RU2170244C2 - Method of preparing household soap and detergents containing sodium silicates - Google Patents

Abstract

FIELD: manufacture of household soap and detergents containing soap. SUBSTANCE: method comprises neutralizing fatty acids and saponifying fats and oils with alkali agent solutions. Alkali agent includes concentrated aqueous solutions of sodium silicates of general formula: Na₂O•mSiO₂ wherein m is 2.8-0.2 mole/mole in amount which allow for complete neutralization of fatty acids and saponification of fatty mixture and change of silicate module to value of 2.8-3.5 mole/mole. EFFECT: simplified manufacturing process, lower manufacturing costs and improved foaming and washing powder in hard water. 2 cl, 7 ex, 1 tbl

Description

 The invention relates to the production of laundry soap and detergents containing soap.

 In the current production / 1 /, the basis of laundry soap and detergents containing soap is produced by neutralizing fatty acids with 25-40% aqueous solutions of sodium carbonate and hydroxide and saponifying triglycerides of fatty acids in vegetable oils and animal fats with sodium hydroxide solutions of the same concentration. As a result of neutralization and saponification reactions, a 40-50% aqueous soap solution is obtained, which is then concentrated by soaking up the so-called. soap core containing already 60-65% of soap in terms of fatty acids.

 In production, the so-called direct method of cooking 60-65% soap, in which the stage of core drying is excluded / 1, 2 /.

 60-65% (based on fatty acids) soap core and saponified mass of direct cooking, containing 23-28% water, after the drying stage is used to obtain household, toilet and detergents.

 Detergents are prepared by mixing a soap base with useful additives such as silicates, sodium tripolyphosphate, sodium peroxoborate, optical brightener, etc.

 An effective, affordable and relatively inexpensive supplement is sodium silicates. Introduced in the formulation of laundry soap or detergent in an amount of 4-20%, they increase the washing ability of soap or detergent in hard water. In addition, as dispersants of calcium and magnesium soaps formed in hard water, silicates significantly prevent the formation of large flakes of Ca-Mg soaps and deposit them on the fabric, and thereby reduce the ash content and graying of the fabric when washed repeatedly with soap in hard water. Sodium silicates with a module value of 2.8 - 3.5 are especially useful: providing this effect, they still have a more gentle effect on the skin compared to silicates with a lower modulus.

The chemical industry produces sodium silicates (Na ₂ O • mSiO ₂ • xH ₂ O) in the form of crystalline sodium metasilicate (m = 1) containing 45% dry metasilicate and about 55% water, as well as a silicate block (m = 2 , 8), which is boiled in water and get a solution containing 30-42% of silicate and 58-70% of water and called liquid glass.

 The introduction of 4-20% silicates containing 55-70% water into the formulation makes it necessary to organize the drying process of a soap base or detergent to ensure the required hardness or flowability.

 Increased energy costs, the complexity of the technology and environmental indicators due to the drying stage are a disadvantage of the accepted technology for the production of soaps and detergents based on soaps containing silicates / 3 /.

 Thus, the introduction of soap and detergents based on soap of sodium silicates, an effective and affordable additive that increases the washing ability and quality of washed products without complicating the process flow chart and increasing energy consumption, is an urgent task.

 The objective of the present invention is to develop an energy-saving environmentally friendly technology for preparing the basis of laundry soap and detergents containing sodium silicates, which are characterized by high washing, foaming ability in hard water and a gentle effect on the skin.

The essence of the technical solution lies in the fact that, to neutralize fatty acids and saponification of fats and oils, not solutions of sodium carbonate and sodium hydroxide in water are used, as in the accepted technology, but aqueous solutions of sodium silicates of the general formula Na ₂ O • mSiO ₂ with the ratio of the number of moles of SiO ₂ to a mole of Na ₂ O (m) from 2.8 to 0.2. It can be some commodity silicates (for example, sodium metasilicate) or products of the interaction of commodity granular (flaky) sodium hydroxide containing 92-95% of the basic substance, with commodity silicate, for example with metasilicate containing up to 55% water or with liquid glass containing 50-70% of water.

The use of the resulting silicate solution as a neutralizing and saponifying fatty acids, fats and oils of the reagent by the proposed method allows:
- without an additional drying step, obtain a soap base containing such an amount of water that the finished product will have the required hardness or flowability;
-increase the modulus of sodium silicate remaining in the soap base to 2.8-3.5, which ensures the gentle effect of the base on the skin.

The method is developed in laboratory, pilot plants and tested in industrial reactors with a volume of 0.2 and 0.5 m ³
The essence of the proposed method is illustrated by examples of implementation
Example 1
In a 3-liter laboratory reactor equipped with an anchor stirrer and placed in an electric bath, 345 g of water glass (41.3% Na ₂ O • 2.8 SiO ₂ ), 140 g of water and 140 g of granulated sodium hydroxide (94% NaOH) are charged ) To the resulting solution with a module of 0.77 at 70 ^o C and stirring serves 1000 g of sunflower oil (KO = 184 mg KOH / g). The mass is heated to 100 ^o C, kept at 100-104 ^o C for 40 minutes, and then poured into a mold for cooling. After cooling to room temperature, 1600 g of solid soap are obtained containing 64.0% soap; 6.0% glycerol; 8.9% silicate with a module of 2.8 and 21.1% water. Foaming ability and resistance to the formation of flakes in hard water are shown in table 2.

Example 2
In the reactor described in Example 1, 700 g of water glass (33% Na ₂ O • 2.8 SiO ₂ ), 150 g of water and 150 g of granular liquid sodium (94% NaOH) are charged. The resulting silicate solution with a module of 1.02 with stirring at a temperature of 60 ^o C load the fat mixture consisting of 500 g of pork fat, 150 g of beef fat and 350 g of sunflower oil. The mass is stirred at 100-104 ^° C. for 40 minutes, after which 25 g of powdered carboxymethyl cellulose, 5 g of optical brightener, 4 g of perfume and 500 g of sodium tripolyphosphate are added to the reactor. The hot mass is discharged into a mold for cooling. Obtain 2430 g of a solid light product containing 42.2% was; 3.9% glycerol; 8% Na ₂ O • 2.8 SiO ₂ ; 22% sodium tripolyphosphate and 22.5% water. The washing ability of the soap was 120% of the standard. Other properties of it are given in table 2.

Example 3
105 g of sunflower oil (saponification coefficient = 184 mg KOH / g, acid number = 40 mg KOH / g), 70 g of commercial crystalline sodium metasilicate (Na ₂ O) are loaded into a 1 L laboratory reactor with an anchor mixer, placed in an electric bath, • 1.0 SiO ₂ = 45%) and 5 g of water. The mass is stirred for 1.5 hours at 100-105 ^o C. Get a viscous soapy mass, the analysis of which shows that the saponification of the oil is completed. Add 30 g of water, mix for another 15 minutes and unload in a mold for cooling. After cooling, 180 g of a light beige solid soap are obtained containing 60% soap; 5% glycerol; 11.3% silicate (Na ₂ O • 3.0 SiO ₂ ) and 23.7% water.

 Some properties of the soap are shown in table 2.

Example 4
120 g of commercial sodium metasilicate (Na ₂ O • 1,0 SiO ₂ = 45%) are loaded into the reactor described in example 3, heated to 80 ^° C with stirring (the metasilicate dissolves in its own crystallization water) and 24 are added. 8 g granular caustic soda (NaOH = 94%). To the resulting silicate solution with a module of 0.6 add 180 g of beef tallow (Ko = 200) and 120 g of an equal mixture of coconut and sunflower oil (Ko = 236). The mass is kept under stirring and heating (100-110 ^o C) for 2 hours, and then unloaded into a mold for cooling. Obtain 430 g of solid light soap containing 71.5% soap; 7% glycerol; 7.8% silicate of the formula Na ₂ O • 3.0 SiO ₂ and 13.7% water.

 Some properties of the soap are shown in table 2.

Example 5
In a 200 L reactor with Z-shaped mixers, equipped with a hinged lid, a steam jacket and a device for turning the reactor, 50 kg of marketable crystalline sodium metasilicate (Na ₂ O • 1,0SiO ₂ = 45%) and 10.4 kg are loaded granular caustic soda (95% NaOH), heated to obtain a silicate solution. To the resulting silicate solution with a module of 0.6 add 75 kg of beef tallow, 40 kg of sunflower oil and 12 kg of fatty acids from the stock of sunflower oil. After 1.5 hours of stirring at 100-105 ^° C., 180 kg of the mass are discharged, which after cooling is a shapeless solid bar of soap. They are passed through a screw machine (pelotosis), the resulting bars of soap are cut into pieces and packaged. The soap contains 72% soap, 6% glycerol, 8% silicate with the composition Na ₂ O • 2.9 SiO ₂ and 14% water.

Example 6
160 kg of pork fat, 15 kg of fatty acids from the stock of sunflower oil are loaded into a reactor with a frame stirrer of 0.5 m ³ volume. A silicate solution with a module of 0.55, prepared in another vessel, is added to a fat mixture heated to 60 ^° C by mixing 26.8 kg of caustic soda (95% NaOH) and 60 kg of water glass (30% Na ₂ O • 2.8 SiO ₂ ) with a temperature of 90 ^o C. The temperature of the mass is raised to 110 ^o C and incubated for 1 h at 110 ± 2 ^o C. Then the mass is cooled to 90 ^o C, add 8 kg of sodium tripolyphosphate; 0.50 kg of optical brightener; 0.25% perfumes, mix for 15 minutes and unload. The cooled solid mass containing 65% soap, 7% silicate, 3% tripolyphosphate, 5% glycerol, 19.7% water, is sawn and produced in the form of pieces or vermicelli.

Example 7 (prototype)
In the reactor described in example 3, load 111 g of a 4% solution containing 46.6 sodium hydroxide and 64 g of water. When the stirrer is working on a solution of caustic soda, having a temperature of 70-80 ^o C, serves 180 g of beef fat (Ko = 200) and 120 g of an equal mixture of coconut and sunflower oil (Ko = 236). If you use a more concentrated solution of caustic soda, the mass will thicken so much that it will not mix, the stirrer will stop and the saponification reaction will slow down. After stirring at 100-105 ^° C for 1 h, 84 g of water glass (Na ₂ O • 2,8SiO ₂ = 40%) was added to the mass, stirred for 20 minutes and unloaded into a mold for cooling. I get 600 g of soap containing 51.2% soap; 4.5% glycerol; 5.6% silicate (Na ₂ O • 2.8 SiO ₂ ) and 38.7% water.

 The resulting soap contains a large amount of water and does not have the necessary hardness. A similar experience in this application (see example 4) allows you to get soap with a content of 13.7% of water and is sufficiently hard for further processing into a product project without drying.

 The soap mass obtained in example 7 before turning into a commercial product must go through the drying stage.

 For clarity, the composition of detergents (and some of their indicators) obtained by the proposed (examples 1 to 6) and known (example 7) methods are summarized in table 1.

 Table 2 shows the properties of detergents obtained by the proposed method, showing their advantages over ordinary laundry soap in foaming ability and resistance to the formation of flocculent deposits of Ca-Mg - soaps in hard water.

LIST OF USED LITERATURE
1. I.M. Tovbin, M.I. Zaliopo, D.M. Zhuravlev. Soap production. Tutorial. Ed. "Food Industry", M. 1965

2. N.T.Kamardin. The advantage of cooking 60% laundry soap by the direct method. Oil and fat industry. 1958, N 1, p. 41
3. P. D. Kupchinsky, M. V. Zotova, S. F. Kiporenko, V. M. Kislov. Production of household soap with useful additives. Oil and fat industry, 1965 N 12, c. 16.

Claims (2)

1. A method of obtaining a base of laundry soap and detergents containing sodium silicates and other useful additives by neutralizing fatty acids and saponification of fats and oils with solutions of alkaline agents, characterized in that concentrated solutions of sodium silicates of the general formula Na ₂ O are used as alkaline agent • mSiO ₂ with a value of m = 2.8 - 0.2 mol / mol in an amount that provides complete neutralization of fatty acids and saponification of the fat mixture and changes in the silicate modulus to a value of 2.8 - 3.5 mol / mol.  2. The method according to claim 1, characterized in that the concentrated sodium silicate solution needed to neutralize and saponify the fat mixture is obtained by reacting solid sodium hydroxide with liquid glass or commercial crystalline sodium metasilicate.

Images