# US 5,352,841 A · Agent for dosing aqueous systems with acrolein, processes for making same, and method of treating an aqueous system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,352,841 A - Document ID: US5352841A - Status: Granted - Kind: A - Application number: 08/165,922 - Filed: 1993-12-14 - Granted: 1994-10-04 - Earliest claimed: 1993-09-24 - Assignees: Degussa AG - Inventors: Peter Werle; Werner Pahling; Martin Trageser - Web page: https://patentgrep.com/patent/US5352841A ## CPC - C07C 45/86: Use of additives, e.g. for stabilisation - A01N 35/02: containing aliphatically bound aldehyde or keto groups, or thio analogues thereof; Derivatives thereof, e.g. acetals - C02F 1/50: by addition or application of a germicide or by oligodynamic treatment {(C02F1/4606, C02F1/467, C02F1/76 take precedence)} - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - A01N: PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF (preservation of food or foodstuff A23); BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES (preparations for medical, dental or toiletry purposes which kill or prevent the growth or proliferation of unwanted organisms A61K); PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract Liquid acrolein, whose hazardous properties make handling difficult, is used to dose aqueous systems with acrolein in a biocidally effective concentration. Disclosed are agents which increase the ease and safety of acrolein handling and which are characterized by a content of 30 to 95% by weight acrolein and 5 to 70% by weight inorganic carrier materials. Silicas are the preferred carrier materials. The powdery or highly viscous mixture of substances will preferably exist in molded form and is additionally provided with a cladding that is impermeable to acrolein vapor. In dosing the aqueous systems, the agents are introduced directly in the water whereupon the acrolein is released. ## Claims ### Claim 1 An agent for dosing aqueous systems with acrolein in a biocidally effective concentration comprising 30 to 95% by weight of acrolein and 5 to 70% by weight of at least one inorganic carrier material, wherein said inorganic carrier material is basically inert relative to acrolein and has a pH value of 3 to 7 in a 5% dispersion in water. ### Claim 2 (depends on 1) The agent according to claim 1, wherein said pH value is between 5 and 7. ### Claim 3 (depends on 2) The agent according to claim 2, wherein said pH value is between 5 and 6.5. ### Claim 4 (depends on 1) The agent according to claim 1, wherein said carrier material exhibits a BET surface area of 100 to 700 m.sup.2 /g. ### Claim 5 (depends on 4) The agent according to claim 4, wherein said carrier material exhibits a BET surface area of 150 to 700 m.sup.2 /g. ### Claim 6 (depends on 1) The agent according to claim 1, wherein said carrier material has an oxidic or silicate structure. ### Claim 7 (depends on 6) The agent according to claim 6, wherein said carrier material is pyrogenic and precipitated silica or neutral to acidic silicate. ### Claim 8 (depends on 7) The agent according to claim 7, wherein said carrier material is a zeolite. ### Claim 9 (depends on 8) The agent according to claim 8, wherein said zeolite is a dealuminized Y-zeolite. ### Claim 10 (depends on 1) The agent according to claim 1, wherein said agent comprises 40 to 85% by weight acrolein, 60 to 15% by weight of at least one silica and/or silicate which exhibit a BET surface area of 150 to 700 m.sup.2 /g and a pH value of 5 to 7 in a 5% dispersion in water, and an effective quantity of at least one acrolein stabilizer. ### Claim 11 (depends on 10) The agent according to claim 10, wherein said stabilizer is hydroquinone in a quantity between 100 and 5000 ppm. ### Claim 12 (depends on 1) The agent according to claim 1, wherein said agent further comprises a tablet dispersing agent in a quantity up to 3% by weight relative to the total of said acrolein and said carrier. ### Claim 13 (depends on 1) The agent according to claim 1, wherein said agent exhibits a solid consistency and takes the form of molded pieces. ### Claim 14 (depends on 1) The agent according to one of claim 1, wherein said agent is present in the form of molded, solid or gelatinous pieces which are enclosed by a cladding material which is water-soluble or penetrable by water or is water-insoluble, wherein said cladding material is basically impermeable to acrolein vapor. ### Claim 15 (depends on 14) The agent according to claim 14, wherein the mass of said pieces is at least 0.1 g. ### Claim 16 (depends on 15) The agent according to claim 15, wherein the mass of said pieces ranges from 0.2 g to 200 g. ### Claim 17 (depends on 16) The agent according to claim 16, wherein the mass of said pieces ranges from 1 g to 50 g. ### Claim 18 (depends on 14) The agent according to claim 14, wherein said cladding material is gelatin, paraffin wax, or polyalkylene. ### Claim 19 (depends on 1) A process for producing the agent according to claim 1, said process comprising mixing said acrolein and said carrier material to form a mixture, homogenizing said mixture, optionally converting said homogenized mixture into a molded body, and optionally enclosing said molded body with a cladding material. ### Claim 20 (depends on 1) A process for producing the agent according to claim 1, said process comprising converting said carrier material to a pressed piece, applying acrolein to said pressed piece, and optionally enclosing said pressed piece with a cladding material. ### Claim 21 (depends on 1) A method of treating an aqueous system to control aquatic life comprising dosing the agent according to claim 1 into said aqueous system in a biocidally effective concentration. ### Claim 22 (depends on 21) The method according to claim 21, wherein said agent is present in the form of molded, solid or gelatinous pieces which are enclosed by a cladding material which is water-soluble or penetrable by water or water-insoluble, wherein said cladding material is basically impermeable to acrolein vapor. ### Claim 23 (depends on 22) The method according to claim 22 further comprising removing or perforating said water-insoluble cladding material to permit the penetration of water.