DE872269C - Process for stabilizing polyalkyleneimines - Google Patents

Description

Procedure for. Stabilization of polyalkylenimines solutions of polymerization products Polyalkylenimines often show the property of becoming gradually more stable to become more viscous. This is especially the case when using crude alkylenimines has polymerized, which are still more or less large amounts of organically bound Contain halogen, which over time gives rise to further polymerisation, or if organic halogen compounds have also been used for the polymerization. It is also often difficult to direct the polymerization so that the desired degree of polymerization is not exceeded.

It has now been found that alkaline agents can be used to produce solutions of polyalkylenimines and stabilize the polymerization of alkylenimines, the z. B. is carried out according to the method of patent 665 791, in the desired state of polymerization or interrupt it immediately when the desired viscosity level is reached can.

Suitable alkaline agents are, for. B. Alkali and alkaline earth metal hydroxides, acetates, alcoholates, phenates or glycolates, and also alkali metal carbonates and especially alkali metal salts of aminocarboxylic acids, such as glycine, sarcosine, Phenylglycine or nitrilotriacetic acid. Solutions of these are expediently used Medium, e.g. B. in water or in water-soluble alcohols. Sufficient for stabilization generally even small amounts thereof; but at least required man such an amount of alkaline agents that are present in the reaction mixture, organically bonded halogen is equivalent.

The process represents a major step forward in particular, than it is now possible, alkylenimines with strongly polymerizing agents to polymerize in a short time and without special precautionary measure rules, without that one must fear that the polymerization will elude control and leads to undesirably high degrees of polymerization.

The parts mentioned in the following examples are parts by weight.

Example i To a mixture of 50 parts of polymeric ethyleneimine, zoo parts of monomeric ethyleneimine and 50 parts of water are added 0.28 parts of ethylene chloride. The mixture is then heated to about 70 ° while passing through carbon dioxide and with stirring, and the bath temperature is increased to 100 ° as the polymerization progresses. Care must be taken to ensure that only a slight reflux of monomeric ethyleneimine can be observed. Since a large amount of heat develops during the polymerization, the temperature of the reaction mixture rises above the bath temperature. As soon as the reaction temperature begins to drop, the reaction mixture is cooled to 70 °, whereupon further zoo parts of ethyleneimine and 0.56 parts of ethylene chloride are added. The mixture is heated again slowly as the polymerization progresses up to a bath temperature of 10 ° and the mixture is kept at this temperature until the reaction product has the desired viscosity. A solution of 4.5 parts of 500% sodium hydroxide solution in 10 parts of water is then added. The reaction mixture is finally diluted to the desired viscosity with water. This remains almost unchanged even after long periods of storage, while a solution that has not been mixed with caustic soda becomes more and more viscous over time.

If you use a solution instead of the above-mentioned amount of sodium hydroxide solution of 1.84 parts of glycine and 2.35 parts of 500 / o strength sodium hydroxide solution in 20 parts of water, this gives a similar result.

EXAMPLE 2 150 parts of ethyleneimine are mixed with 60 parts of water, adds 0.1 part di- (ß-chloroethyl) amine and heats within 5 hours while passing through of carbon dioxide to 10 °, until the self-heating polymerization subsides. Then left at 90 ° more 15o parts of ethylene imine and 0.2 parts of ethylene chloride flow in. After the renewed self-warming has subsided, more are given 300 parts of ethyleneimine and 0.3 parts of hydrochloric acid di- (fB-chloroethyl) amine in three parts while waiting for the reaction to subside. Finally one adds a solution of 1.2 parts of glycine and 1.36 parts of 500 / uiger sodium hydroxide solution in 10 parts Add water. A highly viscous, stable solution is obtained.

Example 3 Addition. a mixture of 50 parts of water, 50 parts polymeric ethyleneimine and 3oo parts of ethyleneimine with o, iq. Share ethylene chloride and 0.18 parts of butylene chloride and heated with stirring until the reaction subsides. Then you add more zoo parts of ethylene imine and 0.4 parts of ethylene chloride and 0.18 Add butylene chloride and repeat this after the polymerization has subsided again, adding another 0.18 parts of butylene chloride. After again A solution of 8.2 parts of N-phenylglycine and 5.7 is allowed to drop in temperature Parts of 50% sodium hydroxide solution in 20 parts of water flow in, there are still 1.6 parts Butylene chloride is added and the mixture is warmed to 10 ° for a short time. A viscous, stable solution.

Claims (1)

PATENT CLAIM: Process for stabilizing solutions of polyalkylenimines and for regulating the polymerization of alkylenimines, characterized in that alkaline agents are added.