JPH0144280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing detergent powder.

Detergent powders are usually produced by spray drying, particularly by spray drying an aqueous clutch slurry of the ingredients in a countercurrent spray drying tower. In order to ensure that evaporation also occurs in the upper zone of the countercurrent spray drying tower, the drying gas (usually air) blown into the tower must be at a relatively high temperature, e.g. 300-450°C; Conditions inside the tower are extremely harsh. Because of these high temperatures, it is difficult to produce detergent powders containing heat-sensitive ingredients by spray drying. It has also been proposed to relax the conditions inside the column by, for example, using co-current technology or lowering the air blowing temperature, but this poses the problem of significantly lowering the yield.

Many detergent powders contain one or more heat-sensitive ingredients. For example, many powders optionally contain large amounts of soap and also contain nonionic surfactants. It has also been proposed to incorporate amines, especially mixtures of amines and soaps, into detergent powders. These soaps, amines and nonionic surfactants are heat-sensitive substances.

The present invention provides a method for producing a detergent powder containing a heat-sensitive component.

The method of making a detergent powder containing one or more heat-sensitive ingredients of the present invention includes: (a) preparing a first aqueous clutcher slurry free of heat-sensitive ingredients; (b) directing the drying gas upwardly into the spray drying tower from a second location below the first slurry spray location; (c) at least one heat-sensitive slurry; The method comprises preparing a second aqueous slurry containing the components and spraying the second slurry into the spray drying tower from a third location below the second drying gas outlet location.

In the present invention, spray drying and spray cooling are performed in essentially a single countercurrent spray drying tower.

According to the invention, there is provided a method for producing detergent powders containing, in addition to a detergent builder, anionic detergent actives or nonionic surfactants and soaps, amines or mixtures thereof. The method includes: (a) preparing a first aqueous clutch slurry comprising at least a portion of an anionic detergent active or nonionic surfactant and a builder;
(b) blowing the high temperature drying gas upward into the spray drying tower from a second position below the first slurry spraying position; (c) preparing a second aqueous slurry containing the soap and/or amine and spraying the second aqueous slurry into the spray drying tower from a third location below the second drying gas outlet location; , consisting of.

It is known to incorporate amines into detergent powders. For example, in British Patent No. 1052847,
Solid fabric softeners, which are complexes of urea and primary, secondary or tertiary amines, are described for use in the wash cycle. British Patent No. 1286054
No. 5,923,903 describes foam control compositions containing fatty acids, nitrogen-containing compounds such as primary, secondary or tertiary amines, and ethoxylated linear alcohols. Also in British Patent No. 1514276,
The use of amines in fabric softening compositions is described. In the composition, the amine is mixed with water or non-surface-active.
Contains together with a diluent in the form of a salt. In this case, the amine, salt, and optionally anionic detergent are slurried and spray dried into a powder composition.

The above-mentioned patents disclose adding amines to detergent powders at a post-spraying stage rather than during the main spraying process.

For effective spray cooling, the temperature of the second slurry when sprayed into the spray drying tower should be about 120~
Preferably the temperature is 160°C, more preferably 140°C
~150℃. This means that this second slurry typically has to be pressurized to more than 4 bar, preferably 8 to 12 bar. It has been found that the best way to bring the slurry to the desired temperature is to press the slurry into a heat converter. When the slurry temperature is 140 DEG -150 DEG C., the slurry is easily atomized by flashing water vapor from the slurry to obtain a spray-dried powder with acceptable particle size. However, if a gas is introduced into the slurry and mixed before the slurry is sprayed, the slurry can be atomized even at low temperatures. In this case, it has been found that the compressed gas has a destructive effect similar to that of flashing water vapor on the sprayed slurry.

The drying gas is easily introduced into the spray drying tower at high temperature and flows upwardly within the tower. Strictly speaking,
It is not possible to have a gas stream present in the part of the tower where the second slurry is sprayed, but in fact the falling of the slurry to be dried causes gas agitation and entrainment. The gas can also be introduced at an angle to the column to impart a swirling motion to the gas.
This high-temperature drying gas flows upward through the tower using the power of ventilation fans. The second slurry is sprayed from a position below the point at which the drying gas is blown out to the lowest part of the column, which is usually in the shape of a cone. As desired,
The second slurry may be sprayed upward into the spray drying tower to increase the passage of droplets/particles within the tower.

The first slurry can contain an anionic detergent active compound and/or a nonionic surfactant, but it is preferable that the first slurry contains a high molecular weight surfactant and is incorporated into the detergent. The method of the present invention is particularly useful for producing powders containing nonionic surfactants because the low molecular weight materials can be added to the second slurry rather than the first slurry. Ethoxylated alcohol nonionic surfactants with carbon chains of less than 12 carbons or ethoxy chains of less than about 20 carbons are low molecular weight materials and are therefore not suitable for addition to the powder via the second slurry. suitable for According to the method of the invention, nonionic surfactants having 5 to 20 carbon atoms in the hydrophobic chain and 6 to 40 carbon atoms in the hydrophilic chain can be added. These nonionic surfactants are present in an amount sufficient to provide a content in the final powder of 2 to 25% by weight, preferably 3 to 20% by weight.

Low molecular weight nonionic surfactants can be spray dried/spray cooled powders of liquid or liquefied substances or combinations of said powders with oxygen bleaches such as sodium perborate monohydrate or tetrahydrate. It can be added to the powder by spraying on top.

As noted above, the method of the present invention is useful for producing detergent powders containing anionic detergent actives alone or in conjunction with nonionic surfactants.
Anionic detergent actives, for example, have hydrophobic chains of approximately
Salts of alkylbenzene sulfonates, alkyl sulfates, primary and secondary olefin sulfonates containing 10 to 25 carbon atoms. The anionic detergent active, when present alone, ranges from about 5 to 35% by weight of the powder, and when present in combination with one or more nonionic surfactants, from about 1 to 35% by weight of the powder.
Added to the slurry in an amount sufficient to provide 15% by weight. Non-soap anionic surfactants are usually not heat sensitive, so they are added to the first slurry.

In order to produce a powder with acceptable particle size from the second slurry, it is preferred to add the amine to the powder together with the soap.

When the heat-sensitive ingredient is soap, generally 1.5
Added to detergent powder in an amount of ~30% by weight. According to the method of the invention, conventional soaps such as sodium soaps of coconut fatty acids, animal fatty acids or mixtures thereof can also be added to the powder;
The method of the invention is particularly applicable to heat-sensitive soaps.
Examples of heat-sensitive soaps include soaps containing unsaturated ethylene bonds, such as soaps made from oleic acid-containing oils, such as sunflower oil. Other examples include soaps containing substantial amounts of short chain ( _C14 or less) fatty acids. Lower grade substances, ie substances of low purity which are often very susceptible to oxidation, are particularly suitable for the process of the invention.

One type of heat-sensitive ingredient added to detergent powder is an amine. The amines to which the method of the present invention can be applied may be primary, secondary, or tertiary, solid or liquid amines, but tertiary amines are particularly preferred since they can impart a softening effect. The amines are particularly suitable for addition to the second slurry together with soap. Preferred amines have the general formula RR′R ² N
(In the formula, R is an alkyl group having 1 to 6 carbon atoms,
R' and ^R2 are primary linear alkyl or alkenyl groups having 10 to 26 carbon atoms). Preferably R
has 1 to 4 carbon atoms, most preferably a methyl group, R′ and R ² preferably have 12 to 22,
Especially with 16-18 carbon atoms. R' and ^R2 are usually linear, but there may be small amounts of branched molecules so long as they do not alter the properties of the compound as a softener.

When the amine is present together with the soap, the relative ratio of amine to soap is between 2 and 25, preferably between 3 and 20.
It is.

The second slurry is also useful for incorporating fluorescent agents. A potential problem of discoloration is always observed when fluorescent agents are added to detergent powders having a relatively low total active detergent content, such as those used in low-foam products. The color change results from some of the fluorescing agent dissolving into the active system during processing and subsequently precipitating out of solution in the form of yellow-green crystals. This problem can be solved by increasing the nonionic surfactant content of the active system, but increasing the amount of nonionic surfactant relative to the anionic surfactant can detergent performance deteriorates.

By adding a large amount of fluorescent agent to the second slurry containing the soap, the problem of discoloration can be solved without increasing the content of nonionic surfactant.

The first slurry contains conventional amounts of conventional detergent powder ingredients. That is, the first slurry contains a detergent builder, an anti-redeposition agent, and a powder structuring agent.
pH control agents such as sodium silicate, soda ash, sodium carbonate and citric acid, fillers such as sodium sulfate and small amounts of antioxidants, fluorescent agents, clays,
It contains several optional ingredients such as scum dispersants, stabilizers such as ethylenediaminetetraacetic acid and organic phosphonates, inorganic salts such as sodium chloride, starch, fungicides and colorants.

The second slurry may include sodium silicate, sodium sulfate, and/or soda ash in addition to soap or other heat-sensitive ingredients.

Other substances may also be added to the powder after spray drying. For example, oxygen and chlorine bleaches such as sodium perborate monohydrate and tetrahydrate, sodium percarbonate and sodium trichlorocyanurate, enzymes, fragrances, and tetraacetylethylenediamine (TAED) and its salts. A bleach activator is added.

Examples of the present invention are shown below.

EXAMPLE Two aqueous clutcher slurries were prepared having the following compositions.

Parts by weight of the first slurry Nonionic surfactant (C ₁₂ EO ₁₂ ) 3.9 Sodium soap (68% solution) 7.6 Sodium tripolyphosphate 26.0 Sodium silicate (neutral, 35% solution) 11.2 Sodium hydroxide (50% solution) 1.7 Sodium carboxymethyl cellulose 1.8 Sodium sulfate 27.6 Water and minor ingredients 30.0 parts by weight of second slurry Sodium soap (68% solution) 15.2 Sodium silicate (neutral, 35% solution) 11.2 Sodium hydroxide (50% solution) 1.7 Nonionic surfactants (C ₁₂ EO ₇ ) 1.3 Increase the slurry temperature to 80℃ and the hot air inlet temperature to
At 400° C., the first slurry was spray dried in a countercurrent spray drying tower.

The second slurry was sprayed into the conical section of the spray drying tower from a position below the hot air inlet with a slurry temperature of 150°C. The single spray-dried powder taken from the bottom of the column is transferred to a conveyor belt where the liquid C ₁₂ EO ₇ non-ionic surfactant is added to the dry powder by weight of 29.4 parts of spray-dried powder to 2.6 parts of non-ionic interface. Sprayed at the ratio of active agent.

In a fluidized bed mixer, 76.7 parts of the spray-dried powder were mixed with 22
It was mixed with parts by weight of sodium perborate tetrahydrate, 1 part by weight of colored sodium tripolyphosphate speckles, 0.2 parts by weight of enzyme and 0.1 part by weight of perfume.

The resulting powder had the following composition.

Weight% Nonionic Surfactant (C ₁₂ EO ₁₂ ) 3.0 Nonionic Surfactant (C ₁₂ EO ₇ ) 3.0 Sodium Soap 12.0 Sodium Tripolyphosphate 21.0 Sodium Silicate 6.0 Sodium Carboxymethyl Cellulose
1.0 Sodium Sulfate 21.2 Sodium Perborate 22.0 Enzyme 0.2 Flavor 0.1 Water and Minor Ingredients Up to 100 Example 2 Two aqueous clutter slurries were prepared having the following compositions.

First Slurry Weight% Sodium Alkylbenzenesulfonate Paste (34%) 18.0 Ethoxylated Alcohol Surfactant 7EO
4.6 Sodium tripolyphosphate 30.5 Sodium sulfate 0.5 Sodium silicate (47.8%) 14.0 Water and minor ingredients Second slurry weight up to 100% fatty acids (average molecular weight 264) 43.4 Sodium hydroxide solution (46.5%) 13.0 Sodium silicate (47.8%) 0.2 Firefly Light agent slurry (32%) 2.5 Methyl dicured tallow amine 16.8 Water and minor components up to 100 Add these two slurries to the first slurry 3.9
1 part of the second slurry to 1 part of the second slurry were simultaneously sprayed into the spray drying tower. The first slurry was sprayed from a position above the hot gas inlet, and the second slurry was sprayed from a position below the hot gas inlet. The spray-dried detergent powder produced had an average moisture content of 14.5% by weight. After cooling in an air lift, the powder was mixed in a fluidized bed mixer with 74.45 parts by weight of spray-dried powder, 25 parts by weight of sodium perborate, 0.4 parts by weight of enzyme and 0.15 parts by weight of
The ratio of parts by weight of fragrance was mixed.

The resulting powder had the following composition.

Weight% sodium alkylbenzene sulfonate
5.9 Exylated alcohol 7EO 4.2 Sodium soap 11.0 Sodium tripolyphosphate 28.0 Sodium sulfate 0.5 Sodium silicate (alkaline) 7.8 Sodium carboxymethyl cellulose
0.8 Fluorescent agent 0.3 Methyl di-cured tallow amine 4.0 Sodium perborate 25.0 Enzyme 0.4 Flavor 0.15 Water and minor ingredients up to 100 The first advantage of the process of the invention is that relatively heat-sensitive ingredients can be removed at lower column temperatures. Therefore, spray drying can be carried out without reducing the yield. A second advantage is that large amounts of heat-sensitive ingredients can be added to detergent powders and achieve the properties typical of synthetic detergent powders (rapid wetting and low gelation) when added to water.

Claims (1)

Claims: 1. (a) preparing a first aqueous clutcher slurry free of heat-sensitive components and spraying the first slurry downwardly into a spray drying tower from a first upper position; (b) (c) preparing a second aqueous slurry containing one or more heat-sensitive components; A method for producing a detergent powder containing one or more heat-sensitive ingredients, comprising spraying a second slurry into a spray drying tower from a third location below a second drying gas outlet location. 2. The method of claim 1, wherein the second aqueous slurry comprises soap. 3. The method of claim 1, wherein the second aqueous slurry comprises an ethoxylated alcohol nonionic surfactant. 4. The method of claim 1, wherein the second aqueous slurry comprises a soap and an amine. 5. The method of claim 1, wherein the second aqueous slurry is heated to a temperature of 120-160°C immediately before spraying into the spray drying tower. 6. The method of claim 1, wherein the second slurry is sprayed upward into the spray drying tower. 7 The first slurry contains an anionic surfactant and optionally a carbon chain with a carbon number of 12 or more or a carbon chain with a carbon number of 12 or more.
and an ethoxylated alcohol nonionic surfactant having 20 or more ethoxy chains. 8. The method of claim 1, wherein the second slurry comprises sodium silicate or soda ash.