Container for emanating volatile substances

Abstract

The invention relates to a container for emanating volatile substances, The container comprises a container body which has at least one opening and is closed by a lid film. The lid film comprises an outer multi-layer film having at least one barrier layer impermeable to the volatile substances, a coextruded inner multi-layer film having at least one layer permeable to the volatile substances. The coextruded inner multi-layer film is bonded on one side to the outer multi-layer film and on another side to the container. The coextruded inner multi-layer film consists of at least a polyethylene layer, a release layer comprising a polymer selected from the group consisting of EVOH and PETg, a peelable interface interposed between the release layer and a layer permeable to the volatile substances, whereby said permeable layer comprises a polymer selected from the group consisting of mVLDLLDPE, ethylene vinyl acetate copolymer, and ethylene n-butyl acrylate copolymer.

Claims

1. Container for emanating volatile substances, comprising a container body having at least one opening closed by a lid film, said lid film comprising an outer multi-layer film having at least one barrier layer impermeable to the volatile substances, a coextruded inner multi-layer film having at least one permeable layer that is permeable to the volatile substances, the coextruded inner multi-layer film being bonded on one side to the outer multi-layer film and on another side to the container, the coextruded inner multi-layer film consisting of at least a polyethylene layer, a release layer comprising a polymer selected from the group consisting of EVOH and PETg, a peelable interface interposed between the release layer and said permeable layer, whereby said permeable layer comprises a polymer selected from the group consisting of mVLDLLDPE, ethylene vinyl acetate copolymer, and ethylene n-butyl acrylate copolymer, said permeable layer being sealed to the container and providing an evaporation rate of the volatile substances of at least 30% of a maximal evaporation rate of said at least one opening of said container body not covered by said permeable layer.

2. Container according to claim 1, characterized in that the evaporation rate of the volatile substances is at least 40% of a maximal evaporation rate of said at least one opening of said container body not covered by said permeable layer.

3. Container according to claim 1, characterized in that the permeable layer comprises an outer layer made of a polymer blend of mVLDLLDPE, LDPE, and LLDPE, a core layer made of a polymer blend of mVLDLLDPE, and LDPE or LLDPE, and a sealing layer made of a polymer blend of mVLDLLDPE, LDPE, and LLDPE.

4. Container according to claim 3, characterized in that the polymer blend of the outer layer comprises 10-30 weight-% mVLDLLDPE, 60-80 weight-% LLDPE, and 10 weight-% LDPE, the polymer blend of the core layer comprises 30-65 weight-% mVLDLLDPE, and 35-70 weight-% LLDPE, and the polymer blend of the sealing layer comprises 10-30 weight-% mVLDLLDPE, 60-80 weight-% LLDPE, and 10 weight-% LDPE, whereby the total content of mVLDLLDPE in the permeable layer is in the range of 10-90 weight percent.

5. Container according to claim 1, characterized in that the permeable layer comprises an optional outer layer made of LDPE or LLDPE, a core layer made of a polymer blend of EVA, PE, and an optional sealing layer made of LDPE or LLDPE.

6. Container according to claim 5, characterized in that the core layer consists of a blend of EVA in the range of 10-90 weight-%, and the remainder PE.

7. Container according to claim 1, characterized in that the permeable layer comprises an optional outer layer made of LDPE or LLDPE, a core layer made of a polymer blend of EBA, PE, and an optional sealing layer made of LDPE or LLDPE.

8. Container according to claim 7, characterized in that the core layer consists of a blend of EBA in range of 10-90 weight-%, and the remainder PE.

9. Container according to claim 1, characterized in that the outer multi-layer film comprises a first PET layer, an aluminum layer as barrier layer to the volatile substances, and a second PET layer.

10. Container according to claim 1, characterized in that the outer multi-layer film comprises a PET layer and a transparent barrier layer to the volatile substances.

11. Container according to claim 10, characterized in that the outer multi-layer film comprises a PET layer and PET-SiO.sub.x layer as barrier layer to the volatile substances.

12. Container according to claim 10, characterized in that the outer multi-layer film comprises a PET layer and PET-AlO.sub.x layer as barrier layer to the volatile substances.

13. Container according to claim 1, characterized in that the outer multi-layer film comprises a metalized PET layer, as barrier layer to the volatile substances.

14. Container according to claim 1, characterized in that there is a small non-bonded region between the release layer and the permeable layer providing a grip tab for separating the lid film between these two layers.

Description

(1) The container according to the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the drawings and in which, purely schematically:

(2) FIG. 1 shows a cross-sectional view of a first embodiment of the lid film;

(3) FIG. 2 shows a cross-sectional view of a second embodiment of the lid film;

(4) FIG. 3 shows a cross-sectional view of a third embodiment of the lid film;

(5) FIG. 4 shows a cross-sectional view of a fourth embodiment of the lid film;

(6) FIG. 1 shows a cross-sectional view of a first embodiment of the lid film 10 according to the present invention. The lid film 10 comprises an outer multi-layer film 23 bonded to a coextruded inner multi-layer film 25. A permeable layer 27 which itself comprises in the embodiment shown three layers is a part of the coextruded inner multi-layer film 25. The layers of the lid film 10 comprise from the outside to the inside the following layers, a PET layer 1, a barrier layer 3 which consists of an aluminum foil, a second PET layer 5. These layers constitute the outer multi-layer film 23 of the lid film 10. The outer multi-layer film 23 is bonded by means of an adhesive layer 7 to the coextruded inner multi-layer film 25 which comprises in sequential order from outside to inside a polyethylene layer 9, an adhesive layer 11, a release layer 13, a peelable interface 15 and a permeable layer 27, whereby the peelable interface is interposed between the release layer 13 and the permeable layer 27. Said permeable layer 27 comprises itself three layers, an outer layer 17, bonded by the peelable interface 15 to the release layer 13, a core layer 19 and a sealing layer 21. The sealing layer 21 is sealed to a container (not shown) housing the volatile substances.

(7) FIG. 2 shows a cross-sectional view of a second embodiment of the lid film 10. The outer multi-layer film 23 is the same as shown in FIG. 1. In contrast to the embodiment shown in FIG. 1 the coextruded inner multi-layer film comprises a permeable layer 27 consisting of a single core layer 19 which is directly bonded via the peelable interface 15 to the release layer 13. The permeable layer 27 consisting of the single core layer 19 is sealed to the container (not shown) and thus faces a product space (not shown).

(8) FIG. 3 shows a cross-sectional view of a third embodiment of the lid film 10. In this embodiment, an alternative outer multi-layer film 23 is shown. The outer multi-layer film comprises a PET layer 1 and an SiO.sub.x coated PET 5 layer whereby the SiO.sub.x coating serves as a barrier layer 3.

(9) FIG. 4 shows a cross-sectional view of a fourth embodiment of the lid film 10. The alternative outer multi-layer 23 comprising a SiO.sub.x coating as a barrier layer 3 interposed between the outer PET layer 1 and the inner PET layer 5 is bonded by means of an adhesive layer 7 to a coextruded inner multi-layer film 25 which comprises a single layered permeable layer 27. Said permeable layer 27 consisting of the single core layer 19 is sealed to the container (not shown) and thus faces a product space (not shown).

(10) In the tables 1 and 2 below the results of evaporation experiments with two different volatile substances compositions Fragrance A and Fragrance B are shown. The values illustrate the weight loss over time in weight-%. Fragrance A is “Herbal Lavender” and fragrance B “Fruity Floral”. Both fragrances are artificial mixtures of different aromatic volatile substances. The main components of Fragrance A are Ethyl Linalool (also 3,7-dimethyl-6-nonadien-3-ol) CAS N. 10339-55-6, Lanvandin Grosso France Oil (also Lavandula Hybrida Oil) CAS N. 8022-15-9, Isocyclocitral (also 3-Cyclohexene-1-carboxaldehyde), CAS #1335-66-6, and Dimyrcetol (also 2,6-Dimethyloct-7-en-2-yl formate+2,6-dimethyloct-7-en-2-ol) CAS N. 18479-58-8/25279-09-8. The main components of Fragrance B are Agrumex HC [also 2-(1,1-dimethyl ethyl) cyclohexanol acetate] CAS N. 88-41-5, Frutonil (also 2-Methyldecanonitrile) CAS N. 69300-15-8, Benzyl Acetate CAS N. 140-11-4, Allyl Caproate (also Allyl Hexanoate) CAS N. 123-68-2

(11) The composition of the permeable layers A, B and C are as follows:

(12) TABLE-US-00001 outer layer EL Permeable EL % EL % EL % Thickness Layer mVLDLLDPE LLDPE LDPE (microns) A 30 60 10 15 B 10 80 10 15 C 30 60 10 10 core layer Core Permeable Core % Core Thickness Layer mVLDLLDPE %LLDPE (microns) A 65 35 70 B 65 35 55 C 65 35 50 sealing layer SL Permeable SL % SL % SL % Thickness Layer mVLDLLDPE LLDPE LDPE (microns) A 30 60 10 15 B 30 60 10 30 C 30 60 10 10 total Caliper mVLDLLDPE Permeable Layer [microns] content [%] A 100 54.5 B 100 46.3 C 70 55.0

(13) TABLE-US-00002 TABLE 1 Weight Loss in % (Fragrance A) Time 0 days 3 days 7 days 14 days reference 0 3.4 6.8 11.8 membrane permeable 0 6.6 18.6 32.0 layer A permeable 0 2.8 14.0 23.8 layer B permeable 0 10.4 22.4 39.2 layer C No layer 0 21.2 46.2 68.6

(14) TABLE-US-00003 TABLE 2 Weight Loss in % (Fragrance B) Time 0 days 3 days 7 days 14 days reference 0 7.2 16.6 28.6 membrane permeable 0 18.0 42.2 65.6 layer A permeable 0 15.6 35.2 57.4 layer B permeable 0 22.0 46.4 71.2 layer C No layer 0 23.4 51.8 74.2

(15) The reference membranes are membranes that have been obtained from commercially available air freshener cartridges and these reference membranes have a thickness of approximately 100 microns.