JPH11246726A - Fluoropolymer composition and method for obtaining thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluoropolymer compsn. which is useful for obtaining a thin film (e.g. an antireflection film) while using a solvent hardly affecting the global warming by dissolving an amorphous fluoropolymer having fluorine- contg. cyclic structures in the main chain in a specific fluorine-contg. solvent. SOLUTION: An amorphous fluoropolymer having fluorine-contg. cyclic structures (pref. fluorine-contg. aliph. cyclic structures, fluorine-contg. triazine cyclic structures, or fluorine-contg. arom. cyclic structures) [e.g. a polymer obtd. by polymerizing pefluoro(butenyl vinyl ether) in the presence of ((CH3 )2 CHOCOO)2 as a polymn. initiator and thermally treating the resultant polymer] is dissolved in a fluorine-contg. solvent represented by the formula: R<1> -O-R<2> (wherein R<1> is a 5-12C polyfluoroalkyl group optionally contg. an ether bond; and R<2> is a 1-5C alkyl group). The solvent is pref. one represented by F(CF2 )6 OCH3 , F(CF2 )7 OCH3 , F(CF2 )8 OCH3 , F(CF2 )9 OCH3 , or F(CF2 )10 OCH3 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorine-containing polymer composition obtained by dissolving an amorphous fluorine-containing polymer having a fluorine-containing ring structure in the main chain thereof in a specific fluorine-containing solvent.

[0002]

2. Description of the Related Art Perfluoropolymers represented by polytetrafluoroethylene, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer and tetrafluoroethylene / hexafluoropropylene copolymer generally have heat resistance and chemical resistance. And a small refractive index and a small dielectric constant. However, these fluoropolymers are generally insoluble in solvents.

WO 96/22356 discloses amorphous tetrafluoroethylene copolymers such as C ₅ F ₁₁ OCH ₃ and C ₅ F
It describes dissolving or dispersing in a solvent such as ₁₁ OC ₂ H ₅ and C ₈ F ₁₇ OCH ₃ to obtain a coating composition. However, there is no example in which an amorphous tetrafluoroethylene copolymer is dissolved in these solvents, and it is unclear whether the amorphous tetrafluoroethylene copolymer is dissolved in these solvents.

On the other hand, a fluorine-containing polymer having a fluorinated aliphatic ring structure in the main chain, which is found in Japanese Patent Publication No. 22229/1996, has a problem that the polymer is crystallized due to the steric effect of the ring structure. It is amorphous because it is inhibited. Even if the fluorinated polymer is a perfluoropolymer, it is dissolved in a specific perfluorosolvent, for example, perfluoro (2-butyltetrahydrofuran), so that there is no pinhole from the perfluorosolvent solution of the fluorinated polymer. There are advantages such as the ability to form a fluoropolymer thin film.

[0005]

In recent years, awareness of global environmental protection has increased, and in particular, the use of specific fluorochlorocarbons has been banned from the viewpoint of protection of the ozone layer, and further, from the viewpoint of global warming, carbon dioxide and perfluorocarbons have been banned. There is a growing need for use and emission limits.

[0006] In particular, perfluoro compounds such as perfluorocarbons are said to have a very high contribution to global warming due to their strong infrared absorbing ability and extremely long life in the atmosphere. For example, the estimated lifetime of perfluorohexane in the atmosphere is said to be hundreds to thousands of years. Such perfluoro compounds absorb infrared rays for a long time and accumulate radiant heat from the earth,
The impact on global warming is considered to be significant.

Under such circumstances, the present invention relates to a solvent having a low contribution to global warming: a fluorine-containing polymer having a fluorine-containing ring structure in its main chain and being amorphous. Hereinafter, it is intended to provide a fluorinated polymer composition obtained by dissolving a fluorinated ring structure-containing polymer).

[0008]

According to the present invention, a polymer having a fluorinated ring structure is prepared by reacting a polymer having a general formula R ¹ —O—R ² (R ¹ is a straight chain having 5 to 12 carbon atoms which may have an ether bond). A chain or branched polyfluoroalkyl group, wherein R ² has 1 carbon atom;
To 5 linear or branched alkyl groups. This is a fluorinated polymer composition dissolved in a fluorinated solvent represented by the formula (1).

The fluorinated solvent of the present invention has a general formula R
¹ -OR ² (R ¹ is a linear or branched polyfluoroalkyl group having 5 to 12 carbon atoms which may have an ether bond, and R ² is a linear Or a branched alkyl group).

[0010] The number of carbon atoms of R ¹ is hardly dissolved is the fluorinated cyclic structure-containing polymer with 4 or less, the number of carbon atoms of R ¹ is the case of 13 or more is industrially hard to obtain, the R ¹ carbon The number is selected from the range of 5-12. The carbon number of R ¹ is 6 to
10 is preferred, and 6-7 and 9-10 are more preferred.

A polyfluoroalkyl group is a group in which two or more hydrogen atoms of an alkyl group are substituted with fluorine atoms, a perfluoroalkyl group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms, and It includes a group in which two or more hydrogen atoms of an alkyl group are substituted with a fluorine atom and one or more hydrogen atoms of an alkyl group are substituted with a halogen atom other than a fluorine atom. As a halogen atom other than a fluorine atom, a chlorine atom is preferable.

The polyfluoroalkyl group is preferably a group in which 60% or more of the hydrogen atoms of the corresponding alkyl group have been substituted with fluorine atoms, more preferably 80%.
That is all. More preferred polyfluoroalkyl groups are perfluoroalkyl groups.

When R ¹ has an ether bond, if the number of ether bonds is too large, solubility will be impaired. Therefore, the number of ether bonds in R ¹ is preferably 1 to 3, more preferably 1 or 2. When the carbon number of R ² is 6 or more, the solubility of the polymer having a fluorinated ring structure is significantly inhibited. Preferred examples of R ² are a methyl group and an ethyl group.

If the molecular weight of the fluorinated solvent is too large, not only will the viscosity of the fluorinated polymer composition increase, but also the solubility of the fluorinated ring structure-containing polymer will decrease.
00 or less is preferable. The fluorine content of the fluorinated solvent is preferably from 60 to 80% by weight in order to enhance the solubility of the fluorinated ring structure-containing polymer. Preferred examples of the fluorinated solvent include the following.

[0015]

## STR1 ## F (CF ₂ ) ₅ OCH ₃ , F (CF ₂ ) ₆ OC
H ₃ , F (CF ₂ ) ₇ OCH ₃ , F (CF ₂ ) ₈ OCH
₃ , F (CF ₂ ) ₉ OCH ₃ , F (CF ₂ ) ₁₀ OCH
₃ , H (CF ₂ ) ₆ OCH ₃ , (CF ₃ ) ₂ CF (OC
H ₃ ) CFCF ₂ CF ₃ , F (CF ₂ ) ₃ OCF (CF
₃ ) CF ₂ OCH ₃ , F (CF ₂ ) ₃ OCF (CF ₃ )
CF ₂ OCF (CF ₃ ) CF ₂ OCH ₃ , F (CF ₂ )
₈ OCH ₂ CH ₂ CH ₃ , (CF ₃ ) ₂ CFCF ₂ CF
₂ OCH ₃ , F (CF ₂ ) ₂ O (CF ₂ ) ₄ OCH ₂ C
H _3.

An example of the estimated life of the fluorine-containing solvent in the air in the present invention is about 1 to 5 years for F (CF ₂ ) ₅ OCH ₃ and F (CF ₂ ) ₅ OCH ₂ CH _3. is there. As the fluorinated solvent in the present invention, F (C
F ₂ ) ₆ OCH ₃ , F (CF ₂ ) ₇ OCH ₃ , F (CF
₂ ) ₈ OCH ₃ , F (CF ₂ ) ₉ OCH ₃ and F (C
F ₂ ) ₁₀ OCH ₃ is preferred, and F (CF ₂ ) ₆ OCH
₃ , F (CF ₂ ) ₇ OCH ₃ , F (CF ₂ ) ₉ OCH ₃
And F (CF ₂ ) ₁₀ OCH ₃ are particularly preferred.

As the fluorinated solvent in the present invention, the fluorinated solvent represented by the aforementioned general formula R ¹ —O—R ² is used.
Species may be used alone or in combination of two or more. Further, it may be a mixed solvent of the fluorinated solvent represented by the above general formula R ¹ -O-R ² and another solvent. In this case, as the other solvent, a solvent that alone cannot dissolve the polymer having a fluorinated ring structure can be used.

As other solvents, for example, F (CF ₂ ) ₄
In the present invention, fluorinated ethers other than the fluorinated solvent such as OCH ₃ and F (CF ₂ ) ₄ OC ₂ H ₅ , hydrocarbons such as hexane, hydrochlorocarbons such as chloroform, and hydrochlorocarbons such as dichloropentafluoropropane. Fluorine-containing aromatic hydrocarbons such as chlorofluorocarbons, meta-xylene hexafluoride and benzotrifluoride, and alcohols such as methanol, ethanol, (perfluorohexyl) ethanol and pentafluoropropanol can be used in combination. The mixing ratio of these other solvents is appropriately selected depending on the concentration of the fluorinated ring structure-containing polymer.
It is preferably 50 parts by weight, more preferably 1 to 30 parts by weight.

The polymer having a fluorine-containing ring structure in the present invention has a fluorine-containing aliphatic ring structure (including a fluorine-containing imide ring structure), a fluorine-containing triazine ring structure or a fluorine-containing aromatic ring structure in the main chain. Although a fluorinated polymer is exemplified, a fluorinated polymer having a fluorinated aliphatic ring structure in the main chain is preferable, and a fluorinated polymer having a fluorinated aliphatic ether ring structure in the main chain is more preferable.

"Having a fluorine-containing ring structure in the main chain"
A structure in which at least one carbon atom constituting a ring is a carbon atom in a carbon chain constituting a main chain, and a fluorine atom or a fluorine-containing group is bonded to at least a part of the carbon atoms constituting the ring. Means to have.

Examples of the fluoropolymer having a fluorinated aliphatic ring structure in the main chain include those obtained by polymerizing a monomer having a fluorinated ring structure and those having two or more polymerizable double bonds. A polymer obtained by cyclopolymerizing a fluorine-containing monomer and having a fluorine-containing aliphatic ring structure in the main chain is preferable.

A polymer having a fluorinated aliphatic ring structure in the main chain obtained by polymerizing a monomer having a fluorinated ring structure is known from JP-B-63-18964.
That is, perfluoro (2,2-dimethyl-1,3-
Dioxole) by homopolymerizing a monomer having a fluorinated ring structure such as tetrafluoroethylene, chlorotrifluoroethylene,
By copolymerizing with a radical polymerizable monomer having no fluorinated ring structure such as perfluoro (methyl vinyl ether), a polymer having a fluorinated aliphatic ring structure in the main chain can be obtained.

A polymer having a fluorinated aliphatic ring structure in the main chain obtained by cyclopolymerization of a fluorinated monomer having two or more polymerizable double bonds is disclosed in 238
111 and JP-A-63-238115. That is, by subjecting a fluorinated monomer having two or more polymerizable double bonds, such as perfluoro (allyl vinyl ether) or perfluoro (butenyl vinyl ether), capable of undergoing cyclopolymerization to cyclopolymerization, or Such a monomer is copolymerized with a radically polymerizable monomer such as tetrafluoroethylene, chlorotrifluoroethylene, or perfluoro (methyl vinyl ether) that does not undergo cyclization polymerization to form a fluorinated aliphatic ring structure in the main chain. Is obtained.

In addition, perfluoro (2,2-dimethyl-
A monomer having a fluorinated ring structure such as 1,3-dioxole) and two or more polymerizable double bonds such as perfluoro (allyl vinyl ether) and perfluoro (butenyl vinyl ether) are subjected to cyclopolymerization. By copolymerizing the obtained fluorine-containing monomer, a polymer having a fluorine-containing aliphatic ring structure in the main chain can be obtained.

In the polymer having a fluorinated aliphatic ring structure in the main chain, polymerized units having a fluorinated aliphatic ring structure in the main chain are at least 20 mol%, preferably 40 mol%, based on all polymerized units of the polymer. Those containing at least mol% are preferred in terms of transparency and mechanical properties.

Specific examples of the polymer having a fluorinated aliphatic ring structure in the main chain include the following general formulas (1) to (1).
Those having a repeating unit selected from (4) are preferred. A fluorine atom in the polymer having a fluorinated aliphatic ring structure in the main chain may be partially substituted with a chlorine atom.

[0027]

Embedded image

[In the general formulas (1) to (4), h is 0
An integer from 0 to 5, i is an integer from 0 to 4, j is 0 or 1, h +
i + j is an integer of 1 to 6, s is an integer of 0 to 5, t is 0 to 4
U is 0 or 1, s + t + u is an integer of 1 to 6,
p, q, and r are each independently an integer of 0 to 5, p + q + r
Is an integer of 1 to 6, and R ^{3 to} R ⁸ are each independently a fluorine atom, a chlorine atom, a deuterium atom or a trifluoromethyl group. ]

As the monomer having a fluorinated ring structure in the present invention, a monomer selected from the compounds represented by the following formulas (5) to (7) is preferable.

[0030]

Embedded image

In the general formulas (5) to (7), R ⁹ to
R ²⁰ is independently a fluorine atom, a chlorine atom, a deuterium atom or a trifluoromethyl group, and R ¹¹ and R ¹² , R
¹⁵ and R ¹⁶ and R ¹⁹ and R ²⁰ may be linked to form a ring. Specific examples of the compounds represented by formulas (5) to (7) include compounds represented by formulas (11) to (18).

[0032]

Embedded image

As the fluorine-containing monomer having two or more polymerizable double bonds, compounds represented by the following general formulas (8) to (10) are preferable.

[0034]

CY ¹ Y ² = CY ³ OCY ⁴ Y ⁵ CY ⁶ Y ⁷ CY ⁸ = CY ⁹ Y ¹⁰ (8) CZ ¹ Z ² = CZ ³ OCZ ⁴ Z ⁵ CZ ⁶ = CZ ⁷ Z ⁸ (9) CW ¹ W ² = CW ³ OCW ⁴ W ⁵ OCW ⁶ = CW ⁷ W ⁸ (10)

[In the general formulas (8) to (10), Y ¹
To Y ¹⁰ , Z ^{1 to} Z ⁸ and W ^{1 to} W ⁸ are each independently a fluorine atom, a chlorine atom, a deuterium atom or a trifluoromethyl group. Specific examples of the compounds represented by the general formulas (8) to (10) include the following compounds. In the formula, D is a deuterium atom.

[0036]

Embedded image CF ₂ ＣＦCFOCF ₂ CF ₂ CF = CF ₂ , C
F ₂ = CFOCD ₂ CF ₂ CF = CF ₂ , CF ₂ = CF
OCCl ₂ CF ₂ CF = CF ₂ , CF ₂ = CFOCF ₂
CF ₂ CD = CF ₂ , CF ₂ = CFOCF ₂ CF ₂ CC
1 = CF ₂ , CF ₂ = CFOCF ₂ CFDCF = CF
₂ , CF ₂ = CFOCF ₂ CFClCF = CF ₂ , CF
₂ = CFOCF ₂ CF ₂ CF = CFCl, CF ₂ = CF
OCF ₂ CF (CF ₃ ) CF = CF ₂ , CF ₂ = CFO
CF ₂ CF (CF ₃ ) CD = CF ₂ , CF ₂ = CFOC
F ₂ CF (CF ₃ ) CCl = CF ₂ , CF ₂ = CFOC
F ₂ CF = CF ₂ , CF ₂ = CFOCF (CF ₃ ) CF
= CF ₂ , CF ₂ = CFOCF ₂ OCF = CF ₂ , CF
₂ = CDOCF ₂ OCD = CF ₂ , CF ₂ = CClOC
F ₂ OCCl = CF ₂ , CF ₂ = CFOCD ₂ OCF =
CF ₂ , CF ₂ = CFOCCl ₂ OCF = CF ₂ , CF
_{2 = CFOC (CF 3) 2} OCF = CF 2.

The concentration of the fluoropolymer in the fluoropolymer composition of the present invention is preferably 0.01 to 50% by weight,
0.1-20% by weight is more preferred. The fluorinated polymer composition of the present invention in which the fluorinated solvent is dissolved in a fluorinated solvent is coated on a substrate, and the fluorinated solvent is dried to dry the fluorinated solvent. A polymer thin film can be formed. The thickness of the thin film is usually 0.01 to 50
It is selected from the range of μm. The substrate can be applied to all shapes and materials. When the thin film is an antireflection film, the substrate is preferably polymethyl methacrylate, polycarbonate, polyethylene terephthalate, or the like. The drying temperature of the fluorinated solvent is appropriately selected depending on the heat-resistant temperature of the substrate, but is preferably 50 to 150 ° C.,
20 ° C. is more preferred. In order to prevent unevenness in film thickness, it is preferable to form a thin film under a static elimination atmosphere.

A fluorinated polymer composition of the present invention in which a fluorinated ring structure-containing polymer is dissolved in a fluorinated solvent is applied on a substrate, and the fluorinated solvent is dried to form a fluorinated solvent on the substrate. After forming the thin film of the ring-containing polymer, the thin film of the fluorine-containing polymer can be obtained by peeling the thin film of the fluorine-containing polymer from the substrate. The thickness of the thin film is usually selected from the range of 0.01 to 50 μm. As the substrate, glass is preferable because the thin film is easily peeled from the substrate and has a high heat resistance temperature. The drying temperature of the fluorinated solvent is appropriately selected depending on the heat resistant temperature of the substrate, but is preferably equal to or higher than the boiling point of the fluorinated solvent. Preferred drying temperature is 50-200 ° C, more preferably 70-200 ° C.
150 ° C. In order to prevent unevenness in film thickness, it is preferable to form a thin film under a static elimination atmosphere. The peeling of the thin film from the substrate is preferably performed in a polar solvent that does not dissolve the polymer having a fluorinated ring structure, particularly in water.

When a thin film having a thickness of 0.1 μm or less is formed, a uniform thin film having a small thickness deviation can be obtained.
The fluorinated solvent represented by the aforementioned general formula R ¹ —O—R ² is preferably ^{one in} which R ¹ is a polyfluoroalkyl group having 6 to 7 carbon atoms. When a thin film having a thickness of 1 μm or more is formed, a uniform thin film having a small thickness deviation is obtained.
The fluorinated solvent represented by the aforementioned general formula R ¹ —O—R ² is preferably ^{one in} which R ¹ is a polyfluoroalkyl group having 9 to 12 carbon atoms.

Examples of the method for forming a thin film include a roll coating method, a casting method, a dipping method, a spin coating method, a casting method on water, a die coating method, a Langmuir-Blodgett method, and the like. In order to improve the adhesion between the substrate and the fluoropolymer, a silane-based, epoxy-based, titanium-based, aluminum-based, etc. An oligomer of a ring agent or the like may be blended.

The obtained thin film can be used while being kept in close contact with the substrate or peeled off from the substrate. Examples of the use of the thin film include a protective coat in the optical field and the electric field, and as the base material in this case, a magnetic disk substrate, an optical fiber, a mirror, a solar cell, an optical disk, a touch panel, a photosensitive and fixing drum, a film capacitor, Various films for glass windows and the like can be mentioned.

Also, a coating type optical waveguide material, an electric wire covering material, an ink repellent (for coating, for printing equipment such as an ink jet printer), a lens material, an adhesive for a semiconductor element (for example, for LOC (lead-on-chip) tape) Adhesive, die bonding adhesive, pellicle film fixing adhesive, semiconductor protective coat (eg, buffer coat film, passivation film, semiconductor element α-ray shielding film, moisture-proof coat agent), interlayer insulating film (eg, for semiconductor element, For liquid crystal display, for multilayer wiring board, optical thin film (pellicle film (K
(for rF excimer laser, for ArF excimer laser), antireflection film for display, antireflection film for resist) and the like.

By using the fluoropolymer composition of the present invention, the composition is transparent without defects such as pinholes,
A thin film can be formed without impairing the properties of the fluorine-containing ring structure-containing polymer, such as a low refractive index and excellent heat resistance and chemical resistance.

[0044]

EXAMPLES "Example 1 (Synthesis example of a polymer containing a fluorinated ring structure)" perfluoro (butenyl vinyl ether) 35
g, 150 g of ion-exchanged water, 6 g of methanol as a molecular weight regulator, and ((CH ₃ ) ₂ CHO as a polymerization initiator.
90 mg of (COO) ₂ was placed in a pressure-resistant glass autoclave having an internal volume of 200 ml. After the inside of the system was replaced with nitrogen three times, suspension polymerization was performed at 40 ° C. for 22 hours to obtain an amorphous polymer having a terminal group due to an initiator. This polymer was heat-treated at 320 ° C. for 60 minutes in air, washed with water and dried. As a result, 33 g of a polymer having a fluorinated ring structure in which the terminal group was converted to a carboxyl group (hereinafter, referred to as polymer A) was obtained.

According to the infrared spectroscopic analysis of the polymer A, 1811 was obtained.
absorption peak attributable to a carboxyl group in cm ^-1 and 1773cm ^-1 were observed. The intrinsic viscosity [η] of the polymer A is
30 in perfluoro (2-butyltetrahydrofuran)
It was 0.35 at ° C. The glass transition point of polymer A is 10
The temperature was 8 ° C, and at room temperature, it was a tough and transparent glassy polymer. The 10% thermal decomposition temperature was 465 ° C., and the light transmittance was as high as 95% or more.

Example 2 (Synthesis Example of Fluorine-Containing Ring Structure-Containing Polymer) Perfluoro (butenyl vinyl ether) 35
g, 150 g of ion-exchanged water, 6 g of methanol as a molecular weight regulator, and ((CH ₃ ) ₂ CHO as a polymerization initiator.
90 mg of (COO) ₂ was placed in a pressure-resistant glass autoclave having an internal volume of 200 ml. After purging the system three times with nitrogen, suspension polymerization was performed at 40 ° C. for 22 hours to obtain a fluorinated ring structure-containing polymer (hereinafter referred to as polymer B).
8 g were obtained.

The intrinsic viscosity [η] of the polymer B is 0.3 in perfluoro (2-butyltetrahydrofuran) at 30 ° C.
It was 5. The glass transition point of the polymer B was 108 ° C., and it was a tough and transparent amorphous polymer at room temperature. The 10% thermal decomposition temperature was 465 ° C. Light transmittance is 9
The refractive index was as high as 5% or more, and the refractive index was as low as 1.34.

Example 3 (Comparative Example) 1 g of polymer A and 99
g of F (CF ₂ ) ₃ OCH ₃ was placed in a glass flask and heated and stirred at 30 ° C. for 24 hours. As a result, Polymer A only swelled and did not dissolve.

Example 4 (Comparative Example) 1 g of polymer A and 99
g of F (CF ₂ ) ₄ OCH ₃ was placed in a glass flask and heated and stirred at 40 ° C. for 24 hours. As a result, although the polymer A partially dissolved, the swollen polymer A remained and did not completely dissolve.

"Example 5 (Example)" 1 g of polymer A and 99
g of F (CF ₂ ) ₆ OCH ₃ was placed in a glass flask and heated and stirred at 40 ° C. for 24 hours. As a result, a colorless, transparent, turbid, uniform solution was obtained. Using this solution, dip coating was performed on a polymethyl methacrylate plate having a single-sided average reflectance of 4% at a pulling rate of 200 mm / min, followed by heat treatment at 80 ° C. for 1 hour to form 0.1 μm on the polymethyl methacrylate plate. Was obtained. The thickness deviation of this film was less than 1%. The average reflectance of one side of this polymethyl methacrylate plate was 1.
It became 0%. This polymethyl methacrylate plate can be used as a low reflection filter.

"Example 6 (Example)" 1 g of polymer A and 99
g of F (CF ₂ ) ₈ OCH ₃ was placed in a glass flask and heated and stirred at 40 ° C. for 24 hours. As a result, a colorless, transparent, turbid, uniform solution was obtained. Using this solution, dip coating was performed on a polymethyl methacrylate plate having a single-sided average reflectance of 4% at a pulling rate of 200 mm / min, followed by heat treatment at 80 ° C. for 1 hour to form 0.1 μm on the polymethyl methacrylate plate. Was obtained. The thickness deviation of this film was 5%. The average reflectance on one side of this polymethyl methacrylate plate was 1.0%.

"Example 7 (Example)" 9 g of polymer B and 91
g of F (CF ₂ ) ₁₀ OCH ₃ was placed in a glass flask and heated and stirred at 50 ° C. for 24 hours. As a result, a colorless, transparent, turbid, uniform solution was obtained. Using this solution, spin coating was performed on a glass plate at a spin speed of 700 rpm for 30 seconds, and then at 80 ° C. for 1 hour, and further for 180 hours.
By performing the heat treatment at 1 ° C. for 1 hour, a uniform and transparent film was obtained on the glass plate. After that, an aluminum frame coated with an adhesive was stuck on the film, and the film was peeled off from the glass plate.
An aluminum frame with a self-supporting film was obtained. The thickness deviation of this film was less than 1%. This frame can be used as a pellicle.

Example 8 9 g of polymer B and 91
g of F (CF ₂ ) ₈ OCH ₃ was placed in a glass flask and heated and stirred at 50 ° C. for 24 hours. As a result, a colorless, transparent, turbid, uniform solution was obtained. Using this solution, spin coating was performed on a glass plate at a spin speed of 700 rpm for 30 seconds, and then at 80 ° C. for 1 hour, and further for 180 hours.
By performing the heat treatment at 1 ° C. for 1 hour, a uniform and transparent film was obtained on the glass plate. The thickness deviation of this film was 6%.

"Example 9 (Example)" Using the solution of the polymer A obtained in Example 7, a spin speed of 700 rpm was formed on a metal substrate.
After performing spin coating at 30 ° C. for 30 seconds, a heat treatment was performed at 80 ° C. for 1 hour and further at 180 ° C. for 1 hour to obtain a uniform transparent film of 1 μm on the metal plate. The absence of pinholes in this film was confirmed by the fact that the electrical resistance of this thin film was 10 ¹⁵ Ωcm or more.

"Example 10 (Example)" In place of polymer B, amorphous perfluoro (2,2-dimethyl-
1,3-dioxolane) / tetrafluoroethylene (6
Using 9 g of a copolymer (5 mol% / 35 mol%) (trade name: Teflon AF1600, manufactured by DuPont), F (CF ₂ )
91 g of (CF ₃ ) ₂ CF (OC instead of ₆ OCH ₃
Except for using H ₃ ) CFCF ₂ CF ₃ , a polymethyl methacrylate plate having a uniform thin film of 0.1 μm was obtained in the same manner as in Example 5. The thickness deviation of this film was less than 1%. The average reflectance on one side of this polymethyl methacrylate plate was 1.0%.

[0056]

EFFECT OF THE INVENTION The fluorine-containing ring structure-containing polymer is used for the global environment,
In particular, it can be solubilized by using a solvent having little effect on global warming, and a thin film of a polymer having a fluorine-containing ring structure can be formed while suppressing adverse effects on the global environment.

Claims (7)

[Claims] 1. An amorphous fluorine-containing polymer having a fluorine-containing ring structure in its main chain and a non-crystalline fluorine-containing polymer represented by the general formula R ¹ —O—R ² (R ¹ is a carbon atom which may have an ether bond) A linear or branched polyfluoroalkyl group having 5 to 12 carbon atoms, and R ² is a linear or branched alkyl group having 1 to 5 carbon atoms. A fluoropolymer composition comprising: 2. The fluorinated ring structure is a fluorinated aliphatic ring structure,
The fluorinated polymer composition according to claim 1, which is a fluorinated polymer having a fluorinated triazine ring structure or a fluorinated aromatic ring structure. 3. The method according to claim 1, wherein the fluorinated solvent is F (CF ₂ ) ₆ OCH ₃ ,
F (CF ₂ ) ₇ OCH ₃ , F (CF ₂ ) ₈ OCH ₃ , F
_{3. The} fluoropolymer composition according to claim 1, which is (CF ₂ ) ₉ OCH ₃ or F (CF ₂ ) ₁₀ OCH ₃ . 4. A thin film of a fluoropolymer is formed on a substrate by applying the fluoropolymer composition according to claim 1, 2 or 3 on a substrate and drying the fluorinated solvent. Method. 5. The method according to claim 4, wherein the thin film is an anti-reflection film. 6. A thin film of a fluoropolymer is formed on a substrate by applying the fluoropolymer composition according to claim 1, 2 or 3 on a substrate and drying the fluorinated solvent. Thereafter, a method of obtaining a fluoropolymer thin film by peeling the fluoropolymer thin film from the substrate. 7. The method according to claim 6, wherein the thin film is a pellicle film.