U.S. patent application number 10/513811 was filed with the patent office on 2005-09-01 for container for a brushable coating composition.
Invention is credited to Booth, Peter, Heather, Louise, Peacop, Alexander James, Smith, Douglas James Broadhurst, Van De Wal, Hendrik.
Application Number | 20050189354 10/513811 |
Document ID | / |
Family ID | 9936334 |
Filed Date | 2005-09-01 |
United States Patent
Application |
20050189354 |
Kind Code |
A1 |
Heather, Louise ; et
al. |
September 1, 2005 |
Container for a brushable coating composition
Abstract
A container (1) containing a coating composition the container
comprising a container body (21) and a lid (7), the lid comprising
a collar (11) and a disc (12), the container body having an opening
provided with a screw-thread (5) cooperable with a screw-thread (6)
on the collar and closeable by said lid characterised in that the
disc is formed of polyethylene terephthalate (PET) which is
sufficiently transparent to allow the coating composition to be
visible therethrough.
Inventors: |
Heather, Louise; (Middlesex,
GB) ; Booth, Peter; (Wiltshire, GB) ; Van De
Wal, Hendrik; (Steenwijk, NL) ; Smith, Douglas James
Broadhurst; (Oxfordshire, GB) ; Peacop, Alexander
James; (Wiltshire, GB) |
Correspondence
Address: |
THE GLIDDEN COMPANY
15885 WEST SPRAGUE ROAD
STRONGVILLE
OH
44136
US
|
Family ID: |
9936334 |
Appl. No.: |
10/513811 |
Filed: |
November 8, 2004 |
PCT Filed: |
May 2, 2003 |
PCT NO: |
PCT/EP03/04842 |
Current U.S.
Class: |
220/288 ;
215/276; 220/377 |
Current CPC
Class: |
B65D 51/145
20130101 |
Class at
Publication: |
220/288 ;
220/377; 215/276 |
International
Class: |
B65D 041/04; B65D
045/30 |
Foreign Application Data
Date |
Code |
Application Number |
May 9, 2002 |
GB |
0210593.0 |
Claims
1. A container (1) containing a coating composition (31) the
container comprising a container body (21) and a lid (7), the lid
comprising a collar (11) and a disc (12), the container body having
an opening (2) provided with a screw-thread (5) co-operable with a
screw thread (6) on the collar (11) and closeable by said lid
characterised in that the disc (12) is formed of polyethylene
terephthalate (PET) which is sufficiently transparent to allow the
coating composition to be visible therethrough.
2. A container containing a coating composition according to claim
1 characterised in that the container body (21) is formed of
PET.
3. A container containing a coating composition according to claim
1 characterised in that the container body (21) is transparent.
4. A container containing a coating composition according to claim
1 characterised in that the collar (11) is formed of a mouldable
material other than PET.
5. A container containing a coating composition according to claim
4 characterised in that the mouldable material is selected from any
one of polyethylene, polypropylene and styrene-butadiene
copolymer.
6. A container containing a coating composition according to claim
5 characterised in that the mouldable material is
polypropylene.
7. A container containing a coating composition according to claim
1 characterised in that the collar (11) and disc (12) are rotatable
relative one to the other.
8. A container containing a coating composition according to claim
7 characterised in that a vertical lifting force is exerted on the
disc (12) as the collar (11) is unscrewed.
9. A container containing a coating composition according to claim
1 characterised in that the lid (7) includes a dependent circular
surface which is sealingly engageable against the rim.
10. A container containing a coating composition according to claim
9 characterised in that the lid includes a pair of concentric (19,
20) surfaces depending downwardly for receiving the rim (10)
therebetween.
11. A container containing a coating composition according to claim
1 characterised in that the lid comprises a collar (11) and a disc
(12) secured to one another.
12. A container containing a coating composition according to claim
11 characterized in that the collar (11) comprises a pair of
annular surfaces extending radially inwardly, between which the
periphery of the disc is held captive.
13. A container containing a coating composition according to claim
12 characterised in that the periphery of the disc (12) forms a
snap fit or interference fit with the collar (11).
14. A container containing a coating composition according to claim
2 characterised in that the container body (21) is transparent.
15. A container containing a coating composition according to claim
3 characterised in that the collar (11) is formed of a mouldable
material other than PET.
16. A container containing a coating composition according to claim
3 characterised in that the collar (11) and the disc (12) are
rotatable relative one to the other.
Description
[0001] This invention relates to a large container or can
containing a coating composition which can has a capacity of above
0.2 litres and can be closed and sealed by a screw-thread lid. The
container is large enough to be useful as a container for paints,
lacquers, varnishes, woodstains and any other coating compositions
of the type which are commonly applied using large brushes (usually
at least 20 mm wide and at least 5 mm broad) at ambient
temperatures (say 5 to 40.degree. C.) to surfaces found in
buildings. Such compositions are often applied by amateur, that is
to say "do-it-yourself" or "DIY" painters. For brevity the
containers will be frequently referred to as "paint containers"
even though they are useful for containing other coating
compositions, usually brushable coating compositions.
[0002] Artists' materials, touch-up paints for motor vehicles, nail
varnishes and other specialist paints which are conveniently sold
in relatively small volumes are often supplied in small tubes or
small jars having openings which are closeable by means of a
screw-thread lid where threads on the lid co-operate with threads
extending around the opening in order to hold the lid in a closing
position on the tube or jar. One such tube is disclosed in British
Patent Specification GB 835 862 published in 1958.
[0003] Screw-thread lids on small tubes or small jars are easy to
use by amateurs provided that the tube or jar is small. Attempts to
use screw-thread lids on larger paint containers (such as paint
container bigger than say 0.2 litres) have not proved successful
because when the screw-threads become covered in paint, as
frequently occurs in normal use, additional force is required to
screw the lid on or off. It is also messy, especially when screwing
the lid on, as some of the excess paint caught between the threads
of the lid and the container is squeezed out onto the neck and body
of the container. Furthermore, the paint which remains trapped
between the threads forms a solid coating on drying and in so doing
sticks the threads of the lid to the threads of the container
opening, increasing the force required still further. The nature of
this solid coating is such that it cannot be re-dissolved by the
liquid paint contained within the container. The problem of
sticking is aggravated when the screw threads of the lid and
container are both made of polyethylene terephthalate (PET) because
the application of a turning force to opposed PET surfaces creates
a combination of sticking and friction, probably unique to PET,
referred to as stiction.
[0004] Throughout this specification references to polyethylene
terephthallate and PET are intended to include not only
polyethylene terephthallate but also its copolymers derived from
mixtures of terephthallic acid and minor amounts of other useful
diacids, such as isophthallic acid, in minor amounts.
[0005] An additional problem arises because any dried solid coating
material which has formed at the rim of the container opening is
broken by the twisting force exerted on the lid, for example during
the initial step of lid removal. Further twisting to complete the
removal of the lid tends to break the solid coating into smaller
pieces driving them into the container. This contaminates the paint
contained therein, frequently making it unusable.
[0006] A further problem with screw-thread lids is that of
providing a good seal between the lid and the container,
particularly when the container is holding an organic solvent based
product such as some paints. A good seal is required to prevent any
leakage of the product or escape of solvent vapour.
[0007] Equally important is the ingress of air, particularly where
the paint is autoxidiseable, such as many gloss paints. By
autoxidiseable is meant that such paint is intended to react with
oxygen in the atmosphere to form a solid coating when applied to a
surface such as a wall. Similarly, the paint inside the container
also reacts with oxygen in the air contained within the container
in the space above the paint. When a good seal is present, once the
oxygen is consumed the reaction stops and the paint remains usable.
However, if more air is able to enter the container due to poor
sealing, the reaction continues and a skin forms on the surface of
the paint. This skin cannot be dissolved in the liquid paint
beneath and attempts to remove it generally result in it breaking
up and falling into the bulk of the paint rendering the whole
contents unusable.
[0008] Traditionally press-fit lids have been preferred for paints
because the press-fit provides a good seal. The press-fit must be
sufficiently tight to provide a degree of shock resistance to avoid
dislodging the lid if the container is accidentally dropped or
knocked. However, such press-fit lids can be difficult to open and
require the use of a special tool. More frequently, in the absence
of a special tool the most conveniently available sharp tool such
as a screwdriver is used instead and this may cause injury when
used carelessly and inappropriately, for example by a DIY
painter.
[0009] When screw-thread lids have been tried, to avoid the need
for an opening tool, it has been found necessary to introduce a
separate gasket to ensure a good seal is still achieved, but this
has never succeeded commercially. It has been found that the gasket
never reseals reliably after the container is first opened and it
is also messy.
[0010] For these reasons, screw-thread lids have not been
commercially successful when used on large paint containers for
supplying paint used in painting buildings.
[0011] A still further and related problem associated with paint
containers is that purchasers and users are unable to see the
colour of the contents.
[0012] Manufacturers provide an indication of the colour of the
paint using small representations, usually in the form of a small
colour region printed on a larger label carrying the manufacturers
livery and stuck to the container body. However, purchasers regard
such colour representations as unreliable and prefer to see the
colour of the actual paint in the container. One way, of course, is
to remove a press-fit lid to inspect the contents prior to purchase
but this is both inconvenient and messy. Furthermore, it introduces
a risk of contaminating the paint with foreign material and
consequently is generally discouraged by retailers. Similarly,
removing a screw-thread lid, although more convenient and less
messy nevertheless retains the risk of contaminating the
contents.
[0013] Providing a transparent container body is one known solution
but of course a large amount of the available space through which
the paint could be seen is taken up by the manufacturer's livery.
Additionally, regulatory instructions regarding health and safety
must also be provided taking up yet more of the available space
thus leaving only a small area through which to view the paint.
[0014] It is an object of this invention to provide a large
container or can containing a coating composition, which is
conveniently closable and reopenable by means of a transparent
screw-thread lid so avoiding the need for a sharp tool and through
which the contents can be seen.
[0015] Accordingly, the present invention provides a container
containing a coating composition, the container comprising a
container body and a screw-threaded lid, the lid comprising a
collar and a disc, the container body having an opening provided
with a screw-thread co-operable with a screw-thread on the collar
and closeable by said lid characterised in that the disc is formed
of polyethylene terephthalate which is sufficiently transparent to
allow the coating composition to be visible therethrough.
[0016] The container body and the collar may be formed of mouldable
material. Suitable examples of such mouldable materials include
polyethylene, polypropylene, styrene-butadiene copolymers and
PET.
[0017] Preferably, the container body is formed of PET as this
material is resistant to both waterborne emulsion paints and paints
containing large amounts of organic solvent.
[0018] Where the container body is formed from PET it is essential
that the collar is formed of a mouldable material other than PET,
such as polyethylene, polypropylene or styrene-butadiene copolymer.
This avoids the problem of stiction.
[0019] Preferably the collar is formed of polypropylene.
[0020] The container body may be transparent or opaque. Preferably
it is transparent.
[0021] Preferably the collar and disc are rotatable relative one to
the other thereby allowing a vertical lifting force to be exerted
on the disc by the collar as the collar is unscrewed. This is
advantageous in circumstances when the disc of the lid is stuck to
the rim of the container as the screw-thread allows a lifting force
to be exerted with mechanical advantage on the stuck disc. This
significantly reduces the force necessary to remove the lid. The
mechanical advantage arises because the vertical movement of the
collar is very small compared to its rotational movement and hence
there is a large gearing effect. As the unscrewing operation
continues, the collar rises lifting the disc thereby breaking the
dried solid coating of paint without the need for excessive
force.
[0022] Preferably, the lid includes a dependent circular surface
which is sealingly engageable against the rim.
[0023] In particular, the lid may include a pair of concentric
surfaces depending downwardly for receiving the rim
therebetween.
[0024] The lid preferably comprises a collar and a disc secured to
one another. More preferably they are secured by means that allow
relative rotation of the collar and disc.
[0025] Conveniently, the collar comprises a pair of annular
surfaces extending radially inwardly, between which the periphery
of the disc is held captive, for example by a snap fit or
interference fit.
[0026] The invention will now be described in detail, by way of
example only, with reference to the accompanying drawings in
which:
[0027] FIG. 1 is a front elevation of a paint can according to this
invention;
[0028] FIG. 2 is a perspective view on a slightly smaller scale of
a combination of the can shown in FIG. 1 and a lid;
[0029] FIG. 3 is a cross section on the line A-A through the lid
and the rim of the container shown in FIG. 2 but shown separated
from one another; and
[0030] FIG. 4 is an enlarged detail view of one side of the lid and
rim of FIG. 3.
[0031] FIG. 1 shows a paint can 1 containing 0.5 litres of paint
31, the can having a container body 21 provided with a circular
opening 2 defined by cylindrical inner surface 3 and cylindrical
outer surface 4, as shown in FIG. 3. Screw-threads 5 extend around
outer surface 4 and are dimensioned so as to be able to receive
screw-threads 6 formed on the inside of screw-thread lid 7 as also
shown in FIG. 3. Threads 5 and 6 can co-operate to retain
screw-thread lid 7 on can 1 as shown in FIG. 2 whereby lid 7 closes
opening 2. Can 1 also has a circumferential rib 8 which acts as a
stop for lid 7 to prevent over-tightening which might increase the
risk of jamming.
[0032] The inner and outer surfaces 3, 4 are joined by a rim 10
formed by a surface which is a straight edge.
[0033] As best seen in FIGS. 3 and 4 the lid 7 is formed in two
parts, comprising a collar 11 and a disc 12. The collar 11
comprises an annular wall 13 with inner and outer surfaces 14, 15.
Screw-threads 6 are provided on the inner surface 14. An annular
flange 16 extends radially inwardly from the top of the wall 13. An
inwardly projecting lip 17 is formed on the inner surface 14 spaced
a short distance below the flange 16 FIG. 3 shows the paint 31.
[0034] The disc 12 is circular and may be slightly convex as shown.
It is formed with a stepped periphery 18 which is received as a
snap fit or interference fit between the flange 16 and the ledge 17
on the collar 11 to secure the collar 11 and the disc 12 together
to form the lid 7.
[0035] A pair of annular, concentric walls 19, 20 depend downwardly
from the lower surface of the stepped periphery 18. The walls 19,
20 are preferably profiled in a rectangle shape. The concentric
walls 19, 20 are dimensioned such that when the lid 7 is screwed
onto the can 1, the profiled surface 9 around the rim of the
opening 2 is received between the two walls 19, 20 to form a
seal.
[0036] Can 1 is conveniently made by a compound injection/blow
moulding process using a suitable thermoplastics material. The use
of injection moulding allows very precise reproduction particularly
of opening 2 and screw-threads 5 which is important to the
achievement of the best possible fluid-tight fit between the
screw-threads 5 and 6 when lid 7 is screwed into its closing
position on can 1.
[0037] In this way a container or can 1 containing a coating
composition 31 can be produced with the container having a
transparent screw-threaded lid through which the paint can be
seen.
* * * * *