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
  • C11D3/16—Organic compounds
  • C11D3/37—Polymers
  • C11D3/3703—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C11D3/3719—Polyamides or polyimides
• • 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
  • C11D3/16—Organic compounds
  • C11D3/26—Organic compounds containing nitrogen
  • C11D3/32—Amides; Substituted amides

Definitions

• This invention relates to an improvement in the rinse step of machine dishwashing operations and to rinse aid compositions for use in the rinsing step of machine dishwashing operations.
• the articles to be cleaned are first cleaned in a main wash step and subsequently rinsed several times to rinse away any adhering main wash product and remaining soil. It is customary to add to the rinsing water in the rinse step a rinse aid composition which causes the articles to dry more evenly and improves the visual appearance of the articles when dry.
• co-builders such as polyacrylates, maleic anhydride/acrylic acid co-polymers, and the various organic polyphosphonates of the Dequest® range
• phosphate-free machine dishwashing compositions have been added to phosphate-free machine dishwashing compositions.
• Applicant has observed that, especially when such a phosphate-free machine dishwashing composition is used as main wash product in machine dishwashing operations, the visual appearance of articles, especially glasses, often deteriorates after a plurality of washings, despite the use of rinse aids.
• the present invention therefore relates to an improved rinse step in a machine dishwashing operation, wherein the improvement comprises the use, in the rinse liquor, of an effective amount of a polyamino acid as defined above.
• the present invention thus provides a solution to the problem of secondary scaling on washed articles in the rinse step, and is particularly of importance for use in conjunction with phosphate-free and phosphorus-free main wash compositions.
• the polyamino acid compounds for use in the present invention can be the homo-polymers of aspartic acid, glutamic acid, glutamine or asparagine, such as polyaspartates or polyglutamates, or can be co-polymers of said amino acids in any combination, wherein the amino acid monomers can be all in the L, D or mixtures of L/D forms.
• n is from 3-500, more preferably from 5-150, and most preferably from 10-100. They are non-phosphorus, non-toxic and biodegradable and are therefore suitable for use in "green" products.
• these polyamino acid compounds are capable to inhibit metal corrosion.
• Preferred compounds are the polyaspartates and polyglutamates because of their commercial availability, e.g. from the Sigma Chem. Corp. and from the Ajinomoto Company.
• Cygnus® - 32 is a polyamino acid product containing about 40% by weight of polyaspartate, supplied by the Cygnus Corporation, USA.
• the other polyamino acids according to the invention may also be preferred for other reasons.
• the polyamino acid according to the invention may be added to the rinse water as such, or it may be added thereto in the form of a liquid solution in water, or in the form of a composition in any suitable physical form comprising the polyamino acid and other suitable or desirable ingredients as normally used in rinse aid products.
• Such other suitable ingredients may be low levels of wetting or detergent surfactants; organic acids such as citric acid; hydrotropes; alcohols; perfumes; germicides; anti-corrosion agents; clays, particularly layered clay minerals, such as the Laponite® clays supplied by Laponite Ind. Ltd etc.
• Suitable physical forms are powders, liquids, tablets, blocks, granulates etc. Liquid is, however, a suitable preferred form.
• the level of the polyamino acid in the rinse liquor is critical. It should be such that the rinse liquor contains the defined polyamino acid in only very low concentrations of below 10 ppm., preferably below 5 ppm., with a particularly suitable range of from about 1 to about 3 ppm. These correspond to a level of less than 10%, preferably less than 5%, suitably from 1% to 3% by weight in rinse aid compositions normally used at a dosage level of about 1 ml/101 rinse water.
• the invention provides a process for warewashing in a dishwashing machine comprising washing the articles in a main wash cycle and rinsing them in a rinse cycle, characterised in that in the rinse step there is added to the rinse water a polyamino acid compound as hereinbefore defined in an amount such that the rinse liquor contains the defined polyamino acid in a concentration of below 10 ppm, preferably below 5 ppm.
• the invention provides a rinse aid composition, suitable for use in an aqueous rinse liquor in the rinse step of a machine dishwashing operation, characterised in that the composition comprises a polyamino acid compound as hereinbefore defined.
• the final rinse experiments was carried out as follows: In a 3 liter glass 0.15 ml of an aqueous rinse aid composition is added to 1.5 liter of hard water (40°FH1 ) /32°FH)2 ) containing 1.5 ml of a 3 g/l main wash solution (simulating 1/1000 carry over). After placing preweighed glass slides (5x5x0.1 cm) in this solution the temperature is raised from 20 to 70°C, at a rate of 2.5°C per minute, and kept constant at 70°C for 10 minutes. This temperature profile simulates a final rinse cycle and is obtained using a submerged electrical heating element and a programmable temperature controller. At the end of this cycle the slides are taken out of the solution.

Landscapes

• 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)
• Detergent Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8210490

Family Applications (1)

Country Status (5)

Cited By (10)

Citations (4)

Family Cites Families (5)

• 1993
  • 1993-03-12 EP EP93200733A patent/EP0561464A1/de not_active Withdrawn
  • 1993-03-17 CA CA 2091825 patent/CA2091825A1/en not_active Abandoned
  • 1993-03-19 AU AU35345/93A patent/AU3534593A/en not_active Abandoned
  • 1993-03-19 JP JP5060360A patent/JPH06100898A/ja active Pending
  • 1993-03-19 BR BR9301243A patent/BR9301243A/pt not_active Application Discontinuation

Patent Citations (4)

Also Published As

Similar Documents

Legal Events