JPH01198699A - Detergent for automatic tableware washer - Google Patents

Abstract

PURPOSE:To obtain the title phosphorus-free detergent readily removing oils and farinaceous dirts, having bleaching performance and stable to enzyme, containing a hydroxy polyfunctional carboxylic acid (salt), polymeric chelating agent, inorganic alkali agent, amylase and bleaching agent of oxygen system in specific ratios. CONSTITUTION:(A) 1-30wt.% hydroxy polyfunctional carboxylic acid (salt) (preferable example; nitric acid, malic acid, tartaric acid or Na-salt, K-salt or ethanolamine-salt thereof) is mixed with (B) 1-10wt.% polymeric chelating agent [preferable example; (meta)acrylic acid (co)polymer having 1,500-10<5> average molecular weight), (C) 35-85wt.% inorganic alkali agent (example; sodium carbonate, borax), (D) 0.2-5wt.% amylase and (E) 5-25wt.% bleaching agent of oxygen system (preferable example; sodium perborate, sodium percarbonate) to afford the aimed detergent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to phosphate-free automatic dishwashing detergents.

[Problems to be solved by conventional techniques and inventions] In recent years,
Automatic dishwashers have rapidly become popular and are now widely used not only for commercial purposes but also for general households.

Conventionally, detergents for automatic dishwashing machines use detergents such as α-amylase to remove starchy stains such as those from boiled rice that adhere firmly to tableware and pigment stains such as tea stains. Phosphorous detergents containing starch-degrading enzymes and chlorine bleaches such as dichloroisocyanurate have mainly been used. On the other hand, since enzymes, fragrances, dyes, etc. are unstable to chlorine bleach, phosphorous detergents that use oxygen bleach instead of chlorine bleach have become available (Unexamined Japanese Patent Publication No. Publication No. 60-60198).

However, now that phosphorus-free detergents are the mainstream among many cleaning agents, phosphate-containing detergents may become a social problem from the point of view of environmental problems.

Therefore, with the spread of automatic dishwashers, there has been a strong demand for technology that eliminates phosphorus without reducing the cleaning power against various types of dirt.

[Means to solve the problem]

As a result of intensive research in response to such demands, the present inventors have developed an oxygen bleaching agent, which uses a combination of a hydroxy polycarboxylic acid or its salt and a polymeric/molecular chelating agent, as Bilgu.
The present invention was completed based on the discovery that when used in enzyme-based detergents, it has the same performance as phosphorus-containing detergents, and that the stability of the enzyme is better than that of phosphorus-containing detergents.

That is, the present invention provides: (a) Polymer chelating agent 1-10% by weight 1(a)
Inorganic alkaline agent 35-85% by weight (d)
Amylase 0.2-5% by weight (e)
To provide a phosphorus-free automatic dishwasher detergent containing 5 to 25% by weight of an oxygen bleach.

Examples of the hydroxy polycarboxylic acid or its salt, which is component (a), used in the present invention include a compound represented by general formula (1) or a water-soluble salt thereof.

■ ■ (XltH, CL, -C)1. C00H, bar C) I
(DH)COO)I.

(Y represents mH or -OH) Among these, citric acid, malic acid, and tartaric acid or a salt thereof are preferred. Examples of the salt include Na) IJum salt, potassium salt, monoethanolamine salt, jetanolamine salt, and triethanolamine salt.

As the component (b) used in the present invention, JP-A-57-14
Examples include divalent metal ion-trapping polymer electrolytes such as those described in Japanese Patent No. 5199; Molecular weight is 1.500
-100,000, especially 3,000-20,000 are preferred.

Component 1(a) used in the present invention includes sodium carbonate, borax, sodium silicate, and the like. Since sodium silicate has a metal corrosion inhibiting effect, it is desirable to use it together with other alkaline agents. carbonate) IJum 30-70% by weight, sodium silicate (S+02/Naa
O ratio is 1/1 to 4/1, preferably 2/1 to 2.5/1
) is most preferably used in combination in an amount of 2 to 15% by weight.

Component 1(a) is a 0.05 to 1% by weight detergent solution with a pH of 9,
Adjust the blending amount so that it becomes 0-11.0.

The amylase that is component (6) used in the present invention may be derived from bacteria.

A preferred amylase is Bacillus lichen.
amylase obtained from P. iformis, particularly preferably "Terma" commercially available from Novo.
myl” (registered trademark).Amylase is 0.2-5
% by weight, so that the saccharification activity determined by the DNS method at the actual concentration of this detergent composition is IXIO' kilounits (the amount of enzyme that produces 1 mH of glucose per minute is 100 units). Make sure that the above is achieved.

In addition, as the oxygen bleaching agent (e), organic hydrochloric acid or its salt such as magnesium monoperoxyphthalate,
Alkali metal perborate (monohydrate or tetrahydrate)
, peroxides that generate hydrogen peroxide in aqueous solution, such as percarbonates and persilicates. Among these hydrogen peroxide adducts, preferred are sodium perborate and sodium percarbonate.

A peroxide that generates hydrogen peroxide in an aqueous solution is preferably used in combination with an activator. Activators include tetraacetylethylenediamine (TAED), tetraacetylglycoluril (TAGU), glucose pentaacetic acid (
GPA) and xylosetetraacetic acid (XTA) are commonly used.

The peroxide/activator is used in a weight ratio of 8/1 to 1/1.

Further, it is preferable to use a small amount of a low-foaming to non-foaming nonionic surfactant in the detergent of the present invention, especially for the purpose of improving the detergency against oil and fat stains. Examples of surfactants of this type include alkoxylated nonionic surfactants in which the alkoxy moiety is selected from the group consisting of ethylene oxide, propylene oxide or mixtures thereof. Specific examples of surfactants preferably used in the present invention include “Plurafac (registered trademark) LF403” and “
Plurafac LF1300" and "Softanol BP7045" (registered trademark) manufactured by Nippon Shokubai Kagaku Kogyo ■.

The detergent of the present invention may further contain stabilizers for oxygen bleaches, proteolytic enzymes, copper corrosion inhibitors, and the like.

Stabilizers include ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), their water-soluble salts, and complexes of these with calcium, magnesium, aluminum, or zinc, which may be added in their raw form. can. In particular, it is preferable to use calcium complexes.

Examples of suitable proteolytic enzymes include B, 5ubtil
Examples include subtilisins obtained from specific strains of Is bacteria and B. licheniformis bacteria. Examples of these include Maxatase® sold by Gist, Alcalase®, Esperase® and Sabinase® from Nova.
registered trademark), etc.

It is effective to add 0.1 to 5% by weight of a fatty acid having a hydrocarbon chain length of about 8 to 18, and further to add benzotriazole or the like to prevent corrosion of copper.

The cleaning compositions of the present invention can generally be prepared in the form of dry granular products. Thus, it can be prepared by dry mixing the powdered or granular components and then spraying the liquid component (such as a nonionic surfactant) onto the mixture according to conventional manufacturing techniques.

〔Effect of the invention〕

As described above, the detergent composition of the present invention has sufficient detergency against oil and starch, which is the basic performance of an automatic dishwasher detergent, is phosphorus-free, and has the ability to remove pigment stains deposited on dishes. In other words, it is a detergent composition for automatic dishwashers that has bleaching performance and good enzyme stability and has high practical value.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these examples.

First, the cleaning conditions and cleaning power employed in the examples will be explained.

Washing conditions: Washing machine used: Fully automatic dishwasher manufactured by Matsushita Electric (model NP)
-600) An aqueous cleaning solution is sprayed from a rotating nozzle to wash tableware placed on the upper surface of the spray trajectory.

Washing temperature: Gradually raise the temperature from 5°C to 55°C.

Washing water: water with hardness of 3.5° DH Detergent concentration: 0.2% Washing time: 20 minutes of washing - 20 minutes of rinsing Amount of circulating water during washing: 2.51 Evaluation of detergency ■ Contamination type of oil and protein mixed stains and Evaluation method (contaminated type) A mixture of 5 g of beef tallow and 1 g of egg was applied on a magnetic plate (diameter 25 cm) and air-dried for one day and night to provide two plates.

(Oil/fat cleaning power evaluation method) Spray the oil red liquid on the washed dish and measure the reaction area on the dish (
The initial contaminated area (SO
), the cleaning rate was determined using the formula below.

Cleaning rate = [(so-s+) /so)
The mixture was stretched and coated on a magnetic dish (diameter 25 cm), air-dried at room temperature for a day and night, and six plates were washed.

(Starch stain cleaning power evaluation method) The area of the blue part (Pl) generated by the color reaction of starch on remaining cooked rice is measured by photo judgment, and the cleaning rate is calculated from the initial contaminated area (So) as in the case of oil stains. It was calculated using the formula.

Cleaning rate = ((S, -P,) /So)
mm) was immersed in a black tea solution and dried 10 times, and then 5 pieces were washed.

(Bleach performance evaluation method) After washing, measure the reflectance (R2) of the plate, and calculate the bleaching rate from the reflectance (Re) of the uncontaminated plate and the reflectance (R1) of the plate 9 before washing using the following formula. Ta.

Bleaching rate = C(R2-R1)/(Re-3,)) xl
OO Example 1 The compositions shown in Table 1 below were prepared according to the evaluation method described above, and the detergency and bleaching blade were evaluated.

Claims (1)

[Claims] 1(a) Hydroxy polyhydric carboxylic acid or salt thereof 1 to 30
Contains: (b) 1-10% by weight of polymeric chelating agent (c) 35-85% by weight of inorganic alkaline agent (d) 0.2-5% by weight of amylase (e) 5-25% by weight of oxygen bleach A phosphorus-free automatic dishwasher detergent characterized by: