HK1061405B - Plastic films containing a fragrance and an odor barrier material within and a method for their production - Google Patents

Description

FIELD OF THE INVENTION

The present invention generally relates to plastic films containing a fragrance within the plastic material, and additionally containing a chemical composition which makes the plastic material impermeable to odors. The plastic films disclosed in the present invention are useful for masking unpleasant odors such as those emitted from waste products, for example from diapers destined for disposal or from household garbage. The films according to the present invention may also be useful for packaging any other item in order to enhance its presentation or appearance by adding a pleasant fragrance, such as cosmetic items.

BACKGROUND OF THE INVENTION

Used disposable diapers tend to emit an unpleasant smell, as does household garbage. Most household garbage pails, or diaper pails, are not of a sophisticated nature, and so, when they are opened to add additional waste to them, the unpleasant odor of their contents is emitted.

The need exists, therefore, for a plastic bag that masks unpleasant odors, such as those emitted by dirty disposable diapers or household garbage. A garbage bag is known in the art that contains a fragrance, but the fragrance is sprayed on the bag externally at the end of the production process, thus the fragrance has an extremely short shelf-life, and so has limited success in masking odors once it reaches the consumer.

It is the object of the present invention to provide a plastic film that contains a fragrance incorporated within which is released slowly over a long period of time, and has a long shelf-life. The film is impermeable to liquids, and the fragrance will mask unpleasant odors of items wrapped in the film. The film additionally contains a chemical composition which makes the plastic material impermeable to odors, an "odor barrier". The film may be formed into a bag useful in waste disposal, or may be used in packaging of any product for which a pleasant fragrance would enhance its presentation or appearance.

It is also the object of the present invention to provide a method for producing a polyethylene or a polypropylene film having a fragrance and an odor barrier material, incorporated within.

Relevant prior art includes WO 98/30621 to Campagnoli, GB 2194791 to Van Breen et al and US Pat No 5496865 to Heese et al. which is summarized herein below.

GB 1538085 teaches a method for producing odorant-polyolefin compositions and articles. The method includes adding a scented composition to a carrier material which is then blended with a polyolefin. There is no requirement that a waxy substance such as bis-amide be present to retard escape of highly volatile scented materials. The reference does not teach or even suggest adding such a chemical composition thereby to produce an impermeable plastic barrier which would form a second line of defense against odors.

WO 98/30621 teaches a method for making scented plastic materials incorporating a fragrance carried on a vinyl acetate containing carrier material. The reference does not teach or even suggest adding a chemical composition which would produce an impermeable plastic barrier which would form a second line of defense against odors.

US 5,496,865 discusses the production of additive charged porous carrier materials generally for use in master batches. In order to make the additive charged porous materials, the basic polymer which may be an olefin requires the use of a foaming agent to form or increase the pores of the basic polymer in which the additives attach themselves by physical or chemical means. Even though a wide range of additives is mentioned in a perfunctory listing of as many additives as possible, including fatty acid diamides, nowhere is there taught or suggested a motivation to use a specific chemical composition or additive to make a plastic substantially impermeable to odors thereby functioning as an odor barrier in packaging or odor masking wrappings. Additionally, no specific combination of a fragrance plus a plastic film substantially impermeable to odors is taught or even suggested.

SUMMARY OF THE INVENTION

As discussed above, the present invention provides a plastic film that contains a fragrance incorporated within, which is released slowly over a long period of time, and has a long shelf-life. The film is impermeable to liquids, and the fragrance masks unpleasant odors of items wrapped in the film. The film additionally contains a chemical composition which makes the plastic material impermeable to odors, that is it functions as an "odor barrier". The film may be formed into a bag useful in waste disposal, or may be used in packaging a product for which a pleasant fragrance would enhance its presentation.

There is provided in accordance with yet another aspect of the present invention, a method for producing a polyethylene or polypropylene film having a fragrance and an odor barrier material incorporated into the film, comprising the steps of adding a liquid fragrance to highly porous pellets of polyethylene or polypropylene polymer or co-polymer at a weight ratio of polymer to fragrance of 3:1 and mixing the combination at 30-40 RPM for approximately five to ten minutes. Then, powdered bis fatty-acid amide is added to the above, at a weight ratio of 3-25%, and further mixing is carried out for an additional five minutes. Polyethylene or polypropylene polymer or co-polymer of approximate particle size of 500µ is added to the mixture at a ratio of 1:1 by weight, the composition is mixed for two minutes at 60 RPM, and extruded on a single screw extruder. The mixture is formed into pellets, which are mixed with polyethylene or polypropylene polymer or co-polymer at a ratio of 50:1 to 20:1 of polymer to above composition. A film is formed.

Further in accordance with one preferred embodiment the powdered bis fatty-acid amide is the product of a diamine and a monocarboxylic acid, the acid being selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxy-stearic acid, arachidic acid, behenic acid, oleic acid or eruca acid. Such bis fatty amides are known per se.

Moreover in accordance with one preferred embodiment the powdered bis fatty-acid amide is present at a ratio of 3-25% by weight.

Still further in accordance with one preferred embodiment the fragrance incorporated within the film is of any source, including a natural or artificial fragrance.

The present invention also relates to a plastic film produced according to the above-mentioned method, for either packaging or for masking unpleasant odors, having a fragrance trapped in the film. The plastic film is made from a polyethylene or polypropylene polymer or co-polymer, and from bis fatty-acid amide, which acts as an odor barrier.

In accordance with one preferred embodiment, the plastic film is formed into a bag useful for packaging or for masking unpleasant odors.

Additionally in accordance with one preferred embodiment, the polyethylene or polypropylene polymer, or co-polymers thereof, in the film is in pellet form.

Additionally in accordance with one preferred embodiment the fragrance incorporated within the film is a combination of more than one fragrance.

Furthermore, in accordance with one preferred embodiment the fragrance incorporated within the bag has the smell of talcum powder.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present invention, a fragrant film can be produced using either polyethylene or polypropylene. A highly porous polymer or co-polymer in pellet form is used, having a void volume of 30-80% and a bulk density of 350 kg/m³. The polymer is mixed in a Henschel-type mixer with a liquid fragrance at a weight ratio of polymer to fragrance of 3:1. Mixing is carried out at 30-40 RPM for five to ten minutes, at 20-25°C (room temperature). Fragrance is absorbed in the porous polymer by capillary force. Fragrance used emitted the smell of talcum powder.

Powdered bis fatty-acid amide is then added at a ratio of 3-25% by weight to the above composition, and mixed for an additional five minutes. The waxy nature of the bis fatty-acid amide prevents premature evaporation of the fragrance during processing and prolongs the shelf-life of the fragrance in the end product to be at least six months. The bis fatty-acid amide also acts as an odor barrier, preventing the escape of foul odor of the waste material to be stored inside the film. The powdered bis fatty-acid amide is based on one of the following: lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxy-stearic acid, arachidic acid, behenic acid, oleic acid or eruca acid. Polymer with an approximate particle of 500µ is then added at a ratio of 1:1 with the above mixture. The entire composition is mixed for an additional two minutes at 60 RPM, then extruded on a single-screw extruder and formed into pellets. The product is then referred to as a "master batch" which can be used to produce polyethylene or polypropylene films, to be applied for use as, for example, a fragrant plastic bag used for masking unpleasant odors. The ratio of polyethylene or polypropylene to "master batch" is between 50:1 to 20:1.

Claims (18)

1. A film for packaging a product or for masking unpleasant odors, including:

   a plastic material;

   a chemical composition which makes said plastic material impermeable to odors; and

   a fragrance for masking odors.
2. A plastic film according to claim 1 wherein said plastic material is chosen from a group consisting of polyethylene, polypropylene and co-polymers thereof.
3. A plastic film according to claim 1, wherein said chemical composition which makes said plastic material impermeable to odors is a waxy composition.
4. A plastic film according to claim 3, wherein said chemical composition which makes said plastic material substantially impermeable to odors is a bis fatty-acid amide.
5. A plastic film according to claim 4, wherein said bis fatty acid-amide is the product of a diamine and a monocarboxylic acid, said acid being selected from a group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxy-stearic acid, arachidic acid, and behenic acid.
6. A plastic film according to claim 5, wherein said bis fatty-acid amide is a bis fatty-acid amide of behenic acid.
7. A plastic film according to claim 4, wherein said bis fatty-acid amide is present in the ratio of 3 to 25% by weight.
8. A bag made from a film, said film comprised as in claim 1.
9. A packaging material made from a film, said film comprised as in claim 1.
10. A method for producing a polyethylene or polypropylene plastic film having a fragrance and an odor barrier material incorporated into said film, comprising the steps:

    a) adding a liquid fragrance to highly porous pellets of polyethylene or polypropylene polymer or co-polymer at a weight ratio of polymer to fragrance of 3:1;

    b) blending said mixture at 30-40 RPM for approximately five to ten minutes;

    c) adding powdered bis fatty-acid amide at a weight ratio of 3-25%, to the above mixture;

    d) blending the mixture for an additional five minutes;

    e) adding polyethylene or polypropylene polymer or co-polymer, of approximate particle size of 500µ at a ratio of 1:1 by weight, to the above composition;

    f) blending the mixture for two minutes at 60 RPM;

    g) extruding the resultant composition on a single screw extruder;

    h) forming the composition into pellets;

    i) mixing said pellets with polyethylene or polypropylene polymer or co-polymer at a w/w ratio of 50:1 to 20:1 of polymer to above composition;

    j) forming a film from said pellets.
11. A method according to claim 10, wherein the powdered bis fatty-acid amide is the product of a diamine and a monocarboxylic acid, the acid being selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxy-stearic acid, arachidic acid, and behenic acid.
12. A method according to claim 10, wherein the powdered bis fatty-acid amide is present at a ratio of 3-25% by weight.
13. A method according to claim 10, wherein the fragrance incorporated within said film is of any source, including a natural or artificial fragrance.
14. A plastic film produced according to the method as defined in claim 10 for packaging or for masking unpleasant odors, comprising:

    polyethylene or polypropylene;

    a bis fatty-acid amide; and

    a fragrance,

    wherein said bis fatty-acid amide acts as an odor barrier.
15. A plastic bag, for either packaging or for masking unpleasant odors, comprising a polyethylene or polypropylene plastic film as defined in claim 14.
16. A plastic film according to claim 14, wherein the polyethylene or polypropylene or co-polymer, thereof from which the film is formed, is in pellet form.
17. A plastic film according to claim 14, wherein the fragrance incorporated within said film is a combination of more than one fragrance.
18. A plastic film according to claim 14 , wherein the fragrance incorporated within said film has the smell of talcum powder.