2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine, a process for its production and use

Abstract

A compound of the structural formula 1 ##STR00001##
as a hardener in epoxy resin composition.

Claims

1. A compound of structural formula 1 ##STR00004##

2. A hardener in epoxy resin composition comprising a 2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine-(CPDA) as a hardener in epoxy resin composition.

3. The hardener of claim 2 wherein the 2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine-(CPDA) has structural formula 1 ##STR00005##

4. An epoxy resin composition comprising the 2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine-(CPDA) of claim 2.

5. The epoxy resin composition of claim 4 wherein the 2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine-(CPDA) has structural formula 1 ##STR00006##

6. The epoxy resin composition of claim 5 wherein the epoxy resin is selected from the group consisting of polyepoxides based on bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and cycloaliphatic types.

7. The epoxy resin composition of claim 5 wherein the epoxy resin is selected from the group consisting of epoxy resins based on bisphenol A and bisphenol F.

8. The epoxy resin composition of claim 5 wherein the epoxy resin is polyepoxides based on bisphenol A diglycidyl ether.

9. The epoxy resin composition of claim 5 wherein the epoxy resin is polyepoxides based on bisphenol F diglycidyl ether.

10. The epoxy resin composition of claim 5 wherein the epoxy resin is selected from the group consisting of polyepoxides based on bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

Description

EXAMPLES

Example 1: Production of 2-(3-(aminomethyl)-3,5,5-trimethylcyclohexyl)propane-1,3-diamine (AMCPDA)

Step A): Synthesis of 2-(3-cyano-3,5,5-trimethylcyclohexylidene)malononitrile

(1) ##STR00003##

(2) A 2 L three-necked flask fitted with two dropping funnels was initially charged with 372 g of isophorone nitrile (IPN) with 340 g of ethanol (EtOH). The reactor contents were kept at room temperature.

(3) 165 g of malononitrile were diluted with 100 g of EtOH and initially charged into a dropping funnel.

(4) 1 g of piperidine as catalyst was diluted with 10 g of EtOH and filled into the second dropping funnel.

(5) The contents of both dropping funnels were then simultaneously added dropwise to the reactor and the reactor was stirred for one hour at room temperature.

(6) The product mixture formed was cooled to 10 C. and the thus precipitating product 2-(3-cyano-3,5,5-trimethylcyclohexylidene)malononitrile was filtered off.

(7) The further purification was effected by recrystallization in cold ethanol and subsequent filtration and drying in a vacuum drying cabinet (45 C., 10 mbar, 3 h).

(8) The product composition was determined by gas chromatography.

(9) The yield of 2-(3-cyano-3,5,5-trimethylcyclohexylidene)malononitrile was 93 wt %.

Step B1): Partial Hydrogenation of 2-(3-cyano-3,5,5-trimethylcyclohexylidene)malononitrile, 1st Hydrogenation Stage

(10) 150 ml of the fixed-bed catalyst Pd/aluminum oxide (1 wt % Pd) was installed in a 2 L pressure autoclave fitted with a catalyst cage.

(11) 1 L of solution comprising 10 wt % of 2-(3-cyano-3, 5, 5-trimethylcyclohexylidene)malononitrile (product from step A) in tetrahydrofuran (THF) was initially charged for the reaction.

(12) The reaction was effected at 75 C. with 50 bar of hydrogen for 5 h.

(13) The entire product solution was discharged from the reactor.

(14) The composition of the product solution was determined by gas chromatography.

Step B2: 2nd Hydrogenation Stage: Full Hydrogenation of Product Solution from Step B1

(15) 150 ml of activated Raney cobalt alloy pellets were installed as a fixed bed in a 2 L pressure autoclave fitted with a catalyst cage. This catalyst had the following composition in weight percent (wt %), the proportions summing to 100 wt % based on the metals present:

(16) cobalt: 75.9 wt %

(17) aluminum: 20.0 wt %

(18) chromium: 1.5 wt %

(19) nickel: 2.6 wt %

(20) A sieve fraction of the catalyst having a statistical distribution between 2.0 and 5.0 millimeters (mm) was employed, wherein up to 10% of the particles may be above the stated upper limit and up to 10% of the particles may be below the stated lower limit.

(21) 1 L of reaction solution (partially hydrogenated product from step B1 in THF) was initially charged for the reaction.

(22) The reaction was effected at 100 C. with 100 bar of hydrogen for 5 h.

(23) The composition of the product solution was determined by gas chromatography.

(24) For use of AM-CPDA as a hardener in epoxy resin systems the product obtained was purified by distillation.

(25) The yield of the two-stage hydrogenation was 76 wt % of AM-CPDA based on the employed dinitrile from stage A.

Example 2: AM-CPDA as a Hardener in Epoxy Resin Systems

(26) The epoxy resin employed was the standard resin Epikote 828 from Hexion having an epoxy equivalent weight of 188 g/eq. Said resin was blended in stoichiometric equality of the H equivalents with the hardener component AM-CPDA (cf. Table 1) and the glass transition temperature (Tg) was determined after a dwell time of one hour at a defined curing temperature (Table 2). The respective reaction conversions were determined via the recorded evolution of heat from the curing reaction in relation to the maximum evolution of heat (Table 3).

(27) TABLE-US-00001 TABLE 1 Ratio of resin to hardener Hardener component AM-CPDA (g) 100 Amount of epoxy resin (g) per 100 g of hardener 496

(28) TABLE-US-00002 TABLE 2 Glass transition temperatures (Tg) after one hour of curing at various temperatures Tgmax. (DSC) 182 C. Tg after 1 h 50 C. 48 C. Tg after 1 h 70 C. 84 C. Tg after 1 h 90 C. 111 C. Tg after 1 h 110 C. 129 C. Tg after 1 h 130 C. 152 C. Tg after 1 h 150 C. 170 C.

(29) TABLE-US-00003 TABLE 3 Conversions Conversion after 1 h 50 C. 56% Conversion after 1 h 70 C. 71% Conversion after 1 h 90 C. 80% Conversion after 1 h 110 C. 91% Conversion after 1 h 130 C. 95% Conversion after 1 h 150 C. 100%

(30) As is readily apparent to a person skilled in the art from Table 1, Table 2 and Table 3, AM-CPDA is a suitable hardener component in epoxy resin systems.