KR20190096405A - Manufacturing Method of Image Display Device - Google Patents

Abstract

The image display apparatus in which the image display member and the curved transparent cover member are laminated via the photocurable resin layer is coated with (A) the photocurable resin composition on the concave surface of the curved transparent cover member, (B ) The applied photocurable resin composition was irradiated with ultraviolet rays to be temporarily cured to form a temporary curable resin layer having a micro pits based on the curing shrinkage of the photocurable resin composition at the center of the concave portion surface. The photocurable resin composition of the quantity corresponding to the micro pits of a stratum layer is apply | coated to a provisionally curable resin layer or an image display member, (D) The image display member and a light transmissive cover member are laminated | stacked through a temporary curable resin layer, (E) It can manufacture by forming an optically cured resin layer by irradiating an ultraviolet-ray to the temporary hardening resin layer clamped between an image display member and a transparent cover member, and hardening it. .

Description

Manufacturing Method of Image Display Device

This invention is a manufacturing method of the image display apparatus in which image display members, such as a liquid crystal display panel, and light transmissive cover members, such as the curved transparent protective sheet arrange | positioned at the surface side, are laminated | stacked through the light transmissive cured resin layer. It is about.

The image display apparatus used for on-vehicle information terminals, such as a car navigation system, after apply | coating a photocurable resin composition to a flat transparent cover member, temporarily hardening by ultraviolet irradiation, and forming a temporary curable resin layer, It is manufactured by laminating | stacking flat image display members, such as a liquid crystal display panel and an organic electroluminescent panel, on a ground layer and carrying out ultraviolet curing with respect to a provisionally curable resin layer again, and hardening it into a photocurable resin layer (patent document) One).

By the way, in order to improve the design and touch feeling of the image display apparatus for vehicle information terminals, it is required to use the transparent cover member of the shape curved in one direction. For this reason, manufacture of such an image display apparatus according to the manufacturing method of patent document 1 is tried.

Japanese Patent Publication No. 2014-119520

Generally, when the photocurable resin composition is photocured by ultraviolet irradiation, curing shrinkage occurs, but in the case of the manufacturing method of Patent Document 1 in which a flat image display member is laminated on a flat transparent cover member, the surface direction in the plane direction Since the coating thickness of a chemical conversion resin composition was thin and uniform about 150 micrometers, it was hard to generate | occur | produce a void even if a photocurable resin layer hardened and shrink | contracted, and the influence of the residual stress of the photocurable resin layer on image quality was negligible.

On the other hand, when the photocurable resin composition is apply | coated to the recessed surface of the transparent cover member of the shape curved in one direction, although the application thickness of the photocurable resin composition near the uncurved side will be about 0-500 micrometers, the recessed surface The coating thickness of the photocurable resin composition in the center portion of the film becomes very thicker than the coating thickness in the vicinity of the side, and in some cases, it becomes thick up to about a few mm thick. For this reason, the cure shrinkage of a photocurable resin composition becomes remarkably large in the center part of a concave part surface, As a result, a dent is formed in a center part, and a space | gap may arise in the display surface of the stacked image display apparatus, Even if voids do not occur, there is a problem that color unevenness occurs in the display due to the residual stress of the photocurable resin layer.

DISCLOSURE OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and an image display device is laminated by laminating an image display member and a curved light-transparent cover member disposed on the surface side thereof through a cured resin layer of a photocurable resin composition. In manufacturing the film, the voids do not occur in the display surface of the stacked image display device, and even if the voids do not occur, the color unevenness does not occur in the display due to the residual stress of the photocurable resin layer. do.

MEANS TO SOLVE THE PROBLEM This inventor apply | coats a photocurable resin composition to the concave surface of a transparent cover member, and after carrying out a temporary curing process, apply | coats a photocurable resin composition to the recess of the center part of the temporary hardening resin layer newly generated by hardening shrinkage, and an image By stacking the display members and performing the main curing process, voids can be prevented from occurring on the display surface of the image display device, and residual stress of the photocurable resin layer can be reduced to prevent color irregularities of the display from occurring. The present inventors have found what is possible and have completed the present invention.

That is, this invention is the manufacturing method of the image display apparatus by which the image display member and the curved transparent cover member are laminated | stacked through the photocurable resin layer,

The following process (A)-(D):

<Step (A)>

Applying the photocurable resin composition to the concave surface of the curved light-transmissive cover member;

<Step (B)>

Irradiating ultraviolet-ray to the applied photocurable resin composition and making it temporarily harden | cure, and forming the temporary curable resin layer which has a micro dent based on the cure shrinkage of a photocurable resin composition in a recessed surface;

<Step (C)>

Applying the photocurable resin composition in an amount corresponding to the micro pits of the temporary curable resin layer to the temporary curable resin layer or the image display member;

<Step (D)>

Laminating an image display member and a light-transmissive cover member via a temporary hardening resin layer; and

<Step (E)>

Forming a light-permeable cured resin layer by irradiating ultraviolet rays to the temporary-curable resin layer sandwiched between the image display member and the light-transmissive cover member to thereby harden it;

It provides a manufacturing method having a.

In the manufacturing method of the image display apparatus of this invention, after apply | coating a photocurable resin composition to the concave part surface of the curved transparent cover member, and carrying out the temporary hardening process, to the indentation of the center part of the temporary hardening resin layer produced by hardening shrinkage | contraction. A photocurable resin composition is apply | coated anew, an image display member is laminated | stacked, and this hardening process is performed. For this reason, a space | gap can be prevented from generate | occur | producing in the display surface of an image display apparatus, Moreover, the residual stress of a photocurable resin layer can be reduced, and a color nonuniformity of a display can not be produced.

1: A is explanatory drawing of the process (A) of the manufacturing method of this invention.
1B is an explanatory diagram of a step (A) of the manufacturing method of the present invention.
1C is an explanatory diagram of a light transmissive cover member.
1D is an explanatory view of the light transmissive cover member.
1E is an explanatory diagram of a light transmissive cover member.
1F is an explanatory view of the light transmissive cover member.
1G is an explanatory diagram of a light transmissive cover member.
It is explanatory drawing of the process (B) of the manufacturing method of this invention.
It is explanatory drawing of the process (B) of the manufacturing method of this invention.
It is explanatory drawing of the process (C) of the manufacturing method of this invention.
It is explanatory drawing of the process (C) of the manufacturing method of this invention.
4 is an explanatory diagram of a step (D) of the manufacturing method of the present invention.
5 is an explanatory diagram of a step (E) of the production method of the present invention.

This invention is a manufacturing method of the image display apparatus by which the image display member and the curved transparent cover member are laminated | stacked through the photocurable resin layer, and are a manufacturing method which has the following process (A)-(E). Hereinafter, it demonstrates in detail for every process, referring drawings.

<Process (A): application process>

First, as shown in FIG. 1A, the curved transparent cover member 1 is prepared, and as shown in FIG. 1B, the recessed surface 1a of the transparent cover member 1 is dispensed with a dispenser D or the like. The photocurable resin composition (2) is apply | coated. Although the application amount of this photocurable resin composition 2 changes with the size, shape, use, etc. of an image display element, 45 (w) x 80 (l) x 3 (t) mm (curvature radius (r): 300 (mm) to the curved light-transmissive cover member, when the image display member of 40 (w) x 80 (l) mm is joined in contact with two uncurved sides of the light-transmissive cover member, preferably 23.44 At cc, the thickness of the curved deepest portion is 670 µm, and more preferably at 23.76 cc, a gap of about 100 µm can be provided between the two uncurved sides of the transparent cover member and the image display member. This gap also depends on the design of the image display device, but is preferably 50 m or more and 800 m or less. Moreover, although such coating amount may be satisfied by one application | coating operation, you may satisfy | fill by several application | coating operation.

(Transparent cover member 1)

As a specific shape of the curved light-transmissive cover member 1, a shape curved in one direction (for example, a shape of the arc side obtained by cutting a cylindrical pipe in a plane parallel to its central axis (hereinafter, referred to as a horizontal trough shape) 1A), a shape curved in the X and Y directions (FIG. 1C), a shape curved in the 360 ° direction (for example, a thermal arc obtained by cutting a sphere into a plane not including its center point) Side shape) (FIG. 1D), etc. are mentioned. The flat part 1b may be formed in the center part of these shapes (for example, FIG. 1E).

When the transparent cover member 1 is in the shape of a transverse groove (FIG. 1A), the inner dam member 3 (FIG. 1F) which partitions the coating region of the photocurable resin composition inside the both ends 1x and 1y, or It is preferable to provide the outer dam material 4 (FIG. 1G) which partitions the application | coating area | region of the photocurable resin composition on the outer side of the both ends 1x and 1y. As the inner dam material 3 and the outer dam material 4, the apply | coated photocurable resin composition can be prevented without making it compatible, and can be formed with the well-known material which can be easily removed after temporary hardening of a photocurable resin composition. have. For example, as the inner dam material 3, what attached the well-known thermoplastic elastomer tape etc. which were provided with the non-adhesive layer in a bank shape inside the edge part of the transparent cover member 1 is mentioned. Examples of the outer dam material 4 include a silicon sheet, a fluororesin sheet, and the like.

In addition, when the transparent cover member 1 is an aspect of FIG. 1C or FIG. 1D, a dam material may not be needed. Moreover, also in the case of the aspect of FIG. 1A, 1B, the surface treatment for preventing the flow of a photocurable resin composition on the surface of the transparent cover member 1 corresponding to the inner dam material 3 (for example, photocurable) Depending on the properties of the resin composition, a roughening treatment, a hydrophilization treatment, or a water repellent treatment may be performed.

As a material of the transparent cover member 1, what is necessary is just the light transmittance by which the image formed in the image display member can be visually recognized, and resin materials, such as glass, an acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate, are mentioned. have. These materials can be subjected to one-sided or two-sided hard coat treatment, anti-reflection treatment, and the like. Dimensional characteristics, such as the shape and curvature of the curvature of the transparent cover member 1, and local physical properties, such as elasticity, can be suitably determined according to a use purpose.

(Photocurable Resin Composition (2))

The property of the photocurable resin composition 2 apply | coated to the recessed surface 1a of the transparent cover member 1 becomes like liquid. When using a liquid thing, the photocurable resin composition 2 can be filled in the recessed surface 1a of the transparent cover member 1 so that a surface of a composition may become flat. Here, a liquid state shows the viscosity of 0.01-100 Pa.s (25 degreeC) with a cone plate type viscometer.

Such a photocurable resin composition (2) can preferably illustrate what contains a base component (component (a)), an acryl-type monomer component (component (b)), and a photoinitiator (component (c)). As needed, it can also contain a plasticizer component (component (d)). In addition, the final cure shrinkage rate of the photocurable resin composition (2) is 3% or more. 5% or more may be sufficient.

Here, "final cure shrinkage rate" means the cure shrinkage rate which generate | occur | produced between the state which hardened the photocurable resin composition 2 from the uncured state completely. Here, hardening completely means the state hardened | cured so that hardening rate may be at least 90% as mentioned later. Hereinafter, the final curing shrinkage rate is referred to as foreground shrinkage rate. Moreover, the cure shrinkage rate which generate | occur | produced between the state which cured the curable resin composition from the state of uncured is called a temporary cure shrinkage rate. In addition, in this main hardening process, the hardening shrinkage rate generate | occur | produced between the state which hardened completely from the state of temporary hardening is called a real hardening shrinkage rate.

Foreground shrinkage rate of the photocurable resin composition measures the specific gravity of the composition of uncured (in other words, before hardening) and the complete hardened | cured material of the solid after complete hardening using an electronic hydrometer (SD-120L made from Alpha Mirae Co., Ltd.), From the specific gravity difference of both, it can calculate by following Formula. In addition, the temporary curing shrinkage rate of the temporary curable resin of the photocurable resin composition is the specific gravity of the composition of the uncured (in other words, before curing) and the temporary cured product of the solid after the temporary hardening, the electron hydrometer (Alfa Mirage Co., Ltd. SD-120L) ), And can be calculated by the following equation from the specific gravity difference between the two. The main curing shrinkage can be calculated by subtracting the temporary curing shrinkage from the foreground shrinkage.

Foreground Shrinkage (%) = [(Compact Hardness Specific Gravity-Specific Hardness Composition Specific Gravity) / Compact Hardened Material Specific Gravity] × 100

Temporary Hardening Shrinkage (%) = [(Temporary Hardened Material Specific Gravity-Specific Cured Composition Specific Gravity) / Temporal Hardened Density] × 100

Main curing shrinkage rate (%) = total curing shrinkage rate-temporary curing shrinkage rate

The base component of component (A) is a film formation component of a light transmissive cured resin layer, and is a component containing at least one of an elastomer and an acryl-type oligomer. You may use both together as a component (a).

As an elastomer, Preferably, the acrylic copolymer which consists of a copolymer of acrylic acid ester, polybutene, a polyolefin, etc. are mentioned preferably. Moreover, the weight average molecular weight of this acrylic acid ester copolymer becomes like this. Preferably it is 5000-50000, The repeating number (n) of polybutene becomes like this. Preferably it is 10-10000.

On the other hand, as an acryl-type oligomer, Preferably, the (meth) acrylate type oligomer which has polyisoprene, a polyurethane, polybutadiene, etc. as frame | skeleton is mentioned. In addition, in this specification, the term "(meth) acrylate" includes an acrylate and a methacrylate.

As a preferable specific example of the (meth) acrylate type oligomer of a polyisoprene frame | skeleton, esterified product of the maleic anhydride adduct of a polyisoprene polymer and 2-hydroxyethyl methacrylate (UC102 (polystyrene conversion molecular weight 17000), (Note ) Kurere; UC203 (polystyrene equivalent molecular weight 35000), Kureray; UC-1 (molecular weight about 25000), Kureray).

Moreover, as a specific example of the (meth) acrylate type oligomer which has a polyurethane frame | skeleton, aliphatic urethane acrylate (EBECRYL230 (molecular weight 5000), Daicel Allnex Co., Ltd .; UA-1, Light Chemical Industry Co., Ltd.) )) And the like.

As a (meth) acrylate type oligomer of a polybutadiene skeleton, a well-known thing can be employ | adopted.

The acrylic monomer component of component (B) is used as a reactive diluent in order to provide sufficient reactivity, applicability | paintability, etc. to a photocurable resin composition in the manufacturing process of an image display apparatus. As such an acryl-type monomer, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, stearyl acrylate, benzyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyl Oxyethyl methacrylate, isobornyl acrylate, dicyclopentanyl acrylate, lauryl methacrylate and the like.

As a photoinitiator of component (C), a well-known radical photopolymerization initiator can be used, for example, 1-hydroxy cyclohexyl phenyl ketone (Irgacure184, BASF Japan Co., Ltd.), 2-hydroxy-1 -{4- [4- (2-hydroxy-2-methylpropionyl) benzyl] phenyl} -2-methyl-1-propane-1-one (Irgacure127, BASF Japan Co., Ltd.), benzophenone, acetophenone Etc. can be mentioned.

When the photopolymerization initiator is too small with respect to a total of 100 parts by mass of the acrylic oligomer and the acrylic monomer component (B) in the base component (A), when the UV curing is insufficient, the outgassing due to cleavage increases and expands. Since there exists a tendency of a defect, Preferably it is 0.1-5 mass parts, More preferably, it is 0.2-3 mass parts.

Moreover, the photocurable resin composition (2) can contain a chain transfer agent for adjustment of molecular weight. For example, 2-mercaptoethanol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, thioglycolic acid 2-ethylhexyl, 2,3-dimercapto-1-propanol, α-methylstyrene dimer Etc. can be mentioned.

Moreover, the photocurable resin composition (2) can also contain general additives, such as adhesion improving agents, such as a silane coupling agent, antioxidant, as needed.

Since the photocurable resin composition (2) is suppressed to less than 3% in the hardening shrinkage rate in the main hardening process after the temporary hardening process mentioned later, it is not essential to contain a plasticizer component fundamentally, but to a cured resin layer In addition to imparting buffering properties, a plasticizer component (component (D)) may be contained within a range that does not impair the effects of the present invention in order to reduce the cure shrinkage of the photocurable resin composition. Therefore, the total content of the base component of component (A) and the acrylic monomer component of component (B) in the photocurable resin composition is preferably 25 to 85% by mass, and the content of the plasticizer component of component (D) is 0 to 65. It is the range of mass%.

The plasticizer component of component (d) does not react with the acrylic monomer component of component (a) and the base component of component (a) under irradiation with ultraviolet rays. Such a plasticizer component contains a solid tackifier (1) and a liquid oil component (2).

As a solid tackifier (1), terpene resins, such as a terpene resin, a terpene phenol resin, and a hydrogenated terpene resin, rosin resins, such as natural rosin, polymeric rosin, rosin ester, hydrogenated rosin, terpene hydrogenated resin, Can be mentioned. Moreover, the non-reactive oligomer which previously polymerized the above-mentioned acryl-type monomer component can also be used, Specifically, the copolymer of butyl acrylate, 2-hexyl acrylate, acrylic acid, cyclohexyl acrylate, and methacrylic acid And copolymers.

The liquid oil component 2 may contain polybutadiene oil, polyisoprene oil, or the like.

<Process (B): temporary curing process>

Next, as shown in FIG. 2A, ultraviolet-ray UV is irradiated to the applied photocurable resin composition 2, and it is temporarily hardened to the recessed surface 1a of the transparent cover member 1 (usually the center part). E) Temporary hardening number which has the micro recess 5a based on the cure shrinkage of the photocurable resin composition 2 (For example, in FIG. 2B, although it is an X-shaped recess, the recess of other shapes, such as a line shape, may be sufficient). The layer 5 is formed. The "smile" in the micro recesses 5a means the volume variation due to temporary curing shrinkage. Here, temporary hardening is for improving the handleability in the state which does not flow the photocurable resin composition (2). The level of such temporary curing is a level at which the curing rate (gel fraction) of the temporary curing resin layer 5 is preferably 10 to 90%, more preferably 40 to 90%. In addition, a curing rate (gel fraction) is a ratio (amount ratio) of the abundance of the (meth) acryloyl group after ultraviolet irradiation with respect to the abundance of the (meth) acryloyl group in the photocurable resin composition (2) before ultraviolet irradiation. It is a numerical value defined as, and it shows that hardening advances so that this numerical value is large.

In addition, hardening rate (gel fraction) is the absorption peak height X of 1640-1620cm <^-1> from the baseline in the FT-IR measurement chart of the resin composition layer before ultraviolet irradiation, and the resin composition layer after ultraviolet irradiation. The absorption peak height Y of 1640-1620cm <^-1> from a baseline in an FT-IR measurement chart can be calculated by substituting the following formula | equation.

Curing Rate (%) = {(X-Y) / X} × 100

Regarding the irradiation of ultraviolet rays, the type, output, cumulative light quantity, etc. of the light source are not particularly limited as long as the curing rate (gel fraction) can be temporarily cured to preferably 10 to 80%. The radical photopolymerization process conditions of a (meth) acrylate can be employ | adopted.

Moreover, it is preferable to select the conditions which the liquid fall of the temporary hardening resin layer 5 does not generate | occur | produce at the time of the bonding operation of the process (C) mentioned later about the ultraviolet irradiation conditions in the above-mentioned hardening rate. Do. When the conditions which do not cause such a liquid fall and a deformation | transformation are expressed by a viscosity, it will be 20 Pa * S or more (corn plate rheometer, 25 degreeC cone and plate C35 / 2, rotation speed 10rpm).

The level of hardening in temporary hardening is hardened | cured so that the cure shrinkage rate generate | occur | produces between the temporary hardened resin layer 5 and hardened resin layer in the main hardening process mentioned later may be less than 3%. That is, in the case of the photocurable resin composition (2) whose foreground shrinkage rate is 5%, at least 2% of the photocurable shrinkage is temporarily cured at the time of temporary curing.

In addition, when the inner dam material 3 and the outer dam material 4 are provided in a process (A), after the process (B) and before a process (C), the inner dam material 3 or the outer dam material 4 is removed. It is preferable. This is because the photocurable resin composition 2 has already been temporarily cured and no resin flow occurs.

<Step (C): Recharge of Photocurable Resin Composition>

Next, the photocurable resin composition 2 of the quantity corresponding to the micro dents 5a of the provisionally curable resin layer 5 is temporarily hardened resin layer 5 (FIG. 3A), or the image display member 6 which is normally flat. (FIG. 3B). Here, the amount corresponding to the micro recesses 5a is the shape of the recesses of the micro recesses 5a using a micro surface shape measuring device (for example, a 3D measuring laser microscope (OLS4000 series), Shimadzu Corporation). It can be calculated by measuring. Or it can also be determined by the temporary curing shrinkage rate and the usage amount (volume) of the photocurable resin composition.

In addition, it is preferable that the photocurable resin composition (2) used at this process uses the same thing as the photocurable resin composition (2) used at the process (A) from a viewpoint of a refractive index, However, if refractive index is substantially the same, a different composition is used. You may use the photocurable resin composition. Moreover, it is preferable to apply | coat the photocurable resin composition so that the photocurable resin composition 2 may be filled in the micro recess 5a by a conventionally well-known method. For example, when apply | coating the photocurable resin composition 2 to the temporary curing resin layer 5 or the image display member 6, it is line shape (FIG. 3A, 3B), X so that the micro recessed part 5a may be filled. What is necessary is just to apply | coat a child shape or a dot shape to a center part.

Moreover, even when the application position of the photocurable resin composition 2 is shift | deviated from the micro recess 5a, since it carries out vacuum bonding, maintaining fluidity, without temporarily hardening the apply | coated photocurable resin composition 2, , The photocurable resin composition 2 can be appropriately moved to the minute recesses 5a.

Examples of the image display member 6 include a liquid crystal display panel, an organic EL display panel, a plasma display panel, a touch panel, and the like. Here, a touch panel means the image display input panel which combined the display element like a liquid crystal display panel, and the position input device like a touch pad.

Moreover, as a preferable aspect of the above-mentioned process (B) and this process (C), in a process (B), while generating a micro dent in the at least center part of the concave surface of a transparent cover member, at the process (C) The aspect which apply | coats the photocurable resin composition corresponding to 70% or more of a micro dent volume to the corresponding temporary hardening resin layer or an image display member is mentioned.

<Process (D): lamination process>

Then, the image display member 6 and the transparent cover member 1 are laminated | stacked through the temporary hardening resin layer 5 (FIG. 4). Lamination | stacking can be performed by pressurizing at 10 degreeC-80 degreeC using a well-known crimping apparatus, but air bubbles enter between the temporary hardening resin layer 5, the image display member 6, or the transparent cover member 1 In order not to go, it is preferable to perform lamination by what is called a vacuum joining method.

Moreover, after a process (D), it is preferable to perform a well-known pressurization defoaming process (process conditions example: 0.2-0.8 MPa, 25-60 degreeC, 5-20min) to a laminated body before a process (E).

<Process (E): this hardening process)>

Subsequently, the light-curable resin layer 7 is formed by irradiating ultraviolet-cured UV light on the temporary curable resin layer 5 sandwiched between the image display member 6 and the light-transmissive cover member 1 to thereby harden it ( 5). Thereby, the target image display apparatus is obtained. In addition, in this process, it is for hardening the temporary hardening resin layer 5 fully, and bonding the image display member 6 and the transparent cover member 1, and laminating | stacking them. The level of the main curing is a level at which the curing rate (gel fraction) of the light-transmissive cured resin layer 7 is preferably 90% or more, more preferably 95% or more.

In addition, the level of the light transmittance of the light transmissive cured resin layer 7 may be light transmissive so that an image formed on the image display member 6 can be visually recognized.

Example

Hereinafter, an Example demonstrates this invention concretely. In addition, in the following Examples, the foreground-curing shrinkage rate, the temporary curing shrinkage rate, and the main curing shrinkage rate of the photocurable resin composition are the specific gravity of each of the photocurable resin composition, the temporary cured product, and the complete cured product. ) SD-120L) was used, and their measurement results were applied to the following equations and calculated.

Foreground Shrinkage (%) = [(Compact Hardness Specific Gravity-Specific Hardness Composition Specific Gravity) / Compact Hardened Material Specific Gravity] × 100

Temporary Hardening Shrinkage (%) = [(Temporary Hardened Material Specific Gravity-Specific Cured Composition Specific Gravity) / Temporal Hardened Density] × 100

Main curing shrinkage rate (%) = total curing shrinkage rate-temporary curing shrinkage rate

Comparative Example 1

(Process (A): coating process)

First, a transparent resin plate (polyethylene terephthalate plate) having a size of 45 (w) x 80 (l) x 3 (t) mm is prepared, and is bent by a known method so that the radius of curvature r becomes 300 mm in the width direction. The resin cover (FIG. 1A) was obtained as the curvilinear translucent cover member.

Separately, 50 parts by mass of (meth) acrylic oligomer (TE-2000, Nippon Procurement Co., Ltd.) having a skeleton of polybutadiene, 20 parts by mass of hydroxyethyl methacrylate, 10 parts by mass of photopolymerization initiator (Irgacure184, BASF Japan (Note) 3 mass parts, 7 mass parts of SpeedCure TPO, and DKSH Japan Co., Ltd. product were mixed uniformly, and the photocurable resin composition was prepared. This photocurable resin composition showed the 5.6% foreground shrinkage rate between 0% and 90% of hardening rates.

Next, both ends of the trough-shaped resin cover were sandwiched between two silicon rubber sheets as an outer dam material (FIG. 1G). The photocurable resin composition prepared in the recessed part of this resin cover was discharged using the resin dispenser so that the thickness in the center part might be 880 micrometers thick, and the photocurable resin composition film was formed.

(Process (B): temporary curing process)

Next, about this photocurable resin composition film | membrane, the ultraviolet-ray of 200mW / cm <^2> intensity | strength was made 6 using ultraviolet irradiation apparatus (LC-8, Hamamatsu Photonics Co., Ltd.) so that accumulated light amount might be 1200mJ / cm <^2>. By irradiating initially, the photocurable resin composition film was temporarily hardened, the temporary hardening resin layer was formed, and the outer dam material was removed further. At the time of temporary hardening, it was observed that a micro recess was formed in the center part of the temporary hardening resin layer (FIG. 2B). In addition, the temporary hardening shrinkage was 3.8%.

In addition, the hardening rate of the temporary hardening resin layer was about 70% when the absorption peak height of 1640-1620cm <^-1> from the baseline in FT-IR measurement chart was calculated | required as an index | index.

(Process (D): lamination process)

Next, on the surface where the polarizing plate of the flat liquid crystal display element of the size of 40 (W) x 80 (L) mm was laminated | stacked, the temporary hardening resin layer side of the light-curable resin layer side obtained by the process (B) It was put as much as possible, and it attached with the vacuum bonding machine (vacuum degree of 50 Pa, bonding pressure 0.07 MPa, bonding time 3 second, normal temperature) from the resin cover side (FIG. 4).

(Process (E): this curing process)

Next, about this liquid crystal display element, the number of temporary hardenings is carried out by irradiating an ultraviolet-ray (200mW / cm <^2> ) by 3000mJ / cm <^2> using an ultraviolet irradiation device (ECS-03601EG, iGraphics Co., Ltd.) from the resin cover side. The ground layer was completely cured to form a light-transmissive cured resin layer. The curing rate of the light transmissive cured resin layer was 98%. Thereby, the liquid crystal display device by which the resin cover curved as the transparent cover member was laminated | stacked on the liquid crystal display element via the transparent curable resin layer was obtained. In addition, the main curing shrinkage was 1.8%.

About the obtained liquid crystal display device, the presence or absence of the generation | occurrence | production of a space | gap was observed visually from the resin cover side, and the bubble-shaped space | gap generate | occur | produced in the substantially center part of the interface of a transparent curable resin layer and a liquid crystal display element.

Comparative Example 2

As a photocurable resin composition, 40 mass parts of (meth) acrylate type oligomers (UC203, Kuraray Co., Ltd.) which have a skeleton of polyisoprene, dicyclopentenyl oxyethyl methacrylate (FA512M, Hitachi Chemical Co., Ltd.) 20 parts by mass, hydroxypropyl methacrylate (HPMA, Nippon Chemical Co., Ltd.) 3 parts by mass, tetrahydrofurfuryl acrylate (light ester THF, Kyisha Chemical Co., Ltd.) 15 parts by mass, lauryl acrylate (Light ester L, Kyoeisha Chemical Co., Ltd.), 20 parts by mass of a polybutadiene polymer (Polyoil 110, Evonik Japan Co., Ltd.), 45 parts by mass of hydrogenated terpene resin (P85, Yashara Chemical Co., Ltd.) Other than using a photocurable resin composition (showing 3.4% foreground shrinkage between 0% and 90% of curing rate) prepared by uniformly blending 4 parts by mass of a photopolymerization initiator (Irgacure184, BASF Japan Co., Ltd.). And the liquid crystal display device were obtained by operation similar to the comparative example 1. .

As a result of visually observing the presence or absence of the generation | occurrence | production of the space | gap with respect to the obtained liquid crystal display device, the space | gap was not observed in the interface of a liquid crystal display device (polarizing plate) and a transparent curable resin layer, but as a result of performing display operation, Color nonuniformity was observed in the indication of the center of a resin cover. In addition, the temporary hardening shrinkage was 3.1% and this hardening shrinkage was 0.3%.

Comparative Example 3

As a photocurable resin composition, 6 mass parts of polyisoprene methacrylates (UC102, Kuraray) as optical radically polymerizable poly (meth) acrylate, and 15 mass parts of dicyclopentenyl oxyethyl methacrylate as a reactive diluent And 5 parts by mass of lauryl methacrylate, 20 parts by mass of polybutadiene (Polyvest110, Evonik Japan) as a plasticizer, 1 part by mass of a photopolymerization initiator (Irgacure184, BASF Japan), and hydrogen as a tackifier. Use the photocurable resin composition (it shows 2.6% foreground shrinkage between 0% and 90% of hardening) prepared and mix | blended 53 mass parts of addition terpene resins (Clearon M105, Yashara Chemical Co., Ltd.) uniformly. A liquid crystal display device was obtained by the same operation as in Comparative Example 1, except that

As a result of visually observing the presence or absence of the generation | occurrence | production of the space | gap with respect to the obtained liquid crystal display device, the space | gap was not observed in the interface of a liquid crystal display device (polarizing plate) and a light-transmissive cured resin layer, but when a display operation was performed, Color nonuniformity was observed in the indication of the center of a resin cover. In addition, the temporary hardening shrinkage was 2.2% and this hardening shrinkage was 0.4%.

Example 1

Between process (B) and process (D) in the comparative example 1, as process (C), in the photocurable resin composition (process (A) of the comparative example 1) of the quantity corresponding to the micro depression of the provisionally curable resin layer The liquid crystal display device was obtained by the same operation as the comparative example 1 except having apply | coated to the center part of the temporary hardening resin layer in the line shape using the resin dispenser used also in the comparative example 1). In addition, the quantity corresponding to the micro depression of the provisionally curable resin layer of the photocurable resin composition was measured by the usage-amount (volume) of the photocurable resin composition, and provisional shrinkage rate, and the quantity was 0.91 cc.

As a result of observing the presence or absence of the generation | occurrence | production of the space | gap with respect to the obtained liquid crystal display device visually from the resin cover side, the space | gap was not observed in the interface of a resin cover and a transparent curable resin layer. Moreover, as a result of performing a display operation, the color nonuniformity was not observed in the display of the center of a resin cover. In addition, the temporary hardening shrinkage was 3.8% and this hardening shrinkage was 1.8%.

Example 2

Between process (B) and process (D) in the comparative example 1, as process (C), in the photocurable resin composition (process (A) of the comparative example 1) of the quantity corresponding to the micro depression of the provisionally curable resin layer The liquid crystal display device was obtained by the same operation as the comparative example 1 except having apply | coated to the center part of the temporary hardening resin layer in the line shape using the resin dispenser used also in the comparative example 1). In addition, the amount corresponding to the micro pits of the provisionally curable resin layer of the photocurable resin composition was 0.91 cc as measured by the amount (volume) and the provisional shrinkage rate of the photocurable resin composition, but was 0.64 cc corresponding to about 70%. Photocurable resin composition was applied.

As for the obtained liquid crystal display device, the presence or absence of generation | occurrence | production of a space | gap was observed visually from the resin cover side, and as a result, the space | gap was hardly observed at the interface of a resin cover and a transparent curable resin layer. Moreover, as a result of performing a display operation, the color nonuniformity was not observed in the display of the center of a resin cover. In addition, the temporary hardening shrinkage was 3.8% and this hardening shrinkage was 1.8%.

Example 3

Between process (B) and process (D) in the comparative example 2, as a process (C), in the photocurable resin composition (process (A) of the comparative example 1) of the quantity corresponding to the micro depression of the provisionally curable resin layer The liquid crystal display device was obtained by the same operation as the comparative example 1 except having apply | coated to the center part of the temporary hardening resin layer in the line shape using the resin dispenser used also in the comparative example 1). In addition, the quantity corresponding to the micro dents of the provisionally curable resin layer of the photocurable resin composition was measured by the usage-amount (volume) of the photocurable resin composition, and provisional shrinkage rate, and the quantity was about 0.74cc.

As a result of observing the presence or absence of the generation | occurrence | production of the space | gap with respect to the obtained liquid crystal display device visually from the resin cover side, the space | gap was not observed in the interface of a resin cover and a transparent curable resin layer. Moreover, as a result of performing a display operation, the color nonuniformity was not observed in the display of the center of a resin cover. In addition, the temporary hardening shrinkage was 3.1% and this hardening shrinkage was 0.3%.

Example 4

Between the process (B) and the process (D) in the comparative example 3, as a process (C), in the photocurable resin composition (process (A) of the comparative example 1) of the quantity corresponding to the micro depression of the provisionally curable resin layer Operation similar to the comparative example 1 except having apply | coated to the liquid crystal display element side of the location corresponding to a line shape in the center part of the temporary hardening resin layer using the dispenser for resin used also in the comparative example 1) The liquid crystal display device was obtained by. In addition, the quantity corresponding to the micro dents of the provisionally curable resin layer of the photocurable resin composition was measured by the usage-amount (volume) of the photocurable resin composition, and provisional shrinkage rate, and the quantity was 0.53 cc.

As a result of observing the presence or absence of the generation | occurrence | production of the space | gap with respect to the obtained liquid crystal display device visually from the resin cover side, the space | gap was not observed in the interface of a resin cover and a transparent curable resin layer. Moreover, as a result of performing a display operation, the color nonuniformity was not observed in the display of the center of a resin cover. In addition, the temporary hardening shrinkage was 2.2% and this hardening shrinkage was 0.4%.

Industrial availability

In the manufacturing method of the image display apparatus of this invention, after apply | coating a photocurable resin composition to the concave part surface of the curved transparent cover member, and carrying out the temporary hardening process, it is a new sight to the dent of the center part of the temporary hardening resin layer produced by hardening shrinkage. A chemical conversion resin composition is apply | coated, an image display member is laminated | stacked, and this hardening process is performed. For this reason, a space | gap can be prevented from generate | occur | producing in the display surface of an image display apparatus, Moreover, the residual stress of a photocurable resin layer can be reduced, and a color nonuniformity of a display can not be produced. Therefore, the manufacturing method of this invention is useful for industrial manufacture of the on-vehicle information terminal provided with a touchscreen.

1 transparent cover member
1a recessed surface of the transparent cover member
1x, 1y both ends
2 photocurable resin composition
3 inner dam material
4 Outside dam ash
5 temporary curing resin layer
5a smile
6 image display member
7 Light-transmitting cured resin layer
D dispenser

Claims (11)

In the manufacturing method of the image display apparatus by which the image display member and the curved transparent cover member are laminated | stacked through the photocuring resin layer,
The following process (A)-(D):
<Step (A)>
Applying the photocurable resin composition to the concave surface of the curved light-transmissive cover member;
<Step (B)>
Irradiating ultraviolet-ray to the applied photocurable resin composition and making it temporarily harden | cure, and forming the temporary curable resin layer which has a micro dent based on the cure shrinkage of a photocurable resin composition in a recessed surface;
<Step (C)>
Applying the photocurable resin composition in an amount corresponding to the micro pits of the temporary curable resin layer to the temporary curable resin layer or the image display member;
<Step (D)>
Laminating an image display member and a light-transmissive cover member via a temporary hardening resin layer; and
<Step (E)>
Forming a light-permeable cured resin layer by irradiating ultraviolet rays to the temporary-curable resin layer sandwiched between the image display member and the light-transmissive cover member to thereby harden it;
Which has a manufacturing method. The method according to claim 1,
The manufacturing method of the light transmissive cover member used at a process (A) having a cross groove shape. The method according to claim 1 or 2,
In the step (B), while generating micro pits in at least the center of the concave surface of the transparent cover member, the photocurable resin composition corresponding to 70% or more of the micro pave volume in the step (C) corresponds to The manufacturing method apply | coated to a temporary hardening resin layer or an image display member. The method according to claim 2 or 3,
An inner dam material or an outer dam material which partitions the application | coating area | region of a photocurable resin composition, respectively is provided in the inside or the outer side of the cross-groove-shaped both ends of a transparent cover member. The method according to claim 4,
The manufacturing method which removes an inner dam material or an outer dam material between a process (B) and a process (C). The method according to any one of claims 1 to 5,
The manufacturing method which laminates a process (D) by the vacuum bonding method. The method according to any one of claims 1 to 6,
The manufacturing method which performs a pressure defoaming process between a process (D) and a process (E). The method according to any one of claims 1 to 7,
The image display member is a liquid crystal display panel, an organic EL display panel, a plasma display panel or a touch panel. The method according to any one of claims 1 to 8,
In the step (B), the photocurable resin composition is irradiated with ultraviolet rays to be temporarily cured so that the curing rate of the temporary curable resin layer is 10 to 90%. The method according to any one of claims 1 to 9,
In the step (E), the temporary curing resin layer is irradiated with ultraviolet rays so that the curing rate of the light-transmissive cured resin layer is 90% or more. The method according to any one of claims 1 to 10,
The photocurable resin composition is a liquid resin composition containing at least one of an elastomer and an acrylic oligomer, an acrylic monomer, and a photopolymerization initiator,
The elastomer is at least one selected from the group consisting of acrylic copolymers, polybutenes and polyolefins,
The manufacturing method of the acrylic oligomer is at least 1 sort (s) chosen from the group which consists of a polyurethane-type (meth) acrylate, a polybutadiene-type (meth) acrylate, and a polyisoprene-type (meth) acrylate.

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