EP1392909B1 - Iron with self-cleaning sole plate - Google Patents

Abstract

The invention relates to an iron comprising a sole plate which forms the ironing surface. An oxidation catalyst, which is active on organic dirt, covers the ironing surface. Said catalyst is active when the soleplate reaches a temperature which is at least equal to or higher than 90° C.

Description

The present invention relates to irons.

Irons have qualities of ease of use and efficiency, depending inter alia on the state and nature of the ironing surface of their sole. The soles could be improved by the care given to the gliding qualities of the ironing surface, combined with the qualities allowing the easier spreading of the linen. One way to obtain these qualities is to use enamelled soles with a smooth-looking enamel, possibly with thicker lines to spread the fabric during the movement of the iron. Other metal soles treated mechanically and / or covered or not with a deposit to facilitate sliding can also be suitable for a satisfactory use.

However, in use, the sole can tarnish by carbonizing more or less diffuse on its ironing surface, and more or less incomplete, various organic particles captured by friction on ironed fabrics.

But when the sole is tarnished, even in a not very visible way, it partially loses its sliding qualities. Insensibly, with the clogging, ironing becomes more difficult. In addition, the user apprehends to use a tarnished iron, fearing that it can alter his clothes.

Iron sole inserts having a hard and resistant layer covered, as indicated by US Pat. No. 4,862,609, are known by a layer which improves the surface properties. But this patent does not indicate a solution to fight against fouling.

The purpose of the invention described below is a self-cleaning iron whose sole is kept clean of any contamination by organic particles, and does not clog in normal use, so as to maintain its original qualities.

The object of the invention is achieved by an iron having a sole whose outer surface comprises the ironing surface, characterized in that an oxidation catalyst comprising a catalytic oxidation agent is present or distributed in and / or on a surface layer of said soleplate, said oxidation catalyst being active with respect to organic fouling, at a temperature of at least 90 ° C.

Thanks to the invention, during ironing, the organic particles captured by the sole are oxidized. They are somehow burned when the iron is hot, any solid residue loses any adhesion and detaches from the sole. The sole stays clean.

In fields very different from ironing, an oxidation catalyst has already been associated with the outer surface of a support.

Glazed self-cleaning surfaces are known, for example in furnaces and cooking utensils as described, for example, in patent US4029603 or patent FR2400876.

US Patent 4,994,430 describes an enamelled coating having a dense layer and on the surface a porous layer carrying a catalyst. But such a porous layer, thick, is incompatible with ironing.

Also known from US5388177 a deodorizing heating element whose enameled surface is coated with catalyst, but the catalyst is intended to only deodorize.

In any case, the solutions described in these documents can not be applied to an iron, because it was feared in particular that, on the one hand, the low roughness requirements for the ironing surface oppose the retention of the catalyst oxidation, and secondly the friction resulting from ironing quickly removes the oxidation catalyst from the outer surface of the soleplate.

The oxidation catalyst is distributed on and / or in the surface layer of the iron soleplate, where it is in contact with soiling.

In practice, the oxidation catalyst is present and / or distributed on the surface, all or part of the outer surface of the sole.

Thus, the oxidation catalyst may be present or distributed between zones predetermined areas of the outer surface of the sole, for example recessed areas of said outer surface, capable of capturing or accumulating soiling, and in general warmer than the ironing surface, which is favorable for oxidation or catalytic.

When the outer surface of the soleplate has one or more recessed portions relative to the remaining planar portion, forming the useful surface or the actual ironing surface, the oxidation catalyst is present or distributed in the recessed portion (s). , excluding the ironing surface.

But, of course, the oxidation catalyst may be present, according to all or part of the ironing surface itself.

The catalytic oxidation agent considered according to the present invention is therefore any element, compound or composition capable of oxidizing, at a temperature of at least 90 ° C., any organic substance such as included in the soils commonly encountered in the environment. treatment (including washing and possibly softening) of textile parts or articles (eg linen)

Such an oxidation catalytic agent may be specific or non-specific for such or such organic substance.

In practice, the oxidation catalyst may or may not comprise, in addition to the catalytic oxidation agent, an inert support, for example in divided form or particles, for example alumina, on the surface (including internal) of which the catalytic oxidation agent is distributed or distributed. The inert support can constitute in itself, in the undivided state, the superficial layer which will be discussed below.

As catalytically active elements, mention may be made of palladium, platinum, vanadium, copper or any composition of such catalytically active elements (in terms of oxidation). In the catalytically active compositions considered according to the present invention may be present oxides of copper, manganese or cobalt, increasing the catalytic efficiency or the stability of the catalytic agent.

In practice, such oxidation catalysts are well known per se, as well as their processes of obtaining, without it being necessary to describe in detail their methods of preparation respectively. Thus, by way of example, with respect to platinum as catalytic oxidation agent, its catalytically active form can be obtained by calcination or decomposition of a chloroplatinic acid salt or any other precursor.

Of course any oxidation catalyst selected according to the present invention must remain sufficiently stable at the working temperature of the ironing surface, and within the limits of the useful life of the iron.

In practice, the oxidation catalyst according to the invention is distributed at least in and / or on the surface layer of the sole of the iron. By "superficial layer" is meant any boundary layer whose thickness may, for example, be at most equal to 500 nanometers and in particular between 20 nanometers and 120 nanometers in contact on one side with another layer or the substrate of the sole, and on the other side providing an interface with the outside, comprising the actual ironing surface. The oxidation catalyst or the catalytic oxidation agent may be distributed in all or part of the outer surface of the sole, in the thickness and / or on the aforementioned outer layer, continuously or discontinuously.

By "ironing surface" is meant all or part of the useful external surface of the sole, coming directly into contact with the laundry during ironing.

When the oxidation catalyst remains on the surface layer of the sole, it can form a layer or a continuous or discontinuous film.

The above-mentioned surface layer may not be distinguishable from the remainder of the soleplate, its substrate or a constituent layer thereof, in which case, in the present description and in the claims hereinafter, the use of the term "layer "superficial" has no other purpose than to distinguish the limited or no thickness of the sole, in which the oxidation catalyst or the catalytic oxidation agent can be distributed and incorporated.

The thickness of the surface layer in which the catalyst or the catalytic oxidation agent may be included depends in particular on the migration depth of the organic soils inside the iron soleplate. iron from its outer surface.

"Organic soiling" means any combustible or oxidizable substance in contact with ambient air, completely or partially. By way of example, mention may be made of any residue of synthetic fibers, as used in textile articles, for example an organic polymer such as polyamide or polyester or any residue of detergent and optionally of softening product.

By way of example, the catalytic oxidation agent comprises a Group IV metal of the Periodic Table or a noble metal, for example palladium and / or vanadium.

The oxidation catalyst being active at a temperature of the sole greater than or equal to 90 ° C, it cleans said sole when it is hot.

In a first mode of operation, the catalyst acts at the ironing temperature of the iron, and the sole is kept permanently clean, as and when the iron ironing.

In a second mode of operation, during a so-called self-cleaning phase, before or after the use of the iron, the iron is set at a high temperature equal to or higher than the highest ironing temperatures. . It is then left on hold for a predetermined time, during which the oxidation catalyst produces its effect. The user can maintain its iron regularly, without waiting for a harmful fouling.

In a first version, the iron comprises a metal sole coated with an enamel with a low porosity and / or roughness, at the micrometer and / or nanometer scale, and the oxidation catalyst belongs to the surface layer of the enamel coating. The enamel is for example a vitreous enamel.

Such an enamel is chosen from low-porosity enamels, for example glazed, known for their ironing qualities, this in comparison with enamels used in furnaces or on grids, which porous ones needlessly require the deposition of a large quantity of oxidation catalyst and do not have the qualities required for an iron soleplate.

The enamel must indeed at least be hard, have a good glide and resist the penetration of hot steam or humidity.

Obtaining or applying the oxidation catalyst or catalytic oxidation agent on or in the above-mentioned surface layer can be carried out by any known means such as by applying any precursor of the catalytic agent of the invention. oxidation, then firing using a pyrolytic process or electrophoresis or electroless electroless deposition or by vapor deposition.

By "precursor" is meant any chemical or physicochemical form, of the oxidation catalyst and / or the catalytic oxidation agent, which is capable of terminating or liberating the latter by any appropriate treatment, for example pyrolysis . By way of example, any salt of chloroplatinic acid is a platinum precursor considered as an oxidation catalyst.

As shown by the examples below, the choice of the composition of the oxidation catalyst or of the catalytic oxidation agent, and / or the conditions for obtaining or applying the latter, are determined not to alter substantially. the intrinsic qualities of the ironing surface, especially its glide.

In a second version, the iron has a metal sole, for example aluminum alloy, and a surface layer is attached to the outer surface of said sole, in the form of a thin layer of a support, by alumina example, for said catalytic oxidation agent of said organic soils.

Alternatively, the sole is coated with a layer of a polymer resistant to any oxidation at high temperature, for example polytetrafluoroethylene, and the surface layer belongs to said polymer layer.

In a third version, the surface layer consists of a thin layer of the oxidation catalyst, comprising an inert support, for example alumina, and a catalytic oxidation agent supported by said support.

In general, the invention also relates to the use of an oxidation catalyst as a self-cleaning agent for all or part of the surface outer sole of an iron.

• La figure 1 est une vue en coupe d'une semelle de fer à repasser selon l'invention.
• La figure 2 est une vue de dessous d'un fer à repasser selon l'invention, montrant la face inférieure de la semelle.

The invention will be better understood on reading the examples below and the accompanying drawings.

• Figure 1 is a sectional view of an iron soleplate according to the invention.
• Figure 2 is a bottom view of an iron according to the invention, showing the underside of the sole.

Example 1

In a first exemplary embodiment, the iron 1 visible in Figure 1 comprises an aluminum sole 2 integral with a heating base 3 of cast aluminum and provided with a heating element 4. The sole 2 is coated on its outer surface 5 more easily seen in Figure 2 by an enamel known for its ironing qualities. The catalyst or catalytic oxidation agent is deposited in a very thin layer on the outer surface. This outer surface 5 comprises the ironing surface 51 itself, and recessed portions 52, 53 for example around the steam outlet orifices 6.

For this purpose, the outer surface is degreased and activated by a slight acid attack, for example with a solution of citric or nitric acid. A precursor of the catalytic oxidation agent is prepared, for example by dissolving palladium nitrate in water at a rate of 2 grams of palladium nitrate per liter. In addition, several companies, for example PCAS in Longjumeau, France, provide more sophisticated precursors. The soleplate is heated to 300 ° C, the precursor is applied in solution on the sole by scrolling under an ultrasonic atomizer, in one or more passes, to obtain a good homogeneity of the application. The whole is baked at about 300 ° C. The thickness of the layer of the oxidation catalyst (palladium) thus obtained may vary from 20 to 120 nanometers. Preferably, the device is adjusted to obtain a thickness of the order of 30 nanometers. It is noted that the palladium deposit is adherent to the ironing surface, and does not disturb the slip characteristics of the underlying enamel significantly.

The effectiveness of the oxidation catalyst can be measured in a closed enclosure. A sole sample is heated to 300 ° C., on which is deposited a piece of fiber, organic polymer, 2 mg, melt representative of soiling. After having measured the initial quantity of carbon dioxide in the enclosure, its increase is noted, attesting to the effectiveness of this solution.

In the example described, there was obtained a 300 degrees catalytic activity that allowed to produce 107 x 10 ^-6 moles of carbon dioxide per hour, for a catalytically active surface, sample 10 square centimeters.

Example 2

In a second embodiment, the enameled sole is heated to 300 degrees. A solution comprising suspended alumina is prepared by mixing 4 grams of tetraethylorthosilicate with 96 grams of 0.6% diluted nitric acid, to which 12.8 grams of "DISPERSAL S" is added.

The latter product based on alumina is supplied by CONDEA. The solution diluted 10 times is sprayed on the sole. The sole is held at 300 degrees for one hour. The spraying is adjusted to obtain a deposit in solid form about 10 micrometers thick, a support of the catalytic oxidation agent, based on alumina. An aqueous solution of palladium nitrate is then sprayed and baked at 300 degrees for one hour.

Compared to the previous example, the activity of the same catalytically active surface sample is increased to 175 × 10 ^-6 moles of carbon dioxide produced per hour.

Example 3

In a third embodiment, the iron comprises an aluminum soleplate. The ironing surface is cleaned by sodium attack followed by neutralization and rinsing. The sole is oxidized in the oven at 560 degrees for 30 minutes, then sprayed with a solution of palladium nitrate at 2 grams per liter. After cooking at 300 degrees for one hour, a catalytically active surface layer or oxidation catalyst, approximately 30 nanometers thick, is obtained.

Gliding qualities substantially similar to those of aluminum are obtained. The interest of this achievement lies in the economy of manufacture. The activity obtained is of the order of 112 × 10 ^-6 moles of carbon dioxide produced per hour, for a catalytically active surface, sample, of 10 cm 2

In a variant of this embodiment, the catalytic oxidation agent is incorporated in a surface layer of the Ormosil type, serving as a support, this term being an abbreviation for the expression "organically modified silicates", as explained in US Pat. the article "Structures and Properties of Ormosils" of the Journal of Sol-Gel Science and Technology, 2, 81-86 (1994), written by John D Mackenzie. Preferably, the surface layer is obtained from a liquid solution intended to produce a gel.

The catalytic oxidation agent is then deposited on and / or in this superficial layer, by a process similar to the previous one using an ultrasonic atomizer. One to four passes make it possible to obtain a good homogeneity.

The whole is then dried and baked at about 300 ° C.

Example 4

In a fourth embodiment, the iron comprises a sole plate made of stainless steel. The ironing surface is cleaned and then passivated in a 20% nitric acid bath. On the ironing surface heated to 300 degrees, an alumina-based solution such as that described in the second embodiment is applied and the sole is held at 300 degrees for one hour to obtain a surface layer serving as a support for the agent. catalytic oxidation. A layer of the catalytic oxidation agent is then deposited in and on this superficial layer, by spraying with an ultrasonic atomizer a solution of palladium nitrate. The whole is then dried and baked at about 300 ° C. A 300 degree efficiency of 151 × 10 ^-6 moles of carbon dioxide produced per hour is measured for a catalytically active surface, sample, of 10 cm 2

In practice, there is a noticeable difference in fouling between two irons, only one of which is provided with a self-cleaning sole according to the invention.

It is also noted that when a soil is thick, it is consumed in the zone in contact with the oxidation catalyst, then peels off the sole. Self-cleaning is achieved without waiting for the complete transformation of soiling.

Although the activity of the oxidation catalyst occurs at low ironing temperatures, however, above 90 ° C, this activity is much greater at elevated temperatures. The user uses her iron as usual. After an ironing session, if necessary, she acts on a cleaning control button. This control changes the set temperature of the iron to a recommended operating temperature of the oxidation catalyst, and marks the beginning of a predetermined self-cleaning phase, during which this temperature is maintained, and beyond which the heating of the iron stops automatically. During this phase, the oxidation catalyst fully exerts its effect. Dirt that may have stuck to the sole is consumed safely, including in the recessed areas 52, 53, after which the sole finds all its original properties.

Claims (9)

1. An iron having a soleplate whose outside surface comprises the ironing surface, said iron being characterized in that an oxidation catalyst comprising a catalytic oxidation agent is present or distributed in and/or on a surface layer of said soleplate, said oxidation catalyst being active on organic dirt at a temperature of not less than 90°C.
2. An iron according to claim 1, characterized in that the soleplate is made of metal and is coated with an enamel that is of low porosity, e.g. that is vitreous, and the surface layer is part of said coating of enamel. -
3. An iron according to claim 1, characterized in that the soleplate is coated with a layer of a polymer that withstands all oxidation at high temperature, e.g. polytetrafluoroethylene, and the surface layer belongs to said layer of polymer.
4. An iron according to claim 1, characterized in that the soleplate is made of metal, and the surface layer is affixed to the outside surface of said soleplate in the form of a thin layer of a support, e.g. alumina, for said catalytic oxidation agent for catalytically oxidizing said organic dirt.
5. An iron according to claim 1, characterized in that the oxidation catalyst comprises a metal of group IV in the periodic table or a noble metal, e.g. palladium and/or vanadium.
6. An iron according to claim 1, characterized in that the surface layer consists of a thin layer of the oxidation catalyst, made up of an inert support, e.g. alumina, and of a catalytic oxidation agent supported by said support.
7. An iron according to claim 1, in which the outside surface has at least one recessed portion that is recessed relative to the remaining portion which is plane and which forms the working or ironing surface, said iron being characterized in that the oxidation catalyst is present in or distributed in said recessed portion, while being excluded from the ironing surface.
8. An iron according to claim 1, characterized in that the oxidation catalyst is present in and distributed between predetermined zones of the outside surface of the soleplate, e.g. recessed zones of the outside surface that might collect or accumulate said dirt.
9. The use of an oxidation catalyst as a self-cleaning agent for self-cleaning of all or part of the outside surface of the soleplate of an iron.

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