EP0359630A1 - Adsorbed liquid constituents and detergent formulations containing them - Google Patents

Abstract

The present invention relates to novel supported liquid constituents based on sodium sulphate and silica, preferably novel antifoam substances composed of the said support and of liquid antifoam compositions containing a polysiloxane and a silica, and to the detergent formulations containing the said substances.

Description

The present invention relates to supported liquid constituents, as well as their preparation process and the detergent formulas containing said substances.

The use of liquid or solid detergent compositions for washing natural or synthetic textiles is today widespread. This washing can be carried out in an artisanal way by hand or automatically using machines.

In the latter case, the presence of abundant amounts of foam and to be avoided unlike artisanal washing. Indeed, the significant formation of foam can cause the machine to overflow with risks for the electrical or electronic system.

Also for a long time, one sought to decrease the formation of the foams by addition to the conventional detergent systems of anti-foaming substances. These substances as well as any other liquid constituent of washing powder formulas must, on the one hand, be in a solid form, so as to be easily incorporated into the detergent powder in the case of solid detergent compositions. They must, on the other hand, have a satisfactory stability, so that after varying periods and storage conditions, they still have the same power.

Non-limiting examples that may be mentioned as liquid component of detergent formulas: defoamers, perfumes, fabric softeners, nonionic type surfactants.

As an anti-foaming agent, it has already been proposed to add a relatively large proportion of soaps with a long alkyl chain (18 to 20 carbon atoms). These soaps have several drawbacks: they must be used in large quantities, they have a weakened anti-foaming power in very soft water and are not versatile, that is to say that they do not have the same anti-foaming power for washing compositions. rich in non-ionic agents, for compositions detergents mainly composed of soaps or for conventional detergent compositions.

In fact, the liquid substances supported by the detergent formulas used in the solid detergent compositions must have a certain number of characteristics:
- They must be presented in the pulverulent state, so that they can be incorporated into the detergent powder after the various heat treatments; because anti-foaming substances, perfumes, non-ionic substances are generally sensitive to temperature.
- They must have an anti-foam function during the entire washing period and at all washing temperatures, that is to say between around 15 and 95 ° C and with all types of detergent formulas.
- They must dissolve easily in the detergent medium so as to release the adsorbed liquid component.
- The support must be neutral vis-à-vis the liquid substance so as not to destroy it either chemically or by an alkalinity problem.
- The support must absorb the liquid substance, it must also protect it from external elements such as the aggressive agents of the detergent formula, water which, for example, tends to hydrolyze the antifoam compound. This protection must sometimes be effective for relatively long periods.
- The support must not be of the phosphate type insofar as currently, environmental protection wants to limit the use of this type of compound in detergent compositions.

The present invention has made it possible to achieve the characteristics described above. It relates to supported liquid constituents for washing formula characterized in that they consist of sodium sulfate adsorbing said liquid constituent which is protected by silica.

This solution to the problem mentioned above makes it possible to absorb a brittle product on a neutral constituent, easily soluble in the washing medium, inexpensive, used in detergent compositions but which had the drawback of not protecting the brittle substance from with regard to the alkalinity of the detergent compositions, especially during prolonged storage periods.

It was not obvious that the sulphate and the silica have the desired properties announced previously. Indeed, among the soluble supports such as sodium carbonate, trisodium phosphate, sodium sulfate, sodium chloride, none has the characteristics previously announced, among the insoluble supports such as amorphous silica, silicoaluminates, clay, bentonites, crystalline silica, none of them either have the required qualities. Only the combination of sodium sulphate as a support for a liquid constituent and silica as a protective agent makes it possible to achieve all of the characteristics mentioned.

The liquid constituent on the support of the present invention preferably has the following constitution expressed by weight:
- sodium sulfate: 83-90%
- liquid constituent: 8-12%
- precipitated silica: 1- 4%

The sodium sulphate used is preferably a sulphate obtained after a calcination step at a temperature between 250 ° C and 400 ° C in an oxidizing atmosphere and in a stirred medium, which has the advantage of increasing the porosity of the support.

The liquid agent adsorbed on this support is constituted, as specified above, but not limited to, by an agent anti-foam, a fragrance, a non-ionic surfactant ...

In the context of the present invention, it is preferred to adsorb an antifoaming agent having a composition as defined in patent EP 210,114.

The silica used is a precipitated amorphous silica whose particle size is less than 0.075 mm. We prefer to use precipitated silica sold by RHONE-POULENC under the brand TIXOSIL 38 A.

The process for the preparation of the liquid constituents on a support of the present invention consists in mixing the antifoaming composition with the sodium sulphate and then in introducing the amorphous silica into a powder mixer.

These supported liquid constituents, object of the invention, can be included in all types of detergent formulas, in particular all-soap formulas, formulas rich in nonionics or more conventional formulas.

As an example of a conventional formula, the following weight formula can be cited: - sodium alkylarylsulfonate ..... 8 - nonionic form of linear fatty alcohol with 18 carbon atoms ethoxylated by 12 ethylene oxide units ..... 3 - nonionic form of linear fatty alcohol with 18 carbon atoms ethoxylated by 50 ethylene oxide units ..... 2 - sodium tripolyphosphate ..... 30 - sodium silicate (2SiO₂, Na₂O) ..... 8 - carboxymethylcellulose ..... 1.5 - perborate ..... 25 sodium sulfate ..... 20 - enzyme, perfume, dye, optical brightener ..... 2.5

Preferably, an amount of supported defoaming constituents is used such that the weight ratio of defoaming constituent supported to the detergent formula is between 1.5 and 3% and preferably about 2%.

The invention will be more fully described with the aid of the following examples which should not be considered as limiting the invention.

EXAMPLE

• 1 - Les proportions du mélange
  . Silice précipiter amorphe commercialisée par RHONE-POULENC sous la marque TIXOSIL 38 A,
  . Sulfate de soude commercialisé par RHONE-POULENC sous la référence B,
  . Antimousse,
  dans les domaines suivants :
  . TIXOSIL [0 à 10 %] avec un témoin à 90 % [dans ce cas, sulfate = 0 %],
  . Sulfate [90 à 80 %], donc avec un témoin silice = 0,
  . Antimousse : constant = 10 %.
• 2 - L'ordre d'introduction des composants selon les 2 possibilités suivantes :
  2-a. Sulfate - TIXOSIL - Antimousse,
  2-b. Sulfate - Antimousse - TIXOSIL.

Using the anti-foam compound described below sold by RHONE-POULENC under the reference 20461, we varied:

• 1 - The proportions of the mixture
  . Amorphous precipitated silica marketed by RHONE-POULENC under the brand TIXOSIL 38 A,
  . Sodium sulphate marketed by RHONE-POULENC under the reference B,
  . Antifoam,
  in the following areas:
  . TIXOSIL [0 to 10%] with a 90% control [in this case, sulfate = 0%],
  . Sulfate [90 to 80%], therefore with a silica control = 0,
  . Antifoam: constant = 10%.
• 2 - The order of introduction of the components according to the following 2 possibilities:
  2-a. Sulfate - TIXOSIL - Antifoam,
  2-b. Sulfate - Antifoam - TIXOSIL.

The mixtures were made using a 5 liter LODIGE laboratory mixer.

The Anti-foam Compound has the following composition:
- 85 to 95% silicone oil, dimethylpolysiloxane, viscosity of around 1000 mPa / s at 25 ° C,
- 5 to 15% precipitated silica having a specific surface of 300 m² / g.

This mixture was treated for approximately 8 hours at 150 ° C., homogenized and ground in the liquid phase.

A - Assessment test

The various solid defoamers thus prepared were added to a foaming detergent base, containing, inter alia, a LABS surfactant mixture, C12 8OE ethoxylated alcohol, C14 4OE ethoxylated alcohol, sodium perborate, a tripolyphosphate-based builder mixture and silicate with SiO₂ / Na₂O ratio = 2.

The addition rate is uniform and equal to 0.2% of active ingredients, or 2% of the premix powders described above.

The complete compositions are then subjected to a foam level test in a MIELE 421 S washing machine with a graduated front window, which makes it possible to visually monitor the anti-foam effect during a complete washing cycle, the temperature changes from ambient (network water temperature) to 95 ° C. The "washing" is done with a load of linen of 3 kg to simulate the mechanical effects.

All the compositions are subject to an immediate test, immediately after the manufacture of the formula and the introduction of the anti-foaming agent (aging = 0) and of a test after 1 or 2 month stay in an oven, closed polyethylene bags, at 40 ° C (aging t = 1 or 2 months).

B - The results

The results are presented in the form of a table giving

* H max = the maximum foam height reached (0 - 22cm). The best results are found at foam levels of 12 - 14 cm.

* T for H = 22 cm = the time for which the height of 22 cm (maximum visible "full window") is obtained, if this is the case .
The closer this figure is to 55 minutes, the better the result.
We accept as good a cycle where the 22 cm are reached after 35 - 40 min, which represents 65 -70% of the total duration.

(* The table also indicates the possible overflow of the machine which are of course unacceptable and lead to the assessment "M" as bad, in the table.)

If this maximum height of 22 cm is obtained at the start of the cycle (after 10 - 15 min for example), it is certain that the mechanical efficiency of stirring the laundry may suffer. We will therefore give a mixed or bad assessment of the result. Type of defoamer (0.2% MA silicone dose) Zero Aging Aging 1 month Aging 2 months H Max T for H = 22 cm Overflow Appreciation H Max T for H = 22 cm Overflow Appreciation H Max T for H = 22 cm Overflow Appreciation Compound alone 22 50 mins no Well 22 35 mins no Well PREMIX (% by weight) Antifoam 10 Sulfate 90 10 - no Well 22 30 mins no ± 22 25 mins no ± Defoamer 10 Silica 90 22 12 mins no 22 12 mins no M 22 8 mins Yes M Sulfate 80 Silica 10 Antifoam 10 22 48 mins no Well 22 12 mins no M Sulfate 83 Silica 7 Antifoam 10 22 42 mins no Well 22 28 mins no ± Sulfate 85 Silica 5 Antifoam 10 22 52 mins no Well 22 15 mins no M 22 11 mins no M Sulfate 87 Silica 3 Antifoam 10 22 40 mins no Well 22 20 mins no M 22 10 minutes no M (introduction 2-a) Sulfate 87 Silicone 10 Silica 3 14 - no Well 22 42 mins no Well 22 40 mins no Well Sulfate 85 Silicone 10 Silica 5 22 22 mins no ± 22 22 mins no ± (introduction 2-b)

Claims (8)

1. Supported liquid constituents for detergent formula characterized in that they consist of sodium sulfate as the adsorbent base of said liquid constituent protected by silica. 2. Liquid constituents according to claim 1 characterized in that they are chosen from antifoam compositions, perfumes, nonionic surfactants and is preferably an antifoam composition. 3. Liquid constituents according to claim 1, characterized in that they have the following constitution by weight:
- sodium sulfate ...... 83 - 90
- liquid constituent .... 8 - 12
- precipitated silica ...... 1 - 4 4. Liquid constituents according to any one of the preceding claims, characterized in that the sodium sulfate is a sodium sulfate calcined at a temperature between 250 ° C and 400 ° C. 5. Liquid constituents according to any one of the preceding claims, characterized in that the precipitated silica has a particle size less than 0.075 mm. 6. Method for preparing the liquid constituents according to any one of the preceding claims, characterized in that in a first step, the liquid constituent is adsorbed on the sodium sulfate, in a second step, the silica is added. 7. Detergent compositions containing a liquid constituent according to any one of claims 1 to 5. 8. Detergent compositions according to claim 7 containing 0.15 to 0.5% by weight of liquid constituents.