ODOUR ELIMINATING AND LIQUID ABSORBING AGENT, ITS PREPARATION, AND USE

Abstract: The present invention relates to an odour eliminating and liquid absorbing agent in the form of agglomerates of fine particulate components. Besides a liquid absorbing component it contains dicalcium phosphate, CaHPO4x2H2O, in an odour eliminating amount. The liquid absorbing component is preferably present in an amount of 60-70 % of the total weight. The invention further relates to a process for preparing the agent and the use of the agent as a litter in toilets or the like for pets.

Description: ODOUR ELIMINATING AND LIQUID ABSORBING AGENT, ITS PREPARATION, AND USE The present invention relates to odour eliminating and liquid absorbing agent in the form of agglomerates of fine particular components, furthermore a process for its preparation, as well as the use of the agent. Odour eliminating and liquid absorbing agents have a general use at different types of decontamination of the environment, e ■9 •, "■ n connection with the cleaning and scavenging of public places and locals. One specific area where it is desirous to obtain an effective agent which is simultaneously odour elimi¬ nating and liquid absorbing, concerns different types of lit¬ ters, such as cat litter. On the market today there are a number of different litter pro¬ ducts, type cat sand, whereby most being based on liquid ab¬ sorbing components, e.g. different types of clays, crushed lightweight concrete, and cellulose containing materials. In EP-B-0 039 522 there is described a liquid absorbing agent based on fibres, inorganic fi ller material, and one or more ad¬ ditives, such as starch, glue, colouring agents, and a biolo¬ gically active material, such as an insecticide, fungicide or bactericide. A commercially avai lable cat litter material based on the above mentioned patent contains, according to the list of contents, 60% of cellulose (paper pulp waste), 35% of kao¬ lin, 4% of lime, and 1% of tensides, and consists of pellets having a size of about 7 mm. All commercially available cat litter products possess however, drawbacks of different kinds, primarily as they are not able to absorb urine and the like type of waste, but annoying smell oc¬ curs after a short time, and so, quite often already before the possible liquid absorption has been uti lized. This means thus a sanitary problem to people and animals, and that the consump¬ tion of cat litter wi ll become relatively higher than what its SUBSTITUTESHEET liquid absorbing capacity allows under the presumption that a bad smelling "cat toi let" is not accepted. Products, mainly ba¬ sed on on clay, wi ll become tacky after use for some time and will stick in a troublesome manner to the box. Further, exist- ing products are not dust-free and several of them can not be flushed down in toi lets due to its density or its surface pro- pert i es . US-A-4,607,594 discloses the use of i.a. calcium dihydrogen- phosphate as a neutralizing agent for eliminating odour from urine. This monoca Iciumphosphate will, however, not react with the ammonia present in 'urine, and wi ll thus not be an effective odour eliminating agent. The object of the present invention is to obtain an agent which is both odour eliminating and liquid absorbing and which fur¬ thermore does not possesses such drawbacks as present at simi¬ lar products described above, as well as a process for its pre¬ paration thereof. For this purpose an odour eliminating and liquid absorbing agent is disclosed which is given in claims 1 to 4 and a pro¬ cess for its preparation as given in claims 5 to 9. The use of the agent is given in claim 10. The agent according to the invention is thus prepared in the form of agglomerates composed by fine particle components. As odour eliminating component the agent contains dicalcium phos¬ phate, CaHP0,x2H 2 0, in active amounts. A liquid absorbing agent is enclosed as well preferably in an amount of 60 to 70 % by weight based on the total weight. Precipitated silica or other silicic acid with a high porosity is very suitable as a liquid absorbing component. Preferably, the agent further contains a fine particle mineral based binding agent, as well, in an amount of 10 to 20 % by weight , based on the total weight. The binding agent is preferably a plastic clay, e.g., a so called SUBSTITUTESHEET ball clay (g rey clay) At the preparation of the agent the ingoing components are pri¬ mari ly dry mixed, optionally after a grinding thereof to equal finess, whereupon water is added to obtain at least a moistened consistency. At the use of si lica and clay, 10 to 35 % of water is hereby requi red, calculated on the dry weight. The moistened mixture is then brought to form larger agglomerates of a prede¬ termined size, which are dried at an elevated temperature to obtain durable agglomerates. The agglomerates are preferably dried at a temperature of between 70 and 120 C. The formation of agglomerates can be carried out in different ways, but it is preferred to granulate or pelletize the fine particulate mixture. At the granulation, for example an a disc or in a drum in a conventional manner, granules having a size of 3 to 7 mm are desi red. At pelleting which i s achieved by ex¬ trusion, pellets having a size of 3-7 x 3-10 mm are desired. In order to increase the porosity of the agent and thereby m¬ proving the absorption capability it is preferred to add an ef¬ fervescent agent to the components present prior to or simul¬ taneously with the dry mixing. As a particularly effective and suitable effervescent agent a preferred addition of a about sto ch i omet r i c amount of lime stone and an acidic pyrophospha- te, e.g. Na-H^P O-- . The agent according to the invention can with great advantage be used as a litter in pet toi lets and the like, i .e. what is dai ly called cat litter. The invention wi ll now be described more in detai l in the form of an example. SUBSTITUTESHEET EXAMPLE The following components were dried, ground to the same finess and dry mi xed . 69% precipitated silica 10% ball clay (grey clay) 15% dicalcium phosphate, CaHPO , x2H ? 0 3% ground lime stone 3% a 2 H 2 P 2 0 7 After dry mixing 29 to 43 % of water was added, calculated on the dry weight and different types of agglomerates were prepa¬ red according to the below given details. 1. Pellets after drying at 100 C in small p eces. 2. Granulation to about 5 mm diameter and subsequent drying at 75°C. 3. Granulation to about 6 mm in size and subsequent drying at 95°C 4. Pelleting by means of extrusion to 4x10 mm pellet size and subsequent drying at 100 C. The thus differently prepared four forms of agglomerates of the agent were then tested in practical tests in a "cat toilet", as well as in a laboratory test. The results of these tests are evident-from Table 1 below. SUBSTITUTESHEET TABLE 1 Product Absorption Mechani cal Odour Flush- Reuse durabi Lity elimination abi lity good 0 very good yes doubt fu I good good very good yes after ai rdry i ng good good very good yes after a.i rd ry i ng very good good very good yes after ai rdry i ng None of the products caused any problem as to stickyness, e.g. to the feet or fur of the cat. All products have to be regarded as having obtained the right hardness as the cats wh ch have used the agent for a longer time had have no inconvenience at digging in the agent. To each fi lling of the cat toi let 600 g were used for 3 cats. The test period for product 1 was 3 days and for the other products it was 4 days . An increase of the clay content to 15% gave an improved plasti¬ city and mechani cal durabi lity without any noti ceable problems A reduction of the si li ca content to about 64% made the produc¬ tion of pellets by means of extrusion more easy without any no¬ ticeable quality problems of the end product. SUBSTITUTESHEET

Claims: C LA IMS . 1. Odour eliminating and liquid absorbing agent in the form of agglomerates of fine particulate components, characterized in that it contains dicalcium phosphate, CaHPO, x2H-,0, in an odour eliminating amount besides a liquid absorbing component. 2. Agent according to claim 1, characterized in that the liquid absorbing component is present in an amount of 60 to 70% of the total weight and that it preferably consists of precipitated silica or another silicic acid having high porosity. 3. Agent according to'claim 1 or 2, characterized in that it also contains a fine particulate, mineral based binding agent in an amount of 7 to 20 % of the total weight. 4. Agent according to any of claims 1-3, characterized in that the binding agent consists of clay. 5. Process for preparing an agent according to claims 1-4, cha- racterized in that the components present are mixed dry, after an optional grinding to the same finess, water is added to ob¬ tain at least a moistened state, the moistened mixture is brought to from agglomerates of a predetermined size, and these are dried at an elevated temperature, preferably between 90 and 110°C. 6. Process according to claim 5, characterized in that the for¬ mation of aggregates is obtained by granulation to granules of a size of 3-7 mm in diameter. 7. Process according to claim 5, characterized in that the for¬ mation of aggregates is obtained by pelletizing to pellets with an approximate size of 3-7 mm x 3-10 mm. SUBSTITUTESHEET 8. Process according to any of claims 5-7, characterized in that an effervescing agent is added to the components present prior to or simultaneous with the dry mixing. 5 9. Process according to any of claims 5-8, character zed in that a mixture of about stoi chiometr i ca I ly equal amounts of lime stone and an acidic pyrophosphate . 10. The use of the agent according to any of claims 1-4, as a '• - litter in toi lets or the simi lar for pets. SUBSTITUTESHEET

Inventors: DAHLGREN SVEN-ERIC, MULLER ARTHUR, NILSSON TORSTEN, DAHLGREN, SVEN-ERIC, MULLER, ARTHUR, NILSSON, TORSTEN
Applicants: KEMIRA KEMI AB
Application year: 1989
Main classification: B01J20
IPC codes: A01K1, B01J20