FR2816631A1 - Cleaning composition for improving visibility through translucent glass substrates in contact with steam, especially in household electrical appliances, comprises a mineral powder - Google Patents

Abstract

Cleaning composition (I) for improving visibility through translucent glass substrates in contact with steam comprises a mineral powder with an average particle size below 60 mu m suitable for contact with food. Independent claims are also included for the following: (1) a process for improving visibility through translucent glass substrates in contact with steam, comprising applying (I) to one or both sides of the substrate using a moist applicator and then rinsing the treated surface(s); (2) a translucent glass substrate treated with (I) such that a 0.9 g water droplet deposited on the substrate will spread to at least 8.2 mm<2>; (3) a household electrical appliance with an internal viewing zone comprising the substrate of (2); (4) use of a (known) composition comprising rock dust, soap flakes, glycerol, tallow, lemon oil, sodium (sic) and vegetable oil for improving visibility through translucent glass substrates in contact with steam.

Description

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La présente invention concerne un produit ou composition nettoyant (e) pour améliorer la vision à travers un substrat à base de verre destiné à être en contact avec de la vapeur majoritairement de l'eau, ainsi que le substrat à base de verre traité avec ladite composition nettoyante. CLEANSING COMPOSITION TO IMPROVE VISION A
THROUGH A GLASS BASED SUBSTRATE, BASED SUBSTRATE
OF GLASS TREATED WITH THE SAID COMPOSITION, PROCESS FOR
TREATMENT OF THE SUBSTRATE The present invention relates to the general field of products or compositions and methods for treating glass-based substrates which are generally transparent, with a view to obtaining good vision through the glass-based substrate, whatever the conditions. conditions under which the glass-based substrate is located or caused to be stressed

The present invention relates to a cleaning product or composition for improving vision through a glass-based substrate intended to be in contact with vapor, mainly water, as well as the glass-based substrate treated with said substrate. cleaning composition.

The present invention also relates to any household appliance comprising an internal viewing zone, equipped with a substrate based on glass treated according to the composition in accordance with the invention, as well as a method for treating the surfaces of a substrate based on glass, intended to give said surface properties improving vision.

The present invention also relates to a new use of a cleaning substance capable of being in contact with foodstuffs, as a product for treating the surfaces of a glass-based substrate In the particular field of household appliances, and in particular in the more restrictive field of cooking appliances such as fryers or multifunction cookers, and for example rice cookers, or even pressure cookers, glass steamer bowls or steam ovens, it turns out

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It is advantageous to provide for the integration into these devices of a viewing zone allowing the user to monitor, or even control, the correct progress of the cooking operation.

To this end, these different devices are provided, as a viewing area, with a surface or a substrate based on transparent glass, which allows the user to have visual access to the interior of the device. the appliance itself being cooked.

These viewing areas are for example formed by windows on fryers or pressure cookers, the windows being generally mounted on and through the thickness of the cover In ovens, especially steam ovens, the viewing areas are formed by the doors of the apparatus, doors in which a glazed surface used for observation is integrated.

The glasses used for these applications can be of different types and in particular made of borosilicates, or soda-lime, whether they are toughened or not, and of flat or curved geometric shape. It is also possible to create vision zones for these products based on specially treated plastic materials.

In general, it turns out, in particular for deep fryers in which the water vapor is often loaded with molecules or greasy particles, that vision deteriorates fairly quickly due to the deposit of drops on the face. internal window. Such phenomena of condensation and deposit of fine droplets also appear on pressure cooker windows or on the internal faces of steam oven doors.

Under these conditions, the user's vision is extremely difficult, since he can no longer clearly distinguish the state of the foodstuff.

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subjected to cooking. This contributes to reducing the efficiency of the vision zones in such household appliances. To attempt to remedy this problem of reduction of vision through the glazed zones equipping household cooking appliances, various solutions have been considered. can cite those consisting in modifying the geometry of the glazed surface and in using a window of flat glass, or else a window of plastic material, or those consisting in using a molded and curved glass.

These solutions provide, under certain conditions, a certain noticeable improvement in vision, but do not make it possible to effectively remedy the vision problems mentioned above, since the formation of fine droplets is always noted in various and varied proportions. on the inside of the windows corresponding to a phenomenon close to misting, despite the larger size of the droplets.

The objects assigned to the invention therefore aim to remedy the various problems mentioned above and to propose a new cleaning product capable of being in contact with foodstuffs and intended to ensure the treatment of a glass-based substrate, which is brought into contact with steam mainly formed by water, said treatment having to make it possible to preserve its visual properties on the surface and / or to improve them and / or to prevent their deterioration.

Another object of the invention aims to provide a new cleaning product which is easy to use. Another object of the invention aims to provide a new cleaning product which provides a vision improving effect which is durable over time. .

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Un autre objet de l'invention vise à proposer un substrat à base de verre qui, après traitement avec le produit nettoyant conforme à l'invention, présente des propriétés de mouillabilité améliorées.

Another object of the invention aims to provide a glass-based substrate which, after treatment with the cleaning product in accordance with the invention, exhibits improved wettability properties.

à être en contact avec de la vapeur majoritairement de l'eau Les objets assignés à l'invention sont atteints à l'aide d'une composition nettoyante pour améliorer la vision à travers un substrat à base de verre translucide qui est destiné à être en contact avec de la vapeur majoritairement formée par de l'eau, ladite composition étant apte à se trouver au contact de denrées alimentaires et comprenant une poudre minérale destinée à être appliquée sur la (les) face (s) du substrat en contact avec la vapeur en conjonction avec un moyen d'application humide, ladite poudre minérale étant formée par des particules d'une taille moyenne inférieure à 60 um lorsque la poudre est appliquée et que les particules sont sollicitées mécaniquement contre la (les) faces. Another object of the invention aims to provide a new method of treating the surfaces of a glass-based substrate, which makes it easy to obtain an improvement in vision when the substrate is in contact with vapor mainly formed by water, without the substrate being scratched Another object of the invention aims to propose a new use of a cleaning substance suitable for being in contact with foodstuffs, to improve the vision properties of a substrate at intended glass base

to be in contact with vapor mainly water The objects assigned to the invention are achieved using a cleaning composition to improve vision through a substrate based on translucent glass which is intended to be in contact with steam mainly formed by water, said composition being suitable for being in contact with foodstuffs and comprising a mineral powder intended to be applied to the face (s) of the substrate in contact with the steam in conjunction with a wet application means, said mineral powder being formed by particles of an average size of less than 60 µm when the powder is applied and the particles are mechanically urged against the face (s).

The objects assigned to the invention are achieved using a substrate based on translucent glass treated with a cleaning composition to improve vision through said substrate, the latter being intended to be in contact with predominantly formed vapor. with water, said composition being suitable for being in contact with foodstuffs and comprising a

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mineral powder intended to be applied to the face (s) of the substrate in contact with the vapor in conjunction with a wet application means, said mineral powder being formed by particles of an average size of less than 60 μm when the powder is applied and the particles are mechanically biased against the face (s), said substrate having a wettability such that a drop of water with a mass of 0.9 gram deposited on the substrate has a spreading surface at least equal to 8.2 mm2 (32.8 x 0.25 mm2).

The objects assigned to the invention are achieved using a process for the surface treatment of a glass-based substrate intended to be in contact with vapor mainly formed by water, said process being intended to improve the vision through said substrate, method in which the substrate is treated by application and mechanical action of an inorganic powder suitable for coming into contact with foodstuffs and formed by particles of a size less than 60 μm when they are mechanically stressed on the concerned face or faces of the substrate, said application being carried out using a wet application means, then in which the treated surface is rinsed.

The objects assigned to the invention are achieved by the use of a cleaning substance suitable for being in contact with foodstuffs and comprising a composition including a mineral powder formed by particles of a size less than 60 μm when they are mechanically stressed on a surface to be treated, as a treatment product to improve vision through a glass-based substrate intended to be in contact with water vapor mainly formed by water The invention will be better understood with the aid of the description which follows and the figures which follow, given purely by way of illustration and without limitation in which:

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- Figures 1 and 2 respectively illustrate the theoretical state of condensation drops responsible for poor and good vision through a glass substrate - Figures 3, 4 and 5 respectively illustrate the typical wettability curves obtained with untreated windows, treated windows (minimum effect) and treated windows (maximum effect) - Figure 6 illustrates, in a synthetic manner, the improving effect obtained by the invention.

In the examples which follow, reference will be made, by way of purely illustrative and non-limiting example, to a household appliance comprising a viewing window arranged in the lid of the fryer, said window constituting the treated viewing zone of the apparatus. home appliance. Such an Illustration is given for purely illustrative and non-limiting, it being understood that the invention can be applicable to any type of household appliance comprising a viewing zone allowing the user to monitor the progress of the cooking. The invention can also be applied to devices other than household appliances, as soon as they bring into play a vision zone formed by a glass-based substrate, comprising a face intended to be in contact with glass. vapor, mainly formed by water vapor.

The invention will also apply in a preferential manner, but in no way limiting, to any type of glass capable of being used in applications in the field of household appliances, whether it is borosilicate glass, soda-lime glass, tempered or not, the glasses or glass-based substrates used being of flat or curved shapes and of varying thicknesses.

In particular, the invention can be applied, at least in the field of household appliances, to devices intended for frying (fryers), to

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pressure cookers, steamer bowls, steam oven doors, or even various cookers such as rice cookers, for example The preferential application referred to being relating to the field of household appliances, It is essential that the composition cleaning agent (or the cleaning product) in accordance with the invention is suitable for being in contact with foodstuffs, and that it therefore meets the food requirements required and prescribed by the French decree of October 27, 1975 and its modifications in 1997 and 1999, relating to cleaning products for equipment that may come into contact with foodstuffs (Official Journal of November 30, 1975 and Corrigendum to the Official Journal of February 5, 1976).

The study of the general phenomenon of vision through a glass-based substrate, which was undertaken by the applicant, made it possible to show that the phenomenon of vision was essentially linked to the behavior of the vapor recondensation drops on the face. of the substrate in contact with the vapor and to the value of the angle e formed by the tangent at the point of liquid-solid interface (surface of the glass) -air to the drop and the base of the drop in contact with the solid.

Thus, as shown in Figure 1, when the recondensed vapor drops form a high angle 0 with the surface of the glass, they prevent vision through the glass by optical deformation Conversely, when the recondensed vapor drops form with the surface of the glass at a low angle 0, as shown in FIG. 2, the drops form between them a film of water which is substantially flat on the face of the glass concerned. As this film of water is generally uniform, vision through the substrate is hardly affected.

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De manière générale, la qualité de la vision à travers un substrat à base de verre évolue donc directement en fonction de la valeur de l'angle 8, plus sa valeur étant faible, meilleure étant la vision.

In general, the quality of the vision through a glass-based substrate therefore changes directly as a function of the value of the angle 8, the lower its value, the better the vision.

effet, il s'avère que le film d'eau, qui se forme sur la face du verre concerné très rapidement et dès le début de la cuisson, perdurera par la suite tout au long de la cuisson sans évolution possible Il s'avère dès lors que l'obtention d'une bonne vision dot nécessairement être obtenue dès les toutes premières minutes de la cuisson. The studies carried out by the applicant have moreover also shown that the evolution of vision over the course of the cooking time, for example in the case of a fryer with a molded and curved window, was very low. In

Indeed, it turns out that the film of water, which forms on the face of the glass concerned very quickly and from the start of cooking, will subsequently persist throughout cooking without any possible development. while obtaining good vision must necessarily be obtained from the very first minutes of cooking.

In summary, the studies carried out have shown that obtaining good vision through a glass-based substrate, in household appliances involving cooking of food generating a vapor phase mainly formed by water ( whether it is a water vapor phase laden with grease in the case of a fryer or water vapor alone in the case of rice cookers for example) required: - obtaining drops of recondensed steam in a flattened shape on the face of the glass concerned, - rapid obtaining at the start of cooking of recondensed drops of steam, these drops having to form a dome shape with maximum flattening.

After having demonstrated that the flattening of the drops of water or liquid charged on the face concerned of the glass substrates was responsible for good vision, the applicant therefore realized that this flattening phenomenon was linked to the particular energy conditions. rampant at the interfaces between the layer or sublayer

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constituting the outermost face of the glass substrate concerned, and the water drops recondensed. The particular and generally dissymmetrical relationships between the different atoms or molecules, constituting the liquid on one side and the solid on the other hand, generate a phenomenon of surface tension which influences the geometry of the drop of water. that in practice, a drop of liquid will not have the same geometry if the substrate is changed, or that a substrate will not be wet in the same way if the composition of the liquid is changed.

The hypothesis put forward by the applicant therefore consisted in trying to restore, or even improve, the wettability of the surface of the glass-based substrate intended to come into contact with the vapor mainly formed by water, inside the glass. the household appliance.

For this, and knowing that the glasses or glass substrates intended for use in household appliances, and in particular in fryers, generally comprise an unknown polluting layer (resulting for example from the manufacturing process, from the storage conditions of the parts, or else assembly and integration operations in the cover), opposing a good spreading of the drops, the applicant sought to obtain a product having a mechanical action on this polluting layer.

At the same time, the applicant has sought to obtain a mechanical action which does not generate the appearance of scratches on the glass, these scratches having both an unsightly appearance but also an appearance which is often harmful to vision.

This is how the applicant was able to demonstrate that the vision properties through a glass-based substrate were greatly improved when a composition was applied to the face of the glass-based substrate.

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comprenant une poudre minérale, destinée à être appliquée au moyen d'un ou en conjonction avec un moyen ou milieu d'application humide, ladite poudre minérale étant formée par des particules d'une taille moyenne inférieure à 60 um, et de préférence Inférieure à 30 um lorsque ces particules sont sollicitées mécaniquement contre la (les) face (s) du substrat Selon l'invention, la taille moyenne des particules de la poudre minérale est

inférieure à 60 um, et de préférence inférieure à 30 um, après une éventuelle désagrégation lors de l'application mécanique sur la surface à traiter, cette application étant alors susceptible de générer la désagrégation des particules, qui prennent alors leur taille moyenne mécaniquement active, étant entendu qu'à l'état Inerte, c'est à dire de non-application, les particules peuvent avoir une taille supérieure à 60 um Il s'est alors en effet avéré que l'application de cette poudre minérale affectait positivement la mouillabilité des gouttes d'eau sans faire apparaître de rayures, du moins à l'oil nu.

comprising a mineral powder, intended to be applied by means of or in conjunction with a wet application means or medium, said mineral powder being formed by particles of an average size of less than 60 μm, and preferably less than 30 μm when these particles are mechanically biased against the face (s) of the substrate According to the invention, the average size of the particles of the mineral powder is

less than 60 μm, and preferably less than 30 μm, after a possible disintegration during mechanical application to the surface to be treated, this application then being capable of generating the disintegration of the particles, which then take their mean mechanically active size, it being understood that in the inert state, that is to say of non-application, the particles may have a size greater than 60 μm It has then in fact been found that the application of this mineral powder positively affected the wettability drops of water without showing any scratches, at least with the naked eye.

According to the invention, it turned out that particles of a smaller average size and for example between 30 and 0.8 μm or better still between 1 and 0.8 μm on the one hand and between 0.6 and 0.05 μm on the other hand made it possible to obtain particularly advantageous results in terms of wettability.

Other values, for example of the order of 0.7 / 0.75 μm, make it possible to obtain results, in terms of wettability, which are also interesting but specific.

It also turned out that the mineral powder according to the invention was particularly effective when the elementary particles composing it had specific geometric shapes, exhibiting numerous peaks and sharp edges.

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The cleaning composition in accordance with the invention consequently makes it possible to obtain an anti-fog type treatment or rather modifying the geometry of the drops forming the mist and improving vision under the conditions referred to above, for a glass-based surface, it being understood that this product is suitable for being in contact with foodstuffs, as has been mentioned previously.

The mineral powder can be combined with various chemically neutral agents or compounds. However, certain compounds can be combined with the mineral powder to give it interesting secondary actions such as in particular degreasing actions. Thus, the mineral powder can be combined with degreasing agents and / or with other agents such as agents facilitating or promoting the evacuation or elimination of the composition and of the detached polluting particles.

Preferably, the mineral powder will represent at least 50%, and for example preferably 65% of the total composition of the product.

Preferably, the composition will comprise at least and approximately 65% of mineral powder formed by alumina or corundum.

The cleaning product in accordance with the invention may be in the form of a simple powder in the dry articular state, the powder being applied in the wet state to the surface, by simple addition of water or by addition. indirect water through a sponge, cloth or cloth capable of absorbing water.

As a variant, the cleaning product in accordance with the invention may also be in the form of a composition formed by the powder incorporated into a gel, a solution or a paste, the gel, the solution or the paste then forming the wet application environment in which the mineral powder is enclosed or integrated.

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Obviously, the hardness of the particles making up the mineral powder must be such that it is not liable to alter the surface of the glass.

Ultimately, the proportion, the average particle size of the powder in the composition may vary without however giving rise to the appearance of scratches as soon as the other elements of the composition are adapted accordingly and in particular the proportion of agents. greasy or degreasing. In other words, the larger the particle size, the correspondingly higher the proportion of degreasing agents.

The effects of the basic treatment of the invention on the variation in the wettability at the surface of the treated glass have been demonstrated by the applicant.

The measurement method developed by the applicant consisted in measuring a measurable and reproducible physical parameter, which is a faithful image of the behavior of the glass in use, corresponding to contact of the glass with vapor mainly formed by water.

The measurable physical parameter chosen consisted in measuring the spreading surface of a drop of liquid of given volume (or mass) on the glass surface concerned.

In general, the measurement method therefore consisted, after depositing drops of water by successive additions of 0.25 grams (measured to the milligram or to the nearest 1 / 1000th of a milliliter), in measuring the spreading surface of the drop on the treated glass surface (or the window) for a given quantity of liquid Depending on the results obtained, the higher the measured spread surface, the lower the angle 6 and the better the vision through the glass will be .

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Such a method therefore makes it possible to differentiate the glasses, treated or not according to the invention, which will allow good vision in use, from those which, on the contrary, will offer poor vision in use.

In particular, the course of the so-called wettability test is as follows.

The test consists in first of all cleaning the glass surface to be tested with, for example, a piece of laboratory paper or hydrophilic cotton type hand towel previously soaked in acetone rectapur (this quality must be absolutely used, because the industrial acetones contain impurities that would remain on the glass after evaporation). The cleaning is carried out by light circular movements, and ends with a cleaning step in which the paper is pulled completely towards the edge of the window, in order to avoid that the acetone does not finish evaporating in the center of t screen, running the risk of concentrating impurities therein.

The quality of the cleaning can be checked by simple visual observation of the window at grazing incidence or by transparency.

The test is continued by depositing in the center of the surface to be tested a drop of water by successive additions of approximately 0.25 grams (measurement carried out precisely as mentioned above). Any addition must be made without disturbing the already existing drop, that is to say that it is advisable to deposit and not to drop, on the top of the drop already spread out, the complementary water. Conveniently, the addition of the additional water (approximately 0.25 grams each time) is carried out using a small diameter needle or pipette tip, in fact allowing the droplets to be absorbed. additional by the drop already spread before they fall.

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The measurement of the spreading surface of the drop on the window is carried out after each successive addition of 0.25 grams, and after a period of fifteen seconds intended to give the drop the time necessary to reach a stable level of spread. .

This measurement makes it possible to plot on a graph the mass of the water drop on the abscissa, and the spreading surface of the water drop on the ordinate.

The test was carried out using a measurement of the mass of water deposited on the glass surface concerned using an electronic balance previously tared at 10-4 grams, and making it possible to support the porthole or the mass of glass. tested. Another method using the deposit of a known volume of water, for example by means of a micro pipette, could also have been used.

The test consisted in photographing, using a digital camera, the drop of water at the end of each successive addition Beforehand, a graph paper is interposed between the weighing plate and the porthole or the glass surface to be tested, the processing of the image then allowing the measurement of the surface of the drop.

As a variant, the test could have consisted in taking advantage of the transparency of the window to project the shadow of the drop onto a screen, in order to make it more easily measurable.In addition, to ensure the reproducibility of the measurements, it The various relevant parameters likely to lead to dispersion of the measurements should be taken into account, namely: - The surrounding atmosphere of the measurement The air in the laboratory must be free of any pollution, in particular avoiding any storage or handling of solvents in the measuring room. The temperature of the

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part must be of the order of 20 to 30 OC, so as to limit as much as possible the inter-facial variations in the solid or the liquid. The hygrometric degree will vary between 50 and 100%, knowing that IF the relative humidity is very high, an adsorption of water on the surface of the window will be expected. '' using drops of distilled water using a classic bu-distiller for example, the water intended for carrying out the measurements must be kept away from air, and in particular from carbon dioxide
The substrate based on treated glass (or window) Its cleaning must be carried out according to the procedure described above.

The beneficial effect provided by the invention was then demonstrated by measuring the surfaces of the spreading of drops of water on the same glass-based substrate, in this case a fryer window. For this, the measurements were carried out on a series of substrates based on untreated glass or corresponding to windows of conventional fryers such as those found on the market today. The results and experimental values are reported in Figure 3 and in Table 1, and were noted as corresponding to wettability of an untreated window, due to the poor vision they provide. The regression line obtained is of the form Y = 19x + 1, in which Y corresponds to the area (a unit area = 0.25 mm2) of spreading of the drop, and in which x corresponds to the mass of the drop of water in grams.

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Résultats expérimentaux Date essai X = masse Y surface 14/09/00 0, 253 5 0, 512 9 0, 761 16 1, 026 21 0, 214 5 0, 499 14 0, 734 19 1, 01 25 0, 253 5 0, 486 il 0, 781 18 1, 011 20 0, 233 7 0, 503 12 0, 77 17 1, 005 21 0, 258 6 0 514 11 , 0, 763 14 1, 105 21 23/08/00 0, 125 4 0, 249 6 0, 513 Il 0, 751 13 1, 014 17 n709/00"0. 242"5 0, 49 9 0, 753 16 0, 997 19 12/09/00 0, 203 4 0, 601 10 1, 0919 Tableau 1 METHOD: Analysis of wettability in water SAMPLE: Untreated curved soda-lime window REPEATABILITY: Long time

Experimental results Test date X = mass Y surface 14/09/00 0, 253 5 0, 512 9 0, 761 16 1, 026 21 0, 214 5 0, 499 14 0, 734 19 1, 01 25 0, 253 5 0, 486 il 0, 781 18 1, 011 20 0, 233 7 0, 503 12 0, 77 17 1, 005 21 0, 258 6 0 514 11, 0, 763 14 1, 105 21 08/23/00 0 , 125 4 0, 249 6 0, 513 Il 0, 751 13 1, 014 17 n709 / 00 "0. 242" 5 0, 49 9 0, 753 16 0, 997 19 9/12/00 0, 203 4 0 , 601 10 1, 0919 Table 1

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The same glass-based substrates or windows of the fryers were then subjected to the corresponding surface treatment, using the cleaning product corresponding to the invention, then the same wettability measurements were carried out.

The results of the measurements and experimental values are shown in FIG. 5 and in Table 2. The regression line obtained is of the form Y = 58x + 9, Y and x corresponding to the same values defined previously.

The study of the results and measurements obtained then revealed that the graph in FIG. 5 in fact corresponded to the maximum improving effect of the surface treatment corresponding to the invention, from untreated glasses, while others glass-based substrates could, while reacting positively to the treatment effect, have a lesser improvement reaction in terms of vision The minimum improving effect which can be obtained by the treatment and by the cleaning product according to the invention can be characterized by the graph illustrated in Figure 4 and Table 3. In this case, the regression line is of the form Y = 32x + 4, in which Y and x are variables identical to those defined previously for the other graphs.

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METHOD: Analysis of wettability in water SAMPLE: Curved soda-lime window (minimum effect) REPEATABILITY: Long time

<tb>
<tb> Experimental <SEP> results
<tb> Date <SEP> test <SEP> X <SEP> = <SEP> mass <SEP> Y <SEP> surface
<tb> 09/14/00 <SEP> 0, <SEP> 267 <SEP> 12
<tb> 0, <SEP> 501 <SEP> 21
<tb> 0, <SEP> 765 <SEP> 29
<tb> 1, <SEP> 041 <SEP> 35
<tb> 0, <SEP> 273 <SEP> 14
<tb> 0, <SEP> 495 <SEP> 23
<tb> 0, <SEP> 75 <SEP> 29
<tb> 1, <SEP> 05 <SEP> 37
<tb> 0, <SEP> 26 <SEP> 13
<tb> 0.501 <SEP> 21
<tb> 0.781 <SEP> 31
<tb> 1, <SEP> 057 <SEP> 40
<tb> 0, <SEP> 26 <SEP> 13
<tb> 0, <SEP> 519 <SEP> 22
<tb> 0, <SEP> 794 <SEP> 32
<tb> 1, <SEP> 015 <SEP> 37
<tb> 0, <SEP> 287 <SEP> 13
<tb> 0, <SEP> 519 <SEP> 19
<tb> 0, <SEP> 764 <SEP> 27
<tb> 1, <SEP> 019 <SEP> 35
<tb> 08/23/00 <SEP> 0, <SEP> 141 <SEP> 8
<tb> 0, <SEP> 259 <SEP> 14
<tb> 0, <SEP> 511 <SEP> 25
<tb> 0, <SEP> 77 <SEP> 33
<tb> 1, <SEP> 044 <SEP> 40
<tb> 09/11/00 <SEP> 0, <SEP> 114 <SEP> 5
<tb> 0, <SEP> 24411
<tb> 0, <SEP> 508 <SEP> 19
<tb> 0, <SEP> 759 <SEP> 27
<tb> 1, <SEP> 016 <SEP> 38
<tb> 09/12/00 <SEP> 0, <SEP> 1978
<tb> 0, <SEP> 617 <SEP> 22
<tb> 1, <SEP> 003 <SEP> 32
<tb>
Table 2

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METHODE : Analyse de la mouillabilité à l'eau ECHANTILLON : Hublot sodocalcique galbé TRAITE (effet maximum) REPETABILITE : Temps long

Résultats expérimentaux Date essai X = masse Y = surface 14/09/000, 2424 0, 49239 0, 727 56 1, 003 67 0, 255 21 0, 505 36 0, 757 52 1, 05666 0, 32129 0, 481 37 0, 751 54 1, 042 66 0, 242 25 0, 508 35 0, 759 54 1 63 0, 25219 0, 503 36 0, 758 51 1, 03265 23/08/00 0, 115 il 0, 25 23 0, 512 42 0, 771 57 1, 01160 11/09/000, 153 18 0, 25931 31 0, 50940 0, 74657 0, 99588 12/09/000, 22516 0, 604 43 1, 04261 Tableau 3

METHOD: Analysis of wettability in water SAMPLE: Curved soda lime window TREATED (maximum effect) REPEATABILITY: Long time

Experimental results Test date X = mass Y = area 09/14/000, 2424 0, 49239 0, 727 56 1, 003 67 0, 255 21 0, 505 36 0, 757 52 1, 05666 0, 32129 0, 481 37 0, 751 54 1, 042 66 0, 242 25 0, 508 35 0, 759 54 1 63 0, 25219 0, 503 36 0, 758 51 1, 03265 08/23/00 0, 115 il 0.25 23 0 , 512 42 0, 771 57 1, 01160 9/11/000, 153 18 0, 25931 31 0, 50940 0, 74657 0, 99588 09/12/000, 22516 0, 604 43 1, 04261 Table 3

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On a practical level, it turns out that the assembly and storage of the fryer windows on the fryer itself are at the origin of uncontrolled alterations of the glass eminently variable, and therefore leading to the presence of a polluting layer great variability in structure and composition at the glass level. This is the reason why the glass substrate at the start can be under different physicochemical conditions, the final improving result obtained can also be different but nevertheless always perceptible.

Nevertheless, it turns out that the beneficial and improving effect of the product and of the surface treatment process according to the invention is framed by the two graphs of the form Y = 32x + 4 (good vision) and Y = 58x + 9 (excellent vision), as shown in figure 6.

The graph of FIG. 6 therefore makes it possible to illustrate in a particularly clear manner the improving effect in terms of vision by the application of a mineral powder in accordance with the invention on the face concerned of a substrate or of a window. of glass, it being understood that the effect obtained, not illustrated by the various graphs, must be obtained without the appearance of scratches on the glass, the mineral powder used must also meet the food requirements with regard to foodstuffs, as defined previously in the body of the description.

The graph of FIG. 6 therefore shows a zone 1 hatched and framed by the graphs Y = 58x + 9 and Y = 32x + 4, which makes it possible to characterize the substrates based on treated glass that have been stripped of their layer. polluting by mechanical treatment based on mineral particles. When these glass substrates have undergone a treatment in accordance with the invention, they consequently exhibit a wettability defined according to the wettability test described above, such as a drop of water deposited on the surface of the treated glass verifies the relation Y 32x + 4.

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Similarly, a glass-based substrate treated with an anti-fog cleaning product according to the invention will exhibit a wettability such that a drop of water with a mass of 0.9 grams deposited on said substrate has a spreading surface. at least equal to 8.2 mm2 (32.8 x 0.25 mm2).

In other words, a glass-based substrate treated according to the invention will have a wettability such that the spreading surface of a drop of water with a mass of 0.9 grams is between 8.2 mm2 and 15.3 mm2 on average The repeatability measurements carried out at the level of the series of experimental values showed that the percentage variability was of the order of 10%, and 10 to 15% respectively for the glass-based substrates with poor vision and those with good or even excellent vision.

The technique for measuring the wettability used therefore proves to be simple to implement, while making it possible to clearly distinguish the wettability properties of the windows or glass-based substrates, depending on whether or not they have received the treatment. according to the invention. Furthermore, the dispersions of results obtained are much less than the variations obtained between the different windows.

According to the invention, the method is a method for treating the surface of a glass-based substrate intended to be in contact with vapor mainly formed by water, said method being intended to improve vision through said substrate, process in which the substrate is treated by application and mechanical action, for example polishing, of a mineral powder capable of coming into contact with foodstuffs and formed by particles of a size less than 60 μm when they are stressed mechanically on the concerned face (s) of the substrate, said application

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being carried out using a wet application means, then in which the treated surface is rinsed.

encore plus préférentielle, comprise entre 1 et 0, 05 um ou encore à défaut, entre 1 et 0, 8 um et entre 0, 6 et 0, 05 um. Les particules peuvent également être de l'ordre de 0, 7 um. The application can be carried out using a wet application means formed by a sponge soaked in liquid and for example water The treatment can be carried out by rubbing (polishing) the mineral powder, using of the sponge, on the concerned face (s) of the substrate, the particles being able to disintegrate into elementary particles of a size less than 60 μm, preferably less than 30 μm and so

even more preferential, between 1.0 and 0.05 μm or alternatively, between 1 and 0.8 μm and between 0.6 and 0.05 μm. The particles can also be on the order of 0.7 µm.

The invention also relates to a novel use of a cleaning substance suitable for being in contact with foodstuffs as a product for the surface treatment of a glass-based substrate, such as a fryer window, to impart to the surface concerned and treated a modifying effect of the geometry of the drops forming the mist.

The new use consists in using a cleaning substance suitable for being in contact with foodstuffs and comprising a composition including a mineral powder formed by particles of a size less than 60 μm when they are mechanically stressed, for example by polishing, on a surface to be treated, as a treatment product for improving vision through a glass-based substrate intended to be in contact with water vapor mainly formed by water. In this way, any appearance of scratches on the surface of the glass-based substrate.

As a new use, the composition comprises an inorganic powder advantageously formed by particles of an average size.

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less than 60 μm and advantageously between 30 and 0.05 μm, and even more preferably between 1.0 and 0.05 μm.

As a new use, the applicant has found that the cleaning product available on the market under the name Pierre d'Argile (registered trademark) meets the required requirements and gives excellent results in improving the vision of portholes. fryers in particular. The composition of this product is.

- rock powder, - soap flakes, - glycerin, - tallow, - lemon oil, - sodium, - vegetable fats.

Claims (12)

CLAIMS 1-Cleaning composition for improving vision through a substrate based on translucent glass which is intended to be in contact with steam mainly formed by water, said composition being suitable for being in contact with foodstuffs and comprising a mineral powder intended to be applied to the face (s) of the substrate in contact with the vapor in conjunction with a wet application means, said mineral powder being formed by particles of an average size of less than 60 um when the powder is applied and the particles are mechanically biased against the face (s). 2-cleaning composition according to claim 1 characterized in that the particles are of an average size between 30 and 0, 8 um, and

between 0, 6 and 0, 05 um 3-Cleaning composition according to claim 1, characterized in that the particles have an average size of the order of 0.7 um 4-Cleaning composition according to one of claims 1 to 3 characterized in that the mineral powder is formed by particles having numerous peaks and sharp edges. 5-A cleaning composition according to one of claims 1 to 4 characterized in that the mineral powder represents at least 50% of the composition, and preferably 65%. 6-A cleaning composition according to one of claims 1 to 5 characterized in that the mineral powder is combined in the composition with degreasing agents and / or with agents facilitating the evacuation of the composition. <Desc / Clms Page number 25> 7-A cleaning composition according to one of claims 1 to 6 characterized in that the mineral powder is alumina. 8-Cleaning composition according to one of claims 1 to 7 characterized in that it is formed by a powder, the wet application means being provided only at the time of application 9-Cleaning composition according to one of claims 1 to 7 characterized in that the composition is formed by a powder incorporated in a gel, a solution or in a paste forming the means of application. 10-Substrate based on translucent glass treated with a cleaning composition to improve vision through said substrate, the latter being intended to be in contact with steam mainly formed by water, said cleaning composition being able to be found in contact with foodstuffs and comprising a mineral powder intended to be applied to the face (s) of the substrate in contact with the vapor in conjunction with a wet application means, said mineral powder being formed by particles of an average size of less than 60 µm when the powder is applied and the particles are mechanically biased against the face (s), said substrate exhibiting a wettability such as a drop of water with a mass of 0.9 gram deposited on the substrate has a spreading surface at least equal to 8.2 mm2 (32.8 x 0.25 mm2). 11-Substrate based on translucent glass treated according to claim 10 characterized in that the spreading surface of a drop of water with a mass of 0.9 gram deposited on the substrate is between approximately 8.2 mm2 and 15.3 mm2. 12-Household appliance comprising an internal viewing zone equipped with a substrate based on treated glass according to claims 10 or 11. <Desc / Clms Page number 26> 13-A process for the surface treatment of a glass-based substrate intended to be in contact with vapor mainly formed by water, said process being intended to improve vision through said substrate, in which process is treated the substrate by application and mechanical action of a mineral powder capable of being in contact with foodstuffs and formed by particles of a size less than 60 μm when they are mechanically stressed on the concerned face (s) of the substrate, said application being carried out using a wet application means, then in which the rinsing of the treated surface is ensured 14-Method according to Claim 13, characterized in that the treatment is carried out by rubbing the mineral powder on the concerned face (s) of the substrate, the particles being able to disintegrate into elementary particles with a size of between 30 and 0, 05 µm. 15-Use of a cleaning substance capable of being in contact with foodstuffs and comprising a composition including a mineral powder formed by particles of a size less than 60 μm when they are mechanically stressed on a surface to be treated, in as a treatment product for improving vision through a glass-based substrate intended to be in contact with water vapor mainly formed by water. 16-Use according to claim 15, characterized in that it consists in using a composition including an inorganic powder formed by particles with a size between 30 and 0.05 μm, and preferably between 1.0 and 0.05 μm <Desc / Clms Page number 27> 17-Use according to claim 16 characterized in that it consists in applying the composition using an application means, such as a sponge, added with water, said composition comprising: - powder of rock, - soap flakes, - glycerin, - tallow, - lemon oil, - sodium, - vegetable fats.