JPH0931490A - Cleaning of article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively wash and remove oil and fat attached to the surface of an article such as (non)metallic parts, electronic parts, glass or lens by contacting a washing object stained with oil and fat with an aqueous degreasing cleaner for industrial use containing a nonionic surfactant at a specific temperature. SOLUTION: A cleaning object stained with oil and fat is brought into contact with an aqueous industrial degreasing cleaner containing a nonionic surfactant preferably a glycol ether compound, a compound of formula, R<1> -X-R<2> [R<1> and R<2> are each H or a 1-18C hydrocarbon group; one of R<1> and R<2> is a >=6C group; X is C(R<3> )(R<4> ) (R<3> and R<4> are each H or a 1-18C hydrocarbon group), COO, CO or O) or an ionic surfactant} at a temperature above the cloud point of the cleaner (preferably <=95 deg.C) to remove the oil and fat from the cleaning object.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for cleaning an article. Specifically, a water-based industrial degreasing detergent containing a nonionic surfactant effectively removes oils and fats attached to the surface of articles such as metal parts, non-metal parts, electronic parts, glass and lenses. A method for cleaning and removing.

[0002]

2. Description of the Related Art In the manufacture of electronic parts, precision machine parts, etc., degreasing and cleaning of adhering oils and fats is necessary throughout the processing steps. For example, when cutting a member,
The cutting oil is applied to the surface of the member in consideration of lubricity between the member and the cutting tool, workability, slow heating effect, etc.
In order to prevent adverse effects on the final product and the like, adhering oils and fats are washed away in the next step.

Conventionally, a chlorine-containing hydrocarbon solvent or a non-halogen-based solvent has been used as such an industrial degreasing detergent. However, although the chlorine-containing hydrocarbon solvent has the advantage that it is nonflammable and has excellent drying property, it cannot be used because of environmental pollution such as ozone layer depletion. As non-halogen solvents, alcohols such as isopropyl alcohol and ethyl alcohol, petroleum solvents such as xylene, toluene and benzene, and water-based alkaline cleaners are used. However, there is a problem in flammability, and alkaline detergents are insufficient in detergency against stains such as oils and fats, and thus it is difficult to use any of them. When the alkalinity of the alkaline detergent is increased, the detergency is improved, but there are drawbacks such as corrosion of metals such as aluminum and copper, and roughening of the surface of the member.

From the current situation, recently, environmental characteristics, odor,
Aqueous industrial degreasing detergents containing nonionic surfactants or ionic surfactants have come to be used as industrial degreasing detergents that can satisfy required performance such as flammability to some extent. . However, the detergency of an aqueous industrial degreasing detergent containing such a surfactant is not sufficient, and since it contains a surfactant, there is a problem of "foaming" during washing.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to environmental characteristics,
It is an object of the present invention to provide a method for effectively cleaning and removing oils and fats attached to articles by using a water-based industrial degreasing detergent that can satisfy required performance such as odor and flammability.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies on a method for cleaning an aqueous industrial degreasing detergent containing a nonionic surfactant in order to solve the above-mentioned problems. It has been found that when a cleaning agent is brought into contact with an article to be cleaned to which oils and fats are attached at a temperature equal to or higher than the cloud point of the cleaning agent, the cleaning power is unexpectedly improved and the problem of "foaming" can be solved. It was

The cloud point is the temperature at which clouding occurs when the temperature of an aqueous solution containing a nonionic surfactant is raised, and is found only in an aqueous solution containing a nonionic surfactant. It is a characteristic. At temperatures above the cloud point, micelles in an aqueous solution form giant micelles due to dehydration and become turbid, so as a general concept, a water-based industrial degreasing wash containing a nonionic surfactant is used. It was considered that the detergency was not sufficient even if the agent was used above the cloud point. Therefore, when washing articles using such industrial degreasing detergents, it has been common knowledge to wash at a temperature at which the detergent does not become cloudy (a temperature below the cloud point). The cloud point of the cleaning agent is used when separating the oil component (surfactant and fats and oils) from the water component in treating the waste liquid of the cleaning agent. The cloud point of the cleaning agent has never been taken into account in order to improve the cleaning power.

As described above, according to the present invention, in the cleaning method using the water-based industrial degreasing cleaning agent containing the nonionic surfactant, the cleaning temperature condition which cannot be conceived from the conventional fixed idea is considered. It was completed based on the new knowledge obtained by adoption.

That is, according to the present invention, a water-based industrial degreasing detergent containing a nonionic surfactant is brought into contact with an article to be washed having oils and fats attached thereto at a temperature not lower than the cloud point of the detergent. And a method for cleaning an article, which comprises removing oils and fats from the article to be cleaned.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The water-based industrial degreasing detergent for use in the present invention is an aqueous solution containing the above-mentioned nonionic surfactant as an active ingredient. The content of the agent is usually 0.1 to 95% by weight. It is preferably 0.5 to 50% by weight, more preferably 0.5 to 20% by weight. If the content of the nonionic surfactant is less than 0.1% by weight, the detergency is insufficient, and if it exceeds 95% by weight, there is a problem in flammability.

Specific examples of the nonionic surfactant include:
Polyoxyalkylene alkyl (alkyl group having 6 carbon atoms
Above) Polyalkylene glycol ether type nonionic surfactants such as ethers, polyoxyalkylene phenol ethers and polyoxyalkylene alkylphenol ethers; polyalkylene glycol ester type nonionic interfaces such as polyalkylene glycol monoesters and polyalkylene glycol diesters Activator;
Examples thereof include alkylene oxide adducts of fatty acid amides; polyhydric alcohol type nonionic surfactants such as sorbitan fatty acid esters and sucrose fatty acid esters; fatty acid alkanolamides and polyoxyalkylene alkylamines. These nonionic surfactants may be used alone or in combination of two or more kinds as appropriate. Here, the alkylene refers to ethylene, propylene or butylene, and the polyoxyalkylene refers to polyoxyethylene, polyoxypropylene, polyoxybutylene or a copolymer thereof.

Among these nonionic surfactants, polyethylene glycol ether type nonionic surfactants are preferable from the viewpoint of detergency. More preferred is general formula (2): R ¹ —O— (CH ₂ CH ₂ O) _m —H (wherein R ¹ is a linear or branched alkyl group having 6 to 20 carbon atoms, or a phenyl group. Or a phenyl group substituted with a linear or branched alkyl group having 7 to 12 carbon atoms, and m represents an integer of 2 to 20)). Particularly, R ¹ has 8 to 16 carbon atoms
Is an alkyl group, and m is preferably an integer of 3 to 16 polyoxyethylene alkyl ether.

Further, the water-based industrial degreasing detergent used in the present invention may contain a glycol ether compound as an active ingredient in addition to the nonionic surfactant. When the glycol ether compound is contained, the detergency is improved, and the stability of the detergent in the washing step and the rinse treatment step is preferable. The glycol ether compound is represented by the general formula (3): R ² O-
^{_{(CH 2 (R 4) CHO}} ) n -R 3 ( wherein, a linear or branched alkyl group of R ² is 1 to 5 hydrogen atoms or carbon, R ³ is a straight chain of 1 to 5 carbon atoms Alternatively, a branched chain alkyl group, R ⁴ is a hydrogen atom or a methyl group, and n is 2 to
It represents an integer of 4). Specific examples of glycol ether compounds include diethylene glycol monomethyl ether, diethylene glycol dimethyl ether,
Diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monopropyl ether, diethylene glycol dipropyl ether, diethylene glycol methyl propyl ether, diethylene glycol ethyl propyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl butyl ether, diethylene glycol ethyl butyl ether, Diethylene glycol propyl butyl ether, diethylene glycol monopentyl ether, diethylene glycol dipentyl ether, diethylene glycol methyl pentyl ether, diethylene glycol ethyl pentyl ether, Ethylene glycol propyl pentyl ether, diethylene glycol butyl pentyl ether; tri corresponding to these - or tetraethylene glycol ethers; di corresponding to these -, tri - or tetra propylene glycol ethers and may be exemplified. These glycol ether compounds can be used alone or in combination of two or more.

In addition to the nonionic surfactant, the aqueous industrial degreasing detergent used in the present invention has the general formula (1): R ¹ -X-R ² [R ¹ and R ² are It is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and ^one of R ¹ and R ² is a hydrocarbon group having 6 or more carbon atoms. X is ^{-C (R 3) (R 4} ) - {R 3, R 4 denotes a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. }, -COO-,
Indicates -CO- or -O-. ] The compound represented by the above can also be contained as an active ingredient. The general formula (1)
When the compound represented by is contained, the detergency is improved with respect to removal of high-viscosity oil and grease. In particular, when the glycol ether compound and the compound represented by the general formula (1) are contained, the detergency is improved and the stability of the industrial degreasing detergent in the washing step and the sluice treatment step is improved. It is preferable because it is excellent.

R ¹ , R ² , R in the general formula (1)
^The hydrocarbon group represented by ³ and R ⁴ may be a linear or branched aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, each of which is bonded to form an alicyclic group. It may be a structure. Further, the above general formula (1) or each hydrocarbon group may have a substituent or an unsaturated bond. The flash point of these compounds is 70.
It is preferably at least ° C. Examples of the compound represented by the general formula (1) include dodecylbenzene, diisopropylbenzene, tetraamylbenzene,
Petroleum solvents such as dodecane, hexadecane, tetradecane, tetradecene, decalin, dimethyldecalin, diisopropylcyclohexane, butylcyclohexane, dodecylcyclohexane, dicyclohexylmethane; terpenes such as paramenthane and pinane; coconut fatty acid methyl ester, isopropyl myristate, stearic acid Fatty acid esters such as 2-ethylhexyl ester, lauric acid methyl ester, oleic acid methyl ester, and oleic acid isobutyl ester; ketones such as methylhexyl ketone and diisobutyl ketone; ethers such as amylxylyl ether and hexyl ether. These compounds can be used alone or in appropriate combination of two or more kinds.

Further, the water-based industrial degreasing detergent used in the present invention contains an ionic surfactant, an organic solvent, an inorganic builder, etc. in order to improve the stability of the detergent in the washing step and the rinsing step. Can also be contained as an active ingredient. As the ionic surfactant, various known sulfuric acid ester-based anionic surfactants such as sulfuric acid ester salts of higher alcohols, alkyl sulfuric acid ester salts, and polyoxyethylene alkyl sulfuric acid ester salts; alkyl sulfonates, alkylbenzene sulfonic acids Various known sulfonate-based anionic surfactants such as salts; phosphate ester-based anionic surfactants such as alkyl phosphate ester salts, polyoxyethylene alkyl phosphate ester salts, and polyoxyethylene alkylphenyl phosphate ester salts Agents; cationic surfactants such as alkylated ammonium salts and quaternary ammonium salts; amphoteric surfactants such as amino acid type and betaine type amphoteric surfactants.

The glycol ether compound, the compound represented by the general formula (1), the ionic surfactant and the like (hereinafter referred to as glycol ether compound and the like) are
These can be used alone or in combination, and the amount thereof can be used within a range in which the water-based industrial degreasing detergent can maintain the characteristic of producing a cloud point. Usually, the amount of the glycol ether compound or the like used is 50% by weight or less, preferably 30% by weight or less of the aqueous industrial degreasing detergent. Further, it is preferable that the proportion of the glycol ether compound or the like in the detergent is adjusted to be smaller than the proportion of water. Even when the water-based industrial degreasing detergent contains a glycol ether compound in addition to the nonionic surfactant, the total content of these active ingredients in the detergent is usually 0.1. ~ 95% by weight.

In the present invention, the water-based industrial degreasing detergent is brought into contact with the article to be washed on which the oils and fats are attached at a temperature equal to or higher than the cloud point of the detergent to remove the oils and fats from the article to be washed.
The cloud point of water-based industrial degreasing detergents depends on the type of active ingredient in the detergent and its content, and cannot be determined unconditionally.Therefore, in washing the article, it depends on the detergent used. Set the cleaning temperature above the cloud point. In addition, the washing temperature is usually preferably set to 15 to 95 ° C. More preferably, it is 35 to 85 ° C. If the washing temperature is less than 15 ° C, the viscosity of oils and fats is generally high and the washing efficiency is poor. If the washing temperature exceeds 95 ° C, water may boil, which is inconvenient for the washing operation. Is also not preferable. For these reasons, it is preferable to use, as the industrial degreasing detergent of the present invention, one prepared so that the cloud point is 95 ° C. or lower. The cleaning time is usually about 10 seconds to 30 minutes.

The means for bringing the water-based industrial degreasing detergent into contact with the article to be cleaned to which the oils and fats adhere is not particularly limited, and various known means can be adopted. For example, a method of directly immersing an article to be cleaned in a water-based industrial degreasing detergent, a method of flushing the detergent using a spray device, a method of brushing by a mechanical means, an ultrasonic cleaning method,
Appropriately select and adopt various methods such as a submerged jet cleaning method, a rocking method, a direct-through cleaning method (for example, a direct-through cleaning device “Direct Path”, a method using Arakawa Chemical Industries, Ltd.). You can Especially in the direct cleaning method,
Even when the content of the active ingredient in the cleaning agent is extremely low, the cleaning can be performed in a short time.

The article from which the oils and fats have been washed off in this way is optionally rinsed and then dried. Examples of the rinse treatment agent include water or petroleum-based solvents, glycol ethers, alcohols and the like.

The articles to be cleaned include metal parts, non-metal parts, electronic parts, glass, lenses and the like.

[0022]

The cleaning method of the present invention has the following effects. (1) Using a water-based industrial degreasing detergent containing a nonionic surfactant capable of satisfying the required performance such as environmental characteristics, odor and flammability, the oils and fats adhering to the article to be washed are effectively used. It can be removed by washing. Conventionally, the water-based industrial degreasing detergent containing a nonionic surfactant, which has been insufficient in detergency, exhibits such an excellent detergency that the washing temperature is not less than the cloud point of the detergent. It is speculated that this is because the nonionic surfactant can retain the original ability to dissolve fats and oils. Further, since it has excellent detergency, it exhibits excellent detergency even when the content of the active ingredient such as the nonionic surfactant in the detergent is as low as about 10% by weight or less. Therefore, the running cost of the cleaning agent can be reduced, and the rinsing step after cleaning can be omitted in many cases. (2) It is possible to suppress "foaming" which is a problem when washing a conventional water-based industrial degreasing detergent. It is presumed that this is because the function as a surfactant is weakened because the cleaning temperature is above the cloud point of the cleaning agent. (3) Since an industrial degreasing detergent containing a neutral nonionic surfactant as a main component is used, it is convenient in handling.

[0023]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Production Example 1 Polyoxyethylene (7 moles added) Nonyl ether 7
Water was added to a mixture of 0 parts by weight and 30 parts by weight of polyoxyethylene (additional mol number 12) nonyl ether, and the content of these mixtures (active ingredient) was 5% by weight, and industrial degreasing was 0.5% by weight. A detergent was prepared. The cloud point of an industrial degreasing detergent containing 5% by weight of the active ingredient is 53 ° C, 0.5
The cloud point of the wt% industrial degreasing detergent was 48 ° C.

Production Example 2 Polyoxyethylene (addition mole number 9) nonyl ether 9
Water was added to a mixture consisting of 0 parts by weight and 10 parts by weight of polyoxyethylene (additional mol number: 15) nonyl ether, and the content of these mixtures (active ingredient) was 5% by weight, and industrial degreasing was 0.5% by weight. A detergent was prepared. The cloud point of an industrial degreasing detergent containing 5% by weight of the active ingredient is 66 ° C, 0.5
The cloud point of the wt% industrial degreasing detergent was 53 ° C.

Production Example 3 Polyoxyethylene (7 moles added) Nonyl ether 4
Water was added to a mixture of 0 parts by weight and 60 parts by weight of isopropyldiglycol to prepare industrial degreasing detergents containing 5% by weight and 0.5% by weight of the mixture (active ingredient). The cloud point of the industrial degreasing detergent containing 5% by weight of the active ingredient was 57 ° C, and the clouding point of the industrial degreasing detergent containing 0.5% by weight was 44 ° C.

Production Example 4 Polyoxyethylene (7 moles added) Laurylamine 1
Water was added to a mixture consisting of 0 parts by weight and 90 parts by weight of butyldiglycol, and the content ratio of these mixtures (active ingredient) was 5
% And 0.5% by weight industrial degreasing detergents were prepared. The cloud point of the industrial degreasing detergent containing 5% by weight of the active ingredient was 38 ° C, and the clouding point of the industrial degreasing detergent containing 0.5% by weight was 23 ° C.

Production Example 5 Polyoxyethylene (7 moles added) Nonyl ether 5
Water was added to a mixture of 6 parts by weight, 24 parts by weight of polyoxyethylene (number of moles added: 12) nonyl ether and 20 parts by weight of tetradecene, and the content of these mixtures (active ingredient) was 5% by weight, 0.5% by weight. % Industrial degreasing detergent was prepared. The cloud point of the industrial degreasing detergent containing 5% by weight of the active ingredient was 51 ° C, and the clouding point of the industrial degreasing detergent containing 0.5% by weight was 45 ° C.

Production Example 6 Polyoxyethylene (7 moles added) Nonyl ether 2
Water was added to a mixture of 0 parts by weight, 30 parts by weight of isopropyl diglycidyl ether and 50 parts by weight of tetradecene, and the content ratio of these mixtures (active ingredient) was 5% by weight.
And 0.5% by weight of an industrial degreasing detergent was prepared. The cloud point of an industrial degreasing detergent with an active ingredient content of 5% by weight is 4
3 ° C, 0.5 wt% industrial degreasing detergent has a cloud point of 35 ° C
Met.

Example 1 A copper terminal (cleaned article A) to which oily cutting oil is adhered or a ceramic electronic part (cleaned article B) to which grease is adhered is used to form a 10 cm × 10 cm × 10 cm having a gap hole.
After being charged in the basket-like container of, the container was placed in an ultrasonic cleaning device (28 kHz, 600 W), and the industrial degreasing detergent containing 5% by weight of the active ingredient prepared in Production Examples 1 to 6 After washing at 75 ° C. for 5 minutes, water was rinsed for 5 minutes. Further, it was dried with hot air at 100 ° C. for 10 minutes.

Comparative Example 1 Example 1 was repeated except that the washing temperature was changed from 70 ° C. to 35 ° C.

Example 2 A copper terminal (article A to be cleaned) having an oily cutting oil attached thereto or a ceramic electronic part (article B to be cleaned) having a grease attached thereto was provided with a clearance of 10 cm × 10 cm × 10 cm.
After being charged in the basket-like container of No. 3, the container was installed in a direct-through type washing device (“Direct Path”, manufactured by Arakawa Chemical Industry Co., Ltd.), and the content of the active ingredient prepared in Production Examples 1 to 6 was 5% % Industrial degreasing detergent at 75 ° C. for 2 minutes and then rinsed with water for 5 minutes. In addition, 80
It was dried with hot air at 3 ° C for 3 minutes.

Comparative Example 2 Example 2 was repeated except that the cleaning temperature was changed from 70 ° C to 35 ° C.

Example 3 A copper terminal (article A to be cleaned) to which oily cutting oil is adhered or a ceramic electronic part (article B to be cleaned) to which grease is adhered is used to form a 10 cm × 10 cm × 10 cm having a gap hole.
Industrial degreasing detergent containing 0.5% by weight of the active ingredient prepared in Production Examples 1 to 6 after the container was placed in an ultrasonic cleaning device (28 kHz, 600 W). Washed at 65 ° C. for 5 minutes. In addition, 100
It was dried with hot air at 10 ° C for 10 minutes.

Comparative Example 3 Example 3 was repeated except that the cleaning temperature was changed from 65 ° C to 20 ° C.

EXAMPLE 4 A copper terminal (article A to be cleaned) having an oily cutting oil attached thereto or a ceramic electronic part (article B to be cleaned) having a grease attached thereto was provided with a clearance of 10 cm × 10 cm × 10 cm.
After being charged in the basket-shaped container of No. 3, the container was installed in a direct washing device (“Direct Path”, manufactured by Arakawa Chemical Industry Co., Ltd.), and the content rate of the active ingredient prepared in Production Examples 1 to 6 was 0. 5
It was washed with 65% by weight of an industrial degreasing detergent at 65 ° C. for 2 minutes. Further, it was dried with hot air at 80 ° C. for 3 minutes.

Comparative Example 4 Example 4 was repeated except that the cleaning temperature was changed from 65 ° C to 20 ° C.

Detergency was judged based on the following criteria from the degree of removal of the adhered matter adhered to the article A to be cleaned or the article B to be cleaned subjected to the cleaning treatment in Examples and Comparative Examples. The evaluation results are shown in Tables 1 to 4. ◎ ---- No deposits remain on the articles. ○ --- A deposit remains on less than 1% of the articles. Δ --- Adhesion remains on less than 1 to 3% of the articles. × −− 3% or more of the articles have deposits.

The degree of "foaming" at the time of washing was visually determined based on the following criteria by observing the washing tank after washing. The evaluation results are shown in Tables 1 to 4. ◎ --- No bubbling. ◯ −− Almost no foaming. △ --Slight foaming. X--Bubbling.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C11D 1/72 C11D 1/72 C23G 5/032 C23G 5/032

Claims (5)

[Claims] 1. An article to be washed to which oils and fats are adhered is contacted with a water-based industrial degreasing detergent containing a nonionic surfactant at a temperature not lower than the cloud point of the detergent to be washed. A method for cleaning an article, comprising removing oils and fats from the article. 2. The method for cleaning an article according to claim 1, wherein the industrial degreasing detergent contains a glycol ether compound. 3. An industrial degreasing detergent has the general formula (1): R
¹ -X-R ² [R ^1, R ² is 1 hydrogen or carbon atoms
18 hydrocarbon groups, and ^one of R ¹ and R ² represents a hydrocarbon group having 6 or more carbon atoms, and X is —C (R
³ ) (R ⁴ )-{R ³ and R ⁴ are hydrogen atom or carbon number 1
~ 18 hydrocarbon groups are shown. }, -COO-, -CO-
Or represents -O-. ] The washing | cleaning method of the article of Claim 1 or 2 which contains at least 1 sort (s) among the compounds represented by these. 4. The method of cleaning an article according to claim 1, 2 or 3, wherein the industrial degreasing detergent contains an ionic surfactant. 5. The method for cleaning an article according to claim 1, wherein the industrial degreasing detergent has a cloud point of 95 ° C. or lower.