FR2701926A1 - Tube for storing and dispensing a product which is, for example, aromatised or perfumed and contains water - Google Patents

Abstract

Tube (C) for storing and dispensing a product which is, for example, aromatised or perfumed and contains water, including a dispensing head fastened onto a flexible multilayer skirt, this skirt essentially comprising a polymeric intermediate layer with a barrier effect (20) against oxygen and the aromas or perfumes, the said layer being moisture-sensitive, and, on each face of this intermediate layer, one or a number of polymeric layers (1; 12, 14, 10) based on polyolefins, all the said layers being continuously bound together, characterised in that the combination of the layers which are situated on the inner face of the said intermediate layer with a barrier effect (1, 21) has a total thickness of between 55 and 135 micrometres, so as to preserve better the aroma or the perfume of a product which is or may be contained therein. This tube preferably comprises one or two means making the dispensing of the contained product easier and more complete. It applies in the packaging industry for, for example, liquid, creamy or pasty products.

Description

TUBE FOR STORING AND DISPENSING A PRODUCT, FOR EXAMPLE AROMATISE
OR PERFUME AND CONTAINING WATER
The invention relates to a tube for storing and dispensing a product, typically liquid, creamy or pasty, this tube for keeping the aroma or the perfume of the product contained.

EP-AO 084 922 = US Pat. No. 4,626,456 discloses a tube for storing and dispensing a product, for example flavored or perfume containing water, this tube comprising a fixed dispensing head. on a flexible multilayer skirt, this skirt essentially comprising an intermediate layer with a barrier effect on oxygen and aromas or perfumes, said layer being sensitive to moisture, as well as on each side of this intermediate layer a or more polymer layers based on polyolefins, all said layers being bonded together. The product contained is, for example, toothpaste, and the intermediate layer with a barrier effect is, for example, EVOH. The structure of the skirt, without a metallic intermediate layer, and comprising essentially polypropylene layers loaded with powders, for example Ca carbonate. , of mica or talc, makes it possible to obtain good retention of creases of crushing of the tube.

It has been observed with such a skirt two disadvantages. On the one hand, and as known for example from US-A-4,407,897, EVOH is very sensitive to moisture. A toothpaste commonly contains 20 to 30% by weight of moisture, and in multilayer barrier-layer tubes
EVOH, there has been a high loss of flavor of such a paste. Moreover, it has been found that the retention of local crushing of the tubes makes emptying the tube difficult.

The Applicant has sought to develop a tube providing better preservation of the aroma or scent of a contained product.

Incidentally, she sought that this tube allows a distribution of the product easier and more complete.

The subject of the invention is a tube as known from the cited document, characterized in that all the layers situated on the inner face of said intermediate barrier layer have a total thickness of between 55 and 140 micrometers, so that to better preserve the aroma or the perfume of a product which is there or will be able to be contained there.

The Applicant's interpretation on this subject is as follows: when the thickness of said layers situated on the inner face of the barrier layer is lower than 55 micrometers, the moisture of the product which passes through these layers degrades rapidly oxygen barrier qualities and aromas or perfumes of said barrier layer, and the flavors or flavors of the product can progress beyond this layer and even escape the tube.

When the thickness of the layers considered is greater than 140 microns, the moisture does not reach the intermediate layer barrier effect in an amount sufficient to degrade its qualities, but the flavors or fragrances are absorbed and retained in significant amounts by said layers. These aromas or perfumes are typically compounds in solution in the water contained in the product, and their evaporation and absorption follow as a first approximation the evaporation and absorption of the water forming said moisture of the product.

Even better results of preserving the aromas or perfumes of the product contained in the tube are obtained when the total thickness of the layers on the intermediate barrier layer is between 65 and 130 micrometers and more preferably between 70 and 120 micrometers. .

The foregoing conditions permit the use of economical polyolefin skirts for the skirt structure and provide excellent welding of the layers with each other, ie the family of polyethylenes.

The applicant has thus been interested in a tube in which the polyolefin-based polymer layers of the skirt consist, on the one hand, of an inner surface layer of low or very low density or linear low density polyethylene, with a specific mass of between 0, 86 and 0.93 g / cm 3, and on the other hand into other layers which are respectively of low density polyethylene (PE.BD) with a specific mass of between 0.90 and 0.93 g / cm 3, or high density polyethylene (HDPE) with a specific gravity of between 0.935 and 0.97 g / cm3.

Wishing then to make it easier and more complete the distribution of the product stored in the tube of the invention, tube which better retains its aroma or its perfume, the Applicant has determined that it was possible to avoid local crushes due to the pressed tubes by improving the elastic resistance to the depression of this skirt. For this, the polyethylene layers of the skirt of the tube contain one or more layers of
PE.HD total thickness greater than or equal to 90 micrometers. The tests thus show that, when the total thickness of PE.HD increases from 84 to 125 micrometers, the elastic reaction force of the skirt to a depression is more than double. When the thickness of the skirt is between 260 and 380 micrometers, for example in the case of a toothpaste tube, said total thickness of the PE.HD layers is preferably between 100 and 140 micrometers, the surface layers being preferably PE.BD, or for the inner layer of low density linear PE. Indeed, it is sought for these surface layers good ductility with good printability for the outside of the tube and good resistance to micro-cracking inside this tube. The total thickness ranges of the preceding PE.HD are to be transposed into relative values with respect to the thickness of the skirt if it is outside the specified range. elastic reaction of the skirt to a depression, the influence of the intermediate layer with a barrier effect, which has higher characteristics than the PE.HD at the same thickness. For the skirt thickness specified above, the sum of twice the thickness of said barrier layer and the total thickness of the HDPE layers is preferably between 130 and 180 micrometers, the previous condition relating to the only total thickness of the PE.HD layers being satisfied or not.

To facilitate fabrication by having surface layers of the nature specified above, i.e., typically PE.BD, it is preferred to use to achieve the desired total PE.HD thickness - a first layer of PE.HD which is inserted between said layer
internal surface and a first intermediate layer of PE.BD
itself located inside the intermediate effect layer
fence; - or a second layer of PE.HD which is inserted between a layer
external PE.BD and a second intermediate layer PE.BD
itself located outside the intermediate effect layer
fence.

Such first and second PE.HD layers are conveniently employed simultaneously, with thicknesses respectively between 10 and 50 micrometers and between 60 and 140 micrometers.

This (or these) layer (s) of PE.HD are typically "in continuity of fusion" with the layers between which they are inserted, their materials being compatible in fusion and the manufacturing process having produced a welding with perfect continuity of structure layers between them. A layer of PE.HD thus inserted can then be distinguished in cross-section by micro-hardness measurements, not by the appearance of the structure. Seams thus welded are obtained by coextrusion of the skirt or welding with overlapping edges of a multilayer blank resulting itself from one or more post-bonding coaminations using an extrusion coating of molten PE.

Typically, the first and second intermediate PE layers are each bonded to one side of the barrier-effect intermediate layer which they frame with a tie layer, often EAA or EMA.

The five layers in question are often used in the form of a multilayer prepared in advance, in which the moisture-sensitive barrier layer is relatively well protected in this respect.

Among the materials of moisture-sensitive intermediate skirt-barrier layers are: EVOH and PVOH (polyvinyl alcohol) whose degradation by moisture is described in
US-A-4,407,897 previously cited, and to a lesser degree of sensitivity modified polyamides and polyamides, for example polymetaxylylene adipamide (MXD6). Such an intermediate barrier layer has a thickness in the skirt typically between 0.01 and 0.05 mm, there may be several barrier layers preferably together with the total thickness above.

To make the distribution of the product stored in the tube of the invention easier and more complete, the Applicant has developed a second means that can be used alone or in combination with the first means imposing a minimum thickness of the PE.HD layers. the upper skirt at 90 micrometers.

This second means is to have between the skirt and the neck of the tube, an annular shoulder crushable. It is known that the shoulder tubes known, by their methods of manufacture, are rigid and form a kind of wall retaining a fraction of the product to be dispensed, typically produces creamy or pasty. Thanks to the manufacturing process which is the subject of the French patent application No.93 01065 of 27.01.1993 of the applicant, a tube is preferably obtained in which the dispensing head comprises a neck of smaller diameter than the skirt and an annular shoulder connecting the neck to the skirt, this shoulder being smooth and of thickness between 0.9 times and 1.25 times and preferably between 0.8 times and 1.25 times the thickness of the skirt and in continuity of structure with the skirt and comprising folds crushed and welded together, said shoulder being easily collapsible laterally.

Said shoulder and typically at least a portion of the neck of the tube contain the barrier layer or layers of the skirt of the tube in the form of folded and crushed extensions included in the previous crushed and welded folds, which are themselves extensions of the at least one barrier layer (s) of the skirt.The neck can be completed by a ring annular PE welded to the head, the shoulder remains at least half crushable.

The second means thus provides both the possibility of an easier and more complete distribution of the product contained in the tube, and a protection of its aroma or its improved perfume at the level of the head of the tube. The tapered folds in places of a barrier layer in the shoulder usually satisfy together the preferred condition of total thickness "0.01 to 0.05 mm", with enhanced efficiency. The manufacturing method resulting in this second means will be briefly described in the Examples.

ADVANTAGE OF THE INVENTION - It provides, with an economic structure of the skirt, a means of
to preserve much better the aroma or the perfume of the contained product; - It allows, moreover, according to its preferential characteristics, to
to limit the local crushing of the tube during the presses, these
acting then on a wider portion of the tube and being once
the other facilitated; - As an alternative or in combination with the limiting effect of these
crushing of the skirt, it offers the possibility of crushing laterally
the head and thus to expel more easily and completely
produced at the end of di sttibuti on.

EXAMPLES
Figures 1 to 3 show in section the skirts of 3 tubes, the first being outside the invention (Figure 1 control), the other two (Figures 2 and 3) according to the invention.

Figure 4 shows, in axial section, an arrangement for measuring the elastic reaction to the depression of a tube skirt, in relation to the first means resulting in an easier and more complete distribution of the product.

Figure 5 is a graph showing the weight gain of skirt samples as a function of the total thickness of the layers inside the barrier layer, in a flavor loss test.

FIG. 6 graphically represents the variation of the sag resistance of the skirt as a function of the total thickness of the layers of
PE.HD that are present.

Figures 7 to 10 relate to the second means resulting in improved distribution, that of a crushable shoulder. FIG. 7 is a perspective view of a comparison tube obtained by forming at room temperature.

FIG. 8 represents a tube according to the invention having a crushable shoulder, in axial half-section.

FIG. 9 represents another collapsible shoulder tube provided with an annular PE ring constituting the outside of its neck, in axial half-section.

Figure 10 shows a micrographic appearance of the top of the shoulder of this tube and the connection of this shoulder with said annular ring in an axial section.

1) Structure of the skirts of the tubes of FIGS. 1 to 3
These structures all have an intermediate layer to
barrier effect 20 of EVOH in thickness 0.02 mm, bonded by two layers
adhesives 21 and 22 in EMA copolymer (ethylene-acid copolymer)
methacrylic) 0.01 mm thick each at PE layers
comprising in contact with these bonding layers 21 and 22 of the PE.BD of
Specific mass 0.92 g / cm3 in layer 1 or undercoat
intermediate 11 or 12. The boundaries of layers of different nature
are marked in solid lines while the invisible boundaries between
underlayments PE.BD and PE.HD, resulting from their assembly in a state
melted at least on the surface, are shown in broken lines.

The term "sublayer" is used here for such layers,
less a boundary surface is invisible, however, they are layers
in its own right for the technical functions studied in this
invention. They can be identified by measures of
microhardness.

It can still be seen in Figs. 1 to 3, that the sub-layers in PE.HD
13 and 14 specific gravity 0.95 g / cm3 are each included between
one said intermediate sublayer of PE.BD 11 or 12 and one
low density internal linear PE 100 underlayment or PE.BD
external 10.

By going from the inside of the skirt to the outside, the successions
thicknesses are as follows, the underlayment details being
indicated in parentheses
- Tube A (control) (Fig.l): layer "1" PE.BD 0.035 mm; layers
EMA "21" 0.01 mm, EVOH "20" 0.02 mm, EMA "22" 0.01 mm;
PE layer "12 + 14 + 10" 0.215 mm (PE.BD "12" 0.082 mm
PE.HD "14" 0.0105 mm - PE.BD "10" external 0.023 mm)
- Tube B (Fig.2): PE inner layer "100 + 13 + 11" of 0.09 mm (PE
linear low density linear "100" of 0.01 mm - PE.HD "13" of
0.02 mm - PE.BD "11" of 0.06 mm); succession EMA, EVOH, EMA as
for A; PE layer "12 + 14 + 10" 0.215 mm of the same composition
only for A.

- Tube C (Fig.3): inner layer "1" in PE.BD 0.125 mm; succession
EMA, EVOH, EMA as for A and B; PE layers "12 + 14 + 10" of
0.175 mm (PE.BD "12" of 0.073 mm - PE.HD "14" of 0.084 mm - PE.BD
"10" external 0.018 mm).

The skirts of tubes A, B, C were rolled-welded from films
blanks having the structures and thicknesses above, then the heads
tubes were overmolded on these skirts.

2) Aroma loss tests
Circular coupons 50 mm in diameter were submitted from the three
above qualities shown in Figs. 1 to 3, at a
impregnation of their inner face in the skirt, that of layer 1
or 100, with a standard toothpaste containing 25% water and
menthol: during 4 weeks with maintenance in an enclosure to
C.

At the end of the test, the sample is cleaned of the toothpaste
remaining on the surface. Her weight gain is determined, she reports
loss of water and aroma.

We want to have a quality which gives, in this test, a decision of
weight per unit area less than 0.66 mg / cm2. A is a control
not satisfying. The results of the tests are shown in the
Table 1 and in Figure 5.

The interpretation is as follows: the weight gain too high of A
corresponds to absorption with degradation of EVOH by moisture
then passed through this EVOH by the water and the aroma, these being then
absorbed both by the outer layers of EVOH 21,12,14 and
10 only for inner layers such as 21 and 1. The
decay from A to B corresponds to a preponderant protective effect
of EVOH layer 20 by the increasing thickness of the layers
and the ascent from B to C corresponds to
the dominating influence of the absorption of water and aroma by
the inner layers, their thickness and therefore their capacity
increasing absorption while the EVOH is sufficiently protected.

3) Pressing test or resistance to the penetration of the skirt
A skirt sample is held to form a dome 16
reproducible hemispherical diameter 25 mm and length 100 mm,
and we come to press it with a rigid rod 17 of diameter 3 mm, according to
the linear generator 18 of the top of this dome. The line layout
interrupted 19 indicates the shape taken by the dome 16 when
the depression of the rod 17 at a constant speed has progressed.

A system (not shown) measures the reaction of the dome 16
or 19 on the rod 17, and determines the maximum. When this
reaction is strong, the skirt of the corresponding tube is more resistant to
in a hurry and its sink remains partly at least in the field
elastic, to avoid local restrictions in contrast to
the teaching of the document EP-AO 084 922.

The test results are shown in Table 2 and on the
Figure 6. The figurative points A, B, C are aligned in Figure 6.

Like the reaction in the absence of PE.HD in the skirt, then
entirely in PE.BD with the exception of EVOH and thin layers
Adhesives 21 and 22 that surround it, is necessarily weakly positive
(figurative point Z), we see that the effect of a growing thickness of
PE.HD on the reaction of the skirt to depression has a growth that
accelerates between 40 and 70 micrometers (portion of curve ZX line
interrupted).

At the level of the thickness 90 micrometers retained as minimum, the effect
is confirmed. The tube B according to the invention has a skirt resistant to
the depression, the tube C is insufficient in this respect. The tube A,
insufficient vis-a-vis losses of aroma and therefore located outside
the invention claimed in the present application, is satifaisant in
resistance to penetration.

4) Second easier and more complete way of distributing the product
content: collapsible shoulder tube (Figs 7 to 10)
The method of obtaining this tube consists of a blank
tubular longer than the skirt and to cut a portion by
forming this single portion heated above the temperature of
melting of its superficial layers, preferably between 140 and 220 ° C in the case of the polyethylene surface layers, by crushing then between tools this portion which is crumpled into folds, the folds being perfectly welded together on each face, the faces of the shoulder being typically obtained perfectly smooth.

Fig. 7 shows a tube having a shoulder formed at ambient, showing that double folds such as 31 and 32 correspond to inward or outward corrugations 32 which have been crushed.

In the hot forming mentioned above, the folds crush strongly including those of the barrier layer 20 included therein. One can get a shoulder 33 thinner than the skirt. FIG. 8 shows a tube 34 with a threaded neck according to the invention, obtained directly by this hot forming, the internal tooling and annular drawers of the external tooling forming between them the thread of the neck at the end of clamping. FIG. 9 represents a tube 36 of the same type obtained by hot forming and then capped with an outer annular ring 37 made of PE supplementing the neck of the tube. This ring 37 is perfectly welded to the outside and to the upper end of the tube. hot forming tube 36, it was set up by conformation with compression of a PE annular blank heated to 1600 C, it is thus a molding in a pasty state which is above the point of fusion. The establishment of an annular ring can also be obtained by injection molding or by ultrasonic welding. The tubes 34 and 36 each have a skirt of the type B, thickness 0.345 mm unmodified by the hot forming of the head, and their annular shoulder 38 has a thickness adjusted to the request between 0.3 and 0.4 mm . In the case of the tube 36 (Figure 9), the annular ring 37 occupies less than half the width of the annular shoulder 38, it can still collapse laterally enough to improve the expulsion of the product.

The section of the tube 36 containing the junction of its shoulder 38 with the annular ring 37 (FIG. 10) shows the effectiveness of the crushing and welding of the pleats in the necking head, as well as the perfect welding of the annular ring 37. a double fold 39 of barrier layer 20 shows an extremity 40 which has
escaped the superposition and the wrinkle crease, followed by two
folds strongly thinned 41;
a second portion 42 of barrier layer 20 belongs to a fold
welded with double fold which contains double layer fold 39
barrier 20;
- on the right of end 40 and double fold 39, is the
ring 37, in PE as the surface layers of the tube 36;
- the continuity of the welding between the folds, and between these folds forming
the shoulder and the ring crown, is perfect.The cut shows by
places the adhesive layers such as 21 but there is no
another discontinuity in the PE that envelops the elements described;
- the thinning obtained is incipient, it can be adjusted to the request
by choosing the hot forming temperature and by tightening
tools.

INDUSTRIAL APPLICATION
Flexible plastic skirt tubes providing improved preservation of the aroma or fragrance of the contained product, for example liquid, creamy or pasty. Tubes also allowing an easier and more complete distribution of the product. Especially in the cosmetics, pharmaceutical, hygienic, food, and cleaning products industries.

TABLE 1
Weighing of skirt samples after 4 weeks impregnation with flavored edging paste

<tb><SEP> Thickness <SEP> of <SEP><SEP> layers located <SEP> on <SEP><SEP> socket of
<tb> Tube <SEP> the <SEP> face <SEP> inner <SEP> of <SEP> the <SEP> layer <SEP> weight
<tb><SEP> EVOH <SEP> (mg / cm2)
<tb> A <SEP> (control) <SEP> 45 <SEP> m <SEP> 0.83
<tb> B <SEP> (Invention) <SEP> 100 <SEP> m <SEP> 0.12
<tb> c <SEP> (Invention) <SEP> 135 <SEP> m <SEP> 0.59
<Tb>
TABLE 2
Maximum reaction of tube skirts to depression in the press test (Fig.4)

<tb> Thickness <SEP> Thickness <SEP> Total Sp <SEP> Reaction
<tb> of <SEP> the <SEP> skirt <SEP> total <SEP> PE.HD <SEP> PE.HD <SEP> + <SEP> max.
<tb> Tube
<tb> (m) <SEP> (m) <SEP> Z <SEP> x <SEP> ep.EVOH <SEP> (N)
<tb><SEP> (m)
<tb> A <SEP> (control) <SEP> 290 <SEQ> 105 <SEQ> 145 <SEP> 6.6
<tb> B <SEP> (Invention) <SEP> 345 <SEP> 125165 <SEP> 8.7 <SEP>
<tb> C <SEP> (Invention) <SEP> 340 <SEP> 84 <SEP> 124 <SEP> 4.2
<Tb>

Claims (14)

 the scent of a product that is or may be contained.  between 55 and 135 micrometers, so as to better preserve the aroma of  Barrier effect (1.21; 100.13.11, 21) has a total thickness included  located on the inner side of said intermediate layer  continuous between them, characterized in that all layers  polyolefin base, all said layers being  one or more polymeric layers (1,100,13,11; and 12,14,10) to  moisture, as well as on each side of this intermediate layer  oxygen and aromas or perfumes, said layer being sensitive to  polymeric intermediate with barrier effect (20) vis-à-vis  flexible, this skirt essentially comprising a layer  dispensing head (38 and 35) attached to a multilayer skirt  flavored or scented example and containing water, comprising a  1. Tube (B, C, 34,36) for storing and dispensing a product, by 2. The tube of claim 1, wherein said total thickness  layers (1,21; 100,13,11,21) located on said inner face  of the intermediate layer is between 65 and 130 micrometers. Tube according to any one of claims 1 or 2, wherein  said polyolefin-based polymeric layers consist of  on the one hand in an inner layer of low polyethylene  (1) or very low density or linear low density (100), mass  between 0.86 and 0.93 g / cm3, and secondly in  other layers that are respectively low polyethylene  specific gravity (PE.BD) of between 0.90 and  0.93 g / cm3, or high density polyethylene (HDPE) mass  specific amount between 0.935 and 0.97 g / cm3 (13.14). 4. Tube (B, 34,36) according to claim 3, wherein said  polyethylene layers contain one or more layers of  PE.HD (13,14) with a total thickness of at least 90 micrometers. The tube of claim 4, wherein said sum of  thicknesses of PE.HD layers (13,14) is between 100 and  140 micrometers, the thickness of said skirt being between 260  and 380 micrometers. 6. Tube according to claim 4, wherein the sum of two times  the thickness of said barrier layer (20) and said thicknesses  layers of PE.HD (13,14) is between 130 and  180 micrometers, the thickness of said skirt being between 260  and 380 micrometers. Tube according to any one of claims 3 to 6, wherein  said polyethylene layers comprise a first layer  (13) PE.HD which is inserted between said surface layer  internal (100) and a first intermediate layer (11) made of PE.BD  itself located inside the intermediate effect layer  barrier (20). The tube of any one of claims 3 to 7, wherein  said polyethylene layers comprise a second layer  (14) of PE.HD which is inserted between an outer layer (10) of PE.BD  tet a second intermediate layer (12) PE.BD itself located  outside the barrier intermediate layer (20). The tube of any one of claims 7 or 8, wherein  said first layer (13) of PE.HD and / or said second layer of  PE.HD (14) is or is in continuous fusion with said layers  of PE.BD (100,11; 12,10) between which she (they) is (are)  inserted (s). 10. Tube (B, 34,36) according to claim 8 depending on the  claim 7, wherein the thicknesses of said first and  second layers (13, 14) of PE.HD are respectively between  10 and 50 micrometers and between 60 and 140 micrometers. 11. Tube (B, 34,36) according to claim 10, wherein said  first and second intermediate layers in PE.BD (11,13) are  each related to a face of said intermediate effect layer  barrier (20) by a tie layer (21,22) of EAA or EMA. Tube according to any one of claims 1 to 11, wherein  said barrier intermediate layer (20) of the skirt is in  one of the materials of the group constitutes by: EVOH, PVOH, PA, PA  modified, and has a thickness of between 0.01 and 0.05 mm. 13. Tube (34,36) according to any one of the preceding claims,  wherein said dispensing head (38 and 35) comprises a  neck (35) of smaller diameter than the skirt and a shoulder  ring (38) connecting the neck (35) to the skirt, this shoulder being  thickness between 0.9 times and 1.35 times the thickness of the  skirt and continuity of structure with said skirt and comprising  folds crushed and welded together, said shoulder (38) being  collapsible laterally. 14. Tube (36) according to claim 13, wherein the crushed folds and  welded together of said shoulder contain extensions  folded and crushed (39,41) of said intermediate effect layer  barrier (20) of the skirt.