JPH0598292A - Cleaner composition for printed circuit board - Google Patents

Abstract

PURPOSE:To provide a cleaner composition excellent in safeness and an ability to remove a very difficultly removable stain of soldering flux and not causing environmental pollution. CONSTITUTION:The title composition comprises a hydrocarbon fraction (A) which boils at 150-240 deg.C, mainly consists of a component substantially free from aromatic hydrocarbons such as naphthalene and biphenyl and prepared by fractionating on a rectifier a residual oil obtained by effecting the hydrogenation of a kerosene fraction which boils at 150-300 deg.C in the presence of a metallic catalyst for the hydrogenation of aromatic nuclei under the condition of a pressure of 10-100kg/cm<2> and a temperature of 100-300 deg.C and separating and removing at least part of the n-paraffins from the product of hydrogenation with a molecular sieve made of a synthetic zeolite, a specified solvent (B) and a surfactant (C).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cleaning composition for printed circuit boards.

[0002]

2. Description of the Related Art Conventionally, after the soldering of a printed circuit board, kerosene, benzene, xylene, and other hydrocarbon solvents, chlorine-based solvents such as trichloroethylene, tetrachloroethylene, and trichloroethane are used to remove the remaining solder flux. Freon-based solvents such as trichlorotrifluoroethane, and water-based detergents containing sodium orthosilicate and caustic soda mixed with a surfactant and a builder are used. In particular, Freon-based solvents or chlorine-based solvents are used for parts such as machines due to their high cleanability and flame retardancy. Further, in recent years, terpenes such as limonene, pinene, and diterpenes have been proposed as cleaning agents with little environmental pollution and high safety.

[0003]

However, none of these detergents satisfies all the conditions required for a detergent composition such as stain removability, deterioration resistance and low toxicity. .. That is, cleaning agents using chlorine-based and freon-based solvents have major problems in safety, toxicity, environmental pollution, etc.
In particular, benzene and xylene are highly toxic compounds that are designated as hazardous substances under the Industrial Safety Law, so it is not preferable to use them as detergents in consideration of the danger and complexity of handling these. .. On the other hand, the water-based cleaning agent is preferable in that it is less dangerous and less toxic than the solvent-based cleaning agent, but may be inferior in cleaning power to some extent and may generate rust. In addition, water-based detergents require specialized processing equipment. Further, terpenes typified by limonene are compounds capable of satisfying both safety and detergency, but not only are they easily deteriorated during use and durability is a problem,
It is difficult to obtain a stable quality product because it is derived from a natural product, it is expensive and the supply amount is limited, and it is not practical as an industrial cleaning agent. In recent years, there is an example of using kerosene for cleaning for the purpose of not using environmental pollutants such as CFCs, but it is not only inferior in cleanability but also has a low flash point and is dangerous to fire when used alone. Kerosene also has the drawback of slow drying. Therefore, the present invention improves the drawbacks of the prior art as described above, and provides a cleaning composition at a low cost, which is excellent in the removability of stains by a solder flux that is particularly difficult to remove, is excellent in safety, and has no environmental pollution. With the goal.

[0004]

In such a difficult situation, the present inventors have conducted diligent research to solve the above-mentioned problems, and as a result, as a result, a specific hydrocarbon fraction, a certain organic solvent, and a surfactant. It was found that a mixture obtained by mixing in a specific ratio can be used as a detergent composition satisfying the above conditions, and the present invention has been completed. The present inventors have also found that the above-mentioned cyclic hydrocarbon fraction uses a hydrocarbon fraction produced as a by-product in a specific process in the petrochemical industry, and thus can be provided at extremely low cost.

That is, the present invention has a boiling point of 150 to 300.
The kerosene fraction in the range of ℃ is pressure 10 to 100 Kg / cm ² and temperature 10 by the metal catalyst for nuclear hydrogenation of aromatic nucleus.
The residual oil obtained by nuclear hydrogenation under the condition of 0 to 300 ° C. and then separating and removing at least a part of the n-paraffins in the kerosene fraction using a molecular sieve made of synthetic zeolite A hydrocarbon fraction as a component (A), which has as its main component a component having a boiling point of 150 to 240 ° C., which is substantially free from aromatic hydrocarbons such as naphthalene and biphenyl, obtained by fractional distillation with a distillation apparatus; The present invention provides a detergent composition comprising a specific solvent as the component (B) and a surfactant as the component (C). The present invention will be described in detail below.

In the present invention, the hydrocarbon fraction of the component (A) is produced by the following method. A kerosene fraction having a boiling point of 150 to 300 ° C. is hydrogenated by an aromatic nuclear hydrogenation metal catalyst. Any conventionally known metal catalyst for hydrogenation of aromatic nuclei can be preferably used as this catalyst. For example, nickel, nickel oxide, nickel /
Diatomaceous earth, Raney nickel, nickel / copper, platinum, platinum oxide, platinum / activated carbon, platinum / rhodium, platinum / lithium /
Alumina, rhodium / activated carbon, palladium, cobalt,
Raney cobalt, ruthenium, nickel / tungsten, tungsten sulfide / nickel sulfide / alumina, cobalt / molybdenum, etc. can be preferably used.

The hydrogen pressure is 10 to 100 kg / cm ² , and the temperature is 100 to 300 ° C. At a pressure lower than 10 Kg / cm ² or at a temperature lower than 100 ° C., the hydrogenation reaction does not proceed sufficiently, and at a pressure higher than 100 Kg / cm ² or a temperature higher than 300 ° C., side reactions such as decomposition reaction take precedence. Is also not preferable. The reaction system may be a batch system or a continuous / flow system.

The aromatic hydrocarbons in the kerosene fraction are nuclear hydrogenated to naphthenes by the above hydrogenation, but usually 100% of the aromatic hydrocarbons contained are not nuclear hydrogenated. A certain amount of aromatic hydrocarbons remain without being hydrogenated depending on the above-mentioned catalyst type, reaction conditions and the like. Further, the hydrogenation treatment is often accompanied by decomposition and isomerization as a side reaction, and products related to these reactions are inevitably included in the hydrogenated kerosene fraction.

Following the above hydrogenation treatment, at least a part of the kerosene fraction is separated and removed using a molecular sieve made of synthetic zeolite to obtain a residual oil. A method for separating and obtaining n-paraffins from a hydrocarbon mixture by repeating adsorption / desorption in a gas phase or a liquid layer using a molecular sieve has hitherto been an industrial method for producing n-paraffins as follows. Has been widely implemented. That is, for example, a molecular sieve made of synthetic zeolite having a large number of pores adjusted to 5 A is used as a fixed bed, and adsorption / desorption of n-paraffins is alternately performed, and the molecular sieve having adsorbed n-paraffin is a low molecular paraffin for desorption. The n-paraffins are desorbed by desorption, and the mixed desorption low-molecular weight paraffin is separated by distillation and recirculated. The Molex method is used, and the adsorption and desorption using a molecular sieve made of a synthetic zeolite also having 5 A pores is used for the gas phase. Adsorbs n-paraffins with, and desorbs them by washing with low molecular weight paraffins TSF method (Texaco Selective Finishing method), which also uses a molecular sieve made of 5A synthetic zeolite. Desorption is performed by alternately repeating pressurization and depressurization, an iso-sieving type, and vapor phase / liquid bed phase By the combined method, adsorption of n-paraphytes to a molecular sieve made of synthetic zeolite having 5A pores is continuously carried out in a liquid bed in an adsorber, and the desorption is operated in a regenerator at a higher temperature than the adsorption. Then, the regenerated molecular sieve may be returned to the adsorption device from the regeneration device and recirculated to the esso method. The n-paraffins can be separated by any method using a molecular sieve made of synthetic zeolite having pores of 5A.

Generally, in separating n-paraffin,
Theoretically, only n-paraffins should be separated. However, depending on the method, hydrocarbons other than n-paraffins are also separated along with n-paraffins, and the resulting residual oil in the residual oil is separated. The contents of components other than n-paraffins may change. Considering such a point, there is a method of industrially separating n-paraffins by using urea crystals, but as the method of the present invention,
The method as described above using a molecular sieve made of synthetic zeolite having pores of 5 A is suitable.

The n-paraffins are separated from the hydrogenated kerosene fraction as described above to obtain a residual oil. Next, this residual oil is subjected to precision distillation. For example, a precision distillation apparatus comprising two or more distillation columns is used to remove light hydrocarbons from the top of the first column, and the target fraction is removed from the top of the second or subsequent columns. Manufactured. Of course, if the distribution efficiency such as the number of distillation stages is appropriate, light hydrocarbons and heavy hydrocarbons are removed from the top and bottom of a precision distillation apparatus consisting of one distillation column, respectively, and the objective is from the center of the column. Fractions can also be produced. The precision distillation may be carried out after the second-stage nuclear hydrogenation described below.

With the above precision distillation apparatus, a boiling point of 150-2
A hydrocarbon fraction mainly containing components in the range of 40 ° C. is obtained. The boiling point of the component of the hydrocarbon fraction of the present invention is required to be in the above range, and if it deviates from this range, the presence of each component and the balance of its content will be lost and the initial purpose cannot be achieved, which is preferable. Absent. That is, in the range lower than the above boiling point range, a large amount of harmful aromatic hydrocarbons such as benzene, toluene and xylene are contained, which is not preferable. Further, if the boiling point temperature exceeds 240 ° C., the boiling point becomes too high, the drying property after washing becomes poor, and the residual odor becomes strong, which is not preferable. The above-mentioned hydrocarbon fraction is substantially free of benzene, toluene, xylene, etc., and has a low content of other aromatic hydrocarbons, and is substantially free of naphthalene and biphenyl. However, in the present invention, for the purpose of higher safety, for example, in order not to contain substantially all kinds of aromatic hydrocarbons, the second stage hydrogenation is applied to the residual oil. It is also possible to carry out a treatment to obtain a fraction containing substantially no aromatic hydrocarbon.

The hydrogenation performed in the second stage on the residual oil can be carried out in the same manner as the hydrogenation in the first stage. Alternatively, nuclear hydrogenation may be performed under milder conditions, that is, lower temperature or lower pressure. The nuclear hydrogenation metal catalyst used in the second stage does not necessarily have to be the same as in the first stage. That is, the catalyst may be the same or different. In any case, it may be appropriately selected from the above-mentioned hydrogenation conditions. Next, after the second-stage nuclear hydrogenation, fine distillation is carried out as necessary as described above. A boiling point of 150-
A hydrocarbon fraction of the component (A) mainly containing components in the range of 240 ° C. is obtained.

When the hydrocarbon fraction of the component (A) thus obtained is used as a cleaning agent, the hydrocarbon fraction of the component (A) is mixed with the solvent of the component (B) in order to remove inorganic dirt and the like. It is necessary to use the surfactant of the component C) in combination. In the present invention, the solvent of the component (B) has 3 carbon atoms.
~ 18 aliphatic monohydric alcohols, esters, ethers,
Formula R-OC _n H _2n OH (in R represents an aliphatic hydrocarbon, n is an integer of 1, 2, 3, 4) one or compound of, selected from the group consisting of aprotic polar solvents A mixture of at least one solvent.

Examples of the aliphatic monohydric alcohol having 3 to 18 carbon atoms include propanol, butanol, pentanol, t-butanol, hexyl alcohol, octyl alcohol, lauryl alcohol, oleyl alcohol, Guerbet alcohol and the oxo method. Examples include various alcohols obtained naturally and synthetically, such as the alcohols mentioned above.

Examples of the ester having 3 to 18 carbon atoms are propyl acetate, butyl acetate, pentyl acetate, hexyl acetate, ethyl propionate, propyl propionate, butyl propionate, pentyl propionate, hexyl propionate, methyl butyrate, ethyl butyrate, Examples include propyl butyrate, butyl butyrate, pentyl butyrate, and hexyl butyrate.

As the ether having 3 to 18 carbon atoms, dimethyl ether, diethyl ether, dipropyl ether,
Examples include dibutyl ether, dipentyl ether, methyl ethyl ether, methyl propyl ether, methyl pentyl ether, ethyl propyl ether, ethyl butyl ether, ethyl pentyl ether, propyl butyl ether, propyl pentyl ether, butyl pentyl ether, glycerin methyl ether.

The general formula R--OC _n H _2n OH (R is 1 carbon atom
To 6 are represented by aliphatic hydrocarbons, and n is an integer of 1,2,3,4), and hydroxydimethyl ether, hydroxymethyl ethyl ether, hydroxymethyl propyl ether, hydroxymethyl isopropyl ether, hydroxymethyl Butyl ether,
Hydroxymethyl pentyl ether, methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, pentyl cellosolve, 3-hydroxypropyl methyl ether, 3-hydroxypropyl ethyl ether, 3-hydroxydipropyl ether, 3-hydroxypropyl isopropyl ether, 3-hydroxy There are propyl pentyl ether, 4-hydroxybutyl methyl ether, 4-hydroxybutyl ethyl ether and the like.

As the aprotic polar solvent, sulfolane, propylene carbonate and the like are preferred because they have no toxicity.

The amount of the above compound or a mixture thereof is preferably 0.001 to 30 parts by weight. This is because if it is outside this range, the effect is not obtained.

As the surface active agent of the component (C), any of anionic active agents, cationic active agents, zwitterionic active agents and the like can be used, but it is nonionic in that it has little effect on the cleaning surface. The system surfactant is the best. For example, polyoxyalalkylene alkyl ether, polyoxyalkylene alkylphenol ether, polyoxyalkylene alkyl fatty acid ester, polyoxyalkylene allylphenol ether, polyoxyalkylene sorbitan fatty acid ether, polyoxyl alkylene alkyl amine, sorbitan acid fatty acid ester, polyoxyalkylene, etc. Is preferred, and the average HLB is 4
The nonionic surfactant of No. 15 to 15 exhibits particularly excellent effects. Here, the polyoxyalkylene is preferably a polymer or copolymer of ethylene oxide, propylene oxide or butylene oxide. The amount of the surfactant is preferably 0.001 to 20 parts by weight. This is because if the content is larger than this, it may remain on the surface of the object to be cleaned and affect the product, and if it is less than this, the effect is not exerted.

Further, if a polyhydric alcohol such as ethylene glycol, propylene glycol, triethylene glycol, glycerin, etc., water and a mixture thereof are contained, the detergency will be further enhanced. The amount is 0.001
˜0.5 parts by weight is desirable. If the content is less than 0.001 parts by weight, the effect of adding them is small, and if it exceeds 0.5 parts by weight, phase separation occurs. When water is added, when it is originally contained in each of the above components, for example, when a component saturated with water is used, the degree thereof is sufficient. If added, it is preferably 0.5% or less in the whole composition in order to prevent rusting of the metal part.

The cleaning composition of the present invention may further contain various organic acids such as alcohols, citric acid, tartaric acid, phthalic acid, etc., preservatives, if necessary, as long as the effects thereof are not impaired.
You may mix | blend a rust preventive agent, a defoaming agent, antioxidant, a cleaning enzyme, etc.

The cleaning composition of the present invention has a particularly excellent effect in cleaning the soldering flux that remains after soldering the printed circuit board. It can be used effectively.

Further, when the composition of the present invention is used for cleaning, it can be cleaned by a conventionally known method. For example, first, ultrasonic cleaning is carried out with an ultrasonic cleaning layer containing the cleaning composition of the present invention, and then the present invention. It can be effectively carried out by continuously carrying out a method such as immersion cleaning in a liquid bath filled with the cleaning composition of above, and finally shower cleaning or steam cleaning with the cleaning composition of the present invention. In addition, after washing, you may post-wash with the component (A) which is one of the components of the cleaning composition of the present invention. Further, even if it is necessary to wash with a chlorofluorocarbon-based solvent, the detergent of the present invention can be used in a much smaller amount than the conventional one when used in combination.

[0026]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples without departing from the gist of the invention.

Production Example of Solvent 1 Boiling range obtained by distillation of crude oil 150 to 300 ° C.
Kerosene fraction (60% by weight of paraffins, 20 naphthenes)
% By weight, aromatic 20% by weight) at 280 ° C., 90 Kg / c
Under the condition of m ² , using a Ni-W catalyst for nuclear hydrogenation of aromatic hydrocarbons as a catalyst, nuclear hydrogenation was carried out, and the obtained product was subjected to the Molex method to obtain a 5 angstrom pore composed of synthetic zeolite. The n-paraffins were separated by feeding to a separation column packed with a molecular sieve having Obtained n
-The boiling point of 177 to 20 is obtained by precision distillation of the residual oil fraction depleted in paraffins by using the precision distillation equipment of two columns.
A hydrocarbon fraction at 0 ° C. was obtained. The composition and properties of this solvent are shown in Table 1.

[0028]

[Table 1]

Production Example of Solvent 2 The residual oil fraction depleted in n-paraffins obtained in the process of the production example of Solvent 1 was treated with a nickel-based catalyst at 200 ° C. and 50 kg / cm ^2. The product obtained after the second stage hydrogenation treatment was subjected to precision distillation using the precision distillation apparatus of the second column to obtain a hydrocarbon fraction having a boiling point of 177 to 200 ° C. The composition and properties of this solvent are shown in Table 1.

Production Example of Solvent 3 Boiling range obtained by distillation of crude oil 150 to 300 ° C.
Kerosene fraction (60% by weight of paraffins, 20 naphthenes)
% By weight, aromatic 20% by weight) at 280 ° C., 90 Kg / c
Under the condition of m ² , using a Ni-W catalyst for nuclear hydrogenation of aromatic hydrocarbons as a catalyst, nuclear hydrogenation was carried out, and the obtained product was subjected to the Molex method to obtain a 5 angstrom pore composed of synthetic zeolite. The n-paraffins were separated by feeding to a separation column packed with a molecular sieve having Obtained n
-The residual oil fraction depleted in paraffins is then subjected to precision distillation using a two-column precision distillation apparatus to obtain a boiling point of 210 to 24.
A hydrocarbon fraction at 0 ° C. was obtained. The composition and properties of this solvent are shown in Table 1.

Examples 1 to 10 and Comparative Examples 1 to 3 cleaning agents were prepared according to the formulations shown in Table 2. In the experiment, the rosin flux was uniformly applied to the comb-shaped electrode type 2 of the glass cloth base material epoxy resin copper clad laminate and soldered (250 ° C, 5 seconds).
What was done was used as a test piece. The cleaning was performed using a 28 kHz ultrasonic wave under the conditions of a liquid temperature of 37 ° C. and 5 minutes. Then, the test piece was placed in a constant temperature and humidity chamber (humidity 95%, temperature 37 ° C.), and after 100 hours, insulation resistance was measured after 1 minute at 100 V DC. The ionic residue was measured separately, and the discoloration and corrosion of the substrate were visually confirmed.

[0032]

[Table 2]

[0033]

By using the cleaning agent of the present invention, the rosin-based flux on the printed circuit board can be effectively removed.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C11D 7:26) 7:24

Claims (2)

[Claims] 1. A cleaning composition for a printed circuit board, comprising the following components (A), (B) and (C). (A) A kerosene fraction mainly composed of components having a boiling point of 150 to 300 ° C. is pressured by a metal catalyst for nuclear hydrogenation of aromatic nuclei to a pressure of 10 to 100 Kg / cm ² , and a temperature of 100 to 300 ° C.
Under the conditions described above, the residual hydrogen obtained by nuclear hydrogenation and then separating and removing at least a part of the n-paraffins in the kerosene fraction using a molecular sieve made of synthetic zeolite is separated by a precision distillation apparatus. 100 parts by weight of a hydrocarbon fraction having a boiling point of 150 to 240 ° C., which does not substantially contain naphthalene and biphenyl as a main component, and (B) an aliphatic monovalent compound having 3 to 18 carbon atoms. alcohols, ethers, esters, formula _{R-OC n H 2n OH (} R represents an aliphatic hydrocarbon having 1 to 6 carbon atoms, n represents 1, 2, 3, 4
0.001) or one or more solvents selected from the group consisting of aprotic polar solvents 0.001
˜30 parts by weight, (C) 0.001 to 20 parts by weight of surfactant. 2. A total of 0.001 to 0.5 parts by weight of a mixture of one or two or more selected from the group consisting of ethylene glycol, propylene glycol, triethylene glycol, glycerin and water. Cleaning composition