WO2001000743A1

WO2001000743A1 - Novel composition container apparatus and process

Info

Publication number: WO2001000743A1
Application number: PCT/AU2000/000709
Authority: WO
Inventors: Barbara Wozniak; Brian Smole; Priscilla Aquino-Perez; Nicholas Cook; John Chadwick; David Francis; Giles Day; David Brien
Original assignee: Selleys Pty Limited
Priority date: 1999-06-24
Filing date: 2000-06-23
Publication date: 2001-01-04
Also published as: AUPQ118399A0

Abstract

A gap sealant, filler or grout composition which includes hollow polymeric spheres for reduced viscosity, to allow the composition to be hand extruded from a flexible tube, instead of a rigid cartridge. The flexibility of the tube requires a novel process and apparatus for filling the composition into the tube and attaching a nozzle (10) onto a neck (11) of the tube (2).

Description

NOVEL COMPOSITION CONTAINER APPARATUS AND PROCESS

Field of the Invention

This invention relates to a novel composition, and in particular to a novel gap sealant, gap filler or grout composition which has reduced viscosity relative to conventional sealants and grouts, thereby allowing it to be packaged in a container which allows for manual extrusion (i.e. by squeezing). The invention also relates to a novel process for filling soft flexible containers with viscous or semi- viscous liquid materials, as well as to a novel container for such materials. The invention is particularly suited to use in water based gap sealant applications and it will be convenient to describe the invention with reference to this application, however it is to be understood that the invention is applicable to all viscous or semi-viscous liquids for which manual extrusion from a container would represent a convenient method of application, dispensing or use.

Background of the Invention

A water based gap sealant is typically used prior to painting for sealing cracks in building. Conventional water based gap sealants are very thick materials which make extrusion by hand (i.e. unaided by any form of mechanical advantage like a cartridge gun) from containers extremely difficult and also make filling of containers in manufacturing more complicated. Reducing the viscosity of a conventional water based gap sealant, e.g. by virtue of adding water or other fluid, does not altogether alleviate the problems mentioned above, since reducing the viscosity by these conventional means is limited because it results in a loss in gap filling capabilities.

It has now been found that the viscosity of a gap sealant, gap filler or grout can be reduced to an extent that it can be manually extruded from a container or package by the incorporation into to the sealant, filler or grout composition of hollow polymeric spheres.

Summary of the Invention

Accordingly in a first aspect the present invention provides the use of hollow polymeric spheres to lower the viscosity of a gap sealant, filler or grout composition.

In a second aspect the invention provides the use of hollow polymeric spheres as a filler for a gap sealant, gap filler or grout composition.

In a third aspect the invention provides a gap sealant, filler or grout composition comprising hollow polymeric spheres together with a conventional resinous base.

The hollow spheres may include a blowing agent or gas in the hollow interior. They should also preferably be made of a material which is compatible with the resin of the filler, sealant or grout, such that there is good adhesion between the spheres and the resin. The spheres preferably have an average diameter of less than lOOμm, more preferably less than 40μm and most preferably between 15 and 25μm. An example of a suitable material is Expancel® by KemaNord Plast. These microspheres consist of a polymeric shell with an enclosed blowing agent. The polymeric material of the shell is a copolymer of vinylidene chloride and acrylonitrile, the blowing agent being isobutane. The microspheres come in expanded and unexpanded form. Preferably the expanded form is used which has an average particle diameter of 15-25μm. The hollow spheres are preferably elastic in nature.

The resin used may be any suitable resin known to the art, such as acylic resins, styrene resins, acrylic/styrene resins and the like.

The composition according to the present invention advantageously exhibit low viscosity while maintaining gap sealing, filling or grouting properties comparable to conventional compositions. The lower viscosity facilitates filling of the composition into soft bottle/tube like containers from which the composition can be manually extruded.

The soft bottle like container should be flexible and preferably be capable of undergoing folding, and may be formed by any suitable means, such as blow moulding or injection moulding. The bottle may be composed of a LDPE/HDPE blend, ethylene vinyl alcohol or similar flexible plastic material which provides a sufficient barrier. Preferably the wall section is from 0.2 to 0.7mm, more preferably about 0.4mm, but may vary due to processing conditions. Such a bottle preferably has a long cylindrical or oval shape to enable it to be held comfortably in the hand while having a volume capacity equivalent to conventional cartridge packaging, i.e. a cartridge. It is preferably made of such soft plastic that it offers little resistance to either vertical or horizontal compressive forces. This greatly facilitates manual extrusion of the contents.

Such a bottle as described above presents problems when filling it with sealant. Because of its necessary flimsy construction and the oval cross-section, conventional automatic bottle filling equipment (whereby a bottle passes along a conveyor) is not reliable because spacing and stabilising the bottle is difficult. A solution is to place the bottles in pucks (cups designed to hold the bottle temporarily during movement along the conveyer) but is expensive in terms of puck fabrication.

There are also problems with applying overcaps to such containers in view of their flimsy construction. Overcaps are generally applied by pressing onto the top of the container over the filling opening, relying on an interference fit between the overcap and the container to keep it securely in place. In view of the flimsy construction of the container, any attempt to apply an overcap would result in deformation of the container and possibly expulsion o some of the contents of the container. It would also be unlikely that the overcap could be applied with sufficient force to provide an interference fit of sufficient strength to keep it in place, especially when screwing on or unscrewing the actual cap to the overcap.

It has now been found that the use of a ridged neck on the opening of the container and one or more, preferably two, supporting tabs (or plates) which engage and support a ridge of the neck during application of the overcap can substantially alleviate or overcome this problem.

Accordingly in a fourth aspect of the present invention there is provided a process for applying an overcap to a soft flexible tube having a neck which includes an aperture for filling said container with a composition, as described above, said neck also including one or more ridges, said process comprising providing one or more supporting tabs or plates to support at least one of said ridges while applying said overcap to said neck such that an interference fit is formed between said overcap and said neck, whereby deformation of said flexible container during application of the overcap is substantially prevented.

Preferably the interference fit results from an interaction between the ridge or ridges on the neck and inner surface of the overcap.

The overcap may be made of any suitable material, such as HDPE or polypropylene, either in copolymer or homopolymer form, although other suitable materials may also be used. Preferably the overcap is composed of HDPE.

The bottles according to the present invention may be filled on a rotating table filling station. Rather than placing the bottles in pucks they may be loaded into slots on the rotating table.

The table moves the bottle to a station where filling of the sealant takes place by insertion of a dosing nozzle into the bottle. The bottle then is moved to a station where a cap/nozzle connector is automatically attached. The cap/nozzle connector provides a seal for the bottle as well as connection point for a conventional sealant applicator nozzle. The attachment is via a press fit onto the bottle. This is so because the bottle being so soft is extremely difficult to hold mechanically if automatically attaching the connector via a conventional screw thread arrangement. The press fit operation does require the filled bottle to be held also but in accordance with an embodiment of the present invention this is conveniently and inexpensively achieved by two tabs, such as metal tabs, moving towards the neck of the bottle from opposite sides, thereby coming to rest under the collar or ridges of the bottle neck. This supports the bottle and prevents it from collapsing when the press fit of the cap/nozzle connector occurs.

In a fifth aspect of the invention, there is provided an apparatus for filling a composition, as described above, into a tube including: a filling station for injecting the composition into the tube; and a fitting station for securing a nozzle to the tube wherein the fitting station includes an attachment device for holding the nozzle and applying a connection force to drive the nozzle onto a neck of the tube for engagement therewith and a gripping assembly for engaging the neck of the tube and supporting the neck against the driving force of the attachment device.

In a sixth aspect, there is provided a method of filling a composition, as described above, into a tube, including: injecting the composition into the tube, engaging a neck of the tube with a gripping assembly, providing a nozzle in an attachment device and driving the nozzle onto the tube by applying a connection force between the gripping assembly and the attachment device.

The process and apparatus according to the present invention is particularly suitable for use with materials having a viscosity of from about 50,000 to 150,000 centipoise as measured by a Brookfield viscometer model HAF, spindle A, speed 5 rpm, although the exact upper limit will be governed by the limits of manual extrusion. The ranges given will allow easy manual extrusion of the composition through an application nozzle which has a 3mm internal diameter opening. Preferably the viscosity is from 60,000 to 68,000 centipoise.

The bottle is preferably oval in cross-section as this facilitates the application of a label to the bottle. The label is generally applied after the overcap.

The bottle cap or outlet nozzle can be screwed onto the overcap after application of the overcap or the cap or nozzle can be supplied separately.

Compared with the prior art gap sealants, fillers and grouts, the low viscosity allows for the use of filling nozzles of smaller diameter. A normal filling nozzle of a conventional sealant for instance would be from about 30 to 40mm in diameter, whereas a nozzle of from 15 to 25mm may be used in the present process. Preferably the filling nozzle has a diameter of about 20mm.

Even though the nozzle is narrow, it is possible to achieve higher filling rates. The narrower nozzle also allows the filling neck aperture to be narrower and this means that a smaller overcap can be used. A small overcap is important as the forces generated unscrewing a cap or nozzle from a large overcap may disrupt the interference fit between the neck and the overcap.

Brief Description of the Drawings

The invention will now be described with reference to the accompanying drawings and examples which illustrate some preferred embodiments of the invention. However it is to be understood that the following description is not to supersede the generality of the preceding description of the invention.

Referring to the figures:

Figure 1 is a diagrammatic representation of an apparatus for filling a sealant into a tube;

Figure 2 is a plan view illustrating a gripping assembly of the apparatus; Figure 3 is side view of the tube; and Figure 4 is a cross-sectional view of a nozzle.

Detailed Description

The apparatus 1 includes a filling station (not shown) where sealant is filled into a tube 2 which is mounted in a holder 3 provided on a rotary table 4. Once the tube is filled with sealant, the table 4 is rotated to position the tube at a fitting station 5. The fitting station includes a gripping assembly 6 which is mounted beneath an attachment device 7 which comprises a ram 8 actuated by an air cylinder 9 to apply a connection force to a nozzle 10 in order to snap engage the nozzle 10 to a neck 11 of the tube 2.

The gripping assembly is shown in more detail in Figure 2 as including a pair of grip plates 12, 13, which are identified by cross-hatch, mounted to a support plate 14 and are movable relative to each other in the direction indicated by arrows 15. When the neck 11 of the tube 2 is positioned in the gripping device 6, the plates 12, 13 are driven toward to each other to engage the neck and thereby provide a support against which the connection force may be applied. As a result, the compliant nature of the tube does not adversely affect the fitting of the nozzle thereto.

The tube 2 is shown in more detail in Figure 3 as including a deformable body 20 tapering into the neck 11. The neck includes an annular ridge 21 which serves to locate the nozzle.

The ridge 21 also provides suitable structure for abutment with the plates 12, 13, to retain the neck 11 in the gripping device during application of the connection force. The nozzle

10 is itself shown in Figure 4 in enlarged section as including a casing 22 with inwardly directed annular tabs 23 for snap engaging under the ridge 21. The casing 22 also includes a cap 24 fitted over an outlet 25. The cap may be punctured or removed in its entirety in order to dispense the contents of the tube. The nozzle also includes a thread form 26 which may be used to subsequently fit a screw cap onto the nozzle after use.

Example 1

ACRONAL BA4007 (Styrene acrylic latex) (889.2 Kg) was added to a paddle mixer/homogeniser. FOAMASTER NX2 (Defoamer) (11.2 Kg) was added and the paddles started. ACTICIDE (biocide) (2.2Kg) was added followed by slow addition of 2-amino-2- methyl-1-propanol (pigment dispersant) (2.2 Kg).

Tetrapotassium pyrophosphate (chelate and pigment dispersant) (4.5 Kg) was premixed with water (12.4 Kg) and added to mixer. The homogeniser was then started.

An organically modified clay /thickening agent (11.0 Kg) was premixed with water (14 Kg) to form a thick paste. This is added to the mixer and the premix drum was rinsed with water (10 Kg) which was also added to mixer. After addition of the paste the paddles and homogeniser are turned on with mixing until lump free (30 min).

Butyl benzyl phthalate (plasticiser) (44.8 Kg) is premixed with hydroxy ethyl cellulose (rheology modifier) (2.44 Kg) until lump free. The paddles are stopped and the premix added. The paddles are then started.

TEXANOL (2,2,4-trimethyl-l,3-pentanediol monoisobutyrate/coalescing agent) is used to flush premix drum and added to mixer with mixing until lump free (15 min). TERIC N40L/PANNOX 140 70% (40 mole ethoxylate of nonyl phenyl) (4.5 Kg) is added with mixing for 5 minutes.

Paddles are turned off and sieved titanium dioxide (14.5 Kg) is added. The paddles are turned on again and calcium carbonate (1104 Kg) is added with mixing (15 minutes). The mixer is turned off and EXPANCEL 551 DE 20 (15 Kg) is added with mixing and addition of water (5.0 Kg).

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps of features.

Claims

The Claims:

1. A gap sealant, filler or grout composition including hollow polymeric spheres.

2. A composition as claimed in claim 1, wherein the spheres include a blowing agent or gas in an interior thereof.

3. A composition as claimed in claim 1 or 2, wherein the spheres have an average diameter of less than lOOμm.

4. A composition as claimed in claim 3, wherein the average diameter is less than 40μm.

5. A composition as claimed in claim 4, wherein the average diameter is between 15 and 25 μm.

6. A composition as claimed in any one of claims 1 to 5, wherein the composition has a viscosity of between 50,000 and 150,000 centipoise.

7. A composition as claimed in claim 6, wherein the viscosity is between 60,000 and 68,000.

8. A process for applying an overcap to a soft flexible container having a neck which includes an aperture for filling said container with a composition as claimed in any one of claims 1 to 7, said neck also including one or more ridges, said process comprising providing one or more supporting tabs or plates to support at least one of said ridges while applying said overcap to said neck such that an interference fit is formed between said overcap and said neck, whereby deformation of said flexible container during application of the overcap is substantially prevented.

9. An apparatus for filling a composition, as claimed in any one of claims 1 to 7, into a tube including: a filling station for injecting the composition into the tube; and a fitting station for securing a nozzle to the tube wherein the fitting station includes an attachment device for holding the nozzle and applying a connection force to drive the nozzle onto a neck of the tube for engagement therewith and a gripping assembly for engaging the neck of the tube and supporting the neck against the driving force of the attachment device.

10. An apparatus as claimed in claim 9, wherein the filling station includes a filling nozzle of from 15 to 25 mm in diameter.

11. A method of filling a composition, as claimed in any one of claims 1 to 6, into a tube, including: injecting the composition into the tube, engaging a neck of the tube with a gripping assembly, providing a nozzle in an attachment device and driving the nozzle onto the tube by applying a connection force between the gripping assembly and the attachment device.

12. A gap sealant, filler or grout tube for containing a composition as claimed in any one of claims 1 to 7, having a flexible plastics wall of a thickness in the order of from 0.2 to 0.7 mm, to allow the tube to be collapsed by hand, to extrude the composition therefrom.

13. A tube as claimed in claim 12, wherein the tube is dimensioned to fit in the hand of a user.

14. A tube as claimed in claim 12 or 13, including a nozzle with an internal diameter in the order of 3mm.