JP2009175180A - Curable resin composition for sealing liquid crystal, and method of manufacturing liquid crystal display panel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition for sealing a liquid crystal, which has an excellent leakage resistance property. <P>SOLUTION: The curable resin composition for sealing a liquid crystal, containing an acrylic resin (1a) or a (meth)acryl modified epoxy resin (1b) having an epoxy group and a (meth)acryl group in a molecule, a thermal radical polymerization initiator (2), and a filler (3), is prepared. In the resin composition, the quantity of a carbon-carbon double bond in the resin composition except the filler (3) is set to be 0.002 to <0.006 mol/g. Such a resin composition has high curing speed due to a fast reaction between a radical species and a (meth)acryl group, and gelation is accelerated, and as a result has an excellent leakage resistance property. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a curable resin composition for liquid crystal sealing, a resin composition for liquid crystal dropping method obtained from the curable resin composition for liquid crystal sealing, and a method for producing a liquid crystal display panel using the sealing agent for liquid crystal dropping method. .

  In recent years, liquid crystal display panels have been widely used as image display panels for various electronic devices such as mobile phones and personal computers because of their advantages such as light weight and high definition. The liquid crystal display panel has a structure in which a liquid crystal material (hereinafter simply referred to as “liquid crystal”) is sandwiched between two transparent substrates having electrodes provided on the surface, and the periphery thereof is sealed with a liquid crystal sealant. It is.

  Although the liquid crystal sealant is used in a small amount, it directly contacts the liquid crystal, which greatly affects the reliability of the liquid crystal display panel. Therefore, in order to achieve high image quality of the liquid crystal display panel, liquid crystal sealants are currently required to have advanced and diverse characteristics.

  Conventionally, liquid crystal display panels are mainly manufactured by a liquid crystal injection method. In the liquid crystal injection method, first, (1) a liquid crystal sealant is applied on one transparent substrate to form a frame, and (2) the liquid crystal sealant is dried by precuring the substrate. The other substrate is bonded, (3) the two substrates are heated and pressed, and the substrates are bonded together to form a frame (cell) of the liquid crystal sealant between the substrates, and (4) empty This is a method of manufacturing a liquid crystal display panel by injecting an appropriate amount of liquid crystal into a cell and then sealing the liquid crystal injection port.

  In the liquid crystal injection method, the liquid crystal sealing agent is conventionally cured by heating. Until now, as a liquid crystal sealant suitable for the liquid crystal injection method, for example, Patent Document 1 has proposed a resin composition using an epoxy resin as a raw material. However, as the demand for liquid crystal display panels increases, the liquid crystal injection method requires a heat treatment at a temperature of 120 to 150 ° C. for several hours to cure the liquid crystal sealant, and it takes time to inject liquid crystals. For this reason, low productivity is regarded as a problem.

  On the other hand, recently, a liquid crystal dropping method has been studied as a method of manufacturing a liquid crystal display panel that is expected to improve productivity. In the liquid crystal dropping method, (1) a liquid crystal sealant is applied on a transparent substrate to form a frame for filling the liquid crystal, (2) a minute liquid crystal is dropped into the frame, and (3) liquid crystal In this method, two substrates are stacked under high vacuum while the sealant is in an uncured state, and then (4) the liquid crystal sealant is cured to produce a panel. Further, in general, in the liquid crystal dropping method, for example, as described in Patent Document 2, a light and thermosetting liquid crystal sealant is used, and in the step (3), the liquid crystal sealant is irradiated with ultraviolet rays or the like. After temporary curing with light irradiation, post-curing by heating is performed.

By the way, in a small liquid crystal display panel used for a mobile phone or the like, metal wiring is complicated, and the metal wiring or black matrix often overlaps a seal pattern made of a liquid crystal sealant. In a light-shielding portion where no light is irradiated, there is a high possibility that the uncured liquid crystal sealant will dissolve into the liquid crystal and the liquid crystal will be contaminated. When the liquid crystal is contaminated, the display property of the liquid crystal display panel is remarkably lowered, which is a big problem. Therefore, in order to prevent liquid crystal contamination at the light-shielding portion, for example, in Patent Document 3, as a liquid crystal sealant that is cured only by heat, a hydrogen bonding functional group and two or more (meth) acryl groups are contained in one molecule. And a curable resin composition for a liquid crystal display element comprising 3 to 40 parts by weight of a thermosetting agent with respect to 100 parts by weight of the curable resin having a hydrogen bond functional group amount of 3.5 × 10 ⁻³ or more. Proposed.
International Publication No. 2004/039885 Pamphlet JP 2002-214626 A Patent No. 3955038

  However, the conventional liquid crystal sealing agent has a problem that the viscosity of the resin used as a raw material is lowered by heating, so that the seal pattern is partially deformed or the liquid crystal breaks through the seal pattern and leaks. Patent Document 3 describes a liquid crystal sealing agent that can improve curability and prevent liquid crystal contamination, but does not describe measures against liquid crystal leakage.

  Then, an object of this invention is to provide the curable resin composition for liquid crystal seals which is excellent in leak resistance. In the present invention, the fact that the seal pattern is partially deformed or the liquid crystal leaks through the seal pattern is also referred to as “liquid crystal leaks”. It is also said to have excellent leak performance.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by optimizing the amount of carbon-carbon double bonds in the resin composition for liquid crystal sealants. The present invention has been completed.

前記一般式（１）中の、
ｍは２〜８の整数を表し、
ｎは１〜４の数を表し、
Ｒ_１は炭素数２〜６の炭化水素基を表し、
Ｒ_２は水素またはメチル基を表し、
Ａは多環芳香族炭化水素基を表わす。
［４］ 前記（１ａ）の樹脂と前記（１ｂ）の樹脂とを合わせた樹脂ユニット１００質量部に対して、３〜３０質量部の（４）エポキシ硬化剤をさらに含む、［１］〜［３］のいずれかに記載の液晶シール用硬化性樹脂組成物。
［５］ 前記（１ａ）の樹脂と前記（１ｂ）の樹脂とを合わせた樹脂ユニット１００質量部に対して、１〜３０質量部の（５）エポキシ樹脂をさらに含む、［１］〜［４］のいずれかに記載の液晶シール用硬化性樹脂組成物。
［６］ 前記（１ａ）の樹脂と前記（１ｂ）の樹脂とを合わせた樹脂ユニット１００質量部に対して、０．３〜５．０質量部の（６）光ラジカル重合開始剤をさらに含む、［１］〜［５］のいずれかに記載の液晶シール用硬化性樹脂組成物。 That is, the said subject is solved by the curable resin composition for liquid crystal seals of this invention regarding the following [1]-[6].
[1] (1a) acrylic resin or (1b) (meth) acryl-modified epoxy resin having an epoxy group and (meth) acryl group in the molecule, (2) thermal radical polymerization initiator, and (3) filler And the amount of carbon-carbon double bonds in the resin composition excluding the filler of (3) above is 0.002 mol / g or more and less than 0.006 mol / g. A curable resin composition for liquid crystal seals.
[2] The content of the thermal radical polymerization initiator of (2) relative to 100 parts by mass of the resin unit in which the resin of (1a) and the resin of (1b) are combined is 0.01 to 3. The curable resin composition for liquid crystal seals according to [1], which is 0 part by mass.
[3] The curable resin for liquid crystal seals according to [1] or [2], wherein the acrylic resin of (1a) is an acrylic group-containing polycyclic aromatic compound represented by the following general formula (1): Composition.

In the general formula (1),
m represents an integer of 2 to 8,
n represents a number from 1 to 4,
R ₁ represents a hydrocarbon group having 2 to 6 carbon atoms,
R ₂ represents hydrogen or a methyl group,
A represents a polycyclic aromatic hydrocarbon group.
[4] The resin unit further comprising 3 to 30 parts by mass of (4) an epoxy curing agent with respect to 100 parts by mass of the resin unit obtained by combining the resin (1a) and the resin (1b). 3] The curable resin composition for liquid crystal seals according to any one of [3].
[5] The resin unit further including 1 to 30 parts by mass of (5) epoxy resin with respect to 100 parts by mass of the resin unit obtained by combining the resin (1a) and the resin (1b). ] The curable resin composition for liquid crystal seals in any one of.
[6] 0.3 to 5.0 parts by mass of (6) radical photopolymerization initiator is further included with respect to 100 parts by mass of the resin unit obtained by combining the resin (1a) and the resin (1b). [1]-[5] The curable resin composition for liquid crystal seals in any one of.

Moreover, the said subject is solved by the liquid-crystal sealing compound for liquid crystal dropping methods of this invention regarding the following [7].
[7] A liquid crystal sealant for a liquid crystal dropping method comprising the curable resin composition for liquid crystal seals according to the above [1] to [6].

Furthermore, the above-mentioned problem is solved by the method for producing a liquid crystal display panel of the present invention relating to the following [8].
[8] (a) One or more substrates having a frame-shaped seal pattern formed so that the pixel array region is surrounded by the curable resin composition for liquid crystal seals according to the above [1] to [6] (B) dropping the liquid crystal in the uncured seal pattern or on the other substrate; and (c) the substrate on which the liquid crystal is dropped and the other substrate. A method for manufacturing a liquid crystal display panel, comprising: a step of superposing under reduced pressure; and (d) a step of curing a liquid crystal sealing agent for a liquid crystal dropping method sandwiched between the substrates by heating.

  According to the present invention, a curable resin composition for liquid crystal seals having excellent leak resistance can be provided. Moreover, since the liquid crystal sealing agent for a liquid crystal dropping method obtained by applying the resin composition is excellent in leak resistance, a high-quality liquid crystal display panel can be provided.

  Next, the present invention will be specifically described. In the present invention, the symbol “˜” includes numerical values at both ends thereof.

  In the present invention, use for sealing the liquid crystal is referred to as “for liquid crystal sealing”, and sealing the liquid crystal in a certain space is referred to as “sealing the liquid crystal”. The “curable resin composition for liquid crystal seal” of the present invention is synonymous with what is generally called “liquid crystal sealant”. Here, what is generally called a “liquid crystal sealant” is a constituent member of a liquid crystal display panel, and is used as an adhesive that encloses liquid crystal and bonds two substrates at a predetermined interval. It refers to a resin composition. And in this invention, the liquid crystal sealing agent used for a liquid crystal dropping method among liquid crystal sealing agents is called "the liquid crystal sealing agent for liquid crystal dropping methods."

1. Curable resin composition for liquid crystal seal The curable resin composition for liquid crystal seal of the present invention (also simply referred to as “resin composition”) comprises (1a) an acrylic resin and / or (1b) an epoxy group in the molecule. A curable resin composition for liquid crystal seals, comprising a (meth) acryl-modified epoxy resin having a (meth) acryl group, (2) a thermal radical polymerization initiator, and (3) a filler, The amount of carbon-carbon double bonds in the resin composition excluding the filler in ()) is 0.002 mol / g or more and less than 0.006 mol / g.

  In the present invention, “the resin composition excluding the filler of (3)” includes, for example, the resin of (1a), the resin of (1b), the thermal radical polymerization initiator of (2), and the filler of (3). When the resin composition is prepared by using the raw material other than the filler (including the organic filler) in (3), that is, only from the resin (1a), the resin (1b), and the thermal radical polymerization initiator (2). A resin composition. The resin composition of the present invention may further contain (4) an epoxy curing agent, (5) an epoxy resin, (6) a radical photopolymerization initiator, or (7) a thermoplastic polymer, which will be described later, in addition to the above raw materials. However, similarly for the resin composition, “the resin composition excluding the filler of (3)” refers to a resin composition in which only raw materials other than the filler of (3) are summed up. In the present invention, the resin (1a) and the resin (1b) that contribute to the curing of the resin composition are each referred to as a “curable resin”, and these resins are collectively referred to as a “resin unit”. Sometimes.

  The resin composition of the present invention is characterized in that: a) at least one curable resin of (1a) or (1b) is used as a raw material; and b) these resins and a thermal radical polymerization initiator. Use in combination, c) The amount of carbon-carbon double bonds in the resin composition is within a predetermined range.

  As described above, the liquid crystal sealant is required to have excellent leak resistance. Liquid crystal leakage is likely to occur as the liquid crystal sealant cures slowly and more uncured portions remain in the cured product. When the liquid crystal sealant is cured with light, the liquid crystal leak becomes more prominent as the seal pattern has more light shielding portions. Therefore, in order to improve leakage resistance, a liquid crystal sealant that can be cured quickly and sufficiently only by heat is preferable.

  However, as described above, since the viscosity of the resin used as the raw material of the conventional liquid crystal sealant is reduced by heating, the liquid crystal may leak due to deformation of the seal pattern even when cured by heat alone. In order to prevent a decrease in the resin viscosity during heating, it is effective to improve the curing rate that allows rapid curing before the viscosity decreases. In that respect, the resin composition of the present invention is a combination of a (meth) acrylic group-containing resin capable of reacting with a radical and (2) a thermal radical polymerization initiator as described in the above b), and the above-mentioned c). Thus, the carbon-carbon double bond amount in the resin composition excluding the filler is designed in a high range of 0.002 to 0.006 mol / g. Thereby, since the adjacent carbon-carbon double bond reacts rapidly in the said resin composition, since the cure rate of a resin composition becomes faster, as a result, it is excellent in leak resistance.

  However, if the amount of carbon-carbon double bonds in the resin composition exceeds 0.006 mol / g, the curing speed increases, but the crosslink density in the cured product increases, so that the substrate and the liquid crystal display panel are cured. The adhesive strength with the object may be lowered. On the other hand, when the amount of the carbon-carbon double bond is less than 0.002 mol / g, the curing rate is lowered. Therefore, the resin composition in which the carbon-carbon double bond amount satisfies the above range is excellent in the balance between curability and adhesiveness with the substrate. Among them, the amount of carbon-carbon double bonds is preferably 0.002 mol / g or more and 0.003 mol / g or less from the viewpoint of excellent balance between curability of the resin composition and adhesion to the substrate. .

ここで、ａは（３）のフィラーを除く樹脂組成物中の（１ａ）の樹脂の配合比率（質量％）、Ｎａは（１ａ）の樹脂の炭素−炭素二重結合量（ｍｏｌ／ｇ）、ｂは（３）のフィラーを除く樹脂組成物中の（１ｂ）の樹脂の配合比率（質量％）、Ｎｂは（１ｂ）の樹脂の炭素−炭素二重結合量を表す。 In the resin composition of the present invention, the amount of carbon-carbon double bonds is adjusted to the above-described appropriate range by appropriately selecting and blending the resin (1a) and the resin (1b). For example, the carbon-carbon double bond amount of a resin composition produced by using the resin (1a) and the resin (1b) in combination can be obtained by the following formula.

Here, a is the blending ratio (mass%) of the resin of (1a) in the resin composition excluding the filler of (3), and Na is the carbon-carbon double bond amount (mol / g) of the resin of (1a). , B represents the blending ratio (mass%) of the resin (1b) in the resin composition excluding the filler (3), and Nb represents the amount of carbon-carbon double bonds in the resin (1b).

  As described above, in the present invention, the amount of carbon-carbon double bonds of the resin composition in which a plurality of curable resins are combined is the same as the weight of the resin composition excluding the filler of (3). The value obtained by multiplying the number divided by the amount of the carbon-carbon double bond of the curable resin. Therefore, what is necessary is just to obtain | require the amount of carbon-carbon double bonds of the resin composition which uses multiple types of (1a) resin or multiple types (1b) resin similarly to the above.

  The amount of carbon-carbon double bonds in the curable resin is determined by dividing the number of carbon-carbon double bonds in the molecule by the molecular weight of the resin, and the unit is mol / g. The molecular weight of each curable resin is preferably measured by GPC using polystyrene as a standard. In this case, the number average molecular weight and the weight average molecular weight are calculated, but the carbon-carbon double bond amount is preferably calculated by the number average molecular weight.

  Next, the resin (1a) and the resin (1b) which are curable resins will be described.

(1a) Resin The (1a) acrylic resin refers to an acrylate and / or methacrylic acid ester monomer having a carbon-carbon double bond in the molecule, or an oligomer thereof. The acrylic resin is roughly classified into (1a-1) a compound in which 2 to 8 substituents containing a (meth) acryl group are introduced into a polycyclic aromatic compound, and (1a-2) a compound other than this. .

(1a-1) Compound in which 2 to 8 substituents are introduced into a polycyclic aromatic compound The compound of (1a-1) above is a compound composed of two or more aromatic rings (polycyclic aromatic compound) ) Is a compound in which 2 to 8 groups containing a (meth) acryl group are introduced. The compound (1a-1) is preferably an acrylic group-containing polycyclic aromatic compound represented by the following general formula (1) from the viewpoint of increasing the curing rate of the resin composition.

前記一般式（１）中の、
ｍは、２〜８の整数を表し、
ｎは、１〜４の数を表し、
Ｒ_１は、炭素数２〜６の炭化水素基を表し、
Ｒ_２は、水素またはメチル基を表し、
Ａは、多環芳香族炭化水素基を表わす。

In the general formula (1),
m represents an integer of 2 to 8,
n represents a number from 1 to 4,
R ₁ represents a hydrocarbon group having 2 to 6 carbon atoms,
R ₂ represents hydrogen or a methyl group,
A represents a polycyclic aromatic hydrocarbon group.

  A in the general formula (1) represents a polycyclic aromatic hydrocarbon group. That is, in the compound of the general formula (1), the substituent (also referred to as “double bond-containing group”) containing a (meth) acrylic group delimited by m is arbitrary in the polycyclic aromatic hydrocarbon compound. It is a compound introduced in 2 to 8 positions. That is, A is a divalent to octavalent group.

  Examples of the polycyclic aromatic hydrocarbon group represented by A include groups derived from a compound having a condensed ring structure in which two or more aromatic rings are linked, such as naphthalene, fluorene, and anthracene skeleton; A group derived from a compound having a non-condensed ring structure in which the above aromatic rings are bonded via an alkylene group without being condensed or the aromatic rings are single-bonded, such as biphenyl, is included.

  Examples of the polycyclic aromatic hydrocarbon group having a non-fused ring structure include cresol novolak type, phenol novolak type, bisphenol A type, bisphenol F type, triphenolmethane type, triphenolethane type, trisphenol type, diphenyl ether And groups derived from biphenyl type compounds. These polycyclic aromatic hydrocarbon groups may have a non-condensed ring structure in which two or more aromatic rings are bonded in a straight chain or a structure in which they are bonded in a side chain.

  The double bond-containing group represented by m in the general formula (1) is a group bonded to A, and is also referred to as “substituent of A” for convenience in the present invention. Moreover, m is the number of substituents containing a carbon-carbon double bond as a double bond, and represents an integer of 2 to 8.

  N in the general formula (1) represents a number of 1 to 4. The polycyclic aromatic compound represented by the general formula (1) is preferably obtained by adding a cyclic ether to a resin described later. In this case, since n may not be constant, n may be an average value.

R ₁ in the general formula (1) is a hydrocarbon group having 2 to 6 carbon atoms, and specific examples of the hydrocarbon group include a linear or branched alkylene group. Among these, R ₁ is preferably a hydrocarbon group having 2 to 5 carbon atoms. Also, R ₂ in the general formula (1) represents a hydrogen or a methyl group, R ₂ can be any group.

  The amount of carbon-carbon double bonds in the acrylic group-containing polycyclic aromatic compound is bonded to the polycyclic aromatic hydrocarbon group represented by A while appropriately selecting the double bond-containing group represented by m. Can be adjusted as appropriate.

  A preferable example of the acrylic group-containing polycyclic aromatic compound is obtained by reacting an epoxy resin with (meth) acrylic acid, and the epoxy group in the epoxy resin is completely (meth) acrylated, that is, epoxy. Resins that do not contain groups are included. Examples of the epoxy resin include a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a triphenolmethane type epoxy resin, a triphenolethane type epoxy resin, and a trisphenol type epoxy. Resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin are included.

  As a resin in which the epoxy group in the epoxy resin is completely (meth) acrylated (also referred to as “fully (meth) acrylated epoxy resin”), 4 mol or more of ethylene oxide or propylene per 1 mol of bisphenol A type epoxy resin Diacrylate and / or dimethacrylate of diol obtained by adding oxide, and diacrylate and / or dimethacrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A type epoxy resin There may be.

  The complete (meth) acrylated epoxy resin can be synthesized by a known synthesis method, but can also be easily obtained as a commercial product. Examples of fully (meth) acrylated epoxy resins include bisphenol A-type epoxy resin-modified diacrylate, which has a product name of “3002A” from Kyoeisha Chemical Co., Ltd. and a product of “EB3700” from Daicel Cytec Co., Ltd. Each is marketed by name.

  Further, the acrylic group-containing polycyclic aromatic compound may be a compound obtained by esterifying a modified product obtained by ring-opening addition of a cyclic ether compound to a polyhydric phenol compound with (meth) acrylic acid. Specific examples thereof include trisphenol tri (meth) acrylate obtained by modifying a trisphenol type resin with propylene oxide (PO) and then esterifying with (meth) acrylic acid.

  The acrylic group-containing polycyclic aromatic compound may be an aromatic carboxylic acid having two or more aromatic rings, or a compound obtained by adding a hydroxyl group-containing acrylic monomer to an aromatic acid chloride. In this case, A in the general formula (1) is a group derived from the aromatic carboxylic acid or the aromatic acid chloride.

(1a-2) Compounds other than (1a-1) The compounds other than (1a-1) corresponding to the acrylic resin of (1a) include the following compounds.

  Diacrylate and / or dimethacrylate such as polyethylene glycol, propylene glycol, polypropylene glycol; diacrylate and / or dimethacrylate of tris (2-hydroxyethyl) isocyanurate; 4 moles or more of ethylene oxide or propylene per mole of neopentyl glycol Diols and / or dimethacrylates of diols obtained by adding oxides; diols or triacrylates and / or di or tris of triols obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane Methacrylate; tris (2-hydroxyethyl) isocyanurate triacrylate and / or trimethacrylate; trimethylol group Pantriacrylate and / or trimethacrylate, or oligomer thereof; pentaerythritol triacrylate and / or trimethacrylate, or oligomer thereof; polyacrylate and / or polymethacrylate of dipentaerythritol; tris (acryloxyethyl) isocyanurate; caprolactone modification Tris (acryloxyethyl) isocyanurate; caprolactone-modified tris (methacryloxyethyl) isocyanurate; polyacrylate and / or polymethacrylate of alkyl-modified dipentaerythritol; polyacrylate and / or polymethacrylate of caprolactone-modified dipentaerythritol; hydroxypivalin Acid neopentyl glycol diacrylate and / or Caprolactone modified hydroxypivalate neopentyl glycol diacrylate and / or dimethacrylate; ethylene oxide modified phosphate acrylate and / or dimethacrylate; ethylene oxide modified alkylated phosphate acrylate and / or dimethacrylate; neopentyl glycol, Trimethylolpropane, pentaerythritol oligoacrylate and / or oligomethacrylate.

  Among them, the compound (1a-2) is preferably trimethylolpropane triacrylate and / or trimethacrylate, or an oligomer thereof; dipentaerythritol polyacrylate and / or polymethacrylate. This is because these compounds can provide a resin composition having excellent adhesion to the member to be bonded.

  The compound (1a-2) is a compound obtained by ring-opening an acid anhydride with a hydroxyl group-containing acrylic monomer and then condensing with phenylglycidyl ether; an aromatic carboxylic acid having one aromatic ring, or A compound obtained by adding a hydroxyl group-containing acrylic monomer to an aromatic acid chloride may also be used.

Regardless of whether the resin of (1a) is a polycyclic aromatic compound or other compounds, its number average molecular weight is in the range of 300 to 2000, and the theoretical solubility parameter (sp value) of Fedors is 10 Those having a thickness of 0.0 to 13.0 (cal / cm ³ ) ^1/2 are preferable. Since the resin (1a) has low solubility and diffusibility in liquid crystal, it can give a resin composition that hardly contaminates the liquid crystal. As a result, a liquid crystal display panel with good display properties can be obtained. Moreover, since the resin composition of (1a) is excellent in compatibility with (5) epoxy resin described later, a uniform resin composition and a cured product can be provided. The number average molecular weight can be measured, for example, by GPC using polystyrene as a standard.

There are various methods and calculation methods for calculating the solubility parameter (sp value). The theoretical solubility parameter of the present invention is preferably based on a calculation method devised by Fedors (Journal of the Adhesion Society of Japan, vol. 22, No. 10 (1986) (53) (566) and the like). This is because this calculation method does not require a density value, so that the solubility parameter can be easily calculated. The Fedors theoretical solubility parameter (sp value) is calculated by the following equation. However, in the following equations, ΣΔel = (ΔH−RT), ΣΔvl = sum of molar capacities.

  If the solubility parameter (sp value) is within the above range, the resin of (1a) becomes less soluble in the liquid crystal, so that a resin composition that hardly contaminates the liquid crystal can be provided. A liquid crystal display panel can be obtained.

The resin of (1a) may be a mixture obtained by combining several kinds of the above-mentioned acrylic resins, and the theoretical solubility parameter (sp value) of the mixture is determined based on each acrylate monomer and / or methacrylate ester to be mixed. It can be calculated based on the sum of the molar fractions of the monomers or these oligomers. The value is also preferably in the range of 10.0 to 13.0 (cal / cm ³ ) ^{1/2 as} described above.

The resin of (1a) having a number average molecular weight of 300 to 2000 and a theoretical solubility parameter (sp value) of Fedors in the range of 10.0 to 13.0 (cal / cm ³ ) ^1/2 Examples include pentaerythritol tetraacrylate (number average molecular weight: 352, sp value 12.1). When the resin (1a) is used as a raw material for an electronic material such as a liquid crystal sealant, the resin (1a) is preferably highly purified by a water washing method or the like.

Resin (1b) The resin (1b) is a (meth) acryl-modified epoxy resin (also simply referred to as “modified epoxy resin”) having at least one epoxy group and (meth) acryl group in the molecule. . The “modified epoxy resin” of the present invention means a resin in which some of a plurality of epoxy groups contained in the epoxy resin are (meth) acrylated.

  Examples of such modified epoxy resins include reacting an epoxy resin with a (meth) acrylic compound such as (meth) acrylic acid or phenyl (meth) acrylate in accordance with a known method, for example, in the presence of a basic catalyst. To obtain.

  Examples of the epoxy resin that can be used as a raw material for the modified epoxy resin include a cresol novolac type epoxy resin, a phenol novolac type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a triphenolmethane type epoxy resin, Phenolethane type epoxy resin, trisphenol type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin are included. Moreover, it is preferable that these epoxy resins are highly purified by a molecular distillation method, a washing method, or the like.

  Among them, as the modified epoxy resin, a bifunctional epoxy resin having two epoxy groups in a molecule such as bisphenol A type epoxy resin and bisphenol F type epoxy resin and acrylic acid are used as a mole of the bifunctional epoxy resin. A resin obtained by reacting the number of the acrylic acid and the number of moles of acrylic acid at a ratio of 1: 1 is preferable. When the resin is used as a raw material for the resin composition, a resin composition having excellent adhesiveness with a member to be bonded can be provided.

  By appropriately changing the blending amount of the epoxy resin and the (meth) acrylic compound, a (meth) acryl-modified epoxy resin having an arbitrary (meth) acrylation rate can be obtained. A (meth) acrylation rate means the ratio of the (meth) acrylated epoxy group with respect to all the epoxy groups contained in an epoxy resin. By appropriately adjusting the (meth) acrylation rate, the curing rate of the resin composition and the curing shrinkage rate of the resin composition can be freely controlled.

  Since the modified epoxy resin has both a (meth) acryl group and an epoxy group in the molecule, it is an epoxy having a high addition polymerization property at the same time as the reaction between carbon-carbon double bonds caused by the (meth) acryl group. Since the groups react quickly, a resin composition having a high curing rate can be obtained. Moreover, since the said resin composition has an epoxy group which contributes to the improvement of the adhesive strength with a board | substrate, a high quality liquid crystal display panel is given. Furthermore, since the modified epoxy resin is highly compatible with the acrylic resin of (1a), the resin composition used in combination with each resin has a high glass transition temperature (Tg) and is uniform and has an adhesive strength to the substrate. Gives a high cured product.

  When the resin composition of the present invention is prepared, the resin (1a) and the resin (1b) may be used in combination, or may be used alone. When these resins are used in combination, the blending ratio of these resins may be an arbitrary ratio. The mixing ratio is preferably (1a) resin: (1b) resin = 10-70: 90-30 in terms of mass ratio, (1a) resin: (1b) resin = 20-50: More preferably, it is 80-50. Thereby, the resin composition which can give the hardened | cured material with high adhesive strength with a board | substrate can be given.

  In addition, when either one of the resins is used, that is, for example, when only the resin (1a) is used without using the resin (1b), the resin composition having good leakage resistance Things are obtained. On the other hand, when only the resin (1b) is used without using the resin (1a), a resin composition that is sufficiently cured by heat alone and has good adhesive strength with the substrate can be obtained. However, the resin composition using only the resin (1b) as described above may reduce the strength of the cured product, but in that respect, together with the resin (1b), the epoxy curing agent (4) described later. If is used, the strength of the cured product can be improved.

(2) Thermal radical polymerization initiator The resin composition of the present invention contains a thermal radical polymerization initiator. A thermal radical polymerization initiator refers to a compound that generates radicals when heated, that is, a compound that absorbs thermal energy and decomposes to generate radical species. The thermal radical polymerization initiator is preferably 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the resin unit. However, when the content of the thermal radical polymerization initiator is too large, the viscosity stability is deteriorated, and when it is too small, the curability is deteriorated. Here, when only one of the resin (1a) or the resin (1b) is used as the curable resin, the thermal radical polymerization start of (2) is started with respect to 100 parts by mass of the resin used alone. What is necessary is just to make content of an agent into said range.

  When the resin composition of the present invention is used as a liquid crystal sealant, as described above, the liquid crystal leaks if the viscosity of the liquid crystal sealant is excessively reduced by heating. It is preferably suppressed. In order to suppress a decrease in resin viscosity during heating, as described above, from the viewpoint of increasing the curing rate of the resin composition and promoting gelation, the amount of carbon-carbon double bonds in the resin composition is within a predetermined range. Although it is useful to adjust in the inside, the fall of the said resin viscosity can be further suppressed by using the thermal radical polymerization initiator of (2) appropriately.

  Gelation of the resin composition is promoted by lowering the 10-hour half-life temperature of the thermal radical polymerization initiator. The 10-hour half-life temperature is the temperature at which the concentration of the thermal radical polymerization initiator becomes half the original when the thermal radical polymerization initiator is subjected to a thermal decomposition reaction at a constant temperature for 10 hours in the presence of an inert gas. It is. This is because if the 10-hour half-life temperature is low, radicals are easily generated even at a relatively low temperature, and the resin composition is easily cured even at a low temperature. Conversely, when the temperature is high, radicals are less likely to be generated, and the curability of the resin composition is reduced.

  Therefore, from the viewpoint of promoting gelation of the resin composition, the 10-hour half-life temperature of the thermal radical polymerization initiator is preferably 40 to 80 ° C, and more preferably 50 to 70 ° C. When the 10-hour half-life temperature is 80 ° C. or lower, further 70 ° C. or lower, when the composition is cured (normally the curing temperature is 80 to 150 ° C.), radicals are easily generated and the curing reaction is promoted. Reduced viscosity reduction during heat curing.

  On the other hand, if the 10-hour half-life temperature of the thermal radical polymerization initiator is too low, the curing reaction tends to proceed even at room temperature, and the stability of the liquid crystal sealant is impaired. However, if the 10-hour half-life temperature of the thermal radical polymerization initiator is 40 ° C., preferably 50 ° C. or higher, a resin having good stability during storage and in the step of applying to a substrate (usually performed at room temperature). A composition is obtained.

  The 10-hour half-life temperature of the thermal radical polymerization initiator is specifically determined as follows.

  First, when the thermal decomposition reaction is handled as a primary reaction equation, the following equation holds.

Ｃ_０：熱ラジカル重合開始剤の初期濃度
Ｃ_ｔ：熱ラジカル重合開始剤のｔ時間後の濃度
ｋｄ：熱分解速度定数
ｔ：反応時間
半減期は熱ラジカル重合開始剤の濃度が半分になる時間、すなわち、Ｃ_ｔ＝Ｃ_０／２となる場合である。よってｔ時間に熱ラジカル重合開始剤が半減期になる場合は以下の式が成り立つ。

C ₀ : Initial concentration of thermal radical polymerization initiator
C _t : concentration of the thermal radical polymerization initiator after t time
kd: thermal decomposition rate constant
t: Reaction time The half-life is the time when the concentration of the thermal radical polymerization initiator is halved, that is, when C _t = C _0/2 . Therefore, when the thermal radical polymerization initiator has a half-life at time t, the following equation holds.

一方、速度定数の温度依存性はアレニウスの式で表されから、以下の式が成立する。

On the other hand, since the temperature dependence of the rate constant is expressed by the Arrhenius equation, the following equation is established.

Ａ：頻度因子
ΔＥ：活性化エネルギー
Ｒ：気体定数（８．３１４Ｊ／ｍｏｌ・Ｋ）
Ｔ：絶対温度（Ｋ）
ＡおよびΔＥの値は、Ｊ．Ｂｒａｎｄｒｕｐほか著、「Ｐｏｌｙｍｅｒ Ｈａｎｄ Ｂｏｏｋ ｆｏｕｒｔｈ ｅｄｉｔｉｏｎ ｖｏｌｕｍ１、ｐａｇｅＩＩ−２〜ＩＩ−６９、Ｊｏｈｎ＆Ｗｉｌｅｙ、（１９９９）」に記載されている。以上から、ｔ＝１０時間とすれば、１０時間半減期温度Ｔが求められる。

A: Frequency factor ΔE: Activation energy R: Gas constant (8.314 J / mol · K)
T: Absolute temperature (K)
The values for A and ΔE are Brandrup et al., “Polymer Hand Book fourth edition volume 1, pages II-2 to II-69, John & Wiley, (1999)”. From the above, if t = 10 hours, the 10-hour half-life temperature T is obtained.

  Examples of the thermal radical polymerization initiator include compounds known as thermal radical polymerization initiators. Of these, organic peroxides and azo compounds are preferred as the thermal radical polymerization initiator.

  Examples of the organic peroxide include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxyester, diacyl peroxide, and peroxydicarbonate.

  Specific examples of these are shown below. The numbers in parentheses next to each compound are the 10-hour half-life temperatures (see Wako Pure Chemicals Catalog, API Corporation Catalog and the aforementioned Polymer Handbook).

  Examples of ketone peroxides include methyl ethyl ketone peroxide (109 ° C.) and cyclohexano peroxide (100 ° C.).

  Examples of peroxyketals include 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane (87 ° C.), 1,1-bis (t-hexylperoxy) cyclohexane (87 ° C. ), 1,1-bis (t-butylperoxy) cyclohexane (91 ° C.), 2,2-bis (t-butylperoxy) butane (103 ° C.), 1,1- (t-amylperoxy) cyclohexane (93 ° C), n-butyl 4,4-bis (t-butylperoxy) valerate (105 ° C), 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane (95 ° C) Is included.

  Examples of hydroperoxides include P-methane hydroperoxide (128 ° C), diisopropylbenzene peroxide (145 ° C), 1,1,3,3-tetramethylbutyl hydroperoxide (153 ° C), cumene hydro Peroxide (156 ° C.) and t-butyl hydroperoxide (167 ° C.) are included.

  Examples of dialkyl peroxides include α, α-bis (t-butylperoxy) diisopropylbenzene (119 ° C.), dicumyl peroxide (116 ° C.), 2,5-dimethyl-2,5-bis (t- Butylperoxy) hexane (118 ° C.), t-butylcumyl peroxide (120 ° C.), t-amyl peroxide (123 ° C.), di-t-butyl peroxide (124 ° C.), 2,5-dimethyl-2 , 5-bis (t-butylperoxy) hexane-3 (129 ° C.).

  Examples of peroxyesters include cumyl peroxyneodecanoate (37 ° C.), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (41 ° C.), t-hexyl peroxyneodecane. Noate (45 ° C.), t-butyl peroxyneodecanoate (46 ° C.), t-amyl peroxyneodecanoate (46 ° C.), t-hexyl peroxypivalate (53 ° C.), t-butyl Peroxypivalate (55 ° C.), t-amyl peroxypivalate (55 ° C.), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (65 ° C.), 2,5- Dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane (66 ° C.), t-hexylperoxy-2-ethylhexanoate (70 ° C.), t-butyl peroxy 2-ethylhexanoate (72 ° C), t-amylperoxy-2-ethylhexanoate (75 ° C), t-butylperoxyisobutyrate (82 ° C), t-hexylperoxyisopropyl monocarbonate (95 ° C.), t-butyl peroxymaleic acid (96 ° C.), t-amyl peroxy normal octoate (96 ° C.), t-amyl peroxy isononanoate (96 ° C.), t-butyl peroxy- 3,5,5-trimethylhexanoate (97 ° C.), t-butyl peroxylaurate (98 ° C.), t-butyl peroxyisopropyl monocarbonate (99 ° C.), t-butyl peroxy-2-ethylhexyl mono Carbonate (99 ° C), t-hexylperoxybenzoate (99 ° C), 2,5-dimethyl-2,5 Sus (benzoylperoxy) hexane (100 ° C.), t-amyl peroxyacetate (100 ° C.), t-amyl peroxybenzoate (100 ° C.), t-butyl peroxyacetate (102 ° C.), t-butyl peroxy Benzoate (104 ° C.) is included.

  Examples of diacyl peroxides include diisobutyryl peroxide (33 ° C.), di-3,5,5-trimethylhexanoyl peroxide (60 ° C.), dilauroyl peroxide (62 ° C.), disuccinic acid peroxide (66 ° C.) and dibenzoyl peroxide (73 ° C.).

  Examples of peroxydicarbonates include di-n-propyl peroxydicarbonate (40 ° C.), diisopropyl peroxydicarbonate (41 ° C.), bis (4-t-butylcyclohexyl) peroxydicarbonate (41 ° C. ), Di-2-ethylhexyl peroxydicarbonate (44 ° C.), t-amyl peroxypropyl carbonate (96 ° C.), and t-amyl peroxy 2-ethylhexyl carbonate (99 ° C.).

(3) Filler The resin composition of the present invention contains (3) a filler. The filler refers to a filler added for the purpose of controlling the viscosity of the resin composition, improving the strength of the cured product, and controlling the linear expansion. By filling the filler, the adhesiveness between the resin composition and a member to be bonded such as a substrate is improved. The filler is not particularly limited as long as it is usually used in the field of electronic materials. Examples of the filler include inorganic fillers and organic fillers.

  Examples of the inorganic filler include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide, silicon dioxide, potassium titanate, kaolin, Talc, glass beads, sericite activated clay, bentonite, aluminum nitride, silicon nitride are included.

  Examples of the organic filler include polymer particles having a softening point temperature exceeding 120 ° C. by the ring and ball method (JACT test method: RS-2). Examples of the polymer particles include copolymers obtained by copolymerizing polystyrene and monomers copolymerizable therewith, polyester fine particles, polyurethane fine particles, and rubber fine particles.

  Among these, as the filler, an inorganic filler is preferable, and silicon dioxide and talc are particularly preferable because they hardly transmit ultraviolet rays. By including an inorganic filler in the resin composition, the linear expansion coefficient of the resin composition is reduced, so that the shape of the resin composition after being applied on the substrate can be favorably maintained.

The shape of the filler is not particularly limited, and may be a regular shape such as a spherical shape, a plate shape, or a needle shape, or an irregular shape. The filler preferably has an average primary particle size of 1.5 μm or less and a specific surface area of 1 to 500 m ² / g. This is because if the average primary particle diameter and specific surface area of the filler are within the above ranges, the balance between thixotropy and viscosity represented by the thixotropy index described later is excellent. 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 can be measured by the BET method described in JIS Z8830.

  The filling amount of the filler is preferably 1 to 50 parts by mass and more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the resin unit. When only one of the resin (1a) and the resin (1b) is used, the filler filling amount may be adjusted in the same manner as when each resin is used alone. Thus, the resin composition in which the filling amount of the filler was adjusted had a thixotropy index ([25 ° C. using an E-type viscometer, viscosity at 0.5 rpm] / [25 ° C. using an E-type viscometer, 5 0.0 Viscosity]) is preferable because it is easy to control the viscosity to 1.1 to 5.0.

  The thixotropy index means the ratio between the viscosity measured at a relatively low shear rate and the viscosity measured at a relatively high shear rate. A fluid having a high thixotropy index has a high viscosity under a low shear rate, but behaves as a low viscosity under a high shear rate. Usually, in the case of manufacturing a liquid crystal display panel, in the step of applying a liquid crystal sealant to a substrate, the sealant is placed under a relatively high shear rate. Liquid crystal sealants are placed under extremely low shear rate conditions. Here, in the step of applying the liquid crystal sealant to the substrate (high shear rate region), it is desirable that the liquid crystal sealant is well applied to the substrate and that the liquid crystal sealant is easily defoamed. The sealing agent is required to have a low viscosity. On the other hand, in the step of curing the liquid crystal sealant, the liquid crystal sealant is required to have a high viscosity in order to prevent the liquid crystal from leaking although it is placed under the condition of a low shear rate. In that respect, a resin composition having a thixotropy index within the above range has good coating properties, defoaming properties, and reliability when used as a liquid crystal sealant.

(4) Epoxy curing agent The resin composition of the present invention may contain an epoxy curing agent. The epoxy curing agent is preferably a latent epoxy curing agent. A latent epoxy curing agent is a curing agent that cures an epoxy resin by heat or light, even if it is mixed with an epoxy resin, but does not cure the epoxy resin under normal storage conditions (room temperature, visible light, etc.) Say. The resin composition containing the latent epoxy curing agent is particularly excellent in thermosetting.

  As the latent epoxy curing agent, known ones may be used. However, a latent epoxy curing agent having a melting point or a softening point temperature by the ring-and-ball method of 100 ° C. or more is preferable because of excellent viscosity stability. Examples of such latent epoxy curing agents include organic acid dihydrazide compounds, imidazoles and derivatives thereof, dicyandiamide, aromatic amines, or mixtures thereof.

  In particular, a resin composition using an amine latent curing agent having a melting point or a softening point temperature by the ring and ball method of 100 ° C. or higher is extremely excellent in viscosity stability at room temperature. Therefore, it is preferable to produce a liquid crystal display panel using a liquid crystal sealant to which the resin composition is applied because screen printing or a dispenser can be used. In screen printing and dispensers, the liquid crystal sealant stays in the device for a long time. If the viscosity stability of the liquid crystal sealant is not sufficient, the frequency of replacing the liquid crystal sealant filled in the device such as the dispenser increases. , Productivity decreases.

  Examples of the amine latent curing agent include dicyandiamides such as dicyandiamide (melting point 209 ° C.), adipic acid dihydrazide (melting point 181 ° C.), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin ( Organic acid dihydrazide such as 2,4-diamino-6- [2′-ethylimidazol-1′-yl] -ethyltriazine (melting point 215 ° C. to 225 ° C.), 2-phenylimidazole (melting point 137) Imidazole derivatives such as ˜147 ° C.).

  The content of the latent epoxy curing agent is preferably 3 to 30 parts by mass with respect to 100 parts by mass of the resin unit. This is because the liquid crystal sealant is excellent in viscosity stability and adhesion reliability. Further, when the resin (1a) or the resin (1b) is used alone, the content of the latent epoxy curing agent may be within the above-described range in which each resin is used alone. The latent epoxy curing agent is preferably highly purified by a water washing method, a recrystallization method, or the like from the viewpoint of obtaining a resin composition with few impurities.

(5) Epoxy resin The resin composition of the present invention may contain an epoxy resin. In the present invention, the epoxy resin refers to a compound having one or more epoxy groups in the molecule (except for the modified epoxy resin (1b) above). As described above, the resin composition of the present invention can be sufficiently cured by heat alone to give a cured product, but there is a concern that the cured product cured only by a (meth) acrylic resin has low strength. . In that respect, when only the resin (1a) is used as a raw material, the combination of the resin (1a) and the epoxy resin (5) gives a high-strength cured product in addition to the speed of curing. An obtained resin composition can be obtained.

  Examples of the epoxy resin include aromatic diols represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, and diols modified with ethylene glycol, propylene glycol, alkylene glycol, and epichlorohydrin. The aromatic polyvalent glycidyl ether compound obtained is included. Hereinafter, for example, a material using bisphenol A as a raw material is expressed as “bisphenol A type epoxy resin”.

  Examples of such epoxy resins include novolak-type polyphenols obtained by the reaction of novolak resins derived from phenol or cresol and formaldehyde, polyalkenylphenols represented by polyalkenylphenols or copolymers thereof, and epichlorohydrin. Valent glycidyl ether compounds; xylylene phenol resin glycidyl ether compounds.

  Among these, cresol novolak type epoxy resin, phenol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, triphenolmethane type epoxy resin, triphenolethane type epoxy resin, trisphenol type epoxy resin Dicyclopentadiene type epoxy resin, diphenyl ether type epoxy resin, and biphenyl type epoxy resin are preferable. Further, the epoxy resin may be a mixture thereof.

  The epoxy resin of the present invention preferably has a softening point by the ring and ball method of 40 ° C. or higher and a weight average molecular weight of 1,000 to 10,000. The softening point and weight average molecular weight of the epoxy resin affect the viscosity of the liquid crystal sealant. Since the resin composition having a softening point and a weight average molecular weight within the above ranges have low solubility and diffusibility in liquid crystals, a liquid crystal display panel having excellent display properties can be provided. Moreover, since the said epoxy resin is excellent also in compatibility with resin of (1a), a uniform resin composition is given and, as a result, the adhesive strength of the hardened | cured material of a resin composition and a board | substrate improves.

  The weight average molecular weight of the epoxy resin can be measured, for example, by GPC using polystyrene as a standard. These epoxy resins are preferably those purified by a molecular distillation method or the like.

(6) Photoradical polymerization initiator The resin composition of the present invention may contain a photoradical polymerization initiator. The photo radical polymerization initiator refers to a compound that generates radicals by light. Since the resin composition containing a radical photopolymerization initiator can be temporarily cured by light, shortening of the curing time and improvement of workability are expected. However, since the resin composition of the present invention can be cured only by heat without using a radical photopolymerization initiator, it is not always necessary to use a radical photopolymerization initiator.

  A known compound can be used as the radical photopolymerization initiator. Examples of photo radical polymerization initiators include benzoin compounds, acetophenones, benzophenones, thioxanthones, α-acyloxime esters, phenylglyoxylates, benzyls, azo compounds, diphenyl sulfide compounds, acylphosphines. Oxide compounds, organic dye compounds, iron-phthalocyanine compounds, benzoins, benzoin ethers, anthraquinones are included.

  Content of radical photopolymerization initiator is 0.3-5.0 mass parts with respect to 100 mass parts of resin units. When the content is 0.3 parts by mass or more, the curability of the resin composition by light irradiation is high and good. By setting the content to 5.0 parts by mass or less, stability at the time of application to the substrate is improved. In addition, when only one of the resin (1a) or the resin (1b) is used as the curable resin, the content of the photoradical polymerization initiator is adjusted in the same manner as the above range in which each resin is used alone. That's fine.

(7) Thermoplastic polymer The resin composition of the present invention may contain a thermoplastic polymer. The thermoplastic polymer is a polymer compound that becomes soft when heated and can be molded into a desired shape. Moreover, the said thermoplastic polymer means the polymer whose softening point temperature is less than 120 degreeC as below-mentioned, and means polymers other than the organic filler applicable to the filler of said (3).

  The softening point temperature of the thermoplastic polymer of the present invention is usually from 50 to less than 120 ° C, preferably from 60 to 80 ° C. When the softening point temperature is within the above range, the thermoplastic polymer melts into the resin composition during thermosetting of the resin composition, and the resin (1a), the resin (1b), the epoxy resin (5) and As a result of compatibility, a decrease in viscosity at the time of heating can be suppressed, and as a result, liquid crystal leakage and the like can be reduced. The softening point temperature can be measured by the ring and ball method (JACT test method: RS-2).

  Moreover, as for content of the said thermoplastic polymer, 1-30 mass parts is preferable with respect to 100 mass parts of resin units. When only one of the resin (1a) or the resin (1b) is used as the curable resin, the content of the thermoplastic polymer may be adjusted in the same manner as in the above-described range where each resin is used alone. .

  The average particle size of the thermoplastic polymer is preferably 0.05 to 5 μm, and more preferably 0.07 to 3 μm. Thereby, the resin composition with favorable compatibility can be obtained. A known polymer may be used as the thermoplastic polymer. Examples of the thermoplastic polymer include a (meth) acrylic acid ester monomer and a monomer copolymerizable with the monomer of 50 to 99.9% by mass: 50 to 0.1% by mass (more preferably 60 to 80% by mass). : 40 to 80% by mass) and a copolymer obtained by copolymerization. Moreover, as this copolymer, what was superposed | polymerized in the state of the emulsion by emulsion polymerization or suspension polymerization is preferable.

  Examples of the (meth) acrylic acid ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl acrylate, 2-ethylhexyl (meth) acrylate, amyl (meth) acrylate, hexadecyl ( Monofunctional (meth) acrylate monomers such as (meth) acrylate, octadecyl (meth) acrylate, butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and glycidyl (meth) acrylate included. Among these, methyl (meth) acrylate, butyl acrylate, 2-ethylhexyl (meth) acrylate, or a mixture thereof is preferable.

  Examples of the monomer copolymerizable with the (meth) acrylic acid ester monomer include acrylamides; acid monomers such as (meth) acrylic acid, itaconic acid and maleic acid; aromatic vinyl compounds such as styrene and styrene derivatives; 1 Conjugated dienes such as 1,3-butadiene, 1,3-pentadiene, isoprene, 1,3-hexadiene, chloroprene; polyfunctional monomers such as divinylbenzene and diacrylates, or mixtures thereof.

(8) Other Additives The resin composition of the present invention can be used as required by coupling agents such as silane coupling agents, ion trapping agents, ion exchange agents, leveling agents, pigments, dyes, plasticizers, antifoaming agents. An additive such as an agent may be further contained. Moreover, a spacer etc. may be mix | blended with the resin composition. Such a resin composition can be a liquid crystal sealant capable of appropriately adjusting the distance (gap) between the substrates in the liquid crystal display panel.

2. Manufacturing method of curable resin composition for liquid crystal seals The curable resin composition for liquid crystal seals of the present invention can be arbitrarily manufactured as long as the effects of the invention are not impaired. For example, the components described above may be mixed and manufactured. The mixing method in that case is not specifically limited, For example, what is necessary is just to mix using well-known kneading machines, such as a double arm type stirrer, a roll kneader, a twin screw extruder, a ball mill kneader, a planetary stirrer. In order to knead the mixture uniformly without gelling, the roll temperature is preferably set to 25 to 35 ° C. The mixture thus obtained is filtered through a filter as necessary, and after vacuum degassing treatment, hermetically filled into a glass bottle or a plastic container.

3. Manufacturing Method of Liquid Crystal Display Panel The liquid crystal display panel of the present invention can be arbitrarily manufactured within a range that does not impair the effects of the invention, and a preferable manufacturing method will be specifically described below.

The liquid crystal display panel of the present invention is
(A) preparing one or more substrates having a frame-shaped seal pattern formed so that the pixel array region is surrounded by the liquid crystal seal curable resin composition of the present invention;
(B) dropping the liquid crystal in the uncured seal pattern or on the other substrate;
(C) a step of superimposing the substrate on which the liquid crystal is dropped and the other substrate under reduced pressure;
(D) a step of curing the liquid crystal dropping method liquid crystal sealant sandwiched between the substrates by heating;
It is preferable to be manufactured through.

  The substrate used in the above method is a constituent member of a liquid crystal display panel, and is usually a transparent substrate such as two sheets of glass. In the present invention, an alignment film may be formed on a substrate facing the liquid crystal display panel substrate. The alignment film is not particularly limited, and a film made of a known organic alignment agent or inorganic alignment agent may be used.

  The seal pattern in the step (a) means the shape of a seal drawn with a resin composition. The state in which the resin composition in the step (b) is uncured means a state in which the curing reaction of the resin composition has not progressed to the gel point.

  The step (d) may include a step of curing the liquid crystal sealant by irradiating light. To irradiate light is to irradiate light (preferably ultraviolet rays) having energy capable of reacting with the curable resin. From the viewpoint of simplifying the manufacturing process of the liquid crystal display panel, it is preferably a process of curing only by heating.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. “%” And “part” described below mean “% by mass” and “part by mass”, respectively.

  The raw materials used in each example and comparative example are as follows.

(1a) Acrylic resin Seven types of acrylic resins were appropriately selected and used. In addition, each resin was diluted with toluene and then washed with ultrapure water 12 times, and a highly purified resin was used.

Acrylic resin 1: Bisphenol A type epoxy resin-modified diacrylate (3002A: manufactured by Kyoeisha Chemical Co., Ltd., molecular weight 600, carbon-carbon double bond amount is 0.0033 mol / g)
Acrylic resin 2: PO-modified trisphenol triacrylate (molecular weight 802, carbon-carbon double bond amount is 0.0037 mol / g)
Acrylic resin 3: trimethylolpropane triacrylate (TMP-A: manufactured by Kyoeisha Chemical Co., Ltd., molecular weight 296, carbon-carbon double bond amount 0.0101 mol / g)
Acrylic resin 4: dipentaerythritol pentaacrylate (M-315: manufactured by Toagosei Co., Ltd., molecular weight 523, carbon-carbon double bond amount is 0.0071 mol / g)

(1b) Modified Epoxy Resin A modified epoxy resin obtained by synthesis by the following synthesis method was used.

[Synthesis Example 1]
In a 500 ml four-necked flask equipped with a stirrer, gas introduction tube, thermometer, and cooling tube, 160 g of bisphenol F type epoxy resin (Epototo YDF-8170C: manufactured by Tohto Kasei Co., Ltd.), 36 g of acrylic acid, and 0.2 g of triethanolamine After charging, the solution was stirred and reacted in a dry air stream while heating at 110 ° C. for 5 hours to obtain an acrylic-modified epoxy resin. The obtained resin was washed 12 times using ultrapure water. Moreover, the carbon-carbon double bond amount of the synthesized modified epoxy resin was 0.0025 mol / g.

(2) Thermal radical polymerization initiator t-amylperoxy-2-ethylhexanoate (Lupazole 575: manufactured by API Corporation, 10 hours half-life temperature 75 ° C.) was used.

(3) Filler Spherical silica (Sea Foster S-30: manufactured by Nippon Shokubai Co., Ltd., average primary particle size: 0.3 μm, specific surface area: 11 m ² / g) was used.

(4) Epoxy curing agent 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (Amicure VDH: Ajinomoto Co., Inc., melting point 120 ° C.) was used.

(5) Epoxy resin An o-cresol novolak-type solid epoxy resin (EOCN-1020-75: manufactured by Nippon Kayaku Co., Ltd., softening point of 75 ° C. by the ring and ball method, epoxy concentration of 215 g / eq) was used.

(6) Photoradical polymerization initiator 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184: manufactured by Ciba Specialty Chemicals) was used.

(7) Thermoplastic polymer Methacrylic acid-alkyl copolymer fine particles (F-325: manufactured by Nippon Zeon Co., Ltd., average primary particle size: 0.5 μm) were used.

[Test method]
A liquid crystal sealant prepared by the method described later was used as a sample, and i) liquid crystal sealant leakage resistance, ii) liquid crystal sealant applicability, and iii) adhesive strength were measured and evaluated according to the following methods.

i) Leak resistance of liquid crystal sealant On a 40 mm × 45 mm glass substrate (RT-DM88PIN: manufactured by EHC) with a transparent electrode and an alignment film, using a dispenser (shot master: manufactured by Musashi Engineering), A liquid crystal sealant to which 1 part of 5 μm glass fiber was added was used to draw a 24 mm × 24 mm seal pattern and a 36 mm × 36 mm seal pattern with a line width of 0.5 mm and a thickness of 50 μm. Next, a liquid crystal material (MLC-11900-000: manufactured by Merck & Co., Inc.) corresponding to the volume in the panel after being bonded using a dispenser was precisely dropped into the 24 mm × 24 mm seal pattern of the substrate.

  The above glass substrate and the opposing glass substrate were overlapped under a reduced pressure of 90 Pa using a vacuum chamber. Subsequently, the laminated glass substrates were released into the atmosphere and cured by heating at 120 ° C. for 60 minutes using the atmospheric pressure difference under the atmosphere (hereinafter referred to as “curing step in the leak resistance test”). .

The linearity (seal linearity) of the seal pattern of the obtained liquid crystal display panel was evaluated by the following method. Since this seal linearity represents the degree of deformation of the seal pattern, it becomes an index of leak resistance. In order to evaluate the seal linearity of the liquid crystal display panel, the ratio between the maximum value and the minimum value of the seal was calculated.
[Ratio between maximum width and minimum width of seal] (%) = [minimum width of seal] / [maximum width of seal] × 100

Based on the calculated ratio, “leak resistance of the liquid crystal sealant” was evaluated as follows.
The above ratio is 95% or more: ○ (Excellent)
When the ratio is 50% or more and less than 95%: Δ (slightly superior)
The above ratio is less than 50%: x (inferior)

ii) Applicability of liquid crystal sealant The liquid crystal sealant used in i) above was filled in a syringe having a needle tip diameter of 0.4 mm under vacuum. Next, using a dispenser (shot master: manufactured by Musashi Engineering Co., Ltd.) in which the syringe is set, 50 seal patterns of 35 mm × 40 mm are provided on a glass substrate for a liquid crystal display panel (manufactured by Nippon Electric Glass Co., Ltd.) of 300 mm × 400 mm. Drawn. At this time, the discharge pressure was 0.3 MPa, and the coating speed was 100 mm / sec. The coating thickness was 20 μm.

From the seal shape of the drawn seal pattern, the “applicability of liquid crystal sealant” was evaluated as follows.
48-50 seal patterns with no seal breakage or seal fading: ○ (Excellent)
Less than 45 to 48 seal patterns with no seal breakage or seal fading: Δ (somewhat better)
Less than 44 seal patterns with no seal breakage or seal fading: x (Inferior)

iii) Adhesive strength Using a screen plate, a circular seal pattern having a diameter of 1 mm was applied to the liquid crystal sealant used in i) above on an alkali-free glass having a size of 25 mm × 45 mm × thickness 5 mm. Next, the same glass used as a pair was bonded together and heated at 120 ° C. for 1 hour while being fixed to prepare an adhesion test piece. The obtained adhesion test piece was peeled off in a direction parallel to the glass bottom surface at a speed of 2 mm / min using a tensile tester (model 210: manufactured by Intesco), and the plane tensile strength was measured.

The “adhesive strength” between the cured liquid crystal sealant and the substrate was evaluated as follows.
Tensile strength of 10 MPa or more: ○ (excellent)
Tensile strength is 7 MPa or more and less than 10 MPa: Δ (slightly excellent)
Tensile strength is less than 7 MPa: x (inferior)

[Example 1]
12 parts of epoxy resin, 52 parts of acrylic resin 2 and 26 parts of modified epoxy resin were heated and dissolved in a mixture, 5 parts of epoxy curing agent, 20 parts of filler, and 5 parts of thermoplastic polymer, In addition, they were premixed with a mixer. Next, this mixture was kneaded using three rolls until the solid raw material became 5 μm or less. Subsequently, the kneaded product was filtered with a filter having an opening of 10 μm (MSP-10-E10S: manufactured by ADVANTEC), and then 1 part of a thermal radical polymerization initiator was added, and further mixed with a mixer, followed by vacuum defoaming The liquid crystal sealing agent was obtained by processing.

  The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0026 mol / g.

[Example 2]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 1 part of a radical photopolymerization initiator was added. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0026 mol / g.

[Example 3]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 7 parts of the epoxy curing agent, 15 parts of the epoxy resin, and the thermoplastic polymer were not used. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0026 mol / g.

[Example 4]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 90 parts of the acrylic resin 2 and 12 parts of the epoxy resin were used, and the modified epoxy resin and the thermoplastic polymer were not used. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0033 mol / g.

[Example 5]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 80 parts of acrylic resin 1, 20 parts of modified epoxy resin, and epoxy curing agent, epoxy resin, and thermoplastic polymer were not used. . Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0031 mol / g.

[Example 6]
Except that 60 parts of acrylic resin 1, 20 parts of acrylic resin 3, 20 parts of modified epoxy resin, and epoxy curing agent, epoxy resin, and thermoplastic polymer were not used, all were the same as in Example 1. A liquid crystal sealant was prepared. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0045 mol / g.

[Example 7]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 100 parts of the acrylic resin 1 was used and the modified epoxy resin, epoxy curing agent, epoxy resin, and thermoplastic polymer were not used. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0033 mol / g.

[Comparative Example 1]
A liquid crystal sealant was prepared in the same manner as Example 1 except that 58 parts of acrylic resin 1, 14 parts of epoxy curing agent, 28 parts of epoxy resin, and modified epoxy resin and thermoplastic polymer were not used. did. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0019 mol / g.

[Comparative Example 2]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 100 parts of the acrylic resin 3 and a modified epoxy resin, an epoxy curing agent, an epoxy resin, and a thermoplastic polymer were not used. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond content in the resin composition other than the filler of 0.0101 mol / g.

[Comparative Example 3]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 100 parts of the acrylic resin 4 and a modified epoxy resin, an epoxy curing agent, an epoxy resin, and a thermoplastic polymer were not used. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0071 mol / g.

[Comparative Example 4]
A liquid crystal sealant was prepared in the same manner as in Example 1 except that 85 parts of acrylic resin 4, 5 parts of epoxy curing agent, 10 parts of epoxy resin, and modified epoxy resin and thermoplastic polymer were not used. did. Further, the liquid crystal sealant was evaluated in the same manner as in Example 1. The liquid crystal sealant had a carbon-carbon double bond amount in the resin composition other than the filler of 0.0060 mol / g.

  Table 1 shows the composition of the liquid crystal sealant and the evaluation results in each example and comparative example.

  From the comparison between Examples and Comparative Examples, it is clear that the liquid crystal sealant having a carbon-carbon double bond amount in a specific range is excellent in the balance of leak resistance, adhesiveness, and coating property. In particular, from the comparison between Examples and Comparative Examples 1 and 4, even in a liquid crystal sealant containing a curable resin, a thermal radical polymerization initiator, and a filler, the amount of carbon-carbon double bonds in the resin composition excluding the filler falls within this range. In the case of the outside, it is apparent that the balance of physical properties is lacking, such as a decrease in leak resistance and adhesive strength. In addition, as is clear from the results of Examples 1 to 3, the amount of carbon-carbon double bonds is 0.002 mol / g or more and 0.003 mol / g or less in order to achieve a good balance of physical properties of the liquid crystal sealant. It turned out that it is a more preferable range.

  The curable resin composition for a liquid crystal seal of the present invention can provide a liquid crystal display panel in which deformation of a seal pattern by a liquid crystal sealant and leakage of liquid crystal are reduced, and thus is useful as a constituent member of a liquid crystal display panel. is there.

Claims (8)

(1a) an acrylic resin or (1b) a (meth) acryl-modified epoxy resin having an epoxy group and a (meth) acryl group in the molecule;
(2) a thermal radical polymerization initiator;
(3) a filler,
A curable resin composition for liquid crystal seals comprising:
The curable resin composition for liquid crystal seals, wherein the amount of carbon-carbon double bonds in the resin composition excluding the filler of (3) is 0.002 mol / g or more and less than 0.006 mol / g. For 100 parts by mass of the resin unit in which the resin (1a) and the resin (1b) are combined,
2. The curable resin composition for a liquid crystal seal according to claim 1, wherein the content of the thermal radical polymerization initiator (2) is 0.01 to 3.0 parts by mass. The curable resin composition for a liquid crystal seal according to claim 1, wherein the acrylic resin (1a) is an acrylic group-containing polycyclic aromatic compound represented by the following general formula (1).

[In the general formula (1),
m represents an integer of 2 to 8,
n represents a number from 1 to 4,
R ₁ represents a hydrocarbon group having 2 to 6 carbon atoms,
R ₂ represents hydrogen or a methyl group,
A represents a polycyclic aromatic hydrocarbon group]   The liquid crystal seal according to claim 1, further comprising 3 to 30 parts by mass of (4) an epoxy curing agent with respect to 100 parts by mass of the resin unit obtained by combining the resin of (1a) and the resin of (1b). Curable resin composition.   The liquid crystal seal according to claim 1, further comprising 1 to 30 parts by mass of (5) epoxy resin with respect to 100 parts by mass of the resin unit obtained by combining the resin of (1a) and the resin of (1b). Curable resin composition.   It further contains 0.3-5.0 mass parts (6) radical photopolymerization initiator with respect to 100 mass parts of resin units which match | combined the resin of said (1a), and said (1b) resin. The curable resin composition for liquid crystal seals according to 1.   The liquid crystal sealing agent for liquid crystal dropping methods containing the curable resin composition for liquid crystal seals of Claim 1. (A) preparing one or more substrates having a frame-shaped seal pattern formed so that the pixel array region is surrounded by the liquid crystal seal curable resin composition according to claim 1;
(B) dropping the liquid crystal in the uncured seal pattern or on the other substrate;
(C) a step of superimposing the substrate on which the liquid crystal is dropped and the other substrate under reduced pressure;
(D) a step of curing the liquid crystal dropping method liquid crystal sealant sandwiched between the substrates by heating;
A method for manufacturing a liquid crystal display panel, comprising: