Patent Description:
Recently, consumers' demand has increased for products of plant origin not only in the food sector, but also in other sectors, including the clothing and fashion accessories sector. This request does not refer only to traditional textile products based on cotton, linen or hemp, but also to materials completely unknown until now for use in these fields, such as soy-based textile products or materials obtained from vegetable waste.

Because of the spread of an increasingly strong animalist sensitivity, moreover, if we think in particular to the leather goods sector, the replacement of traditional leather with products of plant origin presents, in addition to guaranteeing the naturalness and ecology of the product, the further attraction for the consumer of being cruelty-free, that is to avoid acts of cruelty on animals for the sole purpose of obtaining their skin.

However, the products made with these materials are always required to have a pleasing aesthetic appearance to which the consumer is apparently not willing to give up, and also higher quality performances, in addition to a more or less high workability and resistance depending on the application and destination of use. In particular, in the case of ecological leathers, the physical and mechanical characteristics required to the material are particularly stringent, since the material must guarantee sufficient strength and resistance to be able to be sewn for example, or in any case joint with portions of the same or of different materials, to manufacture the finished product in the form of a bag, purse, belt, and the like.

In order to aspire to obtain a material with such characteristics, the starting plant material clearly has to be submitted to treatments which must in their turn guarantee the desired ecology not only of the product following the treatment, but also of the process itself and of the reagents and solvents used to make it.

To date, some attempts have been made to meet the aforementioned market demands, creating materials for use in the clothing and fashion accessories sector starting from plant products, including waste products or in any case fruit, vegetables, mushrooms, etc. So far, however, as far as the Applicant is aware of, such attempts have been aimed at obtaining a material whose natural composition and plant origin could be guaranteed, without however paying attention to its characteristics of robustness and resistance, required to create for example a bag. Or, to obtain these characteristics of robustness and solidity, the attempts made so far have involved treatments which, to obtain the required resistance, completely transformed the structure of the starting material and also inevitably any recall to its original aesthetic appearance.

The publication retrieved from the internet URL: https://www. it/lifestyle/notizie/moda/stilisti/<NUM>/<NUM>/<NUM>/moda-la-buccia-dellananas-per-scarpe-e-borse-couture_6065d06b-ff91-<NUM>-a8e5-3eb04f79d143. html and URL: https://www. com/watch?v=q0Zt9LENfHE, disclose a material of treated ananas peelings.

The Chinese patent application <CIT> discloses a process for preparation of an aqueous disinfecting composition comprising i. glutaraldehyde and root rind.

For these reasons, to date, it is still recognised the need to have an ecological treatment process of products of plant origin, capable of providing a high quality treated material, with the stability and resistance necessary to make it suitable for use in the clothing and fashion accessories sector, while maintaining the original appearance of the original starting product.

Now the Applicant has found that rinds of plant origin, such as for example pineapple or melon rinds, if subjected to a process of treatment with aqueous solutions of an aldehyde agent described in the following, result in a robust and stable, rot-proof material, which also maintains the aesthetic appearance of the starting product.

Advantageously all the reagents and solvents used in this process of treatment are neither toxic for people nor harmful for the environment, therefore they do not create any problems related to the safety of use and to health of the operators who handle them, nor they leave traces or toxic residues in the treated product.

Subject of the present invention is therefore a process for treating rinds of plant origin comprising a step of immersion of said rinds in a bath under stirring for a time ranging between <NUM> hour and <NUM> days, wherein said bath has a pH between <NUM> and <NUM> and comprises an aqueous solution of an agent of treatment selected from the group consisting of glutaraldehyde, acetaldehyde, glyoxal and mixtures thereof, at a concentration of said agent of treatment higher than <NUM>% by weight with respect of the total weight of the solution, wherein said rinds of plant origin are pineapple rinds or melon rinds.

Other important features of the process for treating rinds of plant origin, of the so treated material and of its use, and of the articles made with the material according to the invention are set forth in the following detailed description.

In the following description, unless otherwise specified, percentage quantities are expressed as percentages by weight with respect to the total weight of the composition comprising them.

The Applicant has surprisingly found that rinds of plant origin, when immersed in a bath comprising an aqueous solution of an agent of treatment selected from the group consisting of glutaraldehyde, acetaldehyde, glyoxal and mixtures thereof, acquire improved characteristics of hydrothermal and mechanical resistance with respect to the starting product, and a much greater stability, while maintaining the aesthetic appearance of the starting rinds, with no changes. In addition to a high resistance and stability, the plant material obtainable with the present process has also proved to be rot-proof, contrary to the starting plant product.

Glutaraldehyde is a low molecular weight aliphatic dialdehyde, with formula:
<CHM>.

It is a water-soluble compound, whose aqueous solutions are stable and poorly volatile. It is also a widely used commercial product, whose main uses are:.

Acetaldehyde is the simplest aliphatic aldehyde, with lower molecular weight, of formula
<CHM>.

At room temperature, it is a colourless liquid, widely used in industrial organic synthesis.

Similarly in the form of colourless liquid at room temperature, the glyoxal is the simplest dialdehyde, with formula
<CHM>.

Glyoxal is already widely used in the paper, textile and pharmaceutical industries, where it is used as a precursor in the synthesis of organic compounds.

In a preferred embodiment of the present process, glutaraldehyde is used as a treatment agent.

This result was completely unexpected in nature, composition and consistency of rinds of plant origin, completely different for example from any type of animal-based leather. Moreover, the aesthetic aspect of the starting rinds of plant origin is completely preserved even when the immersion phase is such that it led the aldehyde treatment agent to penetrate inside and throughout the section of the rind. This penetration into the interior of the rind is a preferred condition of the process of this invention since it is more effective in improving the strength and stability of the final material, and it is a condition which can be obtained, for example by subjecting the immersed rinds in the stirring bath, preferably mild, and / or prolonging the immersion for a sufficiently long time. In one aspect of the present process, the rinds immersion phase can last for between <NUM> hour and <NUM> days. Optimal results on pineapple rinds were observed by keeping the rinds immersed in the bath for about <NUM> days under mild agitation. For different rinds, the optimal times with and without agitation can be easily determined by any expert with ordinary skills in the sector within the conditions described above.

As described in detail in the experimental part that follows, this has been observed in particular for pineapple rinds, rinds of plant origin with a particularly original appearance, formed by plaques fused between them, which are completely preserved in the material after treatment with the process of the Invention. The same has been found by subjecting the process of the invention to melon rinds, also chosen for their particular appearance, characterized by more or less evident longitudinal flange and by a more or less thick and evident reticulation. It is understood that pineapple and melon rinds are mentioned herein by way of a non-limiting example, and other rinds of plant origin, in particular those rinds which are original due to their aesthetic appearance, do fall within the scope of the present invention. The material resulting from the present treatment is particularly original and attractive by appearance, and at the same time has acquired a stability and a hydrothermal and mechanical resistance completely unknown to the untreated pineapple or melon rinds, so that, with the rinds treated according to the invention, complex articles such as bags and pouches have been manufactured, by sewing parts of material previously cut according to models. More in general, for the rinds of plant origin, the present process has provided a surprising effect of improving their functional features and performance giving rise to a high performance finished material from a physical and mechanical point of view, rot-proof over time and endowed with high stability and hydrothermal resistance. Thanks to these characteristics, the material thus obtained can be successfully used not only in the fashion sector, in particular for making and / or decorating clothing and leather goods, but also in the furniture and design sector, and in other similar fields.

Within the scope of the present invention, by "aqueous solution of an agent of treatment" which, as stated above, is selected from the group consisting of glutaraldehyde, acetaldehyde, glyoxal and mixtures thereof, it is preferably meant an aqueous solution having a concentration of the aforementioned agent of treatment > <NUM>% by weight, more preferably an aqueous solution of the aforementioned agent having a concentration equal to about <NUM>% by weight with respect to the total weight of the solution.

The bath in the immersion step of the present process can further comprise, in addition to water and agent of treatment, also any additives, dyes, flavours and agents commonly used and acceptable in the field, in particular products derived from sugars and / or from proteic substances, such as moisture correctors and fillers. These latter additives, i.e. products derived from sugars and protein substances respectively having corrective action of humidity and filling action on the internal structure of the material, have proved effective in further improving the stability and product characteristics of the finished material in the present treatment process.

According to an embodiment of the process of the invention, the bath in the immersion step consists of an aqueous solution of the aforementioned agent of treatment with one or more of the aforementioned derivatives of sugars and proteic substances. According to a further embodiment of the process of the invention, the bath in the immersion step consists of an aqueous solution of agent of treatment without any further additives, agents or any substances.

The aforementioned additives may be added ab initio to the immersion bath or may be added thereafter, after the rinds of plant origin have already spent a certain period of time within the bath. This addition can be simultaneous or, preferably, in sequence, keeping the rinds immersed for a certain period of time after each addition, so as to facilitate the penetration into the internal structure of the various substances present in the bath.

In one aspect of the present process, the bath in the immersion step has a pH of between about <NUM> and about <NUM>, and it is preferably about <NUM>.

In the present process, both the immersion step and the possible pre-treatment step are for example carried out at a temperature ranging from about <NUM> and about <NUM>.

According to a preferred embodiment of the present process, the step of immersing the rinds of plant origin in a bath comprising an aqueous solution of the aldehyde agent of treatment is preceded by a step of pre-treatment of the rinds of plant origin in an aqueous solution comprising at least a neutral salt, for example NaCl, and an acid, e.g. formic acid.

Thanks to its characteristics, in particular to their water-solubility and stability in aqueous solution without any other solvents or diluents, the aldehyde agents of the invention represent an ideal product for use in an ecological process, as that of the present invention is. Moreover, the present process, in its simplicity and safety, allows to significantly improve the characteristics of the starting products while preserving the aesthetic aspect too, as opposed to known processes in which the processing of the starting plant product is so strong that it completely transforms the appearance of the plant product, flattening it over that of any ecological leather.

The invention is described in the following by means of examples without, however, being limited thereto, but it is understood that the amounts and percentages of the reagents described can vary, as well as the type of reactors and more generally the type of conditions used while remaining within the range of the present invention.

Starting from <NUM> fresh pineapples their respective rind has been obtained.

A pre-treatment bath with water and NaCl was also prepared, added in such a quantity to reach a density of about <NUM> Bè. It was also added to the salt solution <NUM>/l of an antibacterial agent based on dithiocarbammate and <NUM>/l of formic acid (approximately <NUM>% conc.

The so composed bath was poured into a cylindrical container equipped with a mechanical stirrer and subjected to gentle stirring until all the components were mixed. At this point the pineapple rinds were immersed in the bath and the mild stirring of the bath continued until a pH equal to about <NUM> was reached. Once this pre-treatment phase was concluded, <NUM>/l of formic acid and <NUM>/l of glutaraldehyde (aqueous solution at about <NUM>% concentration) were added to the bath and mild agitation of the immersed rinds is continued for <NUM> days. After this period of time, the bath was progressively basified until it reached a pH of about <NUM> by addition of sodium bicarbonate, then a proteinaceous substance obtained from the hydrolysis of animal collagen was added and mild agitation was continued for further <NUM> hours.

The rinds so treated were taken from the container and completely immersed in a water bath in a new container. Then glycerin was added in a quantity of <NUM>/l and a mild agitation was maintained for <NUM> day.

The rinds treated as described above, once taken from this bath, were subjected to air drying. <FIG> shows one of the pineapple rinds treated as described above. These rinds treated with the invention process have been used, instead of animal-based leather, to make some leather goods. The rinds treated as described above showed a remarkable ease in cutting and sewing, high mechanical strength and stability over time; they also conferred considerable strength to the finished article. In particular, no detachment of the blocks that make up the structure of the pineapple rind has been observed. At the same time, as can be seen from <FIG>, the aesthetic and dimensional characteristics of the starting rind were maintained in full: in particular, the colouring of the starting rind was exactly maintained after the treatment, as well as the appearance of the individual blocks.

Starting from a fruit of the same size and degree of maturation of the samples used in Example <NUM> above, a rind was obtained having the same dimensions as the rinds of Example <NUM>.

The rind of the fresh fruit was then subjected, without any treatment, to air drying for the same time and in parallel with the rinds of Example <NUM>, treated with the process of the invention. The result, comparable to that obtained for any air-dried vegetable peel, is visible in the annexed <FIG>.

As can be seen from the figure, the size of the sample is greatly reduced compared to the sample in <FIG>, the colouring appeared much duller and the shape of the blocks was damaged. Furthermore, once subjected to torsion or other mechanical stresses, this sample broke and, a few days after the start of the experiment, the onset of mold was also observed.

The same treatment described above in Example <NUM> for pineapple rinds was also carried out on melon rinds made from fresh fruit, after having eliminated the pulp, and using the same experimental treatment conditions described above for pineapple rinds. The results were quite similar: the melon rinds treated with the invention process showed in particular a high mechanical strength and stability, in addition to a robustness that allowed precision cutting and sewing to make complex articles. The aesthetic characteristics of the starting rind, characterized by an original relief grid and longitudinal ribs, were instead perfectly maintained after the treatment. In addition to the morphology of the natural rind, the original colour was also maintained.

Claim 1:
A process for the treatment of rinds of plant origin comprising a step of immersion of said rinds in a bath under stirring for a time ranging between <NUM> hour and <NUM> days, wherein said bath has a pH between <NUM> and <NUM> and comprises an aqueous solution of an agent of treatment selected from the group consisting of glutaraldehyde, acetaldehyde, glyoxal and mixtures thereof, at a concentration of said agent of treatment higher than <NUM>% by weight with respect of the total weight of the solution, wherein said rinds of plant origin are pineapple rinds or melon rinds.