US20050058498A1

US20050058498A1 - Cosmetic product dispenser made of barrier material

Info

Publication number: US20050058498A1
Application number: US10/497,180
Authority: US
Inventors: Paolo Botto; Erminio Pellegatta; Carmelo Mule
Original assignee: Benson Srl
Current assignee: Benson Srl
Priority date: 2001-11-29
Filing date: 2002-11-26
Publication date: 2005-03-17
Also published as: FR2832599B1; AU2002360969A1; EP1448075A1; FR2832599A1; WO2003045186A1

Abstract

A cosmetic product dispenser, typically mascara, includes at least a container forming a reservoir for the cosmetic product, and a cap for sealed closure of the reservoir, optionally provided with an applicator for the cosmetic product. All or part of the reservoir, and at least a side wall of the reservoir, are formed by at least a thermoplastic material moulded part. The thermoplastic material includes EVOH and a second thermoplastic material selected from PA, PET, PBT, and ionomer resin.

Description

DOMAIN OF THE INVENTION

The invention relates to the domain of packaging for cosmetic products, typically fluid to semi-solid or paste products, typically such as mascara or lipstick dispensers in the form of tubes, sticks or pencils.

STATE OF THE ART

Many mascara dispensers are already known. “Mascara” is a cosmetic product intended for makeup of eyelashes, and the packaging for this cosmetic product is called a “dispenser”.
For example European application No. 96 830631.6 describes a mascara dispenser.
A mascara dispenser typically comprises an applicator provided with a brush and a receptacle forming a reservoir and containing the mascara, the applicator being able to form a sealed cap for the receptacle.
As illustrated in this European patent application, the dispenser usually comprises a fairly large number of assembled parts.
These parts are usually made of a moulded plastic material, typically PVC, PP or PE.
Problems that Arise
A mascara dispenser must provide sufficiently long life for the mascara, and in particular it must at all costs prevent the mascara from drying, since it must remain sufficiently fluid throughout its life so that the final user can apply it correctly.
Mascara can dry out for two reasons: either because the dispenser is not leak tight, the junction between the cap and the reservoir not being sealed, or because the walls of the different parts of the dispenser are permeable to volatile constituents of the mascara that diffuse through these walls, and particularly through the reservoir walls.
One standard way of measuring the diffusion rate, and therefore evaluating the life of the mascara, is to measure the weight loss rate (WLR) of the mascara dispenser full of mascara. The life of the dispenser increases as the WLR becomes smaller.
Mascara dispenser manufacturers have already attempted to reduce the WLR by increasing the thickness of the dispenser walls, but this solution, although it may be effective for some mascara compositions, firstly increases material costs, and also reduces the contents of dispensers. Moreover, taking account of limitations with manufacturing processes, it is not always possible to obtain the wall thickness that would be necessary to obtain a sufficient barrier.
Moreover, mascara formulations tend to become increasingly complex and to include solvents or constituents with an increasingly wide variety of natures, some can be relatively volatile, so as to improve the final performance of the mascara. Therefore, formulation of mascaras requires increasingly good barrier properties by the dispenser or the material from which the dispenser is made.
Therefore, the applicant has attempted to find a means of making mascara dispensers so as to simultaneously solve all problems that arise, namely the problem of life mentioned above, the problem of high speed manufacturing of dispensers or dispenser parts, the problem of manufacturing parts with relatively small dimensions and acceptable mechanical characteristics, and the dispenser cost problem, and particularly to achieve the lowest possible material costs. Cosmetic packagings are articles that may be deluxe articles or general consumer articles, and consequently are controlled by simultaneous requirements for high quality and low production costs.

DESCRIPTION OF THE INVENTION

According to the invention, the cosmetic product dispenser, typically a mascara dispenser, comprises at least one receptacle forming a reservoir for the said cosmetic product, and a cap for sealed closure of the said reservoir, possibly provided with an applicator for the said cosmetic product, all or part of the said reservoir, and at least one side wall of the said reservoir being formed by at least one moulded thermoplastic part, and is characterised in that the said thermoplastic material comprises EVOH and a second thermoplastic material chosen from among PA, PET, PBT and ionomer resin.
EVOH is an ethylene vinyl alcohol copolymer, and may comprise a percentage of ethylene varying from 20 to 50% in mole % and, according to the invention, the said thermoplastic material may comprise an EVOH percentage varying from 10 to 50% by weight, and preferably an EVOH percentage varying from 20 to 40% by weight.
The applicant has observed that the means according to the invention can solve all problems that arise, namely increasing the life of the dispensers and/or reducing the thickness of the dispenser walls.
According to a first embodiment of the invention, the said thermoplastic material can form a layer of thermoplastic material composed of a mix of EVOH and the said second thermoplastic material.
According to this embodiment of the invention, the said thermoplastic material may comprise a percentage of EVOH varying from 10% to 50% by weight, and a percentage of the said second plastic material varying from 90% to 50% by weight.
Preferably, the said EVOH percentage can vary from 20% to 40% by weight, and the said percentage of the said second plastic material varies from 80% to 60% by weight.
In this embodiment of the invention, the said moulded part may be formed by known techniques widely used for the formation of parts, typically by extrusion-moulding or by injection-moulding, or again by extrusion-blowing or by injection-blowing in the case of concave or hollow parts.
According to a second embodiment of the invention, the said thermoplastic material can form a multilayer material with at least two layers of plastic material, and typically with two layers: an inner layer being composed of a mix of EVOH and the said second thermoplastic material, and an outer layer composed of the said second thermoplastic material.
According to one variant of the invention, in which the said multilayer material may include at least three layers of plastic material and typically three layers of thermoplastic material, a central layer is composed of a mix of EVOH and the said second thermoplastic material, and an inner layer and an outer layer on each side of the central layer, at least one of these layers being composed of the said second thermoplastic material, and one of the inner or outer layers being composed of a third thermoplastic material or by a second thermoplastic material different from the material used in the opposite layer.
At least one face or one side of the said layer composed of the said EVOH mix may be covered by a tie layer, so as to form a multilayer material typically comprising 3 to 5 layers, the said tie layer being chosen to make one of the other two different layers adhesive, in a manner known in itself.
According to another variant of this embodiment, the said thermoplastic material may form a multilayer material with three layers: one layer composed of the said mix of EVOH and the said second thermoplastic material, an adhesive tie layer and a layer typically composed of the said second thermoplastic material or by the said third thermoplastic material.
According to the invention, the said percentage of EVOH in the said mix can vary from 10% to 90% by weight, the said percentage of the said second plastic material in the said thermoplastic material varying from 80% to 60% by weight.
According to a third embodiment of the invention, the said multilayer material may be a material with at least five layers, three layers of thermoplastic material and two tie layers: one layer, typically the central layer, being composed of an EVOH layer, and an inner layer and an outer layer on each side of the said central layer, the inner layer and outer layer composed of the said second thermoplastic material and/or a third thermoplastic material, the said central layer and the said outer and inner layers comprising an adhesive tie layer between them.
The said third thermoplastic material referred to in the above may typically be chosen from among PE or PP.
In this embodiment of the invention, the said moulded part may be formed by co-extrusion of the said multilayer material, followed by moulding or blowing or co-injection.
Regardless of the embodiment of the invention, when the said second thermoplastic material is PA, the PA may preferably be chosen from among amorphous PAs, and totally or partially aromatic PAs.
According to the invention, at least the part(s) forming the reservoir, or the receptacle for the said cosmetic product, is (are) formed from part(s) moulded from the material containing EVOH and the said second thermoplastic material.
But the dispenser assembly, at least the part(s) made of a thermoplastic material forming the wall, may be composed of a material comprising EVOH and the said second thermoplastic material, the said reservoir and the said cap forming the said moulded parts.
According to a preferred but not exclusive embodiment of the invention, the said cosmetic product may be mascara. In this case, the said cap may include a brush as applicator of the said cosmetic product.
Another purpose of the invention consists of the use of a thermoplastic material comprising EVOH and a second thermoplastic material chosen from among PA, PET, PBT, or an ionomer resin to form all or part of a cosmetic product dispenser according to the invention, and more particularly to form a dispenser for typically fluid to semi-solid cosmetic products with a volatile constituent, typically mascara, nail varnish, lipstick, cosmetic products in cream, stick or pencil form, intended particularly for makeup of the face or nails.

EXAMPLE EMBODIMENTS

The body and the cap of mascara dispensers are made by injection moulding or injection blowing when the thermoplastic material consists of a single layer (so-called single layer material) or by co-extrusion blowing when the said thermoplastic material comprises more than one layer (so-called multilayer material).
I—Examples of Single Layer Thermoplastic Material:
these are mixes of EVOH and the said second thermoplastic material, namely PA+EVOH, PET+EVOH, PBT+EVOH, Ionomer resin+EVOH, the content of EVOH by weight varying from 10 to 50% by weight, the corresponding tests being indicated by crosses being shown in bold in the following table:

Second plastic material

% EVOH PA PET PBT Ionomer

10 X X X X

20 X X X X

30 X X X X

40 X X X X

50 X X X X

60 X X X X

70 X X X X

80 X X X X

90 X X X X

100 X X X X
It is observed that the mechanical properties of these mixes (symbolically denoted “EVOH MIX” or “EM” for short in the remainder of this presentation) reduce as the content of EVOH increases, while the barrier properties to volatile mascara products increase, such that in general a good compromise between mechanical properties and barrier properties was typically obtained for an EVOH content by weight equal to not more than 50% (tests shown in bold characters).
II—Examples of Multilayer Thermoplastic Material:
At least one layer of “EM” was used as defined above in the table. In some cases, and particularly when one or two SM layers of second plastic materials are used, it was found advantageous to use an EM layer containing the maximum possible proportion of EVOH, while keeping the weight content by EVOH more than 50%.
When adhesive tie layers are present, they are denoted TL.
The said second plastic materials (PA, PET, PBT, ionomer) were represented generically by SM. When other plastic materials were used, for example PE or PP, they were called “third plastic materials” and generically represented by TM.
In some cases, and particularly when one or two layers SM of second plastic materials are used, it was found advantageous to use an EM layer containing as much EVOH as possible, while maintaining sufficient bond between the SE and SM layers so as to avoid the need for tie layers TL. In other cases, the EM layer was replaced by a 100% EVOH layer.
The structure of a multilayer material has been represented in the following by the sequence of layers, each layer being separated from the next layer by a “/”.
II-A Structures with two layers: EM/SM, EM typically, but not necessarily, comprising the SM material forming the second layer, such that a tie layer TL is not necessary.
II-B Structures with three layers: these structures are of the EM/TL/TM type or the SM/EM/SM type or possibly the SM/EM/SM′ type, where SM′ denotes a second thermoplastic material different from SM.
II-C Structures with four layers: these structures are of the TM/TL/EM/SM type.
II-D Structures with five layers: these structures are of the TM/TL/EM/TL/TM type (where TM′ denotes a third thermoplastic material different from TM) or of the SM or TM/TL/EVOH/TL/SM or TM type, where TM, EVOH denote a 100% EVOH layer.
I-E Structure with six layers: this is a structure with five layers to which a layer of recycled plastic material denoted “R”, typically a recycling polyolefin, has been added, so as to reduce the final material cost. For example the structure TM/TL/EM/TL/R/TM.

Advantages of the Invention

After carrying these tests, particularly with EVOH and amorphous PA mixes, and EVOH mixes with ionomer resin (Surlyn®), the applicant observed that the life particularly of mascaras or nail care products or more generally any cosmetic composition comprising a volatile constituent, can be extended by reducing the weight loss ratio caused by diffusion of the most volatile constituents, typically organic solvents or hydrophobic hydrocarbonated compounds with low or zero polarity, and or the wall thickness can be reduced, without needing to significantly modify usual equipment or production rates, and also without significantly increasing the cost of manufactured products.

Claims

1. Cosmetic product dispenser, typically a mascara dispenser, comprising at least one receptacle forming a reservoir for the said cosmetic product, and a cap for sealed closure of the said reservoir, possibly provided with an applicator for the said cosmetic product, all or part of the said reservoir, and at least one side wall of the said reservoir being formed by at least one moulded thermoplastic part, characterised in that the said thermoplastic material is a mix comprising EVOH and a second thermoplastic material chosen from among PA, PET, PBT and ionomer resin, the EVOH content by weight in the said mix being not more than 50%.

2. Dispenser according to claim 1, in which the EVOH comprises a percentage of ethylene varying from 20 to 50% in mole %.

3. Dispenser according to claim 1, in which the said thermoplastic material comprises an EVOH percentage varying from 10 to 50% by weight.

4. Dispenser according to claim 1, in which the said thermoplastic material forms a layer of thermoplastic material composed of a mix of EVOH and the said second thermoplastic material.

5. Dispenser according to claim 4, in which the said thermoplastic material comprises a percentage of EVOH varying from 10% to 50% by weight, and a percentage of the said second plastic material varying from 90% to 50% by weight.

6. Dispenser according to claim 5, in which the said EVOH percentage varies from 20% to 40% by weight, and the said percentage of the said second plastic material varies from 80% to 60% by weight.

7. Dispenser according to claim 1, in which the said moulded part is formed typically by extrusion-moulding or by injection-moulding, or by extrusion-blowing of the said mix.

8. Dispenser according to claim 1, in which the said thermoplastic material forms a multilayer material with at least two layers of plastic material, and typically with two layers consisting of one layer, typically the inner layer, being composed of a mix of EVOH and the said second thermoplastic material, and one layer, typically the outer layer, typically composed of the said second thermoplastic material.

9. Dispenser according to claim 8, in which the said multilayer material includes at least three layers of plastic material and typically three layers of plastic material, consisting of a central layer composed of a mix of EVOH and the said second thermoplastic material, and an inner layer and an outer layer on each side of the central layer, at least one of these layers being composed of the said second thermoplastic material, and one of the inner or outer layers being composed of a third thermoplastic material.

10. Dispenser according to claim 8, in which the said layer composed of the said EVOH mix is covered by an adhesive tie layer on at least one face or one side, so as to form a multilayer material typically comprising 3 to 5 layers.

11. Dispenser according to claim 8, in which the said thermoplastic material forms a multilayer material with three layers: one layer composed of the said mix of EVOH and the said second thermoplastic material, an adhesive tie layer and a layer typically composed of the said second thermoplastic material or the said third thermoplastic material.

12. Dispenser according to claim 8, in which the said percentage of EVOH in the said mix varies from 10% to 90% by weight, the said percentage of the said second plastic material in the said thermoplastic material varying from 80% to 60% by weight.

13. Dispenser according to claim 8, in which the said multilayer material is a material with five layers, three layers of plastic material and two tie layers: one layer, typically the central layer, being composed of an EVOH layer, and an inner layer and an outer layer on each side of the said central layer, the inner and outer layers composed of the said second thermoplastic material and/or a third thermoplastic material, the said central layer and the said outer and inner layers comprising an adhesive tie layer between them.

14. Dispenser according to claim 9, in which the said third thermoplastic material is chosen from among PE or PP.

15. Dispenser according to claim 8, in which the moulded part is formed by co-extrusion of the said multilayer material, followed by moulding or blowing or co-injection.

16. Dispenser according to claim 1, in which the said second thermoplastic material is a PA preferably chosen from among amorphous PAs, and totally or partially aromatic PAs.

17. Dispenser according to claim 1, in which the reservoir and the said cap form the moulded parts.

18. Dispenser according to claim 1, in which the said cosmetic product is mascara, and in which the said cap includes a brush as applicator of the said cosmetic product.

19. The dispenser of claim 1, wherein a thermoplastic material comprising EVOH and a second thermoplastic material chosen from among PA, PET, PBT, or an ionomer resin are used to form all or part of a cosmetic product dispenser.

20. The dispenser of claim 19, further comprising a typically fluid to semi-solid cosmetic product with a volatile constituent, selected from the group consisting of mascara, nail varnish, lipstick, cosmetic products in cream, stick or pencil form, intended particularly for makeup of the face or nails.