AU604529B2 - Support material for volatile substances usable in deodorizing and scenting blocks - Google Patents

Description

1111 II 1 1111IIII I 11 :I III ii O 1 5 F Ref: 50770 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Complete Specification Lodged: Accepted: Published: Priority: Related Art: Class Int Class Section 49 a-d is cuorr~cL 'ori printig.__ S Name and Address of Applicant: Reckitt Colman rue Ampere 91301 Massy Cedex

FRANCE

s, Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled: Support Material for Volatile Substances Usable in Deodorizing and Scenting Blocks The following statement is a full description of this invention, including the best method of performing it known to me/us 5845/3 5845/2 1 )V F 5845/2, N A CC EPTED A N D A M EN D M EN TS iA i J .ED nR 1 ,t ABSTRACT OF THE DISCLOSURE A support material for volatile substances usable in deodorizing and scenting blocks exposed to Shumid air or to the action of water is in the form of a solid body. All or a significant part of the external surface of this solid body, from which the volatile substance diftuses, has visible roughness. This significantly increases its surface area relative to a smooth surface with the same overall dimensions.

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RECKITT COLMAN M. L. BEYELER Pr it~nt Dirert ran SFP4 To: The Commissioner of Patents Signature D ecarant(s) 11/81 4 Ii 4-, SUPPORT MATERIAL FOR VOLATILE SUBSTANCES USABLE IN DEODORIZING AND SCENTING BLOCKS BACKGROUND OF THE INVENTION Field of the invention The present invention concerns an improved support material for volatile substances usable in deodorizing and scenting blocks exposed to humid air or to the action of water.

To be more precise, the invention concerns support materials of this kind for diffusing the volatile, fragrance-type substance usable in particular for deodorizing or scenting blocks suspended in humid air, such as blocks for bathrooms and for disinfecting toilet bowls.

Description of the prior art Blocks of this kind and the suspension devices containing them are well known for disinfecting atmospheres prone to moisture and to the action of water, as is the case with blocks suspended from the S' 20 edge of toilet bowls. Devices of this kind for use in toilets generally are in the form of parallelepiped or cylindrical baskets with mesh or slotted or perforated Swalls and are subject to the action of moisture or water j which disolves and/or entrains with it the ingredients necessary for either a cleaning action or a disinfecting, scenting or deodorizing action, depending on the nature of these ingredients.

As a general rule, and in the case of compositions for treating toilet bowls in particular, the ingredients of the blocks in question comprise: (a) a descaling agent which may be a substance or a mixture of substances avoiding the accumulation of scale or facilitating its elimination; optionally one or more surfactants functioning as detergent and/or foaming agents; one or more salts favoring the action of the W V i2 surfactant or surfactants (known as "buildurs"); and (d) a deodorizing or fragrance-type volatile substance released in most cases from within the block by evaporation at the surface and by successive dissolving of each of the ingredients in the composition of the block.

The space between the rim of a toilet bowl and the bowl itself is somewhat restricted. Also, some users find the sight of the device containing this block 10 unesthetic.

i; To eliminate these disadvantages, the devices have to be made in such a way that their shape and size make them as small as possible, given the intended objectives. The space available for accommodating the treatment composition is therefore limited.

Also, for the block to be able to satisfy all the needs and requirements ot the consumer, it must have a suitable service life. For this reason modifications have been made to the compositions for treating toilet bowls in order to extend their useful life. There have already been provided, for example, coatings whose objective is to slow down the release of the ingredients in these compositions. Likewise, the latter may include ingredients which feature low solubility or which dissolve at a very slow rate.

Modifications such as these are applicable only if they do not render the composition ineffective by making it too insoluble. As a consequence of such measures, the emission of the fragrance may be prejudiced.

It is known to impregnate absorbent materials with deodorizing or scenting compositions. These materials are in the form of plates, for example, that are suspended in rooms or elsewhere to disinfect or scent the air.

3 The effectiveness of such systems depends on the quantity of volatile substance that has been absorbed by the absorbent material and/or the rate at which this volatile substance diffuses out.

The present invention is directed to improving this rate of diffusion while using an absorbent material with the smallest possible dimensions and most compact possible shape. Also, the invention is directed to a material of this kind applicable to the treatment of toilet bowls, in such a way that the duration of such treatment is prolonged.

SUMMARY OF THE INVENTION According to a first embodiment of the present invention there is provided support material when used to support volatile substances usable in deodorizing and scenting blocks exposed to humid air or to the action of water, in the form of a porous solid body of which all or a significant proportion of the external surface adapted to diffuse said volatile substance has surface enlarging means for significantly increasing its 0 surface area relative to a smooth surface with the same overall dimensions, said surface enlarging means comprising a plurality of visible troughs 0 a0 and/or peaks each having a height or depth approximately 5-25% of the S thickness of said porous solid body.

0 20 The absorbent material may be any porous material in the form of a 1 o mat, a plate, a flat or curved sheet or a block that may be advantageously parallelepiped-shape or cylindrical. These shapes may also be obtained from woven or non-woven fabrics. They may be obtained from fibers or 00 powder incorporated into an appropriate matrix by sintering, adhesive o0.- bonding, surface fusion or coating to form elements of large dimensions 0 0 that can afterwards, if necessary, be cut to the required size.

The material in accordance with the invention may be a particulate absorbent material, for example a granular material featuring a relatively large grain size and cellular structure.

RF R 4 3y RLF/0943y 4 We have noted that a minimum quantity (per unit time) of volatile substance such as a fragrance diffuses into the atmosphere in the case of a support with a relatively small total surface area, leading to insufficient odorization of the atmosphere in a toilet or bathroom.

A material in accordance with the invention in one of the forms described above featuring surface roughness diffuses a much greater quantity of fragrance because of the presence of this surface roughness.

In an advantageous embodiment, the material may comprise over all or part of its visible surface numerous grooves or ribs. This surface may also have a In another embodiment the roughness over all. or part of the visible surface may be obtained by particulate elements, fixed on the totality or part only of the initially smooth surface of the material, these elements 4~ ~<being added by an operation adapted to make them adhere C 21) to the initially smooth surface or surfaces.

Although the substance from which the support material in accordance is made may be of any kind, provided only that it is 'porous and is able to absorb a volatile substance such as as fragrance, certain S 25 substances impregnated in this way have shown themselves capable ot retaining a volatile substance in the presence of water for a longer period than other impregnated materials.

Ii; We have found that materials which are naturally 30 hydrophobic give the best result.

It is thought that when an impregnated material has rapidly lost the amount of volatile substance with which it was impregnated, this loss is due firstly to evaporation or diffusion of' the volatile substance; however, this loss of volatile substance may equally well be due to entrainment by the water with which the material is in contact when it is used under the rims of toilet' bowls, like other ingredients of a composition generally used for disinfecting toilet bowls.

In an even more advantageous embodiment, the support material is chosen such that the surface tension at the volatile substance/ support material interface is IIless than the surface tension at the water/support material interface, whereby loss of the volatile substance in contact with the water is ininimized.

Consequently, the present invention provides also a material in the form of mats, sheets, plates or Vblocks of agomerated particles of natural or synthetic and of organic or mineral nature having the above surface tension characteristics, possibly naturally or otherwise because at least part of the visible surface h.as been advantageously modified by phys ical- chemical Ii means to confer on it such characteristics by a process analogous to that described in French patent application No 82 03599.

These materials include the polyolefins such as polyethylene and polypropylene, polyesters, polyamides, cellulose esters such as cellulose acetate, propionate and butyrate or mixtures and combinations thereof, polyvinyl derivatives such as polyvinyl chloride, acetate or phtalate, rigid and flexible forms of expanded polyurethane, their copolymers and mixtures, glass fibers possibly coated with a f ilm of polyester or I analogous materials.

30 The materials of natural origin include wool, especially in the form of felt. These materials may be in the form of particles or fibers. These fibers may optionally. be transformed into sheets or bundles by known methods such as weaving,, knitting, superposition of layers, adhesive bonding or other methods of 6 manufacturing particle or laminated materials, etc.

Naturally, the material in accordance with the invention may be made in large plates, panels, etc which can be subsequently cut into strips, sheets, plates of small size for use in accordance with the invention.

Conglomerate materials made from particulate elements may be made by sintering, for example, possibly in the presence of solvents, in order to produce absorbing LI~materials. Here again, structures of this kind can be ct ito srip, shetsor bock orparticulate elenrents and treated to increase their diffusion surface area for use in accordance with the invention.

Roughness over all or part of the visible surface of the materials in accordance with the invention may be obtained by forming channels, grooves, ribs, recesses, undulations, *etc.

These surface modifications may be applied to a material that exists already. Given that the rate of absorption depends on the actual surface area, when impregnation is effected by immersion in the fluid in *question, it may be advantageous in this case for the material that is to be, impregnated to have had its surfaces already modified before impregnation is begun.

As the objective is to increase the rate of release or diffusion of the volatile substances during use to deodorize or scent an atmosphere, the surface modification may equally well be effected after impregnation, if required.

However, a method of this kind may entail the risk of a loss of volatile substance during cutting or shaping operations.

The impregnation of the substrate constituted by the material in the forgm of particles, bundles, sheets or plates with a fragrance or deodorizing substance of appropriate nature possibly containing a I7 solvent can be effected by conventional techniques, for example by immersion, by spraying or by injection into the mass to be impregnated, or by any other appropriate means. Such operations are directed to ensuring that the required quantity of the volatile substance per unit of surface area or per unit of weight of the material to be impregnated is actually absorbed. Where a solvent is used, it can remain absorbed or can be eliminated t subsequently, if required, by evaporation. Care will be given to choosing an appropriate solvent and the components of the fragrance or deodorizing substance in "ci order to avoid phenomena of incompatibility with the absorbent material.

Tel The scope and the benefits of the invention will emerge more clearly from the examples described hereinbelow, with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS S. Figures 1 through 7 are evaporation curves relating to the examples described below.

EXAMPLES,

Example 1 A rigid absorbent plate made from natural wood cellulose fibers, of parallelpiped shape and with t dimensions of 70 x 32 x4 mm was machined on its two largest surfaces in the direction of the largest dimension to obtain 12 parallel grooves of square cross-section 1 mm wide and deep, spaced by 2.5 mm.

The total surface area of each largest surface was thereby increased by 70% relative to a smooth surface of the same size, resulting in an 60% increase in the total surface area of the plate.

The plate with grooved surfaces together with a smooth plate the same overall size were impregnated with three grams of isobornyl acetate and then placed in a controled temperature and humidity enclosure.

i 1 1 rt if| i1 i i f S Ir( c rh i r Evaporation of the isobornyl acetate, resulting in a loss in weight of the plates, was monitored by weighing the plates at regular intervals.

The cumulative weight losses of each plate were plotted in the form of graphs showing the relation AP f(t) as shown in figure 1.

The slope of these curves at any point represents the speed of evaporation ot the isobornyl acetate in grams per day, which speed is proportional to 10 the intensity of odorisation by the plate concerned.

The grooved surface plate (continuous curve) loses weight faster than the smooth surface plate (dashed curve).

It is found that evaporation of the isobornyl acetate is faster by approximately 50% from the grooved surface plate, which proves the effectiveness of increasing the diffusion surface area for evaporation of the same fragrance composition from substrates of identical overall dimensions, and thus for increasing the intensity of odorization.

E]xample 2 The substrate in this example is primarily cellulose acetate having' an esterification rate of approximately 2.5. Rigid parallelepipea plates with 25 dimensions 70 x 32 x 5 mm were prepared from a bundle of cellulose acetate fibers bonded together using a small quantity of appropriate solvent and then pressed to form a compact bundle which was then cut to the required length.

This manufacturing process produces plates the largest surfaces of which are either smooth or feature various, relief patterns and therefore a total surface area larger than the apparent surface area.

The plate with the augmented diffusion surface area of this example was obtained by pressing the bundle 9 of fibers between two rollers on which were triangular cross-section reliets.

Following relaxation of the material and cutting of the bundle to the required length of 70 mm, the plate had on both its major surfaces equidistant "Leeds" parallel to the direction of the bundle of fibers and of approximately semicircular cross-section.

Their height was approximately 0.6 mm and they were uniformly distributed across the width of the plate with approximately 6.7 reeds per centimeter (1.5 mm between centers) In this example the largest surfaces of the plate with modified surface were striated only to within approximately 3 mm of each of the two 70 mm edges, so 115 leaving smooth strips 3 mm. wide to either side of the striated area, as required for technical reasons Q.concerned with manipulation ot the plates.

;A striated plate as described above has a clittusion surtace area increased by approximately 20 re~ative to that of a smooth surface plate.

tstriated plate of this kind and a smooth plate were impregnated with 5 g ot a flower fragrance oil substance.

Evaporation of the fragrance was monitored by the same method as in example 1.

The curves of cumulative weight loss as a function of time shown in figure 2 indicate that evaporation of the fragrance from the striated surface plate (continuous curve) is approximately 30% faster than evaporation of the same fragrance from the smooth surface plate (dashed curve).

Exar~ple 3 This example compares the behavior of the tollowing two substrates, exposed or not to the action of water: i a plate based on cellulose acetate with a rate of esterification near 2.5, dimensions of x 32 x 5 mm, smooth surfaces, made by the method described in example 2; a plate based on natural wood cellulose fibers, dimensions 70 x 32 x 4 mm, smooth surfaces, identical to that of example 1.

Five grams of flower fragrance substance were deposited on the plates which were then placed in 10 deodorizing devices designed to be fixed under the rim eof toilet bowls.

Each device was tested individually in the toilet bowl equipping each of identical stalls of the test installation.

The stalls, with a volume of 2.4 m 3 (dimensions 0.8 x 1.2 x 2.5 m) were all subject to the same conditions of temperature, humidity and ventilation.

The intensity of odorization of these stalls by the deodorizing devices was evaluated through a window formed in their door, by trained members of a scent testing panel, on a scale of marks from 1 through very strong intensity, 4: strong intensity, 3: moderate intensity/odor easily perceptible, 2: low intensity/odor difficultly perceptible, 1: zero intensity/odor not perceptible.

The toilet bowls could be flushed independently, by an automatic programming system simulating real conditions of use of the products (for example, flushes per day).

Four deodorizing devices, two for each kind of substrate,. were placed in the bowls of four test stalls tor six weeks. For each kind' of substrate, one sample was subjected to the action of water by the flushing Iprogramming system and the other was kept dry by cutting f off the bowl programming system.

The four devices were designated as follows: A* device with cellulose acetate plate, I 5 subjected to flushing, B: device identical to A but not subjected to flushing, C: device with natural wood cellulose plate, subjected to tiushing, D: device identical to C but not subjected to flushing.

Figure 3 shows the trend for the intensity of odorization of the stalls containing devices A and B over six weeks, evaluated weekly.

Figure 4 shows the trend obtained under the same conditions with devices C and D).

In figure 3 the intensity curves obtained with deodorizing devices A and B are comparable throughout the duration of the test, comprised between approximately 3,3 and 3.5, which shows that there is no loss of effectiveness of the deodorizing device A subjected to the action of water as compared with its homologue B kept dry.

Thus the scented substance is not leached out by the water when it is impregnated into cellulose acetate with a 3- te of esteritication around Fiy'ure 4 shows that in one week the intensity oft odorization of the stall by the device C subjected to the action of water falls to a value near 1 whereas the intensity of device D kept ory remains near the value ot 3 for more than five weeks.

The loss of efficiency of the device ~'is obviously due to rapid leaching out of the scented substance due to the action o-f the water.

A wood cellulose type substrate with no specific 12 treatment is therefore not suited to deodorizing devices in accordance with the present invention.

Example 4 The same tests as for example 3 were conducted with an absorbent sabstrate consisting of sintered polyethylene. Two parallelepiped plates with dimensions of 70 x 32 x 4 mm were cut out from a sheet of sintered polyethylene 4 mm thick.

Five grams of the same type flower scented substance were deposited onto these plates which were then placed in deodorizing devices E and F identical to those of example 3, each being then suspended in the Li toilet bowl of a test stall.

During the six weeks of the test, sample E was subjected to flushing and sample F was kept dry.

Figure 5 shows that the odorization intensity curves for the two devices remained close together and comprised 3.0 and 3.5 throughout the duration of the test.

This obviously shows the ability of the sintered polyethylene baseo substrate to prevent leaching out of the scented substance by the water.

Example Two plates of cellulose acetate, one striated and the other smooth, identical to those of example 2, and impregnated with tive grams of the flower scented substance, were placed in two deodorizing devices respectively G and H.

These devices were suspended in the toilet bowls of two scent testing stalls and subjected to repeated flushing with water by the automatic flushing programming system (30 flushes per day).

Figure 6 shows the trend of the odorizing intensities of the stalls evaluated over six weeks according to the same criteria as example 3.

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4' 0 i 0 r L 13 It is seen that the intensity of the deodorizing device G equipped with a striated plate, and thus having a larger diffusion surtace area, is greater than the intensity of the deodorizing device H equipped with a smooth plate over approximately five weeks.

After five weeks, the intensity for the device G drops below that for the device H because of the faster exhaustion of scented substance (see weight loss curves, example 2, figure 2).

10 More scented substance remains in the substrate of the device H at this time because of the slower evaporation from the smooth plate.

This example therefore illustrates well the increased intensity of odorization obtained under real conditions of use with an absorbent substrate having an increased diffusion surface area.

Correlating with this, tor the same weight ot scentea suostance, the useful lite of a device of this kind is shorter than that ot a device comprising a smooth surfaced substrate.

Example 6 The test of example 5 was repeated with the sintered polyethylene type absorbent substrate from example 4.

A parallelepiped plate of this material with dimensions of 70 x 32 x 4 mm was grooved lengthwise on the two major surfaces using an appropriate tool.

In this way, 30 equilateral triangle cross-section grooves with a side length of 1 mm were cut side by side into the plate.

This increased the diffusion surface area of the largest surfaces of the plate by almost 93%.

This increase represents approximately 78% of the entire surface area of the plate.

The plate grooved in this way and a smooth 1 0 0t 14 surfaced plate impregnated with five grams of the same flower scented substance were placed in respective deodorizing devices J and K.

Following six weeks of testing in scent testing stalls by the same procedure as for example 5, the odorization intensity curves reproduced in figure 7 show that 'the scenting capability of the device J with an increased diffusion surface area plate is significantly greater' than that of the device K equipped with a smooth 10 surfaced plate.

In a preferred embodiment a device designed to H be hooked (suspended) in toilet bowls containing a Snon-scented active substance, preferably in the form of a block ana comprising descaling agents and/or surtactants and/or one or more "builders" has a housing (compartment) for an absorbent material in the form of a thin block impregnated with fragrance of the type used in the above examples. Such absorbent supports have a relatively large external surface area relative to their thickness.

Also, in the case of a thin block, at least one of the largest surfaces ot the block is shaped to feature troughs and peaks intended to increase the evaporation (diffusion) surface area.

25 The relative height (or depth) of the peaks and troughs represent approximately 5 to 25% of the thickness of the block and their width varies proportionately.

The aifference in level between the peaks and troughs is preferably 8 to 20% of the tnickness of the Dlock.

In practice the block has peaks and troughs with a height (depth) ot 10 to 15% of the thickness of the plate.

A surface modified in this way can have between I 4 -i _r three and 15 peaks and between three and 15 troughs per centimeter.

The surface preferably comprises between four and 12 peaks and troughs per centimeter. Specifically, this density is between five and Thus in a relatively small overall volume, but thanks to a large actual surface area, there results a maximum effectiveness of diftusion of any active substance in association with a disinfectant substance.

S 10 It will be obvious that the present invention i has been described by way of non-limiting explanation only and that any modification, in particular with regard to the substitution of technical equivalents, may be made to it without departing from the scope of the invention.

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Claims (14)

1. Support material when used to support volatile substances usable in deodorizing and scenting blocks exposed to humid air or to the action of water, in the form of a porous solid body of which all or a significant proportion of the external surface adapted to diffuse said volatile substance has surface enlarging means for significantly increasing its surface area relative to a smooth surface with the same overall dimensions, said surface enlarging means comprising a plurality of visible troughs and/or peaks each having a height or depth approximately 5-25/ of the thickness of said porous solid body.

2. Material according to claim 1, wherein said solid body is porous and constitutes a mat, plate, flat or curved sheet or block.

3. Material according to claim 1 or claim 2, wherein said external surface adapted to diffuse said volatile substance is discontinuous.

4. Material according to any one of claims 1 to 3, comprising ribs and/or grooves adapted to form said roughness. 00 05. Material according to any one of claims 1 to 3, comprising a projecting matrix of fibers, granules or particles on its surface adapted 0 0 to form said roughness. 0 6. Material according to claim 5, wherein said fibers, granules or S particles are embedded in said matrix or adhesively bonded or fused or sintered onto the surface of said matrix.

7. Material according to any one of claims 1 to 3, comprising conglomerates of granules of particles, cellular or otherwise all or part of the surface of which has been rendered rough.

8. Material according to any one of claims 1 to 7, made from a substance for which the surface tension at the volatile substance/ support 5 material interface is lower than the surface tension at the water/support material interface.

9. Material according to claim 8, wherein the support material is treated by physical-chemical means to have a surface tension at the S volatile substance/ support material interface which is lower than the surface tension at the water/support material interface. Material according to any one of claims 1 to 8, wherein the support material is chosen from the group comprising polyolefins, polyesters, polyamides, cellulose esters, polyvinyl derivatives, rigid or .RLO943y I i, 17 flexible expanded polyurethane, their copolymers and mixtures thereof, and glass fibers, optionally coated with a film of polyester or analogous materials.

11. Material according to claim 10, wherein the polyolefin is selected from polyethylene or polypropylene.

12. Material according to claim 10, wherein the cellulose esters are selected from cellulose acetate, propionate and butyrate or mixtures and combinations thereof.

13. Material according to claim 10, wherein the polyvinyl derivatives are selected from polyvinyl chloride, acetate or phthalate.

14. Material according to any one of claims 1 to 8, based on wool. Device when used to odorize humid atmospheres or toilet bowls having mounted therein a support material according to any one of claims 1 to 14.

16. Device according to claim 15, associated with or forming an integral part of a plate or block of disinfectant substance comprising descaling and/or anti-scaling agents and/or one or more surfactants and/or one or more active or inactive substances contained in a device adapted to be suspended from or attached to the rim of a toilet bowl. 4 a

17. Device according to claim 16, wherein the support material and disinfectant device are in different compartments.

18. Support material, substantially as hereinbefore described with reference to any one of Examples 1 to 5 but excluding any comparative example. h 19. Device when used to deodorize humid atmospheres or toilet bowls S having mounted therein a support material according to claim IS DATED this TWENTY-FIRST day of AUGUST 1990 Reckitt Colman Patent Attorneys for the Applicant SPRUSON FERGUSON RLF/0943y