WO2001000022A1

WO2001000022A1 - Method and composition for protecting sanitary ware against contamination

Info

Publication number: WO2001000022A1
Application number: PCT/FR2000/001750
Authority: WO
Inventors: Gérald de Broissia; Isabelle Hulak
Original assignee: S.A.H.F.F.F. Haut Fourneau, Forges Et Fonderies
Priority date: 1999-06-23
Filing date: 2000-06-23
Publication date: 2001-01-04
Also published as: FR2795328B1; AU6287600A; FR2795328A1

Abstract

The invention concerns a method for protecting users of sanitary ware against biological contamination by contact, which consists in painting said items with an anti-contaminating coating composition comprising a biocidal agent including at least a compound with essentially bactericidal activity, in a proportion ranging between 0.3 and 6 wt. %, preferably between 0.5 and 5 wt. %, relative to the coating composition total weight. The invention is characterised in that the bactericidal agent contains at least a compound of the isothiazole family combined with a aryloxy-alcohol, preferably with a fungicidal compound such as alkylated derivatives of isothiazolinone and/or derivatives of benzimidazole or of iodo-propynyl with carbamate function.

Description

CONTAMINATION PROTECTION METHOD AND COMPOSITION FOR SANITARY ARTICLES

The present invention relates mainly to the design and implementation of compositions based on binders of curable organic resins, in particular when these are made to serve as layers of surface coating, in the form of what are commonly called paintings. In practice, this term designates not only the paints themselves, which contain fillers making them opaque, but also for example transparent varnishes. It is not restrictive of the modes of application of the composition of paint in the liquid state, in general preferably with a brush or other spreading tool or by spraying, or because it is presented in a single or more components.

To protect the users of sanitary articles against biological contamination by contact, the present invention proposes in particular to paint these articles by means of a specially designed anti-contamination coating composition. It therefore relates to not only a process for protecting sanitary articles against biological contamination of users, but also a coating composition suitable for the implementation of this process. And of course, it also relates to the articles treated in accordance with this process, therefore painted using a paint corresponding to such composition.

In addition, the invention is not limited to the treatment of the surface of sanitary articles by application of an anti-contamination coating composition as a paint in the strict sense, applied liquid or pasty in a very thin layer on the solid article. Thus it also concerns an equivalent solution consisting in introducing the anti-contamination composition into the mass of thermoplastic materials constituting by polymerization the above-mentioned articles, at least at the surface, and that in this context it can also be introduced during overmolding during the hardening of the basic thermoplastic composition. A particularly striking example of an article requesting protection of the kind contemplated by the invention relates to toilet seats for toilet bowls, given their repeated use, often involving different people. Whatever precautions these people take, it is not customary to expect them to wash the seat at each use or to have washed immediately before using it. There are therefore significant risks of transmission of contamination factors from one user to another.

However, similar circumstances are found for many other materials for which it is desirable to improve the conditions of sanitary cleanliness, in particular with regard to frequent contact with human skin, or more generally, with biological tissues that hold and carry microbiological contaminating agents with them. As understood by the invention, the concept of sanitary article extends to all these materials and their equivalents.

In such a context, it is perfectly usual to treat surfaces with degreasing and disinfecting solutions, if only with soapy solutions and simple chlorine compositions in household applications. In this case there is no lasting effect. And for public places in particular, the user is likely to doubt the quality of the cleaning carried out before its passage, so that we have come to market sheets of paper in the form of toilet seats and toilet seats. dispensers unroll a protective plastic film, so that each user does not touch the surface that was touched by a previous user. It is obvious that these solutions used according to the prior art lack comfort and convenience of use, if at all that they do not become totally ineffective by negligence of the users.

In addition, paints or varnishes are known, the composition of which is prepared with the addition of various biocidal agents, generally aimed at improving the shelf life in pots, therefore chosen to be active in liquid and non-aerated medium. Some of these additives incorporated into paints are intended to have a destructive effect on populations of microorganisms similar to algae and fungi. We can cite here the international patent application WO 97 46627 for what it describes of a wood protection paint designed to prevent yellowing in the light.

However, it has been observed that the known paints containing various biocidal agents are not satisfactory for the particular applications with which we are concerned here. For example, the antifungal agents which are incorporated into paints which have to resist weathering or exposure to wet conditions, in particular in the marine environment, are intended to delay the attachment and the development of molds or marine plankton, ie that is to say of fungal strains whose particles are of large dimensions compared to the particles of the size of yeasts which constitute the mycoses characteristic of human pathologies.

The conditions to which the sanitary articles considered in the preferred applications of the invention are subject are all different. Exposure to an aqueous medium is only temporary, and contact with users' skin is dry, which is normally more oily than wet. However, in conclusion of a whole series of tests, it has been observed that, under these conditions, the risk of fungal contamination is relatively modest, while at the same time, the risk of retention and development of bacteria linked to human pathologies is much more important.

Thus, to best meet the needs of the practice, such as, at least in part, they have been recalled above, the invention relates to a method for protecting users of sanitary articles against biological contamination by contact between the articles used and human skin, under the conditions encountered in lavatories and other toilets where in particular a toilet seat is available for repeated uses and accessible to various users. In such conditions, the problem is different from that dealt with by example European patent application EP 0 328 421, considering surgical equipment for hospitals.

The process of the invention essentially consists in constituting these articles, at least at the surface, with an anti-contamination composition comprising, in a binder based on organic resins which cure by polymerization or crosslinking, a biocidal agent with essentially bactericidal activity, advantageously in a proportion of between 0.3 and 6% by weight of the total weight of the overall composition, said biocidal agent comprising at least one compound of the family of aryloxy alcohols, preferably in combination with a compound containing an isothiazole group.

According to a preferred embodiment of the invention, said composition for sanitary articles, in particular for seats of toilet bowls and more particularly for the flaps of which they are commonly made, is in the form of a paint to be applied as a coating in which the biocidal agent is present in a curable binder based on organic resins.

According to preferred embodiments in industrial practice, the film-forming composition is based on thermosetting resins in the form of two components, kept separately until they are mixed when the paint is applied to the surface. article to be treated, these two constituents being added with a diluent during mixing. More particularly, said thermosetting resins can be of the polyurethane or acrylic type, the polyurethane resins corresponding to the use of an organic thinner paint and the acrylic resins to the use of an aqueous thinner paint.

Therefore, the invention derives a synergistic interest from advantages which are already known from this kind of compositions and from their curing conditions leading to the final coating. In particular, a paint leading to a smooth, non-porous surface film combines its own effects with those of the biocidal agent to slow down biological contamination, since the coating obtained has less tendency than rough coatings. or porous to retain dust as well as environments favorable to the proliferation of contaminating agents which accumulate with them. It has also appeared that the properties of the coating lead to better durability of the targeted biocidal effect, which constitutes an important advantage for articles of equipment which are not often renewed.

According to other characteristics of the invention, a synergistic effect has been demonstrated due to the combination of several chemical compounds to constitute the above-mentioned biocidal agent. Therefore, in preferred compositions according to the invention, said biocidal agent comprises at least one compound of the family of bactericides with isothiazole group, and preferably among them a compound of the benzo-isothiazolinone type, in combination with an aryloxy- alcohol, the latter being in particular phenoxyethanol or an analogous compound capable like it of causing degradation of the cell wall of microorganisms.

And it is even more advantageous to make it comprise a compound with fungicidal activity of the type of alkylated derivatives of isothiazolinone, preferably such a derivative whose formula also comprises a carbamate function, and / or a compound with an unsaturated halogenated chain, in particular of the iodo-propynyl type, the formula of which comprises a carbamate function. The carbamates make it possible to start the production of carbon dioxide, toxic for bacteria and microorganisms, on the surface of the material, and iso-thiazolinones in particular prevent the reproduction or the production of the enzymes of microorganisms living in the context of the invention. In alkylated isothiazolinones, the typical example is 2-methyl 3-isothiazolinone, but a derivative where the substituent of the nitrogen atom of the thiazole ring is long chain (comprising 5 to 12 carbon atoms for example) can be preferable for solubility reasons.

Other compounds which advantageously complete a formulation to be used according to the invention include halogenated isothiazolinones, such as 5-chloro 2-methyl 3-isothiazolinone, alkylated benzimidazole derivatives with a function carbamate, such as benzimidazole methylcarbamate, dimethylthiourea, unsaturated long chain acids such as undecanoic acid, these acids being advantageously functionalized by a quaternary ammonium group.

Furthermore, and in particular with the biocidal agents defined above, as selected for a paint composition based on polyurethane or acrylic resins, the proportion of biocidal agent is preferably between 0.5 and 5% by weight, and in particular of the order of 1 to 3% by weight relative to the total weight of the overall composition.

By its various characteristics, as they have already been pointed out and such that they will be more fully detailed below, the present invention provides a solution particularly suitable for the surface treatment of articles which have been described as sanitary. It makes it possible to best respond to the concern for cleanliness and the absence of microbiological proliferation that risks contaminating users, in particular by avoiding the spread of bacterial factors whose repeated contact with the skin of individuals promotes development. In other words, the material constituting the articles considered, at least in their accessible surface, disinfects itself during the entire duration of the coating, instead of being only provided with a smooth surface and high densification for reasons of convenience. of washing.

The invention thus applies by preventing the risks of contamination between successive users by dry contact of the skin with an article of current use, such as WC seats and the materials present in collective toilets. . However, the compositions according to the invention may also prove to be most useful for constituting, for example, cleanliness plates on door jambs, handles, stair railings or other support rails, plates electric switches and other manual controls.

The invention will now be more fully described in the context of its preferred characteristics using examples of implementation, which of course are in no way limiting, and using tests whose results demonstrate the anti-contamination effectiveness of the compositions according to these examples when they are used as a coating on sanitary articles.

It is worth remembering here that, unlike all conventional paints, the purpose of the invention is not so much to protect the article to which it is applied, but rather to protect the men who use these articles contamination by contact, which is all the more to be feared since the same articles are used for different users who follow one another and who have no reason to have washed just before, and under conditions of use which make systematic cleaning difficult. In addition, it is important to avoid the risk of irritation of the skin and mucous membranes.

In the examples which follow, unless otherwise indicated, all the quantities will be expressed by weight and all the percentages will be expressed by weight relative to the total weight of the mixture considered. In addition, we have placed ourselves in the case of articles intended for toilets for collective use, and more particularly still for parts made of composite material of melamine polymers and sawdust molded in the form of toilet seat covers.

The coating compositions used are paints based on polyurethane resins. As usual, these are two-component paints which are mixed at the time of use. The first constituent, representing the paint base, is a binder of polyol origin (acrylic or polyester or a mixture of the two). The other constituent is a hardener based on compounds with isocyanate functions.

The hardening of this composition results from the copolymerization and crosslinking between the two chemical compounds. To the whole is added a diluent by means of which the viscosity is adjusted to the mode of application chosen. This diluent is a solvent comprising a mixture of ethyl acetate (or methoxypropanol acetate) and ethyl acetate-glycol. In each of the examples below, the biocidal agents are incorporated into what is called the base of the paint, namely the polyol binder (acrylic or polyester or mixture of the two). In this regard, it has also been verified that the addition to the conventional reference paint of an agent with an essentially bactericidal effect has no effect on the shelf life in the pot.

The total paint composition is then formed by mixing the polyol binder (acrylic or polyester or a mixture of the two) with the isocyanate-based hardener, then applied to toilet seat flaps, and after complete hardening, the coating obtained is subjected to different tests. These tests are carried out by always comparing the coating obtained from a composition according to the invention to that obtained from the same composition without the addition of biocidal agent, used as a reference composition.

More specifically, on articles made of a composite material of sawdust and organic polymers, the paint is applied by spraying with a paint corresponding to the following composition: Polyol base (acrylic or polyester or mixture of the two): 1,00 parts by weight.

Hardener: 20 parts by weight

Thinner: 20 parts by weight

(comprising 20% by weight of ethyl acetate-glycol for 80% by weight of ethyl acetate or methoxypropanol acetate).

The different parts are processed automatically in a chain. They are suspended from racks which first drag them into a spray painting booth, where robots spray paint on the different faces of the parts. The latter then pass into an oven in which the hardening takes place, essentially by hot polymerization, at a temperature of the order of 50 to 60 ° C. The paints according to the invention differ from the reference paints by the addition of a biocidal agent suitably selected to provide an essentially bactericidal activity, the effectiveness and durability of which have also been verified in the coating obtained after curing. In practice, this biocidal agent is each time made up of an at least binary mixture, if not ternary or even quaternary and more, from chemical compounds which are individually known in themselves for other applications. Most of the biocides considered are soluble in organic solvents and in water.

For each example, the precise nature of the compounds and their respective proportions are indicated below (expressed as a percentage by weight of the total weight of the overall composition), from which it can be seen that, in general, the share of each compound in the mixture constituting in total the biocidal agent is always of the same order of magnitude. More precisely, the share of each preferably represents between 1/4 and 4 times the share of each of the others.

Example 1% by weight Phenoxyethanol 0.5

Benzo-isothiazolinone 0.5

Example 2% by weight

Phenoxyethanol 0.5

Example 3% by weight Phenoxyethanol 1

Benzo-isothiazolinone 1

3-iodo 2-propynyl butyl carbamate 0.5

2-methyl 3-isothiazolinone 0.5

Example 4% by weight Phenoxyethanol 1

Benzo-isothiazolinone 1 3-iodo 2-propynyl butyl carbamate 0.5

5-chloro 2-methyl 3-isothiazolinone 0.5

Example 5% by weight

Phenoxyethanol 1 Benzo-isothiazolinone 1

3-iodo 2-propynyl butyl carbamate 1

2-methyl 3-isothiazolinone 0.5

5-chloro 2-methyl 3-isothiazolinone 0.5

Example 6% by weight Phenoxyethanol 1

Benzo-isothiazolinone 1

Benzimidazole methylcarbamate 0.5

2-octyl 3-isothiazolinone 0.5

5-chloro 2-methyl 3-isothiazol inone 0.5

Example 7% by weight

Phenoxyethanol 1

Benzo-isothiazolinone 1

0.25 benzimidazole methylcarbamate

2-octyl 3-isothiazolinone 0.25 5-chloro 2-methyl 3-isothiazolinone 0.25

2-methyl 3-isothiazolinone 0.25

Example 8% by weight

Phenoxyethanol 0.5

Benzo-isothiazolinone 0.5 Benzimidazole methylcarbamate 0.25

2-octyl 3-isothiazolinone 0.25

5-chloro 2-methyl 3-isothiazolinone 0.25

2-methyl 3-isothiazolinone 0.25

Example 9% by weight Phenoxy-ethanol 0.5

Benzo-isothiazolinone 1

Dimethylthiourea 0.5 2-octyl 3-isothiazolinone 0.5

5-chloro 2-methyl 3-isothiazolinone 0.5

2-methyl 3-isothiazolinone 0.5

The articles treated using these paint examples according to the invention were subjected to various tests which made it possible to verify the existence of the activity sought, by comparison with the reference composition which had not received addition of biocidal compound, applied to similar supports, to form a coating of the same thickness in both cases, of the order of 100 micrometers.

First of all, it has been verified that even after cooking, the coatings demonstrate an antifungal activity which is effective in destroying the yeasts chosen from strains referenced with

Candlda Albicans who can deposit there under the conditions of employment of the flappers.

However, and as has already been explained, the microorganisms which tend to develop on flaps coated with reference paints (instead of receiving the paint deposition treatment according to the invention) are mainly bacteria. We therefore set out to determine the effectiveness of the treatment on two types of bacteria, one of Gram positive and the other of Gram negative. For this purpose, reference strains of Staphylococcus Aureus and Pseudomonas Aeruginosa were chosen.

For each bacterium, the procedure was as follows: contacting of calibrated bacterial solutions at low and high concentration (105 and 109 cells / ml respectively) on the painted surface, subculturing of the bacteria still alive and culturing on agar, counting of colonies and comparison of the results obtained between the paint modified according to the invention and the corresponding unmodified paint of reference.

Assuming that the bactericidal activity is obtained at 100% when the decrease in the number shows at least a division by 10, it has been possible to conclude tests that for all of the examples 1 to 9 above, the efficacy is obtained almost 100% for Pseudomonas Aeruginosa when the initial concentration is at the so-called low value. It varies while remaining greater than 70% vis-à-vis this same bacteria when the initial concentration is at its high value.

The values obtained are lower, and nevertheless sufficient with regard to the conditions to which the articles described are exposed, in the case of Staphylococcus Aureus, with variations ranging between 30% and 95% approximately, both for the high concentrations and for low concentrations.

Without wishing to be limiting in the scientific interpretation that one could draw from it, it seems to emerge from the quality of the results obtained that the aryl compounds, whose molecular weight is relatively high compared to their alkyl counterparts, combine their effects with those which can be attributed a significant effect against the development of bacteria, both Gram positive and Gram negative, to facilitate a good distribution of the latter through the paint film, which remains stable during cooking, then throughout the duration of coating life, thus contributing advantageously to the sustainability of the activity. The almost permanent character of the biocidal properties conferred on polyurethane paints seems to result from a chemical reaction between isocyanates and the reactive functions of biocides, in particular those of phenoxyethanol. The increase in viscosity, observed by incorporating phenoxyethanol in polyurethane paint, probably testifies to this chemical reaction.

The parts of the preceding examples were also subjected to tests of resistance to chemical agents and staining products.

Reagents which are traditionally found in toilets, and more particularly in toilets, have been used for this to clean the bowls. In each case, the reagent was placed on the painted part, previously cleaned with hot soapy water and then dried with a clean, dry cloth. After 2 hours of contact, we rinse with water and check if stains remain or if the paint has been attacked.

For each of the paint compositions subjected to the tests, an anti-scale cleaning product was thus used specially provided for cleaning toilet bowls, a solution of caustic soda, bleach (sodium hypochlorite), acid uric to recall urine, and finally eosin, which is a common antiseptic agent with a strong red color.

The results observed are still satisfactory, at least as much as for the same original paint composition in which no biocidal agent has been added. It should be noted that the paint being white, any alteration creating a stain would have been easily visible. We also checked that the surface of the coating remained smooth and even.

Other tests have shown, by the absence of cracking in the areas of the coating which have a significant sensitivity depending on the geometric shape of the part considered and by the absence of swelling, that the coating does not undergo alteration on the surface, on the one hand after an exposure in an oven at 50 ° C in an atmosphere with a relative humidity of 1,00% for 200 hours, on the other hand after immersion in water at 65 ° C for 1 hour. In these tests, the examinations were carried out after observing a drying time of 24 hours.

It appears from these results that the chosen compounds remain perfectly compatible with the conventional constituents of paints based on polyurethane resins, despite the relatively large proportions which are used to ensure the desired bactericidal effect. On the other hand, and in addition to observations with the naked eye and by spectrocolorimetry which confirmed the good conservation of the shade and the degree of gloss, samples were subjected to a test concerning the adhesion power.

In accordance with this test, carried out according to standard NF T30-03, incisions are made on the surface of the coating by means of an adhesive tape having distributed cutting edges. according to a square mesh frame. It is observed to what extent the coating flakes and detaches from the substrate at the location of the incisions. The result is considered satisfactory if the deterioration does not affect more than 5% of the area corresponding to the grid, which has been verified for all the examples above. Finally, the coatings have been found to be free from the danger of intolerance for users. No slight irritation of the skin or mucous membranes has been observed in the body areas concerned or even only likely to come into contact with the surface of the articles treated according to the invention.

Results similar to those presented above can be obtained using an acrylic paint composed of a hydroxylated acrylic resin (prepolymer whose macromolecular chains generally contain two to three alcohol functions) and a melamine-formaldehyde resin (class of aminoplasts) which crosslink hot to form a solid polymer, the whole being added with an aqueous diluent. To obtain an anti-contamination paint based on acrylic resins, the biocidal compositions described in Examples 8 and 9 above are advantageously chosen. Their advantage is to have a lower phenoxyethanol content than in the other compositions, the phenoxyethanol not being soluble in water. Anyway, paints whose solvent is water are generally emulsions, those skilled in the art will know how to choose an emulsifying agent compatible with the use of phenoxyethanol.

The foregoing description clearly explains how the invention achieves the objectives it has set for itself, by demonstrating that, without disturbing the resistance of the coatings to the mechanical and chemical aggressions to which toilet seats are exposed, the incorporation of a biocidal agent in accordance with the invention is effective in preventing microbiological proliferation from bacteria and yeasts which are liable to deposit therein on contact with the skin of a user, and thereby avoid contamination 'a subsequent user.

Claims

1. Method for protecting users of sanitary articles such as WC seats against biological contamination by dry contact with the skin, characterized in that it consists in constituting these articles at least on the surface with an anti-contamination composition comprising, in a binder based on organic curing resins by polymerization, a biocidal agent with essentially bactericidal activity, such as an agent comprising in particular at least one aryloxy-alcohol derivative, in a proportion of 0.3 to 6% by weight relative to the total weight of the composition.

2. Coating composition for sanitary articles, particularly suitable for protecting users of sanitary articles such as toilet seats against biological contamination by dry contact with the skin, characterized in that, in a curable binder based on resins organic, it comprises, in a proportion of 0.3 to 6% by weight relative to the total weight of the composition, a biocidal agent with essentially bactericidal activity comprising at least one compound with an isothiazole group in combination with an aryloxy-alcohol compound.

3. Composition according to claim 2, characterized in that said biocidal agent comprises at least one compound of the benzo-isothiazolinone type in combination with an aryloxy-alcohol compound.

4. Composition according to claim 3, characterized in that said aryloxy-alcohol is phenoxyethanol.

5. Composition according to claim 2, 3 or 4, characterized in that said biocidal agent further comprises a compound with carbamate function.

6. Composition according to claim 3 or 4, characterized in that said biocidal agent further comprises a compound with fungicidal activity of the type of alkylated derivatives of isothiazolinone, in particular such a compound whose formula comprises a carbamate function.

7. Composition according to any one of claims 2 to 6, characterized in that said biocidal agent further comprises a compound containing a halogenated unsaturated chain comprising a carbamate function, such as in particular iodo-propynyl butylcarbamate.

8. Composition according to any one of claims 2 to 7, characterized in that said biocidal agent further comprises a halogenated isothiazolinone compound, such as 5-chloro 2-methyl 3 -isothiazolinone, and / or an alkylated benzimidazole derivative with a carbamate function, such as benzimidazole methylcarbamate, and / or dimethylthiourea, and / or an unsaturated long chain acid such as undecanoic acid, advantageously functionalized with a quaternary ammonium group.

9. Composition according to any one of claims 2 to 8, characterized in that said proportion of biocidal agent is between 0.5 and 5% by weight relative to the total weight of the composition, and in particular of the order from 1% to 3% by weight relative to the total weight of the composition.

10. Composition according to any one of claims 2 to 9, characterized in that it is based on polyurethane resins.