COUVERCLE, DESTINE EN PARTICULIER AUX RECIPIENTS A DENREES ALIMENTAIRES ET SON PROCEDE DE FABRICATION

A LID, PARTICULARLY FOR FOODSTUFF CONTAINERS, AND THE PROCESS USED FOR ITS MANUFACTURE

Abrégé français

Ce couvercle, destiné à des récipients à denrées alimentaires, comprend une coque (3) conformée de telle sorte qu'elle puisse s'ajuster sur l'ouverture d'un récipient et un joint d'étanchéité (8) ne renfermant pas de PVC et comportant une inscription (11). Ce joint d'étanchéité est fixé sur la face inférieure (6) de la coque (3) et permet de fermer le récipient de manière étanche à l'aide du couvercle (1). Ce joint d'étanchéité (8) est plaqué sur la face inférieure (6) du couvercle (1) grâce à l'application d'une peinture adhésive (9) entre cette face inférieure (6) et ledit joint d'étanchéité (8). La peinture (9) peut servir à déterminer l'adhérence du joint (8) à la face inférieure (6) et elle consiste en un mélange de résines synthétiques et d'hydrocarbures avec un pigment métallique ajouté. Un film (10) portant l'inscription (11) est appliqué sur la peinture (9). Cette inscription est réalisée avec une encre dont les caractéristiques chimiques et physiques lui confèrent une affinité avec les matériaux utilisés pour le joint d'étanchéité (8). Il est donc aisé de détacher le joint d'étanchéité (8) de la face inférieure (6) du couvercle (1) sur laquelle l'inscription (11) est reproduite clairement.

Abrégé anglais

A lid for foodstuff containers includes a shell (3) shaped so
that it can be fitted over an opening in a container, and a PVC-free
seal (8), bearing an inscription (11), attached to the bottom
(6) of the shell (3) and able to seal the lid (1) to the container;
the seal (8) is applied to the bottom (6) of the lid (1) by applying
adhesive paint (9) between the bottom (6) and seal (8); this paint
(9) which can be used to control the adherence of the seal (8)
to the bottom (6), consists of a mixture of synthetic resins and
hydrocarbons with added metallic pigment; a film (10) bearing
the inscription (11) is applied over the paint (9), said inscription
made using an ink which has a given chemical-physical affinity
with the materials used for the seal (8); it is, therefore, easy to
detach the seal (8) from the bottom (6) of the lid (1) upon which
the inscription (11) is clearly reproduced.

Revendications

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What is claimed is:
1. A lid for foodstuffs of the type which includes:
- a shell (3) shaped in such a way that it can be fitted over
an opening in a container, said shell having a bottom (6)
whose shape corresponds to a mouth of the container, said
bottom (6) facing the inside of the container when the lid
(1) is closed;
- a seal (8), made of a material which is free from polyvinyl
chloride, said seal being attached to the bottom (6) and
sealing the lid (1) onto the container;
- an adhesive paint (9) applied over a surface of the bottom
(6) to join the seal (8) to the bottom (6), characterised in
that the paint (9) includes a hydrocarbon compound with at
least one metallic pigment, so that the seal (8) can, if
necessary, easily be detached from the bottom (6) of the
shell (3).
2. The lid as described in Claim 1, characterised in that
the paint (9) basically consists of the following components:
2-butoxyethanol, aromatic hydrocarbons C9-C11, n-butanol,
xylol, isobutanol, 2(2-butoxyethoxy) ethanol, synthetic
resins, methyl isobutyl ketone, methoxypropanol and metallic
pigments.
3. The lid as described in Claim 2, characterised in that
the components of the paint (9) are respectively present in
the following weight percentage intervals: 2-butoxyethanol
15%-25%, aromatic hydrocarbons C9-C11 5%-15%, n-butanol 1%-
5%, xylol 1%-5%, isobutanol 5%-15%, 2(2-butoxyethoxy) ethanol
1%-5%, synthetic resisns 30%-40%, methyl isobutyl ketone 1%-
5%, methoxypropanol 10%-20% and metallic pigments 1%-5%.

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4. The lid as described in Claim 1, characterised in that
the seal (8) is easily manually detachable from the bottom
(6) of the shell (3).
5. The lid as described in Claim 1, characterised in that
an inscription (11) is reproduced on a part of the seal (8)
which adheres to the paint (9) on the shell (3), and that the
said inscription (11) a non-stick film (10) is positioned
between the paint (9) and the inscription (11), to reduce the
adhesion of the inscription (11) to the paint (9), thus
creating greater adhesion to a seal (8) side.
6. The lid as described in Claim 5, characterised in that
the film (10) consists of organic pigments, aliphatic
hydrocarbon fractions, polyester-, amino- and wax resins.
7. The lid as described in Claim 5, characterised in that
the film (10) is made of a transparent material.
8. The lid as described in Claim 5, characterised in that
the film (10) is made of a pigmented material.
9. The lid as described in Claim 5, characterised in that
the inscription (11) is made using a UV ink which can be
dried in UV ray ovens.
10. The lid as described in Claim 9, characterised in that
the said UV ink consists of: organic pigments, amino- and/or
polyester- and/or epoxy- resins, acrylic oligomers consisting
of di- and tri- esters of polyfunctional alcohols with
acrylic acid, benzophenone and/or complex ketones or their
derivatives, polyethylene waxes.
11. The lid as described in Claim 1, characterised in that
the lid (1) consists of a bottle cap including the shell (3),

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preferably in the shape of a crown (7) and the seal (8) which
is made of material free of polyvinyl chloride.
12. Process for making a lid according to Claims 1 to 4, and
6 to 9, and 11, characterised in that the process includes
the following operating stages:
- mixing of synthetic resins with a hydrocarbon compound to
which at least one metallic pigment is added, to obtain the
paint (9);
- spreading of the paint (9) on one side of a sheet of metal
suitable for making a plurality of shells;
- drying of the paint (9);
- application of a film (10) over the paint (9) in the areas
in which an inscription (11) will be positioned;
- drying of the film (10);
- creation of the inscription (11) in the areas in which the
film (10) is applied, said inscription (11) adhering less to
the film (10) placed over the paint (9), than to the seal (8)
which is then laid over the inscription;
- cutting and forming of the plurality of shells (3) into the
desired shape;
- application of the seal (8) to the bottom (6) of the shell
(3) over the inscription (11).
13. The process as described in Claim 12, characterised in
that the film (10) is applied using a first plate.
14. The process as described in Claim 12, characterised in
that the drying stages are carried out at temperatures which
vary between 150 and 250°C and with drying times of 5-20
minutes.
15. The process as described in Claim 12, characterised in
that the inscription (11) is applied using a second plate.

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16. The process as described in Claim 12, characterised in
that the film (10) and inscription (11) are applied using the
same plate.
17. The process as described in Claim 12, characterised in
that the inscription (11) is printed in UV ink.

Description

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~,, particularly for foodstuff containers and the ~arocess used
for its manufacture
Technical Field
The present invention relates to a lid, as it is generally
known, for foodstuff containers, in particular for use in prize
competitions in which an inscription is placed on the inside of
the lid.
In particular, it should be noticed that the lid concerned may
be used to seal glass bottles designed to contain liquid
foodstuffs, under pressure or not, which may or may not undergo
heat treatment. In such cases, the said lid is a crown cap which
guarantees the seal between the air and the container. More
precisely, the cap in question has a removable PVC - free seal
with an inscription on the side which faces the bottom of the lid.
PVC - free means those materials which do not contain polyvinyl
chloride, the use of which continues to be reduced, especially in
Northern European countries. The afore-mentioned internal
inscription makes the lids particularly suitable for use in prize
competitions.
Backcrround Art
At present, in accordance with the prior art and for
particular commercial requirements, three different- types of caps
suitable for prize competitions are used.
The first type consists of a cap in the form of a metallic
shell, the internal side having a bottom upon which an opaque PVC -
seal is applied after treatment with adhesive paint. Given its
affinity with the paint, the said seal is easily detached, so that
an inscription present on the bottom of the cap can be read_
The second type of cap, again having an opaque PVC seal,
differs from the first in that the inscription is made in such a
way that it is transferred from the shell to the seal itself:
therefore, this type of cap is ideal for use when the seal must be

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used as proof of a win, since it is easier to send a seal rather
than the entire cap.
The third type of cap has a transparent seal tPVC or PVC
lree> which cannot be detached from the bottom of the cap. There
is an inscription on the bottom of the cap itself, clearly visible
through the seal. However, this cap is impractical for use in
prize competitions, since the entire cap is required as proof of a
win. being less convenient than the second type of cap, since, as
already indicated, it is easier to post a seal than a cap, A
further disadvantage of this third type of cap is that a
sufficiently opaque bottle is required, to prevent the inscription
being read from the outside of the bottle.
None at the three types of PVC-based crown caps made according
to the prior art can be marketed in those states in which the law
forbids the use of PVC crown caps.
To comply with such regulations and requirements and, at the
same time, obtain a cap which has an easily detachable PVC - free
seal, a new technology designed to control the adhesion of the PVC
- tree material to the cap is needed.
niReleanre of the Invention
The main object of the present invention is to overcome the
afore-mentioned disadvantages of the known types of caper by
providing a cap with a PVC - free seal which, if necessary, can
easily be detached from the bottom of the lid shell.
A further aim of the present invention is to create an
inscription which is easily and clearly transferable to the seal,
without the seal adhering to the adhesive paint spread on the
bottom of the lid, using a process which is able to control the
adhesion of the seal to the shell of the lid.
Another aim of the present invention is to provide a simple.
reliable operating process.

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2A
In a first aspect, the present invention provides, a lid
for foodstuf f s of the type which includes : a shel l ( 3 ) shaped
in such a way that it can be fitted over an opening in a
container, said shell having a bottom (6) whose shape
corresponds to a mouth of the container, said bottom (6)
facing the inside of the container of the container when the
lid (1) is closed; a seal (8), made of a material which is
free from polyvinyl chloride, said seal being attached to the
bottom (6) and sealing the lid (1) onto the container; an
adhesive paint (9) applied over a surface of the bottom (6) to
join the seal (8) to the bottom (6), characterised in that the
paint (9) includes a hydrocarbon compound with at least one
metallic pigment, so that the seal (8) can, if necessary,
easily be detached from the bottom (6) of the shell (3).
In a second aspect, the present invention provides a
process for making a lid according to the first aspect,
characterised in that the .process includes the following
operating stages: mixing of synthetic resins with a
hydrocarbon compound to which at least one metallic pigment is
added, to obtain the paint (9); spreading of the paint (9) on
one side of a sheet of metal suitable for making a plurality
of shells; drying of the paint (9); creation of the
inscription (11) in the areas in which the film (10) is
applied, said inscription (11) adhering leas to the film (10)
placed over the paint (9), than to the seal (8) which is then
laid over the inscription; cutting and forming of the
plurality of shells (3) into the desired shape; application of
the seal (8) to the bottom (6) of the shell (3) over the
inscription (11).
The technical specifications o! the present invention and the
process used, according to the alore-mentioned aims, are clearly
described in the claims, and the advantages are apparent lrom the
detailed description which follows with reference to the

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accompanying drawings, which illustrate a preferred embodiment,
and in which:
figure 1 is a schematic plan view from below of the lid
disclosed;
figure 2 is a schematic view of the lid, according to cross-
section II - II shown in figure 1, with some parts cut away to
better illustrate others:
figure 3 is an enlarged detail of the drawing of the crown cap
with detached seal shown in figure 2;
figure 4 shows the lid illustrated in the previous figures, in
a configuration in which the seal is partially detached and with
the transfer of the internal inscription.
In the embodiment illustrated, the lid consists of a cap for
bottles designed to contain liquid foodstuffs which-must not come
into contact with the atmosphere. More specifically, it is a crown
cap, generally used to seal glass bottles containing liquid
foodstuffs which may or may not be under pressure, such as water,
wine, various beverages, etc.
With reference to the accompanying drawings, the lid disclosed
consists of-a crown cap, indicated as a whole by the numeral 1.
The said cap 1 basically consists of a metallic shell 3, which
can be attached to the top of a bottle (not illustrated), and has
a concave surface S defining a bottom 6, the edge of which is
delimited by a crown 7. The cap 1 also has a PVC - free seal 8
(i.e.: made of a material which does not contain polyvinyl
chloride) which is approximately the same size as the bottom 6.
Paint 9 is used to stick the seal 8 to the bottom 6 (see
figure 2).
More precisely, the method used to manufacture the crown cap 1
in question begins with a sheet of metal. The lithographic print
defining the designs which will appear on the outside- of the cap
(usually the product trade-mark) are made on one side of this
sheet of metal, whilst the afore-mentioned layer of-paint 9 is
r
spread on the other side.
- The sheet then goes through the stages of cutting and
formation of the shell which create the cap 1. Finally, the cap 1
is passed inside a heating station, where the paint is melted and

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acts as an adhesive for a seal 8 which is poured into the cap 1,
then formed by a corresponding press which gives it the desired
shape.
Foz the present invention, the said paint 9 consists of a
mixture of synthetic resins and a hydrocarbon compound with added
metallic pigment. A heavy metal is defined as a metal with
comparatively higher physical weight or density in relation to
a light metal, for example magnesium being a light metal and
steel being a heavy metal.
The addition of the awtallic pigment allows the adhesion of
the seal 8 to the bottom 6 of the cap 1 to be controlled: the
greater the concentration of the metallic pigment in the
hydrocarbon compound, the more the paint 9 reproduces the
chemical-physical specifications of the metallic shell 3.
As a result, the adhesion of the seal 8 to the shell 3 is
reduced.
More specifically, the metallic piym~nt may be dosed in such a
way as to ensure that the seal 8 remains stuck to the bottom 6 of
the cap 1 and, at the same time, make it easy to detach by lifting
it off with, for example, a fingernail.
The paint 9 described basically consists of the following
variable quantities of co~onents, in the weight percentages
indicated.
- 2-butoxyethanol 15-25~
- aromatic hydrocarbons C9-C11 5-15i
- n-butanol 1-5~
- xylol 1-5~t
- isobutanol 5-15~
- 2(2-butoxyethoxy> ethanol 1-5t
- synthetic resins.30-40!
- methyl isobutyl ketone 1-5~
- methoxypropanol 10-20~
- metallic pigments 1-5~
A film 10 of transparent or pigmented material is placed
between the paint 9 and the seal 8, said film bearing an
inscription 11, obtained using a W ink. The latter is a special
ink, which can be dried and fixed in UV ray ovens. The film 10 is
only placed on a limited painted area of the bottom 6 of the cap
1, where the inscription li is made.

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The said film 10 basically consists of organic pigments,
aliphatic hydrocarbon fractions, polyester-, amino- and wax
resins. Thanks to the composition of the film 10, the inscription
11 with UV ink positioned precisely over the area treated with the
5 film 10 only slightly adheres to the latter and, as a result,
adheres much more to the seal 8 with which the inscription is in
contact.
The UV ink basically consists of: organic pigments, amino-
and/or polyester- and/or epoxy- resins, acrylic oligomers
consisting of di- and tri- esters of polyfunctional alcohols with
acrylic acid, benzophenone and/or complex --ketones or their
derivatives, polyethylene waxes.
The following is a description of the process for the creation
of the'structure of the lid 1.
First, the paint 9 is prepared by mixing the synthetic resins
with a hydrocarbon compound to which a metallic pigment has been
added.
Then, the paint 9 is spread on one side of a sheet of -
material, normally metallic, with mechanical specifications
suitable for obtaining the shell 3 of the cap 1.
Depending on specific requirements, the said sheet consists of
chrome-plated steel, tin-plated steel, or stainless steel and
aluminium.
The paint 9 is then dried in conventional ovens at
temperatures which vary between 150 and 250C, this drying process
lasting 5 - 20 minutes. The temperature is preferably kept within
the smallest interval of 180 - 190C for a period of 11 23
minutes.
In a later stage of the process, if the cap 1 is to be used to
set commercial prize competitions, the film 10 is applied over the
~, paint 9. It is applied by using a special lithographic plate to
lay the said film 10 only in the painted areas in which the
inscription 11 is to be obtained.
The film 10 is then dried in a second drying operation,
identical to that used to dry the paint 9.
In another stage, the inscription 11 is made on the painted
areas covered by the film 10. The inscription 11 is preferably

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made using the same plate that was used to apply the film 10, and
using UV ink with the afore-said specifications and composition.
The sheet thus treated is ready to be cut, thus obtaining the
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shells. A PVC - free seal 8 is attached to each of the shells, so
as to guarantee the seal between the cap 1 and the bottle.
The above description clearly indicates one of the advantages
of the present invention. That is to say, when the seal 8 is
detached from the bottom 6 of the cap 1, the seal bears a clear
reproduction of the desired inscription 11 (as shown in figure 4).
The use of a paint which contains a metallic pigment allows
the stage in which the seal is detached from the lid to be
controlled, leaving the mechanical specifications and seal of the
crown cap as a whole unchanged, this being an important factor for
the bottlers who use it.
In particular, this bilateral control of the adherence of the
seal to the lid and limited adherence of the writing to the bottom
of the lid is, above all, a result of the identification of
components suitable for obtaining a substance compatible with and
acting upon the PVC - free material, without the latter losing any
of the advantageous specifications present.
The present invention may be subject to numerous modifications
and variations, all of which are encompassed by the design
concept. Moreover, all parts may be substituted with technically
equivalent parts.
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Dessin représentatif