Note: Descriptions are shown in the official language in which they were submitted.
3496
This invention relates generally to collapsible dis-
pensing containers used for packaging pharmaceutical produc-ts,
dentifrice, cosmetics, toiletries and the like, and is particular-
ly related to an improved plastic barrier insert in the head-
piece of the container.
Collapsible dispensing containers are widely used for
packaging various pharmaceutical products, dentifrice ~e.g.,
tooth pastes), medicinal ointments, and the like. The early
containers were usually made of metal or plastic but more recent-
ly such containers have been of laminated wall construction in
which the container body is made of a multi-ply plastic laminate
which includes an intermediate layer of a metal foil, notably
aluminum foil, sandwiched between two thermoplastic layers. The
metal foil layer serves as a barrier against oxygen permeating
into the package and against the volatile ingredients of the
packaged product permeating out and hence it is capable of pro-
tecting the product from deterioration. Dispensing containers of
laminate wall construction are described, for example, in United
States patent No. 3,260,410 issued to Roger Brandt and Ralph
Kaercher on July 12, 1966 and in United States Patent No.
3,347,419 issued to Roger Brandt and Michael Mestenas on October
17, 1967.
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~ ~ ~3~96
While the provision of a metal foil b~rrier layer in
the body o~ the container prevents product permeation and oxygen
absorption in the body region o~ the container, it is essential
that product permeation and oxygen absorption be prevented in
all regions of the container, i.e., in the breast portion æs
well. Thus, in United States Patent No. 3,260,777 which issued
to Roger Brandt on July 12, 1966, in addition to providing a
metallic barrier layer in the tube body, Brandt provides a
barrier insert in the b~reast portion o~ the container. This
metallic barrier member is constituted o~ a metal (e.g~,
aluminum) ~oil and may be embedded in the breast portion o~ the
tube during molding. However, the more desirable curren-t con-
struction contemplates the use o~ a laminate insert wherein the
metallic ~oil interlayer is between two thermoplastic layers.
A similar barrier insert is disclosed by Roger Brandt in United
States Patent No. 3,295,725 which issued on January 3, 1967.
The disclosures oi both o~ the ai'orementioned patents o~ Roger
Brandt are also ~u~ly incorporated herei~ by re~erence.
United States Patent No. 3,260,411 lssued to Frank
Dobson on July 12, 1966 also discloses the use o~ barriers in
bokh the body and headplece oi collapslbl0 dispensing containers
ko prevent product permeation and oxygen absorption :in all
re~ion~ o~ the container.
United States Patent No. 3,565,293 issued to Robert
Schultæ on Pebruary 23, 1971 discloses a barrier layer o~ low
permeability constituted o~ urea ~ormaldehyde thermosetting
resin secured to the inside sur~ace o~ the headpiece.
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~834~6
The inserts disclosed in the aforementioned patents
have not been entirely satisfactory. Metallic inserts and
laminates having a metallic interlayer are difficu~t to fabricate
and install in the headpiece. In addition, they are more expen-
sive than plastic inserts. On the other hand, urea formaldehyde
inserts tend to swell in the presence of products containing
water, such as toothpastes and some pharmaceutical products.
This swelling can crack the breast portion of the tube head, re-
sulting in product leakage through the breast area of the tube
and is obviously unsatisfactory for the package. In addition,
urea formaldehyde inserts are extremely brittle and, therefore,
the inserts can crack during the use of the package.
Accordingly, the present invention provides a collaps-
ible dispensing container of laminated wall construction wherein
a plastic insert is provided at the breast of the container
which will not only provide low essential oil and oY~ygen permea^
tion in all regions of the container, but will also prevent
package failure.
The present invention also provides a thermoplastic
insert in the headpiece of the container wherein the thermoplastic
headpiece is resistant to swelling in the presence of water and
is an effective barrier to essential oils and oxygen.
The present invention further provides such inserts
which do not distort during the injection molding of the tube
heacl to the tube body.
The present invention still Purther provides a plastic
insert constituted from a thermoplastic material which can be
fabricated and installed within the headpiece rapidly for more
efficient and economical production of the container.
According to the present invention a collaps1ble
dispensing container is provided having a deformable bocly and a
t,hermopl~stlc headpiece unitecl thereto, ancl an improved barrier
~3~
member is secured to the interior surface of the headpiece.
The barrier member is preferably constituted of polybutylene
~erephthalate since thjs material is a barrier t~ essential oils,
d~es n~t swell in the presense ~ water a~d ~e~t;frice products,
has a relatiYely shDrt injec~i~n ~olding cycle and ~an be
injected o~er with m~lten polyethylene ~ring the ~ssembly of the
headpiece and the tube body, without distortion.
The barrier insert may also be constituted of injection
moldable grade of polyethylene terephthalate or a b1end of
~ polybutylene terephthalate and injection moldable grade of
polyethylene terephthalate.
The present invention will be further illustrated by
way of the accompanying drawings, wherein like reFerence numerals,
are employed to designate like parts and where;
Figure 1 is a fragmentary side elevational view, partly
in section, of a collapsible dispensing container embodying the
insert of the present invention;
Figure 2 is an enlarged fragmentary sectional view of
the upper right hand portion of Figure l;
Figure 3 is a side elevational view of the barrier
insert, and
Figure 4 is a top view of the barrier insert.
Referring to the drawings, and first to Figure 1,
there is shown a collapsible dispensing container designated
~neraliy as 11 having d tubular body 13 which is closed at its
bottom end 15 and is united at its upper end to a headpiece 19
having a generally cone-shaped barrier member 27 which will also
be hereinafter re~erred to as the insert.
349~
The container body 11 may be of a laminated wall con-
struction capable of protecting the contents of the tube against
oxygen attack and product permeation. Such laminated wall con-
structions for tube bodies are described in several patents,
including the aforementioned patents. Typically, and with
reference to Figure 2, the laminated wall of the tube body com-
prises an exterior layer 23, an intermediate layer 25 and an
interior layer 27, all as hereinafter defined.
The exterior layer 23 is a suitable thermoplastic
material such as polyethylene. This layer may also be constituted
of a composite of two or more layers such as, for example, a
layer of clear polyethylene over a layer of printed paper or
over a layer of printed polyethylene for decorative purposes.
The intermediate layer 25 is a metallic barrier layer,
usually an aluminum foil, which serves as a barrier layer to
protect the product in the container tube against oxygen attack
or product permeation.
~30
3~
The inner l~yer 27 is also constituted of a thermo-
plastic material which is compatible with the contents o~ the
tube and which is capable o~ uniting to the headpiece when the
headpiece ls thermally joined to the tube body. Thus, the
layer 27 may be polyethylene or a composite o~ two or more
layers, such as, for example, an interior polyethylene layer
and an adhesive layer for adhésively joining the interior layer
to the intermediate metal ~oi]. layer.
The headpiece 19 is usually a readily moldable thermo-
plastic layer such as, -Por example, polyethylene and includes
a neck portion 29 which is conveniently threaded ~or engagement
with an internally threaded cap (not shown) to provide a
closure ~or the con-tainer, The headpiece 19 also includes a
breast portion 31 which is united, usually thermally, about its
peripheral band or area 33 to the upper interior oi' the tube
hody 11. The breast portion 31 has an annular lip 36 which
underlies the insert 21 as shown in FIGURE 2.
In order to protect against oxygen attack and prevent
product permeation in all regions o~ the container, the present
invention provides a novel insert member 21 associated with the
headpiece 19 as hereina~ter described in more detail. The
selection o~ a suitable barrier insert in accordance with the
present invention is based on several considerations which not
only Lnclude protection against oxygen attack and product
migration, but also involves consideration o~ manu~acturing
procedure and di~iculties which, in the past, have been
encountered with prior type barrier inserts.
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Thus, in accordance with this invention, i-t has been
found that insert members made of polybutylene terephthalate
(PBT) are particularly well suited for achieving a combination
of desirable objeetives in the manufacture of collapsible
dispensing containers. Among other advantages, the insert used
herein is made entirely of plastic and does not contain a
metallic layer as in the laminated inserts of the type used in
the prior art. Consequently, they can be fabricated more
readilty and at less cost.
In the a~orementioned United States Patent No
3,665,293 ol' 5chultz, the patentee discloses the use of an
insert made ol' various resins selected on the bases of their
impermeability and product compatibility. These resins include
arnino resins, such as urea l'ormaldehyde, polypropylene and
polyamides, such as nylon. In general, Schultz recommends using
other plastic materials, both thermosetting and thermoplastic,
which have the desired degree o~ impermeability and product
compatibility. In addition, the patentee discloses that the
insert may be made oi metal, such as, i'or example aluminum.
In a more recent patent, i.e., United States Paten~
No. 4,132,331 issued to Karl Magerle on January 2, 1979, the
tube body consists oi' three layers; an outside layer oi poly-
ethylene, a barrier sheet oi polyester and an inside layer which
i~, al~o made o~ polye~hylene. The polyester barrier sheet ~or
the tube body in Magerle is polyethylene terephthalate. The
headpiece, however, does not have a polyester insert associated
therewith.
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11~3~fi
It has been discovered that a barrier insert made of
polybutylene terephthalate does not swell in the presence o~
water found in various dentifrices, e.g., toothp~stes, or
medicinal and pharmaceutical products, e.g., shaving creams,
and the like. Also, this material is crystalline ~nd has a
relatively short injection molding cycle. Since it can be
molded more quickly, it can be made at less cost and better
quality even though the cost of the resin is higher. In
addition, unlike other thermoplastics, molten polyethylene used
to ~orm the tube head can be injected directly on top o~ the
PBT insert without distorting it. As it may be appreciated,
freedom ~rom distortion during injection molding is highly
signiiicarlt in the manufacture o~ the collapsible container.
In addition to the a~orementioned properties, an
insert made o~ polybutylene terephthalate provides a barrier
to essential oils and the ingredients which are usually present
in denti~rice and pharmaceutical products, as ~ell as providing
a barrier to oxygen which tends to permeate the product ~rom
outside o~ the package.
As shown in FIGURES 3-4 the PBT insert 21 has a
conical portion 35 which is designed to con~orm to the interior
con~iguration o:~ -the breast portion 31 o~ headpiece 19. The
conical portion 35 ~its tightly into the headpiece as at 37.
In practice, the ba~rier insert 21 is placed in positio n
on the working tool and the tube head 19 is injected thereover.
The injection o~ the tube head 19 serves the dual purpose oi
bonding the head to the sleeve portion to make a completed
package, and i-t also locks the harrier insert securely in
~3~96
position through the annular lip 36. Alternatively, the insert
21 may be snapped into the interior surface of a pre-molded
head having stop type locking ring for this purpose. In general,
however, the manner in which the insert is associated with the
headpiece is not, per se, a critical feature of the present
invention, the same being known from prior patents, including
the aforementioned patent of Schult7.
While the inserts of choice are made of polybutylene
terephthalate, inserts made of injection moldable grade of
polyethylene terephthalate or a blend of polybutylene terephtha-
late with injection moldable grade of polyethylene terephthalate
exhibit similar properties and hence they may be satisfactorily
used in the practice of this invention.
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