TWI583750B - Board coating agent - Google Patents

Description

Circuit board coating agent

The present invention relates to a wiring board coating agent, and more particularly to an end surface of a circuit board (hereinafter, referred to as a wiring board) applied to a metal wiring board, a copper clad laminate, or the like, and a circumferential edge portion including the end surface. Etc., it is possible to protect the circuit board coating agent of the coated portion of the wiring board from various chemicals used in circuit processing.

A circuit board (metal wiring board) based on a metal plate such as an aluminum plate is excellent in heat dissipation and mechanical strength, and can be equipped with a weight member and has a feature of increasing current capacity. When performing circuit processing such as etching treatment on such a metal wiring board, an acid and a base agent are used. In order to prevent the erosion of the end surface portion of the metal wiring board caused by these chemicals, in the past, the tape for preventing corrosion was adhered to the end surface portion of the metal wiring board by hand work, and after the etching treatment or the like, the metal wiring board was manually operated. Remove the tape for erosion prevention. This method is not only expensive as the above-mentioned tape for preventing erosion, but also labor cost because of manual work. Moreover, there is a problem of low work efficiency.

Further, in the circuit board for mounting electronic components, in addition to the above-mentioned metal wiring board, a printed wiring board (i.e., a glass epoxy wiring board) containing a glass epoxy member is widely used. Glass epoxy circuit boards are formed by impregnating epoxy resin on overlapping glass fiber cloth. Therefore, when the glass epoxy circuit board is cut, an epoxy tree is produced. Fine dust composed of grease or fiberglass. These fine dusts may cause problems such as poor contact and deterioration in quality of the circuit board circuit. Therefore, it is necessary to remove the dust generated when the circuit board is cut.

Patent Document 1 below discloses a technique for preventing the scattering of the cut powder from the end surface of the wiring board, coating the ultraviolet curable resin on the end surface of the wiring board, and curing the resin of the coating layer by ultraviolet irradiation.

Further, in the following Patent Document 2, it is disclosed that an ultraviolet curable resin is applied to an end surface of a wiring board based on a metal plate in order to prevent corrosion of a metal plate due to acid and alkali used in circuit processing. Ultraviolet irradiation cures the applied resin to improve the efficiency of the end seal (the curing time is shorter than that of the thermosetting type).

In addition, in order to cope with the reduction in size and miniaturization of electronic devices, the demand for thin copper-clad laminate circuit boards (also referred to as package circuit boards) having a thickness of several tens of μm to several hundreds of μm in recent years is increasing. With such a thin wiring board, it is not easy to apply a resin for protecting the end surface of the wiring board only on the end surface of the wiring board as described above, and it is considered to be applied to the circumferential edge portion of the wiring board including the end surface, for example, in a frame shape. form.

In the case where the wiring board itself is very thin, in order to prevent volume increase and bending when stacking the wiring board on which the frame-like coating film is formed, it is necessary to make the thickness of the coating film sufficiently thin. Further, in order to facilitate the use of the stacked wiring boards, the peeling property between the coating film and the coating film must be good. Further, even a thin coating film must have sufficient resistance to acid and alkali used in circuit processing. However, at the same time, it has been found that a thin and uniform coating film can be easily formed, and the peeling property between the coating film and the coating film after curing is good, and the circuit board coating agent having these characteristics excellent in chemical resistance is not yet developed.

Patent Document 1: JP-A-2005-197443

Patent Document 2: Japanese Patent Publication No. 5-125529

The present invention has been made in view of the above problems, and an object thereof is to provide a coating film which can be easily formed on a wiring board, and which has good peelability between a coating film and a coating film after curing, and which is excellent for acid and alkali. A circuit board coating agent with excellent resistance to chemicals.

In order to achieve the above object, the present inventors have conducted intensive research and found that a circuit board coating liquid containing a urethane resin, a styrene resin, and a tackifier has excellent resistance to acids and alkalis, and is unlikely to occur. The coating film defect such as cissing can easily form a thin uniform coating film on the wiring board, and the peeling property between the coating film and the coating film after curing is good, and the present invention has been completed.

That is, the wiring board coating agent (1) according to the present invention is characterized in that it contains a urethane resin, a styrene resin and a tackifier with respect to a solvent.

According to the coating agent (1) described above, it is excellent in chemical resistance to strong acidity and strong alkalinity, and coating film defects such as shrinkage are less likely to occur, and a thin uniform coating film can be easily formed on the wiring board, and after curing, The peeling property between the coating film and the coating film is good, and the wiring board and the wiring board are stuck together, and the usability of the circuit board after coating is good.

Therefore, by applying the wiring board coating agent to the end surface of the wiring board and the circumferential edge portion including the end surface, it is possible to prevent foreign matter (dust, etc.) from being generated from the end portion of the wiring board during subsequent circuit processing. The phenomenon can also increase the strength of the circuit board. In addition, it is possible to protect the end of the circuit board from the etching solution, the plating solution, etc. (to prevent erosion of the wiring board), and it is no longer necessary to use the glue for preventing erosion which has been used in the past. Belts, etc., can reduce processing costs. Further, the peeling property between the coating film and the coating film after curing is good, and even if the wiring board on which the coating film is formed is stacked on the wiring board, the wiring board and the wiring board are not stuck to each other in the coating film. Thereby, the usability of the wiring board can be made good.

Further, the present invention relates to a wiring board coating agent (2) characterized in that in the above-mentioned wiring board coating agent (1), the urethane resin contains a urethane having a polycarbonate structure. Resin.

According to the above-mentioned wiring board coating agent (2), since the urethane resin contains a urethane resin having a polycarbonate structure, the durability of the coating film can be improved, and it can be used as a strong acid and a strong base. A very excellent coating agent for sexual resistance.

Further, the wiring board coating agent (3) according to the present invention is characterized in that, in the wiring board coating agent (1) or (2), the urethane resin is contained in an amount of 5 to 35% by weight. The styrene resin is from 1 to 10% by weight, and the acrylate resin as the tackifier is from 0.1 to 3% by weight.

According to the above-mentioned circuit board coating agent (3), even from a substance having a relatively high viscosity to a substance having a low viscosity, the effect of the above-mentioned circuit board coating agent (1) can be exerted, and by containing acrylic acid as the above-mentioned tackifier The ester resin can increase the strength of the coating film.

Further, the present invention relates to a circuit board coating agent (4) characterized in that in any of the above-mentioned circuit board coating agents (1) to (3), the solvent is an aqueous medium, and the urethane resin The styrene resin and the tackifier are aqueous resins.

According to the above-mentioned circuit board coating agent (4), since the solvent is an aqueous medium (for example, water or a medium mainly composed of water), the urethane resin, the styrene resin, and the tackifier are water-based resins. (eg aqueous latex resin) Etc.), so it is easy to use and can be used as a coating agent excellent in safety and environment.

Further, the present invention relates to a circuit board coating agent (5) characterized in that in any of the above-mentioned circuit board coating agents (1) to (4), a moisturizing agent as an additive, a wetting accelerator, and At least any one of the antifoaming agents.

According to the above-mentioned wiring board coating agent (5), the performance of the wiring board coating agent can be further improved by the aforementioned additives. By containing the above-mentioned humectant, it is possible to improve the effect of preventing cracking of the coating film during drying of the coating film and after drying. In addition, by containing the wettability promoter, the wettability on the surface of the wiring board is improved, and shrinkage on the wiring board at the time of coating can be prevented, and the coating material having good coating properties can be used. Further, by containing the antifoaming agent, generation of bubbles on the surface of the coating film can be prevented, and the occurrence of the foaming of the coating film can be prevented, and the smoothness of the surface of the coating film can be improved.

Further, the wiring board coating agent (6) according to the present invention is characterized in that, in any of the above-mentioned wiring board coating agents (1) to (5), a coloring agent is further contained.

According to the circuit board coating agent (6), since the coloring agent is contained, it is possible to visually confirm whether the state of the coating on the wiring board is good or not.

Hereinafter, embodiments of the wiring board coating agent according to the present invention will be described, but the scope of the present invention is not limited to these embodiments. The circuit board coating agent according to the present invention contains a urethane resin, a styrene resin and a tackifier with respect to a solvent.

The invention relates to a urethane tree used in a circuit board coating agent A fat is a general term for a polymer having a plurality of urethane-binding groups in a main chain, and is usually produced by reacting a polyhydric alcohol with a compound having a plurality of isocyanate groups in the molecule. As the polyol, a polycarbonate polyol or a polyester polyol is used.

The polycarbonate polyol can be produced, for example, by reacting a carbonate compound with a glycol. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and divinyl carbonate. The diol may, for example, be ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol or 3-methyl-1,5-pentane. Aliphatic diols such as diol, 1,6-hexanediol, heptanediol, octanediol, decanediol, decanediol, dodecanediol, cyclohexanediol, hydrogenated benzenedimethanol, etc. An aromatic diol such as an alicyclic diol or xylylene glycol.

Further, the polyester polyol can be obtained by condensing a condensation of a low molecular weight diol with a dicarboxylic acid. Examples of the low molecular weight diol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and 1,4-butanediol. Among them, ethylene glycol, propylene glycol, and 1,4-butanediol are suitably used. As the dicarboxylic acid, an aliphatic dibasic acid such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid or sebacic acid, isophthalic acid or terephthalic acid can be used. An aromatic dibasic acid such as naphthalenedicarboxylic acid.

The molecular weight of the polycarbonate polyol or the polyester polyol is not particularly limited, but usually the number average molecular weight is from 700 to 4,000, more preferably from 1,000 to 2,500.

Examples of the polyisocyanate compound include aromatic, aliphatic, and alicyclic polyisocyanate compounds. Examples of the aromatic diisocyanate compound include toluene diisocyanate, 4,4-diphenylmethane diisocyanate, xylene diisocyanate, 1,5-naphthalene diisocyanate, toluidine diisocyanate, and phenylene diisocyanate. ,4-diphenyl diisocyanate, dianisidine diisocyanate, 4,4-diphenyl Ether diisocyanate, triphenylmethane triisocyanate, tris(isocyanate benzene) phosphorothioate, tetramethyl benzene diisocyanate, and the like. Examples of the aliphatic diisocyanate compound include trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated 4,4-diphenylmethane diisocyanate, and hydrogenated xylene Isocyanate, lysine diisocyanate, lysine triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-hexa Methyl triisocyanate, bicycloheptyl triisocyanate, and the like. Examples of the alicyclic diisocyanate include cyclohexyl diisocyanate and methylcyclohexyl diisocyanate. These can be used alone or in combination of multiple types.

The reactant of the polyol and the diisocyanate can be further increased in molecular weight by using a chain extender as needed. As the chain extender, a compound containing at least two functional groups containing an active hydrogen atom reactive with an isocyanate group can be used. For example, ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, Aliphatic diols such as 1,6-hexanediol, heptanediol, octanediol, decanediol, decanediol, dodecanediol, cyclohexanediol, alicyclic diol, aromatic A diamine such as a diol, ethylenediamine, propylenediamine, hexamethylenediamine, toluenediamine, benzenedimethyldiamine, diphenyldiamine or diaminodiphenylmethane.

The urethane resin having a polycarbonate structure in the wiring board coating agent according to the present invention may be an organic solvent as a solvent, and preferably water as a medium. In order to disperse or dissolve the urethane resin in water, there is a forced emulsification type using an emulsifier, and a self-emulsifying type or a water-soluble type in which a hydrophilic group is introduced into the urethane resin. In particular, a self-emulsification type in which an ionic group is introduced into a skeleton of a urethane resin due to the adhesion of a liquid storage stabilizer to the obtained coating film It is preferable because it is excellent. Further, examples of the ionic group to be introduced include various compounds such as a carboxyl group, a sulfonic acid, a phosphoric acid, a phosphonic acid, and a quaternary ammonium compound, and a carboxyl group is preferred.

As a method of introducing a carboxyl group into a urethane resin, various methods can be employed in each stage of the polymerization reaction. For example, in the case of synthesizing a prepolymer, a method of using a resin having a carboxyl group as a copolymerization component and a method of using a component having a carboxyl group as a component of a polyhydric phenol, a polyisocyanate, a chain extender, or the like are used.

As the urethane resin used in the present invention, a polycarbonate polyhydric phenol, a polyisocyanate, a chain length extender having a reactive hydrogen atom, and a group having at least one reaction with an isocyanate group and an anionic property are particularly preferable. A resin composed of a compound of a group.

The weight of the anionic group in the urethane resin is preferably from 0.1 to 8% by weight. This is because the weight of the anionic group is small, the water solubility of the urethane resin or the dispersibility in water is poor, and the weight of the anionic group is large, and moisture absorption makes it easy to stick to each other.

The content of the polycarbonate component in the urethane resin is usually from 10 to 90% by weight, preferably from 20 to 70% by weight. When the content is less than 10% by weight, the effect of improving the adhesion of the urethane resin is insufficient, and when it exceeds 90% by weight, the coatability may be deteriorated.

Further, the glass transition temperature (hereinafter referred to as Tg) of the urethane resin in the present invention is 10 ° C or lower, preferably -10 ° C or lower. When a resin having a Tg higher than 10 ° C is used, there is a case where the adhesion is insufficient.

In the present invention, a commercially available polyurethane resin may be used as the aminomethyl ester resin, and as the urethane resin latex, for example, "HYDRAN" (trade name) manufactured by DIC Corporation may be mentioned.

The tackifier used in the circuit board coating agent of the present invention may be an acrylate resin, a gelling agent (colloiding agent), a polymer solution or the like. These tackifiers are added to adjust the viscosity to suit the coating device and the coating method. Among these tackifiers, the acrylate resin is preferable because it can also increase the strength of the coating film.

The acrylate resin is a polymer containing acrylic acid, methacrylic acid, and derivatives thereof. Specifically, for example, acrylic acid, methacrylic acid, methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylamide, acrylonitrile, hydroxy acrylate, etc. Polymers copolymerized with monomers (e.g., styrene, divinylbenzene, etc.) to which they can be copolymerized.

As the acrylate resin, a water-dispersible acrylate resin obtained by emulsion polymerization of an acrylate monomer is preferably used. The acrylate monomer as the water-dispersed acrylate resin raw material is preferably methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, 2-ethyl acrylate. Hexyl ester, lauryl acrylate, isobornyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, methacrylic acid cyclohexane Ethyl (meth) acrylate monomer such as ester, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate or isobornyl methacrylate, acrylic acid, methacrylic acid, etc. A carboxy monomer containing a carboxyl group, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, methacrylic acid-4 -hydroxybutyl ester, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, polytetramethylene glycol monoacrylate, polytetra Methylene glycol monomethyl a hydroxyl group-containing propylene monomer such as acrylate, N,N-Dimethylamino acrylate, N,N-diethylamino acrylate, N,N-dimethylaminoethyl methacrylate, N,N-diethylamino Tertiary amino group-containing propylene monomer such as ethyl methacrylate, 4-(methacryloxy)-2,2,6,6-tetramethylpiperidine, 4-(methacryloxyloxy) a propylene monomer containing a hindered amine group such as -1,2,2,6,6-pentamethylpiperidine, acrylamide, N,N-dimethyl decylamine, N-isopropyl propylene oxime Amine, methylol decylamine, hydroxyethyl acrylamide, N,N-dimethylaminopropyl acrylamide, 2-propenyl guanidino-2-methyl-propane sulfonic acid, diacetone acrylamide醯 containing N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-butoxy methacrylamide, 4-methyl acrylamide ethyl acetonitrile Amino-based acrylonitrile-based monomer, urea-based acryl-based monomer such as 2-methylpropenyloxyethyl-ethylene urea, glycidyl acrylate, methyl glycidyl acrylate, methacrylic acid shrinkage An epoxy group-containing monomer such as glycerin ester, methyl glycidyl methacrylate or vinylbenzyl glycidyl ether. The water-dispersible acrylate-based resin may be composed of these acryl-based monomers alone or in combination of two or more kinds.

It is preferred to use a water-dispersible acrylate-based resin obtained by emulsion polymerization of the above monomers. The number average molecular weight of a suitable water-dispersible acrylate-based resin is, for example, 5,000 to 200,000.

Specific examples of the acrylate-based resin used in the present invention include carboxyl group-containing ethylenically unsaturated monomers such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid, and (meth)acrylic acid. A copolymer of another ethylenically unsaturated monomer such as an ester, ethyl (meth)acrylate or styrene is used as a tackifier for polycarboxylic acids.

The properties of the acrylate resin used in the present invention are not particularly limited, and examples thereof include an emulsion, an aqueous solution and the like. The acrylate resin in the present invention is used The viscosity of the coating liquid is increased to the desired viscosity to improve the workability of the coating, and is adjusted to an easy-to-use viscosity according to the resin, the type of the additive, the concentration, and the like contained in the coating agent.

In the present invention, a commercially available acrylate-based resin can be used as the acrylate-based resin. For example, "VONCOAT" (trade name) manufactured by DIC Corporation can be used as the water-dispersible acrylate-based resin.

Further, the styrene resin used in the wiring board coating agent of the present invention may be exemplified by a styrene alone polymer or a unit containing α-methylstyrene, vinyltoluene or divinylbenzene. a copolymer of styrene or a copolymer of other monomers copolymerizable with styrene and styrene.

Examples of the monomer copolymerizable with styrene include vinyl esters having 2 to 18 carbon atoms such as vinyl acetate and vinyl n-hexanoate, and unsaturated monomers such as acrylic acid, methacrylic acid, maleic acid, and fumaric acid. An unsaturated carboxylic acid ester such as a carboxylic acid, a monomethyl maleate or a dimethyl fumarate, a paraffin such as ethylene or 1-pentene, allyl glycidyl ether or methallyl glycidol An epoxy group-containing unsaturated compound such as ether, a vinyl ether such as isobutyl vinyl ether or octyl vinyl ether, acrylonitrile or vinylidene chloride.

In the present invention, an acrylic styrene resin is preferably used. The acrylic styrene resin is a resin obtained by polymerizing a styrene monomer and an acrylate monomer. As the styrene monomer, styrene, α-methylstyrene or the like can be used. As the acrylate monomer, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, Butyl methacrylate, 2-ethylhexyl methacrylate, and the like. As a suitable acrylic styrene resin, styrene-methyl methacrylate can be exemplified Copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate-butyl acrylate copolymer, styrene-butyl methacrylate, and the like.

In the present invention, a commercially available styrene resin can be used as the styrene resin, for example, as an aqueous acrylic styrene resin, and VONCOAT manufactured by DIC Corporation can be used.

Other additives to be blended in the circuit board coating agent according to the present invention include a humectant, a wetting accelerator, an antifoaming agent, a preservative, and a coloring agent.

Examples of the humectant include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight: 100 to 2000), propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, and the like. Propylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, mesobutanol, pentaerythritol, and the like.

In the present invention, in order to control the amount of addition thereof, polyethylene glycol is preferably used. For example, polyethylene glycol 200 manufactured by Showa Chemical Co., Ltd. or the like can be used.

As the wetting promoter, it can be used from ethylene glycol, polyethylene glycol alkyl ether (alkyl group has 2 to 3 carbon atoms), polyethylene glycol (molecular weight 100 to 800), alkylsulfonic acid (alkyl group) The number of carbon atoms is 2 to 3), an acrylic polymer, a fatty alcohol (having 1 to 3 carbon atoms), an anionic surfactant, a fluorine-based surfactant, or the like. The propylene-based copolymer contains an alkyl (meth) acrylate monomer having an ether group and an alkyl (meth) acrylate monomer copolymer, and preferably the copolymer has a weight average molecular weight of from 3,000 to 200,000, more preferably 5,000. To 50,000. Further, the weight average molecular weight can be determined, for example, by conversion of polystyrene by gel permeation chromatography.

As the preservative (mold inhibitor), an organic preservative and a silver ion-containing preparation can be used. As the organic preservative, an organic nitrogen sulfur compound, an organic aromatic compound, an organic nitrogen compound or the like can be used.

As the colorant, an inorganic pigment, an organic pigment, an aqueous pigment (organic), an oily pigment (organic), an extender pigment, or the like can be used. Specifically, mica, iron oxide, titanium dioxide, CI Pigment Black 7 (CIPigment Black 7), CI Pigment Red 122, CIPigment Orange 16, CI Pigment Green can be cited. 7 (CIPigment Green 7), CI Pigment Violet 23, Basic Green 4, Basic Violet 1 , Basic Orenge 2, Direct Blue 87, Acid Blue 90, CI Pigment Yellow 23, CI Pigment Yellow 3, and the like.

The solvent of the circuit board coating agent according to the present invention may, for example, be water or an organic solvent. Water is preferably used as the solvent in view of safety and environmental factors.

Further, examples of the water-soluble organic solvent include alkyl alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-n-butanol, and t-butanol, and a diol, a propylene glycol, a butanediol, a diethylene glycol, a triethylene glycol or the like, an alkylene glycol having an alkylene group having 2 to 6 carbon atoms, a polyhydric alcohol such as glycerin, or the like Alkylene glycols, guanamines, esters, and the like.

Hereinafter, a method of preparing a wiring board coating agent according to an embodiment will be described. A certain amount of urethane resin, styrene resin, and a solvent (for example, water, etc.) are added to a predetermined container and mixed in a mixer. The mixture is mixed at a low speed (1 to 100 rpm) while adding a certain amount of a humectant, a wetting accelerator, and a preservative. A quantity of color former is then added followed by a quantity of tackifier such as an acrylate resin. Then, the stirring speed of the mixer was increased, and high-speed stirring (200 to 500 rpm) was performed for about 1 hour. After high-speed stirring, a certain amount of antifoaming agent was added, and the stirring speed of the agitator was set to a low speed (1 to 100 rpm) for about 30 minutes to prepare a circuit board coating agent.

Further, the preferred viscosity of the coating agent for the wiring board according to the embodiment is 50 to 120 Pa‧S, and is preferably 0.01 to 1.0 Pa‧S from the viewpoint of making the film thickness thin.

When the viscosity of the circuit board coating agent is lowered, the solvent (water) and the above-mentioned wetting accelerator are appropriately increased, and the content of the urethane resin and the styrene resin is reduced according to the set viscosity, and the micro-adhesion is added by adding The agent (such as an acrylate resin) can prepare a circuit board coating agent having a desired effect even at a low concentration.

[Examples]

Hereinafter, the present invention will be described in detail by way of examples, but the invention is not limited thereto.

(Example 1)

A urethane resin (HYDRAN WLS-213 manufactured by DIC Corporation, average particle diameter: 120 nm, elongation 400%, Tg: -30 ° C, urethane resin concentration: about 35%, was added to the container). Water: about 65%, containing a skeleton derived from polycarbonate) 84.5 parts by weight, styrene resin (VONCOAT SK-105-E, manufactured by DIC Corporation, solid content (propylene resin concentration: about 55%, water: about 45%) 10.0 parts by weight, mixed in a blender.

While mixing at a low speed (0 to 100 rpm), 0.5 part by weight of a humectant (polyethylene glycol 200 manufactured by Showa Chemical Co., Ltd.), 0.5 part by weight of a wettability accelerator, and 0.2 part by weight of a preservative were added. Next, 2.0 parts by weight of a coloring agent was added, and then 1.5 parts by weight of an acrylate resin (VONCOAT 3750-E, acrylate resin, acrylate resin concentration: about 25%, water: about 75%) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour. Further, the aforementioned wettability enhancer and preservative can be appropriately selected from the above-mentioned reagents.

After high-speed stirring, an antifoaming agent (manufactured by Kyoeisha Chemical Co., Ltd.) was added. AQUALEN SB-630) 0.5 parts by weight, the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare a wiring board coating agent according to Example 1.

(Example 2)

In a container, 93.0 parts by weight of urethane resin (HYDRAN WLS-213, manufactured by DIC Corporation) and 6.0 parts by weight of styrene resin (VONCOAT SK-105-E, manufactured by DIC Corporation) were added to the vessel, and the mixture was mixed in a stirrer.

While mixing at a low speed (1 to 100 rpm), 0.5 part by weight of a humectant (polyethylene glycol 200 manufactured by Showa Chemical Co., Ltd.), 0.5 part by weight of a wettability accelerator, and 0.2 part by weight of a preservative were added. Next, 2.0 parts by weight of a coloring agent was added, and then 1.0 part by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After stirring at a high speed, 0.5 parts by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare an example. 2 involved in the circuit board coating agent.

(Example 3)

41.0 parts by weight of a solvent (water) was added to the container, and then 45.0 parts by weight of urethane resin (HYDRAN WLS-213, manufactured by DIC Corporation) was added, and styrene resin (VONCOAT SK-105-E manufactured by DIC Corporation) was added. ) 5.0 parts by weight, mixed in a blender.

While mixing at a low speed (1 to 100 rpm), 0.5 part by weight of a humectant (polyethylene glycol 200 manufactured by Showa Chemical Co., Ltd.), a wettability promoter 4.0 weight Parts, 0.2 parts by weight of preservative. Next, 2.0 parts by weight of a coloring agent was added, and then 2.0 parts by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After stirring at a high speed, 0.5 parts by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to obtain an example. 3 involved in the circuit board coating agent.

(Example 4)

57.0 parts by weight of water as a solvent was added to the container, and then 30.0 parts by weight of urethane resin (HYDRAN WLS-213, manufactured by DIC Corporation) was added, and 4.0 parts by weight of styrene resin (VONCOAT SK-made by DIC Corporation) was added. 105-E), mixed in a blender.

While mixing at a low speed (1 to 100 rpm), 0.5 part by weight of a humectant (polyethylene glycol 200 manufactured by Showa Chemical Co., Ltd.), 4.0 parts by weight of a wettability promoter, and 0.2 part by weight of a preservative were added. Next, 2.0 parts by weight of a coloring agent was added, and then 1.0 part by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After high-speed stirring, 0.5 part by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the agitator was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to obtain an example. 4 involved in the circuit board coating agent.

(Comparative Example 1)

96.6 parts by weight of a urethane resin (HYDRAN WLS-213, manufactured by DIC Corporation) was added to the vessel, and the mixture was mixed in a mixer. While mixing at a low speed (1 to 100 rpm), 0.1 part by weight of a preservative and 0.1 part by weight of a decane coupling agent were added. Next, 2.0 parts by weight of a coloring agent was added, and then 0.8 parts by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After stirring at a high speed, 0.5 part by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare a comparative example. 1 involved in the circuit board coating agent.

(Comparative Example 2)

87.4 parts by weight of a urethane resin (HYDRAN WLS-213, manufactured by DIC Corporation) and 10.0 parts by weight of a hot melt adhesive were placed in a container and mixed in a blender. 0.1 part by weight of a preservative was added while mixing at a low speed (1 to 100 rpm). Next, 2.0 parts by weight of a coloring agent was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After the high-speed stirring, 0.5 parts by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare a comparative example. 2 involved in the circuit board coating agent.

(Comparative Example 3)

An acrylate resin (JONCRYL PDX-7100, manufactured by BASF Japan Co., Ltd., acryl resin concentration: about 30%, water: about 70%), 93.4 parts by weight, was added to the container, and the mixture was mixed in a blender. Mix at low speed (1 to 100 rpm), 0.1 part by weight of a preservative and 0.1 part by weight of a decane coupling agent were added. Next, 2.0 parts by weight of a coloring agent was added, and then 4.0 parts by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After stirring at a high speed, 0.5 part by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare a comparative example. 3 involved in the circuit board coating agent.

(Comparative Example 4)

54.0 parts by weight of a urethane resin (HYDRAN WLS-213, manufactured by DIC Corporation), and 40.0 parts by weight of a thermosetting resin (Dicfine EN-0274, manufactured by DIC Corporation, solid portion (epoxy resin concentration: about) was added to the container. 25%, water: about 75%) mixed in a blender.

While mixing at a low speed (0 to 100 rpm), 0.2 part by weight of a preservative and 1.5 parts by weight of a pH adjuster were added. Next, 2.0 parts by weight of a coloring agent was added, and then 1.8 parts by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After the high-speed stirring, 0.5 parts by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare a comparative example. 4 involved in the circuit board coating agent.

(Comparative Example 5)

Add vinyl acetate resin to the container (made by Chem Chemex) Sumikaflex 520HQ, vinyl acetate concentration: about 45%, water: about 55%) 96.3 parts by weight, mixed in a blender. 0.2 parts by weight of a preservative was added while mixing at a low speed (0 to 100 rpm). Next, 2.0 parts by weight of a coloring agent was added, and then 1.0 part by weight of an acrylate resin (VONCOAT 3750-E, manufactured by DIC Corporation) was added. Then, the stirring speed of the stirrer (200 to 500 rpm) was increased, and high-speed stirring was carried out for about 1 hour.

After the high-speed stirring, 0.5 parts by weight of an antifoaming agent (AQUALEN SB-630 manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the stirring speed of the stirrer was set to a low speed (0 to 100 rpm), and stirring was carried out for about 30 minutes to prepare a comparative example. 5 circuit board coating agent involved.

(acid resistance, alkali resistance test)

In order to confirm the acid resistance and alkali resistance of the circuit board coating agent, an etching process test and a plating process test were performed.

Etching process test The circuit board coating agents (thickness of about 30 to 50 μm) of the above-mentioned Examples 1 to 4 and Comparative Examples 1 to 5 were applied to the end faces of a metal wiring board (aluminum wiring board having a thickness of about 2 mm). The metal wiring board which cured the coating film was etched in the following order (1) to (4), and the state of the coating film portion before and after the etching treatment was confirmed by a microscope.

(1) 3% sodium carbonate solution: 50 ° C, 0.5 minute treatment

(2) Copper chloride solution: 50 ° C, treatment for 15 minutes

(3) sodium hydroxide solution: 50 ° C, 1 minute treatment

(4) Washing

The results are shown in Table 1. Three-stage evaluation was carried out: the coating film was not peeled off to ○, the coating film was partially peeled off to Δ, and when the coating film was almost completely peeled off, it was ×.

Plating process test, in copper-clad laminate (thickness about 100μm, vertical The circuit board coating agents according to the above Examples 1 to 4 and Comparative Examples 1 to 5 were applied in a frame shape (the frame width was about 3 mm) on a circumferential edge portion including the end faces of about 5 cm x 7 cm) (the film thickness was about 30). The copper-clad laminate obtained by curing the coating film was subjected to a plating treatment in the order of (1) to (7) below, and the state of the coating film portion before and after the plating treatment was confirmed by a microscope.

(1) Degreasing liquid (ACL-007: manufactured by Uemura Industrial Co., Ltd.): 50 ° C, 5 minutes of treatment

(2) Acid treatment (sulfuric acid): room temperature, 1 point treatment

(3) Soft etching solution (100 g/L sodium persulfate, 10 ml/L sulfuric acid): 1 minute at room temperature

(4) Pre-dip solution (sulfuric acid 18mL/L): room temperature, 1 minute

(5) Activator solution (KAT-450: manufactured by Uemura Industrial Co., Ltd., 100 ml/L, sulfuric acid 18 ml/L): 30 ° C, 3 points for treatment

(6) Electroless nickel plating (Nimuden NPR-4): 80 ° C, pH 4.6, treatment for 50 minutes

(7) Electroless gold plating (Gobulite TSB-72): treatment at 80 ° C for 5 minutes to form a nickel coating (7 μm or more) and a gold coating (0.4 μm or more), and confirming the portion of the coating film before and after plating with a microscope status.

The results are shown in Table 1. The evaluation was carried out in three stages: the peeling without the coating film was ○, the peeling of the coating film was Δ, and the coating film was almost X when it was peeled off.

In addition, the evaluation of the wettability at the time of coating the copper-clad laminate was carried out by visually observing the coating state of the wiring board coating agent according to Examples 1 to 4 and Comparative Examples 1 to 5 with respect to the wiring board. .

The results are shown in Table 1. Three-stage evaluation was carried out: when the coating was applied without shrinkage on the end faces and the circumferential edge portions of the copper-clad laminate, ○ occurred, and a slight shrinkage occurred as Δ, and a large amount of shrinkage occurred as ×.

Further, regarding the application of the wiring board coating agents according to Examples 1 to 4 and Comparative Examples 1 to 5 to the copper clad laminate, the presence or absence of peeling of the coating film was observed by the rubbing coating film surface.

The results are shown in Table 1. The evaluation was carried out in three stages: ○ when there was no peeling of the coating film, Δ when a small amount of peeling occurred, and × when a lot of peeling occurred.

Further, the peeling property between the coating film after curing and the coating film is a wiring board according to Examples 1 to 4 and Comparative Examples 1 to 5 in which a frame shape is applied to the circumferential edge portion of the copper-clad laminate. The circuit board after the curing of the coating agent is stacked, so that the coating film portion is in close contact, and the peeling property (adhesive condition) is observed.

The results are shown in Table 1. Three-stage evaluation was carried out: the case where there was no adhesion between the coating film and the coating film was ○, and the case where the coating film and the coating film were slightly adhered but peeled off was Δ, and the coating film and the coating film were adhered and could not be simply The case of peeling is ×.

1) and 2) are not used because of poor stability over time.

As is apparent from the above Table 1, the lines involved in Examples 1 to 4 The road plate coating agent is excellent in etching resistance and plating resistance, and is excellent in resistance to strong acidity and alkalinity. In particular, the results of Example 1 were good. Therefore, it is possible to protect the coated portion of the wiring board from the etching solution, the plating solution, or the like (preventing the erosion of the wiring board), and it is not necessary to use the conventionally used tape for preventing erosion, and the processing cost can be reduced.

Further, in the wiring board coating agents according to Examples 1 to 4, coating film defects such as shrinkage are less likely to occur, and a thin uniform coating film can be easily formed on the wiring board (metal wiring board and copper-clad laminate). Further, the coating film after curing is not easily peeled off, and the peeling property between the coating film and the coating film is good, and the wiring board and the wiring board are not stuck, and the usability of the wiring board after coating is good.

Further, by applying the wiring board coating agent to the end surface of the wiring board and the circumferential edge portion including the end surface by the coating device, the brush, or the like, it is possible to prevent foreign matter from occurring at the end portion of the wiring board during subsequent circuit processing ( The occurrence of dust, etc., and the strength of the wiring board can also be improved due to the coating film of the circuit board coating agent.

On the other hand, according to the circuit board coating agents according to Comparative Examples 1 to 5, the resistance to strong acidity and strong alkalinity was low, coating film defects occurred, and the coating film was not formed uniformly and thinly. Moreover, some of the coating film after curing has a low peeling property, a low peeling property between the wiring board and the wiring board, and poor usability of the wiring board after the coating.

Claims (6)

A circuit board coating agent applied to an end surface of a circuit board or a circuit board coating agent for a circumferential edge portion of the end surface, and the solvent is an aqueous medium containing urethane resin of 5 to 35 wt%, styrene resin is 1 to 10% by weight, and the acrylate resin as a tackifier is 0.1 to 3% by weight. The circuit board coating agent according to claim 1, wherein the urethane resin contains a urethane resin having a polycarbonate structure. The circuit board coating agent according to claim 1 or 2, wherein the viscosity is 0.01 to 1.0 Pa‧S. The circuit board coating agent according to claim 1 or 2, wherein the urethane resin, the styrene resin, and the tackifier are aqueous resins. The circuit board coating agent according to claim 4, further comprising at least one of a humectant, a wettability promoter, and an antifoaming agent as an additive. A circuit board coating agent according to claim 5, which further comprises a coloring agent.