RU2495920C1 - Bleaching agent based on granular sodium percarbonate - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a bleaching agent based on granular sodium percarbonate, coated with a stabilising coat. The stabilising coat contains sodium sulphate, sodium carbonate, sodium silicate and additionally a water-soluble optical bleaching agent, in wt %: sodium sulphate - 50-99.5, sodium carbonate - 0.1-49.88, sodium silicate - 0.1-5.0, optical bleaching agent - 0.01-5.0.

EFFECT: invention increases stability and bleaching power of sodium percarbonate.

2 cl, 7 tbl, 4 ex

Description

The present invention relates to granular sodium percarbonate (PCN), coated with a stabilizing shell, which is used as a component of detergents and bleaches in other areas of the chemical industry, as a universal oxidizing agent.

PKN is increasingly used as a component with a bleaching effect in detergents, bleaches and cleaners. For use for these purposes, PCN should have sufficient storage stability as a part of detergents and cleaners, since otherwise, the storage of detergents and cleaners containing it may lead to the loss of active oxygen with the loss of its bleaching effect as a result of sodium percarbonate. PCN is sensitive to contact with moisture, under the influence of which it decomposes in detergents and cleaners with the loss of active oxygen. Therefore, for the manufacture of detergents or cleaners, PCN is usually used in the form of particles in a shell (granules), which protects the PCN particles coated with it from moisture. Shells of inorganic hydrate-forming salts, such as, for example, sodium carbonate, sodium sulfate or magnesium sulfate, and mixtures of such salts (DE 2417572, C01B 15/00, 11/14/1974; EP 0863842, C01B 15/10, are suitable for use for this purpose. , 11/14/1996 and US 4325933, C01B 15/10, 04/20/1982).

Detergents containing PKN should not only have high storage stability, but also have a high detergent effect. In addition, PCN particles should also not be prone to caking under the influence of compressive loads, so that they can be stored in silos without the danger of compaction or caking.

WO 97/19890 (C01B 15/10, 06/05/1997) in example VB5 describes particles of PCN obtained by granulation in a fluidized bed of a core of sodium percarbonate and a shell of sodium sulfate and sodium carbonate when they are contained in it in a mass ratio of 50: fifty. Such PKN particles exhibit high storage stability as part of detergents. However, in WO 97/19890 nothing is said about exactly what properties sodium percarbonate particles must have in order to exhibit a high detergent effect in the detergent composition.

DE 2622610 (C01B 15/00, 05/20/1976) in Example VB5 describes PCN particles with a core of PCN obtained by granulation in a fluidized bed and a shell of sodium sulfate and sodium carbonate when they are contained in it in a mass ratio between them equal to 31 : 69. Such PKN particles exhibit high storage stability as part of detergents. However, DE 2622610 does not say anything about exactly what properties PKN particles must have in order to exhibit a high washing effect in the detergent composition.

EP 0651053 (C11D 17/00, 05/03/1995) describes PCN particles with a shell containing sodium sulfate and sodium carbonate in a molar ratio between them of 1: 0.1 to 1: 3. The examples presented in this publication describe PCN particles with a shell of sodium sulfate and sodium carbonate when they are contained in it in a molar ratio between them equal to 1: 0.29. This molar ratio corresponds to a mass ratio of 82:18. However, EP 0651053 A1 does not contain any information on the structure of the core of the particles and does not say what properties PKN particles should have in order to exhibit a high detergent effect in the detergent composition.

Closest to the proposed invention are granules PKN, coated with a stabilizing shell consisting of a mixture of sodium sulfate, sodium carbonate and sodium silicate, in wt.%:

Sodium sulfate 50-99 Sodium carbonate 0.5-50 Sodium silicate 0.1-3.0

Obtaining granules PKN with a stabilizing shell of the specified composition is described in RU 54931 (C01B 15/00, publ. 07.27.2006). The specified source also does not say anything about exactly what properties PKN granules should have in order to exhibit a high washing effect in the composition of the detergent.

The technical result of the invention is to increase the whitening ability of granules PKN coated with a stabilizing shell, as well as expanding the range of bleaching agents based on granular PKN with high washing and bleaching properties.

This problem is solved in that in the bleaching agent based on granular sodium percarbonate coated with a stabilizing shell containing sodium sulfate, sodium carbonate and sodium silicate, according to the invention, the stabilizing shell further comprises a water-soluble optical brightener in wt.%:

Sodium sulfate 50.0-99.5 Sodium carbonate 0.1-49.88 Sodium silicate 0.1-5.0 Optical brightener 0.01-5.0

The mass fraction of the substances forming the stabilizing shell is 1-20 wt.% By weight of the dry product, mainly 4-10 wt.%.

As optical brighteners use Belofor KD-2, Belofor KD-2C (Russia), Tinopal CBS-X (Switzerland) and other commercially available water-soluble optical brighteners.

The phosphors KD-2 and KD-2C are a disodium salt of 4,4'-bis (2,2-anilino-4 morpholino -1,3,5-triazin-6-ylamino) -stilbene-2,2'-disulfonic acid.

Belofor OLA is 3-phenyl-5,6-benzcoumarin.

Tinopal CBS-X is a lightfast, chlorine resistant, highly soluble fluorescent whitening agent, which is a 4,4'-distearyl derivative of biphenyl.

It was found that when optical bleach is introduced into the stabilizing shell of the granules of PCN, a synergy effect is observed, which saves the components of synthetic detergents or reduces the consumption of synthetic detergent itself to achieve the desired result.

The initial granules of PCN were obtained in a facility where the synthesis process is combined with granulation of the synthesized product by increasing the layers of the product of the interaction of stabilized aqueous solutions of soda and hydrogen peroxide on seed particles-granules of PCN of a fine fraction.

The initial granules of PCN were obtained in a facility where the synthesis process is combined with granulation of the synthesized product by increasing the layers of the product of the interaction of stabilized aqueous solutions of soda and hydrogen peroxide on seed particles-granules of PCN of a fine fraction by the method described in patents RU 2240975, RU 2164215.

A bleaching agent (PKN granules with the proposed stabilizing coating) was obtained by surface treatment of previously obtained PKN granules (initial PKN) with an aqueous solution of a mixture of inorganic salts and optical brightener (coating material) in a fluidized bed with simultaneous drying of the treated product in a stream of hot air in a laboratory setup. The laboratory setup is a laboratory flask to which hot air is supplied and a nozzle is installed, which allows to supply a solution of encapsulating agent to cover the granules of sodium percarbonate.

As a coating material, a salt mixture is used containing sodium sulfate 50.0-99.5%, sodium carbonate 0.1-49.88%, sodium silicate 0.1-5.0% and optical brightener 0.01-5, 0%

The coating material is applied to the initial PCN in the form of an aqueous 10-35% solution with a temperature of 20-45 ° C at the rate of 1-20% dry coating material per weight of dry commercial product, preferably in the range of 4-10%.

Example 1

The bleaching agent was obtained by applying to the PCN granules a coating material in the form of a 27% solution containing 95.9% sodium sulfate, 0.1% sodium carbonate, 2.4% sodium silicate and 1.6% Tinopal CBS-X IUD at a solution temperature of 40 ° C. Table 1 shows the characteristics of the obtained product.

Table 1 Mass of active oxygen,% The mass of the coating material in terms of sodium sulfate Bulk density, g / cm ³ Mass fraction of losses during drying The average particle size, microns Thermal stability, Dewar test, temperature (in base) from 65 ° C, 150 minutes Chemical stability, humidity 80%, temperature 32 ° C (in the base) 13,4 5.8 1.23 0.3 725 66,2 74,2 13,4 5.5 1.22 0.3 728 68.8 73.5 13.3 5.3 1.22 0.4 659 68.9 72,2 13,4 5.2 1.23 0.3 699 69.0 74.0 13.3 5.3 1.21 0.3 720 66,4 72.9 13.3 5.3 1.21 0.3 705 66.8 73.5 13.3 5,4 1.22 0.4 820 68.3 72.8 13,4 5.2 1.23 0.4 752 69.1 72.9 Wed 13.4 5,4 1.22 0.34 726 67.9 73.3

Example 2

A bleaching agent was obtained by coating the granules of PCN with a coating material in the form of a 15% solution containing 91.8% sodium sulfate, 4.5% sodium carbonate, 0.5% sodium silicate and 3.2% Belofor KD-2 C at a solution temperature of 25 ° C. Table 2 shows the characteristics of the obtained product.

table 2 Mass of active oxygen,% The mass of the coating material in terms of sodium sulfate Bulk density, g / cm ³ Mass fraction of losses during drying The average size; particles, microns Thermal stability, Dewar test, temperature (in base) from 65 ° C 150 minutes Chemical stability, humidity 80%, temperature 32 ° C (in the base) 13,2 5.2 1.23 0.4 668 69.2 70.1 13.3 5.1 1.22 0.5 660 69,4 71.0 13.3 5.9 1.23 0.4 698 69.2 72.1 13,2 5.8 1.23 0.4 692 69.8 72,4 13.1 5,4 1.22 0.4 700 69.2 70.1 13.3 5,6 1.22 0.5 709 69.1 70.3 13,4 5.2 1.23 0.5 698 69.3 70.3 13.3 5.9 1.22 0.4 692 69.3 70.6 Wed 13.3 5.5 1.23 0.43 690 69.3 70.9

Example 3

The bleaching agent was obtained by coating the granules of PCN with a coating material in the form of a 25% solution containing 50% sodium sulfate, 46.2% sodium carbonate and 3.0% sodium silicate and 0.8% Belofor KD-2 (conc.) At the temperature of the solution 35 ° C.

Table 3 shows the characteristics of the obtained product according to example 3.

Table 3 Mass of active oxygen,% The mass of the coating material in terms of sodium sulfate Bulk density, g / cm ³ Mass fraction of losses during drying The average particle size, microns Thermal stability, Dewar test, temperature (in base) from 65 ° C, 150 minutes Chemical stability, humidity 80%, temperature 32 ° C (in the base) 13,4 4.8 1.22 0.4 698 70,2 65.6 13.5 4.9 1.21 0.4 695 70,4 65.9 13.3 4,5 1.22 0.4 615 70,4 65.8 13,4 4.3 1.23 0.3 639 70.8 65.0 13,4 4,5 1.22 0.4 628 70.6 65.9 13.5 4.6 1.23 0.4 698 70.8 66,4 13.5 4.8 1.23 0.3 700 70.1 66.9 13.3 4.6 1.24 0.4 702 70,2 70.0 Wed 13.4 4.6 1.23 0.4 672 70,4 66,4

Example 4

The bleaching agent was obtained by coating the granules of PCN with a coating material in the form of a 35% solution containing 97% sodium sulfate, 1% sodium carbonate and 1.9% sodium silicate and 0.1% Tinopal CBS-X at a solution temperature of 55 ° C.

Table 4 shows the characteristics of the obtained product according to example 4.

Table 4 Mass of active oxygen,% The mass of the coating material in terms of sodium sulfate Bulk density, g / cm ³ Mass fraction of losses during drying The average particle size, microns Thermal stability, Dewar test, temperature (in base) from 65 ° C, 150 minutes Chemical stability, humidity 80%, temperature 32 ° C (in the base) 13,2 6.1 1.24 0.4 720 66.5 74,2 13,2 5.8 1.24 0.4 722 66.3 72.3 13.3 5.9 1.23 0.3 725 66.8 74.1 13,4 5,4 1.23 0.3 723 66.9 73,2 13,4 5.2 1.24 0.4 725 66.5 72.1 13.5 5.9 1.24 0.4 730 66.9 72.0 13,4 6.0 1.23 0.3 729 66.7 72.0 13.5 5,0 1.22 0.3 720 66,4 71.9 Wed 13.4 5.7 1.23 0.35 724 66.7 72.7

The result of applying a coating material to the initial granular PCN was an increase in the overall stability of the product by 15-20%.

To assess the effectiveness and advantages of using the proposed bleaching agent in the composition of powdered CMC and bleaches, comparative tests of the product obtained in example 1 were performed.

The increase in whiteness on cotton fabric after bleaching with the following detergent compositions was evaluated:

- the composition of the comparison - PKN coated according to the prototype (96.0% sodium sulfate, 1.6 sodium carbonate, 2.4% sodium silicate) in the base of synthetic detergent and bleach with the addition of optical brighteners Belofor KD-2, Belofor KD-2C and Tinopal CBS-X;

- the investigated composition - PCN with a coating containing 95.9% sodium sulfate, 0.1% sodium carbonate, 2.4% sodium silicate and 1.6% and Tinopal CBS-X in the base of a synthetic detergent and bleach.

As the base CMC used base powder CMC IEC-A of the following composition in wt.%:

Sulfanol 8.8 Ethoxylated alcohols C12-18 (7 EO) 4.7 Soap 3.2 Defoamer DC2-4248S 3.9 Zeolites 4A 28.3 Sodium carbonate 11.6 Sodium salt of a copolymer of acrylic and maleic acids (Sokalan CP5) 2,4 Sodium silicate 3.0 Carboxymethyl Cellulose Sodium 1,2 Diphosphonic acid sodium salt 2,8 Optical brightener 0.2 Sodium sulfate 6.5 Protease enzyme 0.4

The compositions of the studied compositions are shown in table 5.

Table 5 CMC Comparison Composition Test composition Powdered CMC PCN coated prototype 0.54 g / l PCN coated with optical brightener 0.54 g / l Optical brightener 0.01% CMC base Up to 100% CMC base Up to 100% Bleach PCN coated prototype 1.81 g / l PCN coated with optical brightener 1.81 g / l Optical brightener 0.01% - Bleach base Up to 100% Bleach base Up to 100%

Determination of chemical, optical whiteness of cotton fabric and bleaching ability was carried out according to GOST 22567.11-82 “Synthetic detergents. Method for determining whitening ability. "

The essence of the method is to determine the whitening ability by the ratio of the increase in whiteness of the fabric during bleaching by the test detergent composition to the increase in whiteness of the same fabric when bleaching with the comparison composition.

The concentration of the comparison composition and detergent compositions are taken in accordance with the mass fraction:

- PCN (in terms of active oxygen) in the composition of powdered CMC (1.5%) and bleaches (5.0%);

- optical Tinopal CBS-X brightener in the composition of the comparison formulations introduced in an amount of 0.01%

Thus, for powdered CMC, the concentration of PKN was 0.54 g / l, for powder bleaches, respectively, PKN-1.81 g / l,

The reflection coefficients were measured on a Karl-Zeiss Yen leukometer on blue and red filters.

Test conditions:

Consumption: 0.54 g / l for CMC; 1.81 g / l for bleaches.

The fabric is unbleached cotton.

Whitening time - 30 minutes.

Temperature - 60 ° C.

Drying - in vivo (combination of natural and artificial lighting)

The test results are shown in table 6.

Name of indicator Table 6 PKN (composition of comparison) 1.81 g / l PKN 1.81 g / l + optical brightener 0.025 g / l PKN 1.81 g / l + optical brightener - 0.01% Tinopal CBS-X Belfor KD-2 conc. Belfor KD-2S Tinopal CBS-X Belfor KD-2 conc. Belfor KD-2S Reflection coefficient of the original cotton fabric,%: - on the blue light filter (RZ ₁ ) 54.3 54,2 54,4 54.0 54,2 54,4 54.0 - on the red filter (RX ₁ ). 73.0 73.0 73.0 73.1 73.0 73.1 73.0 Whiteness of cotton fabric before bleaching (W ₁ ),% 35.6 35,4 35.8 34.9 35,4 35.7 35.0 Reflection coefficient of cotton fabric after bleaching,%: - on the blue filter 66.6 69.7 70,2 69.7 66,4 66.5 66.3 - on the red filter. 81.5 82.3 82.1 82.5 78.1 77.8 78,4 Whiteness of cotton fabric after bleaching (W ₂ ),% 51.7 57.1 58.3 56.0 54.7 55,2 54,2 The increase in whiteness of cotton fabric after bleaching,% (ΔW) 16.1 21.7 22.5 22.0 19.3 19.5 19,2 Whitening ability according to GOST 22567.11-82,% (in relation to the composition of the comparison) one hundred 135 140 137 120 121 119

From the data presented in table 6, it follows that the use of a bleaching agent based on PKN granules with a stabilizing coating containing additional optical brightener in CMC formulations provides an increase in bleaching ability compared to a composition containing the same ingredients and in the same amount, but mixed with granules PKN with a stabilizing coating according to the prototype.

Table 7 presents comparative data on the expected and actual whitening ability of the proposed whitening agent in the composition of powdered CMC and bleaches.

Table 7 Whitening ability according to GOST 22567.11-82,% Powdered CMC Powder Bleach Expected effect (composition of comparison) Actual result (test composition) Expected effect Actual result one hundred 111 one hundred 121

Based on the data presented, a synergistic effect is evident when optical bleach is introduced into the stabilizing shell of a granular PCN in the proposed mass ratio.

Claims (2)

1. A bleaching agent based on granular sodium percarbonate coated with a stabilizing shell containing sodium sulfate, sodium carbonate and sodium silicate, characterized in that the stabilizing shell further comprises a water-soluble optical brightener, wt.%:
Sodium sulfate 50-99.5 Sodium carbonate 0.1-49.88 Sodium silicate 0.1-5.0 Optical brightener 0.01-5.0 2. The bleaching agent according to claim 1, characterized in that the mass fraction of the substances forming the stabilizing shell is 1-20 wt.% By weight of the dry product, mainly 4-10 wt.%.