Attached to the application for INDUSTRIAL INVENTION PATENT with title:

LUMINESCENT CONTAINER FOR FOOD.

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Technical field

The present invention regards a line of luminescent containers for food use. In particular, these containers are particularly well-suited for being em- ployed as jars, bottles, plates, bowls, glasses, cups and the like.

State of the art

There are containers of luminescent type that are made by applying a luminescent substance on the ex- ternal surface of the container. They are adapted for containing foods, but the luminescent treatment on the external surface is not suitable for coming into contact with the lips and is not very resistant to washing.

There are also systems like that described in EP1925463A2, which incorporate the luminescent pigment in the melted glass; however, these are rather costly systems, since they must reach high temperatures and they are not suitable for plastic table- ware. In order to remedy that stated above, the concept was developed to include the luminescent material between two transparent plate elements, as shown DE102007021188 (Al), where .it is taught to apply luminescent decorations inside one of the transparent elements and then to compose a sandwich.

It was also shown,, in DE 19749234 (Al) , how to add a methacrylate or polymethylmethacrylate, with high charge of inorganic material and with a luminescent pigment, in order to obtain a luminescent plastic material that can be directly used.

The Chinese utility model CN2704286Y describes a glass composed of two layers, constituting a smaller container and a larger container; the lumines- cent material is "spread" on the internal face of the larger container or on the external face of the smaller container; the smaller container is placed inside the larger container such that the two containers form a single entity, in this case the lu- minescent material is luminescent powder or fluorescent powder and can be spread to form various figures in order to attain the best visual effect. In all of the abovementioned cases, it was however not possible to develop a photoluminescent contain- er that unites low production costs and ease of working of the polycarbonate with the possibility of being washed in dishwashers at high temperature, a high impact strength and total non-toxicity necessary for food use.

Objects and summary of the invention

Main object of the present invention is therefore that of providing a product for tableware and similar items that is both simple and economical to make, which does not require the use of costly ma- chinery for being produced and which is capable of ensuring rechargeable photoluminescence forever, both with solar or artificial light source, which is resistant to washing in dishwashers at high temperature; which has high impact strength; which is totally non-toxic.

These and other objects are achieved with a finding in accordance with the attached claims; in particular, for each tableware item, three different pieces are assembled together, of generally concave form and therefore indicated below with the term half-shells .

In a preferential embodiment of the invention, the external half-shell (3) and the internal half-shell (1) are made via injection molding of crystal poly- carbonate, of the type certified for food use. Crystal polycarbonate is a transparent and colorless plastic material, resistant to washing and to food substances.

The intermediate half-shell (2) is instead made via injection molding of polypropylene, to which a pho- toluminescent pigment has been ^" previously added. The sizing of the three half-shells is made in a manner such that the external half-shell (3) can contain the luminescent half-shell (2) and that the luminescent half-shell (2) can contain the internal half-shell (1) .

In order to form a sealable covering, the internal half-shell is higher than the external half-shell, and in particular the edge of the internal half- shell is enlarged until it reaches the external half-shell .

As a non-limiting example, in the figures attached to the present text, said enlargement is achieved by means of a perimeter relief or rim (15); said relief (15) has a main upward enlargement (11) and a secondary downward enlargement (12) .

Said main enlargement (11) constitutes the periphery of the tableware item and confers strength thereto, while said secondary enlargement (12) coo- perates with the external surface (13) of said in- ternal half-shell (1) to form a perimeter channel (24) that receives the edge (19) of the external half-shell (3) .

In this manner, the edge (19) of the external half- shell (3) has its perimeter in contact with said perimeter channel (24) and it is possible to weld together the two half-shells along said contact perimeter, e.g. via the use of an ultrasound welder, or advantageously due to the combined action of an ultrasound welder and a device which increases the contact pressure between the two half-shells.

These and other advantages of the invention will be clearer, together with the- technical characteristics, from the following detailed description of non-limiting embodiment.

Brief description of the drawings

The finding will be better understood by following the description and enclosed drawing, which shows a practical, non-limiting embodiment of the inven- tion, more particularly:

Fig. 1 shows the three half-shells in assembly step, one partially inside the other.

Fig. 2 shows a detail which illustrates that the internal half-shell (1) and the external half- shell (3) form an air space occupied by the inter- nal photoluminescent half-shell (2). In particular, the edge of the internal half-shell (1) is observed that is enlarged at its perimeter into a perimeter relief (15) comprising a main upward enlargement (11) and a secondary downward enlargement (12); the latter, cooperating with the external surface (13) of said internal half-shell (1) forms a channel (24) in which the edge (19) of the external half- shell (3) comes to be engaged.

In Fig. 2, it is also observed that the edge (19) of the external half-shell (3) comprises a lip (35) adapted to be engaged with the end (18) of said secondary enlargement (12) present on said perimeter relief (15) .

- Fig. 3 shows the same detail shown in Fig. 2, after the ultrasound welding operation has occurred, which has sealed the air space that receives the photoluminescent half-shell (2) .

Detailed description of one embodiment: of the in- vention

The present finding consists of a photoluminescent container, made starting from two half-shells, one internal (1) and one external (3) , made of at least partially transparent material. Such half-shells are joined, leaving an air space between them in which an intermediate half-shell (2) is situated, made of photoluminescent material.

In a preferred embodiment of the invention, the external and internal half-shells are made via mold- ing of plastic material, preferably by using crystal polycarbonate.

Still more advantageously, also the internal half- shell is made via molding of plastic material, preferably using polypropylene to which a photolumi- nescent pigment has been added.

In a particularly convenient embodiment of the invention, the photoluminescent pigment is composed of alkaline-earth aluminates or of alkaline-earth silicates .

As said, the internal half-shell (1) and the external half-shell (3) form an air space occupied by the internal photoluminescent half-shell (2). In particular, the edge of the internal half-shell (1) is enlarged at the perimeter into a perimeter re- lief (15) comprising a main upward enlargement (11) and a secondary downward enlargement (12); the latter, cooperating with the external surface (13) of said internal half-shell (1) forms a channel (24) in which the edge (19) of the external half-shell (3) comes to be engaged. The edge (19) of the external half-shell (3) comprises a lip (35) adapted to be engaged with the end (18) of said secondary enlargement (12) present on said perimeter relief (15) .

After having stacked the three shells, by means of an ultrasound welding the edge (19) and the lip (35) are joined together, thus sealing the air space which contains the photoluminescent half- shell (2) .

The ultrasound welding is more efficient if a pressure is exerted between the internal half-shell and the external half-shell.