JP2017110120A - Photocurable resin composition, display element sealing agent and liquid crystal display panel and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable resin composition having high curability with respect to visible light when used as a liquid crystal sealing agent and capable of highly suppressing contamination in a liquid crystal.SOLUTION: The photocurable resin composition comprises: a curable compound (A) having an ethylenically unsaturated double bond in the molecule; a sensitizer (B) having an aminobenzoyl skeleton and an NHCO group in the molecule and having 300 g/eq or less NHCO group equivalent represented by formula (I): (NHCO group equivalent (g/eq))=(molecular weight)/(number of NHCO groups included in one molecule); and a polymerization initiator (C) excluding a polymerization initiator having an aminobenzoyl skeleton in the molecule.SELECTED DRAWING: None

Description

  The present invention relates to a photocurable resin composition, a display element sealing agent, a liquid crystal display panel, and a method for producing the same.

  In recent years, display panels such as liquid crystal and organic EL have been widely used as image display panels for various electronic devices such as mobile phones and personal computers. For example, a liquid crystal display panel includes two transparent substrates having electrodes provided on the surface, a frame-shaped sealing member sandwiched between them, and a liquid crystal material sealed in a region surrounded by the sealing member And have.

  The liquid crystal display panel can be manufactured by, for example, a liquid crystal dropping method. Production of a liquid crystal display panel by a liquid crystal dropping method is as follows: (1) A liquid crystal sealing agent is applied to the inner edge of a transparent substrate to form a frame for filling with liquid crystal; (2) Liquid crystal is dropped into the frame; (3) After superposing two substrates under high vacuum while the liquid crystal sealant is in an uncured state, (4) curing the liquid crystal sealant.

  Thus, in the liquid crystal dropping method, photocuring or thermosetting is performed in a state where the uncured liquid crystal sealant and the liquid crystal material are in contact with each other. Therefore, the liquid crystal sealant is required not only to have high curability but also to reduce contamination of the liquid crystal material.

  As a liquid crystal sealant used in the liquid crystal dropping method, a photopolymerizable oligomer, dimethylaminobenzoic acid and a compound A (photoinitiating compound) obtained by reacting a compound containing two or more epoxy groups in the molecule; A photocurable resin composition containing a compound B (visible light sensitizing compound) obtained by reacting hydroxythioxanthone with a compound having two or more epoxy groups in the molecule has been proposed (for example, Patent Document 1). ). In addition, a sealing agent for liquid crystal display elements including a curable resin, a thioxanthone polymerization initiator, and an amine sensitizer having an aminobenzoyl skeleton has been proposed (for example, Patent Document 2). Furthermore, a sealing agent for liquid crystal display elements including a curable resin and a compound (photopolymerization initiator) obtained by reacting an oxime ester and a polyfunctional isocyanate has been proposed (for example, Patent Document 3).

International Publication No. 2012/0777720 Japanese Patent No. 5759638 JP 2014-98763 A

  However, since the composition shown in Patent Document 3 contains a photopolymerization initiator having low light absorption in the visible light region, the curability to light in the visible light region is low. Since the compositions shown in Patent Documents 1 and 2 contain a compound having an aminobenzoyl skeleton as a photopolymerization initiator or sensitizer, the curability to light in the visible light region is good. It was not possible to sufficiently suppress the elution of the contained compound into the liquid crystal material. Thus, it is desired to provide a photocurable resin composition that has high curability with respect to light in the visible light region and can highly suppress liquid crystal contamination.

  The present invention has been made in view of the above problems. For example, when used as a display element sealant, particularly as a liquid crystal sealant, the photocurability is high in visible light curing and can highly suppress liquid crystal contamination. It aims at providing a resin composition.

（式（４）において、
Ｘは、単結合、炭素数１〜１０のアルキレン基、炭素数１〜１０のアルキレンオキシ基、炭素数６〜１０のアリーレン基、炭素数６〜１０のアリーレンオキシ基又は炭素数６〜１０のアリーレンチオ基を表し、
Ｒ_１及びＲ_２は、それぞれ独立して水素原子又は炭素数１〜１０のアルキル基を表し、
Ｙは、分子内に少なくともｍ個のイソシアネート基を有する化合物から誘導される有機基を表し、
ｍは、１〜５の整数を表す）
［５］ 前記増感剤（Ｂ）の含有量が、前記硬化性化合物（Ａ）に対して０．０１〜１０質量％である、［１］〜［４］のいずれかに記載の光硬化性樹脂組成物。
［６］ 前記重合開始剤（Ｃ）が、チオキサントン骨格を有する、［１］〜［５］のいずれかに記載の光硬化性樹脂組成物。
［７］ 前記硬化性化合物（Ａ）が、分子内にエポキシ基をさらに有する、［１］〜［６］のいずれかに記載の光硬化性樹脂組成物。
［８］ ［１］〜［７］のいずれかに記載の光硬化性樹脂組成物からなる、表示素子シール剤。
［９］ ［８］に記載の表示素子シール剤を用いて、一方の基板にシールパターンを形成する工程と、前記シールパターンが未硬化の状態において、前記シールパターンの領域内、又は前記一方の基板と対になる他方の基板に液晶を滴下する工程と、前記一方の基板と前記他方の基板とを、前記シールパターンを介して重ね合わせる工程と、前記シールパターンを硬化させる工程とを含む、液晶表示パネルの製造方法。
［１０］ 前記シールパターンを硬化させる工程は、前記シールパターンに光を照射して前記シールパターンを硬化させる工程を含む、［９］に記載の液晶表示パネルの製造方法。
［１１］ 前記シールパターンに照射する光は、可視光領域の光を含む、［１０］に記載の液晶表示パネルの製造方法。
［１２］ 一対の基板と、前記一対の基板の間に配置された枠状のシール部材と、前記一対の基板の間の前記シール部材で囲まれた空間に充填された液晶層とを含み、前記シール部材が、［８］に記載の表示素子シール剤の硬化物である、液晶表示パネル。 [1] A curable compound (A) having an ethylenically unsaturated double bond in the molecule, an aminobenzoyl skeleton and an NHCO group in the molecule, and an NHCO group equivalent represented by the formula (I) is 300 g. The photocurable resin composition containing the sensitizer (B) which is / eq or less, and a polymerization initiator (C).
Formula (I): NHCO group equivalent (g / eq) = molecular weight / number of NHCO groups contained in one molecule [2] The sensitizer (B) has 3 or more NHCO groups in the molecule [1 ] The photocurable resin composition of description.
[3] The photocurable resin composition according to [1] or [2], wherein the sensitizer (B) has a burette skeleton or an allophanate skeleton in the molecule.
[4] The photocurable resin composition according to any one of [1] to [3], wherein the sensitizer (B) is a compound represented by the following formula (4).

(In Formula (4),
X is a single bond, an alkylene group having 1 to 10 carbon atoms, an alkyleneoxy group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an aryleneoxy group having 6 to 10 carbon atoms, or an alkyl group having 6 to 10 carbon atoms. Represents an arylenethio group,
R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
Y represents an organic group derived from a compound having at least m isocyanate groups in the molecule;
m represents an integer of 1 to 5)
[5] The photocuring according to any one of [1] to [4], wherein the content of the sensitizer (B) is 0.01 to 10% by mass with respect to the curable compound (A). Resin composition.
[6] The photocurable resin composition according to any one of [1] to [5], wherein the polymerization initiator (C) has a thioxanthone skeleton.
[7] The photocurable resin composition according to any one of [1] to [6], wherein the curable compound (A) further has an epoxy group in the molecule.
[8] A display element sealing agent comprising the photocurable resin composition according to any one of [1] to [7].
[9] Using the display element sealant according to [8], in the step of forming a seal pattern on one of the substrates, and in the state where the seal pattern is uncured, A step of dropping a liquid crystal on the other substrate paired with the substrate, a step of superimposing the one substrate and the other substrate through the seal pattern, and a step of curing the seal pattern. A method for manufacturing a liquid crystal display panel.
[10] The method for manufacturing a liquid crystal display panel according to [9], wherein the step of curing the seal pattern includes a step of irradiating the seal pattern with light to cure the seal pattern.
[11] The method for manufacturing a liquid crystal display panel according to [10], wherein the light applied to the seal pattern includes light in a visible light region.
[12] including a pair of substrates, a frame-shaped sealing member disposed between the pair of substrates, and a liquid crystal layer filled in a space surrounded by the sealing member between the pair of substrates, A liquid crystal display panel, wherein the seal member is a cured product of the display element sealant according to [8].

  According to the present invention, for example, when used as a display element sealant, particularly a liquid crystal sealant, it is an object to provide a photocurable resin composition that has high curability to visible light and can highly suppress liquid crystal contamination. And

1. Photocurable resin composition The photocurable resin composition of the present invention comprises a curable compound (A), a sensitizer (B), and a polymerization initiator (C), and is optionally thermosetting. It may further contain at least one of the compound (D), the thermosetting agent (E), and the other component (F).

1-1. Curable compound (A)
The curable compound (A) contained in the photocurable resin composition of the present invention is a compound having an ethylenically unsaturated double bond in the molecule. The compound having an ethylenically unsaturated double bond in the molecule is preferably a compound having a (meth) acryloyl group in the molecule. The number of (meth) acryloyl groups per molecule is 1 or 2 or more. The compound having a (meth) acryloyl group in the molecule may be a monomer, an oligomer or a polymer. (Meth) acryloyl group means acryloyl group or methacryloyl group, and (meth) acrylate means acrylate or methacrylate.

  Examples of compounds having one (meth) acryloyl group in one molecule include (meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid 2-hydroxyethyl ester. Alkyl esters are included.

  Examples of compounds having two or more (meth) acryloyl groups in one molecule include di (meth) acrylates such as polyethylene glycol, propylene glycol, and polypropylene glycol; di (meth) tris (2-hydroxyethyl) isocyanurate Acrylate; Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol; Diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A Di (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane; diol or tri (meth) acrylate of triol; Di (meth) acrylate of a diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; trimethylolpropane tri (meth) acrylate, or Pentaerythritol tri (meth) acrylate or oligomer thereof; poly (meth) acrylate of dipentaerythritol; tris (acryloxyethyl) isocyanurate; caprolactone-modified tris (acryloxyethyl) isocyanurate; caprolactone-modified tris (methacryloxyethyl) ) Isocyanurate; polyacrylate or polymethacrylate of alkyl-modified dipentaerythritol; polyacrylate of caprolactone-modified dipentaerythritol Hydroxypivalate neopentyl glycol diacrylate or dimethacrylate; caprolactone-modified hydroxypivalate neopentyl glycol di (meth) acrylate; ethylene oxide-modified phosphate acrylate or dimethacrylate; ethylene oxide-modified alkylated phosphate (meta ) Acrylate; neopentyl glycol, trimethylolpropane, pentaerythritol oligo (meth) acrylate and the like.

  The curable compound (A) may further have an epoxy group in the molecule. The number of epoxy groups per molecule is 1 or 2 or more. If the curable compound (A) has not only a (meth) acryloyl group but also an epoxy group in the molecule, the photocurable resin composition containing the curable compound (A) can be provided with photocurability and thermosetting. Thereby, the sclerosis | hardenability of hardened | cured material can be improved.

  The compound having a (meth) acryloyl group and an epoxy group in the molecule can be, for example, a (meth) acrylic acid glycidyl ester obtained by reacting an epoxy compound and (meth) acrylic acid in the presence of a basic catalyst. .

  The epoxy compound to be reacted may be a polyfunctional epoxy compound having two or more epoxy groups in the molecule, and suppresses the decrease in the adhesiveness of the cured product of the photocurable resin composition due to excessive increase in the crosslinking density. In view of this, a bifunctional epoxy compound is preferable. Examples of bifunctional epoxy compounds include bisphenol type epoxy compounds (bisphenol A type, bisphenol F type, 2,2′-diallyl bisphenol A type, bisphenol AD type, hydrogenated bisphenol type, etc.), biphenyl type epoxy compounds, And naphthalene type epoxy compounds. Of these, bisphenol A type and bisphenol F type bisphenol type epoxy compounds are preferred from the viewpoint of good coating properties. The bisphenol type epoxy compound has advantages such as excellent coating properties as compared with the biphenyl ether type epoxy compound.

  The compound having a (meth) acryloyl group and an epoxy group in the molecule may be one kind or a combination of two or more kinds.

  You may combine the compound (A1) which has a (meth) acryloyl group in a molecule | numerator, and does not have an epoxy group, and the compound (A2) which has a (meth) acryloyl group and an epoxy group in a molecule | numerator. Thereby, when the photocurable resin composition further contains an epoxy compound as the thermosetting compound (D), the epoxy compound and a compound having a (meth) acryloyl group in the molecule and no epoxy group Compatibility with (A1) can be improved. Moreover, since the photocurable resin composition contains a sensitizer (B) having appropriate hydrophilicity, the photocurable resin may contain a compound (A1) that is more hydrophobic than the compound (A2). The elution of the composition into a display element, particularly a liquid crystal can be suppressed. The mass ratio of the compound (A2) to the compound (A1) can be, for example, (A2) / (A1) = 1 / 0.4 to 1 / 0.6.

  Although content in particular of the compound (A2) which has a (meth) acryloyl group and an epoxy group in a molecule | numerator is not restrict | limited, For example, it may be 30 mass% or more with respect to the sum total of a sclerosing | hardenable compound (A).

  The weight average molecular weight of the curable compound (A) is preferably about 310 to 1,000. The weight average molecular weight of the curable compound (A) can be measured in terms of polystyrene by, for example, gel permeation chromatography (GPC).

  The content of the curable compound (A) is preferably 40 to 80% by mass and more preferably 50 to 75% by mass with respect to the photocurable resin composition.

1-2. Sensitizer (B)
The sensitizer (B) contained in the photocurable resin composition of the present invention has an aminobenzoyl skeleton and an NHCO group in the molecule.

The aminobenzoyl skeleton contained in the sensitizer (B) is represented by the following formula (1).

R ₁ and R _{2 in} the formula (1) each represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Especially, a C1-C10 alkyl group is preferable, a C1-C5 alkyl group is more preferable, and a methyl group is further more preferable.

  The number of aminobenzoyl skeletons per molecule is 1 or 2 or more. Even if the content of the sensitizer (B) is small, the number of aminobenzoyl skeletons per molecule is preferably 2 or more, from the viewpoint that sufficient sensitivity to light in the visible light region can be obtained. It is more preferable that

  Since the NHCO group contained in the sensitizer (B) exhibits appropriate hydrophilicity, the elution of the sensitizer (B) into the liquid crystal material can be preferably suppressed.

  The number of NHCO groups per molecule is 1 or 2 or more. From the viewpoint of highly suppressing elution of the sensitizer (B) into the liquid crystal material, the number of NHCO groups per molecule is preferably 2 or more, and more preferably 3 or more. The sensitizer (B) has a burette skeleton (—NHCO (N—) CONH—) or an allophanate skeleton (—NHCO (N—) COO—) from the viewpoint of easily increasing the number of NHCO groups per molecule. It is preferable to have.

  The sensitizer (B) may further have an ethylenically unsaturated double bond in the molecule. The sensitizer (B) further having an ethylenically unsaturated double bond in the molecule is, for example, a sensitizer because the sensitizer (B) and the curable compound (A) can undergo a polymerization reaction during curing. Elution to the liquid crystal material of (B) is easy to be suppressed.

  The sensitizer (B) may be an addition reaction product of “aminobenzoyl compound (b1) having a hydroxy group in the molecule” and “compound (b2) having an isocyanate group in the molecule”.

The “aminobenzoyl compound (b1) having a hydroxy group in the molecule” is represented by the following formula (2).

  X in Formula (2) is independently a single bond, an alkylene group having 1 to 10 carbon atoms (for example, a methylene group or an ethylene group), or an alkyleneoxy group having 1 to 10 carbon atoms (for example, a methyleneoxy group or an ethyleneoxy group). Etc.), an arylene group having 6 to 10 carbon atoms, an aryleneoxy group having 6 to 10 carbon atoms (for example, a phenyleneoxy group), or an arylenethio group having 6 to 10 carbon atoms (for example, a phenylenethio group). Among them, an alkylene group having 1 to 10 carbon atoms is preferable because the shift of the absorption wavelength due to the structure of X hardly occurs and the effect of sensitization due to the aminobenzoyl skeleton can be sufficiently obtained.

  A in the formula (2) is an integer of 1 or more, preferably 1. Although the substitution position of the group represented by — (CO—X—OH) is not limited, it is preferably a para position with respect to the amino group.

R ₁ and R _{2 in} Formula (2) each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Especially, a C1-C10 alkyl group is preferable, a C1-C5 alkyl group is more preferable, and a methyl group is further more preferable.

The compound represented by the formula (2) is preferably represented by the following formula (2 ′).

  The “compound (b2) having an isocyanate group in the molecule” is a compound having one or more isocyanate groups in the molecule. A compound having two or more isocyanate groups in the molecule is preferable in that the NHCO group equivalent of the obtained sensitizer (B) can be easily adjusted to a certain level or less. The number of isocyanate groups per molecule is not particularly limited, but is preferably 2 to 4 and more preferably 2 to 3 from the viewpoint that the NHCO group equivalent of the sensitizer (B) can be easily kept below a certain level. preferable.

The compound having two or more isocyanate groups in the molecule preferably further has an NHCO group in the molecule, and includes a burette skeleton (—NHCO (N—) CONH—), an allophanate skeleton (—NHCO (N—) COO— ) Or a urethane skeleton, more preferably a burette skeleton or an allophanate skeleton. That is, a compound having two or more isocyanate groups in the molecule can be represented by, for example, the following formula (3a) or (3b).

（式（γ）のＲ_５は、後述するポリオールに由来する飽和脂肪族炭化水素基又は芳香族炭化水素基を示し、ｎは１以上の整数である） R _{3 in} formula (3a) and R _{4 in} formula (3b) are each a linear, branched or cyclic saturated aliphatic hydrocarbon group or aromatic hydrocarbon group which may have an NHCO group. . The number of NHCO groups contained in R ₃ and R ₄ is 0 or 1 or more, and preferably 2 or more. R ₃ and R ₄ preferably include a structure represented by the following formula (α), (β) or (γ); and may have a structure represented by the following formula (α) or formula (β). More preferred.

(R _{5 in the} formula (γ) represents a saturated aliphatic hydrocarbon group or an aromatic hydrocarbon group derived from a polyol described later, and n is an integer of 1 or more)

  The compound having two or more isocyanate groups in the molecule may be, for example, a diisocyanate burette or allophanate, or a urethane prepolymer obtained by reacting a polyisocyanate and a polyol and having an isocyanate group at the molecular end. .

  Examples of diisocyanates used as raw materials for burettes or allophanates include aliphatic diisocyanates having 1 to 10 carbon atoms such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; cyclohexylene diisocyanate, hydrogenated C6-C15 alicyclic diisocyanate such as xylylene diisocyanate and isophorone diisocyanate; and C6-C15 such as tolylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate Aromatic diisocyanates are included.

  The polyisocyanate used as the raw material of the urethane prepolymer is a polyfunctional aliphatic, alicyclic or aromatic isocyanate, and examples thereof include the above-described diisocyanates. Examples of the polyol used as a raw material for the urethane prepolymer include aliphatic polyols such as ethylene glycol, 1,3-propanediol, polyethylene glycol, dipropylene glycol, and pentaerythritol; 1,4-cyclohexanedimethanol, 1,4- Examples include alicyclic polyols such as cyclohexanediol, hydrogenated bisphenol A, and hydrogenated bisphenol F; aromatic polyols such as phenol A and bisphenol F, and the like.

  In addition to the addition reaction of “aminobenzoyl compound (b1) having a hydroxy group in the molecule” and “compound (b2) having an isocyanate group in the molecule”, the “hydroxy group-containing compound (b3)” is further reacted. May be.

  The “hydroxy group-containing compound (b3)” is a compound having a hydroxy group in the molecule. The hydroxy group of the hydroxy group-containing compound (b3) can react with the isocyanate group of “a compound having two or more isocyanate groups in the molecule” to further form —O—CONH—. Examples of the hydroxy group-containing compound (b3) include monoalcohols having 1 to 20 carbon atoms such as methanol, ethanol, propanol, butanol, pentanol, hexanol, and 1-octadecanol.

  The hydroxy group-containing compound (b3) may further have an ethylenically unsaturated double bond. Thereby, an ethylenically unsaturated double bond can be further introduced into the sensitizer (B). Examples of the hydroxy group-containing compound (b3) having an ethylenically unsaturated double bond in the molecule include (meth) acrylate substituted with a hydroxy group such as 4-hydroxybutyl acrylate.

  The sensitizer (B) is preferably an addition reaction product of “the compound represented by the formula (2 ′)” and “the compound having two or more isocyanate groups in the molecule”; It is more preferable that the compound is an addition reaction product between the compound represented by the formula (3) and the compound represented by the formula (3a) or (3b).

That is, the sensitizer (B) is preferably a compound represented by the following formula (4).

X of formula (4), _{R 1} and _{R 2} are the same meanings X in formula (2), and _{R 1} and _{R 2.}

  Y in the formula (4) represents a group derived from a compound having at least m isocyanate groups in the molecule. The group derived from a compound having at least m isocyanate groups in the molecule is a group derived from a compound having two or more isocyanate groups in the molecule, and from the compound represented by the formula (3a) It is preferably a divalent group derived or a trivalent group derived from a compound represented by the formula (3b).

  M in the formula (4) represents an integer of 1 to 5, preferably 2 or 3.

  Examples of the sensitizer (B) include an addition reaction product of 3-hydroxypropyl-4- (dimethylamino) benzoate and a modified hexamethylene diisocyanate biuret, 3-hydroxypropyl-4- (dimethylamino) benzoate and hexa An addition reaction product with a methylene diisocyanate allophanate modified body and a compound obtained by further reacting these compounds with octadecanol or 4-hydroxybutyl acrylate are included.

  In order to suppress the contamination of the liquid crystal material by the sensitizer (B), it is conceivable to increase the molecular weight of the sensitizer (B). However, if the molecular weight of the sensitizer (B) is simply increased, the content per molecule of the aminobenzoyl skeleton that contributes to light absorption may be relatively reduced. As a result, in order to obtain a certain level of light absorption, it is necessary to increase the content of the sensitizer (B), which may cause contamination of the liquid crystal material. Therefore, in the present invention, it is important to make the ratio of NHCO groups contained in one molecule equal to or greater than a certain value (ie, make the NHCO group equivalent equal to or less than a certain value).

That is, the NHCO group equivalent of the sensitizer (B) is preferably 300 g / eq or less. When the NHCO group equivalent of the sensitizer (B) is 300 g / eq or less, since the number of NHCO groups contained in the sensitizer (B) is relatively large, the hydrophilicity is moderately increased and a photocurable resin is obtained. When the composition is used as a liquid crystal sealant, elution of the sensitizer (B) into the liquid crystal material can be suppressed. The NHCO group equivalent of the sensitizer (B) is more preferably 200 to 290 g / eq, and further preferably 200 to 250 g / eq. When the NHCO group equivalent of the sensitizer (B) is 200 g / eq or more, the moisture resistance of the cured product of the photocurable resin composition is hardly impaired. The NHCO group equivalent of the sensitizer (B) is defined by the following formula (I).
Formula (I): NHCO group equivalent (g / eq) = molecular weight / number of NHCO groups contained in one molecule

The NHCO group equivalent of the sensitizer (B) combines high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC / MS) with NMR measurement or IR measurement. This can be confirmed. Specifically, it can be measured by the following procedure.
1) High-performance liquid chromatographic (HPLC) measurement A solution in which a photocurable resin composition is dissolved in tetrahydrofuran (THF) is centrifuged with a centrifuge to settle particle components such as silica particles and thermoplastic resin particles. Let The obtained solution is filtered through a filter to remove the particle component, thereby obtaining a sample solution. The obtained sample solution is subjected to high performance liquid chromatography (HPLC) measurement under the following measurement conditions.
(HPLC measurement conditions)
Equipment: Acquity TM UPLC H-Class system made by waters
Column: Acquity UPLC BEH C18, 2.1mmID × 100mm Particle size: 1.7μm
Mobile phase: A: Acetonitrile
B: 5 mM ammonium acetate aqueous solution
A / B = 60/40 (0-4 minutes)
95/5 (4-9 minutes)
95/5 (9-10 minutes)
Flow rate: 0.4mL / min
PDA detector: measurement wavelength: 190 to 500 nm, extraction wavelength: 305 nm

2) Liquid Chromatography Mass Spectrometry (LC / MS) Measurement In the measurement of the above 1), the relative molecular mass corresponding to the peak apex of the main peak detected by the detector having a wavelength of 305 nm characteristic of the aminobenzoyl skeleton The composition formula is measured by liquid chromatography mass spectrometry (LC / MS). The “main peak” refers to a peak having the highest intensity (a peak having the highest peak height) among all peaks detected at a detection wavelength of 305 nm.
(LC / MS measurement conditions)
Equipment: Acquity TM H-Class system / SQ Detector made by waters
Column: Acquity UPLC BEH C18, 2.1mmID × 100mm Particle size: 1.7μm
Mobile phase: A: Acetonitrile
B: 5 mM ammonium acetate aqueous solution
A / B = 60/40 (0-4 minutes)
95/5 (4-9 minutes)
95/5 (9-10 minutes)
Flow rate: 0.4 mL / min Ionization: ESI (electrospray ionization), positive / negative ion measurement
PDA detector: Measurement wavelength: 190-500 nm, Extraction wavelength: 305 nm
3) NMR measurement or IR measurement Further, NMR measurement or IR measurement is performed using the sample solution. Thereby, the presence or absence of a spectrum characteristic of the NHCO group or aminobenzoyl skeleton is confirmed, and the chemical structure is specified.
4) The molecular weight obtained in 1) and 2) above and the number of NHCO groups obtained in 3) above are applied to the above formula (I) to obtain the NHCO group equivalent (g / eq).

  In order to make the NHCO group equivalent of the sensitizer (B) within the above range, the sensitizer (B) contains “a compound represented by the formula (2 ′)” and “two or more isocyanate groups in the molecule”. Preferably, it is an addition reaction product of “compound represented by formula (2 ′)” and “compound represented by formula (3a) or (3b)”. Is more preferable.

  The molecular weight of the sensitizer (B) is preferably 500 or more and 5000 or less, for example. When the molecular weight of the sensitizer (B) is 500 or more, it is difficult to elute into the liquid crystal, and thus liquid crystal contamination is easily reduced. When the molecular weight of the sensitizer (B) is 5000 or less, the compatibility with the curable compound (A) is hardly impaired. The molecular weight of the sensitizer (B) is more preferably 500 or more and 3000 or less, and further preferably 700 or more and 1500 or less.

  The molecular weight of the sensitizer (B) can be measured by the methods 1) and 2) in the above-described measurement of NHCO group equivalent.

  The sensitizer (B) may be one type or a combination of two or more types.

  It is preferable that content of a sensitizer (B) is 0.01-10 mass% with respect to the sum total of a sclerosing | hardenable compound (A). When the content of the sensitizer (B) is 0.01% by mass or more, the polymerization initiator (C) can be sufficiently activated, so that sufficient curability is easily obtained. If the content of the sensitizer (B) is 10% by mass or less, elution into the liquid crystal material is difficult to occur without impairing curability. The content of the sensitizer (B) is more preferably 0.1 to 5% by mass, further preferably 0.1 to 3% by mass with respect to the total of the curable compound (A), The content is particularly preferably 0.1% by mass or more and less than 2% by mass.

1-3. Polymerization initiator (C)
The polymerization initiator (C) is a photopolymerization initiator for causing a curing reaction of the curable compound (A). However, the polymerization initiator (C) does not contain the aminobenzoyl skeleton described above.

  The photopolymerization initiator is not particularly limited, but may be a self-cleaving photopolymerization initiator or a hydrogen abstraction photopolymerization initiator.

  Examples of self-cleaving photopolymerization initiators include alkylphenone compounds (for example, benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651); 2-methyl-2 Α-aminoalkylphenones such as morpholino (4-thiomethylphenyl) propan-1-one (IIRGACURE 907); α-hydroxyalkylphenones such as 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184)), acyl Phosphine oxide compounds (such as 2,4,6-trimethylbenzoindiphenylphosphine oxide), titanocene compounds (such as bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3) -(1H-pyrrol-1-yl) -phenyl) titanium, etc.), acetophenone compounds (for example, diethoxyacetophenone, 2-hydroxy Roxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl -(2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl) -butanone etc.), phenylglyoxylate compounds (eg methylphenylglyoxyester etc.), and benzoin ether compounds (eg benzoin, benzoin methyl ether, benzoin isopropyl ether etc.).

  Examples of the hydrogen abstraction type photopolymerization initiator include benzophenone compounds (for example, benzophenone, methyl-4-phenylbenzophenone, o-benzoylbenzoate, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-). Methyl-diphenyl sulfide, acrylated benzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, etc.), thioxanthone compounds (for example, 2- Isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 2-carboxymethoxythioxanthone)-(polytetramethylene glycol 250) diester, etc.), ant Quinone compounds (e.g., 2-ethylanthraquinone, etc.) and benzyl-based compounds.

  Among these, the polymerization initiator (C) is preferably a thioxanthone compound (a compound having a thioxanthone skeleton). This is due to the following reason. A polymerization initiator that absorbs too much visible light may be slightly eluted into a liquid crystal or the like to cause display defects. On the other hand, the thioxanthone compound has an appropriate sensitivity to visible light, and therefore can hardly cause a display defect. On the other hand, the thioxanthone compound alone may be slightly weak in visible light absorption, so that it is easy to adjust to a more appropriate sensitivity by combining the sensitizer (B) from the viewpoint of obtaining sufficient curability.

  The thioxanthone-based compound may further have a hydrophilic functional group (NHCO group or OH group), preferably an NHCO group, from the viewpoint of easily reducing elution into the liquid crystal material.

  The thioxanthone compound having an NHCO group is preferably an addition reaction product of “a thioxanthone compound having a hydroxy group in the molecule (c1)” and “a compound having an isocyanate group in the molecule (c2)”.

The “thioxanthone compound (c1) having a hydroxy group in the molecule” is preferably represented by the following formula (5), and more preferably represented by the following formula (5 ′).

  L in Formulas (5) and (5 ′) is independently a single bond, an alkylene group having 1 to 10 carbon atoms, an alkyleneoxy group having 1 to 10 carbon atoms, an alkylenethio group having 1 to 10 carbon atoms, or a carbon number. It may be a 6-10 arylene group, a C6-C10 aryleneoxy group, or a C6-C10 arylenethio group. Among them, an alkylenethio group having 1 to 10 carbon atoms or an arylenethio group having 6 to 10 carbon atoms is preferable because it easily absorbs light on a long wavelength side.

  P in the formula (5) is an integer of 1 or more, preferably 1. -(L-OH) may be bonded to any of the 1st to 8th carbon atoms of the thioxanthone skeleton, but is preferably bonded to the 2nd or 7th carbon atom.

  The “compound (c2) having an isocyanate group in the molecule” is a compound having one or more isocyanate groups in the molecule, and is synonymous with the above-mentioned “compound (b2) having an isocyanate group in the molecule”. .

  In addition to the addition reaction of the “thioxanthone compound (c1) having a hydroxy group in the molecule” and the “compound (c2) having an isocyanate group in the molecule”, the “hydroxy group-containing compound (c3)” is further reacted. Also good. The “hydroxy group-containing compound (c3)” has the same meaning as the above-mentioned “hydroxy group-containing compound (b3)”.

  The thioxanthone-based compound having an NHCO group is preferably an addition reaction product of “a compound represented by the formula (5 ′)” and “a compound having two or more isocyanate groups in the molecule”.

That is, the thioxanthone compound having an NHCO group is preferably a compound represented by the following formula (6).

  L in Formula (6) is synonymous with L in Formula (5).

  Z in the formula (6) represents a group derived from a compound having at least n isocyanate groups in the molecule. The group derived from a compound having at least n isocyanate groups in the molecule is a group derived from a compound having two or more isocyanate groups in the molecule, and is represented by the above formula (3a). A divalent group derived from a compound or a trivalent group derived from a compound represented by the formula (3b) is preferable.

  N in the formula (6) represents an integer of 2 or more, and is preferably 2 or 3.

  Specific examples of the thioxanthone compound having an NHCO group include an addition reaction product of 2-hydroxythioxanthone and a modified hexamethylene diisocyanate biuret, an addition reaction product of 2-hydroxythioxanthone and a modified hexamethylene diisocyanate allophanate, and these Examples include compounds obtained by further reacting compounds with octadecanol or 4-hydroxybutyl acrylate.

  From the viewpoint of suppressing contamination of the liquid crystal material, the NHCO group equivalent of the thioxanthone compound having an NHCO group is preferably 350 g / eq or less, more preferably 200 to 350 g / eq, and more preferably 230 to 330 g / eq. More preferably. The NHCO group equivalent of the thioxanthone compound is defined by the aforementioned formula (I).

  The molecular weight of the polymerization initiator (C) is preferably 500 or more and 5000 or less, for example. When the molecular weight of the polymerization initiator (C) is 500 or more, it is difficult to dissolve in liquid crystal, and thus liquid crystal contamination is easily reduced. When the molecular weight of the polymerization initiator (C) is 5000 or less, the compatibility with the curable compound (A) is improved. The molecular weight of the polymerization initiator (C) is more preferably 500 or more and 3000 or less, and further preferably 700 or more and 1500 or less.

  The molecular weight of the polymerization initiator (C) is defined in the same manner as the molecular weight of the sensitizer (B) described above. The molecular weight of the polymerization initiator (C) can be measured in the same manner as the molecular weight of the sensitizer (B).

  It is preferable that content of a polymerization initiator (C) is 0.01-10 mass% with respect to the sum total of a sclerosing | hardenable compound (A). When the content of the polymerization initiator (C) is 0.01% by mass or more, sufficient photocurability is easily obtained. If the content of the polymerization initiator (C) is 10% by mass or less, elution into the liquid crystal material is difficult to occur, and sufficient photocurability is easily obtained. The content of the polymerization initiator (C) is more preferably 0.1 to 5% by mass, further preferably 0.1 to 3% by mass with respect to the total of the curable compound (A), The content is particularly preferably 0.1% by mass or more and less than 2% by mass.

  The content ratio by mass of the polymerization initiator (C) and the sensitizer (B) is preferably polymerization initiator (C): sensitizer (B) = 1: 0.05 to 1: 5. If the mass ratio of the polymerization initiator (C) and the sensitizer (B) is within the above range, sufficient curability can be easily obtained even with light having a long wavelength. The content ratio by mass of the polymerization initiator (C) and the sensitizer (B) is more preferably polymerization initiator (C): sensitizer (B) = 1: 0.1 to 1: 2.

1-4. Thermosetting compound (D)
The thermosetting compound (D) is preferably an epoxy compound having an epoxy group in the molecule. However, the thermosetting compound (D) is different from the curable compound (A). The thermosetting compound (D) is more preferably an epoxy compound having no (meth) acryloyl group in the molecule. The epoxy compound may be any of a monomer, an oligomer or a polymer. Epoxy compounds, for example, have low solubility and diffusibility in liquid crystal when using a photocurable resin composition as a liquid crystal sealant, and not only improve the display characteristics of the resulting liquid crystal panel, but also the moisture resistance of the cured product. Can increase sex.

  The epoxy compound may be an aromatic epoxy compound having a weight average molecular weight of 500 to 10000, preferably 1000 to 5000. The weight average molecular weight of the epoxy compound can be measured in terms of polystyrene by gel permeation chromatography (GPC).

  Examples of aromatic epoxy compounds include the reaction of aromatic diols typified by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, etc., and diols modified with ethylene glycol, propylene glycol, alkylene glycol, and epichlorohydrin. Aromatic polyvalent glycidyl ether compound obtained by the above; novolak type obtained by reaction of novolak resin derived from phenol or cresol and formaldehyde, polyphenols typified by polyalkenylphenol and copolymers thereof, and epichlorohydrin Polyvalent glycidyl ether compounds; xylylene phenol resin glycidyl ether compounds and the like are included. Among them, cresol novolac type epoxy compound, phenol novolac type epoxy compound, bisphenol A type epoxy compound, bisphenol F type epoxy compound, triphenolmethane type epoxy compound, triphenolethane type epoxy compound, trisphenol type epoxy compound, dicyclopentadiene type Epoxy compounds, diphenyl ether type epoxy compounds and biphenyl type epoxy compounds are preferred. The epoxy compound may be one type or a combination of two or more types.

  The epoxy compound may be liquid or solid. A solid epoxy compound is preferable from the viewpoint of easily improving the moisture resistance of the cured product. The softening point of the solid epoxy compound is preferably 40 ° C. or higher and 150 ° C. or lower.

  It is preferable that content of a thermosetting compound (D) is 3-20 mass% with respect to a photocurable resin composition. When the content of the thermosetting compound (D) is 3% by mass or more, it is easy to improve the moisture resistance of the cured product of the photocurable resin composition. When the content of the thermosetting compound (D) is 20% by mass or less, an excessive increase in the viscosity of the photocurable resin composition can be suppressed. As for content of a thermosetting compound (D), it is more preferable that it is 3-15 mass% with respect to a photocurable resin composition, and it is further more preferable that it is 5-15 mass%.

1-5. Thermosetting agent (E)
The thermosetting agent (E) is a compound that does not cure the thermosetting compound (D) under normal storage conditions (room temperature, visible light, etc.) but cures the compound when given heat. The photocurable resin composition containing a thermosetting agent (E) is excellent in storage stability and thermosetting. The thermosetting agent (E) is preferably an epoxy curing agent.

  Epoxy curing agent is an epoxy curing agent having a melting point of 50 ° C. or more and 250 ° C. or less, although it depends on the heat curing temperature from the viewpoint of enhancing the viscosity stability of the photo-curable resin composition and not impairing the moisture resistance of the cured product. An epoxy curing agent having a melting point of 100 ° C. or higher and 200 ° C. or lower is more preferable, and an epoxy curing agent having a melting point of 150 ° C. or higher and 200 ° C. or lower is further preferable.

  Examples of the epoxy curing agent include organic acid dihydrazide thermal latent curing agent, imidazole thermal latent curing agent, amine adduct thermal latent curing agent, and polyamine thermal latent curing agent.

  Examples of organic acid dihydrazide thermal latent curing agents include adipic acid dihydrazide (melting point 181 ° C.), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (melting point 120 ° C.), 7,11-octa Decadiene-1,18-dicarbohydrazide (melting point 160 ° C.), dodecanedioic acid dihydrazide (melting point 190 ° C.), sebacic acid dihydrazide (melting point 189 ° C.) and the like. Examples of imidazole-based thermal latent curing agents include 2,4-diamino-6- [2′-ethylimidazolyl- (1 ′)]-ethyltriazine (melting point: 215 to 225 ° C.) and 2-phenylimidazole (melting point) 137-147 ° C.) and the like. The amine adduct thermal latent curing agent is a thermal latent curing agent comprising an addition compound obtained by reacting an amine compound having catalytic activity with an arbitrary compound, and examples thereof include Ajinomoto Fine Techno Co., Ltd. ) Amicure PN-40 (melting point 110 ° C.), Ajinomoto Fine Techno Co., Ltd. Amicure PN-23 (melting point 100 ° C.), Ajinomoto Fine Techno Co., Ltd. Amicure PN-31 (melting point 115 ° C.), Ajinomoto Fine Techno ( Amicure PN-H (melting point: 115 ° C.) manufactured by Ajinomoto Fine Techno Co., Ltd. Amycure MY-24 (melting point: 120 ° C.), Amicure MY-H (melting point: 131 ° C.) manufactured by Ajinomoto Fine Techno Co., etc. It is. The polyamine thermal latent curing agent is a thermal latent curing agent having a polymer structure obtained by reacting an amine and an epoxy. Examples thereof include Adeka Hardener EH4339S (softening point 120 to 130, manufactured by ADEKA Corporation). ° C), and ADEKA Corporation ADEKA HARDNER EH4357S (softening point 73-83 ° C). Of these, dihydrazide thermal latent curing agents, imidazole thermal latent curing agents, amine adduct thermal latent curing agents, and polyamine thermal latent curing agents are preferred. The epoxy curing agent may be only one type or a combination of two or more types.

  It is preferable that content of a thermosetting agent (E) is 3-30 mass% with respect to a photocurable resin composition, It is more preferable that it is 3-20 mass%, It is 5-20 mass%. More preferably. The photocurable resin composition containing the thermosetting agent (E) can be a one-component curable resin composition. The one-component curable resin composition is excellent in workability because it is not necessary to mix the main agent and the curing agent in use.

  The total content of the thermosetting compound (D) and the thermosetting agent (E) is preferably 5 to 50% by mass and more preferably 5 to 35% by mass with respect to the photocurable resin composition. Preferably, it is 5-30 mass%.

1-6. Other ingredients (F)
1-6-1. Thermoplastic resin particles
The photocurable resin composition of the present invention may further contain thermoplastic resin particles as necessary. The thermoplastic resin particles include a thermoplastic resin having a softening point temperature measured by the ring and ball method of 50 to 120 ° C., preferably 70 to 100 ° C., and a number average particle diameter of 0.05 to 5 μm, preferably 0.8. It may be 1 to 3 μm. The photocurable resin composition containing such thermoplastic resin particles can relieve the shrinkage stress generated in the cured product. Moreover, when the number average particle diameter is set to the upper limit value or less, it is possible to prevent the coating stability from being lowered by the thermoplastic resin particles when forming a seal member having a thin line width. The number average particle diameter can be measured with a dry particle size distribution meter.

  Examples of the thermoplastic resin particles include fine particles obtained by suspension polymerization of a resin containing an epoxy group and a double bond group with a monomer capable of radical polymerization. Examples of the resin containing an epoxy group and a double bond group include a resin obtained by reacting a bisphenol F type epoxy resin and methacrylic acid in the presence of a tertiary amine. Examples of radically polymerizable monomers include butyl acrylate, glycidyl methacrylate, and divinylbenzene.

  The content of the thermoplastic resin particles is preferably 5 to 40% by mass and more preferably 7 to 30% by mass with respect to the photocurable resin composition. When the content of the thermoplastic resin particles is within the above range, the thermoplastic resin particles can preferably relieve the shrinkage stress during the heat curing of the photocurable resin composition, and it is easy to form a seal member with a target line width. .

1-6-2. Filler The photocurable resin composition of the present invention may further contain a filler as necessary. A photocurable resin composition containing a filler may have good viscosity, strength of a cured product, linear expansion, and the like.

  Examples of fillers include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, titanium nitride, aluminum oxide (alumina), zinc oxide, silicon dioxide, potassium titanate, Inorganic fillers such as kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, silicon nitride are included. Of these, silicon dioxide and talc are preferable.

The shape of the filler may be a regular shape such as a spherical shape, a plate shape, or a needle shape, or may be an irregular shape. When the filler is spherical, the average primary particle diameter of the filler is preferably 1.5 μm or less, and the specific surface area is preferably 0.5 to ²⁰ m ² / g. The average primary particle diameter of the filler can be measured by a laser diffraction method described in JIS Z8825-1. The specific surface area of the filler can be measured by the BET method described in JIS Z8830.

  It is preferable that content of a filler is 1-50 mass% with respect to a photocurable resin composition. The coating stability of a photocurable resin composition is hard to be impaired as content of a filler is 50 mass% or less. As for content of a filler, it is more preferable that it is 10-30 mass% with respect to a photocurable resin composition.

  The photo-curable resin composition of the present invention is optionally combined with a thermal radical polymerization initiator, a coupling agent such as a silane coupling agent, an ion trapping agent, an ion exchange agent, a leveling agent, a pigment, a dye, a plasticizer, and a quenching agent. An additive such as a foaming agent may be further included.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like. Content of a silane coupling agent may be 0.01-5 mass% with respect to a photocurable resin composition. When the content of the silane coupling agent is 0.01% by mass or more, the cured product of the photocurable resin composition tends to have sufficient adhesiveness.

  The photocurable resin composition of the present invention may further include a spacer for adjusting the gap of the liquid crystal display panel.

1-7. Physical Properties of Photocurable Resin Composition The viscosity of the photocurable resin composition of the present invention at 25 ° C. and 2.5 rpm of the E-type viscometer is preferably 200 to 450 Pa · s, and preferably 300 to 400 Pa · s. It is more preferable that When the viscosity is in the above range, the applicability of the photocurable resin composition by the dispenser becomes good.

  The photocurable resin composition of the present invention can be used as, for example, a sealing agent. The sealing agent is preferably a display element sealing agent used for sealing display elements such as liquid crystal display elements, organic EL elements, and LED elements. The display element sealant is particularly preferably a liquid crystal sealant, and more preferably a liquid crystal sealant for a liquid crystal dropping method.

  Since the sensitizer (B) contained in the photocurable resin composition of the present invention tends to activate the polymerization initiator (C), good curability is easily obtained. This makes it possible to cure in a short time while reducing damage to the display element such as the liquid crystal layer due to light. In addition, since the sensitizer (B) includes a certain amount of hydrophilic NHCO groups in the molecule, elution into the liquid crystal having hydrophobicity can be highly suppressed.

2. Display element panel and manufacturing method thereof The display element panel includes a pair of substrates, a display element disposed between the pair of substrates, and a seal member for sealing the display element. The seal member can be a cured product of the display element sealant of the present invention. The display element sealing agent of the present invention is composed of the photocurable resin composition of the present invention.

  Examples of display elements include liquid crystal display elements, organic EL elements, LED elements, and the like. Among these, a liquid crystal display element is preferable because the photocurable resin composition of the present invention can satisfactorily suppress liquid crystal contamination.

  That is, the liquid crystal display panel of the present invention includes a space surrounded by a pair of substrates, a frame-shaped seal member disposed between the pair of substrates, and a frame-shaped seal member between the pair of substrates. A filled liquid crystal layer (liquid crystal display element). The seal member can be a cured product of the liquid crystal sealant of the present invention. The liquid crystal sealing agent of the present invention comprises the photocurable resin composition of the present invention.

  Each of the pair of substrates is a transparent substrate. The material of the transparent substrate can be glass or plastic such as polycarbonate, polyethylene terephthalate, polyethersulfone and PMMA.

  A matrix-like TFT, a color filter, a black matrix, or the like can be arranged on the surface of one of the pair of substrates. An alignment film may be further disposed on the surface of the one substrate. The alignment film contains a known organic alignment agent or inorganic alignment agent.

  The liquid crystal display panel is manufactured using the liquid crystal sealant of the present invention. Generally, there are a liquid crystal dropping method and a liquid crystal injecting method as a method for manufacturing a liquid crystal display panel, but the liquid crystal display panel of the present invention is preferably manufactured by a liquid crystal dropping method.

The manufacturing method of the liquid crystal display panel by the liquid crystal dropping method is
1) forming a seal pattern of the liquid crystal sealant of the present invention on one substrate;
2) dropping the liquid crystal in a region surrounded by the seal pattern of the substrate or a region of the other substrate facing the region surrounded by the seal pattern in a state where the seal pattern is uncured;
3) a step of superimposing one substrate and the other substrate through a seal pattern;
4) curing the seal pattern.

  In the step 2), the uncured state of the seal pattern means a state in which the curing reaction of the liquid crystal sealant has not progressed to the gel point. For this reason, in the step 2), in order to suppress dissolution of the liquid crystal sealant in the liquid crystal, the seal pattern may be semi-cured by light irradiation or heating.

  In the step 4), only curing by light irradiation may be performed, but after curing by light irradiation, curing by heating may be performed. That is, the step 4) includes a step of irradiating the seal pattern with light to cure the seal pattern; when the liquid crystal sealant further includes the aforementioned thermosetting agent (E), the seal pattern irradiated with light A step of heating and curing may be further included. Since the liquid crystal sealant can be cured in a short time by curing by light irradiation, dissolution in the liquid crystal can be suppressed. By combining curing by light irradiation and curing by heating, damage to the liquid crystal layer due to light can be reduced compared to the case of only curing by light irradiation.

  The light to be irradiated is preferably light having a wavelength of 370 to 450 nm. This is because the light having the above wavelength causes relatively little damage to the liquid crystal material and the drive electrode. For light irradiation, a known light source that emits ultraviolet light or visible light can be used. For irradiation with visible light, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a xenon lamp, a fluorescent lamp, or the like can be used.

  The light irradiation energy may be energy that can cure the curable compound (A). The photocuring time is, for example, about 10 minutes although it depends on the composition of the liquid crystal sealant.

  The thermosetting temperature is 120 ° C., for example, although it depends on the composition of the liquid crystal sealant, and the thermosetting time is about 2 hours.

  The liquid crystal sealant of the present invention has reduced dissolution in liquid crystals. Therefore, a liquid crystal display panel having a cured product of the liquid crystal sealant of the present invention is less contaminated with liquid crystals and can have high quality display performance.

  In the following, the invention will be described in more detail with reference to examples. These examples do not limit the scope of the present invention.

1. Synthesis and Evaluation of Sensitizer (B) and Comparative Compound (Synthesis Example 1)
Into a four-necked flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer, 4.00 g (1.79 × 10 ⁻² mol) of 3-hydroxypropyl-4- (dimethylamino) benzoate, After adding 30 g of toluene and stirring at 80 ° C., 1 drop of dibutyltin was added as a catalyst. Next, a hexamethylene diisocyanate biuret modified product (manufactured by Mitsui Chemicals, Takenate D-165N, isocyanate equivalent 179.5 g / eq) 3.86 g dissolved in 10 g of toluene was added dropwise over 15 minutes, and then a nitrogen atmosphere as it was The mixture was stirred at 80 ° C. for 4 hours. After completion of the reaction, the four-necked flask was allowed to cool at room temperature to separate the precipitated liquid component. The recovered liquid component was sufficiently dried in an oven to obtain Compound B-1.

(Synthesis Example 2)
In a four-necked flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer, 4.00 g (1.79 × 10 ⁻² mol) of 3-hydroxypropyl-4- (dimethylamino) benzoate and toluene 30 g was added and stirred at 80 ° C., and then 1 drop of dibutyltin was added as a catalyst. Next, a hexamethylene diisocyanate allophanate modified product (Mitsui Chemicals, Takenate D-178NL, isocyanate equivalent 216.1 g / eq) of 4.64 g dissolved in toluene 10 g was added dropwise over 20 minutes, and then nitrogen atmosphere as it was The mixture was stirred at 80 ° C. for 3 hours. After completion of the reaction, the precipitated liquid component was separated by allowing the four-necked flask to cool at room temperature. The recovered liquid component was sufficiently dried in an oven to obtain Compound B-2.

(Synthesis Example 3)
Into a four-necked flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer, 4.00 g (1.79 × 10 ⁻² mol) of 3-hydroxypropyl-4- (dimethylamino) benzoate and toluene 30 g was added and stirred at 80 ° C., and 1 drop of dibutyltin was added as a catalyst. Next, a solution prepared by dissolving 2.14 g of a hexamethylene diisocyanate biuret modified product (manufactured by Mitsui Chemicals, Takenate D-165N, isocyanate equivalent 179.5 g / eq) in 10 g of toluene was added dropwise over 15 minutes.
After confirming the disappearance of 3-hydroxypropyl-4- (dimethylamino) benzoate by thin layer chromatography (TLC), 1.94 g (7.16 × 10 ⁻³ ) of 1-octadecanol (manufactured by Tokyo Chemical Industry Co., Ltd.) Mol) was further added dropwise and stirred at 80 ° C. for 2 hours under a nitrogen atmosphere. After completion of the reaction, the 4-necked flask was cooled in an ice bath to separate the precipitated liquid component. The recovered liquid component was sufficiently dried in an oven to obtain Compound B-3.

(Synthesis Example 4)
In a four-necked flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer, 2.00 g (8.95 × 10 ⁻³ mol) of 3-hydroxypropyl-4- (dimethylamino) benzoate and acetic acid After adding 30 g of ethyl and stirring at 70 ° C., 1 drop of dibutyltin was added as a catalyst. Next, a solution prepared by dissolving 1.81 g of hexamethylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) in 10 g of ethyl acetate was added dropwise over 10 minutes, and then stirred at 70 ° C. for 3 hours in a nitrogen atmosphere. After completion of the reaction, the four-necked flask was allowed to cool at room temperature to separate the precipitated liquid component. The recovered liquid component was sufficiently dried in an oven to obtain Compound R-1.

(Synthesis Example 5)
Into a four-necked flask equipped with a stirrer, a nitrogen gas introduction tube, a reflux condenser, and a thermometer, 2.00 g (8.95 × 10 ⁻³ mol) of 3-hydroxypropyl-4- (dimethylamino) benzoate and methyl After adding 30 g of isobutyl ketone and stirring at 80 ° C., 1 drop of dibutyltin was added as a catalyst. Next, a solution prepared by dissolving 2.35 g of dicyclohexylmethane-4,4′-diisocyanate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) in 10 g of methyl isobutyl ketone was dropped over 10 minutes, and then the solution was maintained at 80 ° C. in a nitrogen atmosphere. Stir for hours. After completion of the reaction, the four-necked flask was allowed to cool at room temperature to separate the precipitated liquid component. The recovered liquid component was sufficiently dried in an oven to obtain Compound R-2.

(Synthesis Example 6)
2.00 g (1.32 × 10 ⁻² mol) of 4- (dimethylamino) benzyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd.) into a four-necked flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer And 50 g of toluene were added and stirred at 90 ° C., and 1 drop of dibutyltin was added as a catalyst. Next, a hexamethylene diisocyanate biuret modified product (manufactured by Mitsui Chemicals, Takenate D-165N, isocyanate equivalent 179.5 g / eq) 2.84 g dissolved in toluene 15 g was added dropwise over 10 minutes, and then a nitrogen atmosphere as it was The mixture was stirred at 90 ° C. for 3 hours. After completion of the reaction, the four-necked flask was allowed to cool at room temperature and then filtered. The collected filtrate was evaporated using an evaporator to obtain a liquid compound R-3.

(Synthesis Example 7)
2.00 g (1.32 × 10 ⁻² mol) of 4- (dimethylamino) benzyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd.) into a four-necked flask equipped with a stirrer, a nitrogen gas inlet tube, a reflux condenser, and a thermometer And 30 g of toluene were added and stirred at 90 ° C., and 1 drop of dibutyltin was added as a catalyst. Next, a hexamethylene diisocyanate allophanate modified product (manufactured by Mitsui Chemicals, Takenate D-178NL, isocyanate equivalent 216.1 g / eq) 3.42 g dissolved in toluene 15 g was added dropwise over 10 minutes, and then a nitrogen atmosphere as it was The mixture was stirred at 90 ° C. for 3 hours. After completion of the reaction, the four-necked flask was allowed to cool at room temperature and then filtered. The collected filtrate was subjected to solvent distillation using an evaporator to obtain a liquid compound R-4.

化合物Ｒ−６：４−（ジメチルアミノ）ベンジルアルコール（東京化成工業社製、下記化合物）

化合物Ｒ−７：Ｏｍｎｉｐｏｌ−ＡＳＡ（ＩＧＭ Ｒｅｓｉｎｓ社製、下記化合物）

Compound R-5: 3-hydroxypropyl-4- (dimethylamino) benzoate

Compound R-6: 4- (dimethylamino) benzyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., the following compound)

Compound R-7: Omnipol-ASA (manufactured by IGM Resins, the following compound)

The structures of Compounds B-1 to B-3 obtained in Synthesis Examples 1 to 3 are shown in Table 1, and the structures of Compounds R-1 to R-4 obtained in Synthesis Examples 4 to 7 are shown in Table 2.

(Experimental Examples 1-3, Comparative Experimental Examples 1-7)
The prepared compounds B-1 to B-3 and comparative compounds R-1 to R-7 were evaluated for 1) molecular weight, 2) voltage holding ratio of liquid crystal, and 3) NI point drop of liquid crystal by the following methods. did.

1) Molecular weight A sample solution in which the prepared compound was dissolved in tetrahydrofuran (THF) was prepared, and high performance liquid chromatography (HPLC) measurement was performed under the following measurement conditions. Of all peaks detected at a detection wavelength of 305 nm, the peak with the highest intensity (the peak with the highest height) was taken as the main peak.
(HPLC measurement conditions)
Equipment: Acquity TM UPLC H-Class system made by waters
Column: Acquity UPLC BEH C18, 2.1mmID × 100mm Particle size: 1.7μm
Mobile phase: A: Acetonitrile
B: 5 mM ammonium acetate aqueous solution
A / B = 60/40 (0-4 minutes)
95/5 (4-9 minutes)
95/5 (9-10 minutes)
Flow rate: 0.4mL / min
PDA detector: Measurement wavelength: 190-500nm, Extraction wavelength: 305nm

  For the compound in which the main peak was detected, the relative molecular mass corresponding to the peak apex of the detected main peak was measured by liquid chromatography mass spectrometry (LC / MS).

(LC / MS measurement conditions)
Equipment: Acquity TM H-Class system / SQ Detector made by waters
Column: Acquity UPLC BEH C18, 2.1mmID × 100mm Particle size: 1.7μm
Mobile phase: A: Acetonitrile
B: 5 mM ammonium acetate aqueous solution
A / B = 60/40 (0-4 minutes)
95/5 (4-9 minutes)
95/5 (9-10 minutes)
Flow rate: 0.4 mL / min Ionization: ESI (electrospray ionization), positive / negative ion measurement
PDA detector: Measurement wavelength: 190-500nm, Extraction wavelength: 305nm

2) Voltage holding ratio of liquid crystal 0.1 g of the prepared compound and 1 g of liquid crystal (MLC-7021-000, manufactured by Merck & Co., Inc.) were put into a vial and heated at 120 ° C. for 1 hour to obtain a liquid crystal mixture. Obtained. Next, this liquid crystal mixture is taken out, poured into a glass cell (KSSZ-10 / B111M1NSS05, manufactured by EHC) in which a transparent electrode is formed in advance, a voltage of 1 V is applied, and a voltage holding ratio at 60 Hz is measured by a 6254 type measuring device. It was measured by (Toyo Technica).
The case where the voltage holding ratio was 95% or more was marked with ◎, the case where it was 90% or more and less than 95%, and the case where it was less than 90%.

3) NI point drop of liquid crystal 0.1 g of the prepared compound and 1 g of liquid crystal (MLC-7021-000, manufactured by Merck & Co., Inc.) were put into a vial and heated at 120 ° C. for 1 hour to obtain a liquid crystal mixture. Got. Next, this liquid crystal mixture was taken out, 10 mg was put in an aluminum open pan (Epolide Service), and the NI point was measured with a DTA-TG apparatus (Seiko Instruments).
The case where the amount of change with respect to the NI point of the liquid crystal was less than 3 ° C. was evaluated as を: the case where it was 3 ° C. or higher and lower than 5 ° C.

The obtained measurement results are shown in Table 3.

  As shown in Table 3, in the compounds B-1 to B-3 of Experimental Examples 1 to 3 having an NHCO group equivalent of 300 g / eq or less and having an aminobenzoyl skeleton, the NHCO group equivalent exceeds 300 g / eq. Compounds R-1 and R-2 of Comparative Experimental Examples 1 and 2, Compound R-4 of Comparative Experimental Example 4 having no aminobenzoyl skeleton, Compounds R-5 to R of Comparative Experimental Examples 5 to 7 having no NHCO group It can be seen that the voltage holding ratio of the liquid crystal is higher than that of -7, the NI point drop is small, and elution into the liquid crystal is reduced.

2. Preparation and evaluation of photocurable resin composition (curable compound (A))
Curing compound A-1: methacrylic acid-modified bisphenol F type epoxy resin (95% partially methacrylic product) obtained in Synthesis Example 8 below
(Synthesis Example 8)
160 g of liquid bisphenol F type epoxy resin (Epototo YDF-8170C, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent 160 g / eq), 0.1 g of p-methoxyphenol as a polymerization inhibitor, 0.2 g of triethanolamine as a catalyst, And 81.7 g of methacrylic acid were charged into the flask, dried air was fed, and the mixture was reacted at 90 ° C. with reflux stirring for 5 hours. The obtained compound was washed 20 times with ultrapure water to obtain a methacrylic acid-modified bisphenol F type epoxy resin.
Kyoeisha Chemical Light Acrylate 14EG-A:
Polyethylene glycol diacrylate represented by the following formula (molecular weight 600)

(Sensitizer (B))
Compounds B-1 to B-3 of Synthesis Examples 1 to 3
(Comparative compound)
Compounds R-1 to R-4 of Synthesis Examples 4 to 7, and Compounds R-5 to R-7

(Polymerization initiator (C))
Omnipol-TX: IGM Resins, 2-carboxymethoxythioxanthone)-(polytetramethylene glycol 250) diester

(Thermosetting compound (D))
Epoxy resin: manufactured by JER, Epicoat 1004, softening point 97 ° C

(Thermosetting agent (E))
Adipic acid dihydrazide: Nippon Kasei Co., Ltd., ADH, melting point 177-184 ° C

(Other components (F))
Silica particles: Nippon Shokubai Co., Ltd., S-100
Thermoplastic resin particles (Zeon Kasei Co., Ltd., F351, softening point 120 ° C., average particle size 0.3 μm)
γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)

Example 1
420 parts by mass of the curable compound A-1 obtained in Synthesis Example 8 as the curable compound (A), 200 parts by mass of polyethylene glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate 14EG-A), and a sensitizer (B) 10 parts by mass of Compound B-1 obtained in Synthesis Example 1 and 10 parts by mass of Omnipol-TX (manufactured by IGM Resins) as a polymerization initiator (C), and thermosetting compound (D) 50 parts by mass of epoxy resin (manufactured by JER, Epicoat 1004), 90 parts by mass of adipic acid dihydrazide (ADH manufactured by Nippon Kasei Co., Ltd.) as the thermosetting agent (E), and silica particles (Japan) as the other component (F) 130 parts by mass, manufactured by Catalytic Chemical Co., Ltd., 130 parts by mass of F351 made by Aika Kogyo as thermoplastic resin particles, and γ- A photocurable resin composition was prepared by thoroughly mixing 20 parts by mass of lysidoxypropyltrimethoxysilane (KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.) using a three-roll roll so as to form a uniform liquid. Obtained.

(Examples 2-6, Comparative Examples 1-7)
A photocurable resin composition was obtained in the same manner as in Example 1 except that the type or content of the sensitizer (B) was changed as shown in Table 4 or 5.

  The display characteristics of the obtained photocurable resin composition were evaluated by the following methods.

(LCD panel display characteristics test when no power is supplied)
A 40 mm × 45 mm glass substrate (RT-DM88-PIN, manufactured by EHC) in which a transparent electrode and an alignment film were previously formed using a dispenser (shot master: manufactured by Musashi Engineering) using the obtained photocurable resin composition A 35 mm × 40 mm square seal pattern (cross-sectional area 3500 μm ² ) (main seal) and a similar seal pattern (38 mm × 43 mm square seal pattern) were formed on the outer periphery.

Next, a liquid crystal material (MLC-7021-000, manufactured by Merck & Co., Inc.) corresponding to the panel internal volume after bonding was precisely dropped into the main seal frame using a dispenser. Next, a pair of glass substrates was bonded together under reduced pressure, and then bonded to the atmosphere. Then, the two glass substrates bonded together are held in a light shielding box for 3 minutes, and then the main seal is masked with a substrate coated with a square black matrix of 36 mm × 41 mm, and light having a wavelength of 370 to 450 nm is 3000 mJ. / Cm ² , and after heating at 120 ° C. for 1 hour, polarizing films were pasted on both sides.
○ when the liquid crystal is aligned until the main seal of the liquid crystal panel and there is no color unevenness, Δ when the color unevenness occurs over a range of less than 1 mm in the vicinity of the main seal, 1 mm from the vicinity of the main seal The case where color unevenness occurred over the above range was evaluated as x.

(LCD panel display characteristics test when energized)
A liquid crystal display panel was produced in the same manner as the liquid crystal display panel display characteristic test described above. When this liquid crystal display panel is driven with an applied voltage of 5 V using a DC power source, the liquid crystal display function in the vicinity of the main seal can be exhibited. The case where it occurred was indicated by Δ, and the case where white unevenness occurred over a range of 1 mm or more from the vicinity of the main seal and it was not driven normally was indicated by ×.

The present invention is such that the evaluation result of the display characteristic test at the time of non-energization is ○ and the evaluation result of the display characteristic test at the time of energization is Δ or more. The evaluation results of Examples 1 to 6 are shown in Table 4, and the evaluation results of Comparative Examples 1 to 7 are shown in Table 5.

  As shown in Table 4, the photocurable resin compositions of Examples 1 to 6 including the sensitizer (B) having an aminobenzoyl skeleton and an NHCO group equivalent of 300 g / eq or less It can be seen that a good display characteristic is exhibited both in the non-energized state.

  On the other hand, as shown in Table 5, the photocurable resin compositions of Comparative Examples 1 and 2 including a comparative compound having an NHCO group equivalent of more than 300 g / eq, and a comparative compound having no NHCO group are included. It can be seen that the photocurable resin compositions of Comparative Examples 5 and 6 are inferior in display characteristics. This is presumably because liquid crystal contamination could not be sufficiently suppressed because the comparative compound had little or no hydrophilic NHCO group. Moreover, compared with Examples 1-3 including compounds B-1 to B-3 having an aminobenzoyl skeleton, the light of Comparative Examples 3 and 4 including comparative compounds R-3 and R-4 having no aminobenzoyl skeleton It can be seen that the curable resin composition has poor display characteristics. This is probably because the sensitizing ability of the comparative compound was low, so that the sealing material was not sufficiently cured, and the liquid crystal elution of the sealing material component could not be sufficiently suppressed.

  The present invention can provide a photocurable resin composition that has high curability to visible light when used as, for example, a liquid crystal sealant and can highly suppress liquid crystal contamination.

Claims (12)

A curable compound (A) having an ethylenically unsaturated double bond in the molecule;
A sensitizer (B) having an aminobenzoyl skeleton and an NHCO group in the molecule and having an NHCO group equivalent represented by the formula (I) of 300 g / eq or less;
A photocurable resin composition comprising a polymerization initiator (C) (excluding a polymerization initiator having an aminobenzoyl skeleton in the molecule).
Formula (I): NHCO group equivalent (g / eq) = molecular weight / number of NHCO groups contained in one molecule   The photocurable resin composition according to claim 1, wherein the sensitizer (B) has 3 or more NHCO groups in the molecule.   The photocurable resin composition according to claim 1 or 2, wherein the sensitizer (B) has a burette skeleton or an allophanate skeleton in the molecule. The said sensitizer (B) is a photocurable resin composition as described in any one of Claims 1-3 which is a compound represented by following formula (4).

(In Formula (4),
X is a single bond, an alkylene group having 1 to 10 carbon atoms, an alkyleneoxy group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an aryleneoxy group having 6 to 10 carbon atoms, or an alkyl group having 6 to 10 carbon atoms. Represents an arylenethio group,
R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
Y represents an organic group derived from a compound having at least m isocyanate groups in the molecule;
m represents an integer of 1 to 5)   The photocurable resin composition as described in any one of Claims 1-4 whose content of the said sensitizer (B) is 0.01-10 mass% with respect to the said curable compound (A). object.   The photocurable resin composition according to any one of claims 1 to 5, wherein the polymerization initiator (C) has a thioxanthone skeleton.   The photocurable resin composition as described in any one of Claims 1-6 in which the said curable compound (A) further has an epoxy group in a molecule | numerator.   The display element sealing agent which consists of a photocurable resin composition as described in any one of Claims 1-7. Using the display element sealing agent according to claim 8 to form a seal pattern on one substrate;
In the uncured state of the seal pattern, dropping the liquid crystal on the other substrate that is paired with the one substrate in the region of the seal pattern;
Superimposing the one substrate and the other substrate through the seal pattern;
Curing the seal pattern;
A method for manufacturing a liquid crystal display panel, comprising:   The method for manufacturing a liquid crystal display panel according to claim 9, wherein the step of curing the seal pattern includes a step of curing the seal pattern by irradiating the seal pattern with light.   The method for manufacturing a liquid crystal display panel according to claim 10, wherein the light applied to the seal pattern includes light in a visible light region. A pair of substrates;
A frame-shaped sealing member disposed between the pair of substrates;
A liquid crystal layer filled in a space surrounded by the seal member between the pair of substrates,
A liquid crystal display panel, wherein the seal member is a cured product of the display element sealant according to claim 8.