TWI420205B - Hardening resin composition for liquid crystal sealing and manufacturing method for liquid crystal display panel using the same - Google Patents

Description

Curable resin composition for liquid crystal sealing and method for producing liquid crystal display panel using the same

The present invention relates to a curable resin composition for liquid crystal sealing and a method for producing a liquid crystal display panel using the same.

In recent years, liquid crystal display panels have been widely used as display panels of various electronic devices typified by mobile phones because of their characteristics such as thinness, light weight, and high definition. The liquid crystal display panel is a device having a structure in which the edge of the liquid crystal held by the two substrates is sealed by a liquid crystal sealing agent, and the liquid crystal alignment is controlled by applying a voltage to the liquid crystal, and the modulation of the transmitted light is adjusted to display image.

The liquid crystal display panel can be manufactured, for example, by a liquid crystal injection technique as shown below. In the liquid crystal injection technique, first, a liquid crystal sealing agent is applied onto one of two substrates to form a frame, and then the frame-shaped liquid crystal sealing agent is dried by a pre-hardening treatment. Here, a notch portion serving as a liquid crystal injection port is provided in advance on a part of the frame. Next, after the two substrates are opposed to each other, they are hot-pressed, whereby the substrates are brought together. Thereby, a unit for enclosing liquid crystal is formed between the two substrates. Then, the liquid crystal is injected into the empty cell from the liquid crystal injection port under vacuum, and then the liquid crystal injection port is sealed with a liquid crystal sealing agent or the like to thereby manufacture a liquid crystal display panel.

For the liquid crystal sealing agent for liquid crystal injection, for example, a thermosetting liquid crystal sealing agent containing an epoxy resin as a main component (hereinafter, simply referred to as a thermosetting sealing agent) has been proposed (for example, refer to International Publication No. 2004/039885).

However, in recent years, with the miniaturization, thinness, and high image quality of electronic devices, the demand for liquid crystal display panels is increasing remarkably. Therefore, in the field of manufacturing liquid crystal display panels, there is a strong desire for improvement in productivity, including high quality of products or shortened manufacturing time. However, in the liquid crystal injection technique described above, since the injection time of the liquid crystal is long and the heat-curable sealant is required to be cured at a temperature of 120 to 150 ° C for several hours, it is considered to have a problem of low productivity. .

In view of the above, the liquid crystal dropping technology is attracting attention as a manufacturing method of a liquid crystal display panel which can improve productivity. The liquid crystal dropping technique is usually composed of the following steps. First, a liquid crystal sealing agent is applied onto any of two substrates constituting the liquid crystal display panel by a dispenser or screen printing to form a frame filled with liquid crystal. Next, an appropriate amount of liquid crystal was dropped into the frame, and the two substrates were superposed under a high vacuum through a liquid crystal sealing agent in an uncured state. Then, the two substrates which have been superimposed are returned to atmospheric pressure, the substrates are bonded to each other, and then the liquid crystal sealing agent is cured, whereby a liquid crystal display panel in which liquid crystal is sealed between the two substrates is manufactured. Further, in the present invention, a frame made of a liquid crystal sealing agent is referred to as a sealing portion or a sealing pattern.

Further, in the liquid crystal dropping technique, in order to shorten the curing time of the liquid crystal sealing agent, the liquid crystal sealing agent is temporarily cured by irradiating the liquid crystal sealing agent with ultraviolet rays or the like by using a light and a thermosetting liquid crystal sealing agent. Thereafter, post-hardening is performed by heating (for example, refer to JP-A-2001-133794, JP-A-2002-214626). If this liquid crystal dropping technology is used, it is compared with the previous liquid crystal injection technology. In contrast, the liquid crystal sealing agent can be sealed between the substrates in a shorter period of time, and the hardening time of the liquid crystal sealing agent is shortened, thereby improving productivity. Therefore, the liquid crystal dropping technology has gradually become the mainstream of the manufacturing method of the liquid crystal display panel. .

However, as the wiring of the small panel mounted on the mobile phone becomes more complicated, the seal pattern and the wiring are overlapped with each other, and the light-shielding portion where the light cannot be directly irradiated is easily generated on the seal pattern. However, since the hardening of the liquid crystal sealing agent is insufficient in the light-shielding portion, the liquid crystal may intrude into the sealing pattern when it is post-hardened by heating, resulting in a large amount of occurrence of the following: the sealing pattern is deformed, or the liquid crystal is transmitted through the sealing pattern to cause leakage of the liquid crystal. leakage. If the liquid crystal leaks, the display characteristics of the liquid crystal display panel are remarkably lowered, causing a big problem.

Further, when the liquid crystal is brought into contact with the liquid crystal sealing agent in an uncured state, the uncured liquid crystal sealing agent penetrates into the liquid crystal, which tends to cause contamination of the liquid crystal, and liquid crystal contamination also causes a significant deterioration in display characteristics of the liquid crystal display panel. Therefore, the industry is expected to propose a liquid crystal sealing agent which can suppress liquid crystal leakage or liquid crystal contamination.

In the liquid crystal sealing agent which can improve liquid crystal leakage, for example, a curable resin composition for liquid crystal display elements is proposed, and the viscosity under the measurement conditions of 25 ° C and 1.0 rpm measured by an E-type viscometer is 200 Pa. s~400Pa. s, the viscosity under the measurement conditions of 80 ° C, 1.0 rpm is 20Pa. s~500Pa. s (for example, refer to JP-A-2005-308811, JP-A-2006-023580). In addition, a liquid crystal sealing agent which is sufficiently hardened in the light shielding portion, for example, a liquid crystal is proposed A sealant comprising a photocurable resin, a photoradical polymerization initiator, and a radical chain transfer agent having a disulfide bond (for example, refer to Japanese Patent Laid-Open No. 2006-030481 Bulletin).

Further, in the liquid crystal sealing agent which can suppress liquid crystal contamination at a low level, it is proposed to use a liquid crystal sealing agent having a hydrogen bond functional group amount of 3.5 × 10 ^-3 or more in one molecule in JP-A-2005-308813. Thermosetting resin. The amount of the hydrogen bond functional group in one molecule in this document is defined by the number of hydrogen bond functional groups/molecular weight, and since the resin having a value of 3.5 × 10 ^{-3 or} more has a low affinity for liquid crystal, it can be used as a liquid crystal seal. Liquid crystal contamination at the time of the agent.

However, in recent years, with the increase in the amount of information, the high definition of the liquid crystal display panel has been further developed, and the proportion of the light-shielding portion on the liquid crystal display panel has increased. The prior art disclosed in each of the above documents cannot sufficiently suppress deformation of the sealing portion at the time of heat curing or leakage of liquid crystal to the sealing portion. Further, as shown in Japanese Laid-Open Patent Publication No. 2006-030481, a liquid crystal sealing agent utilizing high activation energy generated by photo radicals is difficult to cause liquid crystal in the case where no uncured portion remains without the current high definition. The sealant hardens.

A method for effectively reducing the case where the liquid crystal sealing agent of the light-shielding portion is not hardened can be considered, and the following methods and the like can be considered: 1) designing a sealing pattern in consideration of light irradiation; 2) when liquid crystal dropping technology is used to harden the liquid crystal sealing agent Ultraviolet radiation was changed to heating. However, the method of 1) imposes limitations on the panel design and is therefore poor. In addition, since the previous, due to photohardenable liquid crystal dense The sealant consumes equipment costs or energy costs for ultraviolet irradiation, and thus has problems in terms of manufacturing cost. On the other hand, in the method of 2), generally, the thermosetting reaction is slower than the photohardening reaction, and the resin viscosity is liable to lower upon heating. Therefore, there has been a problem that it is difficult to solve the problem of liquid crystal leakage, such as a liquid crystal sealing agent which has been used with a thermosetting resin.

Based on the above, the inventors of the present invention conducted preliminary studies on a liquid crystal sealing agent excellent in leakage resistance. As a result, it was found that: 1) the viscosity of the liquid crystal sealing agent at the time of thermosetting, and 2) the composition of the liquid crystal sealing agent corresponding to the curable resin contained in the radical chain transfer agent or the liquid crystal sealing agent, and the hardenability or Leak resistance has an impact.

In addition, the inventors of the present invention have studied the leakage resistance of the liquid crystal sealing agent disclosed in Japanese Laid-Open Patent Publication No. 2005-308813, and it has been found that the leakage resistance is insufficient. In the present study, the leakage resistance of a liquid crystal sealing agent containing a resin having a hydrogen bond functional group amount of 2.1 × 10 ^-3 and an epoxy group amount of 2.9 × 10 ^-3 disclosed in the comparative example of the above document was further carried out. Studies have shown that the leak resistance of the sealant is also insufficient.

In view of the above-mentioned problems, it is an object of the present invention to provide a curable resin composition for liquid crystal sealing which can suppress liquid crystal leakage and liquid crystal contamination, and a state in which high productivity is maintained by using the curable resin composition for liquid crystal sealing. A method of manufacturing a high quality liquid crystal display panel.

As a result of intensive studies, the inventors of the present invention have completed the present invention by focusing on the composition of the resin composition and the viscosity of the resin composition at the time of thermosetting. In other words, the above problem can utilize the curable resin for liquid crystal sealing of the present invention. Composition to solve.

[1] A curable resin composition for liquid crystal sealing comprising an acrylic resin and/or a (meth)acrylic modified epoxy resin, each having one or more epoxy groups in one molecule. And a (meth) acrylonitrile group, a thermal radical polymerization initiator, and a filler, and the viscosity of the curable resin composition for liquid crystal sealing measured by an E-type viscosity meter at 25 ° C and 1.0 rpm is 50 Pa. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s.

[2] The curable resin composition for liquid crystal sealing according to [1], wherein the filler has an average primary particle size of 1.5 μm or less and a specific surface area of 1 m ² / g to 500 m ² /g, and the content of the filler is from 1 part by weight to 50 parts by weight based on 100 parts by weight of the total of the acrylic resin and the (meth)acrylic modified epoxy resin, and [by E-type viscosity] The thixotropy index defined by the viscosity at 25 ° C and 0.5 rpm] / [viscosity at 25 ° C and 5.0 rpm measured by an E-type viscometer] was 1.1 to 5.0.

[3] The curable resin composition for liquid crystal sealing according to [1], wherein the thermal radical polymerization is carried out by subjecting the thermal radical polymerization initiator to a thermal decomposition reaction at a certain temperature for 10 hours. The 10-hour half-life temperature of the above thermal radical polymerization initiator defined by the temperature at which the concentration of the initiator is reduced to half is 40 ° C to 80 ° C.

[4] A curable resin composition for liquid crystal sealing comprising: a radical curable property having a carbon-carbon double bond capable of undergoing radical polymerization in one molecule A resin, a thermal radical polymerization initiator, a radical chain transfer agent, and a filler.

[5] The curable resin composition for liquid crystal sealing according to [4], wherein the radical chain transfer agent is a mercaptan.

[6] The curable resin composition for liquid crystal sealing according to [4], wherein the thiol as the radical chain transfer agent is a secondary thiol having a number average molecular weight of 400 to 2,000.

The hardenable resin composition for liquid crystal sealing of the liquid crystal sealing of the above-mentioned liquid crystal sealing curable resin composition measured by the E type viscosity meter at 25 degreeC and 1.0. The viscosity at rpm is 50Pa. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s.

[8] A curable resin composition for liquid crystal sealing comprising a resin composition having a carbon-carbon double bond capable of radical polymerization, a hydrogen bond functional group, and an epoxy group, and a thermal radical polymerization initiator; And a filler; the resin composition comprising two or more resins selected from the group consisting of: (1A) a radical reactive resin having a hydrogen bond functional group in one molecule; Two carbon-carbon double bonds of radical polymerization and the above hydrogen bond functional group amount is 1.5×10 ^-3 mol/g to 6.0×10 ^-3 mol/g, (1B) radical reactive resin, which is one molecule a hydrogen bond functional group, an epoxy group, and a carbon-carbon double bond capable of undergoing radical polymerization, and the amount of the above hydrogen bond functional group is 1.0×10 ⁻⁴ mol/g to 5.0×10 ⁻³ mol/g, and (1C) an epoxy resin having an epoxy group in one molecule but having no carbon-carbon double bond capable of undergoing radical polymerization, and its softening point measured by a ring and ball method (softening Point) is greater than or equal to 40 ° C, and the weight average molecular weight is 500 ~ 5000; the amount of hydrogen bonding functional groups in the above resin composition is 1.0 × 10 ^-4 mol / g ~ 6. 0 × 10 ^-3 mol / g; the amount of the epoxy group in the above resin composition is 1.0 × 10 ^-4 mol / g - 2.6 × 10 ^-3 mol / g.

[9] The curable resin composition for liquid crystal sealing according to [8], wherein the hydrogen bond functional group in the resin composition is a hydroxyl group.

[10] The curable resin composition for liquid crystal sealing according to [8], wherein the radical reactive resin of the above (1A) is represented by the following formula (a1) or formula (a2) Resin.

In the above formula (a1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom or a methyl group; and R _m each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an allylic group; a hydroxyalkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; n representing an integer of 1 to 4; l representing an integer of 1 to 4; and A being -CH ₂ -, -C (CH ₃ ) an organic group represented by _2- , -SO ₂ -, or -O-.

In the above formula (a2), R ₅ , R ₆ , R ₇ and R ₈ each independently represent a hydrogen atom or a methyl group; and R _q independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an allylic group; a hydroxyalkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; r is an integer of 1 to 4; and p is an integer of 1 to 4.

[11] The curable resin composition for liquid crystal sealing according to any one of [10], wherein the radical reactive resin of the above (1A) is represented by the following formula (a3) or A4) Resin represented.

In the above formula (a3), R ₁ and R ₂ each independently represent a hydrogen atom or a methyl group; and R _m each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an allyl group, and a carbon number of 1; a hydroxyalkyl group of ~4 or an alkoxy group having a carbon number of 1 to 4; n represents an integer of 1 to 4; and A is -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, or - An organic group represented by O-.

In the above formula (a4), R ₅ and R ₆ each independently represent a hydrogen atom or a methyl group.

[12] The curable resin composition for liquid crystal sealing according to [8], wherein the curable resin composition for liquid crystal sealing has a viscosity of 50 Pa at 25 ° C and 1.0 rpm as measured by an E-type viscosity meter. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s.

[13] The curable resin composition for liquid crystal sealing according to [8], wherein the curable resin composition for liquid crystal sealing further contains a radical chain transfer agent.

[14] The curable resin composition for liquid crystal sealing according to [13], wherein the curable resin composition for liquid crystal sealing has a viscosity of 50 Pa at 25 ° C and 1.0 rpm measured by an E-type viscosity meter. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s.

Further, the above problems can be solved by the method for manufacturing a liquid crystal display panel of the present invention.

[15] A method for producing a liquid crystal display panel, which is a method for producing a liquid crystal display panel by bonding two opposing substrates via a curable resin composition for liquid crystal sealing, and a method for producing the liquid crystal display panel In the step of preparing the first substrate, the first substrate includes a frame-shaped display region, and the frame-shaped display region is made of the curable resin for liquid crystal sealing according to the above [1], [4], or [8]. a step of surrounding the pixel array region; a step of dropping liquid crystal into the display region in an unhardened state or another substrate; and a step of overlapping the first substrate and the second substrate facing the first substrate; Heating the liquid crystal sealing tree The step of hardening the lipid composition.

According to the present invention, it is possible to provide a curable resin composition for liquid crystal sealing which can suppress liquid crystal leakage and liquid crystal contamination, and a method for producing a high quality liquid crystal display panel in a state in which high productivity is maintained by using the resin composition.

Next, the present invention will be described in detail. In the following description, the numerical range is defined by "~", but the "~" of the present invention includes the boundary value thereof. For example, "10 to 100" means 10 or more and 100 or less.

The term "liquid crystal sealing" as used in the present invention means "sealing liquid crystal"; and "sealing liquid crystal" means "sealing liquid crystal in a certain space". Therefore, the "curable resin composition for liquid crystal sealing" in the present invention has the same meaning as that generally referred to as "liquid crystal sealing agent". In the liquid crystal display panel, the liquid crystal sealing agent can seal the liquid crystal between the two substrates, and can also function as an adhesive for bonding the two substrates. In the liquid crystal sealing agent, a liquid crystal sealing agent which can be used for a liquid crystal dropping technique is sometimes referred to as a "liquid crystal sealing agent for liquid crystal dropping technology" in the present invention. In the following description, the "curable resin composition for liquid crystal sealing" may be referred to as "composition", "liquid crystal sealing agent" or "sealant".

1. Curable resin composition for liquid crystal sealing

The first liquid crystal sealing curable resin composition of the present invention is characterized in that it contains (1) an acrylic resin, and/or (2) at least one epoxy group and (meth) propylene in one molecule. Mercapto (meth)acrylic acid modification The epoxy resin, (3) thermal radical polymerization initiator, and (4) filler; the viscosity of the curable resin composition for liquid crystal sealing measured at 25 ° C and 1.0 rpm measured by an E-type viscosity meter is 50Pa. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s. In the present invention, acryl and methacryl are collectively referred to as (meth)acryl. In addition, the curable resin composition for liquid crystal sealing of the present invention having the above-described characteristics is also referred to as "curable resin composition for liquid crystal sealing I" or "resin composition I".

The above viscosity is an E-type rotary viscometer (for example, a digital rheometer manufactured by BROOKFIEL, model: DII-III ULTRA), and a CP-52 having a radius of 12 mm and an angle of 3° is used. A cone-and-plate sensor was measured by setting the rotation speed to 1.0 rpm. In this case, the viscosity is measured at a predetermined temperature, and the viscosity at 25 ° C is the viscosity measured by the above method after the curable resin composition I for liquid crystal sealing is allowed to stand at 25 ° C for 5 minutes. The viscosity at 80 ° C means that the above composition is placed in a cup of an E-type rotational viscometer, and is heated to 80 ° C at a temperature increase rate of 5 ° C / min, and then placed at 80 ° C for 5 minutes, and then The viscosity measured by the above method.

The viscosity at 1.0 rpm measured by the above E-type rotational viscometer is greater than 780 Pa. In the case of s, it is preferably measured by a parallel plate method. The reason is that when the above-mentioned E-type rotational viscometer uses a rotor code 5, the measurement limit is about 780 Pa. s. By using the parallel plate method, for example, RheoStress RS150 can be used. A viscoelastic type measuring device such as (manufactured by HAAKE) is carried out in accordance with the standard method of the model.

The curable resin composition I for liquid crystal sealing is characterized in that its viscosity at 50 ° C at 50 ° C is 50 Pa. s~500Pa. s, the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s; better at 25 ° C, 1.0 rpm viscosity is 100Pa. s~400Pa. s. In the step of applying such a composition to a substrate as a liquid crystal sealing agent, it is easy to remove air bubbles contained in the liquid crystal sealing agent, so that a high quality liquid crystal display panel can be provided.

Further, as described above, the curable resin composition I for liquid crystal sealing is characterized in that its viscosity at 80 ° C and 1.0 rpm is more than 500 Pa. s. Usually, when the thermosetting resin is cured by heating, the viscosity of the resin is temporarily lowered, and as the curing reaction proceeds, the viscosity increases again. Generally, when the liquid crystal display panel is manufactured, the curing temperature of the liquid crystal sealing agent is about 80 to 150 °C. As described above, if the viscosity of the composition is excessively lowered in this hardening step, problems such as liquid crystal leakage occur.

Therefore, in order to prevent liquid crystal leakage (improving leakage resistance), an effective method is to suppress a decrease in viscosity of the composition at the time of heat hardening. In order to suppress a decrease in the viscosity of the composition at the time of heat hardening, it is effective to carry out a hardening reaction of the composition before the viscosity reduction occurs, and to increase the viscosity of the composition. In addition, in order to suppress liquid crystal leakage, the composition viscosity at 80 ° C, 1.0 rpm is 500Pa. s as a standard. Therefore, the resin composition I of the present invention is designed in such a manner that the hardening of the composition is promoted by using a thermal radical polymerization initiator having a 10-hour half-life temperature within a predetermined range as described below. Thereby, the viscosity of the composition at 80 ° C, 1.0 rpm is greater than 500Pa. s, the viscosity of the composition can be increased before the viscosity is lowered, so that the viscosity at the time of heat curing can be suppressed from being lowered. Here, from the viewpoint of suppressing the decrease in the viscosity of the composition to a lower level, the viscosity at 80 ° C is preferably 10 ³ Pa. s~10 ⁹ Pa. s, better 10 ³ Pa. s~10 ⁷ Pa. s.

Further, the thixotropic index defined by [viscosity at 25 ° C, 0.5 rpm] / [viscosity at 25 ° C, 5.0 rpm] of the curable resin composition for liquid crystal sealing is preferably 1.1 to 5.0. It is 1.2~2.5. The thixotropic index refers to the ratio of the viscosity measured at a lower shear velocity to the viscosity measured at a higher shear rate. If the ratio is high, the fluid of the above resin composition I flows at a high viscosity at a low shear rate and at a high viscosity at a low viscosity.

When the liquid crystal display panel is manufactured, in the step of applying a liquid crystal sealing agent on the substrate, in the case where the liquid crystal sealing agent is at a high shear rate, and then the substrate is superposed and post-hardened, the liquid crystal sealing agent is in the shearing process. The cutting speed is extremely low. Here, in the step of applying the liquid crystal sealing agent on the substrate (high shear rate region), it is necessary to easily apply the film, and it is easy to defoam the liquid crystal sealing agent. Therefore, it is preferred that the liquid crystal sealing agent has a low viscosity. Further, in the hardening process (low shear rate region), as described above, liquid crystal leakage does not occur, and therefore it is preferred that the liquid crystal sealing agent has a high viscosity. From the above viewpoints, since the curable resin composition I for liquid crystal sealing has good coatability, defoaming property, and reliability when it is used as a liquid crystal sealing agent, the thixotropic index is set to the above range.

This composition I is characterized by: (1) an acrylic resin, and/or (2) A (meth)acrylic modified epoxy resin having at least one epoxy group and (meth)acrylonitrile group in one molecule as a base resin, and containing (3) thermal radical polymerization The starting agent and (4) a filler; and the composition I is a so-called one-liquid curable resin composition in which a main agent (curable resin) and a curing agent (hardening accelerator) in an uncured state are mixed. Since the one-liquid curable resin composition does not need to be mixed with the curing agent at the time of use, it is excellent in workability.

Next, each component of the curable resin composition I for liquid crystal sealing of the present invention will be described.

(1) Acrylic resin

The acrylic resin of the present invention means an acrylate and/or methacrylate monomer, or an oligomer thereof. Examples of these include the following.

Diacrylate and/or dimethacrylate of polyethylene glycol, propylene glycol, polypropylene glycol, etc.; diacrylate and/or dimethacrylate of tris(2-hydroxyethyl)isocyanate; a diacrylate and/or dimethacrylate of a diol obtained by adding ethylene oxide or propylene oxide of 4 mol or more to neopentyl glycol; 1 mol of bisphenol a diacrylate and/or dimethacrylate of a diol obtained by adding 2 moles of ethylene oxide or propylene oxide to A (bisphenol A); added to 1 mole of trimethylolpropane a triol di or triacrylate and/or di or trimethacrylate obtained by forming 3 mol or more of ethylene oxide or propylene oxide; addition to 1 mol of bisphenol A is greater than or equal to Dimer of diol and/or dimethacrylate obtained by 4 moles of ethylene oxide or propylene oxide; tris(2-hydroxyethyl)isocyanate triacrylate and/or Or trimethacrylate; trimethylolpropane triacrylate and/or trimethacrylate, or an oligomer thereof; pentaerythritol triacrylate and/or trimethacrylate, or an oligomer thereof; Polyacrylate and/or polymethacrylate of pentaerythritol; tris(propylene methoxyethyl) isocyanate; caprolactone modified tris(propylene oxyethyl) isocyanate; caprolactone modified tris (methyl Propylene methoxyethyl)isocyanate; polyacrylate and/or polymethacrylate of alkyl modified dipentaerythritol; polyacrylate and/or polymethacrylate of caprolactone modified dipentaerythritol; Pentanic acid neopentyl glycol diacrylate and / or dimethacrylate; caprolactone modified hydroxypivalic acid neopentyl glycol diacrylate and / or dimethacrylate; ethylene oxide modified phosphoric acid Acrylate and/or dimethacrylate; ethylene oxide modified alkylated phosphate acrylate and/or dimethacrylate; neopentyl glycol, trimethylolpropane, pentaerythritol oligoacrylate and / or oligomeric methacrylate and the like.

Further, specific examples of the above acrylic resin include a cresol novolac type epoxy resin, a phenol novolac type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol F type. Epoxy resin, trisphenol methane epoxy resin, trisphenol ethane epoxy resin, trisphenol epoxy resin, phenyl ether epoxy resin, dicyclopentadiene epoxy resin, biphenyl epoxy An epoxy resin obtained by reacting all epoxy groups such as a resin with (meth)acrylic acid is completely (meth)acrylonitrile-based resin. Further, the acrylic resin of the present invention is preferably obtained by high purity by a water washing method or the like.

The acrylic resin of the present invention preferably has a number average molecular weight in the range of 300 to 2,000, and the theoretical solubility parameter (spub value) of Fedors is 10.0 (cal/cm ³ ) ^1/2 to 13.0 (cal). /cm ³ ) Within ^1/2 range. Since the solubility and diffusibility of the acrylic resin in the liquid crystal are lowered, the liquid crystal sealing agent containing the resin can provide a liquid crystal display panel having excellent display characteristics, which is preferable. Further, such an acrylic resin is also excellent in compatibility with the following (6) epoxy resin, so that a homogeneous liquid crystal sealing agent can be provided. The above number average molecular weight can be measured, for example, by gel permeation chromatography (GPC) using polystyrene as a standard.

There are various methods or calculation methods for calculating the solubility parameter (sp value), but the theoretical solubility parameter of the present invention is preferably calculated based on the calculation method designed by Fedors (refer to the Japanese Society of the Society, vol. 22, no. 10 (1986) (53) (566), etc.). The reason for this is that since the calculation method does not require a density value, the solubility parameter can be easily calculated. The theoretical solubility parameters of the above Fedors can be calculated according to the following formula.

Sp value = (Σ △ el / Σ Δvl) ^1/2

Where ΣΔel=(△H-RT), ΣΔvl=the sum of the molar capacity

When the solubility parameter is within the above range, the solubility of the acrylic resin in the liquid crystal is small, and contamination of the liquid crystal can be suppressed. Therefore, the display characteristics of the liquid crystal display panel can be improved, which is preferable.

The acrylic resin may be a mixture of a plurality of the above acrylic resins. In this case, the theoretical solubility parameter of the entire mixed composition may be based on the sum of the molar percentages of the mixed acrylate monomer and/or methacrylate monomer, or the oligomer thereof. And calculate. It is preferred that this value is in the range of 10.0 (cal/cm ³ ) ^1/2 to 13.0 (cal/cm ³ ) ^{1/2 described} above.

Examples of the acrylic resin having a number average molecular weight of 300 to 2,000 and a theoretical solubility parameter of Fedors in the range of 10.0 (cal/cm ³ ) ^1/2 to 13.0 (cal/cm ³ ) ^1/2 include pentaerythritol tetraacrylic acid. The ester (quantitative average molecular weight 352, sp value 12.1).

(2) (meth)acrylic modified epoxy resin having one or more epoxy groups and (meth)acrylonitrile groups in one molecule

The (meth)acrylic modified epoxy resin having one or more epoxy groups and one (meth)acrylonyl group in one molecule in the present invention (may also be simply referred to as "modified ring" The oxygen resin ")" refers to a compound having both a (meth)acryl fluorenyl group and an epoxy group in one molecule.

Examples of the modified epoxy resin include: an epoxy resin such as a bisphenol type epoxy resin or a novolak type epoxy resin, and (meth)acrylic acid or phenyl methacrylate, for example, under an alkaline catalyst. The resin obtained by the reaction.

Examples of the epoxy resin which is a raw material of the above modified epoxy resin include a cresol novolac type epoxy resin, a phenol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, A trisphenol methane type epoxy resin, a trisphenolethane type epoxy resin, a trisphenol type epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, or the like.

Among them, it is preferred that the bisphenol A type epoxy resin and the bisphenol F type epoxy resin have two epoxy groups in the molecule, such as a molar ratio of epoxy group to acrylic acid of approximately 1:1. Epoxy resin is obtained by reacting with acrylic acid Resin. Further, the epoxy resin is preferably purified by a molecular distillation method, a cleaning method, or the like.

Since the modified epoxy resin has both an epoxy group and a (meth)acryloyl group in the resin skeleton, (1) an acrylic resin and the following (6) epoxy resin in the curable resin composition for liquid crystal sealing. Excellent compatibility. Therefore, it is possible to provide a cured product of a composition having a high glass transition temperature (Tg) and excellent adhesion. Since the cured product of the composition is excellent in adhesion, it means that the bonding strength between the cured product and the substrate is high, so that a high-quality liquid crystal display panel can be provided.

In the present invention, (1) an acrylic resin and (2) a modified epoxy resin may be used in any ratio. These include: a) a form in which only (1) an acrylic resin is used without using (2) a modified epoxy resin; or b) a form in which only (2) a modified epoxy resin is used without using (1) an acrylic resin. In this case, in the case of a), it is possible to provide a curable resin composition for liquid crystal sealing which is excellent in leakage resistance. In the case of b), by appropriately combining the (2) modified epoxy resin and the following (5) epoxy curing agent, it is possible to provide a curable resin composition for liquid crystal sealing having a high bonding strength. In the present invention, in the characteristics of the liquid crystal sealing agent, the case where the bonding strength of the liquid crystal sealing agent and the member to be bonded such as the substrate is large is referred to as excellent reliability.

Further, (1) an acrylic resin and (2) a modified epoxy resin may be used in combination. The mixing ratio of each resin is preferably (1) acrylic resin: (2) modified epoxy resin = 10 to 70: 90 to 30, more preferably 20 to 50: 80 to 50. Thereby, it is possible to provide a curable resin composition for liquid crystal sealing which is excellent in reliability. In addition, in the present invention, sometimes merged The resin composition of (1) acrylic resin and (2) modified epoxy resin is referred to as "resin combination".

(3) Thermal radical polymerization initiator

The thermal radical polymerization initiator refers to a compound which generates a radical upon heating, that is, a compound which absorbs thermal energy and decomposes to generate a radical species. Such a thermal radical polymerization initiator is suitable for the case where the liquid crystal sealing agent is cured by heating after bonding the substrate.

Preferably, the 10-hour half-life temperature of the thermal radical polymerization initiator is in the range of 30 ° C to 80 ° C, more preferably 40 ° C to 80 ° C, and particularly preferably 50 ° C to 70 ° C. The 10-hour half-life temperature refers to a temperature at which the concentration of the thermal radical polymerization initiator decreases to half of the original when the thermal radical polymerization initiator is subjected to a thermal decomposition reaction at a predetermined temperature for 10 hours in an inert gas atmosphere. . A liquid crystal sealing agent using a thermal radical polymerization initiator having a 10-hour half-life temperature within the above range is excellent in balance between viscosity stability and hardenability.

As described above, the curable resin composition for liquid crystal sealing preferably suppresses the decrease in viscosity, and suppresses the decrease in viscosity, and promotes hardening of the composition, from the viewpoint of suppressing liquid crystal leakage due to excessive decrease in viscosity during heat curing. The reaction accelerates the gelation. The 10-hour half-life temperature of the thermal radical polymerization initiator is preferably 80 ° C or less, more preferably 70 ° C or less, from the viewpoint of speeding up gelation. In this case, when the composition is subjected to heat curing (normally, the curing temperature is 80 to 150 ° C), radicals are easily generated to promote the curing reaction, so that the viscosity reduction during heat curing can be suppressed.

On the other hand, when the 10-hour half-life temperature of the thermal radical polymerization initiator is too low, the curing reaction can be easily performed at room temperature, which impairs the stability of the liquid crystal sealing agent. In this respect, if the 10-hour half-life temperature of the thermal radical polymerization initiator is 30 ° C, preferably 40 ° C or more, the step of storage or coating onto the substrate (usually at room temperature) In the next step, the stability of the liquid crystal sealing agent is good.

Here, the thermal radical polymerization initiator having a 10-hour half-life temperature of more than 80 ° C is hard to generate a radical. Therefore, the liquid crystal sealing agent containing the thermal radical polymerization initiator has a low curability and is therefore unsatisfactory. On the other hand, when the 10-hour half-life temperature of the thermal radical polymerization initiator is less than 30 ° C, the curing reaction can be easily performed at room temperature, and thus the viscosity of the liquid crystal sealing agent containing the thermal radical polymerization initiator Stability will be significantly reduced. From the above, it is preferred that the 10-hour half-life temperature of the thermal radical polymerization initiator is within the above range.

The 10-hour half-life temperature can be specifically determined in the following manner. First, if the thermal decomposition reaction is regarded as a first-order reaction formula, the following relationship holds.

Ln(C ₀ /C _t )=kd×t

C ₀ : initial concentration of thermal radical initiator

C _t : concentration of thermal radical initiator after t hours

Kd: thermal decomposition rate constant

t: reaction time

The half-life means the time at which the concentration of the thermal radical polymerization initiator is reduced to a general time, that is, C _t = C ₀ /2. Therefore, after the hour, when the thermal radical polymerization initiator reaches the half life, the following formula holds.

Kd=(1/t)×ln2

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

Kd=Aexp(-△E/RT)

The following formula can be derived according to the above formula.

(1/t)×ln2=Aexp(-△E/RT)

A: Frequency factor

△E: activation energy

R: gas constant (8.314 J/mol. K)

T: absolute temperature (K)

The values of A and ΔE are disclosed in Polymer Handbook fourth edition, Volume 1, II-2 to II-69, WILEY-INTERSCIENCE (1999) by J. Brandrup et al. From the above, if t = 10 hours, the 10-hour half-life temperature T can be obtained.

Well-known compounds can be used as the thermal radical polymerization initiator. Representative examples thereof include organic peroxides and azo-compounds.

Organic peroxides are preferably classified as ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxyester. An organic peroxide of diacyl peroxide or peroxydicarbonate is not particularly limited, and a well-known organic peroxide can be used.

Specific examples of the above organic peroxides are shown below. The number in parentheses refers to the 10-hour half-life temperature (refer to the Wako Pure Chemicals Catalog, the API Corporation catalog, and the above Polymer HandBook).

Examples of the ketone peroxides include methyl ethyl ketone peroxide (109 ° C), cyclohexanone peroxide (100 ° C), and the like. Further, examples of the peroxy ketals include 1,1-bis(trihexylperoxy)-3,3,5-trimethylcyclohexane (87 ° C), 1,1-bis (third hexyl) Peroxidic) cyclohexane (87 ° C), 1,1-bis(t-butylperoxy)cyclohexane (91 ° C), 2,2-bis(t-butylperoxy)butane (103 ° C) ), 1,1-(third amyl peroxide) cyclohexane (93 ° C), 4,4-bis(t-butylperoxy)-n-butyl valerate (105 ° C), 2,2-double (4,4-di-t-butylperoxycyclohexyl)propane (95 ° C).

Examples of hydroperoxides include: hydrogen peroxide to menthane (128 ° C), diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl Hydrogen peroxide (153 ° C), cumene hydroperoxide (156 ° C), tert-butyl hydroperoxide (167 ° C), and the like.

Examples of the dialkyl peroxide include: α,α-bis(t-butylperoxy)diisopropylbenzene (119 ° C), dicumyl peroxide (116 ° C), 2 , 5-dimethyl-2,5-bis (t-butyl peroxy) Hexane (118 ° C), tert-butyl cumyl peroxide (120 ° C), third amyl peroxide (123 ° C), di-tert-butyl peroxide (124 ° C), 2, 5-Dimethyl-2,5-bis(t-butylperoxy)-3-hexene (129 ° C).

Examples of peroxyesters include: cumyl peroxyneodecanoate (37 ° C), perylene neodecanoic acid 1,1,3,3-tetramethylbutyl ester (41 ° C), Oxidized neodecanoic acid hexyl ester (45 ° C), peroxy neodecanoic acid tert-butyl ester (46 ° C), peroxy neodecanoic acid third amyl ester (46 ° C), peroxypivalate third hexyl ester (53 ° C), third butyl peroxypivalate (55 ° C), third amyl peroxypivalate (55 ° C), 2-ethylhexanoic acid 1,1,3,3-tetra Methyl butyl ester (65 ° C), 2,5-dimethyl-2,5-bis(2-ethylhexyl thioperoxide) hexane (66 ° C), peroxide 2-ethylhexanoic acid third Hexyl ester (70 ° C), tert-butyl peroxy 2-ethylhexanoate (72 ° C), third amyl peroxy 2-ethylhexanoate (75 ° C), tert-butyl peroxy isobutyrate (82 ° C), hexyl isopropyl monocarbonate (95 ° C), tributyl butyl maleate (96 ° C), tripentyl peroxyoctanoate (96 ° C), peroxidation Triamyl isononanoate (96 ° C), 3,5,5-trimethylhexanoic acid tert-butyl ester (97 ° C), butyl laurate per acid (98 ° C), peroxidation Propyl monobutyl carbonate (99 ° C), over Tert-butyl 2-ethylhexyl monocarbonate (99 ° C), third hexyl peroxybenzoate (99 ° C), 2,5-dimethyl-2,5-bis (benzhydryl peroxide) Hexane (100 ° C), third amyl acetate (100 ° C), third amyl benzoate (100 ° C), tert-butyl peroxyacetate (102 ° C), benzoic acid peroxide Tributyl ester (104 ° C).

Examples of di-mercapto peroxides include: diisobutyl hydrazine peroxide (33 ° C), di-3,5,5-trimethylhexyl peroxide (60 ° C), dilauroyl peroxide (62 ° C), succinic acid peroxide (66 °C), benzoyl peroxide (73 ° C).

Examples of peroxydicarbonates include: di-n-propyl peroxydicarbonate (40 ° C), diisopropyl peroxydicarbonate (41 ° C), bis(4-tert-butylcyclohexyl) peroxydicarbonate ) ester (41 ° C), di-2-ethylhexyl peroxydicarbonate (44 ° C), third pentyl peroxypropyl carbonate (96 ° C), third ethyl pentyl peroxyethyl carbonate (99 ° C).

Next, an azo compound (also referred to as "azo-based thermal radical polymerization initiator") which acts as a thermal radical polymerization initiator will be described. Examples of the azo-based thermal radical polymerization initiator include a water-soluble azo-based thermal radical polymerization initiator, an oil-soluble azo-based thermal radical polymerization initiator, and a polymer azo-based thermal radical polymerization. Starting agent.

Examples of the water-soluble azo-based thermal radical polymerization initiator include: 2,2'-azobis[2-(2-imidazolin-2-yl)propane]disulfate dihydrate (46 ° C), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (57 ° C), 2,2'-azobis{2-[1-(2- Hydroxyethyl)-2-imidazolin-2-yl]propane} dihydrochloride (60 ° C), 2,2'-azobis(1-imino-1-pyrrolidino-2-ethylpropane Dihydrochloride (67 ° C), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propanamide] (87 ° C), 2,2'-azo double [2-(2-Imidazolin-2-yl)propane] dihydrochloride (44 ° C), 2,2'-azobis(2-methylpropionamidine) dihydrochloride (56 ° C), 2 , 2'-azobis[2-(2-imidazolin-2-yl)propane] (61 ° C), 2,2'-azobis {2-methyl-N-[1,1-dual ( Hydroxymethyl)-2-hydroxyethyl]propanamine} (80 ° C).

Examples of the oil-soluble azo-based thermal radical polymerization initiator include: 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (30 ° C), 2, 2' - azobis(dimethyl 2-methylpropionate) (66 ° C), 1,1 '-azobis(cyclohexane-1-carbonitrile) (88 ° C), 1,1 '-[( Cyano-1-methylethyl)azo]carbamamine (104 ° C), 2,2'-azobis(N-cyclohexyl-2-methylpropanamide) (111 ° C), 2, 2'-azobis(2,4-dimethylvaleronitrile) (51 ° C), 2,2'-azobis(2-methylbutyronitrile) (67 ° C), 2,2'-azo Bis[N-(2-propenyl)-2-methylpropanamide] (96 ° C), 2,2'-azobis(N-butyl-2-methylpropanamide) (110 ° C) .

Examples of the polymer azo-based thermal radical polymerization initiator include a polymer azo-based thermal radical polymerization initiator containing a polydimethyl siloxane unit, and a polymer azo containing a polyethylene glycol unit. A thermal radical polymerization initiator or the like. Further, a mixture in which these compounds are arbitrarily combined can also be used as a thermal radical polymerization initiator.

The thermal radical polymerization initiator is preferably from 0.01 part by weight to 3.0 parts by weight per 100 parts by weight of the resin combination in which the above (1) and (2) are combined. When the amount of the thermal radical polymerization initiator is too large, the viscosity stability is deteriorated, and if the amount of the thermal radical polymerization initiator is too small, the hardenability is deteriorated.

(4) Filler

The filler of the present invention refers to a filler added to control the viscosity of the liquid crystal sealing agent, to increase the strength of the cured product, to control linear expansion, and the like. By filling the filler, the subsequent reliability of the liquid crystal sealing agent can be improved. The filler is not limited as long as it is a filler used in the field of electronic materials.

Examples of the above filler include: calcium carbonate, magnesium carbonate, barium sulfate, Magnesium sulfate, aluminum niobate, zirconium silicate, iron oxide, titanium oxide, alumina, zinc oxide, cerium oxide, potassium titanate, kaolin, talc, glass beads ), sericite, activated clay, bentonite, aluminum nitride, tantalum nitride inorganic filler.

Further, an organic filler can also be used in the present invention. The organic filler refers to an organic compound generally having a softening point temperature of more than 120 ° C as measured by a ring and ball method (JACT test method: RS-2). Among them, in the present invention, rubber particles having a softening point of less than or equal to room temperature can also be used as the organic filler. Examples of the organic filler include polymethyl methacrylate, a copolymer formed by copolymerizing polystyrene and a monomer copolymerizable therewith, polyester microparticles, polyurethane fine particles, and rubber microparticles. .

Among them, the filler is preferably an inorganic filler in which the linear expansion ratio of the liquid crystal sealing agent can be kept good, and the cerium oxide and talc are particularly difficult to permeate due to ultraviolet rays.

Regardless of the inorganic or organic filler, the shape of the filler is not particularly limited. That is, a filler of any of a fixed shape or a non-fixed shape such as a spherical shape, a plate shape, or a needle shape can be used. Further, the average primary particle diameter of the filler is preferably 1.5 μm or less, and the specific surface area thereof is preferably 1 m ² /g to 500 m ² /g. The curable resin composition for liquid crystal sealing containing such a filler has a good balance between thixotropy and viscosity. The average primary particle diameter of the filler can be measured by laser diffractometry as disclosed in JIS Z8825-1, and the specific surface area can be determined by the BET method disclosed in JIS Z8830 (Brunauer-Emmett-Teller method). ) Perform the measurement.

Further, from the viewpoint of suppressing liquid crystal leakage, it is preferred to use two or more kinds of fillers in combination. The two or more types of fillers are two or more types of fillers having different materials, two or more fillers having the same material but different average particle diameters, or a combination thereof. When the average particle diameter is different, the average particle diameter of the filler is preferably 0.3 μm or more.

The filler amount of the filler is preferably from 1 part by weight to 50 parts by weight, more preferably from 10 parts by weight to 30 parts by weight, per 100 parts by weight of the resin combination of the above (1) and (2). When the amount of the filler to be filled is in the above range, the thixotropic index of the curable resin composition for liquid crystal sealing is preferably controlled to be in the range of 1.1 to 5.0, which is preferable. The thixotropic index is a value obtained by [viscosity at 25 ° C and 0.5 rpm measured by an E-type viscometer] / [viscosity at 25 ° C and 5.0 rpm measured by an E-type viscometer]. .

(5) Epoxy hardener

The curable resin composition I for liquid crystal sealing may further contain an epoxy hardener. Among them, the epoxy hardener is preferably a latent epoxy hardener. The latent epoxy curing agent means that even if it is mixed in an epoxy resin, the epoxy resin is not cured in a state in which the resin is normally stored (at room temperature, under visible light, etc.), but it can be made by heat or light. Hardener hardened by epoxy resin. By using a latent epoxy curing agent, the thermosetting property of the curable resin composition I for liquid crystal sealing can be improved.

A latent epoxy hardener can be used as known. Among them, the viscosity From the viewpoint of excellent stability, a latent epoxy hardener having a melting point or a softening point temperature of 100 ° C or more as measured by a ring and ball method is preferred. The composition containing this latent epoxy hardener can be used as a one-liquid type. Examples of the latent epoxy hardener include an organic acid dihydrazide compound, imidazole and a derivative thereof, dicyandiamide, aromatic amine, and the like. These latent epoxy hardeners can be suitably combined into a mixture.

In the screen printing or dispenser used for coating a composition, since the composition has a long residence time in the apparatus, it is difficult to use a composition having poor storage stability. In this respect, in particular, the composition of the amine-based latent curing agent having a melting point or a softening point temperature of 100 ° C or more as measured by the ring and ball method is excellent in viscosity stability at room temperature. Used for a long time in screen printing or dispensers.

Examples of the above amine-based latent curing agent include dicyandiamides such as dicyandiamide (melting point: 209 ° C); diterpene adipate (melting point: 181 ° C), 1,3-bis(decylcarbonylethyl) -5-Isopropyl hydrazine (1,3-bis(hydrazino carboethyl)-5-isopropyl hydantoin) (melting point 120 ° C), dioxonium dodecanoate (melting point 190 ° C), 癸Organic acid diterpene such as diterpene diphosphate (melting point: 189 ° C); 2,4-diamino-6-[2'-ethylimidazolium-1'-yl]ethyltriazine (melting point 215 ° C ~225 ° C), imidazole derivatives such as 2-phenylimidazole (melting point: 137 ° C ~ 147 ° C).

From the viewpoint of obtaining the curable resin composition I for liquid crystal sealing excellent in viscosity stability and subsequent reliability, the content of the latent epoxy curing agent is preferably 3 parts by weight with respect to 100 parts by weight of the resin combination. 30 weight Quantities. Further, the latent epoxy curing agent is preferably purified by a water washing method, a recrystallization method, or the like.

(6) Epoxy resin

The curable resin composition I for liquid crystal sealing may further contain an epoxy resin. The epoxy resin of the present invention refers to a compound having one or more epoxy groups in the molecule (excluding the above (2) modified epoxy resin).

Examples of the epoxy resin which can be used in the present invention include: aromatic diols typified by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, etc., and the above aromatic diols A diol formed by reforming an alcohol, propylene glycol or alkanediol, and an aromatic polyglycidyl ether compound obtained by reacting with epichlorohydrin (hereinafter, for example, bisphenol A is used as a raw material) It is expressed as "bisphenol A type epoxy resin"); polyphenols represented by novolac resin, polyalkenylphenol or copolymer thereof derived from phenol or cresol and formaldehyde, and A novolac type polyglycidyl ether compound obtained by a reaction of chlorohydrin; a glycidyl ether compound of xylylene phenol resin.

Among them, the epoxy resin is preferably a cresol novolac type epoxy resin, a phenol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a trisphenol methane type epoxy resin, A trisphenol type epoxy resin, a trisphenol type epoxy resin, a dicyclopentadiene type epoxy resin, a phenyl ether type epoxy resin, and a biphenyl type epoxy resin. These resins can also be used in combination. Further, the epoxy resin is preferably formed by high-purification treatment by a molecular distillation method or the like.

Preferably, the epoxy resin has a softening point of 40 ° C or more as measured by the ring and ball method, and a weight average molecular weight of 500 to 10,000. The reason for this is that when the softening point or the weight average molecular weight of the epoxy resin is within the above range, the solubility and diffusibility of the epoxy resin in the liquid crystal are low, and the display characteristics of the obtained liquid crystal display panel are good. The reason for this is that the compatibility between the epoxy resin and the (1) acrylic resin is good, and the subsequent reliability of the curable resin composition for liquid crystal sealing and the member to be bonded can be improved. From this point of view, it is preferred that the epoxy resin has a weight average molecular weight in the range of from 1,000 to 2,000. The weight average molecular weight of the epoxy resin can be measured, for example, by GPC and using polystyrene as a standard.

(7) Photoradical polymerization initiator

The curable resin composition I for liquid crystal sealing may further contain a photoradical polymerization initiator. The photoradical polymerization initiator is a compound which can generate a radical by light. The curable resin composition I for liquid crystal sealing containing a photoradical polymerization initiator can be temporarily cured by photocuring, so that workability is good. Of course, the curable resin composition I for liquid crystal sealing may not contain a photoradical polymerization initiator. The curable resin composition for liquid crystal sealing which does not contain a photo-radical polymerization initiator can be hardened only by heating, and has the advantage that the light-hardening process which has a large burden on cost can be abbreviate|omitted.

The photoradical polymerization initiator is not particularly limited, and a well-known compound can be used. Examples include: benzoin compounds, acetophenones, benzophenones, thioxanthones, α-acyloxime esters, B Phenyl glyoxylate, benzyl Type, azo compound, diphenylsulfide compound, acyl phosphine oxide compound, organic dye compound, iron phthalocyanine, benzoin , benzoin ether, anthraquinone.

The content of the photoradical polymerization initiator is preferably from 0.1 part by weight to 5.0 parts by weight, more preferably from 0.3 part by weight to 5.0 parts by weight, per 100 parts by weight of the resin combination. The composition of the photoradical polymerization initiator in an amount of 0.3 part by weight or more or more is excellent in hardenability by light irradiation. On the other hand, when the content of the photoradical polymerization initiator is 5.0 parts by weight or less, the stability of the composition when applied to a substrate is good.

When the resin composition containing a photoradical polymerization initiator is hardened, the light source is preferably ultraviolet light, visible light or the like. Further, the amount of light irradiation is preferably from 500 mJ/cm ² to 1800 mJ/cm ² .

(8) Thermoplastic polymer

The curable resin composition I for liquid crystal sealing may further contain a thermoplastic polymer. The thermoplastic polymer is a polymer compound which can be formed into a target shape by being softened by heating.

The thermoplastic polymer which can be used in the present invention has a softening point temperature of usually 50 ° C to 120 ° C, preferably 60 ° C to 80 ° C. When the softening point temperature is within the above range, the thermoplastic polymer is melted in the resin composition during thermal curing of the resin composition, and the above (1) acrylic resin, (2) modified epoxy resin, (6) Since the epoxy resin is compatible, the viscosity of the composition at the time of heating can be suppressed from being lowered, so that liquid crystal leakage and the like can be suppressed. The content of the thermoplastic polymer is preferably from 1 part by weight to 30 parts by weight relative to 100 parts by weight of the resin combination. The above softening point temperature can be measured by the ring and ball method (JACT test method: RS-2).

Further, since the thermoplastic polymer exhibits good compatibility in the curable resin composition for a liquid crystal sealing agent, it is preferred that the average particle diameter is usually in the range of 0.05 μm to 5 μm, preferably 0.07 μm to 3 μm. . Such a thermoplastic polymer can be used, and is preferably 50% by weight to 99.9% by weight: 50% by weight to 0.1% by weight (more preferably 60% by weight to 80% by weight: 40% by weight to 20% by weight). A copolymer obtained by copolymerizing a (meth) acrylate monomer and a monomer copolymerizable with the monomer. Further, the copolymer is preferably a copolymer formed by polymerization in an emulsion state by emulsion polymerization or suspension polymerization.

Examples of the above (meth) acrylate monomer include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl acrylate, 2-ethyl (meth) acrylate Hexyl ester, amyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate A monofunctional (meth) acrylate monomer such as 2-hydroxyethyl (meth) acrylate or glycidyl (meth) acrylate or a mixture of such monomers. Among them, preferred are methyl (meth)acrylate, butyl acrylate, 2-ethylhexyl (meth)acrylate or a mixture of such monomers.

Examples of the monomer copolymerizable with the above (meth) acrylate monomer include: acrylamide; (meth)acrylic acid, itacon Acid monomers such as itaconic acid and maleic acid; aromatic vinyl compounds such as styrene and styrene derivatives; 1,3-butadiene, 1,3-pentadiene, and isoprene a conjugated diene such as an ene, a 1,3-hexadiene or a chloroprene; or a polyfunctional monomer such as a divinylbenzene or a diacrylate. These monomers can also be used in combination.

(9) Other additives

The curable resin composition I for liquid crystal sealing may further contain a coupling agent such as a silane coupling agent, an ion trapping agent, an ion exchange agent, and a leveling agent. Leveling agent), additives such as pigments, dyes, plasticizing agents, antifoaming agents, and the like. Further, in order to adjust the gap of the liquid crystal display panel, a spacer or the like may be blended.

The second liquid crystal sealing curable resin composition of the present invention is characterized in that it contains (10) 1 molecule in addition to the above (3) thermal radical polymerization initiator and (4) filler. A radically curable resin having a radically polymerized carbon-carbon double bond and (11) a radical chain transfer agent. The curable resin composition for liquid crystal sealing of the present invention having the above characteristics is also referred to as "curable resin composition for liquid crystal sealing II" or "resin composition II".

Specific examples of the (3) thermal radical polymerization initiator and the (4) filler contained in the resin composition II are as described above. Among them, the (3) thermal radical polymerization initiator of the resin composition II is particularly preferably an organic peroxide, an azo compound, a benzoin, a benzoin ether or an acetophenone.

(10) A radical curable resin having a carbon-carbon double bond capable of undergoing radical polymerization in one molecule

The radical curable resin (also referred to simply as "radical curable resin") having a carbon-carbon double bond capable of undergoing radical polymerization in one molecule of the present invention means, for example, an ethylenically unsaturated bond in one molecule. A compound capable of undergoing free radical polymerization of a carbon-carbon double bond.

Examples of the radical curable resin include a (meth) acrylate monomer or an oligomer thereof, an allyl alcohol derivative, and a vinyl compound, and are not particularly limited. The above (1) acrylic resin and (2) modified epoxy resin are included in the above-mentioned radical curable resin.

The (meth) acrylate monomer or the oligomer thereof is not particularly limited, and includes, for example, those listed in the above (1) acrylic resin.

Examples of the above allyl alcohol derivative include: triallyl cyanurate, triallyl isocyanurate, diallyl maleate, diallyl adipate, diallyl phthalate, Diallyl isophthalate, triallyl trimellitate, tetraallyl pyromellitate, glycerol diallyl ether, trimethylolpropane diallyl ether, pentaerythritol diallyl ether, pentaerythritol Triallyl ether, allyl ester resin. Examples of the above vinyl compound include divinylbenzene.

In addition, as the radical curable resin, a compound having a functional group containing a carbon-carbon double bond and a different functional group such as an epoxy group in one molecule can be used. The above carbon-carbon double bond is preferably a (meth) acrylonitrile group; and a different functional group is preferably an epoxy group. Since the radical curable resin has both an epoxy group and a (meth) acrylonitrile group in the resin skeleton, it is combined with other radical hardening trees. The above-mentioned (6) epoxy resin which is a fat or an optional component of the composition II has high compatibility. Therefore, the composition containing the radical curable resin is homogeneous, and the reliability is also improved in addition to the improvement in the appearance of the seal.

It is preferred that the number average molecular weight of the radical curable resin and the theoretical solubility parameter (sp value) of Fedors are also the same as those of the above (1) acrylic resin. That is, the number average molecular weight is in the range of 300 to 2,000, and the theoretical solubility parameter is 10.0 (cal/cm ³ ) ^1/2 to 13.0 (cal/cm ³ ) ^1/2 . Since the radical curable resin has low solubility in a liquid crystal and low diffusibility, a composition containing the radical curable resin can provide a liquid crystal display panel having excellent display characteristics. Further, since the radical curable resin is also excellent in compatibility with the above (6) epoxy resin, a homogeneous composition can be provided, and thus a resin composition excellent in reliability can be provided. The method for calculating the number average molecular weight and the solubility parameter (sp value) is the same as the method described in the above description of (1) the acrylic resin, and thus the description thereof will be omitted.

(11) Free radical chain transfer agent

The radical chain transfer agent of the present invention refers to a compound which transfers a living point of a reaction by a chain transfer reaction in a radical polymerization reaction. The radical chain transfer agent (T) reacts with a propagating radical (P.) to form a radical (T.) having a new polymerization activation energy, as shown by the following formula (1). The term "growth free radical (P.)" refers to a radical formed by sequential addition of a polymerizable compound to a radical generated by decomposition of an initiator. The new radical (T.) thus produced is reacted with the polymerizable compound (M) to form a growth radical (P1.) as shown by the following formula (2).

On the other hand, as shown in the following formula (3), the growth radical reacts with the polymerizable compound to form a growth radical P2. . When the positive growth rate constant at this time is Kp and the positive reaction rate constant of the following formula (1) is _ktr , Kp<k _tr must be satisfied in order to generate a radical chain transfer reaction. Further, the details of the radical reaction shown here are disclosed in page 38 of the Radical Polymerization HandBook (1999) and the like.

Formula (1) P. +T→P+T.

Formula (2) T. +M→P1.

Formula (3) P. +M→P2.

As described above, the curable resin composition for liquid crystal sealing of the present invention containing a radical chain transfer agent has a growth radical P which is formed during the hardening reaction. The reaction of the above formula (1) is more likely to occur than the above formula (3). That is, it is easy to generate free radicals T. . T. According to formula (2), it reacts with a polymerizable compound to form P1. . P1. Further, a new T is produced according to the reaction of the formula (1). Free radicals. Since the reactions of the above formulas (1) and (2) are carried out continuously, a large amount of T is formed in the liquid crystal sealing agent. , P1. The radicals are equal, and therefore, the above-mentioned radicals can reach the various portions of the liquid crystal sealing agent to efficiently perform the hardening reaction. As a result, the rate of consumption of the polymerizable compound is increased, the curing time of the liquid crystal sealing agent is shortened, and the amount of the uncured polymerizable compound contained in the liquid crystal sealing agent after curing is reduced.

Examples of the above radical chain transfer agent include: i) mercaptans, ii) α-methylstyrene dimers, iii) terminally unsaturated methacrylates, iv) diphenyl disulfide, etc. Sulfides, and v) porphyrin-cobalt complexes.

i) Mercaptans

Among them, the radical chain transfer agent is preferably i) a mercaptan for the following reason. The thiol refers to a compound having a thiol group in one molecule. Since the thiol group has high reactivity, it exhibits an addition reactivity to the carbon-carbon double bond of the above (10) radical curable resin which is not provided by other radical chain transfer agents. Therefore, when a mercaptan is used as the radical chain transfer agent, in addition to the above-described radical chain transfer reaction, the above-described addition reaction can be caused, so that the curing rate of the liquid crystal sealing agent can be increased.

Further, the thiol group also exhibits addition reactivity to the epoxy group. Therefore, as described below, the resin composition II of the present invention may further contain an epoxy group-containing compound of the above (6) epoxy resin in addition to the above components, and the resin composition II may further increase the curing rate. .

Further, in the hardening reaction accompanying the radical chain transfer reaction, although the curing rate is generally increased, the molecular weight of the cured product is lowered. However, when a mercaptan is used as the radical chain transfer agent, the molecular growth effect of the cured product by the above-described addition reaction can be expected, and further, it is possible to further improve the strength of the liquid crystal sealing agent after curing. Effect.

Examples of the mercaptans which can be used as the radical chain transfer agent include: (i-1) mercaptoesters, (i-2) aliphatic polythiols, and (i-3) aromatics. A polythiol, (i-4) thiol modified reactive silicon oil.

The (i-1) mercaptoester refers to an ester mercaptan compound obtained by reacting a mercaptocarboxylic acid with a polyhydric alcohol. Hereinafter, a mercaptocarboxylic acid, a polyhydric alcohol, and a mercaptoester which can be used for obtaining a mercaptoester will be described.

Examples of the above mercaptocarboxylic acid include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptoisobutyric acid, 3-mercaptoisobutyric acid. Examples of the above polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, bis(trimethylolpropane), pentaerythritol, dipentaerythritol. 1,3,5-tris(2-hydroxyethyl)isotricyanoic acid, sorbitol.

Examples of the above mercapto esters include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), and 2-ethylhexyl 3-mercaptopropionate.

(i-2) Examples of the aliphatic polythiol include: decyl mercaptan, ethanedithiol, propylene dithiol, 1,6-hexanedithiol, 1,10-decanedithiol, diethylene Dimlycol dimercaptan, triethylenedithiol, tetraethylenedithiol, thiodiethylenedithiol, thiotriethyldithiol, thiotetraethylenedithiol. Further, a cyclic thioether compound such as a polythiol compound containing a 1,4-dithiane ring or an addition of an active hydride such as an episulfide resin or an amine The episulfide resin-modified polythiol or the like obtained by the reaction is also included in the above aliphatic polythiol.

(i-3) Examples of the aromatic polythiol include toluene-2,4-dithiol and xylene dithiol. Further, examples of the (i-4) thiol-modified reactive eucalyptus oil include a fluorenyl-modified dimethyl methoxy olefin and a fluorenyl-modified diphenyl siloxane.

The above mercaptans include primary mercaptans and secondary mercaptans. The first-order thiol refers to a thiol compound in which one hydrocarbon group is bonded to a carbon bonded to a thiol group. The term "secondary thiol" refers to a bond on a carbon bonded to a thiol group. A thiol compound having two hydrocarbon groups is formed.

When a primary mercaptan is used as the radical chain transfer agent, as described above, since it has excellent addition reaction with a carbon-carbon double bond group, it has an advantage that the physical properties of the cured product are excellent. Among them, since the reactivity is high, the storage stability of the liquid crystal sealing agent may be lowered. On the other hand, since the addition reactivity of the secondary thiol and the carbon-carbon double bond group is inferior to that of the primary thiol, it has an advantage of excellent storage stability of the liquid crystal sealing agent. Therefore, the radical chain transfer agent of the present invention is more preferably a secondary thiol. A liquid crystal sealing agent containing such a secondary mercaptan is particularly suitable for a so-called one-liquid type liquid crystal sealing agent as described below.

Among them, the secondary thiol is preferably one or two or more secondary thiol groups in the molecule and having a number average molecular weight of from 400 to 2,000. When the liquid crystal sealing agent containing a radical chain transfer agent is hardened, if the radical chain transfer agent does not enter the crosslinked body and remains as a monomer in the cured product, the radical chain transfer agent may The liquid crystal dissolves and diffuses, and the display characteristics of the manufactured liquid crystal display panel are lowered. On the other hand, a polyfunctional secondary thiol having a number average molecular weight of from 400 to 2,000 easily enters the crosslinked body. Therefore, since the liquid crystal sealing agent containing this radical chain transfer agent is not easily dissolved and diffused in the liquid crystal, the display characteristics of the manufactured liquid crystal display panel are good.

The secondary thiol as described above, as described above, is preferably obtained by reacting a polyol with a secondary mercaptocarboxylic acid. Examples of the secondary thiol having a number average molecular weight of 400 to 2,000 include: the above pentaerythritol tetrakis(3-mercaptobutyrate) (number average molecular weight: 544.8), 1,3,5-tris(3-mercaptobutoxy B) -1,3,5-triazine-2,4,6(1H,3H,5H)-trione) (the number average molecular weight is 567.7). The number average molecular weight of the radical chain transfer agent can be measured, for example, by GPC and using polystyrene as a standard.

Next, a chain transfer agent other than thiols will be described.

Ii) α-methylstyrene dimer

The α-methylstyrene dimer refers to a compound having a reactive carbon-carbon double bond in one molecule and functioning as an addition-fragmentation chain transfer agent. Examples of the above α-methylstyrene dimer include: 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene And 1,1,3-trimethyl-3-phenyl indane. The α-methylstyrene dimer of the present invention is not particularly limited, and those skilled in the art can be used.

Iii) terminal unsaturated methacrylates

The term "unsaturated methacrylate" refers to a methacrylate compound having an unsaturated bond at the end and contributing to an addition reaction. Examples of such terminally unsaturated methacrylates include monomers, dimers, ..., n-polymers.

Iv) disulfide

Examples of the disulfide include diphenyl sulfide, polythioether modified epoxy resin, and diethoxymethane-polysulfide polymer.

v) porphyrin cobalt complexes

Examples of the porphyrin cobalt complex include: tetra(2,4,6-trimethylphenyl) porphyrin cobalt (III) (cobalt (III) tetramesityl porphyrin) complex, tetraphenylporphyrin cobalt (III) (cobalt(III) tetraphenyl porphyrin) complex. In addition, the cobalt complex may also be Co-CH ₂ C(CH ₃ ) ₃ , Co-CH(CO ₂ CH ₃ )CH ₃ , Co-CH(CO ₂ CH ₃ )CH ₂ CH(CO ₂ CH ₃ ) CH ₃ .

The free radical chain transfer agent can also be one having an initial transfer inferer. The term "terminating transfer termination" refers to the property of three functions of a radical polymerization initiator, a radical chain transfer agent, and a radical terminator. Such a radical chain transfer agent having an initial transfer termination property can produce a reverse reaction of the above formula (1) by providing light energy or thermal energy, thereby allowing radical generation to undergo chain transfer and improving the hardenability of the liquid crystal sealing agent. .

Examples of the above radical chain transfer agent having an initial transfer terminator include a thiocarbamate compound such as tetraethylthiuram disulfide, and a triphenylmethylazo group. Benzene, tetraphenylethane derivative.

The curable resin composition II for liquid crystal sealing may further contain the above (5) epoxy curing agent and (6) epoxy resin in addition to the above (3), (4), (10), and (11). (7) Photoradical polymerization initiator, (8) Thermoplastic polymer, (9) Other additives. The details of the above-described compounds and the like have been described above, and thus the description thereof will be omitted.

In the resin composition II, the amount of each component is not particularly limited, and from the viewpoints of curability and storage stability of the resin composition II, it is preferred to use 100% by weight of the above (10) radical. The content of the curable resin and (3) the thermal radical polymerization initiator is from 0.01 part by weight to 5.0 parts by weight. The resin composition II has good curability by thermal radicals, and the adhesion strength between the cured product and the substrate is improved. Among them, if it is hard relative to (10) radicals When the content of the (3) thermal radical polymerization initiator is more than 5.0 parts by weight, the viscosity stability of the resin composition II is deteriorated. On the other hand, when the content is less than 0.01 part by weight, the amount of the thermal radical polymerization initiator is too small, and the curability of the resin composition II may be lowered.

Further, the content of the (11) radical chain transfer agent is preferably from 0.01 part by weight to 5.0 parts by weight, more preferably from 0.05 part by weight to 3.0 parts by weight, based on the (10) radical curable resin. The resin composition II is excellent in viscosity stability, and even when the wiring on the substrate is complicated and fine, the curing reaction of the resin composition II can be sufficiently performed, so that the unhardened portion is extremely small, so that liquid crystal leakage can be suppressed or Liquid crystal pollution. When the content of the (11) radical chain transfer agent is more than 5.0 parts by weight with respect to the (10) radical curable resin, (10) a radical curable resin and the above (6) epoxy resin are produced. When the reaction reaction is excessive, the curing reaction is not performed properly, and the viscosity stability may be deteriorated. On the other hand, when the content of the (11) radical chain transfer agent is less than 0.01 part by weight, the effect of causing the radical to undergo chain transfer is poor, and the curability of the resin composition II may be lowered.

Further, the content of the (4) filler is preferably from 1 part by weight to 30 parts by weight, more preferably from 5 parts by weight to 25 parts by weight, per 100 parts by weight of the resin composition II. The resin composition II is more effective as an inorganic filler from the viewpoint of improving moisture resistance, etc., but the resin composition II containing a large amount of inorganic filler is difficult to apply on a substrate because of high viscosity and poor fluidity. Further, the hardened strength of the cured product formed by curing the resin composition II may be lowered. On the other hand, when the amount of the inorganic filler is small, the moisture resistance may be lowered. In terms of the above aspects, the content of the inorganic filler is adjusted to In the resin composition II in the range, the adhesion strength between the cured product and the substrate is improved.

From the viewpoint of improving various properties such as curability or storage stability of the resin composition II, it is preferably 100 parts by weight of (10) radical curable resin, and (5) epoxy hardener. The content is from 1 part by weight to 10 parts by weight, more preferably from 2 parts by weight to 5 parts by weight. The resin composition II in which the content of the epoxy hardener is adjusted within the above range can maintain excellent viscosity stability, and a liquid crystal display panel having high reliability can be manufactured. Further, in the resin composition II, the content of the epoxy resin (6) is preferably from 1 part by weight to 40 parts by weight per 100 parts by weight of the (10) radical curable resin.

The viscosity of the resin composition II measured by an E-type viscometer at 25 ° C and 2.5 rpm is preferably 50 Pa. s~500Pa. s, better is 150Pa. s~450Pa. s. The viscosity of the resin composition II can be appropriately adjusted depending on the amount of each component and the like. The resin composition II having a viscosity (initial viscosity) measured in an above range is measured by an E-type viscometer at 25 ° C and 2.5 rpm, and can be applied to the substrate without uneven coating. Its coating workability is excellent.

Wherein, if the initial viscosity is greater than or equal to 50Pa. s, the seal shape retention after coating is particularly excellent. The term "seal shape retention" refers to a property in which the shape of the seal remains unchanged even after a period of time after application. In addition, if the initial viscosity is greater than or equal to 150Pa. s, the seal shape retention will become better. In addition, if the initial viscosity is less than or equal to 450Pa. s, when the liquid crystal sealant is applied by the dispenser, even if the nozzle diameter of the dispenser is 0.15 The fine diameter of mm~0.5mm is also good in coating workability.

Further, the thixotropic index of the resin composition II, that is, the viscosity η 1 at 25 ° C and 0.5 rpm measured by an E-type viscometer and the ratio η 1 / η of the viscosity η 2 at 25 ° C and 5.0 rpm. 2 is preferably 1.1 to 5.0, and more preferably 1.2 to 2.5. The viscosity of the resin composition II is an E-type rotational viscometer (for example, a digital rheometer manufactured by BROOKFIELD, model: DV-III ULTRA), and a CP-52 type cone having a radius of 12 mm and an angle of 3° is used. A plate type sensor that measures the liquid crystal sealant at a predetermined temperature for 5 minutes.

As described above, the thixotropic index is a ratio of the viscosity measured at a lower shear rate to the viscosity measured at a higher shear rate. Therefore, a fluid having a high thixotropic index will be at a low shear rate. Flows at high viscosity and flow at low shear at low shear rates. Therefore, when the resin composition II is applied at a high shear rate, the resin composition II has a low viscosity, so that the coating property to the substrate is good. In the sealing portion formed of the resin composition II, liquid crystal leakage is less likely to occur, and since the resin composition II is excellent in defoaming property, the liquid crystal display panel produced is excellent in reliability.

The third liquid crystal sealing curable resin composition of the present invention is characterized in that it contains (12) a radical polymerizable in addition to the above (3) thermal radical polymerization initiator and (4) filler. a resin composition of a carbon-carbon double bond, a hydrogen bond functional group, and an epoxy group; the resin composition comprising two or more resins selected from the group consisting of specific resins described below; 12) The amount of the hydrogen bond functional group in the resin composition is 1.0 × 10 ^-4 mol / g to 6.0 × 10 ^-3 mol / g; the amount of the epoxy group in the above (12) resin composition is 1.0 × 10 ⁴ mol /g~2.6×10 ^-3 mol/g. The curable resin composition for liquid crystal sealing of the present invention having the above characteristics is also referred to as "curable resin composition for liquid crystal sealing III" or "resin composition III".

(12) A resin composition having a carbon-carbon double bond capable of radical polymerization, a hydrogen bond functional group, and an epoxy group

The curable resin composition III for liquid crystal sealing of the present invention contains two or more kinds of resins selected from a specific resin group, and contains a carbon-carbon double bond capable of undergoing radical polymerization, a hydrogen bond functional group, And an epoxy group resin composition (also referred to simply as "curable resin").

The carbon-carbon double bond which can be subjected to radical polymerization means a functional group which can be polymerized by a radical. Preferable examples of the carbon-carbon double bond which can be subjected to radical polymerization include a vinyl group, an allyl group, a propylene group, and a methacryl group. Among them, the carbon-carbon double bond which can be subjected to radical polymerization is preferably a (meth) acrylonitrile group.

The hydrogen bond functional group means a functional group or a ligand having hydrogen bonding properties. Examples of the functional group having hydrogen bonding include: -OH group, -NH ₂ group, -NHR group (R represents an aliphatic hydrocarbon group, an aromatic group), -CONH ₂ group, -NH- group, -NHOH group. Examples of the ligand having a hydrogen bond include: -NHCO-coordination, -CONHCO-coordination, or -NH-NH-coordination. Among these, the hydrogen bond functional group of the present invention is preferably a hydroxyl group represented by -OH and an amine urethane ligand represented by -NHCO- (also referred to simply as "amino urethane group"). ).

The above (12) curable resin has a pegability such as (meth) acrylonitrile A free radically polymerized carbon-carbon double bond. Therefore, the (12) curable resin is included in the above (10) radical curable resin.

As described above, the liquid crystal sealing agent is required to have excellent leak resistance. Since the liquid crystal leakage is likely to occur when the liquid crystal sealing agent hardens slowly, when the light is hardened, if the light shielding portion is present, the liquid crystal leakage becomes more remarkable. Therefore, the liquid crystal sealing agent is preferably only heat-treated. hardening. However, in general, when the heat is cured, the viscosity of the liquid crystal sealing agent is lowered, so that liquid crystal leakage occurs even if it is hardened by heating. Therefore, it is effective to reduce the viscosity reduction of the liquid crystal sealing agent upon heating. In order to reduce the viscosity of the liquid crystal sealing agent during heating, it is preferred to increase the hardenability of the curable resin contained in the liquid crystal sealing agent.

According to the above, since the amount of the hydrogen bond functional group of the curable resin contained in the resin composition III is 1.0 × 10 ^-4 mol / g to 6.0 × 10 ^-3 mol / g, the curing rate is fast. Although the mechanism is not clear, it can be presumed that if a certain amount of a hydrogen bond functional group is present, the curable resin molecules are attracted to each other due to hydrogen bonding, and thus exist close to each other, thereby making the hardening reaction better. Easy to carry out. In other words, since the radically polymerizable carbon-carbon double bonds which are adjacent to each other and the epoxy groups which are close to each other react rapidly, the curing resin of the present invention has a high curing rate.

The amount of the hydrogen bond functional group is determined by dividing the number of the hydrogen bond functional groups by the molecular weight of the radical reactive resin, and the unit thereof is mol/g. When the amount of the hydrogen bond functional group in the curable resin is more than the above upper limit, the water resistance of the liquid crystal sealing agent containing the curable resin may be lowered. On the other hand, when the amount of the hydrogen bond functional group in the curable resin is less than the above lower limit, the curability of the liquid crystal sealing agent containing the curable resin is lowered. According to the above, a liquid crystal sealing agent containing a resin having a hydrogen bond functional group content of 1.0 × 10 ^-4 mol / g to 6.0 × 10 ^-3 mol / g is excellent in balance between water resistance and hardenability.

Hydrogen bond functional groups are also associated with liquid crystal contamination. Since liquid crystals are generally hydrophobic, they are not easily compatible (compatible with compounds) having polar groups. According to the above, when the amount of the hydrogen bond functional group in the compound is increased, the polarity of the above compound is increased, so that it is difficult to be compatible with the liquid crystal. Therefore, the liquid crystal sealing agent containing a hardening resin in an amount of 1.0 × 10 ^-4 mol / g to 6.0 × 10 ^-3 mol / g containing a hydrogen bond functional group is less likely to contaminate the liquid crystal.

As described above, the curable resin of the present invention has an epoxy group in the molecule. The epoxy group means a group represented by the following structural formula.

The epoxy group in the curable resin of the present invention has an epoxy group content of 1.0 × 10 ^-4 mol / g to 2.6 × 10 ^-3 mol / g. The amount of the epoxy group is determined by dividing the number of epoxy groups by the molecular weight of the curable resin, and the unit thereof is mol/g. Since the epoxy group has high addition polymerizability, the curable resin having an epoxy group has high curability. Further, the epoxy group can improve the adhesion of the liquid crystal sealing agent to the glass substrate.

The curable resin of the present invention can be obtained by blending two or more kinds of resins selected from the group consisting of resins shown below.

(1A) a radically reactive resin having a hydrogen bond functional group in a molecule and two carbon-carbon double bonds capable of radical polymerization, and the amount of the above hydrogen bond functional group is 1.5 × 10 ^-3 mol/g ~6.0×10 ^-3 mol/g.

(1B) a radically reactive resin having a hydrogen bond functional group, an epoxy group, and a carbon-carbon double bond capable of undergoing radical polymerization in a molecule, and the amount of the above hydrogen bond functional group is 1.0 × 10 ^-4 mol /g~5.0×10 ^-3 mol/g.

(1C) an epoxy resin having an epoxy group in a molecule but having no carbon-carbon double bond capable of undergoing radical polymerization, and having a softening point of 40 ° C or more as measured by a ring and ball method, and a weight average The molecular weight is 500~5000.

In the curable resin of the present invention, the amount of the hydrogen bond functional group and the amount of the epoxy group can be adjusted within the above range by appropriately selecting the (1A) to (1C) resin. The amount of the hydrogen bond functional group of the curable resin of the present invention formed by blending the resin of (1A) to (1C) can be determined as follows.

The number of hydrogen bond functional groups (1A) is set to Na (number), the molecular weight is Ma (g/mol), and the blending ratio is a (wt%).

The number of hydrogen bond functional groups of (1B) is Nb (number), the molecular weight is Mb (g/mol), and the compounding ratio is b (wt%).

When the number of hydrogen bond functional groups of (1C) is Nc (number), the molecular weight is Mc (g/mol), and the compounding ratio is c (wt%), the amount of hydrogen bond functional groups of the curable resin can be determined by the following formula.

Hydrogen bond functional group amount of curable resin = (Na)/(Ma)×a/100+(Nb)/(Mb)×b/100+(Nc)/(Mc)×c/100

The amount of epoxy groups of the curable resin can also be determined in the same manner.

Hereinafter, the (1A) to (1C) resins will be described.

(1A) resin

(1A) The resin is a hydrogen-bonding functional group and two carbon-carbon double bonds capable of undergoing radical polymerization, and the amount of hydrogen bonding functional groups is 1.5×10 ^-3 mol/g to 6.0×10 ^-3 mol. /g resin. In the present invention, the two carbon-carbon double bonds which can be radically polymerized may be simply referred to as "double bonds", and the (1A) resin may also be simply referred to as "radical difunctional resin". The radical difunctional resin preferably contains no epoxy group.

The hydrogen bond functional group of the radical difunctional resin can be obtained in the above manner. The value is from 1.5 × 10 ^-3 mol / g to 6.0 × 10 ^-3 mol / g, preferably from 1.5 × 10 ^-3 mol / g to 3.4 × 10 ^-3 mol / g. The molecular weight of the radical difunctional resin used in the calculation of the amount of the hydrogen bond functional group is preferably determined by GPC and converted in terms of polystyrene. In this case, the number average molecular weight and the weight average molecular weight can be calculated, and the amount of the hydrogen bond functional group is preferably calculated based on the number average molecular weight.

The radical difunctional resin can be obtained, for example, by esterification reaction of a "compound having a double bond and a carboxylic acid in a molecule" with a "compound having a double bond and a hydroxyl group in the molecule".

Examples of the "compound having a double bond and a carboxylic acid in the molecule" include (meth)acrylic acid or a (meth)acrylic acid derivative obtained by reacting (meth)acrylic acid with an acid anhydride. Further, the "compound having a double bond and a carboxylic acid in the molecule" may be obtained by adding a compound obtained by adding 6-hexanolide to a hydroxyalkyl acrylate and further reacting with an acid anhydride. Compound. Examples of the hydroxyalkyl acrylate include hydroxyethyl acrylate and hydroxybutyl acrylate.

Examples of the "compound having a double bond and a hydroxyl group in the molecule" include hydroxyalkyl acrylate, 4-pentaerythritol tri(meth) acrylate, and sorbitol. Tris(meth)acrylate.

The radical difunctional resin can also undergo a ring-opening addition reaction of a carboxyl group of a "compound having a double bond and a carboxylic acid in a molecule" with an epoxy group of a "polyglycidyl ether compound of an aromatic diol" (ring- Obtained by opening addition reaction).

Examples of the "polyglycidyl ether compound of an aromatic diol" include polyhydric glycidyl ether compounds such as bisphenol A, bisphenol S, bisphenol F, bisphenol AD, phenyl ether, and resorcin.

Among them, the radical difunctional resin is preferably a resin obtained by reacting a polyvalent glycidyl ether compound with (meth)acrylic acid, and more preferably a resin represented by the following general formulae (a1) to (a4). Or a mixture of these.

In the formula (a1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom or a methyl group, and R _m each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an allyl group. a hydroxyalkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, n representing an integer of 1 to 4, l representing an integer of 1 to 4, and A being -CH ₂ -, -C ( CH ₃ ) an organic group represented by ₂ -, -SO ₂ -, or -O-.

In the formula (a2), R ₅ , R ₆ , R ₇ and R ₈ each independently represent a hydrogen atom or a methyl group, and R _q independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an allyl group. A hydroxyalkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, r is an integer of 1 to 4, and p is an integer of 1 to 4.

In the formula (a3), R ₁ , R ₂ , R _m , n, and A are the same as defined in the formula (a1).

In the formula (a4), R ₅ and R ₆ are the same as defined in the formula (a2).

Among the above resins, the radical difunctional resin of the present invention is particularly good It is a resin represented by the formula (a3) or (a4).

(1B) resin

(1B) The resin is a resin having a hydrogen bond functional group, an epoxy group, and a double bond in the molecule, and having a hydrogen bond functional group content of 1.0 × 10 ^-4 mol / g to 5.0 × 10 ^-3 mol / g. The (1B) resin can be obtained by reacting an epoxy group of an epoxy resin with a carboxyl group of (meth)acrylic acid or a derivative thereof.

The amount of the hydrogen bond functional group of the (1B) resin can be determined in the above manner. The value of the hydrogen bond functional group is preferably 1.0 × 10 ^-4 mol / g to 5.0 × 10 ^-3 mol / g, more preferably 1.0 × 10 ^-4 mol / g to 3.4 × 10 ^-3 mol / g. The molecular weight used in calculating the amount of the hydrogen bond functional group is preferably a number average molecular weight determined by GPC in the same manner as the radical difunctional resin.

The amount of the epoxy group of the resin (1B) is not particularly limited, and is preferably 1.0 × 10 ^-4 mol / g to 6.0 × 10 ^-3 mol / g, more preferably 1.0 × 10 ^-4 mol / g - 3.5 ×10 ^-3 mol/g.

The number average molecular weight of the (1B) resin is preferably from 300 to 2,000. When the number average molecular weight is within this range, the solubility and diffusibility of the curable resin in the liquid crystal are lowered. Therefore, the liquid crystal sealing agent containing this resin is less likely to contaminate the liquid crystal.

Examples of the epoxy resin which becomes a raw material of the (1B) resin include a cresol novolac type epoxy resin, a phenol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a trisphenol. Methane type epoxy resin, trisphenol ethane type epoxy resin, trisphenol type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin. These resins are preferably highly purified by a molecular distillation method, a washing method, or the like.

Examples of the (meth)acrylic acid derivative which is a raw material of the (1B) resin include a compound having a group reactive with an epoxy group and a (meth)acryl fluorenyl group. Specific examples of such a compound include a compound which is a reaction product of a polyvalent carboxylic acid and a hydroxy (meth) acrylate, and has a carboxyl group.

Specific examples of the polycarboxylic acid include: phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, succinic anhydride, maleic anhydride, fumaric acid, adipic anhydride, 4-(methyl) Propylene methoxyethyl trimellitic anhydride.

Specific examples of the hydroxy (meth) acrylate include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and (meth)acrylic acid. An ethylene oxide adduct, a propylene oxide adduct of (meth)acrylic acid, or a caprolactone modification of (meth)acrylic acid.

Since the (1B) resin has both an epoxy group and a double bond in the molecule, it is excellent in compatibility with the (1A) radical difunctional resin and the (1C) epoxy resin. Therefore, a liquid crystal sealing agent containing (1B) resin, and (1A) a radical difunctional resin or (1C) epoxy resin can provide a uniform cured product. The glass transition temperature (Tg) and the subsequent strength of such a liquid crystal sealing agent are improved.

(1C) resin

The (1C) resin is a resin having no ethylenically unsaturated double bond in the molecule and having one or more epoxy groups. The epoxy resin of the present invention has a softening point of 40 ° C or more as measured by a ring and ball method, and a weight average molecular weight of 500 to 5,000.

(1C) The softening point and molecular weight of the resin can affect the viscosity when the liquid crystal sealing agent is formed. Liquid crystal sealing agent containing (1C) resin having a softening point and a weight average molecular weight within the above range, especially liquid crystal when not hardened Since the viscosity of the curable resin in the sealant is not too low and is in an appropriate range, the seal pattern is less likely to be deformed and is excellent in leakage resistance. The softening point is not particularly limited, and the softening point is preferably 160 ° C or less in order to make the viscosity when the liquid crystal sealing agent is formed in an appropriate range.

In addition, the liquid crystal sealing agent containing the (1C) resin having a softening point and a weight average molecular weight within the above range is less likely to contaminate the liquid crystal because the solubility (1C) of the resin in the liquid crystal is lowered and the diffusibility is lowered. The weight average molecular weight of the (1C) resin can be measured, for example, by GPC and using polystyrene as a standard.

Examples of the above (1C) resin include the following compounds, and the softening point and weight average molecular weight thereof are within the above ranges.

An aromatic diol represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD or the like, or a glycol formed by modifying ethylene glycol, propylene glycol or alkanediol An aromatic polyglycidyl ether compound obtained by a reaction with epichlorohydrin.

A novolac type polyglycidyl ether compound obtained by reacting a polyphenol represented by a novolac resin, a polyalkenylphenol or a copolymer thereof, which is derived from phenol or cresol and formaldehyde, with epichlorohydrin.

A glycidyl ether compound of a benzene dimethylphenol resin.

Specific examples of the novolac type polyglycidyl ether compound include a cresol novolak type epoxy resin and a phenol novolak type epoxy resin. Specific examples of the aromatic polyglycidyl ether compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, trisphenol methane type epoxy resin, and trisphenol. Ethylene type epoxy resin, trisphenol type epoxy resin, dicyclopentadiene type epoxy resin, phenyl ether type epoxy resin, biphenyl type epoxy resin.

The amount of the epoxy group of the (1C) resin can be determined by dividing the number of epoxy groups by the molecular weight of the (1C) resin in the same manner as the (1B) resin. It is preferred that the molecular weight is a molecular weight determined from the value of the epoxy equivalent. The method of calculating the amount of the hydrogen bond functional group when the (1C) resin has a hydrogen bond functional group is also the same as the (1B) resin.

The amount of the epoxy group is equivalent to the reciprocal of the epoxy equivalent, and can be determined by measuring the epoxy equivalent of the resin (1C). The epoxy equivalent can be calculated by dissolving the sample in dioxane, adding a hydrochloric acid-dioxane solution and allowing to stand, and then adding an ethanol/toluene mixture using cresol red ( Cresol red) As an indicator, the epoxy equivalent is calculated from the amount of hydrochloric acid consumed in the sample.

A liquid crystal sealing agent containing a curable resin composed of a (1A) resin and a (1C) resin is particularly excellent in balance between leakage resistance and adhesion strength. Further, the liquid crystal sealing agent containing a curable resin composed of the (1B) resin and the (1C) resin is particularly excellent in adhesion strength. Further, the liquid crystal sealing agent containing a curable resin composed of the (1A) resin and the (1B) resin is particularly excellent in leakage resistance.

Further, when the liquid crystal sealing agent contains (1A) resin and (1C) resin as the curable resin, the blending ratio of these resins is preferably (1A) resin: (1C) resin = 70 to 97 by weight ratio. : 30~3. When the liquid crystal sealing agent contains (1A) resin and (1B) resin as the curable resin, the ratio of the ratio of these resins is preferably (1A) resin: (1B). Resin = 10~70:90~30. When the liquid crystal sealing agent contains (1B) resin and (1C) resin as the curable resin, the ratio of such resins is preferably (1B) resin: (1C) resin = 70 to 97:30 by weight ratio. ~3. When the liquid crystal sealing agent contains (1A) resin, (1B) resin, and (1C) resin as a curable resin, the ratio of such resins is preferably a weight ratio, preferably (1A) resin: (1B) resin. :(1C) Resin = 10~87:10~87:3~30.

The curable resin composition III for liquid crystal sealing may further contain the above (5) epoxy curing agent, (6) epoxy resin, and (7) in addition to the above (3), (4), and (12). Photoradical polymerization initiator, (8) thermoplastic polymer, (9) other additives. The details of these compounds and the like have been described above, and thus the description thereof will be omitted.

2. Method for producing curable resin composition for liquid crystal sealing

The curable resin composition for liquid crystal sealing of the present invention can be arbitrarily produced within a range that does not impair the effects of the invention, and can be prepared, for example, from the above-described respective components. The mixing method is not particularly limited, and for example, a well-known kneading machine such as a two-blade mixer, a roll kneader, a twin-screw extruder, a ball mill or a planetary mixer can be used. In order not to gel the mixture and knead it uniformly, the roll temperature is preferably set at 15 ° C to 35 ° C, more preferably 25 ° C to 35 ° C. Here, from the viewpoint of improving the viscosity stability of the composition, the temperature of the mixture at the time of preparation is preferably in the range of 15 ° C or more and less than 30 ° C. The finally obtained mixture can be filtered by a filter as needed, and the mixture is sealed and filled in a glass bottle or a plastic container after vacuum defoaming treatment.

3. Method of manufacturing liquid crystal display panel

The liquid crystal display panel of the present invention can be produced by using the curable resin composition for liquid crystal sealing of the present invention. Hereinafter, a preferred production method will be described.

The method for producing a liquid crystal display panel is a method for producing a liquid crystal display panel by laminating two substrates facing each other via a curable resin composition for liquid crystal sealing, and the method includes the following steps: 1) preparing a first In the first substrate, the first substrate includes a frame-shaped display region formed by surrounding the pixel array region by the curable resin composition for liquid crystal sealing of the present invention, and 2) in the display region in an unhardened state. a step of dropping a liquid crystal onto the other substrate; 3) a step of superposing the first substrate and a second substrate facing the substrate; and 4) a step of curing the resin composition for liquid crystal sealing by heating.

1) The step is to apply a liquid crystal sealing agent to any one of the two substrates, and prepare a substrate in which the frame-shaped display region is disposed. The frame-shaped display region means a seal shape drawn by the resin composition, which is also called a seal pattern. The substrate is a component that serves as the basis of the display panel, and is usually composed of two pieces of glass or the like. Examples of the two substrates used in the liquid crystal display panel include a glass substrate in which TFTs (thin film transistors) are formed in a matrix, and a substrate in which a color filter and a black matrix are formed. . Examples of the material of the substrate include: glass or Polycarbonate, polyethylene terephthalate, polyether sulfone, PMMA (polymethyl methacrylate).

An alignment film may be formed on the surface on which the respective substrates face. The alignment film is not particularly limited, and for example, those produced by a well-known organic alignment agent or inorganic alignment agent can be used. Further, spacers may be scattered on the substrate in advance. The spacers generally use spherical cerium oxide particles, which can effectively maintain a uniform cell gap. In-plane spacers in a state of being previously dispersed on the substrate or spacers included in the liquid crystal sealing agent can be usually used. Further, the type and size of the spacer are not particularly limited, and those skilled in the art can be used depending on the size of the cell gap required.

Examples of the method of applying the liquid crystal sealing agent on the substrate include coating by a dispenser or coating by screen printing, and is not particularly limited, and a well-known technique can be used. In the production of a small liquid crystal display panel, it is preferred to carry out coating by screen printing from the viewpoint of improving productivity.

In the step 2), an appropriate amount of liquid crystal may be dropped into the display region in the uncured state or on another substrate. The "unhardened state" means a state in which the curing reaction of the resin composition has not proceeded to the gelation point. The above liquid crystal dropping can be usually carried out under atmospheric pressure.

The amount of dripping of the liquid crystal is preferably adjusted in accordance with the size of the frame so that the liquid crystal is accommodated in the frame. Therefore, since the capacity of the liquid crystal is not larger than the capacity of the space (cell) surrounded by the liquid crystal sealing agent existing between the two substrates, no excessive pressure is applied to the frame, so the sealant for the frame is not formed. rupture. In addition, in step (2), in the shape When the liquid crystal is dropped onto the other substrate in the display region, when the substrates are overlapped with each other, the liquid crystal can be dropped into a region which can become a display region.

3) The step is to overlap the substrate on which the liquid crystal is dropped with the other substrate. Since the overlap is caused by the difference in pressure, the substrates are bonded to each other. Therefore, it is preferable to use a vacuum bonding apparatus or the like to overlap under reduced pressure.

In addition, after the step 3), the step of restoring the two stacked substrates to atmospheric pressure from a reduced pressure may also be included. When the substrate which is superposed under reduced pressure in the above manner is returned to the atmospheric pressure environment under reduced pressure, a difference in air pressure is generated between the inner side and the outer side of the frame. Therefore, the two substrates are subjected to two substrates from the two outer sides of the two substrates. Squeeze so that the substrates are attached to each other.

4) The step is to harden the liquid crystal sealing agent existing between the substrates. The liquid crystal sealing agent of the present invention can be rapidly hardened by heating only. The curing treatment conditions such as heating temperature and time can be appropriately selected depending on the composition of the liquid crystal sealing agent. 4) The step may also include the step of irradiating light to harden the liquid crystal sealant. In this case, the liquid crystal sealing agent can be temporarily cured by light irradiation, and then heated to be post-cured. The term "light irradiation" refers to irradiation of light (preferably ultraviolet rays) having energy for causing a reaction of a curable resin. From the viewpoint of simplifying the steps in manufacturing the panel, the step 4) is preferably a step of hardening the liquid crystal sealing agent only by heating.

In the step 4), when the liquid crystal sealing agent is hardened only by heating, the heating condition is preferably 80 ° C to 150 ° C and 10 minutes to 240 minutes, more preferably 100 ° C to 130 ° °C and 30 minutes to 120 minutes. On the other hand, when light irradiation and heat hardening are used in combination, the heating condition is preferably 40 ° C to 90 ° C and 1 minute to 120 minutes. In addition, In any of the above cases, post-hardening may be performed at 110 ° C to 150 ° C for 30 minutes to 90 minutes as needed.

Further, in the recent liquid crystal dropping technology, in order to further improve productivity, a method is employed in which a plurality of frames are formed on a substrate by using a liquid crystal sealing agent, and then an appropriate amount of liquid crystal is dropped on each of the frames or the pair of substrates. The two substrates are bonded to each other. In this method, each liquid crystal display panel is cut out by cutting the outer periphery of the frame after the substrates are bonded to each other, and the present invention can also adopt the method.

The liquid crystal sealing agent of the present invention can be quickly and sufficiently cured by heating only without using light. Therefore, there is no need to consider the problem that the opaque portion remains in the light-shielding portion, and the restriction on the panel design is also very small. Further, since it is not necessary to use an ultraviolet irradiation device or the like during the curing of the liquid crystal sealing agent, the manufacturing cost can be reduced. In addition, as described in the above-mentioned compositions I to III, the liquid crystal sealing agent of the present invention contains a predetermined thermal radical polymerization initiator or a chain transfer agent. Therefore, when the liquid crystal sealing agent is heated, it is generated from radicals or the like. Hardening can be sufficiently carried out in a short period of activation. Therefore, when a black matrix such as a small panel mounted on a mobile phone or a liquid crystal display panel having a complicated wiring is manufactured, there is no problem that the light-shielding portion does not have an unhardened portion.

Here, the black matrix refers to a checkered frame such as a three primary color R (red) G (green) B (blue) that surrounds the light constituting the color filter defined by a photoresist. Further, the means for irradiating with ultraviolet rays or heating is not particularly limited. Examples of the heating device which can be used in the present invention include: oven, hot plate, hot press (hot) Press).

According to the above method, the liquid crystal display panel produced by using the curable resin composition for liquid crystal sealing of the present invention is excellent in leakage resistance and can suppress liquid crystal contamination, and the cured product of the liquid crystal sealing agent and the substrate have high bonding strength. The display characteristics are good.

[Examples]

Hereinafter, the present invention will be described in detail by way of examples and comparative examples of the invention. However, the present invention is not limited to the form shown here. In addition, "%" and "parts" disclosed below mean "wt%" and "parts by weight", respectively.

First, examples and comparative examples performed on the curable resin composition for liquid crystal sealing of the present invention will be described.

[Preparation of materials used in Examples I-1 to 13 and Comparative Examples I-1 to 4]

(1) Acrylic resin

The following resin was diluted with toluene, washed with ultrapure water, and the above procedure was repeated 12 times to carry out high purity treatment.

Acrylic resin 1: bisphenol A type epoxy resin modified diacrylate (3002A: manufactured by Kyoeisha Chemical Co., Ltd., molecular weight 600)

Acrylic resin 2: bisphenol A type epoxy resin modified diacrylate (EB3700: manufactured by DAICEL-CYTEC, molecular weight 485)

(2) modified epoxy resin

A modified epoxy resin synthesized in the following manner (Synthesis Example I-1) was prepared.

[Synthesis Example I-1]

In a 500-ml four-necked flask equipped with a stirrer, an air guide tube, a thermometer, and a cooling tube, 160 g of a bisphenol F-type epoxy resin (Epotohto YDF-8170C: manufactured by Tohto Kasei Co., Ltd.), 36 g of acrylic acid, and 0.2 g of triethanolamine were placed. The mixture was heated and stirred at 110 ° C for 5 hours under a stream of dry air to obtain an acrylic modified epoxy resin. The obtained resin was washed 12 times with ultrapure water.

Prepare the following materials:

(3) Thermal radical polymerization initiator

Thermal radical polymerization initiator 88: 1,1-azobis(2,4-cyclohexane-1-carbonitrile) (V-40: manufactured by Wako Pure Chemical Industries, 10 hours half-life temperature is 88 ° C)

Thermal Radical Polymerization Initiator 75: Tripentyl Peroxide 2-ethylhexanoate (Lupasol 575: manufactured by API Corporation, 10 hour half-life temperature is 75 ° C)

Thermal radical polymerization initiator 65: 2,2'-azobis(2-methylpropionate) (V-601: manufactured by Wako Pure Chemical Industries, 10 hours half-life temperature 65 ° C)

Thermal radical polymerization initiator 51: 2,2'-azobis(2.4-dimethylvaleronitrile) (V-65: manufactured by Wako Pure Chemical Industries, 10 hours half-life temperature 51 ° C)

(4) Filler

Filler 1: Spherical yttrium oxide (Seahostar S-30: manufactured by Nippon Shokubai, average primary particle size of 0.3 μm, specific surface area of 11 m ² /g)

Filler 2: Spherical yttrium oxide (SO-C2: manufactured by ADMATECHS, having an average primary particle diameter of 0.9 μm and a specific surface area of 4 m ² /g)

(5) Epoxy hardener

Latent epoxy hardener 1: 1,3-bis(decylcarbonylethyl)-5-isopropylhydantoin (Amicure VDH: manufactured by Ajinomoto Co., Ltd., melting point 120 ° C)

Latent epoxy hardener 2: Diterpene adipate (ADH: manufactured by Otsuka Chemical Co., Ltd., melting point 181 ° C)

(6) Epoxy resin

Epoxy Resin 1: o-cresol novolac type solid epoxy resin (EOCN-1020-75: manufactured by Nippon Kayaku Co., Ltd., having a softening point of 75 ° C and an epoxy equivalent of 215 g / eq as measured by the ring and ball method)

Epoxy Resin 2: Bisphenol A type epoxy resin (Epikote 828EL: manufactured by JER, epoxy equivalent of 190 g/eq)

(7) Photoradical polymerization initiator

Photoradical polymerization initiator, 1 : 1-hydroxycyclohexyl phenyl ketone (Irgacure 184: manufactured by Ciba Speciality Chemicals)

Photoradical polymerization initiator 2: 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651: manufactured by Ciba Speciality Chemicals)

(8) Thermoplastic polymer

Alkyl methacrylate copolymer fine particles (F-325: manufactured by Zeon Corporation, Japan, having an average primary particle diameter of 0.5 μm).

[Evaluation method]

The evaluation methods performed in Examples I-1 to 13 and Comparative Examples I-1 to 4 will be described. Here, the characteristics of the liquid crystal sealing agent were measured by i) viscosity, ii) leakage resistance of the liquid crystal sealing agent, iii) coating property of the liquid crystal sealing agent, and iv) adhesion strength. The details of each measurement evaluation method are as follows.

i) Viscosity measurement

An E-type rotary viscometer (digital rheometer, model: DII-III ULTRA, manufactured by BROOKFIELD), and a CP-52 cone-plate type sensor with a radius of 12 mm and an angle of 3° are used in the following The measurement was carried out at a rotation speed of 1.0 rpm under the conditions.

Viscosity at 25 ° C: The liquid crystal sealing agent of the present invention was allowed to stand at 25 ° C for 5 minutes and then measured.

Viscosity at 80 ° C: The liquid crystal sealing agent of the present invention was placed in a cup of an E-type rotational viscometer, heated to 80 ° C at a temperature elevation rate of 5 ° C / min, and allowed to stand at 80 ° C for 5 minutes, and then measured.

In the above-mentioned measurement method, when the viscosity of the liquid crystal sealing agent at 80 ° C exceeds the measurement limit and measurement is impossible, the parallel plate method (RheoStress RS150: manufactured by HAAKE) is used for measurement. The measurement by the parallel plate method was carried out immediately after the temperature was raised to 80 ° C at a temperature increase rate of 5 ° C /min according to the standard method of the above-mentioned model.

Ii) leakage resistance of liquid crystal sealant

Using a dispenser (Shotmaster: manufactured by Musashi Engineering Co., Ltd.), a liquid crystal sealing agent to which 1 part of 5 μm glass fiber was added was provided with a thickness of 0.5 mm and a thickness of 50 μm. A 40 mm × 45 mm glass substrate (RT-DM88PIN: manufactured by EHC Co., Ltd.) of an electrode and an alignment film was drawn into a frame shape of 35 mm × 40 mm.

Next, a liquid crystal material (MLC-11900-000: manufactured by Merck Co., Ltd.) having the same amount of panel content as the bonded panel was precisely dropped by a dispenser. Next, the opposing glass substrates were superposed under a reduced pressure of 90 Pa. The load was fixed by applying a load, and after returning to atmospheric pressure, it was heat-hardened at 120 ° C for 60 minutes.

The sealing linearity of the obtained liquid crystal display panel was evaluated in accordance with the following criteria.

[ratio of maximum width to minimum width of seal]%=[minimum width of seal]/[maximum width of seal]×100

The above ratio is greater than or equal to 95%: ○ (excellent)

The above ratio is 50% or more and less than 95%: △ (slightly excellent)

The above ratio is less than 50%: × (poor)

Iii) Coating properties of liquid crystal sealant

A liquid crystal sealing agent to which 1% of 5 μm glass fibers were added was filled under vacuum into a syringe having a needle diameter of 0.4 mm. Then, using a dispenser (Shotmaster: manufactured by Musashi Engineering Co., Ltd.), a glass substrate for a liquid crystal display panel of 300 mm × 400 mm under the conditions of a discharge pressure of 0.3 MPa, a coating thickness of 20 μm, and a coating speed of 100 mm/sec. (made by Nippon Electric Glass Co., Ltd.), 50 frame shapes of 35 mm × 40 mm were drawn.

The seal shape of the drawn seal pattern was evaluated according to the following criteria.

The frame shape of the seal is not broken at all, and the seal is 48 to 50: ○ (excellent)

The above frame shape is less than 45 to 48: △ (slightly excellent)

The above frame shape is less than 44: × (poor)

Iv) subsequent strength

On a 25 mm × 45 mm × 5 mm thick non-alkali glass, a liquid crystal sealant to which 1% of 5 μm glass fiber was added was screen-printed into a circular shape having a diameter of 1 mm, which was bonded to it. The same glass was fixed while being heated at 120 ° C for 1 hour to prepare a test piece. The obtained test piece was peeled in the parallel direction at a speed of 2 mm/min using a tensile tester (model 210: manufactured by Intesco Co., Ltd.), and the plane tensile strength was measured.

The strength was then evaluated according to the following criteria.

Tensile strength is greater than or equal to 10 MPa: ○ (excellent)

Tensile strength is 7 MPa or more and less than 10 MPa: △ (slightly excellent)

Tensile strength less than 7MPa: × (poor)

[Example I-1]

30 parts of acrylic resin, 70 parts of methacrylic acid modified epoxy resin obtained in Synthesis Example I-1, 1 part of a thermal radical polymerization initiator 75 having a 10-hour half-life temperature of 75 ° C in a mixer, 20 parts of the filler 1 were prepared for mixing, and secondly, the solid raw material was kneaded by three rolls until it reached 5 μm or less. Then, the composition was filtered with a filter having a mesh opening of 10 μm (MSP-10-E10S: manufactured by ADVANTEC Co., Ltd.), and then subjected to vacuum defoaming treatment to obtain a resin composition for liquid crystal sealing.

The obtained resin composition for liquid crystal sealing has a viscosity at 25 ° C of 260 Pa at 0.5 rpm. s, 180 Pa at 1.0 rpm. s, 120Pa at 5rpm. s.

The viscosity measured by the E-type rotary viscometer at 80 ° C is greater than 780 Pa. s, the measurement was performed by the parallel plate method (RheoStress RS150: manufactured by HAAKE), and the result was 9.00E+05 Pa. s. In addition, the thixotropic index is 2.2.

In addition, the resin composition for liquid crystal sealing was subjected to various measurements by the above-described evaluation method, and the characteristics thereof were evaluated.

[Examples I-2 to 13]

A resin composition for liquid crystal sealing of the compositions shown in Tables 1 and 2 was obtained in the same manner as in Example I-1. Further, the same evaluation as in Example I-1 was carried out.

[Comparative Example I-1~2]

A resin composition for liquid crystal sealing of the composition shown in Table 3 was obtained in the same manner as in Example 1. Further, the same evaluation as in Example 1 was carried out.

[Comparative Example I-3]

60 parts of acrylic resin 2, 40 parts of epoxy resin 2 were mixed and stirred by a planetary stirring device.

Next, 2 parts of photoradical polymerization initiator 2, 10 parts of thermoplastic polymer, 1 part of decane coupling agent (S510: manufactured by Chisso Co., Ltd.), 10 parts of filler 2, and 10 parts of latent epoxy were further added to the resin. The hardener 2 is mixed and stirred by a planetary stirring device. Then, these mixtures were mixed in a ceramic three-roll mill to obtain a resin composition for liquid crystal sealing. The same evaluation as in Example 1 was carried out on the obtained resin composition.

[Comparative Example I-4]

60 parts acrylic resin 2, 40 parts epoxy with planetary stirring device The resin 2 was mixed and stirred.

Next, 10 parts of a thermoplastic polymer, 1 part of a decane coupling agent (S510: manufactured by Chisso Co., Ltd.), 10 parts of a filler 2, and 10 parts of latent epoxy hardener 2 were further blended in the resin, and the mixture was carried out by a planetary stirring device. Mix and stir. Next, the mixture was further mixed by a ceramic three-roll mill to obtain a resin composition for liquid crystal sealing. The same evaluation as in Example 1 was carried out on the obtained resin composition.

Tables 1 to 3 show the results of leakage property, coatability, and adhesion strength of the liquid crystal dropping technique sealant prepared in Examples I-1 to 13 and Comparative Examples I-1 to 4.

The liquid crystal sealing agents shown in Examples I-1 to 13 are excellent in leakage resistance, coating properties, and adhesion strength. Comparing the results of these examples with the results of Comparative Examples I-1, 3 and 4, it is clear that the viscosity of the liquid crystal sealant at 80 ° C is less than or equal to 500 Pa. When s, there will be problems in terms of leakage resistance. Further, when the examples were compared with Comparative Example I-2, it is clear that the viscosity at 25 ° C and 1.0 rpm is greater than 500 Pa. s, and the thixotropic index is greater than 5, which causes problems in coatability. And by the embodiment I-1 The results of ~13 and Comparative Examples I-3 and 4 show that if the content of the filler is small, there is a problem in terms of the strength of the bonding.

Next, examples and comparative examples of the curable resin composition for liquid crystal sealing of the present invention will be described.

[Examples II-1 to 6, Comparative Examples II-1, 2]

The materials used in the respective examples and the like are as follows.

(3) Thermal radical polymerization initiator

Thermal radical polymerization initiator: 2,2'-azobis(2-methylpropionate) (trade name: V-601, manufactured by Wako Pure Chemical Industries, 10 hours half-life temperature 65 ° C)

(4) Filler

Filler: spherical cerium oxide (Seahostar S-30: manufactured by Nippon Shokubai Co., Ltd., with an average primary particle size of 0.3 μm and a specific surface area of 11 m ² /g)

(5) Epoxy hardener

Thermal latent epoxy hardener: 1,3-bis(decylcarbonylethyl)-5-isopropylhydantoin (Amicure VDH: manufactured by Ajinomoto Co., Ltd., melting point 120 ° C)

(6) Epoxy resin

Epoxy resin: o-cresol novolac type solid epoxy resin (EOCN-1020-75: manufactured by Nippon Kayaku Co., Ltd., softening point measured by the method of ring and ball is 75 ° C, epoxy equivalent is 215 g / eq)

(9) Other additives

Decane coupling agent (γ-glycidoxypropyltrimethoxydecane, KBM-403: manufactured by Shin-Etsu Chemical Co., Ltd.)

(10) Free radical curable resin

The respective resins shown below were diluted with toluene and then purified using ultrapure water. Washing, the above steps are repeated to prepare a highly purified radical curable resin. Here, the radical curable resin 2 described below is a resin synthesized by the method of the following Synthesis Example II-1.

Free radical curable resin 1: bisphenol A type epoxy resin modified diacrylate (3002A: manufactured by Kyoeisha Chemical Co., Ltd., molecular weight 600)

Free radical curable resin 2: 1 (meth)acrylic modified epoxy resin having epoxy group and (meth)acryl fluorenyl group in the molecule

[Synthesis Example II-1]

In a 500-ml four-necked flask equipped with a stirrer, an air guide tube, a thermometer, and a cooling tube, 160 g of a bisphenol F-type epoxy resin (Epotohto YDF-8170C, manufactured by Tohto Kasei Co., Ltd.), 36 g of acrylic acid, and 0.2 g of triethanolamine were placed. The mixture was heated and stirred at 110 ° C for 5 hours under a stream of dry air to obtain an acrylic modified epoxy resin. The obtained resin was washed 12 times with ultrapure water.

(11) Free radical chain transfer agent

Free radical chain transfer agent 1:1,3,5-tris(3-mercaptobutoxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione (Karenz MT NR-1: manufactured by Showa Denko)

Free radical chain transfer agent 2: tetraethyl thiuram disulfide (manufactured by Wako Pure Chemical Industries, Ltd.)

Free radical chain transfer agent 3: diethoxymethane polythioether polymer (Thiokol LP-2: manufactured by Toray Fine Chemicals Co., Ltd.)

Free radical chain transfer agent 4: third-dodecyl mercaptan

[Evaluation method]

The evaluation methods performed in Examples II-1 to 6 and Comparative Examples II-1 and 2 will be described. Here, i) the display property of the liquid crystal display panel, ii) the sealing property of the liquid crystal sealing agent, and iii) the adhesion strength of the cured liquid crystal sealing agent were measured, and the characteristics of the liquid crystal sealing agent were evaluated. The details of each measurement evaluation method are as follows.

i) Displayability of liquid crystal display panel

Using a liquid crystal sealing agent to which 1% of 5 μm glass fiber was added, a 40 mm × 45 mm glass substrate (RT-DM88PIN: manufactured by EHC Co., Ltd.) having a transparent electrode and an alignment film at a line width of 0.5 mm and a thickness of 50 μm was used. On the top, draw a frame shape of 35mm × 40mm. Drawing was performed using a dispenser (Shotmaster: manufactured by Musashi Engineering Co., Ltd.).

Next, a liquid crystal material (MLC-6848-000, manufactured by Merck Co., Ltd.) having the same amount of panel content as the bonded panel was precisely dropped by a dispenser. Next, after the two glass substrates were superposed under a reduced pressure of 90 Pa, they were fixed by applying a load, and then returned to atmospheric pressure from a reduced pressure to bond the substrates to each other. Then, the bonded substrate was placed in a circulating oven, heated at 70 ° C for 30 minutes, and further heated at 120 ° C for 60 minutes to cure the liquid crystal sealing agent.

A polarizing film was attached to both surfaces of the two bonded substrates to form a liquid crystal display panel. With a DC power supply device, a voltage of 5 V was applied to the liquid crystal display panel, thereby driving the liquid crystal display panel. At this time, it was visually observed whether or not the liquid crystal display function in the vicinity of the seal formed by the liquid crystal sealing agent was normally exerted from the initial stage of driving, and the display property of the liquid crystal display panel was evaluated according to the following criteria.

The display function is displayed until the seal boundary is near: ○ (good display)

No display function was observed from the vicinity of the seal boundary to a distance greater than 0.3 mm: × (displayability was significantly poor)

Ii) Liquid crystal sealant sealing

Three liquid crystal display panels were produced in the same manner as in the above-described method of manufacturing a liquid crystal display panel, and the sealing property of a frame (sealing) serving as a display region on each liquid crystal display panel was evaluated in four levels according to the following criteria. .

The main seal is broken, and there is no case where the liquid crystal enters the seal line (hereinafter referred to as insertion): ◎

Although the insertion is visible, there is no damage to the main seal: ○

There is a case where the main seal is broken: △

There are 2 or more main seal breakages: ×

Iii) adhesion strength of the cured liquid crystal sealant

First, on a 25 mm × 45 mm × 5 mm thick alkali-free glass, a liquid crystal sealant to which 1% of 5 μm glass fibers was added was screen-printed into a circular shape having a diameter of 1 mm, and the same pair of glass was bonded to ten. Glyph. Next, the substrate was placed in a circulating oven by sandwiching the bonded two substrates with a clamp, and then heated at 70 ° C for 30 minutes and further heated at 120 ° C. The liquid crystal sealant was hardened for 60 minutes. Thereafter, a polarizing film was attached to both surfaces of the two substrates, and then heated at 120 ° C for 60 minutes in a nitrogen atmosphere to prepare a test piece formed by curing only the liquid crystal sealing agent by heating.

The obtained tensile test piece was peeled off in a direction parallel to the bottom surface of the glass at a speed of 2 mm/min using a tensile tester (model 210: manufactured by Intesco Co., Ltd.) to measure the plane tensile strength.

The strength was then evaluated according to the following criteria.

When the tensile strength is 10 MPa or more: ○ (the strength is good)

When the tensile strength is less than 10 MPa: × (following the strength difference)

Iv) Viscosity stability of liquid crystal sealant

The viscosity stability of the liquid crystal sealing agent prepared by the following method was measured using an E-type rotary viscometer (manufactured by BROOKFIELD Co., Ltd.: digital rheometer, model: DII-III ULTRA). At this time, the viscosity of the liquid crystal sealing agent was measured as the viscosity immediately after preparation, and the viscosity after storage at 25 ° C for 5 days. The measurement was performed using a CP-52 type cone-plate type sensor having a radius of 12 mm and an angle of 3°, and the rotation speed was set to 2.5 rpm.

In the viscosity of the liquid crystal sealing agent to be measured, the viscosity immediately after preparation was set to η 1, and the viscosity after storage for 5 days at 25 ° C was set to η 2 , and the viscosity stability of the liquid crystal sealing agent was evaluated according to the following criteria. .

When the value of η 2 / η 1 is less than 1.5: ○

The case where the value of η 2 / η 1 is greater than or equal to 1.5 and less than 2.0: △

The case where the value of η 2 / η 1 is greater than or equal to 2.0: ×

[Example II-1]

15 parts of epoxy resin and 45 parts of radical curable resin 1 were melt-dissolved at 100 ° C for 1 hour to prepare a uniform solution. Next, after cooling the solution, 20 parts of the radical obtained in the above Synthesis Example II-1 was added. Curable resin 2, 0.5 part of a radical chain transfer agent 1, 15 parts of a filler, 3 parts of a latent epoxy curing agent, and 1 part of a decane coupling agent as an additive, preliminary mixing by a mixer, and then using a three roll The kneading is carried out until the solid raw material reaches 5 μm or less. Next, using a filter having a mesh opening of 10 μm (MSP-10-E10S: manufactured by ADVANTEC Co., Ltd.), the mixture was filtered, and then 0.5 part of a thermal radical polymerization initiator was added, followed by vacuum agitation using a planetary mixer. A bubble treatment is carried out to thereby prepare a liquid crystal sealing agent.

[Example II-2]

A liquid crystal sealing agent was prepared in the same manner as in Example II-1 except that the radical chain transfer agent 2 was used.

[Example II-3]

A liquid crystal sealing agent was prepared in the same manner as in Example II-1 except that the radical chain transfer agent 3 was used.

[Example II-4]

The radical curable resin 1 was set to 42.5 parts, the radical curable resin 2 was set to 15 parts, the radical chain transfer agent 1 was set to 2.5 parts, and the filler was set to 20.5 parts, and the rest were A liquid crystal sealing agent was prepared in the same manner as in Example II-1.

[Example II-5]

The radical curable resin 1 was set to 48 parts, the radical curable resin 2 was set to 15 parts, and the filler was set to 22 parts, and the epoxy resin was set to 10 parts, and the rest were in the same manner as in the examples. A liquid crystal sealing agent was prepared in the same manner as in II-1.

[Example II-6]

A liquid crystal sealing agent was prepared in the same manner as in Example II-1 except that the radical chain transfer agent 4 was set to 0.5 part.

[Comparative Example II-1]

A liquid crystal was prepared in the same manner as in Example II-1 except that the radical curable resin 1 was not used at all, and the radical curable resin 1 was changed to 45.5 parts, and the radical curable resin 2 was changed to 20 parts. Sealants.

[Comparative Example II-2]

A liquid crystal sealing agent was prepared in the same manner as in Example II-1, except that the thermal radical polymerization initiator was not used, and the radical curable resin 1 was set to 45.5 parts.

The amount of each component of the liquid crystal sealing agent used in each of the examples and the comparative examples, and the evaluation results of the sealing property, the bonding strength of the liquid crystal sealing agent to be prepared, and the display property of the liquid crystal display panel using the same are summarized. Shown in Table 4.

As is clear from Table 4, the liquid crystal sealing agents of Examples II-1 to 6 to which the present invention is applied are excellent in the above-mentioned sealing property, adhesive strength, and display property. On the other hand, when the radical chain transfer agent was not used, it was found from the results of Comparative Example II-1 that the display property of Comparative Example II-1 was slightly inferior to that of the examples, and the sealing property was deteriorated. Further, when a thiol-based thermosetting agent is used as the thermosetting agent, it has been confirmed that when a secondary thiol is used, the viscosity stability of the liquid crystal sealing agent can be improved as compared with the use of the primary thiol. On the other hand, when the thermal radical polymerization initiator was not used, it was found from the results of Comparative Example II-2 that Comparative Example II-2 had problems in any of the sealing property, the adhesion strength, and the display property.

[Examples III-1 to 6, Comparative Examples III-1 to 4]

Hereinafter, the curable resin composition for liquid crystal sealing of the present invention III The examples and comparative examples carried out are specifically described.

[Preparation of materials and the like used in Examples III-1 to 6 and Comparative Examples III-1 to 4]

The materials used in the respective examples and the like are as follows.

(3) Thermal radical polymerization initiator

Thermal radical polymerization initiator 1: 2,2'-azobis(2.4-dimethylvaleronitrile) (V-65: manufactured by Wako Pure Chemical Industries, 10 hours half-life temperature 51 ° C, heat start temperature 51 ° C )

Thermal radical polymerization initiator 2: 2,2'-azobis(dimethyl 2-methylpropionate) (V-601: manufactured by Wako Pure Chemical Industries, the 10-hour half-life temperature is 66 ° C, and the onset temperature is 60 ° C)

Thermal Radical Polymerization Initiator 3: Third Ethyl Ethyl Peroxyethyl Ester (Lupasol 575: manufactured by API Corporation, 10 hour half-life temperature is 75 ° C, and the onset temperature is 88 ° C)

Thermal radical polymerization initiator 4:1,1-azobis(2,4-cyclohexane-1-carbonitrile) (Perhexyl O: manufactured by Nippon Oil & Fat Co., Ltd., 10-hour half-life temperature 70 ° C, heat start temperature Is 105 ° C)

(4) Filler

Filler 1: Spherical cerium oxide (Seahostar S-30: manufactured by Nippon Shokubai, average primary particle size of 0.3 μm, specific surface area of 11 m ² /g)

Filler 2: Spherical cerium oxide (SO-C2: manufactured by ADMATECHS, having an average primary particle diameter of 0.9 μm and a specific surface area of 4 m ² /g)

Filler 3: Spherical cerium oxide (SO-C1: manufactured by ADMATECHS, having an average primary particle diameter of 0.25 μm and a specific surface area of 17.4 m ² /g)

Filler 4: talc powder (SG-2000: manufactured by Japan Talc Company, average primary particle size of 1.0 μm, specific surface area of 36.6 m ² /g)

(5) Epoxy hardener

Latent epoxy hardener 1: 1,3-bis(decylcarbonylethyl)-5-isopropylhydantoin (Amicure VDH: Ajinomoto Fine-Techno, melting point 120 ° C)

Latent epoxy hardener 2: Diterpene adipate (ADH: manufactured by Otsuka Chemical Co., Ltd., melting point 181 ° C)

Latent epoxy hardener 3: Amicure PN-23J (Ajinomoto Fine-Techno, melting point 105 ° C)

(7) Photoradical polymerization initiator

Photoradical polymerization initiator: 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651: manufactured by Ciba Speciality Chemicals)

(8) Thermoplastic polymer

Acryl methacrylate copolymer microparticles (F-325: manufactured by Zeon, Japan, with an average primary particle size of 0.5 μm)

(9) Other additives

Coupler 1: decane coupling agent (S-510: manufactured by Chisso Corporation)

Coupler 2: decane coupling agent (KBM-403: manufactured by Shin-Etsu Chemical Co., Ltd.)

(12) Curable resin

The following (1A) resin, (1B) resin, and (1C) resin are appropriately selected and used.

(1A) Resin (radical difunctional resin)

Resin (A-1): the resin synthesized in the following Synthesis Example III-1

Resin (A-2): the resin synthesized in the following Synthesis Example III-2

Resin (A-3): the resin synthesized in the following Synthesis Example III-3

Resin (A-4): the resin synthesized in the following Synthesis Example III-4

Resin (A-5): the resin synthesized in the following Synthesis Example III-5

Resin (A-6): bisphenol A type epoxy acrylate

Resin (A-7): the resin synthesized in the following Synthesis Example III-6

(1B) resin

Resin (B-1): a phenylene ether type partially acrylylated epoxy resin synthesized in the following Synthesis Example III-7

Resin (B-2): bisphenol F type partially acrylylated epoxy resin synthesized in the following Synthesis Example III-8

Resin (B-3): Resorcinol diglycidyl ether type partially acrylylated epoxy resin synthesized in the following Synthesis Example III-9

Resin (B-4): Resin synthesized in the following Synthesis Example III-10

Resin (B-5): the resin synthesized in the following Synthesis Example III-11

Resin (B-6): Resin synthesized in the following Synthesis Example III-12

(1C) resin

Resin (C-1): o-cresol novolac type solid epoxy resin (commercial product)

Resin (C-2): bisphenol A type epoxy resin (commercially available)

Resin (C-3) (comparative): bisphenol A type epoxy resin (commercially available)

[Method of Analysis of Resin]

In addition, in order to grasp the quality and the like of the resin synthesized in each synthesis example, The epoxy equivalent measurement and the oxidation measurement were carried out as appropriate according to the following method.

1) Determination of epoxy equivalent

The epoxy equivalent can be calculated by dissolving the resin in a hydrochloric acid-dioxane solution and then titrating the amount of hydrochloric acid consumed by the epoxy group.

2) Determination of acid value

The acid value was measured in the following manner. First, a resin solution was prepared by dissolving a resin in diethyl ether and an ethanol solution. A phenolphthalein ethanol solution was added to the resin solution. Next, 0.1 equivalent of KOH of ethanol was dropped into the resin solution, and the acid value was calculated from the amount of KOH consumed before the solution became colorless.

[Synthesis Example III-1]

Synthesis of free radical difunctional resin (A-1)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. The flask was charged with 170 g of bisphenol F diglycidyl ether (manufactured by Dainippon Ink and Chemicals, Inc., Epiclon 830S, epoxy equivalent: 170 g/eq), 79 g of acrylic acid, 500 g of toluene, and 0.1 g of tributylammonium bromide. Stirring was carried out to make a homogeneous solution.

The solution was stirred at 90 ° C for 2 hours, and further refluxed, and the mixture was stirred for 36 hours to cause a reaction. Thereafter, the reaction solution was washed with ultrapure water, and then toluene was removed to obtain a resin. The obtained resin had a number average molecular weight of 457 as determined by GPC, and its peak was a single peak. Since the obtained resin had two hydroxyl groups in the molecule, the amount of the hydrogen bond functional group was calculated to be 4.38 × 10 ^-3 mol/g. The structure of the resin obtained in the present synthesis example is as follows.

[Synthesis Example III-2]

Synthesis of free radical difunctional resin (A-2)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. 200 g of Epiclon 850 CRP (bisphenol A type epoxy resin: manufactured by Dainippon Ink Chemicals Co., Ltd.), 100 g of methacrylic acid, 900 g of toluene, 0.4 g of triethylamine, and 0.4 g of p-methoxyphenol were placed in the flask. mixing. This mixture was stirred at 90 ° C for 8 hours to cause a reaction. After completion of the reaction, the reaction mixture was washed with ultrapure water and refined with a column to obtain a 100% methacryl-methylated resin of an epoxy group.

The obtained resin had a number average molecular weight of 513 as measured by GPC, and its peak was a single peak. Since the obtained resin had two hydroxyl groups in the molecule, the amount of the hydrogen bond functional group was calculated to be 3.90 × 10 ^-3 mol/g. The structure of the resin obtained in the present synthesis example is as follows.

[Synthesis Example III-3]

Synthesis of free radical difunctional resin (A-3)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. The flask was charged with 117 g of resorcinol diglycidyl ether (manufactured by Nagase ChemteX Co., Ltd., Denacol EX-201, epoxy equivalent: 117 eq/g), 79 g of acrylic acid, 500 g of toluene, and 1 g of tributylammonium bromide. Stirring was carried out to prepare a homogeneous solution. This solution was stirred at 90 ° C for 2 hours, and further refluxed, and the mixture was stirred for 6 hours to cause a reaction.

Thereafter, the reaction solution was washed with ultrapure water, and then toluene was removed to obtain a resin. The obtained resin had a number average molecular weight of 366 as determined by GPC, and its peak was a single peak. Since the obtained resin had two hydroxyl groups in the molecule, the amount of the hydrogen bond functional group was calculated to be 5.46 × 10 ^-3 mol/g. The structure of the resin obtained in the present synthesis example is as follows.

[Synthesis Example III-4]

Synthesis of free radical difunctional resin (A-4)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. The flask was charged with 100 g of a phenyl ether type epoxy resin (manufactured by Nippon Steel Chemical Co., Ltd.: YSLV-80DE, melting point: 84 ° C), 0.2 g of p-methoxyphenol as a polymerization inhibitor, and 0.2 g as a reaction catalyst. Triethylamine, 40 g of acrylic acid, and 500 g of toluene were stirred to prepare a homogeneous solution. Next, while the air was supplied to the flask, the solution was stirred at 80 ° C for 2 hours, and while refluxing, the mixture was stirred for 36 hours to cause a reaction.

Thereafter, after washing the reaction mixture with ultrapure water, toluene was removed to obtain a 100% acrylonitrile-based resin of an epoxy group. The obtained resin had a number average molecular weight of 459 as determined by GPC, and its peak was a single peak. Since the obtained resin had two hydroxyl groups in the molecule, the amount of the hydrogen bond functional group was calculated to be 4.36 × 10 ^-3 mol/g. The structure of the resin obtained in the present synthesis example is as follows.

[Synthesis Example III-5]

Synthesis of free radical difunctional resin (A-5)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. This flask was charged with 296.2 g (2 moles) of phthalic anhydride, 917.0 g (2 moles) of 2-hydroxyethyl acrylate 6-caprolactone adduct (Placcel FA3, molecular weight: 459 g/mol , manufactured by Daicel Chemical Co., Ltd., 4 g of triethylamine, 0.9 g of hydroquinone, and mixed. The reaction mixture was then stirred at 110 ° C to cause a reaction. The reaction was carried out while monitoring the acid value of the reaction mixture. When the acid value of the reaction mixture reached 48 mgKOH/g, the reaction temperature was 90 °C. Next, 680.82 g (2 mol) of bisphenol A diglycidyl ether and 1.6 g of tetrabutylammonium bromide were added to the reaction mixture, and the reaction was carried out at 90 ° C until the acid value of the reaction mixture reached 2 mgKOH/g. .

Thereafter, 144.1 g (2 mol) of C was further added to the reaction mixture. The olefinic acid and 1.8 g of hydroquinone were introduced into the flask, and the mixture was reacted at 80 ° C for 2 hours, and the temperature was raised to 90 ° C to continue the reaction. The reaction was carried out until the acid value of the reaction mixture reached 2 mgKOH/g.

The mixture after completion of the reaction was washed with ultrapure water, and purified by a column to obtain a resin. This resin reacts a carboxyl group of bisphenol A diglycidyl ether with a carboxyl group of a compound formed by reacting a 6-caprolactone adduct of 2-hydroxyethyl acrylate with phthalic anhydride. And a resin obtained by reacting another glycidyl group of bisphenol A diglycidyl ether with a carboxyl group of "acrylic acid". The resin obtained in the present synthesis example was measured by GPC, and as a result, the peak was a single peak and the molecular weight was 1005. Since the obtained resin had two hydroxyl groups in the molecule, the amount of the hydrogen bond functional group was calculated to be 1.99 × 10 ^-3 mol/g.

Free radical difunctional resin (A-6)

Bisphenol A type epoxy acrylate (EB3700: manufactured by DAICEL-CYTEC Co., Ltd.) was used. The amount of the hydrogen bond functional group was 4.12 × 10 ^-3 mol / g.

[Synthesis Example III-6]

Synthesis of free radical difunctional resin (A-7)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. Into this flask, 172 g of 1,6-hexane diisocyanate (manufactured by Kanto Chemical Co., Ltd.) and 148 g of glycidol (manufactured by Wako Pure Chemical Industries, Ltd.) were placed, and the mixture was stirred at 80 ° C for 1 hour to be mixed. Thereafter, 0.05 g of dibutyltin dilaurate was added to the reaction mixture, and the mixture was stirred at 80 ° C for 2 hours to cause a reaction. Next, 144 g of acrylic acid was added to the reaction mixture, and the mixture was stirred at 90 ° C for 12 hours to cause a reaction. The reaction mixture was subjected to infrared spectroscopic analysis to confirm that the isocyanate-based absorption peak disappeared.

Thereafter, the reaction mixture was washed with ultrapure water and purified by a column to obtain a 100% acrylonitrile-based compound of 1,6-hexanediester diglycidyl ether of diisocyanate. The resin obtained in the present synthesis example was measured by GPC, and as a result, the peak was a single peak and the molecular weight was 460. Since the obtained resin had two hydroxyl groups and two hydroxyethyl carboxylate ligands in the molecule, the amount of the hydrogen bond functional group was calculated to be 8.70 × 10 ^-3 mol/g.

(1B) resin

[Synthesis Example III-7]

Resin (B-1): Synthesis of phenyl ether type partially acrylylated epoxy resin

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. The flask was charged with 100 g of a phenyl ether type epoxy resin (manufactured by Nippon Steel Chemical Co., Ltd.: YSLV-80DE, melting point: 84 ° C), 0.2 g of a p-methoxyphenol group as a polymerization inhibitor, 20 g of acrylic acid, and toluene 500 g. 0.2 g of triethylamine as a reaction catalyst was stirred to prepare a uniform solution. While the air was supplied to the flask, the solution was stirred at 80 ° C for 2 hours, and further refluxed, and the mixture was stirred for 24 hours to cause a reaction.

After the completion of the reaction, the reaction mixture was purified by a column, and then washed with ultrapure water to remove toluene to obtain a 50% propylene-substituted partially acrylylated epoxy resin of an epoxy group. The obtained resin had a number average molecular weight of 386 as determined by GPC, and its peak was a single peak. Since the obtained resin had one hydroxyl group in the molecule, the amount of the hydrogen bond functional group was calculated to be 2.59 × 10 ^-3 mol/g. Further, since the resin has one epoxy group in the molecule, the amount of the epoxy group is calculated to be 2.59 × 10 ^-3 mol/g.

[Synthesis Example III-8]

Resin (B-2): Synthesis of bisphenol F-type partially acrylylated epoxy resin

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. Into this flask, 160 g of a bisphenol F-type epoxy resin (Epotohto YDF-8170C: manufactured by Tohto Kasei Co., Ltd.), 36 g of acrylic acid, and 0.2 g of triethanolamine were placed and stirred. Next, dry air was blown into the flask, and the mixture was stirred at 110 ° C for 5 hours, and the mixture was reacted to obtain an acrylic modified epoxy resin. After the obtained resin was purified by a column, it was dissolved in toluene equivalent to the resin.

After washing the toluene solution of this resin with ultrapure water, toluene was further removed to obtain a partially acrylylated epoxy resin in which 50% of the epoxy group was acrylylated. The obtained resin had a number average molecular weight of 384 as determined by GPC, and its peak was a single peak. Since the obtained resin had one hydroxyl group in the molecule, the amount of the hydrogen bond functional group was calculated to be 2.60 × 10 ^-3 mol/g. Further, since the resin has one epoxy group in the molecule, the amount of the epoxy group is calculated to be 2.60 × 10 ^-3 mol/g.

[Synthesis Example III-9]

Resin (B-3): Synthesis of resorcinol diglycidyl ether type partially acrylylated epoxy resin

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. This flask was charged with 234 g of resorcinol diglycidyl ether (Nagase ChemteX). The company, manufactured by Denacol EX-201, having an epoxy equivalent of 117 eq/g, 72 g of acrylic acid, 500 g of toluene, and 1 g of tributylammonium bromide, was stirred to prepare a uniform solution. This solution was stirred at 90 ° C for 2 hours, and further refluxed, and the mixture was stirred for 6 hours to carry out a reaction.

After completion of the reaction, the reaction mixture was purified by a column and washed with ultrapure water to obtain a 50% propylene-substituted partially acrylylated epoxy resin of the epoxy group. The obtained resin had a number average molecular weight of 294 as determined by GPC, and its peak was a single peak. Since the obtained resin had one hydroxyl group in the molecule, the amount of the hydrogen bond functional group was calculated to be 3.40 × 10 ^-3 mol/g. Since the obtained resin had one epoxy group in the molecule, the amount of the epoxy group was calculated to be 3.40 × 10 ^-3 mol/g.

[Synthesis Example III-10]

Synthesis of Resin (B-4)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. This flask was charged with 296.2 g (2 mol) of phthalic anhydride, 1372.0 g (2 mol) of 2-hydroxyethyl acrylate 6-caprolactone adduct (Placcel FA5, molecular weight: 686 g/mol , manufactured by Daicel Chemical Co., Ltd., 4 g of triethylamine, 0.9 g of hydroquinone. This mixture was stirred at 110 ° C to cause a reaction. The reaction was carried out while monitoring the acid value. When the acid value reached 36 mgKOH/g, the reaction temperature was 90 °C.

Next, 680.82 g (2 mol) of bisphenol A diglycidyl ether and 1.6 g of tetrabutylammonium bromide were added, and heating and stirring were continued until the acid value of the reaction mixture reached 2 mgKOH/g.

After the completion of the reaction, the reaction mixture is washed with ultrapure water and purified by a column to obtain a compound obtained by reacting a 6-caprolactone adduct of 2-hydroxyethyl acrylate with phthalic anhydride. A resin obtained by reacting with bisphenol A diglycidyl ether. The resin was analyzed by GPC, and the peak was a single peak, and the number average molecular weight was 1,160. Since the obtained resin had one hydroxyl group in the molecule, the amount of the hydrogen bond functional group was calculated to be 8.6 × 10 ^-4 mol/g. Since the obtained resin had one epoxy group in the molecule, the amount of the epoxy group was calculated to be 8.6 × 10 ^-4 mol/g.

[Synthesis Example III-11]

Synthesis of Resin (B-5)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. Into this flask, 190 g of a phenol novolac type epoxy resin N-770 (manufactured by Dainippon Ink) and 500 mL of toluene were placed, stirred, and further 0.1 g of triphenylphosphine was added to prepare a uniform solution. While the solution was placed under reflux, 35 g of acrylic acid was added dropwise thereto over 2 hours while stirring. Thereafter, the mixture was stirred under reflux for 6 hours to cause a reaction.

After completion of the reaction, the reaction mixture was purified by column chromatography and washed with ultrapure water to obtain a resin. The resin was measured by GPC, and as a result, the peak was a single peak, and the number average molecular weight was 1,177. The epoxy equivalent of the obtained resin was measured, and as a result, it was found that 50% of the epoxy group was modified with acrylic acid. Since the obtained resin had three hydroxyl groups in the molecule, the number of hydrogen bond functional groups was calculated to be 2.55 × 10 ^-3 mol/g. Since the obtained resin had three epoxy groups in the molecule, the number of epoxy groups was calculated to be 2.55 × 10 ^-3 mol/g.

[Synthesis Example III-12]

Synthesis of Resin (B-6)

Prepare a flask equipped with a thermometer, a cooling tube, and a stirring device. Into this flask, 172 g of 1,6-hexane diisocyanate (manufactured by Kanto Chemical Co., Ltd.) and 148 g of glycidol (manufactured by Wako Pure Chemical Industries, Ltd.) were placed, and the mixture was stirred at 80 ° C for 1 hour to cause a reaction. Then, 0.05 g of dibutyltin dilaurate was added to the reaction mixture, and the mixture was stirred at 80 ° C for 2 hours. Next, 72 g of acrylic acid was added to the reaction mixture, and the mixture was stirred at 100 ° C for 3 hours to be mixed.

After completion of the reaction, the reaction mixture was subjected to infrared spectroscopic analysis to confirm that the absorption peak based on isocyanate disappeared. Next, the reaction mixture was washed with ultrapure water and purified by a column to obtain a 50% acrylamide of a reactant of 1,6-hexanediester and glycidyl ether of diisocyanate. The resin was measured by GPC, and as a result, its peak was a single peak, and the number average molecular weight was 388. Since the obtained resin had two urethane ligands and one hydroxyl group in the molecule, the amount of the hydrogen bond functional group was calculated to be 7.73 × 10 ^-3 mol/g. Since the obtained resin had one epoxy group in the molecule, the amount of the epoxy group was calculated to be 2.58 × 10 ^-3 mol/g.

(1C) resin

Resin (C-1): o-cresol novolac type solid epoxy resin separated by a column (EOCN-1020: manufactured by Nippon Kayaku Co., Ltd., the softening point measured by the ring and ball method is 75 ° C, and the epoxy equivalent is 215g/eq)

Since the epoxy equivalent of this resin was 215 g/eq, the molecular weight per one epoxy group of this resin (C-1) was 215. Therefore, the amount of epoxy groups of this resin was calculated to be 4.65 × 10 ^-3 mol/g. Since the resin does not contain a hydrogen bond functional group, the amount of the hydrogen bond functional group is zero. Further, the weight average molecular weight of this resin was measured by GPC and found to be 1075.

Resin (C-2): bisphenol A type epoxy resin (Epikote 1003: manufactured by JER, having a softening point of 89 ° C and an epoxy equivalent of 720 g / eq as measured by the ring and ball method)

Since this resin has two epoxy groups in the molecule, the molecular weight of this resin is calculated to be 1440. The amount of epoxy groups of this resin was calculated to be 1.39 × 10 ^-3 mol/g. Since this resin hardly has a molecular weight distribution, the weight average molecular weight is also 1440. Further, this resin has a hydroxyl group per repeating unit (molecular weight: 284.4) as shown in the following structural formula. Since the molecular weight of this resin was 1440, n was calculated to be 3.87. Therefore, the average number of hydroxyl groups per molecule was 3.87, so the amount of the hydrogen bond functional group was calculated to be 2.69 × 10 ^-3 mol/g.

In the above formula, the number indicates the molecular weight.

Epoxy resin (C-3) (comparative): bisphenol A type epoxy resin (Epikote 828EL: manufactured by JER, epoxy equivalent of 190 g/eq)

Since the resin (C-3) has two epoxy groups in the molecule, the molecular weight of the resin is calculated to be 380. Therefore, the amount of epoxy groups of this resin was calculated to be 5.26 × 10 ^-3 mol/g. Further, this resin also had a structure represented by the formula (2), and n was calculated to be 0.14. Therefore, since the resin (C-3) had 0.14 hydroxyl groups, the amount of the hydrogen bond functional group was calculated to be 3.7 × 10 ^-4 mol/g. Since the resin is liquid at room temperature, the softening point is less than 40 °C.

[Evaluation method]

The evaluation methods performed in Examples III-1 to 6 and Comparative Examples III-1 to 4 will be described. Here, i) the leakage resistance of the liquid crystal sealing agent, ii) the coating property of the liquid crystal sealing agent, iii) the sealing appearance and the bonding strength, and iv) the viscosity of the liquid crystal sealing agent were measured, and the characteristics of the liquid crystal sealing agent were evaluated. The details of each evaluation measurement method are as follows.

i) leakage resistance of liquid crystal sealant

Into the liquid crystal sealing agent prepared by the following method, a 4.8 μm spherical spacer was further added to prepare a liquid crystal sealing agent to which a spacer was added. Next, a 40 mm × 45 mm glass substrate (RT-DM88PIN: manufactured by EHC Corporation) having a transparent electrode and an alignment film was prepared. Then, the above composition was filled in a dispenser (manufactured by Hitachi Plant Technologies Co., Ltd.), and a square sealing pattern of 35 mm × 40 mm (sectional area: 3500 μm ² ) was drawn on the glass substrate.

A liquid crystal material (MLC-11900-000: manufactured by Merck Co., Ltd.) having the same amount of panel content as that of the bonded panel was precisely dropped into the sealing pattern of the substrate by using a dispenser (manufactured by Hitachi Plant Technologies Co., Ltd.).

The glass substrate and the glass substrate facing each other were superposed under a reduced pressure of 10 Pa using a vacuum bonding apparatus (manufactured by Shin-Etsu Engineering Co., Ltd.). Next, the glass substrates which were overlapped were sandwiched between two 40 mm × 45 mm glass substrates prepared in advance, and a load was applied thereto to fix them. This glass substrate is a Chromium Sputtering using both sides thereof. then, The superposed glass substrate was returned to atmospheric pressure and heated at 120 ° C for 60 minutes to be cured (hereinafter referred to as "hardening step in the leakage resistance test").

According to the following method, the sealing pattern linearity of the liquid crystal display panel which is an index of the leakage resistance, that is, the sealing linearity was evaluated.

[ratio of maximum width to minimum width of seal]% = [minimum width of seal] / [maximum width of seal] × 100

The above ratio is greater than or equal to 95%: ◎ (excellent)

The above ratio is 80% or more and less than 95%: ○ (slightly excellent)

The above ratio is less than 80%: × (poor)

Ii) Coating properties of liquid crystal sealant

The liquid crystal sealing agent used in the above i) was filled into a syringe under vacuum. Next, a syringe equipped with a needle having a diameter of 0.4 mm was placed on a dispenser (manufactured by Hitachi Plant Technologies Co., Ltd.), and then a glass substrate for a liquid crystal display panel of 300 mm × 400 mm (manufactured by Nippon Electric Glass Co., Ltd.) was used. 50 35 mm × 40 mm seal patterns were drawn on the top. At this time, the discharge pressure was set to 0.3 MPa, the cross-sectional area was set to 3500 μm ² , and the coating speed was set to 100 mm/sec.

The seal shape of the drawn seal pattern was evaluated according to the following criteria.

The frame shape of the seal is not broken at all, and the seal is 48 to 50: ◎ (excellent)

The above frame shape is 45 or more and less than 48: ○ (slightly excellent)

The above frame shape is less than 44: × (poor)

Iii) Seal appearance and strength

The liquid crystal sealing agent prepared in the above 1) was applied to a circular seal pattern having a diameter of 1 mm on a 25 mm × 45 mm × 4 mm thick alkali-free glass using a screen. Next, the alkali-free glass and the pair of the same glass were superposed on a cross shape and fixed, and then the fixed pair of glasses were heated at 120 ° C for 60 minutes to be bonded (hereinafter referred to as "following test". Hardening step"). The obtained two glass plates (hereinafter referred to as "test pieces") were stored in a thermostat at 25 ° C and a humidity of 50% for 24 hours, and the appearance of the seal was visually observed. The appearance of the seal can also serve as a standard for liquid crystal contamination of liquid crystal sealants.

The appearance of the seal was evaluated according to the following criteria.

No gaps or outflows were observed by visual inspection: ◎ (excellent)

Visually visible small gaps or outflows: △ (slightly poor)

Visual inspection of outflows and voids: × (poor)

Further, the tensile strength of the test piece taken out from the constant temperature bath was measured at a tensile speed of 2 mm/min using a tensile tester (manufactured by Intesco).

The strength was then evaluated according to the following criteria.

Then the intensity is greater than or equal to 10 MPa: ◎ (excellent)

Then the strength is greater than or equal to 7 MPa and less than 10 MPa: ○ (slightly excellent)

Then the intensity is less than 7 MPa, not 満: × (poor)

Iv) Viscosity measurement of liquid crystal sealant

The viscosity of the composition was an E-type rotary viscometer (manufactured by BROOKFIELD: digital rheometer, model: DV-III ULTRA) and a CP-52 cone-plate type sensor with a radius of 12 mm and an angle of 3°. The measurement was carried out at a rotation speed of 1.0 rpm under the following conditions.

Viscosity at 25 ° C: The liquid crystal sealing agent of the present invention was allowed to stand at 25 ° C for 5 minutes and then measured.

Viscosity at 80 ° C: The liquid crystal sealing agent of the present invention was placed in a cup of an E-type rotational viscometer, heated to 80 ° C at a temperature increase rate of 5 ° C / min, and allowed to stand at 80 ° C for 5 minutes, and then measured.

Here, in the above-described measurement method, when the viscosity of the liquid crystal sealing agent at 80 ° C exceeds the measurement limit and measurement is impossible, the measurement is performed by a parallel plate method (RheoStress RS150: manufactured by HAAKE). The measurement by the parallel plate method was carried out immediately after the temperature was raised to 80 ° C at a temperature increase rate of 5 ° C /min according to the standard method of the above-mentioned model. In addition, the thixotropic index (Ti) is a CP-52 type cone-plate using an E-type rotary viscometer (digital rheometer, model: DV-III ULTRA, manufactured by BROOKFIELD) and a radius of 12 mm and an angle of 3°. The sensor was measured at a rotation speed of 0.5 rpm and 5.0 rpm at 25 ° C, and was expressed by a value of [viscosity at 25 ° C, 0.5 rpm] / [viscosity at 25 ° C, 5.0 rpm].

[Example III-1]

30 parts of resin (A-1), 30 parts of resin (A-3), 30 parts of resin (A-5), 10 parts of epoxy resin, 20 parts of filler 1, 1 part of heat free as a curable resin Base polymerization initiator 1,8 parts epoxy hardener 1. Take The mixer mixes these preparations. Next, the mixture was kneaded by three rolls until the solid raw material reached 4 μm or less. Then, the kneaded material was filtered with a filter having a mesh opening of 10 μm (MSP-10-E10S: manufactured by ADVANTEC Co., Ltd.), and then subjected to vacuum defoaming treatment to obtain a liquid crystal sealing agent.

The amount of the hydrogen bond functional group in the curable resin contained in the liquid crystal sealing agent was 3.55 × 10 ^-3 mol/g, and the amount of the epoxy group was 0.47 × 10 ^-3 mol/g.

The viscosity of the liquid crystal sealing agent thus obtained at 25 ° C is 440 Pa at 0.5 rpm. s, 350 Pa at 1.0 rpm. s, 280Pa at 5rpm. s.

The viscosity measured by the E-type rotary viscometer at 80 ° C is greater than 780 Pa. s, therefore, it was measured by the parallel plate method (RheoStress RS150: manufactured by HAAKE). The result is 9.00E+05Pa. s. The thixotropy index is 1.6.

The liquid crystal sealing agent was evaluated by various tests.

[Examples III-2 to 6]

A liquid crystal sealing agent was prepared in the same manner as in Example III-1 except that each component shown in the following Table 5 was prepared. The same evaluation as in Example III-1 was carried out for each liquid crystal sealing agent.

[Comparative Example III-1]

The respective components shown in the following Table 6 were prepared, and a liquid crystal sealing agent was prepared in the same manner as in Example III-1. The same evaluation as in Example III-1 was carried out for each liquid crystal sealing agent. Among them, "the hardening step in the evaluation of leakage resistance" is to irradiate ultraviolet rays of 3000 mJ before heating at 120 ° C for 60 minutes. And proceed. In addition, "the hardening step in the next test" was also carried out by irradiating ultraviolet rays of 3000 mJ before heating at 120 ° C for 60 minutes.

[Comparative Example III-2, 3]

The respective components shown in the following Table 6 were prepared, and a liquid crystal sealing agent was prepared in the same manner as in Example III-1. The same evaluation as in Example III-1 was carried out for each liquid crystal sealing agent.

[Comparative Example III-4]

The respective components shown in the following Table 6 were prepared, and a liquid crystal sealing agent was prepared in the same manner as in Comparative Example III-1. The same evaluation as in Example III-1 was carried out for each liquid crystal sealing agent.

From the comparison of Examples III-1 to 6 and Comparative Examples III-1 to 4, it is understood that the liquid crystal sealing agent of the present invention containing a curable resin having a hydrogen bond functional group amount and an epoxy group amount within a specific range is resistant to leakage. Excellent in properties, adhesion, and coating properties. In particular, it can be seen from the comparison between the respective examples and Comparative Example III-4 that the softening is contained. The liquid crystal sealing agent of the present invention having an epoxy resin having a specific molecular weight and a specific range is more excellent in leakage resistance and adhesion than a liquid crystal sealing agent containing an epoxy resin having a softening point and a molecular weight outside this range.

[Industrial availability]

The curable resin composition for liquid crystal sealing of the present invention can be quickly and sufficiently cured even if it is not heated by heating alone. Therefore, the liquid crystal sealing agent produced by using the curable resin composition for liquid crystal sealing of the present invention has high curability, is excellent in leakage resistance, and can suppress liquid crystal contamination, so that it can effectively provide display characteristics. Liquid crystal sealing agent for liquid crystal display panel.

This application is based on 1) Application No. JP2007-039938 filed on February 20, 2007, 2) Application No. JP2007-169749 filed on June 27, 2007, 3) Application filed on November 14, 2007 Priority is claimed on the application number JP2007-295925. The contents disclosed in the above specification are all incorporated in the specification of the present application.

Claims (12)

A curable resin composition for liquid crystal sealing comprising: an acrylic resin; and/or a (meth)acrylic acid-modified epoxy resin having one or more epoxy groups each in one molecule and a methyl radical propylene fluorenyl group; a thermal radical polymerization initiator; and a filler, the above thermal radical polymerization initiator relative to 100 parts by weight of the total of the acrylic resin and the (meth)acrylic acid modified epoxy resin The content of the filler is from 1 part by weight to 50 parts by weight, based on 100 parts by weight of the total of the acrylic resin and the (meth)acrylic modified epoxy resin, and the content of the filler is from 1 part by weight to 50 parts by weight. The curable resin composition for sealing has a viscosity of 50 Pa at 25 ° C and 1.0 rpm as measured by an E-type viscosity meter. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s. The curable resin composition for liquid crystal sealing according to claim 1, wherein the filler has an average primary particle diameter of 1.5 μm or less and a specific surface area of 1 m ² /g to 500 m ² /g. The viscosity index defined by the viscometer at 25 ° C and 0.5 rpm] / [viscosity at 25 ° C and 5.0 rpm measured by an E-type viscometer] is 1.1 to 5.0. The curable resin composition for liquid crystal sealing according to claim 1 or 2, wherein the thermal radical polymerization is carried out by subjecting the thermal radical polymerization initiator to a thermal decomposition reaction at a certain temperature for 10 hours. beginning The 10-hour half-life temperature of the above thermal radical polymerization initiator defined by the temperature at which the concentration of the agent is reduced to half is 40 ° C to 80 ° C. A curable resin composition for liquid crystal sealing comprising: a radical curable resin having a carbon-carbon double bond capable of undergoing radical polymerization in one molecule; a thermal radical polymerization initiator; a radical chain transfer agent; The content of the thermal radical polymerization initiator in the filler is 0.01 parts by weight to 5.0 parts by weight based on 100 parts by weight of the radical curable resin, and the radical chain is 100 parts by weight based on 100 parts by weight of the radical curable resin. The content of the filler is from 0.01 part by weight to 5.0 parts by weight, and the content of the filler is from 1 part by weight to 30 parts by weight based on 100 parts by weight of the curable resin composition for liquid crystal sealing, and the curable resin composition for liquid crystal sealing is used. The viscosity at 25 ° C and 1.0 rpm measured by an E-type viscometer was 50 Pa. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s. The curable resin composition for liquid crystal sealing according to claim 4, wherein the radical chain transfer agent is a mercaptan. The curable resin composition for liquid crystal sealing according to Item 4 or 5, wherein the thiol as the radical chain transfer agent is a secondary thiol having a number average molecular weight of 400 to 2,000. A curable resin composition for liquid crystal sealing comprising: a resin composition having a carbon-carbon double bond capable of radical polymerization, a hydrogen bond functional group, and an epoxy group; a thermal radical polymerization initiator; and filling The content of the thermal radical polymerization initiator is 0.01 parts by weight to 5.0 parts by weight, based on 100 parts by weight of the resin composition, and 100 parts by weight of the curable resin composition for liquid crystal sealing, the filler The content of the resin composition is from 2 parts by weight to 30 parts by weight, and the resin composition contains two or more kinds of resins selected from the group consisting of: (1A) a radical reactive resin having hydrogen in one molecule. a bond functional group and two carbon-carbon double bonds capable of undergoing radical polymerization, and the amount of the above hydrogen bond functional group is 1.5×10 ^-3 mol/g to 6.0×10 ^-3 mol/g; (1B) radical a reactive resin having a hydrogen bond functional group, an epoxy group, and a carbon-carbon double bond capable of undergoing radical polymerization in one molecule, and the amount of the above hydrogen bond functional group is 1.0 × 10 ^-4 mol/g to 5.0 ×10 ^-3 mol/g; and (1C) epoxy resin having an epoxy group in one molecule but not having There is a carbon-carbon double bond capable of radical polymerization, and the softening point measured by the ring and ball method is 40 ° C or more, and the weight average molecular weight is 500 to 5000; the amount of the hydrogen bond functional group in the above resin composition is 1.0×10 ^-4 mol/g to 6.0×10 ^-3 mol/g; the amount of epoxy groups in the above resin composition is 1.0×10 ^-4 mol/g to 2.6×10 ^-3 mol/g, and the above liquid crystal sealing The viscosity of the curable resin composition measured at 25 ° C and 1.0 rpm was 50 Pa as measured by an E-type viscosity meter. s~500Pa. s, and the viscosity at 80 ° C, 1.0 rpm is greater than 500Pa. s. The curable resin composition for liquid crystal sealing according to claim 7, wherein the hydrogen bond functional group in the resin composition is a hydroxyl group. The curable resin composition for liquid crystal sealing according to claim 7, wherein the radical reactive resin of the above (1A) is a resin represented by the following formula (a1) or (a2); [In the above formula (a1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom or a methyl group; and R _m each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkene; a propyl group, a hydroxyalkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; n represents an integer of 1 to 4; l represents an integer of 1 to 4; and A is -CH ₂ -, - An organic group represented by C(CH ₃ ) ₂ -, -SO ₂ -, or -O-]; [In the above formula (a2), R ₅ , R ₆ , R ₇ and R ₈ each independently represent a hydrogen atom or a methyl group; and R _q independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkenyl group; A propyl group, a hydroxyalkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; r represents an integer of 1 to 4; and p represents an integer of 1 to 4]. The curable resin composition for liquid crystal sealing according to claim 7, wherein the radically reactive resin of the above (1A) is a resin represented by the following formula (a3) or (a4); [In the above formula (a3), R ₁ and R ₂ each independently represent a hydrogen atom or a methyl group; and R _m each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an allyl group, and a carbon number; a hydroxyalkyl group of 1 to 4 or an alkoxy group having a carbon number of 1 to 4; n represents an integer of 1 to 4; and A is -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, or -O- represents an organic group]; [In the above formula (a4), R ₅ and R ₆ each independently represent a hydrogen atom or a methyl group]. The curable resin composition for liquid crystal sealing according to claim 7, wherein the curable resin composition for liquid crystal sealing further contains a radical chain transfer agent. A method for producing a liquid crystal display panel, which is a method for producing a liquid crystal display panel by bonding two opposing substrates via a curable resin composition for liquid crystal sealing, comprising the steps of preparing a first substrate, The substrate includes a frame-shaped display region which is formed by surrounding a pixel array region with a curable resin composition for liquid crystal sealing as described in claim 1, item 4, or item 7 of the patent application; a step of dropping liquid crystal into the display region or the other substrate in the state; a step of superposing the first substrate and the second substrate facing the second substrate; and curing the resin composition for liquid crystal sealing by heating A step of.