JP2020200449A - Curable resin composition, dry film, cured product and printed wiring board - Google Patents

Abstract

To provide a curable resin composition that gives a small variation in the film thickness of coating films prior to drying or coating films after drying even in a thin film state, and avoids visibility of an underlay metal wire.SOLUTION: The curable resin composition of the present invention comprises a curable resin and an extender. A cured film of the curable resin composition having a film thickness of 12 μm after cured shows a glossiness of 0.5 or more and 40.0 or less at angle of 60°. When 0.3 g of the curable resin composition is mixed with 30 g of propylene glycol monomethylether acetate and measured by use of Microtrac, an average particle diameter D50 is 0.1 μm or more and 1.0 μm or less and a specific surface area CS is 10.0 m2/ml or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a curable resin composition. Furthermore, the present invention relates to a dry film, a cured product, and a printed wiring board using the curable resin composition.

Currently, liquid alkali-developed solder resist ink is used for the solder resist of most printed wiring boards from the viewpoint of high accuracy and high density. Specifically, the coating film after printing and drying the ink. Is exposed and developed to form an image, which is obtained by heating and curing.

By the way, it is known that roughening the solder resist layer improves solder adhesion resistance and wiring concealment during solder flow. Further, since the glossiness of the roughened solder resist layer is appropriately suppressed, good designability can be obtained. For example, Patent Document 1 proposes that the solder resist layer is roughened to reduce the gloss by adding a matting agent to the photosensitive resin composition.

Further, in recent years, from the viewpoint of improving the yield at the time of component mounting, the film thickness of the coating film after drying or curing has been reduced (for example, Patent Document 2). In recent years, stricter film thickness control has been required for thin films.

Japanese Unexamined Patent Publication No. 9-157574 Japanese Unexamined Patent Publication No. 2004-264560

Generally, an extender pigment or a resin is contained in the curable resin composition for the purpose of reducing warpage and improving heat resistance during component mounting. However, since a plurality of components other than the extender pigment and the resin are mixed in the curable resin composition in order to satisfy various required properties, if the mixed state of each component is insufficient, the curing is performed. Concentration imbalances sometimes occurred in the sex resin composition. Therefore, the film thickness of the coating film before drying (hereinafter, also referred to as the coating film before drying) applied to the substrate or the like using the curable resin composition varies, and particularly when the film thickness is thin, for example, the metal of the substrate under the coating film (hereinafter, also referred to as the coating film before drying). (Copper) There was a problem of poor appearance due to "copper visibility" where the wiring became uneven and could be seen through. Further, when the cured coating film (hereinafter, also referred to as a cured coating film) has a low gloss, the problem of poor appearance is more remarkable in the cured coating film. It is presumed that the lower the gloss of the coating film, the higher the contrast, and the more uneven the gloss of the underlying metal (copper) wiring becomes, making it easier to see through.

If the film thickness of the coating film before drying varies widely, the film thickness of the coating film after drying (hereinafter, also referred to as dry coating film) and the coating film after curing may vary widely, so that the substrate is particularly expensive. When NG is determined based on the size of the variation in the film thickness of the coating film before drying and the variation is repaired, the manufacturing process becomes complicated and the productivity may decrease. As described above, in addition to the small variation in the film thickness of the coating film after drying, the small variation in the film thickness of the coating film before drying may be regarded as important.

Therefore, an object of the present invention is to provide a curable resin composition in which the variation in the film thickness of the pre-drying coating film and the dry coating film is small even when the thin film is formed, and the copper appearance phenomenon does not occur. Another object of the present invention is a dry film having a resin layer composed of a dry coating film of the resin composition, a cured product of the resin composition or the resin layer of the dry film, and a printed wiring board having the cured product. Is to provide.

The present inventors have conducted intensive studies and as a result, powder, particularly in the curable resin composition containing the extender pigment to adjust the measured value using the Microtrac, specifically a mean particle diameter D ₅₀ By adjusting not only the value but also the specific surface area CS, the influence of the powder on the coating film surface before and after drying is reduced, and as a result, the film thickness of the coating film before and after drying is reduced even when the film is thin. The present invention has been completed by finding that a curable resin composition having a small variation in the amount of particles and which does not cause a copper appearance phenomenon can be obtained.

That is, the curable resin composition according to the present invention is a curable resin composition containing a curable resin and an extender pigment.
The glossiness at 60 ° in the cured coating film having a film thickness of 12 μm after curing of the curable resin composition is within the range of 0.5 or more and 40.0 or less.
When 0.3 g of the curable resin composition is mixed with 30 g of propylene glycol monomethyl ether acetate and measured using Microtrac, the value of the average particle diameter D ₅₀ is 0.1 μm or more and 1.0 μm or less, and the specific surface area. It is characterized in that CS is 10.0 m ² / ml or more.

In the aspect of the present invention, it is preferable that the average interval Sm of the unevenness of the coating film thickness after drying of the curable resin composition is in the range of more than 0 μm and 12.0 μm or less.

In the aspect of the present invention, it is preferable that the maximum height Ry of the coating film thickness after drying of the curable resin composition is in the range of more than 0 μm and 8.0 μm or less.

In the aspect of the present invention, it is preferable that the extender pigment is at least one of silica and barium sulfate.

In the aspect of the present invention, it is preferable that the silica contains amorphous silica having an oil absorption amount of 180 to 350 ml / 100 g.

In the aspect of the present invention, it is preferable that the curable resin contains a carboxyl group-containing resin.

In the aspect of the present invention, it is preferable that the curable resin contains two or more kinds of carboxyl group-containing resins.

In the aspect of the present invention, it is preferable that at least one of the two or more kinds of carboxyl group-containing resins is a carboxyl group-containing copolymer resin.

A dry film according to another aspect of the present invention is characterized by comprising a support film and a resin layer composed of a dry coating film of the curable resin composition formed on the support film.

A cured product according to another aspect of the present invention is characterized in that it is obtained by curing the curable resin composition or the resin layer of the dry film.

A printed wiring board according to another aspect of the present invention is characterized by comprising the cured product.

According to the present invention, it is an object of the present invention to provide a curable resin composition in which the thickness variation of the pre-drying coating film and the dry coating film is small even when the thin film is formed, and the copper appearance phenomenon does not occur. Further, according to the present invention, a dry film having a resin layer composed of a dry coating film of the resin composition, a cured product of the resin composition or the resin layer of the dry film, and a printed wiring board having the cured product. Can be provided.

It is explanatory drawing when the variation of the dry coating film was measured by the step analysis of the surface roughness measuring machine in an Example.

[Curable resin composition]
The curable resin composition according to the present invention contains a curable resin and an extender pigment. The curable resin composition according to the present invention may further contain a photopolymerization initiator, a sensitizer, a thermosetting catalyst, a colorant and the like as long as it satisfies the following physical properties. Further, the curable resin may contain any one of a thermosetting resin, a carboxyl group-containing resin and a photopolymerizable monomer, and may be a combination of a plurality of types. By satisfying the following physical properties, the curable resin composition according to the present invention can obtain a coating film before and after drying, which has less variation and sagging during coating and less variation in film thickness even when thin film is used. After curing, it is possible to obtain a cured coating film in which the copper appearance phenomenon does not occur. In the present invention, the thin film usually refers to a case where the thickness of the coating film is 20 μm or less before drying and 12 μm or less after drying or curing.

[Physical properties]
The curable resin composition of the present invention has a glossiness of 60 ° in a cured coating film having a film thickness of 12 μm after curing in the range of 0.5 or more and 40.0 or less, preferably 0.8 or more and 35.0 or less. It is more preferably 1.0 or more and 20.0 or less, further preferably 1.0 or more and 10.0 or less, and particularly preferably 2.0 or more and 6.0 or less.
The glossiness can be measured according to JIS Z 8741. A specific method for measuring glossiness will be described. As a premise, on a surface having a refractive index of 1.067, when the incident angle is 60 °, the intensity of light having a reflectance of 10% is assumed to be 100, and the intensity of light having a reflectance of 0% is assumed to be 0. To do. As a result, a value of 1/100 of the intensity of light having a reflectance of 10% corresponds to glossiness 1. The intensity of light on the surface of the cured coating film provided on the substrate is measured using a reflectance meter under geometric conditions with an incident angle of 60 °. Then, the glossiness is calculated by dividing the obtained light intensity by a value of 1/100 of the above-mentioned light intensity having a reflectance of 10%. Simply, a digital variable gloss gloss meter (Micro-Tri-Gloss, manufactured by BYK Gardener) can be used to measure the gloss of each angle on the surface of the cured coating film provided on the substrate. it can. The "60 ° glossiness (Gs (60 °))" is a value of glossiness when the measurement conditions are incident angle = 60 ° and light receiving angle = 60 °.

The cured coating film in the present invention refers to a coating film in which a curable resin composition is cured by performing at least one of photocuring and thermosetting. On the other hand, the dry coating film in the present invention refers to a coating film in which the curable resin composition is dried by heat drying. As a heat-drying method, the surface is bafflor-polished on a 35 μm-thick 300 mm × 150 mm copper foil substrate, printed by screen printing so that the film thickness becomes 12 μm after drying, and heat-dried using a hot air circulation drying furnace. .. From the viewpoint of film thickness adjustment, it is preferable to use a polyester plate of 100 to 200 mesh (with bias), and it is preferable to use a polyester plate of 150 to 180 mesh (with bias) as the printing plate for screen printing. More preferred. Examples of the drying conditions include a temperature of 60 to 100 ° C. for 15 to 90 minutes. Examples of the device include DF610 manufactured by Yamato Scientific Co., Ltd.

On the other hand, as a photo-curing method, the dry coating film formed as described above is photo-cured by irradiation with active energy rays, specifically, a UV conveyor using a high-pressure mercury lamp. Examples of the irradiation amount include 1,000 to 2,000 mJ / cm ² . Examples of the device include QRM-2082 manufactured by ORC Manufacturing Co., Ltd.

As a thermosetting method, a 35 μm-thick 300 mm × 150 mm copper foil substrate whose surface is bafflor-polished is printed by screen printing so that the film thickness after curing is 12 μm, and heat is generated using a hot air circulation drying furnace. Hardens. As the printing plate for screen printing, it is preferable to use a polyester plate of 100 to 200 mesh (with bias), and it is preferable to use a polyester plate of 150 to 180 mesh (with bias) from the viewpoint of film thickness adjustment. More preferred. Examples of the thermosetting condition include 30 to 90 minutes at a temperature of 100 to 220 ° C.

Examples of the drying device used for drying and thermosetting include DF610 manufactured by Yamato Scientific Co., Ltd. When measuring the glossiness in the present invention, it is measured using a cured coating film formed without performing a developing step.

Further, the method for confirming whether or not the cured coating film is formed in the present invention can be confirmed by the following method. That is, in an environment of 25 ° C. and 50% RH, a waste cloth containing isopropyl alcohol (IPA) is placed on the surface of the cured coating film, a weight of 500 g is placed on the waste cloth, and the mixture is allowed to stand for 1 minute. A state in which all or part of the resin layer is not attached to the surface of the waste cloth that has been in contact with the cured coating film after the waste is peeled off is a "cured state", that is, a cured coating film is formed. Judge. On the other hand, the method for confirming whether or not the dry coating film is formed in the present invention is to "dry" the state in which the curable resin composition does not adhere to the finger when the coated surface of the curable resin composition is touched with a finger. It is judged that the dry coating film is formed.

The curable resin composition of the present invention has an average particle diameter D ₅₀ of 0.1 μm or more and 1.0 μm or less, and is preferably 0.1 μm or more and 0.8 μm or less in terms of further suppressing the copper appearance phenomenon. Yes, more preferably 0.1 μm or more and 0.5 μm or less.
Further, the curable resin composition of the present invention has a specific surface area CS of 10.0 m ² / ml or more, and while having a lower gloss, the film thickness of the coating film before and after drying varies even when it is a thin film. In terms of making it smaller and suppressing the copper appearance phenomenon, it is preferably 11.5 m ² / ml or more and 30.0 m ² / ml or less, and more preferably 13.0 m ² / ml or more and 25.0 m ² / ml or less. is there.

If the value of the average particle diameter D ₅₀ as the curable resin composition is 0.1 μm or more and 1.0 μm or less and the specific surface area CS is 10.0 m ² / ml or more, even in the case of a thin film, before or after drying. The variation in the film thickness of the coating film can be made smaller, and the copper appearance phenomenon can be suppressed. This is not always clear, but it is presumed as follows. That is, when the specific surface area CS is within the above range, the powder contained in the composition maintains a high dispersed state, and as a result, sagging occurs even when a thin film is formed using the composition. In addition, the powder contained therein has little effect on the surface of the coating film before and after drying, and as a result, it is considered that the copper appearance phenomenon is suppressed even in a low-gloss thin film. However, this is just a guess, and not necessarily this.

In the present invention, the average particle size D ₅₀ of the curable resin composition is such that the powders such as extender pigments contained in the composition are assumed to be a group of one powder, and the particle size distribution thereof is required. And. That is, when the cumulative curve is obtained with the total product of the assumed one powder group as 100%, the particle size at the point where the cumulative curve is 50% is set to 50% diameter (μm), and the average particle size D. It shall be ₅₀ . On the other hand, the specific surface area CS is the surface area per unit volume when the particle shape in the composition is assumed to be spherical. The above-mentioned average particle diameter D ₅₀ and specific surface area CS are those calculated by the following measurements, respectively. The specific surface area CS (Calculated Specific Surfaces Area) (m ² / ml) of the present invention has a different meaning from the specific surface area (m ² / g) measured by the BET type or other surface area measuring device. is there. First, prepare the following equipment and equipment to be used.
-Particle counter: Microtrack MT3300EX manufactured by Nikkiso Co., Ltd.
・ Circulatory device: ASVR manufactured by Nikkiso Co., Ltd.
Next, input the measurement conditions according to the following procedure. Launch the software attached to the microtrack ("particle size distribution measurement"), proceed from the SET UP screen, and set the time from the measurement condition setting options. Setzero time is 30 sec. , Measurement for 30 sec. , The number of measurements is set to 2. Next, enter the analysis conditions. In the analysis information, the refractive index of the particles is 1.81 (fixed value: the average value of the refractive indexes of all inorganic substances), the characteristics of the particles are transparent, and the shape is non-spherical. Further, in the solvent information, PMA (propylene glycol monomethyl ether acetate) is selected and the solvent refractive index is 1.4. Then enter the scale settings. In the particle size range, the minimum particle size is 0.021 μm and the maximum particle size is 704 μm. Then enter the sampling system. The ASVR was washed 4 times, the flow velocity was 50%, the ultrasonic output was 40 W, and the ultrasonic time was 300 sec. And. After entering all the measurement conditions, press Save to close the measurement condition settings.
Subsequently, the sample is adjusted according to the following procedure. Weigh 0.3 g of a sample (curable resin composition) into a screw bottle, add 30 g of propylene glycol monomethyl ether acetate little by little using a dropper, and dissolve the sample by shaking the screw bottle to prepare a prepared sample. To do. The prepared sample does not undergo external dispersion or pre-dispersion. Next, the adjustment sample is measured. Click the particle size distribution measurement of the software attached to the micro track to open the sample loading screen. Drop a few drops of the adjusted sample into the sample inlet of the main body using a dropper. When the red instruction bar is displayed on the sample loading screen, the adjustment sample is dropped into the sample inlet until it falls within the range from red to green. When it is within the green range, press the measurement button to start the measurement. The process from sample preparation to measurement of the adjusted sample should be performed within 5 minutes. The value of the cumulative average diameter of 50% and the value of the area average diameter MA displayed as the measurement results are read, respectively. The value of the cumulative average diameter of 50% is taken as the value of the average particle diameter D ₅₀ measured by the microtrack. Also, CS = 6 / MA is calculated. The calculated CS value is used as the value of the specific surface area measured by the microtrack.
MA is calculated by the following formula.
_{MA = Σ (a i · d} i) / Σ (a i) = Σ (v i) / Σ (v i / d i)
_{(A i:} surface area per particle, _{d i:} particle diameter of 1 per particle, _{v i:} volume per particle)

In order to make the value of the average particle size D ₅₀ as the curable resin composition 0.1 μm or more and 1.0 μm or less and the specific surface area CS 10.0 m ² / ml or more, a known and commonly used method is applied. However, for example, the selection of the components in the composition, the blending amount thereof, the dispersion method of the powder, the resin, etc. in the composition can be optimized.

In the curable resin composition of the present invention, the average spacing Sm of the unevenness of the coating film thickness after drying is preferably in the range of more than 0 μm and 12.0 μm or less, and more preferably in the range of 1.0 μm or more and 11.0 μm or less. It is more preferably in the range of 2.0 μm or more and 8.0 μm or less.
In the curable resin composition of the present invention, the maximum height Ry of the coating film thickness after drying is preferably in the range of more than 0 μm and 8.0 μm or less, and more preferably in the range of 0.1 μm or more and 6.5 μm or less. It is more preferably in the range of 0.2 μm or more and 2.5 μm or less.
When the average interval Sm and the maximum height Ry of the unevenness of the coating film thickness after drying of the curable resin composition are within the above numerical ranges, the variation in film thickness becomes smaller. This is not always clear, but it can be considered as follows. That is, the surface condition of the dry coating film is stable because the average spacing and the maximum height of the unevenness of the coating film thickness are constant, and as a result, the cured coating film has low gloss and even when it is thin. It is considered that the variation becomes small and the copper appearance phenomenon is suppressed. In the present invention, the average spacing Sm and the maximum height Ry of the unevenness of the coating film thickness shall be measured after being left to stand at room temperature for 30 minutes after being dried.

In the present invention, the above-mentioned "average interval Sm of unevenness" and "maximum height Ry" mean values measured by a measuring device conforming to JIS B0601-1994, respectively. Hereinafter, a specific measurement method will be described. The average spacing Sm and the maximum height Ry of the unevenness can be measured using a shape measuring laser microscope (for example, VK-X100 manufactured by KEYENCE CORPORATION). Shape measurement After starting the main body (control unit) of the laser microscope (VK-X100) and the VK observation application (VK-H1VX manufactured by KEYENCE CORPORATION), the sample to be measured on the xy stage (formed on the substrate, etc.) The dried coating film) is placed. Turn the lens revolver of the microscope unit (Keyence Co., Ltd. VK-X110) to select an objective lens with a magnification of 10 times, and roughly adjust the focus and brightness in the image observation mode of the VK observation application (VK-H1VX). To do. Operate the xy stage so that the part of the sample surface to be measured is in the center of the screen. The 10x magnification objective lens is changed to a 50x magnification, and the autofocus function of the image observation mode of the VK observation application (VK-H1VX) is used to focus on the surface of the sample. You can select the simple mode on the shape measurement tab of the VK observation application (VK-H1VX), press the measurement start button, measure the surface shape of the sample, and obtain a surface image file. After starting the VK analysis application (VK-H1XA manufactured by KEYENCE CORPORATION) and displaying the obtained surface image file, tilt correction is performed.
The observation measurement range (horizontal) in the measurement of the surface shape of the sample is 270 μm. Display the line roughness window, select JIS B0601-1994 in the parameter setting area, select the horizontal line from the measurement line button, display the horizontal line anywhere in the surface image, and press the OK button. , The values of the average spacing Sm (μm) and the maximum height Ry (μm) of the uneven surface are obtained. Further, horizontal lines were displayed at four different places in the surface image, and the values of the average spacing Sm (μm) and the maximum height Ry (μm) of each uneven surface were obtained. The average value of the obtained five numerical values is calculated and used as the average interval Sm value and the maximum height Ry value of the uneven surface of the sample surface.
As for Sm and Ry of the dry coating film, the surface of the substrate is generally sufficiently smoother than the surface of the cured coating film, so that the values of Sm and Ry are not affected by the type of substrate. As the substrate, a known and commonly used substrate can be used, but it is preferable to use a glass substrate.

In order to keep the coating thickness of the curable resin composition after drying within the range of the average interval Sm and the maximum height Ry of the specific irregularities described above, a known and commonly used method can be applied, for example, the composition. Examples include selection of components such as organic solvents in a product, optimization of the blending amount and dispersion method, or combination of the above-mentioned contents. Further, in order to keep the glossiness of 60 ° in the cured coating film having a coating film thickness of 12 μm of the curable resin composition within a specific range, the same known and commonly used method can be applied, but for example, average particles. Examples include adding an extender pigment having a coarse diameter, and mixing a plurality of types of resins having poor compatibility.

Hereinafter, each component constituting the curable resin composition according to the present invention will be described.

[Curable resin]
The curable resin includes a thermosetting resin that contributes to a thermosetting reaction by heating, a photocurable resin that contributes to a photocuring reaction by light irradiation, and a photocurable thermosetting resin that contributes to any of the reactions. Can be mentioned.
Here, the curable resin preferably contains a thermosetting resin and a photocurable resin, and when any of the curable resins is contained, the thermosetting resin is contained in the carboxyl group-containing resin and the molecule. It is more preferable to contain a compound having a plurality of cyclic ether groups or cyclic thioether groups.

The blending amount of the curable resin is preferably 20 to 80% by mass, more preferably 25 to 75% by mass, and further preferably 50 to 70% by mass in terms of solid content per total amount of the curable resin composition. is there. When the blending amount of the curable resin is within the above range, a more excellent cured product can be obtained. Hereinafter, each curable resin will be described.

[Thermosetting resin]
As the thermosetting resin, any known one can be used. When the curable resin composition contains a thermosetting resin, the heat resistance of the cured coating film can be improved. Examples of the thermosetting resin include amino resins such as melamine resin, benzoguanamine resin, melamine derivative, and benzoguanamine derivative, isocyanate compounds, blocked isocyanate compounds, cyclocarbonate compounds, epoxy compounds, oxetane compounds, episulfide resins, bismaleimide, and carbodiimide resins. A known thermosetting resin such as, etc. can be used. Particularly preferred is a thermosetting resin having a plurality of cyclic ether groups or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) in the molecule. The thermosetting resin may be used alone or in combination of two or more.

The thermosetting resin having a plurality of cyclic (thio) ether groups in the molecule is a compound having a plurality of 3, 4 or 5-membered cyclic (thio) ether groups in the molecule, and is, for example, in the molecule. Examples thereof include a compound having a plurality of epoxy groups, that is, a polyfunctional epoxy compound, a compound having a plurality of oxetanyl groups in the molecule, that is, a polyfunctional oxetane compound, and a compound having a plurality of thioether groups in the molecule, that is, an episulfide resin.

Examples of such epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, and phenol novolac type epoxy resin. Examples thereof include cresol novolac type epoxy resin, bisphenol A novolak type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, and triphenylmethane type epoxy resin.

Examples of commercially available epoxy resins include jER 828, 806, 807, YX8000, YX8034, 834 manufactured by Mitsubishi Chemical Corporation, and YD-128, YDF-170, ZX-1059 manufactured by Nippon Steel Chemical & Materials Co., Ltd. Examples thereof include ST-3000, EPICLON 830, 835, 840, 850, N-730A, N-695 manufactured by DIC Corporation, and RE-306 manufactured by Nippon Kayaku Co., Ltd.

Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, and 1,4-bis [(3-3-oxythenylmethoxy) methyl] ether. Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-3- Oxetane) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and polyfunctional oxetane such as oligomers or copolymers thereof, as well as oxetane alcohol and novolak resin. , Poly (p-hydroxystyrene), cardo-type bisphenols, calix arrayes, calix resorcinarenes, etherified compounds with a resin having a hydroxyl group such as silsesquioxane, and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate can also be mentioned.

Examples of the compound having a plurality of cyclic thioether groups in the molecule include bisphenol A type episulfide resin and the like. Further, using the same synthesis method, an episulfide resin in which the oxygen atom of the epoxy group of the novolak type epoxy resin is replaced with a sulfur atom can also be used.

Examples of amino resins such as melamine derivatives and benzoguanamine derivatives include methylol melamine compounds, methylol benzoguanamine compounds, methylol glycol uryl compounds and methylol urea compounds.

As the isocyanate compound, a polyisocyanate compound can be blended. Examples of the polyisocyanate compound include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and Aromatic polyisocyanates such as 2,4-tolylene dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate; bicyclo Alicyclic polyisocyanates such as heptanthriisocyanate; and adducts, burettes, and isocyanurates of the isocyanate compounds mentioned above can be mentioned.

As the blocked isocyanate compound, an addition reaction product of the isocyanate compound and the isocyanate blocking agent can be used. Examples of the isocyanate compound capable of reacting with the isocyanate blocking agent include the above-mentioned polyisocyanate compound and the like. Examples of the isocyanate blocking agent include phenol-based blocking agents; lactam-based blocking agents; active methylene-based blocking agents; alcohol-based blocking agents; oxime-based blocking agents; mercaptan-based blocking agents; acid amide-based blocking agents; imide-based blocking agents; Amine-based blocking agents; imidazole-based blocking agents; imine-based blocking agents and the like can be mentioned.

When the composition contains a carboxyl group-containing resin described later, the amount of the thermosetting resin to be blended is such that the number of functional groups of the thermosetting component that reacts with respect to 1 mol of the carboxyl group contained in the carboxyl group-containing resin is 0.5. It is preferably ~ 2.5 mol, more preferably 0.8 to 2.0 mol.

The thermosetting component preferably contains an alkali-soluble resin having an alkali-soluble group in that the composition can be imparted with alkali developability. Examples of the alkali-soluble resin include compounds having two or more phenolic hydroxyl groups, carboxyl group-containing resins, compounds having phenolic hydroxyl groups and carboxyl groups, and compounds having two or more thiol groups. Among them, a carboxyl group-containing resin or a phenol resin is preferable because the adhesion to the substrate is improved, and a carboxyl group-containing resin is more preferable because the developability is particularly excellent. Hereinafter, the carboxyl group-containing resin will be described.

[Carboxylic group-containing resin]
As the carboxyl group-containing resin, various conventionally known resins having a carboxyl group in the molecule can be used. The carboxyl group-containing resin may or may not have an ethylenically unsaturated double bond in the molecule, but in particular, it contains a carboxyl group having an ethylenically unsaturated double bond in the molecule. A photosensitive resin is preferable from the viewpoint of photocurability and development resistance. In such a case, it corresponds to a photocurable thermosetting resin. When the curable composition of the present invention contains a carboxyl group-containing resin, it may be used not only for alkaline development but also for non-alkali development. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bond is used, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule described later, that is, light It is necessary to use a polymerizable monomer together. Specific examples of the carboxyl group-containing resin include the following compounds (either oligomer or polymer).

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, or isobutylene. Examples of the lower alkyl (meth) acrylate include methyl (meth) acrylate).

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, carboxyl group-containing dialcoic compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate-based polyols and polyether-based compounds. A carboxyl group-containing urethane resin obtained by a double addition reaction of a diol compound such as a polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, and a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) Diisocyanate and bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin ( Meta) A carboxyl group-containing photosensitive urethane resin obtained by a double addition reaction of an acrylate or a modified partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound.

(4) During the synthesis of the resin according to (2) or (3), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added to the terminal (4). Meta) Acryloylated carboxyl group-containing photosensitive urethane resin.

(5) During the synthesis of the resin according to (2) or (3), one isocyanate group and one or more (meth) acryloyl groups are formed in the molecule, such as an isophorone diisocyanate and pentaerythritol triacrylate isomorphic reaction product. A carboxyl group-containing photosensitive urethane resin that is terminally (meth) acrylicized by adding a compound to it.

(6) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or higher polyfunctional (solid) epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride to a hydroxyl group existing in a side chain.

(7) Carboxylic acid obtained by reacting (meth) acrylic acid with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of a bifunctional (solid) epoxy resin with epichlorohydrin, and adding a dibasic acid anhydride to the generated hydroxyl groups. Group-containing photosensitive resin.

(8) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional oxetane resin, and the generated primary hydroxyl group is subjected to two bases such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. A carboxyl group-containing polyester resin to which an acid anhydride is added.

(9) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and (meth). Reacting with an unsaturated group-containing monocarboxylic acid such as acrylic acid, maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipine with respect to the alcoholic hydroxyl group of the obtained reaction product. A carboxyl group-containing photosensitive resin obtained by reacting a polybasic anhydride such as an acid.

(10) Reaction obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide. A carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.

(11) Obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. A carboxyl group-containing photosensitive resin obtained by reacting a reaction product with a polybasic acid anhydride.

(12) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule to the resins (1) to (11).

Among these, it is preferable that the curable resin contains two or more kinds of carboxyl group-containing resins. Further, it is preferable that at least one of the two or more kinds of carboxyl group-containing resins is a carboxyl group-containing copolymer resin in that it is uniformly dispersed while lowering the gloss. This is presumed as follows. That is, since the carboxyl group-containing copolymer resin has poor compatibility, the coating film formed from the curable resin composition has a sea-island structure dispersed in other carboxyl group-containing resins, and their refractive indexes. It is considered that an excellent low-gloss effect is produced because the incident light is diffusely reflected due to the difference between the two. On the other hand, in the case of adding the carboxyl group-containing copolymer resin, it is considered that the copper appearance phenomenon is further suppressed because it can be uniformly dispersed while reducing the gloss even if the composition has a small amount of extender pigment.

Examples of the carboxyl group-containing copolymer resin include the resin (1) and the copolymer resin in (12). The resin of (12) is a carboxyl group-containing resin obtained by copolymerization of (meth) acrylic acid and methyl (meth) acrylate, and further alicyclic such as glycidyl methacrylate or 3,4-epoxycyclohexylmethyl (meth) acrylate. A carboxyl group-containing photosensitive resin obtained by adding a (meth) acrylate having a formula epoxy group is preferable.
Further, the resin in combination with the carboxyl group-containing copolymer resin is preferable in that it is uniformly dispersed while lowering the gloss. A combination with a resin other than the carboxyl group-containing copolymer resin is preferable. Specific examples thereof include resins other than the resins (2) to (11) and the copolymer resins of (12), among which the resins (6), (10) and (11) are copolymerized with (12). Resins other than resin are more preferable.

In addition, in this specification, (meth) acrylate is a generic term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

The carboxyl group-containing resin that can be used in the present invention is not limited to those listed above. In addition, one type of the carboxyl group-containing resin listed above may be used alone, or a plurality of types may be mixed and used.

In the present invention, the acid value of the carboxyl group-containing resin is preferably in the range of 30 to 150 mgKOH / g in consideration of the developability when using a weak alkaline developer such as an aqueous sodium carbonate solution and the drawability of the resist pattern. More preferably, it is in the range of 50 to 120 mgKOH / g. The higher the acid value of the carboxyl group-containing resin, the better the developability. However, since the exposed portion is dissolved by the developing solution, the exposed portion and the unexposed portion may be dissolved and peeled off by the developing solution.

The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, but is generally in the range of 2,000 to 150,000, preferably in the range of 5,000 to 100,000. By using a carboxyl group-containing resin having a weight average molecular weight of 2,000 or more, resolution and tack-free performance can be improved. Further, by using a carboxyl group-containing resin having a weight average molecular weight of 150,000 or less, developability and storage stability can be improved. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

The blending amount of the carboxyl group-containing resin is preferably 20 to 80% by mass, more preferably 20 to 75% by mass, and further preferably 20 to 50% by mass in terms of solid content per total amount of the curable resin composition. Is. The strength of the cured coating film can be improved by setting the content to 20% by mass or more. Further, when the content is 80% by mass or less, the viscosity of the curable resin composition becomes appropriate and the processability is improved.

When the carboxyl group-containing resin contains a carboxyl group-containing copolymer resin, the amount of the carboxyl group-containing copolymer resin compounded is carboxyl in terms of solid content in that the copper appearance phenomenon is suppressed while lowering the gloss. It is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and even more preferably 15 to 50% by mass with respect to 100 parts by mass of the group-containing resin.

[Photocurable resin]
The photocurable resin is a compound having an ethylenically unsaturated group, and examples thereof include polymers, oligomers, and monomers, and may be a mixture thereof. By including the photocurable resin, the strength of the cured film can be improved. The photocurable resin may be used alone or in combination of two or more.

As the compound having an ethylenically unsaturated group, known and commonly used photopolymerizable oligomers, photopolymerizable monomers and the like can be used. Among these, it is preferable to use a photopolymerizable monomer in that the crosslinkability and curability of the cured coating film can be further imparted.

The photopolymerizable oligomer is an oligomer having an ethylenically unsaturated double bond. Examples of the photopolymerizable oligomer include unsaturated polyester-based oligomers and (meth) acrylate-based oligomers. Examples of the (meth) acrylate-based oligomer include epoxy (meth) acrylates such as phenol novolac epoxy (meth) acrylate, cresol novolac epoxy (meth) acrylate, and bisphenol type epoxy (meth) acrylate, urethane (meth) acrylate, and epoxy urethane (meth). ) Acrylic, polyester (meth) acrylate, polyether (meth) acrylate, polybutadiene-modified (meth) acrylate and the like.

The photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). Hydroxyalkyl (meth) acrylates such as acrylates; Mono or di (meth) acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane , Polyvalent alcohols such as dipentaerythritol, trishydroxyethyl isocyanurate, or polyvalent (meth) acrylates of these ethylene oxides or propylene oxide adducts; phenoxyethyl (meth) acrylates, polyethoxydi (meth) acrylates of bisphenol A, etc. (Meta) acrylates of ethylene oxide or propylene oxide adducts of phenols; (meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate; and melamine (meth). Acrylate can be mentioned. As the photopolymerizable monomer, one type may be used alone, or two or more types may be used in combination.

The blending amount of the photocurable resin is preferably 3 to 20% by mass, more preferably 5 to 15% by mass in terms of solid content per total amount of the curable resin composition. When the blending amount of the photopolymerizable monomer is 3% by mass or more, the photocurability is good, and pattern formation is easy in alkaline development after irradiation with active energy rays. On the other hand, when it is 20% by mass or less, halation is unlikely to occur and good resolution is likely to be obtained.

[Constitution pigment]
The extender pigment of the present invention refers to a pigment having a refractive index of 1.40 or more, for example, silica such as amorphous silica, crystalline silica, molten silica, and spherical silica, talc, boehmite, hydrotalcite, slaked lime, and the like. Calcium hydroxide, calcium carbonate, calcium sulfate, potassium carbonate, magnesium carbonate, clay, mica powder, aluminum oxide, aluminum hydroxide, barium sulfate, copper sulfide, alumina, zinc oxide, iron, zinc sulfide, zirconium oxide, chromium oxide, Examples thereof include cadmium oxide, cadmium sulfide, titanium oxide and copper oxide. Among these, silica and barium sulfate are preferable from the viewpoint of dispersibility. One type of extender pigment may be used alone, or two or more types may be used in combination. By containing the extender pigment, the heat resistance can be improved and the variation at the time of application can be reduced. Further, from the viewpoint of lowering the gloss, aluminum silicate or the like containing SiO ₂ and Al ₂ O ₃ as main components may be used.

The presence or absence of surface treatment of the extender pigment is not particularly limited, but surface treatment for enhancing dispersibility may be performed. Aggregation can be suppressed by using an extender pigment that has been surface-treated. The surface treatment method for the extender pigment is not particularly limited, and a known and commonly used method may be used. However, a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group, which is inorganic. It is preferable to treat the surface of the extender pigment.

The average particle size of the extender pigment can be preferably 10 μm or less, but from the viewpoint of dispersibility, it is more preferably 0.1 to 2.0 μm, more preferably 0.1 to 2.0 μm, except for amorphous silica described later. Is 0.15 to 1.0 μm, particularly preferably 0.2 to 0.9 μm. The average particle diameter of the extender pigment, as well as particle size of the primary particles, the average particle size diameter was also included in the secondary particles _{(agglomerates)} (D _50), D ₅₀ measured by a laser diffraction method Is the value of. Examples of the measuring device by the laser diffraction method include Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. The maximum particle size (D ₁₀₀ ) and the particle size (D ₁₀ ) can also be measured in the same manner by the above apparatus. Further, the value of each particle size of the extender pigment described above refers to a value measured as described above for the extender pigment before adjusting (preliminary stirring, kneading) the curable resin composition.

The blending amount of the extender pigment is preferably 20 to 80% by mass, more preferably 25 to 75% by mass, and further preferably 30 to 50% by mass in terms of solid content per total amount of the curable resin composition. .. When the blending amount of the extender pigment is within the above range, the cured product can be made high in strength.

In the curable resin composition of the present invention, silica preferably contains amorphous silica having an oil absorption of 180 to 350 ml / 100 g in that the cured coating film has a lower gloss. The reason why the cured coating film has low gloss by using the amorphous silica is presumed as follows. That is, the amorphous silica having an oil absorption amount within a predetermined range is porous, and the amorphous silica and other extender pigments become denser due to the absorption of oil such as an organic solvent during curing and drying. As a result, it is presumed that the glossiness of the formed cured coating film becomes lower. The oil absorption is more preferably 200 to 300 ml / 100 g. In the present invention, the oil absorption amount is measured in accordance with "JIS K5101-13-1: 2004 Pigment Test Method-Part 13: Oil Absorption Amount-Section 1: Refined Amani Oil Method".

As the amorphous silica, known and commonly used silica can be used, and it may be synthetic or natural. Further, the surface treatment may or may not be performed. The type of surface treatment is the same as that of the extender pigment. Examples of the products include ACEMATT 82, ACEMATT 790, ACEMATT OK 412, and ACEMATT OK 500 (all manufactured by EVONIK DEGUSSA).

The average particle size of the amorphous silica is preferably 3 to 10 μm, and more preferably 4 to 8 μm, because the cured coating film has a lower gloss. The average particle size in this paragraph was measured in the state before kneading as a curable resin composition. The method for measuring the average particle size is the same as that for the extender pigment.

When the amorphous silica is contained in the extender pigment, the amount of the amorphous silica blended is 100 parts by mass in terms of solid content in that the cured coating film is uniformly dispersed while making the cured coating film less glossy. On the other hand, it is preferably 5 to 90 parts by mass, more preferably 10 to 70 parts by mass, and further preferably 12 to 50 parts by mass. Further, when the amorphous silica and other extender pigments are contained in the extender pigment, barium sulfate is preferable in that the cured coating film is uniformly dispersed while having a lower gloss.

The curable resin composition of the present invention may contain the following optional components.

[Photopolymerization initiator]
The photopolymerization initiator is for reacting a carboxyl group-containing resin or a photopolymerizable monomer by exposure. Any known photopolymerization initiator can be used. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

Specific examples of the photopolymerization initiator include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, and bis. -(2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide , Bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, Bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, Bis- (2, Bisacylphosphine oxides such as 4,6-trimethylbenzoyl) -phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethyl Monoacylphosphine oxides such as benzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; phenyl ( 2,4,6-trimethylbenzoyl) ethyl phosphinate, 1-hydroxy-cyclohexylphenylketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1- On, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-hydroxy-2-methyl-1 Hydroxyacetophenones such as −phenylpropan-1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone , P-Methylbenzophenone, Michler's ketone, Methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone and other benzophenones; acetophenone, 2,2-dimethoxy-2-phenyla Setophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl) -1- [4- (4- (4- (4-) Morphorinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chloro Thioxanthones such as thioxanthone and 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butyl anthraquinone, 1-chloroanthraquinone, 2-amyl anthraquinone, 2-aminoanthraquinone and the like. Anthraquinones; Ketals such as acetophenone dimethyl ketal, benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate, p-dimethylbenzoic acid ethyl ester; 1,2 -Octanedione, 1- [4- (phenylthio) phenyl]-, 2- (O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-3 Oxylm esters such as yl]-, 1- (O-acetyloxime); bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1) -Il) phenyl) Titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyll-1-yl) ethyl) phenyl] Titanocenes such as titanium; phenyldisulfide 2 -Nitrofluorene, butyloin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthium disulfide and the like can be mentioned.

Examples of commercially available α-aminoacetophenone-based photopolymerization initiators include Omnirad 907, 369, 369E, and 379 manufactured by IGM Resins. Examples of commercially available acylphosphine oxide-based photopolymerization initiators include Omnirad TPO and 819 manufactured by IGM Resins. Commercially available oxime ester-based photopolymerization initiators include Irgacure OXE01 and OXE02 manufactured by BASF Japan Ltd., N-1919 manufactured by ADEKA Corporation, Adeca Arcurus NCI-831 and NCI-831E, and Changzhou Powerful Electronics New Materials Co., Ltd. Examples thereof include TR-PBG-304.

In addition, JP-A-2004-359639, JP-A-2005-097141, JP-A-2005-22097, JP-A-2006-160634, JP-A-2008-094770, JP-A-2008-509967, Examples thereof include carbazole oxime ester compounds described in JP-A-2009-040762 and JP-A-2011-80036.

The blending amount of the photopolymerization initiator is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass in terms of solid content per total amount of the curable resin composition. When the blending amount of the photopolymerization initiator is 0.1% by mass or more, the photocurability of the curable resin composition is good, and the coating film properties such as chemical resistance are also good. On the other hand, when it is 10% by mass or less, the light absorption on the surface of the resist film (cured coating film) is good, and the deep curability is unlikely to decrease.

A photoinitiator or sensitizer may be used in combination with the photopolymerization initiator described above. Examples of the photoinitiator aid or sensitizer include benzoin compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds. In particular, it is preferable to use thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone. By containing the thioxanthone compound, the deep curability can be improved. Although these compounds may be used as a photopolymerization initiator, they are preferably used in combination with a photopolymerization initiator. In addition, one type of photoinitiator aid or sensitizer may be used alone, or two or more types may be used in combination.

Since these photopolymerization initiators, photoinitiator aids, and sensitizers absorb specific wavelengths, their sensitivity may be lowered in some cases, and they may function as ultraviolet absorbers. However, these are not used only for the purpose of improving the sensitivity of the resin composition. It absorbs light of a specific wavelength as needed to enhance the photoreactivity of the surface, change the line shape and aperture of the resist pattern to vertical, tapered, or reverse tapered, and the accuracy of the line width and aperture diameter. Can be improved.

[Thermosetting catalyst]
A thermosetting catalyst can be added to the curable resin composition of the present invention. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-. Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Examples thereof include amine compounds such as amine, 4-methyl-N and N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Commercially available products include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both are trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., and U-CAT manufactured by San Apro Co., Ltd. Examples thereof include 3513N (trade name of a dimethylamine compound), DBU, DBN, U-CAT SA 102 (all of which are bicyclic amidine compounds and salts thereof). In particular, the present invention is not limited to these, as long as it is a thermosetting catalyst of an epoxy resin or an oxetane compound, or one that promotes the reaction of at least one of an epoxy group and an oxetanel group with a carboxyl group, either alone or 2 You may use a mixture of seeds or more.

In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine-isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine-isocyanulic acid adduct can also be used, preferably as these adhesion-imparting agents. A compound that also functions is used in combination with a thermosetting catalyst. One type of thermosetting catalyst may be used alone, or two or more types may be used in combination.

The blending amount of the thermosetting catalyst is preferably 0.1 to 5 parts by mass, and more preferably 1 to 3 parts by mass in terms of solid content per total amount of the curable resin composition.

[Colorant]
A colorant can be added to the curable resin composition of the present invention. The colorant is not particularly limited, and known colorants such as red, blue, green, and yellow can be used, and any of pigments, dyes, and pigments may be used, but it may reduce the environmental load and affect the human body. It is preferable that the colorant does not contain halogen from the viewpoint of less.

Examples of red colorants include monoazo, disazo, azolake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, quinacridone, etc., and specifically, the following colors. -Index (CI; issued by The Society of Dyersand Colorists) numbered ones.

Examples of monoazo red colorants include Pigment Red 1,2,3,4,5,6,8,9,12,14,15,16,17,21,22,23,31,32,112,114, Examples thereof include 146,147,151,170,184,187,188,193,210,245,253,258,266,267,268,269 and the like. Examples of the disazo-based red colorant include Pigment Red 37, 38, 41 and the like. Further, as a monoazolake-based red colorant, Pigment Red 48: 1,48: 2,48: 3,48: 4,49: 1,49: 2,50: 1,52: 1,52: 2,53: Examples thereof include 1,53: 2,57: 1,58: 4,63: 1,63: 2,64: 1,68. Examples of the benzimidazolone-based red colorant include Pigment Red 171, 175, 176, 185, 208 and the like. Examples of the perylene-based red colorant include Solvent Red 135,179, Pigment Red 123,149,166,178,179,190,194,224 and the like. Examples of the diketopyrrolopyrrole-based red colorant include Pigment Red 254, 255, 264, 270, 272 and the like. Examples of the condensed azo red colorant include Pigment Red 220, 144, 166, 214, 220, 221, 242 and the like. Examples of the anthraquinone-based red colorant include Pigment Red 168, 177, 216 and Solvent Red 149, 150, 52, 207. Further, examples of the quinacridone-based red colorant include Pigment Red 122, 202, 206, 207, 209 and the like.

Examples of the blue colorant include phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds include compounds classified as Pigment. For example, Pigment Blue 15,15: 1,15: 2,15: 3,15: 4,15: 6,16,60. As the dye system, Solvent Blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136, 67, 70 and the like can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Examples of the yellow colorant include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, and the like. For example, the anthraquinone yellow colorant includes Solvent Yellow 163, Pigment Yellow 24, 108, 193, 147, 199, 202 and the like can be mentioned. Examples of the isoindolinone-based yellow colorant include Pigment Yellow 110, 109, 139, 179, 185 and the like. Examples of the condensed azo-based yellow colorant include Pigment Yellow 93, 94, 95, 128, 155, 166, 180 and the like. Examples of the benzimidazolone-based yellow colorant include Pigment Yellow 120, 151, 154, 156, 175, 181 and the like. In addition, as a monoazo yellow colorant, Pigment Yellow 1,2,3,4,5,6,9,10,12,61,62,62: 1,65,73,74,75,97,100, Examples thereof include 104, 105, 111, 116, 167, 168, 169, 182, 183 and the like. Examples of the disazo-based yellow colorant include Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198 and the like. Can be mentioned.

In addition, colorants such as purple, orange, brown, and black may be added. Specifically, Pigment Black 1,6,7,8,9,10,11,12,13,18,20,25,26,28,29,30,31,32, Pigment Violet 19, 23, 29 , 32, 36, 38, 42, Solvent Violet 13, 36, C.I. I. Pigment Orange 1,5,13,14,16,17,24,34,36,38,40,43,46,49,51,61,63,64,71,73, PigmentBrown 23,25, carbon black, etc. Can be mentioned.

The blending amount of the colorant is preferably 0.1 to 2.0% by mass, more preferably 0.3 to 1.5% by mass in terms of solid content per total amount of the curable resin composition.

[Organic solvent]
The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when applied to a substrate or a film, and the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether and other glycol ethers; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, diethylene glycol monoethyl ether acetate, Esters such as butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. , Known and commonly used organic solvents can be used. Among these, when the curable resin composition in the present invention is porous such as amorphous silica, the gloss of the cured coating film formed as a result of easily absorbing oil on the silica surface during curing or drying is performed. Esters are preferred and diethylene glycol monoethyl ether acetate is more preferred in that the degree is lower. One of these organic solvents may be used alone, or two or more of them may be used in combination.

The blending amount of the organic solvent is not particularly limited, and can be appropriately set according to the target viscosity so that the curable resin composition can be easily prepared.

[Other additive ingredients]
If necessary, the curable resin composition of the present invention further includes a photoinitiator, a cyanate compound, an elastomer, a mercapto compound, a urethanization catalyst, a thixotropic agent, an adhesion accelerator, a block copolymer, and a chain transfer agent. , Polymerization inhibitors, copper damage inhibitors, antioxidants, rust preventives, fine powder silica, organic bentonite, thickeners such as montmorillonite, silicone-based, fluorine-based, polymer-based defoaming agents and leveling agents at least. Any one of them, imidazole-based, thiazole-based, triazole-based silane coupling agents, phosphinates, phosphoric acid ester derivatives, phosphorus compounds such as phosphazene compounds, and other flame-retardant components can be blended. As these, those known in the field of electronic materials can be used.

The curable resin composition of the present invention may be used as a dry film.

[Preparation method]
To prepare the curable resin composition of the present invention, each component is weighed and mixed, and then pre-stirred with a stirrer. Subsequently, each component is dispersed in a kneading machine and kneaded to prepare the mixture.

Examples of the kneading machine include a bead mill, a ball mill, a sand mill, a 3-roll mill, a 2-roll mill, and the like. Among these, it is preferable to use a bead mill in terms of reducing the variation in the film thickness of the coating film before and after drying and suppressing the copper appearance phenomenon while having a lower gloss. Dispersion conditions such as the type and particle size of the beads in the bead mill can be appropriately set according to the target viscosity, and examples of the types of beads include zirconia beads and alumina beads. Examples of the particle size of the beads include a range of φ0.015 to 2.0 mm. Of these, the range of φ0.3 to 1.5 mm is more preferable. The bead filling rate is preferably 50 to 95%, and the rotation speed of the rotor is preferably 800 to 1300 rpm. Further, as the target viscosity, it is preferable that the viscosity of the composition at the time of charging the bead mill is 200 dPa · s or less in terms of improving the dispersibility and lowering the gloss of the cured coating film. On the other hand, the lower limit is preferably 50 dPa · s or more. The viscosity in the present invention is 50 ° C., 100 rpm, 30 seconds according to the viscosity measurement method using a 10 cone-plate type rotational viscometer of JIS Z 8803: 2011, and a cone using 3 ° × R9.7 as a cone rotor. It is a value measured by a plate type viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.).

On the other hand, dispersion conditions such as the rotation ratio of each roll of the three-roll mill can be appropriately set according to the target viscosity.

Further, in order to further improve the dispersibility, the raw materials may be first weighed and mixed using a kneader such as a bead mill or a three-roll mill, and then pre-stirred with a stirrer. When the raw material is slurried, it is preferable to weigh and mix a wet dispersant such as a silane coupling agent and then knead with a bead mill or the like. Subsequently, each component including those slurried by a kneader as in the above example may be dispersed and kneaded by a bead mill or the like.

[Use]
The curable resin composition according to the present invention is useful for forming a pattern layer as a permanent coating of a printed wiring board such as a solder resist, a coverlay, and an interlayer insulating layer, and is particularly useful for forming a solder resist. Further, since the curable resin composition of the present invention can form a cured product having excellent film strength even with a thin film, it is used in a printed wiring board that requires thinning, for example, a package substrate (printed wiring board used for a semiconductor package). It can also be suitably used for forming a pattern layer. Further, the cured product obtained from the curable resin composition of the present invention is excellent in flexibility and can be suitably used for a flexible printed wiring board.

Further, the curable resin composition of the present invention can be used not only for forming a pattern layer of a cured coating film but also for an application not forming a pattern layer, for example, a molding application (sealing application).

[Dry film]
The curable resin composition of the present invention is in the form of a dry film including a support (carrier) film and a resin layer composed of a dry coating film of the curable resin composition formed on the support film. You can also. When forming a dry film, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, and a transfer coater are used. , A gravure coater, a spray coater or the like is applied onto a carrier film to a uniform thickness, and the film is usually dried at a temperature of 50 to 130 ° C. for 1 to 30 minutes to obtain a film. The coating film thickness is not particularly limited, but is generally selected as appropriate in the range of 1 to 150 μm, preferably 5 to 60 μm after drying. By using the curable resin composition of the present invention, the variation in the coating film before drying can be reduced, so that the variation can be reduced even if the resin layer made of the dried coating film is a thin film. For example, it may be in the form of a dry film having a thin resin layer of 12 μm or less.

As the support film, any known one can be used without particular limitation. For example, a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a polyimide film, a polyamideimide film, a polypropylene film, a thermoplastic resin such as a polystyrene film or the like can be used. A film made of the above can be preferably used. Among these, a polyester film is preferable from the viewpoint of heat resistance, mechanical strength, handleability and the like. Further, a laminate of these films can also be used as a support film.

Further, the thermoplastic resin film as described above is preferably a film stretched in the uniaxial direction or the biaxial direction from the viewpoint of improving the mechanical strength.

The thickness of the support film is not particularly limited, but can be, for example, 10 μm to 150 μm.

After forming a resin layer made of a dry coating film of the curable resin composition of the present invention on a support film, it is further peeled off from the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is preferable to laminate a possible protective (cover) film. As the peelable protective film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper or the like can be used, and when the protective film is peeled off, the adhesive strength between the resin layer and the support film is increased. However, the adhesive strength between the resin layer and the protective film may be smaller.

The thickness of the protective film is not particularly limited, but can be, for example, 10 μm to 150 μm.

To form a cured coating film on a printed wiring board using a dry film, the protective film is peeled off from the dry film, the exposed resin layer of the dry film is layered on the circuit-formed substrate, and a laminator or the like is used. A resin layer is formed on the base material formed by bonding and circuit formation. Next, the formed resin layer is exposed, developed, and heat-cured to form a cured coating film. The protective film may be peeled off either before or after exposure.

[Cured product]
The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the dry film of the present invention. The cured product of the present invention can be suitably used for printed wiring boards, electronic components, and the like. Since the cured product of the present invention has excellent flexibility, it can be particularly preferably used for a flexible printed wiring board. In addition, the cured product of the present invention is also excellent in infrared shielding property and stability over time.

[Printed circuit board]
The printed wiring board of the present invention has a cured product obtained from the curable resin composition of the present invention or the resin layer of a dry film. As a method for producing a printed wiring board of the present invention, for example, the curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the above organic solvent, and a dip coating method is applied onto the substrate. After coating by a method such as a flow coating method, a roll coating method, a bar coater method, a screen printing method, or a curtain coating method, the organic solvent contained in the composition is volatile-dried at a temperature of 60 to 100 ° C. for 15 to 90 minutes. By (temporarily drying), a tack-free resin layer is formed. Further, in the case of a dry film, a resin layer is formed on the base material by sticking the resin layer on the base material with a laminator or the like so that the resin layer comes into contact with the base material, and then peeling off the carrier film.

The base material includes a printed wiring board and a flexible printed wiring board whose circuit is formed of copper or the like in advance, as well as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, and glass cloth / paper epoxy. , Synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc. are used for high-frequency circuit copper-clad laminates, etc., and all grades (FR-4, etc.) of copper-clad laminates are used. Plates, other metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

It is preferable that the dry film is attached to the substrate under pressure and heating using a vacuum laminator or the like. By using such a vacuum laminator, when a circuit-formed substrate is used, even if the surface of the circuit board is uneven, the dry film adheres to the circuit board, so that air bubbles are not mixed and the circuit board is not mixed. The hole filling property of the recesses on the surface of the substrate is also improved. The pressurizing condition is preferably about 0.1 to 2.0 MPa, and the heating condition is preferably 40 to 120 ° C.

The volatile drying performed after applying the curable resin composition of the present invention on the substrate uses a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, etc. (using a steam-based air heating type heat source). It can be carried out by using a method of bringing hot air in the dryer into countercurrent contact and a method of blowing the hot air from the nozzle onto the support). Examples of the apparatus include DF610 manufactured by Yamato Scientific Co., Ltd. as a hot air circulation drying furnace.

After forming a resin layer on the substrate, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed portion is exposed to a dilute alkaline aqueous solution (for example, 0.3 to 3.0% by mass sodium carbonate). It is developed with an aqueous solution) to form a pattern of the cured product. In the case of a dry film, after exposure, the support film is peeled off from the dry film and developed to form a patterned cured product on the substrate. The exposed resin layer may be exposed and developed by peeling the support film from the dry film before exposure as long as the characteristics are not impaired.

The exposure machine used for the above-mentioned active energy ray irradiation may be a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates ultraviolet rays in the range of 350 to 450 nm. Further, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser based on CAD data from a computer) can also be used. The lamp light source or the laser light source of the direct drawing machine may have a maximum wavelength in the range of 350 to 450 nm. Exposure for image formation may vary depending thickness, etc., generally 10~1,000mJ / cm ^2, preferably be in the range of 20~800mJ / cm ^2. Examples of the apparatus include an HMW-680-GW20 manufactured by ORC Manufacturing Co., Ltd. as an exposure apparatus equipped with a metal halide lamp.

The developing method can be a dipping method, a shower method, a spray method, a brush method, etc., and the developing solution includes potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, etc. Alkaline aqueous solutions such as ammonia and amines can be used.

Further, the cured product is irradiated with active energy rays and then heat-cured (for example, at a temperature of 100 to 220 ° C. for 30 to 90 minutes), or after heat curing and then irradiated with active energy rays (for example, 1,000 to 2,000 mJ / cm). ² ) Or, by performing final finish curing (main curing) only by heat curing, a cured coating film having excellent various properties such as adhesion and hardness is formed. Examples of the apparatus include QRM-2082 manufactured by ORC Manufacturing Co., Ltd. as a UV conveyor using a high-pressure mercury lamp.

The above content is a method for forming a cured coating film using a photocurable thermosetting resin composition, but in the case of only photocuring or thermosetting, it can be produced as follows.
In the case of photocuring only, the curable resin composition of the present invention is applied onto a substrate by pattern printing or the like, and then irradiated with active energy rays (for example, 1,000 to 2,000 mJ / cm ² ) to cure. To form a cured coating film.
On the other hand, in the case of only thermosetting, the curable resin composition of the present invention is applied on a substrate by pattern printing or the like and then cured by heating (for example, at a temperature of 100 to 220 ° C. for 30 to 90 minutes). Form a coating film.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the following, "part" and "%" are all based on mass unless otherwise specified.

(Synthesis of resin varnish 1 of carboxyl group-containing resin)
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 119.4 g of novolak type cresol resin (manufactured by Aika Kogyo Co., Ltd., trade name "Shonol CRG951", OH equivalent: 119.4), 1.19 g of potassium hydroxide and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually added dropwise, and the reaction was carried out at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. Then, the mixture was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with this reaction solution to neutralize potassium hydroxide, and the solid content was 62.1% and the hydroxyl value was 182.2 g / eq. A propylene oxide reaction solution of the novolak type cresol resin was obtained. This was an average of 1.08 mol of alkylene oxide added per equivalent of phenolic hydroxyl group. Next, 293.0 g of an alkylene oxide reaction solution of the obtained novolak-type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were added to a stirrer, a thermometer and air. The mixture was charged into a reactor equipped with a blowing tube, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours with stirring. As for the water produced by the reaction, 12.6 g of water was distilled off as an azeotropic mixture with toluene. Then, the mixture was cooled to room temperature, the obtained reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, and then washed with water. Then, toluene was distilled off while substituting 118.1 g of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak type acrylate resin solution. Next, 332.5 g of the obtained novolak-type acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. , 60.8 g of tetrahydrophthalic anhydride was gradually added with stirring, and the mixture was reacted at 95 to 101 ° C. for 6 hours. In this way, a resin varnish 1 of a carboxyl group-containing resin having a solid content acid value of 88 mgKOH / g, a solid content of 71%, and a weight average molecular weight of 2,000 was obtained.

(Synthesis of resin varnish 2 of carboxyl group-containing resin)
220 g of orthocresol novolak type epoxy resin (manufactured by DIC Corporation, EPICLON N-695, epoxy equivalent: 214, average number of functional groups 7.6) was placed in a four-necked flask equipped with a stirrer and a reflux condenser, and diethylene glycol monoethyl was placed. 214 g of ether acetate was added and dissolved by heating. Next, 0.1 g of hydroquinone as a polymerization inhibitor and 2.0 g of dimethylbenzylamine as a reaction catalyst were added. The mixture was heated to 95-105 ° C., 72 g of acrylic acid was gradually added dropwise, and the mixture was reacted for 16 hours. The reaction product was cooled to 80-90 ° C., 106 g of tetrahydrophthalic anhydride was added, the mixture was reacted for 8 hours, cooled, and then removed. The resin varnish 2 of the carboxyl group-containing resin thus obtained had a solid content of 65%, an acid value of the solid material of 100 mgKOH / g, and a weight average molecular weight of Mw of about 3,500.

(Synthesis of resin varnish 3 of carboxyl group-containing resin)
Diethylene glycol monoethyl ether acetate 650 parts by mass of orthocresol novolac type epoxy resin (manufactured by DIC Corporation, EPICLON N-695, softening point 95 ° C., epoxy equivalent 214, average number of functional groups 7.6) 1070 g, acrylic acid 360 g, and hydroquinone 1.5 g was charged and heated and stirred at 100 ° C. to uniformly dissolve. Next, 4.3 parts by mass of triphenylphosphine was charged, heated to 110 ° C. and reacted for 2 hours, then 1.6 parts by mass of triphenylphosphine was further added, and the temperature was raised to 120 ° C. for another 12 hours. Was done. 525 g of aromatic hydrocarbon (Tesol 150 manufactured by Standard Oil Osaka Sales Co., Ltd.) and 608 g (4.0 mol) of tetrahydrophthalic anhydride were charged into the obtained reaction solution, and the reaction was carried out at 110 ° C. for 4 hours. Further, 142.0 g of glycidyl methacrylate was added to the obtained reaction solution, and the reaction was carried out at 115 ° C. for 4 hours. In this way, a resin varnish 3 of a carboxyl group-containing resin having a solid content acid value of 77 mgKOH / g and a solid content of 65% was obtained.

(Synthesis of resin varnish 4 of carboxyl group-containing resin)
In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux cooler, 325.0 parts by mass of dipropylene glycol monomethyl ether as a solvent was heated to 110 ° C., and 174.0 parts by mass of methacrylic acid was modified with ε-caprolactone. 174.0 parts by mass of methacrylic acid (average molecular weight 314), 77.0 parts by mass of methyl methacrylate, 222.0 parts by mass of dipropylene glycol monomethyl ether, and t-butylperoxy2-ethylhexanoate as a polymerization catalyst. A mixture of 12.0 parts by mass (Perbutyl O manufactured by Nichiyu Co., Ltd.) was added dropwise over 3 hours, and the mixture was further stirred at 110 ° C. for 3 hours to inactivate the polymerization catalyst to obtain a resin solution. After cooling this resin solution, 289.0 parts by mass of Cyclomer M100 (3,4-epoxycyclohexylmethylmethacrylate) manufactured by Daicel Co., Ltd., 3.0 parts by mass of triphenylphosphine and 1.3 parts by mass of hydroquinone monomethyl ether were added. A part was added, the temperature was raised to 100 ° C., and the mixture was stirred to carry out a ring-opening addition reaction of an epoxy group to obtain a carboxyl group-containing resin varnish 4. The carboxyl group-containing resin varnish 4 thus obtained had a non-volatile content of 45.5% by mass and a solid acid value of 79.8 mgKOH / g.

(Examples 1 to 4, Comparative Examples 1 to 3)
(Preparation of curable resin composition)
For each composition, each component was blended according to the formulation shown in Table 1 below, and if necessary, an organic solvent (diethylene glycol monoethyl ether acetate) was blended and premixed with a stirrer. Subsequently, all the compositions of Formulation Examples 1 to 4 were dispersed at 70 ° C. or lower by a bead mill, kneaded and adjusted. On the other hand, the compositions of Formulation Examples 5 to 7 were all dispersed at 70 ° C. or lower by a roll mill, kneaded and adjusted. Although each component of the compositions of Formulation Examples 1 and 5 is the same, the dispersion method is different, and each component of the compositions of Formulation Examples 2 and 6 is the same, but the dispersion method is different. Each component of the compositions 4 and 7 is the same, but the dispersion method is different.
Dispersion by the above bead mill was performed under the following conditions. The compositions of Formulation Examples 1 to 3 and 5 to 7 whose viscosity was adjusted to 100 dPa · s with an organic solvent (diethylene glycol monoethyl ether acetate) were zirconia beads having a particle size of φ1.0 mm, and the composition of Formulation Example 4 had a particle size. φ0.65mm horizontal wet pulverizer with zirconia beads of an (Buhler Co., Ltd.) using each was subjected to a dispersion treatment so as to average particle diameter D ₅₀ listed in Table 2. The filling rate of the zirconia beads was 85%, and the rotation speed of the rotor was 1000 rpm. The viscosity was set to 50 ° C., 100 rpm, and 30 seconds according to the viscosity measurement method using a 10-conical plate-type rotational viscometer of JIS Z 8803: 2011, and a cone plate using 3 ° × R9.7 as the cone rotor. It was measured with a type viscometer (TVEE-33H, manufactured by Toki Sangyo Co., Ltd.).
Regarding the dispersion by the roll mill described above, each composition was subjected to a dispersion treatment using a three-roll mill manufactured by Inoue Seisakusho Co., Ltd. so as to have an average particle size D _{50 shown} in Table 2.

The blending amount in Table 1 indicates a mass portion.
Details of each component in Table 1 are as follows.
* 1: The carboxyl group-containing resin varnish 1 synthesized above, the blending amount is the value in terms of solid content * 2: The carboxyl group-containing resin varnish 2 synthesized above, the blending amount is the value in terms of solid content * 3: Synthesized above The carboxyl group-containing resin varnish 3 and the blending amount are the values in terms of solid content * 4: The carboxyl group-containing resin varnish 4 synthesized above, and the blending amount is the value in terms of solid content * 5: Photopolymerizable monomer (dipentaerythritol hexa) Acrylate (DPHA), manufactured by Nippon Kayaku Co., Ltd.))
* 6: 2- [4- (Methylthio) benzoyl] -2- (4-morpholinyl) propane (manufactured by IGM Resins Co., Ltd., Omnirad 907)
* 7: Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) (BASF Japan Ltd., Irgacure OXE02)
* 8: Bis- (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by IGM Resins Co., Ltd., Omnirad 819)
* 9: 2,4-Diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd., KAYACURE DETX-S)
* 10: Blue colorant (CI Pigment Blue 15: 3)
* 11: Yellow colorant (CI Pigment Yellow 147)
* 12: Red colorant (Pariogen Red K3580, manufactured by BASF Japan Ltd.)
* 13: Bisphenol A type epoxy resin (manufactured by DIC Corporation, EPICLON 840-S)
* 14: Phenolic novolac type epoxy resin (manufactured by DIC Corporation, EPICLON N-770)
* 15: Biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX-4000)
* 16: 1,3,5-Tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (high melting point type, Nissan Chemical Industries, Ltd.) Made by TEPIC-HP)
* 17: Melamine * 18: Barium sulfate (average particle size 0.3 μm (measured before kneading as a curable resin composition)) (Sakai Chemical Industry Co., Ltd., B-34)
* 19: Amorphous silica (average particle size 6.3 μm (measured before kneading as a curable resin composition), oil absorption: 260 ml / 100 g) (made by Ebonic Degussa Japan Co., Ltd., ACE MATT OK 500)

(Measurement of average particle diameter _{D 50} and the specific surface area CS)
For each curable resin composition of each Example and each Comparative Example, the average particle size D ₅₀ (μm) and the specific surface area CS (m ² / ml) were measured as follows.
First, prepare the following equipment and equipment to be used.
-Particle counter: Microtrack MT3300EX manufactured by Nikkiso Co., Ltd.
・ Circulatory device: ASVR manufactured by Nikkiso Co., Ltd.
Next, input the measurement conditions according to the following procedure. Launch the software attached to the microtrack ("particle size distribution measurement"), proceed from the SET UP screen, and set the time from the measurement condition setting options. Setzero time is 30 sec. , Measurement for 30 sec. , The number of measurements is set to 2. Next, enter the analysis conditions. In the analysis information, the refractive index of the particles is 1.81 (fixed value: the average value of the refractive indexes of all inorganic substances), the characteristics of the particles are transparent, and the shape is non-spherical. Further, in the solvent information, PMA (propylene glycol monomethyl ether acetate) is selected and the solvent refractive index is 1.4. Then enter the scale settings. In the particle size range, the minimum particle size is 0.021 μm and the maximum particle size is 704 μm. Then enter the sampling system. The ASVR was washed 4 times, the flow velocity was 50%, the ultrasonic output was 40 W, and the ultrasonic time was 300 sec. And. After entering all the measurement conditions, press Save to close the measurement condition settings.
Subsequently, the sample is adjusted according to the following procedure. Weigh 0.3 g of a sample (curable resin composition) into a screw bottle, add 30 g of propylene glycol monomethyl ether acetate little by little using a dropper, and dissolve the sample by shaking the screw bottle to prepare a prepared sample. To do. The prepared sample does not undergo external dispersion or pre-dispersion. Next, the adjustment sample is measured. Click the particle size distribution measurement of the software attached to the micro track to open the sample loading screen. Drop a few drops of the adjusted sample into the sample inlet of the main body using a dropper. When the red instruction bar is displayed on the sample loading screen, the adjustment sample is dropped into the sample inlet until it falls within the range from red to green. When it is within the green range, press the measurement button to start the measurement. The process from sample preparation to measurement of the adjusted sample should be performed within 5 minutes. The value of the cumulative average diameter of 50% and the value of the area average diameter MA displayed as the measurement results are read, respectively. The value of the cumulative average diameter of 50% is taken as the value of the average particle diameter D ₅₀ measured by the microtrack. Also, CS = 6 / MA is calculated. The calculated CS value is used as the value of the specific surface area measured by the microtrack.

(Measurement of average spacing Sm (μm) and maximum height Ry (μm) of unevenness)
Each of the curable resin compositions of each example and each comparative example was dried on a clean glass substrate (76 mm × 26 mm × 1.1 mmt) surface and used with a 180 mesh polyester plate (with bias) so as to be 12 μm after drying. It was solidly printed by screen printing and dried at 90 ° C. for 15 minutes to form a dry coating film. For the obtained "coating film after drying" (hereinafter referred to as "sample"), using a shape measuring laser microscope (VK-X100 manufactured by KEYENCE CORPORATION), the average spacing Sm (μm) and the maximum height of the unevenness are as follows. Ry (μm) was measured according to JIS B0601-1994, respectively. The measurement was carried out after drying at 90 ° C. for 15 minutes and then leaving at room temperature for 30 minutes.
After activating the main body (control unit) of the shape measurement laser microscope (VK-X100) and the VK observation application (VK-H1VX manufactured by KEYENCE CORPORATION), the above sample to be measured was placed on the xy stage. Turn the lens revolver of the microscope unit (Keyence Co., Ltd. VK-X110) to select an objective lens with a magnification of 10 times, and roughly adjust the focus and brightness in the image observation mode of the VK observation application (VK-H1VX). did. The xy stage was operated so that the part of the sample surface to be measured was centered on the screen. The objective lens with a magnification of 10 times was changed to a magnification of 50 times, and the surface of the sample was focused by the autofocus function of the image observation mode of the VK observation application (VK-H1VX). The simple mode of the shape measurement tab of the VK observation application (VK-H1VX) was selected, the measurement start button was pressed, the surface shape of the sample was measured, and a surface image file was obtained. A VK analysis application (VK-H1XA manufactured by KEYENCE CORPORATION) was started, the obtained surface image file was displayed, and then tilt correction was performed.
The observation measurement range (horizontal) in the measurement of the surface shape of the sample was set to 270 μm. Display the line roughness window, select JIS B0601-1994 in the parameter setting area, select the horizontal line from the measurement line button, display the horizontal line anywhere in the surface image, and press the OK button. The values of the average spacing Sm (μm) and the maximum height Ry (μm) of the uneven surface were obtained. Further, horizontal lines were displayed at four different places in the surface image, and the values of the average spacing Sm (μm) and the maximum height Ry (μm) of each uneven surface were obtained. The average value of the obtained five numerical values was calculated and used as the average interval Sm value and the maximum height Ry value of the uneven surface of the sample surface. The measurement results are shown in Table 2.

(Measurement of glossiness)
On a 35 μm thick 300 mm × 150 mm copper foil substrate whose surface was bafflor-polished, solid printing was performed by screen printing so that the film thickness after curing was 12 μm, and a hot air circulation drying furnace (DF610 manufactured by Yamato Scientific Co., Ltd.) was used. It was cured at 150 ° C. for 60 minutes to form a cured coating film on a copper foil substrate, allowed to cool at room temperature for 30 minutes under a yellow lamp, and left to stand to prepare an evaluation substrate.
In each of the cured coating films formed on the copper foil substrate, a waste cloth containing isopropyl alcohol (IPA) is placed on the surface of the cured coating film in an environment of 25 ° C. and 50% RH, and further, 500 g of the cured coating film is placed on the surface. After placing the weight and letting it stand for 1 minute, the waste cloth was peeled off, and it was confirmed that all or part of the resin layer did not adhere to the surface of the waste cloth in contact with the cured coating film. The glossiness shall be measured using a cured coating film formed by thermosetting without performing a post-exposure development step.
Then, Gs (60 °) on the surface of each cured coating film was measured using a digital variable angle gloss meter (Micro-Tri-Gloss, manufactured by BYK Gardener). The measurement results are shown in Table 2 below.

(Variation of coating film before drying when thin film)
As a method for simply confirming the variation of the coating film before drying in the thin film, a method of confirming the variation of the powder in the curable resin composition was adopted, and the dispersity of the curable resin composition was measured.
Specifically, the curable resin compositions of Examples and Comparative Examples have a width of 90 mm, a length of 240 mm, and a maximum depth in accordance with JIS K5101-5-2: 2004 and JIS K5600-2-5: 1999. The degree of dispersion was measured by using a particle size gauge of 25 μm (manufactured by Daiichi Sangyo Seisakusho Co., Ltd.), and evaluated based on the following evaluation criteria. As for the degree of dispersion, observe the point where remarkable spots start to appear on the gauge. In particular, a point containing 5 to 10 particles in a width of 3 mm along the groove of the gauge is observed, and such a point is defined as the degree of dispersion. Ignore the sparsely appearing spots before the point where the prominent spots begin to appear. Calculate the average value of the three measurements. The evaluation results are shown in Table 2.
◯: The degree of dispersion (mean value of three measurements) was 20 μm or less.
X: Dispersity (mean value of 3 measurements) was more than 20 μm.

(Variation of dry coating film when thin film)
A printability test was conducted as a simple method for confirming the variation in the dry coating film when the thin film was used. Specifically, on a solid glass substrate, solid printing is performed by screen printing using a 180-mesh polyester plate (with bias) so that the film thickness after drying is 12 μm, and a hot air circulation type drying oven (Yamato Scientific Co., Ltd.) It was dried at 90 ° C. for 15 minutes using a company-made DF610), allowed to cool at room temperature for 30 minutes under a yellow lamp, and then left to stand. After being left to stand, it was confirmed that the curable resin composition did not adhere to the finger when the coated surface was touched with a finger. After leaving it to stand, a surface roughness measuring machine (Kosaka Research Institute Co., Ltd .: Surfcoder SE600) is used to randomly measure the step (P) between the dry coating film and the uncoated part at four points, and a three-point designation type is used. Step analysis was performed. Details will be described with reference to the cross section of the dry coating film shown in FIG. In the step analysis by the three-point designation type, two reference points 3 on the surface of the dry coating film 2 on the substrate 1 are input, one evaluation point 5 of the uncoated portion 4 of the substrate 1 is input, and the reference line 6 is input. Ask for. Subsequently, the step (P) between the reference line 6 and the evaluation point 5 is measured. The film thickness and the standard deviation of the film thickness were calculated from each of the measured steps (P), and evaluated based on the following evaluation criteria. The measurement conditions were a measurement magnification of 2,000 times, a feed speed of 0.5 mm / s, and a trace length of 6.0 mm. The evaluation results are shown in Table 2.
◯: The standard deviation was within 1.0 μm.
X: The standard deviation was more than 1.0 μm.

(Confirmation of copper appearance phenomenon)
On a 35 μm thick 300 mm × 150 mm copper foil substrate whose surface was bafflor-polished, solid printing was performed by screen printing using a 180 mesh polyester plate (with bias) so that the film thickness after curing was 12 μm, and hot air circulation drying was performed. An evaluation substrate was prepared by curing at 150 ° C. for 60 minutes using a furnace (DF610 manufactured by Yamato Scientific Co., Ltd.), allowing it to cool at room temperature for 30 minutes under a yellow lamp, and leaving it to stand. In each of the produced evaluation substrates, a waste cloth containing isopropyl alcohol (IPA) was placed on the surface of the cured coating film in an environment of 25 ° C. and 50% RH, and a weight of 500 g was placed on the waste cloth. After allowing to stand for a minute, the waste cloth was peeled off, and it was confirmed that all or part of the resin layer did not adhere to the surface of the waste cloth that was in contact with the cured coating film.
Then, the place where the underlying copper was visible within the range of 70 mm × 70 mm was confirmed by an optical microscope (50 times). The evaluation results are shown in Table 2.
⊚: No part where copper was visible was confirmed.
◯: There were a few places where copper was visible, but there was no problem.
X: Many places where copper was visible were confirmed.

As is clear from Table 2, it can be seen that in the curable resin composition of the example, the variation of the pre-drying coating film and the dried coating film at the time of thin film is small, and the copper appearance phenomenon does not occur.

1: Substrate 2: Dry coating film 3: Reference point 4: Uncoated part 5: Evaluation point 6: Reference line P: Step X: Measurement direction with a surface roughness measuring machine

Claims (11)

A curable resin composition containing a curable resin and an extender pigment.
The glossiness at 60 ° in the cured coating film having a film thickness of 12 μm after curing of the curable resin composition is within the range of 0.5 or more and 40.0 or less.
When 0.3 g of the curable resin composition is mixed with 30 g of propylene glycol monomethyl ether acetate and measured using Microtrac, the average particle diameter D ₅₀ is 0.1 μm or more and 1.0 μm or less, and the specific surface area CS is A curable resin composition, which is 10.0 m ² / ml or more. The curable resin composition according to claim 1, wherein the average interval Sm of the unevenness of the coating film thickness after drying of the curable resin composition is within the range of more than 0 μm and 12.0 μm or less. The curable resin composition according to claim 1 or 2, wherein the maximum height Ry of the coating film thickness after drying of the curable resin composition is within the range of more than 0 μm and 8.0 μm or less. The curable resin composition according to any one of claims 1 to 3, wherein the extender pigment is at least one of silica and barium sulfate. The curable resin composition according to claim 4, wherein the extender pigment further contains amorphous silica having an oil absorption of 180 to 350 ml / 100 g. The curable resin composition according to any one of claims 1 to 5, wherein the curable resin contains a carboxyl group-containing resin. The curable resin composition according to any one of claims 1 to 6, wherein the curable resin contains two or more kinds of carboxyl group-containing resins. The curable resin composition according to claim 7, wherein at least one of the two or more kinds of carboxyl group-containing resins is a carboxyl group-containing copolymer resin. A dry film comprising a support film and a resin layer formed on the support film and composed of a dry coating film of the curable resin composition according to any one of claims 1 to 8. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 8 or the resin layer of the dry film according to claim 9. A printed wiring board comprising the cured product according to claim 10.