EP0500951A1

EP0500951A1 - Halogen-free detergent composition

Info

Publication number: EP0500951A1
Application number: EP91915268A
Authority: EP
Inventors: Kenichiro Nagata; Noboru 373 Horiikecho Yamashita; Shizuo Nishiyama; Giichi Akazome; Koichi Murai
Original assignee: New Japan Chemical Co Ltd
Current assignee: New Japan Chemical Co Ltd
Priority date: 1990-08-31
Filing date: 1991-08-28
Publication date: 1992-09-02
Also published as: WO1992004436A1; KR927003781A; EP0500951A4

Abstract

A halogen-free detergent composition comprising: (a) 100 parts by weight of at least one alcoholic solvent selected from the group consisting of tetrahydrofurfuryl alcohol and alkylene oxide adducts thereof, aliphatic alcohols, alkylene oxide adducts thereof and acetates of said adducts, and (b) about 0.1 to 30 parts by weight of a mixture of cyclohexylamine compounds represented by general formula (5), wherein X and Y may be the same or different from each other and each represents hydrogen or -(AO)qH, provided that X and Y should not be hydrogen atoms at the same time; A represents C₂ to C₃ alkylene; and q represents an integer of 1 to 3.

Description

Technical Field

The present invention relates to an alcohol-based, halogen-free cleaning composition effective for removing oils, rosin-based fluxes, adhesives, waxes and the like which are deposited on electronic parts, the surfaces of various metals and plastics, textile materials and the like.

Background Art

Flons have many excellent properties such that they are low in toxicity, incombustible, chemically stable, do not erode the materials to be cleaned such as plastics materials and the like, maintain a strong permeation, are quick-drying, etc., and therefore flons have been heretofore employed in wide fields such as refrigerants for air conditioners and refrigerators, propellants for sprays, blowing agents for heat insulating materials such as urethane foam and the like and cleaning agents for electric and electronic parts, precision machines and the like.
In recent years, however, destruction of the stratospheric ozone layer owing to flons has been scientifically demonstrated, and use of five kinds of flons such as flon 11, flon 12, flon 113 and the like has begun to be restricted. Flon 113, which accounts for about 50% of the total consumption of flon-based products, is mostly used as a cleaning agent, and there arises a need for development of a halogen-free cleaning agent having a high performance which can replace flon 113. However, a cleaning agent having excellent properties has not yet been known.

Disclosure of the Invention

The present inventors conducted extensive research in order to develop a cleaning composition which has excellent properties as achieved by the conventional flon-based cleaning agents such as high cleaning ability, chemical stability and the like and which contains in no way chlorine, fluorine and like halogen, is free from the possibility of destroying the natural environment and is further improved in cleaning properties. In the process of such research, the present inventors found that, by using aliphatic or alicyclic alcohols having a specific structure or the derivative thereof as a solvent component and adding thereto a predetermined quantity of a specific cyclohexylamine compound, it is possible to obtain a cleaning composition which is pronouncedly improved in cleaning properties as compared with the case where the foregoing solvent component is used alone, and which is suitable for dissolving and removing more general kinds of substances, namely applicable to a wider variety of technical fields. The present inventors further found that an aqueous composition prepared by adding water to the cleaning composition obtained above has outstanding properties such that said aqueous composition is less flammable, is suppressed in irritant action, is thus improved in safety during operation and the like. The present inventors consequently found that this composition is a cleaning composition which serves to sufficiently achieve the aforementioned object, i.e. which can replace flon-based cleaning agents. The present invention has been accomplished based on these novel findings.
Stated more specifically, the present invention provides a halogen-free cleaning composition comprising a mixture of:

(a) the following alcohol solvent, i.e. at least one member selected from
- (1) tetrahydrofurfuryl alcohol and an alkylene oxide adduct thereof represented by the formula (1)
  wherein A is an alkylene group having 2 to 3 carbon atoms, and m is an integer of 0 to 15;
- (2) aliphatic alcohols represented by the formula (2)
  
  R¹OH (2)
  
  wherein R¹ is a straight- or branched-chain alkyl group having 2 to 6 carbon atoms;
- (3) an alkylene oxide adduct of an aliphatic alcohol represented by the formula (3)
  
  R²-O-(AO)_n-H (3)
  
  wherein R² is a straight- or branched-chain alkyl group or an alkenyl group having 6 to 22 carbon atoms, A is as defined above in the formula (1), and n is an integer of 1 to 20; and
- (4) an acetate compound of an alkylene oxide adduct of an aliphatic alcohol represented by the formula (4)
  
  R³-O-(AO)_p-R⁴ (4)
  
  wherein R³ and R⁴ are the same or different and each represents a hydrogen atom, a straight- or branched-chain alkyl group having 1 to 4 carbon atoms or an acetyl group, with the proviso that at least one of R³ and R⁴ represent(s) an acetyl group; A is as defined above in the formula (1), and p is an integer of 1 to 4; and
(b) about 0.1 to about 30 parts by weight, per 100 parts by weight of at least one of the foregoing alcohol solvents, of a cyclohexylamine compound represented by the formula (5)
wherein X and Y are the same or different and each represents a hydrogen atom or a group -(AO)_qH, with the proviso that X and Y can not be a hydrogen atom at the same time; A is as defined above in the formula (1), and q is an integer of 1 to 3.

Each of the components used for the composition of the invention will be described below.

(1) Tetrahydrofurfuryl alcohol (hereinafter briefly referred to as "THFA") and an alkylene adduct thereof
wherein A is an alkylene group having 2 to 3 carbon atoms, and m is an integer of 0 to 15.
A suitable number of moles of the alkylene oxide to be added to THFA is 0 to about 15 moles, preferably 0 to about 8 moles. Addition of alkylene oxide to THFA in an amount of more than 15 moles impairs the ability to dissolve the substance to be removed by cleaning, hence undesirable. Examples of the alkylene oxide having 2 to 3 carbon atoms usable in the present invention are ethylene oxide (hereinafter simply referred to as "EO") and propylene oxide (hereinafter briefly referred to as "PO"). The compound of the formula (1) includes a compound prepared by adding EO or PO singly to THFA and a compound obtained by adding a mixture of EO and PO to THFA (co-addition). The same applies to the alkylene oxide adducts that fall within the various alcohol solvents to be described hereinafter.
Among the compounds represented by the formula (1) above, THFA is known and can be prepared with ease by subjecting furfuryl alcohol to hydrogenation (JOHH A. MONICK, ALCOHOLS Their Chemistry, Properties and Manufacture, p. 272, 1968). The alkylene oxide adduct of THFA can be readily prepared in a conventional manner. These compounds can be used singly or at least two of them are usable in mixture. Of the compounds of the above formula (1), THFA (m = 0) is particularly preferred.
(2) Aliphatic alcohols

R¹OH (2)

wherein R¹ is a straight- or branched-chain alkyl group having 2 to 6 carbon atoms.
Specific examples of the alcohol solvent which belongs to this group are ethanol, isopropanol, n-propanol, isobutanol, secondary butanol, tertiary butanol, n-amyl alcohol, active amyl alcohol, isoamyl alcohol, secondary amyl alcohol, 3-pentanol, tertiary amyl alcohol, fusel oil, n-hexanol, methylamyl alcohol, 2-ethylbutanol, etc. among which ethanol, isopropanol, isobutanol, secondary butanol, tertiary butanol and the like are preferred. These alcohol solvents are usable singly or at least two of them can be used in mixture. Since alcohols having more than 6 carbon atoms are low in solubility in water, it is difficult to prepare an aqueous composition using such alcohols, and the use of such alcohols tends to result in low cleaning ability.
(3) Alkylene oxide adduct of aliphatic alcohols

R²-O-(AO)_n-H (3)

wherein R² is a straight- or branched-chain alkyl group or an alkenyl group having 6 to 22 carbon atoms, A is as defined in the formula (1), and n is an integer of 1 to 20.
The alkylene oxide adducts according to the invention can be readily produced in a conventional manner, namely by adding 1 to 20 moles of alkylene oxide having 2 to 3 carbon atoms to the above specified alcohol having 6 to 22 carbon atoms.
Specific examples of such alcohol are hexanol, heptanol, octanol, 2-ethylhexanol, decanol, undecanol, lauryl alcohol, stearyl alcohol, oleyl alcohol, Guerbet alcohol having 18 carbon atoms, etc. Among these, 2-ethylhexanol is preferred. These alcohols are usable singly or at least two of them can be used in mixture. These alcohols can be those derived from natural fats and oils or synthetic alcohols prepared from petroleum oil.
The number of moles of alkylene oxide to be added to the alcohol is 1 to 20. Generally, it is preferred to add the alkylene oxide to the alcohol in an amount of about 2 to about 8 moles.
When a compound prepared by adding to the above alcohol a mixture of EO and PO is used, the bubbling of the resulting cleaning composition can be suppressed.
(4) Acetate compound of an alkylene oxide adduct of aliphatic alcohol

R³-O-(AO)_p-R⁴ (4)

wherein R³ and R⁴ are the same or different and each represents a hydrogen atom, a straight- or branched-chain alkyl group having 1 to 4 carbon atoms, or an acetyl group, with the proviso that at least one of R³ and R⁴ represent(s) an acetyl group; A is as defined above in the formula (1); and p is an integer of 1 to 4.

Such acetate compounds are known compounds or can be prepared with ease by a known process. Specific examples of such acetate compound are ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol diacetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoisopropyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monoisopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, or mixtures of these compounds, etc. Among these compounds, particularly preferred are ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, or mixtures of these compounds.
The foregoing alcohol solvents (1) to (4) are each usable singly or at least two of them can be used in mixture. Among them, preferred is a cleaning composition comprising the adduct of aliphatic alcohol with alkylene oxide represented by the formula (3) as an essential component.
In the present invention, it is essential to use, in addition to the above alcohol solvents (1) to (4), a cyclohexylamine compound represented by the formula (5)

wherein X and Y are the same or different and each represents a hydrogen atom or a group -(AO)_qH, with the proviso that X and Y can not be a hydrogen atom at the same time; A is as defined above in the formula (1), and q is an integer of 1 to 3.
Examples of such cyclohexylamine compound are adducts of cyclohexylamine with EO, with PO or with a mixture of EO and PO. These compounds are each usable singly or at least two of them can be used in combination. These compounds are known compounds or can be readily prepared by a conventional method, e.g. by adding to cyclohexylamine a specified quantity of alkylene oxide with heating and under normal or elevated pressure using a basic catalyst such as caustic alkali, sodium methoxide or the like. When, among the cyclohexylamine compounds, an EO adduct of cyclohexylamine is used, a cleaning composition having an excellent dissolving power can be obtained. Addition of cyclohexylamine with alkylene oxide serves to elevate the boiling point to improve the safety of the cleaning composition, and further serves to diminish the odor peculiar to cyclohexylamine, whereby the work environment can be improved. In this case, preferably, the number of moles of the alkylene oxide to be added is about 1 to about 6 moles. In particular, when an adduct of cyclohexylamine with 2 moles of ethylene oxide (X = Y = -CH₂CH₂OH, trade name: "WONDAMINE CHE-20P", product of New Japan Chemical Co., Ltd., hereinafter referred to as "CHE") is used, the resulting cleaning composition is outstanding in cleaning ability and is less likely to foam, hence more practical.
The cyclohexylamine compound of the formula (5) is used in an amount of about 0.1 to about 30 parts by weight, preferably about 1 to about 15 parts by weight, per 100 parts by weight of at least one of the above alcohol solvents (1) to (4). Use of the cyclohexylamine compound in an amount less than 0.1 part by weight tends to impair the ability of the resulting cleaning composition to dissolve the substance to be removed by cleaning. Even if the cyclohexylamine compound is used in an amount more than 30 parts by weight, remarkably improved effects can not be produced, resulting in an economical disadvantage, and, with regard to some kinds of articles to be cleaned, e.g. surface-treated electronic parts and the like, there arises a tendency of swelling the surface-protecting film present on the surface of the article to be cleaned as well as the substance to be removed by cleaning.
The cleaning composition according to the invention can be used as a non-aqueous composition consisting essentially of an active ingredient, i.e. a mixture of at least one member of the foregoing alcohol solvents (1) to (4) and the cyclohexylamine compound of the formula (5).
Further, since said mixture is readily miscible with water, an aqueous cleaning composition can be prepared by mixing said mixture with water. Such aqueous cleaning composition is in the form of an aqueous solution or an aqueous emulsion, but is usually in the form of an aqueous solution. With such aqueous composition, the amount of water to be used can be suitably determined according to the intended use. Generally, the aqueous composition is made into an aqueous solution containing the mixture at a concentration of at least 2% by weight but less than 100% by weight, preferably about 10 to about 80% by weight. The aqueous cleaning composition obtained in this way is not deteriorated in cleaning ability and is non-flammable, thus improving the safety from the environmental and operation viewpoints. However, the amount of the mixture is not limited to the above range insofar as the desired effects can be achieved. With the cleaning composition according to the invention, by using at least one member of the above alcohol solvents of the formulas (1) to (4) in combination with a specific quantity of the cyclohexylamine compound of the formula (5), the components synergically act, and improve permeation property and ability to dissolve the substances to be removed by cleaning as compared with the case where each component is used singly, thus pronouncedly improving the cleaning performance.
When required, the cleaning composition of the present invention may have incorporated therein additives conventionally used in the art such as anti-oxidizing agent, mildewproofing agent, rust preventive, anti-foaming agent and the like.
The thus obtained cleaning composition of the present invention is capable of dissolving well fats and oils, mineral oil, silicone oil, waxes, rosin-based fluxes, paraffinic adhesives, rosin-based adhesives and the like and only a small quantity of ionic residual substances remain. For this reason, the cleaning composition of the invention is usable in the fields in which flon-based cleaning compositions have been conventionally used, namely the cleaning composition of the invention is most suitable for removing organic oils adhered to printed circuit boards, ceramic element, condensers, liquid crystal display devices and like electronic parts, brushes, rotors and like electric parts, bearings, chips and like parts of precision machines, parts of optical instruments used for cameras, glasses and the like, parts for motor vehicles, etc. In this case, the kind of the material of the article to be cleaned is not specifically limited. Examples of such material are metals, plastics, elastomer and composite materials thereof, etc. Further, the composition of the invention is applicable to a wide range of fields in which not only flon-based cleaning agents but also other halogen-based cleaning agents have been hitherto used (for example, cleaning agents for laundry, etc.).
An example of the method for removing dirt from an article to be cleaned such as the aforementioned electronic parts using the cleaning composition of the invention will be described below. However, the method of the present invention is not limited to the following example. In general, the cleaning can be conducted by bringing the non-aqueous or aqueous cleaning composition of the invention into contact with the substance to be removed from the article to be cleaned. For example, the article to be cleaned is immersed in the cleaning composition maintained at a temperature of around room temperature to about 80°C for about 1 minute to about several hours to swell the dirt when so required, or the cleaning liquid is stirred, rocked or subjected to supersonic vibration (for about 10 seconds to about 1 hour), or subjected to a combination of these procedures under the foregoing temperature condition for removing the dirt. After the removal, when required, the article is washed with water or rinsed with a lower alcohol having 1 to 4 carbon atoms to remove the remaining cleaning composition, followed by drying.
In this way, the present invention also provides a method for cleaning the surface of an article which is soiled with an organic substance such as the aforementioned fats and oils, mineral oil, silicone oil, waxes, rosin-based fluxes, paraffinic adhesives, rosin-based adhesives or the like, the method being characterized in that the non-aqueous or aqueous cleaning composition of the invention is brought into contact, with the article to be cleaned.
The halogen-free cleaning composition according to the present invention has the following excellent properties, and can replace the conventional flon-based cleaning agents.

(1) The composition of the invention has a high ability to dissolve various substances to be removed by cleaning and is applicable to a wide range of fields.
(2) The composition of the invention is highly safe. In particular, the aqueous composition exhibits remarkable advantages such as decreased flammability, decreased odor and the like.
(3) The composition of the invention is less likely to foam, hence satisfactory in workability.
(4) Unlike flon-based or other chlorine-based cleaning agents, the composition of the invention in no way contains halogen, hence free of the problem from the environmental viewpoint.
(5) When compared with flon-based cleaning agents, the composition of the invention is less susceptible to vaporization for fleeing and can be recovered for repeated use, hence advantageous in view of the cost.
(6) When electronic parts such as printed circuit boards and the like, etc. are cleaned using the composition of the invention, only a small quantity of ionic residual substances remains (coming up to the MIL standard) substantially without exerting an adverse influence on the functions of the article cleaned.
(7) In the case of cleaning electric parts and the like, the composition of the invention is substantially free from the possibility of exerting an adverse influence on the electrical properties (such as resistance characteristics) of the electric parts.

Examples

The present invention will be described below in detail with reference to the following examples. The alcohol solvents used in the following examples are abbreviated as follows.

THFA:: Tetrahydrofurfuryl alcohol
sec-BA:: Secondary butanol
OLEO·9:: Adduct of oleyl alcohol with 9 moles of EO
OLEO·14:: Adduct of oleyl alcohol with 14 moles of EO
EHEO·2:: Adduct of 2-ethylhexanol with 2 moles of EO
EHEO·4:: Adduct of 2-ethylhexanol with 4 moles of EO
EHEO·6:: Adduct of 2-ethylhexanol with 6 moles of EO
EHEO·8:: Adduct of 2-ethylhexanol with 8 moles of EO
PGMEA:: Propylene glycol monomethyl ether acetate
DGBEA:: Diethylene glycol monobutyl ether acetate

CHE:: Adduct of cyclohexylamine with 2 moles of EO (trade name: "WONDAMINE CHE-20P", product of New Japan Chemical Co., Ltd.)

Examples 1 to 5

Into a 200 ml-beaker was placed 150 ml of a cleaning composition having the formulation as shown below in Table 1. The composition was maintained at 60°C with stirring. A test piece (50 x 15 mm) made of a copper plate to which a mineral oil was adhered was cleaned by immersing the test piece in the cleaning composition for 15 minutes with stirring. After the cleaning, the test piece was washed with water for 5 minutes and then dried at 105°C for 30 minutes.
The evaluation for the facility of rinsing was conducted according to the following criteria:

A:: The surface of the article to be cleaned was moistened uniformly
B:: A portion of the surface of the article to be cleaned was not moistened

A:: The surface of the test piece was clean
B:: A small quantity of the mineral oil remained on the surface
C:: A considerable quantity of the mineral oil remained on the surface

In the following examples and comparative examples, the evaluation for the facility of rinsing was conducted according to the same criteria as employed in Examples 1 to 5.

Comparative Example 1

Using a cleaning composition having the same formulation as of the composition used in Example 1 except that the cleaning composition did not contain CHE, a cleaning test for removing mineral oil was conducted in the same manner as in Example 1. Table 1 shows the results.

Table 1

	Example					Comp. Ex.
	1	2	3	4	5	1
THFA	100				100	100
sec-BA		100
EHEO·8			100
PGMEA				100
CHE	5	5	5	5	5	-
War	-	-	-	-	40	-
Evaluation for cleaning ability	A	A	A	A	A	B
Facility of rinsing	A	A	A	A	A	A

Examples 6 to 9

Each of the cleaning compositions as shown in Table 2 was placed into a cleaning chamber of an ultrasonic cleaner (trade name "THREE WAVE ULTRASONIC CLEANER SUS-103", product of Shimadzu Rika Instrument K.K.), and the composition was maintained at 60°C. Electronic parts (a laminate of chips) made of glass to which a paraffinic adhesive was adhered were immersed in the composition and cleaned by using multi-ultrasonic wave (repeated use of waves having wavelengths of 28, 45 and 100 KHz for 30 seconds, the same applies hereinafter) for 10 minutes. The chips thus cleaned were then washed with water for 5 minutes, rinsed with ethanol and dried at 80°C for 1 hour.
The evaluation for the facility of rinsing was conducted in the same manner as in Examples 1 to 5. Further, the state of separation of the chips after the drying and the presence or absence of the remaining residuary adhesive were observed with the unaided eye, followed by evaluation according to the following criteria:

A:: The surface of the chip was clean and the state of separation of the chips was satisfactory.
B:: The surface was cleaned unevenly and there existed some chips which were not fully separated.
C:: The paraffinic adhesive remained on the surface and the chips were not sufficiently separated.

Table 2 shows the results.

Comparative Example 2

Using a cleaning composition having the same formulation as that of the composition used in Example 6 except that the cleaning composition did not contain CHE, a cleaning test for removing paraffinic adhesive was carried out in the same manner as in Example 6. Table 2 shows the results obtained.

Table 2

	Example				Comp. Ex.
	6	7	8	9	2
sec-BA	100			100	100
OLEO·9				25
EHEO·8		100
DGBEA			100
CHE	5	5	5	25	-
Water	-	-	-	60	-
Evaluation for cleaning ability	A	A	A	A	B
Facility of rinsing	A	A	A	A	A

Examples 10 to 16

Each of the cleaning compositions having the formulation as shown below in Table 3 was placed into the cleaning chamber of the same type of ultrasonic cleaner as used in Example 6, and the composition was maintained at 60°C. An electronic element to which a rosin-based solder flux was adhered was immersed in the composition and subjected to ultrasonic cleaning for 5 minutes using ultrasonic waves of multi-wavelengths. Thereafter, the element was washed with water, rinsed with ethanol and dried at 80°C for 1 hour.
The evaluation for the facility of rinsing was conducted in the same manner as in Examples 1 to 5. Further, the state of the electronic element after the drying was observed with the unaided eye, followed by evaluation according to the following criteria:

A:: The surface of the element was clean.
B:: A small quantity of flux remained on the surface.
C:: A considerable quantity of flux remained on the surface.

Table 3 shows the results.

Comparative Example 3

Using a cleaning composition having the same formulation as that of the composition used in Example 10 except that the cleaning composition did not contain CHE, a cleaning test for removing rosin-based solder flux was carried out in the same manner as in Example 10. Table 3 shows the results.

Table 3

	Example							Comp. Ex.
	10	11	12	13	14	15	16	3
THFA	100							100
EHEO·2		100					9.0
EHEO·4			100
EHEO·6				100
PGMEA					100
DGBEA						100
OLEO·14							0.5
CHE	5	5	5	5	5	5	0.5	-
Water	-	-	-	-	-	-	90	-
Evaluation for cleaning ability	A	A	A	A	A	A	A	B
Facility of rinsing	A	A	A	A	A	A	A	A

Examples 17 to 19

A cleaning composition having the formulation as shown below in Table 4 was placed into a cleaning chamber of the same type of cleaner as employed in Example 6 and the composition was maintained at 25°C. An electronic element to which silicone oil was adhered was immersed in the cleaning composition and was subjected to ultrasonic cleaning for 10 seconds using ultrasonic waves of multi-wavelengths. Thereafter, the element was washed with water, rinsed with ethanol and dried at 80°C for 1 hour.
The evaluation for the facility of rinsing was conducted in the same manner as in Examples 1 to 5. Further, the state of the electronic part after the drying was observed with the unaided eye, followed by evaluation according to the following criteria:

A:: The surface of the part was clean.
B:: A small quantity of the silicone oil remained on the surface.
C:: A considerable quantity of the silicone oil remained on the surface.

Table 4 shows the results.

Comparative Example 4

Using a cleaning composition having the same formulation as that of the composition used in Example 17 except that the cleaning composition did not contain CHE, a cleaning test for removing silicone oil was conducted in the same manner as in Example 17. Table 4 shows the results. Table 4

Example Comp. Ex.

17 18 19 4

EHEO·2 100 100

PGMEA 100

DGBEA 100

CHE 5 5 5 -

Evaluation for cleaning ability B A A C

Facility of rinsing A A A A

Examples 20 to 23

Each of the cleaning compositions having the formulation as shown below in Table 5 was placed into the cleaning chamber of the same type of cleaner as employed in Example 6 and the composition was maintained at 70°C. An electronic element to which a wax was adhered was immersed in the composition and subjected to ultrasonic cleaning for 5 minutes using ultrasonic waves of multi-wavelengths. The element was then washed with water, rinsed with ethanol and dried at 80°C for 1 hour.
The evaluation for the facility of rinsing was carried out in the same manner as in Examples 1 to 5. Furthermore, the state of the electronic part after the drying was observed with the unaided eye, followed by evaluation according to the following criteria:

A:: The surface of the electronic part was clean.
B:: A small quantity of the wax remained on the surface.
C:: A considerable quantity of the wax remained on the surface.

Table 5 shows the results.

Comparative Example 5

Using a cleaning composition having the same formulation as that of the composition used in Example 22 except that the cleaning composition did not contain CHE, a cleaning test for removing wax was carried out in the same manner as in Example 22. Table 5 shows the results.

Table 5

	Example			Comp. Ex.
	20	21	22	23	5
EHEO·2	100
EHEO·4		100
EHEO·6			100		100
EHEO·8				100
CHE	5	5	5	5	-
Evaluation for cleaning ability	A	A	B	B	C
Facility of rinsing	B	A	A	A	A

Examples 24 to 28

A cleaning composition having the formulation as shown below in Table 6 was placed into the cleaning chamber of the same type of cleaner as used in Example 6 and the composition was maintained at 80°C. Electronic parts made of glass (a laminate of chips) to which a rosin-based adhesive was adhered were immersed in the composition for 30 minutes and then subjected to ultrasonic cleaning for 10 minutes using ultrasonic waves of multi-wavelengths. The electronic part was thereafter washed with water for 5 minutes, rinsed with ethanol and dried at 80°C for 1 hour.
The evaluation for the facility of rinsing was conducted in the same manner as in Examples 1 to 5. Further, the state of the separation of the chips and the presence or absence of remaining adhesive after the drying was observed with the unaided eye, followed by evaluation according to the following criteria:

A:: The surface of the chip was clean and the state of the separation of the chips was satisfactory.
B:: The surface was cleaned unevenly and there existed some chips which were not sufficiently separated.
C:: The rosin-based adhesive remained on the surface and the state of the separation of the chips was unsatisfactory.

Table 6 shows the results.

Comparative Example 6

Using a cleaning composition having the same formulation as that of the composition used in Example 28 except that the cleaning composition did not contain CHE, a cleaning test for removing rosin-based adhesive was conducted. Table 6 shows the results.

Table 6

	Example					Comp. Ex.
	24	25	26	27	28	6
THFA	100
EHEO·2		100
EHEO·4			100
EHEO·6				100
EHEO·8					100	100
CHE	1	3	5	5	5	-
Water	40	-	-	-	-	-
Evaluation for cleaning ability	A	A	A	A	B	C
Facility of rinsing	A	A	A	A	A	A

Claims

A halogen-free cleaning composition comprising a mixture of:
(a) at least one alcohol solvent selected from the group consisting of
(1) tetrahydrofurfuryl alcohol and an alkylene oxide adduct thereof represented by the formula (1)
wherein A is an alkylene group having 2 to 3 carbon atoms, and m is an integer of 0 to 15;

(2) aliphatic alcohols represented by the formula (2)

R¹OH (2)

wherein R¹ is a straight- or branched-chain alkyl group having 2 to 6 carbon atoms;

(3) an alkylene oxide adduct of an aliphatic alcohol represented by the formula (3)

R²-O-(AO)_n-H (3)

wherein R² is a straight- or branched-chain alkyl group or an alkenyl group having 6 to 22 carbon atoms, A is as defined above in the formula (1), and n is an integer of 1 to 20; and

(4) an acetate compound of an alkylene oxide adduct of an aliphatic alcohol represented by the formula (4)

R³-O-(AO)_p-R⁴ (4)

wherein R³ and R⁴ are the same or different and each represents a hydrogen atom, a straight- or branched-chain alkyl group having 1 to 4 carbon atoms or an acetyl group, with the proviso that at least one of R³ and R⁴ is an acetyl group; A is as defined above in the formula (1); and p is an integer of 1 to 4; and

(b) about 0.1 to about 30 parts by weight, per 100 parts by weight of at least one of the above alcohol solvents, of a cyclohexylamine compound represented by the formula (5)
wherein X and Y are the same or different and each represents a hydrogen atom or a group -(AO)_qH, with the proviso that X and Y can not be a hydrogen atom at the same time; A is as defined above in the formula (1); and q is an integer of 1 to 3.
A composition as defined in claim 1 wherein the alcohol solvent is at least one of tetrahydrofurfuryl alcohol and an alkylene oxide adduct thereof represented by the formula (1).
A composition as defined in claim 1 wherein the alcohol solvent is tetrahydrofurfuryl alcohol.
A composition as defined in claim 1 wherein the alcohol solvent is at least one of the aliphatic alcohols represented by the formula (2).
A composition as defined in claim 1 wherein the alcohol solvent is at least one member selected from ethanol, isopropanol, isobutanol, secondary butanol and tertiary butanol.
A composition as defined in claim 1, characterized in that the alcohol solvent comprises an alkylene oxide adduct of an aliphatic alcohol represented by the formula (3).
A composition as defined in claim 1 wherein the alcohol solvent is at least one alkylene oxide adduct of an aliphatic alcohol selected from hexanol, heptanol, octanol, 2-ethylhexanol, decanol, undecanol, lauryl alcohol, stearyl alcohol, oleyl alcohol and Guerbet alcohol having 18 carbon atoms.
A composition as defined in claim 1 wherein the alcohol solvent is an alkylene oxide adduct of 2-ethylhexanol.
A composition as defined in claim 1 wherein the alcohol solvent is an acetate compound of an alkylene oxide adduct of an aliphatic alcohol represented by the formula (4).
A composition as defined in claim 1 wherein the alcohol solvent is at least one member selected from ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate.
A composition as defined in claim 1 wherein the cyclohexylamine compound is an ethylene oxide adduct of cyclohexylamine.
A composition as defined in claim 1 wherein the cyclohexylamine compound is an adduct of cyclohexylamine with 2 moles of ethylene oxide.
A halogen-free aqueous cleaning composition characterized in that the composition is prepared by adding water to the mixture of the alcohol solvent and the amine compound as defined in claim 1 so that the concentration of the mixture is adjusted to at least 2% by weight but less than 100% by weight.
A composition as defined in claim 13 wherein the alcohol solvent is at least one of tetrahydrofurfuryl alcohol and an alkylene oxide adduct thereof represented by the formula (1) of claim 1.
A composition as defined in claim 13 wherein the alcohol solvent is tetrahydrofurfuryl alcohol.
A composition as defined in claim 13 wherein the alcohol solvent is at least one member of the aliphatic alcohols represented by the formula (2) of claim 1.
A composition as defined in claim 13 wherein the alcohol solvent is at least one member selected from ethanol, isopropanol, isobutanol, secondary butanol and tertiary butanol.
A composition as defined in claim 13, characterized in that the alcohol solvent comprises an alkylene oxide adduct of an aliphatic alcohol represented by the formula (3) of claim 1.
A composition as defined in claim 13 wherein the alcohol solvent is at least one alkylene oxide adduct of an aliphatic alcohol selected from hexanol, heptanol, octanol, 2-ethylhexanol, decanol, undecanol, lauryl alcohol, stearyl alcohol, oleyl alcohol and Guerbet alcohol having 18 carbon atoms.
A composition as defined in claim 13 wherein the alcohol solvent is an alkylene oxide adduct of 2-ethylhexanol.
A composition as defined in claim 13 wherein the alcohol solvent is an acetate compound of an alkylene oxide adduct of an aliphatic alcohol represented by the formula (4) of claim 1.
A composition as defined in claim 13 wherein the alcohol solvent is at least one member selected from ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate.
A composition as defined in claim 13 wherein the cyclohexylamine compound is an ethylene oxide adduct of cyclohexylamine.
A composition as defined in claim 13 wherein the cyclohexylamine compound is an adduct of cyclohexylamine with 2 moles of ethylene oxide.
A cleaning method characterized in that the cleaning composition as defined in claim 1 or claim 13 is brought into contact with an article to be cleaned.