Patent GB-990489-A (GB)
Title: Foamed epoxy resins
IPC: C08G77/38
Filed: 1963-01-11
Abstract: An epoxy-resin foam is produced by allowing a polyepoxy compound and a polyamine to interact in the presence of a borohydride and an organopoly-siloxane comprising a chain of units I and II: <FORM:0990489/C3/1> <FORM:0990489/C3/2> where R1 is a hydrocarbon radical, e.g. an alkyl radical of up to 10 carbon atoms or a phenyl radical and R2 is a divalent hydrocarbon or ether group, e.g.-(CH2)2-, -CH2-O-CH2-or -(CH2)3-O-CH2-.  The ratio of the number (a) of units of type I and the number (b) of units of type II may vary from 10:1 to 1:10 and a+b may be 2 to 100. Terminal groups for the chain may be HO-or (CH3)3SiO-and -H or -Si(CH3)3.  Such compounds may be prepared by the interaction at 150 DEG  C. of an olefinically unsaturated epoxide, e.g. CH2= CHCH(O)CH2 or CH2=CHCH2-O-CH2 CH(O)CH2, and an Si-H bond.  0.5-10% may be present during foaming. Specified polyepoxy compounds are reaction products of epihalohydrins with 4 : 41-dihydroxy-diphenyl-dimethyl - methane, p : p1-dihydroxy - phenyl-propane, N,N1-dimethyl-N :N1-di-2 :3-epoxy-propyl - 4 : 41 - diamino - diphenyl - methane, the diglycidyl ether of butane-1 : 4-diol, the triglycidyl ether of 1 : 1 : 1-trimethylol propane and epoxides of glycol-bis-oxo-dihydroxy-dicyclopentadienyl ether. Mixtures of polyepoxy compounds of different epoxide equivalents, e.g. 180-240 and 300-400, may be used. Specified polyamines are ethylene diamine, propylene diamine, butylene diamine, diethylene triamine, triethylene tetramine, tetraethylene, pentamine, pentaethylene hexamine, hexaethylene heptamine, butane-1 : 4-diol diamino propyl ether, o  : o 1-di-(ethylene diamino)-dibutyl ether and 4 : 41-diamino-dicyclohexyl-methane. The polyamine may be used in up to 30% excess. Specified borohydrides are those of Na, K, Zn, Ca, Mg.  0.5-10% may be present. Accelerators 5-60% diluents, e.g. esters, ketones, ethers, CH2Cl2, C2H4Cl, C2H3Cl3 and CCl3F and 0.3-6% water and alcohols may also be present. The reaction may be carried out at 10-30 DEG C. and may be in a closed mould. In Example (1) an organopolysiloxane was prepared by hydrolysing a mixture of methyl hydrogen dichlorosilane and trimethyl monochlorosilane in water and reacting the product with allyl glycidyl ether at 150 DEG C. using Pt on Al2O3 as catalyst. The product was used to stabilize a foam produced by reacting the diglycidyl ether of 4,41 - dihydroxy - diphenyl - dimethyl - methane with triethylene tetramine in the presence of sodium borohydride and water.  In the other examples the same polyepoxy-compound was foamed using (2) the same stabilizer, sodium borohydride, methanol and bis-[4(2-aminoethylamino) butyl] ether, (3) the same stabilizer, dichloroethylene, bis [4(2-aminoethylamino) butyl] ether, sodium borohydride and methanol, (4) the same stabilizer, CCl3F, bis [4(2-aminoethylamino) butyl] ether, sodium borohydride and methanol (5) an organopolysiloxane prepared using butadiene mono-oxide in place of allyl glycyl ether, sodium borohydride, triethylene tetramine, methanol and water, (6) the polysiloxane of Example 1, sodium boronate, dichloroethylene, triethylene tetramine, isopropyl alcohol and water, (7) the stabilizer of Example 5, triglycyl ether of 1 : 1 : 1-trimethylol propane, potassium boronate, trichloromonofluoromethane, bis [4(2-amino-ethylamino) butyl] ether, methanol and water.