CN111902747A - Method for forming cured film and curable composition - Google Patents

Abstract

The invention provides a method for forming a cured film capable of obtaining a cured film with excellent coating property and patterning property and good light shielding property, and a curable composition capable of obtaining a cured film with excellent coating property and patterning property and good light shielding property. The invention provides a method for forming a hardened film, which comprises the following steps: (1) a step of forming a template having a convex portion on a substrate; (2) forming a coating film between the convex portions of the template by a curable composition; and (3) a step of hardening the coating film, and the hardening composition contains a pigment of a white pigment, a black pigment, or a combination of these; a hardening compound; and a solvent, wherein the content of the pigment is 50 to 90 mass% based on all components except the solvent, and the relative dielectric constant of the solvent is 6.0 or less.

Description

Method for forming cured film and curable composition

Technical Field

The present invention relates to a method for forming a cured film and a curable composition.

Background

The display element or the solid-state imaging element includes a patterned cured film such as a black matrix, a color filter, and a light-shielding film. Conventionally, such a cured film has been widely formed by photolithography using a radiation-sensitive composition (see patent documents 1 and 2). In the black matrix and the like, a pigment such as a black pigment is added to exhibit light-shielding properties and the like.

On the other hand, in recent years, a display device in which a plurality of micro LEDs are arranged, which is called a micro Light Emitting Diode (LED) display or the like, has been developed (see patent document 3).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2004-205862

Patent document 2: japanese patent laid-open No. 2003-302515

Patent document 3: japanese patent laid-open No. 2012-142489

Disclosure of Invention

Problems to be solved by the invention

In the above-described micro LED display, a configuration in which an LED (R-LED) emitting red light, an LED (G-LED) emitting green light, and an LED (B-LED) emitting blue light are disposed as a plurality of micro LEDs has a high technical obstacle in terms of practical use. On the other hand, it is considered that the technical obstacle of the micro LED display 101 having a structure in which only the B-LED 102 is disposed as a micro LED on the Thin Film Transistor (TFT) substrate 105 and the B-LED 102 is combined with the wavelength conversion layer 103a and the wavelength conversion layer 103B is relatively low as shown in fig. 1. Specifically, in the micro LED display 101 of fig. 1, the B-LED 102 and the wavelength conversion layer 103a that converts blue light into red light are combined in a region that emits red light. Similarly, the B-LED 102 and the wavelength conversion layer 103B for converting blue light into green light are combined in a region emitting green light. Only the B-LED 102 is disposed in a region emitting blue light without providing a wavelength conversion layer. Further, a color filter or the like may be further provided in each region.

In this way, when not only the LEDs but also the wavelength conversion layer 103a and the wavelength conversion layer 103b are provided in each region emitting light, in particular, when the film thicknesses of the wavelength conversion layer 103a and the wavelength conversion layer 103b are increased to obtain converted red light and green light with sufficient emission intensity, it is necessary to provide the partition wall 104 that partitions each region to be high. In general, the formation of the partition wall 104 by photolithography is performed as follows: a coating film of a radiation-sensitive composition is formed on one side (lower surface in fig. 1) of the transparent substrate 106, and is exposed and developed. On the other hand, in order to improve the light-shielding property between the regions, it is necessary to increase the concentration of the pigment in the partition wall 104. However, when the partition wall 104 having a high pigment concentration is to be formed by photolithography using a radiation-sensitive composition, it is difficult for the irradiated light to reach the lower part of the coating film, and thus it is difficult to form a partition wall having a high height.

Therefore, the inventors have studied a method for forming a partition wall using a template (also referred to as a pre-pattern (or the like)) serving as a mold for the partition wall. Specifically, first, a template having a convex portion is formed using a radiation-sensitive composition or the like. Then, a curable composition is applied between the convex portions of the template to form a coating film of the curable composition. After the coating film is hardened, the convex portion of the template is removed, whereby a partition wall having a sufficient height can be formed. However, this method is not sufficient in terms of coatability, patterning property, and the like of the curable composition.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for forming a cured film that can obtain a cured film having excellent coatability and patterning properties and having good light-shielding properties, and a curable composition that can obtain a cured film having excellent coatability and patterning properties and having good light-shielding properties.

Means for solving the problems

The invention made to solve the above problems is a method for forming a cured film, including: (1) a step of forming a template having a convex portion on a substrate; (2) forming a coating film between the convex portions of the template by a curable composition; and (3) a step of hardening the coating film, and the hardening composition contains a pigment of a white pigment, a black pigment, or a combination of these; a hardening compound; and a solvent, wherein the content of the pigment is 50 to 90 mass% based on all components except the solvent, and the relative dielectric constant of the solvent is 6.0 or less.

Another invention to solve the above problem is a curable composition comprising: a white pigment, a black pigment, or a combination of these; a hardening compound; and a solvent, wherein the content of the pigment is 50 to 90 mass% based on all components except the solvent, and the relative dielectric constant of the solvent is 6.0 or less.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a method for forming a cured film that can provide a cured film having excellent coatability and patterning properties and having good light-shielding properties, and a curable composition that can provide a cured film having excellent coatability and patterning properties and having good light-shielding properties.

Drawings

Fig. 1 is a schematic explanatory view for explaining an example of the structure of the micro LED display.

Fig. 2 is a first explanatory view of a method for forming a cured film according to an embodiment of the present invention.

Fig. 3 is a second explanatory view of a method for forming a cured film according to an embodiment of the present invention.

Detailed Description

The curable composition and the method for forming a cured film according to one embodiment of the present invention will be described in detail below.

< curable composition >

The curable composition of an embodiment of the present invention comprises:

[A] a white pigment, a black pigment, or a combination of these;

[B] a hardening compound; and

[C] a solvent.

The curable composition contains the [ A ] pigment in an amount of 50 to 90 mass% based on all components except the [ C ] solvent. The relative dielectric constant of the [ C ] solvent is 6.0 or less.

The curable composition can provide a cured film having excellent coatability and patterning properties and having good light-shielding properties. Specifically, in a method of forming a coating film between the convex portions of the template by applying a curable composition and curing the coating film to obtain a cured film, the effect can be preferably exhibited by using the curable composition. The term "excellent patterning property" means that, for example, when a patterned cured film is obtained through a development step, a cured film having a good shape and little peeling of the cured film or generation of cracks can be obtained. The reason why the above-mentioned effect is exhibited by the above-mentioned curable composition is not particularly limited, but the following reason is presumed. When a solvent having a high polarity is used as a solvent for the curable composition, the solvent dissolves into the template of the mold, and the coating property and patterning property are deteriorated. On the other hand, in the curable composition, since the [ C ] solvent having a low polarity and a relative dielectric constant of 6.0 or less is used, the template is less likely to be dissolved, and the coatability and patterning properties are improved. Further, the curable composition has good wet spread between the projections of the template because a [ C ] solvent having a low relative dielectric constant of 6.0 or less is used. Further, since the content of the [ A ] pigment in the curable composition is high, the light-shielding property of the cured film obtained is good. Therefore, according to the curable composition, it can be effectively used as a forming material for a partition wall or the like having a relatively high height which can be preferably applied to a micro LED display or the like. Further, the cured film obtained from the curable composition is usually white, black or gray.

The curable composition may further contain other components in addition to the components [ A ] to [ C ]. Hereinafter, each component will be described in detail.

([ A ] pigment)

[A] The pigment is a white pigment, a black pigment, or a combination of these. The light-shielding property can be evaluated in the form of light reflectance or light density (od (optical density) value). [A] One or more pigments may be used.

(white pigment)

Examples of the white pigment include: calcium carbonate, lead carbonate, barium sulfate, lead phosphate, zinc phosphate, titanium oxide, aluminum oxide, silica, zinc oxide, antimony oxide, zirconium oxide, tin oxide, zinc sulfide, strontium titanate, barium tungstate, lead metasilicate, talc, kaolinite, clay, bismuth oxychloride, calcium hydroxide, hollow silica, and the like.

Examples of The white pigment include compounds classified as pigments (pigments) in The color Index (published by The Society of Dyers and Colourists), i.e., compounds labeled with The color Index (c.i.) number described below.

C.i. pigment white (pigment white)1, c.i. pigment white 2, c.i. pigment white 3, c.i. pigment white 4, c.i. pigment white 5, c.i. pigment white 6: 1, c.i. pigment white 7, c.i. pigment white 8, c.i. pigment white 10, c.i. pigment white 11, c.i. pigment white 12, c.i. pigment white 13, c.i. pigment white 14, c.i. pigment white 15, c.i. pigment white 16, c.i. pigment white 17, c.i. pigment white 18: 1, c.i. pigment white 19, c.i. pigment white 20, c.i. pigment white 21, c.i. pigment white 22, c.i. pigment white 23, c.i. pigment white 24, c.i. pigment white 25, c.i. pigment white 26, c.i. pigment white 28, c.i. pigment white 33, c.i. pigment white 28.

These white pigments may be used by treating the surface with other metals such as alumina, siloxane, zirconia, and zinc oxide.

Among these white pigments, titanium oxide and strontium titanate are preferable in terms of effectively improving the light-shielding property (light reflectivity) of the cured film obtained. The crystal form of titanium oxide is preferably rutile type.

(Black pigment)

As the black pigment, there can be mentioned: carbon black, titanium black, acetylene black, lamp black, bone black, graphite, iron black, aniline black, cyanine black, perylene black, and the like. In addition, as the black pigment, a plurality of kinds of color pigments may be used in combination.

Among these black pigments, carbon black is preferable in terms of effectively improving the light-shielding property of the obtained cured film.

Examples of the carbon black include commercially available carbon blacks as described below.

Mitsubishi chemical company MA7, MA8, MA11, MA77, MA100R, MA100S, MA220, MA230, MA600, MCF88, #5, #10, #20, #25, #50, #32, #33, #40, #44, #45, #47, #50, #52, #55, #650, #750, #850, #900, #950, #960, #970, #980, #990, #1000, #2200, #2300, #2350, #2400, #2600, #2650, #3030, #3050, #3150, #3250, #3400, #3750, #3950, #4000, #4010, OIL7B, OIL9B, OIL11B, OIL30B, OIL31B, OIL31

Printex (Printex) (registered trademark, the same shall apply hereinafter) 3, Printex (Printex)3OP, Printex (Printex)30OP, Printex (Printex)40, Printex (Printex)45, Printex (Printex)55, Printex (Printex)60, Printex (Printex)75, Printex (Printex)80, Printex (Printex)85, Printex (Printex)90, Printex (Printex) a, Printex (Printex) L, Printex (Printex) G, Printex (Printex) P, Printex (Printex) Blintex (Printex) G, Special Black (Special Black) G (Special Black), Printex (Printex)5, Printex (Special Black) G, Printex (Black Printex) P, Printex (Blintex) 5, Special Black (Black specialx) G (Special Black specialx) 5, Black specialx (Black specialx) G (Black specialx) 5, Black specialx (Printex) G, Black specialx (Printex)5, Black specialx (Black specialx) G (Black specialx) 5, Black specialx (Black specialx) 5, Black specials (Black specialx) G, Black specials (black specials) 5, black specials (black specials) 5, black specials (black specialx, black, Special Black (special Black)4, pigment carbon Black (Color Black) FW1, pigment carbon Black (Color Black) FW2, pigment carbon Black (Color Black) FW2V, pigment carbon Black (Color Black) FW18, pigment carbon Black (Color Black) FW18, pigment carbon Black (Color Black) FW200, pigment carbon Black (Color Black) S160 and pigment carbon Black (Color Black) S170

Mannaceae (Monarch) (registered trademark, same below) 120, Mannaceae (Monarch)280, Mannaceae (Monarch)460, Mannaceae (Monarch)800, Mannaceae (Monarch)880, Mannaceae (Monarch)900, Mannaceae (Monarch)1000, Mannaceae (Monarch)1100, Mannaceae (Monarch)1300, Mannaceae (Monarch)1400, Mannaceae (Monarch)4630, Reger (REGAL) (registered trademark, same below) 99, Reger (REGAL)99R, Reger (REGAL)415R, Reger (REGAL)250R, Regal 330, Regal 400, Reg REGAR) (registered trademark, same below) 120, Reg (REGAR) 33, Reg) (REGAR) (registered trademark, registration of Perch) 33, Reg (REGAR) 33, Regal)33, Reg (REGAR) (registered trademark, Reg) (REGAR) 33, Reg) (registered trademark, Reg) (REGAL) (REGAR) 33, REGAL)33, Reg) (registered trademark, Reg) (REGAR) (trademark, REQ) (REGAR) 33, REQ) (registered trademark, REQ) (RPE) (trademark), E) (RPE) (RPR) (registered trademark), E) (RPR) (33

Ravens (RAVEN) (registered trademark, same as below) 11, Ravens (RAVEN)14, Ravens (RAVEN)15, Ravens (RAVEN)16, Ravens (RAVEN)22, RaVEN (RAVEN)30, Ravens (RAVEN)35, Ravens (RAVEN)40, Ravens (RAVEN)410, Ravens (RAVEN)420, Ravens (RAVEN)450, Ravens (RAVEN)500, Raven (RAVEN)780, Ravens (RAVEN)850, Ravens (RAVEN)890H, Raven (RAVEN)1000, Ravenn (RAVEN)1020, Ravenn (RAVEN)7000, Ravenn (RAVEN)1040, Ravenn 1060U, Raven (RAVEN)1080, Ravenn (RAVEN)1170, Ravenn (RAVEN)5000, Ravenn) 570, Ravenn (RAVEN)2000, Ravenn (RAVEN)3500, Ravenn) 150, Ravenn (RAVEN)150, Ravenn (Ravenn) 150, Ravenn (Ravenn) 150, Raven

As the other black pigment, each of the black pigments described in international publication No. 2017/110893 can be preferably used. In addition, as the color pigment in the case of using a plurality of color pigments in combination as a black pigment, an organic color pigment described in international publication No. 2017/110893 or the like can be used.

[A] The lower limit of the average particle diameter of the pigment may be preferably 30nm, more preferably 50nm, still more preferably 100nm, and yet more preferably 200 nm. On the other hand, the upper limit thereof may be preferably 700nm, more preferably 500nm, still more preferably 400nm, and still more preferably 200 nm. Further, when the pigment [ A ] is a white pigment, the average particle size tends to be relatively large. On the other hand, when the pigment [ A ] is a black pigment, the average particle size tends to be relatively small.

[A] The pigment can be purified by recrystallization, reprecipitation, solvent cleaning, sublimation, vacuum heating, or a combination thereof. The pigment may be used by modifying the particle surface with a resin or the like as necessary. Examples of the resin for modifying the particle surface of the pigment include: a vehicle (vehicle) resin described in Japanese patent laid-open No. 2001-108817, or various commercially available resins for dispersing pigments. The pigment may be used by pulverizing primary particles by a so-called salt mill (salt milling). As the method of salt milling, for example, the method disclosed in Japanese patent laid-open publication No. H08-179111 can be used.

[A] The lower limit of the content of the pigment with respect to all components except the [ C ] solvent in the curable composition, that is, the content in the solid content is 50% by mass, preferably 60% by mass, and more preferably 70% by mass. By setting the content of the [ a ] pigment to the lower limit or more, the light-shielding property of the obtained cured film can be improved. On the other hand, the upper limit of the content of the [ A ] pigment is 90 mass%, preferably 85 mass%. By setting the content of the [ A ] pigment to the upper limit or less, good patterning properties and curing properties can be exhibited.

([ B ] hardening Compound)

The curable compound of [ B ] is a curable compound. The curable composition contains [ B ] a curable compound, and therefore exhibits excellent curability and patterning properties. The [ B ] curable compound is preferably a compound having one or more polymerizable groups, and more preferably a compound having two or more polymerizable groups. Examples of the polymerizable group include: cyclic ether groups such as an oxetanyl group and an oxetanyl group, (meth) acryloyl groups, vinyl groups, and N-alkoxymethylamino groups. Among these, cyclic ether groups having a ring member number of 3 to 5 are preferable, and an oxetanyl group are more preferable. That is, the [ B ] curable compound preferably has an oxetanyl group, an oxetanyl group or a combination of these. [B] One or more kinds of the hardening compounds may be used. [B] The curable compound may be [ B1] resin (polymer) or [ B2] compound (monomer) other than resin. The [ B1] resin and the [ B2] compound may also be used in combination.

([ B1] resin)

[B1] The resin is a hardenable polymer. [B1] The resin is preferably a polymer of one or more ethylenically unsaturated monomers (monomers having unsaturated double bonds). [B1] One or more kinds of the resins may be used. The [ B1] resin includes a polymer containing a structural unit (I) having a polymerizable group.

(structural Unit (I))

The structural unit (I) is a structural unit having a polymerizable group. Specific examples of the polymerizable group are as described above.

Examples of monomers providing the structural unit (I) include: acrylic acid glycidyl ester, acrylic acid-3, 4-epoxy cyclohexyl methyl ester, acrylic acid-3, 4-epoxy tricyclo [5.2.1.0 ]^2，6]Acrylic esters such as decyl ester, 3-ethyloxetan-3-yl) methyl acrylate, and 2- (ethyleneoxyethoxy) ethyl acrylate; glycidyl methacrylate, 3, 4-epoxycyclohexane methacrylateEsters, 3, 4-epoxycyclohexylmethyl methacrylate, 3, 4-epoxytricyclo [5.2.1.0 ] methacrylate^2，6]Methacrylates such as decyl ester, 3-ethyloxetan-3-yl methyl methacrylate, and 2- (ethyleneoxyethoxy) ethyl methacrylate; vinyl ether compounds such as vinyl glycidyl ether, and the like. These monomers may be used alone or in combination of two or more.

The structural unit (I) can also be obtained by: a specific group contained in a structural unit in a polymer is reacted with a compound having a group reactive with the specific group and a (meth) acryloyl group or vinyl group as a polymerizable group. Examples thereof include: (1) a method of reacting a polymer having a carboxyl group with an unsaturated compound containing an oxetanyl group or an oxetanyl group, or the like; (2) a method of reacting a polymer having an oxetanyl group or an oxetanyl group with (meth) acrylic acid or the like; (3) a method of reacting a polymer having a hydroxyl group with a (meth) acrylate having an isocyanate group or a vinyl compound; (4) a method of reacting a polymer having an acid anhydride moiety with (meth) acrylic acid or the like. By this method, the structural unit (I) having a (meth) acryloyl group or vinyl group as a polymerizable group can be introduced.

The structural unit (I) is preferably a structural unit containing a cyclic ether group having a ring member number of 3 to 5, more preferably an oxetanyl group or an oxetanyl group, and still more preferably an oxetanyl group. The structural unit (I) is preferably a structural unit derived from a (meth) acrylate ester, and more preferably a structural unit derived from glycidyl (meth) acrylate.

The lower limit of the content of the structural unit (I) with respect to all the structural units of the [ B1] resin is preferably 2 mol%, more preferably 5 mol%. On the other hand, the upper limit of the content of the structural unit (I) may be preferably 60 mol%, more preferably 50 mol%, and still more preferably 35 mol% or 25 mol%.

(structural Unit (II))

[B1] The resin preferably contains a structural unit (II) having a hydrocarbon group having 8 to 30 carbon atoms. The [ B1] resin contains the structural unit (II), and the solubility of the [ B1] resin in the [ C ] solvent is improved. Therefore, the curable composition has improved coatability and the like by containing the [ B1] resin containing the structural unit (II).

Examples of the hydrocarbon group having 8 to 30 carbon atoms include aliphatic hydrocarbon groups having 8 to 30 carbon atoms such as aliphatic chain hydrocarbon groups and aliphatic cyclic hydrocarbon groups, and aromatic hydrocarbon groups having 8 to 30 carbon atoms.

Examples of the aliphatic chain hydrocarbon group having 8 to 30 carbon atoms include:

alkyl groups such as octyl, nonyl, decyl, dodecyl, pentadecyl, octadecyl (stearyl), and tetracosyl;

alkenyl groups such as octenyl, decenyl, and octadecenyl;

alkynyl groups such as octynyl, decynyl and octadecynyl.

Examples of the aliphatic cyclic hydrocarbon group having 8 to 30 carbon atoms include: cycloalkyl groups such as a cyclohexadecyl group, cycloalkenyl groups, cycloalkynyl groups, and the like.

Examples of the aromatic hydrocarbon group having 8 to 30 carbon atoms include: naphthyl, anthracenyl, xylyl, and the like.

Among these, an aliphatic hydrocarbon group is preferable, an aliphatic chain hydrocarbon group is more preferable, and an alkyl group is even more preferable. The lower limit of the number of carbon atoms in the hydrocarbon group is preferably 12, and more preferably 15. On the other hand, the upper limit of the number of carbon atoms is preferably 25, and more preferably 20.

Examples of monomers providing the structural unit (II) include: acrylates such as octyl acrylate, decyl acrylate, stearyl acrylate (stearyl acrylate), ditetradecyl acrylate, and naphthyl acrylate; methacrylates such as octyl methacrylate, decyl methacrylate, octadecyl methacrylate (stearyl methacrylate), ditetradecyl methacrylate, and naphthyl methacrylate; vinyl ether compounds such as octadecyl vinyl ether, and the like. These monomers may be used alone or in combination of two or more.

The lower limit of the content of the structural unit (II) with respect to all the structural units of the [ B1] resin is preferably 20 mol%, more preferably 40 mol%, and still more preferably 50 mol%. On the other hand, the upper limit of the content of the structural unit (II) is preferably 85 mol%, more preferably 75 mol%, and still more preferably 70 mol%.

(structural Unit (III))

[B1] The resin preferably further contains a structural unit (III) having a carboxyl group or a hydroxyl group. Further improvement of patterning properties and the like may be achieved by the [ B1] resin containing the structural unit (III). The structural unit (III) is more preferably a structural unit having a carboxyl group.

Examples of monomers providing the structural unit (III) include: unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and 4-vinylbenzoic acid;

unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid;

anhydrides of said unsaturated dicarboxylic acids;

(meth) acrylates having a hydroxyl group such as 4-hydroxyphenyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate;

and vinyl compounds having a hydroxyl group such as p-hydroxy- α -methylstyrene, p-hydroxystyrene, and 4- (vinylphenyl) methanol. These monomers may be used alone or in combination of two or more.

The lower limit of the content of the structural unit (III) with respect to all the structural units of the [ B1] resin is preferably 1 mol%, more preferably 5 mol%. On the other hand, the upper limit of the content of the structural unit (III) is preferably 30 mol%, more preferably 20 mol%.

(structural Unit (IV))

[B1] The resin preferably further contains a structural unit (IV) having a hydrocarbon group having 1 to 7 carbon atoms, other than the structural units (I) to (III). Further improvement in coatability, patterning properties, and the like can be achieved by the [ B1] resin containing the structural unit (IV).

The hydrocarbon group having 1 to 7 carbon atoms may be any of an aliphatic hydrocarbon group and an aromatic hydrocarbon group. Examples of the hydrocarbon group having 1 to 7 carbon atoms include: an aliphatic chain hydrocarbon group having 1 to 7 carbon atoms, an aliphatic cyclic hydrocarbon group having 3 to 7 carbon atoms, and an aromatic hydrocarbon group having 6 to 7 carbon atoms.

Examples of the aliphatic chain hydrocarbon group having 1 to 7 carbon atoms include: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl; alkenyl groups such as vinyl; alkynyl groups such as ethynyl and the like.

Examples of the aliphatic cyclic hydrocarbon group having 3 to 7 carbon atoms include cyclopentyl and cyclohexyl.

Examples of the aromatic hydrocarbon group having 6 to 7 carbon atoms include a phenyl group and a benzyl group.

Among these, an aliphatic hydrocarbon group is preferable, an aliphatic chain hydrocarbon group is more preferable, and an alkyl group is even more preferable. In addition, tertiary hydrocarbon groups are also preferred. The lower limit of the number of carbon atoms of the hydrocarbon group is preferably 2, more preferably 3, and still more preferably 4. On the other hand, the upper limit of the number of carbon atoms is preferably 6, more preferably 5, and still more preferably 4.

Examples of the monomer providing the structural unit (IV) include: methyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, styrene, and the like. These monomers may be used alone or in combination of two or more.

The lower limit of the content of the structural unit (IV) with respect to all the structural units of the [ B1] resin is preferably 1 mol%, more preferably 5 mol%. On the other hand, the upper limit of the content of the structural unit (IV) is preferably 30 mol%, and more preferably 20 mol%.

(structural Unit (V))

[B1] The resin may further contain a structural unit (V) other than the structural units (I) to (IV).

Examples of monomers providing the structural unit (V) include: maleimide compounds such as N-phenylmaleimide and N-cyclohexylmaleimide, polyethylene glycol methyl ether (meth) acrylate, polypropylene glycol methyl ether (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene glycol mono (meth) acrylate. These monomers may be used alone or in combination of two or more.

The upper limit of the content of the structural unit (V) to all the structural units of the [ B1] resin may be preferably 30 mol%, more preferably 10 mol%, and still more preferably 3 mol%.

[B1] The resin can be obtained by polymerizing the above-mentioned monomers by a conventional method such as radical polymerization.

([ B2] Compound)

[B2] The compound is a hardenable compound other than a polymer. [B2] The compound preferably has one or two or more polymerizable groups. Specific examples of the polymerizable group are as described above. The polymerizable group of the [ B2] compound is particularly preferably an oxetanyl group. [B2] One or more compounds may be used.

The compound [ B2] is preferably a compound having a cyclic ether group or (meth) acryloyl group having a ring member number of 3 to 5, more preferably a compound having an oxetanyl group or an oxetanyl group, and still more preferably a structural unit having an oxetanyl group.

Examples of the compound having an oxetanyl group include:

glycidyl ethers such as butyl glycidyl ether, amyl glycidyl ether and hexyl glycidyl ether;

glycidyl esters such as glycidyl (meth) acrylate;

bisphenol-type diglycidyl ethers such as bisphenol a diglycidyl ether, bisphenol F diglycidyl ether, and bisphenol S diglycidyl ether;

polyglycidyl ethers of polyhydric alcohols such as 1, 4-butanediol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, and glycerol triglycidyl ether.

Examples of the compound having an oxetanyl group include:

3, 3-Dimethyloxetane, 3-diethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-methyl-3-methoxymethyloxetane, 3-ethyl-3- [ (2-ethylhexyloxy) methyl ] oxetane, xylylene-dioxycyclobutane, 3-ethyl-3 { [ (3-ethyloxetan-3-yl) methoxy ] methyl } oxetane, bis [ (3-ethyloxetan-3-yl) methyl ] isophthalate, 1, 4-bis [ (3-ethyloxetan-3-yl) methoxymethyl ] benzene, 1, 3-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, and the like.

In addition, as the compound having an oxetanyl group or oxetanyl group, there can be used:

compounds having a fluorinated hydrocarbon group such as 3- (perfluoropropyl) propene-1, 2-oxide and 3- (perfluorohexyl) propene-1, 2-oxide;

and silane compounds such as 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.

Among the compounds having an oxetanyl group, compounds having an ether bond (-O-) such as 3-ethyl-3- [ (2-ethylhexyloxy) methyl ] oxetane and 3-ethyl-3 { [ (3-ethyloxetan-3-yl) methoxy ] methyl } oxetane are more preferable, and compounds containing an oxetanyl group, a hydrocarbon group and an ether bond are more preferable.

Examples of the compound having a (meth) acryloyl group include:

ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene di (meth) acrylate, triacrylate di (meth) acrylate, 1, 3-butanediol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol diacrylate, tricyclo [5.2.1.0^2，6]Di (meth) acrylate compounds such as decane dimethanol di (meth) acrylate;

tri (meth) acrylate compounds such as tri (2-hydroxyethyl) isocyanurate tri (meth) acrylate, trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate;

tetra (meth) acrylate compounds such as pentaerythritol tetra (meth) acrylate;

and penta (meth) acrylate compounds such as dipentaerythritol penta (meth) acrylate.

In addition, the compounds exemplified as the (meth) acrylates in the monomer providing each structural unit of the [ B1] resin can also be used as the compound having a (meth) acryloyl group.

The number of the polymerizable groups in one molecule of the [ B2] compound is preferably 1 to 3, more preferably 1 and 2, and still more preferably 2.

The lower limit of the content of the [ B ] curable compound with respect to all components except the [ C ] solvent in the curable composition, that is, the content in the solid component may be preferably 3% by mass, more preferably 5% by mass, and further preferably 10%, 15% or 20% by mass. On the other hand, the upper limit of the content of the [ B ] curable compound may be preferably 40% by mass, more preferably 30% by mass, and still more preferably 20% by mass or 10% by mass. By setting the content of the [ B ] curable compound in the above range, good curing properties can be exhibited, and the pattern shape of the cured film obtained is also sufficient. When a white pigment is used as the pigment [ A ], the content of the curable compound [ B ] tends to be relatively large. On the other hand, when a black pigment is used as the [ A ] pigment, the content of the [ B ] curable compound tends to be relatively small.

([ C ] solvent)

[C] The solvent has a relative dielectric constant of 6.0 or less. The upper limit of the relative permittivity of the [ C ] solvent is preferably 5, and more preferably 3. On the other hand, the lower limit of the relative permittivity may be, for example, 1.0 or 1.5. [C] The solvent may be used alone or in combination of two or more. When two or more solvents are used in combination as the [ C ] solvent, the relative dielectric constant is a weighted average of all the solvents.

Examples of the solvent [ C ] include hydrocarbons. The hydrocarbon may be any of an aliphatic hydrocarbon and an aromatic hydrocarbon.

As the aliphatic hydrocarbon, there may be mentioned:

alkanes such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, eicosane, etc.; aliphatic chain hydrocarbons such as alkenes including heptene, octene, dodecene, tetradecene, and eicosene;

cycloalkanes such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclotetradecane, cycloeicosane, and methylcyclohexane; and alicyclic cyclic hydrocarbons such as cycloolefins including cycloheptene and cyclotetradecene.

As the aromatic hydrocarbon, there can be mentioned: benzene, toluene, xylene, and the like.

Among these, aliphatic hydrocarbons are preferable, alkanes and cycloalkanes are more preferable, and alkanes are still more preferable.

The lower limit of the number of carbon atoms of the [ C ] solvent is preferably 5, more preferably 8, and still more preferably 12. On the other hand, the upper limit of the number of carbon atoms is preferably 20, and more preferably 16. By using a solvent having a carbon number in the above range, volatility, coatability, and the like are more favorable.

The content of the [ C ] solvent in the curable composition is not particularly limited. The lower limit of the solid content concentration ([ C ] total concentration of the components excluding the solvent) in the curable composition is preferably 20% by mass, more preferably 40% by mass, even more preferably 50% by mass, and even more preferably 60% by mass. On the other hand, the upper limit of the solid content concentration is preferably 80% by mass, and more preferably 70% by mass. By setting the solid content concentration in the above range, the coating properties, particularly the coating properties when coating by an ink jet method, and the like are more favorable.

([ D ] polymerization initiator)

The curable composition preferably further contains [ D ] a polymerization initiator. The [ D ] polymerization initiator is preferably a thermal acid generator, a thermal radical generator or a combination of these. By further including the polymerization initiator [ D ] in the curable composition, the curing reaction (polymerization reaction) of the curable compound [ B ] in the coating film can be effectively promoted, and thus a cured film having more excellent patterning properties and the like can be formed.

As the thermal acid generator, there may be mentioned: ionic thermal acid generators such as onium salts including sulfonium salts, benzothiazolium salts, ammonium salts, and phosphonium salts; or a nonionic thermal acid generator such as a halogen-containing compound, a diazomethane compound, a sulfone compound, a sulfonate compound, a carboxylate compound, a phosphate compound, a sulfonimide compound, or a sulfone benzotriazole compound. The thermal acid generator is preferably an ionic thermal acid generator.

Specific examples of the ionic thermal acid generator include: triphenylsulfonium, 1-dimethylthionaphthalene-4-hydroxynaphthalene, 1-dimethylthionaphthalene-4, 7-dihydroxynaphthalene, 4-hydroxyphenyl-dimethylsulfonium, 4-hydroxyphenyl-methyl-benzylsulfonium, 2-methylbenzyl-4-hydroxyphenylmethylthiosulfonium, 2-methylbenzyl-4-acetylphenylmethylthiosulfonium, 2-methylbenzyl-4-benzoyloxyphenylmethylthiosulfonium, N, n-dimethylanilinium, N, methanesulfonate such as N-diethylanilinium, trifluoromethanesulfonate, camphorsulfonate, p-toluenesulfonate, hexafluorophosphonate, tetrafluoroborate, tetraphenylborate, tetrakis (pentafluorophenyl) borate, hexafluorophosphoric acid, tris (pentafluoroethyl) trifluorophosphate, and the like.

Examples of the thermal radical generator include: organic peroxides such as alkyl peroxides, acyl peroxides, ketone peroxides, alkyl hydroperoxides, peroxydicarbonates, and sulfonyl peroxides; inorganic peroxides; azo compounds such as azonitrile; sulfinic acids; bis-azido; diazo compounds, and the like.

As specific examples of the thermal radical generator, cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, lauroyl peroxide, peroxodisulfate (peroxodisulfate), hydrogen peroxide, potassium persulfate, ammonium persulfate, perborate, 2 ' -azobisisobutyronitrile, 1 ' -azobis (1-cyclohexane-1-carbonitrile), dimethyl-2, 2 ' -azobisbutyrate, 2 ' -azobis (2-methylbutyronitrile), 2 ' -azobis (2-amidinopropane) dicarbonate, azobiscyanovaleric acid sodium, 2 ' -azobis (2, 4-dimethylvaleronitrile), 2 ' -azobis [2- (2-imidazolin-2-yl) propane ], 2, 2 '-azobis [ 2-methyl-N- [ 1, 1-bis (hydroxymethyl) -2-hydroxyethyl ] propionamide ], 2' -azobis [ 2-methyl-N- [ 1, 1-bis (hydroxymethyl) ethyl ] propionamide ], 2 '-azobis [ 2-methyl-N- (2-hydroxyethyl) propionamide ], 2' -azobis (2-cyanopropanol), 2 '-azobis (2, 4, 4-trimethylpentane), sodium p-toluenesulfinate, 2' -azobis (methyl isobutyrate), and the like.

The lower limit of the content of the polymerization initiator [ D ] in all components other than the solvent [ C ], i.e., in the solid content, in the curable composition is preferably 0.01% by mass, and more preferably 0.05% by mass. On the other hand, the upper limit of the content of the [ D ] polymerization initiator is preferably 5% by mass, and more preferably 3% by mass. The content of the polymerization initiator [ D ] relative to the curable compound [ B ] is preferably, for example, 1 to 20 mass%. By setting the content of the polymerization initiator [ D ] in the above range, good patterning property and curing property can be exhibited, and the pattern shape of the cured film obtained is also sufficient.

([ E ] fluororesin)

The curable composition preferably further contains [ E ] fluororesin. The curable composition containing [ E ] fluororesin can improve the liquid repellency of the cured film obtained. Further, when the liquid repellency of the cured film is high, it is possible to improve the coatability when a layer such as a wavelength conversion layer is formed between the cured films as the partition walls by coating, to improve the shape of the cured film after coating, and the like. [E] The fluororesin includes a structural unit (VI) having a fluorine-containing group. [E] The fluororesin is preferably a polymer of one or more ethylenically unsaturated monomers (monomers having an unsaturated double bond). [E] One or more fluorine resins may be used.

(structural Unit (VI))

The structural unit (VI) is a structural unit having a fluorine-containing group. Examples of the fluorine-containing group include a hydrocarbon group in which at least one hydrogen atom is substituted with a fluorine atom, preferably an alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and a monovalent cycloalkyl group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and more preferably an alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom.

The lower limit of the number of carbon atoms of the fluorine-containing group is preferably 4, and more preferably 6. The upper limit is preferably 16, and more preferably 12. The lower limit of the number of fluorine atoms in the fluorine-containing group is 1, preferably 3, and more preferably 5. The upper limit thereof may be, for example, 30 or 20.

Examples of the alkyl group having 1 to 20 carbon atoms, in which at least one hydrogen atom is substituted with a fluorine atom, include a partially fluorinated alkyl group having 1 to 20 carbon atoms in the alkyl group and at least one hydrogen atom substituted with a fluorine atom, a perfluoroalkyl group, and the like.

Examples of the monovalent cycloalkyl group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom include a partially fluorinated cycloalkyl group and a perfluorocycloalkyl group in which at least one hydrogen atom having 4 to 20 carbon atoms in the cycloalkyl group is substituted with a fluorine atom.

Examples of monomers providing the structural unit (VI) include: trifluoromethyl (meth) acrylate, 2, 2, 2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, perfluoro-n-propyl (meth) acrylate, perfluoroisopropyl (meth) acrylate, perfluoro-n-butyl (meth) acrylate, perfluoroisobutyl (meth) acrylate, perfluoro-tert-butyl (meth) acrylate, 2- (1, 1, 1, 3, 3, 3-hexafluoropropyl) meth (acrylate), 1- (2, 2, 3, 3, 4, 4, 5, 5-octafluoropentyl) meth (acrylate), perfluorocyclohexylmethyl (meth) acrylate, 1- (2, 2, 3, 3, 3-pentafluoropropyl) meth (acrylate, 1- (3, 3, 4) meth (acrylate, fluorinated hydrocarbon (meth) acrylates such as 4, 5, 5, 6, 6, 7, 7, 8, 8, 8-tridecafluorooctyl) ester, 1- (3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 10-heptadecafluorodecyl) meth (acrylate, and 1- (5-trifluoromethyl-3, 3, 4, 4, 5, 6, 6, 6-octafluorohexyl) meth (acrylate). These monomers may be used alone or in combination of two or more.

The lower limit of the content of the structural unit (VI) in the total structural units of the [ E ] fluororesin is preferably 5 mol%, more preferably 10 mol%, and still more preferably 20 mol%. On the other hand, the upper limit of the content of the structural unit (II) is preferably 60 mol%, more preferably 50 mol%, and still more preferably 40 mol%.

(structural Unit (I))

[E] The fluororesin preferably contains a structural unit (I) having a polymerizable group. In the curable composition, when the [ B1] resin and the [ E ] fluororesin are used in combination, the resin containing the structural unit (I) having a polymerizable group and the structural unit (IV) having a fluorine-containing group is the same as the [ E ] fluororesin. On the other hand, in the case where the resin containing the structural unit (I) having a polymerizable group is only a fluorine-containing resin, the resin is [ B1] resin. The [ E ] fluororesin contains the structural unit (I), and the curability or patterning property of the curable composition is further improved. The specific form and preferred form of the structural unit (I) are the same as those described for the structural unit (I) of the [ B1] resin.

The lower limit of the content of the structural unit (I) with respect to all the structural units of the [ E ] fluororesin is preferably 5 mol%, more preferably 10 mol%. On the other hand, the upper limit of the content of the structural unit (I) is preferably 50 mol%, more preferably 40 mol%, and still more preferably 25 mol%.

(structural Unit (II))

[E] The fluororesin preferably contains a structural unit (II) having a hydrocarbon group having 8 to 30 carbon atoms. Since the [ E ] fluororesin contains the structural unit (II), the solubility of the [ E ] fluororesin is lowered, and thus the patterning property and the like of the curable composition are improved. The specific form and preferred form of the structural unit (II) are the same as those described for the structural unit (II) of the [ B1] resin.

The lower limit of the content of the structural unit (II) with respect to the total structural units of the [ E ] fluororesin is preferably 10 mol%, more preferably 20 mol%, and still more preferably 30 mol%. On the other hand, the upper limit of the content of the structural unit (II) is preferably 70 mol%, more preferably 60 mol%, and still more preferably 50 mol%.

(structural Unit (III))

[E] The fluororesin preferably further contains a structural unit (III) having a carboxyl group or a hydroxyl group. Further improvement in coatability, patterning properties, and the like can be achieved by the [ E ] fluororesin containing the structural unit (III). The specific form and preferred form of the structural unit (III) are the same as those described for the structural unit (III) of the [ B1] resin.

The lower limit of the content of the structural unit (III) with respect to all the structural units of the [ E ] fluororesin is preferably 2 mol%, more preferably 5 mol%. On the other hand, the upper limit of the content of the structural unit (III) is preferably 30 mol%, and more preferably 20 mol%.

(other structural units)

[E] The fluororesin may further contain other structural units. Examples of such a structural unit include a structural unit (IV) or a structural unit (V) in the [ B1] resin.

The lower limit of the content of the other structural unit with respect to the total structural units of the [ E ] fluororesin may be 0 mol% or 1 mol%. The upper limit thereof may be preferably 30 mol%, more preferably 10 mol%, and still more preferably 3 mol%.

[E] The fluororesin can be obtained by polymerizing the above-mentioned monomers by a conventional method such as radical polymerization.

The lower limit of the content of the [ E ] fluororesin with respect to all components excluding the [ C ] solvent in the curable composition, that is, the content in the solid content is preferably 0.1% by mass, more preferably 0.5% by mass, and still more preferably 1% by mass. On the other hand, the upper limit of the content of the [ E ] fluororesin is preferably 10 mass%, more preferably 5 mass%, and still more preferably 3 mass%.

([ F ] dispersant)

The curable composition may further contain [ F ] a dispersant. By further including the dispersant [ F ] in the curable composition, the dispersibility of the pigment [ A ] is improved, and the light-shielding property of the cured film obtained can be further improved.

Examples of the [ F ] dispersant include: conventional polyester-based dispersants, polyurethane-based dispersants, nonionic surfactant dispersants, polyether-based dispersants, phosphate-based dispersants, and the like. [F] One or more kinds of the dispersant may be used.

Commercially available products of the dispersant include, for example: diperbick (Disperbyk) -108, Diperbyk (Disperbyk) -109, Diperbyk (Disperbyk) -2055, Antitarale (ANTI-TERRAR) -204, BYK-W966 (manufactured by BYK chemical Co., Ltd.); or agkispa (aiiser) PN411, agkispa (aiiser) PA111 (manufactured by Ajinomoto Fine-techno) and the like.

The lower limit of the content of the [ F ] dispersant with respect to 100 parts by mass of the [ a ] pigment in the curable composition is preferably 0.5 part by mass, and more preferably 2 parts by mass. On the other hand, the upper limit of the content is preferably 50 parts by mass, and more preferably 30 parts by mass.

(other additives)

The curable composition may optionally contain other additives other than the components [ A ] to [ F ]. Examples of additives include: [A] colorants other than pigments, surfactants, adhesion promoters, antioxidants, ultraviolet absorbers, anti-aggregation agents, residue improvers, developability improvers, and the like. However, the upper limit of the content of the other additive to all components other than the [ C ] solvent in the curable composition may be preferably 10% by mass, and more preferably 1% by mass.

Examples of the colorant other than the [ A ] pigment include: fluorescent dyes, blue dyes, violet dyes, red dyes, and the like. The dyes may be classified into perylene dyes, anthraquinone dyes, triarylmethane dyes, phthalocyanine dyes, xanthene dyes, dipyrromethene dyes, and the like according to their structures.

Examples of perylene dyes include: c.i. Solvent Orange (Solvent Orange)55, ramomum Yellow (Lumogen Yellow)083, ramomum Orange (Lumogen Orange)240, ramomum Red (Lumogen Red)305 (above, manufactured by BASF corporation). Examples of the anthraquinone dye include compounds described in paragraphs [0049] to [0064] of Japanese patent laid-open publication No. 2013-053292, and among them, C.I. Solvent Blue (Solvent Blue)35, C.I. Solvent Blue 45, C.I. Acid Blue (Acid Blue)80, C.I. Solvent Blue 104, and C.I. Solvent Blue 122 are preferable. Examples of triarylmethane dyes include compounds described in paragraphs [0048] to [0064] of Japanese patent laid-open publication No. 2013-144724. Examples of the phthalocyanine dye include compounds described in paragraphs [0100] to [0188] of Japanese patent laid-open No. 2007-094181, and among them, C.I. solvent blue 38 and C.I. solvent blue 70 are preferable. Examples of the xanthene dye include compounds described in paragraphs [0010] to [0048] of Japanese patent laid-open publication No. 2013-053292, and among them, an acidic xanthene dye is preferable. Examples of dipyrromethene dyes include: the compound described in paragraphs [0017] to [0105] of Japanese patent laid-open No. 2010-085454, the compound described in paragraphs [0014] to [0095] of Japanese patent laid-open No. 2011-164594, and the compound described in paragraphs [0025] to [0058] of Japanese patent laid-open No. 2012-140586. The "acid dye" is an ionic dye having an anionic portion serving as a color developing group, and an ionic dye having an intramolecular salt formed therein is also included in the acid dye. For example, the "acidic xanthene dye" refers to a compound in which the xanthene chromophore is anionic and has a counter cation, or a compound in which the xanthene chromophore forms an intramolecular salt.

The curable composition may have substantially no radiation sensitivity (property of curing by irradiation with radiation). That is, the curable composition may not contain a photopolymerization initiator such as a photoacid generator or a photoradical generator. However, the curable composition can promote curing of the irradiated portion.

(preparation method)

The method for producing the curable composition is not particularly limited, and the curable composition can be produced by mixing the respective components. For example, it can be prepared by the following method. First, the pigment [ A ] is pulverized in the solvent [ C ] and mixed and dispersed in the presence of the dispersant [ F ] to obtain a pigment dispersion liquid. The operation can be carried out, for example, using a bead mill, a roll mill, or the like. The curable composition can be obtained by adding and mixing other components and, if necessary, a further [ C ] solvent to the obtained pigment dispersion liquid. The curable composition may be subjected to a filtration treatment to remove aggregates, if necessary.

(use)

The curable composition can provide a cured film having excellent coatability and patterning properties and having good light-shielding properties. Therefore, the curable composition can be preferably used as a material for forming a cured film, and can be more preferably used as a material for forming a cured film of a display element or a solid-state image pickup element. The hardened film of the display element or the solid-state imaging element can be particularly preferably used as a material for forming the partition wall.

The partition wall as a hardened film of the display element or the solid-state imaging element is also called a bank (bank), a black matrix, or the like. As the partition wall, there may be mentioned: a partition wall provided between each micro LED and a wavelength conversion layer in a micro LED display (see fig. 1), a partition wall provided between each color filter and the like in a liquid crystal display element, a partition wall provided between each light emitting diode and a color filter and the like in a solid-state imaging element, and the like. Of these, it can be preferably used as a partition wall in a micro LED display. Further, the micro LED display can be more preferably used as a partition wall provided between regions each having a region constituted by a structure including a micro LED and a wavelength conversion layer (see fig. 1). In the micro LED display, another layer such as a color filter layer may be further provided in a region including a space between the micro LED and the wavelength conversion layer.

(method of Forming cured film)

An example of a method for forming a cured film using the curable composition includes:

(1) a step of forming a template having a convex portion on a substrate;

(2) forming a coating film between the convex portions of the template by the curable composition; and

(3) hardening the coating film.

The method for forming a cured film preferably further comprises:

(4) and removing the convex part of the template.

According to the method for forming a cured film using the curable composition, a cured film having excellent coatability and patterning properties and having good light-shielding properties can be obtained.

(1) Template forming step

The projection and the template having the projection are generally formed of a resin as a main component, and preferably, a radiation-sensitive composition containing a resin as a main component. The step of forming a template having a convex portion on a substrate preferably includes:

(1-1) a step of forming a coating film for a template by a radiation-sensitive composition;

(1-2) a step of irradiating with radiation; and

(1-3) a step of obtaining a template by development.

(1-1) coating film Forming step for template

The template coating film forming step is a step of forming a template coating film having a liquid repellent surface by the radiation-sensitive composition. The radiation-sensitive composition generally contains a polymer having an acid-dissociable group (hereinafter also referred to as a "a polymer") and a radiation-sensitive acid generator (hereinafter also referred to as a "b acid generator"). The acid-dissociable group is, for example, a group obtained by substituting a hydrogen atom in an acidic functional group such as a phenolic hydroxyl group, a carboxyl group, or a sulfonic acid group, and is a group that dissociates in the presence of an acid. Details will be made later on with respect to the radiation-sensitive composition. In step (1-1), specifically, as shown in fig. 2(a), a radiation-sensitive composition is applied to the surface of the substrate 10 to form a template coating film 11.

Examples of the material of the substrate 10 include: glass, quartz, silicon, resin, etc. Examples of the resin include: polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether sulfone, polycarbonate, polyimide, a ring-opening polymerization (ROMP) polymer of cyclic olefin, polyacrylate, Acrylonitrile-Butadiene-Styrene (ABS) resin, Acrylonitrile-Ethylene-Styrene (AES) resin, and the like.

The substrate 10 is preferably a conventional resin substrate, glass substrate, or semiconductor substrate. By using such a substrate, the obtained laminate pattern can be used as it is for optical applications such as liquid crystal display devices and solid-state imaging devices.

Before applying the radiation-sensitive composition to the substrate 10, the surface of the substrate 10 may be pretreated as necessary. Examples of the pretreatment include cleaning and surface roughening treatment.

The method for applying the radiation-sensitive composition is not particularly limited, and examples thereof include: conventional methods such as a coating method using a brush or a brush, a dipping method, a spraying method, a roll coating method, a spin coating method (spin coating method), a slit die coating method, a bar coating method, a flexographic printing, an offset printing, an inkjet printing, a dispensing method, and the like.

After the application of the radiation-sensitive composition, the coating film 11 for a template is preferably heated (prebaked). The heating conditions vary depending on the composition of the radiation-sensitive composition, and are, for example, about 60 ℃ to 120 ℃ and about 1 minute to 10 minutes.

The average thickness of the obtained template coating film 11 can be adjusted as appropriate depending on the application, and the lower limit thereof is preferably 0.05 μm, and more preferably 0.1 μm. On the other hand, the upper limit is preferably 30 μm, and more preferably 15 μm.

(1-2) radiation irradiation step

As shown in fig. 2(b), the radiation irradiation step is a step of irradiating (exposing) a partial surface region of the coating film 11 for a template with radiation (hv). Thereby forming a layer 12 comprising a lyophilic surface. The surface of the template coating film 11 obtained from the radiation-sensitive composition has liquid repellency, and the region irradiated with radiation becomes a layer 12 including a lyophilic surface. The layer 12 including the lyophilic surface in the template coating film 11 is an alkali-soluble layer. On the other hand, the region not irradiated with radiation is the layer 13 including the liquid repellent surface.

The layer including the lyophilic surface is, for example, a region having a contact angle with tetradecane smaller than a contact angle with tetradecane of the liquid repellent surface by 30 ° or more. If such a contact angle difference exists, the layer including the lyophilic surface does not need to be a region derived from the template coating film. That is, when the template coating film is removed by development to expose the substrate surface, the substrate surface becomes a layer including a lyophilic surface. The entire surface of the substrate may be exposed, but a part of the surface is preferably a lyophilic surface.

The reason why the layer 12 including the lyophilic surface is formed by irradiation with radiation is as follows. When the radiation-sensitive acid generator in the radiation-sensitive composition generates an acid by irradiation with radiation, the acid-dissociable group of the polymer is dissociated. The surface energy of the irradiated region changes due to dissociation of the acid dissociable group, and wettability is improved. In particular, when the acid-dissociable group has a fluorine atom, the change from the liquid repellency to the lyophilic property is significant.

The irradiation (exposure) with radiation may be performed through a photomask having a predetermined pattern so as to form the layer 12 including the lyophilic surface having the same shape as the pattern shape of the cured film to be formed. By performing exposure through a photomask, irradiation can be efficiently performed even when a complicated pattern is formed. Further, a predetermined pattern may be subjected to drawing exposure using a direct drawing exposure machine or the like.

In the step (1-2), as the radiation to be irradiated, visible light, ultraviolet light, far ultraviolet light, charged particle beam, X-ray, or the like can be used. Of these, radiation having a wavelength in the range of 190nm to 450nm is preferable, and radiation including ultraviolet rays having a wavelength of 365nm is more preferable.

The exposure amount of the radiation in the step (1-2) may be appropriately set within a range in which sufficient dissociation of the acid-dissociable group occurs. The lower limit of the exposure amount is preferably 10mJ in terms of intensity in a wavelength of 365nm of radiation/cm²More preferably 20mJ/cm². On the other hand, the upper limit is preferably 1000mJ/cm²More preferably 500mJ/cm²。

The size and shape of the layer 12 including the lyophilic surface formed may correspond to the size and shape of a desired pattern, and may be linear with a width of 100 μm or less, and preferably may be linear with a width of 0.1 μm to 50 μm.

After the template coating film 11 is exposed to light, the template coating film 11 may be heated. The heating conditions vary depending on the composition of the radiation-sensitive composition, and are, for example, about 50 ℃ to 120 ℃ and about 1 minute to 20 minutes.

(1-3) developing step

The development step is a step of developing the template coating film 11 irradiated with the radiation. By the development, the acid-dissociable groups can be dissociated in the region irradiated with the radiation (the layer 12 including the lyophilic surface). Thus, the irradiated portion becomes a layer including a lyophilic surface, and is removed by the developer. Thereby, the substrate surface is exposed, and the substrate 10 becomes a layer including a lyophilic surface. By going through the development step, as shown in fig. 2(c), the template 15 having the convex portions 14 can be formed. The template 15 includes a plurality of convex portions 14, and is a layer 13 including a liquid repellent surface on which the template coating film 11 remains. That is, the surface of each convex portion 14 of the template 15 is liquid repellent.

As the developing solution used for the development, for example, an aqueous solution in which at least one of alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and the like is dissolved can be used. An appropriate amount of a water-soluble organic solvent such as methanol or ethanol may be added to the aqueous solution of the basic compound.

Examples of the developing method include: liquid coating method, dipping method, shaking dipping method, spraying method, etc. The development time varies depending on the composition of the hardened film-forming composition, and the lower limit of the development time is preferably 5 seconds, and more preferably 10 seconds. The upper limit of the development time is preferably 300 seconds, and more preferably 180 seconds. After the development treatment, for example, a water-flowing washing is performed for 30 seconds to 90 seconds, and then the resultant is dried with compressed air or compressed nitrogen gas, whereby a desired pattern of the template can be obtained.

The difference in contact angle with tetradecane between the surface of the projection 14 (layer 13 including a liquid repellent surface) and the surface of the layer including a lyophilic surface (substrate 10 in fig. 2 c) formed in this manner (contact angle of liquid repellent surface-contact angle of lyophilic surface) is preferably 30 ° or more, more preferably 40 ° or more, and still more preferably 50 ° or more. The upper limit of the contact angle difference is, for example, 70 °.

The contact angle of the surface of the convex portion 14 (the layer 13 including the liquid repellent surface) with respect to tetradecane is preferably 40 ° or more, and more preferably 50 ° or more. The upper limit of the contact angle is, for example, 80 ℃. The contact angle of the surface of the convex portion 14 (layer 13 including the liquid repellent surface) with respect to water is preferably 80 ° or more, and more preferably 90 ° or more. The upper limit of the contact angle is, for example, 140 ℃. By forming the convex portions 14 having such a high liquid repellency, the curable composition in contact with the convex portions 14 of the template 15 is easily moved between the convex portions 14 (the surface of the substrate 10, that is, the layer including the lyophilic surface), and a cured film can be preferably formed along the shape between the convex portions 14 of the template 15.

Through such a developing step, the template 15 including the convex portions 14 including the layer including the liquid-repellent surface can be obtained. In the template, the layer 12 including the lyophilic surface of the template coating film may remain between the convex portions 14 (see fig. 2 d). However, from the viewpoint of adhesion of the obtained cured film, it is preferable that the template 15 be substantially constituted only by the convex portions 14 as shown in fig. 2 (c).

(2) Step of forming coating film of curable composition

The curable composition coating film forming step is a step of forming a coating film 16 between the convex portions 14 of the template 15 by the curable composition (see fig. 3 (a)). The coating film 16 can be formed by applying a curable composition to the template 15 formed on the substrate 10.

The curable composition can be applied by a conventional method. Specifically, there may be mentioned: coating methods using a brush or a brush, dipping methods, spraying methods, roll coating methods, spin coating methods (spin coating methods), slit die coating methods, bar coating methods, flexographic printing, lithographic printing, inkjet printing, dispensing methods, and the like.

Among these, the inkjet method is preferable. By applying the curable composition by an ink jet method to form a coating film, the curable composition can be easily applied to a desired position while saving the amount of liquid.

When the curable composition is applied to the template 15 formed on the substrate 10, the curable composition is repelled by the projections 14 (the layer 13 including the liquid repellent surface) and flows into the surface (lyophilic surface) of the substrate 10 which is the space between the projections 14 (the concave portion). Thereby, the coating film 16 of the curable composition can be formed along the space between the convex portions 14. In particular, since the curable composition has excellent coatability, the curable composition flows well along the gaps between the projections 14 and is difficult to fill. Further, according to the curable composition, the erosion of the template 15 can be suppressed.

(3) Hardening step

The curing step is a step of curing the coating film 16 of the curable composition formed between the convex portions 14 by heating.

The heating method is not particularly limited, and heating using a hot plate, an oven, a dryer, or the like can be mentioned. In addition, heating may also be performed by vacuum baking. The heating conditions are not particularly limited, and may be, for example, 50 ℃ or more and 200 ℃ or less and 1 minute or more and 120 minutes or less.

(4) Removing step

The removing step is a step of removing the convex portion 14 of the template 15. Through the above steps, as shown in fig. 3(c), the cured film 17 having a predetermined pattern formed thereon can be obtained. The removal step may be performed by development or etching, preferably by development.

The removing step preferably comprises:

(4-1) a step of irradiating with radiation; and

(4-2) a step of removing the convex portion of the template by development.

(4-1) radiation irradiation step

(4-1) the radiation irradiation step is a step of irradiating the side of the substrate 10 coated with the curable composition with radiation (hv) (see fig. 3 (b)). In this case, the exposure may be performed through a photomask, or the exposure may be performed without using a photomask. In this case, the exposed acid dissociable groups of the projections 14 of the template 15 are dissociated by the irradiation of the radiation, and thus become alkali soluble (hydrophilic).

Specific examples and preferable examples of the radiation to be irradiated in this step are the same as those in the step (1-2). The exposure amount of the radiation in this step may be the same as that in the step (1-2). After the irradiation of the radiation, the coating film 16 of the curable composition may be heated.

(4-2) developing step

The developing step is a step of developing the coating film 16 of the curable composition subjected to the (4-1) radiation irradiation step. By going through the (4-1) radiation irradiation step, the convex portions 14 of the template 15 become alkali-soluble. Therefore, the projections 14 of the template 15 can be removed by development with an aqueous alkaline solution (see fig. 3b and 3 c). Specific examples and preferable examples of the developer and the developing method in this step are the same as those in the above-mentioned step (1-3).

By such a forming method, as shown in fig. 3(c), the cured film 17 patterned into a predetermined shape can be obtained. In the forming method, the curable composition is used, so that a cured film having excellent coating property and patterning property and good light shielding property can be obtained. According to the above forming method, a cured film having a reverse tapered shape (a shape of a trapezoid or a T-shape with a large top and a small bottom facing downward) can be obtained.

The forming method can be preferably used as a method of forming a hardened film of a display element or a solid-state imaging element. In particular, in the hardened film of the display element or the solid-state imaging element, the forming method can be preferably used as a forming method of a partition wall of the display element or the solid-state imaging element.

For example, when the cured film obtained by the above-described forming method is a partition wall of a micro LED display as an example of a display element, a wavelength conversion layer may be laminated in a predetermined region between the partition walls. The wavelength conversion layer may be formed as a layer containing quantum dots, a fluorescent agent, and the like. The wavelength conversion layer can be formed by applying and curing a wavelength conversion layer-forming composition containing quantum dots, a fluorescent agent, and the like, and a binder resin and the like. Further, when the hardened film obtained by the above-described forming method has high liquid repellency, the coating property of the wavelength conversion film-forming composition is improved. Further, a color filter layer and a transparent layer may be disposed between the partition walls. The color filter layer or the transparent layer may be formed by coating a composition for forming these layers, as in the wavelength conversion layer.

< radiation-sensitive composition >

Hereinafter, a preferred embodiment of the radiation-sensitive composition for forming a template in the method for forming a cured film will be described. As described above, the radiation-sensitive composition generally comprises [ a ] a polymer and [ b ] an acid generator. The radiation-sensitive composition preferably further comprises a solvent (hereinafter also referred to as "c solvent").

([ a ] Polymer)

[a] The polymer is a polymer containing a group having a property of being dissociated by an acid. The acid-dissociable group is preferably a group containing a fluorine atom. The polymer [ a ] has such a group, and thus a liquid repellent coating film can be formed, and a template having a good pattern shape can be obtained by exposure and development.

The acid-dissociable group is more preferably a group having a bond containing an acetal bond, a hemiacetal ester bond, or a combination thereof, in terms of production of a fine template. As such a group, a group represented by the following formula (1-1) or a group represented by the following formula (1-2) is preferable.

[ solution 1]

In the formulae (1-1) and (1-2), R¹And R²Each independently is a hydrogen atom or a methyl group. Each Rf is independently an organic group having a fluorine atom. Denotes a bonding site.

The Rf is preferably a fluorinated hydrocarbon group having 1 to 20 carbon atoms, and more preferably a group represented by the following formulae (1-1) to (1-33), a2, 2, 2-trifluoroethyl group, and a1, 2, 2-trifluoroethyl group.

[ solution 2]

[ solution 3]

[ solution 4]

[a] The polymer is preferably a compound having a structure in which an acid-dissociable group derived from a vinyl ether compound represented by the following formula (1) (hereinafter also referred to as "compound (1)") is introduced into a hydroxyl group of a compound having a hydroxyl group as a precursor. The polymer [ a ] may be a compound having a structure in which an acid-dissociable group derived from the compound (1) is introduced into a carboxyl group of a compound having a carboxyl group as a precursor.

[ solution 5]

In the formula (1), the reaction mixture is,R⁰represents a hydrogen atom or a methyl group. In the formula (1), R^AEach independently represents a methylene group, an alkylene group having 2 to 12 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 4 to 12 carbon atoms, or a group in which one or more hydrogen atoms of these groups are substituted with fluorine atoms.

In the formula (1), R^BRepresents a group in which one or more hydrogen atoms of a hydrocarbon group are substituted with a fluorine atom. In the formula (1), R^BThe fluorinated hydrocarbon group having 1 to 20 carbon atoms is preferable, and specific examples thereof include groups represented by the formulae (1-1) to (1-33) in Rf, 2, 2, 2-trifluoroethyl group, and 1, 2, 2-trifluorovinyl group.

In the formula (1), x represents an integer of 0 to 12, preferably an integer of 0 to 9, and more preferably 0.

Next, a method for obtaining the polymer of [ a ] will be described. The method for obtaining the polymer of [ a ] may be a method using a polymer as a compound which becomes a precursor, or a method using a monomer as a compound which becomes a precursor.

In the method of using a polymer as a precursor compound, the polymer as a precursor contains a hydroxyl group or a carboxyl group in the molecule, and the hydroxyl group or the carboxyl group of the polymer as a precursor is reacted with the compound (1), whereby a polymer [ a ] can be obtained. In the method of using a monomer as a precursor compound, the precursor monomer contains a hydroxyl group or a carboxyl group in the molecule, and the hydroxyl group or the carboxyl group of the precursor monomer is reacted with the compound (1) and then the obtained monomer is polymerized to obtain a polymer [ a ]. Hereinafter, two methods for obtaining the [ a ] polymer will be described more specifically.

(1) Method for using polymer as compound to become precursor

In the method, the polymer (precursor) having a hydroxyl group or a carboxyl group can be obtained by polymerizing a monomer having a hydroxyl group or a carboxyl group, and then the hydroxyl group or the carboxyl group of the polymer which becomes the precursor is reacted with the compound (1) to obtain the polymer [ a ].

The monomer having a hydroxyl group is preferably a (meth) acrylate, and examples thereof include: 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxyphenyl (meth) acrylate, 4-hydroxybenzyl acrylamide, 3, 5-dimethyl-4-hydroxybenzyl acrylamide, and the like.

The monomer having a hydroxyl group is preferably the (meth) acrylate, and in addition to the above-mentioned compounds, compounds having a hydroxyl group and an unsaturated bond such as isopropenylphenol can be used. One or more monomers having a hydroxyl group may be used alone.

Examples of the monomer having a carboxyl group include: (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinate, 2- (meth) acryloyloxyethyl phthalate, 4-carboxyphenyl (meth) acrylate, and the like. One or more monomers having a carboxyl group may be used alone.

The polymer having a hydroxyl group or a carboxyl group, which is a precursor of the polymer [ a ], may be obtained by using only the monomer having a hydroxyl group or a carboxyl group, or may be obtained by copolymerizing the monomer having a hydroxyl group or a carboxyl group with a monomer other than the monomer having a hydroxyl group or a carboxyl group.

Examples of the monomer other than the monomer having a hydroxyl group or a carboxyl group include: a chain alkyl (meth) acrylate, a cyclic alkyl (meth) acrylate, an aryl (meth) acrylate, an unsaturated aromatic compound, a conjugated diene, an unsaturated compound having a tetrahydrofuran skeleton, a maleimide, and a monomer other than these. One monomer other than the monomer having a hydroxyl group or a carboxyl group may be used alone, or two or more monomers may be used. Specifically, the unsaturated compounds described in international publication No. 2014/178279 can be used.

Next, a method for obtaining a polymer [ a ] by reacting a hydroxyl group or a carboxyl group of a polymer having a hydroxyl group or a carboxyl group with the compound (1) can be carried out by the method described in international publication No. 2014/178279.

(2) Method of using monomer as compound to become precursor

In the method, a polymer of [ a ] is obtained by reacting a hydroxyl group or a carboxyl group of a monomer having a hydroxyl group or a carboxyl group with the compound (1) to obtain an adduct and polymerizing these. As such a method for obtaining the polymer of [ a ], there can be referred to the existing methods.

For example, as described in Japanese patent laid-open No. 2005-187609, an adduct is formed by forming an acetal bond from a hydroxyl group of a monomer having a hydroxyl group and a vinyl ether group of the compound (1), or by forming a hemiacetal bond from a carboxyl group of a monomer having a carboxyl group and a vinyl ether group of the compound (1).

Then, using the obtained monomer, the same procedure as in the above-mentioned method for producing a polymer having a hydroxyl group or a carboxyl group can be carried out, thereby obtaining a polymer [ a ].

[a] The polymer may further contain a structural unit other than the structural unit having an acid-dissociable group. However, the lower limit of the content of the structural unit having an acid-dissociable group in the polymer [ a ] is preferably 5 mol%, more preferably 10 mol%, and still more preferably 20 mol%. On the other hand, the upper limit of the content ratio may be 100 mol%, 80 mol%, or 70 mol%.

[a] One kind of the polymer may be used alone, or two or more kinds may be used.

([ b ] acid generator)

[b] The acid generator is a compound that generates an acid at least by irradiation with radiation. Namely, [ b ] the acid generator is a radiation-sensitive acid generator. When the radiation-sensitive composition contains the acid generator [ b ], the acid-dissociative group can be dissociated from the polymer [ a ].

Examples of [ b ] the acid generator include: oxime sulfonate compounds, onium salts, sulfonimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, sulfonate compounds, carboxylate compounds, and the like. [b] One or two or more kinds of acid generators may be used. As the acid generator [ b ], the acid generator described in International publication No. 2014/178279 can be used.

The lower limit of the content of the [ b ] acid generator is preferably 0.1 part by mass, more preferably 1 part by mass, per 100 parts by mass of the [ a ] polymer. The upper limit of the content is preferably 10 parts by mass, and more preferably 5 parts by mass.

([ c ] solvent)

The solvent [ c ] is not particularly limited, and is preferably a solvent capable of uniformly dissolving or dispersing each component such as the polymer [ a ], the acid generator [ b ] and the polymerizable compound of any component.

Preferred [ c ] solvents include: alcohol solvents, ethers, diethylene glycol alkyl ethers, ethylene glycol alkyl ether acetates, propylene glycol monoalkyl ether propionates, aliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, and the like. [c] One or more solvents can be used.

The lower limit of the content of the solvent [ c ] is preferably 100 parts by mass, more preferably 200 parts by mass, based on 100 parts by mass of the components excluding the solvent of the radiation-sensitive composition. On the other hand, the upper limit of the content is preferably 1000 parts by mass, and more preferably 500 parts by mass.

(other optional ingredients)

The radiation-sensitive composition may further contain an optional component such as a sensitizer, an acid diffusion inhibitor (quencher), a polymerizable compound, a radiation-sensitive polymerization initiator, a surfactant, a storage stabilizer, an adhesion promoter, and a heat resistance improver. Specific examples and blending examples of these optional components can be found in International publication No. 2014/178279.

< other embodiment >

The present invention is not limited to the above-described embodiments, and the configuration thereof may be modified within a range not changing the gist of the present invention. For example, the curable composition of the present invention can be used for forming a cured film by a method not using a template.

Examples

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The measurement in examples and the like was performed by the following method.

(average particle diameter of pigment)

The pigment dispersion obtained in the preparation example was diluted 10 times with the solvent used, and the average particle diameter of the pigment was determined using a particle size distribution meter ("L-500" by HORIBA corporation).

(weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn))

The weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) of the polymer in terms of polystyrene were measured under the following conditions.

The measurement method: gel Permeation Chromatography (GPC) method

Standard substance: conversion to polystyrene

An apparatus: "HLC-8220" by Tosoh (TOSOH) Inc "

Column: the protection columns "HXL-H", "TSK gel G7000 HXL", "TSK gel GMHXL" 2 and "TSK gel G2000 HXL" from Tosoh (TOSOH) company are connected in sequence to form

Vehicle: tetrahydrofuran (THF)

Sample concentration: 0.7% by mass

Injection amount: 70 μ L

Flow rate: 1mL/min

(¹H-nuclear magnetic resonance (¹H-Nuclear Magnetic Resonance，¹H-NMR) measurement)

¹H-NMR is performed using CDCl₃The measurement was carried out at a temperature of 25 ℃ using a nuclear magnetic resonance apparatus ("Abelsei III (AVANCEIII) AV 400N" manufactured by Bruker as a solvent.

Synthesis example 1 Synthesis of resin 1

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 78 parts by mass of stearyl methacrylate, 22 parts by mass of glycidyl methacrylate, and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing resin 1 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain resin 1 represented by the following formula as a white solid in a yield of 78%. The following ratio of each structural unit represents a molar ratio (the same applies hereinafter).

[ solution 6]

Synthesis example 2 Synthesis of resin 2

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 78.4 parts by mass of stearyl methacrylate, 16.4 parts by mass of glycidyl methacrylate, 5.2 parts by mass of (4-vinylphenyl) methanol and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing resin 2 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain resin 2 represented by the following formula as a white solid in a yield of 75%.

[ solution 7]

Synthesis example 3 Synthesis of resin 3

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 79.9 parts by mass of stearyl methacrylate, 11.1 parts by mass of glycidyl methacrylate, 3.4 parts by mass of methacrylic acid, 5.6 parts by mass of t-butyl methacrylate, and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing resin 3 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain resin 3 represented by the following formula as a white solid in a yield of 80%.

[ solution 8]

Synthesis example 4 Synthesis of fluororesin 1

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 44 parts by mass of stearyl methacrylate, 14 parts by mass of glycidyl methacrylate, 42 parts by mass of 2- (perfluorohexyl) ethyl methacrylate (manufactured by keminox (chemiox) FAMAC6 ynemate (unimace)) and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing the fluororesin 1 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain fluororesin 1 represented by the following formula as a white solid in a yield of 75%.

[ solution 9]

Synthesis example 5 Synthesis of fluororesin 2

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 44 parts by mass of stearyl methacrylate, 9.2 parts by mass of glycidyl methacrylate, 42 parts by mass of 2- (perfluorohexyl) ethyl methacrylate (manufactured by Caminox (CHEMINOX) FAMAC6 tenimazec (UNIMATEC)), 4.8 parts by mass of t-butyl methacrylate, and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing the fluororesin 2 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain fluororesin 2 represented by the following formula as a white solid in a yield of 75%.

[ solution 10]

[ Synthesis example 6] fluororesin 3

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 44 parts by mass of stearyl methacrylate, 9 parts by mass of glycidyl methacrylate, 42 parts by mass of 2- (perfluorohexyl) ethyl methacrylate (manufactured by keminox (chemiox) FAMAC6 uinimazet (unimace)), 5 parts by mass of (4-vinylphenyl) methanol, and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing the fluororesin 3 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain fluororesin 3 represented by the following formula as a white solid in a yield of 82%.

[ solution 11]

Synthesis example 7 fluororesin 4

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of 2, 2' -azobis (2, 4-dimethylvaleronitrile), 45 parts by mass of stearyl methacrylate, 9.5 parts by mass of glycidyl methacrylate, 45 parts by mass of 2- (perfluorohexyl) ethyl methacrylate (manufactured by caminox FAMAC6 UNIMATEC), 3 parts by mass of methacrylic acid, and 300 parts by mass of tetradecane were charged. Under a nitrogen atmosphere, stirring was slowly performed, and the temperature of the solution was raised to 80 ℃, maintained for 6 hours, and polymerization was performed, thereby obtaining a solution containing the fluororesin 4 as a copolymer. Then, the obtained reaction solution was added dropwise to a large excess of methanol/isopropanol (mass ratio 1: 1) to carry out reprecipitation purification. Thereafter, drying was performed to obtain fluororesin 4 represented by the following formula as a white solid in a yield of 84%.

[ solution 12]

The components used in examples and comparative examples are shown below.

(pigment)

Pigment 1 (white pigment): titanium oxide surface-modified with alumina (C.I. pigment white 6: 1)

Pigment 2 (black pigment): carbon Black ("TPK 1099R" manufactured by CABOT corporation)

(curable Compound and non-curable Compound)

Resin 1: resin 1 synthesized in Synthesis example 1

Resin 2: synthesis of resin 2 synthesized in Synthesis example 2

Resin 3: synthesis of resin 3 synthesized in Synthesis example 3

Resin 4: hydrogenated polybutadiene having hydroxyl groups at both ends (Nisso-PB) GI-3000, Nissan Co., Ltd.) (further, resin 4 is a non-curable compound)

Compound 1: 3-Ethyl-3- [ (2-ethylhexyloxy) methyl ] oxetane represented by the following formula (1) ("OXT-212" available from Toyo Synthesis Co., Ltd.) "

Compound 2: 3-Ethyl-3 { [ (3-ethyloxetan-3-yl) methoxy ] methyl } oxetane represented by the following formula (2) ("OXT-221" from east Asia Co., Ltd.)

Compound 3: 3-glycidoxypropyltrimethoxysilane of the formula (3) ("KBM-403" from shin Etsu Silicone Co.)

Compound 4: 3- (perfluorohexyl) propene-1, 2-oxide represented by the following formula (4) ("Karminal (CHEMINOX) FAEP-6" of Unimatec)

Compound 5: a tricyclo [5.2.1.0 ] represented by the following formula (5)^2，6]Decane dimethanol diacrylate (New Zhongcun chemical company "NK ESTER (ESTER) A-DCP")

[ solution 13]

(solvent)

Vehicle 1: n-decane (relative dielectric constant 1.99)

Vehicle 2: tetradecane (relative dielectric constant 2.04)

Vehicle 3: propylene glycol monomethyl ether acetate (relative dielectric constant 8)

(polymerization initiator)

Initiator 1: n, N-dimethylanilinium tetrakis (pentafluorophenyl) borate represented by the following formula (1)

Initiator 2: 4-hydroxyphenyl-methyl-benzylsulfonium tris (pentafluoroethyl) trifluorophosphate represented by the following formula (2)

Initiator 3: 2, 2' -azobis (methyl isobutyrate) represented by the following formula (3)

[ solution 14]

(fluororesin)

Fluororesin 1: fluororesin 1 synthesized in Synthesis example 4

Fluororesin 2: fluororesin 2 synthesized in Synthesis example 5

Fluororesin 3: fluororesin 3 synthesized in Synthesis example 6

Fluororesin 4: fluororesin 4 synthesized in Synthesis example 7

[ preparation example 1]

A pigment dispersion (a-1) was prepared by mixing and dispersing 60 parts by mass of pigment 1, 2.4 parts by mass of Ajisper PN411 manufactured by Ajinomoto Fine-techno as a dispersant, and solvent 1 in a bead mill for 12 hours so that the solid content concentration became 62.4 mass%. The average particle diameter of the pigment 1 in the pigment dispersion (A-1) was 280 nm.

[ preparation example 2]

A pigment dispersion liquid (a-2) was prepared in the same manner as in preparation example 1, except that "Disperbyk) -108" from BYK chemical (BYK) was used as a dispersant and solvent 2 was used as a solvent. The average particle diameter of the pigment 1 in the pigment dispersion liquid (A-2) was 320 nm.

[ preparation example 3]

A pigment dispersion (a-3) was prepared by mixing and dispersing 55 parts by mass of pigment 2, 10.0 parts by mass of ajiostat PN411 manufactured by Ajinomoto Fine-techno corporation as a dispersant, and solvent 1 using a bead mill for 12 hours so that the solid content concentration became 65.0% by mass. The average particle diameter of the pigment 2 in the pigment dispersion liquid (A-3) was 130 nm.

[ preparation example 4]

A pigment dispersion (a-4) was prepared in the same manner as in preparation example 3, except that the solvent 2 was used as a solvent. The average particle diameter of the pigment 2 in the pigment dispersion liquid (A-4) was 120 nm.

[ preparation example 5]

A pigment dispersion (a-5) was prepared by mixing and dispersing 60 parts by mass of pigment 1, 2.4 parts by mass of Ajisper PN411 manufactured by Ajinomoto Fine-techno as a dispersant, and solvent 3 using a bead mill for 12 hours so that the solid content concentration became 62.4 mass%. The average particle diameter of the pigment 1 in the pigment dispersion liquid (A-5) was 260 nm.

[ example 1]

A curable composition (S-1) was prepared using 91.5 parts by mass of the pigment dispersion (a-1) (containing 55.0 parts by mass of the pigment 1 and 2.1 parts by mass of the dispersant), 42.9 parts by mass of the resin 1, and the solvent 1 so that the solid content concentration became 65% by mass.

Examples 2 to 21 and comparative examples 1 to 3

The curable compositions (S-2) to (S-21) of examples 2 to 21 and the curable compositions (S-1) to (S-3) of comparative examples 1 to 3 were prepared in the same manner as in example 1, except that the kinds and amounts of the respective components were changed as shown in table 1. However, in any of the curable compositions, a solvent was used so that the solid content concentration became 65 mass%. In examples 1 to 5, 7, 9 to 15, and 17, and comparative examples 2 and 3, the pigment dispersion liquid (a-1) was used, in examples 6, 8, and 16, the pigment dispersion liquid (a-2) was used, in examples 18 to 20, the pigment dispersion liquid (a-3) was used, in example 21, and the pigment dispersion liquid (a-4) was used, and in comparative example 1, the pigment dispersion liquid (a-5) was used. In addition, the amounts of the components in table 1 indicate the content (mass%) of the total amount of the components other than the solvent, taken as 100 mass%, and the solvent indicates the content (mass%) of the solvent in all the solvents.

Synthesis example 8 Synthesis of Polymer a (Polymer having acid-dissociable group)

Into a flask equipped with a cooling tube and a stirrer, 8 parts by mass of dimethyl-2, 2' -azobis (2-methylpropionate), 2 parts by mass of 2, 4-diphenyl-4-methyl-1-pentene and 300 parts by mass of propylene glycol monomethyl ether acetate were charged. Then, 60 parts by mass of 4-hydroxyphenyl methacrylate and 40 parts by mass of methyl methacrylate were charged, and the mixture was gradually stirred under nitrogen atmosphere, and the temperature of the solution was increased to 80 ℃ and maintained for 4 hours to polymerize the copolymer-containing solution (solid content concentration: 26.1 mass%, Mw: 23000, and Mw/Mn: 2.6).

Then, 190 parts by mass of propylene glycol monomethyl ether acetate, 0.4 parts by mass of pyridinium-p-toluenesulfonate, and 155 parts by mass of 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 8-tridecafluoro-1-vinyloxyoctane were added to the obtained copolymer, and the mixture was reacted at 80 ℃ in a nitrogen atmosphereFor 2 hours. The obtained reaction solution was added dropwise to a large excess of methanol to carry out reprecipitation purification. Thereafter, the mixture was dried to obtain 230 parts by mass of a polymer a as a white solid copolymer. For the polymer a obtained, use is made of¹H-NMR analysis confirmed that acetalization had proceeded (chemical shift: 5.50ppm, acetal group C-H).

[ PREPARATION EXAMPLE 5] preparation of radiation-sensitive composition

100 parts by mass of the polymer a obtained in Synthesis example 8, 2 parts by mass of PA-528 (Herley (HERAEUS)) as an acid generator, 0.1 part by mass of 2-phenylbenzimidazole as a quencher, and 0.1 part by mass of Pelizalol (Polyfiow) No95 (Kyoho chemical Co., Ltd.) as a surfactant were added, and propylene glycol monomethyl ether acetate as a solvent was added so that the solid content concentration became 30% by mass. Thereafter, the resultant was filtered through a microporous filter having a pore size of 0.5 μm, thereby preparing a radiation-sensitive composition (P-1).

[ evaluation ]

The following evaluations were carried out. The evaluation results are shown in table 2.

(preparation of template)

The radiation-sensitive composition (P-1) thus prepared was applied to a 9.5cm square alkali-free glass substrate ("EAGLE-XG" of Corning corporation, 0.7mm thick) with a thickness of 10 μm using a spinner, and then pre-baked on a hot plate at 90 ℃ for 3 minutes, thereby forming a coating film. With respect to the obtained coating film, a high pressure mercury lamp was used at 300mJ/cm²Exposure amount of (2) via a photomask (line)&Space of 50 μm/450 μm) is irradiated with radiation. Then, the baking was carried out on a hot plate at 90 ℃ for 15 minutes. Thereafter, the substrate was immersed in a 2.38% aqueous solution of ammonium hydroxide in water for 2 minutes, whereby the exposed portion was removed. Thereafter, the plate was dried and baked on a hot plate at 90 ℃ for 15 minutes. Thus, a liquid repellent template (T-1) including projections formed on the substrate is obtained. The contact angle of water on the remaining film was 109 ° and the contact angle of tetradecane was 60 °, and sufficient liquid repellency was confirmed.

(formation of a patterned cured film)

The respective curable compositions obtained in examples and comparative examples were injection-coated on the template (T-1) obtained using the radiation-sensitive composition (P-1), and as a result, the curable compositions were selectively coated on the convex portions of the template (T-1) without remaining on the convex portions. The coating film of the curable composition was cured by heating at 70 ℃ for 2 minutes to remove a part of the solvent and then heating at 130 ℃ for 30 minutes. Thereafter, a high pressure mercury lamp was used at 500mJ/cm²The exposure amount of (2) is used for irradiating the radiation. Then, the baking was carried out on a hot plate at 70 ℃ for 15 minutes. Thereafter, the substrate was immersed in a 2.38% aqueous solution of ammonium hydroxide in hydrogen for 4 minutes, whereby the template (T-1) was removed, thereby obtaining a patterned hardened film (pattern). The obtained pattern width was 50 μm, and a pattern suitable for the template width was formed. However, in comparative example 1, since the etching of the template or the like occurred, selective coating between the convex portions could not be achieved, and the pattern could not be formed. In addition, comparative example 2 was remarkably poor in adhesion, and a pattern could not be formed.

(evaluation of coatability)

The coating properties when the curable composition was injection-coated on the template (T-1) were evaluated in terms of erosion of the template and wet spreading between the projections, on the following criteria.

AA: the template is not eroded by the curable composition, and the wetting spread of the curable composition between the projections after 5 seconds from the application is 5mm or more

A: although there is no corrosion of the template, the wetting spread of the curable composition between the projections after 5 seconds from the application is less than 5mm

C: the template is eroded by the hardening composition

(evaluation of patterning Property)

The presence or absence of cracks (cracks or fracture lines inside the film) and adhesion (whether the film bottom is separated from the substrate surface or grounded without floating up) were confirmed by a Scanning Electron Microscope (SEM) for the obtained cured film, and evaluated according to the following criteria.

AA: no cracks and good adhesion

A: although cracks were observed, the adhesion was good

B: cracks were observed and some portions of poor adhesion existed

C: since a patterned hard film could not be obtained, SEM observation could not be performed

(preparation of cured film)

Each of the curable compositions obtained in examples and comparative examples was coated onto a 9.5cm square alkali-free glass substrate ("EAGLE-XG", 0.7mm thick, manufactured by Corning Ltd.) by using a spin coater. Thereafter, a portion of the solvent was removed using a hot plate at 70 ℃ for 2 minutes. Then, the curable composition was cured at 130 ℃ for 30 minutes to form a cured film having a thickness of 10 μm.

(evaluation of light-blocking Property)

In examples 1 to 17 and comparative examples 1 to 3 using a white pigment, evaluation 1 (reflectance) was performed, and in examples 18 to 21 using a black pigment, evaluation 2(OD value) was performed.

(evaluation of light-blocking Property 1: reflectance)

The reflected light of the formed cured film was measured in a conventional manner using an ultraviolet-visible-infrared absolute reflectance measuring apparatus (spectrophotometer V-670, reflectance measuring cell ARN-731, manufactured by Japan Spectroscopy). The relative reflectance obtained from a standard reflection plate ("Spectralon" (registered trademark)) by Ocean photonics (Ocean photonics) was quantified. The light reflected by the standard reflection plate under a light having a wavelength of 700nm was evaluated as 100% according to the following criteria.

AA: over 75 percent

A: more than 70 percent and less than 75 percent

C: less than 70 percent

(evaluation of light-blocking Property 2: OD value)

The optical density (OD value) of light transmitted through the cured film in the visible light region was measured using a transmission density meter (color temperature of an illumination light source: about 2850K (equivalent to ISO visual Density (visual Density) in International Commission on Illumination (ISO) de l' Eclairage) Standard light source A), and spectral sensitivity characteristics of a light receiving portion, which were 361T (V) by Alice (X-Rite), and evaluated based on the following criteria.

AA: OD value per 1 μm is 4 or more

A: OD per 1 μm is 3.5 or more but less than 4

C: OD per 1 μm is less than 3.5

(evaluation of repellency)

Using an automatic contact angle meter ("DM-501 Hi" of Kyowa interface science), 2.5. mu.L of propylene glycol monomethyl ether acetate was dropped onto the cured film formed in the above manner under an atmosphere of 23 ℃ and 55% RH, and the contact angle was calculated by the θ/2 method. Liquid repellency was evaluated by the following criteria.

AA: over 50 DEG

A: above 40 degree and less than 50 degree

B: less than 40 °

[ Table 1]

[ Table 2]

As shown in table 2, the curable compositions of examples 1 to 21 were excellent in coatability and patterning property, and the cured films obtained therefrom were also excellent in light-shielding property. Further, it is known that: the cured films obtained from the curable compositions of examples 13 to 17 containing a fluororesin were also excellent in liquid repellency.

Industrial applicability

The curable composition of the present invention can be preferably used as a cured film-forming material for a display element or a solid-state imaging element.

Description of the symbols

10: substrate

11: coating film for template

12: layer comprising a lyophilic surface

13: layer comprising a liquid repellent surface

14: convex part

15: form panel

16: coating film

17: hardened film

hv: radiation rays

101: micro LED display

102：B-LED

103a, 103 b: wavelength conversion layer

104: partition wall

105: TFT substrate

106: transparent substrate

Claims (20)

1. A method of forming a hardened film, comprising:

(1) a step of forming a template having a convex portion on a substrate;

(2) forming a coating film between the convex portions of the template by a curable composition; and

(3) a step of hardening the coating film, and

the curable composition comprises a pigment of a white pigment, a black pigment, or a combination of these; a hardening compound; and a solvent, and

the content of the pigment is 50 to 90 mass% based on all the components except the solvent,

the solvent has a relative dielectric constant of 6.0 or less.

2. The method of claim 1, further comprising

(4) And removing the convex part of the template.

3. The method of forming a cured film according to claim 1 or 2, wherein the coating film is formed by applying the curable composition by an inkjet method.

4. The method for forming a cured film according to claim 1, 2 or 3, wherein the cured film is a cured film of a display element or a solid-state imaging element.

5. The method for forming a cured film according to claim 4, wherein the cured film of the display element or the solid-state imaging element is a partition wall.

6. The method of forming a cured film according to any one of claims 1 to 5, wherein the curable compound is a resin containing a structural unit having a hydrocarbon group having 8 or more and 30 or less carbon atoms.

7. The method of forming a cured film according to any one of claims 1 to 6, wherein the curable compound has an oxetanyl group, or a combination of these.

8. The method of forming a cured film according to any one of claims 1 to 7, wherein the curable composition further contains a polymerization initiator of a thermal acid generator, a thermal radical generator, or a combination of these.

9. The method of forming a cured film according to any one of claims 1 to 8, wherein the curable composition further comprises a fluororesin comprising a structural unit having a fluorine-containing group.

10. The method of forming a cured film according to claim 9, wherein the fluororesin contains a structural unit having a hydrocarbon group having 8 to 30 carbon atoms.

11. The method of forming a cured film according to any one of claims 1 to 10, wherein the solvent is an aliphatic hydrocarbon having 5 or more and 20 or less carbon atoms.

12. A curable composition comprising:

a white pigment, a black pigment, or a combination of these;

a hardening compound; and

a solvent, and

the content of the pigment is 50 to 90 mass% based on all the components except the solvent,

the solvent has a relative dielectric constant of 6.0 or less.

13. The curable composition according to claim 12, wherein the curable compound is a resin containing a structural unit having a hydrocarbon group having 8 to 30 carbon atoms.

14. The curable composition according to claim 12 or 13, wherein the curable compound has an oxetanyl group, an oxetanyl group or a combination of these.

15. The curable composition of claim 12, 13 or 14, further comprising

A thermal acid generator, a thermal radical generator, or a combination of these.

16. The hardening composition according to any one of claims 12 to 15, further comprising a fluororesin,

the fluororesin includes a structural unit having a fluorine-containing group.

17. The hardening composition according to claim 16, wherein said fluororesin contains a structural unit having a hydrocarbon group having 8 to 30 carbon atoms.

18. The curable composition according to any one of claims 12 to 17, wherein the solvent is an aliphatic hydrocarbon having 5 or more and 20 or less carbon atoms.

19. The curable composition according to any one of claims 12 to 18, which is used for forming a cured film of a display element or a solid-state image pickup element.

20. The hardening composition according to claim 19, wherein said hardened film is a partition wall.

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