EP3875568B1

EP3875568B1 - Solid self-adhesive formulation for hygiene and fragrance of sanitary articles

Info

Publication number: EP3875568B1
Application number: EP21158447.9A
Authority: EP
Inventors: Claudia Zaniboni
Original assignee: Re Le Vi SpA
Current assignee: Re Le Vi SpA
Priority date: 2020-03-05
Filing date: 2021-02-22
Publication date: 2023-01-25
Anticipated expiration: 2041-02-22
Also published as: PL3875568T3; IT202000004684A1; PT3875568T; ES2943237T3; EP3875568A1

Description

Field of the Invention

The object of the present invention relates to a solid self-adhesive formulation and related products containing said formulation, which when applied to the walls of sanitary ware gradually release the sanitising substances with each flush of water of said sanitary ware.

Background art

State-of-the-art examples of finished self-adhesive commercial products applicable to the walls of sanitary ware, such as toilets (or more commonly WCs), are known to ensure hygiene and/or the delivery of fragrant substances at each flush of water.
In general these products are generally in gel form and are dispensable by means of containers, to prevent the gel from coming into contact with the hands of the user during the application step on the walls of the toilet. The gel is contained in said applicators/dispensers which are generally provided with a plunger or compressible soft walls. The gels are applied to the toilet walls by pushing the plunger of said dispensers with fingers or pressing the soft walls of the container with fingers. Thereby, the gel is pushed outwards in contact with the walls of the toilet to which it adheres.
These containers are particularly made of plastic. For the current standards of eco-sustainability it is increasingly desirable to have products which require less and less use of such materials.
An example of a self-adhesive formulation known and contained in dispensers of such a type is that described in EP1325103 . It is a pasty gel comprising an adhesion promoter, surfactants and water. In this case, water is essential for promoting the adhesion of the adhesion promoter to the sanitary ware surface. In particular, as reported in EP1325103 , a water content of at least 20% by weight, preferably 40 to 70% by weight with respect to the weight of the total composition, is necessary to obtain an adequate adhesion of said promoter to the toilet surface.
On the other hand, a high water content in said formulations is generally not advantageous. In fact, after opening the container of the finished product, since said formulations contain not only hydrophilic but also hydrophobic components, the separation of the two hydrophobic and hydrophilic phases could occur. A high concentration of water could also result in the generation and consequent stagnation of microbial loads or mould in the product remaining inside the container and still to be used, especially if it is not closed properly and therefore remains in contact with the air. WO2012/017276 A1 discloses adhesive toilet cleaning blocks comprising alkylesters of sulphuric acid, alkylpolyglucosides and fragrance.
Finally, if the toilet is not used for a certain period of time the water contained in the gel tends to evaporate, drying the product which not only has a worse aesthetic appearance but is also less effective once the toilet is reused.
Furthermore, the components described in this formulation are all synthetic and therefore are less satisfactory in terms of the current standards of eco-sustainability. Consequently, the need to overcome the aforementioned drawbacks is felt.

Summary of the invention

The applicant has now surprisingly found that it is possible to overcome these drawbacks with the present invention relating to a solid self-adhesive formulation for the hygiene and fragrance of sanitary ware comprising:

between 11% and 80% by weight on the total weight of said solid self-adhesive formulation of a mixture (a) of at least one alkaline salt of an inorganic and/or organic acid;
an anionic surfactant (b) comprising:
- from 5 to 45% by weight on the total weight of said self-adhesive formulation of a composition (b 1) comprising at least 85% by weight on the total weight of the composition (b 1) of a mixture of alkaline salts of mono C12-C18 alkylesters of sulphuric acid;
- from 1% to 5% by weight on the total weight of said solid self-adhesive formulation of a composition (b2) comprising from 8 to 12% by weight on the total weight of the composition (b2) of a mixture of alkaline salts of mono C12-C18 alkylesters of sulphuric acid dispersed in a mixture of fatty alcohols C16-C18;
between 5% to 25% by weight on the total weight of said solid self-adhesive formulation of a non-ionic surfactant (c) consisting of an aqueous dispersion comprising a mixture of C10-16 alkyl poly-glucosides, in quantities comprised between 40 and 60% by weight on the weight of said non-ionic surfactant (c);
a fragrance,

In fact, by virtue of the significantly lower water content compared to other compositions known in the state of the art, the self-adhesive formulation object of the invention is more stable, with a lower tendency to give rise to a two-phase mixture and lastly shows a much lower tendency to dry, if the sanitary ware is not used for a certain period of time.
A further object of the present invention is an adhesive product in the form of a strip to be applied to the walls of sanitary ware comprising:

i) a layer of said strip comprising said solid self-adhesive formulation capable of adhering to the walls of the sanitary ware and
ii) a non-adhesive water-soluble film, preferably containing polyvinyl alcohol arranged on a surface of the layer i), to allow the manual application of said product directly on the walls of the sanitary ware.

This type of product therefore no longer requires the use of plastic containers and dispensers for application and is therefore more environmentally friendly than the current products available on the market.

Detailed Description

For the purposes of the present invention, the term "comprising" is not intended to exclude the presence of further components listed after such a definition, while the term "consisting" or "constituted" is meant to exclude further components not listed after such a definition.
For the purpose of the present invention, the term "self-adhesive" means a product which by virtue of its composition adheres by contact or pressure to the walls of sanitary objects.
For the purposes of the present invention, the term "sanitary ware" means an apparatus consisting of a vessel generally made of ceramic (there are also steel, glass and resin versions) intended for the disposal of excreta of physiological functions such as urination and defecation. For the purpose of the present invention, preferably but not limited to, said sanitary ware is the toilet (or WC) or urinals.
In said formulation the total water content is preferably lower than 10% and more preferably comprised between 5% and 8% by weight on the total weight of said solid self-adhesive formulation.
In said solid self-adhesive formulation at least one salt of mixture (a) is preferably a mixture of sodium sulphate and sodium citrate.
According to a preferred embodiment, the sodium sulphate content in the mixture (a) and comprised between 10% and 50%, preferably between 30% and 50%, more preferably it is 32.6% by weight on the weight of said solid self-adhesive formulation, while the sodium citrate is in concentrations between 1% and 30%, preferably it is 15% by weight on the total weight of the solid self-adhesive formulation.
According to another preferred embodiment, in said solid self-adhesive formulation the surfactant (b1) is contained in quantities comprised between 15% and 35%, more preferably it is 25% by weight on the total weight of said solid self-adhesive formulation.
The surfactant (b1) is the product under the trade name "Empicol LZN MB", anionic-type surfactant comprising at least 85% by weight on the total weight of the composition (b1) of a mixture of alkaline metal salts, preferably sodium, mono C12-C18 alkylesters of sulphuric acid.
It should be noted that preferably in said solid self-adhesive formulation the anionic surfactant (b2) is 3.5% by weight on the total weight of the solid self-adhesive formulation. Said anionic surfactant (b2) is known under the trade name "Empiwax SKBP MB" and it comprises between 8% and 12% by weight on the total weight of the composition (b2) of a mixture of alkaline metal salts (preferably sodium) of mono C12-C18 alkylesters of sulphuric acid dispersed in a mixture of fatty alcohols C16-C18.
Also comprised in said formulation is the non-ionic surfactant (c) known under the trade name "Glucopon 600 CS UP MB" preferably in a concentration of 14% by weight on the total weight of said solid self-adhesive formulation.
In a preferred embodiment, said solid self-adhesive formulation contains a fragrance preferably in a concentration comprised between 0.1% and 5% and more preferably it is 1% by weight on the total weight of said solid self-adhesive formulation.
Said fragrance can be the one known commercially under the name "MINT EUCALYPTUS NP 22129P".
According to a preferred embodiment, the formulation object of the present invention contains at least one plasticiser selected from the group consisting of: xanthan gum, rosin resin, waxy maize starch and mixtures thereof, preferably at concentrations comprised between 0.1% and 10% by weight on the total weight of said solid self-adhesive formulation.
According to a more preferred embodiment, said self-adhesive formulation contains xanthan gum, rosin resin and waxy maize starch.
More preferably, the xanthan gum is in concentrations comprised between 0.1% and 5%, preferably 2% by weight on the total weight of said solid self-adhesive formulation; the rosin resin is in concentrations comprised between 0.1% and 5%, preferably 2% of said solid self-adhesive formulation, and the waxy maize starch in concentrations comprised between 1 and 10%, preferably 5% by weight on the total weight of said solid self-adhesive formulation.
In said oral self-adhesive formulation most of the components used were obtained by semi-synthetic processes starting from products of exclusively natural origin.
"Semi-synthetic processing processes" means chemical processes carried out on products of exclusively natural origin in order to induce a further functionalisation of said products which would make them more suitable for the purposes of the present invention.
Based on this, the commercial products comprising such an oral self-adhesive formulation therefore benefit from the "Ecocert Natural Detergents" certification (https://www. ecocert. com/en/certification-detail/ecological-household-products-natdet).
For example, sodium sulphate is a co-product of the production of viscous fibre from lignin, while the sodium citrate used is produced by fermentation from maize.
It should be noted that "viscous fibre" refers to a natural fibre of plant origin and in particular obtained by the so-called "viscous process" from wood lignin once said lignin has been separated from the cellulose component.
Furthermore, both the anionic and non-ionic surfactants present in said solid self-adhesive formulation derive from chemical transesterification processes from further modified palm oil.
In said solid self-adhesive formulation, the fragrance is also composed mainly of naturally-derived essential oils.
It should be noted that in said solid self-adhesive formulation the plasticisers are also obtained from naturally occurring compounds. For example, xanthan gum is produced by fermentation from a sugar generally selected from glucose, sucrose or lactose. The rosin ester used is produced by esterifying rosin, which constitutes a solid residue from the distillation of the resin of various conifers. Finally, waxy maize starch is produced from maize itself.
Said solid self-adhesive formulation is further used in finished commercial products.
A further object of the present invention is an adhesive product in the form of a strip to be applied to the walls of sanitary ware comprising:

i) a layer of said strip comprising the solid self-adhesive formulation capable of adhering to the walls of the sanitary ware;
ii) a non-adhesive water-soluble film, preferably containing polyvinyl alcohol arranged on a surface of the layer i), to allow the manual application of said product directly on the walls of the sanitary ware.

Preferably, on the surface opposite that where the layer ii) is applied, a removable protective sheet is applied prior to the application of said product on the walls of the sanitary ware.
The non-adhesive water-soluble film ii), preferably containing polyvinyl alcohol (or PVA), prevents the direct contact of said self-adhesive formulation object of the invention with the hands of the user. According to a particularly preferred solution, said layer of non-adhesive water-soluble film is provided with a protrusion or "fin" to facilitate the manual application of said further product object of the present invention. By way of non-limiting illustration, the following examples are given.

1. Formulation example

Function	Commercial name	Chemical name	CAS number	%
Excipient	Sodium sulphate	Anhydrous sodium sulphate	7757-82-6	32.6
Anionic surfactant	Empicol LZN MB	Sodium salts of mono C12-C18 alkylesters of sulphuric acid (92% active matter + 1.5% sodium sulphate + 3% Water + 3.5% non-sulphurated matter)	68955-19-1	24.9
Anionic surfactant	Empiwax SK/BP MB	Sodium salts of mono C12-C18 alkylesters of sulphuric acid (9.7% active matter + 1% water, stearyl alcohol at 100%)	68955-19-1	3.5
Perfume	MINT EUCALYPT US NP 22129P	/	IFRA MIX	1
Non-ionic surfactant	Glucopon 600 CS UP MB	C10-16 alkyl poly-glucosides (51.5% active matter + 48.5% water)	110615-47-9	14
Excipient	Sodium citrate	Trisodium citrate dihydrate (100% active matter)	6132-04-3	15
Plasticiser	Rhodopol 23	Xanthan gum (100% active matter)	11138-66-2	2
Plasticiser	Bremasin SK 4.905	Rosin resin	/	2
Plasticiser	C*Gel 04201	Waxy maize starch (100% active matter)	9005-25-8	5

2. Example of stability and performance of the finished commercial product

2.1 Example of product stability

Stability tests were carried out on the finished commercial product in order to verify that its chemical-physical conditions do not alter over time. The internal procedure used to perform a stability test includes the following conditions:

room temperature, natural light, 3 years
40°C, 3 months (accelerated condition corresponding to 3 years at room temperature)
4°C, 3 months (accelerated condition corresponding to 3 years at room temperature) Stability at the conditions indicated above (in progress for room temperature and finished for 40°C and 4°C) showed no product anomalies, thus demonstrating the proper hold of the designed formula.

2.2 Example of performance

The performance of the finished commercial product was carried out in order to verify the foaming capacity of the product, the duration in terms of flushes and the consumption of said product over time. The internal procedure used to perform a performance test includes the following conditions:

Toilet (or WC), French model (Villeroy & Boch, Voltablanc)
Schedule set to 17 flushes per day
9 litres (L) of water for each flush
Water hardness equal to 35° THF

The performance of said finished commercial product under the conditions mentioned above showed an average duration of 140 flushes. The foaming capacity is in line with a classic product for toilets (or WCs): the foam reaches its peak in the central life phase of the product, decreasing as the end of life is reached.

Claims

Solid self-adhesive formulation for the hygiene and fragrance of sanitary ware comprising:
• between 11% and 80% by weight on the total weight of said solid self-adhesive formulation of a mixture (a) of at least one alkaline salt of an inorganic and/or organic acid;

• an anionic surfactant (b) comprising:
- between 5 and 45 % by weight of the total weight of that solid self-adhesive formulation of a composition (b1) comprising at least 85% by weight of the total weight of the composition (b1) of a mixture of alkaline salts of mono C12-C18 alkylesters of sulphuric acid;

- between 1 % and 5 % by weight of the total weight of that solid self-adhesive formulation of a composition (b2) comprising between 8 and 12% by weight of the total weight of the composition (b2) of a mixture of alkaline salts of mono C12-C18 alkylesters of sulphuric acid dispersed in a mixture of fatty alcohols C16-C18;

• between 5% and 25% by weight on the total weight of said solid self-adhesive formulation of a non-ionic surfactant (c) consisting of an aqueous dispersion comprising a mixture of C10-16 alkyl poly-glucosides, in quantities between 40 and 60% by weight on the total weight of said non-ionic surfactant (c);

• a fragrance,
wherein the total water amount in said solid self-adhesive formulation is lower than or equal to 15% by weight on the total weight of said solid self-adhesive formulation.
Solid self-adhesive formulation according to claim 1, wherein the total water amount is lower than 10%, preferably between 5 and 8% by weight of the total weight of said solid self-adhesive formulation.
Solid self-adhesive formulation according to claim 1 or 2, wherein the salts in the mixture (a) are a mixture of sodium sulphate and sodium citrate.
Solid self-adhesive formulation according to claim 3, wherein the sodium sulphate contained in (a) constitutes between 10 and 50%, preferably between 30 and 50%, more preferably is 32.6% by weight on the weight of said solid self-adhesive formulation, sodium citrate is present in concentrations between 1 and 30%, preferably 15% by weight of the total weight of said solid self-adhesive formulation.
Solid self-adhesive formulation according to anyone of claims from 1 to 4, wherein the surfactant (b1) is contained in the solid self-adhesive formulation in quantities comprised between 15 and 35%, preferably 25% by weight on the total weight of that solid self-adhesive formulation.
Solid self-adhesive formulation according to anyone of the claims from 1 to 5, wherein the concentration of anionic surfactant (b2) is 3.5% by weight on the total weight of said solid self-adhesive formulation.
Solid self-adhesive formulation according to anyone of claims from 1 to 6, wherein the concentration of the non-ionic surfactant (c) is 14% by weight on the total weight of said solid self-adhesive formulation.
Solid self-adhesive formulation according to anyone of claims from 1 to 7, wherein the fragrance concentration is comprised between 0.1 and 5%, preferably 1% by weight on the total weight of said solid self-adhesive formulation.
Solid self-adhesive formulation according to anyone of claims from 1 to 8, containing at least one plasticiser selected from the group consisting of: xanthan gum, rosin resin, waxy maize starch and mixtures thereof, preferably at concentrations comprised between 0.1 and 10% by weight on the total weight of the solid self-adhesive formulation.
Solid self-adhesive formulation according to claim 9, containing xanthan gum, rosin resin and waxy corn starch.
Solid self-adhesive formulation according to claim 10, containing xanthan gum in concentrations comprised between 0.1 and 5%, preferably 2% by weight on the total weight of said solid self-adhesive formulation; rosin resin between 0.1 and 5% preferably 2%, and waxy corn starch in concentrations comprised between 1 and 10% preferably 5% by weight on the total weight of said solid self-adhesive formulation.
Adhesive product in the form of a strip to be applied to the walls of sanitary ware comprising:
i) a layer of said strip comprising the solid self-adhesive formulation according to anyone of claims from 1 to 11 capable of adhering to the walls of the sanitary ware;

ii) a non-adhesive water-soluble film, preferably containing polyvinyl alcohol, placed on a surface of the layer (i), to allow manual application of this product directly on the walls of the sanitary ware.
Adhesive product according to claim 12, wherein, on the surface opposed to the surface in which the layer is applied (ii), a protective sheet is applied being removable before this product is applied to the walls of the sanitary ware.
Adhesive product according to anyone of claims 12 or 13 wherein said non-adhesive film layer (ii) is provided with a protrusion or "fin" to facilitate its application.