Polyhexamethylenimine and process for its preparation

A process is provided for producing polyhexamethylenimine by condensing hexamethylenediamine at 50.degree. to 300.degree. C. in the presence of a palladium catalyst. The process yields substantially linear, high-molecular-weight polyhexamethylenimines, especially novel polyhexamethylenimines having a molecular weight of at least 1,000. Polyhexamethylenimines having a molecular weight of at least 500 are useful as gelling agents for organic liquids.

This invention relates to a process for preparing polyhexamethylenimine. 
More specifically, it relates to a process for preparing 
polyhexamethylenimine by condensing hexamethylenediamine in the presence 
of metallic palladium or a palladium compound. 
The invention also relates to a novel use of polyhexamethylenimine as a 
gelling agent, and to a novel polyhexamethylenimine compound. 
Polycondensation reaction between an alkylenediamine containing 2 to 6 
carbon atoms and an alkylene dihalide containing 1 to 4 carbon atoms in 
the presence of a strong basic compound is known as a process for 
preparing a polyalkylenepolyamine (J. Polymer Sci. 45, 289, 1960). This 
method, however, has the defect that because the resulting reaction 
mixture contains the amine, water, alkaline solution, and salts, it is 
difficult to separate and recover the desired polyalkylene polyamine, and 
treatment of byproducts such as the alkali metal halide requires huge 
cost. Furthermore, no report has been made about the synthesis of a 
polymer of hexamethylenimine by this method. 
A method is also known to produce a polyalkylenimine by condensing 
ethylenediamine or 1,3-propanediamine with the aid of a compound of a 
transition metal of Group VIII of the periodic table as a catalyst. 
However, when ethylenediamine or 1,3-propanediamine is condensed, the 
resulting polyalkylenimine is a di- to tetra-mer of the starting amine, 
and a polyalkylenimine having a high molecular weight cannot be obtained 
(Japanese Laid-Open Patent Publications Nos. 41308/76 and 36608/77). 
It is also known to produce polyhexamethylenimine by ring-opening 
polymerization of hexamethylenimine using an acid catalyst (German Pat. 
No. 1037126). This method requires the use of the expensive 
hexamethylenimine as a raw material, and the reaction must be carried out 
at a temperature of as high as 200.degree. to 350.degree. C. Furthermore, 
separation of the polyhexamethylenimine from the catalyst is not always 
easy. The method also has the defect of not giving polyhexamethylenimine 
having a high degree of polymerization. 
None of these prior art methods have come into commercial acceptance 
because of the various problems described. 
It is an object of this invention therefore to provide a process which can 
easily afford polyhexamethylenimine of high commercial value in high 
yields from a cheap starting material without requiring a high reaction 
temperature. 
Another object of the invention is to provide a process for preparing 
polyhexamethylenimine in which the separation and recovery of the 
resulting polyhexamethylenimine is very easy. 
Still another object of this invention is to provide a process which can 
optionally afford either polyhexamethylenimines of low degrees of 
polymerization or those of high degrees of polymerization. 
The present inventors made extensive investigations in order to achieve 
these objects, and found that when hexamethylenediamine is condensed using 
metallic palladium or a palladium compound at relatively low temperatures, 
polyhexamethylenimine having the desired degree of polymerization can be 
obtained in good yields, and the separation of the catalyst is easy. 
Specifically, the present invention provides a process for producing 
polyhexamethylenimine which comprises condensing hexamethylenediamine at a 
temperature of from 50.degree. to 300.degree. C. in the presence of at 
least one palladium catalyst selected from the group consisting of 
metallic palladium and palladium compounds to form polyhexamethylenimine 
having an average degree of polymerization of at least 3, then separating 
the catalyst from the reaction mixture, and recovering the 
polyhexamethylenimine formed. 
The catalyst used in this invention is metallic palladium or a palladium 
compound. 
The metallic palladium denotes palladium black, or metallic palladium 
supported on a carrier. The carrier is, for example, carbon black, 
magnesium oxide, magnesium chloride, magnesium sulfate, barium sulfate, 
calcium carbonate, barium carbonate, alumina, silica, silica-alumina, or 
molecular sieves. Other carriers which do not hamper the reaction can also 
be used. 
The palladium compound, as referred to in this invention, is a palladium 
complex compound having a valence of 0, 2 or 4. At least one such compound 
can be used. Specific examples of palladium compounds that can be used in 
this invention are listed below. 
(1) Palladium complex compounds expressed by the general formula PdL.sup.1 
L.sup.2 L.sup.3 or PdL.sup.1 L.sup.2 L.sup.3 L.sup.4 wherein L.sup.1, 
L.sup.2, L.sup.3 and L.sup.4 each represent a ligand of the formula 
##STR1## 
M represents P, As or Sb; R.sup.1, R.sup.2 and R.sup.3 represent a halogen 
atom, the group NR.sub.2 (R being hydrogen or alkyl), a C.sub.1-16 alkyl, 
alkenyl, cycloalkyl, cycloalkenyl or aryl group, or derivatives of these; 
and R.sup.4, R.sup.5 and R.sup.6 represent a hydrogen atom, a C.sub.1-16 
alkyl, alkenyl, cycloalkyl, cycloalkenyl or aryl group, or derivatives of 
these. 
Specific examples of these compounds are as follows: 
Pd[P(C.sub.6 H.sub.5).sub.3 ].sub.3, Pd(PH.sub.3).sub.4, Pd[P(C.sub.2 
H.sub.5).sub.3 ].sub.4, 
Pd[P(n--C.sub.3 H.sub.7).sub.3 ].sub.4, Pd[P(i--C.sub.3 H.sub.7).sub.3 
].sub.4, 
Pd[P(n--C.sub.4 H.sub.9).sub.3 ].sub.4, Pd[P(i--C.sub.4 H.sub.9).sub.3 
].sub.4, 
Pd[P(n--C.sub.5 H.sub.11).sub.3 ].sub.4, Pd[P(CH.dbd.CH.sub.2).sub.3 
].sub.4, 
Pd[P(CH.sub.2 -C.sub.6 H.sub.5)(C.sub.3 H.sub.7).sub.2)].sub.4, 
Pd[P(C.sub.10 H.sub.21).sub.3 ].sub.4, 
Pd[P(C.sub.12 H.sub.25).sub.3 ].sub.4, Pd[As(CH.sub.3).sub.3 ].sub.4, 
Pd[Sb(C.sub.2 H.sub.5).sub.3 ].sub.4, Pd[As(CH.dbd.CH.sub.2).sub.3 ].sub.4, 
Pd[As(n--C.sub.3 H.sub.7).sub.3 ].sub.4, Pd(Sb(CH.dbd.CH.sub.2)(C.sub.4 
H.sub.9).sub.2 ].sub.4, 
Pd[As(C.sub.8 H.sub.17).sub.3 ].sub.4, Pd[Sb(cyclo--C.sub.5 H.sub.9).sub.3 
].sub.4, 
Pd[P(cyclo--C.sub.8 H.sub.15).sub.3 ].sub.4, Pd[Sb(CH.sub.3)(cyclo--C.sub.6 
H.sub.11).sub.2 ].sub.4, 
Pd[As(cyclo--C.sub.6 H.sub.11).sub.3 ].sub.4, Pd[P(C.sub.6 H.sub.5).sub.3 
].sub.4, 
Pd[P(ortho--CH.sub.3 -C.sub.6 H.sub.4).sub.3 ].sub.4, Pd[P(meta--CH.sub.3 
--C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(.alpha.--C.sub.10 H.sub.7).sub.3 ].sub.4, Pd[P(para--C.sub.6 H.sub.5 
--C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(para--C.sub.6 H.sub.5 --O--C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[As(C.sub.6 H.sub.5).sub.3 ].sub.4, 
Pd[Sb(C.sub.6 H.sub.5).sub.3 ].sub.4, Pd[Sb(meta--CH.sub.3 --C.sub.6 
H.sub.4).sub.3 ].sub.4, 
Pd[As(para--CH.sub.3 --C.sub.6 H.sub.4).sub.3 ].sub.4, Pd[P(CH.sub.2 
-C.sub.6 H.sub.5)(C.sub.3 H.sub.7).sub.2)].sub.4, 
Pd[P(C.sub.6 H.sub.5).sub.2 (C.sub.6 H.sub.13)].sub.4, Pd[P(C.sub.6 
H.sub.5)(C.sub.2 H.sub.5).sub.2 ].sub.4, 
Pd[As(C.sub.2 H.sub.5)(C.sub.6 H.sub.5).sub.2 ].sub.4, 
Pd[Sb(cyclo--C.sub.6 H.sub.11).sub.2 (OC.sub.6 H.sub.13)].sub.4, 
Pd[P(C.sub.10 H.sub.21).sub.2 (OC.sub.10 H.sub.21)].sub.4, 
Pd[P(CH.sub.2 --C.sub.6 H.sub.5)(OC.sub.3 H.sub.17).sub.2 ].sub.4, 
Pd[As(C.sub.4 H.sub.9)(C.sub.6 H.sub.5)(OC.sub.2 H.sub.5).sub.2 ].sub.4, 
Pd[Sb(CH.sub.3).sub.2 (OC.sub.6 H.sub.5)].sub.4, Pd[P(OCH.sub.3).sub.3 
].sub.4, 
Pd[P(OC.sub.2 H.sub.5).sub.3 ].sub.4, Pd[P(OC.sub.6 H.sub.5).sub.3 ].sub.4, 
Pd[P(OC.sub.6 H.sub.5).sub.2 (OC.sub.3 H.sub.7)].sub.4, 
Pd[P(O--para--NO.sub.2 --C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(O--ortho--CH.sub.3 --C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(O--meta--CH.sub.3 --C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(O--para--CH.sub.3 --C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(O--ortho--Cl--C.sub.6 H.sub.4).sub.3 ].sub.4, 
Pd[P(O--para--Cl--C.sub.6 H.sub.4).sub.3 ].sub.4, Pd[P(OCH.sub.2 C.sub.6 
H.sub.5).sub.3 ].sub.4, 
Pd[As(OCH.sub.3).sub.3 ].sub.4, Pd[Sb(OC.sub.2 H.sub.5).sub.3 ].sub.4, 
Pd[As(OC.sub.3 H.sub.7).sub.3 ].sub.4, Pd[As(OC.sub.6 H.sub.5).sub.3 
].sub.4, 
Pb[Sb(OC.sub.6 H.sub.5).sub.3 ].sub.4, Pd[(CH.sub.3).sub.2 
NP(OCH.sub.3).sub.2 ].sub.4, 
Pd[(CH.sub.3).sub.2 NP(OC.sub.6 H.sub.13).sub.2 ].sub.4, 
Pd[(CH.sub.3).sub.2 NP(OC.sub.6 H.sub.5).sub.2 ].sub.4, 
Pd[(C.sub.2 H.sub.5).sub.2 NP(C.sub.2 H.sub.5)(OC.sub.8 H.sub.17)].sub.4, 
Pd[P(N(CH.sub.3).sub.2).sub.3 ].sub.4, Pd[P(N(C.sub.4 H.sub.9).sub.2).sub.3 
].sub.4, 
Pd[P(N(i--C.sub.3 H.sub.7).sub.2).sub.3 ].sub.4, Pd[P(N(C.sub.6 
H.sub.5).sub.2).sub.3 ].sub.4, 
Pd[((CH.sub.3).sub.2 N).sub.2 As(OC.sub.6 H.sub.5)].sub.4, 
Pd[As(N(C.sub.2 H.sub.5).sub.2).sub.3 ].sub.4, Pd[Sb(N(C.sub.6 
H.sub.13).sub.2).sub.3 ].sub.4, 
Pd(PCl.sub.3).sub.4, Pd(AsCl.sub.3).sub.4, Pd(SbCl.sub.3).sub.4, 
Pd[PCl(CH.sub.3)].sub.4, Pd[PCl.sub.2 (C.sub.6 H.sub.5)].sub.4, 
Pd[SbCl.sub.2 (OC.sub.6 H.sub.5)].sub.4, Pd[AsCl.sub.2 (C.sub.2 
H.sub.5)].sub.4, 
Pd[PCl.sub.2 (cyclo-C.sub.6 H.sub.11)].sub.4, Pd[PCl(C.sub.2 H.sub.5).sub.2 
].sub.4, 
Pd[AsCl(n-C.sub.4 H.sub.9).sub.2 ].sub.4, Pd[PCl(OC.sub.6 H.sub.5).sub.2 
].sub.4, and 
Pd[SbCl(C.sub.6 H.sub.5).sub.2 ].sub.4. 
(2) Palladium complex compounds expressed by the general formula PdA.sup.1 
A.sup.2 L.sup.1 L.sup.2 wherein A.sup.1 and A.sup.2 represent a hydrogen 
atom, a halogen atom, NO.sub.3, CNS, R.sup.4, R.sup.4 CO or R.sup.4 COO, 
and R.sup.4, L.sup.1 and L.sup.2 are as defined above. 
Specific examples of compounds of this group are as follows: 
PdCl.sub.2 (PCl.sub.3).sub.2, PdBr.sub.2 (PCl.sub.3).sub.2, PdCl.sub.2 
[P(C.sub.6 H.sub.5).sub.3 ].sub.2, 
PdCl.sub.2 [P(CH.sub.3).sub.3 ].sub.2, PdCl.sub.2 [P(OCH.sub.3).sub.3 
].sub.2, 
PdBr.sub.2 [P(C.sub.6 H.sub.5).sub.3 ].sub.2, PdBr.sub.2 [P(cyclo-C.sub.6 
H.sub.11).sub.3 ].sub.2, 
Pd(NO.sub.3).sub.2 [P(C.sub.6 H.sub.5).sub.3 ].sub.2, Pd(CNS).sub.2 
[P(C.sub.4 H.sub.9).sub.3 ].sub.2, 
PdCl.sub.2 [As(C.sub.4 H.sub.9).sub.3 ].sub.2, PdCl.sub.2 [As(C.sub.6 
H.sub.5).sub.3 ].sub.2, 
PdCl.sub.2 [Sb(C.sub.6 H.sub.5).sub.3 ].sub.2, PdBr.sub.2 [Sb(C.sub.3 
H.sub.7).sub.3 ].sub.2, 
PdCl(CH.sub.3 CO)[P(C.sub.3 H.sub.5).sub.3 ].sub.2, 
PdCl(C.sub.6 H.sub.5 CO)[P(C.sub.2 H.sub.5).sub.3 ].sub.2, 
PdBr(CH.sub.3)[P(C.sub.2 H.sub.5).sub.3 ].sub.2, Pd(CH.sub.3).sub.2 
[P(C.sub.2 H.sub.5).sub.3 ].sub.2, and 
Pd[P(C.sub.6 H.sub.5).sub.3 ].sub.2 (OOCCH.sub.3).sub.2. 
(3) Palladium complex compounds expressed by the general formula PdL.sup.1 
L.sup.2 Q wherein Q represents a dienophile such as maleic anhydride, 
maleic acid esters, fumaric acid esters, fumaronitrile, benzoquinone, 
naphthoquinone or acetylene dicarboxylic acid esters, and L.sup.1 and 
L.sup.2 are as defined hereinabove. 
Specific examples are as follows: 
##STR2## 
L.sup.1 L.sup.2 in the palladium complex compounds (1) to (3) may be a 
bidentate ligand of the general formula 
##STR3## 
wherein M represents P, As or Sb; R.sup.7, R.sup.8, R.sup.9 and R.sup.10 
represent R.sup.1, R.sup.2, R.sup.3, OR.sup.4, OR.sup.5 or OR.sup.6 
defined hereinabove; and R.sup.11 represents a divalent hydrocarbon group. 
Specific examples of these bidentate ligands are as follows: 
(CH.sub.3).sub.2 P(CH.sub.2).sub.2 P(CH.sub.3).sub.2, (C.sub.2 
H.sub.5).sub.2 P(CH.sub.2).sub.3 P(C.sub.2 H.sub.5).sub.2, 
(cyclo--C.sub.6 H.sub.11).sub.2 P(CH.sub.2).sub.3 P(cyclo--C.sub.6 
H.sub.11).sub.2, 
(n--C.sub.4 H.sub.9).sub.2 PCH.sub.2 P(n--C.sub.4 H.sub.9).sub.2, 
(C.sub.6 H.sub.5 CH.sub.2).sub.2 P(CH.sub.2).sub.2 P(CH.sub.2 C.sub.6 
H.sub.5).sub.2, 
(C.sub.6 H.sub.5).sub.2 P(CH.sub.2).sub.2 P(C.sub.6 H.sub.5).sub.2, 
(C.sub.6 H.sub.5 O).sub.2 PCH.sub.2 P(OC.sub.6 H.sub.5).sub.2, 
(NCCH.sub.2 CH.sub.2).sub.2 P(CH.sub.2).sub.3 P(CH.sub.2 CH.sub.2 CN), 
(C.sub.6 H.sub.5).sub.2 P(CH.sub.2).sub.4 P(C.sub.6 H.sub.5).sub.2, 
(C.sub.2 H.sub.5).sub.2 PCH.dbd.CHP(C.sub.2 H.sub.5).sub.2, 
##STR4## 
(CH.sub.3).sub.2 AS(CH.sub.2).sub.2 As(CH.sub.3).sub.2, (n--C.sub.4 
H.sub.9).sub.2 As(CH.sub.2).sub.3 As(n--C.sub.4 H.sub.9).sub.2, 
(cyclo--C.sub.6 H.sub.11).sub.2 As(CH.sub.2).sub.2 As(cyclo--C.sub.6 
H.sub.11).sub.2, 
(C.sub.6 H.sub.5).sub.2 AsCH.sub.2 As(C.sub.6 H.sub.5).sub.2, 
(C.sub.6 H.sub.5).sub.2 As(CH.sub.2).sub.2 As(C.sub.6 H.sub.5).sub.2, 
(C.sub.2 H.sub.5).sub.2 As(CH.sub.2).sub.4 As(C.sub.2 H.sub.5).sub.2, 
##STR5## 
(CH.sub.3).sub.2 Sb(CH.sub.2).sub.2 Sb(CH.sub.3).sub.2, (i--C.sub.3 
H.sub.7).sub.2 Sb(CH.sub.2).sub.3 Sb(i--C.sub.3 H.sub.7).sub.2, 
(cyclo--C.sub.6 H.sub.11).sub.2 Sb(CH.sub.2).sub.2 Sb(cyclo--C.sub.6 
H.sub.11).sub.2, 
(C.sub.6 H.sub.5).sub.2 SbCH.sub.2 Sb(C.sub.6 H.sub.5).sub.2, 
(C.sub.6 H.sub.5).sub.2 Sb(CH.sub.2).sub.4 Sb(C.sub.6 H.sub.5).sub.2, 
##STR6## 
(4) Palladium complex compounds expressed by the general formula PdA.sup.1 
YL.sup.1 wherein Y is a .pi.-allyl group of the general formula 
##STR7## 
wherein R.sup.12, R.sup.13, R.sup.14, R.sup.15 and R.sup.16 represent a 
hydrogen or halogen atom, a C.sub.1-16 alkyl, alkenyl, cycloalkyl, 
cycloalkenyl or aryl group, or derivatives of these; and A.sup.1 and 
L.sup.1 are as defined hereinabove. 
Specific examples of these compounds are as follows: 
##STR8## 
(5) Palladium complex compounds expressed by the general formula [PdX.sup.1 
X.sup.2 Z].sub.2 wherein X.sup.1 and X.sup.2 represent a halogen atom, and 
Z represents an olefin having 1 to 20 carbon atoms. The olefin denotes a 
monolefin such as an .alpha.-olefin, iso-olefin or internal olefin, a 
diolefin, a polyolefin, a vinyl compound, or derivatives of these. 
Specific examples of these palladium compounds are as follows: 
##STR9## 
(6) Palladium compounds expressed by the general formula PdX.sup.1 X.sup.2 
D wherein D represents a diene such as butadiene, cyclopentadiene or 
cyclooctadiene, derivatives of these dienes, or carbon monoxide; and 
X.sup.1 and X.sup.2 represent a halogen atom. 
Specific examples of these palladium compounds are as follows: 
##STR10## 
(7) Palladium complex compounds expressed by the general formula PdB.sup.1 
B.sup.2 wherein B.sup.1 and B.sup.2 represent D or Y defined hereinabove. 
Specific examples of these compounds are as follows: 
##STR11## 
(8) Palladium complex compounds expressed by the general formula [PdX.sup.1 
Y].sub.2 wherein X.sup.1 and Y are as defined hereinabove. 
Specific examples of these compounds are as follows: 
##STR12## 
(9) Palladium compounds expressed by the general formula 
##STR13## 
wherein R.sup.4 is as defined above. 
Specific examples of these compounds are Pd(OOCCH.sub.3).sub.2, 
Pd(OOCC.sub.2 H.sub.5).sub.2, Pd(OOCC.sub.3 H.sub.7).sub.2, and 
Pd(OOCC.sub.6 H.sub.5).sub.2. 
(10) Palladium compounds expressed by the general formula 
Pd(OR.sup.4).sub.2 wherein R.sup.4 is as defined hereinabove. 
Specific examples are Pd(OH).sub.2, Pd(OCH.sub.3).sub.2, Pd(OC.sub.2 
H.sub.5).sub.2, Pd(O i--C.sub.3 H.sub.7).sub.2, Pd(O t--C.sub.4 H.sub.9), 
and Pd(OC.sub.6 H.sub.5). 
(11) Palladium compounds expressed by the general formula Pd[OCR.sup.4 
.dbd.CH--COR.sup.5 ].sub.2 wherein R.sup.4 and R.sup.5 are as defined 
above. 
Specific examples of these compounds are Pd[OCH.dbd.CH--COCH.sub.3 ].sub.2, 
Pd[OC(CH.sub.3).dbd.CH--COCH.sub.3 ].sub.2, and 
Pd[OC(CH.sub.3).dbd.CH--COC.sub.2 H.sub.5 ].sub.2. 
(12) Palladium compounds expressed by the general formula Pd(R.sup.17 
NC).sub.4, PdX.sub.2 (R.sup.17 NC).sub.2, Pd(R.sup.17 NC).sub.2 or 
PdX.sub.2 (R.sup.17 CN).sub.2 wherein X represents a halogen atom, and 
R.sup.17 represents a C.sub.1-16 alkyl, alkenyl, cycloalkyl, cycloalkenyl 
or aryl group, or derivatives of these. 
Specific examples of these compounds are Pd(para-CH.sub.3 C.sub.6 H.sub.4 
NC).sub.4, Pd(CH.sub.3 NC).sub.2, Pd(para--OCH.sub.3 --C.sub.6 H.sub.4 
NC).sub.4, PdCl.sub.2 --(C.sub.6 H.sub.5 NC).sub.2, and PdCl.sub.2 
(C.sub.6 H.sub.5 CN).sub.2. 
(13) Inorganic salts or oxide of palladium. Specific examples are 
PdI.sub.2, PdCl.sub.2, PdBr.sub.2, Pd(CN).sub.2, Pd(CNS).sub.2, 
Pd(NO.sub.3).sub.2, PdSO.sub.4, PdO, PdI.sub.4, PdCl.sub.4, PdBr.sub.4, 
PdS.sub.2 and PdSe.sub.2. 
(14) Complexes of the palladium compounds (1) to (13) with amines or 
inorganic compounds. 
Specific examples of these compounds are as follows: 
##STR14## 
Pd(NO.sub.2).sub.2 (NH.sub.3).sub.2, Na.sub.2 PdCl.sub.4, K.sub.2 
PdCl.sub.4, K.sub.2 PdBr.sub.4, K.sub.2 Pd(CN).sub.4, (NH.sub.4).sub.2 
PdCl.sub.4, 
H.sub.2 (PdCl.sub.4).sub.2, H.sub.2 (PdCl.sub.6).sub.2, Na.sub.2 
PdCl.sub.6, K.sub.2 PdCl.sub.6, 
(NH.sub.4).sub.2 PdCl.sub.6, PdCl.sub.4 (NH.sub.3).sub.2, and K.sub.2 
Pd(CN).sub.4. 
(15) Palladium compounds (1) to (14) above as supported on carriers. All 
carriers which are used to support metallic palladium can be applied. 
The amount of the catalyst used in this invention is at least 0.0001 mole 
per mole of the starting amine. For commercial operations, amounts in the 
range of 0.0001 to 0.5 mole, preferably 0.001 to 0.2 mole, are suitable. 
If the amount of the catalyst is smaller than the lower limit, the 
reaction time is prolonged to cause commercial disadvantage. When the 
amount of the catalyst is too large, the molecular weight of the product 
is reduced, but there is no other appreciable adverse effect on the 
reaction. However, separation and recovery of the excessive catalyst 
requires more labor and time. 
The reaction in accordance with this invention proceeds easily even in the 
absence of solvent. For convenience, a solvent may be used. Any compounds 
which act as solvent without hampering the reaction can be used in this 
invention as the solvent. Specific examples of the solvent are aromatic 
hydrocarbons such as benzene, toluene or xylene, aliphatic hydrocarbons 
such as n-pentane, n-hexane and n-heptane, alicyclic hydrocarbons such as 
cyclohexane, cyclooctane and methylcyclohexane, ethers such as diethyl 
ether, diisopropyl ether, tetrahydrofuran, dioxane and dimethoxyethane, 
and esters such as ethyl acetate, butyl acetate, ethyl propionate and 
ethyl butyrate. 
The reaction in accordance with this invention can be performed at 
50.degree. to 300.degree. C., preferably 120.degree. to 250.degree. C. Too 
low reaction temperature are commercially disadvantageous because the 
reaction time is prolonged, and too high reaction temperatures, on the 
other hand, will increase the formation of by-products. The reaction time 
is usually at least 5 minutes, preferably from 15 minutes to 100 hours. 
The reaction proceeds favorably by stirring or shaking, and the rate of 
reaction is considerably affected by the amount of the catalyst, the 
reaction temperature, the rate of stirring, etc. The reaction pressure may 
be atmospheric pressure. The reaction can also be performed under elevated 
pressures using ammonia or nitrogen. 
The reaction in accordance with this invention can be performed either 
batchwise or continuously. Alternatively, a semi-batchwise method can be 
used in which hexamethylenediamine is added consecutively. 
Since in the present invention by-products such as water and salts are not 
formed, the desired polyalkylenimine can be easily separated by simply 
separating the catalyst by filtration using a solvent, etc. The catalyst 
separated can be re-used repeatedly. 
When the process of this invention described hereinabove is performed using 
a mixture of hexamethylenediamine and at least one amine of the general 
formula 
##STR15## 
wherein m is an integer of 2 to 9, and n is an integer of 1 to 5 with the 
proviso that when m is 6, n is not 1, 
instead of the hexamethylenediamine alone, a copolymer (to be referred to 
hereinbelow as copolyalkylenimine) having a unit of the formula 
--(CH.sub.2).sub.6 NH-- and a unit of the general formula 
##STR16## 
(m and n are as defined above) can be obtained. 
Examples of amines of the formula 
##STR17## 
which can be co-condensed with hexamethylenediamine include 
ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 
1,5-diaminopentane, 1,9-diaminononane, diethylenetriamine, 
triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 
dipropylenetriamine, and tripropylenetetramine. 
The ratio of the amine of the general formula 
##STR18## 
to hexamethylenediamine used in the co-condensation reaction can be varied 
according to the purpose. Suitably, it is from 1:100 to 100:1, preferably 
from 1:10 to 10:1. 
The amount of the catalyst in the co-condensation method of this invention 
is at least 0.0001 mole, preferably 0.0001 to 0.5 mole, more preferably 
0.001 to 0.2 mole, per mole of the total amount of the amines. 
When hexamethylenediamine is co-condensed with the amine of general formula 
(I) by a semi-batchwise method, one or both of these compounds are 
consecutively fed into the reaction system. Alternatively, a blocked 
copolymer may be prepared by first completing the condensation of one of 
the amines and adding the other amine after completion of the condensation 
of the first-named amine. 
The use of the processes of this invention described hereinabove can afford 
either polyhexamethylenimines or copolyalkylenimines of high degrees of 
polymerization or those of low degrees of polymerization. Specifically, 
polyhexamethylenimines or copolyalkylenimines of low degrees of 
polymerization and high degrees of polymerization with an average degree 
of polymerization of at least 3 can be produced as desired by changing the 
reaction conditions such as the reaction temperature, the reaction time or 
the amount of the catalyst. Furthermore, the amounts of by-products such 
as hexamethylenimine are very small, and the desired polyhexamethylenimine 
or copolyalkylenimine can be produced with high selectivity and in high 
yields. For example, products of low degrees of polymerization can be 
obtained when the amount of the catalyst is increased, and products of 
high degree of polymerization can be obtained when the amount of the 
catalyst is decreased. 
Some of the polyhexamethylenimines obtained by the process of the present 
invention contain a recurring unit of the formula 
EQU --(CH.sub.2).sub.6 NH-- (II) 
and have a molecular weight of at least 1000. These polyhexamethylenimines 
are novel compounds. 
These novel polyhexamethylenimines of the invention are preferably linear 
polymers. The linear polymers, as referred to herein, mean polymers in 
which at least 70% of the entire amines in the polymer molecule consists 
of secondary amino groups (--NH--). In other words, they denote polymers 
in which at least 70% of the recurring units contained in the polymer 
molecule consists of the recurring unit of formula (II) given above. 
The molecular weight of polymer is a number average molecular weight 
measured by using a vapor pressure osmometer. 
Known hexamethylenimine polymers, for example polyhexamethylenimine 
obtained by ring-opening polymerization of a cyclic hexamethylenimine 
monomer (German Pat. No. 1037126), or an oligomer of hexamethylenimine 
formed as a by-product in the synthesis of hexamethylenimine monomer by 
hydrogenating .epsilon.-caprolactam with a cobalt catalyst (T. Ayusawa and 
T. Shimodaira, Ind. Eng. Chem. Prod. Res. Dev., 15, 295 (1976)), have a 
molecular weight of as low as less than 500. The polyhexamethylenimine 
obtained by the ring-opening polymerization of cyclic hexamethylenimine is 
a penta- to hexa-mer, and the oligomer of hexamethylenimine formed as a 
by-product in the catalytic hydrogenation reaction of 
.epsilon.-caprolactam is a tri- to tetra-mer. The polyhexamethylenimine 
obtained by the ring-opening polymerization of cyclic hexamethylenimine 
contains more tertiary amino groups than secondary ones in the polymer 
molecule, and is not a linear polymer. 
The novel polyhexamethylenimine of this invention have a molecular weight 
of at least 1,000, which is far higher than those of the polymers or 
oligomers of hexamethylenimine described in the above-cited literature 
references. Elemental analysis, infrared absorption spectrum, .sup.1 
H--NMR, and .sup.13 C--NMR have shown that the novel 
polyhexamethylenimines of the present invention are polyamines in which 
hexamethylenimine units --(CH.sub.2).sub.6 NH-- are recurring in chain. It 
has also been found from the quantitative analysis of primary, secondary 
and tertiary amines and the measurement of molecular weight by a vapor 
pressure osmometer method that these polymers are polyamines which are 
substantially linear and little branched and have a molecular weight of at 
least 1,000, usually 1,000 to 20,000.

The polyhexamethylenimines of the invention having a molecular weight of at 
least 1,000 have the unique property of rapidly gelling hydrocarbons such 
as benzene or kerosene in the presence of water. Other known 
polyalkylenimine such as polyethylenimine are not known to have the 
property of gelling hydrocarbons in the presence of water. 
It has been discovered that not only the novel polyhexamethylenimines of 
the invention, but also other polyhexamethylenimines of the invention 
having a degree of polymerization of at least 3, preferably a number 
average molecular weight of 500 to 20,000, have properties very similar to 
those of polyethylenimine, and the unique property, not possessed by 
polyethylenimine, of gelling liquid organic compounds, especially 
hydrocarbon compounds, at room temperature. Moreover, it has been found 
that the hydrocarbon compound gel are liquefied by heating, and will be 
reversibly gelled when the temperature is returned to room temperature. 
It has thus been found by the present inventors that 
polyhexamethylenimines, preferably polyhexamethylenimine having a number 
average molecular weight of 500 to 20,000, have very good properties as 
solidifying agents for organic compounds which are liquid at room 
temperature. 
Accordingly, the present invention embraces a solidifying agent capable of 
solidifying a liquid organic compound, said agent comprising as an active 
ingredient a polyalkylenimine having the structure unit of the formula 
--(CH.sub.2).sub.6 NH--; and a method for solidifying liquid organic 
compounds, which comprises adding the solidifying agent to a normally 
liquid organic compound. 
When the molecular weight of the polyhexamethylenimine used as a 
solidifying agent in this invention is too low, the gelling ability of the 
polymer is insufficient. If, on the other hand, its molecular weight is 
too high, its synthesis is difficult, and its solubility in organic 
compounds or the rate of dissolving is insufficient. 
The amount of the polyhexamethylenimine used in this invention to solidify 
the organic compound varies depending upon the type of the organic 
compound, and the strength of the desired solidified compound. It is 
generally 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight, 
per 100 parts by weight of the organic compound. In adding the solidifying 
agent, there is no particular limitation on the temperature. Usually, the 
organic compound can be conveniently solidified by mixing it with the 
solidifying agent at a temperature of 0.degree. to 200.degree. C., 
preferably 10.degree. to 100.degree. C. 
In a water-free condition, the solidifying agent of this invention cannot 
solidify liquid organic compounds. When it is used in contact with water, 
for example in the air, it rapidly solidifies the liquid organic compounds 
even if the amount of water present is small. The amount of water required 
at the time of solidification is 0.02 to 200 parts by weight, preferably 
0.05 to 100 parts by weight, per 100 parts by weight of the organic 
compound. If the amount of water is too small, the rate of solidification 
is retarded, and when the amount of water is too large, the solidifying 
agent forms an emulsion, and hence, the strength of the solidified product 
is reduced. There is no particular restriction on the time of adding 
water. For example, water may be added after mixing the organic compound 
with the polyhexamethylenimine. Or the polyhexamethylenimine may be added 
to a mixture of water and the organic compound. Alternatively water and 
polyhexamethylenimine may be simultaneously added to the organic compound, 
or a mixture of water and polyhexamethylenimine may be added to the 
organic compound. 
The temperature at which to add water to the organic compound is not 
particularly restricted. 
Solidification of the liquid organic compound using the solidifying agent 
of this invention is usually carried out at a temperature of not more than 
50.degree. C. Generally, the rate of solidification is faster at lower 
solidification temperatures. 
Examples of organic compounds which can be solidified by using the 
solidifying agent of this invention are listed below. 
(i) Aliphatic hydrocarbons, aromatic hydrocarbons and alicyclic 
hydrocarbons which are liquid at room temperature, such as hexane, 
heptane, benzene, toluene, styrene, cyclohexane, gasoline, kerosene, light 
oils, heavy oils, lubricating oils, and crude oils. 
(ii) Ester compounds which are liquid at room temperature, such as animal 
and vegetable oils and fats, and synthetic esters such as acrylic or 
methacrylic acid esters, vinyl acetate and prepolymers of unsaturated 
polyester resins. 
(iii) Halogenated hydrocarbons which are liquid at room temperature, such 
as chlorobenzene or methylene chloride. 
The strength of the liquid organic compound solidified by the solidifying 
agent of this invention depends upon the amount of the solidifying agent 
and the amount of water. Generally, the solidified product is in the form 
of jelly to block at room temperature. When heated to a higher 
temperature, it becomes liquid, but on cooling it is again solidified. 
Methods heretofore suggested for solidifying hydrocarbons which are liquid 
at room temperature include, for example, (i) the addition of a metal soap 
and water, (ii) the addition of benzylidene sorbitol, and (iii) the 
addition of an N-acylaminoacid amide, ester or amine salt. These methods, 
however, suffer from one or more difficulties. For example, a large amount 
of the gelling agent is required. Or it is necessary to stir the liquid 
organic compound and the gelling agent vigorously. The gelling agent is 
scarcely soluble in the liquid organic compound. Or the heat stability of 
the gelling agent is low. Thus, none of these methods are entirely 
satisfactory. 
The solidifying agent of this invention removes these defects of the 
conventional gelling agents, and can find a wide range of applications. 
For example, when the solidifying agent is sprayed onto an oil which has 
flowed out, the oil is solidified by moisture in the air or by sea water 
and can be recovered without causing hazards. Furthermore, when the 
solidifying agent of this invention is added to low-boiling fuel oils such 
as a fuel oil for jet airplanes, the oil gels by the moisture in the air 
in the event it comes out of the container, and an accident such as 
explosion can be prevented. A solid fuel can be made by adding the 
solidifying agent of the invention and water to liquid paraffin to make it 
portable. It is also possible to form a moderately flowable gel of a 
reactive monomer such as styrene or a methacrylic or acrylic acid ester by 
adding the solidifying agent of this invention and water, coat it on a 
substrate, and polymerize the coated film by ultraviolet irradiation, etc. 
This technique can be conveniently used for inks and paints. Furthermore, 
since the organic compound solidified by using the solidifying agent of 
this invention has a markedly reduced vapor pressure, it can be 
conveniently used to inhibit the evaporation of volatile organic solvents. 
For example, when the solidifying agent of the invention is added to a 
paint remover and the mixture is applied to a coated surface, the solvent 
gels by the moisture in the air and its evaporation can be inhibited. 
Thus, the paint removing operation can be effectively carried out. 
In addition to the applications described above, the polyhexamethylenimine 
obtained by the process of this invention is also useful as a modifier for 
polyamides, polyesters, alkyd resins and waxes, a dyeing improver for 
fibers and leathers, a raw material for ion exchange resins, an emulsion 
inhibitor, a surface active agent, an antistatic agent, and a coagulating 
agent. 
The copolyalkylenimine can be used in the same applications as described 
above. By carying the proportion and type of the comonomer copolymers 
suitable for various other applications can be prepared. 
Specifically, by co-condensing the amine of the general formula 
##STR19## 
and hexamethylenediamine in optional proportions, copolyalkylenimine 
having various different properties can be obtained. When the amount of 
ethylenediamine is large in the co-condensation of ethylenediamine and 
hexamethylenediamine, the resulting copolyalkylenimine is hydrophilic, and 
has such a high molecular weight as cannot be obtained by the condensation 
of ethylenediamine alone. 
Accordingly, the copolyalkylenimine produced by the present invention may 
have a hydrophilic group such as an ethylenimine unit or propylene imine 
unit introduced into it in order to impart more hydrophilicity to 
polyhexamethylenimine, or an oleophilic group such as a heptamethylenimine 
unit or octamethylenimine unit introduced into it in order to impart 
oleophilicity. The process of this invention is significantly 
characterized by the fact that these hydrophilic or oleophilic groups can 
be introduced in any desired proportions, and moreover, by using a special 
polymerization method, the manner of arranging such groups in a single 
polymer chain can be controlled. 
The following Examples specifically illustrate the present invention. They 
should not be construed as limiting the invention. All parts and 
percentages in these Examples are by weight unless otherwise specified. 
EXAMPLE 1 
A nitrogen-purged 500 ml stainless steel autoclave was charged with 116 g 
of hexamethylenediamine and 5.3 g of palladium black, and with stirring, 
they were heated at 160.degree. C. for 30 hours. As the heating proceeded, 
ammonia was generated, and the internal pressure of the autoclave 
increased. Thus, the ammonia was released occasionally to maintain the 
pressure of the reaction system at less than 6 kg/cm.sup.2. After the 
reaction, the reaction mixture was cooled, and the contents of the 
autoclave were dissolved in methanol. The catalyst was separated by 
filtration, and methanol and low-boiling substances were distilled off 
under reduced pressure to afford 95 g of a yellowish white polymer. The 
amount of ammonia generated in this reaction was 0.98 mole per mole of 
hexamethylene diamine. 
The polymer had an average molecular weight, measured for its benzene 
solution by a vapor pressure osmometer, of 1,315, and an intrinsic 
viscosity, determined for its chlorobenzene solution at 30.degree. C., of 
0.11. The elemental analysis values of this polymer were as follows: 
C: 73.8%, N: 13.3%, H: 12.5%. 
The amines of this polymer were quantitatively analyzed in accordance with 
the method of S. Siggia, J. G. Hanna, I. R. Kerrenski: Anal. Chem., 22, 
1295 (1950). The results were: primary amine 2.9 mole%; secondary amine 
84.0 mole%; tertiary amine 13.1 mole%. The infrared absorption spectrum of 
the resulting polymer is shown in FIG. 1. The .sup.1 H--NMR spectrum of 
this polymer was almost the same as that of the polymer obtained in 
Example 12 which is shown in FIG. 4. 
From the above results of analyses, the polymer obtained by the aforesaid 
reaction was determined to be polyhexamethylenimine having the recurring 
unit --(CH.sub.2).sub.6 --NH--. 
One part of the polyhexamethylenimine obtained was mixed with 25 parts of 
methyl methacrylate. The mixture was transferred into a beaker containing 
0.1 part of water, and allowed to stand in the air for 2 hours at room 
temperature. A jelly-like gel formed. 
One part of the polyhexamethylenimine was mixed with 25 parts of light oil. 
The mixture was transferred into a beaker containing 0.1 part of sea 
water, and allowed to stand in the air for 4 hours at room temperature. A 
jelly-like gel formed. 
EXAMPLE 2 
A nitrogen-purged 500 ml stainless steel autoclave was charged with 116 g 
of hexamethylenediamine and 5.4 g of palladium black, and with stirring, 
they were heated at 161.degree. C. for 98 hours. As the heating proceeded, 
ammonia was generated, and the internal pressure of the autoclave 
increased. Thus, the ammonia was occasionally released to maintain the 
pressure of the reaction system at less than 5 kg/cm.sup.2. After the 
reaction, the reaction mixture was cooled, and the contents of the 
autoclave were dissolved in methanol. The catalyst was separated by 
filtration, and methanol and low-boiling products were distilled off under 
reduced pressure to afford 95 g of a yellowish white polymer. The amount 
of ammonia generated in this reaction was 0.99 mole per mole of 
hexamethylenediamine. 
The polymer had an average molecular weight, measured for its benzene 
solution by a vapor pressure osmometer, of 1,820. Elemental analysis of 
the polymer gave the following results. 
C: 73.2%, N: 13.9%, H: 12.9%. 
The results of the quantitative analysis of amines of this polymer were as 
follows: primary amine 1.9 mole%, secondary amine 85.4 mole%, tertiary 
amine 12.7 mole%. 
The .sup.1 H--NMR spectrum of the resulting polymer is shown in FIG. 2. 
From the above results of analyses, the polymer obtained by the aforesaid 
reaction was determined to be poluhexamethylenimine having the recurring 
unit --(CH.sub.2).sub.6 --NH--. 
One part of the resulting polyhexamethylenimine was mixed with 50 parts of 
liquid paraffin. The mixture was allowed to stand in the air at room 
temperature for 1 hour. A jelly-like gel formed. 
One part of the resulting polyhexamethylenimine was mixed with 50 parts of 
soybean oil. The mixture was allowed to stand in the air at room 
temperature for 1 hour. A jelly-like gel formed. 
EXAMPLE 3 
A nitrogen-purged 500 ml stainless autoclave was charged with 115 g of 
hexamethylenediamine and 5.4 g of palladium black, and with stirring, they 
were heated at 200.degree. C. for 5 hours. As the heating proceeded, 
ammonia was generated, and the internal pressure of the autoclave 
increased. Thus, the ammonia was released occasionally to maintain the 
pressure of the reaction system at less than 8 kg/cm.sup.2. After the 
reaction, the reaction mixture was cooled, and the contents of the 
autoclave were dissolved in methanol. The catalyst was separated by 
filtration, and methanol and low-boiling products were distilled off under 
reduced pressure to afford 94 g of polyhexamethylenimine having an average 
molecular weight of 950. 
The polymer was mixed with hot hexane, and the insoluble portion of the 
polymer was separated by filtration. The residue was dried under reduced 
pressure to afford 21 g of polyhexamethylenimine having an average 
molecular weight of 2,040. When hexane was distilled off under reduced 
pressure from the filtrate, 82 g of polyhexamethylenimine having an 
average molecular weight of 540 was obtained. 
One part of the hot hexane-insoluble polyhexamethylenimine having an 
average molecular weight of 2,040 was mixed with 100 parts of benzene. 
When the mixture was allowed to stand in the air at room temperature for 5 
minutes, a butter-like solid gel formed. 
One part of the hot hexane-soluble polyhexamethylenimine having an average 
molecular weight of 540 was mixed with 5 parts of benzene. The mixture was 
transferred to a beaker containing 0.1 part of water, and allowed to stand 
at room temperature for 1 day. A pudding-like gel formed, which easily 
disintegrated upon touching lightly by a finger. 
One part of the low-boiling product having an average molecular weight of 
142 which had been distilled off under reduced pressure together with 
methanol during the after-treatment of the reaction mixture was mixed with 
5 parts of each of benzene, kerosene, heavy oil and crude oil. The mixture 
was transferred into a beaker containing 0.1 part of water, and allowed to 
stand at room temperature for 1 month. No gellation was noted in any of 
the mixtures tested. 
EXAMPLE 4 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 115 g of hexamethylenediamine and 26.1 g of palladium black, and with 
stirring, they were mixed at 130.degree. C. for 20 hours. After the 
reaction, the reaction mixture was worked up in the same way as in Example 
1 to afford 95 g of polyhexamethylenimine having an average molecular 
weight of 989. 
EXAMPLE 5 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 117 g of hexamethylenediamine and 5.3 g of palladium black, and with 
stirring, they were heated at 220.degree. C. for 30 minutes. Eighty-five 
percent of the hexamethylenediamine charged was reacted. After the 
reaction, the reaction mixture was worked up in the same way as in Example 
1 to afford 80 g of polyhexamethylenimine having an average molecular 
weight of 553. 
One part of the resulting polyhexamethylenimine was mixed with 10 parts of 
gasoline. The mixture was transferred into a beaker containing 0.1 part of 
water, and allowed to stand in the air at room temperature for 1 day. A 
pudding-like gel formed. 
EXAMPLE 6 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 115 g of hexamethylenediamine, 200 ml of benzene and 5.4 g of 
palladium black, and they were heated at 180.degree. C. for 40 hours. 
After the reaction, the benzene was distilled off to afford 92 g of 
polyhexamethylenimine having an average molecular weight of 1,430. 
One part of the resulting polyhexamethylenimine was mixed with 50 parts of 
styrene. When the mixture was allowed to stand in the air at room 
temperature for 1 hour, a pudding-like gel formed. 
EXAMPLE 7 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 117 g of hexamethylenediamine and 11.2 g of palladium acetate, and 
with stirring, they were heated at 161.degree. C. for 32 hours. After the 
reaction, the reaction mixture was worked up in the same way as in Example 
1 to afford 94.5 g of polyhexamethylenimine having an average molecular 
weight of 1,100. 
EXAMPLE 8 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 116 g of hexamethylenediamine and 8.7 g of palladium chloride, and 
with stirring, they were heated at 160.degree. C. for 31 hours. After the 
reaction, the reaction mixture was worked up in the same way as in Example 
1 to afford 91 g of polyhexamethylenimine having an average molecular 
weight of 1,121. 
EXAMPLE 9 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 116 g of hexamethylenediamine and 11.5 g of 
tetrakis(triphenylphosphine)palladium, and they were heated at 163.degree. 
C. for 80 hours. After the reaction, the reaction mixture was worked up in 
the same way as in Example 1 to afford 90 g of polyhexamethylenimine 
having an average molecular weight of 1,213. 
EXAMPLE 10 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 115 g of hexamethylenediamine and 55 g of a catalyst resulting from 
supporting 11% palladium black on molecular sieve. With stirring, they 
were heated at 170.degree. C. for 39 hours. After the reaction, the 
reaction mixture was worked up in the same way as in Example 1 to afford 
94 g of polyhexamethylenimine having an average molecular weight of 1,410. 
EXAMPLE 11 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 117 g of hexamethylenediamine and 50 g of a catalyst resulting from 
supporting 5% palladium black on .alpha.-alumina, and with stirring, they 
were heated at 160.degree. C. for 40 hours. After the reaction, the 
reaction mixture was worked up in the same way as in Example 1 to afford 
97 g of polyhexamethylenimine having an average molecular weight of 1,510. 
EXAMPLE 12 
A nitrogen-purged 500 ml stainless steel autoclave was charged with 117 g 
of hexamethylenediamine and 5.1 g of palladium black, and with stirring, 
they were heated at 165.degree. C. for 29 hours. As the heating proceeded, 
ammonia was generated, and the internal pressure of the autoclave 
increased. Thus, the ammonia was released occasionally to maintain the 
pressure of the reaction system at less than 5 kg/cm.sup.2. After the 
reaction, the reaction mixture was cooled, and the contents of the 
autoclave were dissolved in methanol. The catalyst was separated by 
filtration, and methanol and low-boiling products were distilled off under 
reduced pressure to afford 89 g of a yellowish white polymer. The amount 
of ammonia generated in this reaction was 0.99 mole per mole of 
hexamethylenediamine. 
The polymer had an average molecular weight, measured for its benzene 
solution by a vapor pressure osmometer, of 1,364. The elemental analysis 
values of this polymer were as follows: 
C: 73.57%, N: 13.32%, H: 13.11%. 
From the above elemental analysis values, the composition formula 
(empirical formula) of the polymer was C.sub.6.5 H.sub.13.8 N.sub.1. 
The amines of this polymer were quantitatively analyzed in accordance with 
the method of S. Siggia. The results were as follows: primary amine 2.1 
mole%, secondary amine 84.9 mole%, tertiary amine 13.0 mole%. 
The infrared absorption spectrum of the resulting polymer is shown in FIG. 
3, and its .sup.1 H--NMR spectrum, in FIG. 4. 
The infrared absorption spectrum of the polymer showed absorptions at 3250, 
1460 and 1127 cm.sup.-1 characteristic of the secondary amine, and an 
absorption at 725 cm.sup.-1 characteristic of a zigzag methylene chain 
consisting of at least 4 carbon atoms. Its .sup.1 H--NMR spectrum showed 
an absorption of methylene proton at the .alpha.-position of amino group 
at .delta.2.52 ppm, and absorptions of protons of other methylenes and 
amine at .delta.1.1-1.8 ppm. The area ratio of these absorptions was 
1:2.15. 
From the above results of analyses, this polymer was determined to be a 
linear polymer having the recurring unit 
##STR20## 
One part of the resulting polymer was mixed with 25 parts of each of 
benzene, styrene, kerosene, heavy oil and crude oil. The mixture was 
transferred into a beaker containing 0.1 part of water, and allowed to 
stand at room temperature for 1 hour. A pudding-like gel formed in either 
case. 
A mixture of 1 part of the polymer and 25 parts of benzene was placed in a 
dried and nitrogen-purged flask, and sealed. It was allowed to stand for 1 
month at room temperature in this state. No gel was seen to form. 
EXAMPLE 13 
A nitrogen-purged 500 ml stainless steel autoclave was charged with 230 g 
of hexamethylenediamine and 13 g of tetrakis(triphenylphosphine)palladium, 
and with stirring, they were heated at 173.degree. C. for 98 hours. As the 
heating proceeded, ammonia was generated, and the internal pressure of the 
autoclave increased. Thus, the ammonia was released occasionally to 
maintain the pressure of the reaction system at less than 6 kg/cm.sup.2. 
After the reaction, the reaction mixture was cooled, and the contents of 
the autoclave were dissolved in methanol. The catalyst was separated by 
filtration, and methanol and low-boiling products were distilled off under 
reduced pressure. The residue was mixed with hot hexane, and the insoluble 
portion of the polymer was separated by filtration to afford 53 g of a 
polymer. 
The polymer had an average molecular weight, as measured for its benzene 
solution by a vapor pressure osmometer, of 2,901. The elemental analysis 
values of the polymer were as follows: 
C: 73.13%, N: 13.56%, H: 13.21%. 
The composition formula of the polymer was therefore C.sub.6.3 H.sub.13.6 
N.sub.1. 
The amines of the polymer were quantitatively analyzed, and the results 
were as follows: 
Primary amine 1.8 mole% 
Secondary amine 91.5 mole% 
Tertiary amine 6.7 mole% 
The infrared absorption spectrum and .sup.1 H-NMR spectrum of the polymer 
were almost the same as FIGS. 3 and 4 of Example 12. 
Accordingly, this polymer is considered to be a substantially linear 
polymer having the recurring unit --(CH.sub.2).sub.6 --NH--. 
One part of the resulting polymer was mixed with 50 parts of light oil. The 
mixture was transferred to a beaker containing 0.1 part of water, and 
allowed to stand in the air at room temperature for 30 minutes. A 
pudding-like gel formed. 
COMATIVE EXAMPLE 1 
A nitrogen-purged 500 ml stainless steel autoclave was charged with 150 g 
of hexamethylenimine and 21 g of 47% boron trifluoride ethyl ether, and 
with stirring, they were heated at 270.degree. C. for 24 hours. After the 
reaction, the reaction mixture was cooled, and the contents of the 
autoclave were mixed with a 20% aqueous solution of sodium hydroxide and 
200 ml of benzene in a beaker. The mixture was allowed to stand for 1 day. 
The upper layer was withdrawn, and washed several times with a large 
quantity of water. The unreacted hexamethylenimine and low-boiling 
products were distilled off under reduced pressure to afford 54 g of a 
reddish brown viscous polymer. 
The polymer had an average molecular weight, as measured for its benzene 
solution by a vapor pressure osmometer, of 307. The elemental analysis 
values of the polymer were as follows: 
C: 76.43%, N: 9.49%, H: 14.08%. 
The amines of the polymer were quantitatively analyzed by the method shown 
in Example 1, and the results were as follows: 
Primary amine 10.1 mole% 
Secondary amine 22.9 mole% 
Tertiary amine 67.0 mole% 
The infrared absorption spectrum and the .sup.1 H--NMR spectrum of the 
polymer are shown in FIGS. 5 and 6, respectively. FIGS. 5 and 6 
considerably differed from FIGS. 3 and 4 of Example 12. 
From the results of analyses, it was found that the polymer had a much 
branched structure and was not linear. 
One part of the polymer was mixed with 25 parts of each of benzene, 
styrene, kerosene and heavy oil. The mixture was transferred into a beaker 
containing 0.1 part of water, and allowed to stand at room temperature for 
1 month. No gel was formed in any of the mixtures tested, and the organic 
solutions remained as a uniform solution. 
EXAMPLE 14 
A nitrogen-purged 500 ml stainless steel autoclave was charged with 232 g 
of hexamethylenediamine and 3 g of palladium black, and with stirring, 
they were heated at 150.degree. C. for 35 hours. As the heating proceeded, 
ammonia was generated, and the internal pressure of the autoclave 
increased. Thus, the ammonia was released occasionally to maintain the 
pressure of the reaction system at less than 5 kg/cm.sup.2. After the 
reaction, the reaction mixture was cooled, and the contents of the 
autoclave were dissolved in methanol. The methanol solution was filtered, 
and then methanol and low-boiling products were distilled off under 
reduced pressure to afford 165 g of a white solid polymer having an 
average molecular weight of 1,520. 
One part of the resulting polyhexamethylenimine was mixed with 25 parts of 
each of benzene, styrene, methyl methacrylate, kerosene, heavy oil and 
crude oil. The mixture was transferred into a beaker containing water, and 
allowed to stand at room temperature for 1 hour. All of the mixtures 
became a pudding-like gel. 
A mixture of 1 part of the resulting polyhexamethylenimine and 25 parts of 
benzene was thoroughly dried, sealed in a nitrogen-purged flask, and 
allowed to stand there at room temperature for 1 month. No gel was seen to 
form. 
EXAMPLE 15 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 30 g of ethylenediamine and 5.3 g of 
palladium black, and with stirring, they were heated at 160.degree. C. for 
40 hours. A yellowish white polymer formed. The polymer was dissolved in 
methanol, and the methanol solution was filtered. When the solvent and 
low-boiling products were distilled off by heating under reduced pressure, 
64 g of a polymer having an average molecular weight of 845 was obtained. 
The amount of ammonia generated was 0.98 mole per mole of the starting 
amine. The results of elemental analysis values of the polymer were as 
follows: 
C: 65.6%, H: 12.7%, N: 21.7%. 
It was confirmed from the infrared absorption spectrum and the nucleus 
magnetic resonance spectrum of the product that the low-boiling products 
which had been distilled off under reduced pressure were mainly 
hexametylenimine and piperazine. 
EXAMPLE 16 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 30 g of ethylenediamine, and 5.2 g of 
palladium black, and with stirring, they were heated at 161.degree. C. for 
100 hours. After the reaction, the reaction mixture was worked up in the 
same way as in Example 15 to afford 62 g of copolyalkylenimine having an 
average molecular weight of 1,320. 
EXAMPLE 17 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 57 g of hexamethylenediamine, 29 g of ethylenediamine, and 0.18 g of 
palladium black, and with stirring, they were heated at 230.degree. C. for 
40 hours. After the reaction, the reaction mixture was worked up in the 
same way as in Example 15 to afford 60 g of copolyalkylenimine having an 
average molecular weight of 880. 
EXAMPLE 18 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 29 g of ethylenediamine and 5.4 g of 
palladium black, and with stirring, the mixture was heated at 200.degree. 
C. for 8 hours. After the reaction, the reaction mixture was worked up in 
the same way as in Example 15 to afford 58 g of copolyalkylenimine having 
an average molecular weight of 740. 
EXAMPLE 19 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 59 g of hexamethylenediamine, 30 g of ethylenediamine and 27.0 g of 
palladium black, and with stirring, they were heated at 128.degree. C. for 
50 hours. After the reaction, the resulting mixture was worked up in the 
same way as in Example 15 to afford 55 g of copolyalkylenimine having an 
average molecular weight of 1,432. 
EXAMPLE 20 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 57 g of hexamethylenediamine, 28 g of ethylenediamine and 5.3 g of 
palladium black, and with stirring, they were heated at 218.degree. C. for 
50 minutes. After the reaction, the reaction mixture was worked up in the 
same way as in Example 15 to afford 50 g of copolyalkylenimine having an 
average molecular weight of 492. 
EXAMPLE 21 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 30 g of ethylenediamine, 200 ml of 
benzene and 5.4 g of palladium black, and they were heated at 182.degree. 
C. for 43 hours. After the reaction, benzene was distilled off to afford 
57 g of copolyalkylenimine having an average molecular weight of 780. 
EXAMPLE 22 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 59 g of hexamethylenediamine, 30 g of ethylenediamine and 11.3 g of 
palladium acetate, and with stirring, they were heated at 171.degree. C. 
for 39 hours. After the reaction, the reaction mixture was worked up in 
the same way as in Example 15 to afford 63 g of copolyalkylenimine having 
an average molecular weight of 892. 
EXAMPLE 23 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 87 g of hexamethylenediamine, 15 g of ethylenediamine and 8.7 g of 
palladium chloride, and with stirring, they were heated at 160.degree. C. 
for 35 hours. After the reaction, the reaction mixture was worked up in 
the same way as in Example 15 to afford 79 g of copolyalkylenimine having 
an average molecular weight of 1,085. 
EXAMPLE 24 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 39 g of hexamethylenediamine, 40 g of ethylenediamine, and 11.5 g of 
tetrakis(triphenylphosphine)palladium, and they were heated at 170.degree. 
C. for 100 hours. After the reaction, the reaction mixture was worked up 
in the same way as in Example 15 to afford 55 g of copolyalkylenimine 
having an average molecular weight of 470. 
EXAMPLE 25 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 30 g of ethylenediamine, and 55 g of a 
catalyst resulting from supporting 11% palladium black on molecular sieve, 
and with stirring, they were heated at 170.degree. C. for 40 hours. After 
the reaction, the reaction mixture was worked up in the same way as in 
Example 15 to afford 60 g of copolyalkylenimine having an average 
molecular weight of 890. 
EXAMPLE 26 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 31 g of ethylenediamine and 54 g of a 
catalyst resulting from supporting 5% palladium black on .alpha.-alumina, 
and with stirring, they were heated at 160.degree. C. for 80 hours. After 
the reaction, the reaction mixture was worked up in the same way as in 
Example 15 to afford 64 g of copolyalkenimine having an average molecular 
weight of 939. 
EXAMPLES 27 to 35 
The procedure of Example 15 was repeated under the various conditions shown 
in Table 1. The results are also shown in Table 2. 
Table 1 
__________________________________________________________________________ 
Reaction 
conditions 
Hexa- 
diaminemethylene 
##STR21## Catalyst 
tureTempera- 
Time 
Example 
(g) (g) (g) (.degree.C.) 
(hr) 
__________________________________________________________________________ 
27 58 1,3-Diamino- 
Palladium 
162 72 
propane black 
37 5.4 
28 57 Diethylene- Palladium 
165 83 
triamine black 
52 5.3 
29 55 Tetraethylene- 
Palladium 
160 54 
pentamine black 
95 5.4 
30 59 1,4-Diamino- 
Palladium 
163 38 
butane black 
44 5.4 
31 58 1,9-Diamino- 
Palladium 
163 49 
nonane black 
79 5.2 
32 87 1,3-Diamino- 
Palladium 
165 51 
propane acetate 
19 11.2 
33 88 Triethylene Tetrakis 
164 43 
tetramine (triphenyl- 
37 phosphine) 
palladium 
11.5 
34 88 1,9-Diamino- 
Palladium 
164 62 
nonane black 
40 5.4 
35 29 1,9-Diamino- 
Palladium 
163 63 
nonane black 
119 5.4 
__________________________________________________________________________ 
Table 2 
______________________________________ 
Average 
Yield of molecular Elemental analysis values 
polyalkylen- 
weight of of copolyalkylenimine 
Ex- imine polyalkylen- 
(%) 
ample (g) imine C H N 
______________________________________ 
27 70 1,173 67.2 12.8 19.9 
28 87 852 62.9 12.4 24.7 
29 129 998 62.0 11.1 26.9 
30 80 1,260 69.6 12.9 17.4 
31 110 1,890 73.0 13.3 13.7 
32 80 1,051 71.2 13.0 15.8 
33 93 1,580 66.6 12.7 20.7 
34 120 2,050 74.0 13.2 12.8 
35 122 2,190 74.9 13.4 11.7 
______________________________________ 
EXAMPLE 36 
A dried and nitrogen-purged 500 ml stainless steel autoclave was charged 
with 58 g of hexamethylenediamine, 15 g of ethylenediamine, 19 g of 
1,3-diaminopropane and 5.4 g of palladium, and they were heated at 
175.degree. C. for 120 hours. After the reaction, the reaction mixture was 
worked up in the same way as in Example 15 to afford 70 g of 
copolyalkylenimine having an average molecular weight of 1,290.