JPH062806B2 - Aminobenzylamine composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an aminobenzylamine composition which is liquid at room temperature. More specifically, it is an aminobenzylamine composition mainly composed of m-aminobenzylamine and p-aminobenzylamine which is liquid at room temperature and is excellent as a room-temperature curing type curing agent for use in a thermosetting composition. It relates to a composition.

[Conventional technology]

Aminobenzylamine is an important compound as a heat resistant resin raw material and an epoxy resin curing agent. On the other hand, as the epoxy resin composition, a room temperature curing type is widely used for paints, adhesives, casting, and the like.

However, the conventionally used room temperature curing type epoxy resin composition has a strong odor, absorbs carbon dioxide gas in the air during curing to cause curing failure, and the obtained cured product has poor heat resistance. It was limited in its use because

In order to solve such a defect, it has been proposed to increase the molecular weight of the curing agent, or to use an aromatic amine compound as the curing agent, which has been partially put into practical use.

For example, m-aminobenzylamine is used as a curing agent for epoxy resins, and its cured product is known to have extremely excellent heat resistance and adhesiveness (NR
L Report 6439, US Patent 3,317,468, US Patent 3,79
No. 4,540).

However, m-aminobenzylamine has a melting point of about
It is solid at 40 ℃ and room temperature.

Therefore, when it is used as a curing agent for an epoxy resin for the purpose as described above, the uniform mixing property into the composition is poor and the mixing is insufficient, and as a result, the reaction with the epoxy resin is uniformly and quickly performed. It does not proceed, and adhesiveness, paint adhesion, and molded product strength are not fully exhibited.

In order to improve such a defect, it has been attempted to use an organic solvent, but when volatilizing the organic solvent into the curing agent, there is a safety problem, and bubbles are generated in the resin portion,
Adhesion, paint adhesion, and molded product strength are degraded.

Further, it has been attempted to modify m-aminobenzylamine and use it as a liquid adduct, but a satisfactory one such as a decrease in adhesiveness has not been obtained yet.

[Problems to be solved by the invention]

The object of the present invention is to utilize the characteristics of m-aminobenzylamine as an epoxy resin curing agent, eliminate the disadvantage that it is a solid at room temperature, and use it as a room temperature curing type epoxy resin curing agent. It is to provide a composition.

[Means for solving problems]

In order to achieve the above-mentioned subject, the present inventors diligently studied. As a result, m-aminobenzylamine, which is solid at room temperature but has excellent performance as an epoxy resin curing agent, has not been known for its performance as an epoxy resin curing agent. When mixed,
Surprisingly, the mixture of the two is liquid at room temperature, while the reaction type of m-aminobenzylamine as an epoxy resin curing agent is hardly reduced, and depending on the mixing ratio, m-aminobenzylamine can be used alone. I found it to be excellent. That is, they have found an aminobenzylamine composition that is liquid at room temperature and is useful as a room temperature curable epoxy resin curing agent by mixing m-aminobenzylamine and p-aminobenzylamine.

The present invention provides an aminobenzylamine composition which is liquid at room temperature and comprises 10 to 70% by weight of m-aminobenzylamine and 30 to 90% by weight of p-aminobenzylamine. -Aminobenzylamine:
It is an aminobenzylamine composition which is liquid at room temperature and comprises 95% by weight or more of an aminobenzylamine mixture having a ratio of p-aminobenzylamine of 70 to 10:30 to 90 and 5% by weight or less of o-aminobenzylamine. It is an aminobenzylamine composition that is liquid at room temperature and is used as a curing agent for resins.

In the composition of the present invention, o-, m- and p-aminobenzylamine is not particularly limited in the production method thereof, and can be produced, for example, by the following known method.

That is, m-aminobenzylamine is produced by obtaining m-nitrobenzaldoxime from m-nitrobenzaldehyde and reducing it using Raney nickel catalyst (JR Griffith et al., NRL Report 6439), and p-aminobenzylamine. Is produced by reducing p-aminobenzonitrile with lithium aluminum hydride [NC Brown et al., J. Medicinal Chem., 20, 1189 (197).
7)], o-Aminobenzylamine is produced by reducing o-nitrobenzylamine with red phosphorus and hydriodic acid [S. Gabriel et al., Ber., 37, 3643-3645 (1904)].

The composition of the present invention comprises 10-70% by weight of m-aminobenzylamine and 30-90% by weight of p-aminobenzylamine, preferably 20-60% by weight of m-aminobenzylamine and 40-80% of p-aminobenzylamine. An aminobenzylamine composition obtained by mixing the composition with 95% by weight, and 95% or more of this composition and
-Aminobenzylamine composition comprising 5% by weight or more of aminobenzylamine.

Therefore, in order to obtain such a composition, separately produced o-, m- or p-aminobenzylamine can be obtained by mixing with the above composition.

In addition, aminobenzylamine may be produced as a mixture. That is, when benzylamine is nitrated, nitrobenzylamine is produced as a mixture of o-, m- and p-isomers, so the reaction solution is discharged into water to mainly precipitate m- and p-isomers. A mixture of nitrobenzylamines obtained by isolating the above is catalytically reduced to obtain a mixture consisting mainly of m-aminobenzylamine and p-aminobenzylamine.

Therefore, the aminobenzylamine composition thus obtained is used as it is, or, if appropriate, separately produced m- or p-aminobenzylamine, or o-.
Aminobenzylamine is added to prepare an aminobenzylamine composition having the above composition range.

The aminobenzylamine composition obtained as described above is at room temperature, that is, 0 ° C or higher and 35 ° C or lower, usually 10 to 30 ° C.
It is liquid in the temperature range of ° C.

The liquid composition of the present invention can be left at room temperature and kept in a liquid state for a long time. For example, even if it is stored at around 20 ° C for 7 days, it remains liquid and does not solidify at all.

Further, the effect of the composition of the present invention as an epoxy resin curing agent is not significantly reduced by the inclusion of p-aminobenzylamine, and the effect is the phase of m-aminobenzylamine and p-aminobenzylamine. It is possible to obtain an effect that exceeds the additive effect.

Moreover, since it is liquid at room temperature, it can be effectively applied to a room temperature curable epoxy resin composition.

When the composition ratio is out of the above range, for example, when the ratio of p-aminobenzylamine is increased, it is liquid at room temperature, but the cured product using this has poor thermal stability and long-term heat resistance. .

Further, also in the composition of the present invention containing 5% by weight or less of o-aminobenzylamine, the composition is liquid at room temperature and the performance as a curing agent is maintained.

However, when the proportion of o-aminobenzylamine is increased, the performance as a curing agent deteriorates, which is not preferable.

On the other hand, when the proportion of m-aminobenzylamine exceeds the above range, it does not solidify immediately, but it may solidify during storage or during work, which is not preferable.

As the epoxy resin that can use the aminobenzylamine composition of the present invention as a curing agent, an amine-based epoxy resin,
Phenolic epoxy resin, alcohol epoxy resin, unsaturated compound epoxy resin, glycidyl ester epoxy resin, urethane epoxy resin and other epoxy resins are listed, and good curability for any kind of epoxy resin. give.

[Action]

Although the aminobenzylamine composition of the present invention is excellent in performance as an epoxy resin curing agent, it is a solid at room temperature, and therefore it has a limited application to m-aminobenzylamine. Aminobenzylamine or a mixture of a small amount of o-aminobenzylamine, which is liquid at room temperature and has excellent performance as an epoxy resin curing agent.

Therefore, when the aminobenzylamine composition of the present invention is used as an epoxy resin curing agent, it can be cured at room temperature, and the odor problem such as xylylenediamine, which has been widely used in the conventional room temperature curing type epoxy resin curing agent, is a problem. It gives good curing performance to various epoxy resins without any problems of toxicity, absorption of carbon dioxide gas in the air to form carbonates, and curing failure. Fast curing speed and good workability. Therefore, the thermal decomposition property of the cured product is very small, and the heat resistance and thermal stability are excellent.

〔Example〕

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

Synthesis Example 1 52.9 g of p-nitrobenzaldehyde in 100 ml of methanol
(0.35 mol) was dissolved, and then while maintaining the temperature at 30 ° C, 27.8 g (0.38 mol) of hydroxylamine hydrochloride and 35
The ml solution was added dropwise over 30 minutes. After continuous stirring at the same temperature for 2 hours, the mixture was diluted with 300 ml of water. The precipitated white crystals were filtered and dried to give 55 g (yield 94.7
%) Of p-nitrobenzaldoxime.

Next, this p-nitrobenzaldoxime was charged into an autoclave together with 5 g of Raney nickel catalyst and 500 ml of methanol, and the temperature was 25 to 30 ° C. with vigorous stirring.
The reduction reaction was carried out at a hydrogen pressure of 30 to 50 kg / cm ² for 3 hours. After completion of the reaction, remove the catalyst by filtration and distill to a boiling point of 129.5-1.
18.9 g of a pale yellow oily fraction at 30 ° C./5 to 6 mmHg was obtained. This is p-aminobenzylamine, and the total yield is 44.2%.
Is.

Synthesis Example 2 19.1 g of m-aminobenzylamine was obtained in the same manner as in Example 1 except that m-nitrobenzaldehyde was used as the starting material. Yield 44.7%, melting point 40-43 ° C.

Example 1 Table 1 shows the results of mixing p-aminobenzylamine and m-aminobenzylamine obtained in Synthesis Examples 1 and 2 and storing the mixture at a constant temperature for 7 days.

Synthesis Example 3 At a temperature of 0 ° C. or lower, 107 g (1 mol) of benzylamine was added to 98
% Nitric acid 643 g (10 mol) was added dropwise over 5 hours. After completion of the dropping, the reaction was completed by stirring for 3 hours at a temperature of 20 to 25 ° C.

Next, the reaction solution was discharged into 750 g of ice water, and the precipitated crystals were filtered and washed with a saline solution to obtain 254 g of wet crystals of nitrobenzylamine nitrate (solid content: 61%).

Next, this nitrobenzylamine nitrate was charged into a reduction vessel together with 1.4 g of 5% Pd / C catalyst and 360 ml of water, and the reduction reaction was carried out at a temperature of 25 to 30 ° C. for 7 hours while introducing hydrogen. After completion of the reaction, the mixture was heated to 50 ° C. and filtered to remove the catalyst, and 32 g of granular sodium hydroxide was added to the filtrate for neutralization. Since it separated into two layers upon standing, the lower layer was removed, and the upper layer was distilled to obtain 79.4 g (total yield 65%) of a colorless transparent oily fraction at 130 to 140 ° C / 5 to 7 mmHg. This is a mixture of aminobenzylamines, m-aminobenzylamine 41.3%, p-aminobenzylamine 57.6%, o-aminobenzylamine by gas chromatographic analysis.
The composition was 1.1%. This product was liquid even when stored at 5 ° C. for 7 days.

Synthesis Example 4 At a temperature of 0 ° C. or lower, 107 g (1 mol) of benzylamine was added to 9
Nitration was carried out by dropping into a mixed acid of 8% nitric acid 77 g (1.2 mol) and 98% sulfuric acid 300 g (3 mol), and treated in the same manner as in Synthesis Example 3 to obtain 218 g of wet crystals of nitrobenzylamine sulfate. Obtained.

This was subjected to reduction and post-treatment in the same manner as in Synthesis Example 3 to give a colorless and transparent aminobenzylamine mixture 70.8 (total yield: 5
8.0%) obtained.

Gas chromatography analysis showed m-aminobenzylamine 48.5%, p-aminobenzylamine 50.2%,
The composition was 1.3% of o-aminobenzylamine. This product was liquid even when stored at 5 ° C. for 7 days.

Synthetic Example 4 121 g of nitric acid and potassium nitrate by nitration of benzylamine
1.2-dichloroethane as solvent instead of (1 mol)
The same procedure as in Example 3 was carried out except that 400 ml was used, and colorless and transparent oily m-aminobenzylamine 59.5%, p-aminobenzylamine 36.0%, o-aminobenzylamine 4.5
% Composition. This product was liquid even when stored at 5 ° C. for 7 days.

Examples 2 to 6 and Comparative Examples 1 and 2 Amino epoxy resin made of diaminophenylmethane and epichlorohydrin [trade name, Epotote YH-
434 (Toto Kasei)] 100 parts and 25 parts of various aminobenzylamines obtained in Example 1 and Synthesis Examples 1 to 5 are mixed to cure at room temperature (time until tackiness disappears) and one week after curing. After standing, the glass transition temperature was determined by a dynamic viscoelasticity test. In addition, the thermal decomposition property of the cured product
− Calculated by Tg (air).

The results are shown in Table 2.

[Effects of the Invention] As described in detail above, the aminobenzylamine composition of the present invention has excellent workability as a curing agent for epoxy resins and excellent properties of the curing agent, and is not toxic. It is suitable as a curing agent for resins.

Moreover, since the manufacturing method is easy, the versatility is extremely large.

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Claims (2)

[Claims] 1. An aminobenzylamine composition for an epoxy resin which is liquid at room temperature and comprises 10 to 70% by weight of m-aminobenzylamine and 30 to 90% by weight of p-aminobenzylamine. 2. A room temperature mixture comprising 95% by weight or more of an aminobenzylamine mixture having a ratio of m-aminobenzylamine: p-aminobenzylamine of 70 to 10:30 to 90 and 5% by weight or less of o-aminobenzylamine. Aminobenzylamine composition for liquid epoxy resin.