JP2009168903A - Liquid crystal display and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display superior in adhesion between a liquid crystal panel and a protective base material, and superior in visibility. <P>SOLUTION: This liquid crystal display is provided by laminating (I) a layer formed of at least a cation polymerizing resin composition and (II) a protective layer on an image display part surface of the liquid crystal panel. The cation polymerizing resin composition is characterized by including (A) polyether polyol having three or more of hydroxyl groups, (B) a glycidyl group including compound and (C) a polymerization initiator. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal display that can be used as a display unit for various communication devices and home appliances.

  The liquid crystal display is used as a display unit of home appliances such as a liquid crystal television and information communication terminals such as a mobile phone, and the market is increasing. In particular, as the functionality of portable portable information communication terminals such as mobile phones has been improved, high-level fineness, vividness, and the like have been required for images displayed by them.

  A liquid crystal display used for a display unit such as a mobile phone is generally a liquid crystal display element sealed with a liquid crystal substance, a polarizing plate made of a protective film made of cellulose triacetate or the like and a polarizer, and other various functional films. And a protective substrate made of glass or plastic for the purpose of preventing damage to the liquid crystal panel due to external impact.

  The protective substrate is a state in which an air gap generally referred to as an air gap is secured between the liquid crystal panel and the protective substrate from the viewpoint of preventing the liquid crystal panel from being damaged by direct impact from the outside to the liquid crystal panel. It is often installed at.

  However, since the air layer composed of the air gap and the protective substrate have a large difference in refractive index, for example, in an environment with strong light such as outdoors, at the interface between the air layer and the protective substrate. It may cause light scattering. When the degree of scattering is large, the brightness of the image displayed on the liquid crystal display is lowered, and as a result, the visibility may be significantly lowered.

  As a method for solving the above-described problem, for example, a transparent resin filler made of, for example, a photopolymerization type acrylic resin is filled in a region provided between a liquid crystal display panel for displaying an image and a touch panel. A method is known, and it is known that a display device such as a liquid crystal display obtained by such a method can reduce a decrease in visibility due to an air gap (see, for example, Patent Document 1).

  However, since acrylic resin is a so-called radical polymerization type resin, before curing reaches a practically sufficient level due to, for example, the termination reaction between radicals or the deactivation of radicals due to the influence of oxygen in the atmosphere. May stop. When the curing reaction stops halfway, the uncured component has an adverse effect on the liquid crystal panel and the protective layer, and as a result, a liquid crystal display capable of displaying a high-quality and clear image cannot be obtained. There is.

  In addition, radical polymerization resin compositions generally proceed with a curing reaction while being irradiated with ultraviolet rays, etc., but the polymerization stops with the interruption of irradiation, so that curing can proceed sufficiently. It is necessary to continuously irradiate with ultraviolet rays.

  Therefore, when manufacturing a liquid crystal display, for example, after applying the radical polymerization resin composition on the surface of a transparent protective substrate and laminating a liquid crystal panel on the coating surface in advance, the transparent protective substrate Therefore, it is necessary to continuously irradiate the resin composition layer with ultraviolet rays. As the protective substrate, depending on the application, etc., there may be used a part of which a pattern or characters are printed in advance, and when irradiating ultraviolet rays through such a protective substrate. In addition, since the lower part of the pattern or the like is not sufficiently irradiated with ultraviolet rays, the degree of curing of the composition layer becomes uneven, and as a result, while the liquid crystal display is used for a long time, the protective substrate and the liquid crystal panel In some cases, the adhesion of the protective substrate was lowered, and the protective substrate was lifted or peeled off.

  Moreover, the method of continuously irradiating ultraviolet rays was not a preferable method from the viewpoint of improving the production efficiency of the liquid crystal display.

Japanese Patent Laid-Open No. 2004-77887

  The problem to be solved by the present invention is to provide a liquid crystal display having excellent adhesion between the liquid crystal panel and the protective substrate and excellent visibility.

  Further, the problem to be solved by the present invention is to provide a method for manufacturing a liquid crystal display excellent in visibility with dramatically improved production efficiency.

  In order to solve the problems of the radical polymerizable resin composition as described above, the present inventors, for example, apply a resin composition on the surface of a protective substrate and then directly irradiate the application surface with ultraviolet rays or the like. Then, it was considered important to find a resin composition capable of bonding a liquid crystal panel to the irradiated surface. If this method is possible, curing can proceed sufficiently even when a protective substrate on which a pattern or the like has been printed is used.

  First, the inventors examined using a resin composition of a polymerization curing reaction system different from the radical polymerizable resin composition, and in general, cationic polymerization in which the curing reaction proceeds without continuous irradiation with ultraviolet rays. It has been found that it is effective to use a resin resin composition. Then, when examining the solution of the subject of this invention, examination was advanced based on the cationic polymerization system resin composition.

  As the cationically polymerizable resin composition, for example, cationically polymerizable groups such as hydroxyl groups, alicyclic epoxy groups, glycidyl groups, oxetanyl groups, vinyl ethers, and propenyl ethers are known. Various combinations were considered.

  For example, when a composition containing a hydroxyl group-containing compound such as a polyol, an alicyclic epoxy group-containing compound generally known as a reactive diluent, and a polymerization initiator was examined, the curing reaction proceeded extremely rapidly in the composition. Therefore, after irradiating the composition applied to the surface of the protective substrate with ultraviolet rays, it was difficult to bond a liquid crystal panel to the irradiated surface.

  Thus, when various combinations, such as a cationic group and a reactive diluent, were examined, polyether polyol (A), a glycidyl group containing compound (B), and a polymerization initiator (C) having three or more hydroxyl groups. It has been found that a cationically polymerizable resin composition containing can impart excellent visibility and impact resistance to the liquid crystal display without impairing the sharpness of the image displayed on the liquid crystal display.

  That is, the present invention is a liquid crystal display in which a layer (I) formed using at least a cationic polymerizable resin composition and a protective layer (II) are laminated on the surface of an image display part of a liquid crystal panel, The present invention relates to a liquid crystal display wherein the cationic polymerizable resin composition contains a polyether polyol (A) having three or more hydroxyl groups, a glycidyl group-containing compound (B), and a polymerization initiator (C). Is.

  The present invention also provides cationic polymerization comprising a polyether polyol (A) having three or more hydroxyl groups, a glycidyl group-containing compound (B) and a polymerization initiator (C) on the surface of the image display portion of the liquid crystal panel. After applying the adhesive resin composition and irradiating the application surface with ultraviolet light, the glass substrate or plastic substrate constituting the protective layer (II) is bonded to the application surface, and then heated at 40 to 80 ° C. The present invention relates to a method for manufacturing a liquid crystal display.

  In addition, the present invention provides a polyether polyol (A) having three or more hydroxyl groups and a glycidyl group-containing compound (B) and polymerization initiation on the surface of the glass substrate or plastic substrate constituting the protective layer (II). After applying a cationic polymerizable resin composition containing the agent (C) and irradiating the coated surface with ultraviolet rays, the surface of the image display part of the liquid crystal panel is bonded to the coated surface, and then at 40 to 80 ° C. The present invention relates to a heating method for manufacturing a liquid crystal display.

  The liquid crystal display of the present invention maintains excellent sharpness of displayed images and is excellent in visibility and impact resistance, so that it can be used for, for example, a television receiver or a radio device. In particular, the liquid crystal display of the present invention has a practically sufficient level of visibility even outdoors, for example, and has excellent impact resistance that can withstand strong impacts such as dropping. The present invention can be applied to a display unit of a portable radio device such as a portable television receiver or a mobile phone terminal.

  The liquid crystal display of the present invention is a layer in which a layer (I) formed using at least a cationic polymerizable resin composition and a protective layer (II) are laminated on the image display unit surface of a liquid crystal panel, The cationic polymerizable resin composition contains a polyether polyol (A) having three or more hydroxyl groups, a glycidyl group-containing compound (B), and a polymerization initiator (C).

  Here, the liquid crystal display referred to in the present invention can adjust the transmission of light from a backlight or the like by adjusting the orientation of the liquid crystal material constituting the liquid crystal panel and display a desired image on the image display unit. For example, it is configured by a light source such as a backlight, a color filter, a liquid crystal panel, and at least a layer (I) and a layer (II) laminated on the surface thereof.

  The size and shape of the liquid crystal display of the present invention are not particularly limited, but good visibility can be maintained even when used outdoors, and good even when a strong impact is applied to the liquid crystal display due to falling etc. Therefore, the present invention can be suitably applied to a relatively small display such as a portable wireless device and a portable television receiver.

  First, the layer (I) laminated on the image display unit surface of the liquid crystal panel constituting the liquid crystal display and the cationic polymerizable resin composition constituting the layer will be described.

  The layer (I) is important for imparting excellent visibility and impact resistance to the liquid crystal display. Further, since the layer (I) has been cured relatively uniformly by a cationic polymerization reaction, the sharpness of the image displayed by the liquid crystal panel is not deteriorated.

  The layer (I) varies depending on the field in which the liquid crystal display is used, but preferably has a thickness of approximately 10 to 500 μm, preferably 100 to 500 μm, in order to make the liquid crystal display thin. .

  The layer (I) is a cation containing a polyether polyol (A) having three or more hydroxyl groups, a glycidyl group-containing compound (B), a polymerization initiator (C), and other additives as required. It can be formed using a polymerizable resin composition.

  The cationic polymerizable resin composition proceeds with cationic polymerization of the hydroxyl group of the polyether polyol (A) and the glycidyl group of the glycidyl group-containing compound (B) when irradiated with ultraviolet rays. However, since the cationic polymerization proceeds relatively slowly at room temperature, from the viewpoint of dramatically improving the rate of cationic polymerization and improving the production efficiency of the liquid crystal display of the present invention, It is preferable to heat at a temperature of about 40 to 80 ° C.

  The polyether polyol (A) having three or more hydroxyl groups has three or more hydroxyl groups that contribute to the reaction with the glycidyl group of the glycidyl group-containing compound (B). The number of hydroxyl groups is preferably approximately 30 or less, more preferably 3 to 20.

  As the polyether polyol (A), it is preferable to use those having a number average molecular weight in the range of 300 to 8000, and it is more preferable to use those having a number average molecular weight in the range of 300 to 2000. .

  Examples of the polyether polyol (A) having 3 or more hydroxyl groups include polyether polyols obtained by reacting an alkylene oxide with a reaction initiator having 3 or more active hydrogen-containing groups in the molecule, and hydroxyalkyl. A multi-branched polyether polyol obtained by ring-opening reaction of oxetane (a1) and monofunctional epoxy compound (a2) can be used.

  First, a polyether polyol obtained by reacting a reaction initiator having three or more active hydrogen-containing groups in the molecule with an alkylene oxide will be described.

  Examples of the reaction initiator that can be used for producing the polyether polyol include glycerin, trimethylolpropane, hexanetriol, triethanolamine, erythritol, arabitol, xylitol, ribitol, diglycerin, pentaerythritol, methylglucoside, sorbitol, A sucrose, a sucrose amine compound, etc. can be used, These may be used individually or may use 2 or more types together. As the reaction initiator, it is particularly preferable to use glycerin, trimethylolpropane or sorbitol.

  As said alkylene oxide, ethylene oxide, a propylene oxide, butylene oxide, tetrahydrofuran etc. can be used, for example, These may be used individually or may use 2 or more types together. Of these, it is preferable to use propylene oxide.

  Specific examples of the polyether polyol obtained by the reaction of the reaction initiator with alkylene oxide include, for example, a polyether obtained by reacting ethylene oxide or propylene oxide with a reaction initiator such as glycerin, trimethylolpropane, or sorbitol. It is preferable to use a polyol.

  Further, as the polyether polyol obtained by the reaction of the reaction initiator and the alkylene oxide, it is preferable to use one having a number average molecular weight in the range of 300 to 8000, particularly in the range of 300 to 2000. It is preferable to use one having

  Next, a multi-branched polyether polyol obtained by ring-opening reaction of a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2) that can be used as the polyether polyol (A) will be described. Here, “multi-branch” means a molecular structure in which a molecular chain is further branched into two or more at a point where the molecular chain is branched into two or more.

  As said hydroxyalkyl oxetane (a1), what has a structure represented by following General formula (1) can be used, for example.

(R ₁ in the general formula (1) represents a methylene group, an ethylene group or a propylene group, and R ₂ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxyalkyl group having 1 to 5 carbon atoms. Or a hydroxyalkyl group having 1 to 6 carbon atoms.)
Examples of the alkyl group having 1 to 8 carbon atoms that can constitute R ₂ in the general formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and a 2-ethylhexyl group. Is mentioned.

Examples of the alkoxyalkyl group having 1 to 5 carbon atoms that can constitute R ₂ in the general formula (1) include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a methoxyethyl group, and an ethoxyethyl group. And propoxyethyl group.

Examples of the hydroxyalkyl group having 1 to 6 carbon atoms that can constitute R ₂ in the general formula (1) include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.

As the hydroxyalkyl oxetane (a1), R ₁ in the general formula (1) is a methylene group from the viewpoint that the inertia radius is smaller, the viscosity of the multi-branched polyether polyol is low, and effective for liquefaction And R ₂ is preferably an alkyl group having 1 to 7 carbon atoms, among which 3-hydroxymethyl-3-ethyloxetane and 3-hydroxymethyl-3-methyloxetane are used. More preferably.

  As the monofunctional epoxy compound (a2) that undergoes a ring-opening polymerization reaction with the hydroxyalkyl oxetane (a1), for example, a compound represented by the following general formula (2) can be used.

(In general formula (2), R ₃ represents an organic residue.)
R ₃ in the formula (2) may be bonded to carbon forming an epoxy group via a divalent organic residue or the like to form a ring, and in the general formula (1) those exemplified as R ₂ and may be similar.

  More specifically, as the monofunctional epoxy compound (a2), olefin epoxide, glycidyl ether compound, glycidyl ester compound and the like can be used.

  The olefin epoxide is not particularly limited, and specific examples include propylene oxide, 1-butene oxide, 1-pentene oxide, 1-hexene oxide, 1,2-epoxyoctane, 1,2-epoxydodecane, and cyclohexene oxide. , Cyclooctene oxide, cyclododecene oxide, styrene oxide, fluoroalkyl epoxide having 1 to 18 fluorine atoms, and the like can be used.

  The glycidyl ether compound is not particularly limited, but specific examples include methyl glycidyl ether, ethyl glycidyl ether, n-propyl glycidyl ether, i-propyl glycidyl ether, n-butyl glycidyl ether, i-butyl glycidyl ether, n -Pentyl glycidyl ether, 2-ethylhexyl-glycidyl ether, undecyl glycidyl ether, hexadecyl glycidyl ether, aryl glycidyl ether, phenyl glycidyl ether, 2-methylphenyl glycidyl ether, 4-t-butylphenyl glycidyl ether, 4-nonylphenyl Glycidyl ether, 4-methoxyphenyl glycidyl ether, and fluoroalkyl glycidyl ether having 1 to 18 fluorine atoms It can be used.

  Although it does not specifically limit as said glycidyl ester compound, As a specific example, glycidyl acetate, glycidyl propionate, glycidyl butyrate, glycidyl methacrylate, glycidyl benzoate, etc. can be used.

  As the monofunctional epoxy compound (a2), it is preferable to use an olefin epoxide from the viewpoint that the multi-branched polyether polyol has a low viscosity and is effective for liquefaction. Among them, propylene oxide and 1-butene oxide are preferable. More preferably, 1-pentene oxide or 1-hexene oxide is used.

  The multi-branched polyether polyol can be produced, for example, by a ring-opening polymerization reaction between the hydroxyalkyl oxetane (a1) and the monofunctional epoxy compound (a2). Examples of such production methods include, but are not limited to, the following methods.

  (Method)

  The hydroxyalkyl oxetane (a1) and the monofunctional epoxy compound (a2) are converted into [hydroxyalkyloxetane (a1) / 1 functional epoxy compound (a2)] = 1/1 to 1/10, preferably on a molar basis. Are mixed in a ratio of 1/1 to 1/6, more preferably 1/1 to 1/3.

  The mixture obtained above and a peroxide-free organic solvent such as diethyl ether, di-i-propyl ether, di-n-butyl ether, di-i-butyl ether, di-t-butyl ether, t-amyl methyl ether , T-butyl methyl ether, cyclopentyl methyl ether or dioxolane, the mass ratio of [{(a1) + (a2)} / organic solvent] is 1/1 to 1/5, preferably 1 / 1.5 to A raw material solution is prepared by mixing and dissolving at a ratio of 1/4, more preferably 1 / 1.5-1 / 2.5.

  Next, the polymerization initiator or the organic solvent solution thereof is added for 0.1 to 1 hour, preferably 0.3 to 0.8 hour, more preferably 0.3 to 0.5 hour, and the temperature is -10 ° C to- The solution is added dropwise to the raw material solution cooled to 15 ° C. with stirring.

  The polymerization initiator is preferably 0.01 to 1.0 mol%, more preferably 0.03 to 0, based on the total molar amount of the hydroxyalkyl oxetane (a1) and the monofunctional epoxy compound (a2). 0.7 mol%, particularly preferably 0.05 to 0.5 mol%.

Any polymerization initiator can be used as long as there is no particular problem. For _{example, H 2 SO 4, HCl,} HBF 4, HPF 6, HSbF 6, HAsF 6, p- toluenesulfonic acid, Bronsted acids such as trifluoromethanesulfonic _{acid, BF 3, AlCl 3, TiCl} 4, SnCl 4 , etc. Lewis acid, triarylsulfonium-hexafluorophosphate, triarylsulfonium-antimonate, diaryliodonium-hexafluorophosphate, diaryliodonium-antimonate, N-benzylpyridinium-hexafluorophosphate, N-benzyl Onium salt compounds such as pyridinium-antimonate, triphenylcarbonium-tetrafluoroborate, triphenylcarbonium-hexafluorophosphate, triphenylcarbonium-hexaful Triphenylcarbonium salts such as oroantimonate, p-toluenesulfonyl chloride, methanesulfonyl chloride, trifluoromethanesulfonyl chloride, p-toluenesulfonic acid anhydride, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, p-toluene Examples include alkylating agents such as sulfonic acid methyl ester, p-toluenesulfonic acid ethyl ester, methanesulfonic acid methyl ester, trifluoromethanesulfonic acid methyl ester, and trifluoromethanesulfonic acid trimethylsilyl ester.

From the viewpoint of improving the reactivity, it is preferable to use HPF ₆ , HSbF ₆ , HAsF ₆ , triphenylcarbonium-hexafluorophosphate, and BF ₃ as the polymerization initiator, and among them, HPF ₆ , triphenylcarbohydrate. More preferably, nitro-hexafluorophosphate and BF ₃ are used.

  As the organic solvent when the polymerization initiator is used as an organic solvent solution, peroxide-free organic solvents such as diethyl ether, di-i-propyl ether, di-n-butyl ether, di-i-butyl ether, -T-Butyl ether, t-amyl methyl ether, t-butyl methyl ether, cyclopentyl methyl ether or dioxolane can be used.

  Moreover, when using the organic solvent solution of the said polymerization initiator, from a viewpoint of improving reactivity, the density | concentration of the polymerization initiator in the said solution is 1-90 mass%, Preferably it is 10-75 mass%, More preferably Is 25-65 mass%.

  After completion of the dropwise addition, the raw material solution containing the polymerization initiator is stirred until it reaches 25 ° C., then heated to the refluxing temperature, and the hydroxyalkyloxetane (a1) and monofunctional are added over 0.5 to 20 hours. A polymer solution is obtained by performing a polymerization reaction until most of the epoxy compound (a2) is converted into a multi-branched polyether polyol. The conversion rate of the hydroxyalkyl oxetane (a1) and the epoxy compound (a2) into a multi-branched polyether polyol is confirmed by using gas chromatography, a nuclear magnetic resonance apparatus, and an infrared absorption spectrometer. be able to.

  After completion of the ring-opening polymerization reaction, the polymerization initiator remaining in the obtained reaction solution is deactivated using an equivalent amount of an alkali hydroxide aqueous solution, sodium alkoxide, or potassium alkoxide. Then, after filtering the said reaction solution and extracting a multibranched polyether polyol using a solvent, a multibranched polyether polyol can be obtained by distilling off the organic solvent under reduced pressure.

  The specific structure of the multi-branched polyether polyol may include various structures obtained by subjecting a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2) to a ring-opening polymerization reaction.

  For example, a hydroxyalkyloxetane (a1) represented by the following general formula (1) and a monofunctional epoxy compound (a2) represented by the following general formula (2) are subjected to a ring-opening reaction. The following structural units are included: That is, the multi-branched polyether polyol can be composed of structural units appropriately selected from repeating units and terminal structural units represented by the following structure.

(R ₁ in the general formula (1) represents a methylene group, an ethylene group or a propylene group, and R ₂ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxyalkyl group having 1 to 5 carbon atoms. Or a hydroxyalkyl group having 1 to 6 carbon atoms.)

(In the general formula (2), R ₃ represents an organic residue. R ₃ may be bonded to carbon forming an epoxy group via a divalent organic residue or the like to form a ring. R ₃ may be a group selected from the example of R _2. )

  Here, the solid line portion of each of the structural units of OR1 to OR3, OE1, OE2, ER1, EE1, and EE2 indicates a single bond in the structural unit, and the broken line portion indicates a gap between the structural unit and other structural units. And a single bond forming an ether bond.

  The OR1 to OR3, OE1, and OE2 are structural units derived from the hydroxyalkyl oxetane (a1), of which OR1 to OR3 represent repeating units, and OE1 and OE2 are terminal structures of the multi-branched polyether polyol. Represents a unit.

  ER1, EE1, and EE2 are structural units derived from the monofunctional epoxy compound (a2), in which ER1 represents a repeating unit, and EE1 and EE2 represent terminal structural units of the multi-branched polyether polyol. To express.

  In the multi-branched polyether polyol, a continuous multi-branched structure can be formed by repeating units selected from the OR1 to OR3 and ER1. And the terminal structural unit selected from the said OE1, OE2, EE1, and EE2 can be provided at the terminal of the multi-branched structure. In addition, these repeating units and terminal structural units may exist in any configuration as long as there is no particular problem, and may exist in any proportion and amount. For example, the repeating unit and the terminal structural unit may be present at random, or OR1 to OR3 may constitute the central part of the molecular structure and have the terminal structural unit at the terminal.

  The multi-branched polyether polyol preferably has a primary hydroxyl group and a secondary hydroxyl group in its molecular structure. In particular, due to the secondary hydroxyl group, the curability of the cationic polymerizable resin composition used in the present invention and the adhesion to the substrate can be further improved.

  The molecular structure of the multi-branched polyether polyol has a three-dimensional structure such as a spherical shape or a dendritic shape due to the multi-branching. At this time, the hydroxyl group is presumed to exist facing the outside of the shape. Therefore, even when the reaction rate is lowered due to the presence of secondary hydroxyl groups, most of the hydroxyl groups present in the multi-branched polyether polyol can be sufficiently involved in the reaction, so that the cation used in the present invention It becomes possible to further improve the curability of the polymerizable resin composition and the adhesion to the substrate.

  Thus, from the viewpoint of further improving the curability of the cationic polymerizable resin composition used in the present invention and the adhesion to the substrate, the number of secondary hydroxyl groups in the multi-branched polyether polyol adhesive is high. It is preferably 20 to 70%, more preferably 25 to 60%, based on the total number of hydroxyl groups of the primary hydroxyl group (H1) and secondary hydroxyl group (H2) of the branched polyether polyol.

  The number average molecular weight (Mn) of the multi-branched polyether polyol is preferably one having a number average molecular weight of 1000 to 4000, more preferably 1300 to 3500.

  The hydroxyl value of the multi-branched polyether polyol is preferably 150 to 350 mg · KOH / g, more preferably 170 to 330 mg · KOH / g.

  A multi-branched polyether polyol having a number average molecular weight and a hydroxyl value within such a range is liquid at room temperature and exhibits good fluidity, so that it is blended with a glycidyl group-containing compound (B), an acid generator (C) and the like. The cationically polymerizable resin composition using the multi-branched polyether polyol is easy to apply to the surface of the image display part of the liquid crystal panel or a protective substrate, and has excellent wettability.

  The above-mentioned liquid means that it has fluidity at room temperature, and specifically, the viscosity by a BH type rotational viscometer is 100 Pa · s (25 ° C.) or less from the viewpoint of easy blending. State.

  Examples of the polyether polyol (A) include polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, urethane-modified polyether polyol, polyether ester copolymer polyol, and acrylonitrile and styrene monomer in various polyols. Polyether polyols obtained by graft polymerization of vinyl group-containing monomers (generally referred to as polymer polyols), and polyols in which polyurea is stably dispersed in various polyethers (generally referred to as PHD polyols. PHD is a polyharnsstoff dispersion. Can also be used. These may be used alone or in combination of two or more.

  Next, the glycidyl group-containing compound (B) used in the present invention will be described.

  The glycidyl group-containing compound (B) is important for sufficiently curing the cationic polymerization reaction with the hydroxyl group of the polyether polyol (A). In addition, when an appropriate open time is imparted to the cationic polymerizable resin composition used in the present invention and the composition is irradiated with ultraviolet rays or the like, the liquid crystal panel and the protective substrate can be bonded together. is important.

  Examples of the glycidyl group-containing compound (B) include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and polybutadiene diglycidyl. Ether, cyclohexanedimethanol diglycidyl ether, resorcinol diglycidyl ether, diglycidyl orthophthalate, trimethylolpropane polyglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, phenol novolac polyglycidyl ether, cresol novolac polyglycidyl ether, Biphenyl polyglycidyl ether, naphthalene polyglycol Sidyl ether, hydrogenated bisphenol diglycidyl ether, and the like can be used. Especially, it is preferable to use a diglycidyl ether compound as a compound which relieves the coating film internal stress by hardening shrinkage.

  Further, if necessary, for the polyglycidyl ether compound, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, ethylene oxide-added phenol glycidyl ether, p-tert-butylphenol glycidyl ether, ethylene oxide addition Monofunctional glycidyl ether compounds such as lauryl alcohol glycidyl ether, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane may be used in combination.

  Examples of the cationically polymerizable compound other than the glycidyl ether type epoxy compound that can be used in the present invention include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, limonene diepoxide, 2- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane and other compounds having a cyclohexene oxide group, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-{[(3-ethyloxetane-3-yl) methoxy ] Methyl} oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3- (cyclohexyloxy) methyloxetane, 1,3- Bis [(1-ethyl-3-oxetanyl) meth Oxetane such as cis] benzene, 4,4′-bis [(3-ethyl-3-oxetanyl) methoxy] biphenyl, 3-ethyl-3-{[(3- (triethoxysilyl) propoxy] methyl} oxetane, etc. Examples include a compound having a ring and a compound obtained by epoxidizing an oligomer having a vinyl group such as epoxidized polybutadiene.

  In the glycidyl group-containing compound (B), the mass ratio between the hydroxyl group of the polyether polyol (A) and the glycidyl group of the glycidyl group-containing compound (B) is [hydroxyl group of (A) / (B). Is preferably used at a ratio of 0.9 or more, more preferably at a ratio of 1 to 3. By using the glycidyl group-containing compound (B) in the above ratio, the temperature at which the cationic polymerizable resin composition after irradiation with ultraviolet rays is heated and allowed to proceed with curing is lower than before, generally 40 to 70 ° C. Can be set to a degree.

  Next, the polymerization initiator (C) used in the present invention will be described.

  The polymerization initiator (C) used in the present invention generates an acid component when irradiated with ultraviolet rays, and initiates cationic polymerization of the polyether polyol (A) and the glycidyl group-containing compound (B).

The polymerization initiator (C) can be selected as needed without any particular limitation. For example, the cation moiety is aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, thioxanthonium, (2,4 -Cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron cation, and thianthrenium, and the anion moiety is BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , [BX ₄ ] ^−. (Wherein X represents a functional group in which two or more hydrogen atoms of the phenyl group are substituted by a fluorine atom or a trifluoromethyl group), an aromatic sulfonium salt, an aromatic iodonium salt, Aromatic diazonium salts, aromatic ammonium salts, thioxanthonium salts, (2,4-cyclopentadien-1-yl) [( 1-methylethyl) benzene] -iron salt, etc. can be used alone or in combination of two or more.

  Examples of the aromatic sulfonium salt include bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluoroantimonate, and bis [4- (diphenyl). Sulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- (diphenylsulfonio) phenyl] sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-4- (phenylthio) ) Phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetrafluoroborate, diphenyl-4- (phenylthio) E) Phenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, bis [4- ( Di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bishexafluoroantimony Bis [4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide bistetrafluoroborate, bis [4- ( Di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl] sulfide tetrakis (pentafluorophenyl) borate and the like can be used.

  Examples of the aromatic iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluorophosphate, Bis (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium Hexafluorophosphate, 4-methylphenyl-4- (1-methyl Ethyl) phenyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate Etc. can be used.

  Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis (pentafluorophenyl) borate.

  Examples of the aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl 2-cyanopyridinium tetrakis (pentafluorophenyl) borate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluoroantimonate, 1- (naphthylmethyl) -2-Cyanopyridinium tetrafluoroborate, 1- (naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate, and the like can be used.

  Moreover, S-biphenyl 2-isopropyl thioxanthonium hexafluorophosphate etc. can be used as said thioxanthonium salt.

  The (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron salt includes (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene. ] -Iron (II) hexafluorophosphate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Iron (II) hexafluoroantimonate, 2,4-cyclopentadiene-1- Yl) [(1-methylethyl) benzene] -iron (II) tetrafluoroborate, 2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -iron (II) tetrakis (pentafluorophenyl) ) Borate and the like can be used.

  As the polymerization initiator, for example, CPI-100P, CPI-200K, CPI-101A (manufactured by San Apro Co., Ltd.), Cyracure photocuring initiator UVI-6990, Cyracure photocuring initiator UVI-6922, Cyracure light Curing initiator UVI-6976 (above, manufactured by Dow Chemical Japan Co., Ltd.), Adekaoptomer SP-150, Adekaoptomer SP-152, Adekaoptomer SP-170, Adekaoptomer SP-172 (Asahi, Asahi) Denka Kogyo Co., Ltd.), CI-5102, CI-2855 (above, Nippon Soda Co., Ltd.), Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L, Sun-Aid SI-110L, Sun-Aid SI-180L , Sun-Aid SI-110, Sun-Aid SI-145, Sun-Aid I-150, Sun-Aid SI-160, Sun-Aid SI-180 (manufactured by Sanshin Chemical Industry Co., Ltd.), Esacure 1064, Esacure 1187 (manufactured by Lamberti), Omnicat 432, Omnicat 440, Omnicat 445, Omnicat 550, Omnicat 650, Omnicat BL-550 (manufactured by IG Resin), Irgacure 250 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Rhodosil Photo Initiator 2074 (RHODORSIL PHOTOINITIATOR 2074 (Rhodia Japan) Etc.) are commercially available.

  The amount of the polymerization initiator used is preferably as small as possible from the viewpoint of maintaining good curability and light stability, and specifically, 0.2 parts per 100 parts by mass of the polyether polyol (A). -5 mass parts is preferable, and 0.5-3 mass parts is more preferable.

  The cationically polymerizable resin composition used in the present invention includes, for example, the polyether polyol (A), the glycidyl group-containing compound (B), and various additives as necessary, using a closed planetary mixer or the like. Are mixed and stirred until uniform, and then the mixture obtained above and the polymerization initiator (C) are mixed and stirred.

  The cationic polymerizable resin composition used in the present invention may contain various additives as long as the effects of the present invention are not impaired.

  Next, the protective layer (II) constituting the liquid crystal display of the present invention will be described.

  The protective layer (II) is provided for the purpose of preventing the image display portion of the liquid crystal panel constituting the liquid crystal display of the present invention from being damaged by an external impact. As the protective layer (II), it is preferable to use a glass substrate or plastic substrate that is transparent to such an extent that an image displayed on the liquid crystal panel can be visually recognized. The surface of the substrate may be colored.

  As the plastic substrate, a substrate made of generally used acrylic resin or the like, or a substrate made of PC (polycarbonate), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), modified PPE (polyphenylene ether) or the like. Can be used.

  Next, the liquid crystal panel used in the present invention will be described.

  The liquid crystal panel used in the present invention is not particularly limited as long as a desired image or an image can be displayed, and a commonly used one can be used.

  As the liquid crystal panel, for example, a liquid crystal substance is sealed between transparent substrates made of glass, plastic, or the like, on one or both sides, a polarizing plate, a polarizing filter, an electrode, and a viewing angle compensation film, if necessary. Those obtained by laminating various functional materials can be used.

  The layer (I) and the protective layer (II) are preferably laminated directly on the surface of, for example, a polarizing plate or a polarizing filter constituting the liquid crystal panel, and in particular, laminated on the surface of the polarizing plate. Is preferred.

  As a polarizing plate, generally a plastic substrate made of a hydrophilic polymer such as polyvinyl alcohol, partially formalized polyvinyl alcohol, partially saponified ethylene / vinyl acetate copolymer, dichroism such as iodine or dichroic dye Polyene-based oriented films such as those obtained by adsorbing materials and uniaxially stretched, polyvinyl alcohol dehydrated products, and polyvinyl chloride dehydrochlorinated products can be used.

  Moreover, the surface of the said polarizing plate may be affixed with the protective film which consists of resin called a cellulose acetate resin and what is called a cycloolefin polymer as needed.

  About the thickness of the said liquid crystal panel, what is necessary is just the thickness according to the field | area which uses the liquid crystal display of this invention, a use, a function requested | required, etc.

  Next, the manufacturing method of the liquid crystal display of this invention is demonstrated.

  As a method for producing the liquid crystal display of the present invention, for example, the cationically polymerizable resin composition that is liquid at room temperature is applied to the surface of the image display portion of the liquid crystal panel, and the coating surface is irradiated with ultraviolet rays, and then the coating is applied. There is a method in which the substrate on which the protective layer (II) is formed on the surface is mounted and bonded, and the cured product of the cationic polymerizable resin composition is advanced by heating at 40 to 80 ° C. The cationic polymerizable resin composition may be applied directly on the polarizing plate on the surface of the image display portion of the liquid crystal panel, and a protective film made of cellulose acetate resin or the like is attached to the surface of the polarizing plate. If so, you may go directly to the surface.

  In addition, as a method for producing a liquid crystal display, the cationic polymerizable resin composition that is liquid at room temperature is applied to the surface of the base material on which the protective layer (II) is formed, and the applied surface is irradiated with ultraviolet rays. Thereafter, there may be a method of placing the surface of the image display part of the liquid crystal panel on the coated surface and heating the bonded body at 40 to 80 ° C. to advance the curing of the cationic polymerizable resin composition. .

  Examples of the method of applying the cationic polymerizable resin composition to the surface of the image display unit of the liquid crystal panel or the surface of the base material forming the protective layer (II) include, for example, offset printing, flexographic printing, and roll coating. , Gravure coating method, curtain flow coating method, bar coater method and the like.

  The coating amount of the cationic polymerizable resin composition is preferably about 100 to 300 μm from the viewpoint of thinning the liquid crystal display.

  Next, the application surface of the cationic polymerizable resin composition is irradiated with ultraviolet rays to initiate cationic polymerization of the composition.

  After irradiation, the surface of the image display unit of the liquid crystal panel or a substrate on which the protective layer (II) is formed is placed on the irradiation surface, and is cured for a certain period of time by, for example, pressing, so The liquid crystal display of this invention in which the protective layer was formed in the display part surface through the layer which consists of a cation polymeric resin composition can be obtained.

  In addition, the cationic polymerizable resin composition can advance cationic polymerization only by ultraviolet irradiation, but from the viewpoint of accelerating the polymerization rate and improving the production efficiency of the liquid crystal display of the present invention. After irradiating and laminating the liquid crystal panel and the like, heating is preferably performed at 40 to 80 ° C, and more preferably 40 to 70 ° C.

  If the heating temperature is too high, it may cause deformation of the polarizing plate that makes up the liquid crystal panel, making it impossible to display clear images. If the heating temperature is about room temperature, the production efficiency of the liquid crystal display is improved. It will be difficult to do.

  The cationically polymerizable resin composition used in the present invention can dramatically improve the production efficiency of the liquid crystal display without adversely affecting various parts constituting the liquid crystal display including the polarizing plate. Is possible.

  Moreover, as a method for producing the liquid crystal display of the present invention, the following method can be adopted in addition to the above-described method. For example, for a liquid crystal display in which a liquid crystal panel and a protective layer (II) are integrated in advance, and there is a gap generally called an air gap between the liquid crystal panel and the protective layer (II), the above-mentioned After pouring the cationic polymerizable resin composition into the gap, the inlet is sealed, and then the ultraviolet ray is irradiated from the upper surface of the protective layer (II), and further heated at a temperature of 40 to 70 ° C. It can also be produced by a method in which curing of the conductive resin composition proceeds.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

<Synthesis of multi-branched polyether polyol (A-1)>
In a 2-liter three-necked flask equipped with a reflux condenser, a magnetic stirring bar, and a thermometer, 348 parts by mass (3 mol) of 3-hydroxymethyl-3-ethyloxetane and 348 parts by mass (6 mol) of propylene oxide were sufficiently dried. Were then dissolved in 1 liter of diethyl ether free of peroxide and then cooled in an ice bath at -14 ° C.

Subsequently, a 60 mass% aqueous solution of 5.5 parts by mass of HPF ₆ as an initiator was dropped into the flask in 10 minutes. The mixture in the flask became slightly cloudy.

  The mixture in the flask was then allowed to react overnight at room temperature, and the next morning the clear reaction mixture was refluxed for 3 hours.

Subsequently, the initiator was deactivated using a 9% by mass NaOCH ₃ 30% by mass methanol solution.

  After filtering the reaction mixture after deactivation of the initiator, it was heated at a bath temperature of 75 ° C. under reduced pressure to distill off diethyl ether in the reaction mixture to obtain 667 parts by mass of the multi-branched polyether polyol (A-1). It was. The yield was 89% by mass.

  This multi-branched polyether polyol (A-1) has number average molecular weight (Mn) = 1,440, weight average molecular weight (Mw) = 3,350, hydroxyl value (OHV) = 265 mg · KOH / g, proton From the NMR, the molar ratio of 3-hydroxymethyl-3-ethyloxetane to propylene oxide was 1: 1.9.

  Moreover, the presence of primary hydroxyl groups and secondary hydroxyl groups was confirmed in the molecular structure, and the ratio of the number of secondary hydroxyl groups to the total number of hydroxyl groups was 39.0%.

[Preparation Example 1]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (A-1), EX-216L “cyclohexane dimethanol diglycidyl ether, manufactured by Nagase ChemteX Corporation, trademarks: Denacol, epoxy group "Equivalent weight = 150 g" 37.7 parts by mass was charged and mixed and stirred until uniform.

  Next, 1.75 parts by mass of CPI-200K “diphenyl-4- (phenylthio) phenylsulfonium salt propylene carbonate 50% by mass solution, manufactured by San Apro Co., Ltd.” was mixed and stirred to obtain a cationic polymerizable resin composition. A product was prepared.

[Preparation Example 2]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (A-1), EX-214L “butylene glycol diglycidyl ether, manufactured by Nagase ChemteX Corporation, trademark: Denacol, epoxy group equivalent 30.1 parts by mass of “weight = 120 g” was charged, and mixed and stirred until uniform.

  Next, 1.6 parts by mass of CPI-200K was mixed and stirred to prepare a cationic polymerizable resin composition.

[Preparation Example 3]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (A-1), EX-212L “1,6-hexanediol diglycidyl ether, manufactured by Nagase ChemteX Corporation, trademark: Denacol , 33.9 parts by mass of “epoxy group equivalent weight = 135 g” was mixed and stirred until uniform.

  Next, 1.68 parts by mass of CPI-200K was mixed and stirred to prepare a cationic polymerizable resin composition.

[Preparation Example 4]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (A-1) and 42.8 parts by mass of EX-216L were charged and mixed and stirred until uniform. next,
A cationically polymerizable resin composition was prepared by mixing and stirring 1.86 parts by mass of CPI-200K.

[Preparation Example 5]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (A-1) and 51.4 parts by mass of EX-216L were mixed and stirred until uniform. next,
A cationically polymerizable resin composition was prepared by mixing and stirring 2.03 parts by mass of CPI-200K.

[Preparation Example 6]
In an airtight planetary mixer, 50.0 parts by mass of Exenol 430 “Polypropylene triol, manufactured by Asahi Glass Co., Ltd., hydroxyl equivalent weight = 143.3 g” and 57.6 parts by mass of EX-216L are charged uniformly. Until mixed.

  Next, 2.15 parts by mass of CPI-200K was mixed and stirred to prepare a cationic polymerizable resin composition.

[Preparation Example 7]
In a closed-type planetary mixer, 50.0 parts by mass of Exenol 1030 “Polypropylene triol, manufactured by Asahi Glass Co., Ltd., hydroxyl equivalent weight = 333.3 g” and 24.8 parts by mass of EX-216L are charged until uniform. Mix and stir.

  Next, a cationically polymerizable resin composition was prepared by mixing and stirring 1.5 parts by mass of CPI-200K.

[Preparation Example 8]
In a closed type planetary mixer, 50.0 parts by mass of Exenol 385SO “polypropylene hexanol, manufactured by Asahi Glass Co., Ltd., hydroxyl equivalent weight = 83.3 g” and 99.0 parts by mass of EX-216L are charged until uniform. Mix and stir.

  Next, 2.98 parts by mass of CPI-100P “diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate 50% by mass solution of propylene carbonate, manufactured by San Apro Co., Ltd.” was mixed and stirred, so that cationic polymerization was achieved. A resin composition was prepared.

[Preparation Example 9]
In an airtight planetary mixer, 50.0 parts by mass of Exenol 385SO “polypropylene hexanol, manufactured by Asahi Glass Co., Ltd.” and 99.0 parts by mass of EX-216L were mixed and stirred until uniform.

  Next, 1.49 parts by mass of CPI-100P was mixed and stirred to prepare a cationic polymerizable resin composition.

[Comparative Preparation Example 1]
In a closed planetary mixer, 50.0 parts by mass of the multi-branched polyether polyol (A-1), Cyracure UVR-6110 “3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, Dow Chemical “31.7 parts by mass” manufactured by Japan Co., Ltd. was charged, and mixed and stirred until uniform.

  Next, a cationic polymerizable resin composition was prepared by mixing and stirring 1.63 parts by mass of CPI-200K.

[Comparative Preparation Example 2]
In an airtight planetary mixer, 50.0 parts by mass of Exenol 420 “Polypropylene glycol, manufactured by Asahi Glass Co., Ltd., hydroxyl equivalent weight = 200.0 g” and 41.3 parts by mass of EX-216L are charged until uniform. Mix and stir.

  Next, 1.83 parts by mass of CPI-200K was mixed and stirred to prepare a cationic polymerizable resin composition.

[Comparative Preparation Example 3]
In an airtight planetary mixer, 50.0 parts by mass of Exenol 510 “polyethylene glycol, manufactured by Asahi Glass Co., Ltd., hydroxyl equivalent weight = 2000.0 g” and 4.1 parts by mass of EX-216L are charged and become uniform. Until mixed.

  Next, a cationically polymerizable resin composition was prepared by mixing and stirring 1.08 parts by mass of CPI-200K.

[Comparative Preparation Example 4]
In a closed planetary mixer, 50.0 parts by mass of BAC-45 “polybutadiene-terminated acrylate, Osaka Organic Chemical Co., Ltd.” and IRGACURE 819 “bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide A cationically polymerizable resin composition was prepared by mixing and stirring 2.5 parts by mass of “Ciba Japan Co., Ltd.”.

[Comparative Preparation Example 5]
In a closed planetary mixer, 50.0 parts by mass of EBECRYL 204 “Urethane acrylate, manufactured by Daicel Cytec Co., Ltd.” and 2.5 parts by mass of IRGACURE 819 were mixed and stirred to obtain a cationically polymerizable resin composition. Prepared.

[Examples 1 to 9 and Comparative Examples 1 to 5]
Acrylic plate [PMMA (2 × 100 × 100 mm, manufactured by Engineering Test Service Co., Ltd.)] as a protective substrate using the resin compositions described in Preparation Examples 1-9 and Comparative Preparation Examples 1-5 using an applicator The coating was applied to a thickness of about 200 μm (for example, the protective substrate 1 in FIG. 1). Then, the conveyor-type UV irradiation device CSOT-40 (Japan Storage Battery Co., Ltd., a high-pressure mercury lamp used, the intensity 120 W / cm) using, as the amount of ultraviolet irradiation of about 1000 mJ / cm ^2, the coated surface Was irradiated with ultraviolet rays.

  Then, the surface which consists of a polarizing plate of a liquid crystal panel (for example, liquid crystal panel 3 as shown in FIG. 1) is bonded to the ultraviolet irradiation surface, and cured at 50 ° C. for 1 minute, whereby a liquid crystal display (for example, the liquid crystal display 4 as shown in FIG. 1) is used. ) Was manufactured. In addition, as said liquid crystal panel, the liquid crystal panel of length 100mm * width 100mm * thickness 0.2mm which has the commercially available polarizing plate which has the protective layer which consists of a triacetyl cellulose on both surfaces of the polarizer which consists of polyvinyl alcohol in an image display part. It was used.

[Visibility evaluation method]
Visibility is generally good when the refractive index of the cured product composed of the cationic polymerizable resin composition or the radical polymerizable resin composition and the refractive index of the protective substrate constituting the liquid crystal display are comparable. It is considered to be. Therefore, the visibility of the liquid crystal display of the present invention is determined by measuring the refractive index of the cured product such as the cation or radical polymerizable resin composition obtained in the preparation examples and comparative preparation examples, The evaluation was based on the difference from the rate.

The cationic polymerizable resin compositions of Preparation Examples 1 to 9 and Comparative Preparation Examples 1 to 3 and Comparative Preparation Example 4 and 5 radical polymerizable resin compositions were applied to a thickness of 200 μm on a polypropylene plate using an applicator. Then, using a conveyor type ultraviolet irradiation device CSOT-40 (manufactured by Nippon Battery Co., Ltd., using a high-pressure mercury lamp, strength 120 W / cm), the ultraviolet irradiation amount is 1000 mJ / cm ² to the coated surface The cured product sheet having a film thickness of about 150 μm was obtained by irradiating with ultraviolet rays and then drying at 50 ° C. for 1 minute. In addition, said ultraviolet irradiation amount was based on the value measured in 300-390 nm wavelength range using UV checker UVR-N1 (Nippon Battery Co., Ltd. product).

  The refractive index of the cured product sheet was measured using a refractometer “Sodium D line (589 nm), 25 ° C.” manufactured by Elma.

[Visibility evaluation criteria]
Since the refractive index of a base material made of an acrylic resin generally used as a protective base material for a liquid crystal display is about 1.49, and the refractive index of a base material made of glass is about 1.52, the cured sheet A refractive index in the range close to the refractive index, specifically in the range of 1.45 to 1.55, was evaluated as having practically sufficient visibility.

[Adhesion evaluation method]
(Test piece preparation method)
After leaving each liquid crystal display obtained by the above method in an environment of 80 ° C. for 1000 hours, a product in which floating or peeling occurs between the protective substrate and the liquid crystal panel constituting each liquid crystal display is “bad”. And those with no lift or peeling were evaluated as “good”.

* EX-212L: 1,6-hexanediol diglycidyl ether “manufactured by Nagase ChemteX Corporation”, trademark: Denacol, epoxy group equivalent weight = 135 g)
* EX-214L: 1,4-butanediol diglycidyl ether (manufactured by Nagase ChemteX Corp., trademark: Denacol, epoxy group equivalent weight = 120 g)
* EX-216L: cyclohexane dimethanol diglycidyl ether (manufactured by Nagase ChemteX Corporation, trademark: Denacol, epoxy group equivalent weight = 150 g)
* UVR-6110: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (manufactured by Dow Chemical Japan Co., Ltd., trademark: Cyracure, epoxy group equivalent weight = 137 g).
* Exenol 420: Polypropylene glycol “Asahi Glass Co., Ltd.”
* Exenol 510: Polyethylene glycol “Asahi Glass Co., Ltd.”
* Exenol 430: Polypropylene triol “Asahi Glass Co., Ltd.”
* Exenol 1030: Polypropylene triol “Asahi Glass Co., Ltd.”
* Exenol 385SO: Polypropylene hexanol “Asahi Glass Co., Ltd.”
* BAC-45: Polybutadiene-terminated acrylate “Osaka Organic Chemical Industry Co., Ltd.”
* EBECRYL204: Urethane acrylate “Daicel Cytec Co., Ltd.”
* CPI-100P: 50% by mass solution of diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate in propylene carbonate “San Apro Co., Ltd.”
* IRGACURE 819: Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide “Ciba Japan Co., Ltd.”
[About Examples 1 to 9]
The liquid crystal display of the present invention obtained using a specific cationic polymerizable resin composition has excellent visibility, and since the composition is excellent in curability, the protective substrate and the liquid crystal panel It was found that the film has excellent adhesion without causing floating or peeling.

[Comparative Example 1]
Since the cation polymerizable resin composition used in Comparative Example 1 uses an alicyclic epoxy compound instead of the glycidyl group-containing compound used in the present invention, the adhesion between the protective substrate and the liquid crystal panel is high. It was not enough.

[Comparative Examples 2 and 3]
Since the cationic polymerizable resin composition used in Comparative Examples 2 and 3 uses a polyether polyol having two hydroxyl groups instead of the polyether polyol having three or more hydroxyl groups used in the present invention. The adhesion between the protective substrate and the liquid crystal panel was not sufficient.

[Comparative Examples 4 and 5]
Since the radical polymerizable resin composition undergoes polymerization only while being irradiated with ultraviolet rays, the above-described method has insufficient adhesion between the protective substrate and the liquid crystal panel.

  Further, in the method of continuously irradiating ultraviolet rays until the radical polymerizable resin composition is sufficiently cured, the production efficiency of the liquid crystal display is remarkably lowered.

1 shows a cross-sectional view of a liquid crystal display of the present invention.

Explanation of symbols

Reference numeral 1 denotes a layer made of the protective substrate 1.
Reference numeral 2 denotes a layer made of the cationic polymerizable resin composition 2.
Reference numeral 3 denotes a liquid crystal panel 3.
4 shows a cross-sectional view of the liquid crystal display 4 of the present invention.

Claims (6)

A liquid crystal display in which a layer (I) formed using at least a cationic polymerizable resin composition and a protective layer (II) are laminated on the surface of an image display portion of a liquid crystal panel, the cationic polymerizable resin composition A liquid crystal display, wherein the product contains a polyether polyol (A) having three or more hydroxyl groups, a glycidyl group-containing compound (B), and a polymerization initiator (C). 2. The polyether polyol (A) according to claim 1, wherein the polyether polyol (A) has a number average molecular weight in the range of 300 to 2000 in which an alkylene oxide is added to at least one selected from the group consisting of sorbitol, glycerin and trimethylolpropane. LCD display. 2. The polyether polyol (A) is a multi-branched polyether polyol having 10 or more hydroxyl groups obtained by ring-opening reaction of a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2). A liquid crystal display according to 1. The multi-branched polyether polyol (A) is obtained by opening a hydroxyalkyl oxetane (a1) and a monofunctional epoxy compound (a2) at [(a1) / (a2)] = 1/1 to 1/3 (molar ratio). It has a number average molecular weight of 1000 to 4000 obtained by ring reaction and a hydroxyl value of 150 to 350 mg · KOH / g. In the molecular structure, primary hydroxyl group (H1) and secondary hydroxyl group (H2) are added. The liquid crystal display according to claim 3, wherein the liquid crystal display has a secondary hydroxyl group (H2) at a ratio of 25 to 60% with respect to the total number of hydroxyl groups. The cation polymerizable resin composition according to any one of claims 1 to 4 is applied to the surface of the image display unit of the liquid crystal panel, and the applied surface is irradiated with ultraviolet rays, and then the protective layer (II) is applied to the irradiated surface. A method for producing a liquid crystal display, comprising bonding a glass substrate or a plastic substrate constituting the substrate and heating at 40 to 80 ° C. After applying the cationic polymerizable resin composition according to any one of claims 1 to 4 on the surface of a glass substrate or plastic substrate constituting the protective layer (II), and irradiating the coated surface with ultraviolet rays The manufacturing method of the liquid crystal display which bonds the image display part surface of the said liquid crystal panel to the irradiation surface, and heats at 40-80 degreeC.

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