MXPA98003464A - Coated bleach tablet and met - Google Patents

Abstract

The invention is directed to a coated solid active whitening tablet that provides reduced expansion upon contact with water, such as reduced odor and dust formation. Active bleach sources suitable for a coated bleach tablet of the invention include halogen and oxygen bleaches. Suitable coatings include water-soluble organic and inorganic materials. Coated whitening tablets are particularly beneficial for continuous advancement in well-known dispensing systems

Description

COATED BLEACH TABLET AND METHOD Field of the invention The invention relates to a solid source coated with an active bleach that can be used in bleaching or cleaning processes. The coated solid whitening fountain is suitable for the. continuous advance through a dispensing apparatus ^ when it makes contact with a solvent / water sprinkler assortment.

Background of I a Inv e ntion It is known in the art to use jets to supply a solid product by the use of water or diluents. Such dispensers can be used for many purposes, one of which is to provide active bleach for washing operations. Active bleach is a common component of many washing or sanitizing processes that include washing kitchen utensils. tableware, cutlery, kitchenware, etc. , laundry . health care appliances, food processing equipment, pharmaceutical manufacturing equipment, etc. A variety of active bleaching compositions are known including oxidizing compounds such as halogen and peroxy whiteners. The active halogen compositions have been sanitized. Such sources of halogen may come in the form of gases (Cl2 gas, Br2, etc.), liquids (aqueous sodium hypochlorite) or solids, calcium hypochloride, chlorinated sodium tripolyphosphate, chlorinated isocyanuric acid and others. The solids can be dissolved in water to create a bleach concentrate. The sources of halogen bleach solids have been used in aqueous solutions, particulate powders or in solid tablets or in block form. The solid tablet or block form of the solid active bleach source can be used in aqueous jets. The jets can be calibrated to provide various whitening compositions, frequently to provide from 1 to 28 grams of halogen or 8 to 125 grams of a peroxy bleach, per bleaching cycle. Generally, the solid tablet or block is loaded into an aqueous spout and advanced into a tablet container to settle directly into a container screen at a predetermined distance from an aqueous spray. As the aqueous spray contacts the surface of the solid bleaching material the water dissolves a portion of the bleaching source creating a liquid bleach concentrate that e & directed to a washing bleaching cycle. The fixed distance between the spray nozzle and the tablet is important in regulating the concentration of the bleach released from the tablet. However, solid tablets or blocks may pose a problem in the assortment. For example, the water spray used to dissolve the bleaching tablet can be absorbed by the tablet and can moisten the entire tablet or block causing the tablet to expand. Such tablets moistened in water can be difficult to fill due to expansion which causes the sides of the tablet to expand against the walls of the container. As the water wears the underside of the tablet, the tablet will not advance into the container. Therefore, the constant distance between the aqueous spray nozzle and the product is lost which can cause significant variation in the concentration of the bleach liquor entering the wash site. Some sources of solid bleach tend to flake or dust. The contact with the odor and the powder gives the solid whitening tablets can be annoying or even irritating for some individuals. Encapsulation of the active sources of the halogen bleach with organic and inorganic coatings have been described, for example in, Choy et al, United States Patent No. 4, 741, 858; Olson, U.S. Patent 4,279, 764, U.S. Patent No. 4,279, 764; Brennen, Patent of the States No. 3,637,509; Idudson, U.S. Patent No. 3,650, 961; Alterman, US Pat. No. 3, 983,254 and 3,908, 045. However, the coating of a bleaching tablet has not been described to facilitate the advancement of the tablet in a dispensing apparatus or to reduce odor or dust.

Accordingly, there is a need for processes that use sources of solid bleach to provide a source of solid bleach that can provide a uniform proportion of the solid mass of the source without effecting the distance between the spray nozzle and the product. There is also a need to reduce odor and dusting of solid whitening tablets.

Brief Description of the Invention Brief Description of the Drawings Fig. 1 is an illustration of a water spray type spout apparatus enclosing a tablet container loaded with three coated solid whitening tablets of the invention.

Detailed description of the Invention The present invention provides a coated whitening tablet that provides reduced expansion of the tablet when contacted by the spraying of dissolution / spray water. The coated tablet according to the invention can be used with any suitable solid product dispenser. Examples of suitable spouts are described, for example, in copending U.S. Patent Serial No. 08 / 644,620 or U.S. Patent No. 5,407,598, the descriptions of which are incorporated herein by reference . As used herein, the term "block0," "tablet" or "fragment" refers to a mass of material greater than about 1 gram having a size and shape adapted for introduction into a spout to contact A sprinkling of dissolution / assortment water The sprinkling of water, which dissolves a controlled portion of the tablet, forms an aqueous bleach concentrate which can be directed to a use site such as a washing machine. invention can include a source of active oxidant bleach such as active halogen or active oxygen in a water soluble outer coating One or more layers can be used to coat a solid bleaching tablet to form a coated bleaching tablet of the invention. water may be organic or inorganic.Preferably, the coating is substantially solid at temperatures that are likely to be during storage of the tablets (approximately 4.4 ° to 48.8 ° C). A coated whitening tablet of the invention can also reduce the odor or the formation of a bleaching agent of the tablet whitening agent.

Oxidant bleach A suitable oxidizing bleach for a coated bleach tablet of the invention includes a halogen and peroxy bleach. A halogen bleach includes an active halogen source which may comprise a halogen releasing substance suitable for releasing the active halogen species such as free elemental halogen (CL Br, Cl2, Bc2) or QCI "O OBr", under the Conditions commonly used in detergent bleach cleaning processes for a variety of cleaning purposes. Preferably, the halogen releasing compound releases chlorine or bromide species. The most preferred halogen species is chlorine. Chlorine release compounds include potassium dichloroisocyanurate, sodium dichloroisocyanurate, chlorinated trisodium phosphate, calcium hypochlorite, lithium hypochlorite, monochloramine, dichloramine, pentaisocyanurate [(monotrichloro) -tetra (monopotassium dichloride)], 1-r3-dichloro-5,5-dimethylidentonone, its para-toluene-iodide, tri-chloromelamine, N-chloramine, N-chlorosuccinimide, N, N'-dichloroazodicarbonamide, N-chloroacetyl- urea, N, N-dichloroazodicarbonamide, N-chloroacetyl-urea, N. N-dichloro uryl, chlorinated dicyandiamide, trichlorocyanuric acid, dichloroglyceride, etc. Chlorinated isocyanurate materials including dichloroisocyanurate dihydrate, sodium dichloroisocyanurate, potassium dichloroisocyanurate, etc. are the preferred chlorine sources Chlorinated isocyanurates are commercially available from Montsanto or Olin and other sellers. Peroxy bleach compounds are also suitable for a coated bleach tablet of the invention. Peroxy bleach compounds are represented by organic and inorganic ingredients. Any way, solid peroxy bleach compounds may be satisfactory for use in the present invention. Peroxy bleach compounds include the alkali metal salts of perborates, percarbonates, persilicates, persulfates and perfosphates. Peroxy bleach compounds can also be used. Specific examples of the organic petaxi bleach compounds are aliphatic and aromatic acids. Ct-2.1 mono and diperoxy such as peracetic acid, percaproic acid, peroléic acid, pertetracosenoic acid, peroxalic acid. peradipic acid, perdodecanoic acid, pertetradhedioic acid, peracelic acid, monoperoxyphalic acid, diperoxyterephthalic acid, 4-chlorodieperoxyphthalic acid. Preferred aromatic peracids include the water-soluble salts of diperisophthalic acid, m-chloroperbenzole acid and p-nitrobenzoic acid and their soluble salts. The peroxy bleach compound may also include an activator. Specific examples of the preferred activators may include acylated glycryls, tetra-acetylmethylene diamine, tetraacetyl ethylene diamine, triacetyl isocyanurate and benzyl azole.

Acid anhydride activators which possess at least one double bond between the carbon atoms, in alpha, alpha 'for the carbonyl group of the anhydride radical can also be used. Examples thereof are italic and maleic anhydrides. Especially preferred bleach activators are based on aldehydes, ketone and bisulfite adducts of aldehydes and ketones. Examples of those especially preferred activators include 1,4-cyclohexanedione; cyclohexanone; 3-oxo-cyclohexylacetic acid; 4-tert-butylcyclohexanone nitrate, 5-diethylmethylammonium-2-pentanone; - N-methyl-morpholinyl acetophenone nitrate; acetone; methyl ethyl ketone; 3-pentanone; methyl pyrute; N-methyl-4-oxopiperodin oxide; 1,4-bis (N-methyl-4-oxo-piperidinomethyl) benzene chloride; N- - methyltropinium nitrate; 1-methyl-4-oxo-piperidinium nitrate; N-benzyl-N-methyl-4-oxypiperidinium nitrate; N, N-dimethyl-4-oxo-piperidinium nitrate; di-2-pyridyl ketone; and doral hydrate.

Manufacturing Process of Solid Whitening Tablet The solid form bleach source of the invention can be made using a variety of known forming technologies. The solids formed can be made by compression processes, the use of molten binder agents and others known to those skilled in the art. When two or more sources of active bleach are used, the process for making the formed solids of the invention generally comprises two stages. First, the bleaching powders used in the formed solids are introduced into a mixing apparatus in order to form a homogeneous powder-blister. The commonly available mixing apparatus such as ribbon mixers can be used. The poLvo bleach is then placed in a commonly available press which can compress the powders into a tablet, block or fragment focma. Generally, the premixed powder bleach source is placed in a hopper with feeder systems and measured in a tablet former. The table size can vary from about 1 gram to 100 grams and more. Preferably, the tabLeta comprises from 500-2000 grams and can take any convenient form. A shape that is easily made by compression tablet formers is a disc or cylinder. The diameter of the cylinder may vary from about 0.635 cm to 12.7 cm or more having a thickness of about 0.635 cm to about 12.7 cm, preferably from about 1 27 cm to 7.62 cm. The solid whitening tablet may also be rectangular in shape. The length and width of the rectangular shaped tablet can vary from about 0.635 to 15.24 cm or more and has a thickness of about 0.635 cm to about 12.7 cm. Generally, as used herein, a "side" of the bleaching tablet refers to the thickness dimension. The "upper" and "lower" surface of the tablet refers to opposite circular or rectangular surfaces. Typically, the upper and lower surfaces are identical although the terms are used to connote the orientation of the solid tablet when it is loaded into the tablet container of a dispensing apparatus. A solid whitening tablet suitable for coating according to the invention includes tablets described in Olson et al., U.S. Patent No. 5,407,598, the disclosure of which is incorporated herein by reference.

Water-soluble Coatings A solid whitening tablet according to the invention is prepared by coating a whitening source in a solid form as described above with a water soluble coating. A water soluble coating can be organic or inorganic.

Organic Water Solubble Coatings A suitable organic water soluble material for coating a solid bleach tablet may include emulsion polymers such as polyvinyl chloride., polyurethane polymers, acrylic materials, polyvinyl chloride ethylene chloride copolymers, vinylidene chloride / alkyl methacrylate copolymers, vinyl chloride / vinyl acetate copolymers, isoprene or chloroprene neoprene polymers, vinyl acetate / alkyl acrylate copolymers or any combination of them. Other suitable polymeric materials include water-soluble cellulose ether compounds selected from the group including alkylene cellulose (C? .4), carboxyalkyl cellulose (C1.4), hydroxyalkyl cellulose (C? .4), carboxy cellulose (C1.4) ) alkyl hydroxyalkyl (C? -4). cellulose alkyl hydroxy (C?) alkyl (C? -4) and mies thereof. In one embodiment, the cell ether compound is carboxymethyl cellulose.

Soluble Coatings in Inorganic Water Suitable inorganic materials for coating a solid bleaching tablet of the invention include alkalis such as sodium bicarbonate, sodium sesquicarbonate, sodium borate, potassium bicarbonate, potassium sesquicarbonate, potassium borate, phosphates such as diammonium phosphate, phosphate monocalcium, monohydrate, tricalcium phosphate. calcium pyrophosphate, iron pyrophosphate, magnesium phosphate, monopotassium orthophosphate, potassium pyrophosphate, sodium orthophosphate dihydrate, trisodium orthophosphate decay, tetrasodium pyrophosphate, sodium polyhydrophosphate, a sodium polyphosphate compound, sodium hexametaphosphate, tripolyphosphate of potassium, a potassium polyphosphate compound, neutral or soluble salts such as sodium sulfate, sodium chloride silicates, inorganic sequestrants and antiredeposition agents and hydrates thereof. A suitable inorganic coating material also includes, for example, inorganic clays, such as VanGel B, VanGel O, Lapaaite RDS, available from Southern Clay Products.

Solid Whitening Tablet Coating Procedure Suitable methods for applying a coating to the solid bleaching tablet include dipping, spraying on or painting an aqueous solution of the water-soluble coating material. The coating can be applied only to the sides of the tablet which will be in contact with the walls of the tablet container when the tablets are in the dispensing apparatus. Alternatively, the. Tablets can be coated on the sides and the surface of the tablet away from the spray nozzle or, the tablets can be completely coated. Once the regions of a tablet are covered with an initial coating, subsequent coatings can be applied using similar methods.

Apparatus Apparatus Generally, a dispensing apparatus of the invention includes a tablet container for receiving one or more tablets, a spray nozzle for providing an aqueous spray to dissolve a portion of the tablet to create a bleach concentrate and a perforated member between the tablet and the spray nozzle. Generally, the tablet container includes a first end, which is close to the pierced member, and the walls that enclose the tablets when they are loaded. The tablet container may also include a second end, away from the pierced member, through which the tablets may be loaded into the container. For orientation purposes, a tablet is typically loaded into the tablet container with the upper surface confronting the second end of the container and the lower surface confronting the first end of the container. When the aqueous spray contacts the tablet it corrodes the lower surface of the tablet causing the tablet to advance into the tablet container towards the spray nozzle. As used herein, a "pierced member" refers to a material having openings that allow the passage of the aqueous spray to make contact with the lower surface of the tablet, although it does not allow the tablet or, large pieces that They could be separated from the tablet, pass through the pierced member. Perforated members include screens and meshes that are known in the art. In some dispensing apparatuses, the tablet can make contact directly or rest on the pierced member during the aqueous spray from the nozzle. In other dispensing devices, the tablet is retained in a removed position and on the pierced member. In any placement, the lower surface of the tablet is oriented towards the pierced member and the spray nozzle so that the surface of the tablet is dissolved by the aqueous spray, the tablet must advance the spray nozzle to maintain a fixed distance between the spray nozzle and the contact surface of the tablet. Yes The distance between the tablet and the spray nozzle varies, the amount of bleach released from the tablet may be inconsistent. A problem with some tablets of the prior art is that upon contact with the aqueous spray, the water can be absorbed by the tablet and cause the tablet to expand. The expansion of the tablet into the tablet container can cause friction between the tablet and the wall of the tablet container which prevents the tablet from advancing towards the spray nozzle. The unique coated whitening tablets of the present invention have a reduced likelihood of expansion, thus providing continuous advancement to maintain a predetermined distance between the tablet and the spray nozzle. As used herein, the term "continuous advance" connotes the movement of the coated tablets through the tablet container with a reduced incidence of "suspension" due to expansion of the tablet.

Detailed Description of the Figure Fig. 1 is a cross section of the portion of a dispensing apparatus used to introduce the active halogen bleach concentrate using the coated bleaching tablets of the invention. In Fig. 1, the spout apparatus housing 1, a portion of a general housing of a spout apparatus that can be adapted to supply 1, 2 or more materials in solid form can be configured to supply the coated whitening tablets of the invention. An example of the spout shown in Fig. 1 is the Solid System ll l ™ spout. Such a dispensing apparatus is used in the laundry supply. In Fig. 1, a spray nozzle 2 is shown with a cone-shaped spray 3 directed from the nozzle 2 on the bottom surface 4 of the formed solid 5 contained within the tablet container 6 which is attached to the surplus with a threaded connector 7 and the 8 μl shoulders cooperate with the nozzle housing 9. In the operation of the spout, fresh water is introduced into the spout through the conduit 10, water is sprayed through the nozzle 2 on the lower surface of the solid bleaching tablet coated 5 - creating a concentrate. The concentrate passes through the opening of the capsule 1 1 through the perforated member 12 to the outlet 1 3. Any large portions of the solids formed that are free can be trapped by the sieve 12.

An alternative embodiment of the dispensing apparatus suitable for the present invention is disclosed in copending United States patent application Serial No. 08 / 644,620, the disclosure of which is incorporated herein by reference.

Examples EXAMPLE 1 Solid bleaching tablets as described in Patent No. 5,407, 598 were coated with a 5% aqueous solution of carboxymethylcellulose (CMC) 7LT. (Hercules Aqualon, Wilmington, DE 19899). The 5% CMC was coated on the sides of the tablet using a paint brush. The coating moistened in the pores of the tablets and dried to a smooth finish. The tablets were placed in a Solid Systems HTM dispensing system available from Ecolab, I nc. , St. Paul, MN. The tablets moved freely through the tablet container of the dispenser.

Example 2 A solid bleaching tablet as described in U.S. Pat. 5, 407, 598 was coated on all surfaces with CMC as described in Example 1. The coated bleaching tablet was placed in a stability oven at 48.8 ° C for two weeks. A sample of the surface of the product was titled to determine the loss of chlorine. There was no difference in the percentage of available credit.

Example 3 9 solid bleaching tablets as described in U.S. Patent No. 5,407,598 were coated with a 5% aqueous solution of the Laponite RDS inorganic clay. The solution was painted on the tablet, forming a gel that was dried to a smooth finish.

Example 4 A solid bleaching tablet comprising sodium perborate monohydrate was coated with a 5% aqueous solution of carboxymethylcellulose (CMC) 7LT. The 5% CMC was coated on the sides of the tablets using a paintbrush. The coating moistened within the pores of the tablets and dried to a smooth finish. The tablets were placed in an SS I I dispensing system. The tablets move freely through the tablet container of the supplier Example 5

Claims (20)

1. A 5% CMC aqueous solution was sprayed onto the surface of 6 solid bleach tablets as described in U.S. Pat. No. 5,407, 598. The coating was sprayed using a liquid pressure of 1,406 kg / cm 2.; atomization pressure of 0.703 kg / cm2 and fan pressure of 1 .406 kg / cm
2. 2. A surface (top / bottom) and sides were sprayed. After drying for 5 minutes the tablets were released and the opposite surface and sides sprayed. This provided two coatings on the sides and one coating on each surface. The above specification, examples and data provide a complete description of the preparation and use of the coated bleaching tablets of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims included hereunder. CLAIMS 1 . A method for the continuous advancement of a coated bleaching tablet through a dispensing apparatus, the method comprising: (a), introducing a coated bleaching tablet into the dispensing apparatus, the dispensing apparatus comprising: i) a tablet container, the tablet container having a first end; and ii) a pierced member proximate the first end of the tablet container; (b) the coated bleaching tablet comprising: i) a solid bleaching tablet having a top surface, a bottom surface and a side surface; ij) a water-soluble coating applied to at least a portion of the side surface of the solid bleaching tablet. The method according to claim 1, further comprising contacting the lower surface of the coated bleaching tablet with the perforated member and spraying a solvent through the perforated member to dissolve a portion of the lower surface of the bleaching tablet. rehired.
3. 3. The method according to claim 1, wherein the water-soluble coating is an organic water-soluble coating.
4. 4. The method according to claim 1, wherein the water soluble coating is an inorganic water soluble coating.
5. 5. The method according to claim 1, wherein the organic water-soluble coating is a cellulose ether compound.
6. 6. The method according to claim 5, wherein the cellulose ether compound is carboxymethylcellulose.
7. 7. The method according to claim 4, wherein the inorganic water soluble coating is Laponite RDS.
8. The method according to claim 1, wherein the tablet container further comprises a second end for introducing the coated bleach tablet into the tablet container.
9. The method according to claim 1, wherein the water soluble coating comprises a plurality of coating layers.
10. The method according to claim 9, which includes an organic and an inorganic water soluble coating layer. eleven .
11. The method according to claim 1, wherein the top surface of the coated bleach tablet is coated with the water soluble coating.
12. 12. A method for reducing the powder associated with a solid bleaching tablet, the method comprising a step of: (a) selecting a solid bleaching tablet having an external surface; and (b) applying a water soluble coating to at least a portion of the outer surface of the solid bleaching tablet to provide a coated solid bleaching tablet.
13. The method according to claim 12, wherein the water-soluble coating is applied to the entire outer surface of the solid bleaching tablet.
14. 14. The method according to claim 12, wherein the water soluble coating is an organic water soluble coating.
15. 15. The method according to claim 12, wherein the water soluble coating is an inorganic water soluble coating.
16. 16. The method according to claim 12, comprising providing continuous advancement of the coated solid bleach tablet through a spout apparatus.
17. 17. A method for reducing odor associated with a solid whitening tablet, the method comprising a step of: (a) selecting a solid whitening tablet having an external surface; and (b) applying a water-soluble coating to at least a portion of the solid bleaching tablet to provide a coated solid bleaching tablet.
18. 18. The method according to claim 17, wherein the water-soluble coating is applied to the entire outer surface of the solid bleaching tablet.
19. 19. The method according to claim 17, further providing continuous advancement of the solid bleaching tablet through a spout apparatus. The method according to claim 17, wherein the water soluble coating is an organic water soluble coating. SUMMARY The invention is directed to a coated solid active whitening tablet that provides reduced expansion to contact with water as well as reduced odor and dust formation. Active bleach sources suitable for a coated bleach tablet of the invention include active halogen and oxygen bleaches. Suitable coatings include water-soluble organic and inorganic materials. Coated whitening tablets are particularly beneficial for continuous advancement in known dispensing systems.