JP2554728B2 - Detergent for automatic dishwasher - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to detergents for automatic dishwashers.

2. Description of the Related Art In recent years, automatic dishwashers have begun to spread to general households, but in order to further increase the penetration rate, it is desired to develop a more compact and high-cleaning washing machine. In order to meet the requirements of this type, a method of spraying a detergent solution onto dishes to remove the stains physically attached is usually adopted from the bottom of the dish washing tank. Since miniaturization is an important issue for this type of device, use the smallest possible amount of detergent solution, collect the sprayed detergent solution in the saucer at the bottom of the dish, and wash it again with the washing pump. It is common to use a circulation method in which the material is sent to a nozzle and sprayed.

The most serious problem with this method is the foaming that occurs when the detergent solution is struck on the dishes by spraying.

Foaming not only causes liquid leakage when opening the washing machine, but also gets caught in the washing pump to reduce the discharge pressure,
It makes it impossible to obtain the nozzle pressure required for cleaning. In addition, a device that has a nozzle for spraying so that the detergent solution is evenly sprayed on the tableware and has a mechanism for cleaning while rotating with the spray pressure of the nozzle lowers the discharge pressure due to bubbles and the required spray pressure cannot be obtained. The machine stops functioning. From the above, the foaming power of the detergent for an automatic dishwashing machine is closely related to the function of the apparatus itself, and it is essential that it has a low foaming property or a non-foaming property.

On the other hand, a detergent for an automatic dishwasher using a silicone antifoaming agent has also been proposed, but since the silicone antifoaming agent forms a hydrophobic deposit on the cleaning nozzle or the like, or is itself insoluble in water, May remain on the surface of tableware. In addition, the defoamer tends to gradually disperse in the detergent solution and lose its effectiveness as it is circulated by the wash pump.
Therefore, it is desirable that the surfactant itself in the detergent has a low foaming property or a non-foaming property in order to prevent generation of foam under such severe conditions.

Although low-foaming synthetic detergents have been developed for such purposes, automatic dishwashers are also used in areas where the use of synthetic detergents is restricted. Development is urgent. However, conventional soaps produce bubbles when used in an automatic dishwasher, are extremely inferior in hard water resistance, and have a problem in detergency.

The present invention solves such a conventional problem, and is safer than a detergent having good solubility and no foaming, that is, a conventional detergent for an automatic dishwasher, even when soap having a cleaning power is used as a raw material. The purpose is to provide a new detergent for an automatic dishwasher which is pollution-free and has excellent detergency.

Means for Solving the Problems The present invention provides an alkali metal fatty acid having a total carbon number of 12 or more, which has at least one branched chain at the α-position carbon atom or has two or more hydroxyl groups at any carbon atom, or The present invention relates to a dishwasher detergent containing one or more soaps containing a salt of a nitrogen-containing base. Fatty acid soaps useful in the present invention have the general formula: [In the formula, R ₂ and R ₃ are each independently a hydrogen atom or a saturated or unsaturated aliphatic hydrocarbon group, and R ₁ is a saturated or unsaturated C 4 or more fatty acid having 2 or more hydroxyl groups. A saturated or unsaturated aliphatic hydrocarbon group having 4 or more carbon atoms, which may have one group hydrocarbon group or one hydroxyl group (in the case of, at least one of R ₂ and R ₃ is an aliphatic hydrocarbon group). Is a group), wherein R ₁ , R ₂ and R _{3 have} a total carbon number of 10 or more; and M represents an alkali metal or a nitrogen-containing base].

In the present invention, the soap represented by the general formula [I] is a fatty acid soap having 2 or 3 aliphatic hydrocarbon groups at the α-position carbon or a fatty acid soap having 2 hydroxyl groups in one molecule.

In the formula, R ₁ is an aliphatic hydrocarbon group having 4 or more carbon atoms, preferably 6 to 18, and the hydrocarbon group may have a side chain or an unsaturated bond. R ₁ may have two or more hydroxyl groups in the molecule. R ₂ and R ₃ represent hydrogen or a saturated or unsaturated aliphatic hydrocarbon group which may have a branch, but when R ₁ does not have a hydroxyl group, at least one of R ₂ and R ₃ is a fatty group. It is a group hydrocarbon group. That is, when at least one of the aliphatic hydrocarbon groups bonded to the α-position carbon atom does not have two or more hydroxyl groups, at least two aliphatic hydrocarbon groups are bonded to the α-position carbon atom. ing. This makes it possible to obtain hard water-resistant soap with extremely low foaming property. The number of carbon atoms of the hydrocarbon group of R ₂ and R ₃ is 1 or more, preferably, the number of carbon atoms of either R ₂ or R ₃ is approximately the same as the number of carbon atoms of R ₁ , and the carboxyl group is at approximately the center of the molecule. preferable. The total carbon number of R ₁ , R ₂ and R ₃ is 10 or more, preferably 10 to 20. When it is less than 10, the detergency is insufficient, and when it is more than 20, the water solubility is reduced.

In the formula, M represents an alkali metal or a nitrogen-containing base.
As the alkali metal, potassium and sodium are preferable, and the nitrogen-containing base is ammonia; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and the like; alkylalkanolamines such as methyldiisopropanolamine; Illustrative are heterocyclic amines such as morpholine.

Typical examples of fatty acids used in the present invention include 2
-Methylundecanoic acid, 2,2-dimethyl-4-ethyloctanoic acid, 2-butylundecanoic acid, 2-pentyldecanoic acid, 2- (3-methylbutyl) -3-methylnonanoic acid, 2-butyldodecanoic acid, 2- Heptyl nonanoic acid, 2
-Butyl-2-pentylheptanoic acid, 2-hexylundecanoic acid, 2-heptyldecanoic acid, 2-butyltetradecanoic acid, 2-heptylundecanoic acid, 2-octyldecanoic acid, 2- (1 ', 3', 3 ' -Trimethylbutyl) -5,7,
7-trimethyloctanoic acid, 2-methyloctadecanoic acid, 2-butyl-2-heptylnonanoic acid, 2-methyl-
2-dodecenoic acid, 2-ethyl-9-octadecenoic acid, 3,
11-dioxytetradecanoic acid, 15,16-dioxyhexadecanoic acid, 9,10-dioxyoctadecanoic acid, 11,12-dioxyeicosanoic acid, 8,9,16-trioxyhexadecanoic acid, 8,10, Examples include 16-trioxyhexadecanoic acid and tetraoxyhexadecanoic acid. Particularly preferred is 2-n-heptylundecanoic acid, 2- (1 ', 3', 3'-trimethybutyl)-, which can be easily obtained from natural vegetable oils and fats.
5,7,7-Trimethyloctanoic acid (carboxylic acid nomenclature is 2,
2,4,8,10,10-hexamethylundecane-5-carboxylic acid), 9,10-dioxysteric acid and the like.

Fatty acid soaps obtained from fatty acids having a polar group (carboxyl group, hydroxyl group) in the middle of these molecules have lower foamability than soaps of fatty acids having a carboxyl group at the end of the hydrocarbon chain, and have the same carbon content. When compared in terms of number, the water solubility is excellent, and it is difficult to substitute divalent metal ions such as calcium and magnesium contained in hard water, so that the water resistance is excellent.

The above-mentioned fatty acid soap may be used alone in the detergent of the present invention, but if necessary, other additives to be added to the dishwashing detergent may be added. Examples of these additives include pillers such as sodium sulfate, bentonide, activated clay, diatomaceous earth, sodium carbonate, sodium silicate, sodium bicarbonate, sodium tripolyphosphate, sodium pyrophosphate, inorganic sodium phosphate and the like. Compounds; chelating agents, eg EDT
Organic compounds such as A, chryconate, citrate, and malate; In addition, as enzymes, starch degrading enzymes (amylases), proteolytic enzymes (proteases), fat and oil degrading enzymes (lipases), etc. are added. You can also In addition, when there is a possibility that the contaminant contains a large amount of undenatured protein that serves as a foaming agent such as raw eggs, an antifoaming agent for food addition may be added.

In addition, bactericides; acid aids such as CMC, methylcellulose, hydroxymethylcellulose, etc .; fragrances or deodorants; antioxidants; solubilizers such as ethyl alcohol, sorbitol, glycerin, diglycerin, pentaerythritol, urea when used as liquid agents. , Alkanolamide, etc. may be blended appropriately. However, the detergent of the present invention shows sufficient hard water resistance under normal conditions without the addition of tripolyphosphate or the like.

The detergent of the present invention may additionally use linear fatty acid soap which has been generally used in the past.

Further, as a surfactant other than soap, sucrose ester, sorbitan ester, fatty acid amides and the like can be used in combination.

The fatty acid soap of the present invention is suitably added in an amount of 0.1% by weight or more, more preferably 2.5 to 20% by weight based on the total amount of the detergent.

 Hereinafter, the present invention will be described with reference to examples.

Examples 1 to 10 and Comparative Examples 1 to 4 Solubility and foaming power of the soaps shown below were measured by the following methods. The results are shown in Table 1.

Inventive fatty acid soap 2-n-heptylundecanoate sodium 2-n-heptylundecanoate potassium 2-n-heptylundecanoate ammonium 2- (1 ', 3', 3'-trimethylbutyl) -5,7,7-
Sodium trimethyloctanoate 2- (1 ', 3', 3'-trimethylbutyl) -5,7,7-
Potassium trimethyloctanoate 2- (1 ', 3', 3'-trimethylbutyl) -5,7,7-
Triethanolamine triethanolamine 9,10-sodium dioxystearate 9,10-potassium dioxystearate 9,10-ammonium dioxystearate 9,10-triethanolamine dioxystearate Linear fatty acid soaps (comparison Example) (A) Sodium ricinoleate (monohydroxystearic acid) (B) Sodium stearate (C) Sodium laurate (D) Sodium oleate Solubility test 100 ml of distilled water was placed in a 200 ml beaker at room temperature of 25 ° C. Stir with magnetic stirrer, 250m there
Add soap of g and dissolve it within 1 minute ◎,
Those that dissolve within 2 minutes are represented by O, those that dissolve within 3 minutes are represented by Δ, and those that require 3 minutes or more are represented by X.

Foaming test (Ross & Miles Oil and Soap 18 No.5 194
1) The foamability test was carried out by the Ross Mile method [Oil and Soap Vol. 18 No. 5 (1941)] at a temperature of 35 ° C. and a concentration of 0.25% tap water solution as an anhydrous soap.

From the results shown in Table 1, all of the soaps of the present invention were more soluble than ordinary soaps (Comparative Examples) A to D and had low foaming properties.

Examples 11 to 22 and Comparative Examples 5 to 8 As examples of the soap of the present invention as a detergent for an automatic dishwasher, the following basic treatment examples are selected, but the respective soaps are used as raw materials. A detergent performance test was performed.

1) Preparation of Detergent The soap of the present invention was added to a detergent base having the following composition so as to be 7%, and a performance test was conducted on 12 kinds of examples shown in Table-2.

Detergent base Sodium metasilicate anhydrous 20% Sodium sesquicarbonate 40% Sodium gluconate 10% Sodium citrate 10% Sucrose 10% Coconut oil fatty acid diethanolamide 3% 2) Detergent performance test i) Washing conditions Matsushita Electric Industrial Co., Ltd. Set the used tableware in the automatic dishwasher (NP-600) made, and add 0.17% of each prepared detergent
(5g in about 3) was charged and washed in a predetermined course.

ii) Low foaming test method Measure the number of rotations of the cleaning nozzle and always keep 38-42 rpm during cleaning.
◎, those with a rotation speed of 35 rpm even if the rotation speed drops slightly at low temperature (0 to 30 ° C) or high temperature (30 ° to 60 °) ○, cleaning is possible but rotation speed is 35 rpm The following items are indicated by Δ, and those which cannot be washed due to severe foaming and extremely low rotation speed are indicated by x.

iii) Detergency test method Protein detection method was ninhydrin detection method, fat content detection method was oil red detection method, and starch detection method was iodine detection method. ◎ that does not detect residual dirt at all
A mark that shows almost no stain but a slight stain is indicated by O, a mark that stain remains is indicated by Δ, and a mark that stain is clearly left is indicated by X.

iv) Hard water resistance test method 300 ppm of hard water was put in a glass, and a detergent having a soap content of 0.2% by weight was added to the glass.
After being left for 4 hours in an atmosphere of ℃, it is cooled to room temperature. After discarding the liquid in the glass, rinsing lightly once with tap water, and drying the glass, the degree of cloudiness is evaluated. The one that does not cause fogging is indicated by ◯, the one that causes slight fogging is indicated by Δ, and the one that causes fogging is indicated by X.

3) Evaluation results The evaluation results are shown in Table-2.

As shown in the results of Table 2, the detergents of Examples 11 to 22 in which the soap of the present invention was blended were cleaned more thoroughly than the comparative example. Further, in Comparative Example 8, as soon as washing was started, bubbles were entrained in the pump, and the pumping capacity was significantly reduced. After 5 minutes from the start of washing, spraying was almost impossible and washing could not be performed.

In addition, in the prepared detergent, as a detergent base, inorganic,
Although organic builders were used, these are all auxiliaries for enhancing the cleaning effect and have nothing to do with the essence of the present invention.

EFFECTS OF THE INVENTION The detergent for an automatic dishwashing machine of the present invention has, as shown in formula [I], one or more soaps having a polar group near the center of the molecule and / or two hydroxyl groups in the molecule. It contains the above-mentioned soap, while utilizing the soap's detergency, it has excellent solubility in water due to its special molecular structure. Furthermore, its unique micellar structure enhances hard water resistance and suppresses foaming. As a result, it is possible to provide a highly safe, pollution-free and highly safe detergent without deteriorating the cleaning ability of the automatic dishwasher.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Moriki Fukuda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.・ Chemical Ecology "1979, Kodansha

Claims (1)

(57) [Claims] 1. An alkali metal or nitrogen-containing base salt of a fatty acid having a total of 12 or more carbon atoms having at least one branched chain at the α-position carbon atom or having at least two hydroxyl groups at any carbon atom. Dishwasher detergent containing one or more types of soap.