JP5488779B2 - Resin composition for forming a highly planarized film - Google Patents

Description

  The present invention relates to a planarization film-forming resin composition excellent in planarization and a planarization film obtained therefrom. More specifically, the present invention relates to a flattening film-forming resin composition having high flatness when a step portion is covered, a hardened flattening film, and various materials using the cured film. The planarizing film-forming resin composition excellent in planarization is particularly suitable for an overcoat agent such as an interlayer insulating film and a color filter in a liquid crystal display or an EL display.

  In general, in an optical device such as a liquid crystal display element, an organic EL (electroluminescent) element, and a solid-state imaging element, a protective film is provided to prevent the element surface from being exposed to a solvent or heat during the manufacturing process. Such a protective film is required not only to have high adhesion to the substrate to be protected and high solvent resistance, but also to have performance such as transparency and heat resistance.

  On the other hand, when such a protective film is used as a protective film for a color filter used in a color liquid crystal display device or a solid-state imaging device, the color filter or black matrix resin as a base substrate is generally flattened, that is, Performance as a chemical film is required. In particular, when manufacturing a color liquid crystal display element of STN method or TFT method, it is necessary to strictly perform the bonding between the color filter substrate and the counter substrate so as to have very high accuracy, and the cell gap between the substrates is reduced. Uniformity is essential. In addition, in order to maintain the transmittance of light transmitted through the color filter at a high level, the planarizing film as the protective film also needs high transparency.

  In addition, when used as a protective film for an electrode of a liquid crystal display element or an organic EL element, in recent years, the level difference of the electrode may be increased, and a material having as little flatness as possible is required.

In general, an acrylic resin having high transparency is used for such applications. Such an acrylic resin has a property of imparting heat resistance and solvent resistance by thermosetting or photocuring.
As a general thermosetting method, a method of adding a methylol-based crosslinking agent and an acid catalyst to an acrylic resin having a hydroxy group, and a method of adding an epoxy-based crosslinking agent to an acrylic resin containing a carboxyl group are well known. It has been. In addition, a method of thermosetting by introducing an epoxy group and a carboxyl group into an acrylic resin (see Patent Document 1), and further a thermal radical initiator and a compound having two or more unsaturated double bonds in one molecule A method to be used (see Patent Document 2) has also been proposed.
In addition, as a general photocuring method, a method of adding a compound having two or more unsaturated double bonds per molecule and a photo radical initiator to an acrylic resin, a methylol-based acrylic resin containing a hydroxy group There is known a method of adding a crosslinking agent and a photoacid generator.
However, it cannot be said that the flattening rate of a cured film formed from a conventional thermosetting or photocurable acrylic resin is sufficiently high.
JP 2000-103937 JP 2000-119472 A

  The present invention has been made based on the above circumstances, and is suitable for a flattening film of electrodes and color filters used in liquid crystal display elements and organic EL display elements, and has only high solvent resistance. Instead, it is to provide a resin composition that achieves excellent transparency and high flatness.

That is, as a first aspect, a planarizing film-forming resin composition comprising the following component (A), component (B), component (C), component (D), and solvent (E).
(A) component: an acrylic polymer having a functional group capable of causing a crosslinking reaction with component (D) and having a number average molecular weight of 2,000 to 25,000,
(B) component: a compound having two or more unsaturated double bonds in one molecule (C) component: a compound that generates an acid by heat,
Component (D): Thermally crosslinkable compound (excluding those that crosslink using the acid generated from component (C) as a catalyst)
(E) Solvent.
As a second aspect, the planarizing film-forming resin composition according to the first aspect, wherein the component (A) is an acrylic polymer having the structure of the formula (1).

(In the formula, R ¹ represents an organic group having 1 to 12 carbon atoms.)
As a third aspect, the planarizing film-forming resin composition according to the first aspect or the second aspect, wherein the component (B) is a compound having an ethylenically unsaturated group as an unsaturated double bond.
As a fourth aspect, the planarizing film-forming resin composition according to any one of the first aspect to the third aspect, wherein the component (C) is a sulfonic acid ester.
As a fifth aspect, the component (D) is a thermally crosslinkable compound having two or more blocked isocyanate groups in one molecule, for forming a planarizing film according to any one of the first to fourth aspects. Resin composition.
As a sixth aspect, based on 100 parts by mass of component (A), 3 to 60 parts by mass of component (B), 0.1 to 10 parts by mass of component (C), and 1 to 50 parts by mass of component (D). The planarizing film-forming resin composition according to any one of the first to fifth aspects, comprising:
As a seventh aspect, a planarization film formed from the planarization film forming resin composition according to any one of the first aspect to the sixth aspect.

  The planarization film forming fat composition excellent in planarization of the present invention is not only high in solvent resistance but also highly transparent in the planarization film of electrodes and color filters used in liquid crystal display elements, organic EL display elements, etc. And can be formed while maintaining high flatness.

The resin composition for flattening film formation excellent in the flattening of the present invention generates an acid by the (A) component acrylic polymer, the (B) component compound having an unsaturated double bond, and the (C) component heat. And (E) a thermally crosslinkable compound as a component, and (E) a solvent, and optionally a surfactant as a component (F).
In the present invention, the “planarizing film” includes a protective film for protecting the element surface.
Hereinafter, details of each component will be described.

<(A) component>
The component (A) of the present invention is an acrylic polymer having a functional group for allowing a crosslinking reaction with the component (D) and having a number average molecular weight of 2,000 to 25,000. . In the present specification, the “acrylic polymer” refers to homopolymers and copolymers of monomers having an acrylic group, and copolymers of monomers having an acrylic group and other monomers.

(A) The functional group for allowing a thermal crosslinking reaction with the thermally crosslinkable compound of component (D) contained in the structure of the acrylic polymer of component has a carboxyl group, a hydroxy group, and active hydrogen. It is desirable that it is at least one selected from amino groups.
The amino group having active hydrogen means a primary or secondary amino group having high reaction activity and capable of releasing a proton. Therefore, the amide group does not correspond to an amino group having active hydrogen because it does not have active hydrogen.
Among these, at least one selected from a carboxyl group and a hydroxy group is preferable because the effects of the present invention can be easily obtained.

  Moreover, in order to fully express the effect of this invention, the thing whose glass transition temperature of the acrylic polymer of (A) component is 50 degreeC or more is preferable. When the glass transition temperature (Tg) is 50 ° C. or less, the coating film after pre-baking may be tacked.

  As the above-mentioned acrylic polymer having a high glass transition temperature, an acrylic polymer having a structure represented by the following formula (1) is particularly preferable.

(Wherein R ¹ represents an organic group having 1 to 12 carbon atoms)

Specific examples of R ¹ include methyl group, ethyl group, propyl group, butyl group, cyclopentyl group, cyclohexyl group, phenyl group, benzyl group, dimethylphenyl group, diethylphenyl group, hydroxyphenyl group, carboxyphenyl group, and naphthyl group. And toluyl group.

  Accordingly, the acrylic polymer of the component (A) is a monomer having a functional group for allowing a thermal crosslinking reaction with the thermally crosslinkable compound of the component (D), and represented by the above formula (1). A polymer obtained by using a monomer containing maleimides is particularly preferable because high transparency and high Tg are realized.

  The acrylic polymer as the component (A) may be an acrylic polymer having such a structure, and is not particularly limited with respect to the other skeleton and side chain types of the polymer constituting the acrylic polymer.

  However, the acrylic polymer of the component (A) has a number average molecular weight in the range of 2,000 to 25,000. If the number average molecular weight is over 25,000, the flatness of the step is lowered. On the other hand, if the number average molecular weight is less than 2,000 and the number average molecular weight is too small, curing is insufficient during thermal crosslinking. Solvent resistance may be reduced.

  In the present invention, an acrylic polymer comprising a copolymer obtained by polymerizing a plurality of types of monomers (hereinafter referred to as a specific copolymer) can also be used as the component (A). In this case, the acrylic polymer of component (A) may be a blend of a plurality of types of specific copolymers.

That is, the specific copolymer is an acrylic polymer obtained by copolymerizing at least one monomer appropriately selected from the group of monomers having a functional group for the thermal crosslinking reaction, and preferably the thermal crosslinking reaction. For at least one monomer selected from the group of monomers having a functional group for and a monomer containing a maleimide represented by the above formula (1) as essential constituent units. And those having a number average molecular weight of 2,000 to 25,000 are more preferred.
In the present invention, such a specific copolymer is preferably used as the component (A).

  Hereinafter, although the specific example of the monomer which has a functional group for the said crosslinking reaction is given, it is not limited to these.

  Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, mono- (2- (acryloyloxy) ethyl) phthalate, mono- (2- (methacryloyloxy) ethyl) phthalate, and N- (carboxyphenyl). ) Maleimide, N- (carboxyphenyl) methacrylamide, N- (carboxyphenyl) acrylamide and the like.

Examples of the monomer having a phenolic hydroxy group include hydroxystyrene, N- (hydroxyphenyl) acrylamide, N- (hydroxyphenyl) methacrylamide, N- (hydroxyphenyl) maleimide and the like.
Examples of the monomer having a hydroxy group other than the phenolic hydroxy group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-acryloyloxy-6-hydroxynorbornene-2-carboxyl-6-lactone, 2-hydroxy Examples include ethyl methacrylate, 2-hydroxypropyl methacrylate, and 5-methacryloyloxy-6-hydroxynorbornene-2-carboxyl-6-lactone.

  Further, examples of the monomer having an amino group having active hydrogen include 2-aminoethyl acrylate and 2-aminomethyl methacrylate.

  Further, the specific copolymer may be a copolymer formed by using a monomer other than the monomer having a functional group for the thermal crosslinking reaction (hereinafter referred to as other monomer) as a structural unit.

  Specifically, the other monomer may be any monomer that can be copolymerized with a monomer having at least one of a carboxyl group, a hydroxy group, and an amino group having active hydrogen, and has the characteristics of the component (A). There is no particular limitation as long as it is not impaired.

  Specific examples of other monomers include monomers containing maleimides, acrylic ester compounds, methacrylic ester compounds, acrylonitrile, maleic anhydride, styrene compounds and vinyl compounds.

Examples of the monomer containing maleimides include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.
Examples of the acrylate compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2,2-trifluoroethyl acrylate, and tert-butyl. Acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2- Propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecyl acrylate, and , Etc. 8-ethyl-8-tricyclodecyl acrylate.

  Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl. Methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, γ- Butyrolactone methacrylate, 2-propyl-2-a Man Chill methacrylate, 8-methyl-8-tricyclodecyl methacrylate, and, 8-ethyl-8-tricyclodecyl methacrylate.

  Examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, vinyl naphthalene, vinyl anthracene, vinyl carbazole, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, bromostyrene, and the like.
As the specific copolymer used in the present invention, a polymer obtained by using a monomer containing maleimides is particularly preferable because high transparency and high Tg are realized.

  The method for obtaining the acrylic polymer as the component (A) used in the present invention is not particularly limited. Therefore, the method for obtaining the specific copolymer used in the present invention is not particularly limited. For example, the above one or more monomers are polymerized at a temperature of 50 to 110 ° C. in a solvent with a polymerization initiator or the like if desired. Can be obtained. In that case, the solvent used will not be specifically limited if the monomer which comprises a specific copolymer, and a specific copolymer are melt | dissolved. As a specific example, the solvent described in (E) solvent mentioned later is mentioned.

  The specific copolymer thus obtained is usually in the form of a solution in which the specific copolymer is dissolved in a solvent.

  In addition, the solution of the specific copolymer obtained as described above is re-precipitated by stirring with stirring such as diethyl ether or water, and the generated precipitate is filtered and washed, and then under normal pressure or reduced pressure. Thus, the powder of the specific copolymer can be obtained by drying at room temperature or by heating. By such an operation, the polymerization initiator and unreacted monomer coexisting with the specific copolymer can be removed, and as a result, a purified powder of the specific copolymer can be obtained. If sufficient purification cannot be achieved by a single operation, the obtained powder may be redissolved in a solvent and the above operation may be repeated.

  In the present invention, the powder of the specific copolymer may be used as it is, or the powder may be redissolved in a solvent (E) described later and used as a solution.

<(B) component>
The component (B) of the present invention is a compound having two or more unsaturated double bonds per molecule. In the present specification, the “compound having two or more unsaturated double bonds per molecule” preferably refers to a compound having two or more ethylenically unsaturated groups per molecule, more preferably at the terminal. It refers to a compound having two or more vinyl groups, acrylate groups or methacrylate groups.
In the present invention, a polyfunctional acrylate compound having two or more unsaturated double bonds per molecule is preferred.

  The compound having two or more unsaturated double bonds per molecule as the component (B) has good compatibility with each component in the solution of the resin composition for flattening film formation excellent in the flattening of the present invention. If it is, it will not specifically limit.

  Specific examples of the compound having an unsaturated double bond include dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate. , Pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, tetramethylolpropane tetraacrylate, tetramethylolpropane tetramethacrylate, tetramethylolmethane tetraacrylate, tetramethylolmethane tetramethacrylate, trimethylolpropane tria Relate, trimethylolpropane trimethacrylate, 1,3,5-triacryloylhexahydro-S-triazine, 1,3,5-trimethacryloylhexahydro-S-triazine, tris (hydroxyethylacryloyl) isocyanurate, tris (hydroxy Ethylmethacryloyl) isocyanurate, triacryloyl formal, trimethacryloyl formal, 1,6-hexanediol acrylate, 1,6-hexanediol methacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, ethanediol diacrylate, ethanediol di Methacrylate, 2-hydroxypropanediol diacrylate, 2-hydroxypropanediol dimethacrylate, diethylene Recall diacrylate, diethylene glycol dimethacrylate, isopropylene glycol diacrylate, isopropylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, N, N′-bis (acryloyl) cysteine, N, N′-bis ( Methacryloyl) cysteine, thiodiglycol diacrylate, thiodiglycol dimethacrylate, bisphenol A diacrylate, bisphenol A dimethacrylate, bisphenol F diacrylate, bisphenol F dimethacrylate, bisphenol S diacrylate, bisphenol S dimethacrylate, bisphenoxyethanol full orange Acrylate, bisphenoxyethanol full orange methacrylate Rate, diallyl ether bisphenol A, o-diallyl bisphenol A, diallyl maleate, triallyl trimellitate and the like.

  The above-mentioned polyfunctional acrylate compound can be easily obtained as a commercial product, and specific examples thereof include, for example, KYARAD T-1420, DPHA, DPHA-2C, D-310, D-330, DPCA-20, DPCA-30, DPCA-60, DPCA-120, DN-0075, DN-2475, R-526, NPGDA, PEG400DA, MANDA, R-167, HX -220, HX620, R-551, R-712, R-604, R-684, GPO-303, TMPTA, THE-330, TPA-320, TPA-330, PET-30, RP-1040 (manufactured by Nippon Kayaku Co., Ltd.), Aronix M-210, M-240, M-6200, M-309 Same M-400, Same M-402, Same M-405, Same M-450, Same M-7100, Same M-8030, Same M-8060, Same M-1310, Same M-1600, Same M-1960, M-8100, M-8530, M-8560, M-8560, M-9050 (Made by Toagosei Co., Ltd.), Biscote 295, 300, 360, GPT, 3PA, 400, 260 312 and 335HP (above, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

  The use ratio of the compound having two or more unsaturated double bonds per molecule as the component (B) used in the present invention is 3 to 60 parts by mass with respect to 100 parts by mass of the acrylic polymer of the component (A). It is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass. If this ratio is too small, the flattening property is lowered, and if it is too large, the solvent resistance of the cured flattening film may be lowered or the coating film after pre-baking may be tacked.

<(C) component>
The component (C) is a compound that generates an acid by heat. This is a substance that decomposes during post-baking and generates an acid (sulfonic acid, carboxylic acid, etc.), and its type and structure are not particularly limited as long as it has such properties.

Examples of compounds that generate acid by the heat of component (C) include sulfonic acid ester compounds, sulfonamide compounds, onium salt compounds, sulfonimide compounds, disulfone compounds, sulfonic acid derivative compounds, nitrobenzyl compounds, and benzoin tosylate. Examples include compounds, iron arene complexes, halogen-containing triazine compounds, acetophenone derivative compounds, and cyano group-containing oxime sulfonate compounds. These compounds are not particularly limited and can be applied in the present invention.
In addition, in this invention, the compound which generate | occur | produces an acid with the heat | fever of (C) component may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, the component (C) is considered to contribute to improving the flatness of the coating film and the cured film, although the reason is not clear. In this sense, sulfonic acid esters are preferred.

Specific examples of the compound that generates an acid by heat are shown below, but these are examples and are not limited to these compounds.
Bis (tosyloxy) ethane, bis (tosyloxy) propane, bis (tosyloxy) butane, p-nitrobenzyl tosylate, o-nitrobenzyl tosylate, 1,2.3-phenylenetris (methylsulfonate), p-toluenesulfonic acid Pyridinium salt, p-toluenesulfonic acid morphonium salt, p-toluenesulfonic acid ethyl ester, p-toluenesulfonic acid propyl ester, p-toluenesulfonic acid butyl ester, p-toluenesulfonic acid isobutyl ester, p-toluenesulfonic acid methyl ester Ester, p-toluenesulfonic acid phenethyl ester, cyanomethyl p-toluenesulfonate, 2,2,2-trifluoroethyl p-toluenesulfonate, 2-hydroxybutyl p-tosylate, N-ethyl-4-toluene Sulfonamide,

  Diphenyliodonium chloride, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium mesylate, diphenyliodonium tosylate, diphenyliodonium bromide, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroarsenate, bis (p-tert- Butylphenyl) iodonium hexafluorophosphate, bis (p-tert-butylphenyl) iodonium mesylate, bis (p-tert-butylphenyl) iodonium tosylate, bis (p-tert-butylphenyl) iodonium trifluoromethanesulfonate, bis ( p-tert-butylphenyl) iodoniumtetraf Oroborate, bis (p-tert-butylphenyl) iodonium chloride, bis (p-chlorophenyl) iodonium chloride, bis (p-chlorophenyl) iodonium tetrafluoroborate, triphenylsulfonium chloride, triphenylsulfonium bromide, triphenylsulfonium trifluoromethanesulfonate , Tri (p-methoxyphenyl) sulfonium tetrafluoroborate, tri (p-methoxyphenyl) sulfonium hexafluorophosphonate, tri (p-ethoxyphenyl) sulfonium tetrafluoroborate, triphenylphosphonium chloride, triphenylphosphonium bromide, tri (p -Methoxyphenyl) phosphonium tetrafluoroborate, tri (p-methoxyphenyl) phospho Phosphonium hexafluorophosphonate, tri (p- ethoxyphenyl) phosphonium tetrafluoroborate,

  Compounds that generate an acid by heat can be used alone or in combination of two or more. The introduction amount is selected in the range of 0.1 to 10 parts by mass, preferably 0.5 to 7 parts by mass with respect to 100 parts by mass of the component (A). When this amount is less than 0.1 parts by mass, high planarization properties cannot be obtained, and when this amount is 10 parts by mass or more, the storage stability of the resin composition for forming a planarization film is poor.

<(D) component>
The component (D) is a thermally crosslinkable compound, except that it is crosslinked with the acid generated from the component (C) as a catalyst.
If it is a compound that crosslinks using an acid generated from the component (C) as a catalyst, the crosslinking proceeds rapidly at a low temperature, for example, at the time of pre-baking, so that a film having high flatness cannot be obtained. Accordingly, the component (D) is assumed to start crosslinking at a temperature higher than the acid generation temperature of the component (C), and if the temperature is lower than the temperature at which the component (D) is crosslinked, the acid generated from the component (C) is affected. In the flattening film forming resin composition excellent in flattening according to the present invention, the acid generated from the component (C) and the component (D) start cross-linking during post-baking, and Since the film curing proceeds gradually, the flatness becomes high.

  Examples of the compound satisfying such conditions include compounds having two or more blocked isocyanate groups in one molecule. This may be a compound having two or more blocked isocyanate groups per molecule that can be thermally cured at a conventional post-bake temperature, for example, on a film made of the acrylic polymer of component (A). The type and structure are not particularly limited.

  The compound of component (D) has two or more blocked isocyanate groups in which one or more isocyanate groups (—NCO) are blocked by an appropriate protecting group, and when exposed to a high temperature during thermal curing, The protective group (block part) is removed by thermal dissociation, and the functional group (carboxyl group, amino group having active hydrogen) for thermal curing in the acrylic polymer of component (A) via the generated isocyanate group ) A cross-linking reaction proceeds between each other, for example, the formula (71)

(In the formula, R ² represents an organic group in the block part) A compound having two or more groups in one molecule (this group may be the same or different) may be mentioned. It is done.

  The compound of component (D) having two or more blocked isocyanate groups in one molecule can be obtained, for example, by allowing a suitable blocking agent to act on a compound having two or more isocyanate groups in one molecule. .

  Examples of the compound having two or more isocyanate groups in one molecule include isophorone diisocyanate, 1,6-hexamethylene diisocyanate, methylene bis (4-cyclohexyl isocyanate), trimethylhexamethylene diisocyanate, etc., or their dimers, three And a reaction product of these with diols, triols, diamines, and triamines.

  Examples of the blocking agent include methanol, ethanol, isopropanol, n-butanol, 2-ethoxyhexanol, 2-N, N-dimethylaminoethanol, 2-ethoxyethanol, cyclohexanol, and other alcohols, phenol, o-nitrophenol. , P-chlorophenol, phenols such as o-, m- or p-cresol, lactams such as ε-caprolactam, oximes such as acetone oxime, methyl ethyl ketone oxime, methyl isobutyl ketone oxime, cyclohexanone oxime, acetophenone oxime, benzophenone oxime And pyrazoles such as pyrazole, 3,5-dimethylpyrazole and 3-methylpyrazole, and thiols such as dodecanethiol and benzenethiol.

  The compound of component (D) is one in which the block portion undergoes thermal dissociation at a higher temperature such as the post-baking temperature and the crosslinking reaction proceeds via the isocyanate group, but at a lower temperature such as the pre-baking temperature, the isocyanate In order to prevent the cross-linking by the group from proceeding, it is particularly preferable as the component (D) compound that the thermal dissociation temperature of the block portion is considerably higher than the pre-baking temperature, for example, 150 ° C. to 230 ° C.

  Examples of the compound of the component (D) include the following specific examples.

In the formula, the compound of the component (D) in which the isocyanate compound is derived from isophorone diisocyanate is more preferable from the viewpoint of heat resistance and coating properties, and examples of such compounds include the following.
R in the following formula represents an organic group.

  In the present invention, the compound of component (D) may be used alone or in combination of two or more.

  The compound of component (D) is used in a proportion of 1 to 50 parts by mass, preferably 5 to 40 parts by mass with respect to 100 parts by mass of the acrylic polymer of component (A). If the amount of the component (D) component used is an excessive amount less than the lower limit of the above range, thermal curing is insufficient and a satisfactory cured flattening film cannot be obtained. If the amount used exceeds the upper limit of the above range, the development becomes insufficient and a development residue is generated.

<(E) Solvent>
The (E) solvent used in the present invention dissolves the (A) component to the (D) component and dissolves the (F) component, which will be added as desired, and has such a dissolving ability. If it is a solvent, the kind and structure thereof are not particularly limited.

  Examples of such a solvent (E) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol. Monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxyacetic acid Ethyl, hydroxyethyl acetate, 2-hydroxy-3-methyl Methyl tannate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, lactic acid Examples include butyl, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone.

  These solvents can be used singly or in combination of two or more.

  Among these solvents (E), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 2-heptanone, propylene glycol propyl ether, propylene glycol propyl ether acetate, ethyl lactate, butyl lactate, etc. have good coating properties and safety. Is preferable from the viewpoint of high. These solvents are generally used as solvents for photoresist materials.

<(F) component>
Component (F) is a surfactant. In the resin composition for flattening film formation excellent in the flattening of the present invention, a surfactant can be further contained for the purpose of improving the coating property as long as the effects of the present invention are not impaired. .

  The surfactant as the component (F) is not particularly limited, and examples thereof include a fluorine-based surfactant, a silicon-based surfactant, and a nonionic surfactant. As this type of surfactant, for example, commercially available products such as those manufactured by Sumitomo 3M Co., Ltd., Dainippon Ink Chemical Co., Ltd., or Asahi Glass Co., Ltd. can be used. These commercial products are convenient because they can be easily obtained. Specific examples include F-top EF301, EF303, EF352 (manufactured by Gemco), MegaFuck F171, F173, F-475, F-482, R-08, R-30, BL-20 (large Nippon Ink Chemical Co., Ltd.), Florad FC430, FC431 (Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.) Fluorine-based surfactants such as

  The surfactant of component (F) can be used alone or in combination of two or more.

  When the surfactant is used, the content thereof is usually 0.2% by mass or less, preferably 0.1% by mass or less, in 100% by mass of the resin composition for flattening film formation. Even if the amount of the surfactant used as the component (F) is set to an amount exceeding 0.2% by mass, the effect of improving the coating property becomes dull and not economical.

<Other additives>
Furthermore, the flattening film-forming resin composition excellent in flattening of the present invention, as long as it does not impair the effects of the present invention, an adhesive aid such as a rheology modifier, a silane coupling agent, a pigment, It can contain dyes, storage stabilizers, antifoaming agents, or dissolution accelerators such as polyphenols and polycarboxylic acids.

<Resin composition for flattened film formation>
The resin composition for flattening film formation excellent in the flattening of the present invention generates an acid by the (A) component acrylic polymer, the (B) component compound having an unsaturated double bond, and the (C) component heat. And (F) a thermally crosslinkable compound of component (D) and a solvent (F), and a composition which can further contain one or more of surfactant (F) and other additives as desired. It is a thing.

Especially, the preferable example of the resin composition for planarization film formation excellent in the planarization of this invention is as follows.
[1]: Based on 100 parts by mass of component (A), 3 to 60 parts by mass of component (B), 0.1 to 10 parts by mass of component (C), and 1 to 50 parts by mass of component (D). A resin composition for forming a flattened film.
[2] A planarizing film-forming resin composition further comprising 0.2% by mass or less of the component (F) in the composition of [1] above.

  The ratio of the solid content in the resin composition for forming a flattened film excellent in flattening according to the present invention is not particularly limited as long as each component is uniformly dissolved in a solvent. For example, 1 to 80% by mass And, for example, 5 to 60% by mass, or 10 to 50% by mass. Here, solid content means what remove | excluded the (E) solvent from all the components of the resin composition for planarization film formation.

  The method for preparing the planarizing film-forming resin composition excellent in planarization according to the present invention is not particularly limited. Examples of the preparation method include dissolving the component (A) in the solvent (E) and adding ( Examples include a method in which the B) component, the (C) component, the (D) component, and the (F) component are mixed at a predetermined ratio to obtain a uniform solution.

  In the preparation of the planarization film-forming resin composition excellent in planarization of the present invention, (E) a solution of a specific copolymer obtained by a polymerization reaction in a solvent can be used as it is. When adding the component (B), component (C), component (D), etc. to the solution of component A) in the same manner as above to make a uniform solution, add (E) additional solvent for the purpose of concentration adjustment. May be. At this time, the (E) solvent used in the process of forming the specific copolymer may be the same as the (E) solvent used for adjusting the concentration during the preparation of the resin composition for flattening film formation. May be different.

  Thus, it is preferable to use the prepared solution of the resin composition for forming a flattened film after filtration using a filter having a pore diameter of about 0.2 μm.

<Coating and flattening film>
A planarizing film-forming resin composition excellent in planarization of the present invention is obtained by using a semiconductor substrate (for example, a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, a substrate coated with a metal such as aluminum, molybdenum, or chromium, a glass substrate, By spin coating, flow coating, roll coating, slit coating, spin coating following slit, ink jet coating, etc., and then pre-drying in a hot plate or oven, etc. A coating film can be formed. Then, the resin film for planarization film formation excellent in planarization is formed by heat-processing this coating film.

  As conditions for this heat treatment, for example, a heating temperature and a heating time appropriately selected from the range of a temperature of 70 ° C. to 160 ° C. and a time of 0.3 to 60 minutes are employed. The heating temperature and heating time are preferably 80 to 140 ° C. and 0.5 to 10 minutes.

  The film thickness of the planarizing film-forming resin film formed from the planarizing film-forming resin composition is, for example, 0.1 to 30 μm, for example, 0.2 to 10 μm, The thickness is 2 to 5 μm, and can be appropriately selected in consideration of the level difference of the substrate to be used and optical and electrical properties.

  The post-bake is generally processed at a heating temperature selected from the range of 140 ° C. to 250 ° C. for 5 to 30 minutes when on a hot plate and 30 to 90 minutes when in an oven. The method is taken.

As described above, the planarization film forming resin composition excellent in planarization according to the present invention can sufficiently planarize the step of the substrate and form a cured planarization film having high transparency.
In addition, the cured film obtained from the resin composition for forming a flattened film of the present invention is excellent in solvent resistance, for example, resistance to an organic solvent such as N-methylpyrrolidone.

  Therefore, for example, the flattening film-forming resin composition excellent in flattening according to the present invention cures protective films, flattening films, insulating films and the like in various displays such as thin film transistor (TFT) type liquid crystal display elements and organic EL elements. It is suitable as a material for forming a film, and particularly suitable as a material for forming an interlayer insulating film of a TFT type liquid crystal element, a protective film of a color filter, an insulating film of an organic EL element, and the like.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these Examples.

Ｒ３０：大日本インキ化学工業（株）製 メガファック Ｒ−３０（商品名）〔フッ素系界面活性剤〕[Abbreviations used in Examples]
The meanings of the abbreviations used in the following examples are as follows.
MAA: methacrylic acid MMA: methyl methacrylate HEMA: 2-hydroxyethyl methacrylate HPMA: 2-hydroxypropyl methacrylate CHMI: N-cyclohexylmaleimide BzMA: benzyl methacrylate GBLMA: γ-butyrolactone methacrylate AIBN: azobisisobutyronitrile PGMEA: propylene glycol Monomethyl ether acetate DPHA: KAYARAD DPHA (trade name) manufactured by Nippon Kayaku Co., Ltd. [Dipentaerythritol penta / hexaacrylate]
PTA: pentaerythritol triacrylate PVE1: 1,4-cyclohexanedimethanol divinyl ether PAG1: CGI 1397 (trade name) manufactured by Ciba Specialty Chemicals Co., Ltd. [compound represented by (Formula 5)]
BP: Benzophenone IRG: Irgacure 369 (trade name) [2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one] manufactured by Ciba Specialty Chemicals Co., Ltd.
PTSE: p-toluenesulfonic acid ethyl ester BISTP: bis (tosyloxy) propane PTSAM: N-ethyl-4-toluenesulfonamide NCO1: manufactured by Degussa AG VESTAGON (registered trademark) B 1065 (trade name) [Table of formula S-4 Compound
NCO2: manufactured by Degussa AG VESTANAT (registered trademark) B1358 (trade name) [compound represented by formula S-11]
CYM: CYMEL (registered trademark) 303 (trade name) manufactured by Mitsui Cytec [compound represented by the following formula T-1]

R30: MegaFac R-30 (trade name) [Fluorosurfactant] manufactured by Dainippon Ink & Chemicals, Inc.

[Measurement of number average molecular weight and weight average molecular weight]
The number average molecular weight and the weight average molecular weight of the specific copolymer and specific cross-linked product obtained in accordance with the following synthesis examples were measured using a GPC apparatus (Shodex (registered trademark) columns KF803L and KF804L) manufactured by JASCO Corporation. Was flowed through the column at a flow rate of 1 ml / min (column temperature 40 ° C.) for elution. The following number average molecular weight (hereinafter referred to as Mn) and weight average molecular weight (hereinafter referred to as Mw) are expressed in terms of polystyrene.

[Production of specific copolymer]
<Synthesis Example 1>
MAA 15.5 g, CHMI 35.3 g, HEMA 25.5 g, MMA 23.7 g are used as monomer components constituting the specific copolymer, and AIBN 5 g is used as a radical polymerization initiator, and these are used as solvent PGMEA 200 g. By carrying out a polymerization reaction at a temperature of 60 ° C. to 100 ° C., a solution of the component (A) (specific copolymer) of Mn 4,100 and Mw 7,600 (specific copolymer concentration: 27.5% by mass) Obtained (P1).

<Synthesis Example 2>
CHMI 40.0 g and HEMA 60.0 g are used as monomer components constituting the specific copolymer, and AIBN 5 g is used as a radical polymerization initiator, and these are polymerized at a temperature of 60 ° C. to 100 ° C. in a solvent PGMEA 200 g. By making it react, the solution (specific copolymer density | concentration: 37.5 mass%) of (A) component (specific copolymer) which is Mn6,200 and Mw10,200 was obtained (P2).

<Synthesis Example 3>
BzMA 34.0 g, HPMA 33.0 g, GBLMA 33.0 g are used as monomer components constituting the specific copolymer, and AIBN 3 g is used as a radical polymerization initiator, and these are used in a solvent PGMEA 200 g at a temperature of 60 ° C. A solution (specific copolymer concentration: 37.5% by mass) of component (A) (Mn 14,200, Mw 28,000) (specific copolymer concentration) was obtained by performing a polymerization reaction at ˜100 ° C. (P3) .

<Synthesis Example 4>
As a monomer component constituting the copolymer, 100.0 g of MMA is used, 5 g of AIBN is used as a radical polymerization initiator, and these are subjected to a polymerization reaction at a temperature of 60 ° C. to 100 ° C. in 200 g of a solvent PGMEA, whereby Mn 4 , 500, Mw 8,000 copolymer solution (copolymer concentration: 37.5 mass%) was obtained (P4).

<Synthesis Example 5>
As monomer components constituting the copolymer, 40.0 g of CHMI and 60.0 g of MMA are used, and 5 g of AIBN is used as a radical polymerization initiator, and these are polymerized at a temperature of 60 ° C. to 100 ° C. in 200 g of a solvent PGMEA. Thus, a copolymer solution (copolymer concentration: 37.5% by mass) of Mn5,100 and Mw9,500 was obtained (P5).

<Examples 1 to 7 and Comparative Examples 1 to 8>
According to the composition shown in the following Table 1, (B) component, (C) component, (D) component, (E) solvent, and (F) component are mixed in a predetermined ratio to the solution of component (A), The resin composition for planarization film formation of each Example and each comparative example was prepared by stirring at room temperature for 3 hours to make a uniform solution.
In Comparative Examples 7 and 8, copolymer solutions (P4, P5) were used instead of the component (A) solution.

  About each composition of obtained Example 1 thru | or Example 7 and Comparative Example 1 thru | or Comparative Example 8, formation of the coating film and its property, flatness, transparency, and solvent resistance were evaluated, respectively.

[Formation of coating film and evaluation of its properties]
After applying the resin composition for forming a flattened film using a spin coater, it was pre-baked on a hot plate at a temperature of 110 ° C. for 120 seconds to form a coating film having a thickness of 2.5 μm. The case where the coating film could not be formed or the case where tack was caused was evaluated as x, and the case where a normal coating film was formed was evaluated as ◯.

[Evaluation of flatness]
After applying the flattening film forming resin composition onto a stepped substrate having a height of 0.5 μm, a line width of 50 μm, and a space between lines of 120 μm using a spin coater, prebaking is performed on a hot plate at a temperature of 110 ° C. for 120 seconds. A film having a thickness of 2.5 μm was formed. The film thickness was measured using F20 manufactured by FILMETRICS. This coating film was post-baked by heating at a temperature of 230 ° C. for 30 minutes to form a cured film having a thickness of 2.1 μm. The film thickness difference between the coating film on the stepped substrate line and the coating film on the space was measured. The flattening rate was calculated from the formula: flattening rate = 100 × {1− (film thickness difference of coating film) /0.5}.

[Evaluation of permeability]
The flattening film forming composition was applied onto a quartz substrate using a spin coater, and then prebaked on a hot plate at a temperature of 110 ° C. for 120 seconds to form a coating film having a thickness of 2.5 μm. This coating film was post-baked on a hot plate at a temperature of 230 ° C. for 30 minutes to form a cured film. The cured film was measured for transmittance at a wavelength of 400 nm using an ultraviolet-visible spectrophotometer (SHIMADSU UV-2550 model number, manufactured by Shimadzu Corporation).

[Evaluation of solvent resistance]
The flattening film forming composition was applied onto a silicon wafer using a spin coater and then pre-baked on a hot plate at a temperature of 110 ° C. for 120 seconds to form a coating film having a thickness of 2.5 μm. This coating film was post-baked on a hot plate at a temperature of 230 ° C. for 30 minutes to form a cured film having a thickness of 2.1 μm. This cured film was immersed in N-methylpyrrolidone heated to 40 ° C. for 10 minutes, and then the surface N-methylpyrrolidone was washed away with acetone and further dried at 100 ° C. for 30 seconds. The case where no change in the film thickness was observed was marked with ◯, and the film thickness decreased was marked with x.

[Evaluation results]
The results of the above evaluation are shown in Table 2 below.

  In Examples 1 to 7, the obtained coating films were good and showed high flatness of 60% or more, high transmittance of 90% or more, and excellent solvent resistance.

On the other hand, Comparative Examples 1 to 6 had a high transmittance of 90% or more, but the flatness was as low as 60% or less.
In Comparative Example 7, the pre-baked coating film was tacky and did not have solvent resistance, so that it could not be evaluated thereafter.
In Comparative Example 8, the obtained coating film was good and high flatness and transmittance were obtained, but the solvent resistance was insufficient.

  The resin composition for flattening film formation excellent in flattening according to the present invention forms a cured film such as a protective film, a flattening film, and an insulating film in various displays such as thin film transistor (TFT) type liquid crystal display elements and organic EL elements. It is suitable as a material, and is particularly suitable as a material for forming an interlayer insulating film of a TFT type liquid crystal element, a protective film of a color filter, an insulating film of an organic EL element, and the like.

Claims (6)

A planarizing film forming resin composition comprising the following component (A), component (B), component (C), component (D), and solvent (E).
(A) component: an acrylic polymer having a functional group capable of causing a crosslinking reaction with component (D) and having a number average molecular weight of 2,000 to 25,000,
(B) component: a compound having two or more unsaturated double bonds in one molecule (C) component: a compound that generates an acid by heat,
(D) component: a thermally crosslinkable compound having two or more blocked isocyanate groups in one molecule ;
(E) Solvent. (A) The resin composition for planarization film formation of Claim 1 whose component is an acrylic polymer which has a structure of Formula (1).

(In the formula, R ¹ represents an organic group having 1 to 12 carbon atoms.) (B) The resin composition for planarization film formation of Claim 1 or Claim 2 which is a compound in which a component has an ethylenically unsaturated group as an unsaturated double bond. The planarizing film-forming resin composition according to any one of claims 1 to 3, wherein the component (C) is a sulfonic acid ester. (A) Based on 100 parts by mass of component, it contains 3 to 60 parts by mass of component (B), 0.1 to 10 parts by mass of component (C), and 1 to 50 parts by mass of component (D). The planarizing film-forming resin composition according to any one of Items 1 to 4 . The planarization film | membrane formed from the resin composition for planarization film formation as described in any one of Claims 1 thru | or 5 .