JPS59187006A - Highly dielectric fluororesin film - Google Patents

Abstract

PURPOSE:To obtain titled film with improved solvent resistance, useful as a material for various devices, by the fluorine gas treatment and film-forming operation of a vinylidene fluoride resin having a specific amount of vinylidene fluoride. CONSTITUTION:The objective film can be obtained by carrying out a fluorine gas treatment (e.g., using a fluorine gas diluted with inert gas such as He, Ne, at -80 deg.C- the resin melting point, while gradually raising fluorine gas concentration) and film-forming operation of a vinylidene fluoride resin having >=50mol%, as monomer unit, of vinylidene fluoride. The above treatments (or operations) may be performed in any order.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluororesin film having a high dielectric constant. Further details [-< means vinylidene buttoxide (hereinafter referred to as VDF)
This invention relates to a highly dielectric fluororesin film obtained by directly fluorinating a (abbreviated as ) type resin.

VDF resin is a polymer that has carbon-fluorine bonds with high dipole efficiency and exhibits a high dielectric constant due to its unique structure. For example, a film obtained from polyvinylidene dibutride resin (hereinafter abbreviated as PvDF) exhibits a high value of dielectric constant of 8 to 9 (IKHz). Taking advantage of these characteristics, PvDF film is being considered for use as a material for various devices such as capacitors and electroluminescence. However, recently, with the development of electronic technology, it is expected that polymer materials with even higher dielectric constants will appear.

As a result of intensive research, the present inventors discovered that a VDF resin treated with fluorine gas has a high dielectric constant, and succeeded in obtaining a highly dielectric film.

By the way, attempts to treat polymers with fluorine gas have been made in British Patent No. 710,523 (195
In addition to 4), various methods have been used mainly for hydrocarbon polymers such as polystyrene, polymethyl methacrylate, and polycarbonate.

Furthermore, by treating a polyether polymer with fluorine gas, a double thread oligomer can be obtained from JP-A-52-24.
298 have been attempted, but there are no known methods for treating double-stranded polymers with fluorine gas, especially for modifying them with a focus on high dielectric properties. As mentioned above, using fluorine gas [2] The purpose of fluorinating a polymer is to replace the hydrogen atoms on the polymer surface with fluorine atoms in the case of hydrocarbon polymers, thereby improving the unique performance of the fluorine polymer. That is, it was expected to exhibit water and oil repellency due to a decrease in surface energy, high sliding properties due to a decrease in the coefficient of friction, and further improvements in heat resistance and solvent resistance.

The present invention relates to VDF-based resins treated with fluorine gas and VD
In addition to the above-mentioned properties, we discovered that the F-based resin film has a new property: excellent dielectric properties, which are electrical properties.
．． A new method for producing dielectric acid materials and a new method were completed.

That is, the gist of the present invention is to provide a highly dielectric fluororesin film obtained by treating vinylidene butyride resin having a relative molar ratio or higher with vinylidene butthoride as a monomer unit with fluorine gas, or forming a film of vinylidene butyride resin as a monomer unit. A vinylidene butylene resin having one unit of monomer and more than two units of monomer is formed into a film, and then treated with fluorine gas.1. Highly dielectric fluororesin film.

The main reaction of the fluorine gas treatment of the VDF resin in the present invention, that is, the direct fluorination reaction, can be shown as follows.

4- CH2CF t-+-n10F 2-1-10+CX
2 CF 2+n However: X=H or F The above reaction was shown for PVDF, but other VDF systems m
For example, 'vDF-hexafluoropropylene copolymer, vDF-butylated vinyl donor polymer, VDF-) I
VDF-based copolymers such as J-fluoroethylene copolymers, VDF-tetrafluoroethylene copolymers, or VDF-hydrocarbon monomers (e.g., acrylic acid derivative monomers, methacrylic acid derivative monomers, etc.), as well as VDF-based resins. Blends of these and other polymers can also be used, and in either case, the effects of the present invention can be obtained.

There are no particular restrictions on the physical form of the VDF resin to be treated with fluorine gas, but powder, pellet, sheet, and film forms are suitable (7). Regarding the purity of the fluorine gas used, There are no particular restrictions.

The hydrogen-fluorine exchange reaction of VDF resins is generally slower than that of hydrocarbon resins (e.g. polyethylene, polypropylene, etc.), so strict control of the reaction is not required, but La-4dar technology (R, J, Lagow
et, al,;proc-Natl,,Acad.

Sci, 674 (1970); Polym,
By using a method based on Lett, Ig-177 (1974), that is, by using diluted fluorine gas or by controlling the reaction temperature, fluorinated P resin can be produced with good reproducibility. . In this case, the fluorine gas is diluted with an inert gas such as helium or neon.
Initially, the reaction is carried out at a low fluorine gas concentration, and the concentration is increased over time. Reaction temperature = 80℃ to VD
It is optional up to the melting point of the F-based resin. The fluorination reaction method is
Either a fluorine gas flow system or a batch system in which the accumulated gas is retained in the reactor may be used.

In the present invention, it is not preferable to completely fluorine the VDF resin. Complete fluorination fails to produce a resin with the desired dielectric properties, complete fluorination of powder or pellets results in lack of moldability, and complete fluorination of film results in extreme It is preferable that phenomena such as shrinkage occur (-<no. The fluorination rate indicated by the hydrogen-hydrogen-monofluorine conversion rate of the VDF resin is preferably 50 or less, preferably) - or 25% to
o, iqb are suitable. When the ratio exceeds 50, the improvement in dielectric constant is small.

The fluorinated VDF resin film or the fluorinated VDF resin film formed into powder, pellets, or sheets obtained by the above fluorine gas treatment is as follows:
The dielectric constant is improved compared to that before fluorine gas treatment (7,
Furthermore, improvement in solvent resistance was observed, such as the solubility LK being less than LK for dimethylformamide, dimethylacetamide, and methyl ethyl ketone, which are good solvents for VDF'-based resins.

Hereinafter, the present invention will be explained in detail based on examples.

The flowchart of the fluorination line for the fluororesin used in the Examples is shown in the attached drawings. In the figure, 1
1 is a diluted fluorine gas cylinder, 2 is a helium gas cylinder,
3 is a fluorine gas cylinder, 4 and 5 are gas flow meters, 6 is a gas mixer, 7 is a stainless steel reactor, 8 and 8' are absorption systems,
9 is a stop valve, IO is a pressure regulating pulp, 11 is a flow rate regulation example I PVDF powder sample (Tsurupei Co., Ltd., N-REF XP-sN)
Powder: Particle size of 150 mesh baths) was placed in four nickel boats at intervals of about 3 y each, and inserted into a stainless steel reactor 7 in the fluorination line shown in the figure (7, the inside of the reactor was replaced with helium. Then, at 30°C, 3.4/g (D
Flow rate T8 hours and start fluorination [again. continue,
Fluorine gas was flowed for 40 hours at a flow rate of 3.0'/g.
1. Further basicization was carried out. Next, after replacing the fluorine gas in the reactor with helium gas, each 3y of fluorinated PVDF in the two nickel boats was taken out [7]. The fluorination rate of the above PVDF determined by weight increase is 15.
3%, and the fluorination rate determined by elemental analysis was 14.5.
%Met.

The obtained fluorinated PVDF powder was electrolyzed at a temperature of 210° C. using a hot press to form a film of about 100 μm. Furthermore, after gold was vapor-deposited on both sides of the film, 427
4 A, Multi-FrequencyL
Using a CR meter, the dielectric constant at 5°C and IKHz was measured (7).The formed film was also immersed in dimethylformamide (25°C) to examine its solubility.The results are shown in Table 1.

Example 2 Fluorination was further advanced for each 3y sample in the remaining two nickel boats of Example 1. In addition to the fluorination in Example 1, fluorine gas was thoroughly diluted with helium gas for 2 hours at a flow rate of 3.57 minutes, and then fluorine gas was added at a flow rate of 3.57 minutes.
．． Flow rate of 0'4 for 40 hours [Later, fluorinated PV
DF was distilled out (7.0%).The fluorinated element determined by weight increase was 18.8%, and the fluorinated element determined by elemental analysis was 167%.Next, Example 1 In the same manner as in 1., the dielectric constant and solvent resistance of this fluorinated PVDF were measured.

The results are shown in Table 1.

Example 3 Insert the sample into the reactor in the same manner as in Example 1 (7) After replacing the system with helium, dilute to 4-4 at 30°C (7). Later, fluorinated PVDF was extracted (-).The fluorination rate determined from the increase in weight was 8.5%.

Next, in the same manner as in Example 1 (2), the film was molded (1 to 1), and the dielectric constant and solvent resistance were measured (also, the results are shown in Table 1).

Example 4 A sample was inserted into the reactor in the same manner as in Example 1. After purging the system with helium, the sample was diluted with -F at 30°C and fluorine gas was flowed at a flow rate of 3.0'/min for 6 hours. After that, Futanized PV
I took out my DF. The hydrogenation rate determined by increasing the amount of M was 1.4.

Next, in the same manner as in Example 1, the film was molded (7) and the dielectric constant and solvent resistance were measured. The results are shown in Table 1.

Example-5 A sample was inserted into the reactor in the same manner as in Example 1, the inside of the system was replaced with helium, and fluorine gas diluted at 30°C was heated to 3.0°C.
After reacting for 2 hours at a flow rate of 1/min, the fluorinated PVDF was taken out.The fluorinated PVDF obtained had a fluorinated PVDF ratio of 0.4 as determined from the weight increase.

Next, a film was formed in the same manner as in Example 1, and the dielectric constant and solvent resistance were measured. The results are shown in Table-1.

Example 6 Vinylidene butt 60139 in a 500rn1 polymerization vessel
4.7y of hexafluoropropylene, 400m of trichlorotrifluoroethane, 5.4y of barfluorobutyryl peroxide were charged, polymerization was carried out at 20°C for a set time, and vinylidene butyride-hexafluoroglobylene copolymer powder (vinylidene butylene composition: 96%) was prepared. .3 mol qb) was obtained. The copolymer powder was inserted into a reactor, and fluorine gas diluted at 30°C was heated in 3-2. After flowing at a flow rate of /3) for 6 hours, the fluorinated PVDF was taken out. The hydrogenation rate determined from the increase in weight was 2.1.

Next, a film was formed in the same manner as in Example 1, and the dielectric constant and solvent resistance were measured. The results are shown in Table-1.

Comparative Example I PVDF powder sample (Tsurupei Co., Ltd., Solef XP-8N
Powder (particle size of 150 mesh passes) was prepared using a hot press at a temperature of 210° C. to a thickness of about 1.0 mm.

A micrometer film was prepared, and its dielectric constant and solvent resistance were measured. The results are shown in Table-1.

Comparative Example 2 The vinylidene butyride-hexafluoropropylene copolymer powder obtained in Example 6 was heated at a temperature of 210°C using a hot press.
A film with a thickness of about 100 μm was prepared at ℃, and its dielectric constant and solvent resistance were measured. The results are shown in Table-1.

Examples 7 to 11 PVDF (7# Hei Co., Ltd., 7-L/71010) was molded into a film with a wall thickness of μm at a temperature of 250° C. using a 4° scale extruder. This film has an area of 25mX 100W
A sample of iL was cut out, placed on a copper wire mesh, and inserted into a stainless steel reactor in the fluorination line shown in the attached figure.

Next, after replacing the inside of the reaction system with helium gas, the temperature was 30
Fluorine gas diluted with helium gas at 3.0 °C
m17. at a flow rate of 5 hours (Example 7) and 12 hours, respectively.
Samples were prepared by carrying out the fluorination reaction for 16 hours (Example 8), 16 hours (Example 9), 48 hours (Example 11), and 48 hours (Example 11). The fluorination rate of each sample was determined from the CIFI measurement using ESCA.
Expressed as a molar ratio of %=1. os (Example 7
), 1.20 (Example 8), 1.26 (Example 9)
, 1.32 (Example 10), 1.40 (Example 11
)Met. Next, the dielectric constant and solvent resistance of each film were measured. The results are shown in Table-1.

Example 12 A PVDF film was inserted into a reactor in the same manner as in Examples 7 to 11, and a sufficiently diluted fluorinated gas was added at a temperature of 30° C. for 3 hours. It was run for 2 hours at a flow rate of o'/min. Next, fluorine gas was passed through 4.8" at a flow rate of 7g for 70 hours, and the fluorinated PV
A DF film was obtained. The hydrogenation rate of the sample is expressed as a molar ratio of % determined from the measurement of C+8 using ESCA.
It was 1.75. The dielectric constant and solvent resistance of this film were measured. The results are shown in Table-1.

Examples 13 to 14 Fluorination was carried out in the same manner as in Example 12 while maintaining the temperature inside the reactor at -40°C (Example 13) and 80°C (Example 14) to obtain a fluorinated PVDF film. . The hydrogenation rate of each sample was determined from the measurement of C+8 using ES CA. When expressed as a molar ratio of 1.24 (Example 13
), 1.62 (Example 14). Next, the dielectric constant and solvent resistance of each film were measured. The results are shown in Table-1.

Comparative Example 3 In Examples 7 to 11, PVDF before fluorine gas treatment
The dielectric constant and solvent resistance of the film were measured. The results are shown in Table-1.

Table-1

[Brief explanation of drawings]

The drawing is a flowchart showing an example of an apparatus for directly fluorinating vinylidene butylene resin in order to obtain the highly dielectric fluororesin film of the present invention. 1...10 diluted fluorine gas cylinder, 2...
・Helium gas cylinder, 3... Fluorine gas cylinder, 6... Gas mixer, 7... Stainless steel reactor.

Claims (3)

[Claims] (1) A highly dielectric fluororesin film made by using a vinylidene fluoride resin containing vinylidene fluoride as a monomer unit or more as a raw material, and subjecting it to fluorine gas treatment and film-forming treatment. (2) After treating the vinylidene fluoride resin with fluorine gas, it is formed into a film [Claim No. 1 consisting of (2)
) Highly dielectric fluororesin film described in item 1. (3) A highly dielectric fluororesin film according to claim 11, which is obtained by forming a vinylidene fluoride resin into a film and then treating it with a fluorine gas.