AT394520B - COMPRESSIBLE PASTE DISPENSER CONTAINER - Google Patents

Description

AT 394 520 B

The present invention relates to a compressible paste dispenser container made of a multilayer material, product permeation and absorption and oxygen absorption being substantially suppressed in all areas of the container which are susceptible to this.

Compressible tubes made of metal or plastic have long been known in the packaging sector. Tubes made of extruded metal are brittle, and prolonged use often leads to wall breaks, so that the goods emerge from a location other than the essentially rigid dispenser opening. Of the known metal tubes, aluminum tubes, which are probably the least brittle, are limited in their area of application, since until now it has not been possible to apply a really satisfactory coating to their inner surfaces if it was necessary to attack and corrode the metal by alkaline or to prevent acidic ingredients and contamination of the content by the reaction products. In addition to the relatively fragile nature of a metal tube, the inner coating mentioned requires an additional manufacturing step, which necessarily increases the price of the finished article.

Tubes made of polyethylene and other plastics are used to package many materials; it has been observed that certain goods spoil after some time in such packaging. Plastics, such as polyethylene, are somewhat permeable when used in the wall thicknesses used for tubular containers. The essential oils contained in most flavoring toothpastes decrease in volume during storage of the container, making the toothpaste less palatable. Furthermore, the wall of the plastic container absorbs oxygen over time and eventually the product decomposes, which has indeed been observed with fluoride toothpastes. Another disadvantage of the plastic tube is that its surface is not able to accommodate printing or decorative material without further. Furthermore, plastic tubes, such as those made of polyethylene, have a memory effect; d. that is, they do not remain compressed after squeezing, which is particularly disadvantageous for toothpaste tubes.

Accordingly, in order to counter the above-mentioned problems, it has been proposed to provide a metal foil barrier layer between the goods and the polyethylene tube body. The compressibility problem is countered by the fact that the metal layer transfers its compressibility to the plastic. Furthermore, the metal foil barrier layer between the goods and the polyethylene tube body prevents the aforementioned loss of essential oils and the absorption of oxygen. The metal barrier layer has been proposed as an intermediate layer between adjacent polyethylene sheets, and a laminate is to be formed by heat with or without suitable adhesives. While a structure of this general type has the effect of preventing product permeation and oxygen absorption through the tube body to some extent, this is especially true when the inner thermoplastic layer is a copolymer of ethylene and a polar group-containing monomer which copolymerizes with the former -bar is. Nevertheless, the possibility of decomposing the goods remains, albeit to a much lesser extent.

From CA-PS 728 525 a laminated tube is known which contains an inner layer made of polyethylene. The problem of the absorption of flavor oil by the thermoplastic wall is discussed and the use of nylon to overcome it is proposed.

US Pat. No. 4,139,665 describes a laminate which contains no metal. In this laminate, polypropylene is used, inter alia, as an inner layer in order to act as a barrier layer against moisture and water vapor. A thermoplastic acrylonitrile copolymer serves as a flavor barrier. This laminate is different from the present invention in that it contains no metal foil. Furthermore, US Pat. No. 4,139,665 contains no indication of the effectiveness of polypropylene as a flavor barrier layer.

US Pat. No. 3,958,721 describes a compressible laminated tube which also contains no metal layer. Although this tube contains polypropylene, there is no indication that the low odor permeability and the high resistance to oil are guaranteed by the polypropylene film.

In none of the above references is polypropylene described as the inner layer of compressible laminated tubes containing metal foils. In the cases where polyolefins are mentioned, no indication of the high resistance to absorption of essential flavor oils is given. In fact, the problem with polyethylene is its high flavor absorption.

The following shows that, surprisingly, polypropylene, a chemical closely related to polyethylene, is essentially non-absorbent to flavor oils.

It is an important object of the present invention to provide a compressible dispenser container whose body has a laminated wall structure. Accordingly, the paste dispenser container according to the invention is characterized by at least one layer of a metal foil, at least one layer of paper and at least one layer of polypropylene, at least one of the polypropylene layers being adjacent to the pasta within the container.

The tubular container according to the invention thus has a multiplicity of layers adhering to one another, the metal foil being a barrier against product migration and oxygen absorption and a further of these layers consisting of polypropylene. The last layer forms the inner layer and preferably the outer layer, various further laminate layers being arranged between them.

These further layers include paper and suitable adhesives and binders, e.g. B. a copolymer of -2-

AT394 520 B

Ethylene and acrylic acid.

The compressible dispenser according to the invention can be produced from the corresponding laminate film using conventional and known apparatus. Examples of such an apparatus and method can be found in U.S. Patent 3,832,964.

For the production of laminated tubes according to the invention, a tube body is formed from a barrier layer and a polypropylene or copolymer of the same laminated thereon; the laminated tube body is then brought together on a molded part with a barrier part also located thereon.

The invention is explained in more detail below with reference to figures, in which the same numerals always mean the same parts; show it:

1 shows a cross section of part of a container according to the invention along the line (I-I) in Fig. 2. and FIG. 2 shows a side view of the compressible dispenser container according to the invention, parts of the container wall being removed in order to make the laminate structure visible.

The paste dispenser container (10) consists of an innermost layer (11) made of polypropylene. The second layer (12) above is an adhesive layer that connects the polypropylene layer (11) to the third layer (13), which is a metal foil, such as an aluminum foil. The fourth layer (14) is a further adhesive which adhesively attaches the other surface of the metal foil layer (13) to a paper layer (15). The outermost layer (16) consists of polypropylene.

The polypropylene is particularly suitable because it shows very poor taste absorption properties, as can be seen from the following tables, in which polypropylene is compared with polyethylene, the thicknesses of the layers or coatings being the same.

Table i

Absorption of undiluted flavor oil by polymers

Absorbtion (Ψο) Polypropylene Tenite 4230G (Eastman) 1.3 Polypropylene F120F (United States Steel) 1.6 Polypropylene FP200F (United States Steel) 2.3 Polypropylene Vestrolen P3200 (Hids Plastic) 2.3 Low Density Polyethylene Tenite 154 (Eastman ) 5.5 low density polyethylene Lupolen 1804H (BASF) 5.6 ± 0.14

Tables

Loss of flavoring from flavored toothpaste to polymers

Flavor loss *

Polypropylene Tenite 4230G (Eastman) 31 polypropylene F120F (United States Steel) 38 -3-

AT 394 520 B

Table II (continued)

Loss of flavoring from flavored toothpaste to polymers

Flavor loss *

Polypropylene F200F (United States Steel) 38 low density polyethylene Lupolen 1804H (BASF) 100 low density polyethylene Tenite 154 (Eastman) 130 * Based on BASF low density polyethylene, which was arbitrarily set to 100; the smaller the number, the less flavoring is lost from the toothpaste.

TU table

Relative flavor absorption by polymers from flavored toothpaste * 22 ° C 32 ° C 49 ° C aluminum 0 0 0 polypropylene FP200F (United States Steel) 34 51 55 polypropylene F120 (United States Steel) 55 68 73 low density polyethylene 6560 (ARCO) 76 76 83 low density polyethylene NPE853 (Norchem) 69 76 104 low density polyethylene Lupolen 1804H (BASF) 100 ± 19 107 ± 14 119 ± 10 * All numbers refer to BASF low density polyethylene, which was set to 100 at 22 ° C; the smaller the number, the less flavoring agent has been absorbed.

According to the invention, the adhesive can be a copolymer of ethylene and acrylic acid or methacrylic acid or their sodium or zinc salts in a diluent system.

The metal foil is preferably aluminum foil.

The paper layer is preferably wrapping paper.

The respective thickness of the layers is in the range from: 12.7 pm to 76.2 pm, preferably 25.4 pm, for the polypropylene layer (11), sufficient thickness to ensure adhesion, for the adhesive layer (12), 12.7 pm to 50 , 8 pm preferably 25.4 pm, for the metal foil layer (13), sufficient thickness to ensure adhesion, for the adhesive layer (14), 38.1 pm to 63.5 pm, preferably 50.8 pm, for the paper layer (15) and -4-

Claims (5)

AT 394 520 B 88.9 μm to 127.0 μm, preferably 101.6 μm, for the polypropylene layer (16). The outermost polypropylene layer (16) adheres to the paper layer (15) by applying enough heat and pressure to the laminate. If the application of heat and pressure is not appropriate, a suitable adhesive is used. The compressible container according to the invention overcomes the disadvantages mentioned in the prior art. The laminated container body and a barrier shoulder piece completely prevent product permeation and oxygen absorption. The outer layer made of polypropylene is thermoplastic and weldable at the side seam formation level and offers adequate protection for the paper and metal foil intermediate layer. Seam formation in a compressible toothpaste tube of the general type described herein is described in U.S. Patent 3,295,725. The outer layer of polypropylene and paper can be omitted if the barrier film is of sufficient thickness to withstand damage; in this case, a thermoplastic material is introduced into the overlapping seam area when the same is welded. Furthermore, in the case of a three-layer laminate made of paper, metal foil and a polypropylene, as described, the outer layer can be made of paper. Since the outermost and innermost layers are preferably the same, the folded edges of the tubes produced are conveniently heat sealed. A suitable adhesive can be used if heat welding is not possible. This modification comes in addition to the four-day laminates mentioned above, from the outside in, polypropylene, paper, metal foil and polypropylene. Suitable adhesives are used between the laminate layers, if necessary. Polypropylene can also be used for the shoulder piece, the cap, the neck, the piston and the structure of the dispenser valves or for other toothpaste dispensers, in particular in connection with the inner parts that are used in the Contained toothpaste are exposed, and here too, of course, if necessary, suitable adhesives can be used. PATENT CLAIMS 1. Compressible paste dispenser container made of a multilayer laminate, characterized by at least one layer made of a metal foil, at least one layer made of paper and at least one layer made of polypropylene, wherein at least one of the polypropylene layers is adjacent to the pasta within the container. 2. paste dispenser container according to claim 1, characterized by an outer fourth layer (16) made of a polypropylene. 3. Container according to claim 1 or 2, characterized in that the innermost layer (11) made of polypropylene is attached to the metal foil (13) with an adhesive (12). 4. Container according to claim 2 or according to claims 2 and 3, characterized in that the third layer (15) of paper is attached to the outermost layer (16) made of polypropylene with an adhesive. 5. Container according to one of claims 2 to 4, characterized in that the adhesive is a copolymer of ethylene and acrylic acid. For this 1 sheet drawing -5-