FI95927B - Solid piece of detergent and method of making it - Google Patents

Description

95927

Solid detergent body and method for its preparation Fast detergent block and method for the manufacture of detergents

The present invention relates to a solid detergent body for forming an aqueous chemical solution having a substantially constant concentration. Such chemical bodies are used in industrial cleaning processes, such as mechanical dishwashing or fabric washing, and generally include temporal ingredients, detergents, building materials, and so on.

Industrial dishwashers generally include a wash tank containing the cleaning solution used in the washing process. In this process, the dirt or dishes are soaked in a washing solution and then rinsing water that flows into the washing tank. In each cycle, the cleaning efficiency of the washing liquid is reduced, firstly, because the stain removal treatment reduces it, and secondly, because the rinsing water dilutes the washing liquid. The cleaning solution is therefore fortified at certain intervals by the addition of a new cleaning liquid from a distribution system which usually gives a concentrated aqueous solution of alkaline and / or surfactant chemical composition.

Several methods are known for converting solid chemicals to a concentrated solution depending on the nature of the solid. For example, according to U.S. Patent 2,371,720, a solid powdered chemical can be dissolved by placing it on a sieve and spraying water on said sieve from below.

Alternatively, the powdered material can be dissolved in a "water reservoir type" dispenser. In such a distribution. in the device, the powdery material is immersed in water, which then becomes loaded with the powder or even saturated. When new water is added, the excess solution flows into the overflow pipe leading to the washing machine.

It is also possible to use solid washing materials, for example in the form of briquettes described in U.S. Patents 2,382,163, 2,382,164 and 2,382,165. The briquettes can be used in conjunction with a "water reservoir type" dispenser.

A more recent type of solid detergent is in the form of a cast or piece, in which a solid detergent body weighing several kilograms is formed by pouring a concentrated aqueous slurry into a tank where, on cooling, it solidifies as a result of hydration of salts, especially sodium tripolyphosphate. Such solid castings are described, for example, in European Patent 3,769.

These solid, molded articles require dispensing systems to spray solvent into the article while it is inside the container to gradually dissolve the present surface to form a concentrated solution. Such a distribution system is described, for example, in European Patent Application 244,153.

Solid detergent articles have gained some popularity in the field of industrial dishwashing because they are dust-free and therefore relatively safe when products are often used with aggressive or corrosive chemicals. In addition, hydrated solids are economical to use because they can be manufactured and transported as very dense products.

One of the disadvantages of the above-mentioned solid detergent bodies is the difficulty of incorporating or adding bleach to them due to the incompatibility of the bleaching systems with the basic components of the body and the composition of the body. with the elevated temperatures used in the production process.

·· - This is true when using a hypochlorite type bleach, usually sodium hypochlorite, as well as when using an organic chlorine type bleach.

In addition, the elevated processing temperatures required for the production of concentrated sludges adversely affect the stability of the heat labile components. For example, sodium tripolyphosphate decomposes to form ortho and pyrophosphates with poor structural properties.

It has now been found that it is possible to produce solid detergent bodies which form an even denser product than the solid bodies obtained by hydration and which can be used to add a stable bleach to the body.

Equally surprising was the continuous formation or release of chemicals in the article as water was sprayed onto the article.

According to the invention, there is provided a solid detergent composition in the form of a body of compressed granular material having a body weight of 1 to 5 kg.

Furthermore, according to the invention, there is provided a method of making these bodies, wherein the powder is compressed in a mold at a pressure of 3 to 30 kilos Newtons per square centimeter (KN / cm 2) to form a solid body.

The invention further relates to the use of a solid detergent body according to the invention in an industrial dishwashing process.

According to the invention, there is provided a solid detergent composition in the form of a body formed by a compressed granular material having a weight of 1 to 5 kg. The pieces can be used for various purposes in industrial cleaning, such as mechanical dishwashing (eg bottle washing). Depending on the intended use, the article contains 5-80% by weight, preferably 5-65% by weight of an alkaline substance such as sodium or potassium hydroxide, metasilicate or ··. carbonate. Mixtures for mechanical dishwashing are the most alkaline and contain sodium hydroxide and / or potassium hydroxide.

95927 - · τ 4

In addition, the body contains 5 to 70% by weight, preferably 10 to 50% by weight, of structural material. This may be a zeolite or phosphate builder or some other suitable hardness precipitant or hardness sequestrant.

The compressed article further contains 3-15% by weight of a bleaching component, for example an active chlorine bleaching agent such as sodium dichloroisocyanurate. A particular advantage of the extrudates according to the invention is that large amounts of such bleaching agents can be included and that the bleaching agent remains stable for several months. In the control bodies formed by hydration, the active chlorine content is known to decrease rapidly over time.

The pieces may additionally contain 0-10% by weight of polymer. Suitable polymers are, for example, acrylic acid polymers such as Acrysol LMW 45 ND (ex Rohm & Haas) or Goodrite K 7058 D (ex BF Goodrich).

For dishwashing purposes, a defoaming agent such as a low-foaming nonionic surfactant is generally used in the washing solution, and such agents may in fact be added to the solids of the invention.

Amounts of 0-5% by weight proved to be suitable.

*: The articles of the invention may additionally contain suitable minor ingredients such as bleach stabilizers, enzymes, etc. Additional components may be sealing aids, for example calcium stearate, hydrophobic silica or talcum powder, and solubility aids may be, for example, polyethylene glycol or carbowaccholide.

•

The weight, shape and dimensions of the extruded parts may vary according to the intended use. In mechanical dishwashing, it has been found that pieces weighing about 1.5 kg are very suitable.

5,95927

According to the invention there is further provided a method of making a solid detergent article as described above. In this method, a suitable granular detergent powder corresponding to the desired chemical mixture is compressed in a mold at a pressure of 3-30 KN / cm2.

This treatment can be carried out in a suitable press, preferably a hydraulic press such as LAEIS Hydraulische Doppeldriickpresse, TYP HPF 630, manufactured by LAEIS, Germany-BRD. It has proven to be particularly advantageous in the production of a body by two or more successive compressions with an increase in pressure. In the first step, pre-sealing is performed at a relatively low pressure, followed by one or more steps at maximum pressure. Such a treatment provides a greater or better seal than using a single compression.

Because the compression can be performed at ambient temperature, large amounts of thermolabile components such as STP or enzymes can be added to the bodies. This is considered to be an exceptional advantage of the invention. After manufacture, the pieces should be packed as soon as possible due to their hygroscopic nature.

The invention also relates to the use of the solid bodies according to the invention in an industrial dishwashing process.

In use, the compressed body is placed in a suitable dispenser where water is sprayed to form an aqueous solution of the solid detergent. Depending on the nature of the solid, the water may also form a slurry or suspension of the chemical. For the purposes of this invention, all three of these possibilities are hereinafter referred to as aqueous solutions.

Suitable dispensers for solid bodies are known in the art. Good continuous yield or formation was achieved, for example, by placing the extruded body 6 95927 according to the invention in the dispensing device described in the applicant's British Patent Application No. 2,226,233.

The invention will now be further elucidated by considering the following non-limiting examples.

Examples 1-5 4.3 kg portions of each detergent mixture (% by weight) shown in Table I were pressed in a LAEIS hydraulic press, TYP HPF 630, to form solids having dimensions of 17.5 x 21 cm and a height of 7.5 cm. Compression was performed in two steps. First, a pressure of 5.3 KN / cm2 was applied and then a second compression was performed at a pressure of 6.4 KN / cm2.

Table I

1 2 3 4 5

Sodium tripolyphosphate 30.5 30.0 29.0 31.0 0 phate.6 aq.

Sodium tripolyphosphate 0 0 0 0 30.5 phate.O aq.

NaOH 59.0 51.0 49.0 62.0 59.0

Polyacrylate 5.0 5.0 5.0 5.0 5.0 • i

Na-dichloroiso-3,5 0 0 0 3,5 cyanurate

Triton DF 12 * 2.0 2.0 2.0 2.0 2.0

Dequest 2041 ** 0 2.0 2.0 0 0

Sodium metasil 0 10.0 0 0 0 kate.5 aq.

Sodium perborate 0 0 10.0 0 0 thymonohydrate TAED 0 0 3.0 0 0 95927 7

The resulting pieces were then stored in a sealed container for 3 months at 20 or 30 ° C. Their sodium tripolyphosphate content (STP) and active chlorine content were then analyzed. The results are shown in Table II. The STP content and the active chlorine content are expressed as a percentage of the values in the starting material.

* ethoxylated fatty alcohol, antifoam ** ethylenediamine tetra (methylenephosphonic acid)

Table II

Examples 12345

Storage temperature 20 20 20 20 20 ° C 30 30 30 30 30 STP content% after three months external 90.2 82.8 67.3 92.7 90.2 90.1 12.9 16.7 91.4 90, 1 inside 90.2 84.4 86.8 91.5 94.3 91.1 11.8 92.8 94.4

Active chlorine content% after three months outside 81.0 78.9 82.4 81.7 inside 87.3 84.4 77.6 83.0

Physical out- unchanged shattered fragile unchanged unchanged '* vision after three unchanged cracked decomposed unchanged unchanged after one month •. - 8 95927

Example 6

To study the formation of chemicals from a solid detergent body according to the invention, a body was prepared according to Example 1. It was then sawn into smaller pieces measuring 7.5 x 7.5 x 16 cm. One such piece was placed in the dispenser described in the applicant's British Application No. 2,226,233. It was then sprayed with 200 ml portions of water for 10 seconds with intervals of 60 seconds. The water temperature was 20 ° C and the German hardness 7 °. The conductivity of the effluent was measured as a function of the spray rate. The results are shown in the figure below. As can be seen from the figure, the composition of the effluent was found to be substantially constant over a long period of more than 4 hours.

Claims (6)

95927 A solid detergent composition for use in industrial dishwashing processes in the form of a body formed of compressed granular material and having a weight of 1 to 5 kg, characterized in that it comprises: 5 to 80% by weight of an alkaline substance; 5-70% by weight of sodium tripolyphosphate as a building material; and 3-15% by weight of bleach. Solid detergent composition according to Claim 1, characterized in that the bleaching agent is your active chlorine bleach. Solid detergent composition according to Claim 1, characterized in that your active chlorine bleach is sodium or potassium dichloroisocyanurate. A process for preparing a solid detergent composition according to claim 1 or 2, characterized in that a powder having a corresponding composition is compressed in a mold at a pressure of 3 to 30 KN / cm 2 to form a solid body. A method according to claim 3, characterized in that the body is formed by two or more successive compressions by increasing the pressure. Use of a solid detergent composition according to claim 1 or 2 in an industrial dishwashing process. 10 95927