CS244205B1 - Process for producing cationized starch - Google Patents

Abstract

Process for preparing cationized starch by reacting a condensation product prepared from 1 to 4 parts of ammonium sulfate and 1 part of formaldehyde at 20 to 50 ° C for 30 to 240 minutes; cured at 1 part of the condensation product to 10 to 15 parts of potato, foam or corn starch. After homogenization of the condensation tube and the starch, cationization takes place for 15 to 60 minutes at 20 to 25 ° C, after which the reaction product is dried at a temperature below 80 ° C; optionally after diluting with water to 20 to 30% of the dry matter thermally treated and dried.

Description

(54) Method for producing cationized starch

A process for producing cationized starch by reacting a condensation product prepared from 1 to 4 parts ammonium sulfate and 1 part formaldehyde at a temperature of 20 to 50 ° C for 30 to 240 minutes; 1 part of the condensation product per 10 to 15 parts of potato, wheat or corn starch. After homogenization of the condensation product and starch, the cation is carried out for 15 to 60 minutes at 20 to 25 ° C, after which the reaction product is dried at a temperature of up to 80 ° C; optionally, after dilution with water to 20 to 30% dry matter, thermally treat and dry.

The invention relates to a process for the production of cationized starches.

Cationized Starches are technically important substances used as auxiliaries in various industries and agriculture. Their use is constantly expanding.

Chemically, starches are either nitrogen-containing ethers which, in acidic environments, provide a cationically positively charged group (araino or imino ethers) or ethers containing a quaternary ammonium group.

Ethers with tertiary amino groups are prepared, for example, by the reaction of a alkaline starch suspension and a suitable tertiary amine containing halogen in one of the alkyl chains - e.g., 2-chloroethyldimethylamine, 2-chlorotriethylamine, and the like.

The resulting tertiary aminoalkyl starch is converted to a cationic salt by treatment with, for example, hydrochloric acid. Starch ethers with quaternary ammonium groups are most often prepared by reacting starch with 2,3- (epoxypropyl) trimethylammonium chloride. The reaction is carried out at a temperature of 40 to 50 ° C in a mildly alkaline environment.

In this reaction, however, harmful residues remain in the starch, which limits the applicability of the product to hygienically undemanding purposes.

Said cationic agents have a large molecule which is difficult to penetrate into native starch grains. They require chemical treatment of starch before alkalization - alkalization.

In addition, they are either expensive or made from less available raw materials, which increases the cost of manufacturing the product.

Significant cheaper and simplified production of cationized starches can be achieved according to the invention by cationizing the reaction of starch with formaldehyde condensation products with ammonium salts or amines.

The reaction of formaldehyde with ammonium salts in a weakly acidic environment produces a mixture of methanol- and dimethanolainin; Depending on the reaction conditions, methylene amine may be formed as the end product in an acid medium.

At higher temperatures, a mixture of methyl, dimethyl and trimethylamine can be obtained. Reaction of formaldehyde and primary or secondary amines in aqueous solution produces methylated amine derivatives in the cold, methylation occurs in the heat in nitrogen.

For the production of cationized starch, it is desirable to carry out the reaction in such a way as to produce predominantly methanolamine, as more substituted derivatives may cause starch crosslinking, which is usually undesirable for the use of the product.

The process for the preparation of cationized starches by reaction with the condensation products of formaldehyde with ammonium salts in a weakly acidic medium according to the invention is characterized in that the cationic agent is a solution of formaldehyde and ammonium sulphate or other ammonium selenium or organic amine in a molar ratio of 1: 1 to 1. 1: 4. After 30 to 240 minutes, one part of the reaction mixture is added to 10 to 15 parts potato, corn or wheat at 30 to 50 ° C; starch and homogenized in the mixer.

After 15 to 60 minutes, the product is either dried at a temperature of up to 80 ° C or dispersed in water to a dry matter content of 20 to 30 weight percent and thermally modified and dried.

In the first case, the cationized starch is lubricated by the user, in the second case the product is water-soluble.

The process according to the invention is advantageous in that the raw materials for cationization are available and inexpensive and the process does not require pre-treatment of the starch with alkalization. As a result, the cationization apparatus is also simpler.

Example 1

26 parts of ammonium sulfate and 8 parts of 38% formaldehyde are dissolved in 50 parts by weight of water. The reaction mixture was heated at 20 ° C for 3 hours and added to 100 parts of dry potato starch. After homogenization, it is left to stand for 15 minutes and then dried at 80 ° C.

The water extracted sample contains 0.6% nitrogen per dry matter.

Example 2

The procedure is the same as in Example 1, except that the amount of monium sulfate is 19.5 parts and corn starch is used instead of potato starch. The bound nitrogen content is 0.85%.

Example 3

Working procedure as in Example 1, except that 21 parts of ammonium chloride are used instead of ammonium sulfate. The product contains 0.54% bound nitrogen.

Example 4

The procedure is the same as in Example 2, except that wheat starch is used and the product is dried at room temperature. The combined nitrogen content of the product was 2.4%.

Example 5

The procedure is the same as in Example 2, except that the tempering time of the ammonium sulfate and formaldehyde solution is 1 hour. The combined nitrogen content of the product was 0.84% t

Example 6

13 parts of ammonium sulfate and 16 parts of 38% formaldehyde solution are dissolved in 40 parts of water. The reaction mixture is heated at 30 ° C for 1 hour and then added to 100 parts dry potato, wheat or corn starch. After 1 hour reaction at 20-25 °, the product is diluted with 400 parts of water, thermally filtered at an oil temperature and dried on a drying cylinder.

Example 7

A mixture of 13 parts of ammonium sulfate and 32 parts of 38% formaldehyde is heated to boiling and evaporated to dryness. 16 parts of a 38% formaldehyde solution and 20 parts of water are added to the cooled crystalline product containing a mixture of methyl, dimethyl, and triethylamine sulfate. After 1 hour at 20-25 ° C, the reaction mixture is added to 100 parts of starch and after 1 hour reaction at 20-25 ° C the product is worked up as in Example 6.

SUBJECT OF THE INVENTION

Claims (2)

Process for the production of cationized starches, characterized in that the cation is carried out by condensation products of formaldehyde with inorganic ammonium salts in a slightly acid medium, preferably with ammonium sulphate in a ratio of 1 to 4 parts ammonium sulphate per part 38 of formladehyde condensed for 30 to 240 minutes at a temperature of 20 to 50 ° C and introducing one part by weight of the condensation product to 10 to 15 parts of potato, maize or wheat starch; by homogenization and after 15 to 60 minutes at 20 to 25 ° C by drying at a temperature of up to 80 ° C. \ 2. A process according to claim 1, characterized in that the reaction product of the starch and the cationic agent is dispersed in water to a dry matter content of 20 to 30% by weight, thermally modified and dried. Severography, n. P., MOST Price 2,40 Kčs