Polymer, photosensitive resin composition, cured product, member for display device, and display device

Abstract

To provide a polymer enabling formation of a cured product exhibiting superior developability and heat resistance, and a photosensitive resin composition including the polymer.SOLUTION: A polymer comprises, relative to 100 mass% of all structural units of the polymer, 0.5-5.0 mass% of a structural unit represented by the following general formula (1), the polymer having a weight-average molecular weight of 20000 or less and a molecular weight distribution of 2.0-3.0, and comprising a polymerizable double bond in a side chain. (In the formula, R1 and R2 are the same or different and each represent a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms, which may have a substituent.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer, a photosensitive resin composition, a cured product, a display device member, and a display device. More specifically, the present invention relates to a polymer, a photosensitive resin composition, a cured product, a display device member, and a display device, which can provide a cured product having excellent developability and heat resistance. [Background technology]

[0002] Polymers that can be cured by heat or active energy rays are used in a variety of applications depending on the properties of the polymers, including various optical components and electrical / electronic devices, such as color filters, inks, printing plates, printed wiring boards, semiconductor devices, and photoresists, used in liquid crystal displays and solid-state imaging devices.

[0003] In recent years, optical components and electrical and electronic devices have become smaller, thinner, and more energy-efficient, and as a result, higher performance is required for the various components used. To meet these demands, research is being conducted on polymers with even better properties.

[0004] Various polymers or polymer compositions with excellent properties are known. For example, a curable resin composition capable of forming a coating film with excellent heat resistance and transparency is known, which comprises a polymer obtained by polymerizing a monomer component containing an ether dimer and a curing component comprising a compound having a multifunctional (meth)acrylate and / or an epoxy group (Patent Document 1). Also proposed is a polymer obtained by copolymerizing a specific monomer, an ether dimer of a 2-(hydroxyalkyl)acrylic acid ester, an unsaturated monomer containing a carboxyl group, and an unsaturated monomer containing a hydroxyl group as monomer components (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-300204 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-82317 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the polymer obtained by cyclopolymerizing an ether dimer through radical polymerization has excellent heat resistance, it has the problem of having a relatively slow development rate and poor developability.

[0007] In view of the above-mentioned current situation, an object of the present invention is to provide a polymer capable of giving a cured product having excellent developability and heat resistance, and a photosensitive resin composition containing the polymer. [Means for solving the problem]

[0008] In order to solve the above problems, the present inventors have conducted extensive research on polymers used in photosensitive resin compositions and have found that a cured product having excellent developability and excellent heat resistance can be obtained by having structural units having a specific ring structure in a specific range of proportion, having a weight average molecular weight and molecular weight distribution within specific ranges, and having a polymerizable double bond in the side chain, which has led to the completion of the present invention.

[0009] That is, the present invention includes the following aspects. <1> A polymer, characterized in that the polymer contains 0.5 to 5.0 mass% of structural units represented by the following general formula (1), relative to 100 mass% of all structural units of the polymer, has a weight average molecular weight of 20,000 or less, a molecular weight distribution of 2.0 to 3.0, and has polymerizable double bonds in side chains.

[0010] [ka]

[0011] (In the formula, R 1 and R 2are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms which may have a substituent. <2> The above polymer has an acid value of 20 mgKOH / g or more. <1> The polymer according to claim 1. <3> The polymer has a polymerizable double bond equivalent of 380 to 5000 g / equivalent. <1> or <2> The polymer according to claim 1. <4> the above <1> ~ <3> 1. A photosensitive resin composition comprising the polymer according to any one of 1 to 8, a polymerizable compound, and a photopolymerization initiator. <5> the above <4> A cured product obtained by curing the photosensitive resin composition described in 1. <6> The above on the substrate <5> A member for a display device, comprising a cured product of the above. <7> the above <5> A display device comprising the cured product according to claim 1. [Effects of the Invention]

[0012] The polymer of the present invention can give a cured product having excellent developability and heat resistance, and the polymer and a photosensitive resin composition containing the polymer are suitably used in various optical members, electric and electronic devices, etc. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. Note that a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention. In addition, in this specification, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid", and "(meth)acrylate" means "acrylate and / or methacrylate".

[0014] 1. Polymer The present invention relates to a polymer, characterized in that the polymer contains 0.5 to 5.0 mass% of structural units represented by the following general formula (1), relative to 100 mass% of all structural units of the polymer, has a weight-average molecular weight of 20,000 or less, a molecular weight distribution of 2.0 to 3.0, and has polymerizable double bonds in side chains.

[0015] [ka] (In the formula, R 1 and R 2 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms which may have a substituent.

[0016] The polymer of the present invention, having the above-described structure, can provide a cured product with excellent developability and heat resistance. Although the presence of a ring structure represented by the above general formula (1) improves the heat resistance of the polymer, there has been a problem of reduced developability. The polymer of the present invention has a weight-average molecular weight and molecular weight distribution within a predetermined range even when the amount of the ring structure is reduced, thereby improving developability while maintaining good heat resistance.

[0017] The reason why the above polymer can provide a cured product with excellent developability and heat resistance is believed to be as follows. That is, heat resistance is improved when the polymer contains the structural unit represented by the general formula (1), but if the content is high, development properties deteriorate. On the other hand, if the content of the structural unit represented by the general formula (1) is low, development properties improve but heat resistance deteriorates. The polymer of the present invention can achieve both excellent developability and heat resistance by setting the content of the structural unit in the polymer and the molecular weight distribution of the polymer within specific ranges.

[0018] The polymer contains 0.5 to 5.0% by mass of the structural unit represented by general formula (1) (hereinafter also referred to as "structural unit (A)"), relative to 100% by mass of all structural units in the polymer. The polymer contains the structural unit (A), which improves heat resistance, and by keeping the content of the structural unit (A) within the above range, not only heat resistance but also developability becomes excellent.

[0019] In the above general formula (1), R 1 and R 2are the same or different and represent a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 25 carbon atoms.

[0020] The hydrocarbon group having 1 to 25 carbon atoms, which may have a substituent, is not particularly limited, and examples thereof include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, t-amyl, stearyl, lauryl, and 2-ethylhexyl; aryl groups such as phenyl; alicyclic groups such as cyclohexyl, t-butylcyclohexyl, dicyclopentadienyl, tricyclodecanyl, isobornyl, adamantyl, and 2-methyl-2-adamantyl; alkoxy-substituted alkyl groups such as 1-methoxyethyl and 1-ethoxyethyl; and aryl-substituted alkyl groups such as benzyl. Among these, hydrocarbon groups having primary or secondary carbon atoms that are difficult to eliminate by acid or heat are preferred, in order to further improve the heat resistance of the resulting polymer; methyl, ethyl, cyclohexyl, and benzyl are more preferred, and methyl is most preferred.

[0021] The hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, even more preferably 1 to 3 carbon atoms, and particularly preferably 1 carbon atom, from the viewpoint of heat resistance.

[0022] Above R 1 and R 2 may be the same or different, but are preferably the same in that the transparency and heat resistance of the polymer can be further improved.

[0023] The structural unit (A) can be obtained by polymerizing a monomer component containing a monomer (a) capable of introducing the structural unit (A). Examples of the monomer (a) include compounds represented by the following general formula (a):

[0024] [ka] (In the formula, R 1 and R 2 is the same as the above general formula (1).

[0025] The monomer (a) is preferably a symmetrical ether dimer, that is, 2,2'-[oxybis(methylene)]bisacrylic acid or dialkyl 2,2'-[oxybis(methylene)]bis-2-propenoate.

[0026] Specific examples of the symmetrical ether dimer include 2,2'-[oxybis(methylene)]bisacrylic acid, dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, diethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, di(n-propyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(isopropyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, and di(n-butyl)-2,2'-[oxybis(methylene)]bis-2-propenoate. penoate, di(isobutyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(t-butyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(t-amyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(stearyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(lauryl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(2-ethylhexyl)-2,2'-[oxybis(methylene)]bis-2- propenoate, di(1-methoxyethyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(1-ethoxyethyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, dibenzyl-2,2'-[oxybis(methylene)]bis-2-propenoate, diphenyl-2,2'-[oxybis(methylene)]bis-2-propenoate, dicyclohexyl-2,2'-[oxybis(methylene)]bis-2-propenoate, di(t-butylcyclohexyl)-2,2'-[oxybis(methylene)]bis-2-propenoate di(dicyclopentadienyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(tricyclodecanyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, di(isobornyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, diadamantyl-2,2'-[oxybis(methylene)]bis-2-propenoate, di(2-methyl-2-adamantyl)-2,2'-[oxybis(methylene)]bis-2-propenoate, and the like.Among these, dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, diethyl-2,2'-[oxybis(methylene)]bis-2-propenoate, dicyclohexyl-2,2'-[oxybis(methylene)]bis-2-propenoate, and dibenzyl-2,2'-[oxybis(methylene)]bis-2-propenoate are particularly preferred, and dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate is most preferred.

[0027] The polymer may have only one type of the structural unit (A), or may have two or more types.

[0028] In the above polymer, the content of the structural unit (A) is preferably 0.8 to 4.0 mass %, more preferably 1.0 to 3.8 mass %, and even more preferably 1.2 to 3.5 mass %, relative to 100 mass % of all structural units of the above polymer, in order to achieve both heat resistance and developability.

[0029] In addition to the structural unit (A), the polymer preferably contains a structural unit (B) having an acid group. By containing the structural unit (B) having an acid group, the polymer becomes alkali-soluble and can exhibit developability. Examples of the acid group include functional groups that undergo a neutralization reaction with alkaline water, such as a carboxy group, a phenolic hydroxyl group, a carboxylic anhydride group, a phosphate group, and a sulfonic acid group. Among these, a carboxy group is preferred in terms of developability and versatility.

[0030] The polymer having the structural unit (B) having an acid group can be obtained, for example, by a method (b1) of polymerizing a monomer component containing an acid group-containing monomer; a method (b2) of polymerizing a monomer containing a hydroxyl group-containing monomer to obtain a hydroxyl group-containing polymer, and then reacting a polybasic acid or polybasic acid anhydride with the hydroxyl groups of the polymer to introduce an acid group (carboxyl group); or a method (b3) of polymerizing a monomer component containing an epoxy group-containing monomer to obtain an epoxy group-containing polymer, and then subjecting the epoxy groups of the polymer to an addition reaction with the acid groups of the acid group-containing monomer to ring-open the epoxy groups, and then reacting the hydroxyl groups generated in this process with a polybasic acid or polybasic acid anhydride to introduce an acid group (carboxyl group). Among these, the method (b1) of polymerizing a monomer component containing an acid group-containing monomer is preferred because of its simplicity. That is, the structural unit (B) having an acid group is preferably a structural unit derived from an acid group-containing monomer.

[0031] The acid group-containing monomer may be a compound having the acid group and a polymerizable double bond in the molecule. Examples of the polymerizable double bond include a (meth)acryloyl group, a vinyl group, an allyl group, and a methallyl group. Among these, a (meth)acryloyl group is preferred in terms of reactivity.

[0032] Specific examples of the acid group-containing monomer include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, cinnamic acid, and vinylbenzoic acid; unsaturated polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid; long-chain unsaturated monocarboxylic acids in which the unsaturated group and the carboxyl group are chain-extended, such as β-carboxyethyl (meth)acrylate, mono(2-acryloyloxyethyl) succinate, and mono(2-methacryloyloxyethyl) succinate; unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; and phosphoric acid group-containing unsaturated compounds such as Light Ester P-1M (manufactured by Kyoeisha Chemical Co., Ltd.). Among these, carboxylic acid monomers (unsaturated monocarboxylic acids, unsaturated polycarboxylic acids, long-chain unsaturated monocarboxylic acids, and unsaturated acid anhydrides) are preferred from the viewpoints of versatility and availability. In terms of reactivity, alkali solubility, etc., the acid group-containing monomer is more preferably an unsaturated monocarboxylic acid, and even more preferably (meth)acrylic acid.

[0033] Examples of the hydroxyl group-containing monomer in the above method (b2) include compounds having a hydroxyl group and the above-mentioned polymerizable double bond, and specific examples include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2,3-hydroxypropyl (meth)acrylate.

[0034] Examples of the polybasic acid or polybasic acid anhydride in the above method (b2) include polybasic acids such as succinic acid, maleic acid, phthalic acid, and tetrahydrophthalic acid; dibasic acid anhydrides such as succinic anhydride (also known as succinic anhydride), maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, and itaconic anhydride; and polybasic acid anhydrides such as trimellitic anhydride. Among these, polybasic acid anhydrides are preferred, with succinic anhydride and tetrahydrophthalic anhydride being more preferred, and succinic anhydride being most preferred.

[0035] The epoxy group-containing monomer in the method (b3) may be a compound having an epoxy group and a polymerizable double bond in the molecule, preferably an epoxy group-containing (meth)acrylate. Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, β-ethylglycidyl (meth)acrylate, vinylbenzyl glycidyl ether, allyl glycidyl ether, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and vinylcyclohexene oxide. Among these, glycidyl (meth)acrylate and (3,4-epoxycyclohexyl)methyl (meth)acrylate are preferred, with glycidyl (meth)acrylate being more preferred.

[0036] Examples of the acid group-containing monomer, polybasic acid or polybasic acid anhydride in the above method (b3) include the same as those mentioned above.

[0037] The reactions in (b2) and (b3) above can be carried out by known methods.

[0038] The polymer may have only one type of the structural unit (B), or may have two or more types.

[0039] In the above polymer, the content of the structural unit (B) is preferably 3% by mass or more, more preferably 10 to 30% by mass, and even more preferably 12 to 25% by mass, relative to 100% by mass of all structural units of the above polymer, from the viewpoint of development characteristics.

[0040] From the viewpoint of development characteristics, the acid value of the polymer is preferably 20 mgKOH / g or more, more preferably 65 to 200 mgKOH / g, and even more preferably 80 to 160 mgKOH / g. The acid value is a value obtained by measurement by neutralization titration using a potassium hydroxide (KOH) solution, and is the acid value per 1 g of resin solid content.

[0041] The polymer has a polymerizable double bond in a side chain. Therefore, the polymer preferably further has a structural unit (C) having a polymerizable double bond in a side chain. In terms of curing properties, the polymerizable double bond is preferably a (meth)acryloyl group.

[0042] The polymer having the structural unit (C) can be obtained, for example, by polymerizing a monomer component containing an acid group-containing monomer or a monomer having a group reactive with an acid group to obtain an acid group-containing polymer or a polymer having a group reactive with an acid group, and then reacting the acid group or the group reactive with an acid group of the polymer with a monomer having a group reactive with an acid group or an acid group-containing monomer to introduce a polymerizable double bond into the side chain of the polymer. Examples of the acid group-containing monomer include those described above. Examples of the group reactive with an acid group include epoxy groups, isocyanate groups, amino groups, oxazoline groups, and hydroxyl groups. Examples of the monomer having a group reactive with an acid group include the epoxy group-containing monomers and hydroxyl group-containing monomers described above, isocyanate group-containing monomers such as 2-isocyanatoethyl acrylate, amino group-containing monomers, and compounds having a double bond with an oxazoline group such as vinyloxazoline and isopropenyloxazoline. The reaction in the above method can be carried out by a known method.

[0043] The polymer may have only one type of the structural unit (C), or may have two or more types.

[0044] In the above polymer, the content of the structural unit (C) is preferably 4 to 60 mass %, more preferably 10 to 55 mass %, and even more preferably 20 to 50 mass %, relative to 100 mass % of all structural units of the above polymer, in order to form a crosslinked structure.

[0045] The polymerizable double bond equivalent of the polymer is preferably 380 to 5000 g / equivalent. When the polymerizable double bond equivalent is within the above range, the curability is good and the heat resistance and developability can be improved. From the viewpoint of forming a crosslinked structure and improving properties, the polymerizable double bond equivalent of the polymer is more preferably 380 to 3000 g / equivalent, and even more preferably 400 to 2000 g / equivalent.

[0046] The polymerizable double bond equivalent is the mass of the solid content of the polymer solution per 1 mol of polymerizable double bonds in the polymer. The mass of the solid content of the polymer solution is the mass of the monomer components that constitute the polymer. In this specification, the polymerizable double bond equivalent can be determined by dividing the amount (g) of polymer charged in the polymer solution by the amount (mol) of polymerizable double bonds in the polymer.

[0047] The polymer may contain other structural units (D) in addition to the structural units described above. Examples of the other structural units (D) include structural units derived from the hydroxyl group-containing monomers and epoxy group-containing monomers described above, as well as structural units derived from the following monomers: N-substituted maleimide monomers such as N-cyclohexylmaleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, Nt-butylmaleimide, N-dodecylmaleimide, N-benzylmaleimide, and N-naphthylmaleimide; α-Allyloxymethyl acrylate; alkyl-(α-allyloxymethyl)acrylate monomers such as methyl α-allyloxymethylacrylate, ethyl α-allyloxymethylacrylate, n-propyl α-allyloxymethylacrylate, i-propyl α-allyloxymethylacrylate, n-butyl α-allyloxymethylacrylate; alkoxyalkyl-(α-allyloxymethyl)acrylate monomers such as methoxyethyl α-allyloxymethylacrylate, methoxyethoxyethyl α-allyloxymethylacrylate, methoxyethoxyethoxyethyl α-allyloxymethylacrylate, 3-methoxybutyl α-allyloxymethylacrylate, ethoxyethyl α-allyloxymethylacrylate; hydroxyethyl α-allyloxymethylacrylate, hydroxypropyl α-allyloxymethylacrylate, hydroxybutyl α-allyloxymethylacrylate, fluoroethyl α-allyloxymethylacrylate, difluoroethyl α-allyloxymethylacrylate, α-allyloxy α-(unsaturated alkoxyalkyl)acrylate monomers such as vinyl methylacrylate, allyl α-allyloxymethylacrylate, methallyl α-allyloxymethylacrylate, crotyl α-allyloxymethylacrylate, propargyl α-allyloxymethylacrylate, cyclopentyl α-allyloxymethylacrylate, cyclohexyl α-allyloxymethylacrylate, tricyclodecanyl α-allyloxymethylacrylate, isobornyl α-allyloxymethylacrylate, adamantyl α-allyloxymethylacrylate, dicyclopentadienyl α-allyloxymethylacrylate, phenyl α-allyloxymethylacrylate, methylphenyl α-allyloxymethylacrylate, benzyl α-allyloxymethylacrylate, diphenylmethyl α-allyloxymethylacrylate, diphenylethyl α-allyloxymethylacrylate, triphenylmethyl α-allyloxymethylacrylate, naphthyl α-allyloxymethylacrylate, and anthranyl α-allyloxymethylacrylate; Methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, n-amyl (meth)acrylate, s-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentaerythritol (meth)acrylate (Meth)acrylic acid ester monomers such as tungsten, 4-(1-methoxy)ethoxycyclohexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, 1,4-dioxaspiro[4,5]dec-2-yl methacrylic acid, (meth)acryloylmorpholine, 4-(meth)acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane, 4-(meth)acryloyloxymethyl-2-methyl-2-cyclohexyl-1,3-dioxolane, and 4-(meth)acryloyloxymethyl-2,2-dimethyl-1,3-dioxolane; Aromatic vinyl monomers such as styrene, vinyltoluene, α-methylstyrene, and methoxystyrene; (Meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; Macromonomers having a (meth)acryloyl group at one end of the polymer molecular chain, such as polystyrene, polymethyl (meth)acrylate, polyethylene oxide, polypropylene oxide, polysiloxane, polycaprolactone, and polycaprolactam; Conjugated dienes such as 1,3-butadiene, isoprene, and chloroprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, 2-hydroxyethyl vinyl ether, and 4-hydroxybutyl vinyl ether; N-vinyl compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylimidazole, N-vinylmorpholine, and N-vinylacetamide; Unsaturated isocyanates such as isocyanatoethyl (meth)acrylate and allyl isocyanate; hindered amine compounds having a polymerizable group, such as 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (ADK STAB LA-82, manufactured by ADEKA Corporation) and 2,2,6,6-tetramethyl-4-piperidyl methacrylate (ADK STAB LA-87, manufactured by ADEKA Corporation); Hindered phenol compounds having a polymerizable group, such as 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole (RUVA93, manufactured by Otsuka Chemical Co., Ltd.).

[0048] In particular, the structural unit (D) preferably contains a structural unit derived from a (meth)acrylic acid ester, from the viewpoints of imparting coating film strength, adhesion to the substrate, dispersibility of coloring materials, and the like, in addition to heat resistance and developability.

[0049] The polymer may have only one type of the structural unit (D), or may have two or more types.

[0050] In the above polymer, the content of the structural unit (D) is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass, relative to 100% by mass of all structural units of the above polymer, in order to impart properties other than heat resistance and developability.

[0051] The polymer has a weight average molecular weight of 20,000 or less and a molecular weight distribution of 2.0 to 3.0. By having the weight average molecular weight and molecular weight distribution within the above ranges, the developability can be improved.

[0052] The weight average molecular weight of the polymer is preferably from 5,000 to 18,000, and more preferably from 8,000 to 15,000, in order to further improve the developability.

[0053] The molecular weight distribution (weight average molecular weight / number average molecular weight) of the polymer is preferably from 2.1 to 2.9, and more preferably from 2.2 to 2.8, in order to further improve developability.

[0054] The weight-average molecular weight and number-average molecular weight of the polymer can be measured by gel permeation chromatography (GPC), specifically, by the method described in the Examples below. The molecular weight distribution can be calculated by dividing the weight-average molecular weight by the number-average molecular weight.

[0055] <Method of producing polymer> The method for producing the polymer of the present invention is not particularly limited as long as it is a method that can obtain a polymer having the above-mentioned structural units, and examples include a method of polymerizing a monomer component containing a monomer that can introduce each of the above-mentioned structural units, and a method of polymerizing a polymer component to obtain a base polymer, and then subjecting another compound to an addition reaction with a group possessed by the base polymer to obtain a polymer having predetermined structural units.

[0056] The method for polymerizing the monomer components is not particularly limited, and commonly used techniques such as bulk polymerization, solution polymerization, and emulsion polymerization can be used. Among these, solution polymerization is preferred because it is industrially advantageous and allows for easy structural adjustment such as molecular weight. Furthermore, the polymerization mechanism of the monomer components can be based on a polymerization method based on a mechanism such as radical polymerization, anionic polymerization, cationic polymerization, and coordination polymerization, but a polymerization method based on a radical polymerization mechanism is preferred because of its industrial advantages. The molecular weight of the polymer obtained by polymerizing the above-mentioned monomer components can be controlled by appropriately adjusting the amount and type of polymerization initiator, the polymerization temperature, and the type and amount of chain transfer agent. For example, when the same type of monomer is used, a polymer with a high molecular weight can be obtained by reducing the amount of polymerization initiator or the amount of chain transfer agent. The molecular weight can also be controlled by living radical polymerization or by mixing polymers with different molecular weight distributions.

[0057] Examples of the polymerization initiator include organic peroxides such as t-butylperoxy-2-ethylhexanoate and azo compounds such as 2,2'-azobis(isobutyronitrile), which are commonly used as polymerization initiators. Examples of the chain transfer agent include mercaptan-based chain transfer agents such as alkyl mercaptans, mercaptocarboxylic acids, and mercaptocarboxylic acid esters, which are commonly used as chain transfer agents. These may be used alone or in combination of two or more. The amounts of these agents added can be appropriately determined using known methods.

[0058] Examples of the solvent used in the polymerization include aromatic hydrocarbon solvents such as toluene, xylene, and benzene; aliphatic hydrocarbon solvents such as hexane, pentane, heptane, and cyclohexane; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; halogenated hydrocarbon solvents such as chlorobenzene, dichloromethane, chloroform, and 1,2-dichloroethane; nitrile solvents such as acetonitrile, propionitrile, and valeronitrile; ester solvents such as methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; amide solvents such as dimethylformamide (DMF), dimethylacetamide, and N-methylpyrrolidone; diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol), and cyclopentyl methyl ether (CPME). ), ether-based solvents such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether; fluorine-based solvents such as perfluorohexane, perfluorocyclohexane, pentafluorobenzene, octafluorotoluene; alcohol-based solvents such as monoalcohols such as methanol, ethanol, isopropanol, n-butanol, s-butanol, glycols such as ethylene glycol, propylene glycol, and polyhydric alcohols such as glycerin; carbonate-based solvents such as ethylene carbonate, propylene carbonate, dimethyl carbonate (dimethyl carbonate), diethyl carbonate (diethyl carbonate), divinyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, di-sec-butyl carbonate (dibutyl carbonate), dihexadecyl carbonate, di-2-ethylhexyl carbonate, diphenyl carbonate (diphenyl carbonate), and dicyclohexyl carbonate; DMSO, nitromethane, and the like. These may be used alone or in combination of two or more.

[0059] The polymerization concentration when polymerizing the monomer composition (reaction liquid) containing the above-mentioned monomer components is preferably 5 to 80 mass %, more preferably 10 to 70 mass %, and even more preferably 20 to 60 mass %. The polymerization concentration is the mass % of the monomers used relative to 100 mass % of the reaction liquid.

[0060] Regarding the polymerization conditions, the polymerization temperature may be appropriately set depending on the type and amount of the monomer used, the type and amount of the polymerization initiator, etc., and is, for example, preferably 75 to 130° C., more preferably 80 to 120° C. Similarly, the polymerization time can also be appropriately set and is, for example, preferably 1 to 5 hours, more preferably 2 to 4 hours.

[0061] In particular, the method for producing the above polymer preferably includes a step (P-1) of polymerizing a monomer component, and a step (P-2) of reacting a compound having a polymerizable double bond with the base polymer obtained in the step (P-1).

[0062] The monomer component in the step (P-1) preferably contains at least the monomer (a) capable of introducing the structural unit (A) and an acid group-containing monomer or a monomer having a group reactive with an acid group. In particular, the monomer component more preferably contains the monomer (a) and an acid group-containing monomer in terms of ease of polymerization.

[0063] The polymerization reaction in the step (P-1) can be carried out by the same method as the polymerization method described above. In the step (P-1), known additives such as polymerization initiators, polymerization inhibitors, catalysts, etc., which are commonly used, may also be used.

[0064] When an acid group-containing monomer is used in the step (P-1), the compound having a polymerizable double bond in the step (P-2) may be a compound having a group reactive with an acid group. When a monomer having a group reactive with an acid group is used in the step (P-2), the compound may be an acid group-containing monomer. When a monomer having a group reactive with an acid group is used in the step (P-2), the compound having a group reactive with an acid group may be the above-mentioned monomer having a group reactive with an acid group.

[0065] The reaction conditions in the above step (P-2) are not particularly limited and can be carried out by a known method, for example, the reaction temperature is preferably 60 to 140° C. The reaction time is preferably 5 to 15 hours. In the above step (P-2), it is also preferable to use a known catalyst, such as a commonly used amine compound such as triethylamine or dimethylbenzylamine; an ammonium salt such as tetraethylammonium chloride; a phosphonium salt such as tetraphenylphosphonium bromide; or an amide compound such as dimethylformamide.

[0066] The method for producing the polymer may include other steps in addition to the reaction step described above. Examples of the other steps include an aging step, a neutralization step, a dilution step, a drying step, a concentration step, and a purification step. These steps can be carried out by known methods.

[0067] 2. Photosensitive resin composition The polymer of the present invention can be combined with a polymerizable compound and a photopolymerization initiator to form a photosensitive resin composition. Such a photosensitive resin composition containing the above-mentioned polymer, polymerizable compound, and photopolymerization initiator also constitutes one aspect of the present invention. The photosensitive resin composition of the present invention contains the above-mentioned polymer, and therefore can provide a cured product with excellent developability and heat resistance.

[0068] In the photosensitive resin composition, the content of the polymer is not particularly limited and may be appropriately set depending on the purpose, application, the blending of other components, etc., but is, for example, preferably 5 to 80 mass %, more preferably 7 to 70 mass %, and even more preferably 10 to 60 mass %, relative to 100 mass % of the total solid content of the photosensitive resin composition. In this specification, the term "total solid content" refers to the total amount of components that form the cured product (components excluding solvents and curing catalysts that volatilize during the formation of the cured product).

[0069] (polymerizable compound) The polymerizable compound is a low molecular weight compound having a polymerizable unsaturated bond (also referred to as a polymerizable unsaturated group) that can be polymerized by irradiation with active energy rays such as free radicals, electromagnetic waves (e.g., infrared rays, ultraviolet rays, X-rays, etc.), and electron beams. Examples of the polymerizable compound include monofunctional compounds having one polymerizable unsaturated group in the molecule and polyfunctional compounds having two or more polymerizable unsaturated groups.

[0070] Examples of the polymerizable compound include aromatic vinyl monomers such as styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, divinylbenzene, diallyl phthalate, and diallyl benzene phosphonate; vinyl ester monomers such as vinyl acetate and vinyl adipate; methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, β-hydroxyethyl (meth)acrylate, (2-oxo-1,3-dioxolan-4-yl)-methyl (meth)acrylate, (di)ethylene glycol di(meth)acrylate, and the like. Examples of the polymerizable compound include (meth)acrylic monomers such as tri(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and tris(hydroxyethyl)isocyanurate tri(meth)acrylate; triallyl cyanurate; unsaturated polyester; epoxy acrylate; urethane acrylate; polyester acrylate, etc. These polymerizable compounds may be used alone or in combination of two or more.

[0071] The content of the polymerizable compound is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, and even more preferably 15 to 60% by mass, relative to 100% by mass of the total solid content of the photosensitive resin composition.

[0072] (Photopolymerization initiator) Examples of the photopolymerization initiator include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one ("IRGACURE907", manufactured by BASF); benzoin and its alkyl ethers such as benzoin; acetophenones; anthraquinones; thioxanthones such as 2,4-dimethylthioxanthone; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzophenones such as benzophenone and 4,4'-bis-diethylaminobenzophenone; acylphosphine oxides, and and xanthones; α-aminoketone compounds; α-hydroxyketone compounds; oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime) ("OXE01", manufactured by BASF); benzoin compounds; thioxanthone compounds; halomethylated triazine compounds; halomethylated oxadiazole compounds; and biimidazole compounds such as 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole. Specific examples of the photopolymerization initiator include the photopolymerization initiators described in JP 2014-148610 A. These may be used alone or in combination of two or more.

[0073] The content of the photopolymerization initiator is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, and even more preferably 1 to 15% by mass, relative to 100% by mass of the total solid content of the photosensitive resin composition.

[0074] The photosensitive resin composition may also contain other components in addition to the above-mentioned components, as necessary. Examples of such other components include solvents; colorants (pigments, dyes); dispersants; heat resistance improvers; leveling agents; development aids; inorganic particles such as metal oxide particles; silane-based, aluminum-based, and titanium-based coupling agents; fillers; thermosetting resins such as phenolic resins and polyvinylphenols; multifunctional epoxy compounds; curing aids such as multifunctional thiol compounds; plasticizers; polymerization inhibitors; ultraviolet absorbers; antioxidants; matting agents; antifoaming agents; antistatic agents; slip agents; surface modifiers; thixotropic agents; thixotropic aids; quinone diazide compounds; polyhydric phenol compounds; cationically polymerizable compounds; and thermal acid generators. These may be used alone or in combination of two or more. These other components may be appropriately selected from known compounds, and the amounts used may be appropriately determined.

[0075] <Preparation of Photosensitive Resin Composition> The method for preparing the photosensitive resin composition is not particularly limited, and any known method may be used, such as a method of mixing and dispersing the above-mentioned components using various mixers or dispersers. The mixing and dispersing step is not particularly limited, and may be performed by any known method. Furthermore, the composition may further include other steps that are usually performed.

[0076] 3.Cured product The present invention also provides a cured product obtained by curing the above-described photosensitive resin composition. The cured product has excellent heat resistance.

[0077] The method for curing the photosensitive resin composition to obtain a cured product is not particularly limited, and known methods may be used. For example, the photosensitive resin composition is applied to a substrate by a known method, and the applied product is dried as needed to form a coating film. Next, the coating film is exposed to light through a photomask, and after exposure, the unexposed portion is dissolved in an alkaline aqueous solution and subjected to alkaline development. Next, the coating is washed as needed, and then heated (post-cured) to obtain a cured product. The coating, drying, exposure, alkaline development, and heating can be performed by known methods, such as the method described in JP 2014-148610 A.

[0078] When the cured product is a cured film, the thickness of the cured film may be appropriately set depending on the purpose and application, but from the viewpoints of good optical properties, mechanical properties and ease of handling, it is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and even more preferably 1 to 10 μm.

[0079] 4.Applications The polymer and photosensitive resin composition of the present invention have excellent developability. In addition, the cured product thereof has excellent heat resistance. Therefore, the polymer and photosensitive resin composition of the present invention can be suitably used in applications requiring developability and heat resistance.

[0080] The above polymers and photosensitive resin compositions are preferably used in applications such as color filters, black matrices, photospacers, black column spacers, inks, printing plates, printed wiring boards, semiconductor elements, photoresists, insulating films, films, and organic protective films used in liquid crystal, organic EL, quantum dot, and micro LED liquid crystal displays, solid-state imaging elements, and touch panel display devices, as well as various optical components and electrical and electronic devices.

[0081] 5. Display device components, display devices The present invention also provides a display device member having the above-described cured product on a substrate. The cured product (cured film) formed from the above-described photosensitive resin composition has excellent heat resistance and is suitable as a transparent member, and is also useful as a protective film or insulating film in various display devices. The substrate is not particularly limited and can be appropriately selected from known substrates depending on the purpose and application. For example, the substrates described in JP-A-2014-148610 can be mentioned. A display device having the above-described cured product is also one of the preferred embodiments of the present invention. [Example]

[0082] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0083] The various evaluation methods used in the present examples are as follows. <Molecular weight measurement> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured by gel permeation chromatography (GPC) under the following conditions: The molecular weight distribution was determined by dividing the weight average molecular weight by the number average molecular weight. Device: HLC-8320GPC (Tosoh Corporation) Column: TSKgel SuperHZM-M (Tosoh Corporation) x 4 Detector: RI Eluent: tetrahydrofuran (THF) Flow rate: 0.6mL / min Column temperature: 40℃ Sample injection volume: 10 μL Standard material: Standard polystyrene

[0084] <Solid content> The solution obtained by dissolving 1 g of the polymer solution in 4 g of acetone was naturally dried at room temperature and further dried under reduced pressure (160°C / 5 mmHg) for 5 hours, then allowed to cool in a desiccator and its weight was measured. The non-volatile content of the polymer solution was calculated from the weight loss, and this was taken as the solid content (% by mass) of the polymer solution.

[0085] <Acid value> 90 ml of acetone and 10 ml of water were added to 0.5 to 1 g of polymer solution, and the mixture was stirred to dissolve uniformly. The solution was titrated using an automatic titrator ("COM-555" manufactured by Hiranuma Sangyo Co., Ltd.) with a 0.1 mol / L KOH aqueous solution as the titrant to measure the acid value of the solution. The acid value per 1 g of solids (mg KOH / g) was then calculated from the acid value of the solution and the solids content.

[0086] <Polymerizable double bond equivalent (g / equivalent)> It was determined by dividing the amount (g) of the polymer content of the polymer solution by the amount (mol) of polymerizable double bonds in the polymer.

[0087] <Heat resistance coloring> A photosensitive resin composition was prepared by adding 20.0 parts of Light Acrylate DPE-6A (dipentaerythritol hexaacrylate, manufactured by Kyoeisha Chemical Co., Ltd.) and 5 parts of Irgacure 907 (manufactured by BASF Japan Ltd.) to 250 parts of the polymer solution obtained in the Examples and Comparative Examples. The resulting photosensitive resin composition was applied using a spin coater (1H-D7, manufactured by Mikasa Co., Ltd.) in a coating amount of 0.3 to 0.9 mg / cm2 in terms of solid content. 2 The curable resin compositions were uniformly coated onto a 5 cm square glass substrate (soda lime glass AS-2K, manufactured by Toshin Riko Co., Ltd.) so that the coating amount (calculated as the coating amount after the heat resistance test) was changed by changing the rotation speed of the spin coater, and three coated plates with different coating amounts were prepared. One of the three plates had a coating amount of 0.6 mg / cm. 2 To ensure that the amount of application is close to 0.6 mg / cm, one sheet must be applied. 2 To achieve a larger value, one sheet must have a coating amount of 0.6 mg / cm 2 These coated plates were dried at 100°C for 3 minutes to obtain laminates in which a coating film was formed on the glass substrate. The resulting laminate was heat-treated at 260°C for 3 hours using a Perfect Oven incubator (manufactured by Espec Corporation) and then cooled to room temperature in a desiccator. After cooling, the coating surface of the laminate was measured using a spectrophotometer (manufactured by Konica Minolta, Inc., CM-3700A) to obtain the b* value after heat treatment. For each coating, an approximate straight line (calibration curve) of the coating amount (x) and the b* value (y) was calculated from the measurements of the three coatings prepared as described above, and the b* value was calculated when the coating amount was 0.6 mg / cm. 2 The b* value in this case was used as the result of the heat discoloration resistance of each coating film. It can be said that the smaller the b* value, the less yellowing after heating and the better the heat discoloration resistance.

[0088] <Development speed> (Preparation of Colored Photosensitive Resin Composition) A colored photosensitive resin composition was obtained by adding 35 parts of the polymer obtained in the examples and comparative examples, 30 parts of the pigment dispersion, 30 parts of dipentaerythritol hexaacrylate (DPHA), and 5 parts of IRGACURE (registered trademark) OXE02 (manufactured by BASF Japan Ltd.) in terms of solid content, and then adding a dilution solvent (propylene glycol monomethyl ether acetate) to a solid content concentration (non-volatile content) of 20% by mass and stirring. The pigment dispersion was prepared by the following method. (Preparation of pigment dispersion) 12.9 parts of propylene glycol monomethyl ether acetate, 0.4 parts of Disparlon DA-7301 (manufactured by Kusumoto Chemical Co., Ltd.) as a dispersant, 2.25 parts of CI Pigment Green 58 and 1.5 parts of CI Pigment Yellow 138 as colorants were mixed, and the mixture was dispersed for 3 hours using a paint shaker to obtain a pigment dispersion (solid content 22% by mass).

[0089] (Development speed evaluation) The colored photosensitive resin composition obtained above was applied to a 10 cm square glass substrate by spin coating, and after heat treatment (90°C, 3 minutes), the resulting film was irradiated with 60 mJ / cm of light using a UV aligner (manufactured by Dai Nippon Kaken Co., Ltd., product name "MA-1100") equipped with a 2.0 kW ultra-high pressure mercury lamp through a photomask with 30 μm line-and-space openings at a distance of 50 μm from the coating film.2 The resist was exposed to light at an exposure dose of 1000 kJ / cm² (equivalent to 365 nm illuminance), and a 0.05% aqueous potassium hydroxide solution was sprayed using a spin developer to dissolve and remove the unexposed areas. The remaining exposed areas were then developed by washing with pure water for 10 seconds, and the developability was evaluated. Specifically, the coating film developed through the photomask as described above was observed with a surface roughness meter (manufactured by Ryoka Systems Co., Ltd., product name "VertScan2.0"), and the time (seconds) required for the unexposed area to flow after spraying the 0.05% potassium hydroxide aqueous solution was evaluated as the development rate.

[0090] Example 1 A separable flask equipped with a condenser was prepared as a reaction vessel. Separately, a monomer dropping vessel containing 4.4 parts of dimethyl-2,2'-[oxybis(methylene)]bis-2-propenoate (hereinafter also referred to as "MD"), 64.0 parts of methacrylic acid (hereinafter also referred to as "MAA"), 40.0 parts of cyclohexyl methacrylate (hereinafter also referred to as "CHMA"), 91.6 parts of methyl methacrylate (hereinafter also referred to as "MMA"), 4.0 parts of t-butylperoxy-2-ethylhexanoate (manufactured by NOF Corporation, "Perbutyl O", hereinafter also referred to as "PBO"), and 40 parts of propylene glycol monomethyl ether acetate (hereinafter also referred to as "PGMEA") was prepared with thorough stirring. A chain transfer agent dropping vessel containing 14 parts of n-dodecanethiol (hereinafter also referred to as "n-DM") and 32 parts of PGME was prepared with thorough stirring. A reactor was charged with 390 parts of PGMEA and purged with nitrogen. The reactor was then heated in an oil bath with stirring until the temperature reached 90°C. After the reactor temperature stabilized at 90°C, the monomer and chain transfer agent additions were initiated. The additions were carried out over 135 minutes, maintaining the temperature at 90°C. Sixty minutes after the additions were complete, the temperature was raised to 110°C. The temperature was maintained at 110°C for three hours. A gas inlet tube was then attached to the separable flask, and bubbling with a 5 / 95 (v / v) oxygen / nitrogen mixed gas began. Next, 50.0 parts of glycidyl methacrylate (hereinafter also referred to as "GMA"), 0.40 parts of 6-t-butyl-2,4-xylenol (hereinafter also referred to as "TBXN"), and 0.8 parts of triethylamine (hereinafter also referred to as "TEA") were added to the reactor, and the reaction was continued at 110°C for 12 hours. Thereafter, 85 parts of dilution PGMEA was added to adjust the solid content, and the mixture was cooled to room temperature to obtain a polymer solution with a solid content of 30%. The physical properties of the obtained polymer are shown in Table 1. The obtained polymer was also evaluated for heat discoloration resistance and development speed using the methods described above. The results are shown in Table 1.

[0091] (Examples 2 to 6, Comparative Examples 1 to 3) A polymer solution was obtained in the same manner as in Example 1, except that the monomer composition was changed to the formulation shown in Table 1, and the heat discoloration resistance and development time were evaluated. The results are shown in Table 1. In Table 1, BzMA represents benzyl methacrylate.

[0092] Example 7 A separable flask equipped with a condenser was prepared as the reaction vessel. A monomer dropping vessel was prepared containing 3.8 parts MD, 39.2 parts MAA, 40.0 parts CHMA, 117.0 parts MMA, 4.0 parts PBO, and 40 parts PGMEA, all thoroughly stirred and mixed. A chain transfer agent dropping vessel was prepared containing 11 parts n-DM and 32 parts PGMEA, all thoroughly stirred and mixed. 390 parts PGMEA was charged into the reaction vessel, purged with nitrogen, and then heated in an oil bath with stirring until the reaction vessel temperature reached 90°C. After the reaction vessel temperature stabilized at 90°C, the monomer dropping vessel and the chain transfer agent dropping vessel began dropping. The dropping was carried out over 135 minutes, each while maintaining the temperature at 90°C. 60 minutes after the end of the dropping, the temperature was raised to 110°C, and the reaction vessel was maintained at 110°C for 3 hours. Next, a gas inlet tube was attached to the separable flask, and bubbling of a 5 / 95 (v / v) oxygen / nitrogen mixed gas began. Next, 16.0 parts of GMA, 0.40 parts of TBXN, and 0.8 parts of TEA were charged into the reaction vessel, and the mixture was allowed to react at 110°C for 12 hours. After that, 11 parts of dilution PGMEA was added to adjust the solid content, and the mixture was cooled to room temperature to obtain a polymer solution with a solid content of 30%. The physical properties of the obtained polymer are shown in Table 1. Furthermore, the heat coloration resistance and development speed of the obtained polymer were evaluated using the methods described above. The results are shown in Table 1.

[0093] Example 8 A separable flask equipped with a condenser was prepared as the reaction vessel. A monomer dropping vessel was prepared containing 5.0 parts MD, 88.0 parts MAA, 40.0 parts CHMA, 67.0 parts MMA, 4.0 parts PBO, and 40 parts PGMEA, all thoroughly stirred and mixed. A chain transfer agent dropping vessel was prepared containing 11 parts n-DM and 32 parts PGMEA, all thoroughly stirred and mixed. 390 parts PGMEA was charged into the reaction vessel, purged with nitrogen, and then heated in an oil bath with stirring until the reaction vessel temperature reached 90°C. After the reaction vessel temperature stabilized at 90°C, the monomer dropping vessel and the chain transfer agent dropping vessel began dropping. The dropping was carried out over 135 minutes, each while maintaining the temperature at 90°C. 60 minutes after the dropwise addition was completed, the temperature was raised to 110°C, and the reaction vessel was maintained at 110°C for 3 hours. Next, a gas inlet tube was attached to the separable flask, and bubbling of a 5 / 95 (v / v) oxygen / nitrogen mixed gas began. Next, 83.0 parts of GMA, 0.40 parts of TBXN, and 0.8 parts of TEA were charged into the reaction vessel, and the mixture was allowed to react at 110°C for 12 hours. After that, 148 parts of dilution PGMEA was added to adjust the solid content, and the mixture was cooled to room temperature to obtain a polymer solution with a solid content of 30%. The physical properties of the obtained polymer are shown in Table 1. Furthermore, the heat coloration resistance and development speed of the obtained polymer were evaluated using the methods described above. The results are shown in Table 1.

[0094] Comparative Example 4 A separable flask equipped with a condenser was prepared as the reaction vessel. A monomer dropping vessel was prepared containing 4.4 parts MD, 66.4 parts MAA, 40.0 parts CHMA, 89.2 parts MMA, 4.0 parts PBO, and 40 parts PGMEA, all thoroughly stirred and mixed. A chain transfer agent dropping vessel was prepared containing 5.7 parts n-DM and 32 parts PGMEA, all thoroughly stirred and mixed. 390 parts PGMEA was charged into the reaction vessel, purged with nitrogen, and then heated in an oil bath with stirring until the reaction vessel temperature reached 90°C. After the reaction vessel temperature stabilized at 90°C, the monomer dropping vessel and the chain transfer agent dropping vessel began dropping. The dropping was carried out over 135 minutes, each while maintaining the temperature at 90°C. 60 minutes after the dropwise addition was completed, the temperature was raised to 110°C, and the reaction vessel was maintained at 110°C for 3 hours. Next, a gas inlet tube was attached to the separable flask, and bubbling of a 5 / 95 (v / v) oxygen / nitrogen mixed gas began. Next, 50.0 parts of GMA, 0.40 parts of TBXN, and 0.8 parts of TEA were charged into the reaction vessel, and the mixture was allowed to react at 110°C for 12 hours. After that, 93 parts of dilution PGMEA was added to adjust the solid content, and the mixture was cooled to room temperature to obtain a polymer solution with a solid content of 30%. The physical properties of the obtained polymer are shown in Table 1. Furthermore, the heat coloration resistance and development speed of the obtained polymer were evaluated using the methods described above. The results are shown in Table 1.

[0095] (Comparative Example 5) A separable flask equipped with a condenser was prepared as the reaction vessel. A monomer dropping vessel was prepared containing 4.4 parts MD, 64.0 parts MAA, 40.0 parts CHMA, 91.6 parts MMA, 4.0 parts PBO, and 40 parts PGMEA, all thoroughly stirred and mixed. A chain transfer agent dropping vessel was prepared containing 5.7 parts n-DM and 32 parts PGMEA, all thoroughly stirred and mixed. 110 parts PGMEA was charged into the reaction vessel, purged with nitrogen, and then heated in an oil bath with stirring until the reaction vessel temperature reached 90°C. After the reaction vessel temperature stabilized at 90°C, the monomer dropping vessel and the chain transfer agent dropping vessel began dropping. The dropping was carried out over 135 minutes, each while maintaining the temperature at 90°C. 60 minutes after the end of the dropping, the temperature was raised to 110°C, and the reaction vessel was maintained at 110°C for 3 hours. Next, a gas inlet tube was attached to the separable flask, and bubbling of a 5 / 95 (v / v) oxygen / nitrogen mixed gas began. Next, 50.0 parts of GMA, 0.40 parts of TBXN, and 0.8 parts of TEA were charged into the reaction vessel, and the mixture was allowed to react at 110°C for 12 hours. After that, 85 parts of dilution PGMEA was added to adjust the solid content, and the mixture was cooled to room temperature to obtain a polymer solution with a solid content of 30%. The physical properties of the obtained polymer are shown in Table 1. Furthermore, the heat coloration resistance and development speed of the obtained polymer were evaluated using the methods described above. The results are shown in Table 1.

[0096] [Table 1]

[0097] From Table 1, it was confirmed that polymers having 0.5 to 5.0 mass% of structural units represented by the above general formula (1) relative to 100 mass% of all structural units of the polymer, having a weight average molecular weight of 20,000 or less, a molecular weight distribution of 2.0 to 3.0, and having polymerizable double bonds in the side chains, give cured products with excellent developability and heat resistance.

Claims

1. A polymer, The polymer has a structural unit represented by the following general formula (1) in an amount of 0.5 to 5.0% by mass relative to 100% by mass of all structural units of the polymer: The weight average molecular weight is 20,000 or less, and the molecular weight distribution is 2.0 to 3.

0. Contains polymerizable double bonds in the side chain A polymer characterized by: 【Chemical 1】 (In the formula, R １ and R ２ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms which may have a substituent.

2. 2. The polymer according to claim 1, wherein the acid value of the polymer is 20 mg KOH / g or more.

3. 2. The polymer according to claim 1, wherein the polymer has a polymerizable double bond equivalent of 380 to 5000 g / equivalent.

4. A photosensitive resin composition comprising the polymer according to claim 1, a polymerizable compound, and a photopolymerization initiator.

5. A cured product obtained by curing the photosensitive resin composition according to claim 4.

6. A member for a display device, comprising the cured product of claim 5 on a substrate.

7. A display device comprising the cured product according to claim 5.

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