CS260712B1 - Liquid preparation for increasing the fastness of dyes on the fiber and the method of its production - Google Patents

Abstract

The solution presents liquid preparations for increasing the fastness of substantive wet dyes based on dicyandiamide-formaldehyde condensates containing, based on the preparation as a whole, 1.2 to 4 percent by weight of ammonium chloride and/or sulfate and 35 to 50% water, having a liquid consistency even at low temperatures, high and long-term stability at normal and elevated temperatures, easy solubility even in cold water and high cationic activity. They are prepared by an energy-saving and economically effective reaction of dicyandiamide with ammonium chloride and/or sulfate, with formaldehyde and with ammonia.

Description

The invention relates to liquid preparations for increasing the fastness of dyes to fibers and a method of their production.

Preparations for increasing the fastness of substantive dyes when wet are characterized by a liquid consistency even at low temperatures, high and long-term stability at normal and elevated temperatures, easy solubility even in cold water and high cationic efficiency.

Anionic azo dyes soluble in water have a strong affinity for cellulose. Their characteristic property is to be drawn out of the aqueous solution onto cellulose fibers and to fix themselves thereon — substantively. Fixing substantive dyes with cationic preparations enlarges the molecule of the dye stored in the intermicellar spaces of the cellulose fiber and also reduces its solubility. Both changes prevent easy release of the dye from the fiber, especially during wet treatment of the textile product. Fixing primarily increases wet fastness.

Currently, a wide range of liquid and powder preparations are used for fixing anionic, water-soluble azo dyes, mostly based on dicyandiamide-formaldehyde condensates, which have a number of disadvantages.

Powdered fixatives are prepared from solutions of dicyandiamide formaldehyde condensates, which are not very stable in aqueous solution and easily condense into a highly viscous to solid mass that is difficult to dissolve in water.

According to previously known procedures, cationic fixing preparations based on dicyandiamide formaldehyde precondensates are produced in an acidic environment and stabilized by drying.

For example, dicyandiamide condenses in an aqueous medium in the presence of acids to a water-insoluble condensate with varying amounts of formaldehyde, usually with one to three moles of formaldehyde per mole of dicyandiamide.

The composition of the resin is as follows:

- íý - C Ξ N !

• · — N — C ~ · · J 12.

The condensation product is neutral, soluble in concentrated acids.

The resin prepared in this way is treated in an aqueous environment with acetic, formic, hydrochloric or sulfuric acid, which results in hydration of the nitrile groups, leading to alkalinity of the resin, which simultaneously forms a salt with the acid present.

+ t2.H^0 + nCH^OOH

-N - CHa nh-co-nh.

CH^COO _u

- N - CH~

The next production process proceeds in the opposite direction. Dicyandiamide is treated with a mineral or organic acid in an aqueous medium to obtain a stable salt of the strong organic base of dicyandiamine.

_χ NH-CO-NHr,

HSO^

Subsequent condensation with formaldehyde in an aqueous medium produces a cationic resin in the form of an organic base sulfate, soluble in water and dilute acids.

Another industrially used method is a process in which dicyandiamide is heated with ammonium chloride and converted via biguanide to guanidine chlorhydrate, which is further condensed with formaldehyde on a cationic resin in the form of the chlorhydrate of the organic base.

NH-C ΞΝ

NH II

NH

N H|, CT HpN ™ Č NH — Č NH^

N He on

HCt h-, ra.

NH \ e Π , \ '-x O

H /~,\ί-Ο· NH- Cíp \

CH,

H - V Ç~ C ™ NH-C Hp~ / \ ^i! NH(HCt)?.

20OH/H.

The disadvantage of the previously known processes is the very energy-intensive technology. The prepared cationic resin is unstable in aqueous solutions and is stabilized by the addition of salts, e.g. sodium acetate, and drying.

The addition of sodium acetate, which is added at a rate of 0.9 to 1 part by weight per 1 part by weight of dicyandiamide, causes the release of acetic acid during production and drying due to the acidic nature of the resin. Before drying, which is usually carried out in spray dryers, it is necessary to add a solution of sodium chloride or sulfate in the amount of 2.5 to 3 parts by weight of solutions of these salts per 1 part by weight of dicyandiamide in order to reduce the sticking of the resin to the walls of the dryers.

The dried product contains 40 to 50% by weight of salts and is poorly soluble in water. Before preparing the application solution, the dried product must be kneaded in hot water, i.e. first prepare a slurry from the powder and then dissolve it in warm water, because directly dosing the powder product into warm water forms poorly soluble lumps of this preparation. The dried preparation, containing anhydrous sodium acetate, is hydrotropic and easily absorbs air moisture, which results in the preparation sticking together.

The above-mentioned shortcomings are eliminated by liquid preparations for increasing the fastness of substantive wet dyes based on dicyandiamide formaldehyde condensates of the general formula

NH

H ~ c - N H -· CH$~ OH í L

I i· í Ή

I | í ι V —· H — C — N H — C Hs)— O H \ -i

NiI where n is 4 to 16 and

X represents 2HCl or H2SO4, containing, based on the weight of the preparation as a whole, 35 to 50% water and 1.2 to 4% ammonium chloride and/or sulfate salts.

The method of preparing a stable liquid fixative consists in condensing dicyandiamide with ammonium chloride or sulfate and or their mixture with formaldehyde and ammonia in such a way that a mixture of 1 mole of dicyandiamide is condensed with 2.5 to 3.1 moles of formaldehyde and 1.5 to 2.1 moles of ammonium chloride and/or 0.75 to 1.55 moles of ammonium sulfate and 0.1 to 0.33 moles of ammonium hydroxide at a temperature of 90 to 125 °C.

It has been found that the addition of ammonia, preferably ammonia water, before the beginning or during condensation in an amount of 0.1 to 0.3 moles per 1 mole of dicyandiamide yields a stable, slightly viscous aqueous solution of dicyandiamide-formaldehyde condensate (resin), which dissolves well even in cold water. The fixing agent prepared in this way achieves a high efficiency that is unknown in liquid preparations produced to date and is comparable in its high efficiency to powder preparations.

The use of alkaline ammonium salts and other nitrogenous bases, such as ammonium phosphate, ammonium carbonate, hexamethylenetetramine, triethanolamine and pyridine, was also tested. However, none of these substances achieved the same results as ammonia in the form of ammonia water, both in terms of the feasibility of the operating technology and in the quality and effectiveness of the preparation.

For example, using ammonium carbonate can achieve comparable results as with ammonia, but the reaction process produces a rapid release of carbon dioxide, which causes strong foaming even with slow dosing. The foam formed is difficult to remove, and therefore this salt is not suitable for industrial production of the preparation.

When using hexamethylenetetramine or triethanolamine, the product has a high viscosity, is poorly soluble in water and its cationic activity is lower. Salts are excreted from products prepared using alkaline phosphates, which also have lower activity. When using pyridine, the activity is also lower, the viscosity is high and the product has an unpleasant odor.

Preparations for increasing wet fastness are equally effective whether they are chloride or sulfate of an organic base, or a mixture thereof.

The preparations according to the invention belong to the group of cationic preparations which substantially increase the fastness of substantive dyes and prints on cotton, linen, cellulose, rayon, viscose, cupro and acetate, as well as mixtures of these fibres with animal fibres, to water, sea water, moisture, sweat, wet ironing, finishing, sizing, wet brushing, re-dyeing, scouring and home washing.

Solutions of the preparation according to the invention are stable to water hardness, diluted acids and alkalis, as well as metal salts, which allows its use in combination with metal salts, thereby increasing both wet fastness and light fastness of dyes for which treatment with metal salts alone is not effective. This expands the possibility of using substantive dyes even in cases where versatile fastness is required.

The preparations according to the invention are highly stable, their fixing efficiency has not changed even after 18 months of storage at normal temperatures. The viscosity and color also remain unchanged. When stored at extremely low temperatures, i.e. at -15 to 25 degrees Celsius, they solidify, but when heated to -5 to 0 °C, they reversibly pass into solutions.

Example 1

Cotton fabric "Callot" dyed with Saturn Red F 3B (C.I. Direct Red 80) was dyed by thoroughly rinsing in water to remove the dye adhering to the surface of the fiber. A 1% solution of the preparation was prepared in a fixing device, a tub with a squeegee (so-called long bath).

The cotton fabric was fixed in this solution for 30 minutes at a temperature of 27 to 29° C. The fabric was then freed from the fixing solution, rinsed with water and dried.

The fixing efficiency of the product was determined on a companion fabric of the same material and wool. Fastness tests were performed on the dyed fabric without fixing in the product in comparison with the fabric fixed in the product by tests in water, sweat and washing.

The three numbers of the stability data represent:

Change in shades of the original embedding sample on a backing fabric of the same material and the sample after the embedding test on a wool backing fabric

The color fastness is graded with numbers up to 5, from the lowest fastness to the highest.

Saturn water red

F3B:

sweat pH 5.5 sweat pH 8 wash 40 °C

1—2 1—2 1—2 3 unstable 4—5 3—4 3—4 3—4 3—4 4—5' 4 4-5 4-5 4—5 4—5 3—4 established 4—5 4—5 4—5 4—5 4 4-5 4—5 4—5

Example 2

A cotton-linen blend fabric dyed with Saturn Red LB (C.I. Direct Red 99) was thoroughly rinsed in water to remove the dye adhering to the surface of the fiber.

A 1% solution of the fixative was prepared using a Foulard fixing device. The mixed fabric was fixed in the solution for 30 minutes at a temperature of 25

Saturn's water had a pH of 5.5 at 100 degrees Celsius. The fabric was then stripped of the solution, rinsed with water and dried.

The fixing efficiency of the product was tested on a companion fabric made of the same material, i.e. a cotton-linen and wool blend. Fastness tests were performed on the dyed fabric without fixing and compared with the fabric fixed in a 1% solution of the product by water fastness tests at 30 °C, perspiration and washing.

sweat pH 8 washing °C

1 1 1 2 unstable 4 2—3 4 3—4 3—4 3—4 3 4—5 4—5 4—5 3-4 3—4 established 4 4—5 3—4 4-5 3—4 4—5 4—5 4-5

Example 3

Linen fabric dyed with Saturn Blue LBRR (C.I. Direct Blue 71) was thoroughly rinsed in water to remove the dye adhering to the fiber surface.

A 2% fixative solution was prepared in a continuous short-passage fixer.

Linen fabric was fixed in a solution of this preparation for 8 minutes at a temperature of 60 °C. Then the fabric was freed from the fixing solution, rinsed with water and dried. The fixing efficiency of the preparation was tested on a companion fabric made of the same material, i.e. linen and then on wool. Fastness tests were carried out on a dyed fabric without fixing and compared with the fabric fixed in the preparation, namely by tests of fastness in water, sweat and washing.

Saturn blue LBRR water sweat pH 5.5 1 1 unstable 3—4 3-4 3—4 3—4 4—5 4-5 established 4-5 4 4-5 4—5 Example 4 Fabric from acetate silk dyed-

Saturn Turquoise Blue LG (C.I. Direct Blue 86) was thoroughly rinsed in water to remove the dye adhering to the fiber. A 1% solution of the fixative, stored for 18 months at normal temperature before use, was prepared in a Foulard fixing device. The dyed fabric was fixed in this solution for 30 minutes at 45 °C. After fixing, it was rinsed with water and dried. Light fastness was determined by xenotest on fixed and unfixed samples of acetate silk fabric.

Light fastness has 8 levels of fastness. 1 — (very low) to 8 — (excellent).

Measurement result:

sweat pH 8 washing °C

1 2 3—4 3—4 3—4 4—5 4—5 3—4 4—5 4—5 4—5 4-5 Permanence in the light unsteady fabrics 4 to 5. Permanence in the light established fabrics 6 to 7.

Example 5

Into an enameled reactor with a volume of 3.5 cubic meters, equipped with a stirrer and a duplicator for heating and cooling, 1000 kg of formaldehyde with a concentration of 37% by weight was introduced, to which 600 kg of dicyandiamide and 580 kg of ammonium chloride were added with stirring, and then 80 kg of ammonia water with a content of 25% by weight of ammonia. The mixture was heated to 85 °C by the heat of reaction and then heated to the boiling point, i.e. 118 °C. After 20 minutes, when the violent boiling ended, another 460 kg of formaldehyde was added to the reaction mixture at a gentle boil, which lasted 30 minutes. After this amount of formaldehyde was added, the boiling point temperature dropped to 108 °C. The reaction mixture was maintained at this temperature for another 45 minutes and then cooled to 60 degrees Celsius and drained. A clear, slightly viscous preparation with high cationic activity was obtained.

Example 6

900 kg of formaldehyde with a concentration of 37 percent by weight was introduced into an enameled reactor, and 950 kg of ammonium sulfate and 600 kg of dicyandiamide were added with stirring. The reaction mixture was heated to a boiling point of 120 ^C C, 150 g of ammonia water with a content of 25% ammonia was added. After a violent boiling, which lasted 20 minutes, 850 kg of formaldehyde was added to the reaction mixture over 30 minutes. During the addition of formaldehyde, the reaction mixture was maintained at a gentle boil, which was reduced to 105 °C after all the formaldehyde had been added. Then the reaction mixture was maintained at a temperature of 95 to 105 °C for another 90 minutes, then cooled to 60 °C, 300 l of water was added and drained from the reactor. A clear, slightly viscous liquid fixative with high cationic activity was obtained.

Example 7

400 kg of formaldehyde with a concentration of 37% by weight and 400 kg of water were introduced into the enameled reactor and 410 kg of ammonium sulfate, 340 kg of ammonium chloride and 600 kg of dicyandiamide were added while stirring. The reaction mixture was heated to boiling point, i.e. 120 °C and at this temperature 120 kg of ammonia water with a content of 25% by weight of ammonia was added to the reaction mixture within 15 minutes. Then 1,220 kg of formaldehyde with a concentration of 37% by weight was added to the reaction mixture at a gentle boil and the reaction mixture was maintained at a temperature of 105 “C for 45 minutes. Then the reactor contents were cooled to 60 °C and drained. A clear, slightly viscous liquid fixing agent with high cationic activity was obtained.

Claims (2)

Liquid preparation for enhancing the stability of dyes on the fiber based on dicyandiamidoformaldehyde condensates of the general formula I nh / II - M · C · N HCH / · On / On V-N-C-NH ....... CH 2 - / OH In H NH where n is 4 to 16 and X is 2 HCl or. H2SO4, characterized in that it contains from 35 to 50% by weight of the composition as a whole. % water and 1.2 to 1.4 wt. chloride and / or. ammonium sulfate. Process for the preparation of a liquid preparation of the formula I according to claim 1, characterized in that a mixture of 1 mole of dicyandiamide with 2.5 to 3.1 mole of formaldehyde in the presence of 1.5 to 2.1 mole of ammonium chloride and / or 0 is condensed. 75 to 1.55 moles of ammonium sulfate and 0.1 to 0.3 moles of ammonium hydroxide at 90 to 120 ° C for 60 to 120 minutes.