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
  • C11D3/395—Bleaching agents
  • C11D3/3955—Organic bleaching agents
• • 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
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/0047—Detergents in the form of bars or tablets
  • C11D17/0065—Solid detergents containing builders
  • C11D17/0073—Tablets
  • C11D17/0078—Multilayered tablets
• • 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
  • C11D3/04—Water-soluble compounds
  • C11D3/08—Silicates

Definitions

• Machine dishwashing generally consists of a pre-rinse cycle, a cleaning cycle, one or more intermediate rinse cycles, a rinse cycle and a drying cycle. This applies to machine washing in the home as well as in business.
• HGSM HGSM
• the pre-clearing zone corresponds in principle to the pre-rinse cycle of an HGSM.
• the cleaning agent added to the cleaning zone is used in the so-called pre-clearing zone to support, pre-clean the surfaces to be cleaned from the adhering food residues.
• GGSM in which the pre-clearing zone is only operated with fresh water, but a pre-clearing zone with cleaning agent solution is more effective than pre-clearing with fresh water alone.
• One or more tablets can be dosed, for example, in a free part of the cutlery basket, but also elsewhere in the machine.
• tablet-shaped cleaning agents are adequately described in the patent literature.
• DE-OS 16 17 088 tablets for automatic dishwashing which are obtained by pressing a powdery mixture of sodium silicate with a ratio of Na2O: SiO2 such as 1: 3.25 to 2: 1 and a water content of 0 to 20% , polymeric alkali phosphates, active chlorine compounds, low-foaming non-ionic surfactants compatible with the active chlorine compounds, fillers such as alkali metal carbonates, chlorides or sulfates, white paraffin oil and tablet binders, which are said to be stable in storage and transportation.
• Such tablets are also known from DE-OS 28 57 001 which contain essentially the same constituents, however should have a particularly high level of alkalinity, which can be achieved, inter alia, by adding alkali metal hydroxide.
• a high level of alkalinity is unsuitable for the use of the agents in the household because improper handling of the agents can lead to skin irritation and can also damage the decor.
• the present invention was therefore based on the object of providing multilayer, in particular two-layer detergent tablets, the first layer of which cools due to the inlet Tap water largely dissolves in the pre-rinse cycle of the HGSM and there develops the highest possible alkalinity in combination with a good network effect.
• a second layer should correspond to the current detergent formulations for automatic dishwashing in the usual way and should therefore be equipped with an active chlorine carrier. At most, it should be slightly dissolved by the cold tap water in the pre-rinse cycle, but should dissolve completely in the HGSM wash cycle.
• the invention thus relates to multi-layer, in particular two-layer detergent tablets for machine dishwashing, containing generally common alkaline components, in particular from the group of alkali metal silicates and pentaalkali metal phosphates, low-foaming nonionic surfactants, active chlorine compounds and tableting aids, which are characterized in that they are soluble in a first, cold water Layer of alkali metasilicate nonahydrate and 7 to 22.4, preferably 15 to 18 wt .-% pentalkalitriphosphate containing water of crystallization in a ratio of 0: 1 to 1: 0, preferably 0.35: 1 to 1: 1, based on the anhydrous substances, and low-foaming nonionic surfactants and in a second layer, which quickly dissolves at increasing temperatures, alkali metal silicate and pentaalkali metal phosphate in a weight ratio of 2: 1 to 1: 2, preferably 1: 1 to 1.7: 1, based on anhydrous substances and active chlorine-containing compounds ending
• the alkali metasilicate used in the second layer is preferably the anhydrous product.
• a mixture of anhydrous metasilicate and its nonahydrate in a weight ratio of at most 1.2: 1 can also be used.
• the dissolving or disintegrating properties were determined of compressed detergent mixtures, in order to subsequently obtain a multilayer tablet with the desired dissolution profile by combining a composition which is readily soluble in cold water with a composition which is only soluble at increasing temperatures.
• the desired dissolution profile of a two-layer tablet is to be understood as an almost complete dissolution of the 1st layer with a slight detachment of the 2nd layer in the pre-rinse cycle and a rapid and complete detachment of the remaining tablet in the cleaning cycle of all commercially available HGSMs with rising water temperatures.
• the tablets Lying on a sieve with a mesh size of 2 mm, the tablets were moved up and down in water at 20 ° C. in such a way that they were at the highest point with the base just at the level of the water surface.
• the amount of water was 800 g, the number of strokes was 25 per minute.
• the time required for the disintegration or dissolution of the individual tablets was measured or, for dissolving times of more than 5 minutes after 5 or 10 minutes, the residues remaining on the sieve were weighed out.
• the wetting of the surfaces to be cleaned by the alkaline detergent components in the pre-rinse cycle can be improved by adding surfactants.
• Surfactants are usually incompatible with active chlorine-releasing compounds. However, their simultaneous use in a two-layer tablet without impairing the chlorine carrier is possible if the two compounds are separated from each other in a different layer.
• the proportion of surfactant in the layer provided for the pre-rinse cycle is 0.5 to 10% by weight, preferably 1 to 5% by weight, based on the pre-rinse cycle layer.
• Suitable surfactant components are the known low-foaming nonionic surfactants, such as the ethoxylation products of long-chain alcohols and alkylphenols, and the free hydroxyl groups of the polyethylene glycol ether residue can be substituted by ether or acetal groups or by polypropylene glycol ether residues to reduce the tendency to foam.
• the block polymers of ethylene oxide with polypropylene oxide are also suitable.
• the preferred tabletting aid is 0.5 to 2.5, preferably 1 to 2% by weight of calcium hydrogenphosphate dihydrate (to reduce segregation) and 1 to 5, preferably 2 to 3% by weight of sodium acetate, anhydrous (to prevent sticking) Tool parts) used.
• the proportions of these tabletting aids which are safe from an application point of view with regard to cleaning performance, can be varied beyond the ranges mentioned in order to obtain a recipe to be able to optimally press door variants.
• the sodium acetate content also affects the solubility of the tablet. Higher amounts of sodium acetate lead to improved solubility in cold water in the pre-rinse cycle.
• a further improvement in solubility can also be achieved by adding other water-soluble salts such as. B. sodium chloride can be achieved, but is usually not necessary with the appropriate choice of starting materials.
• Other usual tableting aids such as. B. lubricants to improve the compressibility (z. B. stearates, talc, glycerides, etc.), disintegrants (z. B. cellulose derivatives, attapulgite (Mg-Al-silicate) etc.) and other auxiliaries can be used in principle, they are undesirable from an application technology point of view and also burden the formulation (costs and additional inert fillers).
• These otherwise customary aids can be dispensed with in the production of tablets according to the present invention.
• the compressed, colored raw materials can be less soluble than compressed, uncolored raw materials.
• Staining of sodium metasilicate nonahydrate had the least influence on solubility. You can dissolve or suspend the dye in the surfactant and spray it together with the nonahydrate, e.g. B. in a Lödige mixer. An aqueous dye solution can also be introduced with simultaneous drying using a fluidized bed process. The colored nonahydrate is then optionally mixed with other components and, after compression, leads to a uniformly colored tablet layer. For aesthetic reasons For reasons, the tablets can also be pressed in colored layers.
• Tablets consisting of a mixture of anhydrous sodium metasilicate with a grain size of less than 0.8 mm and anhydrous pentasodium triphosphate are suitable for the cleaning cycle in the HGSM, whereby the dissolution profile of the tablets can be influenced by adding sodium metasilicate nonahydrate.
• the compressibility of raw material mixtures containing almost anhydrous sodium metasilicate depends on the particle size distribution. With a fine grain fraction (less than 0.8 mm), good tabletting properties of the raw material mixture are obtained, while dust (less than 0.2 mm) and unscreened material (20 to 100% larger than 0.8 mm) lead to mixtures that are difficult to tablet .
• completely anhydrous metasilicates e.g. manufactured after a sintering or melting process
• the tablets are mechanically stable even after storage.
• hydrothermally produced metasilicate with a residual moisture content of approx. 2% the grain size distribution did not play a decisive role. However, after the tablets had been stored under indoor climate conditions, the surface had weathered. Large tablets then also tend to crack. A residual moisture content of more than 2% in the metasilicate is therefore undesirable.
• Metasilicates in anhydrous form and as nonahydrate and also the anhydrous triphosphate are preferred in the form of their Na trium salts used.
• Their total amount in the mixture to be pressed for the cleaning cycle was 88 to 98, preferably 95 to 97% by weight.
• Active chlorine carriers are also common components of cleaning agents for HGSM. Trichloroisocyanuric acid was preferred as the active chlorine carrier, but also other known solid compounds such as e.g. B. sodium dichloroisocyanurate, its dihydrate and potassium dichloroisocyanurate can be used in the marketable form without impairing the tablettability. Their amounts are 0.5 to 5.0, preferably 1.0 to 2.5% by weight, based on the total tableting mixture.
• tabletting aids are added to the cleaning aisle tablet layer as described for the pre-rinse layer, the amounts of which can also be varied.
• Customary chlorine-stable dyes and fragrances can also be added to the tableting mixtures for the cleaning cycle.
• Tablets are pressed in two layers on rotary presses equipped with two dosing and two pressing stations (e.g. Fette / Perfecta 3002, Fette / P3, Kilian / -RU-ZS).
• the first dosing station contains the mixture of the detergent layer, which is smaller in mass, generally for the pre-rinse cycle. It is used to fill in the rotating Matrices located matrices. This material is pre-compressed at the first press station. Subsequently, at the second dosing station, the pre-pressed 1st layer is overlaid with the second detergent mixture, which is then intended for the cleaning cycle.
• the two-layer tablet is pressed at the second pressing station and then pushed out of the die with the lower punch.
• the detergent layer for the pre-rinse cycle which was smaller in mass, was filled into the die of the press and pre-compressed.
• the upper punch was pulled out of the die by turning the handwheel backwards.
• the detergent layer intended for the cleaning cycle was filled into the die and, together with the pre-rinse cycle cleaning layer already present, pressed into the tablet with the flexural strength required for the desired dissolution profile. Examples of the compacts obtained in this way and their properties are listed in Table 2.
• the layer intended for the pre-rinse cycle was referred to in the table as layer 1 and the layer provided for the cleaning cycle as layer 2.
• the compression can be done with die lubrication, with usual lubricants such as. B. paraffin oil, almond oil or water or aqueous solutions can be used.
• lubrication was carried out directly through holes in the die, by spraying the lower punch or by means of felt rings soaked in lubricant on the lower punch. Lubrication may also be dispensed with in the case of raw material mixtures with particularly favorable pressing properties.
• the pressing conditions were optimized with regard to the setting of the desired dissolution profile with sufficient tablet hardness.
• the flexural strength served as a measure of the tablet hardness (method: compare Ritschel, "Die Tablette", C. Contor, 1966, page 313). Tablets with a flexural strength of greater than 12 kp, preferably greater than 15 kp, were sufficiently stable under simulated transport conditions.
• the specific weight of the tablets differs in the layers due to the recipe; it is between 1 and 2 g / cm3, preferably between 1.2 and 1.4 g / cm3 for the pre-wash detergent layer and preferably between 1.4 and 1.7 g / cm3 for the main wash detergent layer.
• the specific weight of the total compact is preferably between 1.35 and 1.55 g / cm3.
• the shape of the tablet can also influence the dissolution rate via the outer surface exposed to the H2O attack. For reasons of stability, compacts with a diameter to height ratio of 0.6 to 1.5: 1, preferably 1: 1, were produced.
• the weight of the single tablet can be varied within technically reasonable limits. Depending on the size of the tablets, 1, 2 or more are used. Tablets of 20 to 30 g in weight are preferred, two of which must be used. Larger tablets are generally more sensitive to breakage and, moreover, can be compressed at a lower speed, which leads to a loss in performance in their manufacture. In the case of smaller tablets, the handling advantage compared to powdered cleaning agents (simple dosing) would be reduced.
• EO mole of ethylene oxide
• PO mole of propylene oxide
• the two cleaning agent mixtures were first prepared in a conventional mixer (Lödige, Forberg), with layer 1 (for the pre-rinse cycle) spraying the nonahydrate with the nonionic containing the alizarin brilliant, pure blue, GLW before mixing.
• the mixture was pressed on an eccentric press from Fette, type "Exacta 31" with pressing tools which are equipped with Vulkolan were coated.
• the lower punch of the press was first moved into the lowest point of the die and the mixture of layer 1 was poured into the die.
• the top punch was inserted into the bore of the die by actuating the handwheel so that the filled material was pre-compressed from 8.2 mm fill height to 6 mm.
• the handwheel backwards the upper punch was pulled out of the die without the pre-compressed mass being expelled through the lower punch.
• the mixture of layer 2 was overlaid in the die. According to the density of the mixture of 0.89 g / cm3, the filling height of the second layer was 21.8 mm.
• the tablet After changing the immersion depth (by changing the eccentric setting), the tablet was pressed mechanically to a height of 17.3 mm.
• the compression ratio of the total tablet was 1: 1.73.
• the pressing pressure required for compression was 1,400 kp / cm2.
• the tablets obtained had a flexural strength greater than 15 kp. Approx. 22% of the entire tablet detached when used in the pre-rinse cycle. Layer 1 was almost completely replaced after the pre-wash program. After the cleaning cycle, the tablet was completely dissolved. No cracks in the tablet or weathering of the surface were found after storage.
• the multi-layer detergent tablets can be opened into one before the start of the pre-rinse cycle Zone which exposes the tablets to the dissolving power of the tap water flow, e.g. B. in the cutlery basket of a household dishwasher, and the automatically controlled cleaning process can be started.
• the invention therefore also relates to the use of the multilayer detergent tablets for cleaning dishes in automatic household dishwashers, which is characterized in that the tablets are opened in the machine even before the start of the pre-wash cycle in a zone which exposes the tablets to the dissolving power of the tap water inflow of the pre-wash cycle , for example by placing it in the cutlery basket, and then initiating the automatically controlled cleaning process.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
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Cited By (24)

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• 1985
  • 1985-11-21 DE DE19853541146 patent/DE3541146A1/de not_active Withdrawn
• 1986
  • 1986-11-12 DE DE8686115738T patent/DE3677154D1/de not_active Expired - Fee Related
  • 1986-11-12 AT AT86115738T patent/ATE60354T1/de not_active IP Right Cessation
  • 1986-11-12 EP EP86115738A patent/EP0224128B1/fr not_active Expired - Lifetime
  • 1986-11-17 US US06/931,503 patent/US4828749A/en not_active Expired - Fee Related
  • 1986-11-18 CA CA000523270A patent/CA1277889C/fr not_active Expired - Fee Related
  • 1986-11-21 JP JP61279535A patent/JPS62129395A/ja active Pending

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