JPH0578289A - 2,7-bis(4-aminophenoxy) naphthalene and its production - Google Patents

Abstract

PURPOSE:To provide a new compound useful as a raw material for polyimides having excellent flexibility and moldability. CONSTITUTION:2,7-Bis (4-aminophenoxy) naphthalene of formula I. The compound of formula I is obtained by reacting a p-halogeno-nitro-benzene of formula II (X is halogen) with 2,7-dihydroxynaphthalene in the presence of a basic substance such as an alkali metal hydroxide in an aprotic polar solvent such as DMF and subsequently reducing the obtained compound of formula III

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel 2,7-bis (4-aminophenoxy) naphthalene and a method for producing the same. This 2,7-bis (4-aminophenoxy) naphthalene (hereinafter abbreviated as BAPN) is used as a raw material for polyamides, polyimides, polyamideimides, bismaleimides and epoxy resins, in addition to other maleimide compounds and epoxy compounds. It can be used as a curing agent.

[0002]

2. Description of the Related Art This BAPN is a compound that has not been known so far. However, the positional isomer pair 2,6-bis (4-aminophenoxy) naphthalene is a known compound, for example, JP-A 64-29431 and 64-64.
33166 and the like.

[0003]

In recent years, heat-resistant resin materials are required to satisfy not only thermal and mechanical performances but also various performances represented by flexibility and molding processability in the use as a composite material. ing. Polyimide resin has been attracting attention as such a material, but polyimide resin has a drawback that it is difficult to perform molding, although it has high performance. For example, the most typical aromatic polyimide (Du, Pont, trade name "Vespel") consisting of 4,4'-diaminodiphenyl ether and pyromellitic dianhydride is insoluble and infusible, and is therefore referred to as powder sintering. Use a special method. However, with this method, it is difficult to obtain a processed product having a complicated shape, and in order to obtain a satisfactory molded product, the molded product must be further finished by cutting or the like, which is a major drawback that the processing cost becomes high. ..

For the purpose of improving such drawbacks, various methods for improving the starting diamine component have been tried. For example, it is a method of introducing an ether bond group into the molecule or increasing the number of molecular chains. However, it is hard to say that what has been attempted up to now has found one that completely satisfies the required performance such as flexibility and moldability. On the other hand, some polymers having a naphthalene skeleton are known to have liquid crystallinity, and are considered as a means for improving flexibility and molding processability. In addition, compared to a linear bonding mode, a bonding mode having a folded structure can be expected to improve flexibility.

Therefore, there is a demand for a diamine compound as a resin raw material which is a combination of these methods and which can sufficiently satisfy the flexibility and molding processability.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems, and as a result, completed the present invention. That is, the present invention uses the formula (1)

[0007]

[Chemical 4] 2,7-bis (4-aminophenoxy) naphthalene represented by the formula (2)

[0008]

[Chemical 5] Formula (3) (Chemical Formula 6) obtained by reacting p-halogenonitrobenzene represented by the formula with 2,7-dihydroxynaphthalene in the presence of a base in an aprotic polar solvent.

[0009]

[Chemical 6] The present invention provides a method for producing 2,7-bis (4-aminophenoxy) naphthalene of the formula (1) by reducing 2,7-bis (4-nitrophenoxy) naphthalene represented by

In the BAPN of the present invention, two benzene rings are connected to a naphthalene ring by ether groups, and the ether group and amino groups at both ends are located at the para position. Therefore, the polyimide resin obtained from this diamine is excellent in heat resistance and mechanical properties, and the substitution position of the ether group on the naphthalene skeleton is at the 2,7-position, so that the molding processability derived from the folded structure of the molecule is high. Have. For example, a polyimide obtained from 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride has a 5% weight loss temperature of 555 ° C. showing heat resistance,
The melt viscosity by a Koka type flow tester showing moldability was 9000 poise at 400 ° C.

This BAPN is 2,7 represented by the equation (2).
-Bis (4-nitrophenoxy) naphthalene 2,7-
It can be obtained by a condensation reaction of dihydroxynaphthalene and p-halogenonitrobenzene, which can be reduced to produce. The method for producing BAPN of the present invention will be described in detail. 2,7-dihydroxynaphthalene is condensed with p-halogenonitrobenzene in an aprotic polar solvent to give 2,7-bis (4-nitrophenoxy) naphthalene. In the step of producing (reaction of the first step), 2,7-
For dihydroxynaphthalene, the other raw material p-
Nitrohalogenobenzene is used in an amount of 2.0 to 3.0 mol, preferably 2.05 to 2.5 mol. This p
Specific examples of the -halogenonitrobenzene include p-fluoronitrobenzene, p-chloronitrobenzene, p-
-Bromonitrobenzene, p-iodonitrobenzene and the like, and industrially p-chloronitrobenzene is preferable.

The basic substance used in this first step reaction is an alkali metal oxide, hydroxide, carbonate,
Hydrogen carbonates, hydrides and alkoxides are preferable, and hydroxides and carbonates are preferable. Specifically, sodium oxide, lithium oxide, potassium hydroxide, sodium hydroxide, lithium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, sodium hydride, potassium-t-butoxide, sodium methoxide. , Sodium ethoxide, etc. are used. The amount used is usually 2 equivalents or more, preferably 2.05-2.5 equivalents in small excess with respect to the starting 2,7-dihydroxynaphthalene. In this reaction, quaternary ammonium salt, quaternary phosphorus salt, or macrocyclic polyether such as crown ether, nitrogen-containing macrocyclic polyether such as cryptate, nitrogen-containing chain polyether, polyethylene glycol and its alkyl ether Such phase transfer catalyst, copper powder, copper salt and the like may be added as a reaction accelerator. An aprotic polar solvent is used as the reaction solvent. Specifically, N-methylformamide, N, N
-Dimethylformamide, dimethyl sulfoxide, dimethyl sulfone, sulfolane, 1-methyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, N,
Examples include N, N ′, N′-tetramethylurea, hexamethylphosphotriamide, N-methylpyrrolidone, and the like. The amount of these solvents used is not particularly limited,
Usually, 1 to 10 times the weight of the raw material is sufficient.

In carrying out the reaction, it is possible to add a small amount of an azeotropic dehydrating agent such as toluene and carry out the reaction while azeotropically dehydrating under heating under reflux. The reaction temperature is usually 20 to 240.
C., preferably 60 to 160.degree. C., and the reaction time is 1 to 10 hours. The end point of the reaction can be determined by thin layer chromatography, high performance liquid chromatography and the like. After completion of the reaction, the reaction solution is concentrated or discharged as it is into water and the precipitated product is filtered to obtain crude 2,7-bis (4-nitrophenoxy) naphthalene.

Next, a method (second step reaction) of reducing the obtained 2,7-bis (4-nitrophenoxy) naphthalene to obtain BAPN will be described. In this reaction, usually, a method of reducing a nitro group to an amino group (for example, New Experimental Chemistry Course, Volume 15, Oxidation and Reduction [II], Maruzen (197).
Although 7)) can be applied, catalytic reduction or hydrazine reduction is industrially preferable. In the case of catalytic reduction, the reduction catalyst used is a metal catalyst generally used for catalytic reduction, for example, nickel, palladium, platinum, rhodium,
Ruthenium, cobalt, copper, etc. can be used. It is industrially preferable to use a palladium catalyst. These catalysts can be used in a metal state, but usually, they are used by supporting them on the surface of a carrier such as carbon, barium sulfate, silica gel, alumina, and celite, and nickel, cobalt, copper, etc. are used as Raney. It is also used as a catalyst. The amount of the catalyst used is not particularly limited, but is in the range of 0.01 to 10% by weight with respect to the raw material,
Usually, it is in the range of 2 to 8% by weight when it is used in a metal state, and in the range of 0.1 to 5% by weight when it is supported on a carrier.

The reaction solvent is not particularly limited as long as it is inert to the reaction. For example, methanol, ethanol, alcohols such as isopropyl alcohol, ethylene glycol, glycols such as propylene glycol, ethers, dioxane, tetrahydrofuran, ethers such as methyl cellosolve, hexane, aliphatic hydrocarbons such as cyclohexane, benzene, toluene, Aromatic hydrocarbons such as xylene, esters such as ethyl acetate and butyl acetate, and aprotic polar solvents such as N, N-dimethylformamide can be used. When a reaction solvent which is immiscible with water is used and the reaction proceeds slowly, it can be accelerated by adding a commonly used phase transfer catalyst such as a quaternary ammonium salt or a quaternary phosphonium salt.

The amount of the solvent used is not particularly limited and is sufficient to suspend or completely dissolve the raw materials, but usually 0.5 to 10 times by weight of the raw materials is sufficient. The reaction temperature is not particularly limited. Generally 2
The range of 0 to 200 ° C, particularly 20 to 100 ° C is preferable.
The reaction pressure is usually from atmospheric pressure to 50 atm.
In the reaction, a catalyst is usually added in a state where raw materials are dissolved or suspended in a solvent, and then hydrogen is introduced at a predetermined temperature with stirring to carry out a reduction reaction. The end point of the reaction can be determined by the amount of absorbed hydrogen, thin layer chromatography, high performance liquid chromatography, or the like.

On the other hand, in the case of hydrazine reduction, the hydrazine is usually used in a small excess with respect to the theoretical amount, and preferably 1.2 to 2 times the amount of hydrazine is used for the reduction reaction. As the catalyst, the above-mentioned metal catalyst or iron chloride catalyst generally used for catalytic reduction is used. Specifically, palladium /
Activated carbon, platinum / activated carbon or catalysts in which ferric chloride is adsorbed on activated carbon are used. The amount of the catalyst used is not particularly limited and is usually in the range of 0.01 to 30% by weight as a metal with respect to the nitro compound as the raw material.

As the reaction solvent, the same solvent as in the case of catalytic reduction can be used. The reaction temperature is not particularly limited and is generally in the range of 20 to 150 ° C, particularly 40 to 12
0 ° C is preferred. In the reaction, usually, a catalyst is added in a state where raw materials are dissolved or suspended in a solvent, and then hydrazine is added dropwise at a predetermined temperature under stirring to carry out a reduction reaction. The end point of the reaction can be determined by thin layer chromatography or the like. After completion of the reaction, the reaction solution is filtered while hot to remove the catalyst, and then the solvent is distilled off if necessary, followed by cooling or diluting with water or the like to obtain the desired diamine in good yield. Hereinafter, the method of the present invention will be described more specifically by way of examples.

[0019]

【Example】

Example 1 [First-step reaction] In a glass reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser with a water separator, 160.1 g (1.0 mol) of 2,7-dihydroxynaphthalene, p- Nitrochlorobenzene 346.7 g (2.2 mol), potassium carbonate 165.6 g (1.2 mol), N, N-dimethylformamide 500 ml and toluene 75 ml were charged, and the temperature was raised to an internal temperature of 140 to 145 ° C. And kept stirring for 4 hours. During this time, water produced in the reaction was collected by a water separator provided in the reflux condenser. After completion of the reaction, the internal temperature was gradually cooled to 120 ° C., and then the mixture was filtered while hot to remove inorganic salts, and washed with 180 ml of N, N-dimethylformamide. After adding 125 ml of water to the filtrate, 2
When gradually cooled to 5 ° C., crystals were precipitated. This was filtered, washed and dried to obtain 386.7 g of crude 2,7-bis (4-nitrophenoxy) naphthalene (yield 96.1%). This was recrystallized with 2 liters of 2-methoxyethanol to obtain 352.6 g (yield 87.6%) of pure 2,7-bis (4-nitrophenoxy) naphthalene. Purity by high performance liquid chromatography is 99.9% (Are
a%). Melting point 169.8-
170.6 ° C. [Second-stage reaction] Next, 120.7 g of the above 2,7-bis (4-nitrophenoxy) naphthalene was placed in a glass reaction container equipped with a stirrer, a thermometer, and a reflux condenser.
(0.3 mol) and 600 g of 2-methoxyethanol were charged and the internal temperature was raised to 100 ° C. with stirring. Then 6.0 g of activated carbon and 0.27 g of ferric chloride were added,
While keeping the internal temperature at 90 to 110 ° C, 93.8 g (1.5
80% aqueous hydrazine solution (mol) was added dropwise over 2 hours.
After completion of the dropping, the reaction was completed by continuing stirring for 1 hour.
Next, the reaction solution was filtered while hot at the same temperature, and 327 g of water was added to the resulting solution and gradually cooled to 25 ° C., whereby crystals were precipitated. This was filtered, washed, and dried to give 91.9 g (yield 89.5%) of 2,7-bis (4-aminophenoxy).
I got naphthalene. The purity measured by high performance liquid chromatography was 99.0% (Area%). Melting point 170.9 to 172.4 ° C. Elemental analysis result C H N calculated value (%) 77.2 5.3 8.2 Measured value (%) 77.0 5.6 8.1

Example 2 [First-step reaction] In a glass reaction vessel equipped with a stirrer, a thermometer and a reflux condenser with a water separator, 80.1 g (0.5 mol) of 2,7-dihydroxynaphthalene was added. , P-nitrobromobenzene 222.3 g (1.1 mol), potassium carbonate 82.8 g (0.6 g), N, N-dimethylformamide 250 ml and toluene 38 ml were charged, and the internal temperature was adjusted to 140 to 145 ° C. The temperature was raised. While maintaining the same temperature, stirring was continued for 5 hours to complete the reaction. During this time, water produced in the reaction was collected by a water separator provided in the reflux condenser. After the reaction was completed, the internal temperature was cooled to 130 ° C., and the mixture was filtered while hot to remove inorganic salts, and 90 ml of N, N-
It was washed with dimethylformamide. 62.5 ml in the filtrate
When water was added dropwise and the mixture was cooled to 25 ° C, crystals were precipitated. This was filtered, washed and dried to obtain 183.5 g of 2,7-bis (4-nitrophenoxy) naphthalene (yield 91.2%). Recrystallization from 950 ml of 2-methoxyethanol gave 171.8 g (yield 85.2%) of pure 2,7-bis (4-nitrophenoxy) naphthalene. Purity by high performance liquid chromatography is 99.
It was 4%. [Second-stage reaction] Next, in a glass closed container equipped with a stirrer, a reflux condenser, and a thermometer, 80.5 g (0.
2 mol), 5% palladium / activated carbon catalyst (ME
(Chemcat Company) 1.6 g and 2-methoxyethanol 480 g were charged, and hydrogen was introduced with stirring at a temperature of 35 to 40 ° C. to absorb 27.1 liters (1.21 mol) of hydrogen in about 9 hours. did. After completion of the reaction, the reaction solution was filtered at the same temperature to remove the catalyst. Next, the temperature of this solution is raised to 70 ° C., and 250 g of water is added to add 25
When gradually cooled to ° C, crystals were precipitated. This was filtered, washed and then dried to obtain 59.1 g (yield 86.3%) of 2,7-bis (4-aminophenoxy) naphthalene. The purity measured by high performance liquid chromatography was 99.0%.

Application Example 1 3,7-bis (4-aminophenoxy) naphthalene 34.2 g (0.1 mol), 3, in a container equipped with a stirrer, a reflux condenser, a water separator and a nitrogen inlet tube. 3 ', 4, 4'
-Diphenyl ether tetracarboxylic dianhydride 29.
45 g (0.095 mol), phthalic anhydride 1.78 g
1.4 g of (0.012 mol) γ-picoline and 255 g of m-cresol were charged, and the mixture was heated to 145 ° C. with stirring under a nitrogen atmosphere. During this time, it was confirmed that about 3.5 cc of water was distilled. Further, the reaction was carried out at 140 to 150 ° C. for 4 hours. Then, the mixture was cooled to room temperature, discharged into about 1.5 liters of methyl ethyl ketone, and then filtered. After discharging this polyimide powder to methyl ethyl ketone, 1
60.6 g (yield 98.
5%) of polyimide powder was obtained. The polyimide powder thus obtained had an inherent viscosity of 0.51 dl / g. The logarithmic viscosity is a value measured at 35 ° C. after 0.50 g of polyimide powder was dissolved by heating in 100 ml of a mixed solvent of p-chlorophenol / phenol (weight ratio 9/1). The glass transition temperature (Tg) of this polyimide was 235 ° C. The 5% weight loss temperature in air was 555 ° C. In the infrared absorption spectrum of this polyimide powder, the characteristic absorption bands of imide are 1780 cm ⁻¹ and 1720 cm.
Absorption around ^-1 was noticeable.

The elemental analysis values of the obtained polyimide powder were as follows. Elemental analysis result CHN calculated value (%) 74.1 3.3 4.6 measured value (%) 74.0 3.4 4.6 This polyimide powder is insoluble in halogenated hydrocarbons such as methylene chloride and chloroform. Met.

Furthermore, the melt viscosity of this polyimide was measured using a Koka type flow tester, using a load of 100 kg and an orifice of 0.1 cm in diameter and 1 cm in length. There was 9000 poise at 400 ° C., and the obtained strand was reddish brown transparent and rich in flexibility.

[0024]

EFFECTS OF THE INVENTION 2,7-Bis (4-aminophenoxy) naphthalene according to the present invention is a novel substance, and a highly heat-resistant polyimide resin excellent in flexibility and moldability is provided by using it as a raw material. be able to.

Claims (5)

[Claims] 1. Formula (1) (Formula 1) 2,7-bis (4-aminophenoxy) naphthalene represented by 2. Formula (2) (Formula 2) Formula (3) (Chemical Formula 2) obtained by reacting p-halogenonitrobenzene represented by and 2,7-dihydroxynaphthalene in the presence of a basic substance in an aprotic polar solvent Of 2,7-bis (4-aminophenoxy) naphthalene represented by the formula (1), which is obtained by reducing 2,7-bis (4-nitrophenoxy) naphthalene. Production method. 3. The basic substance is an oxide of an alkali metal,
The 2,7-bis (4-aminophenoxy) naphthalene according to claim 2, which is at least one selected from the group consisting of hydroxides, carbonates, hydrogen carbonates, hydrides and alkoxides. Manufacturing method. 4. The production of 2,7-bis (4-aminophenoxy) naphthalene according to claim 3, wherein 2 equivalents or more of a basic substance is used with respect to 1 equivalent of 2,7-dihydroxynaphthalene. Method. 5. The aprotic polar solvent is N-methylformamide, N, N-dimethylformamide, dimethyl sulfoxide, dimethyl sulfone, sulfolane, 1-methyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinium. The 2,7-bis (4) according to claim 2, which is at least one selected from the group consisting of non-, N, N, N ', N'-tetramethylurea, hexamethylphosphotriamide and N-methylpyrrolidone. -Method for producing aminophenoxy) naphthalene.