JPH0215084A - Fluorine-containing pyromellitic dianhydride and preparation thereof - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (Y is H or CnF2n+1; n is 1-10). EXAMPLE:Ditrifluoromethylpyromellitic dianhydride. USE:A monomer for the synthesis of polyimides having low thermal expansion coefficients, low dielectric constants and low reflective indexes. PREPARATION:The compound of formula I is prepared by oxidizing and dehydrating a fluorine-containing durene of formula II. The compound of formula II is prepared e.g., by reacting a compound of formula III with CnF2n+1I.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel fluorine-containing pyromellitic anhydride that can be used as a monomer for polyimide, and a method for producing the same.

(Prior Art) Polyimide has superior heat resistance among various organic polymers, and has begun to be widely used in fields ranging from space and aviation to electronic communications. Particularly recently, it is expected that they not only have excellent heat resistance but also have various performances depending on the purpose. For example, printed circuit boards and interlayer insulating films for L8 engineering are expected to have low thermal expansion coefficients and dielectric constants, and in the field of optical communications, low refractive index is expected. However, polyimides that fully satisfy these properties have not been obtained. In order to obtain these polyimides, the main chain of the polyimide must be made as rigid as possible to exhibit low thermal expansion, and the monomer tetracarboxylic acid Low dielectric constant for dianhydrides or diamines,
One possible method is to introduce a substituent that exhibits low refractive index properties. For example, regarding epoxy resins, the Journal of Polymer Science
lymer 5science) Part
) c, PolymerLet
ters), Vol. 24, p. 249 (1986), by introducing polyfluorine substituents into the curing agent of epoxy resins, we have achieved the lowest dielectric constant of any epoxy resin to date. Achieved.

Furthermore, as shown in JP-A No. 61-44969, by introducing polyfluorine substituents, we have achieved the lowest refractive index of any epoxy resin to date. ing. By introducing a fluorine substituent in this way, a reduction in dielectric constant and refractive index can be expected.

(Problems to be Solved by the Invention) However, there is no report that A-4 achieves a low thermal expansion coefficient, low dielectric constant, and low refractive index by introducing a fluorine substituent into polyimide. In addition, there are few examples of synthesis of fluorinated acid anhydrides and fluorinated diamines for fluorinated polyimides.
It is expected that many monomers for fluorinated polyimide will appear in the future.

An object of the present invention is to provide a fluorine-containing pyromellitic anhydride necessary for synthesizing a polyimide having a low coefficient of thermal expansion, a low dielectric constant, and a low refractive index that conventional polyimides do not have, and a method for producing the same. There is a particular thing.

(Means for Solving the Problems) To summarize the present invention, the first invention of the present invention relates to fluorine-containing pyromellitic anhydride, which has the following general formula (■): (wherein Y is hydrogen or It is characterized by being represented by a CnF2n+1 group, where n represents a number from 1 to 10).

And, the second invention of the present invention is an invention related to the method for producing the fluorine-containing pyromellitic anhydride of the first invention,
It is characterized by oxidizing and dehydrating fluorine-containing durene represented by the following general formula (1): (in the formula, Y and n have the same meanings as in formula 1).

As a result of molecular design of tetracarboxylic dianhydride, the present inventors found that aliphatic polyimide main chains do not become rigid and lose low thermal expansion, so pyromellitic anhydride consisting of rigid aromatic Since it was preferable, the fluorine groups were introduced at the 1 and 4 positions of the aromatic ring, and the fluorine-containing pyromellitic anhydride shown in Formula 1 was synthesized.

The fluorine-containing bilomerite) M anhydride of formula 1 is synthesized by oxidation and dehydration of fluorine-containing durene of formula (1), and the fluorine-containing durene of formula (2) can be synthesized, for example, according to the reaction formula shown in the following old formula.

Examples of fluorine-containing iodides include trifluoromethyl iodide, pentafluoroethyl iodide, heptafluoropropyl iodide, perfluoro-n-butyl iodide, perfluoro-n-pentyl iodide, and perfluoro-n-iodide. xyl iodide, 1-
Examples include iodoperfluorohbutane, 1-iodoperfluorooctane, and 1-iodoperfluorodecane.

The solvent for this reaction is preferably a polar solvent such as dimethylformamide or pyridine, and activated copper powder is added as a catalyst. The reaction conditions were: 150°C to 250°C in an autoclave;
The reaction time is 10 to 150 hours at 20 to 300 atmospheres, and the higher the number of n in the fluorine-containing iodide in formula m, the higher the temperature, pressure, and time required.

Next is the oxidation and dehydration reaction from the fluorine-containing durene of formula (1) to the fluorine-containing pyromellitic anhydride of formula (1), which can be carried out using conventional oxidation and dehydration ring closure techniques.

For example, oxidation of a methyl group using a potassium permanganate method, a nitric acid method, etc., and an acid anhydride method using an acetic anhydride method, a heat dehydration method, etc. can be used. Alternatively, a method of directly converting the acid anhydride by air oxidation using vanadium pentoxide as a catalyst can be used.

(Examples) The fluorine-containing pyromellitic anhydride of the present invention and the method for producing the same will be described in detail below using Examples, but the present invention is not limited to these Examples.

Example 1 (Synthesis of fluorine-containing durene) 500 - diiodized durene in an autoclave! P(
78 mmol), trifluoromethyl iodide 40
f' (204 mmol), activated copper powder 50f? (470
mmol) and dry dimethylformamide were added thereto, and the mixture was heated and stirred at 150° C. for 50 hours in an autoclave.

After cooling, the copper powder was filtered from the reaction mixture, 1.5 mm of water was added to the filtrate, and the precipitated solid was filtered, dried, and purified by sublimation to give 17.6 mm of ditrifluoromethyldurene. I got it. South point, 6
Elemental analysis at 2° C. Calculated value: C15533 i H, 4,48° Actual value: 0,5×31 i”+4.51 The infrared absorption spectrum, NMR spectrum, and mass spectrum were consistent with the predicted structural formula.

(Synthesis of fluorine-containing pyromellitic anhydride) Trifluoromethyldurene △ 17, . 5t (65 mmol), 300 g of pyridine, and 150 ml of water were added and the temperature was raised to 100°C, and then potassium permanganate 5A7f (156 mmol) was slowly added and stirred for 3 hours. The reaction mixture was filtered, the solvent in the filtrate was removed using an evaporator, the product was added to 400 g of sodium hydroxide, and the temperature was raised to 100°C, followed by 64.59 (410 mmol) of potassium permanganate. Add Tsukusi. After stirring for 1.5 hours, ethanol is added to decompose excess potassium permanganate and filtered.

After cooling the filtrate, add an aqueous hydrochloric acid solution to make it acidic, and a precipitate will separate out. This precipitate was recrystallized from water to obtain ditrifluoromethylpyromellitic acid.

This ditrifluoromethylpyromellitic acid was dissolved in vacuum for 15 minutes.
After heating at 0°C for 2 hours, purification was performed to obtain ditrifluoromethylpyromellitic anhydride I CL5? I got it.

This product has an infrared absorption spectrum of 1800 cp (vertical axis: absorption rate value, horizontal axis: dual wave number (dl)) shown in Figure 1.
There are two absorptions specific to acid anhydrides at 1200 cm-' and 1870 cm-', an absorption based on the O-F group at 1200 cm-', no proton absorption appears in the NMR spectrum, and the following. As shown in the figure, the measured value and calculated value were almost in agreement with each other in elemental analysis, so it was confirmed that this was the target compound.

Elemental analysis, calculated value IC, 4CL70j measured value: 0,
4 168 Example 2 (Synthesis of fluorine-containing durene) Durene diiodide 5a6f (
100 mmol A/ ), Hetetafluoropropyl iodide 1189 (400 mmol), Activated copper powder 3 & 6
P (600 mmol) and dry dimethylformamide 2
00m/input tL, 16DC1200 in autoclave
The mixture was heated and stirred at atmospheric pressure for 120 hours. After cooling, 8 powders and solids were filtered and dried from the reaction mixture, and purified by sublimation to obtain 1.4-
Dihebutafluoropropyldurene 2a6? of? ■It was.

Melting point, 66℃ Elemental analysis, calculated value: C14α86; H12,574 River
Constant @:C,4(L89HH, 2-61 Infrared absorption spectrum, NMR spectrum, and Himass vector were consistent with the predicted structural formula.

(Synthesis of fluorine-containing pyromellitic anhydride) 1,4-dihebutafluoropropyl pyromellitic anhydride was obtained in the same manner as in Example 1. As in Example 1, this infrared absorption spectrum shows two absorptions specific to acid anhydrides at 1800 tyn-' and 1870 cm-', and 12
that absorption based on C-Pi appeared at 00 cm-';
It was confirmed that it was the target compound because no proton absorption appeared in the NMR spectrum, and as shown below, the measured value and calculated value in elemental analysis were almost in agreement.

Elemental analysis, calculated value IC, 5468; measured value 2 0.34.
68 Example 3 Using 1-durene iodide as a starting material, 1-trifluoromethylpyromellitic anhydride was synthesized via 1-trifluoromethyldurene in the same manner as in Example 1.

As in Example 1, the infrared absorption spectrum of this product showed two absorptions specific to acid anhydrides at 1800 cm and 1870 cm, and an absorption based on the C-F group at 1200 ctn. It was confirmed that this was the target compound because a single proton peak appeared in the NMR spectrum, and as shown below, the measured value and the calculated value almost matched in the elemental analysis.

Elemental analysis, calculated value: J4 &17; H, α36 measured value; a
, 41b587H, 138 Example 4 Using 1-durene iodide as a starting material, 1-hebutafluoropropylpyromellitic anhydride was synthesized via 1-hebutafluoropropyl durene in the same manner as in Example 2.

Similar to Example 1, this infrared absorption spectrum showed two absorptions specific to acid anhydrides at 1800 cm-' and 1870 cm-' and an absorption based on the C-F group at 1200 cm-'. In particular, a single proton peak appeared in the NMR spectrum, and as shown below, the measured values and calculated values in elemental analysis were almost in agreement, so it was confirmed that this was the target compound.

Elemental analysis, calculated value: 0.4 [134; , 4-dibarfluorodecyl durene to synthesize 1,4-dibarfluorodecylpyromellitic anhydride.

This product is the same as Example 1. In the infrared absorption spectrum, two absorptions peculiar to acid anhydrides appeared at 1800 crn-Otori and 1870 cm-', and an absorption based on the C-F group appeared at 1200-1. It was confirmed that this was the target compound because no proton absorption appeared in the NMR spectrum, and as shown below, the measured values and calculated values were almost in agreement in elemental analysis.

Elemental analysis, calculated value: a, 2a7s measurement position 20.

2 a 75 Example 6 Using 1-durene iodide as a starting material, 1-perfluorodecylpyromellitic anhydride was synthesized via 1-barfluorodecyl durene in the same manner as in Example 2.

As in Example 1, in the infrared absorption spectrum of this product, two absorptions peculiar to acid anhydrides appeared at 1800 crn' and 1870 cm', and an absorption based on the C-F group appeared at 1200 cm-'. It was confirmed that this was the target compound because a single proton peak appeared in the NMR spectrum, and as shown below, the measured values and calculated values almost matched in the elemental analysis.

Elemental analysis, calculation @t: C,52,153i 11.0
．． 13 Measured value: C, 32, 61iH1α15 Example 7 (Synthesis of fluorine-containing polyimide) In an Erlenmeyer flask, add 12.75f of ditrifluoromethylpyromellitic anhydride, 7.652 of o-+-lysine, and N-methyl-2- Pyrrolidone (NMP) 1152 was added. This mixture was stirred at room temperature under a nitrogen atmosphere for 6 days to obtain an NMP solution of polyamic acid (η: 65 poise). Pour this onto an aluminum plate, flatten it with a doctor blade, heat it at 100℃ for 1 hour, then at 200℃ for 1 hour.
A tough polyimide film was obtained by heating and curing at ℃ for 1 hour.

(Effects of the Invention) As explained above, the fluorine-containing pyromellitic anhydride of the present invention can be reacted with a diamine to obtain a polyimide in the same manner as ordinary pyromellitic anhydride, and a new fluorinated This has the advantage that polyimide can be synthesized.

[Brief explanation of the drawing]

FIG. 1 is an infrared absorption diagram of ditrifluoromethylpyromellitic anhydride, which is an example of the fluorine-containing pyromellitic anhydride of the present invention.

Claims (1)

[Claims] 1. The following general formula I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, Y is hydrogen or C_nF_2_n_+_1 group, and n represents a number from 1 to 10) A fluorine-containing pyromellitic anhydride characterized by the following: 2. The following general formula II: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[II] (In the formula, Y is hydrogen or C_nF_2_n_+_1 group, n represents a number from 1 to 10) Fluorine-containing durene 2. The method for producing fluorine-containing pyromellitic anhydride according to claim 1, wherein the fluorine-containing pyromellitic anhydride is oxidized and dehydrated.