JP4596856B2 - Sealing material for liquid crystal panel and liquid crystal panel using the same - Google Patents

Description

  The present invention relates to a sealing material for a liquid crystal panel and a liquid crystal panel using the same. In particular, a liquid crystal panel sealing material capable of realizing good adhesion, elasticity, and liquid crystal reliability when used in a liquid crystal panel including a plastic substrate made of a plastic multilayer film, etc., and a liquid crystal using the same Regarding panels.

  Since it is thinner and lighter and consumes less power than a CRT, a liquid crystal panel is used as a display for OA equipment monitors, portable electronic devices, car navigation systems, and the like. In a liquid crystal panel, a liquid crystal layer is sandwiched between a pair of substrates having transparent electrodes on the inner surface, and a sealing material is disposed on the outer periphery of the substrate so as to surround the liquid crystal layer, thereby sealing (sealing) the liquid crystal layer. ).

  For example, a glass substrate is used as the substrate of such a liquid crystal panel. By the way, since the liquid crystal constituting the liquid crystal layer has a high polarity and a strong tendency to swell or dissolve the constituents of the sealing material, a liquid crystal panel composed of a glass substrate has a high degree of crosslinking and does not swell due to the liquid crystal as a sealing material. A thermosetting epoxy resin (epoxy compound) as a material is preferably used. Thus, in the liquid crystal panel in which the liquid crystal layer between the glass substrates is sealed by the sealing material made of epoxy resin, good adhesive strength and liquid crystal resistance are realized.

  On the other hand, in recent years, with the spread of notebook personal computers, mobile phones, PDAs (Personal Digital Assistants) and the like, displays suitable for carrying are desired. In response to such demands, the liquid crystal panels used for these use plastic substrates that do not break when carried and are superior to glass substrates in terms of weight reduction and thickness reduction. In addition, liquid crystal panels that are applied to prepaid cards, etc. where thinness is inevitable, can be easily damaged if they are made using a glass substrate and the thickness of the substrate becomes as thick as about 0.3 mm, and excessive distortion occurs when it is carried. Therefore, it is desired to use a plastic substrate.

  In a liquid crystal panel composed of a plastic substrate, the use of an epoxy resin as a sealing material causes the following problems. That is, in a liquid crystal panel composed of a plastic substrate having flexibility, when the liquid crystal panel is bent, the sealing material composed of an epoxy resin having high hardness is distorted, and the sealing material is peeled off due to the stress. In a liquid crystal panel composed of a glass substrate, the panel deformation is suppressed due to the high hardness of the substrate, and thus the sealing material does not peel off, but in a liquid crystal panel equipped with a plastic substrate, it is composed of an epoxy resin. Since the sealing material cannot follow the slight deformation of the panel, peeling occurs with a weak force. As a result, the liquid crystal leaks and the liquid crystal panel is damaged.

  Further, when a sealing material made of an epoxy resin is applied to a liquid crystal panel provided with a plastic substrate, the following problems occur when the epoxy resin is thermally contracted by heating to be cured. That is, in a liquid crystal panel provided with a glass substrate, the adhesion between the glass substrate and the transparent electrode is high, so the transparent electrode does not peel off from the surface of the glass substrate with the thermal contraction of the epoxy resin. In a liquid crystal panel provided with a plastic substrate, the transparent electrode peels from the surface of the plastic substrate due to distortion caused by thermal shrinkage when the epoxy resin is cured.

  In general, when a liquid crystal panel is formed using a plastic substrate, a plurality of barrier layers made of an inorganic material are provided on the front and back surfaces of the plastic substrate in order to prevent the permeation of moisture and gas from the outside. Since the barrier layer made of an inorganic material is provided on the plastic substrate made of an organic material, the adhesion of the barrier layer to the plastic substrate is weak, and therefore the epoxy resin constituting the sealing material The plastic substrate and the barrier layer easily peel off as the heat shrinks.

  On the other hand, there is also a sealing material composed of an epoxy resin improved so as not to cause distortion at the time of thermosetting, but such a sealing material has an extremely long curing time of 2 days and is not mass-produced. Also, when curing the epoxy resin, the curing temperature must be raised to a minimum of about 150 ° C. in order to give the epoxy resin sufficient strength, but the plastic substrate has a low heat resistance, and thus about 150 ° C. Deformation occurs when heated up to

  In view of the above points, in a liquid crystal panel provided with a plastic substrate, it is necessary to use a sealing material that has flexibility and can follow the deformation of the liquid crystal panel and has a high peel strength. Further, such a sealing material is required to have little thermal shrinkage at the time of curing and not to cause distortion in the transparent electrode and gas barrier layer disposed on the surface of the plastic substrate after curing.

  From such a demand, it is conceivable to apply a sealing material composed of a urethane resin which is a flexible and crosslinkable resin as a sealing material for a liquid crystal panel provided with a plastic substrate. If a sealing material made of urethane resin is used, peeling of the sealing material can be prevented by the flexibility of the urethane resin even if the liquid crystal panel is curved or bent.

  However, the sealing material composed of urethane resin has lower liquid crystal resistance than epoxy resin, and if the urethane resin of the sealing material and the liquid crystal come into direct contact in the liquid crystal panel, the urethane resin swells and impurities into the liquid crystal Emissions occur. Therefore, in a liquid crystal panel provided with a sealing material made of urethane resin, the thickness of the liquid crystal panel is increased because the urethane resin swells with the liquid crystal over time even when the liquid crystal panel can be initially displayed. As a result, the display becomes impossible. In addition, when the sealing material is configured by mixing anisotropic conductive particles, there is a problem such as poor conduction.

  In addition, in the method of manufacturing a liquid crystal panel in which a sealing material composed of urethane resin is applied to the surface of a plastic substrate by screen printing or the like, the curing time of the urethane resin is extremely short. As the curing begins, when the urethane resin is spread thinly, the curing of the resin is promoted and the screen is clogged. For this reason, when the sealing material comprised with a urethane resin is used, the workability | operativity will fall.

  On the other hand, it is conceivable to achieve both properties, ie, liquid crystal resistance and flexibility by mixing the epoxy resin and the urethane resin to form the sealing material. In this case, the epoxy resin and the urethane are used. Both of them are separated due to the poor compatibility with the resin, and therefore the target sealing material cannot be realized.

  Therefore, as a method of obtaining a sealing material having flexibility that can follow the deformation of a plastic substrate and excellent in adhesiveness and curability, a substance that imparts flexibility to an epoxy resin cured product and an epoxy resin cured product is used. There is a method of forming a sealing material using a composition obtained by mixing a curing agent contained. In the sealing material obtained by this method, flexibility is imparted to the cured epoxy resin, so that the peel strength can be increased, and the liquid crystal resistance of the cured epoxy resin can be utilized. Examples of the substance that imparts flexibility to the cured epoxy resin include trifunctional thiol compounds and urethane resins.

  For example, the polyalkylene glycol represented by the following formula (1), the urethane polyisocyanate represented by the following formula (2), and the general formula represented by the following formula (3) 3 There is a sealing material composed of a composition containing a functional thiol compound as an essential component (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-273580

  As described above, in the method using a trifunctional thiol compound for imparting flexibility to the cured epoxy resin, the trifunctional thiol compound has a strong odor and gives an unpleasant feeling to the worker. Moreover, since the sealing material obtained by such a method is not sufficiently flexible, curing distortion occurs when the sealing material is cured at a high temperature exceeding 80 ° C., and the peel strength decreases. Therefore, at the initial stage of the sealing material curing process, it is necessary to set the curing temperature at a low temperature of 80 ° C. or less so that curing distortion does not occur. Therefore, it takes a long time to cure the sealing material. Accordingly, not only the odor but also the workability is remarkably lowered from this point.

  An object of the present invention is to solve the above-mentioned problems, by using a sealing material for a liquid crystal panel capable of realizing excellent peel strength and liquid crystal resistance and excellent workability, and the sealing material for a liquid crystal panel. An object of the present invention is to provide a liquid crystal panel that is improved in reliability and mass productivity.

In order to solve the above-described problems and achieve the above object, a liquid crystal panel sealing material according to the invention of claim 1 is composed of a composition prepared by mixing a main agent and a curing agent. The main agent includes an epoxy resin, a medium-polar polyol resin that is a precursor of a urethane resin , and an inorganic filler , and the curing agent is an isocyanate compound that is a precursor of a urethane resin and a silane coupling. agent only contains, relative to the total weight of the epoxy resin and the polyol resin contained in the base resin, the ratio of the weight of the epoxy resin is not more than 68% 32% or more, the epoxy resin is a bisphenol a type epoxy Including at least one of resin, bisphenol F type epoxy resin and phenol novolac type epoxy resin, When the polyol resin has a molecular weight of 1000 or more, the polyol resin is a polyester polyol or a polylactone, and when the polyol resin is the polyester polyol, at least one of a dibasic acid component and a glycol component constituting the polyester polyol And the number of moles of isocyanate groups in the isocyanate compound is at least three times the number of moles of hydroxyl groups in the polyol resin, and the main agent and the curing agent The proportion of the weight of the inorganic filler is 15% or more and 30% or less with respect to the total weight of, and is composed of a composition containing a component having a polyoxazolidone ring formed by mixing the main agent and the curing agent It is characterized by that.

In such a configuration, the isocyanate group in the isocyanate compound and the hydroxyl group in the polyol resin react to produce a urethane bond, and the excess isocyanate group reacts with the epoxy group in the epoxy resin to produce an oxazolidone ring. Further, the remaining epoxy groups react with each other to produce a cured epoxy resin. In this case, due to the presence of the oxazolidone ring product, the urethane product and the cured epoxy resin show good compatibility, and therefore, the flexibility of the urethane product and the liquid crystal resistance of the cured epoxy resin were combined. A liquid crystal sealing material excellent in adhesion, elasticity, and liquid crystal resistance can be realized. Moreover, since the generation of the urethane bond, the generation of the oxazolidone ring, and the curing of the epoxy resin are performed with a good balance, it is possible to achieve both peel strength and liquid crystal resistance. Moreover, in the composition which mixed the main ingredient and the hardening | curing agent, it becomes possible to implement | achieve the viscosity etc. excellent in workability | operativity.

  The ratio of the total weight of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, and the phenol novolac type epoxy resin to the total weight of the epoxy resin contained in the main agent is approximately 70% or more. It is characterized by.

  According to such a configuration, since the sealing material for a liquid crystal panel is constituted by the aromatic epoxy resin having higher chemical resistance than the aliphatic epoxy resin, it is possible to realize better liquid crystal resistance.

  Moreover, the number of carbon atoms contained in the repeating unit constituting the polylactone is 6 or less.

The main agent further includes an epoxy resin curing agent, and the epoxy resin curing agent is an imidazole compound. According to this configuration, curing of the epoxy resin is promoted. Therefore, when a liquid crystal panel is manufactured using this liquid crystal panel sealing material, mass productivity can be improved.

  The liquid crystal panel according to claim 5 is a liquid crystal panel having a configuration in which liquid crystal sandwiched between a pair of substrates is sealed with a liquid crystal panel seal material, wherein the liquid crystal panel seal material is It is a sealing material for liquid crystal panels as described in any one of 1-4.

  According to such a configuration, it is possible to achieve good peel strength and liquid crystal resistance in the sealing material for liquid crystal panels as described above, so that reliability and mass productivity can be improved.

  According to the sealing material for a liquid crystal panel according to the present invention, it is possible to realize a sealing material for a liquid crystal panel which is excellent in peel strength and liquid crystal resistance and excellent in workability. By using such a liquid crystal panel sealing material, it is possible to improve the reliability and mass productivity of the liquid crystal panel formed of a plastic substrate.

  Exemplary embodiments of a sealing material for a liquid crystal panel and a liquid crystal panel using the same according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
FIG. 1 is a schematic cross-sectional view showing a configuration of a liquid crystal panel according to the present invention. 2 and 3 are schematic cross-sectional views showing the detailed configuration of the substrate of the liquid crystal panel of FIG. As shown in FIG. 1, the liquid crystal panel 110 has a configuration in which a liquid crystal layer 102 is sandwiched between a pair of substrates 100 arranged to face each other.

For example, as shown in FIG. 2, the substrate 100 has a gas barrier layer 202 formed on the front and back surfaces of a plastic base material 201 having flexibility, and an SiO ₂ layer 203 and a transparent electrode 204 on the surface of one gas barrier layer 202. Are sequentially stacked. As another configuration example of the substrate 100, as shown in FIG. 3, the hard coat layer 300 may be formed on the front and back surfaces of the plastic substrate 201, and then the same configuration as that in FIG. 2 may be formed.

  The plastic substrate 201 is made of, for example, polycarbonate, modified acrylic resin, polymethacrylic resin, polyethersulfone, polyethylene terephthalate, norbornene resin, and the thickness thereof is about 50 μm to 250 μm. The transparent electrode 204 is made of a conductive film such as an ITO film. The gas barrier layer 202 and the hard coat layer 300 have the same configuration as that conventionally used.

  As shown in FIG. 1, in the liquid crystal panel 110, the substrate 100 shown in FIG. 2 or 3 is arranged between the substrates 100 with the surface on which the transparent electrode 204 is formed facing each other with a predetermined interval. Liquid crystal layer 102 is formed by filling the space with liquid crystal. Although the configuration of the liquid crystal layer 102 is not particularly limited, for example, here, the liquid crystal layer 102 is configured by a sparrow isotropic nematic liquid crystal.

  A sealing material 101 is disposed on the peripheral portions of both substrates 100 so as to surround the liquid crystal layer 102, and the liquid crystal layer 102 is sealed. Thereby, the configuration of the liquid crystal panel 110 in which the liquid crystal layer 102 is sealed between the pair of substrates 100 is realized.

  The sealing material 101 is composed of a two-component mixed composition prepared by mixing a main agent and a curing agent. Specifically, the sealing material 101 is made of a composition obtained by mixing an epoxy resin, an epoxy resin curing agent, a polyol resin and an inorganic filler and a curing agent containing an isocyanate compound and a silane coupling agent. Composed.

  The composition constituting the sealing material 101 is obtained by the following reaction. First, by mixing the main component containing each of the above components and a curing agent, a state in which a polyol resin, which is a precursor of a urethane resin, and an isocyanate compound coexist and a state in which an epoxy resin coexists is realized. In such a state, as shown in FIG. 4, the isocyanate group in the isocyanate compound and the hydroxyl group in the polyol resin react to generate a urethane bond.

  Further, following the reaction of FIG. 4, as shown in FIG. 5, the epoxy group in the epoxy resin reacts with the excess isocyanate group to form a polyoxazolidone ring. Further subsequently, the epoxy groups in the epoxy resin that have not reacted with the isocyanate groups react with each other and harden over time to produce a cured epoxy resin.

  As a result of the above three reactions, a component having a urethane bond (hereinafter referred to as a urethane resin component), a component having an oxazolidone ring (hereinafter referred to as an oxazolidone ring component), and a cured epoxy resin component are mixed. Thus, the sealing material 101 is constituted by this composition. Here, in such a composition, since there is an oxazolidone ring component, conventionally, it is a urethane resin component and an epoxy resin cured product component that have poor compatibility and cause phase separation, but the polyoxazolidone ring component has good compatibility. Is realized. Therefore, in such a composition, phase separation between the urethane resin component and the cured epoxy resin component does not occur.

  Thus, in the sealing material 101 composed of the composition containing the urethane resin component and the cured epoxy resin component in a good mixed state, good liquid crystal resistance is realized by the cured epoxy resin component, and it is flexible. Good flexibility is realized by the urethane resin component and the polyoxazolidone ring component having the property (flexibility). And in this sealing material 101, the characteristic excellent in elasticity, moisture resistance, heat resistance, and peeling strength is realizable.

  Therefore, in the liquid crystal panel 110 of FIG. 1, the sealing material 101 can be prevented from being deteriorated (specifically, swelling or the like) due to the liquid crystal, and is flexible even if the substrate 100 is deformed such as bending. Since 101 adapts to the substrate deformation, the sealing material 101 does not peel off due to the substrate deformation.

  Here, the epoxy resin contained in the main agent is preferably an aromatic epoxy resin such as bisphenol A type, bisphenol F type, and phenol novolac type epoxy resin. Since the aromatic epoxy resin is more excellent in chemical resistance than the aliphatic epoxy resin, the sealing material 101 having higher liquid crystal resistance can be realized by using the aromatic epoxy resin.

  Further, the epoxy resin may be composed of one kind of compound or may contain a plurality of kinds of compounds. When the epoxy resin includes a plurality of types of compounds, it is preferable that the aromatic epoxy resin is included at a ratio of approximately 70% or more with respect to the total weight of the epoxy resin. Thereby, the liquid crystal resistance is improved.

  When the molecular weight of the polyol resin contained in the main agent is small, the liquid crystal resistance is improved, but the peel strength is lowered. Therefore, in order to satisfy the balance between the liquid crystal resistance and the peel strength, it is preferable to use a polyol resin having a relatively large molecular weight. Specifically, it is preferable to use a polyol resin having a molecular weight (here, a weight average molecular weight) of about 1000 or more, more preferably about 2000 or more.

  Also, a polyol resin having a high hydrophilicity such as polyalkylene glycol improves the liquid crystal resistance but decreases the peel strength. Therefore, a polyol resin having a polarity capable of satisfying a good balance between liquid crystal resistance and peel strength is used. Specifically, except for hydrophilic ones such as polyalkylene glycols, medium-polar polyol resins such as polyester polyols and polylactones are used.

  In addition, since the number of carbon atoms in the polyol resin affects the liquid crystal resistance and the peel strength, a polyol resin having a carbon atom number that can satisfy a good balance between the liquid crystal resistance and the peel strength is used. For example, when a polyester polyol is used as the polyol resin, the number of carbon atoms contained in at least one of the dibasic acid component and the glycol component constituting the polyester polyol is preferably 6 or less. When polylactone is used, the number of carbon atoms contained in the repeating unit is preferably 6 or less.

  On the other hand, with respect to the mixing ratio of the epoxy resin, polyol resin, and isocyanate compound, if the polyol resin is large, the reaction of FIG. 4 is promoted, so the number of unreacted isocyanate groups decreases, and therefore the reaction of FIG. 5 does not proceed. The remaining epoxy group reacts alone to accelerate the curing of the epoxy resin. Therefore, the composition obtained in this case has a high hardness, and therefore, the adhesion of the sealing material 101 to the substrate 100 in the liquid crystal panel 110 of FIG. 1 is lowered, and sufficient peel strength cannot be realized. On the other hand, if the amount of the polyol resin is too small, the reaction shown in FIG. 5 is promoted so that good peel strength can be realized, but sufficient liquid crystal resistance cannot be realized.

  Therefore, an epoxy resin, a polyol resin, and an isocyanate compound are mixed in a ratio that can satisfy a good balance between liquid crystal resistance and peel strength. Specifically, here, when the total weight of the epoxy resin and the polyol resin in the main agent is 100%, the weight ratio of the epoxy resin is about 30 to 70%. Further, the number of moles of isocyanate groups in the isocyanate compound contained in the curing agent is approximately three times or more the number of moles of hydroxyl groups in the polyol resin contained in the main agent. By adopting such a configuration, it becomes possible to proceed the reaction of FIGS. 4 and 5 and the curing reaction of the epoxy resin with a good balance, and thus the sealing material 101 that satisfies both the liquid crystal resistance and the peel strength is provided. can get.

As the epoxy resin curing agent contained in the main agent, a general curing catalyst can be used. For example, it is preferable to use an epoxy resin curing agent composed of an imidazole compound, a tertiary amine, dicyandiamide, a BF ₃ complex salt, a phenol resin, or the like, and particularly, an epoxy resin curing agent composed of an imidazole compound. Furthermore, although the case where the main agent contains an epoxy resin curing agent is illustrated here, the epoxy resin curing agent may be used as necessary.

  Such an epoxy resin curing agent takes into consideration the effects on workability due to acceleration of curing of the epoxy resin and the characteristics of the liquid crystal panel 100 (see FIG. 1) (for example, electrical reliability such as voltage holding ratio and current consumption value). Then, use amount is set appropriately. For example, when the total weight of the epoxy resin is 100%, the weight of the epoxy resin curing agent is about 0.5% or more, preferably about 1 to 25% (that is, about 0.5% with respect to 100 parts by weight of the epoxy resin). Part or more, preferably about 1 to 25 parts by weight).

  As the inorganic filler (filler) contained in the main agent, for example, silica, amorphous silica, glass fiber, carbonates of various metals, sulfates, alumina, titanium oxide and the like are used. Further, anisotropic conductive particles may be used in order to conduct with the transparent electrode 204 (see FIG. 2 or 3) of the substrate 100 in FIG.

  The ratio of the inorganic filler in the main agent is such that the weight of the inorganic filler is about 15% to about 30% when the total weight of the main agent and the curing agent is 100%. When the ratio of the inorganic filler in the total weight of the main agent and the curing agent is lower than about 15%, the viscosity of the mixture of the main agent and the curing agent (that is, the sealing material 101 before curing) becomes low. Here, when the liquid crystal panel 110 of FIG. 1 is manufactured, this mixture is disposed on the peripheral edge of the substrate 100 by printing coating. Therefore, if the viscosity of the mixture is low, the mixture flows from above the substrate 100 after printing coating. For this reason, it becomes difficult to manufacture the liquid crystal panel 100. Further, when the ratio of the inorganic filler in the total weight of the main agent and the curing agent is higher than about 30%, the viscosity of the mixture of the main agent and the curing agent becomes high, so that it is difficult to perform printing coating on the substrate 100, Therefore, it becomes difficult to manufacture the liquid crystal panel 100.

  The silane coupling agent in the curing agent serves to increase the adhesion at the interface between the sealing material 101 and the substrate 100 in FIG. The constituent material of the silane coupling agent is not particularly limited. For example, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxy A silane coupling agent is composed of silane or the like.

  For example, the amount of the silane coupling agent used is about 0.5% or more and about 5% or less, preferably about 0.5 to 3%, more preferably 0 when the total weight of the main agent and the curing agent is 100%. About 5 to 1% (that is, about 0.5 to 5 parts by weight, preferably about 0.5 to 3 parts by weight, more preferably 0.5 to 1 part by weight based on 100 parts by weight of the main agent and the curing agent) Part by weight).

  With this configuration, the adhesion of the sealing material 101 to the substrate 100 is improved, and it is possible to prevent moisture and the like from entering the liquid crystal panel 110 from the outside. If the amount of the silane coupling agent used is less than the above range, sufficient adhesion cannot be realized between the sealing material 101 and the substrate 100, and if it is more than the above range, workability is improved. This is not preferable.

  Furthermore, the main agent and the curing agent of the sealing material 101 may include components other than those described above. For example, you may add the reaction catalyst of an isocyanate compound as needed. As the reaction catalyst for the isocyanate compound, organometallic compounds such as tertiary amines and organotin compounds can be used. The amount of the reaction catalyst used is about 0.3% or more, preferably about 0.5 to 10% when the total weight of the isocyanate compound is 100% (that is, about 0.1 to 100 parts by weight of the isocyanate compound). 3 parts by weight or more, preferably about 0.5 to 10 parts by weight).

  As described above, according to the liquid crystal panel 110 of the present embodiment, the sealing material 101 has good flexibility derived from the urethane resin component and the oxazolidone ring component and good liquid crystal resistance derived from the epoxy cured product component. Thus, excellent adhesion, elasticity, and liquid crystal resistance are realized in the sealing material 101. Therefore, it is possible to realize good reliability and characteristics in the liquid crystal panel 110.

  Further, since the trifunctional thiol compound that causes a problem of odor as shown in the conventional example is not used for the sealing material 101, the operator is not uncomfortable, and therefore, the workability is improved and the high temperature is high. Therefore, the curing time of the sealing material 101 can be shortened. Therefore, the liquid crystal panel 110 can achieve good mass productivity.

  FIG. 6 is a diagram for explaining the composition constituting the sealing material 101 of FIG. 1 in the examples. In an Example, as shown in FIG. 6, the sealing material 101 is comprised with the composition of Examples 1-5 and Comparative Examples 1-10. Details of Examples 1 to 5 and Comparative Examples 1 to 10 will be described below.

Example 1
50 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) 35 g of polyester polyol having a trifunctional molecular weight of 3000 (“Kuraray Polyol F-3010” manufactured by Kuraray Co., Ltd.) and bifunctional having a molecular weight of 4000 15 g of polyester polyol (“Kuraray polyol P-4010” manufactured by Kuraray Co., Ltd.), 30 g of silica powder (“UA-5105” manufactured by Showa Denko KK) as an inorganic filler (filler), and amorphous silica (Nippon Aerosil Industry Co., Ltd.) A product obtained by mixing 17 g of “R-972” manufactured by 3 rolls (total weight 147 g) was used as a main agent.

  Also, 88 g of HDI TMP adduct type, 75% ethyl acetate solution of trifunctional isocyanate (“Coronate HL” manufactured by Nippon Polyurethane Industry Co., Ltd.) and 12 g of silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g of this mixture was prepared as a curing agent, and 73.5 g of this mixture was used so that the weight ratio of the main agent / curing agent was 2: 1.

(Example 2)
30 g of polyfunctional phenol novolac type epoxy resin (“Epicoat 152” manufactured by Japan Epoxy Resin Co., Ltd.), 48 g of polyester polyol having a molecular weight of 3000 and trifunctional (“Kuraray Polyol F-3010” manufactured by Kuraray Co., Ltd.) 22 g of polyester polyol (“Kuraray polyol P-4010” manufactured by Kuraray Co., Ltd.), 40 g of silica powder (“UA-5105” manufactured by Showa Denko KK) as an inorganic filler (filler), amorphous silica (manufactured by Nippon Aerosil Kogyo Co., Ltd.) "R-972") 10 g mixed with 3 rolls (total weight 150 g) was used as the main agent.

  Further, 67 g of a mixture of HDI trimer type, trifunctional isocyanate (“Coronate HX” manufactured by Nippon Polyurethane Industry Co., Ltd.) 55 g, and silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) 12 g is used as a curing agent. Prepared. And 50 g of this mixture was used so that the blending weight ratio of the main agent / curing agent was 3: 1. In this case, the ratio (wt%) between the epoxy resin and the polyol resin in the main agent is epoxy resin / polyol resin = 32/68 wt%.

(Example 3)
70 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) 21 g of polyester polyol with a trifunctional molecular weight of 3000 (“Placcel L330AL” manufactured by Daicel Industrial Co., Ltd.) ("Placcel 240" manufactured by Daicel Chemical Industries, Ltd.) 9g, 70g of silica powder ("UA-5105" manufactured by Showa Denko KK) as the inorganic filler (filler), and amorphous silica ("R manufactured by Nippon Aerosil Industrial Co., Ltd.") -972 ") 5 g mixed with 3 rolls (total weight 175 g) was used as the main agent.

  Also, 88 g of 75% ethyl acetate solution of trifunctional isocyanate which is a polyfunctional alcohol adduct of HDI (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and a silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) ) 100 g of a mixture with 12 g was prepared as a curing agent. Then, 87.5 g of this mixture was used so that the weight ratio of the main agent / curing agent was 2: 1. In this case, the ratio (wt%) between the epoxy resin and the polyol resin in the main agent is epoxy resin / polyol resin = 68/32 wt%.

Example 4
56 g of bifunctional bisphenol F-type epoxy resin (“Epicoat 807” manufactured by Japan Epoxy Resin Co., Ltd.), 56 g of trifunctional polyester polyol having a molecular weight of 3000 (“Kuraray Polyol F-3010” manufactured by Kuraray Co., Ltd.), bifunctional and having a molecular weight of 4000 28 g of polyester polyol (“Kuraray Polyol P-4010” manufactured by Kuraray Co., Ltd.), 28 g of silica powder (“UA-5105” manufactured by Showa Denko Co., Ltd.) as an inorganic filler (filler), and amorphous silica (Nippon Aerosil Industry Co., Ltd.) A product obtained by mixing 21 g of “R-972” manufactured by 3 rolls (total weight 189 g) was used as a main agent.

  Also, 88 g of 75% ethyl acetate solution of trifunctional isocyanate which is a polyfunctional alcohol adduct of HDI (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and a silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) ) 100 g of a mixture with 12 g was prepared as a curing agent. And 94.5 g of this mixture was used so that the blending weight ratio of the main agent / curing agent was 2: 1.

(Example 5)
50 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.), 50 g of bifunctional and molecular weight 2000 polyester polyol (“Kuraray Polyol P-2010” manufactured by Kuraray Co., Ltd.), inorganic filler (filler) ) 30 g of silica powder (“UA-5105” manufactured by Showa Denko KK) and 17 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Kogyo Co., Ltd.) with three rolls (total weight 147 g) The main agent was used.

  Also, 88 g of HDI TMP adduct type, 75% ethyl acetate solution of trifunctional isocyanate (“Coronate HL” manufactured by Nippon Polyurethane Industry Co., Ltd.) and 12 g of silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g of the above mixture was prepared as a curing agent. And 73.5 g of this mixture was used so that the blending weight ratio of the main agent / curing agent was 2: 1.

(Comparative Example 1)
18.8 g of dimer acid-modified epoxy resin (“Epicoat 872” manufactured by Japan Epoxy Resin Co., Ltd.), 18.7 g of a polyalkyl glycol both-end epoxy compound (“EX-810” manufactured by Nagase ChemteX Corporation), and a trifunctional molecular weight of 3000 Polyester polyol (Kuraray Co., Ltd. “Kuraray Polyol F-3010”) 35 g, bifunctional polyester polyol 4000 molecular weight (Kuraray Co., Ltd. “Kuraray Polyol P-4010”), talc powder as an inorganic filler (filler) (LMP-100 manufactured by Nippon Talc Co., Ltd.) 40 g and 5 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Kogyo Co., Ltd.) mixed with three rolls (total weight 132.5 g) as the main agent . Moreover, 66.3 g of the same curing agent as in Example 1 was used as the curing agent. In this case, the blending weight ratio of the main agent / curing agent is 2: 1.

(Comparative Example 2)
100 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.), 4 g of epoxy curing agent (“Curesol C17” manufactured by Shikoku Kasei Kogyo Co., Ltd.), silica powder (Showa) 30 g of “UA-5105” manufactured by Denko Co., Ltd., 17 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Kogyo Co., Ltd.), and 12 g of silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) 163 g of a composition mixed with three rolls was prepared.

(Comparative Example 3)
35 g of a trifunctional polyester polyol having a molecular weight of 3000 (Kuraray Co., Ltd. “Kuraray Polyol F-3010”), 15 g of a bifunctional polyester polyol having a molecular weight of 4000 (Kuraray Co., Ltd. “Kuraray Polyol P-4010”), an inorganic filler ( As a filler), 15 g of silica powder (“UA-5105” manufactured by Showa Denko KK) and 8 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Kogyo Co., Ltd.) are mixed with three rolls (total weight 73 g). The main agent was used. The curing agent used was 36.5 g of the same curing agent as in Example 1. In this case, the blending weight ratio of the main agent / curing agent is 2: 1.

(Comparative Example 4)
25 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.), 53 g of polycaprolactone triol having a molecular weight of 3000 (“Placcel L330AL” manufactured by Daicel Chemical Industries, Ltd.), polyester polycaprolactone diol having a molecular weight of 4000 ( 22 g of Daicel Chemical Industries, Ltd. “Placcel 240”, 30 g of silica powder (“UA-5105”, Showa Denko Co., Ltd.) as an inorganic filler (filler) and amorphous silica (“R-972, manufactured by Nippon Aerosil Kogyo Co., Ltd.) )) 17 g mixed with 3 rolls (total weight 147 g) was used as the main agent. Further, as the curing agent, 73.5 g of the same curing agent as in Example 1 was used. In this case, the blending weight ratio of the main agent / curing agent is 2: 1, and the ratio (wt%) of the epoxy resin and the polyol resin in the main agent is epoxy resin / polyol resin = 25/75 wt%.

(Comparative Example 5)
75g of bifunctional bisphenol A type epoxy resin ("Epicoat 828" manufactured by Japan Epoxy Resin Co., Ltd.) 17.5g of trifunctional polyester polyol having a molecular weight of 3000 ("Kuraray Polyol F-3010" manufactured by Kuraray Co., Ltd.) Polyester polyol of molecular weight 4000 (Kuraray Co., Ltd. “Kuraray Polyol P-4010” 7.5 g, inorganic filler (filler) 30 g of silica powder (Showa Denko Co., Ltd. “UA-5105”) and amorphous silica (Nippon Aerosil) “R-972” manufactured by Kogyo Co., Ltd.) was mixed with 17 g of 3 rolls (total weight 147 g), and 77.5 g of the same curing agent as in Example 1 was used as the curing agent. In this case, the compounding weight ratio of the main agent / curing agent is 2: 1, and the epoxy resin and the polyol in the main agent are mixed. Ratio of Le resin (wt%) is an epoxy resin / polyol resin = 75/25 wt%.

(Comparative Example 6)
The same main agent (total weight 147 g) as in Example 1 was used. In addition, 88 g of a 75% ethyl acetate solution of trifunctional isocyanate which is a polyfunctional alcohol adduct of TDI (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and a silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) ) 100 g of a mixture with 12 g was prepared as a curing agent, 29.4 g of which was used. In this case, the blending weight ratio of the main agent / curing agent is 5: 1, and the number of moles of isocyanate groups is 1.9, which is smaller than three times the number of moles of hydroxyl groups.

(Comparative Example 7)
50 g of a bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.), a polyester polyol having 9 repeating units of glycol components and a molecular weight of 2000 (“Kuraray Polyol O-2010 manufactured by Kuraray Co., Ltd.”) 50 g, 40 g of silica powder (“UA-5105” manufactured by Showa Denko KK) as an inorganic filler (filler) and 15 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Kogyo Co., Ltd.) are mixed in three rolls. The product (total weight 155 g) was used as the main agent. The curing agent used was 77.5 g of the same curing agent as in Example 1. In this case, the blending weight ratio of the main agent / curing agent is 2: 1.

(Comparative Example 8)
50 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.), 50 g of polyester polyol (“Kuraray Polyol P-510” manufactured by Kuraray Co., Ltd.), silica powder as an inorganic filler (filler) 30 g of “UA-5105” manufactured by Showa Denko Co., Ltd. and 17 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Industrial Co., Ltd.) mixed with three rolls (total weight 147 g) were used as the main agent. The curing agent used was 98 g of the same curing agent as in Example 1. In this case, the blending weight ratio of the main agent / curing agent was 3: 2.

(Comparative Example 9)
50 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) 35 g of polyester polyol having a molecular weight of 3000 and trifunctional (“Kuraray Polyol F-3010” manufactured by Kuraray Co., Ltd.) Polyester polyol (Kuraray Co., Ltd. “Kuraray Polyol P-4010” 15 g, inorganic filler (filler) 20 g of silica powder (Showa Denko “UA-5105”) and amorphous silica (Nippon Aerosil Kogyo Co., Ltd.) “R-972”) 5 g mixed with 3 rolls (total weight 125 g) was used as a main agent, and the same curing agent 62.5 g as in Example 1 was used. / The mixing weight ratio of the curing agent is 2: 1, and the inorganic filler (filler) is the main agent and the curing agent. The percentage of in a total weight is 13.3wt%.

(Comparative Example 10)
50 g of bifunctional bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) 35 g of polyester polyol having a molecular weight of 3000 and trifunctional (“Kuraray Polyol F-3010” manufactured by Kuraray Co., Ltd.) Polyester polyol (Kuraray Co., Ltd. “Kuraray Polyol P-4010” 15 g, silica powder (Showa Denko “UA-5105”) 50 g as an inorganic filler (filler) and amorphous silica (Nippon Aerosil Kogyo Co., Ltd.) “R-972”) 40 g mixed with 3 rolls (total weight 190 g) was used as the main agent, and the same curing agent 95 g as in Example 1 was used. The compounding weight ratio of the agent is 2: 1, and the inorganic filler (filler) is composed of the main agent and the curing agent. Percentage in the total weight is 31.6wt%.

A sealing material 101 is composed of the compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 10, and the liquid crystal cell has the same configuration as the liquid crystal panel 110 in FIG. 1 (hereinafter referred to as the liquid crystal cell 110). Was made. Here, the sealing material 101 is applied to the peripheral portion of the substrate 100 using a screen printing method, a spacer is provided, the pair of substrates 100 are arranged to face each other, and the pressure is applied, for example, at 0.55 kgf / cm ^2. Firing was performed at 130 ° C. for 4 hours.

  And the peeling test was done about each of the liquid crystal cell 110 provided with the sealing material 101 which consists of a composition of Examples 1-5 and Comparative Examples 1-10 obtained as mentioned above. In this peeling test, the case where peeling occurs at the interface between the substrate 100 and the sealing material 101 is evaluated as poor, and the case where peeling does not occur at the interface between the substrate 100 and the sealing material 101 is evaluated as good. Here, when the peel strength is good, as shown in FIG. 7, peeling does not occur at the interface between the substrate 100 and the sealing material 101, but peeling (breakage) occurs at other portions. .

  Further, for each of the liquid crystal cells 110 corresponding to Examples 1 to 5 and Comparative Examples 1 to 10 obtained as described above, the liquid crystal resistance evaluation test of the sealing material 101 was performed. Here, based on the temporal change of the driving voltage of the manufactured liquid crystal cell 110, the temporal change of the panel thickness in the vicinity of the sealing material 101, and the temporal change of the conduction state in the upper and lower transparent electrodes 204 (see FIG. 2 or FIG. 3). The liquid crystallinity was evaluated, and those having a small change with time were evaluated as good, and those having a large change were evaluated as defective. Such a change with time is caused, for example, by the sealing material 101 being swollen by the liquid crystal of the liquid crystal layer 102.

  The results of the peel test and the liquid crystal resistance evaluation test of the liquid crystal cell 110 as described above are shown in FIG. As shown in FIG. 8, in the liquid crystal cell 110 corresponding to Examples 1 to 5, good liquid crystal resistance and peel strength were shown. On the other hand, in the liquid crystal cell 110 corresponding to Comparative Examples 1 to 8, both the liquid crystal resistance and the peel strength could not be satisfied.

  Further, when the liquid crystal cell 110 is manufactured using the sealing material 101 made of the composition of Comparative Example 9, since the viscosity of the composition is as low as 100 dPas or less, the composition is applied to the substrate 100 by a screen printing method. Even then, it will flow from the substrate 100 thereafter. Therefore, the liquid crystal cell 110 could not be manufactured. Further, when the liquid crystal cell 110 is manufactured using the sealing material 101 made of the composition of Comparative Example 10, since the viscosity of the composition is as high as 500 dPas or more, the composition is applied to the substrate 100 by a screen printing method. Can not do it. Therefore, the liquid crystal cell 110 could not be manufactured.

  Furthermore, in Example 6 and Example 7, and Comparative Example 11 and Comparative Example 12, the firing conditions, peel strength, and adhesive strength of the sealing material 101 were examined.

(Example 6 and Example 7)
Here, as Example 6 and Example 7, the sealing material 101 was composed of the same composition as in Example 1 above.

(Comparative Example 11 and Comparative Example 12)
About the comparative example 11 and the comparative example 12, the following compositions were prepared and the sealing material 101 was comprised. 20 g of polyoxypropylene glycol (“PP-1000” manufactured by Sanyo Chemical Co., Ltd.), 80 g of bisphenol A type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent 190), γ-glycidoxypropyltrimethoxysilane (Tisso Corporation) 1 g of company-made “Sila Ace S-510”), 80 g of titanium oxide (“CR-EL” manufactured by Ishihara Sangyo Co., Ltd.) and 3 g of amorphous silica (“R-972” manufactured by Nippon Aerosil Co., Ltd.) as inorganic fillers What was mixed by the roll was made into the main ingredient.

  In addition, 80 g of trifunctional thiol compound (“THEIC-BMPA” manufactured by Sakai Chemical Co., Ltd., active hydrogen equivalent 78), 20 g of urethane type polyisocyanate (“Duranate D-101” manufactured by Asahi Kasei Co., Ltd.), trisdimethylaminomethylphenol Yakuzo Co., Ltd. “TAP”) 0.5 g, Titanium oxide (“Ishihara Sangyo Co., Ltd.“ CR-EL ”) 80 g as inorganic filler, and amorphous silica (Japan Aerosil Co., Ltd.“ R-972 ”) 5 g Was mixed with three rolls as a curing agent. And this main ingredient and the hardening | curing agent were mixed and the composition was prepared. In this case, the blending weight ratio of the main agent / curing agent is 1: 1.

  In Example 6 and Example 7, and Comparative Example 11 and Comparative Example 12, the sealing material 101 is composed of the composition prepared as described above, and the same method as in Example 1 above is used. A liquid crystal cell 110 having the configuration shown in FIG. Here, a plastic substrate 201 (see FIG. 2 or 3) made of polycarbonate (“HD200-60B” manufactured by Teijin Ltd.) is used for the substrate 100 of the liquid crystal cell 110. In Example 6 and Comparative Example 11, the plastic substrate 201 is thick. A liquid crystal cell 110 having a thickness of about 0.2 mm was produced. In Example 7 and Comparative Example 12, a liquid crystal cell 110 having a thickness of about 0.12 mm was produced.

  Further, here, the sealing material 101 was fired under the following three conditions to manufacture the liquid crystal cell 110. Specifically, the firing conditions were as follows: firing at 60 ° C. for 8 hours, further firing at 120 ° C. for 4 hours, firing at 110 ° C. for 11 hours, and firing at 130 ° C. for 4 hours.

  Subsequently, a peel test was performed on the liquid crystal cells 110 of Examples 6 and 7 and Comparative Examples 11 and 12 produced under each firing condition by the same method as in Example 1 above. . The results are shown in FIG. 9 and FIG.

  9 and 10 are diagrams showing peel strength and adhesive strength in the liquid crystal cells 110 of Examples 6 and 7 and Comparative Examples 11 and 12 produced under each firing condition. As shown in FIGS. 9 and 10, the liquid crystal cells 110 of Example 6 and Example 7 show better peel strength and adhesive strength than Comparative Examples 11 and 12 under any firing conditions. It was. In particular, in Example 6 and Example 7, good results can be obtained in baking at 130 ° C. for 4 hours, and a strong odorous trifunctional thiol compound such as Comparative Example 11 and Comparative Example 12 is used. Since the sealing material 101 is formed without using it, the mass productivity of the liquid crystal cell 110 was superior to that of Comparative Examples 11 and 12.

  The sealing material for a liquid crystal panel according to the present invention is useful as a sealing material for a liquid crystal panel that can realize good peeling strength and good liquid crystal resistance and is excellent in workability. In addition, a liquid crystal panel manufactured using such a liquid crystal panel sealing material is useful as a liquid crystal panel capable of realizing good reliability and mass productivity.

It is typical sectional drawing which shows the structure of the liquid crystal panel concerning embodiment of this invention. It is typical sectional drawing which shows the detailed structure of the board | substrate of the liquid crystal panel of FIG. It is typical sectional drawing which shows the detailed structure of the board | substrate of the liquid crystal panel of FIG. It is a figure which shows the production | generation reaction of a urethane bond. It is a figure which shows the production | generation reaction of a polyoxazolidone ring. It is a figure for demonstrating the composition which comprises the sealing material in Examples 1-5 and Comparative Examples 1-10. It is a figure for demonstrating the peeling test in Examples 1-5 and Comparative Examples 1-10. It is a figure which shows the result of the peeling test and liquid crystal resistance test in Examples 1-5 and Comparative Examples 1-10. It is a figure which shows the result of the peeling test of Examples 6 and 7 and Comparative Examples 11 and 12 on each baking conditions. It is a figure which shows the result of the peeling test of Examples 6 and 7 and Comparative Examples 11 and 12 on each baking conditions.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Substrate 101 Sealing material 102 Liquid crystal layer 110 Liquid crystal panel 201 Plastic base material 202 Gas barrier layer 203 SiO ₂ layer 204 Transparent electrode 300 Hard coat layer

Claims (5)

A sealing agent for a liquid crystal panel composed of a composition prepared by mixing a main agent and a curing agent,
The main agent includes an epoxy resin, a medium-polar polyol resin that is a precursor of a urethane resin , and an inorganic filler,
Wherein the curing agent is seen containing an isocyanate compound and a silane coupling agent which is a precursor of a urethane resin,
The ratio of the weight of the epoxy resin to the total weight of the epoxy resin and the polyol resin contained in the main agent is 32% or more and 68% or less,
The epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin and phenol novolac type epoxy resin,
The molecular weight of the polyol resin is 1000 or more,
The polyol resin is a polyester polyol or polylactone,
When the polyol resin is the polyester polyol, the number of carbon atoms contained in at least one of the dibasic acid component and the glycol component constituting the polyester polyol is 6 or less,
The number of moles of isocyanate groups in the isocyanate compound is at least three times the number of moles of hydroxyl groups in the polyol resin;
The ratio of the weight of the inorganic filler to the total weight of the main agent and the curing agent is 15% or more and 30% or less,
A sealing material for a liquid crystal panel , comprising a composition containing a component having a polyoxazolidone ring produced by mixing the main agent and the curing agent .   The total weight of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin and the phenol novolac type epoxy resin is 70% or more with respect to the total weight of the epoxy resin contained in the main agent. The sealing material for liquid crystal panels of Claim 1.   The sealing material for a liquid crystal panel according to claim 1 or 2, wherein the number of carbon atoms contained in the repeating unit constituting the polylactone is 6 or less.   The main agent further includes an epoxy resin curing agent,
  The said epoxy resin hardening | curing agent is an imidazole compound, The sealing material for liquid crystal panels as described in any one of Claims 1-3 characterized by the above-mentioned.   In a liquid crystal panel having a configuration in which a liquid crystal sandwiched between a pair of substrates is sealed with a sealing material for a liquid crystal panel,
  The said sealing material for liquid crystal panels is a sealing material for liquid crystal panels as described in any one of Claims 1-4, The liquid crystal panel characterized by the above-mentioned.

Images