 5 ° C./min. As shown in FIG. 19, the even-odd effect at the transition point from the liquid crystal to the isotropic liquid was clearly recognized.

  On the other hand, Table 6 and FIG. 20 show the phase transition temperatures of the compound represented by Chemical Formula 8 (m = 6). The temperature increase and decrease in DSC were measured at 5 ° C./min. As shown in FIG. 20, an even-odd effect at the transition point from the liquid crystal to the isotropic liquid is recognized, but the even-odd effect at the transition point (melting point) from the crystal to the liquid crystal is not recognized when n is 6 or less. It can also be seen that the smaller the n, the wider the liquid crystal temperature range of the compound shown in Chemical Formula 8.

  FIG. 21 shows a compound shown in Chemical formula 8 (m = 3, n = 5), a compound shown in Chemical formula 8 (m = 4, n = 5), a compound shown in Chemical formula 8 (m = 6, n = 5), Chemical formula 8 A differential scanning calorimeter (DSC) in the temperature rising process of the compound (m = 8, n = 5) shown in FIG. 2 is shown, and FIG. 22 shows a differential scanning calorimeter (DSC) in the temperature lowering process of this mixture. As shown in FIG. 21, the melting point decreased as the number of m increased. In particular, in the compound shown in Chemical Formula 8 (m = 8, n = 5), the melting point was as low as 70 ° C., but the liquid crystal temperature range was narrower than other compounds with n = 5.

  FIG. 23 shows the relationship between the liquid crystal temperature range and the mixing ratio in the mixed system of the compound shown in Chemical formula 8 (m = 3, n = 5) and the compound shown in Chemical formula 8 (m = 6, n = 5). Furthermore, the compound shown in Chemical formula 8 (m = 3, n = 5), the compound shown in Chemical formula 8 (m = 4, n = 5), the compound shown in Chemical formula 8 (m = 6, n = 5), FIG. 24 shows a differential scanning calorimeter (DSC) of a temperature rising process of a mixture in which four types of compounds shown in Chemical Formula 8 (m = 8, n = 5) are mixed at a molar ratio of 1: 1: 1: 1. . The above four equimolar mixtures had a broad transition point, but the liquid crystal temperature range was 55 ° C. to 149 ° C., although the transition point from the liquid crystal to the liquid did not change much, but the melting point was significantly lowered. From the above, it can be seen that the compound (n = 5) shown in Chemical Formula 8 is mixed with the compound shown in Chemical Formula 8 having a different number of m, the transition temperature from the liquid crystal to the liquid changes only slightly, and the melting point greatly decreases. .

  Next, Table 7 shows liquid crystal phases and liquid crystal temperature ranges of the compounds represented by Chemical formula 11. As shown in Table 7, it can be seen that the liquid crystal temperature range of the compound shown in Chemical formula 11 is wider when m and n are smaller.

  Since the compound represented by Chemical Formula 3 has two biphenyl groups which are liquid crystal sites, it has a feature that the enthalpy change when changing from liquid crystal to liquid is large. For comparison, the DSC of the compound represented by Chemical Formula 16 in which the biphenyl group, which is a liquid crystal moiety similar to the compound represented by Chemical Formula 8, is one compound was examined. The result is shown in FIG. The compound shown in Chemical formula 16 had no liquid crystallinity when n = 3. Moreover, although the liquid crystal temperature of n = 6 and n = 8 is low compared with the compound shown in Chemical formula 3 in the compound shown in Chemical formula 16, the enthalpy change when changing from the liquid crystal to the liquid is much higher than the compound shown in Chemical formula 3. I understand that it is small. The enthalpy change of the compound shown in Chemical formula 16 (n = 6) was 1.2 J / g, and the enthalpy change of the compound shown in Chemical formula 16 (n = 8) was 1.9 J / g.

（式中、ｎ＝３〜１２）

(Where n = 3 to 12)

  On the other hand, the enthalpy change of the compound (m = 4, n = 5) shown in FIG. 21 shown in FIG. 21 is 9.5 J / g, and the enthalpy change of the compound (m = 4, n = 5) shown in FIG. 7.5J / g, the enthalpy change of the compound shown in Chemical formula 8 (m = 6, n = 5) is 7.4J / g, the enthalpy change of the compound shown in Chemical formula 8 (m = 8, n = 5) is 10.3J / g. In other words, the enthalpy change when the compound shown in Chemical formula 8 changes from liquid crystal to liquid is 6 to 8 times that of the compound shown in Chemical formula 16, so that the compound shown in Chemical formula 8 can create a stable liquid crystal state. Recognize.

  Next, the polymerization of the compound shown in Chemical Formula 3 carried out in this Example and the mixture of the compound shown in Chemical Formula 3 and polybutadiene (molecular weight 2 million to 3 million) were linked to the polybutadiene in the chemical formula 3, A method for preparing a polybutadiene elastomer in which polybutadienes are crosslinked will be described.

  The compound shown in Chemical formula 8 and the polymerization initiator 2,2′-azobis (isobutyronitrile) (radical initiator) are heated in a mixed solvent of dimethyl sulfoxide and toluene at 60 to 80 ° C. for 12 to 40 hours. The polymer was obtained by radical polymerization. In this example, a mixed solvent of dimethyl sulfoxide and toluene was used, but only dimethyl sulfoxide may be used instead of the mixed solvent.

  Next, a polymer obtained by radical polymerization of the compound shown in Chemical Formula 8 and polybutadiene were mixed at a weight ratio of 1: 5 to 1: 1 and dissolved in chloroform. When the solid produced after evaporation of chloroform was heated to 230 ° C., cross-linking occurred between the polybutadienes, and a liquid crystal elastomer in which the compound represented by Chemical Formula 3 was bonded to the polybutadiene chain was obtained. In this embodiment, a combination of (m = 3, n = 5), a combination of (m = 3, n = 7), a combination of (m = 3, n = 9), and (m = 3, n = 11) Liquid crystal elastomers were prepared in the same procedure for a total of four types of combinations.

  FIG. 26 shows the DSC change of a mixture in which the weight ratio of the compound represented by Chemical Formula 8 (m = 3, n = 11) and polybutadiene (molecular weight: 2 million to 3 million) is 1: 2. 261 is a DSC curve of the first temperature rising process of the mixture of the compound shown in Chemical formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). Reference numeral 262 denotes a DSC curve in the temperature rising process of only the compound shown in Chemical Formula 8 (m = 3, n = 11). When a mixture in which the weight ratio of the compound shown in Chemical formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) is 1: 2 is heated to 230 ° C. in the first temperature raising process, A large endotherm is observed near 200 ° C. due to the cross-linking between polybutadienes and the connection between the polybutadiene chain and the compound shown in Chemical Formula 8, indicating that a rubber-like elastic body can be obtained.

  263 is the second time after a mixture of the compound shown in Chemical Formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) is heated to 230 ° C. once. It is a DSC curve of the temperature rising process. It can be seen that the rubber-like elastic body does not generate a large endotherm that occurs in the first temperature raising process even if it is heated at 230 ° C. for the second and subsequent times. This indicates that crosslinking between the polybutadienes has already been completed.

  H.264 is the second temperature drop after heating a mixture of the compound shown in Chemical Formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) to 230 ° C. once. DSC curve of the process, and 265 is a DSC curve of the temperature lowering process of only the compound shown in Chemical Formula 8 (m = 3, n = 11). 266 is the third time after once heating the mixture of the compound shown in Chemical formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) to 230 ° C. It is a DSC curve of the temperature lowering process. It can be seen that when this rubber-like elastic body is heated at 200 ° C. for the second time and thereafter, two melting points or two transition points from liquid crystal to liquid are generated. It can be seen that in the second temperature increase process, there are two transition points from the liquid crystal to the liquid in the temperature increase process, and in the second temperature decrease process, there are two melting points.

  FIG. 27 shows the DSC of the liquid crystal elastomer after crosslinking of a mixture of the compound shown in Chemical Formula 8 (m = 3, n = 9) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). 271 is a DSC curve in the temperature raising process of only the compound (m = 3, n = 9) shown in Chemical Formula 8, and 272 is the compound (m = 3, n = 9) shown in Chemical Formula 8 and polybutadiene (molecular weight 200). FIG. 3 is a DSC curve of a second temperature raising process after the mixture is once heated to 230 ° C. 273 is a DSC curve of the temperature lowering process of the mixture of the compound shown in Chemical formula 8 (m = 3, n = 9) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). , DSC curve of the temperature lowering process of only the compound (m = 3, n = 9) shown in Chemical formula 8. Since the peak is broad in the temperature raising process, it is difficult to understand that there are two transition points, but in the temperature lowering process, there are two transition points.

  FIG. 28 shows the DSC of the liquid crystal elastomer after crosslinking of a mixture of the compound shown in Chemical Formula 8 (m = 3, n = 7) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). 281 is a DSC curve of the temperature rising process of only the compound shown in Chemical formula 8 (m = 3, n = 7), and 282 is the compound shown in Chemical formula 8 (m = 3, n = 7) and polybutadiene (molecular weight 200). FIG. 3 is a DSC curve of a second temperature raising process after the mixture is once heated to 230 ° C. It can be seen that there are two peaks in the temperature raising process.

  As described above, the results of two melting points or two transition points from liquid crystal to liquid were found in many mixtures of the compound shown in Chemical Formula 8 and polybutadiene. In the DSC of the liquid crystal elastomer thus obtained, there are two peaks at the melting point or the transition point from the liquid crystal to the liquid, indicating that the compound shown in Chemical Formula 8 is not bonded to the polybutadiene. This is because there are two types of cases.

  FIG. 29 shows a mixture of the compound shown in Chemical Formula 8 (m = 3, n = 5) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) once heated to 230 ° C. and then heated at 156. It is a polarizing microscope photograph which shows the place where the liquid crystal is developing at ° C. FIG. 30 shows a mixture of the compound shown in Chemical formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) once heated to 230 ° C. and then heated. It is a polarizing microscope photograph which shows the place where the liquid crystal is developing at 153 degreeC of the course. As shown in FIGS. 29 and 30, liquid crystals were confirmed in any liquid crystal elastomer.

  The liquid crystal elastomer obtained by heating the polybutadiene chain obtained above and the compound shown in Chemical Formula 8 at 230 ° C. is swollen in an organic solvent such as chloroform, toluene, methyl laurate, acetone, etc. become.

  As described above, the novel compound shown in Chemical Formula 3 is a biphenyl derivative having a liquid crystallinity having a carbon-carbon double bond (vinyl group) at the terminal and having two liquid crystalline portions (mesogens). . This compound has a feature that the liquid crystal temperature range is wide and the enthalpy change at the transition point from the liquid crystal to the liquid is large. When the liquid crystal molecules containing the novel compound are mixed with polybutadiene and heated to 230 ° C., the polybutadiene is crosslinked and the liquid crystal molecules are bonded to the polybutadiene to form a liquid crystal elastomer. This can be said to be suitable for practical use as a liquid crystal elastomer.

10 is a polarizing micrograph showing a nematic liquid crystal at 155 ° C. in the temperature lowering process of the compound (m = 3, n = 3) shown in Chemical Formula 8. 10 is a polarizing micrograph showing a nematic liquid crystal at 114 ° C. in the temperature rising process of the compound (m = 3, n = 5) shown in Chemical Formula 8. 10 is a polarizing microscope photograph showing a nematic liquid crystal at 110 ° C. in a temperature rising process of a compound (m = 3, n = 6) shown in Chemical Formula 8. 10 is a polarizing microscope photograph showing a nematic liquid crystal at 140 ° C. in a temperature rising process of a compound (m = 3, n = 7) shown in Chemical Formula 8. 10 is a polarizing micrograph showing a nematic liquid crystal at 118 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 8). 10 is a polarizing microscope photograph showing a smectic A liquid crystal at 151 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 9). 10 is a polarizing micrograph showing a smectic A liquid crystal at 105 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 10). 10 is a polarizing microscope photograph showing a nematic liquid crystal at 110 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 10). 10 is a polarizing micrograph showing a smectic A liquid crystal at 146 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 11). 10 is a polarizing micrograph showing a smectic A liquid crystal at 109 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 12). 10 is a polarizing microscope photograph showing a nematic liquid crystal at 120 ° C. in the temperature rising process of the compound shown in Chemical Formula 8 (m = 3, n = 12). 10 is a polarizing micrograph showing a nematic liquid crystal at 171 ° C. in the temperature lowering process of the compound (m = 4, n = 5) shown in Chemical Formula 8. 7 is a polarizing micrograph showing a nematic liquid crystal at 206 ° C. during the temperature rising process of the compound represented by Chemical Formula 11 (m = 3, n = 3, R = Me). 21 is a polarizing micrograph showing a nematic liquid crystal at 127 ° C. in the temperature lowering process of the compound represented by Chemical Formula 11 (m = 11, n = 11, R = Me). 6 is a polarizing micrograph showing a nematic liquid crystal at 114 ° C. during the temperature rising process of the compound represented by Chemical Formula 11 (m = 12, n = 12, R = H). 7 is a polarizing micrograph showing a nematic liquid crystal at 95 ° C. in the temperature lowering process of the compound shown in Chemical Formula 11 (m = 12, n = 12, R = Me). Nematic at 172 ° C. in the temperature lowering process of the mixture obtained by mixing the compound represented by Chemical formula 8 (m = 3, n = 5) and the compound represented by Chemical formula 8 (m = 6, n = 5) at a molar ratio of 1: 1. It is a polarizing microscope photograph which shows a liquid crystal. The compound shown in Chemical formula 8 (m = 3, n = 5), the compound shown in Chemical formula 8 (m = 4, n = 5), the compound shown in Chemical formula 8 (m = 6, n = 5), and Chemical formula 8 4 is a polarizing micrograph showing a nematic liquid crystal at 84 ° C. in a temperature rising process of a mixture obtained by mixing four types of the compounds shown in (4) with the compound (m = 8, n = 5) at a molar ratio of 1: 1: 1: 1. It is a figure which shows the relationship between the phase transition temperature of the compound (m = 3) shown in Chemical formula 8, and the alkyl chain n (n = 3-12). It is a figure which shows the relationship between the phase transition temperature of the compound (m = 6) shown in Chemical formula 8, and the alkyl chain n (n = 3-12). Compound shown in Chemical formula 8 (m = 3, n = 5), Compound shown in Chemical formula 8 (m = 4, n = 5), Compound shown in Chemical formula 8 (m = 6, n = 5), Compound shown in Chemical formula 8 It is a figure which shows the differential scanning calorimeter (DSC) of the temperature rising process of (m = 8, n = 5). Compound shown in Chemical formula 8 (m = 3, n = 5), Compound shown in Chemical formula 8 (m = 4, n = 5), Compound shown in Chemical formula 8 (m = 6, n = 5), Compound shown in Chemical formula 8 It is a figure which shows the differential scanning calorimeter (DSC) of the temperature fall process of (m = 8, n = 5). It is a figure which shows the relationship between the mixing ratio of the mixed system of the compound (m = 3, n = 5) shown in Chemical formula 8 and the compound (m = 6, n = 5) shown in Chemical formula 8 and the liquid crystal temperature range. The compound shown in Chemical formula 8 (m = 3, n = 5), the compound shown in Chemical formula 8 (m = 4, n = 5), the compound shown in Chemical formula 8 (m = 6, n = 5) and the compound shown in Chemical formula 8 It is a figure which shows the differential scanning calorimeter (DSC) of the temperature rising process of 4 types of equimolar mixtures of (m = 8, n = 5). It is a figure which shows the temperature rising process DSC of the compound (n = 3) shown in Chemical formula 16, the compound (n = 6) shown in Chemical formula 16, and the compound (n = 8) shown in Chemical formula 16. It is a figure which shows the DSC of the mixture of the compound (m = 3, n = 11) shown in Chemical formula 8 and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). It is a figure which shows DSC of the liquid crystal elastomer after bridge | crosslinking of the compound (m = 3, n = 9) shown in Chemical formula 8 and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). It is a figure which shows DSC of the liquid crystal elastomer after bridge | crosslinking of the compound (m = 3, n = 7) shown in Chemical formula 8, and the polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2). A mixture of the compound shown in Chemical Formula 8 (m = 3, n = 5) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) was heated once to 230 ° C. and then heated at 156 ° C. in the temperature rising process. It is a polarization micrograph which shows the place which has expressed. A mixture of the compound shown in Chemical Formula 8 (m = 3, n = 11) and polybutadiene (molecular weight 2 million to 3 million) (weight ratio 1: 2) was heated once to 230 ° C. and then heated at 153 ° C. in the temperature rising process. It is a polarization micrograph which shows the place which has expressed.

Explanation of symbols

261 DSC curve of the first heating process of the mixture 262 DSC curve of the heating process of only the compound shown in Chemical Formula 8 (m = 3, n = 11) 263 The second rising after heating the mixture to 230 ° C. once DSC curve 264 of temperature process DSC curve 264 of the second temperature decrease process after heating the mixture once to 230 ° C. 265 DSC curve 266 of the temperature decrease process of the compound (m = 3, n = 11) alone DSC curve of the third temperature decrease process after heating to once at 270 ° C DSC curve of the temperature increase process of only the compound (m = 3, n = 9) shown in Chemical Formula 272 2 after heating the mixture to 230 ° C once DSC curve of the second temperature rising process 273 DSC curve of the temperature decreasing process of the mixture 274 DSC curve of the temperature decreasing process of only the compound shown in Chemical formula 8 (m = 3, n = 9) 281 Compound shown in Chemical formula 8 (m = , N = 7) only DSC curve of the second heating process after the DSC curve 282 mixture Atsushi Nobori process was once heated up to 230 ° C. of

Claims (5)

A liquid crystal material comprising a compound represented by the formula:

Wherein R is H and A is (CH ₂ ) _m
R is H or Me, A is COO (CH ₂ ) _m ,
m is 2 or more, and n is 3 or more. ) A plurality of polybutadiene chains cross-linked to each other;
A liquid crystal elastomer comprising: a compound represented by Chemical Formula 2 bonded to at least a part of the plurality of polybutadiene chains.

Wherein R is H and A is (CH ₂ ) _m
R is H or Me, A is COO (CH ₂ ) _m ,
m is 2 or more, and n is 3 or more. ) Reacting 4-cyano-4′-hydroxybiphenyl with a compound represented by Chemical Formula 3 to produce a compound represented by Chemical Formula 4;
Reacting the compound shown in Chemical Formula 4 with 4′-hydroxy-4-biphenylcarboxylic acid to produce the compound shown in Chemical Formula 5;
A method for producing a liquid crystal material, comprising: reacting the compound represented by Chemical Formula 5 with the compound represented by Chemical Formula 6 to produce a compound represented by Chemical Formula 7.

(Where n = 3 or more, X is a halogen atom)

(Where n = 3 or more, X is a halogen atom)

(Where n = 3 or more)

(In the formula, m = 2 or more, X is a halogen atom)

(Where m = 2 or more, n = 3 or more) Reacting 4-cyano-4′-hydroxybiphenyl with a compound represented by Chemical Formula 8 to produce a compound represented by Chemical Formula 9;
Reacting the compound represented by Chemical Formula 9 with 4′-hydroxy-4-biphenylcarboxylic acid to produce the compound represented by Chemical Formula 10;
Reacting the compound shown in Chemical Formula 10 with the compound shown in Chemical Formula 11 to produce a compound shown in Chemical Formula 12,
A method for producing a material for liquid crystal, comprising the step of reacting the compound represented by Chemical Formula 12 with acrylic acid or methacrylic acid to produce the compound represented by Chemical Formula 13.

(Where n = 3 or more, X is a halogen atom)

(Where n = 3 or more, X is a halogen atom)

(Where n = 3 or more)

(In the formula, m = 2 or more, X is a halogen atom)

(In the formula, m = 2 or more, n = 3 or more, X is a halogen atom)

(Where, m = 2 or more, n = 3 or more, R = H or Me) A method for producing a liquid crystal elastomer, comprising mixing polybutadiene and a compound represented by Chemical Formula 14 and heating within a range of 180 ° C to 250 ° C.

Wherein R is H and A is (CH ₂ ) _m
R is H or Me, A is COO (CH ₂ ) _m ,
m is 2 or more, and n is 3 or more. )

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