JP5007453B2 - Black curable resin composition - Google Patents

Description

  The present invention relates to a black curable resin composition having excellent resolution, for example, when used as a solder resist of a printed wiring board, it can cope with fine pitch and miniaturization of the electrode, The present invention relates to a black curable resin composition that is excellent in black color tone and can prevent a change in color tone even after heat treatment.

  A printed wiring board is used to form a pattern of a conductor circuit on a substrate and to mount electronic components on the soldering land of the pattern by soldering, and the circuit portion excluding the soldering land is used as a permanent protective film. It is covered with a solder resist film. This prevents solder from adhering to unnecessary parts when soldering electronic components to a printed wiring board, and prevents circuit conductors from being directly exposed to air and being corroded by oxidation or humidity. To do.

  In recent years, with the advancement of technology, the demand for miniaturization and weight reduction has further increased in the electronics field. Accordingly, in order to arrange more compact electronic components at high density, the conductors of printed wiring boards There is a demand for fine pitches, miniaturization, and high accuracy of circuit patterns. Accordingly, the solder resist film is also required to have higher performance in terms of various properties such as resolution, dimensional accuracy, and heat resistance, and one of such solder resist films is black. There is something.

  As a material for forming a black solder resist film, a solder resist composition in which a colorant blended in a carboxyl group-containing resin is a black colorant and one or more colorants other than the black colorant has been proposed. (Patent Document 1). However, since the black solder resist composition of Patent Document 1 has a black color, the light absorption at the time of exposure increases, and it is particularly difficult for light to reach the deep part of the solder resist coating film. Therefore, the photocuring in the deep part of the solder resist coating film is not sufficient, and the size of the solder resist coating film deep part becomes too small after development, and the cured coating film is peeled off from the printed wiring board. There was a problem.

  Therefore, the colorant blended in the carboxyl group-containing resin is yellow colorant and purple colorant, yellow colorant and blue colorant and red colorant, green colorant and purple colorant, and green colorant and red colorant. A black solder resist composition has been proposed that is blackened by using any combination selected from the group (Patent Document 2). However, in Patent Document 2, since it is blackened with a colorant other than the black colorant, adjustment to black is difficult and complicated, and the content of the colorant is increased to increase the blackness. After all, there was a problem that the resolution performance was not sufficient.

JP2008-257045 JP 2010-91876 A

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

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

  In the said aspect, a carbon black type | system | group black colorant and a perylene type | system | group black colorant are mix | blended with the colorant of a black curable resin composition, and the mixture ratio of the perylene type | system | group black colorant in all the black colorants is 53 mass%. By setting it as the above, the light used for exposure for photocuring reaches the coating film deep part of a black curable resin composition, and fully photocures from the surface part of a coating film to the deep part. The carbon black-based black colorant is to replenish and improve blackness by reducing the brightness of the black curable resin composition.

  An aspect of the present invention is the black curable resin composition, wherein the transmittance of light having a wavelength of 300 to 400 nm of the (E-2) perylene-based black colorant is 3% or more. In the above aspect, since a perylene-based black colorant having a light transmittance of 3% or more at a wavelength of 300 to 400 nm is blended, it is necessary for photocuring up to the deep part of the black curable resin composition coated on the substrate. A certain amount of ultraviolet light is reliably reached.

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

  An embodiment of the present invention is a black curable resin composition characterized by further containing (F) a blue colorant. By adding a blue colorant in addition to the above black colorants, the chromaticity index (a * value) is reduced from the positive value side to 0 while reducing the lightness (L * value) measured with a color difference meter. Adjust to the vicinity. An embodiment of the present invention is the black curable resin composition, wherein the (F) blue colorant is a phthalocyanine-based blue colorant.

  An embodiment of the present invention is a black curable resin composition characterized by further containing (G) a yellow colorant. In addition to each of the above black colorants, by adding a yellow colorant, the L * value measured with a color difference meter is lowered, and the chromatic index (b * value) is adjusted from the negative value side to near zero. To do. An embodiment of the present invention is the black curable resin composition, wherein the (G) yellow colorant is an anthraquinone yellow colorant.

  The aspect of this invention is the hardened | cured material which hardened the above-mentioned black curable resin composition. An aspect of the present invention is a cured product characterized in that the L * value is 25 or less, and the a * value and the b * value are both in the range of −2 to 2. An aspect of the present invention is a cured product characterized in that the transmittance of light having a wavelength of 400 nm at a film thickness of 20 μm is 7.0% or more. Moreover, the aspect of this invention is a printed wiring board characterized by apply | coating the above-mentioned black curable resin composition as a soldering resist.

  According to the aspect of the present invention, the blending ratio of the perylene-based black colorant in the total amount of the black colorant to be blended is 53% by mass or more so that the light used for exposure for photocuring is a black curable resin. Since it reaches the deep part of the coating film of the composition, it is sufficiently photocured from the surface part to the deep part of the coating film. In this way, photocuring sufficiently proceeds to the deep part of the coating film, so even if it is applied to a substrate such as a printed wiring board having a fine pitch circuit pattern, the coating film is lost or missing due to insufficient photocuring in the deep part. And the resolution is improved. In addition, since photocuring sufficiently proceeds to the deep part of the coating film, it is possible to prevent the width dimension of the deep part of the cured coating film from being reduced after development. Therefore, the width dimension of the deep part of the cured coating film approaches the width dimension of the surface part of the cured coating film, and the dimensional accuracy of the cured coating film is improved.

  According to the aspect of the present invention, since a perylene-based black colorant having a light transmittance of 3% or more at a wavelength of 300 to 400 nm is blended, it is ensured that the coating film is not dropped or lost due to insufficient photocuring in the deep part of the coating film. And resolution and dimensional accuracy are improved.

  According to the aspect of the present invention, the a * value can be adjusted from the positive value side to the vicinity of the 0 value while lowering the L * value measured with a color difference meter by further blending a blue colorant as necessary. Therefore, it is easy to adjust the darkness and color condition of black.

  According to the aspect of the present invention, by further adding a yellow colorant, the b * value can be adjusted from the minus value side to the vicinity of the 0 value while decreasing the L * value measured with a color difference meter. It is easy to adjust the darkness and color.

  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 comprises (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a diluent, (D) an epoxy compound, and (E) a black coloring. A black curable resin composition containing an agent, wherein the (E) black colorant contains (E-1) a carbon black black colorant and (E-2) a perylene black colorant. In the (E) black colorant, the content of the (E-2) perylene 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 is a photosensitive carboxyl group-containing resin having at least one photosensitive unsaturated double bond, photosensitive unsaturated double bond. Any carboxyl group-containing resin having no bond can be used. As an example of the component (A), at least a part of the epoxy group of a polyfunctional epoxy resin having two or more epoxy groups in the molecule is reacted with a radically polymerizable unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid. Mention may be made of polybasic acid-modified epoxy (meth) acrylates obtained by obtaining (meth) acrylates and reacting the produced hydroxyl groups with polybasic acids or anhydrides thereof.

  Any polyfunctional epoxy resin may be used as long as it is a bifunctional or higher functional epoxy resin, and there is no particular limitation on the epoxy equivalent, but one having a molecular weight of usually 1000 or less, preferably 100 to 500 is used. Examples of the polyfunctional epoxy resin include biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, rubber modified epoxy resin such as silicone modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol A type, bisphenol. Phenol type novolak type epoxy resin such as F type, bisphenol AD type, cresol novolak type epoxy resin such as о-cresol novolak type, bisphenol A novolak type epoxy resin, cyclic aliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, Glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol modified novolac type epoxy resin, polyfunctional modified novolak type epoxy resin, phenols and phenolic hydroxyl group Examples thereof include condensate type epoxy resins with aromatic aldehydes. Moreover, what introduce | transduced halogen atoms, such as Br and Cl, to these resin can also be used. Of these, rubber-modified epoxy resins such as silicone-modified epoxy resins are preferred from the viewpoint of the flexibility of the coating film. These epoxy resins may be used alone 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. At least one of acrylic acid and methacrylic acid (hereinafter referred to as (meth)). Acrylic acid is sometimes preferred.) Acrylic acid is particularly preferred. What reacted (meth) acrylic acid is epoxy (meth) acrylate. There is no restriction | limiting in particular in the reaction method of an epoxy resin and radically polymerizable unsaturated monocarboxylic acid, For example, it can react by heating an epoxy resin and acrylic acid in a suitable diluent.

  The polybasic acid or polybasic acid anhydride reacts with a hydroxyl group generated by the reaction between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid to give the resin a free carboxyl group. The polybasic acid to be used or its anhydride is not particularly limited, and either saturated or unsaturated can be used. Polybasic acids include, for example, succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4- Ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydro Examples include phthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid, and diglycolic acid. Examples of polybasic acid anhydrides include these anhydrides. These compounds may be used alone or in combination of two or more.

  In the present invention, the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin can also be used as a photosensitive resin. However, one or more carboxyl groups in the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin have one or more. It is good also as the photosensitive resin which further introduce | transduced the radically polymerizable unsaturated group by making the glycidyl compound which has a radically polymerizable unsaturated group and an epoxy group react, and also improved photosensitivity.

  The photosensitive resin with improved photosensitivity has a photopolymerization reaction because the radical polymerizable unsaturated group is bonded to the side chain of the polymer skeleton of the precursor photosensitive resin by the reaction of the last glycidyl compound. It has high properties and can have excellent photosensitivity. Examples of the compound having one or more radically polymerizable unsaturated groups and an epoxy group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, and the like. In addition, you may have multiple glycidyl groups in 1 molecule. The above-mentioned compounds having one or more radically polymerizable unsaturated groups and epoxy groups may be used alone or in combination of two or more.

  The lower limit of the acid value of the carboxyl group-containing photosensitive resin is 30 mg KOH / g, preferably 40 mg KOH / g, from the viewpoint of reliable alkali development. On the other hand, the upper limit of the acid value is 200 mgKOH / g from the viewpoint of preventing dissolution of the exposed area with an alkali developer, and 150 mgKOH / g is preferable from the viewpoint of preventing moisture resistance of the cured product and preventing deterioration of electrical characteristics.

  The lower limit of the weight average molecular weight of the carboxyl group-containing photosensitive resin is 3000, preferably 5000, from the viewpoint of the toughness of the cured product and the touch drying property. 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 the diluent (C) and the like and smooth alkali developability.

  Examples of commercially available carboxyl group-containing photosensitive resins include ZFR-1124, FLX-2089 (manufactured by Nippon Kayaku Co., Ltd.), Cyclomer P (ACA) Z-250 (Daicel Chemical Industries ( Co., Ltd.), Lipoxy SP-4621 (manufactured by Showa Polymer Co., Ltd.) and the like. These resins may be used alone or in combination of two or more.

(B) Photopolymerization initiator The photopolymerization initiator is not particularly limited as long as it is generally used. For example, oxime initiators, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin -N-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane- 1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy -2-propyl Ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2- Examples include ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4 diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, and P-dimethylaminobenzoic acid ethyl ester. These may be used alone or in combination of two or more. The compounding quantity of a photoinitiator is 5-20 mass parts with respect to 100 mass parts of carboxyl group-containing photosensitive resin, and 8-15 mass parts is preferable.

(C) Diluent Diluent is, for example, a photopolymerizable monomer that is a reactive diluent, and sufficiently cures the carboxyl group-containing photosensitive resin to have acid resistance, heat resistance, alkali resistance, and the like. Used to get things. Examples of the photopolymerizable monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) phosphate ) Acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate Rate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta Examples include reactive diluents such as (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more. The compounding quantity of an above-described reactive diluent is 2.0-40 mass parts with respect to 100 mass parts of carboxyl group-containing photosensitive resin, and 10-25 mass parts is preferable.

  Moreover, in order to adjust the viscosity and drying property of a black curable composition as a diluent, it replaces with the said reactive diluent or uses the organic solvent which is a non-reactive diluent with the said reactive diluent. Also good. 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 alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. Petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl Examples include acetates such as carbitol acetate. The amount of the organic solvent used is preferably 40 to 500 parts by weight with respect to 100 parts by weight of the carboxyl group-containing photosensitive resin.

(D) Epoxy compound The epoxy compound is for increasing the crosslinking density of the cured product to obtain a cured coating film having sufficient mechanical strength. Examples of the epoxy compound include 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 novolak type epoxy resin, p-tert-butylphenol novolak type, etc.), bisphenol F and bisphenol S with epichlorohydrin. Bisphenol F-type and bisphenol S-type epoxy resins obtained by reaction, alicyclic epoxy resins having cyclohexene oxide groups, tricyclodecane oxide groups, cyclopentene oxide groups, and the like, tris (2,3-epoxypropyl) isocyanurate , Triglycidyl isocyanurate having a triazine ring such as triglycidyl tris (2-hydroxyethyl) isocyanurate, dicyclopentadiene type epoxy resin, Adama It can be exemplified Tan type epoxy resin. These compounds may be used alone or in combination of two or more. The compounding quantity of an epoxy compound is 10-50 mass parts with respect to 100 mass parts of carboxyl group-containing photosensitive resin from the point which obtains the coating film of sufficient mechanical strength after hardening, and 20-30 mass parts is preferable. .

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

(E-1) Carbon black-based black colorant The carbon black-based black colorant imparts concealing power and jet blackness to a cured product. An example of the carbon black black colorant is carbon black. The type of carbon black is not particularly limited, and examples thereof include furnace black, channel black, and acetylene black. Examples of the carbon black pigment include those having a color index number such as CI pigment black 6, 7, 9, 18 or the like. These may be used alone or in combination of two or more.

(E-2) Perylene-based black colorant The perylene-based black colorant imparts concealing power and blackness to the cured product formed from the black curable resin composition of the present invention, and ultraviolet rays are applied to the black curable resin composition. It imparts light transparency. The kind of the perylene-based black colorant is not particularly limited, but a perylene-based black colorant having a light transmittance of 3% or more at a wavelength of 300 to 400 nm is preferable from the viewpoint of photocuring in the deep part of the coating film. It is easy to adjust the color condition of black, that is, to reduce the color tone such as redness contained in black and impart jetness, or to suppress discoloration after heat resistance, the above light transmittance characteristics A perylene-based black colorant having a light transmittance of 20% or less in addition to light having a wavelength of 400 to 700 nm is more preferable. Furthermore, in addition to the above-described light transmittance characteristics at wavelengths of 300 to 400 nm and wavelengths of 400 to 700 nm, it is at least between 1669 and 1671 cm ⁻¹ , and between 1548 and 1550 cm ⁻¹ , from the point that imparting jetness is easier. , during 1498～1500Cm ^-1, during 1402～1404Cm ^-1, during 1283～1285Cm ^-1, during 822～824Cm ^-1, absorption between during 763～765Cm ^-1 and 739～741Cm ^-1 A perylene-based black colorant having an infrared absorption peak at a position is particularly preferable.

  Examples of perylene-based black colorants having a light transmittance of 3% or more at a wavelength of 300 to 400 nm include, for example, “Paliogen Black S 0084”, “Lumogen Black FK 4280”, and “Lumogen Black FK” manufactured by BASF Akchengezelshaft. 4281 "and the like. Among these, “Lumogen Black FK 4280” and “Lumogen Black” are perylene black colorants having a light transmittance of 3% or more at a wavelength of 300 to 400 nm and a light transmittance of 20% or less at a wavelength of 400 to 700 nm. FK 4281 ”. “Paliogen Black S 0084” has a light transmittance of 20% or less on the shorter wavelength side than the wavelength of 680 nm, but a light transmittance of more than 20% at a wavelength of 680 nm or more. “Lumogen Black FK 4280” has a light transmittance of 20% or less at a wavelength of 300 to 750 nm. “Lumogen Black FK 4281” has a light transmittance of 20% or less at a wavelength of 300 to 900 nm.

Among them, in addition to the transmittance characteristics of the optical wavelength 300~400nm and wavelength 400~700nm described above, further for at least 1669～1671Cm ^-1, during 1548～1550Cm ^-1, during 1498～1500Cm ^-1, during the 1402~1404cm ^-1, during 1283~1285cm ^-1, during 822~824cm ^-1, it has an infrared absorption peak in the absorption position between between 763～765Cm ^-1 and 739～741Cm ^-1 Examples of perylene black colorants include “Lumogen Black FK 4281”. Incidentally, "Lumogen Black FK 4280" is above the respective absorption position does not have an infrared absorption peak, at least during 1542～1544Cm ^-1, during 1502～1504Cm ^-1, between 1284～1286Cm ^-1 And an infrared absorption peak at an absorption position between 748 and 750 cm ⁻¹ . These perylene-based black colorants may be used alone or in combination of two or more.

  In addition to the above-described black colorants, known black colorants such as aniline black, titanium black, azo black, and graphite may be further blended as necessary.

  The lower limit of the blending amount of the black colorant is 0.1 parts by mass with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin from the point of imparting a concealing force and blackness to the cured product, and the appearance of black From the point of view, 0.2 part by mass is preferable. The upper limit of the blending amount of the black colorant is 20 parts by mass from the point of forming a fine cured coating line with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, and the resolution and dimensions of the cured product. From the point of obtaining accuracy, 10 parts by mass is preferable. The lower limit of the content of the perylene-based black colorant in the total amount of the black colorant is 53% by mass from the viewpoint of ultraviolet light transmission, and 60% by mass from the point of photocurability in the deep part of the coating film. And 65 parts by mass is particularly preferable from the viewpoint of resolution. On the other hand, for the content of the perylene-based black colorant in the total amount of the black colorant, the upper limit is 90% by mass from the point of imparting jet blackness by bringing the a * value close to 0, and the L * value is lowered. That is, 85% by mass is preferable from the viewpoint of obtaining blackness, and 80% by mass is particularly preferable from the viewpoint of appearance as black.

(F) Blue colorant The blue colorant is added to the cured product formed from the black curable resin composition of the present invention by lowering the L * value by the color difference meter to increase the blackness and adding the a * value by the color difference meter. It mix | blends in order to give a jet blackness close to the 0 value direction from the side. When a carbon black black colorant and a perylene black colorant are blended, redness appears in the color tone of the cured product and may have a positive a * value. From this, by adding a blue colorant, the a * value of the cured product approaches 0 value, redness is suppressed, and the cured product has jetness.

  The type of the blue colorant is not particularly limited, and examples thereof include phthalocyanine-based, anthraquinone-based, and dioxazine-based pigments. Specific examples of the blue colorant 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, and Pigment Blue 60. And the like with color index numbers. Of these, the phthalocyanine type is preferable from the viewpoint that the adjustment of the darkness and color condition of black is easy and jet blackness is easily obtained. These may be used alone 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 is brought close to the 0-value direction to suppress redness. If the a * value of the cured product having a predetermined thickness is in the vicinity of the 0 value (for example, in the range of −2 to 2), the blue colorant may not be added. A predetermined amount of a blue colorant may be added in order to bring out jetness. When adjusting the color tone with darkness and redness of black, for example, the lower limit of the blending amount is 5 mass from the point of producing jet blackness by suppressing the redness of the cured product with respect to 100 mass parts of the black colorant. Part is preferable, and 10 parts by mass is particularly preferable from the viewpoint of blackness. Further, 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 close to 0 value, and particularly preferably 30 parts by mass from the viewpoint of resolution.

(G) Yellow colorant The yellow colorant increases the blackness by lowering the L * value by a color difference meter to the cured product formed from the black curable resin composition of the present invention, and minus the b * value by a color difference meter. It mix | blends in order to give a jet blackness close to the 0 value direction from the side. When a carbon black black colorant and a perylene black colorant are blended, purple color appears in the color tone of the cured product and may have a negative b * value. From this, by adding a yellow colorant, b * value of hardened | cured material approaches 0 value, purpleness is suppressed, and hardened | cured material comes to have jet blackness.

  The kind of the yellow colorant is not particularly limited, and examples thereof include anthraquinone series, monoazo series, disazo series, condensed azo series, benzimidazolone series, and isoindolinone series. Specific examples of the yellow colorant include Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202 (above, anthraquinone series), 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, monoazo), Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198 (above, disazo 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, benzimidazolone series), Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185 (above, isoindolinone series) Include those of the index number. Among these, an anthraquinone type is preferable in terms of easy adjustment of blackness and color and easy jetting. 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 is brought closer to the 0-value direction and the purple color is suppressed. If the b * value of the cured product having a predetermined thickness is in the vicinity of 0 value (for example, in the range of −2 to 2), it is not necessary to add a yellow colorant. A predetermined amount of a yellow colorant may be added in order to bring closeness and bring out jetness. When adjusting the darkness and purple color tone of black, for example, the lower limit of the blending amount is 5 parts by mass from the point of producing a jet blackness by suppressing the purpleness of the cured product with respect to 100 parts by mass of the black colorant. 10 parts by mass is particularly preferable from the viewpoint of blackness. Further, 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 b * value of the cured product close to 0 value, and particularly preferably 30 parts by mass from the viewpoint of resolution.

  About the color tone of the hardened | cured material of the black curable resin composition of this invention, 30 or less are preferable from the point of blackness, and L * value by a color difference meter has especially preferable 25 or less. Moreover, as for the a * value and b * value by a color difference meter, -3-3 are both preferable from a jet black point, and -2-2 are especially preferable. Further, the transmittance of light having a wavelength of 400 nm in a cured product having a film thickness of 20 μm is preferably 7% or more, particularly preferably 8% or more, from the viewpoint of photocurability in the deep part of the coating film. Therefore, the black curable resin composition of the present invention takes into account the above-described components (A) to (D) and any of the following optional factors while taking into account the L * value, a * value, b * value, and transmittance of the cured product. Ingredients, and colorants of the above components (E) to (G) are blended in an appropriate blending ratio.

  In the black curable resin composition of the present invention, in addition to the above components, various additive components such as antifoaming agents, various additives, extender pigments, thickeners and the like can be appropriately blended as necessary. it can.

  A well-known thing can be used for an antifoamer, for example, a silicone type, a hydrocarbon type, an acrylic type etc. can be mentioned. Examples of additives include dispersants such as coupling agents such as silane, titanate, and alumina, boron trifluoride-amine complex, dicyandiamide (DICY) and its derivatives, organic acid hydrazide, and diaminomaleonitrile (DAMN). And its derivatives, melamine and its derivatives, guanamine and its derivatives, amine imide (AI) and latent curing agents such as polyamine, metal salts of acetylacetone such as acetylacetonate Zn and acetylacetonate Cr, enamine, tin octylate, Examples thereof include quaternary sulfonium salts, triphenylphosphine, imidazole, imidazolium salts and curing accelerators such as triethanolamine borate. The extender is for increasing the physical strength of the cured product, and examples thereof include silica, barium sulfate, alumina, aluminum hydroxide, talc, and mica. Moreover, organic bentonite etc. can be mentioned as a thickener.

  The method for producing the black curable resin composition of the present invention described above is not limited to a specific method. For example, the components described above are mixed at a predetermined ratio and then mixed and dispersed at room temperature with a three roll. Can do.

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

  The black curable resin composition of the present invention produced as described above, for example, on a printed wiring board having a circuit pattern formed by etching a copper foil, screen printing method, roll coater method, bar coater method, spray coater Apply to the desired thickness using the method, curtain flow coater method, gravure coater method, etc., and heat for about 15-60 minutes at a temperature of about 60-80 ° C. to volatilize the solvent in the black curable resin composition Pre-drying is performed to form a tack-free coating film. Then, the negative film which has the pattern which made translucent except the land of the said circuit pattern was stuck on the apply | coated black curable resin composition, and an ultraviolet-ray is irradiated from it. Then, the coating film is developed by removing the non-exposed areas corresponding to the lands with a dilute alkaline aqueous solution. As a developing method, a spray method, a shower method, or the like is used. As a dilute alkali aqueous solution used, a 0.5 to 5% sodium carbonate aqueous solution is generally used, but other alkalis can also be used. Next, it is thermally cured by performing post-cure for 20 to 80 minutes with a hot-air circulating dryer or the like at 130 to 170 ° C. to form a cured coating film of the target black curable resin composition on the printed wiring board. be able to.

  An electronic circuit unit is formed by soldering an electronic component to the printed wiring board coated with the cured coating film thus obtained by a jet soldering method, a reflow soldering method, or the like.

  The black curable resin composition of the present invention, in addition to the application to be applied to a printed wiring board as a solder resist, by an appropriate coating method, the backlight for streetlights, the backsheet surface for solar cells with emphasis on aesthetics, It can also be used on the backsheet surface of LEDs.

  Next, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Examples 1-13, Comparative Examples 1-5
Each component shown in the following Table 1 is blended at the blending ratio shown in the following Table 1, and after preliminary mixing with a stirrer, the mixture is dispersed at room temperature using three rolls, Examples 1 to 13, Comparative Example The black curable resin composition used in 1-5 was prepared. And the prepared black curable resin composition was apply | coated on the board | substrate using the test piece preparation process mentioned later, and the test piece was created. Unless otherwise indicated, the compounding quantity of each component shown in following Table 1 shows a mass part.

The details of each component in Table 1 are as follows.
(A) Carboxy group-containing photosensitive resin / Lipoxy SP-4621: Polybasic acid-modified cresol novolac epoxy acrylate resin (B) Photopolymerization initiator / Irgacure 907: Ciba Specialty Chemicals 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one Irgacure 369: Ciba Specialty Chemicals Co., Ltd., 2-Benzyl-2-dimethyl Amino-1- (4-morpholinophenyl) -butanone-1
(C) Diluent / EDGAC: Sanyo Chemical Co., Ltd., diethylene glycol monoethyl ether acetate (D) epoxy compound / EPCRON 860: Dainippon Ink & Chemicals, bisphenol A type epoxy resin (E) black colorant・ Carbon black: Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.
・ LUMOGEN BLACK FK4281: manufactured by BASF Akchengezelshaft ・ LUMOGEN BLACK FK4280: manufactured by BASF Aktiengesellschaft : Toyo Ink Mfg. Co., Ltd., Phthalocyanine pigment (G) Yellow colorant, Chromophthalo Yellow AGR: Ciba Specialty Chemicals Co., Ltd., anthraquinone pigment, etc., DICY-7 is Japan Epoxy Resin ( It is a curing accelerator manufactured by Co.

Test piece preparation process After the glass epoxy substrate (FR-4) having a circuit pattern formed thereon was surface-treated by buffing, the black curable resin compositions of Examples 1 to 13 and Comparative Examples 1 to 5 were screen printed. After each coating, preliminary drying was performed at 80 ° C. for 20 minutes in a BOX furnace. After preliminary drying, the coating film was exposed to 500 mJ / cm ² with an exposure device (OMW HMW-680GW), developed with 30 ° C., 1% aqueous sodium carbonate solution, and then heated at 150 ° C. in a BOX furnace at 60 ° C. And a cured coating film of the black curable resin composition was formed on the glass epoxy substrate to prepare a test piece. The thickness of the cured coating film was 20 μm.

Evaluation (1) Resolution The remaining line and the missing space of the exposed part formed through a predetermined photomask (line 30 to 130 μm) were visually confirmed and evaluated.
(2) Undercut For a substrate on which a cured coating line was formed using a photomask having a width of 100 μm, the substrate was cut and the line was observed from the cut surface. The width (x) on the surface side of the line and the bottom side (deep part) Side) width (y) was measured, and undercut was evaluated from (xy) / 2.
(3) L * value, a * value, b * value Measured with a color difference meter SE2000 (Nippon Denshoku Industries Co., Ltd.).
(4) Transmittance The glass epoxy substrate on which the cured coating film was formed was measured by measuring the transmittance of light with a wavelength of 400 nm, and using the separately measured transmittance of light with a wavelength of 400 nm of the glass epoxy substrate alone as a curing. The transmittance of the coating film was measured. A UV spectrophotometer U-3310 (Hitachi High Technology Co., Ltd.) was used for the transmittance measurement.
(5) Discoloration after heat resistance after soldering After the test piece was immersed in a solder bath at 260 ° C. for 20 seconds, the state of the cured coating film was visually observed to evaluate the degree of discoloration.

  Table 2 shows the resolution, undercut, L * value, a * value, b * value, transmittance, and discoloration after solder heat resistance of Examples 1 to 13 and Comparative Examples 1 to 5.

  From Examples 1 to 13 and Comparative Examples 1 to 4 in Table 2, a mixture of carbon black and a perylene-based black colorant, and a black colorant having a blending ratio of the perylene-based black colorant of more than 52% by mass is used. Then, the transmittance of light with a wavelength of 400 nm was improved, and a cured product having excellent resolution and low undercut was obtained. Furthermore, the a * value was able to suppress a large departure from the 0 value even if it was not near the 0 value (for example, in the range of −2 to 2) or near the 0 value. Thus, since the black curable resin composition of the present invention has a light transmittance of 7.5% or more at a film thickness of 20 μm of the cured coating film of 7.5% or more, it can be photocured to the deep part of the coating film. Moreover, since it can be photocured to the deep part of the coating film, it has a resolution of 70 μm or less, and therefore can be applied to fine pitch circuit patterns. Furthermore, since the undercut can be suppressed to 26 μm or less, even if the circuit pattern has a fine pitch, it is possible to prevent line peeling and chipping and improve the dimensional accuracy of the line. And since the a * value can be kept low, it is easy to adjust the blackness, that is, to reduce the shade of red, purple, etc. in the black and bring out jetness.

  Further, from Examples 2, 8 and 10, a perylene-based black coloring having a light transmittance of 3% or more at a wavelength of 300 to 400 nm and a light transmittance of 400 to 700 nm is also 20% or less. The agents “Lumogen Black FK 4281” (Example 2) and “Lumogen Black FK 4280” (Example 8) have “Paliogen Black S 0084” having a light transmittance of more than 20% at a wavelength of 680 to 700 nm. Since the L * value can be kept lower than in Example 10), and the a * value and b * value can be brought closer to the zero value, the hue such as redness and purpleness can be suppressed while increasing the blackness. It was easier to achieve jetness.

Also, from Examples 2 and 8, between the 1669～1671Cm ^-1, during 1548～1550Cm ^-1, during 1498～1500Cm ^-1, during 1402～1404Cm ^-1, during 1283~1285cm ^-1, 822 during the ~824cm ^-1, during 763~765cm ^-1, a perylene black colorant having an infrared absorption peak in the absorption position between 739～741Cm ^-1 "Lumogen black FK 4281" (example 2) , Because L * value was kept lower than “Lumogen Black FK 4280” (Example 8), and a * value and b * value could be brought closer to 0 value. It was easier.

  Further, when a perylene-based black colorant having a light transmittance of 300 to 400 nm for light of 3% or more and a light transmittance of 400 to 700 nm for light of 20% or less is used, color change after solder heat resistance is suppressed. I was able to.

  Moreover, from Examples 1-9, 9-19 mass parts of blue colorants and 30 mass parts or less of yellow colorants are blended with respect to 100 mass parts of the black colorant, whereby a * value and b * value are obtained. All were made into the range of -2-2, and hues, such as reddishness in black, were suppressed and jet blackness could be given to hardened | cured material.

  From Comparative Example 5, when the blending amount of the black colorant was 21.8 parts by mass or more with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin, the cured product line did not remain and the resolution was deteriorated.

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

Claims (12)

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 colorant. Because
The (E) black colorant contains (E-1) a carbon black-based black colorant and (E-2) a perylene-based black colorant, and the (E- 2) The black curable resin composition, wherein the content of the perylene-based black colorant is 53% by mass or more.   The black curable resin composition according to claim 1, wherein the (E-2) perylene black colorant has a light transmittance of 3% or more at a wavelength of 300 to 400 nm.   The black curable resin composition according to claim 1 or 2, wherein the (E-2) perylene black colorant has a light transmittance of 20% or less at a wavelength of 400 to 700 nm. The (E-2) perylene-based black colorant has an infrared absorption spectrum measurement of at least 1669 to 1671 cm ⁻¹ , 1548 to 1550 cm ⁻¹ , 1498 to 1500 cm ⁻¹ , 1402 to 1404 cm ^−. during the ^1, during 1283～1285Cm ^-1, during 822～824Cm ^-1, during 763～765Cm ^-1, claims, characterized in that it comprises an infrared absorption peak in the absorption position between 739～741Cm ^-1 Item 4. The black curable resin composition according to any one of Items 1 to 3.   The black curable resin composition according to claim 1, further comprising (F) a blue colorant.   The black curable resin composition according to claim 5, wherein the (F) blue colorant is a phthalocyanine-based blue colorant.   Furthermore, (G) yellow coloring agent is contained, The black curable resin composition of Claim 5 or 6 characterized by the above-mentioned.   The black curable resin composition according to claim 7, wherein the (G) yellow colorant is an anthraquinone yellow colorant.   Hardened | cured material which hardened the black curable resin composition of any one of Claims 1 thru | or 8.   The L * value is 25 or less, and both a * value and b * value are in the range of -2 to 2, and the cured product according to claim 9.   The cured product according to claim 9 or 10, wherein the 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, wherein the black curable resin composition according to any one of claims 1 to 8 is applied as a solder resist.