JP2008281997A - Method for manufacturing image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently cure a resin in a forming-region of a light-shielding portion while attaining a high-luminance, high-contrast display without having display defects due to deformation of an image display unit during manufacture of a thin image display wherein the resin is interposed between a protective unit having the light-shielding portion and the image display unit. <P>SOLUTION: The method for manufacturing an image display device comprises a step wherein a photocurable resin composition is interposed between a base unit 2 having an image display unit such as a liquid crystal display panel 8 and a light-transmitting protective unit 3 having a light-shielding portion 5, and a cured resin layer 15 is formed by photocuring the resin composition. In this method, a resin composition having a curing shrinkage rate of not more than 5% and a storage modulus of the cured product at 25°C of not more than 1.0×10<SP>7</SP>Pa, thereby obtaining a cured resin layer 15 having a visible light transmittance of not less than 90% is used as the photocurable resin composition. The method further comprises a step wherein a curable resin composition 11 containing a thermal polymerization initiator is interposed at least between the light-shielding portion 5 and the base unit 2 and then the curable resin composition 11 is heated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an image display device such as a liquid crystal display device (LCD) used in, for example, a mobile phone, and more particularly to a method for manufacturing an image display device in which a transparent protective portion is provided on an image display portion.

  Conventionally, for example, a liquid crystal display device 101 shown in FIG. 7 is known as this type of image display device. The liquid crystal display device 101 has a transparent protection unit 103 made of, for example, glass or plastic on a liquid crystal display panel 102.

  In this case, in order to protect the surface of the liquid crystal display panel 102 and the polarizing plate (not shown), a gap 104 is provided between the liquid crystal display panel 102 and the protective part 103 by interposing a spacer 104 between the protective part 103. Is provided.

  However, the presence of the gap 105 between the liquid crystal display panel 102 and the protection unit 103 causes light scattering, resulting in a decrease in contrast and brightness, and the presence of the gap 105 hinders thinning of the panel. It has become.

  In view of such problems, it has also been proposed to fill the gap between the liquid crystal display panel and the protective portion with a resin (for example, Patent Document 1). However, the liquid crystal display is caused by the stress during curing shrinkage of the cured resin. Deformation occurs in the optical glass plate that sandwiches the liquid crystal of the panel, causing display defects such as alignment disorder of the liquid crystal material.

  Further, in the liquid crystal display device 101, a black frame-shaped light shielding portion (not shown) called a black matrix is provided in the protective portion 103 around the liquid crystal display panel 102 in order to improve the brightness and contrast of the display image. It is formed.

  However, in such a configuration, if the space 105 between the liquid crystal display panel 102 and the protective portion 103 is filled with the photocurable resin composition and photocured, the photocurable type in the light shielding portion forming region is formed. The resin composition may become uncured due to insufficient light.

JP 2005-55641 A

  The present invention has been made in consideration of such problems of the conventional technology, and the object of the present invention is to provide a thin type in which a resin is interposed between a protective part having a light shielding part and an image display part. When manufacturing an image display device, it is possible to display an image with high brightness and high contrast without causing a display defect due to deformation of the image display unit, and the resin in the formation region of the light shielding unit is also sufficiently cured. To provide technology.

In order to achieve the above object, the present invention provides a cured resin by photocuring a photocurable resin composition between a base having an image display portion and a translucent protective portion having a light shielding portion. A method of manufacturing an image display device including a step of forming a layer,
The photocurable resin composition has a cure shrinkage of 5% or less, a storage modulus of the cured product at 25 ° C. of 1.0 × 10 ⁷ Pa or less, and a light transmittance in the visible light region of the resin cured product layer of 90%. Using the resin composition as described above,
Provided is a method for manufacturing an image display device, which includes a step of heating a curable resin composition containing a thermal polymerization initiator between at least a light-shielding part and a base, and heating the curable resin composition.

  In particular, the present invention provides a mode in which a curable resin composition containing a thermal polymerization initiator interposed between a light shielding part and a base part is used as a photocurable resin composition, and light irradiation and heating are performed thereon.

  Moreover, in this aspect, the aspect which performs the light irradiation with respect to the photocurable resin composition interposed between a light-shielding part and a base from the outer side surface side of the formation surface of a light-shielding part is provided.

  In the present invention, the image display unit may be a liquid crystal display panel.

  In the present invention, the protective part may be made of an acrylic resin.

  In the present invention, the protective part may be made of optical glass.

  According to the present invention, a photocurable resin composition is interposed between a base portion having an image display portion and a translucent protective portion having a light shielding portion, and photocured to form a cured resin layer. Since there is a step of interposing a curable resin composition containing a thermal polymerization initiator between at least the light-shielding part and the base and heating the curable resin composition, the resin composition also in the formation region of the light-shielding part The object can be sufficiently cured.

  Further, in the present invention, the photocurable resin composition interposed between the non-light-shielding part and the base part does not contain a thermal polymerization initiator, but contains a thermal polymerization initiator only between the light-shielding part and the base part. When the photocurable resin composition is interposed, the amount of the thermal polymerization initiator used can be reduced. In addition, since the entire curable resin composition interposed between the protective part and the base part contains a thermal polymerization initiator, the heating time and the heating temperature can be relatively reduced as compared with the case of heat curing, The influence on the plastic material frequently used in the periphery of the image display device can be reduced.

  Further, in the present invention, when light irradiation to the photocurable resin composition interposed between the light shielding part and the base part is performed from the side surface side of the light shielding part forming region, the photocurable resin composition in the light shielding part forming region is performed. Since the object is reliably irradiated with light, the photocurable resin composition in that region can be sufficiently cured.

Furthermore, the internal stress accumulated when the resin is cured can be approximated by the product of the storage elastic modulus after curing and the curing shrinkage rate. According to the present invention, the photocurable resin composition has a curing shrinkage rate. 5% or less and the cured product having a storage elastic modulus at 25 ° C. of 1.0 × 10 ⁷ Pa or less is used, so that the influence of stress at the time of resin curing shrinkage is minimized on the image display part and the protective part. Can be suppressed. Therefore, almost no distortion occurs in the image display unit and the protection unit. As a result, it is possible to display an image with high luminance and high contrast without display defects.

  In particular, when the image display unit is a liquid crystal display panel, display defects such as disorder of alignment of the liquid crystal material can be reliably prevented and high-quality image display can be performed.

  Furthermore, according to the present invention, since the cured resin is interposed between the image display unit and the protection unit, it is strong against impact.

  In addition, it is possible to provide a thin image display device as compared with the conventional example in which a gap is provided between the image display unit and the protection unit.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same numerals indicate the same or equivalent components.

  1A to 1C are cross-sectional process diagrams showing the main part of one embodiment of a method for manufacturing an image display device according to the present invention, and FIG. 2 shows a process for manufacturing the image display device in the same embodiment. It is a top view which shows the principal part.

  As shown in FIG. 1, in the present embodiment, a base 2 having an image display unit that is connected to a drive circuit (not shown) and displays a predetermined image, and a protection unit 3 are bonded together by a cured resin layer 15.

  Here, the image display device is not particularly limited and can be applied to various types of devices, for example, liquid crystal display devices such as mobile phones and portable game devices. Hereinafter, the present invention will be described taking a case of manufacturing a liquid crystal display device as an example.

  The protection part 3 is formed of a light-transmitting member 4 having, for example, a rectangular flat plate shape having the same size as the base part 2. As this translucent member 4, optical glass and plastics (acrylic resin etc.) can be used suitably, for example.

  In a region corresponding to the peripheral edge of the liquid crystal display panel 8 on the surface of the translucent member 4 on the base 2 side, for example, a black frame-shaped light shielding portion 5 is provided. The light shielding portion 5 is formed in a layer shape having a uniform thickness by, for example, a printing method.

  On the other hand, the base 2 has, for example, a frame-like frame 6, and a liquid crystal display panel (image display unit) 8 is attached to a region inside the frame 6, and further, a portion of the liquid crystal display panel 8 on the back side of the apparatus. A backlight 7 is attached to the main body.

  In addition, as shown in FIG. 2, a plurality of spacers 9 are intermittently provided at predetermined intervals on the periphery of the frame 6 on the image display surface side. The spacer 9 has a thickness of about 0.05 to 1.5 mm, so that the distance between the surfaces of the liquid crystal display panel 8 and the protection unit 3 is maintained at about 1 mm.

  Further, in the present embodiment, in particular, the bonding surface 6 a of the frame 6 of the base portion 2 and the bonding surface 5 a of the light shielding portion 5 of the protection portion 3 are parallel to each other.

  In the present embodiment, when the protective part 3 and the base part 2 are bonded together, first, as shown in FIG. 1A, photocuring or heat curing is possible in the region inside the spacer 9 on the substrate 2. A predetermined amount of curable resin composition 11 is dropped.

  The dripping amount is preferably such that the thickness of the cured resin layer 15 after the protective portion 3 and the base portion 2 are bonded is 50 to 200 μm.

The curable resin composition 11 has a storage elastic modulus (25 ° C.) of the resin cured product of 1 × 10 ⁷ Pa or less, preferably 1 × 10 ³ to 1 × 10 ⁶ Pa, and the refractive index of the resin cured product. Is preferably 1.45 or more and 1.55 or less, more preferably 1.51 or more and 1.52 or less, and the transmittance in the visible light region is 90% or more when the thickness of the resin cured product is 100 μm. The one prepared as described above is used.

In general, even if the main resin component constituting the curable resin composition is common, if the resin component or monomer component blended together is different, the storage elastic modulus (25 ° C.) of the cured resin obtained by curing the resin component is 1 Although it may exceed 10 ⁷ Pa, a resin composition that becomes such a cured resin is not used as the curable resin composition 11.

  Further, this curable resin composition 11 has a curing shrinkage ratio of preferably 5.0% or less, more preferably 4.5% or less, particularly preferably 4.0% or less, and further preferably 0 to 2%. It shall be prepared as follows. Thereby, when the curable resin composition 11 is cured, the internal stress accumulated in the cured resin can be reduced, and the interface between the cured resin layer 15 and the liquid crystal display panel 8 or the protection unit 3 is distorted. You can prevent what you can do. Therefore, when the curable resin composition 11 is interposed between the liquid crystal display panel 8 and the protective portion 3 and the curable resin composition 11 is cured, the cured resin layer 15 and the liquid crystal display panel 8 or the protection are provided. Scattering of light generated at the interface with the portion 3 can be reduced, the brightness of the display image can be increased, and visibility can be improved.

  The degree of internal stress accumulated in the cured resin when the resin composition is cured is evaluated by the average surface roughness of the cured resin obtained by dropping the resin composition on a flat plate and curing it. can do. For example, the average surface roughness of a cured resin obtained by dropping 2 mg of a resin composition on a glass plate or an acrylic plate and curing it with UV irradiation at a curing rate of 90% or more should be 6.0 nm or less. For example, when a curable resin composition is interposed between the liquid crystal display panel 8 and the protective part 3 and cured, the distortion generated at the interface between them can be ignored in practice. In this regard, according to the curable resin composition 11 used in this embodiment, the average surface roughness can be 6.0 nm or less, preferably 5.0 nm or less, and more preferably 1 to 3 nm. Therefore, the distortion generated at the interface of the cured resin can be ignored in practice.

  Here, as a glass plate, what is used as a glass plate which clamps the liquid crystal of a liquid crystal cell, or a protective plate of a liquid crystal cell can be used preferably. Moreover, as an acrylic board, what is used as a protective plate of a liquid crystal cell can be used preferably. The average surface roughness of these glass plates and acrylic plates is usually 1.0 nm or less.

  Such a curable resin composition 11 mainly comprises an oligomer or a polymer, an acrylate monomer, a photopolymerization initiator, and a thermal polymerization initiator, and other additives such as a sensitizer, a plasticizer, a transparent What added particle | grains etc. in the range of the objective of this invention can be used.

  Here, as the oligomer or polymer, polyurethane acrylate, polybutadiene acrylate, polyisoprene acrylate or esterified product thereof, terpene-based hydrogenated resin, butadiene polymer, epoxy acrylate oligomer, or the like can be preferably used.

  As the acrylate monomer, isobornyl acrylate, dicyclopentenyloxyethyl methacrylate, hydroxymethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, lauryl acrylate, benzyl acrylate and the like can be preferably used.

  As a photopolymerization initiator, 1-hydroxy-cyclohexyl-phenyl-ketone (trade name IRGACURE 184: manufactured by Ciba Specialty Chemicals), 2-hydroxy-1- {4- [4- (2-hydroxy-2- Methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one (trade name IRGACURE 127: manufactured by Ciba Specialty Chemicals), 1-hydroxy-cyclohexyl-phenyl-ketone (trade name DAROCUR 1173: Ciba (Specialty Chemicals Co., Ltd.) can be preferably used, but is not particularly limited thereto.

  The protection unit 3 may be given a function of cutting the ultraviolet region from the viewpoint of ultraviolet protection for the display unit. In that case, as the photopolymerization initiator used in the present invention, it is preferable to use a photopolymerization initiator that can be cured even in the visible light region (for example, trade name SpeedCure TPO: manufactured by Nippon Shibel Hegner Co., Ltd.).

  As the thermal polymerization initiator, an organic peroxide that acts as an initiator by heat can be suitably used. In the case where the liquid crystal display panel 8 is used as the image display portion as in the present embodiment, a plastic material such as an acrylic resin is often used as the material of the panel, and its heat resistance is 80 ° C. Therefore, it is preferable to use an organic peroxide having a 10-hour half-life temperature of 100 ° C. or lower as the thermal polymerization initiator.

  Here, the half-life of the organic peroxide refers to the time until the concentration of the organic peroxide is reduced to half of the initial value, and the temperature at which this half-life is 10 hours is referred to as the 10-hour half-life temperature.

Examples of the thermal polymerization initiator having a 10-hour half-life temperature of 100 ° C. or less include trade name Perbutyl O (C ₁₂ H ₂₄ O ₃ ) manufactured by Nippon Oil & Fats Co., Ltd. and trade name Parroyl TCP manufactured by Nippon Oil & Fats Co., Ltd. _(C 12 _H 24 _{O 3),} and the like. The names perbutyl and paroyl are registered trademarks.

  The blending amount of the thermal polymerization initiator is preferably 1 to 10% by weight with respect to the acrylic resin in the curable resin composition 11 from the viewpoint of securing an appropriate reaction temperature and reaction time.

  Next, as shown in FIG. 1B, the protective part 3 is disposed on the spacer 9 of the base part 2, the back surface of the protective part 3 is brought into contact with the curable resin composition 11, and the base part 2, the protective part 3, The curable resin composition 11 is interposed in the space between the two.

  Thereafter, as shown in FIG. 1B, the curable resin composition 11 b in the image display area corresponding to the non-formation area of the light shielding part 5 is irradiated with ultraviolet rays 34 through the translucent member 4.

  The irradiation direction of the ultraviolet rays 34 is not particularly limited, but is orthogonal to the surface of the translucent member 4 from the viewpoint of achieving more uniform curing of the curable resin composition 11b in the image display region. It is preferable to make it the direction to do.

  At the same time, as shown in FIGS. 1B and 2, a UV light irradiation device 31 having a fine irradiation unit 30 made of, for example, an optical fiber is used to cure between the light shielding unit 5 and the base 2. From the outer side surface side of the bonding surface 5a of the light shielding portion 5 (that is, the formation surface of the light shielding portion) to the mold resin composition (that is, the curable resin composition in the region where the light shielding portion 5 is formed) 11a The ultraviolet rays 32 may be directly radiated through the gap between the frame 6 and the light shielding portion 5 between the nine.

  The irradiation direction of the ultraviolet rays 32 is not particularly limited and can be set to 0 ° or more and less than 90 ° with respect to the horizontal direction, but is more uniform than the curable resin composition 11a in the formation region of the light shielding portion 5. From the viewpoint of achieving proper curing, it is preferable to irradiate the bonding surface 6a of the frame 6 of the base portion 2 and the bonding surface 5a of the light shielding portion 5 of the protection portion 3 with the ultraviolet rays 32 substantially in parallel.

  In addition to the irradiation with the ultraviolet ray 34, as shown in FIGS. 1B and 2, a UV light irradiation device (not shown) is used, and the curable resin composition 11 a between the light shielding portion 5 and the base portion 2 is applied. The ultraviolet ray 33 may be irradiated through the translucent member 4 from the inner side surface side of the bonding surface 5 a of the light shielding portion 5.

  In this case, the irradiation direction of the ultraviolet ray 33 is determined by considering the irradiation efficiency of the ultraviolet ray 33 with respect to the curable resin composition 11a between the light-shielding part 5 and the base part 2 and the like. It is preferable that the angle is 10 ° to 45 ° obliquely from above with respect to the bonding surface 5 a of the three light shielding portions 5.

  In addition, as long as the heating with respect to the curable resin composition 11a of the formation area of the light-shielding part 5 demonstrated below is enough, irradiation of the ultraviolet rays 32 and 33 may be abbreviate | omitted.

  In this embodiment, the curable resin composition 11a in the formation region of the light-shielding portion 5 is heated simultaneously with the irradiation of the ultraviolet ray 34 on the curable resin composition 11b in the image display region, or before or after the irradiation with the ultraviolet ray 34.

  In this case, the heating temperature is not particularly limited, but is preferably 60 to 100 ° C. from the viewpoint of preventing deformation of the plastic material portion. As a heating method, it is possible to heat the curable resin compositions 11a and 11b as a whole by placing the image display device on a heating stage after ultraviolet irradiation or during ultraviolet irradiation, and a liquid crystal display panel. It is also possible to arrange a heater in the area where the light shielding portion 5 around the area 8 is formed.

  In this way, by performing irradiation with ultraviolet rays 32, 33, and 34 and heating, as shown in FIG. 1C, the curable resin composition 11b in the image display region and the curable resin composition 11a in the light shielding portion forming region. Both are cured to form a cured resin layer 15 to obtain the target image display device 1.

  According to such this embodiment, in the bonding process of the protective part 3 and the base part 2, using the curable resin composition 11 containing both the photopolymerization initiator and the thermal polymerization initiator, The curable resin composition 11 b is irradiated with ultraviolet rays 34 through the transparent member 4, and the curable resin composition 11 a in the formation region of the light shielding part 5 is heated, and the light shielding part 5 as necessary. Since the ultraviolet rays 32 and 33 are irradiated from the inner side and the outer side surface of the bonding surface 5a, the curing in the formation region of the light shielding portion 5 as well as the curable resin composition 11b in the image display region. The mold resin composition 11a can also be sufficiently cured.

  In addition, by using the specific curable resin composition 11 as described above, it is possible to minimize the influence of stress at the time of resin curing shrinkage on the liquid crystal display panel 8 and the protective part 3. The display panel 8 and the protection unit 3 are hardly distorted. As a result, the liquid crystal display panel 8 is not deformed, so that it is possible to display an image with high luminance and high contrast without display defects.

  Furthermore, the cured resin layer 15 obtained by curing the curable resin composition 11 is resistant to impact and has a thinner image display than the conventional example in which a gap is provided between the image display unit and the protection unit. Device 1 can be obtained.

  In the above-described embodiment, a predetermined amount of the curable resin composition 11 that can be photocured and thermally cured is dropped on the inner region of the spacer 9 on the base 2. For example, as shown in FIG. Alternatively, a predetermined amount may be dropped on the surface of the protective part 3 on the light shielding part 5 side, and the protective part 3 and the base part 2 may be bonded together so that the protective part 3 is turned over.

  In this case, photocuring and thermosetting of the curable resin composition 11 can be performed in the same manner as in the embodiment described above, as shown in FIGS.

  In addition, as shown in FIG. 4, the image display device 1 may be manufactured by omitting the spacer 9. In this case, the above-mentioned curable resin composition 11 is applied onto the base portion 2, the protective portion 3 is overlaid thereon, and photocuring and thermosetting are performed as described above.

  FIGS. 5A to 5C are cross-sectional process diagrams showing the main parts of still another embodiment. Hereinafter, parts corresponding to those in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5A, also in this embodiment, the base portion 2 and the protection portion 3 having the above-described configuration are used.

  In the present embodiment, first, a predetermined amount of the photocurable resin composition 10 is dropped on the liquid crystal display panel 8 of the base 2. As this photocurable resin composition 10, the thing similar to the above-mentioned curable resin composition 11 which can be photocured and thermally cured is used except not mix | blending a thermal-polymerization initiator.

  Further, as shown in FIG. 5A, in the region inside the spacer 9 on the base portion 2, the region facing the light-shielding portion 5 of the protection portion 3 (in this embodiment, both the frame 6 and the liquid crystal display panel 8). A predetermined amount of the curable resin composition 11 that can be photocured and thermally cured.

  Then, as shown in FIG. 5 (a), on the spacer 9 of the base portion 2, the protective portion 3 has a photocurable resin composition 10a whose back surface is in the image display region, and a curable resin in the light shielding portion forming region. It arrange | positions so that the composition 11a may be contacted.

  Thereafter, as shown in FIG. 5B, the photocurable resin composition 10 a in the image display region is irradiated with ultraviolet rays 34 through the translucent member 4.

  Further, if necessary, simultaneously with the irradiation of the ultraviolet ray 34, as shown in FIG. 5 (b), the UV light irradiation device 31 is used, and the curable resin composition 11a between the light shielding portion 5 and the base portion 2 is applied. Under the above-described conditions, the ultraviolet rays 32 are directly irradiated from the outer side surface side of the bonding surface 5a of the light shielding part 5, that is, between the spacers 9 through the gap between the frame 6 and the light shielding part 5. You can also.

  Using a UV light irradiation device (not shown), ultraviolet light is passed through the translucent member 4 from the inner side surface of the bonding surface 5a of the light shielding part 5 to the curable resin composition 11a between the light shielding part 5 and the base part 2. 33 can also be irradiated.

  By irradiation with these ultraviolet rays 32 and 33, the resin can be cured quickly and reliably.

  Also in the present embodiment, at least the curable resin composition 11a between the light shielding part 5 and the base part 2 is heated.

  Then, by irradiating the ultraviolet ray 34 and heating the resin, or further irradiating the ultraviolet rays 33 and 32 as necessary, as shown in FIG. 5C, a photocurable resin composition in the image display region. 10a and the curable resin composition 11a in the light-shielding part forming region are cured to form the cured resin layers 14 and 15, and the target image display device 1A is obtained.

  According to this embodiment, in addition to the effects described in the above-described embodiments, the curable resin composition 11 containing a thermal polymerization initiator is disposed only between the frame 6 of the base portion 2 and the light shielding portion 5. Since it hardens | cures, the usage-amount of a thermal-polymerization initiator can be decreased. Moreover, compared with the case where a thermal polymerization initiator is contained in the entire curable resin composition interposed between the protective part 3 and the base part 2 and heat-cured, the heating time is relatively short and the heating temperature is lowered. Therefore, there is an advantage that the influence on the plastic material or the like constituting the image display apparatus is small. In addition, the same effects as those of the above-described embodiment can be obtained.

  Also in this embodiment, as shown in FIG. 6, the spacer 9 may be omitted to manufacture the image display device 1A.

  In addition, the present invention is not limited to the above-described embodiment, and various changes can be made. For example, the ultraviolet irradiation with respect to the curable resin composition in the image display region and the ultraviolet irradiation with respect to the curable resin composition in the light shielding portion forming region may be performed simultaneously or in separate steps.

  Further, when the curable resin composition 11a is arranged in the light shielding part forming region, a gap may be partially provided in a side part between the frame 6 and the bonding surfaces 6a and 5a of the light shielding part 5. Thereby, when irradiating the ultraviolet-ray 32 from the outer side surface side of the formation surface of a light-shielding part, light can be reliably reached to a resin composition and fully hardened.

  Furthermore, the present invention can be applied not only to a liquid crystal display device but also to various panel displays such as an organic EL and a plasma display device.

  EXAMPLES Hereinafter, although an experiment example is given and this invention is demonstrated concretely, this invention is not limited to a following example.

  The following resin compositions a to h were prepared.

<Resin composition a>
50 parts by weight of polyurethane acrylate (trade name UV-3000B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), 30 parts by weight of isobornyl acrylate (trade name IBXA, manufactured by Osaka Organic Chemical Industry Co., Ltd.), organic peroxide (product) Name perbutyl O, manufactured by Nippon Oil & Fats Co., Ltd. 5 parts by weight, photopolymerization initiator (trade name IRGACURE 184, manufactured by Ciba Specialty Chemicals), photopolymerization initiator (trade name SpeedCure TPO, Nippon Siber Hegner Co., Ltd.) 1) parts by weight were kneaded in a kneader to prepare a resin composition a.

<Resin composition b>
Without adding organic peroxide, polyurethane acrylate (trade name UV-3000B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 50 parts by weight, isobornyl acrylate (trade name IBXA, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 30 Part by weight, 3 parts by weight of a photopolymerization initiator (trade name IRGACURE 184, manufactured by Ciba Specialty Chemicals), 1 part by weight of a photopolymerization initiator (trade name: SpeedCure TPO, manufactured by Nippon Shibel Hegner Co., Ltd.) The resin composition b was prepared by kneading.

<Resin composition c>
70 parts by weight of esterified product of maleic anhydride adduct of polyisoprene polymer and 2-hydroxyethyl methacrylate, 30 parts by weight of dicyclopentenyloxyethyl methacrylate, 10 parts by weight of 2-hydroxybutyl methacrylate, 30 parts by weight of terpene-based hydrogenated resin The resin composition c was prepared by kneading 140 parts by weight of a butadiene polymer, 4 parts by weight of a photopolymerization initiator, and 0.5 parts by weight of a photopolymerization initiator for visible light region using a kneader.

<Resin composition d>
100 parts by weight of esterified product of maleic anhydride adduct of polyisoprene polymer and 2-hydroxyethyl methacrylate, 30 parts by weight of dicyclopentenyloxyethyl methacrylate, 10 parts by weight of 2-hydroxybutyl methacrylate, 30 parts by weight of terpene hydrogenated resin A resin composition d was prepared by kneading 210 parts by weight of a butadiene polymer, 7 parts by weight of a photopolymerization initiator, and 1.5 parts by weight of a photopolymerization initiator for visible light region using a kneader.

<Resin composition e>
70 parts by weight of an esterified product of maleic anhydride adduct of polyisoprene polymer and 2-hydroxyethyl methacrylate (trade name UC-203, manufactured by Kuraray Co., Ltd.), dicyclopentenyloxyethyl methacrylate (trade name FA512M, Hitachi Chemical) 30 parts by weight of Kogyo Co., Ltd., 10 parts by weight of 2-hydroxybutyl methacrylate (trade name Light Ester HOB, manufactured by Kyoeisha Chemical Co., Ltd.), terpene-based hydrogenated resin (trade name Clearon P-85, Yasuhara Chemical Co., Ltd.) 30 parts by weight, 35 parts by weight of a butadiene polymer (trade name Polyoil 110, manufactured by Nippon Zeon Co., Ltd.), 5 parts by weight of a photopolymerization initiator (trade name: Irgacure 184D, manufactured by Ciba Specialty Chemicals), start of photopolymerization Agent (trade name SpeedCure TPO, Nippon Siber Hegner (stock) 2) parts by weight were kneaded with a kneader to prepare a resin composition e.

<Resin composition f>
A resin composition f was prepared by kneading 50 parts by weight of polybutadiene acrylate, 20 parts by weight of hydroxylethyl methacrylate, 3 parts by weight of a photopolymerization initiator, and 1 part by weight of a photopolymerization initiator for visible light region in a kneader.

<Resin composition g>
50 parts by weight of polyurethane acrylate (trade name UV-3000B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), 30 parts by weight of tricyclodecane dimethanol acrylate (trade name NK ester LC2, manufactured by Shin-Nakamura Chemical Co., Ltd.), photopolymerization A resin composition g was prepared by kneading 3 parts by weight of an initiator (IRGACURE 184, manufactured by Ciba Specialty Chemicals) and 1 part by weight of a photopolymerization initiator (trade name SpeedCure TPO, manufactured by Nippon Siebel Hegner) with a kneader. Prepared.

<Resin composition h>
50 parts by weight of polybutadiene acrylate (trade name TE-2000, manufactured by Nippon Soda Co., Ltd.), 20 parts by weight of isobornyl acrylate (trade name IBXA, manufactured by Osaka Organic Chemical Industry Co., Ltd.), photopolymerization initiator (IRGACURE 184, A resin composition h was prepared by kneading 3 parts by weight of Ciba Specialty Chemicals Co., Ltd. and 1 part by weight of a photopolymerization initiator (trade name SpeedCure TPO, manufactured by Nippon Siebel Hegner Co., Ltd.) with a kneader.

Experimental Example 1-1 [Curing Rate of Resin Composition]
The resin composition a and the resin composition b are dropped in an amount of 0.2 g on the inner region of the spacer on the liquid crystal display substrate as shown in FIG. 1A, respectively, and have a light shielding part with a width of 2.0 mm as a protective part. The acrylic plate was placed on the spacer, and then the resin composition was photocured under the following curing conditions A to D, respectively. As shown in Table 1, a liquid crystal display device was produced.

  And the acrylic board of the obtained liquid crystal display device was peeled off, and the cure rate of the hardened | cured material of each resin composition a and b was measured so that it might mention later. The results are shown in Table 1.

Curing condition A:
A UV lamp (manufactured by Ushio Inc.) was used to irradiate ultraviolet rays with an integrated light amount of 5,000 mJ from a location about 10 cm away from the acrylic plate, and the resin composition was photocured to prepare a liquid crystal display device.

Curing condition B:
In addition to the irradiation conditions of curing condition A, a heater was placed around the frame and heated at 80 ° C. for 60 minutes.

Curing condition C:
In addition to the irradiation condition of the curing condition A, ultraviolet rays having an accumulated light amount of 5,000 mJ were irradiated from an area about 3 cm away from the entire periphery of the frame on which the light shielding portion of the liquid crystal display device was formed, using an optical fiber.

Curing condition D:
In addition to the irradiation condition of curing condition A, the liquid crystal display device is placed on a heating stage, heated at 80 ° C. for 60 minutes, and from a distance of about 3 cm over the entire periphery of the frame where the light-shielding portion of the liquid crystal display device is formed. Using an optical fiber, ultraviolet light with an integrated light amount of 5,000 mJ was irradiated.

Curing rate measurement method:
From each of the resin composition before irradiation and the cured product after irradiation, those cured components (monomer, oligomer) are extracted using acetonitrile in an amount that the resin composition and the cured product are 0.2 wt%, and liquid The peak intensity I ₀ of the cured component in the resin composition and the peak intensity I ₁ of the cured component in the cured product were obtained by chromatography, and the curing rate was calculated by the following formula.

Experimental example 1-2
Resin compositions a and b were used in the same manner as in Experimental Example 1-1 except that an acrylic plate having a light-shielding portion with a width of 5.0 mm was used as a protective portion, and a liquid crystal display device was produced by changing the curing conditions. The cure rate of the cured resin in the obtained liquid crystal display device was measured. The results are shown in Table 2.

硬化条件Ａ：アクリル板側からの紫外線照射のみ
硬化条件Ｂ：アクリル板側からの紫外線照射と加熱ヒータによる加熱
硬化条件Ｃ：アクリル板側からの紫外線照射と側面側からの紫外線照射
硬化条件Ｄ：アクリル板からの紫外線照射と加熱ステージによる加熱と側面側からの紫外線照射

Curing condition A: Only ultraviolet irradiation from the acrylic plate side Curing condition B: Ultraviolet irradiation from the acrylic plate side and heat curing condition by a heater C: Ultraviolet irradiation from the acrylic plate side and ultraviolet irradiation curing condition from the side surface D: UV irradiation from acrylic plate, heating by heating stage and UV irradiation from side

硬化条件Ａ〜Ｄ：表１の硬化条件と同一

Curing conditions A to D: the same as the curing conditions in Table 1

  As is clear from Tables 1 and 2, when only ultraviolet irradiation is performed from the acrylic plate side (curing condition A), the resin composition a containing both the photopolymerization initiator and the thermal polymerization initiator is also light The resin composition b including a polymerization initiator but not including a thermal polymerization initiator had a good curing rate in the central portion of the image display portion, but was directly below the light shielding portion regardless of the width of the light shielding portion. In this case, the curing was not sufficient.

  In addition, when UV irradiation is performed from the acrylic plate side and the side surface side (curing condition C), when the width of the light shielding part is narrow (2 mm), both at the center of the image display part and immediately below the light shielding part. Although good curability was exhibited, when the width of the light-shielding portion was increased (5 mm), the curing rate was directly below the light-shielding portion (75%: see Table 2 Curing Conditions C of Resin Composition b).

  On the other hand, when both ultraviolet irradiation and heating are performed using the resin composition a (curing conditions B and D), regardless of the width of the light shielding portion, the central portion of the image display portion and the portion immediately below the light shielding portion are used. In any case, the curing rate of the resin composition was improved to 95%, and very good results were obtained.

Experimental Example 2: Various measurements of cured resin The resin compositions a to g are dropped onto a white glass plate having a thickness of 100 μm so as to have a predetermined film thickness, and are conveyed by a UV conveyor to have a predetermined thickness. The cured resin product was obtained and used as a sample. About each sample, "light transmittance", "storage elastic modulus", "curing shrinkage rate", and "surface roughness" were measured as follows.

(Light transmittance)
With respect to each sample (thickness of cured resin 100 μm), the transmittance in the visible light region was measured by an ultraviolet-visible spectrophotometer (V-560 manufactured by JASCO Corporation), and all were 90% or more.

[Storage modulus]
For each sample, a viscoelasticity measuring device (DMS6100 manufactured by Seiko Instruments Inc.)
The storage elastic modulus (Pa) (25 ° C.) was measured at a measurement frequency of 1 Hz. The obtained results are shown in Table 3.

[Curing shrinkage]
For the curing shrinkage (%), the specific gravity of the resin liquid before curing and the solid after curing was measured using an electronic hydrometer (SD-120L manufactured by MIRAGE), and was calculated from the difference in specific gravity between the two by the following equation. The obtained results are shown in Table 3.

[Surface roughness]
For each resin composition, 2 mg of each resin composition was dropped onto a glass plate for a liquid crystal cell, and a predetermined area (2.93 mm × 2.20 mm) strain (Ra: average) generated by internal stress generated during UV curing. Surface roughness) was measured with a three-dimensional non-contact surface roughness meter manufactured by Zygo. The obtained results are shown in Table 3.

As is clear from Table 3, the resin compositions a to e have a storage elastic modulus of 4 × 10 ³ to 1 × 10 ⁶ Pa and a cure shrinkage of 1.0 to 4.5%, and therefore average The surface roughness Ra = 1.5 to 5.5 nm showed almost no distortion, and good results were obtained. In contrast, the resin composition f (Ra = 12.4 nm), the resin composition g (Ra = 36.5 nm), and the resin composition h (Ra = 64.2 nm) have a large Ra, and the resin is cured. It is understood that the interface between the resin and the glass plate is distorted due to the internal stress. Therefore, when such a resin composition is filled and cured between the base portion and the protective portion, the interface between the image display portion and the protective portion is distorted, so that the occurrence of a problem that the image is distorted cannot be eliminated.

The present invention is useful for manufacturing an image display device such as a liquid crystal display device.

It is sectional process drawing which shows the principal part of one Embodiment of this invention method. It is a top view which shows the principal part of the manufacturing process of the image display apparatus in the embodiment. It is sectional process drawing which shows the principal part of the deformation | transformation aspect of the embodiment. It is sectional process drawing which shows the principal part of other embodiment. Furthermore, it is sectional process drawing which shows the principal part of different embodiment. Furthermore, it is sectional process drawing which shows the principal part of different embodiment. It is sectional drawing which shows the principal part of the display apparatus which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image display apparatus 1A ... Image display apparatus 2 ... Base part 3 ... Protection part 4 ... Translucent member 5 ... Light-shielding part 5a ... Bonding surface of light-shielding part 6 ... Frame 6a ... Frame bonding surface 7 ... Backlight 8 ... Liquid crystal display panel (image display section)
DESCRIPTION OF SYMBOLS 9 ... Spacer 10 ... Photocurable resin composition 10a ... Photocurable resin composition in an image display area 11 ... Curable resin composition which can be photocured and thermally cured 11a ... Curable resin in a light-shielding part forming area Composition 11b: Curable resin composition in image display region (non-light-shielding region) 14 ... Resin cured product layer 15 ... Resin cured product layer 30 ... Irradiation unit 31 ... UV light irradiation device 32, 33, 34 ... UV

Claims (13)

An image display apparatus comprising a step of interposing a photocurable resin composition between a base portion having an image display portion and a light-transmitting protective portion having a light-shielding portion and photocuring to form a cured resin layer. A manufacturing method comprising:
The photocurable resin composition has a cure shrinkage of 5% or less, a storage modulus of the cured product at 25 ° C. of 1.0 × 10 ⁷ Pa or less, and a light transmittance in the visible light region of the resin cured product layer of 90%. Using the resin composition as described above,
A method for producing an image display device, comprising a step of heating a curable resin composition containing a thermal polymerization initiator between at least a light shielding part and a base part.   The production method according to claim 1, wherein the curable resin composition containing a thermal polymerization initiator interposed between the light shielding part and the base part is a photocurable resin composition.   The photocurable resin composition interposed between the non-light-shielding part and the base part of the protective part does not contain a thermal polymerization initiator, but contains a thermal polymerization initiator interposed between the light-shielding part and the base part. The manufacturing method of Claim 2 which performs light irradiation and a heating with respect to a photocurable resin composition. The curable resin composition interposed between the light-shielding part and the base part has a curing shrinkage of 5% or less and a cured product having a storage elastic modulus at 25 ° C of 1.0 x 10 ⁷ Pa or less. The manufacturing method in any one of. The storage elastic modulus in 25 degreeC of the hardened | cured material of a photocurable resin composition is 1 * 10 < ³ > -1 * 10 < ⁶ > Pa, The manufacturing method in any one of Claims 1-4.   The manufacturing shrinkage rate of a photocurable resin composition is 4.0% or less, The manufacturing method in any one of Claims 1-5.   The manufacturing method according to claim 1, wherein the cured resin layer has a thickness of 50 to 200 μm.   The manufacturing method of Claim 3 which performs light irradiation with respect to the photocurable resin composition interposed between a light-shielding part and a base from the outer side surface side of the formation surface of a light-shielding part.   A photocurable resin composition comprising at least one polymer selected from polyurethane acrylate, polyisoprene acrylate or esterified product thereof, terpene hydrogenated resin and butadiene polymer, isobornyl acrylate, dicyclopentenyloxyethyl methacrylate The manufacturing method in any one of Claims 1-7 containing 1 or more types of acrylate monomers chosen from 2-hydroxybutylmethacrylate, and a photoinitiator.   The manufacturing method according to claim 1, wherein the image display unit is a liquid crystal display panel.   The manufacturing method according to claim 1, wherein the protective part is made of an acrylic resin.   The manufacturing method according to claim 1, wherein the protective part is made of optical glass.   An image display device manufactured by the manufacturing method according to claim 1.

Images