DD221462A1 - METHOD FOR PRODUCING POLYMERIC UREA DERIVATIVES - Google Patents

Abstract

This can be used to produce modifiers which are used in particular in the coatings industry, in the woodworking and textile industry and in the manufacture of adhesives. The aim of the invention is to produce polymeric urea derivatives from vinyl alcohol-containing polymers / copolymers and urea-formaldehyde condensates in such a way that the starting nitrogen compound is predominantly covalently bonded to the polymer. For this purpose, a solution of mono- or polymethylolated urea compounds or their low molecular weight ethers is added in a non-aqueous solvent at temperatures below 383 K to an already dissolved mixture of acidic catalyst and vinyl alcohol-containing polymers or copolymers.

Description

VEB Leuna-Werke. Leuna, the

"Walter Ulbricht"

LP 8401.

Title of the invention

Process for the preparation of polymeric urea derivatives

Field of application of the invention

The invention relates to a process for the preparation of polymeric urea derivatives which are used as modifiers, in particular in the coatings industry, in the woodworking and textile industry and in the manufacture of adhesives.

Characteristic of the known technical solutions

It is known that the condensation products of urea and formaldehyde can be modified according to the requirements of all the woodworking and the textile and paint industry.

The modifiers added before, during or after the condensation reaction of urea with formaldehyde have the task of improving properties such as viscosity and aging behavior.

1 & 0EI.1993 * i37ül8

formaldehyde elimination, rollability, brittleness, water and chemical resistance of cured amino resin layers and to influence the adhesion of corresponding solutions to paper and textile fabric.

One group of such modifiers are lower and middle alcohols (U.S. Patent No. 3,957,731, DE-AS No. 1,445,271), which are reacted in various ways with the amino resin products.

Furthermore, it is known that one can modify aqueous Aminoharzlösungen with high molecular weight polyvinyl compounds. The water-soluble polyvinyl alcohol (JP-PS 58 015 520) is preferably used for this purpose.

If water-insoluble polyvinyl compounds or their copolymers are used, they are diaperated in the urea-formaldehyde solution (British Patent 1,287,829).

Due to the reactivity of the urea-formaldehyde condensates with one another, a direct chemical reaction between them and polymers and copolymers containing vinyl groups can only be realized to a small extent in an aqueous medium. The reactions of this kind cited in the literature are likely, according to recent analytical investigations in the. The majority are physically mixed material systems with characteristic properties.

In order to counteract this disadvantage, DE-PS 3,043,616 has proposed the separate preparation of an amino resin modifier, which is then added to the actual amino resin solution.

In the case of polyvinyl alcohol, G. A. Permjakova used dimethylformamide as solvent (Naucno-issledovatelskie trudy VHIIPIK 1971, 20, 115 - 120).

However, the use of dimethylformamide as the solvent alone does not cause any change in the direction of chemically linked components with new properties. The performance parameters of the products thus produced continue to point to mixtures of high polymers with self-condensed urea-formaldehyde compounds.

Object of the invention

The aim of the invention is to produce polymeric urea derivatives so that modifiers with a new property pattern arise.

Explanation of the essence of the invention

The object of the invention is to produce polymeric urea derivatives from vinyl alcohol-containing polymers or copolymers and urea-formaldehyde condensates in such a way that the starting nitrogen compound is predominantly covalently bonded to the polymer.

This object is achieved in that in non-aqueous solvent at temperatures below 383 K to an already dissolved mixture of acid catalyst and vinyl alcohol-containing polymers or copolymers, a solution of mono- or polymethylolierten urea compounds or their low molecular weight ethers is added.

Here are ala solvent dimethyl sulfoxide, dimethylformamide, IT methyl caprolactam or solvent mixtures containing them in embossing.

The polymer / copolymer is first dissolved with heating and stirring. This is followed by the catalyst addition. Mineral acids, organic acids, their anhydrides and cation exchangers are used. The separately dissolved urea derivative is slowly added dropwise in the third reaction step. The non-aqueous solvent, the dosing order and the use of dilute solutions prevent the self-condensation of the reactive urea derivatives. In addition, in order to avoid decomposition of the urea derivatives at temperatures below 383 K, but in any case below the melting point of these substances. Any water of reaction does not need to be distilled off.

The reaction is terminated by precipitation of the reaction products in methanol or in methanol / acetone. If a purification of unreacted adsorbed urea derivatives erfoderlich, a reprecipitation can be connected in a known manner.

embodiments

.Example 1

In a three-necked flask equipped with a heater, stirrer and reflux condenser, 200 ml of dimethylformamide and 15 g of polyvinyl alcohol are heated to 70 ⁰ C with stirring. After 2 hours, 30 ml of pre-swollen, strongly acidic cation exchanger 0K80 are added.

After a further 15 minutes, the dropwise addition of 30 g of monomethylol harnate dissolved in 200 ml of dimethylformamide begins. Daa dropwise addition is carried out after 2 hours, and the reaction is terminated by filtration. After precipitation in methanol / acetone, a product is obtained which contains 18.5 % of nitrogen.

Beiapiel 2

In the above apparatus, 150 ml of dimethylformamide, 535 ml of toluene and 29 g of ethylene-vinyl alcohol copolymer are heated to 100 ⁰ C. Έβ ch adding 2 g of p-Toluolaulfonaäure starting the dropwise addition of 10.8 g in 410 ml of dimethylformamide gelöatem Monomethylolharnatoff. After 4 hours, the reaction is stopped as described above. Daa product contains 5 % nitrogen, is more flexible than the Auagangacopolymere and has a 30% lower dynamic glass transition temperature. The tensile strength is 28% higher.

Claims (1)

invention claim A process for the preparation of polymeric urea derivatives by reacting meth.ylolierter urea compounds with vinyl alcohol-containing polymers or copolymers, characterized in that in non-aqueous solvent at temperatures below 383 K to an already dissolved mixture of acidic catalyst and vinyl alcohol-containing polymers or copolymers, a solution of mono - or polymethyloierten urea compounds or their low molecular weight ethers is added.