JPH1067740A - Fluorine-containing compound and liquid crystal polymer prepared by polymerization thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel compound which is useful for a liquid crystal polymer bearing a perfluoro pyrrolidine structure which can be expected to show a good orientation. SOLUTION: This novel compund is represented by formula I(R is H, methyl; Y is an alkylene; n is 1 or 2), typically 4'-[4-(6-acryloyloxyhexyloxy)benzoyloxy] 4-biphenilyl perfluoro-2-pyrrolidinopropionate. The compound of formula I is prepared by reaction of a hydroquinone or biphenyldiol of formula II with a perfluoro(2-pyrrolidinopropionyl fluoride) to form an ester of formula IV, followed by reaction of the product with 4-alkyloxybenzoyl chloride of formula V.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel fluorine-containing compound and a liquid crystal polymer obtained by polymerizing the same.

[0002]

2. Description of the Related Art Fluorine-containing liquid crystal compounds have attracted attention as useful compounds for producing liquid crystals having good responsiveness, that is, excellent switching characteristics, because of their large spontaneous polarization and low viscosity.

For example, Gray et al. Reported a liquid crystal compound containing a fluorinated aromatic ring (GWGray e).
tal. Liq. Cryst., 11, 531 (1992)). Wen et al. Also reported a liquid crystal compound containing a fluorinated aromatic ring (J. Wen et al. J. Fluorine Chem., 66, 15 (19
94)). Also, there are many reports on liquid crystal compounds containing a perfluoroalkyl group (D. Coates et al. J. C.
hem. Soc., Perkin Trans II, 300 (1976); ACGriffi
n et al. Mol. Cryst. liq. Cryst., 41, 141 (1978);
S.Misaki et al. Mol. Cryst. Liq. Cryst., 66, 123
(1981); AVIvashchenko et al. Mol. Cryst. Liq. Cr
yst., 67, 235 (1981); A. Sakaigawa etal. Mol. Crys
t. liq. Cryst., 206, 147 (1991) etc.).

However, a liquid crystal compound in which fluorine is introduced into an aromatic ring has a problem that the synthesis requires multiple steps. Further, among liquid crystal compounds containing a perfluoroalkyl group, only those having a linear perfluoroalkyl group are conventionally known. On the other hand, in recent years, the range of applications of liquid crystal polymer compounds has been expanding in the fields of general-purpose plastics and engineering plastics, and there has been a demand for the development of liquid crystal polymer compounds that have hitherto not been known in order to meet new demands.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art in liquid crystal compounds and to provide a novel liquid crystal polymer compound and a novel monomer compound useful for the synthesis thereof.

[0006]

Means for Solving the Problems The present inventors bind a perfluorinated cyclic dialkylamino group to a mesogen and also introduce an acrylic group or a methacryl group to form a novel perfluoroalkyl group having a bulky perfluoroalkyl group. The compound was successfully developed. Further, they have found that a novel side chain type liquid crystal polymer can be obtained by polymerizing this compound as a monomer, and have completed the present invention.

[0007]

DETAILED DESCRIPTION OF THE INVENTION That is, the present invention firstly provides the following formula (I):

Embedded image (Wherein, R represents H or a methyl group, Y represents an alkylene, and n represents 1 or 2). Such a compound is a novel compound without any report in the past.

The alkylene chain usually has about 1 to 12 carbon atoms. In general, as the number of carbon atoms increases, the transition temperature tends to decrease. About 6 carbon atoms are preferable. n is 1 or 2, and as described later, a compound of n = 2 is useful as a raw material (monomer) of a liquid crystal polymer.

The compound of the formula (I) can be synthesized by any method of linking constituent parts, but typically can be synthesized by the following scheme.

[0010]

Embedded image

[0011]

Embedded image

That is, first, perfluoro (2-
Reaction of pyrrolidinopropionyl fluoride) (formula (III)) with hydroquinone or biphenyldiol (formula (II)). The reaction was performed in THF, diethyl ether, 1,4
Hydroquinone or biphenyldiol is dissolved in a solvent such as dioxane, and perfluoro (2-pyrrolidinopropionyl fluoride) is added dropwise to the above solution, preferably in the presence of a base such as pyridine. Hydroquinone or biphenyldiol is used in excess, preferably 1 to 3 times, in molar ratio to fluoride. If the molar ratio is less than the lower limit, the yield decreases due to side reactions. Use of the molar ratio exceeding the upper limit does not affect the reaction efficiency or the yield, and leads to an increase in the reaction cost. The reaction temperature is preferably from 0 ° C. to about room temperature. If the reaction temperature is lower than the lower limit, the reaction rate will decrease. If the reaction temperature exceeds the upper limit, the yield decreases due to side reactions.

The ester synthesized using perfluoro (3-pyrrolidinopropionyl fluoride) and hydroquinone is weak to humidity such as being immediately hydrolyzed in methanol, but was synthesized using perfluoro (2-pyrrolidinopropionyl fluoride). It has been confirmed that the ester compound is stable to moisture.

After completion of the reaction, unreacted hydroquinone or biphenyldiol is removed to obtain ester (IV), which is reacted with 4-alkyloxybenzoic acid (V). 4
-Alkyloxybenzoic acid (V) is preferably used as an acid chloride, and the acid chloride is added dropwise to an ester (IV) dissolved in a solvent such as hexane or diethyl ether in the presence of a base such as pyridine. Can do it. The acid chloride is used in a molar ratio of 1 to 1.5 times the ester (IV). If it is less than the lower limit, the reaction does not proceed sufficiently. Even if the amount exceeds the upper limit, the reaction efficiency and the yield are not affected, and the reaction cost is increased. The reaction temperature is preferably from 0 ° C. to about room temperature. If it is less than the lower limit, the reaction rate will decrease. If it exceeds the upper limit, the yield will decrease due to side reactions.

The compound thus obtained can be used for synthesizing a liquid crystal polymer compound. That is, the present invention secondly provides a liquid crystal polymer obtained by polymerizing the compound. However, as shown in a test example described later, when n = 1, the obtained polymer immediately becomes an isotropic liquid from a glassy state, and therefore, a compound of n = 2 is used for polymer synthesis.

The polymerization reaction can be carried out in accordance with known acrylic polymer synthesis conditions. For example, T
0.1 to 5 in a solvent such as HF, benzene or toluene.
An initiator such as azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO) in an amount of about mol% is added, and polymerization is carried out thermally or photochemically. The heating temperature is preferably from 50 to 80C. Although the degree of polymerization of the polymer can be changed according to the purpose, usually, the number average molecular weight is preferably about 10,000 to 1,000,000. If it is less than the lower limit, the phase transition temperature is lowered, and similarly to those monomers, a liquid crystal phase may not be developed. If it exceeds the upper limit, the solubility in the solvent will decrease.

[0017]

EXAMPLES Hereinafter, the structure and effects of the present invention will be described more specifically with reference to examples and comparative examples. However, these are examples and do not limit the scope of the present invention. Example 1 (1) Synthesis of 4 '-(perfluoro-2-pyrrolidinopropionyloxy) -4-biphenylol (Bp-Py) 7.71 g (41.4 mmol) of 4,4'-biphenyldiol and
1.5 ml of pyridine was added to THF to make a total volume of 30 ml, and 5.00 g of perfluoro-2-pyrrolidinopropionyl fluoride was added to this solution at 0 ° C. under an argon atmosphere.
(13.8 mmol) was added dropwise. After the mixture was stirred at room temperature for 30 minutes to progress the reaction, the pressure was reduced to remove the solvent and excess pyridine. The product was separated by column chromatography and recrystallized from hexane to give 3.73 g of the title compound (yield 51%). IR (KBr): 3560 cm ^-1 (OH), 1780 cm ^-1 (C = O) ¹ H-NMR (CDCl ₃ ; δ (TMS)): 7.60 (d, 2H, J = 8.8 Hz)
), 7.44 (d, 2H, J = 8.6), 7.21 (d, 2H,
J = 8.8), 6.91 (d, 2H, J = 8.6), 4.90 (broa
ds, 1H) Melting point: 129 ° C

(2) 4 '-[4- (6-acryloyloxyhexyloxy) benzoyloxy] 4-biphenylyl perfluoro-2-pyrrolidinopropionate (Aa-
Synthesis of Bp-Py) 2.14 g (7.32 mmol) of 4- (6-acryloyloxyhexyloxy) benzoic acid and traces of 2,6-di-tert
To -butyl-p-cresol was added 9 g of thionyl chloride and a catalytic amount of N, N-dimethylformamide. The solution was stirred at room temperature for 1 hour under an argon atmosphere. The solvent and unreacted thionyl chloride were removed under reduced pressure to obtain a viscous acid chloride. 3.50 g (6.64 mmol) of Bp-Py prepared in (1) and 1 ml of pyridine were dissolved in 15 ml of ether cooled to 0 ° C., and the acid chloride was dissolved in 22 ml of hexane. It was dropped. After the mixture was stirred at room temperature for 30 minutes to progress the reaction, the pressure was reduced to remove the solvent and excess pyridine. The product was separated by column chromatography and recrystallized from methanol to give 3.43 g of the title compound (yield: 64%). IR (KBr): 2945cm ^-1 (CH), 1795, 1725cm ^-1 (C =
O) ¹ H-NMR (CDCl ₃ ): 8.16 (d, 2H, J = 8.8 Hz), 7.6
4 (d, 2H, J = 8.5), 7.60 (d, 2H, J = 8.6)
), 7.30 (d, 2H, J = 8.5), 7.25 (d, 2H,
J = 8.6), 6.98 (d, 2H, J = 8.8), 6.40 (dd,
1H, J ₁ = 17.4, J ₂ = 1.4), 6.13 (dd, 1H, J
_{1 = 17.4, J 2 = 10.6} ), 5.81 (dd, 1H, J 1 = 10.
6, J ₂ = 1.4), 4.19 (t, 2H, J = 6.3), 4.06
(T, 2H, J = 6.3), 2.20-1.3 (m, 8H) Melting point: 80 ° C

Example 2 Synthesis of 4 '-[4- (6-methacryloyloxyhexyloxy) benzoyloxy] 4-biphenylyl perfluoro-2-pyrrolidinopropionate (Ma-Bp-Py) In step (2), instead of 4- (6-acryloyloxyhexyloxy) benzoic acid, 2.23 g of 4-
The same procedure was repeated except that (6-methacryloyloxyhexyloxy) benzoic acid was used to obtain the title compound. IR (KBr): 2940cm ^-1 (CH), 1790, 1710cm ^-1 (C =
O), 1640 (C = C) ¹ H-NMR (CDCl ₃ ): 8.16 (d, 2H, J = 8.9 Hz), 7.6
5 (d, 2H, J = 8.6), 7.60 (d, 2H, J = 8.6)
), 7.30 (d, 2H, J = 8.6), 7.26 (d, 2H,
J = 8.6), 6.97 (d, 2H, J = 8.9), 6.10 (s,
1H), 5.55 (s, 1H), 4.17 (t, 2H, J = 6.5
), 4.06 (t, 2H, J = 6.1), 1.95 (m, 3
H), 2.04-1.34 (m, 8H) Melting point: 83 ° C

Example 3 (1) Synthesis of 4- (perfluoro-2-pyrrolidinopropionyloxy) phenol (Hq-Py) 1.67 g (15.2 mmol) of hydroquinone and 1.5 ml of pyridine were dissolved in THF to give a total volume of 10 ml. 5.00 g (13.8 mmol) of perfluoro-2-pyrrolidinopropionyl fluoride was added dropwise to this solution at 0 ° C under an argon atmosphere. The mixture was stirred at room temperature for 30 minutes to progress the reaction, and then the pressure was reduced to remove the solvent and excess pyridine. The product was separated by column chromatography and recrystallized from hexane to give 3.43 g of the title compound. In addition,
The product was identified by IR spectrum and
Performed by ¹ H NMR. (2) 4- [4- (6-acryloyloxyhexyloxy) benzoyloxy] phenyl perfluoro-2-
Synthesis of pyrrolidinopropionate (Aa-Hq-Py) The title compound was obtained in the same manner as in (2) of Example 1, except that Hq-Py was used instead of Bp-Py. IR (KBr): 2930 cm ^-1 (CH), 1790, 1725 cm ^-1 (C = O) ¹ H-NMR (CDCl ₃ ): 8.13 (d, 2H, J = 9.0 Hz), 7.25
(D, 4H), 6.97 (d, 2H, J = 9.0), 6.40 (d
_{d, 1H, J 1 = 17.4} , J 2 = 1.5), 6.12 (dd, 1
H, J ₁ = 17.4, J ₂ = 10.5), 5.81 (dd, 1H, J ₁
= 10.5, J ₂ = 1.5), 4.18 (t, 2H, J = 6.4),
4.06 (t, 2H, J = 6.2), 2.20-1.30 (m, 8H) Melting point: 47 ° C

(3) 4- [4- (6-methacryloyloxyhexyloxy) benzoyloxy] phenyl perfluoro-2-pyrrolidinopropionate (Ma-Hq-Py)
The title compound was obtained in the same manner as in Example 2, except that Hq-Py was used instead of Bp-Py. IR (KBr): 2950cm ^-1 (CH), 1790, 1730, 1710cm
^-1 (C = O), 1645 cm ^-1 (C = C) ¹ H-NMR (CDCl ₃ ): 8.11 (d, 2H, J = 8.9 Hz), 7.24
(M, 4H), 6.96 (d, 2H, J = 8.9), 6.08
(S, 1H), 5.53 (s, 1H), 4.16 (t, 2H, J
= 6.4), 4.04 (t, 2H, J = 5.8), 1.93 (m, 3
H), 2.08-1.31 (m, 8H) Melting point: 54 ° C

Example 4 0.300 g of the monomer (Aa-Bp-Py) obtained in Example 1 (2) was
Dissolve in 0.8 ml of THF, add 1.0 mol% of 2,
2'-azobisisobutyronitrile [radical initiator]
Was added, and after sufficient degassing, polymerization was carried out at 60 ° C. for 48 hours. After the completion of the polymerization reaction, the reaction mixture was diluted with THF and poured into methanol. The precipitated polymer was dried under vacuum, and purified by reprecipitation from methanol to obtain 0.240 g of a polymer. IR spectrum, ¹ H-NMR and ⁷ H-NMR
As a result, it was confirmed that poly (Aa-Bp-Py) was obtained. Ma-B
Polymerization was carried out under the conditions shown in Table 1 in the same manner for p-Py, Aa-Hq-Py and Ma-Hq-Py.

[0023]

[Table 1]

The molecular weight and the phase transition temperature of each polymer were measured. Table 2 shows the results. The molecular weight was measured by gel permeation chromatography. Specifically, it is a value measured using a Tosoh GMH6 column with standard polystyrene using THF as an eluent.
For the measurement of the phase transition temperature, DSC7 manufactured by Perkin-Elmer Co. was used.
The transition phase is identified by observing the texture with a polarizing microscope (using Nikon SMZ-1B crossed Nicols) using a scanning differential thermal analyzer (both at a heating rate and a cooling rate of 5 ° C / min). Was. Fan-shaped texture is observed in the smectic phase of poly (Aa-Bp-Py) and poly (Ma-Bp-Py), and liquid crystal state is observed in poly (Aa-Hq-Py) and poly (Ma-Hq-Py) Was not

[0025]

[Table 2] As shown in the results, according to the method of the present invention, a liquid crystal polymer exhibiting a liquid crystal state over a wide temperature range can be produced.

[0026]

According to the present invention, a novel compound having a bulky perfluoroalkyl, a mesogen and a polymerizable functional group can be obtained. This compound or its intermediate is stable to moisture. Further, by using a compound having a biphenyl structure among the compounds according to the present invention as a monomer, a liquid crystal polymer compound having a perfluoropyrrolidine structure, which can be expected to have better orientation than ever, can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiji Hayashi 153 Kitabukuro-Kita, Konan City, Aichi Prefecture (72) Inventor Haruhiko Fukaya 5-187-1, Kyosaicho, Obu City, Aichi Prefecture (72) Inventor Naohiro Terasawa Aichi Prefecture 1-402 1-478 Nishi-Shiga-cho, Kita-ku, Nagoya-shi (72) Inventor Takashi Abe 7-6-4 Oshizawadai, Kasugai-shi, Aichi Prefecture (72) Inventor Kota Omori 3-6-1 Ibarjima, Akita-shi, Akita Pref. Inside Tochem Products

Claims (2)

[Claims] (1) The following formula (I): (Wherein, R represents H or a methyl group, Y represents alkylene, and n represents 1 or 2). 2. The compound according to claim 1, wherein n =
Liquid crystal polymer obtained by polymerizing 2).