JP2827059B2 - Fluorinated polyamic acid, fluorinated polyimide and methods for producing them - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorinated polyimide having a small number of C--H bonds, and more particularly to an optoelectronic integrated circuit (OEI).
The present invention relates to a low-light-loss polyimide which can be used as an optical material for an optical waveguide in C).

[0002]

2. Description of the Related Art Plastic materials are superior to inorganic materials in that they have excellent characteristics such as light weight, excellent impact resistance, excellent workability, and easy handling. It has been used for various optical applications such as optical disks, optical disk substrates, and optical lenses. Among them, plastic is used in the near infrared region (wavelength =
0.8 to 2.5 μm) when used as an optical material,
The first problem in comparison with inorganic materials is a large light loss. There are two main causes of loss in plastics: light scattering and light absorption. Wavelengths used for optical communication will shift to longer wavelengths in the future (from 0.85 μm to 1.3 μm to 1.5 μm). Accordingly, it is considered that the latter cause, that is, the loss due to vibrational absorption, which is essential to the molecular structure, becomes dominant, and greatly restricts the optical waveguide properties of the plastic optical material. In particular, those having a carbon-hydrogen bond (CH bond) in the molecular chain, such as PMMA and PS, have a large light loss in the near-infrared region, because the absorption intensity of harmonics is hardly attenuated. It has become. In order to reduce the harmonics due to the C—H bond and shift it to longer wavelengths, it has been proposed to replace hydrogen in the molecular chain with deuterium (D) or fluorine (F), Specific studies have already been made on materials in which hydrogen in PMMA or PS is replaced with deuterium or fluorine [for example, Toshinori Kaino, Appl. Phys. Lett., Vol. 48, pp. 757 ( 1
986)]. However, since these plastic optical materials do not have the heat resistance (260 ° C.) required for producing an OEIC on a substrate, for example, various steps are required to apply them to an optoelectronic integrated circuit or the like. On the other hand, polyimide resin is known as one of the most excellent heat resistance among plastics, and its application to optical materials has recently been studied (IBM, Honeywell, NTT).
However, all of the polyimides studied so far have a large number of phenyl C—H bonds in the molecular chain.
A harmonic sound of a stretching vibration of an H bond or a harmonic of a stretching vibration of a C—H bond and a bending sound appear, and a large absorption loss exists in the near infrared region.

[0003]

That is, a plastic material used as an optical material for OEIC in the near-infrared region has a problem of insufficient heat resistance and a large light loss due to the presence of a CH bond. The present invention has been made in view of such circumstances, and an object thereof is to provide a plastic optical material having sufficient heat resistance to produce an optoelectronic integrated circuit and having a small light transmission loss in the near infrared region. It is in.

[0004]

SUMMARY OF THE INVENTION To summarize the present invention, a first invention of the present invention relates to a fluorinated polyimide, and has the following general formula (1):

Embedded image (Wherein X represents O or S, and R represents a tetravalent organic group containing at least one hydrogen). Further, a second invention of the present invention relates to a method for producing the fluorinated polyimide of the first invention, and comprises the following general formula (Formula 2):

Embedded image (Wherein X represents O or S) and a diamine represented by the following general formula (Formula 3):

Embedded image Wherein R represents a tetravalent organic group containing at least one hydrogen, or a tetracarboxylic acid dianhydride or a tetracarboxylic acid thereof or a reactive derivative thereof. It is characterized by ring-closing the corresponding fluorinated polyamic acid. A third invention of the present invention relates to a fluorinated polyamic acid, and has the following general formula (Formula 4):

Embedded image (Wherein X represents O or S, and R represents a tetravalent organic group containing at least one hydrogen). The fourth invention of the present invention relates to a method for producing a fluorinated polyamic acid of the third invention, and comprises a diamine represented by the general formula (Chemical Formula 2) and a diamine represented by the general formula (Chemical Formula 3). With a tetracarboxylic dianhydride, or a tetracarboxylic acid thereof, or a reactive derivative thereof.

The present inventors have measured the absorption spectra of various existing polyimides and polyimide optical materials in the infrared and near-infrared regions, calculated the light loss in the near-infrared region, and earnestly investigated the causes. investigated. As a result, the first cause of large light loss in the near infrared region is
It has been clarified that harmonic absorption of stretching vibration of C—H bonds in an alkyl group, a phenyl ring or the like is absorbed by harmonics of stretching vibration of C—H bonds, and combined sound of bending vibration.

[0006] The fluorinated polyimide of the present invention has a structure in which all monovalent elements bonded to carbon of the phenyl ring of the diamine component of the raw material are fluorine and have a structure having no C—H bond in the repeating unit, thereby obtaining a near red light. By reducing the vibration absorption based on the C—H bond, which is the largest cause of light loss in the external region, and by introducing an imide bond into the main chain structure to form a polyimide, sufficient light for producing an optoelectronic integrated circuit is obtained. Heat resistance (260 ° C. or higher) can be provided. Acid anhydride used when producing the fluorinated polyimide of the present invention,
Examples of tetracarboxylic acids and acid chlorides and esters as reactive derivatives thereof include the following. Here, examples of tetracarboxylic acids include (trifluoromethyl) pyromellitic acid, pentafluoroethyl pyromellitic acid, bis {3,5-di (trifluoromethyl) phenoxy} pyromellitic acid, 2,3
3 ', 4'-biphenyltetracarboxylic acid, 3,3',
4,4'-tetracarboxydiphenyl ether, 2,
3 ', 3,4'-tetracarboxydiphenyl ether, 3,3', 4,4'-benzophenonetetracarboxylic acid, 2,3,6,7-tetracarboxynaphthalene,
1,4,5,7-tetracarboxynaphthalene, 1,
4,5,6-tetracarboxynaphthalene, 3,3 ′,
4,4'-tetracarboxydiphenylmethane, 3,
3 ', 4,4'-tetracarboxydiphenyl sulfone, 2,2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 5,5 '-Bis (trifluoromethyl) -3,3', 4,4'-tetracarboxybiphenyl, 2,2 ', 5,5'-tetrakis (trifluoromethyl) -3,3', 4,4'- Tetracarboxybiphenyl, 5,5'-bis (trifluoromethyl) -3,3 ', 4,4'-tetracarboxydiphenyl ether, 5,5'-bis (trifluoromethyl)-
3,3 ', 4,4'-tetracarboxybenzophenone, bis {(trifluoromethyl) dicarboxyphenoxy} benzene, bis {(trifluoromethyl) dicarboxyphenoxy} (trifluoromethyl) benzene,
Bis (dicarboxyphenoxy) (trifluoromethyl) benzene, bis (dicarboxyphenoxy) bis (trifluoromethyl) benzene, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl) benzene, 3,4,9,10-tetra Carboxyperylene,
2,2-bis {4- (3,4-dicarboxyphenoxy) phenyl} propane, butanetetracarboxylic acid, cyclopentanetetracarboxylic acid, 2,2-bis {4-
(3,4-dicarboxyphenoxy) phenyl {hexafluoropropane, bis (trifluoromethyl) dicarboxyphenoxy} biphenyl, bis {(trifluoromethyl) dicarboxyphenoxy} bis (trifluoromethyl) biphenyl, bis} ( Trifluoromethyl)
Dicarboxyphenoxy diphenyl ether, bis (dicarboxyphenoxy) bis (trifluoromethyl) biphenyl, hexafluoro-3,3 ', 4,4'
-Oxybisphthalic acid, 1,3-bis (3,4-dicarboxyphenyl) tetramethyldisiloxane, bis (3,4-dicarboxyphenyl) dimethylsilane and the like. In the present invention, in addition to the above carboxylic acids, for example, difluoropyromellitic acid, di (trifluoromethyl) pyromellitic acid, di (heptafluoropropyl) pyromellitic acid, hexafluoro-
3,3 ', 4,4'-biphenyltetracarboxylic acid, hexafluoro-3,3', 4,4'-benzophenonetetracarboxylic acid, 1,4-bis (3,4-dicarboxytrifluorophenoxy) tetra In addition to a carboxyl group such as fluorobenzene, a tetracarboxylic acid containing no hydrogen may be used in combination. Among these, trifluoromethyl pyromellitic dianhydride, which is a fluorinated dianhydride having a fluoroalkyl group introduced into the benzene ring of pyromellitic dianhydride, and 1,4-di (trifluoromethyl) pyromellitic Methods for producing acid dianhydride, 1,4-di (pentafluoroethyl) pyromellitic dianhydride and the like are described in Japanese Patent Application No. 63-165056.

The method for producing a polyamic acid according to the present invention may be the same as that for producing ordinary polyamic acid.
The reaction is carried out in a polar organic solvent such as -methyl-2-pyrrolidone, N, N-dimethylacetamide (DMAc), N, N-dimethylformamide. In the present invention, not only a diamine and a tetracarboxylic acid component are used as a single compound, but also a mixture of a plurality of diamines and a tetracarboxylic acid component may be used. In such a case, the total number of moles of a plurality or a single diamine and the total number of moles of a plurality or a single tetracarboxylic acid component are equal or almost equal.

When diamines are used as a plurality of mixtures, examples of the diamines that can be used in combination with the diamine used in the present invention other than the diamine [general formula (2)] include m-phenylenediamine, 2,4-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodulene, 4- (1H,
1H, 11H-eicosafluoroundecanoxy)-
1,3-diaminobenzene, 4- (1H, 1H-perfluoro-1-butanoxy) -1,3-diaminobenzene, 4- (1H, 1H-perfluoro-1-heptanoxy) -1,3-diaminobenzene , 4- (1H, 1H-
Perfluoro-1-octanooxy) -1,3-diaminobenzene, 4-pentafluorophenoxy-1,3-diaminobenzene, 4- (2,3,5,6-tetrafluorophenoxy) -1,3-diaminobenzene , 4- (4
-Fluorophenoxy) -1,3-diaminobenzene,
4- (1H, 1H, 2H, 2H-perfluoro-1-hexanoxy) -1,3-diaminobenzene, 4- (1
H, 1H, 2H, 2H-perfluoro-1-dodecanoxy) -1,3-diaminobenzene, p-phenylenediamine, 2,5-diaminotoluene, 2,3,5,6-tetramethyl-p-phenylenediamine 2,5-diaminobenzotrifluoride, bis (trifluoromethyl) phenylenediamine, diaminotetra (trifluoromethyl) benzene, diamino (pentafluoroethyl) benzene, 2,5-diamino (perfluorohexyl) benzene, 2, 5-diamino (perfluorobutyl) benzene, benzidine, 2,2'-dimethylbenzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 2,2'-dimethoxybenzidine,
3,3 ', 5,5'-tetramethylbenzidine, 3,
3'-diacetylbenzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, octafluorobenzidine, 3,3'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'-
Diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 2,2-bis (p-aminophenyl) propane,
3,3'-dimethyl-4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 1,2-bis (anilino) ethane, 2,
2-bis (p-aminophenyl) hexafluoropropane, 1,3-bis (anilino) hexafluoropropane, 1,4-bis (anilino) octafluorobutane,
1,5-bis (anilino) decafluoropentane,
7-bis (anilino) tetradecafluoroheptane,
2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ether, 3,3'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ether, 3,3 ', 5,5'- Tetrakis (trifluoromethyl) -4,4'-diaminodiphenyl ether, 3,
3'-bis (trifluoromethyl) -4,4'-diaminobenzophenone, 4,4 "-diamino-p-terphenyl, 1,4-bis (p-aminophenyl) benzene, p-bis (4- Amino-2-trifluoromethylphenoxy) benzene, bis (aminophenoxy) bis (trifluoromethyl) benzene, bis (aminophenoxy) tetrakis (trifluoromethyl) benzene,
4,4 ′ ″-diamino-p-quarterphenyl,
4,4'-bis (p-aminophenoxy) biphenyl,
2,2-bis {4- (p-aminophenoxy) phenyl} propane, 4,4'-bis (3-aminophenoxyphenyl) diphenylsulfone, 2,2-bis {4-
(4-aminophenoxy) phenyl} hexafluoropropane, 2,2-bis {4- (3-aminophenoxy)
Phenyl {hexafluoropropane, 2,2-bis} 4
-(2-aminophenoxy) phenyl} hexafluoropropane, 2,2-bis {4- (4-aminophenoxy) -3,5-dimethylphenyl} hexafluoropropane, 2,2-bis {4- (4- Aminophenoxy)-
3,5-ditrifluoromethylphenyl @ hexafluoropropane, 4,4'-bis (4-amino-2-trifluoromethylphenoxy) biphenyl, 4,4'-bis (4-amino-3-trifluoromethylphenoxy) ) Biphenyl, 4,4'-bis (4-amino-2-trifluoromethylphenoxy) diphenylsulfone, 4,4 '
-Bis (3-amino-5-trifluoromethylphenoxy) diphenylsulfone, 2,2-bis {4- (4-amino-3-trifluoromethylphenoxy) phenyl}
Hexafluoropropane, bis {(trifluoromethyl) aminophenoxy} biphenyl, bis [{(trifluoromethyl) aminophenoxy} phenyl] hexafluoropropane, diaminoanthraquinone, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, Bis {2-[(aminophenoxy) phenyl] hexafluoroisopropylbenzene, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,4-bis (3
-Aminopropyldimethylsilyl) benzene, bis (4
-Aminophenyl) diethylsilane and the like.

In the above-mentioned polymerization solution of polyamic acid or the like, the concentration of the solution is 5 to 40% by weight (preferably 10 to 25% by weight), and the rotational viscosity (25 ° C.) of the polymer solution is 50%. Preferably, it is で 5000 poise.

As a method for producing a film of a fluorinated polyimide having a low light loss rate according to the present invention, an ordinary method for producing a polyimide can be used. For example, a polyamic acid solution is spin-coated on an aluminum plate and heated stepwise from 70 ° C. to 200 ° C. in a nitrogen atmosphere (70 ° C. for 2 hours, 160 ° C. for 1 hour, 25 ° C.)
(0 ° C. for 30 minutes, 350 ° C. for 1 hour) to imidize. Thereafter, this aluminum plate is immersed in 10% hydrochloric acid, and the aluminum plate is dissolved to obtain a polyimide film.

[0011]

EXAMPLES Hereinafter, the fluorinated polyamic acid and fluorinated polyimide of the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In each of the following examples, the imidation was confirmed from the characteristic absorption due to the symmetric and asymmetric stretching vibration of the carbonyl group in the infrared absorption spectrum. The light transmittance was measured by measuring an ultraviolet-visible absorption spectrum.

Example 1 Bis (2,3,5,6-tetrafluoro-4-aminophenyl) ether represented by the following structural formula (Formula 5) is placed in an Erlenmeyer flask:

Embedded image 6.883 g (20.00 mmol) and 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride represented by the following structural formula (Formula 6):

Embedded image 8.885 g (20.00 mmol) and DMAc8
9 g were added. This was stirred at room temperature in a dry nitrogen stream for 48 hours to obtain a polyamic acid DMAc solution. This is cast on a silicon wafer and placed in an oven at 70 ° C.
Heat imidation was performed at 160 ° C. for 1 hour, 250 ° C. for 30 minutes, and 350 ° C. for 1 hour. This sample was immersed in a 10% hydrochloric acid aqueous solution, and the aluminum plate was dissolved to obtain a polyimide film. When the infrared absorption spectrum of this polyimide film was measured, absorption specific to the imide group appeared at 1785 cm ⁻¹ , confirming that the imidization had completely progressed. When the light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, it was smaller than the conventional polyimide film produced in Comparative Example 1 shown below, as shown in FIG. That is, the solid line in FIG. 1 is a graph showing the wavelength dependence of the light absorbance of the fluorinated polyimide of Example 1 and the broken line is the polyimide of Comparative Example 1. In the figure, the vertical axis indicates absorbance (arbitrary unit), and the horizontal axis indicates wavelength (μm).

Example 2 6.883 g of bis (2,3,5,6-tetrafluoro-4-aminophenyl) ether (20.
00 mmol) and pyromellitic dianhydride represented by the following structural formula (Formula 7):

Embedded image 4.362 g (20.00 mmol) and DMAc6
4 g were put. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 2 shown below.

Example 3 6.883 g of bis (2,3,5,6-tetrafluoro-4-aminophenyl) ether (20.
00 mmol) and a biphenyltetracarboxylic dianhydride represented by the following structural formula (Formula 8):

Embedded image 5.884 g (20.00 mmol) and DMAc7
2 g were added. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 3 shown below.

Example 4 6.883 g of bis (2,3,5,6-tetrafluoro-4-aminophenyl) ether (20.
00 mmol) and a benzophenonetetracarboxylic dianhydride represented by the following structural formula (Formula 9):

Embedded image 6.445 g (20.00 mmol) and DMAc7
6 g were put. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 4 shown below.

Example 5 Bis (2,3,5,6-tetrafluoro-4-aminophenyl) sulfide represented by the following structural formula (Formula 10) was placed in an Erlenmeyer flask.

Embedded image 7.205 g (20.00 mmol), 8.885 g (20.00 mmol) of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, and 91 g of DMAc were added. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 5 shown below.

Example 6 In an Erlenmeyer flask, 7.205 g of bis (2,3,5,6-tetrafluoro-4-aminophenyl) sulfide (2
0.00mmol) and pyromellitic dianhydride 4.36
2 g (20.00 mmol) and 66 g of DMAc were charged. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The wavelength of this polyimide film 0.8 ~
The light absorption in the range of 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 6 shown below.

Example 7 An Erlenmeyer flask was charged with 7.205 g of bis (2,3,5,6-tetrafluoro-4-aminophenyl) sulfide (2
0.0084 mmol), 5.884 g (20.00 mmol) of biphenyltetracarboxylic dianhydride and DMA
c 35 g was put. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 7 shown below.

Example 7 In an Erlenmeyer flask, 7.205 g of bis (2,3,5,6-tetrafluoro-4-aminophenyl) sulfide (2
0.00mmol), 6.445 g (20.00 mmol) of benzophenonetetracarboxylic dianhydride and D
77 g of MAc were charged. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The light absorption of this polyimide film in the wavelength range of 0.8 to 1.7 μm was smaller than that of the conventional polyimide film produced in Comparative Example 8 shown below.

Comparative Example 1 An Erlenmeyer flask was charged with 4,4 represented by the following structural formula (Formula 11).
4'-diaminodiphenyl ether:

Embedded image 4.0048 g (20.00 mmol), 8.885 g (20.00 mmol) of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, and 73 g of DMAc were added. This was obtained in the same manner as in Example 1 to obtain a polyimide film. When the light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, as shown by the broken line in FIG. In the vicinity of 1.4 μm, the absorption due to the harmonics of the C—H bond stretching vibration and the bending sound is combined, and in the vicinity of 1.65 μm, the overtone of the C—H bond stretching vibration becomes the overtone. The resulting absorption appeared.

Comparative Example 2 An Erlenmeyer flask was charged with 4.0048 g (20.00 mmol) of 4,4'-diaminodiphenyl ether, 4.362 g (20.00 mmol) of pyromellitic dianhydride and 47 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film. When the light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, the same absorption spectrum as the absorption spectrum of Comparative Example 1 appeared.

Comparative Example 3 In a conical flask, 4.0048 g (20.00 mmol) of 4,4′-diaminodiphenyl ether and 5.884 g of biphenyltetracarboxylic dianhydride (20.
00 mmol), and 56 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film. The wavelength of this polyimide film is 0.8 to 1.7 μm
When the absorption spectrum of light in the range was measured, absorption substantially similar to the absorption spectrum of Comparative Example 1 appeared.

Comparative Example 4 In an Erlenmeyer flask, 4.0048 g (20.00 mmol) of 4,4'-diaminodiphenyl ether and 6.445 g (20.00 mmol) of benzophenonetetracarboxylic dianhydride were added.
mmol) and 59 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film. When the light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, it showed absorption substantially similar to the absorption spectrum of Comparative Example 1.

Comparative Example 5 An Erlenmeyer flask was charged with 4,4 represented by the following structural formula (Chemical Formula 12).
4'-diaminodiphenyl sulfide:

Embedded image 4.3260 g (20.00 mmol), 8.885 g of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride and (20.00 mmol),
And 75 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film. When the light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, it showed absorption substantially similar to the absorption spectrum of Comparative Example 1.

Comparative Example 6 A conical flask was charged with 4.3260 g (20.00 mmol) of 4,4'-diaminodiphenyl sulfide, 4.362 g (20.00 mmol) of pyromellitic dianhydride and 49 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film. When the light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, it showed absorption substantially similar to the absorption spectrum of Comparative Example 1.

Comparative Example 7 4.3260 g (20.00 mmol) of 4,4'-diaminodiphenyl sulfide and 5.884 g (20.00 m) of biphenyltetracarboxylic dianhydride were placed in an Erlenmeyer flask.
mol), and 58 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film. When the light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured, it showed absorption substantially similar to the absorption spectrum of Comparative Example 1.

Comparative Example 8 In an Erlenmeyer flask, 4.3260 g (20.00 mmol) of 4,4'-diaminodiphenyl sulfide and 6.445 g (20.0 g) of benzophenonetetracarboxylic dianhydride were added.
0 mmol), and 61 g of DMAc. This was obtained in the same manner as in Example 1 to obtain a polyimide film.
The light absorption spectrum of this polyimide film in the wavelength range of 0.8 to 1.7 μm was measured.
Approximately the same absorption spectrum as the absorption spectrum appeared.

[0028]

As described above, according to the present invention, there is provided a novel fluorinated polyamic acid and a fluorinated polyimide, and the fluorinated polyimide is different from the conventional fluorinated polyamide acid in light transmission in the near infrared region. It has excellent properties and is useful as an optical material for optical communication.

[Brief description of the drawings]

FIG. 1 is a graph showing the wavelength dependence of light absorbance of the fluorinated polyimide of Example 1 and the dashed line of the polyimide of Comparative Example 1, respectively.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08G 73/10 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A compound represented by the following general formula (1): (Wherein X represents O or S and R represents a tetravalent organic group containing at least one hydrogen). A fluorinated polyimide containing a repeating unit represented by the following formula: 2. The following general formula (Formula 2): (Wherein X represents O or S) and a diamine represented by the following general formula (Formula 3): Wherein R represents a tetravalent organic group containing at least one hydrogen, or a tetracarboxylic acid dianhydride or a tetracarboxylic acid thereof or a reactive derivative thereof. The method for producing a fluorinated polyimide according to claim 1, wherein the corresponding fluorinated polyamic acid is ring-closed. 3. The following general formula (Chem. 4): (Wherein X represents O or S and R represents a tetravalent organic group containing at least one hydrogen). A fluorinated polyamic acid containing a repeating unit represented by the following formula: 4. A diamine represented by the general formula (Formula 2):
A tetracarboxylic dianhydride represented by the general formula (Formula 3),
4. The method for producing a fluorinated polyamic acid according to claim 3, wherein the method is reacted with a tetracarboxylic acid or a reactive derivative thereof.