JPH10110031A - Water-repellent polyimide, its precursor solution, precursor, and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyimide having excellent water repellency inaccessible so far by forming one having a specified molecular structure wherein fluorinated substituents are introduced into the ends of polyimide molecule. SOLUTION: This polyimide has a structure of formula 1 [wherein Rf is -Cm F2m-1 (wherein m is an integer of 6 or greater); X is O, S or a single bond; R1 is a divalent organic group; R2 is a tetravalent organic group; and (n) is an integer of 5 or greater]. Examples of the Rf include -C6 F11 and -C9 F17 . The polyimide is produced by heating a polyimide precursor solution obtained by mixing the principal constituents comprising a solution of a polyamic acid consisting of repeating units represented by formula 2 (wherein R1 and R2 are the same as defined in formula 1) and a fluorinated acid anhydride represented by formula 3 (wherein Rf and X are the same as defined in formula 1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel water-repellent polyimide, a precursor solution thereof, a precursor thereof, and a method for producing the same.

[0002]

2. Description of the Related Art Polyimide is one of various organic polymers having excellent heat resistance, and thus has begun to be widely used in the fields of space and aviation to the field of electronic communication. In particular, recently, it is expected that not only excellent heat resistance but also various performances may be obtained depending on applications. For example, printed circuit boards and interlayer insulating films for LSIs are expected to have a small thermal expansion coefficient and a small dielectric constant, and are expected to have a small refractive index in optical communication-related fields, particularly for cladding materials of optical waveguides.
Further, in order to maintain stable physical property values, it is necessary that the water absorption is small. However, polyimide generally has a property of having a large water absorption because it has many imide groups having a large polarity in a molecule. So far, as a polyimide having a low water absorption, for example, the materials of the 3rd SAMPE Electronics International Conference, pp. 209-217, 198
June 20-22, 2009 (3rd International SAMPE El
ectronics Conference, June 20-22, pp. 209-217, 198
As shown in 9), the water absorption of the polyimide is reduced by introducing fluorine into the molecular structure of the polyimide. When polyimide is used as a protective film for a component used in a humid atmosphere, it is effective to impart water repellency to the surface of the polyimide material. Also, when polyimide is used as a heat-resistant release material, water repellency and oil repellency on the surface are effective. However, existing polyimides have a problem that even if they contain fluorine in the molecule, the contact angle of water on the surface thereof is relatively small, and a large water repellency cannot be obtained. On the other hand, as an organic polymer material having excellent water repellency, polytetrafluoroethylene (P
TFE) is typical. PTFE exhibits excellent water repellency because the material surface is a —CF ₂ — group having a high fluorine content. As a method for imparting water repellency to other polymer materials, for example, Journal of Polymer
Science, Polymer Chemistry Edition,
Vol. 22, pp. 831-840, 1984 [Jour
nal of Polymer Science: Polymer Chemistry Editio
n, 22, 831-840 (1984)], an epoxy resin is represented by the following structural formula (Formula 7),
_A perfluorobutenyloxy group which is a fluorine-containing substituent containing _three groups:

[0003]

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[0004] By introducing a small amount of water, an epoxy resin having water repellency is realized. In this fluorinated epoxy resin, the introduction of a small amount of perfluorobutenyloxy group imparts excellent water repellency due to the presence of a large amount of -CF ₃ groups of the introduced perfluorobutenyloxy group on the material surface. It is possible. However, the above PTF
E and the fluorinated epoxy resin had a problem that heat resistance was inferior to polyimide.

[0005]

There have been attempts to improve the water repellency of the polyimide surface by introducing a fluorine-containing substituent containing a large amount of --CF ₃ groups into the polyimide having excellent heat resistance at the terminal of the polyimide molecule. Was not done. An object of the present invention is to provide a polyimide having excellent water repellency, a precursor solution, a precursor thereof, and a method for producing the same, which have not been provided by conventional polyimides.

[0006]

SUMMARY OF THE INVENTION In summary, the first invention of the present invention relates to a polyimide having excellent water repellency, and has the following general formula (1):

[0007]

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[Wherein Rf is -C _m F _2m-1 (where m is 6
X is O, S, or a single bond, R ₁ is a divalent organic group, R ₂ is a tetravalent organic group, and n is an integer of 5 or more.] It is characterized by having. Further, the second invention of the present invention relates to a polyimide having excellent water repellency, and in the above general formula (Formula 1), Rf is -C ₆ F ₁₁ or -C ₉ F _17. Features. The third invention of the present invention relates to a polyimide precursor solution having excellent water repellency, and has the following general formula (Formula 2):

[0009]

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[Wherein R ₁ and R ₂ have the same meanings as in the general formula (Chemical Formula 1)]

[0011]

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[Wherein, Rf and X have the same meaning as in the general formula (Chemical Formula 1)]. The fourth invention of the present invention relates to a polyimide precursor solution having excellent water repellency, and in the above general formula (Formula 2), Rf is -C ₆
Characterized in that it is a F ₁₁ or -C ₉ F _17. The fifth invention of the present invention relates to a polyimide precursor having excellent water repellency, and has the following general formula (Formula 4):

[0013]

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Wherein Rf, X, R ₁ and R ₂ have the same meaning as in the general formula (1), and k is an integer of 5 or more. The sixth invention of the present invention is an invention relating to a polyimide precursor having excellent water repellency, and in the general formula (Formula 4), Rf is -C ₆ F ₁₁ or -C ₉ F ₁₇ . There is a feature. The seventh invention of the present invention relates to a method for producing a polyimide precursor solution having excellent water repellency, and relates to a polyamic acid comprising a repeating unit represented by the above general formula (Formula 2). It is characterized in that a solution and a fluorinated anhydride represented by the above general formula (Formula 3) are mixed as a main component. The eighth invention of the present invention relates to a method for producing a polyimide precursor solution having excellent water repellency, and in the seventh invention, Rf of the above general formula (Formula 3) is characterized in that it is a -C ₆ F ₁₁ or -C ₉ F _17. The ninth invention of the present invention is an invention relating to a method for producing a polyimide having excellent water repellency, wherein a solution of a polyamic acid comprising a repeating unit represented by the above general formula (Formula 2) is provided, Is characterized by heating a precursor solution of the water-repellent polyimide of the first invention, which is obtained by mixing a fluorinated anhydride represented by the general formula (Chem. 3) as a main component and mixing them. Further, a tenth invention of the present invention relates to a method for producing a polyimide having excellent water repellency, and in the ninth invention,
Rf in the above general formula (Chemical Formula 3) is -C ₆ F ₁₁ or -C ₉ F
₁₇ is characterized. An eleventh invention of the present invention relates to a method for producing a polyimide precursor solution having excellent water repellency, and comprises the following general formula (Formula 5):

[0015]

Embedded image H ₂ N—R ₁ —NH ₂

[Wherein, R ₁ has the same meaning as in the general formula (1)] and a diamine represented by the following general formula (6):

[0017]

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Wherein R ₂ has the same meaning as in the general formula (Chemical Formula 1), and the fluorinated anhydride represented by the general formula (Chemical Formula 3) in an organic solvent And reacting them. In addition, the first aspect of the present invention
Invention 2 relates to a method for producing a polyimide precursor solution having excellent water repellency. In the eleventh invention, Rf in the above general formula (Formula 3) is -C ₆ F ₁₁ or -C characterized in that it is a ₉ F _17. The thirteenth invention of the present invention relates to a method for producing a polyimide having excellent water repellency, and comprises a diamine represented by the above general formula (Chemical Formula 5) and a diamine represented by the above general formula (Chemical Formula 6). A polyamic acid solution obtained by mixing an acid dianhydride and a fluorinated anhydride represented by the above general formula (Formula 3) in an organic solvent is heated. Further, a fourteenth invention of the present invention relates to a method for producing a polyimide having excellent water repellency. In the thirteenth invention, Rf of the above-mentioned general formula (Formula 3) is -C ₆ F ₁₁ or characterized in that it is a -C ₉ F _17.

The present inventors have conducted various studies on the molecular structure and synthesis method of polyimide, and the contact angle of polyimide surface with water. As a result, -CF was added to a solution obtained by dissolving a polyamic acid as a polyimide precursor in a polar organic solvent.
After adding a small amount of the fluorinated anhydride containing a large number of _three groups, heating it, or adding a small amount of the above fluorinated anhydride to the acid dianhydride used as a raw material when synthesizing the polyamic acid after obtaining a polyamic acid by Te carry out the polymerization, by imidizing this by combining the fluorine-containing acid anhydride containing a large amount of -CF ₃ group at the terminal of the polyimide molecule, the contact angle with water of the polyimide To increase
It has been clarified that water repellency can be imparted.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. First end to the polyfluorinated substituent Rf (although Rf of polyimide represented by the general formula (1) One polyimide molecule of the invention is a component of the present invention are represented by -C _m F _2m-1 , M represents an integer of 6 or more). Here, m of Rf may be an integer of 6 or more. However, when m is extremely large, the heat resistance of the polyimide is reduced, and a polyamic acid solution, which is a precursor solution of the polyfluorine compound containing Rf at the time of production, is prepared. M, it is preferable that m is 12 or less, since uniform mixing becomes difficult. On the other hand, when m is less than 6, the proportion of fluorine that causes the polyimide to exhibit water repellency becomes small, and it becomes impossible to impart sufficient water repellency to the polyimide surface. Specific examples of the structure of _{Rf, -C 6 F 11, -C} 9 F 17, -C 10 F 19, -
C ₁₂ F _{23 and the} like can be mentioned. The polyimide of the present invention has greater water repellency than existing fluorine-containing polyimides due to the presence of a large number of —CF ₃ groups in the Rf group at the molecular end near the surface of the obtained polyimide film.

As for X, Rf may be directly bonded to the aromatic ring, or may be bonded via oxygen (O) or sulfur (S). Further, in the general formulas (Chem. 1) and (Chem. 4), n and k each represent an integer of 5 or more. When n and k are less than 5, the polyimide chain is short, that is, the molecular weight of the polyimide is Since the size of the polyimide film becomes small, the strength of the obtained polyimide film becomes extremely weak, which is not suitable.

Specific examples of the polyimide precursor other than the molecular terminal and the structure of the polyimide include 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl,
4,4'-oxydianiline, 3,4'-oxydianiline, 2,4'-oxydianiline, tetrafluoro-
m-phenylenediamine, bis (4-amino-tetrafluorophenyl) ether, bis (4-amino-tetrafluorophenyl) sulfone or the like is used as a diamine, while pyromellitic dianhydride, 3,3 ′, 4 ,
4'-biphenyltetracarboxylic dianhydride, 2,2-
Bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 1-trifluoromethyl-2,3,5,6-benzene Tetracarboxylic dianhydride, 1,4-ditrifluoromethyl-2,3,5,6-
Benzenetetracarboxylic dianhydride, 1,4-difluoromethyl-2,3,5,6-benzenetetracarboxylic dianhydride or 1,4-bis (3,4-carboxytrifluorophenoxy) tetrafluorobenzene Using dianhydrides and the like as acid dianhydrides, polymerizing these diamines and tetracarboxylic dianhydride to obtain polyamic acid,
Further, there may be mentioned a polyimide obtained by dehydrating and ring-closing this.

Next, a method for producing these water-repellent polyimides, precursors thereof, and precursor solutions will be described. The first method is to prepare a precursor solution of a water-repellent polyimide by mixing a fluorinated anhydride with a polyamic acid solution obtained by polymerizing various acid dianhydrides and diamines in an organic solvent, This is heated and imidized to cause an exchange reaction between the fluorinated anhydride added at the same time as the dehydration ring-closure reaction (imidation reaction) of the amic acid and the acid dianhydride component of the polyamic acid, thereby causing a terminal of the polyimide molecule Fluorine-containing group (R
f) is introduced to produce a water-repellent polyimide. In this case, in advance, an equimolar amount of an acid dianhydride and a diamine as a raw material of the polyimide are used, and the resulting mixture is polymerized in a polar solvent to produce a high-molecular-weight polyamic acid solution. Is added. The polyamic acid used may be a derivative such as an acid dianhydride in which the acid dianhydride as the raw material for the synthesis is derived from tetracarboxylic acid or an acid chloride derived from these acids. Examples of the polar solvent used for the production of polyamic acid include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, dimethylformamide, dimethylsulfoxide, and γ-butyrolactone. Since the reaction from the monomeric dianhydride and the diamine to the polyimide is an equilibrium reaction with depolymerization, the fluorinated anhydride is mixed with a solution of the polyamic acid, which is a precursor of the polyimide having a high molecular weight, and further heated. By doing so, the fluorinated anhydride added to the molecular terminal generated by the depolymerization reacts, and the fluorinated group (R
A polyimide having (f) can be produced. A larger amount of the fluorinated anhydride can impart a greater water repellency to a larger amount, but with an increased amount,
Since the proportion of the molecular terminal increases, that is, the molecular weight decreases, and the mechanical strength of the polyimide decreases, it is preferable that the content be 20% by weight or less based on the mass of the polyimide.

In the second method, various acid dianhydrides, diamines and a small amount of a fluorinated anhydride are polymerized in an organic solvent to form a water-repellent polyimide having a fluorinated group (Rf) at a terminal. This is a method for producing a water-repellent polyimide by producing a precursor and further heating and imidizing the solution of the precursor to introduce a fluorine-containing group (Rf) into a terminal of the polyimide molecule. In the synthesis of general polyimide, polymerization is carried out using an equimolar amount of an acid dianhydride and a diamine, but in the present production method, the amount of the acid dianhydride is reduced according to the amount of the fluorinated anhydride used, and the acid dianhydride is reduced. Anhydride groups of anhydrides and fluorinated acid anhydrides, that is, groups represented by the following formula (Formula 8):

[0025]

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And the amino group of the diamine (-N
H ₂ ) are used to make them equal. The addition amount of the fluorinated anhydride is also the same as in the first production method, and is preferably 20% by weight or less based on the mass of the polyimide. Also, the polar solvent used may be the same as in the first case in this case.

[0027]

EXAMPLES Hereinafter, the water-repellent polyimide of the present invention and the method for producing the same will be described more specifically with reference to examples, but the present invention is not limited to these examples. The structure of the polyimide was confirmed by characteristic absorption due to symmetric and asymmetric stretching vibration of the carbonyl group in the infrared absorption spectrum. The measurement was performed using a polyimide film on a silicon substrate as a measurement sample and a silicon wafer having the same specifications as the silicon wafer used for the substrate as a reference. The increase in the molecular weight was confirmed by measuring the intrinsic viscosity of the precursor by a polymer dilute solution viscosity method. In each of the following examples, the contact angle of polyimide surface with water was CA-Z manufactured by Kyowa Interface Science Co., Ltd.
It measured using the mold contact angle measuring device.

Example 1 2,2-bis (3,4-) represented by the following structural formula (Formula 9)
Dicarboxyphenyl) hexafluoropropane dianhydride (6FDA):

[0029]

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And 2, represented by the following structural formula (Formula 10)
2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (TFDB):

[0031]

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The polyamic acid solution (6FDA / T) having a solid concentration of 15% by weight was obtained by polymerizing the same in an equimolar amount and polymerizing the same in N, N-dimethylacetamide (DMAc).
FDB solution) in 20 g of perfluorobutenyloxyphthalic anhydride (PFP) represented by the following structural formula (Formula 11)
A):

[0033]

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Was added and stirred at room temperature for 2 days to obtain a homogeneous precursor solution having a PFPA content of 19.5%. The intrinsic viscosity of this precursor was 0.6 dl / g, which was found to be high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under a nitrogen atmosphere at 70 ° C. for 2 hours, 160 ° C. for 1 hour, 250 ° C. for 30 minutes, and 350 ° C. for 1 hour. By this operation, a film thickness of 5 μm is formed on the silicon substrate.
Was obtained. In this polyimide, in the general formula (Chemical Formula 1), R ₁ is represented by the following structural formula
2):

[0035]

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R ₂ is a divalent organic group represented by the following structural formula (Formula 13):

[0037]

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A tetravalent organic group represented by the formula: wherein Rf is -C ₉ F
_17. It has a molecular structure in which X is oxygen (O). FIG. 1 shows the infrared absorption spectrum of the obtained polyimide film. In FIG. 1, the vertical axis indicates transmittance, and the horizontal axis indicates wave number (cm ^-1 ). The spectrum includes 1730 and 1790 cm
^{At -1} , sharp absorption peaks were observed based on the symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, confirming that polyimide was synthesized.
In addition, absorption was observed around 1200 cm ⁻¹ based on the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent, which confirmed that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of this polyimide film surface with water was measured and found to be 97.7 °.

Example 2 PF was added to 20 g of the 6FDA / TFDB solution used in Example 1.
Add 0.302 g of PA and stir at room temperature for 2 days
To obtain a uniform PFPA content of 9.2%.
A precursor solution was obtained. The intrinsic viscosity of this precursor is 0.7 dl
/ G, which is high molecular weight. This solution
Was spin-coated on a silicon substrate, and
Heat curing was performed under the same conditions. With this operation, silicon
A polyimide film having a thickness of 5 μm was obtained on the substrate. Obtained
The infrared absorption spectrum of the polyimide film was measured.
1,730 and 1,790 cm^-1Polyimide imitation
Based on symmetric and asymmetric stretching vibrations of the carbonyl group of the do ring
A sharp absorption peak was observed, indicating that polyimide
It was confirmed that they could be synthesized. In addition, 1200cm ^-1
In the vicinity, the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent
Absorption due to dynamics was observed.
Confirm that the fluorine-containing substituent has been introduced into the
Was. Measure the contact angle of this polyimide film surface with water.
It was 94.6 °.

Example 3 PF was added to 20 g of the 6FDA / TFDB solution used in Example 1.
0.153 g of PA was added, and the mixture was stirred at room temperature for 2 days to obtain a uniform precursor solution having a PFPA content of 4.9%. The intrinsic viscosity of this precursor is 0.7 dl
/ G, which is high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. When the infrared absorption spectrum of the obtained polyimide film was measured, sharp absorption peaks were observed at 1730 and 1790 cm ^-1 based on the symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, and the polyimide was synthesized from this. I confirmed that it was done. 1200 cm ^-1
In the vicinity, absorption based on the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent was observed, confirming that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of the polyimide film surface with water was measured and found to be 89.6 °.

Example 4 Pyromellitic dianhydride (PMDA) represented by the following structural formula (Formula 14):

[0042]

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And TFDB were used in equimolar amounts, and this was added to DM
20 g of a polyamic acid solution (PMDA / TFDB solution) having a solid content of 10% by weight obtained by polymerization in Ac
0.155 g of FPA was added and the mixture was stirred at room temperature for 2 days to obtain a uniform precursor solution having a PFPA content of 12.4%. The intrinsic viscosity of this precursor is 0.7
dl / g, which was found to be high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. This polyimide, wherein the general formula (Formula 1), R ₁
Is a divalent organic group represented by the above formula (Formula 13), and R ₂ is a structural formula (Formula 15):

[0044]

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A tetravalent organic group represented by the formula: wherein Rf is -C ₉ F
_17. It has a molecular structure in which X is oxygen (O). FIG. 2 shows the infrared absorption spectrum of the obtained polyimide film. The vertical and horizontal axes in FIG. 2 are the same as those in FIG. In this spectrum, sharp absorption peaks were observed at 1730 and 1780 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, and it was confirmed that the polyimide was synthesized. Also, 1200
In the vicinity of cm ^−1, absorption based on the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent was observed, and it was confirmed that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of the polyimide film surface with water was measured and found to be 91.1 °.

Example 5 PF was added to 20 g of the PMDA / TFDB solution used in Example 4.
0.144 g of PA was added, and the mixture was stirred at room temperature for 2 days to obtain a uniform precursor solution having a PFPA content of 6.7%. The intrinsic viscosity of this precursor is 0.8 dl
/ G, which is high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. When the infrared absorption spectrum of the obtained polyimide film was measured, sharp absorption peaks were observed at 1730 and 1780 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide. From this, polyimide was synthesized. I confirmed that it was done. 1200 cm ^-1
In the vicinity, absorption based on the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent was observed, confirming that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of the polyimide film surface with water was measured and found to be 84.8 °.

Example 6 PF was added to 20 g of the PMDA / TFDB solution used in Example 4.
0.089 g of PA was added and the mixture was stirred at room temperature for 2 days to obtain a uniform precursor solution having a PFPA content of 4.3%. The intrinsic viscosity of this precursor is 1.0 dl
/ G, which is high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. When the infrared absorption spectrum of the obtained polyimide film was measured, sharp absorption peaks were observed at 1730 and 1780 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide. From this, polyimide was synthesized. I confirmed that it was done. 1200 cm ^-1
In the vicinity, absorption based on the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent was observed, confirming that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of this polyimide film surface with water was measured and found to be 81.1 °.

Example 7 PMDA and 4,4'- represented by the following structural formula (Formula 16)
Oxydianiline (ODA):

[0049]

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PFPA was added to 20 g of a polyamic acid solution (DMDA / ODA solution) having a solid content of 10% by weight, which was obtained by polymerizing this in an equimolar amount in DMAc.
By adding 424 g and stirring the mixture at room temperature for 2 days, a uniform precursor solution having a PFPA content of 17.4% was obtained. The intrinsic viscosity of this precursor was 0.7 dl / g, which was found to be high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. In this polyimide, in the above general formula (Chemical formula 1), R ₁ is the following structural formula (Chemical formula 17):

[0051]

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R ₂ is a divalent organic group represented by the above formula (Formula 15), and Rf is —C ₉
F ₁₇ has a molecular structure in which X is oxygen (O). FIG. 3 shows the infrared absorption spectrum of the obtained polyimide film.
The vertical and horizontal axes in FIG. 3 are the same as those in FIG. In this spectrum, sharp absorption peaks were observed at 1720 and 1780 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, which confirmed that the polyimide was synthesized. Also, 120
At around 0 cm ^−1, absorption based on the stretching vibration of the carbon-fluorine bond of the fluorine-containing substituent was observed, confirming that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of the polyimide film surface with water was measured and found to be 85.3 °.

Example 8 In an Erlenmeyer flask, 3.416 g (10.67 mmol) of TFDB and 4.442 g (10.00 mmol) of 6F
DA and 49.0 g of DMAc were added, and 0.792 was added.
g (1.333 mmol) of PFPA was added. This was stirred at room temperature under a nitrogen atmosphere for 3 days to obtain a polyamic acid in DMAc solution. The intrinsic viscosity of this precursor is 0.7
dl / g, which was found to be high molecular weight. This solution was spin-coated on a silicon substrate, and cured by heating under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. At this time, the polyamic acid solution and the polyimide are represented by the general formulas (Chem. 4) and (Chem. 1), respectively.
R ₁ is a divalent organic group represented by the structural formula (Formula 12), R ₂ is a tetravalent organic group represented by the structural formula (Formula 13), Rf is —C ₉ F ₁₇ , It has a molecular structure in which X is oxygen (O). When the infrared absorption spectrum of the obtained polyimide film was measured, sharp absorption peaks were observed at 1730 and 1790 cm ^-1 based on the symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, and the polyimide was synthesized from this. I confirmed that it was done. In addition, around 1200 cm ⁻¹ , the carbon-
Absorption based on the stretching vibration of the fluorine bond was observed, which confirmed that the fluorine-containing substituent was introduced into the polyimide molecule. The contact angle of this polyimide film surface with water was measured and found to be 94.2 °.

Comparative Example 1 20 g of the 6FDA / TFDB solution used in Example 1 was spin-coated on a silicon substrate, and heated and cured under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. The infrared absorption spectrum of the obtained polyimide film was measured.
Sharp absorption peaks were observed at 20, 20 and 1790 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, and it was confirmed that the polyimide was synthesized. However, when the contact angle of the polyimide film surface to water was measured, the value was 77.0 °, which was smaller than that of Examples 1 to 3 and Example 8.

Comparative Example 2 20 g of the PMDA / TFDB solution used in Example 4 was spin-coated on a silicon substrate, and heated and cured under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. The infrared absorption spectrum of the obtained polyimide film was measured.
Sharp absorption peaks were observed at 20, 20 and 1790 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, and it was confirmed that the polyimide was synthesized. However, when the contact angle of this polyimide film surface to water was measured, the value was 75.9 °, which was smaller than that of Examples 4 to 6.

Comparative Example 3 20 g of the PMDA / ODA solution used in Example 7 was spin-coated on a silicon substrate, and heated and cured under the same conditions as in Example 1. By this operation, a polyimide film having a thickness of 5 μm was obtained on the silicon substrate. When the infrared absorption spectrum of the obtained polyimide film was measured, 171 was obtained.
Sharp absorption peaks were observed at 0 and 1780 cm ^-1 based on symmetric and asymmetric stretching vibrations of the carbonyl group of the imide ring of the polyimide, and it was confirmed that the polyimide was synthesized. However, when the contact angle of this polyimide film surface to water was measured, the value was found to be in Example 7.
And 70.2 °.

From these results, it has been clarified that the water-repellent polyimide of the present invention has a larger contact angle with water than the existing polyimide, and exhibits a large water-repellent property. In addition, the above-mentioned general formula (Formula 1), general formula (Formula 4),
The water-repellent polyimides of the present invention represented by the general formulas (Chemical Formula 5) and (Chemical Formula 6) and precursors thereof, and further, in their production methods, R ₁ and R ₂ are the same as the organic groups described in the present examples. Other than divalent and tetravalent organic groups, and Rf
Since m in the -C _m F _2m-1 are possible similar to the embodiment as long as 6 or more integer other than 9 synthesis, excellent water repellency similar to the embodiment can be achieved.

[0058]

As described above, the water-repellent polyimide of the present invention has excellent water repellency that is not provided by conventional polyimides, in addition to the excellent heat resistance of conventional polyimides. And it is extremely useful as a protective film material for optical components and a release material.

[Brief description of the drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of a polyimide film obtained in Example 1 of the present invention.

FIG. 2 is a diagram showing an infrared absorption spectrum of a polyimide film obtained in Example 4 of the present invention.

FIG. 3 is a view showing an infrared absorption spectrum of a polyimide film obtained in Example 7 of the present invention.

Claims (14)

[Claims] 1. A compound represented by the following general formula (1): [Wherein Rf is -C _m F _2m-1 (where m denotes the 6 or more integer), X is O, S, or a single bond, R ₁ is a divalent organic group, R ₂ is a tetravalent organic A group, n represents an integer of 5 or more]. 2. In the general formula (Formula 1), Rf is —C ₆
Water repellency polyimide according to claim 1, wherein the a F ₁₁ or -C ₉ F _17. 3. The following general formula (Formula 2): Wherein R ₁ and R ₂ have the same meanings as in the general formula (Chemical Formula 1), and a solution of a polyamic acid comprising a repeating unit represented by the following General Formula (Chemical Formula 3) 2. The precursor solution of a water-repellent polyimide according to claim 1, wherein the main component is a fluorinated anhydride represented by the general formula (1). . 4. In the general formula (Formula 2), Rf is —C ₆
Precursor solution water repellency polyimide according to claim 3, characterized in that the F ₁₁ or -C ₉ F _17. 5. The following general formula (Formula 4): _{2. The} structure according to claim ₁ , wherein Rf, X, R ₁ and R ₂ have the same meaning as in the general formula (Chemical Formula 1), and k represents an integer of 5 or more. The precursor of water-repellent polyimide. 6. In the general formula (Formula 4), Rf is —C ₆
Precursor of water-repellent polyimide of claim 5, wherein the a F ₁₁ or -C ₉ F _17. 7. A polyamic acid solution comprising a repeating unit represented by the general formula (Chemical Formula 2) according to claim 3, and a solution thereof.
The method for producing a precursor solution of a water-repellent polyimide according to claim 3, wherein the fluorinated anhydride represented by the general formula (Formula 3) is mixed as a main component. 8. The water-repellent water according to claim 3, wherein Rf in the general formula (Chemical Formula 3) is -C ₆ F ₁₁ or -C ₉ F _17. A method for producing a polyimide precursor solution. 9. A polyamic acid solution comprising a repeating unit represented by the general formula (Chemical Formula 2) according to claim 3, and a polyamic acid solution.
2. A precursor solution of a water-repellent polyimide according to claim 1, which is obtained by mixing the fluorinated anhydride represented by the general formula (Chem. 3) as a main component and mixing them. Item 7. The method for producing a water-repellent polyimide according to Item 1. 10. The water-repellent liquid according to claim 1, wherein Rf in the general formula (Chemical Formula 3) is -C ₆ F ₁₁ or -C ₉ F _17. Method for producing polyimide. 11. A diamine represented by the following general formula (Chem. 5): H ₂ N—R ₁ —NH ₂ (where R ₁ has the same meaning as in the general formula (Chem. 1)) General formula (Formula 6): Wherein R ₂ has the same meaning as in the general formula (Chemical Formula 1); and a fluorinated anhydride represented by the general formula (Chemical Formula 3) according to claim 3 in an organic solvent. 6. The method for producing a precursor solution of a water-repellent polyimide according to claim 5, wherein the solution is mixed and reacted. 12. The water-repellent liquid according to claim 5, wherein Rf in the general formula (Chemical Formula 3) according to claim 3 is —C ₆ F ₁₁ or —C ₉ F _17. A method for producing a polyimide precursor solution. 13. A diamine represented by the general formula (Chem. 5) according to claim 11 and an acid dianhydride represented by the general formula (Chem. 6), and a compound represented by the general formula (Chem. 3) according to the claim 3. The method for producing a water-repellent polyimide according to claim 1, wherein the polyamic acid solution obtained by mixing the represented fluorinated anhydride in an organic solvent is heated. 14. The water-repellent liquid according to claim 1, wherein Rf in the general formula (Chemical Formula 3) according to claim 3 is —C ₆ F ₁₁ or —C ₉ F _17. Method for producing polyimide.