JP6694230B2 - Alkali-soluble resin and curable resin composition containing the same - Google Patents

Description

  The present invention relates to an alkali-soluble resin, a curable resin composition containing the same, a cured product formed by using the curable resin composition, a photo spacer containing the same, and a display device.

  In a liquid crystal cell of a liquid crystal display device, a liquid crystal layer is formed between a pair of substrates, and spacers are arranged in order to keep the distance between the substrates constant. In recent years, a columnar spacer (photospacer) formed by photolithography has been used as this spacer (for example, Patent Documents 1 and 2). The photo spacer is required to have characteristics such as adhesion to a glass substrate, flexibility capable of following compression force, and elastic recovery force when the compression force is relaxed.

  The photo spacer is formed by applying a curable resin composition on a glass substrate, exposing it with a predetermined mask, exposing it, and then developing it. Therefore, the curable resin composition is required to have developability capable of promptly removing development residues, in addition to satisfying the above characteristics. Patent Document 3 describes that an acrylic resin having a repeating unit having a ring structure in its main chain is used to obtain a photosensitive resin composition for a photo spacer having high solubility in a developing solution.

  Further, when a decomposed product (outgas) is generated in a high temperature step during curing, which mixes with the liquid crystal and causes deterioration of display performance, a curable resin composition in which generation of the decomposed product is suppressed is required.

JP, 2009-53663, A JP, 2009-175647, A WO2014 / 038576

Therefore, the object of the present invention is to increase the molecular weight of the alkali-soluble resin having a main chain ring structure and an acid group, while having excellent developability, the thermal decomposition resistance is improved, the curable resin composition An object of the present invention is to provide an alkali-soluble resin that can reduce outgas at the time, shorten pattern formation time, and improve productivity. Further, when a curable resin composition is used, an alkali-soluble resin that can maintain good developability even if the amount of polyfunctional monomer in the curable resin composition is increased due to high elastic recovery rate is provided. To do.
Another object of the present invention is to improve developability and thermal decomposition resistance, shorten pattern formation time and improve productivity, reduce outgassing, and increase the amount of polyfunctional monomer. It is intended to provide a curable resin composition capable of maintaining developability.
Still another object of the present invention is to provide a cured product (preferably a photospacer) and a display device in which the generation of outgas is reduced and the productivity is improved while maintaining a high elastic recovery rate.

  In the acrylic resin having a repeating unit having a ring structure in the main chain, when the molecular weight of a specific size or more, the present inventors, adhesion to a glass substrate, flexibility and compression that can follow the compression force Alkali-soluble resin capable of producing a curable resin composition in which particularly excellent developability is obtained, further excellent heat resistance is obtained, and outgassing is suppressed, while having properties such as elastic recovery when the force is relaxed The present invention has been completed and the present invention has been completed.

That is, the alkali-soluble resin of the present invention comprises (a1) an acid group-containing monomer and / or (a2) a monomer capable of imparting an acid group after polymerization, and (a) a monomer capable of introducing an acid group into a side chain, and an aromatic compound. Group-substituted maleimides, alkyl-substituted maleimides, and the following general formula (8) or (9)
[In said general formula (8)-(9), R < ¹¹ >, R < ¹² >, R < ¹³ > is a hydrogen atom or a C1-C30 linear or branched alkyl group each independently. ]
A base polymer synthesized from a monomer component containing at least one monomer selected from the group consisting of 1,6-dienes represented by: and capable of introducing an acid group into the side chain (a). When the monomer (a2) is a monomer capable of imparting an acid group after the polymerization, it is a base polymer which has been subjected to a post-treatment for imparting an acid group after the polymerization, or the base polymer is a carbon-carbon diamine. An alkali-soluble resin that is a polymer obtained by introducing a heavy bond,
The content of the monomer capable of introducing an acid group into the side chain (a) is 10% by mass or more and 80% by mass or less in 100% by mass of all the monomer components used for synthesizing the base polymer.
The content of at least one monomer selected from the group consisting of the aromatic-substituted maleimides, the alkyl-substituted maleimides, and the 1,6-dienes represented by the general formula (8) or (9) is as described above. 2% by mass to 50% by mass in 100% by mass of all monomer components used for synthesizing the base polymer,
The weight average molecular weight is 22,000 or more, the weight loss rate measured at 230 ° C. for 30 minutes in a nitrogen atmosphere using a thermogravimetric apparatus is 0 to 3.0%, and the monomer component is further represented by the following general formula ( C)
[In the general formula (C), R ¹ , R ² and R ³ are each independently a hydrogen atom or a methyl group; R 4 is an aromatic hydrocarbon group having 2 or more aromatic rings and having 10 to 20 carbon atoms. AO is an oxyalkylene group having 2 to 20 carbon atoms; x is an integer of 0 to 2; y is 0 or 1; m represents the average number of moles of the oxyalkylene group added, and is less than 1.2. ]
Which has a (c1) oxyalkylene group and contains a monomer that introduces two or more aromatic rings at the end of the side chain,
Among the monomers having the (c1) oxyalkylene group and introducing two or more aromatic rings at the ends of the side chains, (c2) the oxyalkylene group having an oxyalkylene chain length of 1 and the end of the side chain The content of the monomer that introduces two or more aromatic rings is 20% by mass or more based on 100% by mass of the monomer component.

The curable resin composition of the present invention contains any one of the above alkali-soluble resins and a polyfunctional monomer.
The polyfunctional monomer preferably has a functionality of 4 to 10.

The cured product of the present invention is a cured product obtained by curing the curable resin composition.
Moreover, the photo spacer of the present invention contains the above-mentioned cured product.
Furthermore, the display device of the present invention includes the above photo spacer.

According to the present invention, while having excellent developability, thermal decomposition resistance is improved, outgas when the curable resin composition is reduced, pattern formation time is shortened and productivity is improved. A resin can be provided. Further, when the curable resin composition is used, an alkali-soluble resin that can maintain good developability even if the amount of the polyfunctional monomer in the curable resin composition is increased for high elastic recovery is provided. it can.
Further, developability and thermal decomposition resistance are improved, pattern formation time is shortened, productivity is improved, outgassing is reduced, and good developability can be maintained even if the amount of polyfunctional monomer is increased. A curable resin composition can be provided.
Furthermore, it is possible to provide a cured product (preferably a photo spacer) and a display device in which the production of outgas is reduced and the productivity is improved while maintaining a high elastic recovery rate.

(A) And (b) is an example of the schematic sectional drawing of the photo spacer of a favorable shape.

1. Alkali-Soluble Resin The alkali-soluble resin of the present invention is synthesized from a monomer component containing (a) a monomer capable of introducing an acid group into a side chain and (b) a monomer capable of introducing a ring structure into a main chain as essential monomers. The resulting base polymer or a polymer obtained by adding a compound having a carbon-carbon double bond with a part or all (preferably a part) of the acid group of the base polymer as a reaction point. The alkali-soluble resin of the present invention can be suitably used for a photo spacer.

  As the alkali-soluble resin, any appropriate resin can be used as long as the specific monomer is used. The alkali-soluble resin is preferably an acrylic resin, a polyester resin, or a polyether resin, more preferably an acrylic resin.

1-1 Base Polymer A base polymer is obtained by synthesizing a monomer component containing (a) a monomer capable of introducing an acid group into a side chain and (b) a monomer capable of introducing a ring structure into a main chain as essential monomers. Be done. (A) The alkali-soluble resin has a repeating unit having an acid group in the side chain by synthesizing using a monomer capable of introducing an acid group in the side chain.

1-1-1 (a) Monomer capable of introducing an acid group into a side chain (a) Monomer capable of introducing an acid group into a side chain [hereinafter, may be simply referred to as (a) acid group-introducing monomer], An (a1) acid group-containing monomer originally having an acid group and (a2) a monomer capable of imparting an acid group after polymerization are included. When a monomer capable of imparting an acid group after polymerization (a2) is used, a treatment (post-treatment) for imparting an acid group as described below is performed after the polymerization.

  Examples of the acid group-containing monomer (a1) include (meth) acrylic acid, 2- (meth) acryloyloxyethylsuccinic acid, and monomers having a carboxyl group such as itaconic acid; maleic anhydride, itaconic anhydride, and the like. And a monomer having a carboxylic acid anhydride group. Among these, a monomer having a carboxyl group is preferable, and (meth) acrylic acid is particularly preferable. Examples of the monomer (a2) capable of providing an acid group after the polymerization include monomers having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate; monomers having an epoxy group such as glycidyl (meth) acrylate; 2-isocyanate. Examples thereof include monomers having an isocyanate group such as natoethyl (meth) acrylate. The acid group-introducing monomer (a) may be used alone or in combination of two or more kinds.

  The post-treatment for imparting an acid group varies depending on the type of the monomer (a2) capable of imparting an acid group after the polymerization. For example, when a monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate is used, an acid anhydride such as succinic anhydride, tetrahydrophthalic anhydride, maleic anhydride should be added. You can When a monomer having an epoxy group such as glycidyl (meth) acrylate is used, for example, a compound having an amino group and an acid group such as N-methylaminobenzoic acid or N-methylaminophenol is added, or For example, an acid anhydride such as succinic anhydride, tetrahydrophthalic anhydride or maleic anhydride can be added to the hydroxyl group generated after addition of an acid such as (meth) acrylic acid. When a monomer having an isocyanate group such as 2-isocyanatoethyl (meth) acrylate is used, for example, a compound having a hydroxyl group and an acid group such as 2-hydroxybutyric acid can be added.

(A) the content of the acid group-introduced monomer, all monomer components 100% by mass to be used for the synthesis of the base polymer is 10 mass% or more, 15% by mass or more is good preferred, with 80 wt% or less Yes, and preferably 70% by mass or less. When the content of the (a) acid group-introduced monomer is low, sufficient alkali developability may not be exhibited, and a carbon-carbon double bond as a radically polymerizable unsaturated double bond is sufficiently contained in the alkali-soluble resin. It may not be possible to introduce a quantity. On the other hand, if the content of the (a) acid group-introduced monomer is too large, the proportion of the monomer (b) described below that can introduce a ring structure into the main chain decreases, so that the heat resistance and substrate adhesion of the cured product become poor. Will be enough.

1-1-2 (b) Monomer capable of introducing ring structure into main chain The alkali-soluble resin of the present invention is (b) a monomer capable of introducing ring structure into the main chain [hereinafter, simply referred to as (b) ring structure introducing monomer. In some cases, it has a repeating unit having a ring structure in the main chain.

  Examples of the ring structure include a repeating unit having a maleimide structure, an N-substituted maleimide structure, a lactone ring structure, a glutaric anhydride structure, a maleic anhydride structure, or the like. Among them, a maleimide structure or an N-substituted maleimide structure is preferable. By using an alkali-soluble resin having a repeating unit having a maleimide structure or an N-substituted maleimide structure in the main chain, a curable resin composition having higher solubility in a developing solution can be obtained. Specifically, the repeating unit having a ring structure in the main chain is preferably at least one selected from the repeating units represented by the general formulas (1) to (3), and represented by the general formula (1). Is more preferable. By using the alkali-soluble resin having the structural unit represented by the general formula (1), it is possible to obtain a curable resin composition capable of forming a cured product having higher breaking strength.

  The repeating unit having a ring structure in the main chain may be at least one kind selected from the repeating units represented by the general formulas (4) to (7). Among them, the repeating unit represented by the general formula (4) or (7) is preferable.

In formulas (4) to (7), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently a hydrogen atom or a straight chain or branched chain having 1 to 30 carbon atoms. An alkyl group, preferably a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms. It is a group, More preferably, it is a methyl group.

  The repeating unit having a ring structure in the main chain is composed of (b) a ring structure-introducing monomer. Examples of the (b) ring structure-introducing monomer include maleimide, benzylmaleimide, phenylmaleimide, naphthylmaleimide, N-o-hydroxyphenylmaleimide, Nm-hydroxyphenylmaleimide, Np-hydroxyphenylmaleimide, N-o. -Chlorophenylmaleimide, Nm-chlorophenylmaleimide, Np-chlorophenylmaleimide, N-o-methylphenylmaleimide, Nm-methylphenylmaleimide, Np-methylphenylmaleimide, N-o-methoxyphenylmaleimide, Aromatic substituted maleimides such as Nm-methoxyphenylmaleimide and Np-methoxyphenylmaleimide; cyclohexylmaleimide, methylmaleimide, ethylmaleimide, propylmaleimide, isopropylmaleyl Alkyl-substituted maleimides such as de, and the like. Of these, aromatic substituted maleimides are preferable. Specifically, maleimide, benzylmaleimide, phenylmaleimide and cyclohexylmaleimide are preferable, benzylmaleimide, phenylmaleimide and cyclohexylmaleimide are more preferable, and benzylmaleimide is more preferable. Examples of the (b) ring structure-introducing monomer constituting the repeating units represented by the general formulas (4) to (7) include 1,6-dienes represented by the general formula (8) or (9). Can be mentioned. These monomers may be used alone or in combination of two or more.

In formulas (8) and (9), R ¹¹ , R ¹² and R ¹³ are as described in (4) to (7) above.

  When the alkali-soluble resin of the present invention has a structural unit having a ring structure in its main chain, it is possible to obtain a curable resin composition having high solubility in a developing solution. (B) N-substituted maleimide-based monomers, dialkyl-2,2 ′-(oxydimethylene) diacrylate-based monomers and α- (unsaturated alkoxyalkyl) acrylate-based monomers as the ring structure-introducing monomer The form containing at least one monomer selected from the group consisting of is one of the preferred forms of the present invention. The (b) ring structure-introducing monomer is preferably a monomer capable of introducing an N-substituted maleimide structure into the main chain.

(B) the amount of the ring structure introduced monomer, all monomer components 100% by mass to be used for the synthesis of the base polymer is 2 wt% to 50 wt%, good Mashiku 5 mass% to 40 mass% And more preferably 5% by mass to 30% by mass.

1-1-3 (c) of the monomer present invention capable of introducing an oxyalkylene group in the side chain an alkali-soluble resin that has an oxyalkylene group in a side chain. Furthermore, in addition to the oxyalkylene group, that have two or more aromatic rings in the side chain. The introduction of two or more aromatic rings further improves the elastic recovery of the cured product obtained. Although the reason for this is not clear, it may be because the aromatic ring adopts a stack structure and the interaction is expressed, which is not the hardness due to increasing the crosslink density but the hardness due to the interaction. Guessed. The two or more aromatic rings may be condensed rings such as naphthalene ring and anthracene ring.

  Examples of the monomer capable of introducing an oxyalkylene group into the side chain (c) include o-biphenyloxyethyl (meth) acrylate [ethoxylated o-phenylphenol (meth) acrylate], o-biphenyloxyethoxyethyl (meth) acrylate, m-biphenyloxyethyl acrylate, p-biphenyloxyethyl (meth) acrylate, o-biphenyloxy-2-hydroxypropyl (meth) acrylate, p-biphenyloxy-2-hydroxypropyl (meth) acrylate, m-biphenyloxy- 2-Hydroxypropyl (meth) acrylate, N- (meth) acryloyloxyethyl-o-biphenylcarbamate, N- (meth) acryloyloxyethyl-p-biphenylcarbamate [the following formula (10) is N-acryl Royloxyethyl-p-biphenyl = carbamate], N- (meth) acryloyloxyethyl-m-biphenyl = carbamate and other oxyalkylene biphenyl group-containing monomers; o-terphenyloxyethyl (meth) acrylate and other terphenyloxyalkylenes Group-containing monomers and the like can be mentioned.

The monomer capable of introducing an oxyalkylene group in (c) side chain, (c1) having an oxyalkylene group is a monomer capable of introducing two or more aromatic rings at the end of the side chain. (C1) having an oxyalkylene group, as a monomer capable of introducing two or more aromatic rings at the end of the side chain is a monomer represented by the following general formula (C).

In the general formula (C), R ¹ , R ² and R ³ are each independently a hydrogen atom or a methyl group; R ⁴ is an aromatic hydrocarbon having two or more aromatic rings having 10 to 20 carbon atoms. Group; AO is an oxyalkylene group having 2 to 20 carbon atoms; x is an integer of 0 to 2; y is 0 or 1; m represents the average number of moles of the oxyalkylene group added, and is less than 1.2 . As R ⁴ , a biphenyl group is preferable. The aromatic hydrocarbon group may have a substituent.

  Specifically, the monomer of the following formula (10) or the following formula (11) is preferable, and the monomer of the following formula (11) is more preferable.

In the monomer of the above formula (11), when n is smaller, a non-inverted taper-shaped photo spacer described later tends to be easily obtained. Specifically, when an oxyalkylene chain is contained in a monomer molecule containing two or more aromatic rings, 50% or more of the number n of oxyalkylene chains (the number of added oxyalkylene groups) is preferably 1. The average number of moles of added oxyalkylene groups is 1 . 2 less der is, 1 a monomer [(c2) oxyalkylene chain length has an oxyalkylene group is 1, may be referred to a monomer capable of introducing two or more aromatic rings at the end of the side chain] is Most preferred. As the monomer of the above formula (11), a commercially available product, for example, trade name "HRD-01", manufactured by Nippon Distillery Co., Ltd. can be used.

  The content of the monomer capable of introducing an oxyalkylene group into the side chain (c) is preferably 0.5% by mass or more, and more preferably 5% by mass or more in 100% by mass of all the monomer components used for synthesizing the base polymer. It is more preferably 8% by mass or more, further preferably 70% by mass or less, and more preferably 60% by mass or less. When the content of the monomer capable of introducing an oxyalkylene group into the side chain (c) is small, the hardness (effect of improving the elastic recovery rate) of the obtained cured product may be insufficient. On the other hand, if the content of the monomer capable of introducing an oxyalkylene group into the side chain (c) is too large, the content of the (a) acid group-introducing monomer or the (b) ring structure-introducing monomer decreases, so that alkali development The resulting cured product may be inferior in heat resistance or may have insufficient heat resistance or substrate adhesion.

The content of the monomer (c2) having an oxyalkylene group having an oxyalkylene chain length of 1 and capable of introducing two or more aromatic rings at the end of a side chain is 100% by mass of a monomer component for synthesizing the base polymer. Ru der least 20 mass% in.

  The alkali-soluble resin of the present invention may further have a constitutional unit having two or more oxyalkylene groups in the side chain, in addition to the constitutional units described above. The constitutional unit having two or more oxyalkylene groups in its side chain can be obtained, for example, by polymerizing a monomer capable of introducing two or more oxyalkylene groups in its (c3) side chain.

  Examples of the constitutional unit having two or more oxyalkylene groups in the side chain include constitutional units represented by the following general formula (12).

In the general formula (12), R ²¹ , R ²² and R ²³ are each independently a hydrogen atom or a methyl group, and preferably a hydrogen atom. R ²⁴ is a linear or branched alkyl group having 1 to 20 carbon atoms, a linear or branched alkenyl group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms. And preferably a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a linear alkenyl group having 2 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms. , More preferably a linear alkyl group having 1 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and further preferably a linear alkyl group having 1 to 5 carbon atoms, It is a phenyl group or a biphenyl group, particularly preferably a methyl group, a phenyl group or a biphenyl group. The alkyl group, alkenyl group and aromatic hydrocarbon group may have a substituent. A ₁ O represents an oxyalkylene group. The oxyalkylene group represented by A ₁ O has 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and further preferably 2 carbon atoms. The repeating unit may contain one or more oxyalkylene groups. x ₁ represents an integer of 0 to 2. y ₁ represents 0 or 1. m ₁ represents the average number of moles of the oxyalkylene group added, and is 2 or more, preferably 2 to 100, more preferably 2 to 50, and further preferably 2 to 15.

  Examples of the monomer capable of introducing two or more oxyalkylene groups into the side chain (c3) include monomers represented by the following general formula (13).

In the general formula (13), R ²¹ , R ²² , R ²³ , R ²⁴ , A ₁ O, x ₁ , y ₁ and m ₁ are as described in the general formula (12).

  Specific examples of the monomer represented by the general formula (13) include phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate (EO4 mol), methoxypolyethylene glycol (meth) acrylate (EO9 mol), methoxypolyethylene. Glycol (meth) acrylate (EO13 mol), methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, butoxydiethylene glycol (meth) acrylate, 2-ethylhexyldiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate. , Methoxy polypropylene glycol (meth) acrylate, nonylphenoxy polyethylene glycol ( Data) acrylate (EO4-17 moles), nonylphenoxy polypropylene glycol (meth) acrylate (PO5 mol), EO-modified cresol (meth) acrylate (EO2 mol), and the like. In the present specification, the notations such as “EO2 mol” and “PO5 mol” represent the average number of moles of oxyalkylene groups added.

  The content of the monomer capable of introducing two or more oxyalkylene groups in the side chain (c3) is preferably 0.5% by mass to 55% by mass in 100% by mass of all the monomer components used for synthesizing the base polymer. Is more preferable, 1 mass% to 50 mass% is more preferable, and 1 mass% to 45 mass% is further preferable.

  When the alkali-soluble resin has a repeating unit having two or more oxyalkylene groups in its side chain, the resulting cured product has a higher crosslink density and can form a cured product having a higher strength. Can be obtained. When the curable resin composition is constituted by combining such an alkali-soluble resin and a polyfunctional monomer described later (preferably a polyfunctional monomer having no oxyalkylene group), the above effect becomes particularly remarkable. ..

1-1-4 (d) Monomer capable of introducing two or more aromatic rings into the side chain (d) The monomer capable of introducing two or more aromatic rings into the side chain is referred to in the above (c). ) Refers to monomers other than the monomers exemplified as the monomer capable of introducing an oxyalkylene group into the side chain. The two or more aromatic rings may be condensed rings such as naphthalene ring and anthracene ring.

  (D) As the monomer capable of introducing two or more aromatic rings into the side chain, biphenyl group-containing monomers such as biphenyl (meth) acrylate and o-phenylphenol glycidyl ether acrylate; naphthalene ring-containing monomers such as vinylnaphthalene; Examples include terphenyl group-containing monomers such as phenyl (meth) acrylate.

1-1-5 (e) Monomer capable of introducing an amide bond into the side chain It is also a preferred embodiment to introduce an amide bond into the alkali-soluble resin of the present invention. By introducing the amide bond, the strength of the cured product obtained from the curable resin composition can be further improved. Although the reason for this is not clear, the presence of amide bonds causes stronger interactions such as hydrogen bonds between polymer molecular chains, resulting in better recovery even after a strong compressive force is applied. Is presumed to occur.

  The monomer (e) capable of introducing an amide bond into the side chain is represented by the following general formula (14).

  In formula (14), R (a) and R (b) each independently represent a hydrogen atom other than a (meth) acryloyl group, an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group. Examples of the substituent include a phenyl group, a hydroxyl group, an alkoxy group and the like. R (a) and R (b) may form a ring structure composed of a non-metal atom together with the nitrogen atom bonded to them, and examples thereof include the ring structure represented by the following general formula (15). ..

  (E) As the monomer capable of introducing an amide bond into the side chain, (meth) acryloylmorpholine (morpholino (meth) acrylate), (meth) acrylamide, N-methyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-isobutyl (meth) acrylamide, Nt-butyl (meth) acrylamide, Nt-octyl (meth) acrylamide, diacetone (meth) acrylamide, N-hydroxymethyl (meth) Acrylamide, N-hydroxyethyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N-phenyl (meth) acrylamide, N-benzyl (meth) acrylamide, N-triphenylmethyl (meth) acrylamide, N, N-dimethyi (Meth) acrylamide and the like, may be used alone or two or more thereof.

  (E) The content of the monomer capable of introducing an amide bond into the side chain is preferably 2% by mass or more, more preferably 5% by mass or more, in 100% by mass of all the monomer components used for synthesizing the base polymer. It is preferably 70% by mass or less, and more preferably 40% by mass or less. (E) When the amount of the monomer capable of introducing an amide bond into the side chain is small, sufficient strength may not be exhibited. (E) If there are too many monomers that can introduce an amide bond in the side chain, the hydrophilicity may become too strong, and thus the adhesion to the substrate may decrease, so that a spacer having a good shape is formed. It can be difficult.

1-1-6 Other Copolymerizable Monomers The monomer components used for obtaining the base polymer include (a) a monomer capable of introducing an acid group in the side chain and (b) a ring structure introduced in the main chain. An essential monomer such as a monomer that can be used, a suitably used monomer that can introduce an oxyalkylene group in a side chain, a monomer that can introduce two or more aromatic rings in a side chain, and a monomer that can introduce two or more aromatic rings in a side chain. In addition to the monomer capable of introducing an amide bond, in order to further improve the properties of the resulting cured product, other copolymerizable monomer may be contained, if necessary. Examples of such a copolymerizable monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n- (meth) acrylate. Butyl, isobutyl (meth) acrylate, t-butyl (meth) acrylate, methyl 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, ( (Meth) acrylic acid esters such as tricyclodecyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate; styrene, vinyltoluene, α -Aromatic vinyl compounds such as methylstyrene; Butadiene such as butadiene and isoprene Or substituted butadiene compounds, ethylene, propylene, vinyl chloride, ethylene or substituted ethylene compound such as acrylonitrile, vinyl esters such as vinyl acetate and the like.

  Among these, (meth) acrylic acid esters are preferred. These other copolymerizable monomers may be used alone or in combination of two or more.

  When these other copolymerizable monomers are used, the content ratio in 100% by mass of all the monomer components used for synthesizing the base polymer is not particularly limited, but preferably 0% by mass to 55% by mass, more preferably Is 5% by mass to 50% by mass, and more preferably 10% by mass to 45% by mass.

1-2 Alkali-Soluble Resin Introducing Carbon-Carbon Double Bond in Side Chain The alkali-soluble resin of the present invention has a carbon-carbon group having a part or all (preferably a part) of the acid group of the base polymer as a reaction point. It includes a polymer to which a compound having a carbon double bond is added. Thus, introducing a carbon-carbon double bond into the side chain of the base polymer is also a preferred embodiment. The carbon-carbon double bond can also be introduced into the alkali-soluble resin by adding a polymer capable of introducing a carbon-carbon double bond to a side chain to the monomer component for synthesizing the base polymer.

  If the alkali-soluble resin has a repeating unit having a carbon-carbon double bond in the side chain, the alkali-soluble resins can be radically polymerized with each other, or the alkali-soluble resin and the polyfunctional monomer can be radically polymerized with each other. Therefore, a three-dimensionally crosslinked cured product can be obtained, and a curable resin composition that can form a cured product having higher exposure sensitivity and higher breaking strength can be obtained. The method of introducing a carbon-carbon double bond into the side chain of the alkali-soluble resin will be described later.

  As the alkali-soluble resin, a polymer in which a compound having a carbon-carbon double bond is added with a part or all (preferably a part) of the acid group of the base polymer as a reaction point is preferable.

  The alkali-soluble resin of the present invention may be a random copolymer or a block copolymer.

1-3 Molecular Weight The weight average molecular weight of the alkali-soluble resin is 22,000 or more when measured by gel permeation chromatography (GPC) using a tetrahydrofuran (THF) solvent. The upper limit is preferably 200,000 or less. It is more preferably 23,000 to 150,000, further preferably 25,300 to 100,000, particularly preferably 25,500 to 80,000, and most preferably 26,000 to 50,000. Within such a range, the compatibility with the polyfunctional monomer described later is improved, the thermal decomposition resistance is improved, and the outgas when the curable resin composition is reduced, and the developability is further improved, and the pattern is improved. It is possible to obtain a curable resin composition that can significantly reduce the formation time and that has a suitable viscosity for forming a cured product and has good coatability.

  The molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the alkali-soluble resin is preferably 1.1 to 6, more preferably 1.2 to 4, and particularly preferably 2 to 2. It is 4. When the molecular weight distribution is within the above range, the coatability and the chemical resistance of the cured product tend to be excellent.

  The acid value of the alkali-soluble resin is preferably 20 mgKOH / g to 300 mgKOH / g, more preferably 30 mgKOH / g to 200 mgKOH / g, and further preferably 40 mgKOH / g to 150 mgKOH / g. Within such a range, it is possible to obtain a curable resin composition that is more excellent in alkali developability, has less development residue, and is capable of forming a cured product having more excellent adhesion.

1-4 weight reduction rate the alkali-soluble resin of the present invention, the weight reduction rate was measured at 230 ° C. 30 minutes under a nitrogen atmosphere using a thermogravimetric measuring apparatus is from 0 to 3.0%. The weight reduction rate can be measured using a thermogravimetric measuring device TGA-50 (manufactured by SHIMADZU). When the weight reduction rate is within the above range, the thermal decomposition resistance is higher, and the outgas when the curable resin composition is prepared can be further reduced. Therefore, when it is used as a photo spacer in a display device, it is possible to further suppress deterioration in display performance.

1-5 Manufacturing Method of Base Polymer The base polymer is synthesized by polymerizing the monomer components for constituting the base polymer. As the polymerization method, a solution polymerization method is preferable, and the polymerization temperature and the polymerization concentration (polymerization concentration = [total mass of monomer mixture / (total mass of monomer mixture + mass of solvent)] × 100) are the monomer mixture to be used ( Although it depends on the composition and ratio of the (monomer component) and the molecular weight of the target polymer, the polymerization temperature is preferably 40 to 150 ° C., and the polymerization concentration is 5 to 60% by mass, and more preferably the polymerization temperature is 60 to 130. C., and the polymerization concentration is preferably 10 to 50% by mass.

  In the present invention, a chain transfer agent may be used in the polymerization of the base polymer. Examples of the chain transfer agent include known monofunctional thiol compounds such as n-dodecyl mercaptan and β-mercaptopropionic acid, as well as mercapto-modified polysiloxane having both ends (manufactured by Shin-Etsu Silicone Co .; X-22-167B; ); R is a bifunctional thiol compound such as alkylene group), a side chain mercapto-modified side chain polyfunctional mercapto-modified polysiloxane (manufactured by Shin-Etsu Silicone; KF2001, KF2004; the following formula (17); Can be used.

  When both-terminal mercapto-modified polysiloxane is used, two base polymer molecules are bonded via both-terminal mercapto-modified polysiloxane. When a side chain polyfunctional mercapto-modified polysiloxane is used, a branched polymer having a base polymer bonded to the side chain mercapto group is obtained. By using these mercapto-modified polysiloxanes, a polysiloxane bond is introduced into the obtained polymer. One or more of these mercapto-modified polysiloxanes may be used in combination with a known monofunctional thiol compound such as n-dodecyl mercaptan or β-mercaptopropionic acid. The elastic recovery rate is further improved by using the mercapto-modified polysiloxane. The reason for this is that by introducing a polysiloxane part which is hardly soluble in the solvent into the polymer, aggregation of the polysiloxane part occurs in the resin composition, forming pseudo fine particles, and the pseudo fine particles recover elasticity. It is presumed that it is contributing to the improvement of the rate.

  The chain transfer agent is preferably used in the range of 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and 0.1 part by mass or more and less than 2 parts by mass with respect to 100 parts by mass of the monomer component. More preferable. Within this range, an alkali-soluble resin having a weight average molecular weight (Mw) of about 22,000 to 200,000 can be obtained. When Mw exceeds 200,000, the finally obtained alkali-soluble resin becomes too high in viscosity to make it difficult to form a coating film, while when it is less than 22,000, developability and thermal decomposition resistance become insufficient. ..

  When a solvent is used in the polymerization of the above-mentioned monomer components, the solvent used in a usual radical polymerization reaction may be used. Specifically, for example, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, and other ethers; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and other ketones; ethyl acetate, butyl acetate, propylene glycol monomethyl ether Esters such as ether acetate and 3-methoxybutyl acetate; alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether and propylene glycol monomethyl ether; aromatic hydrocarbons such as toluene, xylene and ethylbenzene; Chloroform; dimethyl sulfoxide; and the like. These solvents may be used alone or in combination of two or more.

  When radically polymerizing the above-mentioned monomer component, a radical polymerization initiator which is usually used may be added, if necessary. The polymerization initiator is not particularly limited, and examples thereof include cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amyl. Organic peroxides such as peroxy-2-ethylhexanoate and t-butylperoxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1,1′-azobis (cyclohexane Carbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis (2-methylpropionate), and other azo compounds. These polymerization initiators may be used alone or in combination of two or more. The amount of the initiator used may be appropriately set depending on the composition of the monomer components used, the reaction conditions, the molecular weight of the target polymer, and the like, and is not particularly limited, but the weight average molecular weight is several without gelation. From the viewpoint of being able to obtain tens of thousands of polymers, the amount is preferably 0.1 parts by mass to 15 parts by mass, more preferably 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of all the monomer components.

1-6 Application of carbon-carbon double bond to alkali-soluble resin Application of carbon-carbon double bond to alkali-soluble resin involves reacting a part or all (preferably a part) of the acid group of the base polymer. It can be carried out by adding a compound having a carbon-carbon double bond as a point. A known method can be adopted for the carbon-carbon double bond introduction reaction to the base polymer, and the carbon-carbon double bond introduction monomer is added to the acid group in the base polymer in the presence of oxygen or other polymerization inhibitor and a catalyst. To react with.

The treatment for imparting a carbon-carbon double bond to the base polymer differs depending on the type of the monomer (a) used to obtain the base polymer and capable of introducing an acid group into the side chain, and examples thereof include the following methods. Be done.
(I) When a monomer having a carboxyl group such as (meth) acrylic acid or itaconic acid is used as the monomer capable of introducing an acid group into the side chain (a):
A compound having an epoxy group and a double bond such as glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, o- (or m-, or p-) vinylbenzyl glycidyl ether may be added. A compound having a double bond with an isocyanate group such as 2-isocyanatoethyl (meth) acrylate, or a vinyl ether group such as 2-vinyloxyethoxyethyl (meth) acrylate and a carbon-carbon double bond. The compound having can be added.
(Ii) (a) When a monomer having a carboxylic acid anhydride group such as maleic anhydride or itaconic anhydride is used as the monomer capable of introducing an acid group into the side chain:
A compound having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and a carbon-carbon double bond can be added.
(Iii) (a) Glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, o- (or m-, or p-) vinylbenzyl as a monomer capable of introducing an acid group into the side chain When a monomer having an epoxy group such as glycidyl ether is used:
A compound having an acid group such as (meth) acrylic acid and a polymerizable carbon-carbon double bond can be added.

  Among these, the method of adding glycidyl (meth) acrylate to the acid group in the base polymer (including the case of being added in the post-treatment) can easily introduce an ethylenically unsaturated double bond into the side chain. However, it has the advantage of less coloring. Since the acid group is consumed by this carbon-carbon double bond introduction reaction, the amount of the consumed acid group (carbon-carbon double bond introduction amount) is taken into consideration, and the (a) acid in the monomer component is taken into consideration. It is preferable to determine the amount of the group-introduced monomer used. This is because if there are too few acid groups in the alkali-soluble resin, alkali developability may not be exhibited. Therefore, from the above viewpoint, the acid value of the finally obtained alkali-soluble resin is preferably about 20 to 250 mgKOH / g, more preferably 30 to 200 mgKOH / g, and further preferably 35 to 150 mgKOH / g.

  Glycidyl (meth) acrylate is preferably reacted in an amount of 5 parts by mass or more, more preferably 10 parts by mass or more, particularly preferably 15 parts by mass or more, with respect to 100 parts by mass of the base polymer. When the amount of glycidyl acrylate (meth) is less than 5 parts by mass, the amount of double bonds in the side chain of the resulting alkali-soluble resin is too small and the exposure sensitivity is lowered, or a dense cured coating film cannot be formed. The characteristics may deteriorate. Further, a hydroxyl group formed by the addition of glycidyl (meth) acrylate to an acid group has an action of enhancing the solubility in an alkali developing solution, but the decrease in the hydroxyl group causes insufficient solubility in the alkali developing solution. May occur. The addition amount of glycidyl (meth) acrylate is preferably 170 parts by mass or less, more preferably 150 parts by mass or less, and further preferably 140 parts by mass or less, relative to 100 parts by mass of the base polymer. If the amount of glycidyl (meth) acrylate added is too large, the storage stability of the resin composition may be reduced, or the solubility in an organic solvent may be reduced.

  Further, the introduction of the carbon-carbon double bond into the side chain of the alkali-soluble resin is carried out by synthesizing a base polymer by adding a monomer obtained by subjecting (meth) acrylic acid to a ring-opening addition reaction of a cyclic lactone to synthesize a base polymer. It is also possible to modify the terminal carboxyl group of the derived structural unit with, for example, 3,4-epoxycyclohexyl (meth) acrylate. Further, a method in which a cyclic lactone is reacted with the carboxyl group of the base polymer and then modified with, for example, 3,4-epoxycyclohexyl (meth) acrylate or the like can be mentioned. The ring-opening addition reaction of the cyclic lactone and modification with 3,4-epoxycyclohexyl (meth) acrylate or the like can be performed by known methods.

2. Curable resin composition The curable resin composition of the present invention contains the above-mentioned alkali-soluble resin and a polyfunctional monomer. Practically, the curable resin composition of the present invention may further contain a polymerization initiator (preferably a photopolymerization initiator), a solvent and an additive.
The curable resin composition of the present invention is particularly preferably used for a negative photosensitive resin composition.

  By using the curable resin composition of the present invention, a cured product (preferably a photo spacer) can be formed by photolithography. In the curable resin composition of the present invention, the content of the alkali-soluble resin is preferably 5 to 60% by mass based on the solid content of the curable resin composition. The solid content means the mass content of the components forming the cured product (excluding the solvent that volatilizes during the formation of the cured product), as determined by the measurement method described below.

2-1 Polyfunctional Monomer The polyfunctional monomer contained in the curable resin composition of the present invention is preferably a compound having at least two ethylenically unsaturated double bonds in the molecule. Considering the ease of radical polymerization, a polyfunctional monomer having an acrylic group is more preferable.

  Examples of polyfunctional monomers include divinylbenzene, diallylphthalate, diallylbenzenephosphonate, and other polyfunctional aromatic vinyl monomers; (di) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane diamine. (Meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol Tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, tripentaerythritol di (meth) acrylate, tripentaerythritol tri (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate , Tripentaerythritol hepta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tris (hydroxyethyl) isocyanurate tri (meth) acrylate, and other polyfunctional (meth) acrylates; these monomers are caprolactone-modified or alkylene oxides Examples include modified polyfunctional monomers and the like.

  Among them, preferably, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol hepta (meth) acrylate, tripentaerythritol octa (meth) acrylate, Tris (hydroxyethyl) isocyanurate tri (meth) acrylate and the like are preferable. When these polyfunctional monomers are used, a cured product having a high crosslink density can be obtained because of the large number of functional groups.

  The functional number of the polyfunctional (meth) acrylates is preferably 4 or more, more preferably 5 or more. Further, from the viewpoint of further suppressing cure shrinkage, the number of functional groups is preferably 10 or less, more preferably 9 or less, and further preferably 8 or less. The molecular weight is not particularly limited, but from the viewpoint of handling, for example, 2000 or less is suitable.

  In the present invention, the polyfunctional monomer may or may not have an oxyalkylene group. Preferably, a polyfunctional monomer having no oxyalkylene group is used.

  The content ratio of the polyfunctional monomer is preferably 30 parts by mass to 95 parts by mass, more preferably 40 parts by mass to 90 parts by mass, and further preferably 55 parts by mass in 100 parts by mass of the solid content of the curable resin composition. Parts by mass to 90 parts by mass.

In the present invention, the content ratios of the alkali-soluble resin and the polyfunctional monomer preferably satisfy the following (Formula 1) in mass ratio.
(Alkali-soluble resin) / (polyfunctional monomer) = 40/60 to 10/90 (Formula 1)
More preferably, the following (formula 2) is satisfied.
(Alkali-soluble resin) / (Polyfunctional monomer) = 35 / 65-15 / 85 (Formula 2)
By satisfying the above relational expression, the developability and the elastic recovery rate of the obtained cured product tend to be kept high.

2-2 Polymerization initiator The curable resin composition of the present invention practically contains a polymerization initiator. Of these, photopolymerization initiators are preferred. The photopolymerization initiator may be any one that decomposes and / or reacts with light (including ultraviolet rays and electron beams) to generate radicals.

  Examples of the photopolymerization initiator include benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, and benzoin ethyl ether; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 1,1-dichloroacetophenone. Anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone and 2-chlorothioxanthone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino- Α-Amino ketones such as lopan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; 2-hydroxy-1- {4- [4- (2-hydroxy Α-hydroxyketones such as 2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one; acylphosphine oxides, xanthones and the like. These photopolymerization initiators may be used alone or in combination of two or more kinds.

  Of these, an α-aminoketone compound is preferably used, and an α-aminoketone compound represented by the following general formula (18) is more preferably used. By using such a compound, it is possible to obtain a curable resin composition which can form a photospacer having a non-inverted taper shape and a small diameter.

In formula (18), X ¹ and X ² each independently represent a methyl group, an ethyl group, a benzyl group or a 4-methylbenzyl group, and preferably a methyl group. —NX ³ X ⁴ is a dimethylamino group, a diethylamino group or a morpholino group, preferably a dimethylamino group or a morpholino group, and more preferably a morpholino group. X ⁵ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, a dimethylamino group, or a morpholino group, and preferably carbon It is an alkylthio group or morpholino group having 1 to 8 carbon atoms, more preferably an alkylthio group or morpholino group having 1 to 3 carbon atoms, and further preferably a methylthio group.

  More preferably, an α-hydroxyketone-based compound may be used in combination, more preferably an α-hydroxyketone-based compound represented by the following general formula (19) or the following general formula (20) is used, and further preferably: The α-hydroxyketone compound represented by the general formula (20) is used. By using such a compound, it is possible to obtain a curable resin composition capable of forming a photospacer having a non-inverted taper shape and a small diameter.

In the general formula (19), X ⁶ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms. Alternatively, it is an alkoxy group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkoxy group having 1 to 2 carbon atoms. X ⁷ and X ⁸ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group. Further, X ⁷ and X ⁸ may be bonded to each other to form a cycloalkyl group having 4 to 8 carbon atoms (preferably 6 to 8 and more preferably 6).

In formula (20), X ^{9 to} X ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and more preferably It is a methyl group. Further, X ⁹ and X ¹⁰ , and / or X ¹¹ and X ¹² may be bonded to each other to form a cycloalkyl group having 4 to 8 carbon atoms.

  The above alkyl group, alkoxy group, alkyl group and cycloalkyl group may have a substituent. Examples of the substituent include a hydroxyl group, a carboxyl group, a sulfo group, a cyano group, and a halogen atom.

  The content ratio of the photopolymerization initiator is preferably 0.01% by mass or more and more preferably 0.1% by mass or more in the solid content of the curable resin composition. Moreover, 40 mass% or less is preferable, 20 mass% or less is more preferable, and 10 mass% or less is especially preferable.

  In addition, the content ratio of the photopolymerization initiator is preferably 0.1 parts by mass to 40 parts by mass, and more preferably 0.5 parts by mass with respect to 100 parts by mass of the total amount of the alkali-soluble resin and the polyfunctional monomer. Parts by mass to 20 parts by mass, particularly preferably 1 part by mass to 10 parts by mass. Within the above range, radical curing can be more sufficiently promoted, and it becomes easier to prevent elution of the remaining radical polymerization initiator and to secure solvent resistance.

  Further, in addition to the photopolymerization initiator, a photopolymerization initiation assistant may be used in combination. It is also possible to use a combination of a plurality of photopolymerization initiation assistants. Specific examples of the photopolymerization initiation aid include 1,3,5-tris (3-mercaptopropionyloxyethyl) -isocyanurate and 1,3,5-tris (3-mercaptobutyloxyethyl) -isocyanurate (Showa Denens Co., Ltd., Karenz MT (registered trademark) NR1), trifunctional thiol compounds such as trimethylolpropane tris (3-mercaptopropionate); pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercapto). Butyrate) (Karenzu MT (registered trademark) PE1 manufactured by Showa Denko KK) and other tetrafunctional thiol compounds; and difunctional thiol compounds such as dipentaerythritol hexakis (3-propionate) and other polyfunctional thiol compounds.

2-3 Additive The curable resin composition of the present invention may contain any appropriate additive as necessary. Examples of the additives include fillers such as aluminum hydroxide, talc, clay, and barium sulfate, dyes, pigments, defoamers, coupling agents (preferably silane coupling agents), leveling agents, sensitizers, releasing agents. Examples include mold agents, lubricants, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, polymerization inhibitors, thickeners, dispersants, and inorganic materials.

  The curable resin composition of the present invention may contain a polymerization inhibitor. By containing the polymerization inhibitor, the storage stability of the curable resin composition is improved, and the resolution after development is improved depending on the use. Specific examples of the polymerization inhibitor include phenol, catechol, resorcinol, hydroquinone, 4-t-butylcatechol, 2,6-di (t-butyl) -p-cresol, phenothiazine and 4-methoxyphenol.

  The content of the polymerization inhibitor is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more in the solid content of the curable resin composition. On the other hand, from the viewpoint of keeping the hardness of the cured product high, 5% by mass or less is preferable, and 1% by mass or less is more preferable.

  The curable resin composition of the present invention may contain an ultraviolet absorber (UV absorber). When making a spacer, the lower diameter tends to be larger than the upper diameter, but this is because the light that reaches the glass substrate is reflected and the coating film on the bottom of the spacer causes incident light from above and the glass substrate. This is because the photocuring proceeds too much by receiving both of the reflected light from. When the composition contains an ultraviolet absorber, excess light energy is absorbed, and thus it is possible to effectively suppress an increase in the lower diameter of the spacer.

  As the ultraviolet absorber, one having a maximum absorption wavelength (peak) at a wavelength of 280 to 380 nm is preferable. This is because it does not overlap with the peak of the photopolymerization initiator. Specifically, the compound represented by the following chemical formula is preferable because the maximum absorption wavelength does not overlap with the peak of the photopolymerization initiator and the compound is easily available.

  Among the above compounds, the TINUVIN (registered trademark) series and CHIMASSORB (registered trademark) are available from BASF Japan Co., Ltd., and SEESORB (registered trademark) is available from Cypro Kasei Co., Ltd., respectively.

  The amount of the ultraviolet absorber is preferably 0.03 to 1.0 mass% in 100 mass% of the solid content of the curable resin composition. Within this range, it is possible to obtain a spacer having a small elastic diameter and a level of elastic recovery that is practically unproblematic. If the ultraviolet absorber is added too much, even if the amount of the photopolymerization initiator is increased, the upper side of the spacer is cured, but the lower side may be insufficiently cured, which is not preferable. On the other hand, if the amount of the ultraviolet absorber is less than 0.03% by mass, it is impossible to absorb the excess light and the reflected light with respect to the glass substrate is insufficiently suppressed, so that the lower diameter of the spacer may not be reduced. .. The UV absorber is more preferably 0.05% by mass or more, further preferably 0.1% by mass or more, more preferably 1.0% by mass or less, further preferably 0.75% by mass or less, 0.6% by mass. The following are particularly preferred.

  The content ratio of the ultraviolet absorber is preferably 0.05 parts by mass to 10 parts by mass, more preferably 0.1 parts by mass to 5 parts by mass with respect to 100 parts by mass of the total of the alkali-soluble resin and the polyfunctional monomer. Yes, and more preferably 0.2 to 3 parts by mass. If the content ratio of the ultraviolet absorber exceeds 10 parts by mass, a non-inverted taper-shaped photo spacer may not be obtained.

  The curable resin composition of the present invention does not require a coupling agent in order to express the adhesiveness with the substrate, but the adhesiveness can be further expressed by adding an appropriate amount of the coupling agent.

  The coupling agent has a property of binding to an oxidized surface of an inorganic substance by a hydrolysis reaction or a condensation reaction. As such a coupling agent, specifically, for example, a coupling agent having a reactive group such as a vinyl group, a (meth) acrylic group, an epoxy group, an amino group, a mercapto group, or an isocyanate is suitable. Among them, those having a vinyl group, a (meth) acryloyl group and / or an epoxy group as a reactive group are preferable. More preferably, it is a (meth) acryloyl group. Further, as the central metal, for example, those containing silicon, zirconia, titanium, and / or aluminum are preferable, and among them, those having silicon as the central metal are preferable, and a silane coupling agent is more preferable. By using the silane coupling agent, the adhesiveness and surface hardness of the cured product can be made more sufficient. The content of the coupling agent is suitably 0.5% by mass or more in 100% by mass of the total solid content of the curable resin composition. From the viewpoint of storage stability and the like of the curable resin composition, it is preferably 20% by mass or less. It is more preferably 15% by mass or less, still more preferably 10% by mass or less.

2-4 Solvent The curable resin composition of the present invention may contain any appropriate solvent. Examples of the solvent include ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, 3-methoxy. Esters such as butyl acetate; alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether; aromatic hydrocarbons such as toluene, xylene, ethylbenzene; chloroform, dimethyl sulfoxide, etc. Can be mentioned. The amount of the solvent can be set to any appropriate amount depending on the desired viscosity of the curable resin composition.

  An ester solvent is preferably used as the solvent used during the polymerization of the alkali-soluble resin, because each component can be uniformly dissolved and the developability and transparency can be improved. Further, a compound having a boiling point of 110 to 250 ° C. under atmospheric pressure is more preferable.

  By setting the boiling point to 110 ° C. or higher, drying proceeds appropriately during curing, and a good cured product can be obtained. On the other hand, when the boiling point is 250 ° C. or less, the amount of the residual solvent in the cured product can be suppressed to a small amount, and the curing shrinkage at the time of heat curing can be further reduced, so that a better cured product can be obtained.

  The curable resin composition of the present invention may contain various solvents such as acetates, ketones and ethers other than the above.

  In particular, a mode in which an ester-based solvent and an alcohol-based solvent are used in combination as a solvent is one of the preferable modes, and the amount of the alcohol-based solvent is more preferably 25% by mass or less based on 100% by mass of the total solvent. , 20 mass% or less is particularly preferable.

  There is no particular limitation on the content of the solvent in the curable resin composition of the present invention, and any amount can be used depending on the application. For example, the amount of solvent is preferably 40 to 90% by mass of the entire curable resin composition.

2-5 Use of Curable Resin Composition The curable resin composition of the present invention is excellent in developability and curability, and can accurately form a molded article having a desired shape. Such a curable resin composition of the present invention can be used as, for example, a photocurable coating material or a photocurable ink, in addition to being used for forming a photo spacer. It can also be used as a material for a color filter, an overcoat, an insulating film, a protective film, or the like. The curable resin composition of the present invention can exert the above effects particularly when used as a negative type curable resin composition for curing a light irradiation site.

2-6 Method for producing curable resin composition The curable resin composition of the present invention may contain, for example, an alkali-soluble resin, a polyfunctional monomer, a photopolymerization initiator, and optionally a radically polymerizable oligomer and other additives. It is obtained by adding the solvent to the above-mentioned solvent, stirring and dissolving it uniformly, and then filtering the obtained solution.

3. Cured Product The cured product of the present invention is obtained by curing the curable resin composition (preferably a photo spacer described later). The method for forming a cured product is not particularly limited, and for example, the curable resin composition is applied to a substrate such as glass or a transparent plastic film and dried to form a coating film, and then photolithography. Can be formed by. Since the cured product of the present invention is produced from the curable resin composition having improved developability, reduced pattern formation time, and improved productivity, it has high productivity while maintaining a high elastic recovery rate.

  At the time of development, it is preferable to use an alkaline aqueous solution. Highly sensitive development can be performed with less environmental load. As the alkaline component, potassium hydroxide, sodium hydroxide, sodium carbonate and the like are preferable. The alkali concentration is preferably 0.01 to 5% by mass, more preferably 0.02 to 3% by mass, and most preferably 0.03 to 1% by mass. If the alkali concentration is lower than the above range, the curable resin may have insufficient solubility. On the contrary, if the alkali concentration is high, the solubility may be too high and the developability may be poor. Further, a surfactant may be added to the alkaline aqueous solution.

In photolithography, for example, a UV aligner (TME-150RNS, manufactured by TOPCON) equipped with a 2.0 kW ultra-high pressure mercury lamp with a photomask placed at a distance of about 150 μm from the coating film has an intensity of 50 mJ / cm ² ( The coating film of the curable resin composition is photocured by irradiating with ultraviolet rays at an illumination intensity of 365 nm). After UV irradiation, 0.05 mass% potassium hydroxide aqueous solution was sprayed on the coating film for 40 seconds by a spin developing machine to dissolve and remove the unexposed area, and the remaining exposed area was washed with pure water for 10 seconds. By developing, a cured product (columnar molded body) can be obtained. After that, post baking (post heating) may be performed. The distance to the photomask, UV intensity, development conditions, etc. can be changed as appropriate.

4. Photospacer The photospacer of the present invention contains the above cured product. The photo spacer of the present invention can be obtained using the curable resin composition. By using the curable resin composition, it is possible to form a photospacer having excellent adhesion to a substrate and high elastic recovery and breaking strength. Furthermore, the photospacer of the present invention is excellent in shape by being produced by photolithography using the curable resin composition of the present invention. For example, it is possible to obtain a photo spacer 10 [FIG. 1 (a)] having substantially no difference in diameter in the height direction, or a photo spacer 20 [FIG. 1 (b)] whose upper portion is thinner than its lower portion. In the present specification, a shape having substantially no diameter difference in the height direction and a shape in which the upper portion is narrower than the lower portion are collectively referred to as a “non-inverted taper shape”.

  The photo spacer of the present invention can be suitably used as a spacer of a liquid crystal display, more specifically, a liquid crystal cell of a liquid crystal display.

  The photo spacer can be formed by photolithography. Specifically, the curable resin composition is applied to a substrate and then dried, and a photomask is placed on the obtained coating film to expose the coating film, and the coating film is cured, and then developed. Spacers can be formed. According to photolithography, a photo spacer can be formed at any position. For example, in a liquid crystal display device, a photo spacer is formed only on a black matrix to prevent deterioration of display characteristics due to the spacer. can do.

  Examples of the method for applying the curable resin composition include a method using a spin coater, a bar coater, a gravure coater, a roll coater, a knife coater, an applicator, or the like. The drying temperature is preferably 40 ° C to 200 ° C, more preferably 70 ° C to 100 ° C. The drying time is preferably 1 minute to 30 minutes, more preferably 2 minutes to 10 minutes.

  The photomask is arranged at any appropriate position according to the desired size of the photo spacer. The photomask is arranged on the coating film, and the distance between the coating film and the photomask is preferably 0 μm to 500 μm, more preferably 10 μm to 400 μm.

UV radiation intensity during the exposure (365 nm intensity equivalent), preferably ^{10mJ / cm 2 ~200mJ / cm 2} , more preferably ^{20mJ / cm 2 ~150mJ / cm 2} .

  An alkaline aqueous solution is preferably used for the development. This is because development with high sensitivity can be performed with less load on the environment. As the alkaline component, for example, potassium hydroxide, sodium hydroxide, sodium carbonate or the like is used. The alkali concentration of the alkaline aqueous solution is preferably 0.01% by mass to 5% by mass, more preferably 0.02% by mass to 3% by mass. Within such a range, the photocurable resin composition can be appropriately dissolved to form the photospacer with good developability. A surfactant may be further added to the alkaline aqueous solution.

  Post-baking may be performed after the development. The heating temperature during post-baking is preferably 150 ° C to 300 ° C, more preferably 180 ° C to 250 ° C. The heating time is preferably 10 minutes to 90 minutes, more preferably 20 minutes to 60 minutes. When the curable resin composition of the present invention contains an alkali-soluble resin having a constitutional unit having two or more oxyalkylene groups in its side chain, post-baking can form a photospacer having a high crosslink density.

Examples of the shape of the photo spacer of the present invention include a cylindrical shape, a prism shape, a truncated cone shape, and a truncated pyramid shape. Thickness at the bottom of the photo spacers, in terms of the horizontal cross-sectional area of the photo spacers, preferably 3μm ² ~500μm ^2, more preferably 15μm ² ~100μm ^2. When the shape of the photo spacer is a cylindrical shape or a truncated cone shape, the diameter at the bottom of the photo spacer can be set to any appropriate range. Practically, the thickness is preferably 2 μm to 20 μm, more preferably 3 μm to 10 μm. The height of the photo spacers can be set to any suitable height depending on the desired substrate spacing. The height of the photo spacer is, for example, 1 μm to 10 μm.

  As described above, the photo spacer of the present invention preferably has a non-inverted taper shape. The horizontal cross-sectional area A1 of the portion H1 distant from the bottom of the photo spacer in the height direction (photo spacer height L × 1/2) and the height direction from the bottom of the photo spacer (photo spacer height L × 1 / 4) The ratio (A2 / A1) of the distant portion H2 to the horizontal sectional area A2 is preferably 1 to 1.3, more preferably 1 to 1.2. The photo spacer having A2 / A1 in such a range has excellent substrate adhesion, and has high elastic recovery rate and breaking strength. Further, the photo spacer can prevent bubbles from being mixed into the liquid crystal layer and contribute to improvement in display performance of the display device.

  In one embodiment, the compressibility of the photospacer of the present invention is 10% to 90%. The method of evaluating the compression rate will be described later.

  The lower limit of the elastic recovery rate of the photospacer of the present invention is preferably 55% or more, more preferably 60% or more, and further preferably 65% or more. The larger the elastic recovery rate, the more preferable. The upper limit of the elastic recovery rate of the photo spacer of the present invention is, for example, 100%. By using the photo spacer having a high elastic recovery rate, it is possible to solve the problem in manufacturing the liquid crystal cell. The method for evaluating the elastic recovery rate will be described later.

  In one embodiment, when the diameter of the lowermost photo spacer having a cylindrical or truncated cone shape is 6 μm to 8 μm, the elastic recovery rate of the photo spacer of the present invention is preferably 65% to 100%. Is.

  The relationship between the elastic recovery rate b (%) of the photo spacer of the present invention and the diameter a (μm) at the bottom of the photo spacer when the shape of the photo spacer is columnar or truncated cone is a practical diameter. In the range of a, preferably b> 3.1a + 45.

  The breaking strength of the photospacer of the present invention is preferably 20 mN or more (for example, 20 to 300 mN), more preferably 50 mN or more. The larger the breaking strength, the more preferable.

  In one embodiment, when the photo spacer having a cylindrical or truncated cone shape has a diameter of 6 μm to 8 μm at the bottom, the fracture strength of the photo spacer of the present invention is preferably 145 mN to 300 mN.

5. Display Device The present invention also includes a display device (preferably a liquid crystal display device) using the photo spacer of the present invention. As a basic configuration mode of a liquid crystal display device, (a) a driving side substrate on which driving elements such as thin film transistors (TFTs) and pixel electrodes (conductive layers) are arranged, and a counter electrode (conductive layer) are provided. A structure in which a counter substrate and a counter substrate are arranged so as to face each other with a photo spacer interposed therebetween, and a liquid crystal material is sealed in a gap between the counter substrate, and (b) a drive substrate and a counter substrate having a counter electrode (conductive layer) as a photo spacer The liquid crystal display device of the present invention can be suitably applied to various liquid crystal display devices. The configuration and materials used for the liquid crystal display device are not particularly limited, and any known configuration and material can be adopted. For example, the configurations and materials disclosed in JP 2011-180549 A and JP 2009-162871 A can be adopted.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The evaluation of the examples and comparative examples was performed as follows. Moreover, below, a part means a mass part and% means the mass%.

[Evaluation methods]
(1) Weight average molecular weight: Mw
THF was used as an eluent with GPC (HLC-8220GPC, manufactured by Tosoh Corp.), and TSKgel Super HZM-N (manufactured by Tosoh Corp.) was used as a column, and the standard polystyrene was calculated.

(2) Solid content The copolymer solutions prepared in Examples A-1 to A-8, Reference Example A-9, Examples A-10 to A-13, and Comparative Examples A-14 to A-18 were aluminum cups. About 0.3 g was weighed out, and about 1 g of acetone was added to dissolve it, followed by air drying at room temperature. Then, using a hot air dryer (trade name: PHH-101, manufactured by ESPEC CORPORATION), the product was dried at 140 ° C. for 3 hours, then allowed to cool in a desiccator, and the weight was measured. From the weight reduction amount, the weight of the solid content (acrylic resin) of the polymer solution was calculated.

(3) Acid Value The copolymer solutions prepared in Examples A-1 to A-8, Reference Example A-9, Examples A-10 to A-13 and Comparative Examples A-14 to A-18 were 1. 5 g was precisely weighed, dissolved in a mixed solvent of 90 g of acetone and 10 g of water, and titrated with a 0.1 N KOH aqueous solution. The titration was performed using an automatic titrator (trade name: COM-555, manufactured by Hiranuma Sangyo Co., Ltd.), and the acid value per 1 g of the polymer was determined from the solid content concentration (mgKOH / g).

(4) Thermal decomposition resistance To 2 g of the copolymer solutions prepared in Examples A-1 to A-8, Reference Example A-9, Examples A-10 to A-13 and Comparative Examples A-14 to A-18. The solution obtained by adding 4 g of tetrahydrofuran was dropped into 60 g of hexane, and the precipitated acrylic resin was separated and taken out, followed by vacuum drying at 40 ° C. overnight. 10 mg of the obtained acrylic resin powder was weighed, and the weight loss rate at 230 ° C. for 30 minutes in a nitrogen atmosphere was measured using a thermogravimetric analyzer TGA-50 (manufactured by SHIMADZU).

(5) Evaluation of developability The curable resin composition was applied onto a 10 cm square glass substrate by a spin coater, and dried in an oven at 90 ° C for 3 minutes. After drying, a pattern photomask of 8 μmφ was placed at a distance of 100 μm from the coating film, and an intensity of 50 mJ / cm ² was applied by a UV aligner (TME-150RNS, manufactured by TOPCON) equipped with an ultrahigh pressure mercury lamp of 2.0 kW. The sample was irradiated with ultraviolet rays (converted to illuminance of 365 nm). After UV irradiation, a 0.05% aqueous solution of potassium hydroxide was sprayed on the coating film by a spin developing machine for 20 to 90 seconds to dissolve and remove the unexposed area, and the remaining exposed area was washed with pure water to 10 times. It was developed by washing with water for 2 seconds. The spacer formed after development was confirmed with a laser microscope (VK-9700, manufactured by Keyence Corporation), and the development speed was evaluated by the shortest time (break time) at which the unexposed portion was completely removed.
Regarding the development residue, after development, the presence or absence of unmelting residue of the curable resin composition was evaluated by visual observation.

(6) Adhesion of Photo Spacer The presence or absence of defects in the formed photo spacer was visually observed and evaluated according to the following criteria.
◯: No adhesion and very good adhesion Δ: Partially deficiency and good adhesion ×: Total deficiency, poor adhesion

(7) Compressibility of Photo Spacer The compressibility of the photo spacer was measured using a micro compression tester (trade name: HM2000, manufactured by Fisher Instruments). With a 100 μm square flat indenter, the load speed and unloading speed were both 4.7 mN / sec, a load of up to 80 mN was applied, and then unloading to 0.49 mN was performed. A load-deformation amount curve at time was created. At this time, the compression rate was calculated by the following equation, with the deformation amount under load of 80 mN under load being L1.
Compressibility (%) = L1 × 100 / spacer height

(8) Elastic Recovery Rate of Photospacer The elastic recovery rate of the photospacer was measured using a micro compression tester (trade name: HM2000, manufactured by Fisher Instruments). With a 100 μm square flat indenter, the load speed and unloading speed were both 4.7 mN / sec, a load of up to 80 mN was applied, and then unloading to 0.49 mN was performed. A load-deformation amount curve at time was created. At this time, the elastic recovery rate was calculated by the following formula, with the amount of deformation under load of 80 mN under load being L1 and the amount of deformation under load of 0.49 mN during unloading being L2.
Elastic recovery rate (%) = (L1-L2) × 100 / L1

(9) Breaking Strength of Photo Spacer The breaking strength of the photo spacer was measured using a micro compression tester (trade name: HM2000, manufactured by Fisher Instruments). A load of up to 300 mN was applied with a 100 μm square flat indenter at a load speed and a unloading speed of both 4.7 mN / sec, and the load when the spacer was broken was read from the load-deformation amount curve.

(10) Thickness (diameter of horizontal cross section) and height of photo spacer The diameter and height of the photo spacer were measured using a laser microscope (trade name "VK-9700", manufactured by Keyence Corporation).

[Example A-1]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, in a monomer dropping tank, as a monomer composition, 15 g of benzylmaleimide (BzMI), 44.5 g of acrylic acid (AA), 1 mol of ethoxylated phenylphenol acrylate (trade name "HRD-01", manufactured by Nippon Distilling Co., Ltd., below. HRD-01) 40.5 g, t-butylperoxy-2-ethylhexanoate (trade name "Perbutyl (registered trademark) O", manufactured by NOF CORPORATION, hereinafter also referred to as PBO) 2 g, propylene glycol methyl ether 48 g of acetate (PGMEA) and 12 g of propylene glycol monomethyl ether (PGME) were added and mixed with stirring. Further, 1.1 g of dodecyl mercaptan (nDM), 21 g of PGMEA and 5 g of PGME were charged as a chain transfer agent solution into the chain transfer agent dropping tank, and mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Then, in the reaction tank, 69 g of glycidyl methacrylate (GMA), 0.3 g of 6-tert-butyl-2,4-xylenol (trade name "topanol", manufactured by Tokyo Chemical Industry Co., Ltd.) as a polymerization inhibitor, and dimethylbenzyl as a catalyst. 0.5 g of amine (DMBA), 18 g of PGMEA, and 4 g of PGME were charged and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-1) containing 39.1 weight% of acrylic resin (alkali-soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 24,000, the acid value was 54 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.3%. The production conditions of the copolymer solution, the solid content concentration, the weight average molecular weight (Mw), the acid value, and the weight loss rate at 230 ° C. for 30 minutes were measured in Examples A-2 to A-13 and Comparative Examples A-14 to A-18. In addition, it is shown in Table 1.

[Example A-2]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 15 g of BzMI, 55 g of AA, 30 g of HRD-01, 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into the monomer dropping tank as a monomer composition, and mixed with stirring. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-2) containing acrylic resin (alkali-soluble resin) 39.3 weight%. The weight average molecular weight (Mw) of the acrylic resin was 24500, the acid value was 103 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.8%.

[Example A-3]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 42 g of AA, 43 g of HRD-01, 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank, and mixed with stirring. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-3) containing acrylic resin (alkali-soluble resin) 39.0 weight%. The weight average molecular weight (Mw) of the acrylic resin was 22,500, the acid value was 44 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.4%.

[Example A-4]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 40.5 g of HRD-01, 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank and stirred and mixed. Further, 0.8 g of nDM, 21 g of PGMEA, and 5 g of PGME were added as a chain transfer agent solution into the chain transfer agent dropping tank, and mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-4) containing acrylic resin (alkali soluble resin) 39.5weight%. The weight average molecular weight (Mw) of the acrylic resin was 30,200, the acid value was 56 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.1%.

[Example A-5]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 40.5 g of HRD-01, 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank and stirred and mixed. In addition, 0.2 g of nDM, 21 g of PGMEA and 5 g of PGME were added as a chain transfer agent solution into the chain transfer agent dropping tank, and mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-5) containing acrylic resin (alkali-soluble resin) 39.8 weight%. The weight average molecular weight (Mw) of the acrylic resin was 40100, the acid value was 55 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.0%.

[Example A-6]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, in the monomer dropping tank, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 38.5 g of HRD-01, methoxy polyethylene glycol (400) acrylate (trade name "light acrylate 130A", manufactured by Kyoeisha Chemical Co., Ltd., ethylene oxide mole). 2g (Pin number n = 9, hereinafter also referred to as 130A), 2g of PBO, 48g of PGMEA and 12g of PGME were charged and mixed with stirring. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-6) containing 39.3 weight% of acrylic resin (alkali-soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 24100, the acid value was 56 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.3%.

[Example A-7]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 20.5 g of HRD-01, 20 g of dicyclopentanyl acrylate (DCPA), 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank, and mixed with stirring. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-7) containing 39.0 weight% of acrylic resin (alkali soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 24500, the acid value was 53 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.5%.

[Example A-8]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 20.5 g of HRD-01, 20 g of benzyl acrylate (BzA), 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank, and mixed with stirring. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-8) containing 39.2 weight% of acrylic resin (alkali soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 24800, the acid value was 54 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.6%.

[ Reference Example A-9]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 10 g of BzMI, 76 g of AA, 14 g of HRD-01, 2 g of PBO, 30 g of PGMEA and 30 g of PGME were put into a monomer dropping tank as a monomer composition, and mixed with stirring. Moreover, nDM1.6g, PGMEA13g, and PGME13g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it stirred and mixed.

  70 g of PGMEA and 70 g of PGMEA were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 124 g of GMA, 0.3 g of topanol, 0.7 g of DMBA as a catalyst, 53 g of PGMEA, and 53 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 12 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-10) containing 39.6 weight% of acrylic resin (alkali-soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 23400, the acid value was 54 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.9%.

[Example A-10]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 23 g of AA, 62 g of HRD-01, 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank and stirred and mixed. Further, 1.2 g of nDM, 21 g of PGMEA and 5 g of PGME were added as a chain transfer agent solution into the chain transfer agent dropping tank, and mixed by stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 30 g of GMA, 0.3 g of topanol as a polymerization inhibitor and 0.5 g of DMBA as a catalyst were charged into a reaction tank, and the reaction was carried out at 110 ° C. for 1 hour and 115 ° C. for 8 hours. Then, the mixture was cooled to room temperature to obtain a copolymer solution (A-10) containing 35.0% by weight of an acrylic resin (alkali-soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 23,000, the acid value was 56 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 0.8%.

[Example A-11]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, in the monomer dropping tank, as a monomer composition, dimethyl-2,2 '-[oxybis (methylene)] bis-2-propenoate (MD) 15g, AA44.5g, HRD-01 40.5g, PBO2g, PGMEA48g. And 12 g of PGME were added and mixed with stirring. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-11) containing 39.0 weight% of acrylic resin (alkali-soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 23800, the acid value was 53 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.3%.

[Example A-12]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of (α-allyloxymethyl) methyl acrylate (AMA), 44.5 g of AA, 40.5 g of HRD-01, 2 g of PBO, 48 g of PGMEA and 12 g of PGME were put into a monomer dropping tank and stirred and mixed. did. Moreover, nDM1.1g, PGMEA21g, and PGME5g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  After 112 g of PGMEA and 28 g of PGME were charged into a reaction tank and the atmosphere was replaced with nitrogen, the temperature of the reaction tank was raised to 90 ° C. by heating with an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, in a reaction tank, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 18 g of PGMEA and 4 g of PGME were charged, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-12) containing 39.1 weight% of acrylic resin (alkali soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 23700, the acid value was 54 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.4%.

[Example A-13]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 30 g of BzMI, 44.5 g of AA, 25.5 g of HRD-01, 1.5 g of PBO, 42 g of PGMEA, and 18 g of PGME were put into the monomer dropping tank as a monomer composition, and mixed with stirring. In addition, 0.3 g of nDM, 18 g of PGMEA and 8 g of PGME were added as a chain transfer agent solution into the chain transfer agent dropping tank, and mixed with stirring.

  98 g of PGMEA and 42 g of PGME were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 16 g of PGMEA, and 6 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-13) containing 39.5 weight% of acrylic resin (alkali soluble resin). The weight average molecular weight (Mw) of the acrylic resin was 24100, the acid value was 55 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 1.2%.

[Comparative Example A-14]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 15 g of BzMI, 44.5 g of AA, 40.5 g of HRD-01, 2 g of PBO, 42 g of PGMEA and 18 g of PGME were put into a monomer dropping tank as a monomer composition, and mixed with stirring. Moreover, nDM2g, PGMEA18g, and PGME8g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it stirred and mixed.

  98 g of PGMEA and 42 g of PGME were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 16 g of PGMEA, and 6 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-14) containing acrylic resin 39.1weight%. The weight average molecular weight (Mw) of the acrylic resin was 17,500, the acid value was 54 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 3.2%.

[Comparative Example A-15]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, 15 g of BzMI, 44.5 g of AA, 40.5 g of HRD-01, 2 g of PBO, 42 g of PGMEA and 18 g of PGME were put into a monomer dropping tank as a monomer composition, and mixed with stirring. Moreover, nDM5g, PGMEA18g, and PGME8g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it mixed with stirring.

  98 g of PGMEA and 42 g of PGME were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 16 g of PGMEA, and 6 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and the copolymer solution (A-15) containing acrylic resin 38.8 weight% was obtained. The weight average molecular weight (Mw) of the acrylic resin was 10,400, the acid value was 55 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 5.1%.

[Comparative Example A-16]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, BgMI15g, AA44.5g, HRD-01 38.5g, 130A2g, PBO2g, PGMEA42g and PGME18g were thrown in and mixed with a monomer dropping tank as a monomer composition. Moreover, nDM2g, PGMEA18g, and PGME8g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it stirred and mixed.

  98 g of PGMEA and 42 g of PGME were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 16 g of PGMEA, and 6 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-16) containing acrylic resin 39.4 weight%. The weight average molecular weight (Mw) of the acrylic resin was 17,500, the acid value was 55 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 3.1%.

[Comparative Example A-17]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 20.5 g of HRD-01, 20 g of DCPA, 2 g of PBO, 42 g of PGMEA and 18 g of PGME were put into a monomer dropping tank and stirred and mixed. Moreover, nDM2g, PGMEA18g, and PGME8g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it stirred and mixed.

  98 g of PGMEA and 42 g of PGME were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 16 g of PGMEA, and 6 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-17) containing 39.1 weight% of acrylic resin. The weight average molecular weight (Mw) of the acrylic resin was 17,800, the acid value was 56 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 3.6%.

[Comparative Example A-18]
A separable flask equipped with a cooling tube was prepared as a reaction tank. On the other hand, as a monomer composition, 15 g of BzMI, 44.5 g of AA, 20.5 g of HRD-01, 20 g of BzA, 20 g of PBO, 42 g of PGMEA and 18 g of PGME were put into a monomer dropping tank, and mixed with stirring. Moreover, nDM2g, PGMEA18g, and PGME8g were thrown in as a chain transfer agent solution in the chain transfer agent dropping tank, and it stirred and mixed.

  98 g of PGMEA and 42 g of PGME were charged into a reaction tank, and after nitrogen substitution, the temperature of the reaction tank was raised to 90 ° C. by heating in an oil bath while stirring. After the temperature of the reaction tank was stabilized at 90 ° C., the monomer composition and the chain transfer agent solution were added dropwise. The monomer composition and the chain transfer agent solution were added dropwise over 180 minutes while maintaining the temperature at 90 ° C. 30 minutes after the dropping was completed, 0.5 g of PBO was added. After a further 30 minutes, the temperature of the reaction vessel was raised to 115 ° C. After maintaining the temperature at 115 ° C. for 1.5 hours, a gas introduction tube was attached to the separable flask, and bubbling of oxygen / nitrogen = 7/93 (v / v) mixed gas was started. Next, 69 g of GMA, 0.3 g of topanol as a polymerization inhibitor, 0.5 g of DMBA as a catalyst, 16 g of PGMEA, and 6 g of PGME were charged into a reaction tank, and reacted at 110 ° C. for 1 hour and at 115 ° C. for 8 hours. Then, it cooled to room temperature and obtained the copolymer solution (A-18) containing acrylic resin 39.4weight%. The weight average molecular weight (Mw) of the acrylic resin was 17,400, the acid value was 54 mgKOH / g, and the weight loss rate at 230 ° C. for 30 minutes was 3.5%.

[Example 1]
89 g of the above copolymer solution (A-1) (that is, 35 g of acrylic resin), 65 g of tripentaerythritol octaacrylate (trade name "Biscoat # 802", manufactured by Osaka Organic Chemical Co., Ltd.) as a polyfunctional monomer, and photopolymerization initiation. As an agent, 1.7 g of 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one (trade name “IRGACURE (registered trademark) 907”, manufactured by BASF Japan Ltd.) and a UV absorber As a mixture of 0.5 g of 2- (2-hydroxy-4-octoxyphenyl) -2H-benzotriazole (trade name "SEESORB707" manufactured by Cipro Kasei Co., Ltd., hereinafter referred to as SB707), the solid content concentration becomes 35% by weight. PGMEA, and filter with a filter with a pore size of 0.5 μm The composition was prepared.

The photosensitive resin composition for photo spacers was applied onto a 10 cm square glass substrate by a spin coater and dried in an oven at 90 ° C. for 3 minutes. After drying, a photomask was placed at a distance of 100 μm from the coating film, and an intensity of 50 mJ / cm ² was applied by a UV aligner (trade name “TME-150RNS” manufactured by TOPCON) equipped with a 2.0 kW ultra-high pressure mercury lamp ( The film was irradiated with ultraviolet rays at 365 nm illuminance conversion). After UV irradiation, 0.05% potassium hydroxide aqueous solution is sprinkled on the coating film by a spin developing machine for 20 to 90 seconds to dissolve and remove the unexposed area, and the remaining exposed area is washed with pure water for 10 seconds. By doing so, development was performed to form a cylindrical photo spacer. At this time, the shortest development time (break time) capable of forming a spacer and the presence or absence of a development residue were confirmed [Evaluation (5)], and the obtained photospacer was subjected to the above evaluations (6) to (10). The results are shown in Table 2.

[Examples 2 to 19, Reference Example 20, Examples 21 to 24]
A photospacer was formed in the same manner as in Example 1 except that the composition of the photosensitive resin composition for photospacer was changed to the composition shown in Table 2, and the same evaluation as in Example 1 was performed. The results are shown in Table 2.
In Table 2, dipentaerythritol hexaacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) is described as “DPHA”, and pentaerythritol tetraacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) is described as “PETA”.
Regarding the UV absorber, in Table 2, the trade name "Tinuvin 479" manufactured by BASF Japan Ltd. is described as "T479".

[Comparative Examples 1 to 7]
A photospacer was formed in the same manner as in Example 1 except that the composition of the photosensitive resin composition for photospacer was changed to the composition shown in Table 3, and the same evaluation as in Example 1 was performed. The results are shown in Table 3.

  As shown in Table 1, in the alkali-soluble resins of Examples, the weight loss rate measured at 230 ° C for 30 minutes was as low as 0 to 3.0%, and the thermal decomposition resistance was improved. Furthermore, the alkali-soluble resins of the examples were compatible with various polyfunctional monomers. Therefore, the alkali-soluble resin of the present invention can be applied to commonly used polyfunctional monomers.

Further, as shown in Tables 2 and 3, by using a curable resin composition containing a specific alkali-soluble resin in which the weight average molecular weight of the alkali-soluble resin is 22000 or more, the developability is improved and the development residue is reduced. It was possible to form a photospacer having excellent adhesion without causing it. In the comparative example, the break time was 70 or more, but in the example, it was confirmed that the break time was significantly improved to 25 to 40, and a remarkable effect on the developability was obtained.
Further, even when the ratio of (alkali-soluble resin) / (polyfunctional monomer) is in the range of 40/60 to 10/90, the elastic recovery rate of the obtained photospacer is more excellent as the development time is shortened, and the elastic recovery is improved. Even if a large amount of polyfunctional monomer was used to improve the rate, the unique effect that the developing time (break time) could be shortened was obtained.

  INDUSTRIAL APPLICABILITY The alkali-soluble resin of the present invention and the curable resin composition containing the same can be suitably used for producing spacers for liquid crystal cells. It can also be used as a material for a color filter, an overcoat, an insulating film, a protective film, or the like. Furthermore, it can also be used as a photocurable coating material or a photocurable ink.

10, 20 Photo spacer

Claims (6)

(A1) a monomer containing an acid group and / or (a2) a monomer capable of providing an acid group after polymerization, (a) a monomer capable of introducing an acid group into a side chain, an aromatic-substituted maleimide, an alkyl-substituted maleimide, And the following general formula (8) or (9)
[In said general formula (8)-(9), R < ¹¹ >, R < ¹² >, R < ¹³ > is a hydrogen atom or a C1-C30 linear or branched alkyl group each independently. ]
A base polymer synthesized from a monomer component containing at least one monomer selected from the group consisting of 1,6-dienes represented by: and capable of introducing an acid group into the side chain (a). When the monomer (a2) is a monomer capable of imparting an acid group after the polymerization, it is a base polymer which has been subjected to a post-treatment for imparting an acid group after the polymerization, or the base polymer has a carbon-carbon dimer. An alkali-soluble resin that is a polymer obtained by introducing a heavy bond,
The content of the monomer capable of introducing an acid group into the side chain (a) is 10% by mass or more and 80% by mass or less in 100% by mass of all the monomer components used for synthesizing the base polymer,
The content of at least one monomer selected from the group consisting of the aromatic-substituted maleimides, the alkyl-substituted maleimides, and the 1,6-dienes represented by the general formula (8) or (9) is 2% by mass to 50% by mass in 100% by mass of all monomer components used for synthesizing the base polymer,
The weight average molecular weight is 22,000 or more,
The weight loss rate measured in a nitrogen atmosphere at 230 ° C. for 30 minutes using a thermogravimetric measuring device is 0 to 3.0%,
The monomer component is further represented by the following general formula (C)
[In the general formula (C), R ¹ , R ² and R ³ are each independently a hydrogen atom or a methyl group; R 4 is an aromatic hydrocarbon group having 2 or more aromatic rings and having 10 to 20 carbon atoms. AO is an oxyalkylene group having 2 to 20 carbon atoms; x is an integer of 0 to 2; y is 0 or 1; m represents the average number of moles of the oxyalkylene group added, and is less than 1.2. ]
Which has a (c1) oxyalkylene group and contains a monomer that introduces two or more aromatic rings at the end of the side chain,
Among the monomers having the (c1) oxyalkylene group and introducing two or more aromatic rings at the ends of the side chains, (c2) the oxyalkylene group having an oxyalkylene chain length of 1 and the end of the side chain The content of the monomer that introduces two or more aromatic rings into 20% by mass or more based on 100% by mass of the monomer component,
Alkali-soluble resin. A curable resin composition comprising the alkali-soluble resin according to claim 1 and a polyfunctional monomer. The curable resin composition according to claim 2, wherein the polyfunctional monomer has a functionality of 4 to 10.   A cured product obtained by curing the curable resin composition according to claim 2.   A photospacer comprising the cured product according to claim 4.   A display device comprising the photo spacer according to claim 5.