DISINFECTANT/POLYVINYLCHLORIDE RESIN

COMPOSITIONS

The present invention relates to a composition comprising a solid halogen-containing disinfectant material having dispersed therein fine particle- sized polyvinylchloride (PVC) resin. In particular, the present invention relates to solid formed tablets of a pool sanitizer material [e.g., calcium hypochlorite or trichloroisocyanuric acid (TCCA) or sodium dichloroisocyanurate (SDCC) ] having fine particle-sized PVC resin dispersed therein. A wide variety of solid halogen-containing materials are known to serve as effective disinfect¬ ing and/or sanitizing agents. For example, tablets of calcium hypochlorite or trichloroisocyanuric acid have been added to the water in swimming pools and the like to disinfect and sanitize that water. Such tablets provide a continuous source of available halogen for disinfecting and sanitizing water supplies over a longer period of time than granular products. A problem of using simple tablets of calcium hypochlorite, trichloroisocyanuric acid or other pool sanitizers is that they often do not have the desired dissolving rate (i.e., they may dissolve too fast) for a given application. Ordinary skilled artisans in the disinfectant and sanitizer field have attempted to overcome this problem by use of specially shaped tablets, the inclusion of certain additives into the tablets, or the use of certain dissolving apparatus.

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Examples of specially shaped tablets are shown in U.S. Patent Nos. 4,876,003 (Casberg) (encased pool chemical tablet with domed ends); 4,928,813 (Casberg) (encased pool chemical capsule with extended ends); and 5,137,731 (Casberg) (chemical tablet with central hole and partially exposed top and bottom) .

Examples of additives added to halogen- containing disinfectants are shown in U.S. Patent Nos. 4,692,335 (Iwanski) (calcium hypochlorite tablet with a solid wax binder additive); 5,009,806 (Johnson et al.) (calcium hypochlorite with finely- divided poly fluorinated polymer additive dispersed throughout granules); and 5,205,961 (Shenefied et al.) (granular calcium hypochlorite surface coated with polyfluorinated polymer) . Also, lime has been added to calcium hypochlorite tablets to control the dissolution rate of the tablets.

Examples of certain dissolving apparatus are shown in U.S. Patent No. 4,546,503 (Casberg) (specially shaped container for pool chemical tablet); 4,867,196 (Zetena et al.) (3-compartment chemical feeder); and 5,133,381 (Wood et al.) (3- compartment chemical feeder with adjustable hopper) . However, there is still a need in the art for better ways to control the dissolving rate of halogen-containing disinfectants such as pool sanitizers.

Separately, U.S. Patent No. 3,842,006 (issued to Burt on October 15, 1974) teaches the use of polyvinylchloride resin particles mixed with sand as a filter medium for swimming pools.

Japanese Patent Application (Kokai) No. 4- 279650 (assigned to Shikoku Chemical Industries and published on October 5, 1992) teaches a plastic product obtained by formation of a plastic sol consisting of (1) polyvinyl chloride (a paste resin of polyvinyl chloride latex) ; (2) a plasticizer; (3) a stabilizer; and (4) a solid chlorine substance including chloroisocyanurate acid and its salt, or calcium hypochlorite. This plastic product (a mat, sheet, or insole) is useful as a deodorant or bactericide.

Accordingly, the present invention is directed to a composition characterized by a solid halogen- containing disinfectant material having an effective dissolving rate-controlling amount of a fine particle-sized polyvinylchloride resin dispersed therein.

One preferred aspect of the present invention is directed to a solid formed article characterized by a compressed solid halogen-containing disinfectant material having an effective dissolving rate-controlling amount of a fine particle-sized polyvinylchloride resin dispersed therein.

The term "solid halogen-containing disinfectant material" is used in the present specification and claims includes any solid halogen-containing material known as a disinfecting and/or sanitizing agent. These materials include those chemicals that are believed to function as a disinfecting agent by virtue of the formation of a hypohalite ion (e.g., hypochlorite ion) or hypohalous acid (e.g. , hypo- chlorous acid) when the material is dissolved in an aqueous medium. Representative examples of such

solid halogen-containing disinfectant materials include hypochlorites such as calcium hypochlorite, lithium hypochlorite; chlorinated isocyanuric acids such as dichloroisocyanuric acid (DCCA) and trichloroisocyanuric acid (TCCA) ; sodium and potassium salts of said chlorinated isocyanuric acids such as sodium dichloroisocyanurate (SDCC) ; chlorinated and brominated hydantoins such as 1,3- disbromo-5,5-dimethylhydantoin; N-halo-2- oxazolidinones such as 3-chloro-4,4-dimethyl-2- oxazolidinone; and N,N -dihalo-2-imidazolidinone such as l,3-dichloro-4,4,5,5-tetramethyl-2- imidazolidinone. The present invention encompasses any halogen-containing disinfectant made by any process that is compatible with the polyvinyl¬ chloride PVC resin component of the present composition. Numerous descriptions of making these solid-containing disinfectant materials exist and each of aforementioned commercially available solid halogen-containing disinfectants can be prepared by methods well known to the ordinary skilled artisan.

The second critical component of the present invention is fine particle-sized polyvinylchloride resins or PVC resins. The terms "polyvinylchloride" and "PVC" as used in the specification and claims are used to include fine particle size poly¬ vinylchloride resins as well as mixtures of such polymers, copolymers made from vinyl chloride monomers units and other monomer units; mixtures of PVC resins; mixtures of PVC copolymers or mixtures of PVC resins with PVC copolymers. Examples of a PVC copolymer include poly(vinyl chloride/vinyl ester) copolymers (e.g., GEON 138). PVC resins

useful in the present invention may also contain minor quantities of other ingredients (e.g., plasticizers, stabilizers, and colorants) . The main purpose for using PVC in the present invention is to adjust the dissolving rate of the solid halogen- containing disinfectant material. The presence of PVC resins lowers the water solubility of the halogen-containing disinfectant materials. It is especially used to slow the dissolving rate of calcium hypochlorite compared to additives like lime. Only small amounts of PVC resin are needed to effectively adjust the dissolving rate of the halogen-containing disinfectant material. There¬ fore, a given weight of a formed article of the present invention will contain a higher percentage of available halogen disinfectant compared to a similar prior art formed article containing lime instead. This means that the formed articles of the present invention (e.g., tablets) can be stored longer before use (i.e., before the average chlorine levels in such articles fall below an acceptable level) and will dissolve for a longer period of time.

The term "fine particle-sized" as applied to polyvinylchloride resin means any particle of polyvinylchloride resin small enough to be dispersed in the halogen-containing disinfectant material. Generally, PVC resin materials having an average particle size from about 0.05 to about 5 microns are preferred. Average particle sizes from about 0.1 to about 2 microns are more preferred.

Fine particle-sized polyvinylchloride resins have many other advantages for using them as a

dissolving, rate-controlling additive for a halogen- containing disinfectant. One, it is difficult to ignite. Two, it has little or no affect on the reactivity of halogen-containing disinfectants such as calcium hypochlorite when used in previously claimed low concentrations (i.e., it passes the standard glycerin test with calcium hypochlorite) . Three, it is believed to improve the tabletability of such halogen-containing disinfectants. PVC resins, even in fine particle sizes, do not increase the dustiness of calcium hypochlorite as do some additives such a lime. Also, PVC resins slightly reduce tablet injection pressures for calcium hypochlorite products, thus improving tableting processes. Fourth, PVC appears to reduce scale formation and skimmers and residual build-up in calcium hypochlorite dispensers. It was observed that PVC resins cause flocced particle formation when the formed tablets of the present invention dissolve. This flocced form may be helpful in reducing scaling. Fifth, PVC is readily available and relatively inexpensive. Sixth, PVC does not increase pH or alkalinity of water as the addition of a necessary amount of lime does. Thus, a pool operator would not have to add a counterbalancing amount of acid as when lime is used as additive. Seventh, PVC is generally whiter than many halogen- containing sanitizers. Its presence makes the resulting formed articles (e.g., tablets) whiter. Eight, the fine particle size of PVC resins used herein can make the resulting formed articles (e.g., tablets) smoother. Ninth, PVC resins can be colored or pigmented. Therefore, the formed articles or

tablets can be easily color-differentiated from similar shaped halogen-containing disinfectant material.

The term "effective dissolving rate-controlling amount" as applied to PVC resins in the present specification and claims refers to any amount of PVC resin will effectively control the dissolving rate of an halogen-containing disinfectant material, yet below amounts that will cause unacceptable reactivity with that disinfectant material.

Generally, amounts from about 0.01% to 0.5% by weight, based on total solids (i.e., combined weight of sanitizer plus PVC additive) , are preferred when the disinfectant material is calcium hypochlorate. If the disinfectant material is a chlorinated isocyanuric acid (e.g., SDCC or TCCA) or sodium or potassium salts thereof (e.g., SDCC), then preferred amounts may be from about 0.25% to about 3%, based on total solids. In accordance with one preferred embodiment of the present invention, the fine particle-sized polyvinylchloride is mixed or blended with granules of calcium hypochlorite in amounts to control the dissolution rate of the hypochlorite in water. Typically, about 0.01 to about 0.5 parts by weight of the PVC resin need to be added to about 99.99 to about 99.5 parts of calcium hypochlorite granules. As mentioned above, blends of granulated calcium hypochlorite containing the polyvinylchloride resin may be then formed into solid articles (e.g., tablets) by suitable size-enlarging apparatus and processes. Such solid article dissolves more slowly when placed in contact with water.

Commercial calcium hypochlorite granules generally have a principle size distribution between about -6 and +100 U.S. Sieve Series, i.e., the granules vary in size principally between about 0.132 inches (3.36 millimeters) and about 0.006 inches (0.149 millimeters). More commonly, the particles will have a principle size distribution between about -6 and +60 U.S. Sieve Series, i.e., between about 0.132 inches (3.36 millimeters) and about 0.0098 inches (0.250 millimeters).

Particularly suitable for use in producing solid articles from the described granule calcium hypochlorite is a product having a size distribution between -10 and +45 U.S. Sieve Series, i.e., the granules are principally between 0.079 and 0.014 inches (2.00 and 0.354 millimeters). Particles smaller than 50 U.S. Sieve Series (0.297 milli¬ meters) that are present in the granular calcium hypochlorite product represent a minor percentage, usually less than 5%, of the material charged to the size enlargement device.

Commercially available calcium hypochlorite may vary in its composition depending on the commercial source and the process used to prepare the product. Typically, commercially available granular calcium hypochlorite contains at least 60 weight percent available chlorine (as calcium hypochlorite), e.g., between about 60 and 78 weight percent available chlorine, more particularly between about 65 and 75 weight percent available chlorine. Moisture (water) may comprise between about 1% and 15%, more particularly between about 4 and about 10 weight percent, of the calcium hypochlorite product. The

remainder of the calcium hypochlorite article of commerce is typically composed of varying amounts of residual salts, such as sodium chloride, calcium chloride, calcium hydroxide, and calcium chlorate, depending on the process used to prepare the calcium hypochlorite.

Granular calcium hypochlorite is typically sufficiently free-flowing to allow it to be introduced into conventional size enlarging compaction devices wherein it is compacted with pressure into the shape desired (e.g. , a tablet) . Size-enlarging devices that may be used to prepare calcium hypochlorite articles include a molding press, tableting press, roll-type press, pellet mill, and screw extruder. These devices are known in the art. The compressed article may be prepared in any convenient desired shape or size, e.g., a brick, briquette, triangle, doughnut, star, pellet, tablet, and the like, depending on the intended use of the article or product differentiation desired by the manufacturer. Preferably, the shape is that of a tablet. The compressed article may typically have a mass of between about 1 gram and 350 grams or more, e.g., between about 5 and 300 grams. The compressed article may be of a size which may be inserted readily into a skimmer or dissolving basket used with swimming pools or dissolvers used to form concentrated solutions of calcium hypochlorite. In the case of a 300 gram tablet, it is preferred that the diameter of such tablet be between about 2.5 inches (6.35 centimeters) and about 3.5 inches (8.9 centimeters), e.g., between about 3.125 and 3.25 inches (7.9 and 8.3 centimeters), and be about 1 to

2 inches (2.5-5.1 centimeters), e.g., 1.25 inches (3.2 centimeters) thick.

Solid articles, such as tablets, of compressed granular calcium hypochlorite prepared with the polyvinylchloride resin material treated granular calcium hypochlorite described hereinabove dissolve more slowly than tablets prepared from calcium hypochlorite that does not contain a polyvinyl¬ chloride resin additive when such tablets are placed in a skimmer basket used in association with swimming pools and contacted with circulating pool water. The slow dissolution of the aforesaid article thereby provides a source of available chlorine for disinfecting and sanitizing pool water over the period of time required to dissolve substantially all the calcium hypochlorite tablet. Such tablets may also be used in flow-thru tablet feeders where their slower dissolving rate reduces the frequency that the feeder needs to be recharged. In accordance with another preferred embodiment of the present invention, the PVC resin may be applied to the surface of calcium hypochlorite granules in the form of a polymer emulsion or suspension. This may be accomplished by spraying an aqueous suspension or emulsion of PVC resin (e.g., 1-25% by weight) onto granulates of disinfectant material and then those coated granules are preferably compressed together in tablet form. See U.S. Patent No. 5,205,961 (Shenefiel et al.) as an example of this coating technique.

The present invention is further illustrated by the following Examples and comparison Examples. All parts and percentages are by weight and all tempera-

tures are in degrees Celsius unless explicitly stated otherwise.

EXAMPLE 1 AND COMPARISONS 1-3

Three mixtures of a granular calcium hypochlorite productvi and a fine particle-sized polyvinyl¬ chloride homopolymerv-y were mixed together in various percentages. The percentages by weight of PVC in each mixture is shown in Table 1 below. The reactivity of these three mixtures as well as the same pure calcium hypochlorite were measured by a standard glycerine test. This glycerine test determines the reactivity of a calcium hypochlorite product by observing whether or not a self- propagating reaction occurs in a sample of the product (100 grams) after initiation with glycerine (four drops from a medicine dropper) at room temperature. The results of these tests are given in Table 1. As can be seen from those results, too much polyvinylchloride added, causes excess reactivity with the calcium hypochlorite.

Table 1

Reactivity of Calcium Hypochlorite/ Polyvinylchloride Mixtures

Example or Additive {% % Rating Comparison by weight) Reacted Pass/Fail

C-1 None 7 Pass

E-l 0.50 5 Pass

C-2 1.50 78 Marginal

C-3 3.00 100 Fail

© HTH« RG (made by Olin Corporation of Stamford, Connecticut). This product contains about 65-70% available chlorine; about 3-4% total alkalinity; about 15-17% sodium chloride. Its loose bulk density is about 0.93 grams per cubic centimeter.

Θ GEON 125A (Made by GEON Company) . This product is a multi¬ purpose polyvinylchloride dispersion resin having an inherent viscosity of 0.85; a water content by Karl Fisher of 0.05%; methanol extractables of 3.7% and a residual vinyl chloride monomer content of 5.4 ppm. This resin is a fine white powder with an average particle size of approximately one micron. It also has a specific gravity of 1.4 and a bulk density of 20-25 lb/cubic feet.

EXAMPLES 2-4 AND COMPARISONS 4 AND 5

Various amounts of a fine particle-sized polyvinylchloride resin ^ were blended with a spatula into a calcium hypochlorite granules v-D and then blended for 20 minutes in V-shaped blender at 30 rpm. This V-shaped blender (Model 014-215-0053) was made by Bison Gear and Engineering Corporation of Downers Grove, Illinois. It can be equipped with either 2,800 ml container for large amounts or 200 ml container for small quantities. Tablets (1.8 inch diameter, 300 ± 2 grams with domed ends) were pressed at 17.5 to 18 tons pressure on a Wabash

Press. Each tablet length was 3.95 ± 0.03 inches; including 0.38 inch domed heights. A 6 mil clear PVC shrink band (77 mm lay flat dimensions by 108 ± 2 mm length) was shrunk around the tablet so that the end openings were 1.05 ± 0.1 inch diameter and part of the domed ends extended out beyond the shrink band.

Each of these tablets were tested for dissolving time in a Hayward SP1084 skimmer attached to a 110 gallon tank. A small stone (about 1 inch in diameter) was set on the bottom of the skimmer basket to limit movement of the tablets. Water at 29°C was circulated at 40 gallons per minute for eight hours per day. The water was replaced daily. The total time for dissolving each tablet is given

in Table 2 below. As can be seen from those results, the comparison test with no additive present showed that a pure calcium hypo-chlorite tablet dissolved at a relatively fast rate. The comparison test with 1.5% by weight lime present in the tablet significantly extended the dissolving time. Increasing amounts of fine particle-sized polyvinylchloride resin also extended the dissolving time of the calcium hypochlorite tablets. A small amount of flocced residue was observed at the ends of each tablet with both the lime-containing and PVC-containing tablets. The floe with the PVC- containing tablets was larger than with the lime- containing tablet.

Table 2

Changes in Dissolving Time with Additives

Example or Dissolving Comparison Additive Time (days)

C-4 None 2.2

C-5 1.5% Lime 6.1

E-2 0.25% PVC 15.3

E-3 0.07% PVC 10.3

E-4 0.04% PVC 3.4

HTH» RG (made by Olin Corporation). GEON 125A (manufactured by GEON Company.

EXAMPLES 5-10 AND COMPARISONS 6 AND 7

Various mixtures of PVC resin O lime or both with a calcium hypochlorite granules were blended using the same technique as the previous experiments and then pressed into 5.0 gram, 1.0 inch diameter tablets at 10,000 pound pressure with a Carver press. The resulting tablet thicknesses were 0.192 to 0.198 inches. The various mixtures are described in Table 3, below. The dissolving times of each tablet were determined using a floater made from a Hayward SP1084 skimmer basket in a plastic foam float ring. The tablets in triplicate were placed on fiberglass screening (16 x 16 strands per inch) and set in the floater. The floater in 110 gallon tank of tap water (pH = 7.4 at start) at 29°C and circulated at 20 gallons per minute for 24 hours per day. The tablets were weighed periodically for determination of weight loss. The results are given in Table 3 below.

As can be seen, all of various PVC resins outperformed lime at the same 0.25% additive levels. Combination of a PVC resin and lime give the longest dissolving times. Also, tablets containing lime alone produced much more turbid water than from tablets containing PVC resin alone.

10

© HTH* RG (made by Olin Corporation). © GEON 125A polyvinylchloride resin (made by GEON Company).

15 © GEON 138 is a high molecular weight, low viscosity vinyl chloride/vinyl ester copolymer having an inherent viscosity of 1.20; a water content by Karl Fisher of 0.06%; methanol extractables of 2.3%; and a residual vinyl chloride monomer content of 3.9 ppm. The average particle size is 0.1 to 1 micron; specific gravity is 1.4 and bulk density is 20-25 pounds per cubic foot.

© GEON 180X5 is polyvinylchloride homopolymer having an inherent viscosity of 0.90; a water content

20 by Karl Fisher of 0.07%; methanol extractables of 4.5% and a residual vinyl chloride content of 1.7 ppm. The average particle size is 0.1 to 1 micron; specific gravity is 1.4; and bulk density is 20-25 pounds per cubic foot.

EXAMPLES 11 AND COMPARISONS 8-10

Trichloroisocyanuric acid^ (TCCA) and PVC resin $/ were blended together at various additive levels and pressed into 1.0 inch diameter tablets at 10,000 pound pressure with a Carver press. The tablets weighed 5 grams and had a 0.21 inch thickness.

The dissolving times were determined using a floater made a Hayward SP084 skimmer basket in a plastic foam float ring. The tablets in triplicate were placed on fiber glass screening (16x16 strands per inch) and set in the floater. The floater was placed in a 110 gallon tank of tap water (pH=7.4 at start) at 29°C and circulated at 20 gallons per minute for 24 hours per day. Caustic was used to maintain the pH at 7.2-7.8. The results are shown in Table 4 below.

Table 4

Dissolving Rates of TCCA and PVC Resin Blends

Time to

Example or Amount of Dissolve Comparison Additive 100% Tablet

(*) (Minutes)

C-8 0 30

E-l 0.25 30

C-9 1.5 70

C-IO 3.0 80

© Olin CDB-90 trichloroisocyanuric acid. This TCCA product has an available chlorine content of about 89-92%; gas volatiles of about 0.6%; and bulk density of 61 pounds per cubic foot. Its particle size distribution was +10 mesh (0.1%); +20 mesh (69%); +40 mesh (29%); +100 mesh (1.6%); and -100 mesh or pan (0.8%).

© GEON 180X5.

EXAMPLES 12 AND COMPARISONS 11-13

Sodium dichloroisocyanurate*- ⁶ -' (SDCC) and PVC resin -ywere blended together at various additive levels and pressed into 1.0 inch diameter tablets at 10,000 pound pressure with a Carver press. Each tablet weighed 10 grams and had a 0.47 inch thickness.

The dissolving times were determined using a floater made from a Hayward SP1084 skimmer basket in a plastic foam float ring. The tablets in tripli¬ cate were placed on fiber glass screening (16x16 strands per inch) and set in the floater. The floater was placed in a 110 gallon tank of tap water [pH=7.4] at 29°C and circulated at 20 gallons per minute per day. Caustic was used to maintain pH=7.2 to 7.8. The results are shown in Table 5 below.

Table 5

Dissolving Rates of SDCC and PVC Resin Blends

Example PVC Amount Time for or of Dissolving

Comparison Additive 100% Tablet

(%) (Minutes)

C-ll 0 <3

E-12 0.25 <6

C-12 1.50 13.5

C-13 3.0 17.25

© Olin CDB-56 sodium dichloroisocyanurate. This SDCC product has an available chlorine content of 55-56%; bulk density of 1.0 gram per cubic centimeter and particle size of +20 mesh (44.0%); +40 mesh (54.9%); +60 mesh (0.8%); +100 mesh (0.1%); and -100 or pan (0.2%).

© GEON 125A.

EXAMPLES 13-15 AND COMPARISONS 14 AND 15

Five calcium hypochlorateG tablets were made. Three of these tablets were a 10.5 ounce tablet. Two of the tablets were 21 ounce tablets. One of the 10.5 ounce tablets contained 1.5% lime. The other two 10.5 ounce tablets contained various amounts of PVC resin ^2). One of the 21 ounce tablets contained an amount of a different PVC resinv-U The other 21 ounce tablet contained no additive. The 10.5 tablets were made as described in Examples 2-4 and Comparisons 4-5. The 21 ounce tablets were made as described below.

Each of these tablets were tested for dissolving time in a Hayward SP1084 Skimmer attached to a 110 gallon tank. A small stone (about 1 inch in diameter) was set in the bottom of the skimmer basket to limit movement of each tablet. Water at 29°C was circulated at 40 gallons per minute for eight hours per day. The water was replaced daily. The results are shown in Table 6 below.

Comparison 14 is a percent commercially available tablet (10.5 oz HTH® Duration® calcium hypochlorite tablet) containing 1.5% lime to extend the dissolv¬ ing rate. Example 13 is tablet containing only 0.055% PVC resin© instead of 1.5% lime. Thus, it contains 27 times less additive and has a higher available starting chlorine, yet will have a much less effect of pH and alkalinity and still achieves similar dissolving time and rate. Example 14 is another 10.5 ounce tablet that will contain much less PVC resin additive, have a higher available chlorine, have less effect on pH and alkalinity,

have double the dissolving time and one-half the dissolving rate, all compared to present commercial product. Example 15 and Comparison 15 all both 21 ounce cylindrical tablets with domed ends. The length of the tablet (dome-to-dome) was 3.95 ± 0.05 inches including 0.56 inch domed heights and diameter was 2.68 ± 0.02 inches. These tablets were covered by a 3 mil clear PVC shrink band (110 mm lay flat dimension by 113 ± 2 mm length) shrunk around the tablet so that the end openings 1.56 ± 0.05 inches diameter and part of the domed ends extended out beyond the shrink band. These larger tablets were pressed at 24 tons. Example 15 is a tablet containing a different PVC resin additive^, that has a higher available chlorine, has less effect on pH and alkalinity, and has about double the feed rate compared to the 10.5 ounce tablet of Example 14. It also has a similar dissolving time and rate. Comparison 15 is a tablet containing no additives and has a very short dissolving time. A 21 ounce tablet of the present invention could be used in a swimming pool when the family goes on vacation.

Table 6

Large Size Calcium Hypochlorite Tablets with Various Additives

AvCl © Nominal

Example or Size of Type of Amount of Reduction Dissolving Comparison Tablet Additive Additive By Times

(oz.) (%) Additive (days)

( ^% )

C-14 10.5 Lime 1.5 0.975 6

E-13 10.5 pvcC-y 0.055 0.0375 6 I t

E-14 10.5 PVC© 0.2-0.25 0.13- 12-15 0.1625

E-15 21 PVC© 0.25 0.1625 6-8

10 C-15 21 None ^{0 0} 1

© AvCl = available chlorine. © HTH* RG. © GEON 125A.

EXAMPLE 17 AND COMPARISON 16 Comparison of PVC and Polvtetrafluoroethylene (PTFEΪ

A sample of GEON 125A polyvinylchloride was added to granular calcium hypochlorite product. GEON 125A is dry, non-sticky, loose white powder that flows easily when tipped from a bottle. It blends easily with granular calcium hypochlorite.

TEFLON® K10 polytetrafluoroethylene resin (available from DuPont) is white powder that sticks together (is cohesive) , sticks to polyethylene bag, is putty-like, rubbery and is much more difficult to blend into the same granular calcium hypochlorite product than GEON 125A.

A comparison test was run on GEON 125A and TEFLON K10. The same amount (0.30 grams) of each were separately placed on the surface of 250 ml of tap water in a beaker at 20°C. The GEON 125A dispersed into the water and settled to the bottom of the beaker. After 24 hours, the water was quite clear and no particles were on the top surface of the water. In contrast, the TEFLON K10 clumped together and floated on the surface, even after stirring. It did not disperse or settle on bottom. After 24 hours, there was no change. While the invention has been described above with reference to specific embodiments thereof, it is apparent that many changes, modifications, and variations can be made without departing from the inventive concept disclosed herein. Accordingly, it is intended to embrace all such changes, modifica¬ tions, and variations that fall within the spirit and broad scope of the appended claims.