CS209064B1 - Process for preparing an aqueous solution of N-methylolacrylamide - Google Patents

Abstract

A method for preparing methylolacrylamide by reacting acrylamide with paraformaldehyde at pH 8 to 11, whereby the hydroxymethylation of acrylamide is carried out by gradually introducing a homogeneous mixture of paraformaldehyde and acrylamide into water with additives of a polymerization inhibitor.

Description

(54) A process for preparing an aqueous solution of N-methyl acrylamide

A process for the preparation of methylolacrylamide by reacting acrylamide with paraformaldehyde at pH 8-11 by carrying out the hydroxymethylation of acrylamide by successively introducing a homogeneous mixture of paraformaldehyde and acrylamide into water with polymerization inhibitor additives.

and '2

The invention relates to a process for preparing an aqueous solution of N-methylolacrylamide by reacting acrylamide * with paraformaldehyde according to the following scheme:

C \

NH

N-methylolacrylamide is formed as an intermediate in the preparation of butoxymethyl acrylamide and is prepared by reacting a homogeneous mixture of paraformaldehyde and acrylamide in butanol. If it is necessary to obtain pure N-methylolacrylamide for some other processes, isolation from the alcoholic solution is necessary.

It has now been found that an aqueous solution of N-methylolacrylamide can be obtained with a very good yield when the reaction is carried out in an aqueous medium.

The above disadvantage is overcome by a process for the preparation of an aqueous solution of N-methylolacrylamide by reacting acrylamide with paraformaldehyde at pH 8-11 according to the invention, which comprises carrying out the hydroxymethylation of acrylamide by successively introducing a homogeneous mixture of paraformaldehyde and acrylamide. 60 ° C and a pH of the reaction mixture of 8 to 11, wherein the molar ratio of water,

CH ² = CH ² CH ² NHCH ₂ OH paraformaldehyde and acrylamide is 0.1 to 0.8: 0.8 to 1.2: 0.8 to 1.2, preferably 0.34: 1.15: 1.

The example below illustrates an embodiment of the invention.

Example

Into a 1/41 flask equipped with a stirrer and a thermometer, 25 g of water, 0.014 g of sodium nitrite as polymerization inhibitor are initially introduced and the pH is adjusted to 9 with 5% aqueous NaOH solution. 71 g acrylamide and 34.6 g 97% paraformaldehyde. After the mixture was introduced into the flask, the contents were stirred at 50-55 ° C for 30 minutes. During this time and during the addition of the mixture, the pH of the solution is continuously controlled and maintained at 9. After the reaction, the methylolacrylamide solution is adjusted to pH = 7 with dilute H ₂ SO _{4. A} total of 135 g of 78% methylolacrylamide aqueous solution is obtained. ·

Claims (1)

SUBJECT VYNALEZU A process for the preparation of methylolacrylamide by reacting acrylamide with paraformaldehyde at pH 8-11, characterized in that the hydroxymethylation of acrylamide is carried out by successively introducing a homogeneous mixture of paraformaldehyde and acrylamide into water with polymerization inhibitor additives at 40-60 ° C and pH of the reaction mixture 8-11. the molar ratio of water, paraformaldehyde and acrylamide is 0.1 to 0.8: 0.8 to 1.2: 0.8 to 1.2, preferably 0.34: 1 to 1: 1.