JPH0853402A - Cyanoethyl fluoroacrylate - Google Patents

Abstract

PURPOSE:To obtain a new cyanoethyl alpha-fluoroacrylate useful for synthesizing a polymer having a high strength, dielectric and orienting properties and transparency. CONSTITUTION:This cyanoethyl alpha-fluoroacrylate is expressed by formula I. The compound of formula I is obtained by reacting, e.g. an acryloyl halide of formula II containing fluorine and having the fluorine as a substituent group at the alpha-position with ethylene cyanohydrin. A polymer obtained by using the new compound of formula I can be used for an organic electronic material, e.g. an organic semiconductor resin, a highly dielectric resin, a highly oriented resin or an antistatic resin. The polymer obtained from the compound of formula I is further useful for a liquid crystal material, e.g. a material for a polymer- dispersed type liquid crystal(PDLC) or a liquid crystal-polymer complex(LCPC) utilizing the high orienting properties of the cyanoethyl group to an electric field.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to α-fluoroacrylic acid cyanoethyl ester useful as an intermediate for various synthetic products. The compound has a particularly high strength,
It is useful for the synthesis of polymers having high dielectric properties, high orientation and high transparency, and the obtained polymers are organic electronic materials such as organic semiconductor resins, high dielectric resins, high orientation resins, antistatic resins. Etc. can be used. Also, α
A polymer of fluoroacrylic acid cyanoethyl ester is a liquid crystal material utilizing a high orientation of a cyanoethyl group with respect to an electric field, for example, a resin dispersion type liquid crystal material (PDL).
C), liquid crystal-polymer composite (LCPC), etc. are useful.

[0002]

2. Description of the Related Art Conventionally, alkyl esters and aryl esters of α-fluoroacrylic acid have been known. These are useful as intermediates for various synthetic products, and are particularly used for producing polymers. These polymers have properties such as giving a solid having high strength and being excellent in transparency, and therefore have been reported to be useful as an optical material such as a lens (Japanese Patent Laid-Open No. 61-141711, JP-A-61-141711). Kaisho 6
2-38418). As the alkyl ester residue, for example, a C1-C5 alkyl group such as methyl, ethyl, propyl, butyl, neopentyl, etc., and as the aryl ester residue, for example, phenyl, halogen-substituted phenyl, etc. have been reported (Germany Patent No. 2,95
0,491, JP-A-62-298556). However, these are all low polar ester residues and have a low dielectric constant.

On the other hand, examples of the polar ester residue include trifluoroethyl having a fluorine atom,
There are those having a fluoroalkyl group such as hexafluoroisobutyl (JP-A-62-26247 and JP-A-62-1).
67742). However, even those having these fluoroalkyl groups cannot obtain a sufficient dielectric constant.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an .alpha.-fluoroacrylic acid ester having a high strength and a polarity sufficient for use in applications such as organic electronic materials. A material containing a high polar group is expected to have a high dielectric constant due to its orientational polarization, and is expected to be useful as an organic electronic material such as a binder for an organic dispersion type electroluminescence (EL) or a film capacitor. Further, due to its high orientation, it is expected to be useful for liquid crystal materials.

[0005]

The present invention provides a formula containing a cyanoethyl group having a high dipole capacity in an ester residue:

Embedded image The α-fluoroacrylic acid cyanoethyl ester represented by The present compound can be produced, for example, according to the following procedure. That is, the formula:

[Chemical 3] (In the formula, X represents a halogen element.) A fluorine-containing acrylic acid halide having fluorine at the α-position as a substituent is reacted with ethylene cyanohydrin to form an α-fluoro compound represented by the above formula. Acrylic acid cyanoethyl ester is obtained.

Examples of the above-mentioned fluorine-containing acrylic acid halides include α-fluoroacrylic acid chloride, α-fluoroacrylic acid bromide, α-fluoroacrylic acid fluoride, and the like. These include, for example, α-fluoroacrylic acid or their derivatives. It can be easily produced by reacting a salt with a halogenating agent such as thionyl chloride, phosphorus pentachloride, phosphorus trichloride, phosphorus tribromide, benzoyl chloride and the like.

Ethylene cyanohydrin is used in an amount of 0.8 times mol or more, preferably 1.0 times to 3 times mol, based on the fluorine-containing acrylic acid halide. If the amount used is less than 0.8 times by mole, the reaction rate of the fluorine-containing acrylic acid halide decreases, and the yield decreases. If the amount used exceeds 3 times the molar amount, it becomes necessary to recover and purify excess ethylene cyanohydrin, and the operation becomes complicated.

The above reaction is preferably carried out in a solvent. Any solvent can be used as long as it is not reactive with the above-mentioned fluorine-containing acrylic acid halide. For example, ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane, halogenated hydrocarbons such as dichloromethane and 1,2-dichloroethane, aliphatic compounds such as n-hexane, n-heptane, cyclohexane, benzene, toluene and xylene. , Alicyclic, or aromatic hydrocarbons. The amount of solvent used is 1 by weight with respect to the fluorine-containing acrylic halide.
˜50 times, preferably 5 to 20 times. If the amount used is less than 1 time, the heat of reaction cannot be sufficiently relaxed and side reactions occur. If the amount exceeds 50 times, the productivity per batch will be low, and the operations such as recovery and purification of the solvent used will be complicated.

The above-mentioned reaction is advantageously carried out in the presence of a basic substance as a hydrohalic acid scavenger, and the basic substance may be a trialkylamine such as triethylamine or tributylamine, or pyridine. Organic bases such as The basic substance is used in an amount of 0.5 to 2 times, preferably 0.8 to 1.2 times the mol of the fluorine-containing acrylic acid halide. If the amount is less than 0.5 times by mole, the function as a hydrohalic acid scavenger is not sufficiently exerted, and if the amount is more than 2 times by mole,
Side reactions occur due to the action of excess basic substances.

The reaction is carried out at a reaction temperature of 80 ° C. or lower, preferably −20 to 50 ° C., for 0.5 to 48 hours, preferably 1 to
Do it for 10 hours. At a temperature higher than 80 ° C., there are problems such as a decrease in yield due to an increase in side reactions and coloring of products. When the reaction time exceeds 48 hours, similar side reactions tend to increase. When the reaction time is shorter than 0.5 hours, the reaction does not proceed sufficiently and the yield decreases.

The reaction is carried out by mixing fluorine-containing acrylic halide, ethylene cyanohydrin, and a basic substance in a solvent, but the mixing method and mixing order of the above reaction reagents are not particularly limited. The α-fluoroacrylic acid cyanoethyl ester produced by the reaction can be used after purification such as distillation according to the purpose. The formed α-fluoroacrylic acid cyanoethyl ester is a colorless liquid at room temperature. Refractive index is 1.31, boiling point is 71 mm to 73 ° C. under 1 mmHg,
The density at 25 ° C. is 1.35 g / cm ³ . Moreover, the average transmittance in the wavelength range of 380 to 650 nm is 99% or more. The α-fluoroacrylic acid cyanoethyl ester can be polymerized and can also be copolymerized with other vinyl compounds. The polymerization method of α-fluoroacrylic acid cyanoethyl ester is not particularly limited as long as it is a method capable of polymerizing a conventionally known acrylic monomer. For example, in the presence of a polymerization initiator and, if necessary, a chain transfer agent, bulk polymerization, solution polymerization, suspension polymerization, or the like, or photopolymerization or the like can be performed.

Examples of the above-mentioned polymerization initiator include peroxides such as dialkyl peroxide, diacyl peroxide, ketone peroxide, peroxyketal, peroxyester, peroxydicarbonate and hydroperoxide, and 2,2'-. Azobisisobutyronitrile, 2,
2'-azobis (2-methylbutyronitrile), 2,
2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-cyclopropylpropionitrile), Examples thereof include azo compounds such as 1,1′-azobis (cyclohexane-1-carbonitrile) and sulfur compounds such as potassium persulfate and sodium persulfate. The amount of the above-mentioned polymerization initiator to be used may be usually selected in the range of 0.1 to 5 parts by weight, preferably 0.1 to 1 part by weight, relative to 100 parts by weight of α-fluoroacrylic acid cyanoethyl ester. If the amount used is unnecessarily large, α-
The molecular weight of the fluoroacrylic acid cyanoethyl ester polymer may decrease, or unreacted impurities may remain to adversely affect the electrical characteristics.

Examples of the chain transfer agent include mercaptans such as n-butyl mercaptan, octyl mercaptan, lauryl mercaptan, benzyl mercaptan and cyclohexyl mercaptan. The chain transfer agent may be used in an amount of usually 5 parts by weight or less, preferably 1 part by weight or less, relative to 100 parts by weight of α-fluoroacrylic acid cyanoethyl ester. Also in this case, if the amount used is more than necessary, problems similar to those of the polymerization initiator tend to occur.

[0014]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the description of these examples. Example 1 22.5 g (0.20) of α-fluoroacrylic acid chloride
(7 mol) in 100 ml of distilled dichloromethane to give a solution of ethylene cyanohydrin 14.7
g (0.207 mol) and triethylamine 20.9 g
The mixed solution with (0.207 mol) was added at a temperature of 5 ° C. to 3
It was added dropwise in 0 minutes. The mixture was further stirred and mixed at a temperature of 25 ° C. for 2 hours, and the obtained solid was filtered off. After adding 0.005 g of hydroquinone monomethyl ether to the filtrate, it was distilled under reduced pressure. As a result, boiling points 71 to 73
19.2 g of α-fluoroacrylic acid cyanoethyl ester having a temperature of 1 ° C. (1 mmHg) was obtained. Being α-fluoroacrylic acid cyanoethyl ester means that IR,
Confirmed by NMR spectrum.

FIG. 1 shows the IR spectrum. 2260
cm ^-1 peak

[Chemical 4] The peak at 1750 cm ^-1 is C = O, 1660 cm
The peak at ^-1 indicates CH ₂ = CF- and the peak at 1160 cm ^-1 indicates C-F. 2 and 3 show a ¹³ C-NMR spectrum and a ¹ H-NMR spectrum, respectively. The solvent is D
An MSO-d _e, shift criterion at ¹³ C-NMR spectrum 39.5 ppm (solvent), is 0.0 ppm (DSS external standard) in ¹ H-NMR spectrum. The correspondence between peaks and chemical structures is shown below.

[Chemical 5]

[Table 1]

Application Example of α-fluoroacrylic acid cyanoethyl ester polymer
Production 10 g of α-fluoroacrylic acid cyanoethyl ester, azobisisobutyronitrile (AIBN) 0.01
g, 0.03 g of lauryl mercaptan, and 200 g of dimethyl sulfoxide were placed in a pressure-resistant glass container and deaerated. The glass container was then sealed and heated at 60 ° C for 3 hours. After cooling the reaction mixture to room temperature, the resulting mixture was poured into 1 liter of methanol for crystallization. The crystallized product was recovered, dissolved again in 100 g of dimethyl sulfoxide, and then poured into 1 liter of methanol for crystallization. After the purification by dissolution-crystallization was repeated 3 times, the purified product was dried at 80 ° C. for 8 hours to obtain 8.6 g of a colorless solid. The obtained polymer is I
From the R and NMR spectra, it was confirmed to be the target α-fluoroacrylic acid cyanoethyl ester polymer.

Reference Example 1 Purified acrylic acid cyanoethyl ester monomer 30
0.05 g of 2,2'-azoisobutyronitrile was dissolved in 150 g of acetone, and 60 g was dissolved in an argon gas atmosphere.
Heated at ℃ for 1 hour. After cooling, it was poured into methanol to crystallize the reaction product. The obtained crystallized product was redissolved in acetone and poured into methanol for recrystallization. After repeating this operation three times, the purified product was dried at 60 ° C. under reduced pressure to obtain 25.5 g of a cyanoethyl acrylate polymer as a pale yellow rubbery solid.

Reference Example 2 30 g of purified acrylic acid cyanoethyl ester monomer
Instead of using a mixture of purified acrylic acid cyanoethyl ester monomer 12.5 g and purified methacrylic acid cyanoethyl ester monomer 13.9 g, the same reaction as in Comparative Example 1 was carried out, and post-treatment was carried out. As a result, 23.7 g of a colorless solid was obtained. Elemental analysis of this revealed that the nitrogen content was 10.6% and that a 1: 1 (molar ratio) copolymer of acrylic acid cyanoethyl ester and methacrylic acid cyanoethyl ester was obtained.

Reference Example 3 30 g of pullulan (PF-20 manufactured by Hayashibara Laboratory) was added to pure water 12
After dissolving in 0 g and adding 36 g of 25% sodium hydroxide aqueous solution, 120 g of acetone and then 1 acrylonitrile
50 g was added and reacted at room temperature for 14 hours. Acetic acid 13.5
g to neutralize, pour into pure water with stirring,
The reaction was crystallized. The obtained crystallized product was redissolved in acetone and then recrystallized with pure water for purification. After repeating this operation 3 times, the purified product was dried under reduced pressure at 60 ° C. to obtain 55 g of white purified cyanoethylated pullulan. From the result of nitrogen analysis, the degree of cyanoethylation was 85%.

Physical Properties Test (1) Physical Properties of Film The polymers obtained in Application Examples and Reference Examples 1 to 3 were dissolved in dimethylformamide and cast on a glass plate, and the temperature was 100 ° C. for 2 hours and then 120 ° C. for 2 hours. It was dried to form a film having a thickness of about 50 μm. The film was cut into 1 cm x 4 cm strips to give test pieces, and 25 pieces were obtained using Autograph DDS-10T-S (manufactured by Shimadzu Corporation).
Tensile strength and elongation were measured in an atmosphere of ℃ and relative humidity of 55% RH. In addition, using the same test piece, the spectrophotometer U
380-650 by V-160A type (manufactured by Shimadzu Corporation)
The light transmittance in the wavelength range of nm was measured. The measured values are shown in Table 2. It was found that the product of the present invention has excellent film properties and transparency.

(2) Electrical Properties The polymers obtained in Application Examples and Reference Examples 1 to 3 were dissolved in dimethylformamide, cast on an aluminum sheet and dried at 100 ° C. for 2 hours and then at 120 ° C. for 2 hours. A film having a thickness of about 50 μm was prepared. Aluminum is deposited on the surface of this film to make a measurement sample,
Measurements were performed using an LF impedance analyzer 4192 model (trade name, manufactured by Yokogawa HP), and the values of the relative permittivity and the dielectric loss tangent obtained are shown in Table 2. It was found that the product of the present invention exhibits stable electric characteristics in a wide temperature range. (3) Moisture absorption amount The polymers obtained in Application Examples and Reference Examples 1 to
Was allowed to stand in an atmosphere of relative humidity of 75% RH and the equilibrium moisture absorption was measured. The measured values are shown in Table 2. It was found that the product of the present invention has low hygroscopicity.

The results of measuring the average molecular weight, softening temperature and thermal decomposition temperature of the polymers obtained in the application examples and reference examples are shown in Table 2.

[Table 2]

[0023]

INDUSTRIAL APPLICABILITY The α-fluoroacrylic acid cyanoethyl ester according to the present invention has a functional group such as a double bond group, a fluorine group and a cyano group in the molecule, and thus is useful as an intermediate for various synthetic products. . In particular, the double bond group can be polymerized by using a radically effective initiator or photopolymerization. Since a polymer of α-fluoroacrylic acid cyanoethyl ester and a copolymer containing the constitutional unit thereof have high strength, high dielectric property, high orientation and high transparency, they can be used in organic electronic materials such as organic semiconductor resins and It is useful for dielectric resin, highly oriented resin, antistatic resin, liquid crystal material and the like.

[Brief description of drawings]

FIG. 1 is a diagram showing an IR spectrum of α-fluoroacrylic acid cyanoethyl ester.

FIG. 2 is a chart showing a ¹³ C-NMR spectrum of α-fluoroacrylic acid cyanoethyl ester.

FIG. 3 is a chart showing ¹ H-NMR spectrum of α-fluoroacrylic acid cyanoethyl ester.

Continuation of the front page (72) Inventor Shigehiro Nagura 28, Nishi-Fukushima, Kubiki-mura, Nakabuki-gun, Niigata Prefecture 1 Shin-Etsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. The formula: Α-fluoroacrylic acid cyanoethyl ester represented by: