JP2567037B2 - 1,1-diaminodiphenylethane and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel 1,1-diaminodiphenylethane (hereinafter referred to as m-DDE) and a method for producing the same. More specifically, it relates to the provision of a useful m-DDE represented by formula (I) and a method for producing m-DDE by condensing 3-amino-α-methylbedyl alcohol and aniline in the presence of an acid catalyst.

This m-DDE is a curing agent for epoxy resin raw material or other epoxy compound, a bismaleimide raw material or other bismaleimide compound curing agent, an isocyanate compound raw material or other isocyanate compound curing agent and polyimide, polyamide. It can be used in various fields such as a raw material for polyamide-imide.

[Conventional technology]

Conventionally, 1,1-bis (4-aminophenyl) ethane has been known, but the meta-based compound of the present invention has not been known.

[Problems to be Solved by the Invention]

In recent years, in the fields of epoxy resins, addition-type polyimide resins, etc., cured resins having excellent mechanical strength, particularly impact resistance and bending strength, have been demanded. The matrix resin for heat-resistant composite materials is required to have the ability to withstand a momentary impact such as stress concentration, and ideally, elastic deformation like rubber is drawing attention as an important element. As a criterion for determining such elastic deformation, the elongation at break of the matrix resin is particularly important. The larger the elongation of the matrix resin, the more the defects of the reinforcing material such as glass fiber and carbon fiber required for the composite material can be compensated. That is, the strength of the entire composite material is improved. With respect to such required performances, para-type methylenedianiline, 1,1-bis (4-aminophenyl) ethane and the like which have hitherto been known cannot overcome the drawbacks.

Further, in these matrix resins and the like, in addition to heat resistance and dimensional stability, long-term storage stability is important, and it is required that deterioration due to light and oxygen in the air is small. This oxidation resistance is mainly derived from the structure of the resin, conventionally known diamine compounds having a methylene bond such as 4,4-methylenedianiline produced from aniline and formalin, Since it has a weak point of deterioration with time due to the light and oxygen, its use is limited.

The object of the present invention is to provide diamine compounds which do not have these disadvantages.

[Means for solving the problem]

The present inventors have completed the present invention as a result of intensive studies to achieve the above object.

That is, the present invention has the formula (I) Represented by 1,1-diaminophenylethane, particularly 1,1-wherein the bonding position of the amino group is at the 3,2'-position and / or the 3,4'-position.
Provision of diaminophenylethane and 3-amino-α
-Methylbenzyl alcohol and aniline are condensed in the presence of an acid catalyst, represented by formula (I) 1,
This is a method for producing 1-diaminodiphenylethane. .

When the m-DDE of the present invention is used as a curing agent for an epoxy resin or a bismaleimide compound, a high performance cured resin can be obtained.

For example, when the resin of the present invention is used as a curing agent for a bismaleimide compound, the cured resin has excellent mechanical strength and dimensional stability, and there is no problem with heat resistance and stability against light and oxygen in the air. . As a specific example, when the resin of the present invention is used as a curing agent for bismaleimide derived from methylenedianiline, impact resistance of the cured resin, thermal decomposition initiation temperature in air, moisture absorption rate Is superior to Kelimide 1050 (trade name: molding grade, manufactured by Rhone Poulenc) resin when methylenedianiline is used as a curing agent.

Further, when used as a curing agent for epoxy resin Epicoat 828 (manufactured by Ciel Chemical Co.) derived from bisphenol A, it is superior in bending strength, elongation and the like as compared with the case where methylenedianiline is used.

Therefore, the development of the m-DDE of the present invention made it possible to develop a high-performance composite material or the like that overcomes various problems that have been conventionally demanded but could not be solved.

 Next, a method for producing the m-DDE of the present invention will be described.

When 3-nitroacetophenone obtained by nitration of acetophenone is catalytically reduced, 3-amino-α-methylbedyl alcohol can be obtained in good yield. This 3-amino-
When α-methylbenzyl alcohol is reacted with aniline in the presence of an acid catalyst, the compound of formula (II) A compound with a secondary amine bond represented by is produced in the middle, which is further increased in (1) acid catalyst. (2) Raise the reaction temperature. (3) Prolong the reaction time. And the like, or a combination thereof, to give a m-DDE of the present invention represented by the formula (I).

This transfer reaction can be confirmed by tracing the methine proton by ¹ H-NMR or by observing the decrease of the compound of the formula (II) by high performance liquid chromatography.

The starting materials 3-amino-α-methylbenzyl alcohol and aniline are used in an amount of 3 to 20 mol, preferably 3 to 10 mol, of aniline to 1 mol of 3-amino-α-methylbenzyl alcohol. . The smaller the amount of aniline used, the lower the absorption rate of m-DDE. This is because 3-amino-α-methylbenzyl alcohol undergoes some self-condensation reaction, and the molar ratio with aniline is the volume. There are problems such as efficiency and the amount of catalyst used, and it is decided in consideration of economic efficiency.

As the acid catalyst, an inorganic or organic acid, particularly a mineral acid such as hydrochloric acid, phosphoric acid, sulfuric acid or nitric acid, or a Friedel-Crafts type catalyst such as zinc chloride, stannic chloride, aluminum chloride or ferric chloride, Organic sulphonic acids such as methanesulfonic acid or p-toluenesulfonic acid, and further super strong acids such as trifluoromethanesulfonic acid and Nafion H (trade name: manufactured by DuPont) may be used alone or in combination. . Industrially preferable is inexpensive hydrochloric acid. The amount of the catalyst used is 3-amino-α of the raw material.
-In the range of 1 mol% to 100 mol%, preferably 3 to 50 mol% based on the total amount of methylbenzyl alcohol and aniline.
Is. Although the reaction temperature is in the range of 50 to 220 ° C., a temperature of 100 ° C. or higher, preferably 120 ° C. or higher is required to cause the transfer reaction, and therefore, even if the condensation reaction is performed in the range of 50 to 220 ° C. Finally, it is necessary to age it at about 120-180 ° C. The reaction time is mostly required for the rearrangement reaction, and the condensation reaction can be carried out at about the elevated temperature. Therefore,
The time required for aging is 3 to 30 hours.

In the method for producing m-DDE of the present invention, the reaction can be carried out without a solvent. After completion of the reaction, the acid used as the catalyst is neutralized with a dilute alkaline aqueous solution such as an aqueous solution of caustic soda, an aqueous solution of potassium hydroxide and aqueous ammonia, and then separated. The desired product can be obtained by vacuum distillation.

The m-DDE obtained by the method of the present invention is obtained as a mixture of 3,4'-form and 2 ', 3-form, the composition ratio of which varies depending on the kind, amount or reaction temperature of the acid catalyst. Varies, but usually the ratio of 3,4'-body / 2 ', 3-body is 80/20 to 50
/ 50 (weight ratio). The larger the acid strength or the larger the amount of the acid catalyst, the more the 3,4′-form tends to increase and the 2 ′, 3-form tends to decrease. Moreover, the influence of the reaction temperature is not so large.

M obtained as a mixture of 3,4′-form and 2 ′, 3-form
-DDE can be isolated by any method such as distillation, column chromatography, and recrystallization. Therefore, the m-
The composition ratio of the 3,4′-form / 2 ′, 3-form when DDE is used is not limited to the above-mentioned ratio obtained by the reaction depending on the application, and can be freely selected in any ratio. is there.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 330.4 g of 3-nitroacetophenone in a closed container of 3
(2 mol), 5% Pd / C catalyst 13.2g and methanol 2000m
l and hydrogen was introduced with vigorous stirring. When the reaction temperature was maintained at 50-55 ° C for 12 hours, 179
Absorbed hydrogen. Since no more absorption was observed, it was terminated. Next, this reaction system was purged with nitrogen and then filtered to remove the catalyst. After the filtrate is concentrated, it is vacuum distilled to 3
255.2 g of -amino-α-methylbenzyl alcohol was obtained.

 Absorption rate 93%, boiling point 135-136 ℃ / 3mmHg, melting point 64-65 ℃ Elemental analysis results are as follows.

Elemental analysis value CHN calculated value (%) 70.05 8.08 10.21 Measured value (%) 70.52 8.10 10.14 Next, 68.6 g (0.5 mol) of this 3-amino-α-methylbenzyl alcohol and 372.4 g (4 mol) of aniline were added. Charged to the reactor, catalyst 23% 35% hydrochloric acid solution 234.6g (2.25mol)
Was added and the temperature was raised while introducing nitrogen gas. While removing distilled water to the outside of the system, the temperature was raised to 150 ° C and the reaction was carried out at the same temperature for 15 hours. After completion of the reaction, the mixture was cooled to 110 ° C., and 640 g of a 15% aqueous caustic soda solution was added thereto for neutralization. Since it was separated into two layers when left standing, the lower aqueous layer was separated and removed to obtain an upper reddish brown oily organic layer. The organic layer was vacuum distilled to obtain a pale yellow oily substance.

 Yield 81g, Boiling point 186-188 ℃ / 2mmHg Elemental analysis results were as follows.

Elemental analysis value (as C ₁₄ H ₁₆ N ₂ ) C H N calculated value (%) 79.2 7.6 13.2 Measured value (%) 79.7 7.7 12.7 The analysis results by high performance liquid chromatography were as follows.

A component 32.0% (area ratio) B component 67.3% (area ratio) Other 0.6% (area ratio) From this composition, A component and B component were separated by column chromatography.

When these were identified by ¹ H-NMR analysis, the A component was
1,1- (2,3'-diaminodiphenyl) ethane, B
It was confirmed that the component was 1,1- (3,4'-diaminodiphenyl) ethane. Component A has a melting point of 63-65 ° C and ¹ H-NMR
The results are as follows. Of ¹ H-NMR analysis (solvent CDC1 _3, internal standard TMS) ppm (δ) 1.60 (d, 3H, −CH Me −) 3.2 to 3.5 (m, 4H, NH ₂ ) 3.96 (q, 1H, −CH Me −) 6.48 (brs, 1H, 2′−H) 6.52 ( d, 1H, 3-H, J _3-4 = 7.8Hz) 6.63 (d, 2H, 4'-Hand6'-H, J _{4'-5 '} = J
_{6'-5 '} = 7.6Hz) 6.84 (t, 1H, 5-H, J _5-4 = J _5-6 = 7.5Hz) 7.07 (t, 1H, 5'-H, J _5'-4' = J _{5'-6 '} = 7.6H
z) 7.08 (t, 1H, 4-H, J _4-3 = J _4-5 = 7.5Hz) 7.28 (d, 1H, 6-H, J _6-5 = 7.5Hz) B component is liquid ¹ The result of 1 H-NMR is as follows. ¹ H-NMR (solvent CDC1 _3, internal standard TMS) ppm (δ) 1.55 (d, 3H, −CH Me −) 3.3 to 3.6 (m, 4H, NH ₂ ) 3.96 (q, 1H, − CH Me−) 6.47 to 6.52 (m, 2H, 2-Hand4-H ) 6.61 (d, 2H, 3'-Hand5'-H, J _{3'-2 '} = J
_{5'-6 '} = 8.5Hz) 6.63 (d, 1H, 6-H, J _6-5 = 7.6Hz) 7.00 (d, 2H, 2'and6'-H, J _2'-3' = J _{6 ' -5 '}
= 8.5Hz) 7.05 (t, 1H, 5-H, J _5-6 = J _5-4 = 7.6Hz) Example 2 68.5 g (3-amino-α-methylbenzyl alcohol obtained in this Example 1 0.5 mol) to aniline 465.5 g
(5 mol) 115 g of 35% hydrochloric acid aqueous solution (1.1 mol) as a catalyst
Was used in the same manner as in Example 1 except that the reaction was carried out at 140 to 150 ° C. for 24 hours to obtain the target product as a pale yellow oil.

Yield 85.5g (Yield 80.5%) Analysis result by high performance liquid chromatography 2,3 'body 46.6% (area ratio) 3,4' body 56.2% (area ratio) Other 0.2% (area ratio) Example 3 Example 186.2 g of aniline against 68.6 g (0.5 mol) of 3-amino-α-methylbenzyl alcohol obtained in 1.
(2 mol) and aniline sulfate 284.3 g (1 mol) were used and reacted at 120 to 140 ° C. for 9 hours.

Post-treatment after the reaction was carried out in the same manner as in Example 1 to obtain the desired product.

Yield 79.5g (Yield 75%) Analysis result by high performance liquid chromatography 2,3 'body 24.1% (area ratio) 3,4' body 75.8% (area ratio) Others 0.1% (area ratio) Use example 1 Example 40 parts by weight of m-DDE obtained in 1 and 100 parts by weight of bismaleimide-S (manufactured by Daiwa Kasei Kogyo) were mixed,
A prepolymer was prepared by heating and melting at 10 ° C. for 10 minutes.

The appearance, softening temperature, gelling time, and bulk specific gravity of this polymer are shown in Table 1 as Experimental Example 1. For comparison, the results obtained in the same manner with commercially available Kelimide-1050 (trade name: molding grade, manufactured by Nippon Polyimide Co., Ltd.) are shown in Table 1 as Comparative Experimental Example 1.

Next, each of the prepolymer and Kelimide-1050 was compression-molded at a temperature of 200 ° C. under a pressure of 40 kg / cm ² for 1 hour and then post-cured at 250 ° C. for 4 hours to obtain a cured test piece. Created. The mechanical strength and thermophysical properties of this test piece were measured. The results are shown in Table 1 as Experimental Example 1 and Comparative Experimental Example 1, respectively.

USE EXAMPLE 2 m-DDE obtained according to Examples 2 and 3 was epicoated 8
Used as a curing agent for 28 (manufactured by Ciel Kagaku). As a comparison 4,
4'-Methylenedianiline was used as well. These were compounded under the conditions shown in Table-2, and the mixture was cast to measure the mechanical properties of the cured resin after processing. The results are shown in Table-2.

[Effects of the Invention] As described above in detail, the cured composition using the m-DDE of the present invention does not impair heat resistance and is particularly excellent in elongation at break. It can be said that this is a material suitable as a matrix resin for composite materials, and sufficiently satisfies the high performance required in recent years. Further, since it can be produced from an inexpensive raw material by a simple process, it is suitable for industrial production, and supplying a useful meta-type diamine compound at low cost greatly contributes to the development of industry.

Claims (2)

(57) [Claims] 1. A formula (I) (However, the bonding position of the amino group is at the 3,2'-position and / or the 3,4'-position) 1,1-diaminodiphenylethane. 2. The method for producing 1,1-diaminodiphenylethane according to claim 1, wherein 3-amino-α-methylbedyl alcohol and aniline are condensed in the presence of an acid catalyst.