OXIDANT BLEACH CONTAINER

Abstract: A transparent, durable container for housing and delivering a free-flowing granular dry oxidant bleach composition, said container being constructed of a heteropolymeric plastic which maximizes transmission of water vapour for minimum decomposition of the oxidant bleach stored within the container. The container may include a fragrancing means located remote from said bleach composition to fragrance the unfilled portion of the container, said fragrancing means being isolated from said bleach composition by an appertured barrier which allows the fragrance to contact the bleach composition but does not allow the bleach composition to contact the fragrancing means. In one embodiment the container (2) comprises a bottle (3) and a closure (18) therefor for containing and dispensing a free-flowing granular oxidant bleach composition, the container including fragrancing means (22) for fragrancing the interior of the container and barrier means (24) isolating the fragrance means from contact by an oxidant bleach contained within the container and for allowing fragrance means to communicate with the interior.

Description: The invention relates to a container according to the preamble of claim 1 (US-A-4444673). The container is carefully constructed to avoid or minimize interaction between the container material and an oxidant bleach, a fragrance, or both, contained therein, to prevent formation of malodors and to minimize decomposition of the oxidant bleach composition. Containers for delivering dry detergents constructed of both plastics and cardboard have been disclosed in the prior art. For example, Joshi et al, U.S. 4,444,673, 4,351,740 and 4,269,722, disclose a clear bottle, with a hollow handle, for dispensing dry detergents. However, the material used to construct such containers for detergent is not critical. Other prior art discloses containers provided with venting means to alleviate pressure, of gases evolved by materials disposed within the container, e.g., Snyder, U.S. 4,007,848, or Whitney, U.S. 4,392,005. Still other references disclose fragrancing containers, for instance, Kittscher et al, U.S. 4,475,663, shows a pail having a perfumed disc which also acts as a gasket for a carrying handle, and E.P. 4463, shows a carton impregnated with perfume to fragrance the head space of the carton. However, none of the prior art discloses, teaches or suggests that a plastic container which is used to house an oxidant bleach must be constructed of a material that avoids decomposition of the bleach and/or the formation of malodors via interaction of the bleach with the plastic container material. Further, nothing in the art discloses, teaches or suggests that when a fragrance disposed within a plastic container housing an oxidant bleach for fragrancing the bleach, or the headspace thereof, there may be interaction between the fragrance and the container, resulting in additional malodor formation. Thus, a conventional fragrancing means used in such an environment may not only be ineffective to solve the problem it was originally intended to solve, but in fact it may exacerbate the problem. The prior art has failed to recognize such problems, or to provide or suggest any means of solving such problems, and the teachings of the prior art, such as that outlined above, are not instructive with respect to the problems solved by the present invention. The invention provides a transparent, durable container for housing and delivering a free-flowing granular peracid bleach composition. The container comprises a plastic bottle and a closure therefor, as is known for example from U.S. 4,444,673. However the container is constructed of a special heteropolymeric plastic which maximizes transmission of water vapour through the wall of the container from an oxidant bleach stored within the container thus minimizing decomposition of the bleach. The container may also include fragrancing means located remote from said bleach composition to fragrance the unfilled portion of the container, said fragrancing means being isolated from said bleach composition by a barrier means which allows the fragrance to contact the bleach composition but does not allow the bleach composition to contact the fragrancing means. The heteropolymeric plastic is further selected to prevent interaction with a fragrancing means which is located within the container at a location remote from the oxidant bleach. The container includes a venting means to reduce the concentration of malodors from the oxidant bleach. The container includes a closure having a recessed portion containing suitable amount of fragrance combined with an amorphous polymer. Brief Description of the Drawings Fig. 1 depicts a front elevational view of a container embodying the present invention, including a closure shown in section; Fig. 2 shows the closure of the container of Fig. 1, partially in section; Fig. 3 shows an exploded view of the closure of Fig. 2; Fig. 4 shows the barrier means of the present invention. Fig. 5 shows one embodiment of a venting means of the container; Fig. 6 shows yet another embodiment of the venting means of the invention; Fig. 7 shows yet still another embodiment of the venting means of the invention; and Fig. 8 shows a further embodiment of the venting means of the invention. Fig. 9 shows a sectional view of the container of Fig. 1, taken along lines 9-9 thereof. Fig. 10 shows stabilities of an oxidant contained in bottles made of different plastics stored at 100°F. (37.5°C). Detailed Description of the Preferred Embodiment Peracid-based bleaches include a number of effective dry bleach formulations which have excellent soil and stain removal properties. Peracid bleaches work much in the manner of other oxidant bleaches, such as sodium hypochlorite and sodium perborate, by oxidizing soil on fabrics. Preferred examples of these sorts of peracid bleaches are the diperacids disclosed in Marynowski et al, U.S. 4,337,339; and European Patent Application No. 86306443.2 (0212976). However, packaging of peracid bleaches has proved to be problematic. Because of their great ability to oxidize, peracid bleaches can actually decompose themselves as well as numerous other substances. Further, such peracid bleaches will contain residual amounts of moisture, and if the moisture becomes concentrated, rapid second order decomposition can occur which results in the decomposition of the peracid bleach. Also, these peracid bleaches, such as the long chain diperacid known as diperoxydodecanedioic acid ("DPDDA"), contain long chain acids and diacids which typically are quite malodorous. Therefore, some means of suppressing such malodors in consumer products is desirable. The typical solution to reducing such malodors in such consumer products is to include a fragrance in the composition. However, applying a fragrance directly to an organic diperacid is unsatisfactory because the fragrance will itself be decomposed by the diperacid, possibly leading to a worse malodor. Therefore, such conventional fragrancing techniques not only fail to solve the problem but actually increases the problem. 1. The Container Material In order to present a novel and attractive container to the consumer, it is desirable to incorporate this dry bleach product in a transparent container. Transparent containers represent attractive and cost effective ways of packaging and marketing dry peracid bleaches. As mentioned, clear containers have been used to house dry, granular detergents but not dry granular peracid bleach compositions. However, it has now been discovered that use of certain plastic resins to construct containers for peracid bleaches will accelerate the decomposition of such bleaches due to their failure to transmit moisture released from the peracid bleach composition. The use of prior art clear plastic materials to house oxidant bleaches is a problem because such plastic materials are generally more water impermeable than cartons and thus residual or developed moisture present in the bleach composition will not evaporate. The presence of this residual moisture may lead to decomposition of the oxidant bleach or may expedite other oxidative reactions. Surprisingly, it has also been discovered that the use of certain heteropolymeric plastics as the material for construction of the container of the invention provides a sufficient rate of moisture transmission to avoid such decomposition. Applicants have discovered that certain hydrocarbon polymers, such as, polyethylene and polypropylene, which are, low cost plastic materials, typically used in a variety of bottle applications, will actually increase the instability of peracid bleach compositions contained in a container constructed thereof; but that the use of heteropolymeric plastics avoids the decomposition of the bleach which arises from their ability to release residual or developed moisture in the bleach formula. Furthermore, it has also been surprisingly discovered that certain of such heteropolymeric plastics also avoids an interaction with fragrances that react with some plastics to form malodors. It is not entirely understood why heteropolymeric plastics are necessary to construct dispensers which avoid such decomposition problems. Applicants theorize that, the phenomenon of increased product decomposition corresponds to the water vapour transmission properties of the plastic materials which is related to the polarizability of the substituents of the plastic. The term heteropolymeric plastic as used in the present invention comprises polymers which include polymers containing monomer units which have at least one heteroatom such as N, O, F, and in certain cases other halogen atoms and also copolymers which contain styrene monomer units; and which have water vapour transmission rates of 2g/day/645 cm²/25.4 µm thickness (2g/day/100 in²/ml thickness) or greater. The most preferred plastics are those selected from the group consisting essentially of butadiene/styrene copolymers, polyvinyl chloride, acrylonitrile, polyethylene terephthlate glycol, and mixtures thereof. It has been found that, if necessary, some amount of conventional plastics can be incorporated with any of the above heteropolymeric plastics to increase strength, clarity, to lower materials cost, etc., so long as the above criterion is satisfied. A particularly preferred plastic is a styrene butadiene copolymer, commercially available from Phillips Chemical Company under the trademark "K-resin". K-resin polymers have excellent visual clarity and a light transmission value of at least 90-91%. These polymers have high strength and durability (elastic modulus of about 191,000 psi as measured under ASTM method D790, or 1,316 MPA). These polymers can be injected molded, blow molded or thermoformed, as desired. These butadiene/styrene copolymers can be blended with other resins to lend different properties as described above. Other resins which can be blended with butadiene styrene copolymers include general purpose polystyrene, high impact polystyrene, styrene-acrylonitrile, styrene methylmethacrylate and polypropylene, so long as the above criterion is satisfied. Acrylonitrile is another material which is preferred for use in constructing the container of the invention. Acrylonitrile is generally prepared by the reaction of acetylene and hydrogen cyanide in the presence of a catalyst under relatively high temperatures, among other methods (see Seymour, Introduction to Polymer Chemistry (1971), pages 362-363.) Acrylonitriles have good stability and durability. Another suitable heteropolymer is polyethylene terephthalate glycol. This heteropolymer can be produced by reacting glycol with terephthalic acid in the presence of a catalyst. The resulting plastic is very durable and has good clarity. (See e.g., Oswin, Plastic Films and Packaging, page 109). Polyvinyl chloride also provides the moisture transmission characteristics desirable for the present invention. However, presently available commercial polyvinyl chlorides appear to suffer from one significant drawback with respect to certain contemplated applications since they react with certain fragrances to produce malodors. However, they are an acceptable plastic in the absence of the fragrancing means. Suitable methods of forming and manufacturing the containers of the invention are disclosed in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Vol. 18, pages 184-206 (1982), the disclosure of which is incorporated herein by reference. It is particularly preferred that the bottle of this invention be blow molded. This is usually accomplished by, generally, providing a mold into which is introduced molten resin in the form of a parison. After the air is fed into the die, the parison expands to fill the mold and then is cooled to form the bottle. Thereafter, the bottle is removed from the mold. Thermoforming presents another excellent method for making the bottles of the invention. 2. The Closure The containers according to the invention require closures for obvious reasons. The closures of the present invention are internally threaded and have a depending skirt portion wider than the upper portion of the closure. The closure may be constructed of plastics which are generally different than the plastic used for the bottle portion of the container since it does not experience extended contact with the peracid bleach. However, polyvinyl chloride should be avoided due to the fragrance reaction problems discussed above. The closure comprises an end wall or panel, and an annular wall depending therefrom, which includes an upper, internally threaded portion, and a lower skirt portion. An annular finish abutment rim is provided at the upper limit of the threads and is spaced from the end panel. The closure of the invention is provided with a relatively deep well defined by the internal portion of the closure from the end panel to just below the last top turn of the internal threads. This well may range in volume from 0.25 to 10cm³, although this is not critical. The well is provided to house a self-adhering fragrancing means, discussed below. By having a defined volume, it is most convenient to apply or insert the fragrancing means directly in to the well in a premeasured amount. In order to protect the fragrancing means from contact with the oxidant bleach, both when the closure is used as a measuring cup and if the fragrancing means were to accidentally jar loose from the closure during storage, a barrier means is provided, as detailed below. The barrier means typically is a perforated disc and can function in the manner of a liner for the closure. The closure also contains venting means, as disclosed in greater detail below. 3. Fragrancing Means In order to overcome the problem of malodors emanating from the preferred long chain diperacids housed in the inventive container, a fragrancing means is provided to fragrance and permeate the head space, or unfilled portion, of the container. The fragrancing means is preferably located in an area remote from where the oxidant bleach composition is located. In a preferred embodiment, as disclosed in EP 86306442.4 a small strip of fragranced material is affixed to an area remote from the oxidant bleach. In the present container, this is accomplished by placing the fragranced material in the closure well. The fragranced material generally comprises an amorphous hydrophobic, self-adhering polymeric material into which a fragrance has been intimately dispersed. The fragrance is usually a proprietary material which is commercially available from manufactures such as International Flavors and Fragrances, Givaudon and Firmenich, Inc. Further potential examples of appropriate fragrances may be disclosed in Whyte, U.S. 4,339,356, Staller, U.S. 4,540, 721, published European application EP 147191, and Hooper et al, U.S. 4,579,677 and U.S. 4,347,153, the disclosures of which are incorporated herein by reference. The polymer matrix material used to encompass the fragrance is selected from water-miscible, water-dispersible and hydrophobic polymers. However, as described, it is preferably a hydrophobic, amorphous polymer which can be melted and the fragrance oil can be admixed therewith. Suitable materials include ethylene/ethylacrylate blends, polyethylene/polypropylene blends, polyamides, polyesters and ethyl/vinyl acetate co-polymers. It is particularly preferred to use an ethyl/vinyl acetate co-polymer due to its self-adhering properties when solidified at room temperature, and because of its ability to contain relatively large volumes of fragrancing material. A typical hot melt fragrance composition may contain from about 10-60 wt.% of the fragrance oil and about 10-75% vinyl acetate in the ethylene/vinyl acetate co-polymer. Such fragrance/adhesive mixtures should have an equivalent hot melt index of from 1-50,000; and a hot metal ring and bol softening point of from 150-300°F. About 0.25-10 grams of the fragranced adhesive are applied to the well area of the closure described above. The head space, or unfilled portion, of the container is not critical and is dependant upon the amount of oxidant bleach which is in the container compared with the total volume of the container. Of course, this space will increase as bleach material is used from the container. 3. Barrier Means In order to protect the fragrancing means from contact with the oxidant bleach, and to contain the fragrancing means within the closure, a barrier means is provided in the closure adjacent the fragrancing means. The barrier means comprises an apertured disc, although other designs are feasible, e.g., cross-hatched reticular, etc. The preferred barrier means of the invention comprises a disc made of polyethylene having a series of apertures provided therein. Although the size of the apertures is not critical, it is preferred that the average bore size of the apertures be smaller that the average particle size of the oxidant bleach composition. Therefore, the apertures will typically have an average bore size of about 0.25mm to about 4mm. The number of apertures contained within the disc is also not critical. However, the number of apertures per unit area is preferably in the range of about 0.3 apertures/ cm² to about 16 apertures/ cm². 4. Venting Means It is also advantageous to provide venting means in the container of the invention to allow gaseous exchange between the interior of the container and the surrounding atmosphere. In this manner, concentration of malodors, such as those arising from the preferred long chain diperacids, is avoided. The venting means comprises a channel from the interior of the bottle finish to the atmosphere through defined space provided between bottle and closure threads. The venting means includes passage means for communicating the interior of the bottle finish with the threads. In one embodiment this comprises ramps or raised portions on the lower surface of an abutment rim adjacent the upper limit of the threads of the closure which prevent complete sealing of the container finish with the closure when the closure is rotationally closed down of the neck portion. As will be described is greater detail below, the passage means provides for a beneficial venting of gases within the container to the surrounding atmosphere. In further preferred embodiments of the venting means, selected slots or apertures can be provided in the neck portion of the container communicate gases between the bottle finish interior and the space between the finish and cap threads. These are further disclosed in greater detail below. 5. Oxidant Bleach Composition The preferred oxidant bleach composition of the invention comprises a dry granular peracid composition including organic peracid granules, diluents, pH control agents, and exotherm control agents. Preferred peracids have the structure wherein R is a linear alkyl chain of 6 to 12 carbon atoms in the chain. Particularly preferred for use is diperoxydodecanedioic acid (DPDDA). This particular type of diperacid is relatively stable and has excellent stain and soil removal performance. In order to prevent exothermic decomposition, an exotherm control, such as magnesium sulfate is generally added. The ratio of magnesium sulfate is to DPDDA is generally in the range of about 0.15:1 to 0.9:1, most preferably 0.35:1 to 0.75:1 on a weight basis. It is also preferred that the amount if water present as water of hydration of the magnesium sulfate be about 50-70% by weight of the magnesium sulfate when the diperacid granule contains a molar equivalent or excess of sodium sulfate to magnesium sulfate. This level of water corresponds roughly to about magnesium sulfate with 4 molecules of water of hydration. However, in the oxidant bleach granule, this most likely exists as a double salt of magnesium sulfate and sodium sulfate. Other components are present in the diperacid composition to act as bulking agents or diluents, such as sodium sulfate. Other materials can be present in the diperacid composition, such as adipic acid (pH control agent), polyacrylic acid (binder), fluorescent whitening agents, enzymes, bluing agents, and the like known to those skilled in the art. A preferred embodiment of the invention will now be described by reference the drawings referred to previously. Referring to the drawings, Fig. 1 depicts a container, shown generally at 2. The container bottle is constructed of a butadiene/styrene co-polymer and its closure is constructed of polyethylene. Bottle 3 has a body portion 4 which includes a hollow handle 6 defined by an elongated aperture 8 in the body portion 4. The interior of the handle is in communication with the rest of the body interior. The bottle 3 also has a neck or finish 14, joined to the body, which is externally threaded with helical threads 16. The bottle body comprises a reinforced base plate 40, upstanding side walls 11, and end walls 12 joining the side walls in spaced relationship; and reinforced areas 42 connecting the base plate with the side walls and end walls. Recessed areas 44 may be provided on the side walls for placement of appropriate labels. The dispenser also includes a closure 18, having an upper portio, 19, closed by an end wall or panel, and provided with internal helical threads, 46, spaced from such end wall. The threads 16 and 46 are complementary and cooperate when the cap closure 18 is rotationally closed down on the finish 14. The closure also includes a depending skirt 20 connected to and depending from the upper portion 19. The closure 18 is preferably provided with appropriate measuring lines (not shown), as it is intended to act also as a measuring cup for use in measuring and dispensing appropriate amounts of oxidant bleach. Turning now to Figs. 2 and 3, the closure includes an annular rim 25 provided on its interior surface and spaced from the end panel. The space between the end panel and the rim defines a well 26 provided for disposition of a fragrancing means therein. The well 26 (which has been somewhat exaggerated for emphasis) has a sufficient volume such that a fragrancing means 22 having a premeasured amount of a fragrance entrapped within a polymeric matrix can be easily filled or injected into the well 26. To protect the fragrancing means 22 from the oxidant bleach granules when the closure is used as measuring cap, as well as to isolate the fragrancing means 22 from the bleach granules contained within the container during storage, a barrier means 24, is provided in the cap adjacent the fragrancing means. The barrier means, preferably comprises an apertured disc, having a series of apertures 28. This barrier means also serves to prevent the fragrancing means from coming into intimate contact with the oxidant bleach 38 should the fragrancing means dislodge or detach from the well of the cap closure 18 due to a sharp blow. In order to permit venting of gases within the container, threads 46 and 16 are arranged to provide a gas passage 55 there between. In addition, the annular skirt 20 is broader than the corresponding portion of the container which provides an annular channel 56 there between. Furthermore, annular rim 25 has a stepped or ramped lower surface 31 which prevents the rim of finish 14, and thus bottle 3 from being completely sealed by the cap closure 18, and allows gas communication from the interior of the container, through passageways 55 and 56, to the atmosphere. Other embodiments of the venting means of the dispenser are shown in Figs. 5 to 8 inclusive. In each of these embodiments, the neck 14 is provided with apertures, notches or the like to allow venting of gases from the container to the channel defined by the finish and closure threads. In Fig. 5, semicircular notches 48 are provided in neck; in Fig. 6, apertures 50 are provided in the neck 14; in Fig. 7, V-shaped notches 52 are provided in the neck 14; and in Fig. 8, a square cut notch 54 is provided in the neck 14. Although unshown, the closure 18 can be further internally stabilized by the provision of wings or other axial stabilizers inside of the skirt 20. EXPERIMENTAL In Example I below, the stability of DPDDA bleach compositions in bottles composes of various plastic materials is compared. As will be shown in such Examples, surprisingly improved stability of such oxidant formulations is demonstrated by the inventive containers. Example I In 4 oz. bottles without the fragrancing means, made of plastics described below, a DPDDA bleach composition was formulated as follows: Ingredient wt.% DPDDA product (20% active) 15.86 Buffer 18.20 Brightener granules 3.00 Enzyme 1.47 Misc. 0.79 Agglom. Na₂SO₄ 60.68 100.00 4 oz. bottles were filled to 90% of the volume with the above compositions. These bottles were stored at 100°F for eight weeks. Thereafter, the products were assayed to determine amount of active oxygen % A.O. remaining. As demonstrated in Figure 10, the heteropolymeric plastics resulted in much better bleach stability at high temperature. This indicates much better long term stability when these materials are used. In an odor test, Example II, the odor resulting from use of the preferred heteropolymer, butadiene/styrene, was much better than that resulting from the use of a polyvinyl chloride plastic in Example III. Example II Samples of the oxidant bleach were stored in vented butadiene/styrene bottles with fragrancing means at 100°F for eight weeks and evaluated for fragrance intensity, character change and base coverage (i.e. identifiable as original fragrance). In the 100°F samples, the samples were recognizable as containing original fragrance and were not offensive. Example III A bottle composed of polyvinyl chloride which included a fragrancing means was substituted. At 100°F, the smell was unpleasant.

Claims: A transparent, durable container comprising a plastic bottle and a closure therefor which bottle contains a granular free-flowing composition characterized in that the composition is a peracid bleach composition and that the plastic is a heteropolymer having a water transmission of at least 2g/day/645 cm²/25.4 µm thickness (2g/day/100 in²/mil thickness). A container as claimed in claim 1 characterised in that the peracid is a diperacid of the formula: wherein R is a linear alkyl chain of 6 to 12 carbon atoms in the chain. A container as claimed in claim 1 or claim 2 characterised in that the plastic comprises a polymer and/or copolymer selected from the group consisting essentially of polyvinyl chloride, butadiene/styrene, acrylonitrile and polyethylene terephthalate glycol and is particularly a butadiene/styrene copolymer. A container as claimed in any of claims 1 to 3 characterised in that it further comprises venting means for venting the interior of the container to the atmosphere. A container as claimed in claim 4 characterised in that the venting means comprises means such that when the closure is combined with the finish of said bottle, an incomplete seal forms which allows for gaseous interchange. A container as claimed in claim 4 characterised in that the bottle includes a finish and said venting means comprises at least one aperture provided in said finish. A container as claimed in claim 6 characterised in that the bottle includes a finish, and a closure adapted to close said finish in rotating engagement therewith, and said venting means includes a gas passage provided between said closure and said finish. A container as claimed in any of claims 1 to 7 characterised in that said container further includes fragrancing means for fragrancing the interior of the container, and barrier means isolating the fragrance means from contact with the bleach composition contained within the container and for allowing the fragrance means to communicate with the container interior. A container as claimed in claim 1 characterised in that the fragrancing means comprise a fragrance incorporated in a nonrigid organic polymer. A container as claimed in claim 9 characterised in that the said organic polymer of the fragrancing means is selected from the group of water-miscible, water-dispersible and hydrophobic polymers. A container as claimed in claim 10 characterised in that the polymer of the fragrancing means is a hydrophobic polymer, which is a copolymer of ethylene and vinyl acetate. A container as claimed in any of claims 9 to 11 characterised in that the closure houses said fragrancing means and said barrier means. A container as claimed in claim 12 characterised in that the barrier means further comprises a plurality of apertures which allow ingress of the fragrance to the unfilled portion of the container but do not allow any of the granular bleach composition to contact the fragrancing means. A container as claimed in claim 13 characterised in that the apertures have an average bore size smaller than the average particle size of said bleach composition, prerably of 0.25 mm to 4 mm, and more particularly in which the number of apertures/area is in the range of 0.3 apertures/cm² to about 16 apertures/cm².

Inventors: CAMPBELL, EDWARD, MITCHELL, FRANCES E., STEICHEN, DALE S.
Applicants: THE CLOROX COMPANY
Application year: 1987
Main classification: B65D1
IPC codes: B65D51