Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/12—Water-insoluble compounds
  • C11D3/124—Silicon containing, e.g. silica, silex, quartz or glass beads
  • C11D3/1246—Silicates, e.g. diatomaceous earth
  • C11D3/128—Aluminium silicates, e.g. zeolites
  • C11D3/1286—Stabilised aqueous aluminosilicate suspensions

Definitions

• the invention relates to a stabilized, aqueous suspension of synthetically produced zeolite, in particular of type A, and the use of the suspension for the production of low-phosphate and phosphate-free, optionally active chlorine-containing, powdered detergents and cleaning agents.
• type A synthetic zeolites in particular NaA zeolite
• sodium tripolyphosphate in detergents and cleaning agents has become increasingly important in recent years.
• Numerous zeolite-containing detergents with low-phosphate and phosphate-free formulations have already appeared on the market.
• the use of zeolite A as a novel water-insoluble detergent component on an industrial scale has also led to new developments in detergent and cleaning technology;
• the processing of the zeolite in the form of storage-stable, free-flowing suspensions with the highest possible zeolite content should be emphasized here.
• DE-2 527 388 A 1 describes organic, macromolecular, carboxyl and / or hydroxyl group-containing polymer compounds with molecular weights of above 1500, including those derived from natural products such as the polysaccharides. 0.5 to 6.0 percent by weight of these are required to stabilize aqueous suspensions containing more than 40 percent by weight of zeolite.
• aqueous zeolite suspensions which consist of industrially produced A-type zeolite, water and an organic macromolecular polymer compound containing carboxyl and / or hydroxyl groups and having molecular weights above 1500 as a stabilizer can be substantially improved, when the polysaccharide xanthan gum derived from a natural product is added as a stabilizer.
• the improvement consists in a much lower stabilizer content.
• the amount of the suspension stabilizer in the suspension according to the invention can be in the range from 0.05 to 0.25, preferably in the range from 0.10 to 0.15 or 0.20 percent by weight, based on the total stabilized aqueous zeolite suspension.
• suspension stabilizers for zeolite suspensions are already known from DE-3 016 433 A1, but they are very high polymer synthetically produced polyacrylamides or their copolymers.
• the zeolite content can be up to 60, preferably 40 to 55 percent by weight, based on the total stabilized aqueous zeolite suspension.
• Xanthan gum is based on Römpps Chemie-Lexikon, 7th edition (1973), pages 1355 and 1356 and Kirk-Othmer “Encyclopedia of Chemical Technology” 3rd edition (1980), volume 12, pages 62 to 64 Product understood that is known under the Anglo-Saxon name “Xanthan Gum”.
• Xanthan gum is a high molecular weight polysaccharide, i.e. H. an exocellular heteropolysaccharide with a molecular weight of about 2,000,000 and higher, which is produced by various species of Xanthomonas, for example Xanthomonas campestris. They are hydrophilic colloids. Numerous publications deal with their production by aerobic propagation and cultivation of bacteria of the genus Xanthomonas in aqueous nutrient media. The basic work is described in U.S. Patent No. 3,000,790.
• hydrophilic colloids produced by Xanthomonas campestries are polysaccharides that contain mannose, glucose, glucuronic acid, O-acetyl residues and acetyl-linked pyruvic acid. They arise as an exocellular reaction product of the bacterial species mentioned when they are aerobically grown in aqueous nutrient solutions which, in addition to the usual growth-promoting components, contain in particular water-soluble carbohydrate compounds.
• the zeolite A used according to the invention can by numerous known methods, for. B. by precipitation from solutions of sodium silicate and sodium aluminate and subsequent hydrothermal treatment or by hydrothermal treatment of destructured kaolin and sodium hydroxide.
• a number of processes have become known for the industrial production of zeolite A for detergent purposes, in which the zeolite A crystals are formed with rounded corners and edges and the formation of oversize (grit) is avoided by specific process parameters.
• the zeolite A is generally obtained as a moist filter cake with about 40 to 60% water content. Because of its thixotropic properties, this filter cake can be easily stirred and immediately mixed with the suspension stabilizer.
• the suspension according to the invention is low-viscosity at room temperature and up to 50 ° C. and can be pumped and stirred without problems for up to 7 days of storage. Even after further unlimited storage at room temperature, there is only a slight, soft sediment that can be easily stirred up again.
• the suspension according to the invention also shows excellent rheological properties at elevated temperatures, i.e. H. in the range between 50 and 80 ° C. In some technical processing equipment for zeolite suspensions for the production of powder detergents, the zeolite suspension must be warmed up, i.e. H. at temperatures above 50 ° C.
• the suspension remains stable at this temperature over a longer period of time and does not disintegrate.
• the pH of the aqueous zeolite suspension which is approximately pH 11 to 14, is not significantly changed by the neutralizing stabilizer according to the invention.
• the stabilizer used according to the invention is of course without a negative influence on the calcium binding capacity of the zeolite and although the sensitivity of xanthan gum to strongly oxidizing agents such as hypochlorite is known, no impairments were observed when using the claimed suspensions for the production of dishwasher detergents containing active chlorine.
• the suspensions according to the invention can therefore be prepared by simply mixing the constituents.
• the aqueous suspension of the zeolite which is still moist and undried from its production, is preferably used by converting the moist filter cake obtained after separating the mother liquor and washing with water into a flowable suspension by stirring. A further addition of water is generally not necessary.
• the stabilizer added according to the invention is used in the form of a pale yellow powder.
• the suspensions according to the invention can be prepared with zeolite concentrations of at least 20 percent by weight; however, for economic reasons, i.e. H. For example, to save transport and energy costs, set the water content in the suspensions as low as possible.
• the suspensions according to the invention are generally prepared at elevated temperatures, ie. H. at approx. 60 'C, which speeds up the mixing process.
• Dried zeolite powder can be used if the zeolite filter cake that is still moist from the production is not available.
• the stabilized zeolite suspensions are used as liquid raw materials according to the usual manufacturing processes for such agents. It should also be noted that the addition of the suspensions has no negative influence on the foaming behavior of the washing and cleaning agents.
• the stabilized zeolite suspensions can also be directly by conventional drying measures, for. B. by spray drying, into a powder that can be easily redispersed in water. In the production of powdered cleaning agents using the suspensions according to the invention, in particular using the spray drying method, very low-dust products are obtained which are readily wettable.
• the suspensions according to the invention are also suitable for the production of powdered dishwashing detergents.
• the suspension was assessed empirically, i.e. it is not based on precisely measurable quantities and can therefore only be made in a direct comparison within a series of tests.
• test results are shown in the following table. They show that the suspensions according to the invention were stable even at elevated temperature and could be processed without problems after storage.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Silicates, Zeolites, And Molecular Sieves (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
• Colloid Chemistry (AREA)
• Detergent Compositions (AREA)

Applications Claiming Priority (2)

Publications (3)

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• 1984
  • 1984-03-05 DE DE19843408040 patent/DE3408040A1/de not_active Ceased
• 1985
  • 1985-02-27 DE DE8585102149T patent/DE3572509D1/de not_active Expired
  • 1985-02-27 EP EP85102149A patent/EP0154291B1/de not_active Expired
  • 1985-03-04 JP JP60041382A patent/JPS60204615A/ja active Granted

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