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
  • C11D3/04—Water-soluble compounds
  • C11D3/08—Silicates
• • 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
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3902—Organic or inorganic per-compounds combined with specific additives
• • 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
  • C11D3/3951—Bleaching agents combined with specific additives

Definitions

• the invention relates to a method for cleaning, disinfecting and rinsing dishes in commercial dishwashers with the aid of cleaning agents based on alkali metal silicates, substances containing active chlorine and / or active oxygen, optionally with the addition of alkali phosphates and disinfectants, and a rinse aid in the form of a surfactant Based on adducts of ethylene oxide and / or propylene oxide with higher molecular weight polyalkylene glycols or with fatty alcohols with 10 to 18 carbon atoms and a suitable agent.
• both the process and the means used must perform a whole series of tasks, such as the safe detachment of burnt-on food residues, for which alkali hydroxides in particular have been used in increasing concentrations, the germicidal and disinfection, and the removal of tar residues containing chlorine - or oxygen-active substances is effected.
• the metal parts of the dishwasher must not be attacked, which can be prevented with alkali metal silicates, which also have a cleaning effect.
• the temperature of the cleaning liquor which has been raised more and more to 85 ° C today, because it can achieve a double effect. At one point, it was previously thought that germs and bacteria could be killed more safely at higher temperatures.
• the problem underlying the invention is to find a way out here and not to have to resort to ever higher temperatures, ever more aggressive agents and higher concentrations.
• the object on which the invention is based is therefore to create a method and an agent which has a lower energy requirement, requires fewer agents to be used and nevertheless enables the dishes to be cleaned properly, reliably kills germs and bacteria and does not cause any foam problem.
• a very important feature of the process according to the invention and the cleaning agent used for it, which is surprising in its effect, is the very high proportion of alkali metal silicate of more than 60% by weight, preferably even more than 75% by weight. Metasilicates have so far been added to such cleaning agents because they have a certain cleaning effect and, above all, a protective effect on the metal parts from corrosion. In practice, however, their proportion has been predominantly 10 to 40% by weight. Additional percentages are only given in isolated cases. However, considerable amounts of alkali polyphosphates and of alkali and temperatures of 60 to 85 ° C. have always been considered necessary for a good cleaning action.
• this easily accessible and therefore inexpensive and chemically non-aggressive substance can be used as the main component in such a cleaning process and in a suitable cleaning agent - and this at unusually low cleaning temperatures of 25 to 45 ° C, preferably 35 up to 45 ° C, - if one uses the synergistic effect of the interaction with the certain, as such known group of surfactants based on adducts of ethylene oxide with higher molecular weight polyalkylene glycols and / or adducts of ethylene and / or propylene oxide with fatty alcohols.
• the cleaning agent of the specified composition suitable for carrying out the method is preferably used in solid form as a powder or more advantageously in block form.
• a powder detergent has the advantage that the individual components do not influence each other and storage is not a problem.
• the cleaning agent can also be used in liquid form, expediently in about 30% dissolution in water and / or in lower alcohols with 1 to 4 carbon atoms.
• the advantage of the liquid cleaning agent is that when it is added to the dishwasher, it is spontaneously distributed in the cleaning liquor and its effect unfolds and can be dosed with simple dosing devices.
• the amount of cleaning agent is expediently from 0.3 to 2 g / liter in the case of solid cleaning agent, preferably from 0.7 to 0.9 g / liter, and expediently from 0.6 to 6 g / liter in the case of liquid cleaning agent, preferably from 1 to 2 g / liter.
• the preferred temperature range is 35 to 45 ° C.
• the process and the detergent used in conjunction with the surfactants of the rinse aid are extremely effective in killing even the most resistant and thermostable pathogens such as streptococcus faecium.
• a preferred composition of the cleaning agent consists of about 85% by weight of alkali metasilicate, about 10% by weight of a substance containing active chlorine or active oxygen and optionally alkali polyphosphates up to 5% by weight.
• nonionic surfactants required for the synergistic effect based on adducts of ethylene oxide and / or propylene oxide with higher molecular weight polyalkylene glycols or with fatty alcohols with 10 to 18 carbon atoms are known as rinse aids, for example from the European patent already mentioned, so that they are not here must be described in more detail. Further developments and modifications are of course also possible, such as the end-capped alkyl polyethylene glycol ethers.
• the reaction product of a fatty alcohol having 10 to 12 carbon atoms and 4 moles of ethylene oxide and 6 moles is preferably suitable as a surfactant for carrying out the process according to the invention Propylene oxide.
• surfactants are low-foaming and readily biodegradable.
• the process according to the invention also makes it possible to lower the temperature considerably and thus save energy costs by reducing the temperature from the previously customary 80 to 90 ° C. to 30 to 60 ° C., preferably to 50 to 60 ° C.
• the higher temperature range of 50 to 60 ° C is also preferred for rinsing only because the requirements for lower temperatures are not yet met by today's technology.
• the new process also opens up new paths for machine technology, so that rinsing can then take place at 30 ° C and a temperature of approx. 25 ° C results in the cleaning liquors without any separate heating.
• both the rinse aid is separately fed to the rinse aid line and the detergent is fed separately to the wash tank and thus primarily used for their actual task, in order then to work together synergistically in the wash tank in the sense of the invention.
• the alkali metal silicate is primarily the sodium salt, but also the potassium salt, preferably in the hydrate-free one Form to which the quantities refer. If the penta- or decahydrate is used, the amounts indicated must be increased accordingly.
• the compounds containing active chlorine are also known as such, such as sodium N-monochloramidosulfonic acid, sodium N-chloro-p-toluenesulfonamide and trichloroisocyanuric acid.
• Sodium dichloroisocyanurate or its dihydrate is particularly preferred.
• sodium hypochlorite is an easily accessible and convenient variant.
• active oxygen-containing substances such as perborates
• Borax has emerged as the preferred active oxygen-containing substance or a substance which fully exhibits the effect of one, which, surprisingly, in the preferred amount of 20-30% by weight completely takes over the effect of the sodium dichloroisocyanurate which has been predominantly used to date, is environmentally friendly and is readily available.
• alkali polyphosphates up to about 5% by weight are useful and do not include the serious environmental problems that this class of substances causes in the amounts used to date. If necessary, this substance can also be omitted entirely or replaced by less safe substances such as phosphorus derivatives.
• the ratio of formaldehyde to glutaraldehyde to glyoxal is preferably approximately 1: 1: 10. They are used in amounts of up to 5 parts by weight, based on 100 parts by weight of the cleaning agent according to the invention.
• the germ killing and disinfection is so perfected that practically no germs are found in the usual tests. This also contributes significantly to being able to reduce alkali polyphosphates extremely strongly or to be able to drop them entirely and to clean them at low temperatures.
• liquid or are used in liquid form (formalin) cleaning agents with this additive are particularly suitable as liquid cleaners.
• the liquid / aldehyde mixture is expediently sprayed onto the powder in the required amount.
• aldehydes peracetic acid, peroxides, hydrogen peroxide, succinic acid dialdehyde, biguanides and quaternary ammonium compounds such as dialkyl-dimethyl-ammonium chloride, alkyl-dimethyl-benzyl-ammonium chloride and alkyl-methyl-ethyl-benzyl-ammonium chloride.
• alkyl in the above compounds means an aliphatic radical having 1 to 7 carbon atoms.
• the percentages essentially correspond to those of the powdered cleaning agent.
• the mixture of substances is appropriately dissolved in water at a concentration of about 30%. Only with borax as an oxygen-active substance is it advisable to choose a higher concentration up to 50%.
• the use in block form is particularly preferred because, in a very simple form, suitable metering devices allow exact metering to the cleaning device.
• This form of use also has the advantage that individual components of the cleaning agent or different compositions in the form of several blocks are expediently used and the cleaning agent can be optimally combined from standardized compositions depending on the requirements of the dishes to be cleaned.
• Such a block-shaped cleaning agent has hitherto been produced by melting the components and pouring the melt into a metering container. This method is disadvantageous in that it in turn consumes energy. In addition, certain components of the cleaning agent can decompose during melting.
• a preferred method for producing a cleaning agent in block form is therefore to mix the mixed powder with about 10 to 20 parts by weight of water, to introduce it into a metering container and to allow it to solidify and harden.
• a rinse aid according to Example 6d is added to the rinse water at 0.1 g / liter in the pressure line.
• the dishes obtained after the rinsing process have been dried without water drops and have been perfectly cleaned without starch and protein residues (detection by iodine test).
• the pathogen streptococcus faecium which has proven to be the most resistant of its kind, was brought to a reduction factor of log 6 even with a high pre-contamination of 108 / ml or dishes. This means better hygiene performance than the standard set by the Society for Hygiene and Microbiology with a reduction factor of log 5.
• the cleaning methods previously used which worked at a cleaning temperature of 60 to 70 ° C and a rinsing temperature of 80 to 90 ° C, often did not even reach that of the value required by the standard.
• the rinse liquor must be transferred into the tanks of the main and pre-rinse cycle in a countercurrent process.
• the surfactants of the rinse aid thus fulfill a double function, namely rinsing and drying the dishes without leaving any residue, and on the other hand transferring them into the cleaning liquid to effectively clean them with environmentally friendly substances with considerable energy savings.

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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)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Detergent Compositions (AREA)

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Cited By (5)

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• 1988
  • 1988-09-28 DE DE19883832885 patent/DE3832885A1/de active Granted
• 1989
  • 1989-09-26 EP EP19890117721 patent/EP0361380A3/fr not_active Withdrawn
  • 1989-09-28 JP JP25083789A patent/JPH02196897A/ja active Pending

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