SYNTHESIS OF AND COMPOSITIONS CONTAINING DIAMINOACETALS AND DIAMINOKETALS
The present invention relates to the reduction of polycyano compounds to produce polyamines, in particular diaminoacetal and diaminoketal compounds, and their use as curing agents in epoxy resin compositions. The reduction with molecular hydrogen can be carried out using a metal catalyst selected from GROUP VIII and a catalytic promoter. The reduction can include anhydrous or aqueous ammonia. The reaction can be carried out in continuous and batch modes with catalyst and solvent recycling. The epoxy resin composition consisting of an epoxy resin and a polyamine curing agent that can be used in fiber-reinforced composite materials, coating materials, and the like.
1 . A process for preparing a compound represented by Formula (1) from a compound of Formula (2):
wherein:
each of R 1 and R 2 is independently selected from the group consisting of hydrogen, alkyl group, cycloalkyl group and aromatic group; or both of R 1 and R 2 forms a cyclic radical;
each of R 3 , R 4 , R 5 , and R 6 is independently selected from the group consisting of hydrogen, alkyl group, cycloalkyl group and aromatic group;
R 3 and R 4 can combine with each other to form a cyclic radical;
R 5 and R 6 can combine with each other to form a cyclic radical; and
each m and n is independently an integer ranging from 1 to 3; the process comprising reducing the compound of Formula (2) with a reducing agent to produce the compound of Formula (1) at a temperature of from about 15° C. to about 200° C.
2 . The process of claim 1 , wherein the reducing agent comprises molecular hydrogen.
3 . The process according to claim 1 , wherein the catalyst is recycled.
4 . The process of claim 1 , wherein the reduction is carried out in the presence of a metal-containing catalyst.
5 . The process of claim 1 , wherein the reduction is carried out in the presence of a catalyst and a catalyst promoter.
6 . The process of claim 2 , wherein the reduction is carried out at molecular hydrogen pressure of from about 80 psi to about 3000 psi.
7 . The process of claim 1 , wherein the reduction is carried out in the presence of ammonia.
8 . The process of claim 1 , wherein the reduction is carried out in the presence of anhydrous ammonia.
9 . The process of claim 1 , wherein the reduction is carried out in the presence of aqueous ammonia.
10 . The process of claim 7 , wherein the ammonia is recycled ammonia.
11 . The process of claim 1 , wherein the reduction is carried out in the presence of ammonia, the ammonia being present in an amount of from about 1 mole to about 40 moles per mole of the compound of Formula (2) used.
12 . The process of claim 1 , wherein the reduction is carried out in the presence of a solvent.
13 . The process according to claim 1 , wherein the reduction is carried out in a batch reactor.
14 . The process according to claim 1 , wherein the reduction is carried out in a continuous reactor.
15 . The process according to claim 14 , wherein the continuous reactor is selected from the group consisting of a flow reactor, a continuous stirred tank reactor, a trickle bed reactor, a loop reactor, a bubble reactor, a tube reactor, a pipe reactor, and a slurry reactor.
16 . The process according to claim 1 , wherein the compound of Formula (2) is selected from the group consisting of:
17 . The process according to claim 1 , wherein the compound of Formula (1) is selected from the group consisting of:
18 . The process according to claim 1 , wherein each m and n is independently 1 or 2.
19 . The process according to claim 1 , wherein m and n are 1.
20 . The process according to claim 1 , wherein m and n are 2.
21 - 36 . (canceled)