TWI525390B - Black hardening resin composition - Google Patents

Description

Black curable resin composition

The present invention relates to a black curable resin composition having excellent resolution, and can be used for, for example, a solder resist for a printed wiring board, and can be adapted to the miniaturization and miniaturization of the electrode, and further excellent in black color tone even after heat treatment. It is also possible to prevent a black curable resin composition having a change in color tone.

The printed wiring board is used for forming a conductor circuit on a substrate, and the electronic component is mounted by soldering on the soldering ground of the pattern, and the circuit portion other than the soldering land is covered with a solder resist film as permanent protection. Membrane. Thereby, it is possible to prevent the solder from adhering to an unnecessary portion when the printed wiring board is soldered to the electronic component, and to prevent the circuit conductor from being directly exposed to the air and being corroded by oxidation or humidity.

In addition, in recent years, with the advancement of technology, the demand for miniaturization and weight reduction has increased in the field of electronics. Accordingly, in order to arrange more compact electronic parts at a high density, it is required to conductors of printed wiring boards. Macrotype, miniaturization, and high precision of circuit patterns. In response to this, the solder resist film is required to have higher performance in various properties such as resolution, dimensional accuracy, and heat resistance, and thus one of the solder resist films is a black solder resist film.

As a material for forming a black solder resist film, a solder resist composition (Patent Document 1) in which a coloring agent blended with a carboxyl group-containing resin is one or more kinds of coloring agents other than a black coloring agent and a black coloring agent is proposed. However, since the black solder resist composition of Patent Document 1 has black color, light absorption during exposure increases, and it is difficult for light to reach the deep portion of the solder resist coating film in particular. Therefore, in the deep portion of the solder resist coating film, photohardening is not sufficient, and the size of the deep portion of the solder resist coating film after development may be too small, and the resolution of the cured coating film may be peeled off from the printed wiring board or the problem of defective line residue. .

Thus, there has been proposed a black solder resist composition (Patent Document 2) which is characterized in that a coloring agent blended in a carboxyl group-containing resin is used as a yellow coloring agent and a purple coloring agent, a yellow coloring agent, a blue coloring agent, and a red color. The colorant, the green colorant and the purple colorant, and any combination selected among the group of the green colorant and the red colorant are blackened. However, in Patent Document 2, in order to blacken the coloring agent other than the black coloring agent, it is difficult to adjust to black, complicated, or to increase the blackness, the content of the coloring agent is increased, and the analytical performance is still insufficient. problem.

[Previous Technical Literature] [Patent Literature]

Patent Document 1 Japanese Special Open 2008-257045

Patent Document 2, JP-A-2010-91876

In view of the above circumstances, an object of the present invention is to provide a black curable resin composition which has excellent resolution and is easily adjusted to black and which can prevent color tone change after heat treatment.

The aspect of the present invention is a black curable resin composition comprising (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a diluent, (D) an epoxy compound, and E) A black curable resin composition of a black colorant, characterized in that the (E) black colorant contains (E-1) a carbon black-based black colorant and (E-2) an anthraquinone-based black colorant, and the foregoing ( E) Among the black colorants, the content of the (E-2) fluorene-based black colorant is 53% by mass or more.

In the above aspect, the carbon black-based black colorant and the lanthanide-based black colorant are blended in the coloring agent of the black curable resin composition, and the blending ratio of the lanthanide black colorant in all the black colorants is When it is 53% by mass or more, the light for exposure for photohardening reaches the deep portion of the coating film of the black curable resin composition, and is sufficiently photocured from the surface portion to the deep portion of the coating film. The carbon black black colorant reduces the brightness of the black curable resin composition, and supplements and improves the blackness.

The aspect of the present invention is a black curable resin composition characterized in that the transmittance of light having a wavelength of 300 to 400 nm of the (E-2) fluorene-based black colorant is 3% or more. In the above aspect, since the lanthanum black coloring agent having a light transmittance of 300 to 400 nm at a wavelength of 3% or more is blended, the ultraviolet light of the light amount required for photohardening can surely reach the black curable resin coated on the substrate. The deep part of the composition.

The aspect of the present invention is a black curable resin composition characterized in that the transmittance of light having a wavelength of 400 to 700 nm of the (E-2) fluorene-based black colorant is 20% or less. The aspect of the present invention is a black curable resin composition characterized in that the (E-2) fluorene-based black colorant is at least 1669 to 1671 cm ^-1 and 1548 to 1550 cm in infrared absorption spectrum measurement. ^-1, and between 1498 ~ 1500cm ^-1, between 1402 ~ 1404cm ^-1, between 1283 ~ 1285cm ^-1, between 822 ~ 824cm ^-1, between ^{763 ~ 765cm -1, 739 ~ 741cm} -1 The absorption position between them has an infrared absorption peak.

The aspect of the invention is a black curable resin composition characterized by further comprising (F) a blue colorant. In addition to the above-described respective black colorants, a blue coloring agent is further blended, whereby the chromaticity index (a* value) is adjusted from the positive side to the vicinity of 0 while the brightness (L* value) measured by the color difference meter is lowered. Furthermore, the aspect of the invention is a black curable resin composition characterized in that the blue colorant (F) is an indigo blue coloring agent.

The aspect of the invention is a black curable resin composition characterized by further containing (G) a yellow colorant. In addition to the above-described respective black colorants, a yellow colorant is further blended, whereby the L* value measured by the color difference meter is lowered, and the chromaticity index (b* value) is adjusted from the negative side to the vicinity of 0. Further, the aspect of the invention is a black curable resin composition characterized in that the (G) yellow colorant is an anthraquinone yellow colorant.

The aspect of the invention is a cured product obtained by curing the black curable resin composition. Further, the aspect of the present invention is a cured product characterized in that the L* value is 25 or less, the a* value, and the b* value are all in the range of -2 to 2. The aspect of the invention is a cured product characterized in that the transmittance of light having a wavelength of 400 nm when the film thickness is 20 μm is 7.0% or more. Furthermore, a mode of the present invention is a printed wiring board characterized in that the black curable resin composition is applied as a solder resist.

According to the aspect of the present invention, the blending ratio of the lanthanoid black colorant is set to 53% by mass or more in the total amount of the blended black colorant, whereby the light for exposure for photohardening reaches black curability. Since the coating film of the resin composition is deep, it is sufficiently photohardened from the surface portion to the deep portion of the coating film. Since the photocuring proceeds sufficiently to the deep portion of the coating film, even if it is applied to a substrate such as a printed wiring board having a macro circuit pattern, it is possible to prevent the film from being detached or damaged due to insufficient light hardening in the deep portion. Resolution. Further, since the photocuring is sufficiently performed to the deep portion of the coating film, it is possible to prevent the width dimension of the deep portion of the cured coating film from being reduced after development. Therefore, the width dimension of the deep portion of the cured coating film is close to the width dimension of the surface portion of the cured coating film, and the dimensional accuracy of the cured coating film is improved.

According to the aspect of the present invention, the bismuth-based black coloring agent having a transmittance of 3% or more of light having a wavelength of 300 to 400 nm is blended, so that it is possible to surely prevent the coating film from falling off or being damaged due to insufficient light hardening in the deep portion of the coating film. The resolution and dimensional accuracy are further improved.

According to the aspect of the present invention, by further blending the blue colorant as needed, the L* value measured by the color difference meter can be lowered, and the a* value can be adjusted from the positive side to the zero value, so that black The concentration and color tone are easy to adjust.

According to the aspect of the present invention, by further blending the yellow colorant, the L* value measured by the color difference meter can be lowered, and the b* value can be adjusted from the negative side to the zero value, so the black density and color tone Easy to adjust.

Next, each component of the black curable resin composition of the present invention will be described. The black curable resin composition of the present invention contains (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a diluent, (D) an epoxy compound, and (E) a black colorant. The curable resin composition, wherein the (E) black colorant contains (E-1) a carbon black-based black colorant and (E-2) an anthraquinone-based black colorant, and among the aforementioned (E) black colorants, the aforementioned (E-2) The content of the lanthanum black colorant is 53% by mass or more.

(A) carboxyl group-containing photosensitive resin

The carboxyl group-containing photosensitive resin is not particularly limited, and any of a photosensitive carboxyl group-containing resin having one or more photosensitive unsaturated double bonds and a carboxyl group-containing resin having no photosensitive unsaturated double bonds can be used. Examples of the component (A) include at least a part of an epoxy group of a polyfunctional epoxy resin having two or more epoxy groups in the molecule, and a radically polymerizable unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid. The (meth)acrylic acid epoxy ester obtained by the reaction, and the polybasic acid modified (meth)acrylic acid epoxy ester obtained by reacting the produced hydroxyl group with a polybasic acid or an anhydride thereof.

The above-mentioned polyfunctional epoxy resin may be used as long as it is a bifunctional or higher epoxy resin. Although there is no particular limitation on the epoxy equivalent, it is usually used in an amount of 1,000 or less, preferably 100 to 500. Examples of the polyfunctional epoxy resin include a rubber modified epoxy resin such as a biphenyl type epoxy resin, a naphthalene type epoxy resin, a dicyclopentadiene type epoxy resin, or a polyfluorene modified epoxy resin; ε- Caprolactone modified epoxy resin, bisphenol A type, bisphenol F type, bisphenol AD type and other phenol novolak type epoxy resin; o-cresol novolac type and other cresol novolak type epoxy resin; bisphenol A novolac type epoxy resin; cyclic aliphatic polyfunctional epoxy resin; glycidyl ester type multifunctional epoxy resin; glycidylamine type multifunctional epoxy resin; heterocyclic polyfunctional epoxy resin; A novolac type epoxy resin; a polyfunctional modified novolac type epoxy resin; an epoxidized epoxy resin having a phenolic group and a phenolic hydroxyl group and an aromatic aldehyde, and the like. Further, a halogen atom such as Br or Cl may be introduced into the resin. Among these, a rubber-modified epoxy resin such as a polyfluorene-modified epoxy resin is preferable from the viewpoint of flexibility of the coating film. These epoxy resins may be used singly or in combination of two or more.

The radically polymerizable unsaturated monocarboxylic acid to be used is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and the like, and at least one of acrylic acid and methacrylic acid is preferable (hereinafter also referred to as It is (meth)acrylic acid), and particularly preferably acrylic acid. The (meth)acrylic acid is reacted with epoxy (meth)acrylate. The reaction method of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and for example, it can be reacted by heating an epoxy resin with acrylic acid in a suitable diluent.

The polybasic acid or polybasic acid anhydride reacts with a hydroxyl group formed in the reaction between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid to carry a carboxyl group which is free from the resin. The polybasic acid or the anhydride thereof to be used is not particularly limited, and both saturated and unsaturated can be used. Examples of the polybasic acid include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, and 4-methyltetrahydrophthalic acid. Formic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid Dicarboxylic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, endomethylene tetrahydrogenated Examples of the phthalic acid, methyl endethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid, and oxydiglycolic acid, and the polybasic acid anhydrides include the acid anhydrides. These compounds may be used singly or in combination of two or more.

In the present invention, the polybasic acid-modified unsaturated monocarboxylic acid epoxy resin may be used as a photosensitive resin, but a carboxyl group of the polybasic acid-modified unsaturated monocarboxylic acid epoxy resin may be used. A photosensitive resin having a photopolymerization property in which a radically polymerizable unsaturated group is reacted with an epoxy group-containing glycidyl compound to further introduce a radical polymerizable unsaturated group.

In the photosensitive resin having improved photosensitivity, the radically polymerizable unsaturated group is bonded to the polymer skeleton side chain of the photosensitive resin of the precursor by the reaction of the final glycidyl compound, and thus the photopolymerization reactivity is high. And can have excellent photosensitive properties. Examples of the compound having one or more radical polymerizable unsaturated groups and an epoxy group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and pentaerythritol triacrylate monoglycidyl ether. Wait for example. Further, a plurality of glycidyl groups may be present in one molecule. The above-mentioned compound having one or more radically polymerizable unsaturated groups and an epoxy group may be used singly or in combination of two or more.

The lower limit of the acid value of the carboxyl group-containing photosensitive resin is 30 mgKOH/g, preferably 40 mgKOH/g from the viewpoint of reliably performing alkali development. On the other hand, the upper limit of the acid value is 200 mgKOH/g from the viewpoint of preventing the exposure of the exposed portion by the alkali developing solution, and from the viewpoint of preventing deterioration of moisture resistance and electrical properties of the cured product, Preferably it is 150 mgKOH/g.

In addition, the lower limit of the weight average molecular weight of the carboxyl group-containing photosensitive resin is 3,000, preferably 5,000, from the viewpoint of the toughness of the cured product and the dryness of the touch. On the other hand, the upper limit of the weight average molecular weight is 200,000, preferably 50,000, from the viewpoint of compatibility with a diluent of the component (C) or the like and ease of alkali developability.

The commercially available ones of the carboxyl group-containing photosensitive resins include ZFR-1124, FLX-2089 (above, manufactured by Nippon Kayaku Co., Ltd.), and Cyclomer-P (ACA) Z-250 (manufactured by Daicel Chemical Industry Co., Ltd.). Ripoxy SP-4621 (Showa Polymer Co., Ltd.) and the like are taken as examples. These resins may be used singly or in combination of two or more.

(B) Photopolymerization initiator

The photopolymerization initiator is not particularly limited as long as it is generally used, and examples thereof include an anthraquinone initiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin. Butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -Phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio) Phenyl]-2-morpholinyl-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl) ketone, benzophenone, p-phenyl Benzophenone, 4,4 ' -diethylaminobenzophenone, dichlorobenzophenone, 2-methyloxime, 2-ethylhydrazine, 2-tert-butylhydrazine, 2-Aminoguanidine, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4 diethylthioxanthone Benzyl dimethyl ketal, acetophenone dimethyl ketal, P-dimethylamine benzoic acid ethyl ester, and the like are exemplified. These may be used alone or in combination of two or more. The blending amount of the photopolymerization initiator is 5 to 20 parts by mass, preferably 8 to 15 parts by mass, based on 100 parts by mass of the carboxyl group-containing photosensitive resin.

(C) thinner

The diluent is, for example, a photopolymerizable monomer of a reactive diluent, and is used for sufficiently photocuring a carboxyl group-containing photosensitive resin to obtain a cured product having acid resistance, heat resistance, alkali resistance, and the like. Examples of the photopolymerizable monomer include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylic acid. Ester, polyethylene glycol di(meth) acrylate, neopentyl glycol adipate di(meth) acrylate, hydroxytrimethyl acetic acid neopentyl glycol di(meth) acrylate, dicyclopentane Alkyl di(meth) acrylate, caprolactone modified dicyclopentenyl di(meth) acrylate, ethylene oxide modified bis (meth) acrylate, allylated cyclohexyl (Meth) acrylate, trimeric isocyanate di(meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tris (A) Acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, ginseng(propyleneoxyethyl)trimeric isocyanate, propionic acid modified For example, reactive diluents such as pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone modified dipentaerythritol hexa (meth) acrylateThese systems may be used singly or in combination of two or more. The blending amount of the above reactive diluent is 2.0 to 40 parts by mass, preferably 10 to 25 parts by mass, per 100 parts by mass of the carboxyl group-containing photosensitive resin.

Further, as the diluent, in order to adjust the viscosity or drying property of the black curable composition, an organic solvent of a non-reactive diluent may be used instead of the above reactive diluent, or the above reactive diluent may be used in combination. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, isopropanol and cyclohexanol; and lipids such as cyclohexane and methylcyclohexane. Cyclic hydrocarbons; petroleum ethers such as petroleum ether and petroleum brain; 2-ethoxyethanols such as 2-ethoxyethanol (Cesare) and butyl 2-ethoxyethanol; carbitol and butyl Carbitol such as carbitol; ethyl acetate, butyl acetate, 2-ethoxyethanol acetate, butyl 2-ethoxyethanol acetate, carbitol acetate, butyl acetate An example of an acetate or the like of an alcohol ester or the like is exemplified. The blending amount in the case of using an organic solvent is preferably 40 to 500 parts by weight based on 100 parts by weight of the carboxyl group-containing photosensitive resin.

(D) epoxy compound

The epoxy compound is used to increase the crosslinking density of the cured product and to obtain a cured coating film having sufficient mechanical strength. The epoxy compound is, for example, an epoxy resin. Examples of the epoxy resin include bisphenol A type epoxy resin; novolak type epoxy resin (phenol novolak type epoxy resin, o-cresol novolac type epoxy resin, and p-butyl phenol novolak type) a bisphenol F-type or bisphenol S-type epoxy resin obtained by reacting bisphenol F or bisphenol S with epichlorohydrin; further having an epoxycyclohexane group, an epoxy tricyclodecyl group, and a ring An alicyclic epoxy resin such as oxycyclopentanyl; a triazine ring having a triazine ring such as ginseng (2,3-epoxypropyl)trimeric isocyanate or triglycidyl ginate (2-hydroxyethyl)trimeric isocyanate Glycidyl tripolyisocyanate; dicyclopentadiene type epoxy resin; adamantane type epoxy resin as an example. These compounds may be used singly or in combination of two or more. The blending amount of the epoxy compound is from 10 to 50 parts by mass, preferably from 20 to 30% by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin, from the viewpoint of obtaining a coating film having sufficient mechanical strength after curing. Share.

(E) black colorant

In the present invention, a (E-1) carbon black-based black colorant and (E-2) anthraquinone-based black colorant are blended as a black colorant.

(E-1) carbon black black colorant

The carbon black black colorant is a one that imparts a concealing power and a blackening property to a hardened material. Examples of the carbon black-based black colorant include carbon black. The type of carbon black is not particularly limited, and examples thereof include furnace black, channel black, and acetylene black. Further, examples of the carbon black-based pigment include those of C.I. Pigment Black 6, 7, 9, 18 and the like. These systems may be used singly or in combination of two or more.

(E-2) lanthanide black colorant

The oxime black coloring agent imparts a hiding power and a blackness of the cured product formed of the black curable resin composition of the present invention, and imparts ultraviolet light transmittance to the black curable resin composition. The type of the lanthanum black coloring agent is not particularly limited, but from the viewpoint of photocurability in the deep portion of the coating film, a lanthanum black coloring agent having a transmittance of light having a wavelength of 300 to 400 nm of 3% or more is preferable. It is more preferable to adjust the black color tone, that is, to reduce the color tone such as red contained in black, to impart blackiness, and to suppress discoloration after soldering heat resistance, and to have the above-described light transmittance characteristics. A fluorene-based black colorant having a transmittance of light having a wavelength of 400 to 700 nm of 20% or less. Further, from the viewpoint of more easily imparting blackness, it is particularly preferably at least 1669 to 1671 cm ^-1 and 1548 to 1550 cm in addition to the transmittance characteristics of light having a wavelength of 300 to 400 nm and a wavelength of 400 to 700 nm. ^-1, and between 1498 ~ 1500cm ^-1, between 1402 ~ 1404cm ^-1, between 1283 ~ 1285cm ^-1, between 822 ~ 824cm ^-1, between 763 ~ 765cm ^-1 and 739 ~ 741cm ^-1 The absorption position between the points has an infrared absorption peak of the lanthanide black colorant.

Examples of the fluorene-based black coloring agent having a transmittance of 3% or more of light having a wavelength of 300 to 400 nm include "Paliogen Black S 0084", "Lumogen Black FK 4280", and "Lumogen Black FK 4281" manufactured by BASF Aktiengesellschaft. For example. Among them, the lanthanum black coloring agent having a transmittance of light having a wavelength of 300 to 400 nm of 3% or more and a transmittance of light having a wavelength of 400 to 700 nm of 20% or less is exemplified by "Lumogen Black FK 4280" and "Lumogen Black FK 4281". "." In addition, although "Paliogen Black S 0084" has a light transmittance of 20% or less on the side shorter than the wavelength of 680 nm, the transmittance of light having a wavelength of 680 nm or more exceeds 20%. "Lumogen Black FK 4280" has a transmittance of light of 20% or less at a wavelength of 300 to 750 nm. The transmittance of "Lumogen Black FK 4281" at a wavelength of 300 to 900 nm is 20% or less.

Wherein, in addition to a wavelength of 400 300 ~ 400nm and the transmittance characteristics of the above ~ 700nm wavelength light, and further at least between 1669 ~ 1671cm ^-1, between 1548 ~ 1550cm ^-1, between 1498 ~ 1500cm ^-1 between 1402 ~ 1404cm ^-1, between 1283 ~ 1285cm ^-1, between 822 ~ 824cm ^-1, 763 ~ 739 ~ ¹ and between the absorption position between ^{-1 765cm 741cm} having an infrared absorption peak perylene For the black coloring agent, "Lumogen Black FK 4281" can be cited. Further, "Lumogen Black FK 4280" has no infrared absorption peak at each of the above absorption positions, and is at least between 1542 and 1544 cm ^{-1 ,} between 1502 and 1504 cm ^{-1 ,} between 1284 and 1286 cm ^-1 , and between 748 and 750 cm ^- The absorption position between ¹ has an infrared absorption peak. These oxime-based black coloring agents may be used singly or in combination of two or more.

Further, in addition to the respective black colorants described above, a known black colorant such as aniline black, titanium black, azo black or graphite may be further blended as needed.

The lower limit of the blending amount of the black colorant is 0.1 part by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin, from the viewpoint of the appearance of the black color, from the viewpoint of the hiding power of the cured product and the degree of blackness. Good is 0.2 parts by mass. From the viewpoint of forming a fine hard coating film line, the upper limit of the black colorant blending amount is 20% by mass based on 100 parts by mass of the carboxyl group-containing photosensitive resin, and from the viewpoint of obtaining the cured product resolution and dimensional accuracy. In other words, it is preferably 10 parts by mass. In addition, the content of the lanthanum black coloring agent accounts for the total amount of the black coloring agent, and the lower limit value is 53% by mass from the viewpoint of the transparency of ultraviolet light, and from the viewpoint of photocurability in the deep portion of the coating film, It is preferably 60% by mass, and particularly preferably 65 parts by mass from the viewpoint of resolution. On the other hand, the content of the lanthanum black coloring agent accounts for the total amount of the black coloring agent, and the upper limit value is 90% by mass from the viewpoint of imparting blackness to the a* value close to 0, and the L* value is lowered. That is, it is preferably 85% by mass from the viewpoint of obtaining a blackness, and particularly preferably 80% by mass from the viewpoint of the appearance of black.

(F) blue colorant

In order to reduce the L* value of the color difference meter and increase the blackness of the cured product formed by the black curable resin composition of the present invention, the a* value of the color difference meter is approached from the positive value side to the zero value direction to impart darkness. Sex, will blend blue colorants. When the carbon black-based black colorant and the lanthanide black colorant are blended, the color tone of the cured product may appear red with a positive a* value. Thus, by adding a blue coloring agent, the a* value of the cured product is brought close to a value of 0 to suppress red color, and the cured product has blackness.

The type of the blue coloring agent is not particularly limited, and examples thereof include pigments of anthracycline, anthraquinone, and bisoxazine. Specific examples of the blue coloring agent include Pigment Blue 15, Pigment Blue 15: 1, Pigment Blue 15: 2, Pigment Blue 15: 3, Pigment Blue 15: 4, Pigment Blue 15: 6, Pigment Blue 16, Pigment Blue 60 is the color index number. Among them, from the viewpoint of easily adjusting the concentration and color tone of black and easily exhibiting blackness, it is preferably an anthracycline system. These systems may be used singly or in combination of two or more.

The blending amount of the blue colorant can be appropriately selected within a range in which the a* value of the cured product approaches the value of 0 and suppresses red. As long as the a* value of the cured product of the specified thickness is near the value of 0 (for example, in the range of -2 to 2), the blue colorant may not be added, and even in the vicinity of the value of 0, the blackness is exhibited to be closer to the value of 0. A specified amount of blue colorant can also be added. In the case of adjusting the concentration of black and the color of red doping, for example, from the viewpoint of suppressing the black color of the cured product, the lower limit of the blending amount is compared with respect to 100 parts by mass of the black colorant. It is preferably 5 parts by mass, and particularly preferably 10 parts by mass from the viewpoint of blackness. Moreover, the upper limit is preferably 50 parts by mass with respect to 100 parts by mass of the black colorant from the viewpoint of bringing the a* value of the cured product to a value of 0. From the viewpoint of the resolution, it is particularly preferable. 30 parts by mass.

(G) yellow colorant

In order to reduce the L* value of the color difference meter by the cured product of the black curable resin composition of the present invention, the degree of blackness is lowered, and the b* value of the color difference meter is brought close to the zero value from the negative side to impart blackness. A yellow colorant is blended. When a carbon black-based black colorant and a lanthanide black colorant are blended, the color tone of the cured product may appear purple and have a negative b* value. Thus, by adding a yellow coloring agent, the b* value of the cured product is brought close to a value of 0 to suppress purple, and the cured product has blackness.

The type of the yellow coloring agent is not particularly limited, and examples thereof include an anthraquinone type, a monoazo type, a diazotized type, a condensed azo type, a benzimidazolone type, and an isoindolinone type. Specific examples of the yellow coloring agent include Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202 (above, lanthanide); Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, 183 (above is a monoazo system); Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198 (above is diazotization); Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180 (above condensed azo); Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181 (above is benzimidazolone); Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185 (above Isoporphyrinone) Index numbers are. Among them, from the viewpoint of black concentration and easy adjustment of color tone, it is preferable to use a lanthanum system. These may be used alone or in combination of two or more.

The blending amount of the yellow colorant can be appropriately selected within a range in which the b* value of the cured product approaches the value of 0 to suppress purple. As long as the b* value of the cured product of the specified thickness is in the vicinity of the value of 0 (for example, in the range of -2 to 2), the yellow coloring agent may not be added, and even if it is near the value of 0, the blackness is exhibited to be closer to the value of 0. A specified amount of yellow colorant can also be added. In the case of adjusting the concentration of black and the hue with a purple color, for example, from the viewpoint of suppressing the blackness of the cured product, the lower limit of the blending amount is compared with respect to 100 parts by mass of the black colorant. It is preferably 5 parts by mass, and particularly preferably 10 parts by mass from the viewpoint of blackness. In addition, the upper limit is preferably 50 parts by mass with respect to 100 parts by mass of the black colorant from the viewpoint of the b* value of the cured product being close to 0. From the viewpoint of the resolution, it is particularly preferable. 30 parts by mass.

In the color tone of the cured product of the black curable resin composition of the present invention, the L* value of the color difference meter is preferably 30 or less, and particularly preferably 25 or less from the viewpoint of blackness. Further, the a* value and the b* value of the color difference meter are preferably -3 to 3 and particularly preferably -2 to 2 from the viewpoint of blackness. In addition, in the cured product having a thickness of 20 μm, the transmittance of light having a wavelength of 400 nm is preferably 7% or more, and particularly preferably 8% or more from the viewpoint of photocurability in the deep portion of the coating film. Therefore, the black curable resin composition of the present invention blends the above (A) to the appropriate blending ratio while considering the L* value, the a* value, the b* value, and the transmittance of the cured product. (D) component, any of the following components, and the coloring agent of the above (E)-(G) component.

In the black curable resin composition of the present invention, various additional components such as an antifoaming agent, various additives, a pigment extender, a tackifier, and the like can be appropriately blended as needed in addition to the above components.

As the antifoaming agent, a known one can be used, and examples thereof include polyoxyalkylene-based, hydrocarbon-based, and acrylic-based. Examples of the additive include dispersing agents such as a coupling agent such as a decane system, a titanate/ester system, and an alumina system; boron trifluoride-amine complex, dicyandiamide (DICY) and derivatives thereof, and organic acid hydrazine; , diamine maleimonitrile (DAMN) and its derivatives, melamine and its derivatives, decylamine and its derivatives, amine quinone imine (AI) and polyamines and other potential hardeners, acetonitrile acetone Zn And a hardening accelerator such as a metal salt of acetamidine acetone such as acetonitrile acetone, an enamine, a tin octylate, a sulfonium salt, a triphenylphosphine, an imidazole, an imidazole salt, and a triethanolamine borate. The pigment extender is used to increase the physical strength of the cured product, and examples thereof include vermiculite, barium sulfate, aluminum oxide, aluminum hydroxide, talc, and mica. Further, examples of the tackifier include organic bentonite and the like.

The method for producing the black curable resin composition of the present invention is not limited to a specific method. For example, the above components may be blended at a predetermined ratio and then mixed and dispersed at room temperature in three rolls.

Next, a method of applying the black curable resin composition of the present invention described above will be described. Here, a case where the black curable resin composition of the present invention is applied as a solder resist to a printed wiring board will be described as an example.

The black curable resin composition of the present invention produced as described above is used, for example, by a screen printing method, a roll coating method, a rod coating method, or a spray coating on a printed wiring board having a circuit pattern formed by etching a copper foil. The coating is applied to a desired thickness by a method such as a curtain flow coating method or a gravure coating method, and is heated at a temperature of about 60 to 80 ° C in order to volatilize the solvent in the black curable resin composition. It is pre-dried for about 60 minutes to form a non-stick coating film. Thereafter, a negative film having a pattern in which the above-described circuit pattern is soldered to the outside of the circuit pattern is adhered to the applied black curable resin composition, and ultraviolet rays are irradiated from above. The non-exposed areas corresponding to the aforementioned solder joints are then removed with a dilute aqueous alkali solution to develop a coating film. For the development method, a spray method, a shower method, or the like is used. The dilute alkali aqueous solution used is generally a 0.5 to 5% sodium carbonate aqueous solution, but other bases may be used. Then, post-curing is performed for 20 to 80 minutes in a hot air circulation type dryer such as 130 to 170 ° C to thermally cure the target, and a target black curable resin composition can be formed on the printed wiring board. Hardened coating film.

The electronic component is formed by soldering the electronic component to the printed wiring board covered with the hardened coating film thus obtained by a jet welding method, a reflow soldering method, or the like.

The black curable resin composition of the present invention can be applied to a printed wiring board in addition to a solder resist, and can be used for a backlight for a street lamp, a surface of a back sheet for a solar cell that emphasizes aesthetics, and an appropriate coating method. The back surface of the LED, etc.

[Examples]

The embodiments of the present invention are described below, but are not limited to the examples, without departing from the gist of the present invention.

Examples 1 to 13 and Comparative Examples 1 to 5

Each component shown in the following Table 1 was blended at a blending ratio shown in the following Table 1, and premixed by a stirrer, and then mixed and dispersed at room temperature using three rolls to prepare Examples 1 to 13, Comparative Examples. A black curable resin composition used in 1 to 5. Next, the prepared black curable resin composition was applied onto a substrate by using a test piece preparation step described later to prepare a test piece. The blending amount of each component shown in the following Table 1 means a part by mass unless otherwise specified.

In addition, the detailed description of each component in Table 1 is as follows.

(A) carboxyl group-containing photosensitive resin

‧Ripoxy SP-4621: Shouhe Polymer Co., Ltd., polyacid modified cresol novolac type epoxy acrylate resin

(B) Photopolymerization initiator

‧IRGACURE 907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropan-1-one manufactured by Ciba Specialty Chemicals Co., Ltd.

‧IRGACURE 369: 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, manufactured by Ciba Specialty Chemicals Co., Ltd.

(C) thinner

‧EDGAC: Sanyo Chemical Co., Ltd., Diethylene Glycol Ether Acetate

(D) epoxy compound

‧EPCRON 860: Dainippon Ink Chemical Industry Co., Ltd., bisphenol A epoxy resin

(E) black colorant

‧carbon black: electric chemical industry (shares) system, "Denka Black"

‧LUMOGEN BLACK FK4281: Made by BASF Aktiengesellschaft

‧LUMOGEN BLACK FK4280: Made by BASF Aktiengesellschaft

‧Paliogen Black S 0084: Made by BASF Aktiengesellschaft

(F) blue colorant

‧Lionol Blue FG-7351: Toyo Ink Manufacturing Co., Ltd., anthocyanin pigment

(G) yellow colorant

‧Chromophtal Yellow AGR: Ciba Specialty Chemicals (share), bismuth pigment

Others, DICY-7 is a hardening accelerator made by Japan Epoxy Resin Co., Ltd.

Test piece making step

The glass epoxy substrate (FR-4) having a circuit pattern was formed and subjected to surface treatment by buff polishing, and then the black curable resin compositions of Examples 1 to 13 and Comparative Examples 1 to 5 were applied by screen printing. Prepare for drying at 80 ° C for 20 minutes in a BOX furnace. After preliminary drying, the film was exposed to 500 mJ/cm ² by an exposure apparatus (HMW-680GW, manufactured by Oak Co., Ltd.), and then developed at 30 ° C and 1% sodium carbonate aqueous solution, and then subjected to 150 ° C for 60 minutes in a BOX furnace. After hardening, a hard coating film of a black curable resin composition was formed on a glass epoxy substrate to prepare a test piece. The thickness of the cured coating film was 20 μm.

Evaluation (1) Resolution

The remaining line of the exposed portion formed by the specified photomask (line 30 to 130 μm) and the vacant pitch were visually confirmed and evaluated.

(2) undercut

The substrate after the line of the cured coating film was formed using a mask having a width of 100 μm, the substrate was cut, and the line was observed from the cut surface, and the width (x) and the width of the bottom side (deep side) on the surface side of the line were measured. (y), undercut by (xy)/2.

(3) L* value, a* value, b* value

It was measured by a color difference meter SE2000 (Nippon Denshoku Industries Co., Ltd.).

(4) Transmittance

For the glass epoxy substrate on which the cured coating film is formed, the transmittance of light having a wavelength of 400 nm is measured, and the transmittance of light having a wavelength of 400 nm of the glass epoxy substrate alone measured is used for the reference line, thereby measuring the transmission of the cured coating film. rate. The transmittance was measured using a UV spectrophotometer U-3310 (Hitachi High Technology Co., Ltd.).

(5) Discoloration after soldering heat resistance

The test piece was immersed in a solder bath at 260 ° C for 20 seconds, and the state of the cured film was visually observed to evaluate the degree of discoloration.

Tables 2 show the resolution, undercut, L* value, a* value, b* value, transmittance, and discoloration after heat treatment of Examples 1 to 13 and Comparative Examples 1 to 5.

From Examples 1 to 13 and Comparative Examples 1 to 4 of Table 2, it is understood that when a black colorant having a blend ratio of the lanthanoid black colorant of more than 52% by mass is used in the mixture of the carbon black and the lanthanide black colorant, the wavelength The transmittance of light of 400 nm is improved, and a cured product having excellent resolution and low undercut can be obtained. Further, the a* value is in the vicinity of the value of 0 (for example, in the range of -2 to 2), or even if it is not in the vicinity of the value of 0, it is possible to suppress a large deviation from the value of 0. As described above, in the black curable resin composition of the present invention, when the film thickness of the cured coating film is 20 μm, the transmittance of light having a wavelength of 400 nm is 7.5% or more, and thus the photocuring can reach the deep portion of the coating film. Further, since the photo-curing can reach the deep portion of the coating film and has a resolution of 70 μm or less, it is also possible to respond to the circuit pattern of the macro. Further, since the undercut can be suppressed to 26 μm or less, even a macro circuit pattern can prevent peeling or chipping of the wire, and the dimensional accuracy of the wire can be improved. Then, since the a* value can be suppressed to a low level, it is easy to adjust the black tone, that is, to reduce the hue of red or purple in black, and to produce blackness.

Further, in Examples 2, 8 and 10, the transmittance of light having a wavelength of 300 to 400 nm is 3% or more, and the transmittance of light having a wavelength of 400 to 700 nm is 20% or less. Lumogen Black FK 4281" (Example 2) and "Lumogen Black FK 4280" (Example 8), compared to "Paliogen Black S 0084" having a transmittance of light exceeding 280 to 700 nm of 20% (Example 10) ), the L* value can be suppressed to a lower level, and the a* value and the b* value can be brought closer to the vicinity of the value of 0, so that it is easier to increase the blackness while suppressing the hue such as red or purple to produce blackness.

Further, the embodiments 2,8 embodiments, between 1669 ~ 1671cm ^-1, between 1548 ~ 1550cm ^-1, between 1498 ~ 1500cm ^-1, between ^{1402 ~ 1404cm -1, 1283 ~ 1285cm} -1 between, between 822 ~ 824cm ^-1, between 763 ~ 765cm ^-1, 739 ~ 741cm ^-1 position between the absorbent perylene black colorant having infrared absorption peak i.e. "Lumogen black FK 4281" (Example 2), Compared with "Lumogen Black FK 4280" (Example 8), the L* value can be suppressed to a lower level, and the a* value and the b* value can be closer to the value of 0, so that the blackness is more likely to occur. .

In addition, when the transmittance of light having a wavelength of 300 to 400 nm is 3% or more and the transmittance of light having a wavelength of 400 to 700 nm is 20% or less, it is possible to suppress discoloration after solder heat resistance.

Further, in Examples 1 to 9, by blending 9 to 19 parts by mass of the blue coloring agent with respect to 100 parts by mass of the black coloring agent and 30 parts by mass or less with the yellow coloring agent, the a* value and the b* value can be obtained. They all fall within the range of -2 to 2, and suppress the color tone such as red in black, and impart a blackening property to the cured product.

In the case of the comparative example 5, when the blending amount of the black coloring agent is 21.8 parts by mass or more based on 100 parts by mass of the carboxyl group-containing photosensitive resin, the line of the cured product disappears and the resolution deteriorates.

[Industrial availability]

The black curable resin composition of the present invention has excellent resolution, is easily adjusted to black, and can prevent color change after heat treatment, and thus has high use value in the field of solder resist, for example.

Claims (12)

A black curable resin composition containing (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a diluent, (D) an epoxy compound, and (E) a black colorant. The curable resin composition characterized in that the (E) black colorant contains (E-1) a carbon black-based black colorant and (E-2) anthraquinone-based black colorant, and the (E) black colorant The content of the above (E-2) fluorene-based black colorant is 53% by mass or more. The black curable resin composition of claim 1, wherein the (E-2) lanthanum black colorant has a transmittance of 3% or more of light having a wavelength of 300 to 400 nm. The black curable resin composition according to claim 1 or 2, wherein the (E-2) fluorene-based black colorant has a transmittance of light of a wavelength of 400 to 700 nm of 20% or less. The black curable resin composition according to claim 1 or 2, wherein the (E-2) anthraquinone black colorant is at least 1669 to 1671 cm ^-1 and 1548 to 1550 cm in infrared absorption spectrum measurement. ^-1, and between 1498 ~ 1500cm ^-1, between 1402 ~ 1404cm ^-1, between 1283 ~ 1285cm ^-1, between 822 ~ 824cm ^-1, between ^{763 ~ 765cm -1, 739 ~ 741cm} -1 The absorption position between them has an infrared absorption peak. The black curable resin composition according to claim 1 or 2, further comprising (F) a blue colorant. The black curable resin composition of claim 5, wherein the (F) blue colorant is an anthocyanin-based blue colorant. For example, the black curable resin composition of claim 5, It further contains (G) a yellow colorant. The black curable resin composition of claim 7, wherein the (G) yellow colorant is a lanthanide yellow colorant. A cured product obtained by hardening a black curable resin composition according to any one of claims 1 to 8. For example, in the hardened material of claim 9, wherein the L* value is 25 or less, the a* value and the b* value all fall within the range of -2 to 2. A cured product of the ninth or tenth aspect of the patent application, wherein a transmittance of light having a wavelength of 400 nm at a film thickness of 20 μm is 7.0% or more. A printed wiring board obtained by coating a black curable resin composition according to any one of claims 1 to 8 as a solder resist.