JP5886758B2 - Compound suitable for photopolymerization initiator, photopolymerization initiator, and photocurable resin composition - Google Patents

Description

  The present invention relates to a compound obtained by reacting a specific organic acid compound and / or hydroxy compound with an epoxy group-containing compound, a photopolymerization initiator and a photocurable resin composition using the compound.

In recent years, many liquid crystal display panels having features of light weight, high definition, and low power consumption have been produced by a liquid crystal dropping method as display panels for various devices such as large liquid crystal televisions and mobile phones.
The liquid crystal dropping method is a method in which a light and heat combined curable liquid crystal sealing agent is applied onto a substrate on which an electrode pattern and an alignment film are applied, and the substrate on which the liquid crystal sealing agent is applied, or a pair of substrates. After the liquid crystal is dropped on the substrate, the opposite substrate is bonded, and the substrate is quickly fixed by photo-curing by ultraviolet irradiation or the like, so that the substrate is quickly fixed, that is, the cell gap is formed. This is a technique for manufacturing a liquid crystal display panel by completely curing a sealant by thermal curing.
In such a liquid crystal dropping method, photocuring and thermosetting reactions proceed in a state where the uncured sealant and the liquid crystal are in contact with each other. Therefore, the liquid crystal sealant is used during the curing process, that is, before and after photocuring. Reduction of the contamination to the liquid crystal derived from the liquid crystal sealant before and after curing is required.
Similarly, a sealing agent such as an airtight sealant for electronic components is also required to reduce contamination of the electronic component derived from the sealing agent during the curing process.

  In addition, due to the recent improvement in performance of liquid crystal panels, characteristics may change due to the influence of ultraviolet light in the alignment direction, type of alignment film, and liquid crystal material, and a sealant that can be cured in the visible light region with low energy Is required.

As a photocurable resin composition used in the field of electronic materials such as liquid crystal sealants, Patent Document 1 discloses a photosensitizer that is a diaminobenzophenone derivative having a number average molecular weight of 400 to 3000, and a number average molecular weight of 350. A photocurable resin composition containing ˜3000 hydrogen abstraction type photoradical polymerization initiator and a specific monomer and / or monomer is disclosed.
Patent Document 2 discloses a reaction product of a specific epoxy compound and thioxanthonecarboxylic acid as a self-polymerizing photopolymerization initiator for curing a coating of coating material or printing ink.

JP 2005-263987 A JP 2004-224993 A

However, the diaminobenzophenone derivative having a specific number molecular weight, which is a photosensitizer disclosed in Cited Document 1, has a photosensitization property in the visible light region and hardly generates outgas, but the functional group is an amino acid derived from a primary amine. Since it is a group, there is a problem that the storage stability becomes unstable.
The main application of the self-polymerization type photopolymerization initiator disclosed in Citation 2 is paint and printing ink, and the outgas to be used is odor, which affects high-speed response such as a liquid crystal seal. It could not cope with the contamination level due to outgas, dissolution in liquid crystal, bleed, etc.

  It is an object of the present invention to provide a compound that can be used as a photopolymerization initiator having a photocurable property in the visible region, in which an outgas suitable for a sealing agent for electronic parts and the like, particularly a liquid crystal sealing agent is hardly generated, and photopolymerization including the compound It is to provide an initiator and a photocurable resin composition.

The present invention has the following configuration.
(1) A compound obtained by reacting an organic acid compound and / or a hydroxy compound with a compound containing at least two epoxy groups in the molecule, wherein the compound is
Compound A wherein the organic acid compound is dimethylaminobenzoic acid, or
A compound which is compound B wherein the hydroxy compound is hydroxythioxanthone.
(2) A photopolymerization initiator comprising a photoinitiating compound and a visible light sensitizing compound,
The photoinitiating compound is the compound A;
A photopolymerization initiator in which the visible light sensitizing compound is the compound B.
(3) A photocurable resin composition comprising a photopolymerizable monomer or oligomer and the photopolymerization initiator described in (2).

  ADVANTAGE OF THE INVENTION According to this invention, the compound which can be used for the photopolymerization initiator which is suitable for sealing agents, such as a liquid crystal sealing agent, such as an electronic component, and is hard to generate outgas and has photocurability in visible region, The light containing the said compound A polymerization initiator and a photocurable resin composition can be provided.

Contamination of Example 1 Contamination of Example 2 Contamination of Example 3 Contamination of Comparative Example 1 Contamination of Comparative Example 2 Contamination of Comparative Example 3 Wiring part to be tested for orientation. The line (wiring part) / space (liquid crystal part) is 200 μm / 200 μm. Orientation of the wiring part of Example 4 Orientation of the wiring part of Reference Example 1

〔Compound〕
The compound of the present invention is a compound obtained by reacting an organic acid compound and / or a hydroxy compound with a compound containing at least two epoxy groups in the molecule (hereinafter also referred to as an epoxy group-containing compound),
Compound A wherein the organic acid compound is dimethylaminobenzoic acid, or
Compound B wherein the hydroxy compound is hydroxythioxanthone,
The carboxyl group of dimethylaminobenzoic acid and the hydroxyl group of hydroxythioxanthone react with the epoxy group of the epoxy group-containing compound to form a hydroxyl group.

The compound of the present invention is a photopolymerization initiator for a sealant such as a liquid crystal sealant,
Compound A acts as a photoinitiated compound that is photoexcited by a visible light sensitizing compound,
Compound B acts as a visible light sensitizing compound.
Here, the visible light sensitizing compound refers to a compound that absorbs visible light having a wavelength of 380 nm or more, preferably 400 nm or more, and more preferably 420 nm or more. A compound that has no absorption but has absorption for ultraviolet light and generates radicals.

  When the compounds A and B act as a photoinitiating compound or a visible light sensitizing compound in the photocuring reaction, the compound itself does not cleave, so that the decomposition product does not volatilize and liquid crystal contamination does not occur. Since the molecular weight of the compound itself is large and hardly volatilized, liquid crystal contamination due to volatilization of the compound itself is difficult to occur. Moreover, the residue derived from diaminobenzoic acid constituting the compound A has an amino group derived from a tertiary amine and is excellent in stability because it acts as a catalyst in the photocuring reaction.

  Compound B is a so-called hydrogen abstraction type photoradical polymerization initiating compound that absorbs active energy rays, and a photoradical polymerization initiator in a triplet excited state forms an excited state complex with a hydrogen donor, that is, an exciplex. However, since hydrogen radicals are extracted from the hydrogen donor to generate active radicals to initiate radical polymerization, there are few decomposition products and almost no outgas component is generated.

  In addition, since the compounds A and B have an OH group in the molecule and a high polarity, they are usually excellent in compatibility with a highly polar photopolymerizable oligomer used in a photocurable resin composition, Since the polarity of the liquid crystal material is different and the solubility in the liquid crystal is low, it is considered that the liquid crystal is excellent in contamination control.

Compound A can be produced by reacting diaminobenzoic acid, which is an organic acid compound, with an epoxy group-containing compound,
Compound B can be produced by reacting hydroxythioxanthone, which is a hydroxy compound, with an epoxy group-containing compound.

  Specifically, diaminobenzoic acid or hydroxythioxanthone and an epoxy group-containing compound are preferably used in the presence of a trivalent organic phosphate compound and / or an amine compound as described below from the viewpoint of a basic catalyst and reactivity. , 100 equivalent% of diaminobenzoic acid or hydroxythioxanthone is reacted with 1 equivalent of epoxy group. Next, the reaction product is purified by removing the basic catalyst by filtration, centrifugation, or washing with water.

As an epoxy group-containing compound used when producing compounds A and B,
From the viewpoint of ensuring photoinitiation in which compound A is photoexcited by a visible light sensitizing compound,
From the viewpoint of ensuring the visible light sensitization of compound B, it is a polyfunctional epoxy resin containing at least two epoxy groups, preferably an aliphatic or aromatic bifunctional epoxy resin.
Polyfunctional epoxy resins include trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether, phenol novolac glycidyl ether, cresol novolac glycidyl ether, tetraglycidyl diaminodiphenylmethane, tri Glycidylaminophenol and the like,
As the aliphatic bifunctional epoxy resin, polyethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, hexanediol diglycidyl ether and the like are preferable,
Preferred examples of the aromatic bifunctional epoxy resin include bisphenol A type diglycidyl ether, bisphenol F type diglycidyl ether, bisphenol AD type diglycidyl ether, biphenyl type diglycidyl ether, resorcinol type diglycidyl ether, and the like.
Diethylene glycol diglycidyl ether represented by the following formula (5) and bisphenol A diglycidyl ether represented by the following formula (6) are more preferable.

From the viewpoint of stably ensuring photoinitiation that is photoexcited by the visible light sensitizing compound,
Compound A is obtained by reacting diaminobenzoic acid and diethylene glycol diglycidyl ether, which is represented by the following formula (1):
Or a compound A1 represented by:
The following formula (2) obtained by reacting diaminobenzoic acid and bisphenol A diglycidyl ether:
Compound A2 represented by the formula is more preferable.

From the viewpoint of ensuring stable visible light sensitization,
Compound B is obtained by reacting hydroxythioxanthone and diethylene glycol diglycidyl ether, the following formula (3):
Compound B1 represented by:
The following formula (4) obtained by reacting hydroxythioxanthone and bisphenol A diglycidyl ether:
Compound B2 represented by the formula is more preferred.

(Photopolymerization initiator)
The photopolymerization initiator of the present invention is
A photopolymerization initiator comprising a photoinitiating compound and a visible light sensitizing compound,
The photoinitiating compound is Compound A and / or the visible light sensitizing compound is Compound B.

  Thus, the photopolymerization initiator of the present invention is outgassed by using Compound A or Compound B in at least one of the photoinitiator compound and the visible light sensitizing compound, as compared with the conventional photopolymerization initiator. Therefore, the photocurable resin composition suitable for the sealant can be constituted. In the photopolymerization initiator of the present invention, suitable compounds A and B include those described above for compounds A and B.

  In the photopolymerization initiator of the present invention, when compound A is used as the photoinitiator compound, examples of the visible light sensitizing compound include alkyldiaminobenzophenone, diaminobenzophenone, alkylaminobenzoate, anthracene, thioxanthone, coumarin, ketocoumarin, Cyanine, phthalocyanine, naphthalocyanine and the like can be used, and from the viewpoint of efficiency of reactivity by energy transfer, a benzophenone skeleton and / or a thioxanthone skeleton is preferable, a thioxanthone skeleton is more preferable, and a compound B is more preferable.

In the photopolymerization initiator of the present invention, when using Compound B as the visible light sensitizing compound, as the photoinitiating compound,
Self-cleavable benzoin compounds, acetophenones, hydroxyacetophenones, α-aminoacetophenones, α-acyl oxime esters, acylphosphine oxide compounds, azo compounds, etc. can be used,
Hydrogen abstraction type benzophenones, benzoin ethers, benzyl ketals, dibenzosuberones, anthraquinones, xanthones, thioxanthones, halogenoacetophenones, dialkoxyacetophenones, hydroxyacetophenones, halogenobisimidazoles, halogenotriazines Etc. can be used.

  The photoinitiating compound is preferably a hydrogen abstraction type from the viewpoint of suppressing liquid crystal contamination due to outgas, and among them, benzophenones, anthraquinones, and thioxanthones are more preferable, thioxanthones are more preferable, and these number average molecular weights are It is preferable that it is 500-3000. More preferably, compound A is used as the photoinitiating compound.

  In the photopolymerization initiator of the present invention, the molar ratio of the photoinitiating compound to the visible light sensitizing compound (photoinitiating compound / visible photosensitizing compound) is preferably from the viewpoint of supplying a stable and sufficient radical. It is 1/5 to 1/1, more preferably 1/3 to 1/1, and still more preferably 1/2 to 1/1.

[Photocurable resin composition]
The photocurable resin composition of the present invention contains a photopolymerizable monomer or oligomer and the photopolymerization initiator of the present invention.

As the photopolymerizable monomer or oligomer, known materials can be used,
From the viewpoint of suppressing contamination due to dissolution in liquid crystals,
(Meth) acrylic acid ester monomers and / or oligomers thereof and partial (meth) acrylated epoxy resins obtained by reacting bisphenol A type epoxy resins with (meth) acrylic acid are preferred,
A partial (meth) acrylated epoxy resin obtained by reacting a bisphenol A type epoxy resin with (meth) acrylic acid is more preferred.

As (meth) acrylic acid ester monomers and / or oligomers thereof,
Preferably, 2-hydroxyethyl (meth) acrylate, di, tri- or tetraethylene glycol di (meth) acrylate, epoxy-modified di (meth) acrylate, urethane-modified di (meth) acrylate,
More preferably, epoxy-modified di (meth) acrylate, urethane-modified di (meth) acrylate,
More preferred is epoxy-modified di (meth) acrylate.

A partial (meth) acrylated epoxy resin obtained by reacting a bisphenol A type epoxy resin with (meth) acrylic acid is obtained as follows.
First, bisphenol A type epoxy resin and (meth) acrylic acid are added in the presence of a basic catalyst, preferably in the presence of a trivalent organic phosphoric acid compound and / or an amine compound. ˜90 equivalent% is reacted. Next, the reaction product is purified by removing the basic catalyst by filtration, centrifugation, and / or washing with water.
As the basic catalyst, a known basic catalyst used by a reaction between an epoxy resin and (meth) acrylic acid can be used. A polymer-supported basic catalyst in which a basic catalyst is supported on a polymer can also be used.

  Examples of the trivalent organic phosphorus compound include alkylphosphines such as triethylphosphine, tri-n-propylphosphine, tri-n-butylphosphine and salts thereof, triphenylphosphine, tri-m-tolylphosphine, tris- (2 Arylphosphines such as, 6-dimethoxyphenyl) phosphine and salts thereof, phosphorous acid triesters such as triphenyl phosphite, triethyl phosphite and tris (nonylphenyl) phosphite and salts thereof. Trivalent phosphine / ethyl bromide, triphenyl phosphine / butyl bromide, triphenyl phosphine / octyl bromide, triphenyl phosphine / decyl bromide, triphenyl phosphine / isobutyl bromide, triphenyl phosphine / Examples thereof include propyl chloride, triphenylphosphine / pentyl chloride, triphenylphosphine / hexyl bromide and the like. Of these, triphenylphosphine is preferable.

  Examples of amine compounds include secondary amines such as diethanolamine, tertiary amines such as triethylamine, triethanolamine, dimethylbenzylamine, trisdimethylaminomethylphenol, trisdiethylaminomethylphenol, 1,5,7-triazabicyclo [ 4.4.0] dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo [4.4.0] dec-5-ene (Me-TBD), 1,8- Diazabicyclo [5.4.0] undec-7-ene (DBU), 6-dibutylamino-1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3. 0] Strongly basic amines such as non-5-ene (DBN) and 1,1,3,3-tetramethylguanidine and salts thereof. Among these, 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) is preferable. Examples of the salt of the amine compound include benzyltrimethylammonium chloride and benzyltriethylammonium chloride.

From the viewpoint of easy handling of the resin composition, i.e., a viscosity suitable for defoaming property, coating property, and printability,
In the photocurable resin composition of the present invention, the content of the photopolymerizable monomer or oligomer is preferably 50 to 90% by weight, more preferably 60 to 80% by weight, and still more preferably 70 to 80% by weight.

  From the viewpoint of reducing the remaining of the uncured portion of the photopolymerizable monomer or oligomer and suppressing the contamination of the liquid crystal, and suppressing the influence on the contamination due to the elution of the photoinitiator component to the liquid crystal, the photopolymerizable monomer or oligomer. The photopolymerization initiator of the present invention is preferably 0.5 to 5.0 parts by weight, more preferably 0.5 to 3.0 parts by weight with respect to 100 parts by weight.

When used as a sealant, particularly a liquid crystal sealant, the photocurable resin composition containing the photopolymerization initiator of the present invention is capable of emitting light even with visible light, which greatly reduces outgassing and hardly damages liquid crystals and alignment films. The curable resin can be cured.
On the other hand, with the recent increase in the density of wiring of electronic components, the following problems have arisen particularly in the liquid crystal field in which the ODF method is adopted.

  The ODF method is a method in which a liquid crystal panel can be created by directly dropping, bonding, and releasing the liquid crystal in a closed loop of a sealing agent under vacuum. Compared to the conventional injection method, liquid crystal This is a mainstream method for manufacturing liquid crystal panels using a large-sized substrate.

The liquid crystal substrate produced by the ODF method is composed of a resin that has both a (meth) acrylic group that is a photocurable functional group and an epoxy group that is a thermosetting functional group. Is temporarily cured and then thermally cured.
At this time, if the reaction of the (meth) acrylic group due to ultraviolet irradiation is insufficient, or if it is not exposed to ultraviolet rays due to the shadow of wiring etc., the liquid crystal sealant component flows out to the liquid crystal during thermal curing, This may cause display defects.

  In recent years, as described above, there is an increasing number of cases where photocuring by visible light, which has lower energy than ultraviolet rays, is incorporated, and further, the higher density of wiring tends to make ultraviolet rays difficult to hit. Is becoming more prominent.

  Since the photocurable resin composition of the present invention contains the photopolymerization initiator of the present invention, it is not only cured with visible light but also with a low irradiation amount of ultraviolet rays, so that it is a shadow portion. However, it can be cured and contribute to solving the above problems.

The photocurable resin composition of the present invention preferably further contains a thermosetting agent in order to solve the above-described new problem at a high level.
As a thermosetting agent, from the viewpoint of fast curing speed and good viscosity stability even at low temperatures,
Preferred is at least one compound selected from the group consisting of mixed crystal hydrazide compounds, organic acid dihydrazide compounds, imidazole and derivatives thereof, dicyandiamide, aromatic amines, aliphatic amines and derivatives thereof,
More preferred are hydrazide mixed crystal compounds and / or organic acid dihydrazide compounds,
A hydrazide mixed crystal compound is more preferable.

The hydrazide mixed crystal compound refers to a compound that satisfies the following rules (I) and (II).
(I) Two or more crystalline hydrazide compounds having at least one hydrazide group in one molecule are heated and melted to a melting point or higher to obtain a heated melt, and then the heated melt is cooled and solidified. It must be a compound that can be obtained.
(II) It has a diffraction peak peculiar to a mixed crystal at 5.5 to 7.5 ° with a Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum of the compound by CuKα ray.

  In the compound, a hydrazide compound having a hydrazide group is preferably contained in an amount of 5 to 70% by weight, more preferably 5 to 50% by weight, still more preferably 5 to 30% by weight, and still more preferably 10 to 20% by weight.

The hydrazide-based mixed crystal compound can be produced by a method including a step of heating and mixing two or more crystalline hydrazide compounds to a melting point or higher and a step of cooling and solidifying the mixture.
In the present invention, from the viewpoints of melting point, reactivity during heat, and storage stability, the crystalline hydrazide compound used as a raw material is preferably represented by the general formula (1):

[Wherein, R represents a hydrogen atom, an alkyl group, or an aryl group which may have a substituent. And a monohydrazide compound represented by the general formula (2):

[In formula, A shows the alkylene group which may have a substituent, the arylene group which may have a substituent, or an oxo group. The hydrazide compounds disclosed in paragraphs 0020 and 0021 of JP-A No. 2010-143872 are preferred.

  In the present invention, as a crystalline hydrazide compound used as a raw material of a hydrazide mixed crystal compound, at least one kind is a dibasic having two or more hydrazide groups from the viewpoints of melting point, thermal reactivity, and storage stability. The dihydrazide is preferably an acid dihydrazide, and the hydrazide compound to be combined with the dibasic acid dihydrazide may be a monohydrazide compound and / or a polyfunctional hydrazide compound such as tribasic acid trihydrazide, but there are two hydrazide compounds. Dibasic acid dihydrazide having the above hydrazide group is more preferable.

As dibasic acid dihydrazide,
Preferably, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodencannic acid dihydrazide, hexadecanedioic acid dihydrazide, Dihydrazide, carbohydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 1,4-naphthoic acid dihydrazide, 4,4′-bisbenzenedihydrazide, Hydroquinone diglycolic acid dihydrazide, resorcinol diglycolic acid dihydrazide, catechol diglycolic acid dihydrazide, 4 , 4′-ethylidenebisphenol-diglycolic acid dihydrazide, 4,4′-vinylidenebisphenol-diglycolic acid dihydrazide, one or more compounds selected from the group consisting of
More preferably, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodencanic diacid dihydrazide, hexadecanediodic dihydride dihydrazide, One or more compounds selected from the group consisting of acid dihydrazides.

As monohydrazide compounds,
Preferably, it is at least one compound selected from the group consisting of acetohydrazide, propionic acid hydrazide, pentanoic acid hydrazide, lauric acid hydrazide, cyclohexanecarbohydrazide, salicylic acid hydrazide, p-hydroxybenzoic acid hydrazide, naphthoic acid hydrazide,
More preferably, it is at least one compound selected from the group consisting of acetohydrazide, propionic acid hydrazide, pentanoic acid hydrazide, lauric acid hydrazide, cyclohexanecarbohydrazide and salicylic acid hydrazide.

Above all, as a combination of dibasic acid dihydrazide,
Adipic acid dihydrazide and sebacic acid dihydrazide,
Adipic acid dihydrazide and decandiodihydrazide,
A combination of sebacic acid dihydrazide and decandiodihydrazide is preferred.

In the photocurable resin composition of the present invention, the content of the thermosetting agent has sufficient thermal reactivity, and from the viewpoint of maintaining storage stability,
For 100 parts by weight of photopolymerizable monomer or oligomer,
The amount is preferably 5 to 50 parts by weight, and more preferably 5 to 30 parts by weight.

  The photocurable resin composition of the present invention preferably contains a coupling agent such as filler particles and a silane coupling agent from the viewpoint described later, and if necessary, a photopolymerizable monomer suitable for the present invention. Or oligomer, curing agent other than thermosetting agent, initiator other than photopolymerization initiator suitable for the present invention, elastomer, chain transfer agent, ion trap agent, ion exchange agent, leveling agent, pigment, dye, plasticizer, Additives such as antifoaming agents can be included.

The filler particles are used for the purpose of improving the adhesive reliability of the curable composition by controlling the viscosity of the curable composition, improving the strength of the cured product obtained by curing the curable composition, or suppressing the linear expansion. Added. As the filler particles, inorganic particles for fillers and / or organic resin particles for fillers can be preferably used, but inorganic particles for fillers are preferable from the viewpoint of a low linear expansion coefficient and reduced cure shrinkage due to the development of adhesive strength. .
As inorganic particles for fillers, calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, titanium oxide, alumina, zinc oxide, silicon dioxide, kaolin, talc from the viewpoint of easily obtaining a particle size suitable for a sealant. At least one inorganic particle selected from the group consisting of glass beads, sericite activated clay, bentonite, aluminum nitride, and silicon nitride is preferred, and at least one selected from the group consisting of silicon dioxide, talc, alumina, and bennite The above inorganic particles are more preferable, silicon dioxide and / or talc are more preferable, and silicon dioxide is still more preferable.
As an organic resin particle for filler, polymethyl methacrylate, polystyrene, and a copolymer obtained by copolymerizing these monomers and other monomers from the viewpoint of developing the effect of addition as adhesive strength by stress relaxation during curing. Selected from the group consisting of polymers, polyester fine particles, polyurethane fine particles, rubber fine particles, and core-shell type fine particles composed of a shell containing a copolymer having a high glass transition temperature and a core of a copolymer having a low glass transition temperature. A core shell comprising at least one organic resin particle, preferably a polyester fine particle, polyurethane fine particle, rubber fine particle, and a shell containing a copolymer having a high glass transition temperature and a copolymer core having a low glass transition temperature At least selected from the group consisting of type fine particles More preferably seeds or organic resin particles, core-shell type fine particles composed of a core of a copolymer having a shell and a low glass transition temperature comprising a copolymer having a high glass transition temperature is more preferable. In the core-shell type fine particles, it is preferable that the copolymer having a high glass transition temperature is polymethacrylic acid and the copolymer having a low glass transition temperature is butyl acrylate.

  In the photocurable resin composition of the present invention, the content of the inorganic particles for the filler is based on 100 parts by weight of the photopolymerizable monomer or oligomer from the viewpoint of improvement in adhesion due to stress dispersion effect and improvement in linear expansion coefficient. 2 to 40 parts by weight, and more preferably 5 to 30 parts by weight.

When the thermosetting resin composition of the present invention is used as a liquid crystal sealing agent, the silane coupling agent is preferable as an adhesion aid for favorably bonding the liquid crystal sealing agent and the liquid crystal display panel.
As the silane coupling agent, one or more selected from the group consisting of γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-isocyanatopropyltrimethoxysilane And γ-glycidoxypropyltrimethoxysilane is more preferable.

  In the photocurable resin composition of the present invention, the content of the coupling agent is 0.1 to 10 weights with respect to 100 parts by weight of the photopolymerizable monomer or oligomer from the viewpoint of maintaining adhesive strength, particularly moisture resistance strength. Parts, preferably 0.5 to 2 parts by weight.

Example 1 Synthesis of Compound A1 Denacol EX-850L (diethylene glycol diglycidyl ether, manufactured by Nagase ChemteX Corporation) 13.7 g
14.8 g of 4-dimethylaminobenzoic acid,
PS-PPh ₃ (basic catalyst in which triphenylphosphine (PPh ₃ ) is supported on polystyrene (PS), manufactured by Biotage Corp.) 900 mg,
200 ml of toluene was mixed and stirred at 110 ° C. for 48 hours.
The reaction mixture was cooled to room temperature and the catalyst was removed by filtration.
The solvent was distilled off under reduced pressure to obtain an amine adduct of Denacol EX-850L.
Identification was performed by HPLC, and it was confirmed that 70% or more of the target component was contained.

[Example 2] Synthesis of Compound A2 Epicron EXA-850CRP (bisphenol A diglycidyl ether, manufactured by DIC Corporation) 1.70 g,
4-dimethylaminobenzoic acid 1.57 g,
PS-PPh ₃ (manufactured by Biotage) 50 mg,
20 ml of toluene was mixed and stirred at 110 ° C. for 48 hours.
The reaction mixture was cooled to room temperature and the catalyst was removed by filtration.
The solvent was distilled off under reduced pressure to obtain an amine adduct of Epicron EXA-850CRP.
Identification was performed by HPLC, and it was confirmed that 70% or more of the target component was contained.

Example 3 Synthesis of Compound B1 Denacol EX-850L (diethylene glycol diglycidyl ether, manufactured by Nagase ChemteX Corporation) 13.7 g
14.8 g of hydroxythioxanthone,
PS-PPh ₃ (manufactured by Biotage) 900 mg,
200 ml of toluene was mixed and stirred at 110 ° C. for 48 hours.
The reaction mixture was cooled to room temperature and the catalyst was removed by filtration.
The solvent was distilled off under reduced pressure to obtain an amine adduct of Denacol EX-850L.
Identification was performed by HPLC, and it was confirmed that the target component was contained by 60% or more.

Example 4 Synthesis of Compound B2 Epiclone EXA-850CRP (bisphenol A diglycidyl ether, manufactured by DIC Corporation) 1.70 g,
2.17 g of 2-hydroxythioxanthen-10-one,
PS-PPh ₃ (Biotage) 100 mg,
PS-TBD (solid catalyst with 1,5,7-triazabiccyclo [4.4.0] dec-5-ene supported on PS, basic catalyst, manufactured by Biotage) 100 mg,
20 ml of toluene was mixed and stirred at 110 ° C. for 48 hours.
The reaction mixture was cooled to room temperature and the catalyst was removed by filtration.
The solvent was distilled off under reduced pressure to obtain a thioxanthone adduct of EXA-850CRP.
Identification was performed by HPLC, and it was confirmed that the target component was contained by 60% or more.

(A) Synthesis of photopolymerizable oligomer (PR850CRP: partially methacrylated epoxy resin of bisphenol A type epoxy resin) 320.2 g of bisphenol A type epoxy resin (EXA850CRP, manufactured by DIC Corporation),
90.4 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.)
PS-PPh ₃ (manufactured by Biotage) 1.5 g and BHT 100 mg were mixed and stirred at 100 ° C. for 6 hours.
After completion of the reaction, the catalyst was removed by filtration to obtain a partially methacrylated epoxy resin.
(B) Photopolymerization initiator decomposition type (visible light curing type): Irgacure, I-369 (manufactured by BASF Japan)
Decomposable type (reactive group-containing type): EY resin, KR-2 (manufactured by KS Corporation)
(C) Thermosetting agent (hydrazide mixed crystal compound)
ADH: Adipic acid dihydrazide (Otsuka Chemical Co., Ltd.)
C3: Mixed crystal thermosetting agent (manufactured by Kyoritsu Chemical Industry Co., Ltd.)
VDH: Dihydrazide with isopropyl hydantoin skeleton (manufactured by Ajinomoto Fine Techno Co., Ltd.)
(D) Resin filler: methabrene, J-5800 (manufactured by Mitsubishi Rayon Co., Ltd.)
(E) Inorganic filler: Silica (Seahoster, KE-C50HG, manufactured by Nippon Shokubai Co., Ltd., 0.5 μm)
(F) Coupling agent: KBM403 (manufactured by Shin-Etsu Chemical Co., Ltd.)

Example 5
A photopolymerization initiator composed of 1 part by weight of photoinitiating compound A1 and 1 part by weight of visible light sensitizing compound B1 was dissolved in 100 parts by weight (100 g) of photopolymerizable oligomer PR-850CRP.
Thereafter, 1 part by weight of a coupling agent, 10 parts by weight of an inorganic filler, and 15 parts by weight of a thermosetting agent are mixed, and using a three roll mill (roll dimensions, φ121 × 250 mm, manufactured by Inoue Seisakusho Co., Ltd.), a pressure of 5 MPa, two passes. Were sufficiently kneaded to obtain a curable resin composition.

[Examples 6 and 7 and Comparative Examples 1 to 3]
Under the same conditions as in Example 5, the compositions of Examples 6 and 7 and Comparative Examples 1 to 3 shown in Table 1 were mixed and then sufficiently kneaded using three rolls to obtain each resin composition.
In Comparative Example 3,
As a photoinitiating compound, EHA (product name: DAROCURE EHA, component name: 2-ethylhexyl-4- (dimethylamino) benzoate, manufactured by BASF),
As the photosensitizing compound, DETX (product name: Photocure DETX, component name: 2,4-diethylthioxanthone, manufactured by EUTEC CHEMICAL) was used.

Example 8
A photopolymerization initiator composed of 1 part by weight of photoinitiating compound A1 and 1 part by weight of visible light sensitizing compound B1 was dissolved in 100 parts by weight (100 g) of photopolymerizable oligomer PR-850CRP.
Thereafter, 1 part by weight of a coupling agent, 10 parts by weight of an organic filler, 5 parts by weight of an inorganic filler, and 15 parts by weight of a thermosetting agent are mixed, and a three-roll mill (roll dimensions, φ121 × 250 mm, manufactured by Inoue Seisakusho) is used. Then, the mixture was sufficiently kneaded in two passes at a pressure of 5 MPa to obtain a curable resin composition.

[Examples 9 to 12 and Reference Example 1]
Under the same conditions as in Example 8, the compositions of Examples 9 to 12 and Reference Example 1 shown in Table 2 were mixed and then sufficiently kneaded using three rolls to obtain each photocurable resin composition.

[Evaluation conditions]
(1) Weight loss by heating Using a differential thermal balance (TG-DTA, product name: Thermoplus TG8120, manufactured by Rigaku Corporation), each weighed photoinitiator is placed in an aluminum pan and heated at a rate of 10 ° C / min to 300 ° C. The proportion of weight loss when the temperature was raised to was measured. A larger amount of reduction indicates that it tends to volatilize as outgas, and an increase in the amount of volatilization contaminates the liquid crystal, resulting in poor display.

(2) Reaction rate The photocurable resin composition
One side is glass for LCD of 25mm x 25mm thickness 0.7mm,
The other with a PET film of 25 mm × 25 mm thickness 0.1 mm,
Scissors so that the thickness of the photocurable resin composition is 0.5 mm,
Using a UV irradiation device (UVX-01224S1, manufactured by USHIO INC.), Irradiation with light energy of 200 to 3000 mJ / cm ² was performed at a UV irradiation illuminance of 100 mW / cm ² to obtain a sample for measuring curability.
At this time, using an ultraviolet ray / heat ray cut filter,
(I) Irradiation with ultraviolet and visible light having a wavelength of 340 nm to 450 nm and (ii) a wavelength of 420 nm to 450 nm was performed.
The measurement of the curing rate was measured using FT-IR (Spectrum One, manufactured by PerkinElmer)
The reaction rate (conversion rate) of the (meth) acryl group was calculated from the peak area of the (meth) acryl group in the obtained IR spectrum.
Calculation of the reaction rate was calculated based on the area of absorption 1500 cm ^-1 the reduction of the area of the double bonds of the benzene ring of (meth) absorption 1630 cm ^-1 (or 945 cm ^-1) of the acryl group.

(3) Outgas amount TG-DTA (manufactured by Rigaku Corporation) was used to measure outgas at 120 ° C. for 60 minutes, and the amount of volatile components from the sealant was compared.
When the amount of volatile components is 1.5% or less,
When the amount of volatile components is 1.5% or more, “×”
It was.

(4) Contamination On an ITO glass substrate (60 mm × 70 mm) with an alignment film (Sunever SE-7492, manufactured by Nissan Chemical Industries, Ltd.) which was rubbed with a photocurable resin composition at a cross-sectional area of 4000 μm ² using a seal dispenser. X 0.7 mmt).
Thereafter, liquid crystal (TN liquid crystal, MLC-11900-080, manufactured by Merck & Co., Inc.) was dropped on the substrate, and the upper and lower substrates were bonded together by a liquid crystal dropping method (ODF method) to prepare a test liquid crystal cell.
The test liquid crystal cell, ultraviolet (UV irradiation apparatus: UVX-01224S1, manufactured by Ushio Inc., ^{illuminance: 200mJ: 100mW / cm 2 /} 365nm in 2 seconds) and then cured by irradiation with,
Thereafter, thermosetting was performed in a hot air oven at 120 ° C. for 1 hour to prepare a test-use cured liquid crystal cell for an orientation test.
About the obtained hardening liquid crystal cell for a test, the alignment state of the liquid crystal at the time of sealing was confirmed.
The confirmation was performed with an optical microscope, and the polarizing plate was observed in a transmission state with a test cell sandwiched in a crossed Nicol state.
The microscope picture which shows the orientation state of the corner part of the hardening liquid crystal cell for a test is shown in FIGS. 1 to 6 are all a scale of 900 μm in length × 1200 μm in width.
The evaluation criteria for the orientation of the liquid crystal was judged by the presence or absence of alignment disorder during sealing.
“○” indicates that the alignment disorder is 50 μm or less during sealing.
`` X '' when there is more alignment disorder
It was.

(5) Stability Measure the viscosity change at room temperature (25 ° C.) of the photocurable resin composition,
When the viscosity change after 5 days is 20% or less,
"X" when the viscosity change after 5 days is 20% or more
Judged.
The measurement of viscosity is
The photocurable resin composition is treated at a constant temperature so that the temperature is 25 ° C.,
Attach 3 ° x R7.7 cone rotor to RE-105U viscometer (manufactured by Toki Sangyo Co., Ltd.), set 0.15 ml of target resin composition in cone rotor, and light at 25 ° C at 2.5 rpm The viscosity of the curable resin composition was measured.
The photocurable resin composition immediately after preparation as a measurement object was allowed to stand at 25 ° C. for 5 days,
The viscosity of the photocurable resin composition after 5 days was measured by the above method,
The initial viscosity is the viscosity immediately after preparation of the photocurable resin composition,
The rate of change from the initial viscosity was calculated to evaluate stability.
When the measurement range was exceeded, measurement was impossible. Note that the measurement range over reference is 1,200,000 mPa · s.

(6) Thermosetting The viscosity of the photocurable resin composition to be measured by a rotational rheometer (Rheo Stress 300, manufactured by Haake) is
After thermosetting starts,
If the saturated viscosity is reached within 60 minutes, “◎”,
“○” indicates that the saturated viscosity is reached within 120 minutes.
“X” indicates that the saturated viscosity is not reached even after 120 minutes.
Judged.
The measurement of viscosity is
The viscosity change at 120 ° C. was measured for the photocurable resin composition to be measured using a rotary rheometer (Rheo Stress 300, manufactured by Haake).
Using a parallel plate, the sample amount was 0.6 g, the gap was 1 mm, and the strain control mode. The temperature was raised from room temperature to 120 ° C. at 20 ° C./min, and measurement was performed for 120 minutes while maintaining 120 ° C. The time to reach a viscosity (saturated viscosity) at which no change in viscosity was observed was measured.

(7) Electrical characteristics An ampoule test was performed with a sealant, and voltage holding ratio (VHR) and ion density (ID) were measured and evaluated.
[Preparation of measurement sample]
The photocurable resin composition 0.1g mix | blended with the ampule bottle is put, and 1g of TN liquid crystal (MLC-11900-080, the product made by Merck) is added. This ampoule bottle was put into a 120 ° C. oven for 1 hour, and then allowed to stand at room temperature. After returning to room temperature (25 ° C.), the liquid crystal part was taken out and filtered through a 0.2 μm filter to obtain a liquid crystal sample for electrical property evaluation. .
[Measurement of voltage holding ratio and ion density]
An electric characteristic evaluation cell was fabricated using a liquid crystal sample for electric characteristic evaluation. The cell was prepared by using a commercially available sealant (World Lock No. 5) on an ITO glass substrate (55 mm × 60 mm × 0.7 mmt) with a rubbing-treated alignment film for TN liquid crystal (Sunever SE-7492, manufactured by Nissan Chemical Industries, Ltd.). 717, manufactured by Kyoritsu Chemical Industry Co., Ltd.) as a frame sealant, a liquid crystal sample for electrical property evaluation is dropped on the substrate, and the upper and lower substrates are bonded together by a liquid crystal dropping method (ODF method), and ultraviolet rays (UV irradiation) device: UVX-01224S1, manufactured by Ushio Inc., illuminance and radiation ^{time: 3000mJ, 100mW / cm 2 /} 365nm at 30 sec) and then cured by irradiation with, followed for 1 hour thermoset at 120 ° C. in a hot air oven, electric A test liquid crystal cell for characteristic evaluation was prepared.
The voltage holding ratio was measured using a liquid crystal physical property evaluation apparatus (6254C, manufactured by Toyo Technica Co., Ltd.). The voltage holding ratio at an applied voltage of 5 V, 60 Hz, and 16 msec was measured. The measurement was performed at 50 ° C.
The evaluation criteria for the electrical characteristics were judged from the value of the voltage holding ratio.
When the value of the voltage holding ratio is 98% or more, “○”,
“×” when the voltage holding ratio is 98% or less
It was.

(8) Orientation of wiring part After mixing in the blending examples shown in Table 2, using a three-roll mill (roll dimensions, φ121 × 250 mm, manufactured by Inoue Seisakusho), each was kneaded sufficiently with a pressure of 5 MPa and two passes. Photocurable resin compositions (Examples 8 to 12 and Reference Example 1) were obtained. The thus obtained photocurable resin composition was subjected to a rubbing treatment with a seal dispenser at a cross-sectional area of 4000 μm ² and a wiring pattern with an alignment film (Sunever SE-5661, manufactured by Nissan Chemical Industries Ltd.) (Cr / line / space: Dispense coating was performed on a glass substrate (200 mm / 200 mm) (60 mm × 70 mm × 0.7 mmt).
Thereafter, liquid crystal (VA liquid crystal, MLC-6609, manufactured by Merck & Co., Inc.) is dropped on the substrate, the gap is set to 4 μm, and the upper and lower substrates are bonded together by the liquid crystal dropping method (ODF method) to produce a test liquid crystal cell. did.
The test liquid crystal cell, ultraviolet (UV irradiation apparatus: UVX-01224S1, manufactured by Ushio Inc., illuminance and radiation ^{time: 3000mJ, 100mW / cm 2 /} 365nm at 10 sec) and then cured by irradiation with hot air thereafter 120 ° C. Heat curing was performed in an oven for 1 hour to prepare a test-use liquid crystal cell for an orientation test.
About the obtained hardening liquid crystal cell for a test, the orientation state of the liquid crystal at the time of sealing between wiring was confirmed. The confirmation was performed with an optical microscope, and the polarizing plate was observed in a transmission state with a test cell sandwiched in a crossed Nicol state. The micrograph which shows the orientation state of the wiring part of the hardening liquid crystal cell for a test is shown in FIGS. 7 to 9 are all a scale of 900 μm in length × 1200 μm in width.
The evaluation criteria for the orientation of the liquid crystal was judged by the presence or absence of alignment disorder during sealing.
“○” indicates that the alignment disorder is 20 μm or less during sealing.
`` X '' when there is more alignment disorder
It was.

From the above results (Table 1), when a 340 nm filter was used (general process conditions), no alignment failure occurred in the examples at 200 mj and 2000 mj. On the other hand, Comparative Example 1 and Comparative Example 2 were found to cause orientation failure under either condition.
In addition, when a 420 nm filter is used (special liquid crystal panel manufacturing conditions, which may become the mainstream in the future), in Comparative Example 2, which is a conventional photoinitiator, the curing of the sealant does not proceed, and the liquid crystal panel It turns out that there is a problem with the reliability of.
From the above, the compounds A1, A2, B1 and B2 of the present invention, the photopolymerization initiator and the photocurable resin composition using this compound, are useful as the photoinitiator of the liquid crystal sealant for the dropping method. Is high.
According to the above results (Table 2), when the thermosetting compound was further added to the compounds A1, A2, B1 and B2 of the present invention, and when the thermosetting compound was a hydrazide mixed crystal compound, these compounds were used. It has been clarified that the photopolymerization initiator and the photocurable resin composition can be used as a liquid crystal sealant useful for producing a high-quality liquid crystal panel.

Claims (2)

Following formula (3):

A compound represented by Following formula (4):

A compound represented by