JPS63121848A - Composition for peeling electrodeposited coating film - Google Patents

Abstract

PURPOSE:To enable an electrodeposited coating film to be peeled in a short time by using a peeling composition consisting of a kind of amine selected from tertiary amines, and mono-, di-, and trialkanol-amines, and an aqueous alkaline solution, and specifying the ratio of said amine to said solution. CONSTITUTION:The composition to be used for peeling the electrodeposited coating film contains a kind of amine selected from tertiary amines, preferably, the compound represented by formula (1), and mono-, di-, and trialkanol-amines, represented by formulae (2), (3), and (4), respectively, and the 1-10wt.% aqueous alkaline solution in an amine to solution weight ratio of 1/4-1/20. In these formulae, each of R1-R3 is CnH2n+1 (n=2-5); each of R4-R6 is CnH2n+1 (n=0-4), phenyl, or cyclohexyl; and m is 2, 3, or 4, thus permitting the electrodeposited coating film enhanced in surface hardness and adhesion to copper by heat treatment at high temperature or for lengthened time, or increase of an amount of a hardening component to be easily peeled in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a composition for removing an electrodeposition paint film, and more specifically, a composition for removing an electrodeposition paint film, and more specifically, a resist for through holes and pattern formation formed by electrodeposition coating (electrodeposition paint film removal composition). The present invention relates to a composition used for peeling off a film.

[Conventional technology]

As a method for manufacturing through-hole printed wiring boards, the following method has been proposed in which through-holes and pattern-forming resists are formed by electrodeposition coating.

As shown in Figure 1 (1), there are through holes 2 in designated locations.
After forming a plated copper layer 3 by performing through-hole plating on the substrate 1 having copper foil layers 1a on both sides, as shown in FIG. Resist coating layer 4 with a pattern opposite to the circuit pattern to be obtained
Then, as shown in FIG. 1(3), an electrodeposition paint film 5 is formed on the exposed portion of the plated copper layer 3 by electrodeposition.
, and then, as shown in FIG. 1(4), the resist coating layer 4 is peeled off, and then, as shown in FIG. 1(5), the resist coating layer 4 exposed by the removal is removed. The plated copper layer and the copper foil layer that are unnecessary for the circuit are removed by processing and notching, and then the electrodeposited paint film 5 is peeled off with a release agent to form a structure as shown in FIG. 1 (6). Obtain a through-hole printed wiring board.

As a stripping agent used for removing the above-mentioned electrodeposition paint film, for example, the following are known as a stripping agent for anionic electrodeposition paint film.

(1) Petroleum-based thinner or hydrocarbon-based solvent.

+21 2.5% by weight or more of sodium hydroxide aqueous solution.

(3) A mixture containing 1 to 30% by weight, particularly 5 to 25% by weight of the following organic solvents in the above sodium hydroxide aqueous solution.

■ Aprotic organic polar solvent Amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone;
and sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide.

■Glycols Ethylene glycol monomers and polymers such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; and ethylene glycol monoethyl ether, -
Ethylene glycol compounds such as ethylene glycol-monoalkyl ethers such as monomethyl ethers, mono- and dialkyl ethers of polyethylene glycol.

■ Monohydric water-soluble alcohols such as methanol, ethanol, and isopropyl alcohol; and polyhydric alcohol compounds such as pentaerythritol and glycerin.

In addition, the surface hardness of the electrodeposited paint film is increased to prevent the risk of damage to the electrodeposition paint film and damage to the circuit pattern due to dirt adhering to the rolls or the residual smell of the etching solution during board transportation. It is necessary to In addition, in order to prevent the possibility that the electrodeposition paint film will be peeled off together with the resist coating layer when the resist coating layer of the reverse pattern is removed using a brush or a high-concentration alkaline aqueous solution at high temperature, the electrodeposition paint film It is necessary to improve the adhesion with copper.

[Problem that the invention seeks to solve]

In order to improve the surface hardness of the electrodeposition paint film and its adhesion to copper, it is generally necessary to increase the temperature or lengthen the heat treatment time of the paint film after the electrodeposition coating, or to increase the heat treatment time of the electrodeposition paint film. The amount of the curing component can be increased, but the electrodeposited paint film, which has improved surface hardness and adhesion to copper, cannot be removed or takes a long time to remove with the conventional remover mentioned above. There is a problem that requires

Therefore, an object of the present invention is to provide a peeling method that can easily remove an electrodeposition paint film in a short period of time, which has improved surface hardness and adhesion to copper by heat treatment at high temperatures or for a long time or by increasing the amount of curing component. An object of the present invention is to provide a composition.

[Means for solving problems]

As a result of various studies to achieve the above object, the present inventors have found that when using a composition in which specific amines are added to an aqueous sodium hydroxide solution, the removal rate is 1/2 that of using a conventional stripping agent.
It has been found that the electrodeposition paint film can be easily peeled off in about 115 hours.

The present invention has been made based on the above findings, and includes at least one amine selected from the group consisting of tertiary amines, mono-, di-, and trialkanolamines, and 1 to 10
% by weight of an alkaline aqueous solution, and the weight ratio of the amines to the alkaline aqueous solution (amines/alkaline aqueous solution) is from 1/4' to 1/20. It is something to do.

Hereinafter, the composition for stripping an electrodeposition paint film of the present invention will be described in detail.

Among the amines that are constituent components of the composition of the present invention, preferred tertiary amines include compounds represented by the following formula (1), and preferred mono-, di-, and trialkanolamines include the following: Equation (2) 1 Equation (3) 9
Examples include compounds represented by formula (4).

R3 [However, R+, R2 and R3 are C, H2, respectively.

(n-2 to 5). ] [However, m represents 2 to 4, and R4 and R5 each
8211-1-1 (n = 0 to 4), represents a 7x nyl group or a hasycyclohexyl group. ] [However, m represents 2 to 4, R6 is C,, H211+1
(n-0 to 4) represents a phenyl group or a cyclohexyl group. ] The above-mentioned amines are particularly dialkanolamines represented by the above formula (3), in which R6 is c2Hs -C
Compounds that are 3R7, Ca Hq , phenyl group or cyclohexyl group are preferred.

Preferred alkaline aqueous solutions that are constituents of the composition of the present invention include sodium hydroxide aqueous solutions, potassium hydroxide aqueous solutions, and the like.

If the above-mentioned alkaline aqueous solution has an alkali concentration of less than 1% by weight, the stripping ability will be insufficient or the life of the stripping solution will be shortened, and if it exceeds 10% by weight,
Because discoloration occurs due to oxidation of the copper surface,
The concentration used is 1 to 10% by weight, preferably 3 to 8% by weight.

Furthermore, the weight ratio of the amines to the alkaline aqueous solution having the above concentration (amine ratio/alkaline aqueous solution) is 1/
It is 4 to 1/20, preferably 115 to 1/10. If the weight ratio is greater than 1/4, the compatibility with the alkaline aqueous solution will decrease and copper will dissolve, and if it is less than 1/20, the peeling ability will be insufficient.

The composition of the present invention comprising the above-mentioned amines and the above-mentioned alkaline aqueous solution may become suspended when heated to 50 to 80°C, and although it is effective even when used in this suspended state, in this case , can be made uniform by adding alcohols. Examples of such alcohols include ethylene glycol, diethylene glycol, and alkyl ethers thereof, and these alcohols can be added in about the same amount as the above-mentioned amines.

Peeling of the electrodeposition paint film using the composition of the present invention involves immersing the substrate on which the electrodeposition paint film is formed in the composition of the present invention.
Alternatively, the composition of the present invention may be sprayed onto the electrodeposited paint film in a manner similar to the conventional method of using a stripping agent.

〔Example〕

Examples of the present invention are listed below along with comparative examples.

Example 1 A stripping composition of the present invention was prepared by adding and mixing 20 parts by weight of N-n-butyliminodiethanol to 80 parts by weight of a 4% aqueous sodium hydroxide solution.

Using this stripping composition as a stripping agent for the electrodeposition paint film and the anionic electrodeposition paint prepared as described below, a through-hole printed wiring board was manufactured as described below, and a through-hole printed wiring board was manufactured as described below. The effect of the stripping composition was observed.

[Preparation of anionic electrodeposition paint]

Preparation of alkyd running solution 620 g of soybean oil fatty acid (acid value 155), rosin (acid value 1
70) 500g, tall oil fatty acid (acid value 170) 600
After reacting 140 g of linoleic acid, 140 g of linoleic acid, and 300 g of maleic anhydride at 200°C under a nitrogen atmosphere for 3 hours, the mixture was cooled to 100°C, and 150 ml of xylene was added to the reaction solution.

Add 1000 g of pentaerythritol and 900 g of trimellitic anhydride and heat to 150°C again until the acid value reaches 10.
When the temperature reached 0, the reaction was stopped and cooled. During this time, xylene was removed under reduced pressure. Then, after cooling to 70℃,
680 g of isopropyl alcohol and 500 g of triethylamine were added and dissolved to obtain a modified alkyd resin solution with a solid content of about 70% by weight.

Preparation of electrodeposition paint Add 120 g of the above modified algide resin solution to water-soluble melamine resin [■ Sanwa Chemical, Nikara Tsuku MX706
(solid content 70%)) After adding 140 g and mixing well, water was added and dispersed so that the nonvolatile content was 15%.

Next, triethylamine was added so that pt+ was 8.2 to obtain an anionic electrodeposition paint.

[Manufacture of through-hole printed wiring boards] 30
A substrate (glass epoxy double-sided copper foil-clad laminate) 1 having copper foil layers 1a on both sides in which through holes 2 with a hole diameter of 0 μm are formed is plated with copper, and through holes are formed as shown in FIG. 1 (1). 2 and the copper foil layer 1 on both sides of the substrate 1.
After forming the plated copper layer 3 on both sides of the substrate 1, an etching resist ink (manufactured by Sanei Kagaku ■, etching resist 5ER-420C) is screen printed on the plated copper layer 3 on both sides of the substrate 1. A resist coating layer 4 with a reverse pattern of the circuit pattern is formed so that the circuit pattern portion of the plated copper layer 3 is exposed and the circuit unnecessary portion of the plated copper layer 3 is covered with the resist as shown in FIG. 1(2). A substrate coated with coating layer 4 was obtained.

The thus obtained substrate on which the resist coating layer 4 of the reverse pattern was formed was immersed in the anionic electrodeposition paint prepared as described above, the exposed copper part of the substrate was used as an anode, and the Using a stainless steel plate immersed in the electrodeposition paint as a cathode, a DC current of 100 μm is applied for 1 minute to perform electrodeposition coating on the exposed copper portion of the substrate (the portion where the resist coating layer 4 is not formed). A coating film was formed. Next, the substrate was washed with water for 1 minute to wash away the adhering electrocoating paint that had not been electrocoated, and after draining, the coating film was cured by heat treatment at 150 ° C. for 20 minutes using a hot air dryer. , 1st
A substrate on which an electrodeposition paint film 5 was formed as shown in FIG. 3 was obtained. Next, after cooling this substrate, it was immersed in a 2% sodium hydroxide aqueous solution at 40° C. for 2 minutes to peel off the resist coating layer 4, and as shown in FIG. 1 (4), the plated copper was removed. A substrate was obtained in which the unnecessary portion of layer 3 was exposed. Next, this substrate was washed with water, drained, and etched by immersing it in a 40 Baume ferric chloride aqueous solution at 50° C. for 10 minutes, and as shown in FIG. 1 (5), the resist coating layer 4 was peeled off and removed. A substrate was obtained in which the exposed portion of the plated copper layer that did not require a circuit and the portion of the copper foil layer below that that did not require a circuit were dissolved and removed.

Thereafter, the above-mentioned etched substrate was washed with water, drained, and then immersed in the above-mentioned stripping composition of the present invention heated to 50°C to peel off the electrodeposited paint film 5, as shown in FIG. (6)
A through-hole printed wiring board as shown in Figure 1 was obtained. At this time, the time required to peel off the electrodeposited paint film 5 (required time for peeling) was 2 minutes.

Comparative Example 1 Through-hole printing was carried out under the same conditions as in Example 1, except that a release agent consisting of 80 parts by weight of a 4% aqueous sodium hydroxide solution and 20 parts by weight of diethylene glycol was used instead of the release composition of the present invention. Manufactured a wiring board. At this time, the time required to remove the electrodeposition paint film was 10 minutes or more, and a portion of the electrodeposition paint film remained on the wall of the through hole.

Comparative Example 2 Except that the heat treatment conditions for the coating film were 130°C and 10 minutes,
A through-hole printed wiring board was manufactured under the same conditions as in Comparative Example 1. At this time, the time required to peel off the electrodeposition paint film was 2 minutes, but the resulting through-hole printed wiring board was
Because the heat treatment of the coating film was insufficient, the surface hardness of the electrodeposition coating film and its adhesion to copper were insufficient, and as a result, damage to the circuit pattern was observed in some areas.

In the above Example 1, Comparative Example 1 and Comparative Example 2, the heat treatment conditions of the coating film, the composition of the release agent used, the time required for removal,
and peeling temperature are summarized in Table 1 below.

Table 1 Example 2 The stripping composition of the present invention used in Example 1 was used as a stripping agent for the electrodeposition paint film, and the anionic electrodeposition paint prepared as follows was used to remove the coating film. The heat treatment conditions were 130℃,
A through-hole printed wiring board was manufactured under the same conditions as in Example 1 except that the heating time was 25 minutes. At this time, the time required to peel off the electrodeposition paint film was 1.5 minutes.

[Preparation of anionic electrodeposition paint]

To 120 g of the modified alkyd resin solution obtained in Example 1, 21 g of water-soluble melamine resin [Cymel 254B (non-volatile content: 80%), manufactured by Mitsui Sui Anamitsu ■] was added and mixed well, and then the non-volatile content was adjusted to 15%. Add water to disperse. Next, triethylamine was added to adjust the pH to 8.2 to obtain an anionic electrodeposition paint.

Comparative Example 3 Through-hole printing was performed under the same conditions as in Example 2, except that a release agent consisting of 80 parts by weight of a 4% aqueous sodium hydroxide solution and 20 parts by weight of diethylene glycol was used instead of the release composition of the present invention. Manufactured a wiring board. At this time, the time required to peel off the electrodeposition paint film was 10 minutes.

Comparative Example 4 The amount of curing component made of water-soluble melamine resin was 7.3
A through-hole printed wiring board was manufactured under the same conditions as in Comparative Example 3, except that 5 g of electrodeposition paint was used. At this time, the time required to peel off the electrodeposited paint film was 2 minutes, but the resulting through-hole printed wiring board had a small amount of curing component in the electrodeposition paint, so the surface hardness of the electrodeposition paint film and the copper Adhesion was insufficient, and damage to the circuit pattern was observed in some areas.

Table 2 below shows the weight ratio of the melamine resin and alkyd resin of the electrodeposition paint used, the composition of the stripping agent used, the required stripping time, and the stripping temperature in the above Example 2, Comparative Example 3, and Comparative Example 4. are summarized in the following.

Table 2 Note] *1 Weight ratio of melamine resin and alkyd resin in electrodeposition paint (melamine resin/alkyd resin) Examples 3 to 6 The stripping composition of the present invention having the composition shown in Table 3 below was All except that they were used as removers for painted paint films
Through-hole printed wiring boards were manufactured under the same conditions as in Example 1. The time required to peel off the electrodeposition paint film at this time is shown in Table 3 below.

Table 3 Notes] *1 Tributylamine *2 Monoethanolamine *3 Triethanolamine *4 N-cyclohexyliminodiethanol *5 Diethylene glycol [Effects of the Invention] According to the composition for removing electrodeposition paint films of the present invention, high temperature Alternatively, an electrodeposition paint film whose surface hardness and adhesion to copper have been improved by long-term heat treatment or by increasing the amount of curing component can be easily peeled off in a short time.

[Brief explanation of the drawing]

FIG. 1 is a schematic view schematically showing a method for manufacturing a through-hole plated wiring board using the stripping composition of the present invention as a stripping agent for an electrodeposition paint film. 1... Board, 1a... Copper foil layer, 2... Through hole, 3
...Plated copper layer, 4.Resist coating layer, 5.Electrodeposition paint film

Claims (7)

[Claims] (1) consisting of at least one amine selected from the group consisting of tertiary amines and mono-, di-, and trialkanolamines, and an alkaline aqueous solution of 1 to 10% by weight;
The weight ratio of the amines and the alkaline aqueous solution (amines/alkaline aqueous solution) is 1/4 to 1/20;
A composition for removing electrodeposited paint films. (2) The composition for removing an electrodeposition paint film according to claim (1), wherein the tertiary amine is a compound represented by the following formula (1). Formula (1) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, R_1, R_2 and R_3 are each C_nH_2
_n_+_1 (n=2 to 5) is shown. ] (3) The composition for removing an electrodeposition paint film according to claim (1), wherein the monoalkanolamine is a compound represented by the following formula (2). Formula (2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, m represents 2 to 4, and R_4 and R_5 each represent C
_nH_2_n_+_1 (n=0 to 4) represents a phenyl group or a cyclohexyl group. ] (4) The composition for removing an electrodeposition paint film according to claim (1), wherein the dialkanolamine is a compound represented by the following formula (3). Formula (3) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, m indicates 2 to 4, and R_6 is C_nH_2_n
_+_1 (n=0-4) represents a phenyl group or a cyclohexyl group. ] (5) The composition for removing an electrodeposition paint film according to claim (1), wherein the trialkanolamine is a compound represented by the following formula (4). Formula (4) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, m indicates 2 to 4. ] (6) The composition for removing an electrodeposition paint film according to claim (1), which contains an alcohol. (7) The composition for removing an electrodeposition paint film according to claim (7), wherein the alcohol is ethylene glycol, diethylene glycol, or an alkyl ether thereof.