Cat litter containing fluorescent cat attractants

Abstract

A cat litter comprising an absorbent and at least one fluorescent compound, the at least one fluorescent compound being free of cat urine and attracting cats to defecate in the cat litter. The cat litter comprises a solid granular material coated with a cellulose solution containing at least one fluorescent substance.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 406785 (filed September 15, 2022), the contents of which are incorporated herein by reference. Statement Regarding Government-Sponsored Research Not applicable. Annex Not applicable.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to compositions, methods and devices for enticing cats to eliminate in litter boxes using fluorescent compounds. [Background technology]

[0003] A cat litter box is what cats use to eliminate urine and feces. It contains a layer of cat litter that catches the urine and feces. Cat litter is granular and absorbent, which makes it easy for the urine and feces to clump together after they are excreted into the litter box. This clump is usually sifted out of the litter box with a scoop and discarded.

[0004] Elimination in the home, also known as inappropriate elimination or elimination outside the litter box ("OOB" - out-of-box elimination), is a significant behavioral problem for pet owners. House soiling can be unbearable for owners and can damage the human-pet bond. In many cases, this situation leads to cats being surrendered to shelters. Shelters find it difficult to rehome cats with OOB problems, and such cats are often euthanized. In this regard, OOB elimination behavior is responsible for more cat deaths than any other behavioral problem or many feline illnesses.

[0005] Traditional measures to combat domestic excretion include changing cat litter daily, providing more litter boxes, stopping scolding, and spaying or neutering cats. Pet owners find these measures largely ineffective.

[0006] Attractants are added to cat litter to attract cats to the litter for defecation. These include pheromones, blackcurrant oil, black seed oil, catnip, cat grass, chamomile, lavender, licorice, silver vine, metalactone, 3-mercapto-3-methylbutan-l-ol, musk oil, peppermint oil, pine oil, rosemary, vanillin, and white truffle oil. However, the effectiveness of these attractants is limited. Therefore, there is still a need for an attractant that will draw cats to cat litter for defecation.

[0007] International Publication No. 2016 / 170475 relates to a technique for attracting cats to defecate in cat litter using the cat pheromone precursor L-Feminine, and is incorporated herein by reference. U.S. Patent Publication No. US2021 / 0087161 discloses a method and use of a composition containing 2,2-dimethyl-1,3-dioxolane-4-methanol in pet litter, particularly for promoting pet defecation in litter. This publication is incorporated herein by reference. Summary of the Invention [Problem to be solved by the invention]

[0008] It has been reported that cats have the ability to see blue and ultraviolet (UV) light. Cats cannot see red. Since many fluorescent compounds emit blue and UV light, it is likely that cats are attracted to fluorescent compounds. Using these compounds in cat litter can attract cats to the litter.

[0009] None of the above documents disclose cat litter that has a fluorescent component and that attracts cats to defecate. [Means for solving the problem]

[0010] The present invention provides an improved cat litter comprising at least one absorbent material and at least one fluorescent compound, wherein the at least one fluorescent compound attracts cats and causes them to defecate in the litter. In a preferred embodiment, the at least one fluorescent compound is coated on part or all of the absorbent material.

[0011] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Detailed Description of the Preferred Embodiments The following description of the preferred embodiment is merely illustrative and is not intended to limit the invention, its application, or uses in any way.

[0013] The claimed pet litter comprises at least one absorbent material and at least one fluorescent compound. The absorbent material can be any absorbent material or combination of absorbent materials commonly used in pet litter. Typically, the absorbent material is a dry, granular material. Preferably, the absorbent material is selected from the group consisting of clay, silica gel, wood (such as pine, poplar, cedar, fir, and spruce), agricultural products, and combinations thereof. More preferably, the absorbent material is selected from the group consisting of clay, silica gel, and combinations thereof. In one embodiment, the absorbent material is a clay, such as calcium montmorillonite or sodium montmorillonite (including sodium bentonite and calcium bentonite), smectite, vermiculite, attapulgite, opal clay, and / or kaolin. The absorbent material, particularly the clay, can be a clumping or non-clumping type.

[0014] The at least one fluorescent compound in the present invention must be a compound that is not harmful to cats or the environment. Fluorescent whitening agents, also known as optical brighteners, are fluorescent materials that absorb UV light and emit visible light (blue-violet). When exposed to white light, fluorescent whitening agents can also emit UV light. Preferably, fluorescent whitening agents are hydrophilic, water-soluble compounds, primarily anionic diaminostilbene (DAS) or distyryl biphenyl (DSBP) derivatives with low aquatic toxicity. The most common class of compounds with this property are stilbenes, such as 4,4'-diamino-2,2'-stilbenedisulfonic acid and 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonic acid sodium salt. 4,4'-Bis(benzoxazolyl)-cis-stilbene and 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole) are also highly fluorescent and are used as optical brighteners.

[0015] Optionally, the coating solution includes about 0-5% by weight glycerin.

[0016] The at least one fluorescent compound in the present invention is not limited to fluorescent whitening agents, however, cat urine is well known to be a fluorescent substance, and the fluorescent compounds of the present invention do not include cat urine.

[0017] In a preferred embodiment, the composition in the pet litter of the present invention is coated on at least a portion of the absorbent material. For example, the composition can be sprayed onto at least a portion of the absorbent material. In fact, similar effects have been observed regardless of the percentage of absorbent material coated with the composition. Preferably, the composition in the cat litter of the present invention is coated on at least 1% of the absorbent material. More preferably, the composition comprises 1% to 55% by weight of the cat litter. Most preferably, the composition comprises about 2% to 20% by weight of the cat litter. Typically, the coated absorbent contains about 0.01 to about 10.0% by weight of the fluorescent material. More preferably, the amount of fluorescent material is about 0.05 to 5.0% by weight of the fluorescent material-coated material. The amount of cellulose in the coated absorbent ranges from 0.01 to 10.0% by weight.

[0018] In another embodiment, the cat litter comprises a solid particulate material mixed with an absorbent material, and the composition is coated onto the non-absorbent solid particulate material. For example, the fluorescent composition can be sprayed onto a solid particulate material such as sand, polymer, plastic, etc. to coat the particles, and then mixed with the absorbent material.

[0019] Coatings can be applied by a variety of methods, including dipping and spraying. One method of coating is through the use of a fluidized bed. A fluidized bed is formed when a quantity of solid particulate material is placed under conditions suitable to cause the solid / fluid mixture to behave as a fluid. This is typically accomplished by introducing a pressurized fluid into the particulate medium. This allows the medium to take on many of the properties and characteristics of ordinary fluids, such as being free-flowing under gravity and being pumpable using fluid-type techniques.

[0020] In one embodiment, the coating can be applied as a dry coating. A dry powder fluorescent material can be applied to a wet or tacky solid particulate material to adhere to the solid particulate material. This method involves using a commercially available coating tumbler that rotates, rolls, vibrates, and / or otherwise agitates the particles. This method keeps the outer surfaces of the particles tacky, making it easier for the powder coating formulation to adhere to each particle. In a preferred method, the material is wetted with an aqueous solution containing a cellulose ether, and then the dry powder is applied to the solid particulate material. The cellulose ether acts as an adhesive, holding the dry powder to the granules.

[0021] In a preferred embodiment, the dry powder is applied to an absorbent material, such as cat litter. The litter must be moistened to facilitate coating with the dry powder, but not to cause clumping of the litter. The particle coating should be complete, with no noticeable gaps. Furthermore, it is desirable for the coating to adhere and not flake off after the litter has dried. Furthermore, the coated litter should be similar in shape and density to prevent separation from uncoated litter.

[0022] In one preferred method of applying a coating, the coating formulation is applied using a liquid, such as water, and a pressurized gas, such as compressed air. The pressurized gas not only serves to evaporate or atomize the liquid-containing coating formulation, but also to agitate or move the particles around in a drum, container, or enclosed container, such as a commercially available coating tumbler. In one such preferred method of applying the coating formulation to uncoated particles, the fluorescent material is mixed with a liquid, such as water, which can be sprayed from a nozzle with compressed air into an enclosed container, such as a drum or other container. The enclosed container agitates the particles contained therein, helping to coat the particles with minimal disturbance or damage to the particles during the coating process. The drum or container into which the particles are placed during such a coating process is preferably rotated, vibrated, or otherwise agitated to facilitate coating of each particle.

[0023] The at least one fluorescent material is liquid-coated onto the particles, preferably using a cellulose ether solution or slurry, to adhere the coating to the particles. Preferably, the cellulose ether is a water-soluble cellulose ether. Non-limiting examples of water-soluble cellulose ethers include carboxy(lower alkyl)celluloses such as carboxymethyl cellulose, carboxy(lower alkyl)hydroxy(lower alkyl)celluloses such as carboxymethylhydroxyethyl cellulose, (lower) alkylcelluloses such as methylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose (HPMC), and ethylhydroxyethylcellulose, (lower) alkylhydroxy(lower) alkylcelluloses such as hydroxyethylcellulose and hydroxypropylcellulose (HPC), mixed hydroxy(lower alkyl)celluloses such as hydroxyethylhydroxypropylcellulose, mixed (lower) alkylcelluloses such as methylethylcellulose, and alkoxy derivatives of hydroxyethylhydroxypropylcellulose, in which the alkoxy groups are linear or branched and contain 2 to 8 carbon atoms. The most preferred coatings are comprised of HPC and / or HPMC.

[0024] Non-cellulosic coatings such as poly(vinylpyridine) are also suitable for applying fluorescent materials.

[0025] The coating may be applied as a solution or suspension. The process for preparing the coating solution varies depending on the solution used. To prepare hydroxypropyl cellulose (HPC) solution (commercially available as KLUCEL™ from Ashland) or hydroxypropyl methylcellulose (HPMC) solution (commercially available as HYPROMELLOSET™ from Dow Chemical), the aqueous solution is typically a two-step process. Granular HPC or HPMC is dispersed in water. After dispersion, the HPC or HPMC dissolves to form a solution. At least one fluorescent compound is added to the aqueous solution. In the case of HPC and HPMC, both celluloses are readily soluble in polar solvents such as alcohol. In a preferred embodiment, the coating solution is applied to the solid absorbent agent in a ratio of 1:3 to 1:30. More preferably, the coating solution is added to the solid absorbent agent in a ratio of 1:4 to 1:25.

[0026] The preferred concentration of cellulose ester in the solution or suspension is in the range of about 1 to 20% by weight. The cellulose ester recommended for this coating is HPC, which provides an effective coating that adheres well and dries efficiently.

[0027] Examples of Hydroxypropyl Cellulose Coating Solutions of the Present Invention A basic hydroxypropyl cellulose (HPC) solution for dry coating was prepared as follows: 2% hydroxypropyl cellulose (HPC) solution.

[0028] [Table 1] How to prepare HPC solution: 1. Measure the glycerin into a silicone bowl. 2. Slowly mix in the HPC. 3. Stir for 1 minute. 4. Add water and stir. Stir for 5.5 minutes.

[0029] Example 1: Dry-coated optical brightener powder application procedure The dry optical brightener powder is KEYFLUOR™ WHITE OB, sold by Millikin. The fluorescent compound contained in the optical brightener is 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), CAS number 7128-64-5, which is insoluble in water. It is applied as a dry powder. Layering the optical brightener powder with the HPC coating is the standard method for applying the HPC coating by spraying in a coating tumbler. The HPC solution wets the absorbent particles, which are then coated with the dry optical brightener powder.

[0030] To achieve this, the process begins with: Step (1) With the coating tumbler running continuously at room temperature, use the sprayer in the coating tumbler to dispense enough HPC solution onto the absorbent material to lightly moisten it. The absorbent material used was BOXIECAT® Unscented Premium Clumping All-Natural Clay Cat Litter, which has a very low dust content. It is made from pure natural clay and contains no chemical additives. Step (2) Immediately add a relatively small amount of optical brightener powder to the wet absorbent material in the coating bowl. Step (3) Spray the wet absorbent and powder with enough HPC solution to adhere the powder. Step (4) The solution is allowed to partially dry. Step (5) Repeat steps (2) through (4) until all of the optical brightener powder has been added. Step (6) The remaining solution is quickly added, and heat is applied as needed to dry the coating and capture any remaining powder.

[0031] Example 1: Application of dry-coated optical brightener powder BOXIECAT cat litter coated with 1.78% optical brightener

[0032] [Table 2]

[0033] Example 1 - Results The coated cat litter did not clump. The cat litter was evenly coated and maintained approximately the same shape and size. The coating adhered to the litter when dry and did not flake off. The coated product glowed uniformly under ultraviolet light.

[0034] Example 2: Wet Coating Procedure: This procedure uses Pylaklor White S-15A, a water-soluble optical brightener, which can be dissolved in a coating solution and applied in liquid form. Pylaklor White S-15A is manufactured by Pylam Dyes and contains 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonic acid, sodium salt. The coating solution must be sufficiently non-viscous so that it can be atomized and sprayed onto solid particles. It must also contain enough cellulose to create tack for adhering to the particles upon drying. Furthermore, the coating solution must contain enough optical brightener to be detectable under ultraviolet light.

[0035] [Table 3]

[0036] [Table 4]

[0037] [Table 5]

[0038] Example 2 Procedure for preparing coating solutions for Examples 2, 2A and 2B: 1. Glycerin was measured into a silicone bowl. 2. Klucel HPC and Pylaklor optical brightener were added and stirred to form a mixture. 3. The mixture was stirred for 1 minute. 4. Water was added to the mixture and stirred. 5. The mixture was stirred for 5 minutes to form the coating solution.

[0039] Example 2 Procedure for applying the coating solution to the absorbent material:

[0040] [Table 6]

[0041] Example 2 Procedure: Application of coating solution to absorbent cat litter: The coating solution should be added slowly and carefully to avoid creating clumpy coated cat litter. Step (1) While the coating tumbler is continuously rotating at room temperature, use an atomizer to dispense a sufficient amount of coating solution into the coating tumbler to lightly wet the absorbent material. In a preferred method, approximately 1 to 10% by weight of the coating solution is dispensed at once. Carefully monitor the litter to prevent it from becoming overly wet and clumping. Step (2) Wait a sufficient time for the coating solution to dry, typically about 0.3 to 3.0 minutes. Step (3) Repeat steps (1) and (2) until all of the coating solution has been added. Step (4) is to dry the coating by adding heat as needed to complete the coating. An alternative to the intermittent method described above is to add the coating solution very slowly and continuously. To speed up the process, heat can be added with a blower or other heat source.

[0042] Results of Example 2: The granular cat litter coated with the coating solution was non-clumping, flowable, and approximately the same size and shape as the uncoated cat litter. It mixed well with the uncoated cat litter and glowed under ultraviolet light. The final coated product contained approximately 0.20% by weight of fluorescent material.

[0043] Example 3 - Absorbent Coating - BOXIECAT Coating Liquid Example 2A was applied to the BOXIECAT Cat Litter Absorbent according to the procedure for adding coating liquid to the absorbent of Example 2 as follows: Coating Liquid Example 2A: 400.0 g absorbent, BOXIECAT Cat Litter: 4000.0 g absorbent / Coating Liquid: 10 Results: The coated cat litter was granular and did not harden. When exposed to ultraviolet light, the cat litter glowed.

[0044] Example 4 - Absorbent Coating - BOXIECAT Coating Solution Example 2A was applied to BOXIECAT Cat Litter Absorbent according to the procedure of Example 2 as follows. The addition of coating solution to the absorbent was as follows: Coating Solution Example 2A: 200.0 g Absorbent, BOXIECAT Cat Litter: 4147.0 g Absorbent / Coating Solution: 20.7 g Result: The coated cat litter was granular and did not clump. The cat litter glowed when exposed to ultraviolet light.

[0045] Example 5 - Absorbent Coating - BOXIECAT The coating solution of Example 2B was applied to the BOXIECAT cat litter absorbent according to the procedure for adding the coating solution to the absorbent of Example 2, and the coating solution was added to the absorbent as follows: Coating Solution Example 2A: 600.0 g absorbent, BOXIECAT cat litter: 4000.0 g absorbent / Coating Solution: 6.7 Results: The coated cat litter was granular and did not harden. When exposed to ultraviolet light, the cat litter glowed.

[0046] Example 6 - Blend of Coated and Uncoated Absorbents - BOXIECAT The coated cat litter of Example 5 was mixed with BOXIECAT cat litter (uncoated) as follows: Coated BOXIECAT cat litter Example 5: 720.0g Uncoated BOXIECAT cat litter: 3279.0g Uncoated / Coated: 4.55 Results: The two types of cat litter were dry mixed in a coating tumbler for approximately 10 minutes and then tested for uniformity. When the mixture was exposed to UV light, the coated particles glowed. The materials did not separate and remained uniformly mixed.

[0047] Example 7 - Blend of Coated and Uncoated Absorbents - BOXIECAT The coated cat litter of Example 4 was mixed with BOXIECAT cat litter (uncoated) as follows: Coated BOXIECAT Cat Litter Example 5: 1440.0g - 18% Uncoated BOXIECAT cat litter: 6560.0.0g - 82% Uncoated / Coated: 4.56 Two different cat litters were dry mixed in a coating tumbler for approximately 10 minutes and then tested for uniformity. When the mixture was exposed to UV light, the coated particles glowed. The materials did not separate and remained uniformly mixed.

[0048] Example 8 - Sand Coating The coating solution of Example 2B was applied to untreated sand following the procedure for adding the coating solution of Example 2 to the absorbent as follows: Coating solution Example 2B: 74.98 g Sand: 500.0g Sand / coating solution: 6.67 Result: The sand was coated.

[0049] Example 9 - Coating of granular zeolite The zeolite was coated with the coating solution of the present invention. The coated zeolite was mixed with BOXIECAT cat litter in a 1 / 20 ratio.

[0050] Example 10 - Absorbent Coating - SmartCat The coating solution of Example 2B was applied to Smartcat™ All-Natural Clumping Cat Litter, a chemical-free, biodegradable cat litter made from 100% American-grown grasses, sold by Pioneer Pet / Smartcat. The procedure for adding the coating solution to the absorbent was as in Example 2: Coating solution Example 2A: 40.6 g Absorbent, BOXIECAT cat litter: 500.0g Absorbent / coating solution: 12.3 Result: The cat litter was coated.

[0051] Example 11 - Blend of Coated and Uncoated Absorbents - Smartcat The coated cat litter of Example 10 was mixed with BOXIECAT cat litter (uncoated) as follows: Coated Smartcat Cat Litter Example 10: 816.5g - 18% Uncoated BOXIECAT cat litter: 3719.4g - 82% Uncoated / Coated: 4.56 Result: The mixture separated.

[0052] Example 12 - Absorbent Coating - Ultra Microcrystal Cat Litter® The coating solution of Example 2B was applied to silica gel cat litter, Ultra Micro Crystal Cat Litter. The coating solution was added to the absorbent according to the procedure of Example 2 as follows: Coating liquid example 2B: 150g Absorbent, BOXIECAT cat litter: 1000.0g Absorbent / coating liquid: 6.7 Results: The coated cat litter did not clump and was evenly coated.

[0053] Example 13 - Mixture of Coated and Uncoated Absorbents - Ultrafine Crystals The coated cat litter of Example 12 was mixed with Boxiecat cat litter (uncoated) as follows: Coated ultrafine crystals: 5% by weight Uncoated BOXIECAT: 95% by weight Absorbent / Coated Absorbent: 19 Results: The coated particles in the mixed cat litter luminesced when irradiated with UV light.

[0054] In addition to at least one fluorescent compound, the present invention includes other additives suitable for cat litter products, such as antibacterial and antifungal agents, such as those disclosed in U.S. Patent No. 9,266,089, which is incorporated herein by reference.

[0055] The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application to those skilled in the art. Because various changes may be made to the exemplary embodiments described above with reference to the corresponding drawings without departing from the scope of the present invention, all matter set forth in the foregoing description and accompanying drawings should be interpreted as illustrative and not limiting. Therefore, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following appended claims and their equivalents.

Claims

1. 1. A cat-attracting cat litter comprising at least one dry, solid absorbent and at least one fluorescent compound, wherein said at least one fluorescent compound is free of cat urine.

2. 2. The cat litter of claim 1, wherein the at least one fluorescent compound comprises an anionic diaminostilbene (DAS) or distyrylbiphenyl (DSBP) derivative.

3. 3. The cat litter of claim 2, wherein the at least one fluorescent compound is selected from the group consisting of 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonic acid sodium salt, 4,4'-bis(benzoxazolyl)-cis-stilbene, 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), and combinations thereof.

4. 10. The cat litter of claim 1, wherein the absorbent material is selected from the group consisting of clay, silica gel, wood, agricultural products, and combinations thereof.

5. A method for producing cat-attractive cat litter, comprising the steps of coating dry granular material: (a) dispensing the cellulose solution into the dry granular material to lightly moisten said material; (b) Immediately add a small amount of dry fluorescent compound to the wet material. (c) applying the cellulose solution to the wet material by spraying the cellulose solution onto the wet material and the dried fluorescent compound; (d) partially drying the cellulose solution (e) Repeat steps (b) through (d) until all of the dried fluorescent compound has been added. (f) Add the remaining cellulose solution and heat the coating to form cat litter.

6. 2. The method for making cat litter according to claim 1, wherein the dry granular material is an absorbent material.

7. The method for producing cat litter according to claim 6, wherein the cellulose solution is a hydroxypropyl cellulose solution.

8. 8. The method for producing cat litter according to claim 7, wherein the fluorescent compound is selected from the group consisting of 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonic acid sodium salt.

9. 1. A method for producing cat litter having cat-attractive properties, comprising coating a dry granular material comprising: Lightly wetting the dry granular material by gradually adding a coating solution to the material, wherein the dry granular material is moistened but not clumped, the coating solution containing a fluorescent compound, and repeating this as necessary to completely coat the granular material; and drying the coated granular material, wherein the coated dry granular material is not clumped, and the coated dry granular material is cat litter.

10. The method for producing cat litter according to claim 9, wherein the coating solution comprises a cellulose solution.

11. The method for producing cat litter according to claim 10, wherein the cellulose solution is a hydroxypropyl cellulose solution.

12. 10. The method of claim 9, wherein the dry, granular material is an absorbent material.

13. 13. The method of claim 12, wherein the absorbent material is selected from the group consisting of clay, silica gel, wood, agricultural products, and combinations thereof.

14. 10. The method for producing cat litter according to claim 9, wherein the fluorescent compound is selected from the group consisting of 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonic acid sodium salt.

15. 15. The method for producing cat litter of claim 14, wherein the coating solution is applied in a ratio of 1:3 to 1:30 to the solid absorbent, the coating solution comprises 1 to 20% by weight of hydroxypropyl cellulose, and the coating solution comprises about 0 to 5% by weight of glycerin.

16. Cat litter comprising dry granular material coated with a coating comprising at least one fluorescent compound, wherein the cat litter is completely coated with the compound, the coating comprises a cellulose-based material, the coating adheres to the dry granular material, and the coated granular material is not clumped together.

17. 17. The coated cat litter of claim 16, wherein the dry granular material is selected from the group consisting of clay, silica gel, wood, agricultural products, and combinations thereof, the cellulosic material is hydroxypropyl cellulose, and the at least one fluorescent compound is selected from 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonic acid sodium salt, 4,4'-bis(benzoxazolyl)-cis-stilbene, 2,2'-(2,5-thiophenediyl)-bis(5-tert-butylbenzoxazole), and combinations thereof.

18. 18. The coated cat litter of claim 17, wherein the amount of hydroxypropyl cellulose in the cat litter is in the range of 0.01 to 10.0% by weight, and the amount of the fluorescent compound is in the range of about 0.01 to 10.0% by weight.

19. 20. The coated cat litter of claim 18, wherein the coated cat litter is a mixed cat litter mixed with a dry absorbent material.

20. 16. The coated cat litter of claim 15, wherein the dry granular material is a non-absorbent material.

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