Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B11/00—Oxides or oxyacids of halogens; Salts thereof
  • C01B11/02—Oxides of chlorine
  • C01B11/022—Chlorine dioxide (ClO2)
  • C01B11/023—Preparation from chlorites or chlorates
  • C01B11/024—Preparation from chlorites or chlorates from chlorites

Definitions

• the present invention is generally related to broad spectrum disinfectants, sanitizers, cleaners or deodorizers using chlorine dioxide compositions, and more particularly, to methods for producing chlorine dioxide compositions having improved long term stability by the proper choice of pH and through the careful choice of other product formula ingredients.
• CIO2 chlorine dioxide
• hypochlorite peroxide
• quaternary amines quaternary amines
• Chlorine dioxide is an effective biocide and can clean and deodorize.
• CIO2 does not chlorinate organic compounds.
• it is inherently less stable than other biocides such as quaternary amines. Due to instability, most applications involve producing chlorine dioxide at the source of use. Therefore, chlorine dioxide must be properly formulated to be viable.
• a disinfectant or sanitizing or cleaner/deodorizer product that maximizes the stability of the active ingredients so that the product has a suitable shelf-life and is ready to use after manufacturing.
• Stable products have a longer shelf-life, better consumer appeal, and are easier to use.
• a stable product can use conventional package that are readily available and cheaper.
• the invention is a device for delivering stabilized chlorine dioxide having improved long term stability by the proper choice of pH.
• a number of synthesis reactions are known for producing chlorine dioxide.
• the preferred method is the acidification of chlorite.
• the device includes a delivery device configured to deliver a solution to a target application and a stabilized chlorine dioxide (CIO2) product that is configured to be delivered using the delivery device.
• the chlorine dioxide is produced using a method that includes adding a first amount of Hydrochloric acid (HCI) to a second amount of Sodium chlorite (NaCIO2) that is dissolved in water, the first amount being greater than the second amount; agitating the HCL and NaCI02 for at least 10-15 minutes to mix the chemicals and thus allowing the chemical to react to completion; adding a third amount of Dowfax to the solution and slowly agitate the HCI, NaCI02 and Dowfax solution to distribute the Dowfax; and after the reaction to generate chlorine dioxide (CIO2) in solution has gone to completion, adding a fourth amount of Sodium Hydroxide (NaOH) to adjust the pH of the resulting CI02 solution to a desired pH and concentration.
• HCI Hydrochloric acid
• NaCIO2 Sodium chlorite
• the invention is a method of making a high concentration chlorine dioxide with improved long-term stability comprising.
• the method includes adding 42.61 g/l 10% Hydrochloric acid (HCI) to 3.20g/l Sodium chlorite (NaCIO 2 ) dissolved in water; agitating the HCL and NaCIO2 for at least 10-15 minutes to mix the chemicals; adding 1.50g/l of Dowfax and slowly agitate the HCI, NaCI02 and Dowfax solution to distribute the Dowfax; and adding 42.23g/l of 5% Sodium Hydroxide (NaOH) to adjust the pH of the CIO2 solution to a desired pH.
• HCI Hydrochloric acid
• NaCIO 2 Sodium chlorite
• the invention is a method for producing a high concentration chlorine dioxide with improved long-term stability.
• HCI Hydrochlor
• the delivery device is a spray bottle and the stabilized CIO2 is a sprayable solution; the delivery device is a wipe and the stabilized CI02 is a solution integrated into the wipe; the delivery device is a tablet and the stabilized CIO2 is integrated into the tablet; the delivery device delivers a laundry detergent and the stabilized CIO2 is integrated into the laundry detergent; the delivery device delivers a deodorizer and the method of producing the CIO2 further comprises adding a fragrance ingredient compatible with CI02; the delivery device is a cleaning device and the stabilized CIO2 is produced as a concentrate that can be used at full strength or diluted with water.
• the CIO2 concentration is 1200-1300 PPM.
• the CI02 concentration is 1250 PPM
• the CIO2 is: a sprayable solution configured to work with a spray bottle; the CIO2 is a concentrated solution configured to be used at full strength or diluted with water prior to use; the method further comprising adding a fragrance ingredient compatible with CIO2 to produce a fragranced solution.
• Figure 1 shows a stability profile of chlorine dioxide compositions with differing pH levels vs. time.
• Figure 2 shows a stability profile of chlorine dioxide and surfactant compositions with differing pH levels vs. time.
• Figure 3 shows a stability profile of chlorine dioxide and surfactant compositions with differing pH levels vs. time.
• Figure 4 shows a stability profile for a series of samples with Dowfax
• Figure 5 shows a plot of the percent of CIO2 remaining as a function of pH.
• the present invention is directed to improve the stability of chlorine dioxide (CIO2) compositions and products.
• CIO2 chlorine dioxide
• the inventor has found that the stability of the chlorine dioxide can be significantly improved by the proper choice of pH, and through the careful choice of other product formula ingredients.
• the product has a suitable shelf-life and is ready to use after manufacturing. This stabilization benefit applies regardless of the reaction method used to produce chlorine dioxide.
• the improved stability of CIO2 is due to adjusting the pH.
• the relationship between pH and stability may not be recognized, and that could explain the limited number of CIO2 based product in the market.
• the increased stability of CIO2 would make a product more desirable than a similar product with limited shelf-life, or a product that must be mixed prior to use.
• Chlorine dioxide can be produced by a number of reactions with sodium chlorite (NaCIO2).
• NaCIO2 sodium chlorite
• Several industrial methods of synthesis of chlorine dioxide are known such as acidification of chlorite, oxidation of chlorite by chlorine, oxidation of chlorite by persulfate.
• Other suitable reactions include the reaction of acetic anhydride with chlorite, the reduction of chlorates by acidification in the presence of oxalic acid, and the reduction of chlorates by sulfurous anhydride.
• Acidification of chlorite according to the following reaction is particularly appealing due to the availability, cost and ease of use of hydrochloric acid. It is understood that regardless of the method used to produce chlorine dioxide, the stability of the solution is controlled by pH and the proper choice of other ingredients.
• Any suitable acid may be used in the process disclosed.
• hydrochloric acid sulfuric acid, nitric acid, phosphoric acid, acetic acid, citric acid, sulfamic acid, succinic acid, and oxalic acid.
• Acids may be moderate to strong acids that are capable of reacting with sodium chlorite to form CIO2.
• the strongest acids are “mineral acids.” Common examples are hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid. These are characterized as having pKa values ⁇ 1. Strong acids react very quickly with sodium chlorite.
• Moderately strong acids include many organic acids. Examples include acetic acid, citric acid, sulfamic acid, succinic acid, and oxalic acid. These are characterized as having pKa values pKa about 5. The acid needs to react with sodium chlorite to form CIO2. If the pka is too high, the reaction will not occur or will be very slow. The lower the pKa, the stronger the acid and the faster the reaction with sodium chlorite.
• the process may also include a caustic, such as sodium hydroxide to adjust the solution pH
• NaCI02 sodium chlorite
• HCI hydrochloric acid
• a first batch of CIO2 (3-134), prepared as described in Formula (1 ) was split into two subsamples.
• the pH of one subsample was adjusted to pH 3.66 with Sodium Hydroxide (NaOH) (3-134A) and the other subsample was not adjusted and was pH 1.70 (3-134B).
• the pH of one subsample was adjusted to pH 3.62 (3-131 A) and the second subsample was not adjusted and was pH 1.96 (3-131 B).
• the samples were stored in closed amber glass jars. At various times, aliquots were removed and the CI02 was assayed using the iodometric titration.
• Figure 1 is a plot of the CIO2 concentration vs. time for the samples. As seen in the plot, increasing the pH results in a much more stable product, i.e. slower loss of the CI02 concentration over time. Raising the sample pH also has the key benefit of preventing the initial rapid drop in CIO2 typically seen in the first few days after synthesis of CIO2. Preventing this initial drop in activity is more cost effective for manufacturing and makes it easier to achieve the desired concentration.
• Figure 2 shows a stability profile of another set of samples with surfactant added (3-142), in this case, Dowfax 3B2 surfactant.
• the CIO2 (3-142) was prepared as described in Formula (1) and split into two subsamples. The pH of one subsample was adjusted to pH 3.64 (3-142B) with Sodium Hydroxide (NaOH) and the other subsample was not adjusted and was pH 1.73 (3-134A). Both samples were stored in closed amber glass jars. At various times, aliquots were removed and the CIO2 was assayed using the iodometric titration.
• Figure 2 is a plot of the CIO2 concentration with vs. time. This plot again shows increasing the pH to 3.64 results in a much more stable product than the pH 1.73 sample, i.e. slower loss of the CIO2 concentration over time.
• Figure 3 shows a stability profile of another set of samples with surfactant added (3-170), in this case, Dowfax 3B2 surfactant.
• Figure 3 is similar Figure 2 but with samples at a broader range in pH.
• the CIO2 with surfactant was prepared as described and split into seven subsamples.
• the pH of the first subsample 3-170A was not adjusted and was pH 1 .76.
• the pH of the other subsamples 3-170B to 3-170G were adjusted with Sodium Hydroxide (NaOH). All samples were stored in closed amber glass bottles.
• NaOH Sodium Hydroxide
• 3-170 A pH 1.76 3-170B adjusted to pH 2.34 3-170C adjusted to pH 3.00 3-170D adjusted to pH 3.64 3-170E adjusted to pH 4.17 3-170F adjusted to pH 4.97 3-170G adjusted to pH 7.18
• FIG. 3 shows the effect of pH on stability.
• the graph shows raising the pH in subsamples 3-170B to 3-170G improved stability.
• sample 3-170G with pH 7.18 was not as stable as the samples as pH 4.97 (3-170F), suggesting there may be an optimal pH range for stability where pH ⁇ 5 appears to have better stability than pH 3.6.
• Figure 4 shows the stability profile for yet another series of samples with Dowfax 3B2 (Sample series 3-176A-J). The same procedure was used in preparing the samples. A large sample batch was prepared which was then split into ten sub samples. The pH of the subsamples was adjusted by addition of sodium hydroxide. The samples were stored at room temperature in closed amber glass bottles. At various times, aliquates from the subsamples were removed and the concentration of CIO2 was assayed using an iodometric titration. The sample pH’s were checked and adjusted if necessary to the original sample pH. The initial concentration of CIO2 was 545 PPM. Table A shows the concentration of CIO2 and the corresponding calculated percent remaining based on the initial concentration at 6, 14 and 37 weeks.
• Table 1 shows a base solution composition used for disinfectant/sanitizer solution depicted in Figure 1 3-134 A/B.
• NaCIO2 is dissolved in deionized water.
• the aliquot of 10% HCI was added.
• the mixture is stirred and allowed to react for 15 minutes.
• the batch was then split into two 11 subsamples.
• Chlorine dioxide decomposes more quickly when exposed to light, is temperature sensitive and it reacts with many organic compounds. Proper shielding from light and clean production facilities and handling procedures, and material purity are essential to improve stability and avoid unwanted reactions with organic contaminants during production.
• the resulting concentration of chlorine dioxide can be tailored to meet the desired biocidal performance.
• the product of the concentration and the contact time l.e. c x t constant.
• doubling the concentration can result in a reduction of concentration to yield a similar degree of micro efficacy.
• Table 3 shows typical ranges of ingredients to produce sanitizer/disinfecting/deodorizing solutions.
• the examples described above had a starting concentration of about 550 PPM CIO2.
• the present invention also contemplates making a solution of chlorine dioxide with higher concentration 1200-1300 PPM having a pH 4.5-6.5 for various applications.
• the upper limit of HCI assumes a several fold molar excess of HCI to speed the reaction rate.
• Table 4 shows an example of ingredients for producing a product having about 1250 PPM CI02 and Ph 5.91.
• a batch of the 1250 PPM CIO2 was prepared as described in Table 4 and was split into two subsamples. The pH of one subsample was not adjusted and was pH 1.50 and the second subsample adjusted using 42.3 gm of 5% NaOH to a pH 5.91 .
• the production/manufacturing for the CIO2 based solution should follow general manufacturing guidelines that are typically followed in the production of hypochlorite or peroxide containing based products. All contact surfaces in the production equipment, filling and line and packaging should be in good condition. They must/should be emptied and thoroughly rinsed so as to prevent cross contamination prior to use. Such practices are generally followed in the production of hypochlorite containing products or other products where contamination is undesirable/not tolerated.
• the entire production process for the solution would be conducted under clean room conditions, in order to minimize the possibility of contamination of the solution by environmental contaminants, such as airborne particles.
• All contact surfaces including without limitation surfaces of production equipment, filling equipment and packaging, should be thoroughly cleaned of contaminants prior to use.
• Deionized water should be used to prepare or dilute the Solution during production of the finished product.
• the pH of the finished product should be adjusted to improve stability and/or to achieve the desired product pH. If the product is required to have a specific pH, the overall stability of the CI02 could subsequently be affected. It is therefore preferred to have the product pH fall within the range of pHs that promotes the improved stability.
• Surfactant and other adjuncts can be added to the basic solution to create a range of products.
• Surfactants such as Dowfax 3B2 help facilitate cleaning and wetting of surfaces to improve the micro efficacy of chlorine dioxide.
• Gum thickeners can be added to thicken the product to improve contact time on a vertical surface or potentially as in a hand sanitizer.
• gum thickeners may include, but not limited to, xanthan gum, Kelzan AP-AS (from CP Kelco), Keltrol (from CP Kelco) or other suitable gum thickener.
• the key is that the adjuncts must be reasonably stable with chlorine dioxide.
• the benefits of proper pH choice also apply to the addition of adjuncts. We are not limited to just these two ingredients. Optimizing the pH will improve stability of formula containing the desired adjuncts.
• a concentrated product could have applications such as a floor cleaner, general cleaner/deodorizer, use in toilet bowl, or in laundry applications.
• the concentrated product is a product that may be used full strength or be diluted prior to use.
• the product is prepared using a stabilized formula and then diluted by adding additional water or adding the concentrated formula to water.
• An example of a concentrated product and how one is used, is Pine -Sol. You can use Pine -Sol full strength or dilute it. The standard calculations would apply in terms of dilutions i.e. add product to an equal amount of water would dilute it by 50% etc.
• the concentrate could be a refill for a spray product.
• the concentration of the chlorine dioxide and the surfactant would be higher in the concentrated product to allow for dilution so that the diluted product will still have ingredients to be effective.
• Higher concentration of CIO2 may be used to sanitize or disinfect while a lower concentration of CIO2 in the diluted form may be good for general cleaning and deodorizing.
• the concentrated product should be safe to use and have a suitable shelf life for storage.
• the product may include other ingredients, such as fragrance, dyes, or thickeners, etc to change the aesthetics or the form of the product or even change other performance attributes.
• gum may he added to make a gel product.
• CIO2 product disclosed herein may be used in many different products depending on the final dilution and concentration. Uses may include sanitizer or disinfectant, floor cleaner, general cleaner/deodorizer, use in toilets, mouthwash or in laundry applications. The product may be used along or combined with other products.
• CIO2 product be delivered in many different forms, depending on the application. Below are some non-limiting examples.
• the CIO2 product may use many different delivery devices depending on the application.
• the CIO2 product may be packaged in a spray bottle or package of wipes.
• the CIO2 product be in a squirt bottle,
• Floor Cleaner - The CI02 product may be provided in a con centrated solution that can be used either at full concentration or diluted, such as Pine-Sol.
• the CIO2 product may be provided in a spray bottle, like Lysol, or disinfecting wipes like Clorox Wipes.
• Toilet - The CIO2 product m ay be provided in a tablet form to drop-in the bowl or put in the toilet tank for each flush, like Clorox tablets.
• the tables may be different concentration, such as the drop-in bowl tablet may have a higher concentration than the tank tablet.
• Laundry - The CIO2 product may be mixes in a laundry detergent, or may be a separate solution additive, like Lysol Laundry Sanitizer Additive, or as beads that are thrown in the wash, like Downy Fresh Scent Booster Beads
• the present invention is directed to improve the stability of chlorine dioxide (CIO2) compositions and products by the proper choice of pH, and through the careful choice of other product formula ingredients.
• CIO2 chlorine dioxide
• the product has a suitable shelf-life and is ready to use after manufacturing.
• the device includes a delivery device configured to deliver a solution to a target application and a stabilized chlorine dioxide (CIO2) product that is configured to be delivered using the delivery device.
• the chlorine dioxide is produced using a method that includes adding a first amount of Hydrochloric acid (HCI) to a second amount of Sodium chlorite (NaCIO2) that is dissolved in water, the first amount being greater than the second amount; agitating the HCL and NaCIO2 for at least 10-15 minutes to mix the chemicals and thus allowing the chemical to react to completion; adding a third amount of Dowfax to the solution and slowly agitate the HCI, NaCIO2 and Dowfax solution to distribute the Dowfax; and after the reaction to generate chlorine dioxide (CIO2) in solution has gone to completion, adding a fourth amount of Sodium Hydroxide (NaOH) to adjust the pH of the resulting CIO2 solution to a desired pH and concentration.
• HCI Hydrochloric acid
• NaCIO2 Sodium chlorite
• the invention is a method of making a high concentration chlorine dioxide with improved long-term stability comprising.
• the method includes adding 42.61 g/l 10% Hydrochloric acid (HCI) to 3.20g/l Sodium chlorite (NaCIO2) dissolved in water; agitating the HCL and NaCIO2 for at least 10-15 minutes to mix the chemicals; adding 1.50g/l of Dowfax and slowly agitate the HCI, NaCIO2 and Dowfax solution to distribute the Dowfax; and adding 42.23g/l of 5% Sodium Hydroxide (NaOH) to adjust the pH of the CIO2 solution to a desired pH.
• HCI Hydrochloric acid
• NaCIO2 Sodium chlorite
• the invention is a method for producing a high concentration chlorine dioxide with improved long-term stability.
• HCI Hydrochloric
• the delivery device is a spray bottle and the stabilized CIO2 is a sprayable solution; the delivery device is a wipe and the stabilized CIO2 is a solution integrated into the wipe; the delivery device is a tablet and the stabilized CIO2 is integrated into the tablet; the delivery device delivers a laundry detergent and the stabilized CIO2 is integrated into the laundry detergent; the delivery device delivers a deodorizer and the method of producing the CIO2 further comprises adding a fragrance ingredient compatible with CIO2; the delivery device is a cleaning device and the stabilized CIO2 is produced as a concentrate that can be used at full strength or diluted with water.
• the desired pH is 4.5 - 6.5, and in other embodiments the desired pH is 5.91 .
• the CIO2 is: a sprayable solution configured to work with a spray bottle; the CIO2 is a concentrated solution configured to be used at full strength or diluted with water prior to use; the method further comprising adding a fragrance ingredient compatible with CIO2 to produce a fragranced solution.

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• 2020
  • 2020-05-26 EP EP20937200.2A patent/EP4157497A4/de active Pending
  • 2020-05-26 CA CA3185170A patent/CA3185170A1/en active Pending
  • 2020-05-26 AU AU2020450618A patent/AU2020450618A1/en active Pending
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