JPS61158439A - Substrate containing polypropylene and article manufacture from said substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application: The present invention relates generally to container technology, and more particularly to a collapsible dispensing container having a laminated wall construction in the body portion, thereby , product permeation and absorption and oxygen absorption are substantially prevented in all areas of the container structure.

Prior Art: Collapsible tubes made of metallic and plastic materials have long been known in the packaging field. Extruded metal tubes are inherently brittle and repeated use very often results in wall cracking and product oozing from locations other than the inherently rigid dispensing zero. Although aluminum tubes are perhaps the least brittle of conventional metal tubes, their application is somewhat limited because, to date, they are susceptible to corrosion and corrosion of alkaline and pickling contents. Given the need to prevent corrosion and contamination of the contents by reaction products, it has not been possible to apply completely satisfactory coatings onto the internal surfaces.

Despite the relatively common nature of metal tubes, the internal coating methods described above require additional processing steps, which necessarily increases the cost of the final article.

Tubes formed from polyethylene and other plastic materials have had wide commercial success in the packaging of many products, but some other products deteriorate after some time while being contained within them. has been heard. Plastics, exemplified by polyethylene, are somewhat permeable when used with the wall thicknesses used in tubular containers, and essential oils, which are included in most dentifrices for flavoring purposes, can be used during storage within the container. volume and make the dentifrice taste unpalatable.

It has also been discovered that the plastic container walls absorb oxygen over a long period of time, eventually causing the product to degrade, and that this actually occurs in the case of fluoride-containing toothpastes. Yet another disadvantage of plastic tubes is that their surfaces cannot readily accept printing and decorative materials. Additionally, plastic tubes, as exemplified by polyethylene, have a memory effect, ie, do not remain compressed when deflated, a particular drawback for dentifrice tubes.

To overcome the above problems, it has been proposed to provide a metal foil barrier between the product and the polyethylene tube body. This solves the compressibility problem in that the metal layer imparts its compressibility to the plastic. Additionally, a metal foil barrier between the product and the polyethylene tube body prevents the above loss of essential oil and oxygen absorption.

This metal barrier was proposed as an interlayer between polyethylene facing sheets, and the laminate was formed thermally with or without a suitable adhesive. However, while a structure of this general property is effective in preventing some product permeation and oxygen absorption through the tube body, it is important to note that the inner thermoplastic layer contains ethylene and polar groups that can copolymerize with it. Particularly when co-mers with monomers, the potential for product deterioration remains, albeit much smaller.

The following prior art methods are noted here: Marchak (Canadian Patent A728.525) discloses a laminated tube comprising an inner layer of polyethylene. He recognized the problem of perfume oil absorption by thermoplastic walls and advocated the use of nylon to overcome this.

Herero (US Pat. No. 4,139,655) discloses metal-free laminates. This laminate is designed to act as a barrier against moisture and water vapor, among other things.
Polypropylene is used as the inner layer. Thermoplastic acrylonitrile copolymers serve as flavor barrier materials. This laminate differs from the present invention in that it does not contain metal foil. Furthermore, Herrero failed to recognize the effectiveness of polypropylene as a flavor barrier.

Yoshio et al. (U.S. Pat. No. 3,958,721) teaches a collapsible laminated tube, which also does not include metal sheets. Although the tube contains polypropylene, they note that the p+) vinyl alcohol film provides low permeability to odors and high resistance to oil.

None of the above documents specify polypropylene as the inner layer of the collapsible laminate tube containing metal foil. In those cases where polyolefins are mentioned, no indication is made of a high resistance to absorption of flavoring essential oils. In fact, a problem with polyethylene is its high flavor absorption.

Surprisingly, it has now been shown that polypropylene, a chemical closely related to polyethylene, is virtually non-absorbent to perfume oils. The tube includes 41J propylene as the innermost and outermost layers, paper, aluminum foil, and adhesive as middle layers.

Problem to be Solved by the Invention: Therefore, an important object of the present invention is to provide a collapsible dispensing container with a laminated wall construction in the body portion.

Another object of the present invention is to provide a tubular container having a plurality of adhesive layers in the container body,
One of the layers provides a barrier to product migration and oxygen absorption, such as a metal foil, and another of the layers is polypropylene or a copolymer or mixture thereof varying in density and crystallinity. The latter layer is the innermost layer and preferably the outermost layer between which different additional layers are sandwiched.

Such additional layers consist of paper and suitable adhesives and binders, such as copolymers of ethylene and acrylic acid.

The collapsible dispensing containers of the present invention can be assembled from the laminated substrates of the present invention by conventional known equipment. A device and method of this type is known from US Pat. No. 3,832,964, which is incorporated herein by reference.

Another object of the present invention is to provide a method for manufacturing a laminated tube, in which the tubular body is formed of a barrier layer and a polypropylene or copolymer thereof laminated thereto, the laminated tube body then being molded. Parts for (fo
rmingmember) and adjacent to the blocking member still placed above it.

Other objects and advantages of the invention will become more apparent as the description progresses.

Alternative ways to solve the problem: The thermoplastic resin of the present invention is polypropylene.

Referring now first to FIG. 1, a substrate 10 is shown in cross-section, thereby illustrating the components of the sandwich that will build up the laminate structure.

It can be seen that the innermost layer 11 is polypropylene.

A second layer 12 thereon is an adhesive layer that joins the polypropylene layer 11 with a third layer 13 which is a metal foil such as aluminum foil. Fourth layer 14 is another adhesive that adhesively fixes the other side of metal foil layer 13 to paper layer 15. The outermost layer 16 is polypropylene.

Polypropylene is particularly useful because it has extremely low flavor absorption properties as seen in the following table, where polypropylene is compared to polyethylene with the same layer or coating thickness.

Table 1 Pure fragrance oil absorption of Holimer Absorption (%) Polypropylene, Tenite 4230G (Easman) 1,3 Polypropylene, F'120F' (United State Steel) 1.6 Polypropylene, F'P2O0F' (United State Steel)
2.3 Polypropylene, Vestrolene P3200 (Hüls Plastics) 2.3 Low density polyethylene, Tenite 154 (Eastman) 5.5 Low density polyethylene, Lupolene 1804H (BASF'
) 5.6±0.
Table 14 ■ Polypropylene, Tenite 4230G (Eastman) 31 Polypropylene, F'120F (United State Steel) 38 Polypropylene, F200F' (United State Steel) 38 Low density polyethylene, Lupolene 1804H (BASF)
100 low density polyethylene, Tenite 154 (Eastman) 13
゜※BASF's low density polyethylene optionally 10
Relative value set to 0.

The lower the number, the less flavor is lost from the dentifrice.

Table ■ Aluminum 0
0 0 Polypropylene, F'P2O0F (Unite State Steel) 3
4 51 55 Polypropylene, E”12
0 (United States Steel) 5
5 68 73 Low density polyethylene, 6560 (Arco) 76
76 83 Low density polyethylene, NPE853 (Norchem) 69
76 104 Low density polyethylene, Lupolene 1
804H (BASF) 10 discharges 1
9107±14119-1-10* All numbers are 7
Relative to BASF low density polyethylene set at 100 at 2 below. The lower the number, the less flavoring will be absorbed.

It is envisaged that the adhesive within the scope of the present invention will be a copolymer of ethylene and acrylic acid or methacrylic acid or their sodium or zinc salts in a diluted system.

The metal foil may preferably be an aluminum foil.

The paper layer is preferably kraft paper.

The thickness range of each layer is as follows: Polypropylene layer 11 - 0.5 mil to 3.0 mil, preferably 1
．． 0 mil; adhesive layer 12 - sufficient thickness to ensure adhesion; metal foil layer x
3-o, s mill to 2. O mil, preferably 2.0 mil; adhesive layer 14-sufficient thickness to ensure adhesion; paper layer 15-
1.5 mils to 2.5 mils, preferably 2.0 mils; polypropylene layer 16-3.5 mils to 50 mils, preferably 40 mils.

The top polypropylene layer 16 adheres to the paper layer 15 by applying sufficient heat and pressure to the substrate.

A suitable adhesive should be used if the application of heat and pressure is not appropriate. FIG. 2 is an example of a layered structure for a collapsible container, the layers being shown the same as in FIG. 1, with layer 11 being the innermost layer and the other layers being of the same material as shown. They are in the same order.

From the foregoing, it is believed to be clear that the present invention provides a collapsible container structure that substantially alleviates problems heretofore unsolved in the art industry. The laminated substrate and barrier shoulders substantially eliminate product permeation and oxygen absorption.

The outermost layer of polypropylene is a thermoplastic resin that is meltable during the side stitching step and provides adequate protection to the intermediate layers of paper and metal foil. A collapsible tube suturing technique of the general type disclosed herein can be found in US Pat. No. 3,295,725, which is incorporated herein by reference. However, the outer layer of polypropylene and paper can be used in the side seams of the overlap if the foil barrier is of sufficient thickness to resist damage and when using such a system. This can be avoided by pouring thermoplastic resin into the umbilical seal.

Additionally, the outer layer may be paper, foil and paper in a three-ply laminate formed of polypropylene and copolymers thereof as described. Since the outermost and innermost layers are preferably the same, the folded edges of tubes made from this substrate are conveniently thermally bonded. Any suitable adhesive can be used when heat bonding is not possible. This modification is an addition to the four-ply laminate, which consists of polypropylene, paper, foil and polypropylene from the outside in. It is anticipated that a suitable adhesive will be used between the layers whenever necessary.

Polypropylene may also be used in shoulder pieces, caps, necks, pistons, and other dentifrice dispensing dispensing valve assemblies, particularly in connection with the internal portions that dispense the dentifrice content. , and here again, of course, a compatible adhesive can be used when necessary.

Additionally, when cast as a film onto the internal surface of a fiber drum used for storing flavored dentifrice, this material slows the loss of flavor into the drum, thereby extending shelf life.

While various modifications of the invention have been disclosed herein, these and other changes may, of course, be practiced without departing from the novel concept of the invention.

[Brief explanation of drawings]

In the figures, the same numerals are used to refer to the same parts throughout the figures; however, Figure 1 is a cross-section of a fragment of the laminated substrate of the present invention, and Figure 2 embodies the novel concept of the present invention. 1 is an elevational view of a collapsible dispensing container with portions of the body wall removed to better illustrate the laminated structure; FIG. (5 people outside)

Claims (1)

Claims: 1. A substrate of material layers consisting of a first layer of polypropylene, a second layer of metal foil, a third layer of paper, and a fourth layer of polypropylene. 2. The substrate according to claim 1, wherein the first layer of polypropylene is fixed to the metal foil with an adhesive. 3. A substrate according to claim 1, wherein the third layer of paper is adhered to the fourth layer of polypropylene with an adhesive. 4. The substrate according to claim 1, wherein the first layer of polypropylene is fixed to the metal foil with an adhesive, and the third layer of paper is fixed to the fourth layer of polypropylene with an adhesive. . 5. The substrate according to claim 4, wherein the adhesive is a copolymer of ethylene and acrylic acid. 6. A first innermost layer of polypropylene, a second layer of metal foil,
A material layer collapsible paste dispensing container consisting of a third layer of paper and a fourth outermost layer of polypropylene. 7. The container according to claim 6, wherein the first layer of polypropylene is fixed to the metal foil with an adhesive. 8. A container according to claim 6, wherein the third layer of paper is adhered to the fourth layer of polypropylene with an adhesive. 9. The container according to claim 6, wherein the first layer of polypropylene is fixed to the metal foil with an adhesive, and the third layer of paper is fixed to the fourth layer of polypropylene with an adhesive. . 10. The container of claim 9, wherein the adhesive is a copolymer of ethylene and acrylic acid.