JP3268658B2 - Fluorine-containing p-terphenyl derivative and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates, p has a fluorine atom, such as novel fluorine-containing terphenyl tetracarboxylic dianhydride which can be a raw material for polyimide and various condensation polymer - terphenyl (p-terphenyl) derivative And a method for producing the same.

[0002]

2. Description of the Related Art Polyimides composed of polycondensates of tetracarboxylic dianhydride and diamine have excellent heat resistance and dimensional stability, and have been highly evaluated in a wide range of industrial fields from the space, aviation and electronics fields. It has gained. If More recently introducing fluorine substituents into the polyimide skeleton low dielectric constant, water moisture resistance, the improvement of physical properties such as low refractive index seen et <br/> Re Rukoto, such fluorine-containing polyimide Jer <br/> Ctronics is expected as a new material in the field of optical materials
Have been.

However, the heat resistance of the fluorinated polyimide tends to decrease as the amount of fluorine introduced increases.
Therefore, the emergence of a fluorinated polyimide having a balanced performance between heat resistance and various physical properties improved by the introduction of fluorine is desired.

[0004]

The fluorine-containing tetracarboxylic dianhydride obtained by introducing a fluorine atom into tetracarboxylic dianhydride, one of the raw materials of polyimide, is described in JP-B-43-1876. 2-bis (3,4-
Dicarboxyphenyl) hexafluoropropane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] described in JP-B-2-14365.
Hexafluoropropane dianhydride and 4,4'-bis [2- (3,4-dicarboxyphenyl) hexafluoroisopropyl] diphenyl ether dianhydride described in JP-A-2-639 are known. However, the fluorinated polyimides obtained by using these fluorinated tetracarboxylic dianhydrides have not yet sufficiently solved the above-mentioned problems.

[0005]

The present inventors Means for Solving the Problems] refers to the various polyimide materials have been disclosed in the prior art result of repeating various studies, fluorinated tetracarboxylic acids having a novel structure, its anhydride , And its alkyl esters. The present invention also provides a method for producing the fluorinated tetracarboxylic acid, and a raw material compound thereof .

That is, the present invention relates to p -terphenyl-
2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,4
3 ", 4" -tetracarboxylic acid, its anhydride, and its alkyl ester, the method for producing this tetracarboxylic acid, and 2 ', 3', 5 ', 6'-tetrafluoro-
3,4,3 ", 4" -tetramethyl- p -terphenyl
It is.

[0007] The tetracarboxylic acid and its anhydride of the present invention are considered to be advantageous in terms of heat resistance of polyimide because they have a rigid skeleton in which aromatic nuclei are directly bonded. The form of introduction of fluorine is also a more compact form than a form such as a fluorine-containing alkyl chain, that is, a form in which a fluorine atom is directly connected to an aromatic nucleus . Balanced performance is demonstrated. on the other hand,
Conventionally known fluorine-containing tetracarboxylic dianhydride has a structure in which aromatic nuclei are linked by a hexafluoroisopropyl group, an ether group, or the like as a feature of its skeleton, and such a structure is from the viewpoint of heat resistance of polyimide. It is a disadvantageous skeleton when considered.

The anhydride of the tetracarboxylic acid of the present invention is preferably a dianhydride. This is because a dianhydride is usually used as a raw material for polyimide. Further, as the alkyl ester of the tetracarboxylic acid of the present invention, a tetraalkyl ester is preferable. However, by adjusting the equivalent ratio of the alkanol to the tetracarboxylic acid in the alkyl esterification, any mono-tetraalkyl ester or a mixture thereof can be obtained. The alkyl group in the alkyl ester is not particularly limited, but is preferably a lower alkyl group (having 4 or less carbon atoms).

[0009] The present invention also provides p -terphenyl-2 ',
3 ′, 5 ′, 6′-tetrafluoro-3,4,3 ″,
This is a method for producing 4 ″ -tetracarboxylic acid, that is,
2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,4
Oxidizing 3 ″, 4 ″ -tetramethyl- p -terphenyl, wherein p -terphenyl-2 ′, 3 ′,
This is a method for producing 5 ′, 6′-tetrafluoro-3,4,3 ″, 4 ″ -tetracarboxylic acid. This tetracarbon
Acid anhydrides are produced by dehydrating and ring closing this tetracarboxylic acid . Alkyl esters of the tetracarboxylic acid is prepared by reacting the tetracarboxylic acid and an alkanol.

[0010] Further, 2 ', 3', 5 ', 6'-tetrafluoro-3,4,3 ", 4" -tetramethyl- p -terphenyl is an organolithium derived from halogeno- o -xylene. compound with hexafluorobenzene is double cross-coupling-ring obtained. Further, the halogeno - o - instead of organolithium compounds derived from xylenes, halogeno - o - can be used a Grignard reagent derived from xylene.

Hereinafter, the manufacturing method will be described in detail.
First, 2 ', 3', 5 ', 6'-tetrafluoro-3,
4,3 ", 4" -tetramethyl- p -terphenyl is
Halogeno - o - metal lithium according to a conventional method of xylene or
Others o is reacted with an organolithium compound - was a xylylene ruri Ji <br/> um, is obtained by double cross-coupling-rings and hexafluorobenzene. Also similarly, halogeno - o - after a Grignard reagent is reacted with magnesium metal according to a conventional method xylene, also double cross-coupling-rings and hexafluorobenzene obtained. In addition, as halogen in halogeno- o -xylene, halogen other than fluorine, that is, chlorine, bromine, or iodine is preferable.

[0012] halogeno - o - the time of the reaction xylene and organolithium compound or metallic magnesium, a halogeno - o
-Lithium metal equal to or more than gram atom with respect to xylene,
Organolithium, or metallic magnesium is used.
If less than an equivalent gram atom is used, unreacted halogeno-ortho-xylene may form a by-product tetramethyl-biphenyl during double cross coupling .
This is not preferable in terms of the yield and purity of the target product. Metal remaining unreacted, it is preferable that removed by filtration before the normal double cross-coupling. When using organic lithium, use a glass filter under a nitrogen atmosphere, suspend and wash with petroleum ether, dissolve in ether, cool in an ethanol-dry ice bath, and recrystallize. preferable.

[0013] o - xylylene ruri lithium and o - xylylene luma grayed <br/> Neshiumu bromide the conventional reaction conditions for producing a temperature 0 ° C. ~ solvent reflux temperature, a reaction time of 1 to 10 hours.

[0014] The amount of hexafluorobenzene to be used in the double cross-coupling, as unreacted hexafluorobenzene does not remain, to the coupling
It is preferable to use 1 / 3-3 / 5 mol of the organic metal compound that.

[0015] Double cross-coupling reaction is o - xylene <br/> For re Ruri lithium, -78 ℃ ~0 ℃, preferably -3
The reaction is performed at 0 ° C. to −10 ° C., and the reaction time is usually 1 to 5 hours. When the reaction temperature is high, tetramethyl-biphenyl
Or it produces a tar, a yield of the desired product, in terms of purity problems. o - in the case of xylene luma magnesium bromide, carried out at 20 ℃ ~60 ℃, the reaction time is usually 30 to 60
Time. After the double cross-coupling reaction, it is preferable to take out water and an acid aqueous solution in order to remove a metal salt and then take out the product. The product can be purified by recrystallization with an aromatic solvent.

Next, the above products 2 ′, 3 ′,
5 ′, 6′-Tetrafluoro-3,4,3 ″, 4 ″ -tetramethyl- p -terphenyl is oxidized to give p -terphenyl-2 ′, 3 ′, 5 ′, 6′-tetrafluoro- 3,
4,3 ", 4" -tetracarboxylic acid is produced.

The oxidation is preferably a two-stage oxidation method in which nitric acid is oxidized and then permanganate is oxidized. For example, first 2 ',
3 ′, 5 ′, 6′-tetrafluoro-3,4,3 ″,
Nitric acid oxidation of 4 "-tetramethyl- p -terphenyl
This is performed at 70 to 180 ° C. for about 2 hours. After the reaction, the precipitate is filtered, extracted with an aqueous alkali solution, filtered, and the mother liquor is subjected to acid precipitation to obtain a mixture of the target substance, tetracarboxylic acid, and a reaction intermediate thereof. Then it was uniformly dissolved mixture into 5-7% of an aqueous alkaline solution to complete the reaction to the purpose Te tetracarboxylic acid permanganic acid oxidation. After filtering the by-produced manganese dioxide, p in acid precipitation process - terphenyl-2 ', 3', 5 ', 6'-tetra-fluoro-3,
4,3 ", 4" -tetracarboxylic acid is obtained.

Further, p -terphenyl-2 ′, 3 ′,
5 ', 6'-tetrafluoro-3,4,3 ", 4" - tetracarboxylic dianhydride is obtained by a tetracarboxylic acid dehydrated closed ring by conventional methods. For example, in acetic anhydride
After heating at 00 to 120 ° C for 0.5 to 1 hour, hot filtration,
Obtained by recrystallization. Esterification can also be performed by a conventional method.

The p -terphenyl-2 ′, 3 ′,
5 ', 6'-tetrafluoro-3,4,3 ", 4" - tetracarboxylic dianhydride, as well alone or in other tetracarboxylic dianhydride and tricarboxylic anhydride, such as polyimide It is preferably used as a raw acid anhydride component. Examples of the diamines forming a polyimide in combination with the above include the following diamines. These diamines are used alone or in combination of two or more,
Alternatively, it can be used in combination with other diamines or other amine compounds. By using the tetracarboxylic dianhydride of the present invention, an excellent fluorine-containing polyimide which has never been obtained can be obtained.

M-phenylenediamine, p-phenylenediamine, tetrafluoro-m-phenylenediamine,
Tetrafluoro-p-phenylenediamine, 4,4'-
Diaminobiphenyl, 4,4′-diaminooctafluorobiphenyl, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, bis (tetrafluoro-4-aminophenyl) ether, 2,2
-Bis (4-aminophenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) tetrafluorobenzene, 4,4'-bis (4-aminophenoxy) octafluorobiphenyl.

Hereinafter, the present invention will be described specifically with reference to Examples and the like, but the present invention is not limited to these Examples.

[0022]

EXAMPLES Example 1 2 ′, 3 ′, 5 ′, 6′-Tetrafluoro-3,4,4
Synthesis of 3 ", 4" -tetramethyl- p -terphenyl

[0023] 1) o-key synthesis drying tube silyl lithium, nitrogen inlet tube, 撹拌device, Dimroth condenser dropping funnel, after a two liter four-necked flask equipped with a thermometer was sufficiently dried under an atmosphere of dry nitrogen gas Then, 14.7 g of a lithium wire was added to 250 ml of dehydrated ether, and stirring was started. Next, 185 g of 4-bromo- o -xylene (purity 70%) and ether 50 were added from the dropping funnel.
0 cc of the mixture was added dropwise over 2 hours. Since heat is generated simultaneously with the dropwise addition, the reaction temperature is adjusted to 25 to 30 while cooling in an ice bath.
C. After the completion of the dropwise addition, the reaction was continued at 25 to 30 ° C. for 2 hours until metallic lithium disappeared.

[0024] 2) o - double cross-coupling of xylylene Ruri lithium and hexafluorobenzene reaction

Next, the reaction system was cooled to −30 ° C. in an ethanol-dry ice bath, and 75 g of hexafluorobenzene was added.
And a mixed solution of 500 cc of ether was dropped over 2 hours. During this time, the reaction temperature was kept at -20C to -30C. Further, the reaction was continued for 1 hour while maintaining the temperature. After completion of the reaction, an ice-cooled 0.5N aqueous hydrochloric acid solution was added, and the precipitated solid was separated by filtration. After further drying, recrystallization was performed with toluene. The yield was 86.6 g.

2 ', 3', 5 ', 6'-tetrafluoro-3,4,4 obtained by double cross coupling
3 ", 4" -tetramethyl- p -terphenyl has a purity of 97 to 98% (by HPLC, the same applies hereinafter), and a melting point (m
p) 182-183 ° C.

₁ H-NMR (90 MHz, CDCl ₃ ,
TMS): δ 7.25 ppm (S, 6H), δ 2.33
ppm (S, 12H), ₁₉ F-NMR (84 MHz, C
DCl ₃ , CFCl ₃ ): δ-145.1 ppm (S,
4F) .

Example 2 2 ', 3', 5 ', 6'-Tetrafluoro-3,4,4
Synthesis of 3 ", 4" -tetramethyl- p -terphenyl

[0029] 1) Synthesis apparatus o- xylylene luma magnesium bromide was used the same apparatus as that used in Example 1. 24.3 g of metallic magnesium and 250 cc of tetrahydrofuran were charged into a 2-liter 4-neck flask. Next, a mixed solution of 185 g of 4-bromo- o -xylene and 250 cc of tetrahydrofuran was added dropwise over 1 hour.
The reaction temperature was kept at 40 ° C. while cooling with an ice bath. After completion of the dropwise addition, the reaction was carried out for 5 hours while maintaining the temperature at 40 ° C., and the metal magnesium was completely reacted to synthesize a Grignard reagent.

[0030] 2) o-xylylene luma magnesium bromide and a mixture of hexafluorobenzene 75g of tetrahydrofuran 200cc leave the double cross-coupling reaction The reaction system of hexafluorobenzene was maintained at 40 ° C. for 1
It was dropped over time. After the completion of the dropwise addition, the reaction was continued at 40 ° C. for 50 hours. After completion of the reaction, 500 cc of toluene was added,
Ice-cooled water was added, liquid separation was performed, and the toluene layer was recrystallized, and 2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,
4,3 ", 4" -tetramethyl- p -terphenyl was obtained.

Example 3 Synthesis of p -terphenyl-2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,4,3 ″, 4 ″ -tetracarboxylic acid

20 g of 2 ', 3', 5 ', 6'-tetrafluoro-3,4,3 ", 4" -tetramethyl- p -terphenyl and 151 g of 35% nitric acid are placed in an autoclave at 170-180 ° C. For 2 hours. After the reaction, the precipitate was separated by filtration, extracted with a 5% aqueous alkali solution, filtered, and the mother liquor was subjected to acid precipitation with 36% hydrochloric acid. Next, 19.5 g of this reaction intermediate was dissolved in 200 g of a 7% aqueous sodium hydroxide solution, and 22 g of potassium permanganate was gradually added at 80 ° C. over 12 hours while confirming disappearance of purple color. After the reaction, manganese dioxide was filtered off, subjected to acid precipitation with 36% hydrochloric acid, washed with water and dried to obtain 5.2 g of a fine white powder.

The IR (KBr tablet method) of this product was 1700
cm ^-1, showed a strong absorption peak at 1250 cm ^-1, it was confirmed that a carboxylic acid.

Then, methanol 6 was added to the white fine powder.
After adding 00 cc and 30 ml of 96% sulfuric acid, the mixture was refluxed for 8 hours to carry out methyl esterification. Further, recrystallization was performed with methanol to obtain 3.3 g of a 97% pure tetramethyl esterified product. The mp of this one is 199-20
It was 0 ° C.

₁ H-NMR (90 MHz, CDCl ₃ ,
T M S): δ 7.65 to 7.93 ppm (m, 6H),
δ 3.95 ppm (S, 12H) , ₁₉ F-NMR (8
4.1 MHz, CDCl ₃ , CFCl ₃ ): δ-14
3.3 ppm (S, 4F) .

[0036] The following methyl ester, mixture of water 60 g, 1 liter of methanol and potassium hydroxide 30g
The mixture was refluxed for 8 hours to hydrolyze. After drying, a differential thermal analysis revealed an endothermic peak at 276 ° C.

Example 4 Synthesis of p -terphenyl-2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,4,3 ″, 4 ″ -tetracarboxylic dianhydride 2.75 g of the obtained white powder was acetic anhydride 10
The mother liquor was slowly heated at 0 ° C. for 10 to 15 minutes at 115 ° C., and after hot filtration, the mother liquor was allowed to cool. As a result, a light brown powder was precipitated to obtain 1.94 g of a powder. FIG. 1 shows the infrared absorption spectrum (KBr tablet method) of this product. 1700cm
Peak of carboxylic acid disappeared ^-1, appeared peaks characteristic is two to 1800cm acid anhydride in the vicinity of ^-1.

₁ H-NMR (90 MHz, DMSO-d ₆
, TMS): δ8.26 to 8.37 ppm (m, 6
H) , ₁₉ F-NMR (84.1 MHz, DMSO-d
₆ , CFCl ₃ ): δ 142.6 ppm (S, 4F) .

When a differential thermal analysis was performed, an endothermic peak appeared at 275 ° C. Elemental analysis revealed carbon 59.55.
%, 1.42% hydrogen and the theoretical value of carbon is 59.73.
%, 1.36% hydrogen, and p -terphenyl-
2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,4
It was confirmed to be 3 ", 4" -tetracarboxylic dianhydride.

[0040]

According to the present invention, p -terphenyl-2 ',
3 ′, 5 ′, 6′-tetrafluoro-3,4,3 ″,
4 ″ -Tetracarboxylic acid or its dianhydride is a novel fluorine-containing aromatic carboxylic acid dianhydride, and is extremely useful as a raw material for a polyimide resin or the like which has excellent heat resistance, improves moisture resistance, and lowers the dielectric constant. It is useful.

[Brief description of the drawings]

FIG. 1 shows p -terphenyl-2 ′, 3 ′, 5 ′,
6 is a graph showing an infrared absorption spectrum of 6′-tetrafluoro-3,4,3 ″, 4 ″ -tetracarboxylic dianhydride.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C07C 63/72 C07C 51/275 C07D 307/89 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] (1) p -terphenyl-2 ′, 3 ′, 5 ′,
6'-tetrafluoro-3,4,3 ", 4" -tetracarboxylic acid, an anhydride thereof, or an alkyl ester thereof. 2. A 2 ', 3', 5 ', 6'-tetrafluoro-3,4,3 ", 4" - tetramethyl - p - terphenyl - p, which comprises oxidizing a terphenyl -
2 ′, 3 ′, 5 ′, 6′-tetrafluoro-3,4
A method for producing 3 ", 4" -tetracarboxylic acid. 3. 2 ', 3', 5 ', 6'-Tetrafluoro-3,4,3 ", 4" -tetramethyl- p -terphenyl.