JPH0848720A - Fluorine-containing acrylic acid cyanoethyl ester polymer - Google Patents

Abstract

PURPOSE:To prepare an alpha-fluoroacrylic acid cyanoethyl ester polymer which has high film strength, high permittivity, high orientation, and high transparency and is resistant to environmental conditions such as temp., humidity and the like. CONSTITUTION:The polymer comprises repeating structural units represented by the formula (where n is the number of repeating units and not less than 50 on the average).

Description

Detailed Description of the Invention

[0001]

The present invention has high film strength, high dielectric constant, high orientation and high transparency,
The present invention relates to an α-fluoroacrylic acid cyanoethyl ester polymer which is stable against environmental conditions such as humidity. The polymer can be used as an organic electronic material such as an organic semiconductor resin, a high dielectric resin, a highly oriented resin, an antistatic resin, or the like, and a liquid crystal material utilizing the orientation of the cyanoethyl group with respect to an electric field, such as a resin. It is useful as a material for dispersed liquid crystal (PDLC) and a member for liquid crystal-polymer composite (LCPC).

[0002]

2. Description of the Related Art Hitherto, cyanoethyl acrylate and its polymer have been known, and the usefulness of the polymer has been reported as a polymer having high dielectric property (polymer processing, vol. 2), p84-87,
(1990)). However, the polymer of acrylic acid cyanoethyl ester is a rubber-like elastic body at room temperature,
It was difficult to obtain a good film. Further, the polymer has a problem that the dielectric constant and the dielectric loss greatly vary depending on the temperature. Therefore, although attempts have been made to improve the dielectric properties and film forming properties of acrylic acid cyanoethyl ester by copolymerization, none satisfying both of these two properties has been obtained.

On the other hand, as a high dielectric material having a good film forming ability, conventionally, cyanoethylated cellulose, cyanoethylated hydroxyalkyl cellulose (US Pat. No. 3,096,289), cyanoethylated pullulan (JP-A-56-18601), etc. Is known. These compounds are obtained by cyanoethylating the hydroxyl groups in the raw material. However, since the introduction rate of cyanoethyl substituents is limited and free hydroxyl groups remain in the molecule, the hygroscopicity is high. Therefore, when used as an electric / electronic material, there is a problem with respect to the environment, such as a change in electric characteristic value due to moisture absorption.

[0004]

An object of the present invention is to provide a film having high film strength, high dielectric constant, high orientation and high transparency, and having a stable weight against environmental conditions such as temperature and humidity. To provide a coalesce.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention provide a polymer having a high strength film, a high dielectric constant, no residual hydroxyl group, and excellent environmental resistance such as moisture absorption resistance. As a result of earnest research on

Embedded image The present invention found that an α-fluoroacrylic acid cyanoethyl ester polymer having a repeating structural unit represented by the formula (wherein n represents an average value of 50 or more repeating units) meets the above-mentioned object. Was conceived. Less than,
The present invention will be described in detail.

The polymer of the present invention has an average value of the number of repeating units of the above structural units of 50 or more, preferably 80 to 20,
000, more preferably 100 to 10,000, high molecular weight linear polymer. When the average value of the number of repeating units is less than 50, a film having sufficient strength cannot be obtained. When the average value exceeds 20,000, the solubility of the polymer in the solvent becomes small, which may cause a problem in processability. Therefore, the average value is preferably 20,000 or less.

The α-fluoroacrylic acid cyanoethyl ester polymer in the present invention has the formula:

[Chemical 3] It is produced by polymerizing α-fluoroacrylic acid cyanoethyl ester represented by The α-fluoroacrylic acid cyanoethyl ester can be produced according to the following procedure. That is, the formula:

[Chemical 4] (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 halide include α-fluoroacrylic acid chloride, α-fluoroacrylic acid bromide, α-fluoroacrylic acid fluoride and the like. These can be easily produced, for example, by reacting α-fluoroacrylic acid or a salt thereof with a halogenating agent such as thionyl chloride, phosphorus pentachloride, phosphorus trichloride, phosphorus tribromide and benzoyl chloride. .

Ethylene cyanohydrin is used in an amount of 0.8 times or more, preferably 1.0 to 3 times the mole of the fluorine-containing acrylic acid halide. If the amount used is less than 0.8 times the molar amount, the yield will decrease due to a decrease in the reaction rate of the fluorine-containing acrylic acid halide. 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, but any solvent can be used as long as it has no reactivity with the above 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 the solvent used is 1 to 50 times, preferably 5 to 20 times the weight ratio of the fluorine-containing acrylic acid halide. 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.

Further, the above reaction is advantageously carried out in the presence of a basic substance as a hydrohalic acid scavenger. As the basic substance, trialkylamines such as triethylamine and tributylamine, and organic bases such as pyridine are used. The basic substance is used in an amount of 0.5 to 2 times, and preferably 0.5 to 2 times the molar amount of the fluorine-containing acrylic acid halide.
It is used in an amount of 8 to 1.2 times the molar amount. If the amount is less than 0.5 times by mole, the function as a hydrohalic acid scavenger is not sufficiently exhibited, and if the amount is more than 2 times by mole, a side reaction occurs due to the action of an excessive basic substance.

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, while when it is shorter than 0.5 hours, the reaction does not proceed sufficiently and the yield decreases. As a method of operating the reaction, fluorine-containing acrylic acid halide, ethylene cyanohydrin, and a basic substance are mixed 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 1.31, boiling point 1 mm
71-73 ℃ under Hg, the density at 25 ℃ is 1.35
It is g / cm ³ . Moreover, the average transmittance in the wavelength range of 380 to 650 nm is 99% or more.

The method for polymerizing 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.

[0016]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the description of these Examples. Example 1 (1) Production of α-fluoroacrylic acid cyanoethyl ester 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
There was obtained 19.2 g of α-fluoroacrylic acid cyanoethyl ester as a colorless transparent liquid having a temperature of 1 ° C (1 mmHg). α
It was confirmed by IR and NMR spectra that it was fluoroacrylic acid cyanoethyl ester.

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

Embedded image 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 criteria 0.0ppm in ¹ H-NMR spectrum (DSS external standard), ¹³ C-NMR
It is 39.5 ppm (solvent) in the spectrum. The correspondence between peaks and chemical structures is shown below.

[Chemical 6]

[Table 1]

(2) Preparation of α-fluoroacrylic acid cyanoethyl ester polymer 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.

FIG. 4 shows an IR spectrum. 2260
cm ^-1 peak

[Chemical 7] , The peak at 1780 cm ^-1 is C = O, 1160 cm
The peak at ^-1 indicates CF. FIG. 5 shows a ¹³ C-NMR spectrum. The solvent is DMSO-d _e, shift criterion is 39.5 ppm (solvent). The correspondence between peaks and chemical structures is shown below.

Embedded image

[Table 2]

Comparative 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.

Comparative 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.

Comparative 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 Example 1 and Comparative Examples 1 to 3 were dissolved in dimethylformamide, cast on a glass plate, and heated at 100 ° C. for 2 hours and then at 120 ° C. for 2 hours. It was dried for an hour 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 3. It was found that the product of the present invention has excellent film properties and transparency.

(2) Electric Properties The polymers obtained in Example 1 and Comparative Examples 1 to 3 were dissolved in dimethylformamide, cast on an aluminum sheet, and then heated at 100 ° C. for 2 hours and then at 120 ° C. for 2 hours.
It was dried for an hour to form a film having a thickness of about 50 μm. Aluminum is vapor-deposited on the surface of this film to prepare a measurement sample, and measurement is performed using an LF impedance analyzer 4192 type (trade name, manufactured by Yokogawa HP), and the values of relative permittivity and dielectric loss tangent obtained are shown in Table 3. It was shown to. It was found that the product of the present invention exhibits stable electric characteristics in a wide temperature range.

(3) Moisture Absorption Amount of the polymer obtained in Example 1 and Comparative Examples 1 to 25
Equilibrium moisture absorption was measured by leaving in an atmosphere of 75% relative humidity at RH. The measured values are shown in Table 1. It was found that the product of the present invention has low hygroscopicity.

Table 3 shows the results obtained by measuring the average molecular weight, the softening temperature and the thermal decomposition temperature of the polymers obtained in Examples and Comparative Examples.

[Table 3]

[0027]

Industrial Applicability The α-fluoroacrylic acid cyanoethyl ester polymer according to the present invention has high film strength, high dielectric constant, high orientation, high transparency, high environmental stability, etc. It can be used as a coating material. In addition to its general use as a film, sheet and coating film, it is particularly useful as an organic electronic material such as a binder for organic dispersion type electroluminescence (EL) or a capacitor material, and also as an antistatic agent, an electrophotographic photoreceptor or a liquid crystal alignment. It is also useful as a member for a film.

[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.

FIG. 4 is a diagram showing an IR spectrum of poly (α-fluoroacrylic acid cyanoethyl ester).

FIG. 5 is a chart showing ¹³ C-NMR spectrum of poly (α-fluoroacrylic acid cyanoethyl ester).

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

Claims (2)

[Claims] 1. The formula: (In the formula, n represents an average value of 50 or more repeating units.) An α-fluoroacrylic acid cyanoethyl ester polymer having a repeating structural unit. 2. The average value of the number of repeating units is 80 to 20,
The α-fluoroacrylic acid cyanoethyl ester polymer according to claim 1, which is 000.