JP2553133B2 - Polymer thermotropic liquid crystal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention exhibits liquid crystallinity due to the thermal properties of a substance in a wide temperature range including room temperature, for example, an image display device, an information writing device or other various types. The present invention relates to a polymer thermotropic liquid crystal having applications.

(Prior Art) Recently, as a polymer compound, a lyotropic liquid crystal that exhibits liquid crystallinity when dissolved in a solvent and a thermotropic liquid crystal that exhibits liquid crystallinity as a thermal property (Th
ermotropic: Thermally induced liquid crystal is known. These polymer compounds (resins) exhibiting liquid crystallinity are expected to have various uses because they can have a crystalline state having strength that can withstand use and a liquid crystal state with excellent processability, and are being researched and developed. There is.

Among the above-mentioned compounds, the polymer thermotropic liquid crystal can control the crystal state by temperature without using a solvent. For this reason, various applications can be expected as well as a molding material.

Such polymer thermotropic liquid crystals are known, for example, those disclosed in the document: "Liquid Crystallinity of Polyurethane Containing Biphenyl Unit" (Polymer Papers, Vol.43, No.5, pp311 to 314, 1986). Has been.

According to the above-mentioned documents, in the polyurethane obtained from 4,4′-di (2-hydroxyethyloxy) biphenyl and various diisocyanates, the property as the above-mentioned polymer thermotropic liquid crystal is observed. . Various polymer thermotropic liquid crystals disclosed in this document have a predetermined temperature (hereinafter referred to as T _m ) at which a transition from a crystalline state to a liquid crystal state is observed within a predetermined range of about 135 to 188 (° C). And the transition temperature from the liquid crystal state to the isotropic liquid state (hereinafter referred to as T _i ) are observed at predetermined values within the range of about 172 to 203 (° C.). In addition, the temperature difference between T _m and T _i that can maintain the liquid crystal state (hereinafter referred to as T _i −T _m ).
Have been shown to be within the range of about 15 to 58 (deg) for each compound (for details, refer to the above-mentioned literature).

(Problems to be Solved by the Invention) However, in the above-mentioned conventional polymer thermotropic liquid crystal, it begins to exhibit the property as a liquid crystal by heating.
T _m is about 135 (° C.) or higher, and the temperature range in which the liquid crystal state can be maintained is about 58 (deg) or lower. Because of this,
The above-mentioned T _m is suitable as a heat-molding temperature when used as a resin material, but when used as a display device or the like by utilizing the function as a shutter element, the T _m is higher than room temperature, However, there was a problem that the temperature range T _m −T _i was narrow.

In view of the above-mentioned conventional problems, an object of the present invention is to provide a polymer thermotropic liquid crystal that maintains a liquid crystal state in a wide temperature range including room temperature and can be used for various functional devices.

(Means for Solving the Problem) In order to achieve this object, according to the polymer thermotropic liquid crystal according to the first invention of this application, the following general formula (However, R in the formula is CH _{2 l} , , L, m, and n are l = 5 to 7, m = 17, and n = 3 to
Represents an integer of 220. ).

Further, according to the polymer thermotropic liquid crystal according to the second invention of this application, the following general formula (However, R in the formula is CH _{2 l} , , L, m, and n are l = 5 to 7, m = 17, and n = 3 to
Represents an integer of 220. ).

(Operation) According to the polymer thermotropic liquid crystal according to the first and second inventions of this application, the side chain has a hydrophilic main chain derived from an amino group or an ammonium bromide group and a diisocyanate. As mentioned above, an alkyl group is attached to the amino group or ammonium bromide group, and has an amphipathic polyurethane structure. Therefore, the processability and strength as a resin, which is a polymer having amphipathicity, and the optical effect as a liquid crystal substance can be achieved.

(Example) Hereinafter, the Example of this invention is described in detail. Further, in the following description, in order to facilitate the understanding of the present invention, reference will be made to a suitable synthesis method for obtaining the polymer thermotropic liquid crystal according to the present application, and description will be given under specific numerical conditions.

First, an example of the polymer thermotropic liquid crystal which is the first invention of this application will be described. The polymer thermotropic liquid crystal according to the first aspect of the present invention is obtained by synthesizing the diethanolstearylamine and various diisocyanates. In the following description, the synthesis of diethanolstearylamine will be described, and then the synthesis of the polymeric thermotropic liquid crystal according to the first invention of this application having an amphiphilic polyurethane structure will be described in detail. In addition, raw materials in the following description,
Although the details of the solvent and the like are omitted, all of them are easily available, and those having a sufficient purity chemically in practical use were used.

Synthesis of diethanolstearylamine Hereinafter, synthesis of diethanolstearylamine, that is,
A case where the coefficient m in the following general formula (III) is 17 will be described as an example.

First, stearyl bromide 33.3 (g) (equivalent to 0.1 mol)
And diethanolamine 42.0 (g) (corresponding to 0.4 mol) are precisely weighed and added to about 500 (ml) of isopropanol (hereinafter referred to as IPA) as a solvent. Then, the solvent to which these mixtures were added was refluxed for about 3 hours,
A reaction mixture is obtained.

Next, the reaction mixture is concentrated under reduced pressure until it has a volume of about 1/3, and then cooled.

Next, after adding a suitable amount of chloroform to the above-mentioned concentrated solution, the solution is washed several times with pure water. Thereafter, the solution (corresponding to the chloroform layer) obtained by the washing is dehydrated by a conventionally known method, and concentrated to precipitate diethanolstearylamine in the same manner as described above. Furthermore, the above-mentioned diethanol stearyl amine was recrystallized several times using ether to obtain a sample.

The reaction relating to the synthesis of such diethanolstearylamine is shown below as a reaction formula.

The diethanolstearylamine obtained by the above reaction formula and related to the examples of the present invention was analyzed by infrared absorption spectrum (IR) method and proton-nuclear magnetic resonance spectrum ( ¹ H-NM
Were identified by a R) method (using DMSO-d _6).

First, according to the measurement results of the IR method, it is thought that it is derived from the expansion and contraction of the hydroxyl group (-OH) of the hydrophilic group at the head, and the result is 3250 (cm ^-1 )
The absorption peak of was observed. Furthermore, as the measurement results of the ¹ H-NMR method, Table 1 below shows the functional groups containing protons that are considered to be derived from the respective measured values.

Synthesis of Polymer Thermotropic Liquid Crystal Hereinafter, as an example of the first invention of this application, a method for synthesizing a polymer thermotropic liquid crystal using the diethanolstearylamine obtained by the above formula and various diisocyanates This will be described in detail.

In this example, the above-mentioned diethanolstearylamine and each of the diisocyanates described below were added at a molar ratio of 1: 1 in a suitable amount of dimethylformamide as a solvent, and the temperature was about 120 ° C. for 5 hours. The compounds according to Examples 1 to 5 were obtained by reacting with each other.

As Example 1 diisocyanates In Example 1, using hexamethylene diisocyanate _{(NCO- (CH 2) 6 -NCO} ), according to the synthesis method described above, to obtain a polyurethane compound shown as the compound pp 17 .

Example 2 In this Example 2, 4,4′-dicyclohexylmethane diisocyanate (NCO—C ₆ H ₁₀ —CH ₂ —C ₆ H ₁₀ —NCO) was used as the diisocyanate according to the above-described synthesis method. A polyurethane compound shown as a compound on page 17 was obtained.

Example 3 In this Example 3, ω,
ω'- using diisocyanate-1,3-dimethylcyclohexane _{(NCO-CH 2 -C 6 H} 10 -CH 2 -NCO) as diisocyanates to give a polyurethane compound shown as the compound pp 17.

Example 4 In this Example 4, 2,4-tolylene diisocyanate was used as a diisocyanate for obtaining the polyurethane compound shown as a compound on page 18 according to the above-mentioned synthesis method. Was used.

Example 5 In this Example 5, 4,4 ′ was prepared according to the above-mentioned synthesis method.
- diphenylmethane diisocyanate _{(NCO-C 6 H 4 -CH} 2
With -C ₆ H ₄ -NCO) as diisocyanates to give a polyurethane compound shown as compound 18, pp.

Further, in order to confirm that these compounds are polyurethane compounds,
It was identified by the method. That is, in the urethane bond (-NH-CO-O-) formed by the combination of diethanolstearylamine and diisocyanate, the amino group (-NH
The spectrum derived from the stretching of −) and the carbonyl group (−
The above compounds ~ were identified by the presence / absence of a spectrum derived from the stretching of CO-).

IR Method Measurement Data (i) Compound, Compound and Compound -NH-3350 (cm ^-1 ) -CO-1690 (cm ^-1 ) (2) Compound and Compound -NH-3350 (cm ^-1 ) -CO-1710 (Cm ⁻¹ ) The molecular weight of each of these compounds was measured by a conventionally known method, and it was found that the molecular weights of all the compounds were about 2,000 to 50,000, and the maximum molecular weight was about 100,000. From this, it can be understood that the value of n indicating the degree of polymerization in the structural formulas shown on pages 17 to 18 is about 3 to 110, and about 220 at the maximum.

From these measurement results, it can be understood that the above-mentioned compounds to are amphipathic polyurethane compounds of the above-mentioned respective diisocyanates and diethanolstearylamine.

-Measurement of temperature characteristics of compound-Next, the compound according to the example of the first invention described above-
With respect to, the results of measuring the above-described T _m and T _i will be described.

In this example, conventionally known differential scanning calorimetric analysis was performed as the measurement of the transition point, and the temperature was measured for each of the compounds. The results are shown in Table 2 on the next page.

As can be understood from Table 2, in the compounds of Examples according to the first invention, the temperature T _{m at} which the crystalline state transitions to the liquid crystal state is 20 ° C. (room temperature at the time of measurement) or less, and The difference between T _m and the temperature T _{i at} which the liquid crystal state isotropically transitions is, for example, 280 (deg) or more in the case of a compound.

Furthermore, for the purpose of confirming that each of these compounds ~ effectively acts as a liquid crystal substance, a polarization microscope observation was carried out, showing a light-shielding state in the temperature range of T _m ~ T _i and exhibiting an amphipathic property. A lamella-like striped pattern was observed, and it was confirmed that a transmissive state was exhibited at temperatures above T _i .

Next, an example of the polymer thermotropic liquid crystal which is the second invention of this application will be described in the same manner as the above-mentioned example.

-Synthesis of Diethanolmethyl Stearyl Ammonium Bromide First, the synthesis of diethanol methyl stearyl ammonium bromide, that is, the case where the coefficient m in the following general formula (VI) is 17 will be described as an example.

First, 35.7 (g) of diethanolstearylamine (corresponding to 0.1 mol) obtained by the above reaction formula and 9.5 (g) of methyl bromide (corresponding to 0.1 mol) were precisely weighed, and ethanol was used as a solvent for about 500 Add to (ml). After that,
The mixture is sealed in a pressure bottle and kept at a temperature of about 80 ° C for 24 hours to obtain a reaction mixture.

Next, the precipitate obtained by cooling the above reaction mixture to about room temperature was collected by filtration, and the precipitate was recrystallized several times using ethanol to obtain a sample.

The reaction relating to the synthesis of such diethanolmethyl stearyl ammonium bromide is shown below as a reaction formula.

The diethanolmethyl stearyl ammonium bromide obtained by the above reaction formula and according to the example of the fourth invention was identified by the IR method and the ¹ H-NMR method (using DMSO-d ₆ ) in the same manner as described above.

First, according to the measurement results of the IR method, it is considered that it originates from the expansion and contraction of the hydroxyl group (-OH) of the hydrophilic group at the head, and is 3300 (cm ^-1 ).
The absorption peak of was observed. Further, the measurement results of the ¹ H-NMR method are shown in Table 3 below in the same manner as in Table 1 described above.

However, * 1 indicates a triplet signal.

-Synthesis of polymer thermotropic liquid crystal Hereinafter, as an example of the second invention of this application, a polymer thermotropic liquid crystal using the diethanolmethyl stearyl ammonium bromide obtained by the above formula and various diisocyanates The synthesis method will be described in detail.

In this example, in a suitable amount of dimethylformamide as a solvent, the above-mentioned diethanolmethylstearyl ammonium bromide and each diisocyanate described below were added at a molar ratio of 1: 1 and the temperature was about 120 ° C. for 5 hours. The compounds according to Examples 6 to 10 were obtained by reacting over a period of time.

As Example 6-diisocyanate In Example 6, using hexamethylene diisocyanate _{(NCO- (CH 2) 6 -NCO} ), according to the synthesis method described above, to obtain a polyurethane compound shown as the 27 pages compound.

Example 7 In this Example 7, 4,4′-dicyclohexylmethane diisocyanate (NCO—C ₆ H ₁₀ —CH ₂ —C ₆ H ₁₀ —NCO) was used as the diisocyanate according to the above-described synthesis method. A polyurethane compound shown as a compound on page 27 was obtained.

Example 8 In this example 8, ω,
ω'- using diisocyanate-1,3-dimethylcyclohexane _{(NCO-CH 2 -C 6 H} 10 -CH 2 -NCO) as diisocyanates to give a polyurethane compound shown as compound 27, pp.

Example 9 In this Example 9, 2,4-tolylene diisocyanate was used as a diisocyanate to obtain the polyurethane compound shown as a compound on page 28 according to the above-mentioned synthesis method. Was used.

Example 10 In this Example 10, 4,4 ′ was prepared according to the above-mentioned synthesis method.
- diphenylmethane diisocyanate _{(NCO-C 6 H 4 -CH} 2
Using -C ₆ H ₄ -NCO) as diisocyanate to give a polyurethane compound shown as compound 28, pp.

Further, for the purpose of confirming that these compounds are polyurethane compounds, these compounds were identified by the IR method in the same manner as described above. As a result, the same measurement result as the measurement data described above was obtained. Therefore, the formation of the above-mentioned urethane bond (-NH-CO-O-) was also observed in the compounds ~ synthesized from diethanolmethyl stearyl ammonium bromide and diisocyanate.

The molecular weight of each of these compounds was measured in the same manner as described above.
The molecular weight was in the range of about 2,000 to 50,000, and about 100,000 at the maximum. From this, it can be understood that the value of n indicating the degree of polymerization in the structural formulas shown on pages 27 to 28 is also about 3 to 110 and about 220 at the maximum.

Therefore, from these measurement results,
Can be understood to be an amphipathic polyurethane compound of each of the above-mentioned diisocyanates and diethanolmethylstearylamine bromide.

-Measurement of temperature characteristics of compound-Next, the compound according to the embodiment of the second invention described above-
With respect to, the results of measuring the above-described T _m and T _i will be described.

As described above, the differential scanning calorimetric analysis was carried out to measure the transition point, and the temperature was measured for each of the compounds. The results are shown in Table 4.

As can be understood from Table 4, in the compounds of Examples according to the second invention, the transition temperature T _m from the crystalline state to the liquid crystal state is about room temperature of 20 ° C. or less, and
The difference between T _m and the temperature T _{i at} which the liquid crystal state isotropically transitions is, for example, 280 (deg) or more in the case of a compound.

Furthermore, in the same manner as described above, for the purpose of confirming that each of the compounds ~ effectively acts as a liquid crystal substance, observation with a polarizing microscope was performed, and in the temperature range of T _{m to} T _i, a light shielding state was shown, A lamellar striped pattern showing amphipathicity was observed, and it was confirmed that a permeable state was exhibited at temperatures above T _i .

From the above description and various measurement results, it can be understood that the compounds 1 to 3 according to this example are amphiphilic polyurethane compounds and thermotropic liquid crystals.

Although the embodiments of the present invention have been described above, it is obvious that the present invention is not limited to the above-mentioned embodiments.

For example, in the above-mentioned Examples, specific diisocyanates were illustrated and described in the synthesis of the polymer thermotropic liquid crystal. However, for example, hexamethylene diisocyanate (when this hexamethylene diisocyanate is used, l in — (CH ₂ ) ₁ — of R in the above general formulas (I) and (II) is 1 = 6. In the case of using this pentamethylene diisocyanate (in the case of using this pentamethylene diisocyanate, 1 in-(CH ₂ ) _1- of R in the general formulas (I) and (II) described above.
Becomes l = 5. ), Heptamethylene diisocyanate (when this heptamethylene diisocyanate is used,-(C in R of the general formulas (I) and (II)) is used.
_L in H ₂ ) _l − is l = 7. ), Etc., 4,4'-
2, instead of dicyclohexylmethane diisocyanate
4'-dicyclohexylmethane diisocyanate or
3,4'-dicyclohexylmethane diisocyanate,
ω, ω′-diisocyanate-1,3-dimethylcyclohexane instead of ω, ω′-diisocyanate-1,2-
Dimethylcyclohexane or ω, ω'-diisocyanate-1,4-dimethylcyclohexane, 2,5-tolylene diisocyanate or 2,6-tolylene diisocyanate instead of 2,4-tolylene diisocyanate, or other Even if the above diisocyanate is used, it can be expected that the same effects as those in the above-described examples can be obtained.

The above-mentioned materials, numerical conditions and other specific conditions are
It is obvious that design changes and modifications can be arbitrarily made within the scope of the object of the present invention.

(Effects of the Invention) As is apparent from the above description, according to the polymer thermotropic liquid crystal according to the first and second inventions of the present application, the polymer thermotropic liquid crystal according to the above-mentioned configuration is processed as an amphipathic resin. It has properties and strength and an optical effect as a liquid crystal substance near room temperature. Therefore, the liquid crystallinity can be utilized in a wide temperature range including room temperature, and it can be easily and easily processed into a film by various processing techniques such as a rolling method and a casting method. Further, compared with a conventionally known liquid crystal substance that needs to be hermetically sealed, by processing into the above-mentioned film shape, for example, application to an optoelectronic device such as a display device, a recording device and a polarizing element. Furthermore, various developments such as application to resin fibers such as lyotropic liquid crystal can be expected.

Therefore, the polymer thermotropic liquid crystal according to this application can maintain the liquid crystal state in a wide temperature range including room temperature and can be used for various functional devices and the like, and its economical effect is great.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Kaifu 1-7-12 Toranomon, Minato-ku, Tokyo Oki Denki Kogyo Co., Ltd. (72) Inventor Tadao Nakaya 4-2 Kita Kasugaoka, Ibaraki-shi, Osaka No. 29 (72) Mamoru Tanaka 4-15-10 Takenodai, Nishi-ku, Kobe City, Hyogo Prefecture (72) Inventor Tetsuya Kondo 102 Yonedacho Island, Takasago City, Hyogo Prefecture (56) Reference JP-A-59-213403 (JP, A) JP-A-63-28979 (JP, A) JP-A-51-136738 (JP, A) JP-A-53-33630 (JP, A) JP-A-52-27809 (JP, A) US Pat. A) West German patent 1966065 (DE, A)

Claims (2)

(57) [Claims] 1. The following general formula (However, R in the formula is CH _{2 l} , , L, m, and n are l = 5 to 7, m = 17, and n = 3 to
Represents an integer of 220. ) A polymer thermotropic liquid crystal characterized by being represented by. 2. The following general formula: (However, R in the formula is CH _{2 l} , , L, m, and n are l = 5 to 7, m = 17, and n = 3 to
Represents an integer of 220. ) A polymer thermotropic liquid crystal characterized by being represented by.