JP3747554B2 - Detergent composition for light metals - Google Patents

Description

で表される化合物であって、好ましくはＬ−グルタミン酸イミノ二酢酸アルカリ塩である。式中、Ｍｅはナトリウム、カリウム、アルカノールアミン等のアミン類またはアンモニウム類であるが、特に、ナトリウムが好ましい。なお、これらのＭｅはそれぞれ、同一種類のものであってもよく、互いに異なるものであってもよい。
【００１９】
上述のグルタミン酸イミノ二酢酸アルカリ塩はアミノ酸であるグルタミン酸、好ましくはＬ−グルタミン酸の誘導体であって、エチレンジアミン四酢酸アルカリ塩（ＥＤＴＡ）に匹敵するほどの優れたカルシウムイオン捕捉能を有する。この捕捉能は特にｐＨ９以上のアルカリ領域で著しく向上する。
【００２０】
しかも、グルタミン酸イミノ二酢酸アルカリ塩はキレート性能としてのカルシウムイオン捕捉能に優れているにもかかわらず、アルミニウム等の軽金属材料に対する腐食性はＥＤＴＡに比べて大幅に小さい。
【００２１】
さらに、このグルタミン酸イミノ二酢酸アルカリ塩はＥＤＴＡよりも脱脂性に優れ、硬表面上に付着した油脂汚れを容易に洗浄する。しかも、これを陰イオン界面活性剤ないしは非イオン界面活性剤と併用すると、脱脂効果は大幅に向上して発泡性も向上し、両者の相乗効果が生じる。
【００２２】
本発明に使用される界面活性剤は陰イオン界面活性剤ないしは非イオン界面活性剤であって、軽金属材料の硬表面に付着した油脂、たん白質、炭水化物等の有機質汚れ、ほこり等の無機質汚れを洗浄する作用を呈するのみならず、発泡剤としての作用をも兼ね備える。
【００２３】
陰イオン界面活性剤としては、直鎖アルキルベンゼンスルホネート、α−オレフィンスルホネート、パラフィンスルホネート等のスルホン酸塩、高級アルコールサルフェート、高級アルキルエーテルサルフェート等の硫酸エステル塩、さらにはポリオキシエチレンアルキルエーテルの酢酸アルカリ塩、あるいはリン酸エステル等が挙げられる。
【００２４】
また、非イオン界面活性剤としては、高級アルコールエチレンオキサイド付加物やアルキルフェノールエチレンオキサイド付加物、プルロニック型非イオン界面活性剤等のポリエチレングリコール型非イオン界面活性剤、脂肪酸アルカノールアミド、砂糖の脂肪酸エステル、ソルビットやソルビタンの脂肪酸エステル等の多価アルコール型非イオン界面活性剤、さらには、アルキルアミンオキサイドやアルキルポリグリコシド等が挙げられる。
【００２５】
上述の陰イオン界面活性剤および非イオン界面活性剤は本発明では使用目的に応じてそれぞれ単独で、一種または複数種を用いてもよく、あるいはこれらを組み合わせて複数種で用いることもできる。例えば、本発明を泡洗浄に用いる場合には、界面活性剤として陰イオン界面活性剤を選定することが好ましく、特に、アルキルポリグリコシドと高級アルコール硫酸エステル塩との混合物は発泡性に著しく優れているので好ましい。
【００２６】
さらに、本発明におけるグルタミン酸イミノ二酢酸アルカリ塩と界面活性剤との配合比率は重量比でグルタミン酸イミノ二酢酸アルカリ塩：界面活性剤＝１：２〜４：１の範囲内、好ましくは１：1.５〜２：１の範囲であり、この範囲内で本発明効果が著しく発揮される。
【００２７】
また、本発明にかかる洗浄剤組成物は水溶液の状態でｐＨ値が９〜11、好ましくは９〜10の範囲の弱アルカリ性であり、この範囲内で本発明効果が著しく発揮される。
【００２８】
なお、本発明組成物は上述成分のほかに、ｐＨ値を上述範囲に維持するためのｐＨ緩衝剤、例えば、炭酸ナトリウム、エタノールアミン等のアルカリ剤を含有することができ、さらに、所望に応じて可溶化剤、水溶性溶剤等を含有することもできる。
【００２９】
上述の本発明組成物は粒状体あるいは液体の形態で調製され、使用に際して、洗浄すべき軽金属表面の汚れの程度に応じ、あるいは、泡洗浄等の使用目的に応じ、適宜濃度に水で稀釈して使用される。
【００３０】
【発明の実施例】
以下、本発明を実施例により詳細に説明するが、本発明はこれら実施例に何ら限定されるものではない。
【００３１】
なお、実施例で用いられる各化合物は以下のように略記する。
【００３２】
直鎖アルキルベンゼンスルホン酸ナトリウム ： ＬＡＳ
ヤシ脂肪酸ジメチルアミンオキサイド ： ＡＯ
Ｌ−グルタミン酸イミノ二酢酸ナトリウム ： ＧＬＤＡ
エチレンジアミン四酢酸ナトリウム ： ＥＤＴＡ
トリエタノールアミン ： ＴＥＡ
【００３３】
実施例 １
ポリオキシエチレンアルキルエーテル系非イオン界面活性剤（アデカトールＳＯ・１３５旭電化工業（株）製）の0.１５％水溶液中に、キレート剤としてＬ−グルタミン酸イミノ二酢酸ナトリウム（ＧＬＤＡ）およびエチレンジアミン四酢酸ナトリウム（ＥＤＴＡ）（いずれも公知の製造方法によって合成されたもの）をそれぞれ添加混合してキレート剤がそれぞれ0.１Ｗ／Ｖ％含有された、表１に示す各ｐＨ値の試料水溶液を調製し、これら各水溶液のカルシウムイオン捕捉能（ＣＶ値）を測定した。
【００３４】
ＣＶ値測定は自動滴定装置を用い、光度滴定法により行なった。すなわち、上述の試料水溶液１00mlをそれぞれ２00mlビーカーに採取し、これら各試料水溶液に指示薬として１％ラウリン酸ナトリウム水溶液５mlと、イソプロピルアルコール10mlを添加し、光度滴定電極の設置された自動滴定装置により、滴定溶液として0.０１Ｍ酢酸ナトリウム水溶液をそれぞれ用いて滴定を行った。カルシウムイオン捕捉能はキレート剤１ｇに対する炭酸カルシウムのｍｇ数で示した。測定結果を表１に示す。
【００３５】
【表１】

【００３６】
表１から明らかなように、ＧＬＤＡを含む本発明試料のカルシウムイオン捕捉能はｐＨ９−11の弱アルカリ性の条件で著しく高くなり、従来使用されているキレート剤ＥＤＴＡにほぼ匹敵する。
【００３７】
実施例 ２
実施例１と同様にしてアデカトールＳＯ・１３５の0.１５％水溶液にキレート剤としてＧＬＤＡおよびＥＤＴＡを添加混合して、キレート剤が0.２Ｗ／Ｖ％含有した水溶液を調製し、これら水溶液について、それぞれアルミニウムに対する腐食試験を行なった。
【００３８】
腐食試験は次のようにして行なった。まず、0.２Ｗ／Ｖ％のキレート剤の含有した上記各水溶液に、それぞれ0.２Ｍ炭酸ナトリウムおよび0.２Ｍ炭酸水素ナトリウムを添加混合して表２に示す各ｐＨ値の試料水溶液を調製した。
【００３９】
次いで、得られた各ｐＨ値の水溶液に、予め表面を清浄して重量を測定したアルミニウム板を水温25℃の条件下で８時間浸漬した。その後、アルミニウム板を水溶液から取り出して水ですすぎ、乾燥の後、重量測定し、浸漬前と浸漬後の重量差を腐食率（％）として求め、結果を表２に示した。
【００４０】
【表２】

【００４１】
表２の結果から、ＧＬＤＡを含む本発明試料のアルミニウム材質に対する腐食性はいずれのｐＨ値についてもＥＤＴＡを含む試料に比べて著しく小さいことがわかる。
【００４２】
実施例 ３
表３に示す各ｐＨ値の試料水溶液について、それぞれ、油脂汚れの除去試験を行なった。
【００４３】
油脂汚れの除去試験は次のようにして行った。まず、0.２Ｗ／Ｖ％のキレート剤（ＧＬＤＡまたはＥＤＴＡ）と、0.０５Ｗ／Ｖ％のポリオキシエチレンアルキルエーテル系非イオン界面活性剤とをそれぞれ含む水溶液に0.２Ｍ炭酸ナトリウムおよび0.２Ｍ炭酸水素ナトリウムを添加混合して表３に示される各ｐＨ値の試料水溶液を調製した。
【００４４】
なお、これとは別に牛脂汚れの付着したステンレス板（テストピース）を次のようにしてつくった。まず、牛脂を同量のクロロホルムに溶解した。次いで、この溶液に、あらかじめ表面を清浄して光沢度を測定したステンレス板を浸漬し、引き上げの後、クロロホルムを乾燥させることによりテストピースをつくった。
【００４５】
次いで上述各ｐＨ値の試料水溶液に、上述の牛脂汚れの付着したステンレス板（テストピース）を水温25℃の条件下で15分間浸漬した。
【００４６】
その後、ステンレス板を水溶液から引き上げてオーバーフロー状態の静水中で軽くすすぎ、室温で一夜乾燥の後、ステンレス板表面の洗浄状態を判定した。
【００４７】
洗浄状態の判定は洗浄前と洗浄後のテストピースの光沢度を測定し、下式より洗浄効率（％）を算出することにより行った。
【００４８】
【数１】

【００４９】
なお、本実施例で使用した上述ポリオキシエチレンアルキルエーテル系非イオン界面活性剤はアデカトールＳＯ１３５（旭電化工業（株））である。測定結果を表３に示す。
【００５０】
【表３】

【００５１】
表３から明らかなように、ＧＬＤＡを含む本発明試料の牛脂汚れに対する洗浄性はｐＨが９−11の範囲では、ＥＤＴＡを含む試料の洗浄性に比べて著しく優れている。
【００５２】
実施例 ４
表４に示す各試料No.1〜５を調製し、これら各試料の水溶液について、油脂汚れの除去性試験を行った。なお、各試料水溶液のｐＨはいずれもｐＨ10である。
【００５３】
各試料の水溶液は次のようにしてつくった。まず、表４の各組成の0.５％水溶液をつくった。次いで、これら各水溶液に0.２Ｍ炭酸ナトリウムと0.２Ｍ炭酸水素ナトリウムをそれぞれ添加混合し、ｐＨ１0.０に調整して各試料の水溶液を調製した。
【００５４】
これら各試料水溶液に、実施例３と同じようにしてつくった牛脂汚れテストピースを浸漬し、実施例３と同様にして洗浄状態を判定し、油脂汚れの除去性を試験した。結果を表４に示す。
【００５５】
【表４】

【００５６】
表４から明らかなように、牛脂汚れに対する洗浄性はＬＡＳとＧＬＤＡの併用により著しく向上した。（試料No.4および５）。
【００５７】
実施例 ５
表５に示される各成分（％）を含有する試料No.1〜５を調製し、これら各試料を、炭酸カルシウムがそれぞれ50ppm および70ppm 含有した水に稀釈して２％洗浄剤水溶液を調製した。これら水溶液について透明性を目視で観察することにより、各硬度の水に稀釈したときの水溶液の安定性について判定した。結果を表５に示す。
【００５８】
【表５】

【００５９】
表５の結果から明らかなように、ＧＬＤＡが含有されない試料No.1では、炭酸カルシウムを70ppm 含有すると濁り（白濁）が生じた。これに対して、試料No.2〜５（本発明）では、いずれも透明性が維持され、高硬度の水に稀釈しても安定であった。
【００６０】
また、これら試料No.1〜５の２％水溶液について、発泡スプレーを用いて垂直硬表面にスプレーしたところ、透明稀釈水溶液（試料No. ２〜５）に比べ、濁りを生じた試料No.1は発泡性が著しく劣った。
【００６１】
実施例 ６
ＬＡＳ５％、ＧＬＤＡ20％、硫酸ナトリウム75％からなる洗浄剤組成物の0.５％水溶液を表７に示す各ｐＨに調整して試料No.1〜５を得た。これら各試料について油脂汚れ除去性およびアルミニウムに対する腐食試験を行った。
【００６２】
試料のｐＨは各試料に0.２Ｍ炭酸ナトリウム、0.２Ｍ炭酸水素ナトリウムおよび0.２Ｍ水酸化ナトリウムをそれぞれ添加混合して調整した。
【００６３】
油脂汚れ除去性については、実施例３と同様に作製した牛脂汚れテストピースを、水温25℃の各試料に15分間浸漬の後、引き上げ、実施例３と同様にして洗浄効率（％）を算出することにより行った。
【００６４】
アルミニウムに対する腐食試験は各試料に、予め表面を清浄して重量を測定したアルミニウム板を実施例２と同様にして浸漬し、腐食率（％）を求めることにより行った。同時にアルミニウムの表面状態も観察した。結果を表６に示す。表６中、○印は表面変化なく、光沢を有することを示し、×印は表面腐食がみられ、白色化したことを示す。
【００６５】
【表６】

【００６６】
表６の結果から、油脂汚れ除去性については試料No.1（ｐＨ８）ではやや劣るが、試料No.2〜５、すなわち、ｐＨが９以上になると洗浄性が高くなることがわかる。
【００６７】
アルミニウムに対する腐食については、試料No.5（ｐＨ12) ではアルミニウム板表面に腐食がみられ、白化していた。一方、試料No.1〜４、すなわち、ｐＨが11以下では、アルミニウム板表面に変化がなく、光沢を有していた。
【００６８】
以上の結果より、試料No.2〜４、すなわち、洗浄剤水溶液のｐＨが９〜11の範囲では、油脂汚れ除去性に優れ、かつ、アルミニウム板表面に対する変化がみられず、光沢性を有しており、したがって、洗浄性に優れるとともに、アルミニウム材質への影響も小さく、本発明の好ましい範囲であるということができる。
【００６９】
実施例 ７
表７の各成分（％）を含有する洗浄剤組成物を炭酸カルシウムが１00ppm 含有する水に稀釈して２％洗浄剤水溶液を調製し、試料No.1〜３とした。これら各試料を５時間アルミニウム板表面上にスプレーしてアルミニウム板表面の状態を目視観察した。
【００７０】
【表７】

【００７１】
表７の結果より、キレート剤（ＥＤＴＡ、ＧＬＤＡ）が含まれてない試料No.1では、発泡状態が悪く、また、キレート剤としてＥＤＴＡを使用した試料No.2では、発泡状態は改善されたものの、アルミニウム板表面への腐食が起こる。一方、キレート剤としてＧＬＤＡを使用した試料No.3では、発泡状態およびアルミニウムの表面状態のいずれも良好であった。
【００７２】
実施例 ８
本発明洗浄剤組成物（表４の試料No.4）をＣＯＤで５00ppm になるように水で稀釈した、さらに、化学工業排水を処理している活性汚泥設備から活性汚泥を採取し、この活性汚泥を小型の３槽直列曝気型活性汚泥設備に上述の稀釈液とともに供給し、曝気をして生物分解のテストを行った。
【００７３】
７〜８日経過した後の処理排水中のＣＯＤは50〜75ppm 程度に低減されており、分解率が85〜90％であった。
【００７４】
【発明の効果】
以上のとおり、本発明にかかる洗浄剤組成物は油脂除去性に優れ、アルミニウムを始めとする軽金属材料への影響が少なく、微生物分解性にも優れ、しかも発泡性が優れる等の特徴を有しており、泡洗浄および軽金属用洗浄に適しているということができる。[0001]
BACKGROUND OF THE INVENTION
The present invention is less affected by corrosion on light metal surfaces such as aluminum materials, and is applied to foam cleaning with excellent cleaning effect and foamability even when using high hardness cleaning water, and also excellent in microbial degradability, In particular, the present invention relates to a light metal cleaning composition suitable for hard surface cleaning of various facilities and apparatuses made of light metal materials.
[0002]
[Prior art]
In recent years, various light metal materials such as aluminum materials have been used in beverage filling apparatuses and food processing facilities that require precision, or vehicles, aircraft, containers, and the like that require light weight.
[0003]
Devices, facilities, vehicles, aircraft, containers, etc. using these light metal materials need to clean the outer surface, that is, the hard surface with a cleaning agent having a high cleaning effect.
[0004]
As such a cleaning agent having a high cleaning effect, conventionally, a cleaning agent containing a chelating agent such as sodium ethylenediaminetetraacetate (EDTA) and having a high pH value has been used.
[0005]
However, such a cleaning agent with a high cleaning effect repeatedly wipes the surface of the light metal material and contacts the surface for a long time, corroding the surface of the light metal material or causing whitening or blackening to lose the surface gloss. It may cause problems such as clogging and further melting the surface to open holes.
[0006]
Recently, a foam cleaning technique has been adopted to efficiently clean a wide hard surface. In this case, the detergent contains an anionic surfactant for the purpose of increasing foaming.
[0007]
However, this anionic surfactant is greatly affected by the hardness of the water used for dilution, and when diluted with high-hardness water, the anionic surfactant is insolubilized and does not foam, and at the same time, the cleaning performance decreases.
[0008]
In order to solve such a problem, a chelating agent such as sodium ethylenediaminetetraacetate (EDTA) is contained in the detergent containing the anionic surfactant as described above. However, a cleaning agent containing a chelating agent such as EDTA causes the above-described problems with light metal materials.
[0009]
In this way, when a light metal material such as aluminum is cleaned, if a chelating agent is added to improve the cleaning effect of the cleaning agent, a problem occurs on the surface of the light metal material.
[0010]
Therefore, as a cleaning agent for the surface of the light metal material, a surfactant having a small influence on the hardness of the diluted water is selected, and a cleaning agent whose pH value is adjusted to a value close to neutrality, or further, There has been a demand for a cleaning agent that does not need to contain a chelating agent such as EDTA while adding a silicate effective for preventing corrosion of light metals.
[0011]
[Problems to be solved by the invention]
However, this type of cleaning agent has low cleaning performance, and therefore, physical means such as contacting the surface of the light metal material with the cleaning agent solution for a long time or rubbing the surface is required for cleaning.
[0012]
Further, a cleaning agent that does not use a chelating agent such as EDTA is difficult to foam due to the influence of the hardness of the diluted water. Therefore, in the case of foam cleaning, a large amount of surfactant is required in the cleaning agent.
[0013]
In the case of a cleaning agent containing silicate, the silicate is likely to adhere to the metal surface, which sometimes becomes the core of the soil, and makes the surface after cleaning easily soiled.
[0014]
Therefore, the object of the present invention is to use a high hardness water as dilution water or washing water without using a chelating agent or silicate such as EDTA described above, having little influence of corrosion on the surface of the light metal and having high hardness. Detergent composition for light metals that exhibits excellent cleaning effects and foaming properties, is also excellent in microbial degradability, and is particularly suitable for hard surface cleaning of various equipment and devices made of light metal materials, and has improved the above-mentioned drawbacks of the known techniques To provide things.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in a detergent composition comprising a chelating agent and a surfactant comprising an anionic surfactant and / or a nonionic surfactant, the chelating agent is glutamic acid. It is an iminodiacetic acid alkali salt , and the pH of the aqueous solution is in the range of 9 to 11 .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0017]
As described above, the present invention is characterized by the specific use of glutamic acid iminodiacetic acid alkali salt as a chelating agent.
[0018]
The alkali salt of glutamic acid iminodiacetic acid has the general formula:

Preferably, it is L-glutamic acid iminodiacetic acid alkali salt. In the formula, Me is an amine such as sodium, potassium, alkanolamine or ammonium, and sodium is particularly preferable. Note that these Mes may be of the same type or different from each other.
[0019]
The aforementioned glutamic acid iminodiacetic acid alkali salt is a derivative of glutamic acid, preferably L-glutamic acid, which is an amino acid, and has an excellent calcium ion scavenging ability comparable to ethylenediaminetetraacetic acid alkali salt (EDTA). This scavenging ability is remarkably improved especially in the alkaline region of pH 9 or higher.
[0020]
Moreover, although the alkali salt of glutamic acid iminodiacetic acid is excellent in calcium ion scavenging ability as a chelating property, the corrosiveness to light metal materials such as aluminum is significantly smaller than that of EDTA.
[0021]
Furthermore, this glutamic acid iminodiacetic acid alkali salt is more excellent in degreasing properties than EDTA, and easily cleans oil stains adhering to the hard surface. Moreover, when this is used in combination with an anionic surfactant or a nonionic surfactant, the degreasing effect is greatly improved and the foaming property is also improved, resulting in a synergistic effect of both.
[0022]
The surfactant used in the present invention is an anionic surfactant or a nonionic surfactant, which removes organic dirt such as oils and fats, proteins and carbohydrates attached to the hard surface of light metal materials, and inorganic dirt such as dust. In addition to exhibiting a cleaning action, it also functions as a foaming agent.
[0023]
Anionic surfactants include sulfonates such as linear alkylbenzene sulfonates, α-olefin sulfonates and paraffin sulfonates, sulfate esters such as higher alcohol sulfates and higher alkyl ether sulfates, and alkali acetates of polyoxyethylene alkyl ethers. Examples thereof include salts and phosphate esters.
[0024]
Nonionic surfactants include higher alcohol ethylene oxide adducts and alkylphenol ethylene oxide adducts, polyethylene glycol type nonionic surfactants such as pluronic type nonionic surfactants, fatty acid alkanolamides, sugar fatty acid esters, Examples include polyhydric alcohol type nonionic surfactants such as sorbitol and fatty acid esters of sorbitan, and alkylamine oxides and alkylpolyglycosides.
[0025]
In the present invention, the above-mentioned anionic surfactant and nonionic surfactant may be used alone or in combination of one or more according to the purpose of use, or may be used in combination of two or more. For example, when the present invention is used for foam cleaning, it is preferable to select an anionic surfactant as the surfactant. In particular, a mixture of an alkyl polyglycoside and a higher alcohol sulfate ester salt is extremely excellent in foamability. This is preferable.
[0026]
Furthermore, the blending ratio of glutamic acid iminodiacetic acid alkali salt and surfactant in the present invention is within the range of glutamic acid iminodiacetic acid alkali salt: surfactant = 1: 2 to 4: 1, preferably 1: 1. The range is from 0.5 to 2: 1, and the effects of the present invention are remarkably exhibited within this range.
[0027]
Further, the cleaning composition according to the present invention is weakly alkaline with a pH value of 9 to 11, preferably 9 to 10 in the state of an aqueous solution, and the effects of the present invention are remarkably exhibited within this range.
[0028]
In addition to the above-mentioned components, the composition of the present invention can contain a pH buffer for maintaining the pH value in the above-mentioned range, for example, an alkali agent such as sodium carbonate and ethanolamine. Solubilizers, water-soluble solvents and the like.
[0029]
The above-described composition of the present invention is prepared in the form of granules or liquid, and is diluted with water to an appropriate concentration according to the degree of soiling of the light metal surface to be cleaned or the purpose of use such as foam cleaning. Used.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples at all.
[0031]
In addition, each compound used in an Example is abbreviated as follows.
[0032]
Sodium alkylbenzene sulfonate: LAS
Palm fatty acid dimethylamine oxide: AO
L-glutamic acid iminodiacetic acid sodium salt: GLDA
Sodium ethylenediaminetetraacetate: EDTA
Triethanolamine: TEA
[0033]
Example 1
L-glutamic acid iminodiacetic acid sodium salt (GLDA) and ethylenediaminetetraacetic acid as a chelating agent in a 0.15% aqueous solution of a polyoxyethylene alkyl ether nonionic surfactant (Adecatol SO · 135 manufactured by Asahi Denka Kogyo Co., Ltd.) Sodium (EDTA) (both synthesized by known production methods) was added and mixed to prepare sample aqueous solutions of each pH value shown in Table 1, each containing 0.1 W / V chelating agent. The calcium ion scavenging ability (CV value) of each of these aqueous solutions was measured.
[0034]
The CV value was measured by a photometric titration method using an automatic titrator. That is, each 100 ml of the above sample aqueous solution was collected in a 200 ml beaker, and 5 ml of 1% sodium laurate aqueous solution and 10 ml of isopropyl alcohol were added to each of the sample aqueous solutions as an indicator, and an automatic titrator equipped with a photometric titration electrode was used. Titration was performed using 0.01M aqueous sodium acetate solution as a titration solution. The calcium ion scavenging ability was shown by the number of mg of calcium carbonate with respect to 1 g of chelating agent. The measurement results are shown in Table 1.
[0035]
[Table 1]

[0036]
As is apparent from Table 1, the calcium ion scavenging ability of the sample of the present invention containing GLDA is remarkably increased under the weakly alkaline conditions of pH 9-11 and is almost comparable to the conventionally used chelating agent EDTA.
[0037]
Example 2
In the same manner as in Example 1, GLDA and EDTA were added and mixed as a chelating agent to a 0.15% aqueous solution of Adekatol SO · 135 to prepare an aqueous solution containing 0.2 W / V% of the chelating agent. Each was subjected to a corrosion test on aluminum.
[0038]
The corrosion test was conducted as follows. First, 0.2 M sodium carbonate and 0.2 M sodium hydrogen carbonate were added to and mixed with each of the above aqueous solutions containing a 0.2 W / V% chelating agent to prepare sample aqueous solutions having respective pH values shown in Table 2. .
[0039]
Next, an aluminum plate whose surface was previously cleaned and weighed was immersed in the obtained aqueous solution of each pH value for 8 hours under the condition of a water temperature of 25 ° C. Thereafter, the aluminum plate was taken out from the aqueous solution, rinsed with water, dried, weighed, the weight difference before and after immersion was determined as the corrosion rate (%), and the results are shown in Table 2.
[0040]
[Table 2]

[0041]
From the results in Table 2, it can be seen that the corrosivity of the inventive sample containing GLDA to the aluminum material is remarkably smaller than the sample containing EDTA at any pH value.
[0042]
Example 3
About the sample aqueous solution of each pH value shown in Table 3, the removal test of fat and oil stains was done, respectively.
[0043]
The removal test for fat and oil stains was performed as follows. First, an aqueous solution containing 0.2 W / V% of a chelating agent (GLDA or EDTA) and 0.05 W / V% of a polyoxyethylene alkyl ether-based nonionic surfactant, respectively, was added with 0.2M sodium carbonate and 0.1%. 2M sodium hydrogen carbonate was added and mixed to prepare sample aqueous solutions having respective pH values shown in Table 3.
[0044]
Apart from this, a stainless steel plate (test piece) with beef tallow dirt was prepared as follows. First, beef tallow was dissolved in the same amount of chloroform. Next, a stainless steel plate whose surface was previously cleaned and gloss was measured was immersed in this solution, and after pulling up, chloroform was dried to prepare a test piece.
[0045]
Subsequently, the stainless steel plate (test piece) to which the above-mentioned beef tallow dirt adhered was immersed in the sample aqueous solution having each pH value for 15 minutes under the condition of a water temperature of 25 ° C.
[0046]
Thereafter, the stainless steel plate was pulled up from the aqueous solution and rinsed lightly in overflowing still water. After drying overnight at room temperature, the cleaning state of the stainless steel plate surface was determined.
[0047]
The determination of the cleaning state was performed by measuring the glossiness of the test piece before and after cleaning, and calculating the cleaning efficiency (%) from the following equation.
[0048]
[Expression 1]

[0049]
The polyoxyethylene alkyl ether nonionic surfactant used in this example is Adecatol SO135 (Asahi Denka Kogyo Co., Ltd.). Table 3 shows the measurement results.
[0050]
[Table 3]

[0051]
As is clear from Table 3, the cleanability of the sample of the present invention containing GLDA against beef tallow soil is significantly superior to the cleanability of the sample containing EDTA in the pH range of 9-11.
[0052]
Example 4
Samples Nos. 1 to 5 shown in Table 4 were prepared, and the oily soil removal property test was performed on the aqueous solutions of these samples. The pH of each sample aqueous solution is pH 10.
[0053]
An aqueous solution of each sample was prepared as follows. First, a 0.5% aqueous solution having each composition shown in Table 4 was prepared. Next, 0.2M sodium carbonate and 0.2M sodium hydrogen carbonate were added and mixed with each of these aqueous solutions, and adjusted to pH 10.0 to prepare an aqueous solution of each sample.
[0054]
The beef tallow test pieces prepared in the same manner as in Example 3 were immersed in each of these sample aqueous solutions, and the washing state was determined in the same manner as in Example 3 to test the removability of fat and oil stains. The results are shown in Table 4.
[0055]
[Table 4]

[0056]
As is clear from Table 4, the detergency against beef tallow soil was remarkably improved by the combined use of LAS and GLDA. (Sample No. 4 and 5).
[0057]
Example 5
Sample Nos. 1 to 5 containing each component (%) shown in Table 5 were prepared, and each of these samples was diluted with water containing 50 ppm and 70 ppm of calcium carbonate, respectively, to prepare a 2% detergent aqueous solution. . By visually observing the transparency of these aqueous solutions, the stability of the aqueous solutions when diluted in water of each hardness was determined. The results are shown in Table 5.
[0058]
[Table 5]

[0059]
As is clear from the results in Table 5, sample No. 1 containing no GLDA was turbid (white turbid) when 70 ppm of calcium carbonate was contained. On the other hand, samples Nos. 2 to 5 (invention) all maintained transparency and were stable even when diluted with high-hardness water.
[0060]
In addition, when 2% aqueous solutions of these sample Nos. 1 to 5 were sprayed onto a vertical hard surface using a foaming spray, the sample No. 1 in which turbidity was generated compared to the transparent diluted aqueous solution (sample Nos. 2 to 5). Was significantly inferior in foamability.
[0061]
Example 6
Samples Nos. 1 to 5 were obtained by adjusting a 0.5% aqueous solution of a detergent composition comprising LAS 5%, GLDA 20%, and sodium sulfate 75% to each pH shown in Table 7. Each of these samples was subjected to a grease stain removal property and a corrosion test on aluminum.
[0062]
The pH of the sample was adjusted by adding and mixing 0.2 M sodium carbonate, 0.2 M sodium hydrogen carbonate and 0.2 M sodium hydroxide to each sample.
[0063]
For the oil stain removal property, the beef fat stain test piece produced in the same manner as in Example 3 was immersed in each sample at a water temperature of 25 ° C. for 15 minutes, then pulled up, and the cleaning efficiency (%) was calculated in the same manner as in Example 3. It was done by doing.
[0064]
The corrosion test for aluminum was performed by immersing an aluminum plate whose surface was previously cleaned and measured for weight in the same manner as in Example 2 and obtaining the corrosion rate (%). At the same time, the surface condition of aluminum was also observed. The results are shown in Table 6. In Table 6, ◯ indicates that the surface is glossy without change, and X indicates that the surface is corroded and whitened.
[0065]
[Table 6]

[0066]
From the results shown in Table 6, it can be seen that the oil / fouling stain removability is slightly inferior in sample No. 1 (pH 8), but the detergency increases when sample Nos. 2 to 5, that is, the pH is 9 or more.
[0067]
Regarding corrosion to aluminum, in sample No. 5 (pH 12), the aluminum plate surface was corroded and whitened. On the other hand, in sample Nos. 1 to 4, that is, when the pH was 11 or less, the aluminum plate surface did not change and had gloss.
[0068]
From the above results, in samples Nos. 2 to 4, that is, in the range of pH of the cleaning agent aqueous solution of 9 to 11, it is excellent in oil and fat stain removability, and no change with respect to the surface of the aluminum plate is observed, and it has gloss. Therefore, it is excellent in cleaning properties and has little influence on the aluminum material, which can be said to be a preferable range of the present invention.
[0069]
Example 7
The detergent composition containing each component (%) in Table 7 was diluted in water containing 100 ppm of calcium carbonate to prepare a 2% detergent aqueous solution, which was designated as Sample Nos. 1 to 3. Each of these samples was sprayed on the aluminum plate surface for 5 hours, and the state of the aluminum plate surface was visually observed.
[0070]
[Table 7]

[0071]
From the results of Table 7, the sample No. 1 containing no chelating agent (EDTA, GLDA) has a poor foaming state, and the sample No. 2 using EDTA as the chelating agent has an improved foaming state. However, corrosion on the aluminum plate surface occurs. On the other hand, in sample No. 3 using GLDA as the chelating agent, both the foamed state and the aluminum surface state were good.
[0072]
Example 8
The cleaning composition of the present invention (Sample No. 4 in Table 4) was diluted with water to a COD of 500 ppm, and activated sludge was collected from activated sludge equipment treating chemical industrial wastewater. The sludge was supplied to a small 3-tank serial aeration type activated sludge facility together with the above-described dilution solution, aerated, and tested for biodegradation.
[0073]
The COD in the treated waste water after 7 to 8 days had been reduced to about 50 to 75 ppm, and the decomposition rate was 85 to 90%.
[0074]
【The invention's effect】
As described above, the cleaning composition according to the present invention has characteristics such as excellent oil and fat removal properties, little influence on light metal materials such as aluminum, excellent microbial degradability, and excellent foamability. It can be said that it is suitable for foam cleaning and light metal cleaning.

Claims (4)

In a detergent composition comprising a chelating agent and a surfactant comprising an anionic surfactant and / or a nonionic surfactant, the chelating agent is glutamic acid iminodiacetic acid alkali salt , and the pH of the aqueous solution is A cleaning composition for light metals , which is within a range of 9 to 11 .   2. The light metal detergent composition according to claim 1, wherein the glutamic acid iminodiacetic acid alkali salt is a glutamic acid iminodiacetic acid sodium salt, potassium salt, or alkanolamine salt. The detergent composition for light metals according to claim 1, wherein a blending ratio of the alkali salt of glutamic acid iminodiacetic acid and the surfactant is within a range of 1: 2 to 4: 1 by weight.   A cleaning method for light metal, wherein the cleaning composition for light metal according to claim 1 is applied to foam cleaning.