JP5370721B2 - Cationic polymerizable resin composition for adhesion between image display part of liquid crystal panel and protective substrate thereof, liquid crystal display and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cation polymerizable resin composition not damaging visibility or the like of a liquid crystal display and excellent in adhesion, wherein the cation polymerizable resin composition is almost exclusively used to apply an image display of a liquid crystal panel comprising a liquid crystal display to a protective substrate thereof. <P>SOLUTION: The cation polymerizable resin composition for applying an image display of a liquid crystal panel to a protective substrate thereof, comprises a polycarbonate polyol (A), a glycidyl group-containing compound (B) and a polymerization initiator (C). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal display applicable to a display unit of various communication devices, home appliances, and the like, and a cationic polymerizable resin composition that can be used for manufacturing the same.

  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 and vividness have been required for images displayed by the mobile information communication terminals.

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

  From the viewpoint of preventing damage to the liquid crystal panel due to direct impact from the outside to the liquid crystal panel, the protective base material should be installed in a state where a space generally called an air gap is secured between the protective base material and the liquid crystal panel. There are many.

  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. Light scattering may occur, and if the degree of this 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, a method of filling the air gap with a resin is known. For example, in a region provided between a liquid crystal display panel for displaying an image and a touch panel, for example, light A method of filling a transparent resin filler made of a polymerization type acrylic resin is known (see, for example, Patent Document 1).

  However, since the acrylic resin is a so-called radical polymerization type resin, the curing reaches a practically sufficient level due to, for example, the effect of radical deactivation due to the termination reaction between radicals or the influence of oxygen in the atmosphere. May stop before. 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. was there.

  In addition, as a protective base material for a liquid crystal display, a base material on which characters or the like are partially printed, or a base film with a black background film or the like attached to the base material extension may be used. The lower part of such a portion cannot sufficiently supply light capable of sufficiently proceeding radical polymerization, so that the degree of curing of the composition layer becomes uneven, and as a result, the protective group In some cases, the protective base material may be lifted or peeled off due to a decrease in adhesiveness between the material and the liquid crystal panel over time.

  Therefore, when manufacturing the liquid crystal display using a radical polymerizable resin composition, for example, the radical polymerization resin composition is applied to the surface of a transparent protective substrate, and the liquid crystal panel is previously applied to the application surface. Although it is necessary to continuously irradiate the resin composition layer with ultraviolet rays through the transparent protective substrate after being laminated, it is said that such a method is preferable from the viewpoint of improving the production efficiency of the liquid crystal display. I wanted to.

Japanese Patent Laid-Open No. 2004-77887

The problem to be solved by the present invention is a cationically polymerizable resin composition capable of imparting improved visibility of a liquid crystal display and improved adhesion between the liquid crystal panel and a protective substrate, and is exclusively an image of the liquid crystal panel. It is to provide a cationic polymerizable resin composition used for adhesion between a display unit and a protective substrate.
Further, the problem to be solved by the present invention is, for example, a liquid crystal display excellent in visibility even when used outdoors, etc. and having excellent adhesion between the image display portion of the liquid crystal panel and the protective substrate. Is to provide.
In addition, the problem to be solved by the present invention is a leap in production efficiency of a liquid crystal display that is excellent in visibility and excellent in adhesion between the liquid crystal panel and the protective substrate even when used outdoors, for example. It is providing the manufacturing method of a liquid crystal display which improves it automatically.

  In order to solve the problems when the radical polymerizable resin composition as described above is used, the present inventors use a polymerization curing reaction system resin composition different from the radical polymerizable resin composition. investigated. Specifically, it has been found that it is effective to use a cationic polymerization resin composition in which the curing reaction proceeds even without continuously irradiating ultraviolet rays, and the investigation is based on the cationic polymerization resin composition. Advanced.

  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.

  Subsequently, while examining various combinations such as a cationic group and a reactive diluent, a cationic polymerizable resin composition containing a polycarbonate polyol (A), a glycidyl group-containing compound (B), and a polymerization initiator (C). It has been found that an object can impart excellent visibility and adhesion to the liquid crystal display without impairing the clarity of the image displayed on the liquid crystal display.

On the other hand, the present inventors have further studied to further improve the visibility of the liquid crystal display. Specifically, the cured product of the cationic polymerizable resin composition may be slightly discolored by being affected by light or heat caused by a backlight or the like for a long period of time. In some cases, the property slightly decreased over time. This was considered to be caused by residual chlorine derived from epichlorohydrin, which is a raw material for producing the glycidyl group-containing compound (B), and an inorganic chloride as an additive.
As a result, when an attempt was made to use the cationic polymerizable resin composition having a reduced amount of residual chlorine as the cationic polymerizable resin composition, the amount of chlorine remaining in the total amount of the composition was 1500 ppm or less. In some cases, it has been found that the discoloration and the like can be prevented and excellent visibility can be imparted.

That is, the present invention relates to cationic polymerization for adhesion between an image display part of a liquid crystal panel and its protective substrate, comprising a polycarbonate polyol (A), a glycidyl group-containing compound (B), and a polymerization initiator (C). The present invention relates to a resin composition.
The present invention also relates to a cationic polymerizable resin composition in which the amount of chlorine remaining in the total amount of the cationic polymerizable resin composition is 1500 ppm or less.

  In the present invention, at least a layer (1) formed using a cationic polymerizable resin composition and a protective layer (2) made of a protective base material are laminated on the surface of the image display unit of the liquid crystal panel. A liquid crystal display, wherein the cationic polymerizable resin composition contains a polycarbonate polyol (A), a glycidyl group-containing compound (B), and a polymerization initiator (C). It is.

  Moreover, this invention apply | coats the said cationic polymerizable resin composition to the image display part surface of the said liquid crystal panel, and after irradiating an ultraviolet-ray to this application | coating surface, the protection layer (2) which comprises the irradiation surface comprises The present invention relates to a method for producing a liquid crystal display, in which a glass substrate or a plastic substrate as a substrate is bonded and heated at 40 to 80 ° C.

Moreover, this invention apply | coated the said cationic polymerizable resin composition to the surface of the glass base material or plastic base material as a protective base material which comprises the said protective layer (2), and irradiated the ultraviolet-ray to this coating surface Then, the image display part surface of the said liquid crystal panel is bonded together to the irradiation surface, and it is related with the manufacturing method of a liquid crystal display heated at 40-80 degreeC.
It is about.

  The liquid crystal display of the present invention can be used for, for example, a television receiver and a wireless device because it maintains excellent sharpness of an image to be displayed and is excellent in visibility and adhesion. In particular, since the liquid crystal display of the present invention has a practically sufficient level of visibility even outdoors, for example, it can be used in a display unit of a portable radio such as a portable television receiver or a portable telephone terminal. Can be applied.

  The cationically polymerizable resin composition of the present invention contains a polycarbonate polyol (A), a glycidyl group-containing compound (B), a polymerization initiator (C), and other additives as necessary, It can be used for adhesion between an image display portion of a liquid crystal panel constituting a liquid crystal display and its protective substrate.

  Here, the liquid crystal display referred to in the present invention can control 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. In addition to a light source such as a backlight, a color filter, a liquid crystal panel, and a layer (2) made of a protective substrate that protects the surface of the image display unit of the liquid crystal panel from external impacts, for example, Furthermore, a layer (1) formed of a cationically polymerizable resin composition as an adhesive layer between the surface of the image display unit of the liquid crystal panel and the protective substrate and a layer capable of imparting excellent visibility to the liquid crystal display Is required.

  The liquid crystal panel is, for example, a liquid crystal substance sealed between transparent substrates made of glass, plastic, etc., on one or both sides, such as a polarizing plate, a polarizing filter, an electrode, and a viewing angle compensation film as necessary. It refers to a laminate of various functional substrates, and changes the orientation of the liquid crystal substance by applying a voltage to adjust the transmission of light from a backlight or the like.

  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, a cationically polymerizable resin composition for adhesion between an image display portion of a liquid crystal panel and a protective substrate thereof, which constitutes the layer (1) laminated on the surface of the image display portion of the liquid crystal panel The composition will be described.

  The cationic polymerizable resin composition used in the present invention is important for forming a layer (1) that can impart excellent visibility and adhesion to a liquid crystal display. Further, since the cationic polymerizable resin composition is cured relatively uniformly by the cationic polymerization reaction, the sharpness of the image displayed by the liquid crystal panel is not lowered.

  As said cationically polymerizable resin composition, what contains a polycarbonate polyol (A), a glycidyl group containing compound (B), and a polymerization initiator (C) can be used.

  Examples of the polycarbonate polyol (A) used in the cationic polymerizable resin composition include those obtained by esterifying a dialkyl carbonate such as dimethyl carbonate or a cyclic structure-containing carbonate such as ethylene carbonate with various polyols. Among them, it is preferable to use one having two hydroxyl groups.

  Examples of the polyol include 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, cyclohexanedimethanol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol (PTMG). A diol can be used, and among them, it is preferable to use a combination of cyclohexanedimethanol and 1,6-hexanediol because the visibility and adhesion of the liquid crystal display can be improved.

  Specifically, polycarbonate diol (A1) which is an esterified product of carbonate ester and dicyclohexanedimethanol represented by the following chemical formula (I), carbonate ester represented by the following chemical formula (II) and 1, It is preferable to use a mixture with polycarbonate diol (A2) which is an esterified product with 6-hexanediol for the above reasons.

（化学式（I）中のｍは、２〜２０の整数を表す。）

(M in chemical formula (I) represents an integer of 2 to 20.)

（化学式（II）中のｎは、２〜２０の整数を表す。）

(N in chemical formula (II) represents an integer of 2 to 20.)

  The polycarbonate diol (A1) and the polycarbonate diol (A2) have a molar ratio of [(A1) / (A2)] in the range of 20/80 to 60/40, from the viewpoint of preventing deterioration of adhesiveness over time. It is preferable that

  The polycarbonate diol (A) is preferably one having a number average molecular weight of 500 to 3,000, preferably 500 to 1,500, from the viewpoint of preventing deterioration of adhesiveness over time. More preferred.

  The polycarbonate diol (A) is preferably contained in an amount of 30 to 95% by mass, more preferably 40 to 80% by weight, based on the total amount of the cationic polymerizable resin composition of the present invention.

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

  The glycidyl group-containing compound (B) has a glycidyl group that can be ring-opened by a polymerization initiator (C) described later to form a crosslinked structure, and is a cationic polymerization reaction with a hydroxyl group of the polycarbonate polyol (A). And is an essential component for achieving excellent visibility and adhesion. In addition, it is important for providing a suitable open time to the cationic polymerizable resin composition of the present invention and enabling the liquid crystal panel and the protective substrate to be bonded after the composition is irradiated with ultraviolet rays or the like. is there.

  Examples of the glycidyl group-containing compound (B) include aliphatic glycidyl compounds having three glycidyl ether groups such as trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, polyglycerol triglycidyl ether, and diglycerol triglycidyl ether. Trimethylolpropane diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, propylene glycol diglycidyl ether, diethylene glycol di Glycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, 1,6-diglycy It may be used glycidyl compounds having two glycidyl ether groups Le naphthalene.

  As the glycidyl group-containing compound (B), it is preferable to use a compound having two or more glycidyl ether groups in order to give good normal adhesive strength, and it is more preferable to use 2 to 6 compounds. preferable.

  Among them, as the glycidyl group-containing compound (B), it is excellent to use the aliphatic glycidyl compound having the three glycidyl ether groups or the aliphatic glycidyl compound having the two glycidyl ether groups. It is more preferable for imparting adhesiveness, and the combined use of the aliphatic glycidyl compound and the aliphatic glycidyl compound is particularly preferable for imparting more excellent adhesiveness.

  The glycidyl group-containing compound (B) can generally be produced using epichlorohydrin as a raw material. In the obtained glycidyl group-containing compound (B), a part of chlorine derived from the epichlorohydrin and the like is contained. May remain. In general, commercially available glycidyl group-containing compounds usually have about several to 10 to several percent of chlorine remaining.

  Here, the chlorine referred to in the present invention is used in combination with chlorine and chloride derived from raw materials such as epichlorohydrin used in the production of the glycidyl group-containing compound (B), and the cationically polymerizable resin composition of the present invention. It refers to inorganic chlorides such as sodium chloride resulting from various additives. The cationic polymerizable resin composition containing a relatively large amount of chlorine as referred to in the present invention may cause slight discoloration over time.

Therefore, it is preferable to use the glycidyl group-containing compound (B) that has been subjected to treatment such as removal of chlorine by a method such as rectification. The rectification is preferably performed at a temperature of about 50 to 200 ° C. for about 1 to 200 hours, for example.
As a result, the amount of chlorine remaining in the total amount of the cationic polymerizable resin composition of the present invention is 1500 ppm or less, preferably 1000 ppm or less, thereby preventing the occurrence of discoloration over time. In addition, the quantity of chlorine said by this invention can be measured based on JISK1200-3-2.

  The glycidyl group-containing compound (B) is preferably contained in the total amount of the cationic polymerizable resin composition of the present invention in an amount of 5 to 40% by mass, and more preferably in the range of 10 to 30% by weight.

  The glycidyl group-containing compound (B) has a mass ratio of the hydroxyl group of the polycarbonate polyol (A) and the glycidyl group of the glycidyl group-containing compound (B) [glycidyl group / (B) A) Hydroxyl group]] is preferably used at a ratio of 1.0 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.

  In the present invention, in addition to the polycarbonate polyol (A) and the glycidyl group-containing compound (B), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, limonene diepoxide, if necessary. , Compounds having a cyclohexene oxide group such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 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 Oxetanes such as methoxy] benzene, 4,4′-bis [(3-ethyl-3-oxetanyl) methoxy] biphenyl, 3-ethyl-3-{[(3- (triethoxysilyl) propoxy] methyl} oxetane and the like. A compound having a ring, a compound obtained by epoxidizing an oligomer having a vinyl group such as epoxidized polybutadiene, or the like can be used.

  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 polycarbonate diol (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 salt, aromatic ammonium salt, thioxanthonium salt, (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.

  Examples of the polymerization initiator (C) include CPI-100P, CPI-200K, CPI-101A (manufactured by San Apro Co., Ltd.), a syracure photocuring initiator UVI-6990, and a syracure photocuring initiator UVI-6922. Syracure photocuring initiator UVI-6976 (manufactured by Dow Chemical Japan Co., Ltd.), Adekaoptomer SP-150, Adekaoptomer SP-152, Adekaoptomer SP-170, Adekaoptomer SP-172 ( Asahi Denka Kogyo Co., Ltd.), CI-5102, CI-2855 (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 Id SI-150, Sun-Aid SI-160, Sun-Aid SI-180 (above, manufactured by Sanshin Chemical Industry Co., Ltd.), Esacure 1064, Esacure 1187 (above, made by Lamberti), Omnicat 432, Omnicat 440, Omni Cat 445, Omni Cat 550, Omni Cat 650, Omni Cat BL-550 (manufactured by IG Resin), Irgacure 250 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Rhodosil Photo Initiator 2074 (RHODORSIL PHOTOINITIATOR 2074 (Rhodia Japan Co., Ltd.) are commercially available.

  The amount of the polymerization initiator (C) used is preferably as small as possible from the viewpoint of maintaining good curability and light stability. Specifically, the polycarbonate diol (A) and the glycidyl group-containing compound (B) From 0.1 to 5 parts by mass in terms of non-volatile content is preferable, and 0.5 to 3 parts by mass is more preferable.

  The cationic polymerizable resin composition used in the present invention comprises, for example, the polycarbonate diol (A), the glycidyl group-containing compound (B), and various additives as necessary using a closed planetary mixer or the like. It can be produced by mixing and stirring until uniform, and then mixing and stirring the mixture obtained above and the polymerization initiator (C).

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.
However, from the viewpoint that the amount of chlorine remaining in the total amount of the cationically polymerizable resin composition of the present invention is 1500 ppm or less, preferably 1000 ppm or less, it is preferable to use as little inorganic chloride as sodium chloride.

Next, the liquid crystal display of the present invention will be described.
As described above, the liquid crystal display of the present invention comprises at least a polycarbonate polyol (A), a glycidyl group-containing compound (B) and a polymerization initiator (C) on the surface of the image display portion of the liquid crystal panel. A layer (1) formed using a product and a protective layer (2) made of a protective substrate are laminated.

  Here, the layer (1) can be formed by using the cationic polymerizable resin composition, and the thickness varies depending on the field of use of the liquid crystal display, but the thickness of the liquid crystal display is reduced. In order to achieve both good effects of the present invention, the thickness is preferably about 10 to 500 μm, more preferably 100 to 500 μm.

  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 plastic substrate or glass 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.

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

  As described above, as the liquid crystal panel, a liquid crystal substance is sealed between transparent substrates made of glass, plastic, or the like, on one side or both sides, a polarizing plate, a polarizing filter, an electrode, and, if necessary, a viewing angle. What laminated | stacked various functional provision base materials, such as a compensation film, can be used.

  The layer (1) and the protective layer (2) are directly laminated on the surface of the image display unit of the liquid crystal panel, specifically on the surface of a polarizing plate, a polarizing filter or the like constituting the outermost part of the liquid crystal panel. In particular, it is preferable to sequentially laminate on the surface of the polarizing plate.

  The polarizing plate is generally a plastic substrate made of a hydrophilic polymer compound such as polyvinyl alcohol, partially formalized polyvinyl alcohol, partially saponified ethylene / vinyl acetate copolymer, and two colors such as iodine and dichroic dye. Polyene-based oriented films such as those obtained by adsorbing a functional material 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 protective base material for forming the protective layer (2) is placed on the surface, bonded together, and curing of the cationic polymerizable resin composition proceeds.

  However, since the cationic polymerizable resin composition causes cationic polymerization to proceed relatively slowly at room temperature after UV irradiation, the rate of cationic polymerization is dramatically improved and the production efficiency of the liquid crystal display of the present invention is improved. In view of the above, it is preferable to heat at a temperature of about 40 to 80 ° C. after irradiation with ultraviolet rays.

  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 protective base material forming the protective layer (2) is placed on the surface, and the bonded material is heated at 40 to 80 ° C. to advance the curing of the cationic polymerizable resin composition. 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 protective base material that forms the protective layer (2), and the applied surface is irradiated with ultraviolet rays. After that, even if there is a method of placing the surface of the image display part of the liquid crystal panel on the coated surface and heating the bonded together at 40 to 80 ° C. to advance the curing of the cationic polymerizable resin composition Good.

  Examples of the method for applying the cationic polymerizable resin composition to the surface of the image display unit of the liquid crystal panel or the surface of the protective substrate for forming the protective layer (2) include, for example, screen printing, offset printing, flexographic printing. Method, roll coat method, gravure coat method, curtain flow coat method, bar coater method and the like.

  After bonding the protective substrate and the image display part of the liquid crystal panel, using a cationically polymerizable resin composition on the surface of the image display part of the liquid crystal panel, for example, by curing for a certain period of time, such as by pressing The liquid crystal display of this invention in which the protective layer (2) was formed through the formed layer (1) can be obtained.

  In addition, the cationic polymerizable resin composition can proceed with cationic polymerization only by ultraviolet irradiation without undergoing a heating step, but without causing deformation of the polarizing plate constituting the liquid crystal panel, From the viewpoint of accelerating the polymerization reaction and improving the production efficiency of the liquid crystal display of the present invention, it is preferable to heat at 40 to 80 ° C. after irradiating ultraviolet rays to laminate the liquid crystal panel and the like, and 40 to 70 ° C. It is more preferable.

  As described above, the cationic polymerizable resin composition used in the present invention dramatically increases the production efficiency of the liquid crystal display without adversely affecting the various components constituting the liquid crystal display including the polarizing plate. It is possible to improve.

  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 (2) are integrated in advance, and there is a gap generally called an air gap between the liquid crystal panel and the protective layer (2), 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 (2), 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. Further, from the viewpoint of uniformly curing, the cationic polymerizable resin composition irradiated with ultraviolet rays in advance is poured into the void immediately after irradiation, the inlet is sealed, and then at a temperature of 40 to 70 ° C. Curing of the cationic polymerizable resin composition may be advanced by heating.

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

[Example 1]
UM-90 (1/1), Ube Industries, Ltd., trademark: etanacol, number average molecular weight: about 900, 1,6-hexanediol and carbonate are reacted as polycarbonate polyol in a closed planetary mixer And a mixture of polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol and carbonate with a mass ratio of 1: 1, hereinafter referred to as “UM-90 (1/1)”. Omitted. ) 50.0 parts by mass, EX-216L (cyclohexanedimethanol diglycidyl ether, manufactured by Nagase ChemteX Corp., trademark: Denacol, epoxy group equivalent weight = 150 g as a glycidyl group-containing compound, hereinafter abbreviated as “EX-216L” 18.3 parts by mass were charged and mixed and stirred until uniform.

  Next, 1.37 parts by mass of CPI-100P (diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate 50% by mass solution of propylene carbonate, manufactured by San Apro Co., Ltd., hereinafter abbreviated as “CPI-100P”). Were mixed and stirred to prepare a cationically polymerizable resin composition.

Next, the site | part which can permeate | transmit an ultraviolet-ray among the protective base material 1 (Acrylic board (length 10cm x width 10cm x thickness 2mm) which consists of polymethylmethacrylate) using the applicator for the cationic polymerizable resin composition obtained above. 11 and a protective substrate 1 having a portion 12 to which a film that does not transmit ultraviolet light is applied (specifically, see FIG. 2).
Next, using a conveyor type UV irradiation device CSOT-40 (manufactured by Nippon Battery Co., Ltd., using a high-pressure mercury lamp, strength 120 W / cm), each application surface is adjusted so that the UV irradiation amount is about 1000 mJ / cm ^2. Was irradiated with ultraviolet rays.

  Thereafter, a surface made 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, thereby obtaining a liquid crystal display (for example, as shown in FIG. 4) was produced. 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.

[Example 2]
A cationically polymerizable resin composition was prepared in the same manner as described in Example 1, except that the amount of CPI-100P used was changed from 1.37 parts by mass to 2.73 parts by mass. A liquid crystal display was produced in the same manner.

[Example 3]
Instead of the EX-216L, 25.9 parts by mass of “EX-212L” (1,6-hexanediol diglycidyl ether, manufactured by Nagase ChemteX Corporation, trademark: Denacol, epoxy group equivalent weight = 135 g) was used. A cationically polymerizable resin composition was prepared in the same manner as described in Example 1 except that the amount of CPI-100P used was changed from 1.37 parts by mass to 1.52 parts by mass. A liquid crystal display was produced in the same manner as described.

[Example 4]
Except for using 26.2 parts by mass of EX-214L (1,4-butanediol diglycidyl ether, manufactured by Nagase ChemteX Corporation, trademark: Denacol, epoxy group equivalent weight = 120 g) instead of EX-212L Prepared a cationically polymerizable resin composition by the same method as described in Example 3, and then produced a liquid crystal display by the same method as described in Example 3.

[Example 5]
UM-90 (1/3) instead of UM-90 (1/1) (number average molecular weight: about 900, polycarbonate diol obtained by reacting 1,6-hexanediol and carbonate, and 1 Other than using 50.0 parts by mass of a mixture of polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol base and carbonate ester with a mass ratio of 1: 3, Ube Industries, Ltd., trademark: etanacol) Prepared a cationically polymerizable resin composition in the same manner as in Example 1, and then produced a liquid crystal display in the same manner as in Example 1.

[Example 6]
A cationically polymerizable resin composition was prepared in the same manner as in Example 3 except that 50.0 parts by mass of UM-90 (1/3) was used instead of UM-90 (1/1). Further, a liquid crystal display was produced in the same manner as described in Example 3.

[Example 7]
A cationically polymerizable resin composition was prepared in the same manner as in Example 4 except that 50.0 parts by mass of UM-90 (1/3) was used instead of UM-90 (1/1). Further, a liquid crystal display was produced in the same manner as described in Example 4.

[Example 8]
UM-90 (3/1) instead of UM-90 (1/1) (number average molecular weight: about 900, polycarbonate diol obtained by reacting 1,6-hexanediol and carbonate, and 1 Except for using 50.0 parts by mass of a mixture of polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol and carbonate ester with a mass ratio of 3: 1 (Ube Industries, Ltd., trademark: etanacol). A cationically polymerizable resin composition was prepared in the same manner as in Example 3, and a liquid crystal display was produced in the same manner as in Example 3.

[Comparative Example 1]
Instead of EX-216L, 20 parts by mass of “Aron oxetane, OXT-221 (3-ethyl-3-{[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane, manufactured by Toagosei Co., Ltd.)” A cationically polymerizable resin composition was prepared in the same manner as described in Example 1 except that it was used and the amount of CPI-100P used was changed from 1.37 parts by mass to 1.40 parts by mass. A liquid crystal display was produced in the same manner as described in Example 1.

[Comparative Example 2]
Instead of the EX-216L, 20 parts by mass of cyclohexanedimethanol / divinyl ether (1,4-bis (vinyloxymethyl) cyclohexane, manufactured by BASF Japan Ltd.) is used, and the amount of CPI-100P used is 1 Except for changing from 37 parts by weight to 1.40 parts by weight, a cationically polymerizable resin composition was prepared in the same manner as described in Example 1, and a liquid crystal display was prepared in the same manner as in Example 1. did.

[Comparative Example 3]
In a closed planetary mixer, 50 parts by mass of BAC-45 (Osaka Organic Chemical Co., Ltd., polybutadiene-terminated acrylate, average molecular weight 3000) and IRGACURE 819 (Ciba Japan Co., Ltd., bis (2,4 , 6-trimethylbenzoyl) phenylphosphine oxide) was prepared and mixed and stirred until uniform to prepare a radical polymerizable resin composition.
Next, a liquid crystal display was produced in the same manner as in Example 1 except that the radical polymerizable resin composition was used.

[Comparative Example 4]
Instead of BAC-45 (Osaka Organic Chemical Co., Ltd., polybutadiene terminal acrylate, average molecular weight 3000), 50 parts by mass of EBECRYL 204 (Daicel Sydec Co., Ltd., directional group urethane acrylate, molecular weight 2000) is used. Except for the above, a radical polymerizable resin composition was prepared in the same manner as in Comparative Example 3, and a liquid crystal display was produced in the same manner.

[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, and the value of the refractive index of the protective substrate. The evaluation was based on the difference from the rate.
Specifically, 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. Evaluation was made based on whether or not the refractive index of the cured sheet was in a range close to the refractive index. Moreover, it evaluated also based on evaluation of the visual clarity of the image displayed on the liquid crystal display produced in the Example etc. visually.

The cationic polymerizable resin compositions obtained in Examples 1 to 8 and Comparative Examples 1 and 2 and the radical polymerizable resin compositions obtained in Comparative Examples 3 and 4 are 200 μm thick on a polypropylene plate using an applicator. After application, a conveyor type ultraviolet irradiation device CSOT-40 (manufactured by Nippon Battery Co., Ltd., using a high-pressure mercury lamp, strength 120 W / cm) is used so that the ultraviolet irradiation amount is 1000 mJ / cm ^2. The coated surface was irradiated with ultraviolet rays, and then heated at 50 ° C. for 1 minute to obtain a cured product sheet having a thickness of about 150 μm. 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 universal Abbe refractometer (ER-7MW, sodium D line (589 nm), 25 ° C.) manufactured by Elma Sales Co., Ltd.

[Visibility evaluation criteria]
"◎" when the refractive index of the cured product is in the range of 1.45 to 1.55 and the image of the liquid crystal display displayed outdoors on a clear day is clear, and the refractive index is within the above range. Although the image sharpness is slightly inferior to the above, “◯”, the refractive index is out of the above range, and the image is inferior in “△”, the refractive index is out of the above range. In addition, the case where the sharpness of the image was remarkably inferior was evaluated as “x”.

[Adhesion evaluation method]
Each liquid crystal display obtained by the above method was allowed to stand in an environment of 80 ° C. for 1500 hours, and then the presence or absence of floating or peeling between the protective substrate constituting the liquid crystal display and the liquid crystal panel was visually evaluated.
Specifically, the adhesiveness of the entire contact surface including both the part 11 that can transmit ultraviolet rays and the part 12 that does not transmit ultraviolet rays is visually evaluated. ”,“ ○ ”if there is a slight floating, but there is no practical problem,“ △ ”especially if the floating is seen in the part 12,“ × ”if the floating is noticeable in both parts ".

UM-90 (1/1): polycarbonate diol obtained by reacting 1,6-hexanediol and carbonate, and polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol and carbonate A mixture with a mass ratio of 1: 1, “Ube Industries, Ltd., trademark: Etanacol”
UM-90 (1/3): polycarbonate diol obtained by reacting 1,6-hexanediol and carbonate, and polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol and carbonate Mixture with a mass ratio of 1: 3, “Ube Industries, Ltd., trademark: Etanacol”
UM-90 (3/1): polycarbonate diol obtained by reacting 1,6-hexanediol and carbonate ester, and polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol and carbonate ester Mixture with a mass ratio of 3: 1, “Ube Industries, Ltd., trademark: Etanacol”
OXT-221: 3-ethyl-3-{[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane “manufactured by Toagosei Co., Ltd., trademark: Aron Oxetane”
Cyclohexanedimethanol divinyl ether: 1,4-bis (vinyloxymethyl) cyclohexane “BASF Japan Ltd.” EX-212L: 1,6-hexanediol diglycidyl ether “Nagase ChemteX Corp.” Trademark: Denacol, epoxy group equivalent weight = 135 g)
EX-214L: 1,4-butanediol diglycidyl ether “manufactured by Nagase ChemteX Corporation”, trademark: Denacol, epoxy group equivalent weight = 120 g)
EX-216L: cyclohexanedimethanol diglycidyl ether “manufactured by Nagase ChemteX Corp.”, trademark: Denacol, epoxy group equivalent weight = 150 g)
BAC-45: Polybutadiene-terminated acrylate “Osaka Organic Chemical Co., Ltd.”
EBECRYL204: Urethane acrylate “Daicel Cytec Co., Ltd.”
CPI-100P: 50% by mass solution of propylene carbonate of diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate “manufactured by San Apro Co., Ltd.”
IRGACURE819: Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide “Ciba Japan Co., Ltd.”

[About Examples 1 to 8]
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 oxetane monomer instead of the glycidyl group-containing compound used in the present invention, the adhesion between the protective substrate and the liquid crystal panel is not sufficient. It was.

[Comparative Example 2]
Since the cationic polymerizable resin composition used in Comparative Example 1 uses a vinyl ether monomer instead of the glycidyl group-containing compound used in the present invention, the adhesion between the protective substrate and the liquid crystal panel is not sufficient. It was.

[Comparative Examples 3 and 4]
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.

FIG. 1 shows a cross-sectional view of the liquid crystal display of the present invention. FIG. 2 shows a front view of the protective substrate 1.

Explanation of symbols

Reference numeral 1 denotes a layer made of the protective substrate 1.
11 shows the site | part (internal dimension 8 cm x 8 cm) which can permeate | transmit an ultraviolet-ray among the protective base materials 1. FIG.
Reference numeral 12 denotes a portion of the protective substrate 1 where a film that does not transmit ultraviolet rays is attached.

2 shows the layer 2 which consists of a cation polymeric resin composition.
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 (8)

A polycarbonate diol (A1) having a structure represented by the following chemical formula (i), a polycarbonate polyol (A) containing the polycarbonate diol (A2) represented by the following chemical formula (ii), and a glycidyl group-containing compound having two or more glycidyl ether groups (B), and comprising a polymerization initiator (C), Ri bonding cationically polymerizable resin composition der of the image display unit of the liquid crystal panel and its protective substrate, the cationically polymerizable resin composition A cationically polymerizable resin composition for adhesion between an image display part of a liquid crystal panel and its protective substrate , wherein the refractive index of the cured product is in the range of 1.45 to 1.55 .

(M in chemical formula (i) represents an integer of 2 to 20.)

(In the chemical formula (ii), n represents an integer of 2 to 20) The cationic polymerizable resin composition for adhesion between an image display part of a liquid crystal panel and a protective substrate thereof according to claim 1, wherein the number average molecular weight of the polycarbonate polyol (A) is in the range of 500 to 3,000. The cation polymerizable resin composition for adhesion | attachment with the image display part of the liquid crystal panel of Claim 1, and the protection base material of Claim 1 whose quantity of the chlorine which remains in the whole quantity of the said cation polymerizable resin composition is 1500 ppm or less. The cationically polymerizable resin for adhesion between the image display unit of the liquid crystal panel and its protective substrate according to claim 1, wherein the glycidyl group-containing compound (B) is an aliphatic glycidyl compound having two or more glycidyl ether groups. Composition. A liquid crystal display in which at least a layer (1) formed using a cationic polymerizable resin composition and a protective layer (2) made of a protective substrate are laminated on the surface of an image display unit of a liquid crystal panel, The cation polymerizable resin composition includes a polycarbonate diol (A1) having a structure represented by the following chemical formula (i) and a polycarbonate diol (A2) represented by the following chemical formula (ii), a glycidyl ether group glycidyl group-containing compound having two or more (B), and contains a polymerization initiator (C), the refractive index of the cured product of the cationically polymerizable resin composition area by der of 1.45 to 1.55 A liquid crystal display characterized by that.

(M in chemical formula (i) represents an integer of 2 to 20.)

(In the chemical formula (ii), n represents an integer of 2 to 20) The liquid crystal display of Claim 5 whose number average molecular weights of the said polycarbonate polyol (A) are the ranges of 500-3000. The liquid crystal display according to claim 5 , wherein the amount of chlorine remaining in the total amount of the cationic polymerizable resin composition is 1500 ppm or less. The liquid crystal display according to claim 5 , wherein the glycidyl group-containing compound (B) is an aliphatic glycidyl compound having two or more glycidyl ether groups.

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