TW201726876A - Photocurable resin composition and method for producing picture display device - Google Patents

Abstract

To provide a photocurable resin composition capable of reducing the degree of elasticity in a light permeable curable resin layer under a low temperature environment. Provided is a photocurable resin composition containing: a (meth)acrylic oligomer; a (meth)acrylate monomer; a polymerization initiator; and a plasticizer. The plasticizer includes at least one kind of polybutadiene in which a 1,2 bond ratio being below 80% and polyisoprene in which a 1,2 bond ratio being below 80%.

Description

Photocurable resin composition and method of manufacturing image display device

The present invention relates to a method for producing a light-transmitting and hardening resin layer by using an optically-transparent optical member disposed on a surface of a light-transmitting resin layer and then laminating a layer to form an image display device. A photocurable resin composition and a method of producing an image display device. This application is based on the Japanese application number No. 2015-171790, which was filed on September 1, 2015 in Japan, and the Japanese application number 2015-192011, which was filed on September 29, 2015 in Japan. Those who claim priority are referred to in this application by reference.

For example, a video display device such as a liquid crystal display panel such as a liquid crystal display panel or an organic EL panel is provided with a photocurable resin composition to form a photohardenable resin. A layer of a resin composition. After that, the photocurable resin composition layer is irradiated with light and cured to form a light-transmitting and curing resin layer. As described above, the image display device is manufactured by laminating the image display member and the translucent optical member.

The photocurable resin composition contains, for example, a (meth) acrylate oligomer component, an alkyl (meth) acrylate monomer component, a photopolymerization initiator, and a plasticizer component. The photocurable resin composition (for example, refer to Patent Documents 1 and 2).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2014-237745

[Patent Document 2] International Publication No. 2013/013568

In order to obtain a more sufficient adhesive strength, it is desirable to design the glass transition temperature of the light-transmitting and hardening resin layer (hardened product of the photocurable resin composition) to a high temperature of a temperature higher than the use temperature.

Here, there is a tendency that the higher the elastic modulus of the light-transmitting and hardening resin layer in a low-temperature environment, the light-transmitting hardened resin layer and the adherend (for example, light transmission) due to a drop impact or the like in a low-temperature environment. The more easily the optical member or the image display member is peeled off. It is known that this tendency is remarkable especially when the glass transition temperature of the layer of the curable resin composition is high. Therefore, a photocurable resin composition capable of reducing the elastic modulus of the light-transmitting and hardening resin layer in a low-temperature environment is required.

The present invention has been made in view of such a conventional situation, and provides a photocurable resin composition capable of reducing the elastic modulus of a light-transmitting and hardening resin layer in a low-temperature environment.

The photocurable resin composition of the present invention contains a (meth)acrylic oligomer having a urethane skeleton, a (meth) acrylate monomer, a polymerization initiator, and a plasticizer. Further, the plasticizer contains at least one of a polybutadiene having a 1,2 bond ratio of less than 80% and a polyisoprene having a 1,2 bond ratio of less than 80%.

Further, the method for producing an image display device of the present invention has the steps of: applying a photocurable resin composition to the surface of the translucent optical member or the surface of the image display member; and displaying the image display member and the transmissive optical a step of bonding the member via the photocurable resin composition; and a step of curing the photocurable resin composition; and the photocurable resin composition is the photocurable resin composition.

The present invention is achieved by using a (meth)acrylic oligomer having an amine ester skeleton, a (meth)acrylic monomer, a 1,2 bond ratio of less than 80% of polybutadiene, and 1, The photocurable resin composition of at least one of polyisoprene having a bonding ratio of less than 80% can reduce the elastic modulus of the light-transmitting and hardening resin layer in a low-temperature environment.

1‧‧‧ shading layer

2‧‧‧Transparent optical components

2a‧‧‧The light-shielding layer of the translucent optical member forms the side surface

3‧‧‧Photocurable resin composition layer

3A‧‧‧Photocurable resin composition

4‧‧ ‧ step

5‧‧‧ Temporary hardening resin layer

6‧‧‧Image display component

7‧‧‧Transparent hardening resin layer

10‧‧‧Image display device

31, 32‧‧‧ glass plates

33‧‧‧glass joint

34‧‧‧ Spacer

35‧‧‧Transparent hardening resin layer

36‧‧‧ fixture

Fig. 1A is an explanatory view showing an example of a step (A1) of a method of manufacturing a video display device.

Fig. 1B is an explanatory view showing an example of a step (B1) of a method of manufacturing a video display device.

Fig. 1C is an explanatory view showing an example of a step (C1) of the method of manufacturing the image display device.

Fig. 1D is an explanatory view showing an example of a step (C1) of a method of manufacturing a video display device.

Fig. 2A is an explanatory view showing an example of a step (A2) of a method of manufacturing a video display device.

Fig. 2B is an explanatory view showing an example of a step (A2) of the method of manufacturing the image display device.

2C is an explanatory view showing an example of the step (B2) of the method of manufacturing the image display device.

2D is an explanatory view showing an example of the step (B2) of the method of manufacturing the image display device.

2E is an explanatory view showing an example of a step (C2) of the method of manufacturing the image display device.

2F is an explanatory view showing an example of the step (D2) of the method of manufacturing the image display device.

2G is an explanatory view showing an example of the step (D2) of the method of manufacturing the image display device.

3A is an explanatory view showing an example of a step (A3) of the method of manufacturing the image display device.

Fig. 3B is an explanatory view showing an example of a step (A3) of the method of manufacturing the image display device.

3C is an explanatory view showing an example of the step (B3) of the method of manufacturing the image display device.

3D is an explanatory view showing an example of the step (B3) of the method of manufacturing the image display device.

3E is an explanatory view showing an example of a step (C3) of the method of manufacturing the image display device.

4 is a perspective view showing a glass joined body in which a light-transmitting and hardening resin layer is formed.

Figure 5 is a cross-sectional view taken along line A-A' of Figure 4.

Fig. 6 is a cross-sectional view for explaining a bonding strength test of a glass bonded body in which a light-transmitting and hardening resin layer is formed.

Fig. 7 is a plan view showing the adhesion strength test of the glass joined body in which the light-transmitting and hardening resin layer is formed.

Hereinafter, embodiments of the present invention will be described in detail in the following order. In the present specification, the term "(meth)acrylate" includes acrylate and methacrylate. Further, the term "(meth)acryl fluorenyl) includes an acryl fluorenyl group and a methacryl fluorenyl group.

1. Photocurable resin composition

2. Method of manufacturing image display device

3. Embodiment

<1. Photocurable resin composition>

The photocurable resin composition of the present embodiment contains a (meth)acrylic oligomer having an amine ester skeleton (hereinafter also referred to as an urethane oligomer (A)) and a (meth) acrylate monomer. , a polymerization initiator, and a plasticizer, and the plasticizer contains a polybutadiene having a 1,2 bond ratio of less than 80%, and a polyisoprene having a 1,2 bond ratio of less than 80%. At least one. By using such a photocurable resin composition, the elastic modulus of the light-transmitting and hardening resin layer in a low-temperature environment can be reduced.

The photocurable resin composition contains an acrylic oligomer and a (meth) acrylate monomer as a radical polymerizable component, and contains an urethane acrylate oligomer (A) as an acryl oligomer.

[Acrylic oligomer]

The acrylic oligomer is used as a reactive diluent for imparting sufficient reactivity and coating properties to the photocurable resin composition. The photocurable resin composition contains an urethane acrylate oligomer (A), and may contain an acryl oligomer other than the urethane amide oligomer (A) as needed.

[Amino acid acrylate oligomer (A)]

The urethane acrylate oligomer (A) is an oligomer compound having a (meth) acrylonitrile group and an amine ester bond.

The weight average molecular weight of the urethane acrylate oligomer (A) is preferably from 1,000 to 100,000, more preferably from 1,000 to 70,000, still more preferably from 1,000 to 50,000.

The urethane acrylate oligomer (A) is obtained, for example, by reacting a polyisocyanate compound, a (meth) acrylate having a hydroxyl group or an isocyanate group, and a polyol compound. Got it.

Examples of the polyisocyanate compound include isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-benzenedimethyl diisocyanate, and 1,4-benzoic acid. Diisocyanate such as bis-isocyanate or diphenylmethane-4,4'-diisocyanate.

Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. Base) 4-hydroxybutyl acrylate, polyethylene glycol (meth) acrylate. Examples of the (meth) acrylate having an isocyanate group include methacryloxyethyl isocyanate.

Examples of the polyhydric alcohol compound include polyhydric alcohol compounds such as an alkylene type, a polycarbonate type, a polyester type, and a polyether type. Specific examples thereof include polyethylene glycol, polypropylene glycol, and polytetramethylene. Base diol, polycarbonate diol, polyester diol, polyether diol, and the like.

Specific examples of the urethane amide oligomer (A) include TEAI-1000 (manufactured by Nippon Soda Co., Ltd.), EBECRYL 230 (manufactured by Daicel Allnex Co., Ltd.), CN9014, CN9893, CN964, CN9001, and CN9788. , CN9783 (above is manufactured by Sartomer Co., Ltd.), UA-1 (manufactured by Light Chemical Industry Co., Ltd.), and the like.

The content of the urethane amide oligomer (A) of the photocurable resin composition is preferably from 5 to 40% by mass, more preferably from 20 to 40% by mass. The urethane acrylate oligomer (A) may be used alone or in combination of two or more. In the case where two or more kinds of urethane amide oligomers (A) are used in combination, it is preferred that the total amount thereof satisfies the above range.

[Other (meth)acrylic oligomers]

Examples of the other (meth)acrylic oligomer include a (meth)acrylate oligomer having a polyisoprene or a polybutadiene in the skeleton. As a (meth) propyl group having a polyisoprene skeleton Specific examples of the enoate oligomer include an ester of a maleic anhydride adduct of a polyisoprene polymer and 2-hydroxyethyl methacrylate (UC102, UC203, UC-1 ( The above is manufactured by Kuraray Co., Ltd.)).

When the photocurable resin composition contains another (meth)acrylic oligomer, the content of the other (meth)acrylic oligomer in the photocurable resin composition is preferably from 1 to 20% by mass. More preferably, it is 1 to 15% by mass. Other (meth)acrylic oligomers may be used alone or in combination of two or more. In the case where two or more other (meth)acrylic oligomers are used in combination, it is preferred that the total amount thereof satisfies the above content range.

[(Meth)acrylate monomer]

The (meth) acrylate monomer is not particularly limited, but is preferably a (meth) group having a ring structure from the viewpoint of more effectively reducing the elastic modulus of the light-transmitting and hardening resin layer in a low-temperature environment. Acrylate monomer. Further, the (meth) acrylate monomer may further contain another (meth) acrylate monomer.

The (meth) acrylate having a ring structure preferably has an alicyclic hydrocarbon group as a ring structure. The carbon number of the alicyclic hydrocarbon group is preferably from 4 to 30, more preferably from 4 to 20, still more preferably from 8 to 14. The alicyclic hydrocarbon group may have a single ring structure or a polycyclic structure. The alicyclic hydrocarbon group may be saturated or unsaturated. The alicyclic hydrocarbon group may also have a substituent.

The photocurable resin composition preferably contains a (meth) acrylate monomer represented by any one of the following formulas (1) to (3) (hereinafter, also referred to as a specific (meth) acrylate monomer. ).

(In the formulae (1) to (3), R each independently represents a hydrogen atom or a methyl group, and X represents -O-, -O(CH ₂ ) _n O-, -O(CH ₂ CH ₂ O) _n -, Or -O(CH(CH ₃ )CH ₂ O) _n -, Y represents -O-, -O(CH ₂ ) _m O-, -O(CH ₂ CH ₂ O) _m -, or -O(CH( CH ₃ )CH ₂ O) _m -, n and m each independently represent an integer from 1 to 10)

In the formulae (1) to (3), R preferably each independently represents a hydrogen atom. In the formulae (1) to (3), X preferably each independently represents -O-. In the formula (3), Y preferably represents -O-. In the formulae (1) to (3), n and m are preferably each independently an integer of 1 to 6.

The specific (meth) acrylate monomer is preferably a (meth) acrylate monomer represented by the above formula (1) or formula (2). Specifically, the specific (meth) acrylate monomer is preferably dicyclopentanyl acrylate, dicyclopentanyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, and methyl group. At least one of dicyclopentenyloxyethyl acrylate. More preferably, it is at least one of dicyclopentanyl acrylate and dicyclopentanyl methacrylate.

Other than the specific (meth) acrylate monomer having other ring structures (A Specific examples of the acrylate monomer include, for example, isodecyl (meth)acrylate.

Further, specific examples of the (meth) acrylate other than the (meth) acrylate monomer having a ring structure include hexanediol diacrylate.

The content of the (meth) acrylate monomer in the photocurable resin composition is preferably 15 to 45% by mass, more preferably 20 to 40% by mass. The (meth) acrylate monomers may be used alone or in combination of two or more. In the case where two or more (meth) acrylate monomers are used in combination, it is preferred that the total amount thereof satisfies the above range.

Further, in the photocurable resin composition, the content of the (meth) acrylate monomer having a ring structure is preferably from 1 to 35% by weight, more preferably from 10 to 35% by mass.

[Polymerization initiator]

The polymerization initiator is preferably a photoradical polymerization initiator, more preferably at least one of an alkylphenone photopolymerization initiator and a mercaptophosphine oxide photopolymerization initiator, and further It is preferred to contain an alkylphenone photopolymerization initiator and a mercaptophosphine oxide photopolymerization initiator. As the alkylphenone-based photopolymerization initiator, 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by BASF Corporation), 2-hydroxy-1-{4-[4-(2-hydroxy-2-) can be used. Methyl-propenyl)benzyl]phenyl}-2-methyl-1-propan-1-one (Irgacure 127, manufactured by BASF Corporation) and the like. As the mercaptophosphine oxide photopolymerization initiator, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide (Lucirin TPO, manufactured by BASF Corporation) or the like can be used. Examples of the other polymerization initiator include benzophenone and acetophenone.

The content of the photopolymerization initiator is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, per 100 parts by mass of the total of the radical polymerizable component. By setting it as such a range, it is possible to more effectively prevent insufficient hardening at the time of light irradiation, and more effectively prevent an increase in outgassing due to cracking. The polymerization initiator may be used alone or in combination of two or more. Use together In the case of two or more kinds of polymerization initiators, it is preferred that the total amount thereof satisfies the above range.

[Plasticizer]

The photocurable resin composition contains at least one of polybutadiene having a 1,2 bond ratio of less than 80% and polyisoprene having a 1,2 bond ratio of less than 80% as a plasticizer. The photocurable resin composition can reduce the elastic modulus of the cured product of the photocurable resin composition in a low temperature environment by containing such a plasticizer.

The photocurable resin composition is particularly preferably a hydride of polybutadiene having a 1,2 bond ratio of less than 80%, and a hydride of polyisoprene having a 1,2 bond ratio of less than 80%. At least one is used as a plasticizer. Thereby, even when the glass transition temperature of the curable resin composition layer is high, the elastic modulus of the cured product of the photocurable resin composition in a low temperature environment can be more effectively reduced. Moreover, the bonding strength can also be made good.

The upper limit of the bonding ratio of 1,2 in the above polybutadiene is preferably 75% or less, more preferably 70% or less. Further, the lower limit of the 1,2 bond ratio in the polybutadiene is preferably 50% or more, more preferably 55% or more, still more preferably 60% or more.

Specific examples of the polybutadiene having a 1,2 bond ratio of less than 80% include Krasol HLBH-P2000 (1,2 hydride of polybutadiene having a bonding ratio of 65%, manufactured by Crayvalley Co., Ltd.) Krasol HLBH-P3000 (1,2 hydride of polybutadiene with a bonding ratio of 65%, manufactured by Crayvalley), Krasol LBH-P2000 (1,2 polybutadiene with a bonding ratio of 65%, Crayvalley Made by the company), Krasol LBH-P3000 (1,2 bond-capacity 65% polybutadiene, manufactured by Crayvalley), LBH-P5000 (1,2 bond-capacity 65% polybutadiene, Crayvalley Manufacturing) and so on.

The upper limit of the bonding ratio of 1,2 in the polyisoprene is preferably 70% or less, more preferably 60% or less, still more preferably 50% or less. Further, the 1,2 bond in the above polyisoprene The lower limit of the ratio is preferably 10% or more, more preferably 15% or more, and still more preferably 20% or more.

Specific examples of the polyisoprene having a 1,2 bond ratio of less than 80% include EPOL (1,2 hydride of polyisoprene having a bonding ratio of 20%). )))).

The number average molecular weight of the plasticizer is preferably 1,000 or more. By setting it as such a range, bleed-out can be suppressed more effectively. The upper limit of the number average molecular weight of the plasticizer is preferably 20,000 or less, more preferably 10,000 or less.

The structure of the molecular terminal of the plasticizer is not particularly limited, and examples thereof include a hydrogen atom, a hydroxyl group, an acrylonitrile group, an isocyanate group, and a carboxyl group, and a hydroxyl group is preferable.

The content of the plasticizer in the photocurable resin composition is preferably from 15 to 50% by mass, more preferably from 25 to 45% by mass. By setting it as such a range, the elastic modulus of the light-transmitting-hardening resin layer in a low temperature environment can be more effectively reduced. The plasticizers may be used alone or in combination of two or more. In the case where two or more plasticizers are used in combination, it is preferred that the total amount thereof satisfies the above range.

Further, in the plasticizer, the total content of the polybutadiene having a 1,2 bond ratio of less than 80% and the polyisoprene having a 1,2 bond ratio of less than 80% is preferably 30% by mass. The above is more preferably 50% by mass, still more preferably 80% by mass or more. By setting it as such a range, the elastic modulus of the light-transmitting-hardening resin layer in a low temperature environment can be more effectively reduced.

The photocurable resin composition may further contain other plasticizers other than the above plasticizer. Examples of the other plasticizer include a solid adhesion-imparting agent and a liquid oil component. Examples of the solid adhesion-imparting agent include terpene resins such as terpene resins, indophenol resins, and hydrogenated terpene resins, and rosin resins such as natural rosin, polymerized rosin, rosin ester, and hydrogenated rosin. Examples of the liquid oil component include a polybutadiene-based oil and a polyisoprene-based oil.

[Other ingredients]

The photocurable resin composition may contain other components than the above components within a range that does not impair the effect of reducing the elastic modulus of the light-transmitting and hardening resin layer in a low-temperature environment. For example, the photocurable resin composition may further contain a chain transfer agent in order to adjust the molecular weight. As the chain transfer agent, for example, 2-mercaptoethanol, lauryl mercaptan, epoxypropyl thiol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol can be mentioned. , α-methylstyrene dimer, and the like. Further, the photocurable resin composition may further contain an adhesion improver such as a decane coupling agent, an antioxidant, or the like.

The photocurable resin composition can be prepared by uniformly mixing the above components in accordance with a known mixing method.

The photocurable resin composition is preferably in a liquid form. By using the photocurable resin composition as a liquid, for example, in the method of manufacturing an image display device described below, the step formed on the side surface of the light shielding layer and the light shielding layer of the light transmissive optical member can be more reliably eliminated. . Here, the photocurable resin composition is in the form of a liquid, and it is preferable that the viscosity at 25 ° C measured by a B-type viscometer is 0.01 to 100 Pa s.

The photocurable resin composition preferably has a glass transition temperature of 40 to 80 ° C. The measurement conditions of the glass transition temperature are as described in the following examples.

Specifically, the photocurable resin composition is preferably an average hardening rate of the cured resin obtained by photoradical polymerization in the atmosphere by light irradiation, and an outermost surface of the cured resin. The glass transition temperature in the case where the hardening rate is 90% or more (preferably 97% or more) is hardened to satisfy the above range.

The reason for focusing on the cured resin of the photoradical polymerization in the atmosphere is that it is difficult to cause hardening of the hardened resin due to oxygen in the atmosphere. The hardening conditions which affect the various properties of the hardened resin due to the hardening of the hardening. Moreover, it is preferable that the hardening rate of the outermost surface of the cured resin is 90% or more because the surface of the cured resin can be practically ignored even when the hardening of the surface of the cured resin is caused. The characteristics such as the adhesion are reduced. Furthermore, it is preferable that the glass transition temperature of the cured resin of the cured ratio is in the above range, and if it is within this range, the adhesion of the cured resin of the formed film can be prevented or maintained. Characteristics such as sex deteriorate.

Here, the curing rate (gel fraction) is defined as the amount of (meth)acryl fluorenyl group present in the photocurable resin composition layer after light irradiation with respect to (meth) before light irradiation. The ratio of the ratio of the amount of the acrylonitrile group (the ratio of consumption), and it is shown that the larger the value, the harder the curing. Specifically, the curing rate can be obtained by using the photocurable resin composition layer before the light irradiation in the FT-IR measurement chart, the absorption peak height (X) of the distance reference line of 1640 to 1620 cm ^-1 , and after the light irradiation. The light-curable resin composition layer (translucent cured resin layer) was calculated by substituting the following equation for the absorption peak height (Y) of the distance reference line from 1640 to 1620 cm ^-1 in the FT-IR measurement chart.

Hardening rate (%) = [(X-Y) / X] × 100

The hardening rate of the surface of the cured resin is, for example, a hardening rate measured for a cured resin of a film having a thickness of 10 μm or less (for example, 5 μm thick). Further, the curing rate of the entire cured resin material means, for example, a curing rate measured for a cured resin of a resin having a thickness of 100 μm or more (for example, 200 μm thick).

The elastic modulus of the cured resin of the photocurable resin composition at -20 ° C is preferably 3.0E+08 Pa or less, more preferably 2.9E+08 Pa or less. Further, the lower limit of the elastic modulus of the cured resin of the photocurable resin composition at -20 ° C is usually preferably 1.0 E + 08 Pa or more. Further, the resin cured product of the photocurable resin composition preferably has an elastic modulus at 25 ° C of 1.0 E + 08 Pa. under. The lower limit of the elastic modulus of the cured resin of the photocurable resin composition at 25 ° C is usually preferably 1.0 E + 06 Pa or more. The measurement conditions of the elastic modulus are as described in the following examples. Here, the resin cured product refers to an average hardening rate of the cured resin obtained by photoradical polymerization by light irradiation in the atmosphere, and a hardening rate of the outermost surface of the cured resin. 90% or more (preferably 97% or more) makes it harder.

The transmittance of the cured resin of the photocurable resin composition is preferably 90% or more, more preferably 92% or more. By satisfying such a range, the visibility of the image formed on the image display member constituting the image display device can be made better. Here, the term "resin cured product" means the same as the above-mentioned resin cured product.

<2. Method of Manufacturing Image Display Device>

Hereinafter, the first to third embodiments of the method of manufacturing the video display device will be described in detail with reference to the drawings. In the drawings, the same reference numerals denote the same constituent elements.

[First Embodiment]

[Step (A1)]

In the step (A1), the photocurable resin composition is applied onto the surface of the light transmissive optical member or the surface of the image display member. Fig. 1A is an explanatory view showing an example of a step (A1) of a method of manufacturing a video display device. The translucent optical member 2 having the light shielding layer 1 formed on the peripheral portion of one surface is prepared, and the photocurable resin composition 3A is applied onto the surface of the translucent optical member 2.

The light shielding layer 1 is provided, for example, to increase the contrast of the image. In the light-shielding layer 1, a paint colored in black or the like is applied by a screen printing method or the like, and dried and cured. The thickness of the light shielding layer 1 is usually 5 to 100 μm.

The translucent optical member 2 may have a light transmissive property capable of visually recognizing an image formed on the image display member. For example, a plate-shaped material or a sheet material such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate or polycarbonate may be mentioned. For these materials, hard coating treatment, anti-reflection treatment, or the like may be applied to one side or both sides. The physical properties such as the thickness or the modulus of elasticity of the light-transmitting optical member 2 can be appropriately determined depending on the purpose of use.

[Step (B1)]

In the step (B1), the image display member and the light transmissive optical member are bonded together via a photocurable resin composition. Fig. 1B is an explanatory view showing an example of a step (B1) of a method of manufacturing a video display device. The light-transmitting optical member 2 is bonded to the image display member 6 via the photo-curable resin composition 3A. Thereby, the photocurable resin composition layer 3 is formed between the image display member 6 and the translucent optical member 2.

[Step (C1)]

In the step (C1), the photocurable resin composition is cured. Fig. 1C is an explanatory view showing an example of a step (C1) of the method of manufacturing the image display device. The photocurable resin composition (photocurable resin composition layer 3) sandwiched between the image display member 6 and the translucent optical member 2 is irradiated with light (preferably ultraviolet rays) to be cured. Thereby, the image display device 10 in which the image display member 6 and the translucent optical member 2 are laminated via the translucent cured resin layer 7 as shown in FIG. 1D can be obtained.

The light irradiation is preferably carried out so that the curing rate of the light-transmitting and curing resin layer 7 is 90% or more, and more preferably 95% or more. By satisfying such a range, the visibility of the image formed on the image display member 6 can be improved. Here, the hardening rate means the same as the above-described hardening rate. Type, output, illuminance, and cumulative amount of light source when hardening There is no particular limitation, and for example, a photoradical polymerization treatment condition of a known (meth) acrylate irradiated with ultraviolet rays can be employed.

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

The modulus of elasticity of the light-transmitting and hardening resin layer 7 at -20 ° C and the modulus of elasticity at 25 ° C are synonymous with the modulus of elasticity of the cured resin at -20 ° C and the modulus of elasticity at 25 ° C, preferably a range The same is true.

In the first embodiment, the photocurable resin composition 3A is applied to the surface of the translucent optical member 2 on the side where the light shielding layer 1 is formed. However, the image display member 6 may be used. The surface of the surface is coated with a photocurable resin composition 3A.

[Second Embodiment]

[Step (A2)]

2A and 2B are explanatory views showing an example of the step (A2) of the method of manufacturing the image display device. First, as shown in FIG. 2A, a translucent optical member 2 having a light shielding layer 1 formed on a peripheral portion of a single surface is prepared. Further, as shown in FIG. 2B, the surface 2a of the translucent optical member 2 is cured by eliminating the step 4 formed between the light shielding layer 1 and the light shielding layer forming side surface 2a of the translucent optical member 2. The resin composition is applied thicker than the thickness of the light shielding layer 1 to form the photocurable resin composition layer 3. Specifically, it is preferable that the entire surface of the light-shielding layer forming side surface 2a of the light-transmitting optical member 2, which also includes the surface of the light-shielding layer 1, is applied so that the photocurable resin composition is flat so as not to be made It produces a step. Thickness of the photocurable resin composition layer 3 It is preferably 1.2 to 50 times the thickness of the light shielding layer 1, more preferably 2 to 30 times the thickness.

The coating of the photocurable resin composition may be carried out as long as it can obtain a necessary thickness, and may be carried out once or in multiple times.

[Step (B2)]

In the step (B2), the photocurable resin composition layer formed in the step (A2) is temporarily hardened by light irradiation to form a temporarily cured resin layer.

2C and 2D are explanatory views showing an example of the step (B2) of the method of manufacturing the image display device. As shown in FIG. 2C, the photocurable resin composition layer 3 formed in the step (A2) is temporarily hardened by irradiating light (preferably ultraviolet rays) to form the temporarily cured resin layer 5. The reason why the photocurable resin composition layer 3 is temporarily hardened is that the photocurable resin composition is in a state of not flowing from the liquid state, and as shown in FIG. 2D, it does not flow downward even if it is reversed upside down. Improve operability. Moreover, by performing the temporary hardening, the light-transmitting-hardened resin layer 3 between the light-shielding layer 1 and the image display member can be sufficiently photo-cured without being removed from the same, and the hardening shrinkage can be reduced.

The temporary curing of the photocurable resin composition layer 3 is preferably performed so that the curing rate of the temporarily cured resin layer 5 is 10 to 80%, more preferably 40 to 80%, and still more preferably It is done in 70~80% way.

The light irradiation is not particularly limited as long as the curing rate is preferably 10 to 80%, and the type, output, illuminance, and integrated light amount of the light source are not particularly limited. For example, it can be irradiated by ultraviolet rays. Photopolymerization conditions for photopolymerization of acrylates.

Further, it is preferable that the light irradiation is within the range of the above-described curing rate, and in the bonding operation of the following step (C2), the condition that the temporarily cured resin layer 5 is not dripped or deformed is selected. example For example, when expressed by viscosity, it is preferably 20 Pa ‧ or more (cone rheometer, 25 ° C, cone and 钣 C35/2, rotation speed 10 rpm).

[Step (C2)]

In the step (C2), the image display member and the translucent optical member are bonded together via the temporarily cured resin layer.

2E is an explanatory view showing an example of a step (C2) of the method of manufacturing the image display device. As shown in FIG. 2E, the translucent optical member 2 is bonded to the image display member 6 from the side of the temporarily cured resin layer 5. The bonding can be carried out, for example, by pressurization at 10 to 80 ° C using a known pressure bonding device.

[Step (D2)]

In the step (D2), the temporary curing resin layer disposed between the image display member and the translucent optical member is irradiated with light to be substantially hardened, whereby the image display member and the translucent optical member are translucent. The cured resin layer was laminated to obtain an image display device.

2F and 2G are explanatory views showing an example of the step (D2) of the method of manufacturing the image display device. As shown in FIG. 2F, the temporarily cured resin layer 5 sandwiched between the image display member 6 and the translucent optical member 2 is irradiated with light (preferably ultraviolet rays) to be completely cured. The reason why the temporarily cured resin layer 5 is completely cured is that the temporarily cured resin layer 5 is sufficiently cured, and the image display member 6 and the translucent optical member 2 are subsequently laminated. Thereby, the image display member 6 and the translucent optical member 2 are laminated via the translucent cured resin layer 7, and the image display device 10 shown in FIG. 2G is obtained. Further, the temporarily cured resin layer 5 may be completely cured by irradiating light to the temporarily cured resin layer 5 between the light shielding layer 1 of the light-transmitting optical member 2 and the image display member 6 as needed.

The hardening of the light-transmitting-hardenable resin layer 7 is preferably 90% or more, and more preferably 95% or more. The type, output, illuminance, and integrated light amount of the light source when the main curing is performed are not particularly limited. For example, photopolymerization treatment conditions of a known (meth) acrylate irradiated with ultraviolet rays can be employed.

In the second embodiment, an example in which a photocurable resin composition is applied to the surface 2a on the side of the light-transmitting optical member 2 on which the light-shielding layer 1 is formed is described, but the surface of the image display member 6 may be used. A photocurable resin composition was applied.

[Third embodiment]

[Step (A3)]

3A and 3B are explanatory views showing an example of the step (A3) of the method of manufacturing the image display device. As shown in FIG. 3A, a translucent optical member 2 having a light shielding layer 1 formed on a peripheral portion of a single surface is prepared, as shown in FIG. 3B, to the surface 2a of the translucent optical member 2 to be removed from the light shielding layer 1 The photocurable resin composition is applied thicker than the thickness of the light shielding layer 1 so as to form a step 4 formed by the light shielding layer forming side surface 2a of the light transmitting optical member 2.

[Step (B3)]

3C and 3D are explanatory views showing an example of the step (B3) of the method of manufacturing the image display device. As shown in FIG. 3C, the photocurable resin composition applied in the step (A3) is irradiated with light (preferably ultraviolet rays) to cure the photocurable resin composition to form the light-transmitting and hardening resin layer 7 ( Figure 3D). The curing rate of the light-transmitting and hardening resin layer 7 is preferably 90% or more, and more preferably 95% or more.

[Step (C3)]

3E is an explanatory view showing an example of a step (C3) of the method of manufacturing the image display device. As shown in FIG. 3E, the translucent optical member 2 is bonded to the image display member 6 from the side of the translucent cured resin layer 7. Thereby, the image display device 10 is obtained. The bonding can be carried out in the same manner as in the above step (C2).

In the method of manufacturing the image display device described above, the case of using the light-transmitting optical member in which the light-shielding layer is formed has been described. However, the light-transmitting optical member not having the light-shielding layer may be used to form the image display device.

[Examples]

Hereinafter, embodiments of the invention will be described. In the present embodiment, a photocurable resin composition was prepared, and an image display device having a light-transmitting and curing resin layer using the photocurable resin composition was produced. Further, with respect to the produced image display device, a drop impact test at -20 ° C, a bonding strength at 25 ° C, a transmittance, an elastic modulus at -20 ° C, an elastic modulus at 25 ° C, and a glass transition temperature were evaluated. Furthermore, the invention is not limited to the embodiments.

In the present embodiment, the following abbreviation is used.

[(meth)acrylic oligomer having an amine ester skeleton]

TEAI-1000: Made by Japan Soda Co., Ltd.

EBECRYL230: Made by Daicel Allnex Co., Ltd.

CN9014: Aliphatic acrylate, manufactured by Sartomer

[(Meth)acrylate monomer]

FA511AS: Dicyclopentyl acrylate, manufactured by Hitachi Chemical Co., Ltd.

Light Acrylate IB-XA: Isodecyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.

HDDA: hexanediol diacrylate, Miramer M200, manufactured by Miwon Specialty Chemical Co., Ltd.

[Plasticizer]

HLBH-P2000: 1,2 hydride of polybutadiene with a bonding ratio of 65% (hydrogenated polybutadiene with hydroxyl groups at both ends, Krasol HLBH-P2000), manufactured by Crayvalley

HLBH-P3000: 1,2 hydride of polybutadiene with a bonding ratio of 65% (hydrogenated polybutadiene with hydroxyl groups at both ends, Krasol HLBH-P3000), manufactured by Crayvalley

LBH-P2000: 1,2 polybutadiene with a bonding ratio of 65% (polybutadiene with hydroxyl groups at both ends, Krasol LBH-P2000), manufactured by Crayvalley

LBH-P3000: 1,2 polybutadiene with a bonding ratio of 65% (polybutadiene with hydroxyl groups at both ends, Krasol LBH-P3000), manufactured by Crayvalley

EPOL: 1,2 hydride of polyisoprene with a bonding ratio of 20% (hydrogenated polyisoprene with hydroxyl groups at both ends), manufactured by Idemitsu Kosan Co., Ltd.

GI-1000: 1,2 hydride of polybutadiene with a bonding ratio of 85% or more (hydrogenated polybutadiene with hydroxyl groups at both ends), manufactured by Japan Soda Co., Ltd.

GI-2000: 1,2 hydride of polybutadiene with a bonding ratio of 85% or more (hydrogenated polybutadiene with hydroxyl groups at both ends), manufactured by Japan Soda Co., Ltd.

GI-3000: 1,2 hydride of polybutadiene with a bonding ratio of 85% or more (hydrogenated polybutadiene with hydroxyl groups at both ends), manufactured by Japan Soda Co., Ltd.

G-1000: 1,2-bonded polybutadiene with a bonding ratio of 85% or more (polybutadiene with hydroxyl groups at both ends), manufactured by Japan Soda Co., Ltd.

G-2000: 1,2-bonded polybutadiene with a bonding ratio of 85% or more (polybutadiene with hydroxyl groups at both ends), manufactured by Japan Soda Co., Ltd.

[Polymerization initiator]

Irg184: 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF

[Preparation of photocurable resin composition]

The components of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared by uniformly mixing the components in the amounts shown in Table 1 (parts by mass).

[Example 1]

A photocurable resin composition was prepared using 35 parts by mass of TEAI-1000, 25 parts by mass of FA511AS, 40 parts by mass of HLBH-P2000, and 1 part by mass of Irg184.

[Embodiment 2]

A photocurable resin composition was prepared in the same manner as in Example 1 except that HLBH-P2000 was changed to an equivalent amount of HLBH-P3000.

[Example 3]

A photocurable resin composition was prepared in the same manner as in Example 1 except that 25 parts by mass of FA511AS was changed to 20 parts by mass of Light Acrylate IB-XA and 5 parts by mass of HDDA.

[Example 4]

A photocurable resin composition was prepared in the same manner as in Example 1 except that 40 parts by mass of HLBH-P2000 was changed to 20 parts by mass of HLBH-P3000 and 20 parts by mass of GI-1000.

[Comparative Example 1]

A photocurable resin composition was prepared in the same manner as in Example 1 except that the HLBH-P2000 was changed to the same amount of GI-1000.

[Comparative Example 2]

A photocurable resin composition was prepared in the same manner as in Example 1 except that the HLBH-P2000 was changed to an equivalent amount of GI-2000.

[Comparative Example 3]

A photocurable resin composition was prepared in the same manner as in Example 1 except that the HLBH-P2000 was changed to an equivalent amount of GI-3000.

The photocurable resin compositions of Examples 5 and 6, and Comparative Examples 4 and 5 were prepared by uniformly mixing the components in the amounts shown in Table 2 (parts by mass).

[Example 5]

A photocurable resin composition was prepared using 25 parts by mass of EBECRYL 230, 30 parts by mass of FA511AS, 45 parts by mass of LBH-P2000, and 1 part by mass of Irg 184.

[Embodiment 6]

A photocurable resin composition was prepared in the same manner as in Example 5 except that LBH-P2000 was changed to an equivalent amount of LBH-P3000.

[Comparative Example 4]

A photocurable resin composition was prepared in the same manner as in Example 5 except that LBH-P2000 was changed to an equivalent amount of G-1000.

[Comparative Example 5]

A photocurable resin composition was prepared in the same manner as in Example 5 except that LBH-P2000 was changed to an equivalent amount of G-2000.

The photocurable resin compositions of Example 7 and Comparative Example 6 were prepared by uniformly mixing the components in the amounts shown in Table 3 (parts by mass).

[Embodiment 7]

A photocurable resin composition was prepared by using 30 parts by mass of CN9014, 35 parts by mass of FA511AS, 35 parts by mass of EPOL, and 1 part by mass of Irg184.

[Comparative Example 6]

A photocurable resin composition was prepared by using 30 parts by mass of CN9014, 35 parts by mass of FA511AS, 35 parts by mass of GI-3000, and 1 part by mass of Irg184.

[Production of image display device]

Using the photocurable resin composition obtained in each of the above Examples and Comparative Examples, a video display device was produced by the following steps.

A glass plate having a size of 45 (w) × 80 (l) × 0.4 (t) mm was prepared, and a thermosetting type black ink (MRX ink, Imperial Ink Manufacturing Co., Ltd.) was used, and a dry thickness of 40 μm was used to make a 4 mm wide film. The light-shielding layer is applied to the entire peripheral portion of the glass sheet by screen printing, and dried to prepare a glass plate with a light-shielding layer.

The photocurable resin composition was sprayed onto the light shielding layer forming surface of the glass plate with the light shielding layer using a resin dispenser.

The liquid crystal display element having a thickness of 40 (w) × 70 (1) mm is laminated on the surface of the polarizing plate, and the glass plate is placed on the side of the photocurable resin composition so as to be on the side of the polarizing plate, and the glass plate is used. The weight is attached to the glass plate. The thickness of the photocurable resin composition which wetted and diffused between the polarizing plate and the glass plate was 150 μm.

Ultraviolet irradiation apparatus (UVL-7000M4-N, manufactured by USHIO LIGHTING Co., Ltd.) was used to irradiate ultraviolet rays at 3000 mJ/cm ² from the glass plate side to cure the photocurable resin composition to form a light-transmitting and hardening resin layer. The hardening ratio of the light-transmitting and hardening resin layer was 97%. Thereby, a liquid crystal display device in which a glass plate as a translucent optical member is laminated on a liquid crystal display element via a translucent cured resin layer is obtained.

[Evaluation]

[drop impact test]

The obtained image display device was dropped from the height of 1 m, and the interface between the non-translucent-curable resin layer and the liquid crystal display element and the interface between the translucent-curable resin layer and the glass plate were evaluated as "○". When there is peeling, it is evaluated as "X". The results are shown in Tables 1 to 3.

[Next strength test]

As shown in FIGS. 4 and 5, a photocurable resin composition was dropped on the center portion of the glass plate 31 having a thickness of 1 mm, and placed on the spacers 34 of 150 μm so that the glass plates 32 having a thickness of 1 mm were placed orthogonally. Thereby, a glass bonded body 33 in which a photocurable resin composition layer having a diameter of 3 mm and a thickness of 150 μm was formed between the glass plates 31 and 32 was obtained. Then, an ultraviolet ray having a strength of 200 mW/cm ^{2 was} irradiated from the side of the glass plate 32 so that the photocurable resin composition layer was completely cured to form a light-transmitting hardened resin layer, using an ultraviolet ray irradiation device so that the integrated light amount was 3,000 mJ/cm ² . 35. Then, as shown in FIGS. 6 and 7, the glass plate 32 located on the lower side of the glass joined body 33 is fixed, and the glass plate 31 located on the upper side is peeled off at a speed of 5 mm/min in the vertical direction by using the jig 36, and the following is used. The benchmark is evaluated next to the status. For the measurement of the subsequent strength, AGS-X manufactured by Shimadzu Corporation was used. Then, the strength is calculated by dividing the stress required for separating the glass plate 31 from the glass plate 32 at 25 ° C, and dividing the stress by the unit area of the light-transmitting and hardening resin layer 35. When the adhesive strength (25 ° C) was 500 N/cm ² or more, it was evaluated as "○", and when the adhesive strength was less than 500 N/cm ² , it was evaluated as "X". The results are shown in Tables 1 to 3.

[penetration rate]

Determination of image display using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, UV-2450) The transmittance of the visible light region of the light-transmitting and hardening resin layer in the device. The results are shown in Tables 1 to 3.

[Elastic Modulus]

The elastic modulus (-20 ° C and 25 ° C) of the light-transmitting and hardening resin layer in the image display device was calculated using a viscoelasticity measuring device. The measurement was carried out using a viscoelasticity measuring apparatus (manufactured by Seiko Instruments Co., Ltd., DMS6100) at a measurement frequency of 1 Hz in a tensile mode. The results are shown in Tables 1 to 3.

[glass transition temperature]

The glass transition temperature of the light-transmitting hardened resin layer in the image display device was measured. The measurement was carried out using a viscoelasticity measuring apparatus (manufactured by Seiko Instruments Co., Ltd., DMS6100) at a measurement frequency of 1 Hz in a tensile mode. The results are shown in Tables 1 to 3.

As shown in Examples 1 to 7, it is known that a (meth)acrylic oligomer having a urethane skeleton, a (meth) acrylate monomer, a polymerization initiator, and a bonding ratio of 1, 2 are less than 80%. In the case of a photocurable resin composition of at least one of polybutadiene and polyisoprene having a 1,2 bond ratio of less than 80%, the glass transition temperature of the light transmissive resin composition layer Higher, it can also reduce the elastic modulus of the light transmissive resin composition layer in a low temperature environment. Also, we can see the drop impact of -20 °C Sex, and penetration rates are also good.

In particular, as in Examples 1 to 4 and 7, it was found that a (meth)acrylic oligomer having a urethane skeleton, a (meth) acrylate monomer, a polymerization initiator, and a bonding ratio of 1, 2 were not used. In the case of a photocurable resin composition of at least one of a hydride of polybutadiene of 80% and a hydride of polyisoprene having a 1,2 bond ratio of less than 80%, -20 ° C The drop impact is also excellent, and the strength is also good.

On the other hand, as in Comparative Examples 1 to 6, it was found that polybutadiene having a bonding ratio of less than 80% and a polyisoprene having a bonding ratio of less than 80% were used. In the case of at least one kind of photocurable resin composition, it is difficult to reduce the elastic modulus of the light transmissive resin composition layer in a low temperature environment. Further, it is understood that the drop impact at -20 ° C is also not good.

1‧‧‧ shading layer

2‧‧‧Transparent optical components

3‧‧‧Photocurable resin composition layer

3A‧‧‧Photocurable resin composition

6‧‧‧Image display component

7‧‧‧Transparent hardening resin layer

10‧‧‧Image display device

Claims (11)

A photocurable resin composition comprising: a (meth)acrylic oligomer having an amine ester skeleton, a (meth) acrylate monomer, a polymerization initiator, and a plasticizer, and the above plasticizer At least one of polybutadiene having a 1,2 bond ratio of less than 80% and polyisoprene having a 1,2 bond ratio of less than 80%. The photocurable resin composition according to claim 1, wherein the plasticizer contains a hydride of polybutadiene having a 1,2 bond ratio of less than 80%, and a bonding ratio of 1,2 is not reached. At least one of 80% of the hydride of polyisoprene. The photocurable resin composition according to claim 1 or 2, wherein the content of the plasticizer is 15 to 50% by mass. The photocurable resin composition of claim 2, wherein the hydride of the polybutadiene having a 1,2 bond ratio of less than 80% and the bonding ratio of 1,2 are not in the plasticizer The total content of the hydride of the polyisoprene of 80% is 30% by mass or more. The photocurable resin composition according to claim 1 or 2, wherein the (meth) acrylate monomer contains a (meth) acrylate monomer having a ring structure. The photocurable resin composition according to claim 1 or 2, wherein the (meth) acrylate monomer contains (meth) represented by any one of the following formulas (1) to (3) Acrylate monomer: (In the formulae (1) to (3), R each independently represents a hydrogen atom or a methyl group, and X represents -O-, -O(CH ₂ ) _n O-, -O(CH ₂ CH ₂ O) _n -, Or -O(CH(CH ₃ )CH ₂ O) _n -, Y represents -O-, -O(CH ₂ ) _m O-, -O(CH ₂ CH ₂ O) _m -, or -O(CH( CH ₃ )CH ₂ O) _m -, n and m each independently represent an integer from 1 to 10). The photocurable resin composition according to claim 1 or 2, wherein the (meth) acrylate monomer contains isodecyl acrylate, isodecyl methacrylate, dicyclopentyl acrylate, methacrylic acid. At least one of dicyclopentyl ester, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, and dicyclopentenyloxyethyl methacrylate. The photocurable resin composition according to claim 1 or 2, wherein the content of the (meth) acrylate monomer is 15 to 45% by mass. The photocurable resin composition according to claim 1 or 2, wherein the cured resin obtained by curing the photocurable resin composition has an elastic modulus at -20 ° C of 3.0 E + 08 Pa or less. The photocurable resin composition of claim 1 or 2, wherein the light is hardened The glass transition temperature of the cured resin of the cured resin composition is 40 to 80 °C. A method for producing an image display device, comprising the steps of: applying a photocurable resin composition on a surface of a translucent optical member or a surface of an image display member; and passing the image display member and the translucent optical member via a step of bonding the photocurable resin composition; and a step of curing the photocurable resin composition; and the photocurable resin composition is photohardening according to any one of claims 1 to 10. Resin composition.