DK164288B - MACHINE DISHWORKS BASED ON CHLORISOCYANURATE DERIVATIVES AND PROCEDURES FOR THE PREPARATION OF SUCH ANIMALS - Google Patents

Description

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DK 164288 B

The present invention relates to a novel machine dishwashing agent containing a wax-coated chlorine isocyanurate derivative, a plasticizer selected from polyphosphates, an alkali-producing agent, at least in part consisting of sodium silicates, and a surfactant. The invention also relates to a process for making such a machine dishwashing detergent.

10 Household washing machine washing involves both the detergent effect of the dishwashing detergent and the mechanical effect of the water. In addition to its detergent action, the detergent must have a disinfectant capacity as well as water softening properties. The detergent must therefore have a strong detergent effect, but its composition must also be such that it does not cause the formation of foam which is detrimental to the mechanical action of the water. This is why, as is well known, dishwashing agents consist of: a softener generally selected from polyphosphates. One may mention among the polyphosphates used sodium tripolyphosphate, sodium hexamethaphosphate and sodium pyrophosphate as well as the corresponding potassium polyphosphates; 25 is an alkalinity forming agent consisting essentially of an anhydrous sodium metasilicate or in penta-hydrate form. (As is well known, sodium silicate may partially replace sodium carbonate, sodium sulfate, or sodium hydroxide); a non-foaming surfactant of the nonionic type selected from the following product classes: ethoxylated linear alcohols, condensates of ethylene oxide and propylene oxide, alkoxyamines, polyethoxy ethers of fatty alcohols, ethoxylated alkylphenols and phosphoric acid esters of fatty alcohols. (For the sake of efficiency

DK 164288 B

2, the biodegradation and cost are preferably a surfactant selected within the class consisting of ethoxylated linear alcohols); and 5 a disinfectant.

The disinfectant used which releases active chlorine is generally a solid chlorine-based product of the chloroisocyanurate derivatives. It is most often a sodium or potassium salt of dichloroisocyanuric acid.

The following compounds have so far been used in practice: anhydrous sodium dichloroisocyanurate with a 63% active chlorine content, a sodium dichloroisocyanurate dihydrate 15 with 56% active chlorine, anhydrous potassium dichloroisocyanurate with 59% active chlorine, potassium dichloroisocyanurate monohydrate or 56% calcium dichloroisocyanurate tetrahydrate with 56% active chlorine. The active chlorine is defined as being the oxidizing capacity due to the positive chlorine. For a better understanding of what is meant by positive chlorine, it should be remembered that chlorine present in the chlorinated derivatives described above is bound to a nitrogen atom and that it is present in the oxidation step + 1, i.e. Cl +. During an oxidation-reduction process, the Cl + ion unites with two electrons to be converted to the Cl (chloride) state. Two equivalents of an oxidizing agent are released, corresponding to 71 g of elemental chlorine, although the atomic weight is only 35.5. It also means that an atom Cl + has the same oxidizing capacity as a molecule of elemental chlorine d2.

Among the other chlorinated disinfectants of the chloroisocyanurate family there is a member containing about 35 91% active chlorine: trichloroisocyanuric acid. Therefore, it would be advantageous to be able to use this compound because of its high content of

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3 active chlorine. Unfortunately, it has not been able to be used until now, since it has been found to be too responsive to the other components of the detergent compositions, especially in relation to the surfactants. The detergents containing trichloroisocyanuric acid are unstable during storage, and they lose significant amounts of both chlorine and of the surfactant through mutual destruction. A means has now been found to stabilize trichloroisocyanuric acid, in particular to stabilize the compound for the production of detergent compositions which are stable during storage and which are suitable for dishwashing dishes in dishwashers.

Thus, the present invention relates to a novel machine dishwashing agent suitable for dishwashing dishes in a dishwasher containing a plasticizer selected from polyphosphates, an alkali-forming agent selected from sodium silicates, a nonionic surfactant, and a wax-coated chlorisocyanurate derivative, and this machine dishwashing agent is characterized in that the chlorisocyanurate derivative used is trichloroisocyanuric acid coated with a paraffin wax having a melting point of less than 60 ° C, which is used at a concentration of 1-10% by weight. calculated on the weight of the acid.

Paraffin waxes have been found to be compatible with trichloroisocyanuric acid. Furthermore, when used in relatively small quantities, they provide a good stabilization of the acid. Furthermore, they are dispersible under the washing conditions, i.e. in aqueous media at a temperature of 50-60 ° C.

The paraffin waxes consist of a mixture of high molecular weight solid hydrocarbons (eg having a melting point lower than 60 ° C and higher than 40 ° C and a viscosity at 100 ° C of less than 6 centipoise. 4

DK 164288 B

reversed at a concentration of 1-10 wt. relative to the trichloroisocyanuric acid, preferably at a concentration of 3-5 weight percent. At concentrations above 5%, difficulties are encountered in carrying out the coating, and it is necessary to modify the reaction conditions to obtain a suitable coating. Use of quantities greater than 10% does not lead to any significant improvement in the storage stability of the detergent compositions concerned. The use of amounts of less than 1% leads to poor stabilization of the acid.

The process according to the invention for the preparation of the present machine dishwashing detergent is characterized by the characterizing part of claim 3.

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The machine dishwashing agents of the present invention are prepared by first coating the chloroisocyanuric acid with paraffin wax. This coating process is carried out in an industrial mixer of any type, such as a drum mixer, preferably in a mixer equipped with a heating device. It is also possible to use a cement mixer rotary mixer in which the molten wax is sprayed onto the acid heated to a temperature in the vicinity of 50 ° C. The temperature used allows a good distribution of the paraffin wax which solidifies upon cooling. The wax-coated trichloroisocyanuric acid is then mixed in another mixer with the other components of the machine dishwasher.

The various other components used in the preparation of the machine dishwashing agents of the invention are used in conventional mutual weight ratios.

The plasticizer selected from polyphosphates is used at a concentration of 25-60% by weight, preferably

DK 164288 B

5 show 40-50% by weight, calculated in relation to the weight of the detergent.

The alkalinity-forming agent selected from sodium silicates is used at a concentration of 30-70% by weight, preferably 40-60% by weight, relative to the weight of the dishwashing liquid. As is well known, sodium silicate may be partially replaced by sodium carbonate, sodium sulfate or sodium hydroxide. The nonionic surfactant is used at a concentration of 0.5-4% by weight, preferably at a concentration of 1-3% by weight. in relation to the weight of the detergent. The paraffin wax coated trichloroisocyanuric acid is used at a concentration of 0.5-5% by weight, preferably 1-3% by weight, relative to the weight of the detergent.

The following examples further illustrate the invention. EXAMPLE 1 20

Trichloroisocyanuric acid is first stabilized by paraffin wax as follows:

The acid is heated to a temperature of 50 ° C and then placed in a pill coating apparatus. While this apparatus is rotating, paraffin wax is sprayed from above using a spray gun. The application temperature allows a good distribution of the wax species which solidifies upon cooling. The paraffin wax used has a melting point below 60 ° C and a viscosity of 100 ° C of less than 6 centistokes. Various mixtures of acids and waxes are prepared using different percentages of paraffin wax. The mixtures thus obtained are used to prepare the related machine dishwashing detergents.

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6

Machine detergents are prepared with the following compositions (the proportions are expressed in parts by weight): sodium tripolyphosphate: 50 parts, 5 sodium metasilicate (anhydrous or as 5 hydrate water hydrate): 50 parts "PLURAFAC" RA 43 (ethoxylated nonionic surfactant manufactured by the company PCUK): 2 parts, and trichloroisocyanuric acid coated with paraffin wax: 2 parts.

First, in a rotary type mixer, a sodium tripolyphosphate and nonionic surfactant premix is prepared. After 20 minutes, a homogeneous mixture is obtained. Then the metasilicate is added to the mixer. After 20 minutes, the over-extracted trichloroisocyanuric acid is added. The total composition then remains in the rotary mixer for 20 minutes. The percentage content of chlorine, as determined by iodometric titration, in the detergent mixture is then 1.65%.

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The machine dishwashing detergent thus prepared is placed in plastic bags which are covered with a non-hermetic closure. The bags are stored in a controlled oven under the following conditions: 30 temperature: 40 ° C, relative humidity: 80%.

Samples are taken after a storage period of between 1 35 and 3 months and the residual chlorine content is determined by iodometric titration. Table 1 shows the results obtained after 50 days of storage of the detergent mixture prepared from anhydrous sodium metasilicate and trichloroisocyanuric acid coated by paraffin wax used in various percentages (expressed as weight percent). The results for remaining chlorine are expressed as percentages of the original chlorine content.

TABLE 1 10 - TRICHLORISOCYANOIC ACID Machine dishwashing detergent% residual chlorine

Not coated with paraffin wax 39

Coated with 5% 15 paraffin wax with m.p. 50-52 ° C 81

Coated with 5% paraffin wax with m.p. 40-42 ° C 78 20 Coated with 5% paraffin wax with m.p. 58-60 ° C 68.5 EXAMPLE 2 25

Example 1 is repeated, however, using sodium metasilicate pentahydrate instead of the anhydrous sodium metasilicate of Example 1 using the dishwasher detergent. Table 2 shows the results obtained.

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8 TABLE 2 TRICHLORISOCYANOIC ACID Machine detergent% residual chlorine 5 --—

Not coated with paraffin wax 14

Coated with 5% paraffin wax with m.p. 50-52 ° C 38.5

Coated with 5% paraffin wax with: m.p. 40-42 ° C 26.5

Coated with 5% paraffin wax with m.p. 58-60 ° C in Example 5

Examples 1 and 2 are repeated, using paraffin wax having a melting point of 40-42 ° C. Samples are taken after a storage period of 80 days. Table 3 shows the results obtained for dishwashing detergents prepared from either anhydrous sodium metasilicate or sodium metasilicate pentahydrate.

25 1 35 9 urine ιοΗ-Αοο d TABLE 3 TRICHLORISOCYANOIC ACID% residual chlorine 5 machine-maker on detergent detergent prepared from water based on meta-free sodium silicate, metasilicate pentahydrate

Uncoated acid 20 10 10: Acid coated with 1% wax 30 15

Acid coated with 2% wax 60 25 15 ---

Acid coated with 5% wax 78 26.5

Acid coated with 10% wax 78 27 20 25 1 35

Claims (4)

A machine dishwashing detergent containing a wax-coated chloroisocyanurate derivative, a plasticizer selected from polyphosphates, an alkalinity-forming agent consisting at least in part of sodium silicates, and a surfactant characterized in that the chloro-isocyanurate derivative with cichlorosuric acid derivative is trichloro a melting point below 60 ° C and used at a concentration of 1-10 wt. calculated on the acid. Machine dishwashing detergent according to claim 1, characterized in that the amount of paraffin wax used is 3-5% by weight. calculated on the acid. Process for preparing the machine dishwashing detergent according to claim 1 or 2, characterized in that the trichloroisocyanuric acid is coated with paraffin wax in an amount of 1-10% by weight. calculated on the acid before it is mixed with the other components in the dishwasher detergent. Process according to claim 3, characterized in that the molten wax is sprayed onto the trichloroisocyanuric acid heated to 50 ° C. 1 35