TW201544330A - Transparent sheet material with pressure-sensitive adhesive layer, display device, production processes therefor, and pressure-sensitive adhesive sheet - Google Patents

Abstract

Provided are: a transparent sheet material coated with a pressure-sensitive adhesive layer, the sheet material, when adhered to an adherend, being capable of making bubbles remaining at the interface between the adherend and the pressure-sensitive adhesive layer rapidly disappear; a display device in which the display panel is protected by the transparent sheet material; processes for producing the transparent sheet material coated with a pressure-sensitive adhesive layer and the display device; and a pressure-sensitive adhesive sheet. The transparent sheet material (1) coated with a pressure-sensitive adhesive layer comprises a transparent sheet material (10) and, formed on at least one surface of the transparent sheet material (10), a pressure-sensitive adhesive layer (14) constituted of a cured object formed from a curable resin composition, wherein the pressure-sensitive adhesive layer (14) has a concentration of hydroxy groups of 100 * 10<SP>-6</SP> to 600 * 10<SP>-6</SP> mol/g and a concentration of urethane bonds of 0 to 150 * 10<SP>-6</SP> mol/g.

Description

Transparent surface material with adhesive layer, display device, and manufacturing method thereof, and adhesive sheet

The present invention relates to a transparent surface material with an adhesive layer, a display device for protecting a display panel with a transparent surface material, a method for manufacturing the same, and an adhesive sheet.

As a display device which protects a display panel with a transparent surface material, the following are known, for example.

(1) A display device in which a display panel and a transparent surface material are bonded via an adhesive sheet (see Patent Documents 1 and 2).

(2) A display device in which a display panel and a transparent surface material with an adhesive layer are bonded to the display panel with an adhesive layer (see Patent Documents 3 to 5).

When the display device of (1) is manufactured, the display panel is used in a decompression environment so that the interface between the display panel and the adhesive sheet and the interface between the transparent surface material and the adhesive sheet do not leave air bubbles (voids). After bonding with the transparent face material via the adhesive sheet, it is returned to the atmospheric pressure environment.

Moreover, in the case of manufacturing the display device of (2), a transparent surface material of the display panel and the adhesive layer is provided in a reduced pressure environment so that no air bubbles (voids) remain at the interface between the display panel and the adhesive layer. After the adhesive layer is attached to the display panel, it is placed back to the atmospheric pressure environment.

According to the methods, even if bubbles are left at the interface, the pressure in the bubble can be utilized by returning the display device in a reduced pressure environment to the atmospheric pressure environment (ie, The pressure difference between the pressure in the decompressed state and the pressure applied to the adhesive sheet or the adhesive layer (i.e., atmospheric pressure) causes the bubble volume to decrease, thereby causing the bubble to disappear.

However, in the case of using the previous adhesive sheet or the transparent face material with the adhesive layer, it is time consuming to disappear the bubbles remaining at the above interface. If the bubble remaining in the above interface disappears, it takes time, and the productivity of the display device is lowered.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2006-290960

Patent Document 2: Japanese Patent Laid-Open Publication No. 2009-263502

Patent Document 3: International Publication No. 2011/148990

Patent Document 4: International Publication No. 2012/077726

Patent Document 5: International Publication No. 2012/077727

The present invention provides a transparent surface material which adheres to an adhesive layer which can be quickly disappeared at the interface between the adherend and the adhesive layer when the adherend and the transparent surface material are bonded via the adhesive layer; the manufacturing will be pasted When the transparent surface material and the transparent surface material are bonded via the adhesive layer, the method of leaving the transparent surface material of the adhesive layer which can be quickly disappeared at the interface between the adhesive composition and the adhesive layer can suppress the residual air bubbles on the display panel and the adhesion. a display device for the interface of the layer; a method for producing a display device capable of suppressing bubbles remaining at the interface between the display panel and the adhesive layer with good productivity; and remaining in the adherend and the adhesive sheet when bonded to the adherend The bubbles on the interface can quickly disappear into the adhesive sheet.

The inventors of the present invention conducted an effort to study the relationship between the characteristics of the adhesive layer and the disappearance rate of the bubbles remaining at the interface between the adherend and the adhesive layer, and found that the concentration of the hydroxyl group or the urethane in the adhesive layer was found. When the concentration of the key is large, it takes time to disappear the bubble.

The transparent surface material with an adhesive layer of the present invention has a transparent surface material and an adhesive layer formed on the hard surface of the curable resin composition formed on at least one surface of the transparent surface material, and the hydroxyl group concentration in the adhesive layer is 100. ×10 ^-6 to 600×10 ^-6 mol/g, and the concentration of the urethane bond in the above adhesive layer is 0 to 150×10 ^-6 mol/g.

The total concentration of the hydroxyl groups in the adhesive layer and the concentration of the urethane bond in the adhesive layer is preferably from 100 × 10 ^-6 to 750 × 10 ^-6 mol/g.

The solubility parameter of the above adhesive layer is preferably from 17.5 to 18.5 (J/cm ³ ) ^1/2 .

The curable resin composition preferably contains a curable oligomer (A) having an addition polymerizable unsaturated double bond and a low molecular weight polymerizable compound (B) having an addition polymerizable unsaturated double bond, and Either or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) have a hydroxyl group. Either or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) may have a urethane bond.

The curable resin composition preferably contains a curable oligomer (A) having an addition polymerizable unsaturated double bond, a low molecular weight polymerizable compound (B) having an addition polymerizable unsaturated double bond, and a non-curable oligomer (C) having an addition polymerizable unsaturated double bond, and the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curing oligomer (C) At least one of them has a hydroxyl group. At least one of the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) may have a urethane bond.

The transparent surface material of the adhesive layer of the present invention preferably further has a peelable protective film covering the surface of the adhesive layer.

The method for producing a transparent face material with an adhesive layer of the present invention is a method for producing a transparent face material with an adhesive layer of the present invention, and has the following step (α) and the following step (γ).

(α) a step of supplying the curable resin composition in a liquid form to the surface of the transparent surface material, and partially curing the curable resin composition to form a partially cured product, if necessary; (γ) A step of curing the curable resin composition or the partially cured product to form the adhesive layer.

The method for producing a transparent surface material with an adhesive layer of the present invention preferably further has the following step (β).

(β) A step of covering the surface of the curable resin composition or the partially cured product with a protective film.

Preferably, the above step (α) is the following step (α1), the step (β) is the following step (β1), and the step (γ) is the following step (γ1).

(α1) The liquid curable resin composition is supplied to the surface of the transparent surface material in a layered manner, and the curable resin composition supplied to the surface of the transparent surface material is partially cured to form a partially cured product. Step of the layer; (β1) a step of covering the surface of the partially cured layer with a protective film; (γ1) a step of further hardening the layer of the partially cured product to form the adhesive layer.

Further, preferably, the step (α) is the following step (α21) and the following step (α22), the step (β) is the following step (β2), and the step (γ) is the following step (γ21). And the following steps (γ22).

(α21) a step of forming a frame shape on a peripheral portion of the surface of the transparent face material; (α22) a step of supplying the curable resin composition to a region surrounded by the crucible; (β2) in a reduced pressure environment; The support surface material with a protective film is superposed on the surface of the layer of the curable resin composition so that the protective film is in contact with the surface of the layer of the curable resin composition, and the layer of the curable resin composition is obtained as described above. a step of forming a transparent surface material, the protective film, and the laminate of the above-mentioned ruthenium seal; (γ21), wherein the laminate is placed in a pressure environment higher than the above step (β2), and the curable resin composition is allowed to be a step of hardening the layer to form the above adhesive layer; (γ22) After the above step (γ21), the support surface material is peeled off from the protective film.

A display device according to the present invention includes a display panel and a transparent surface material attached to the adhesive layer of the present invention, and the adhesive layer is bonded to the display panel so that the adhesive layer contacts the display panel.

The manufacturing method of the display device of the present invention is a method for manufacturing the display device of the present invention, and the display panel and the transparent surface material of the adhesive layer are overlapped in such a manner that the adhesive layer contacts the display panel in a reduced pressure environment. And fit.

The adhesive sheet of the present invention comprises a cured product of a curable resin composition, and the hydroxyl group concentration in the adhesive sheet is 100×10 ^-6 to 600×10 ^-6 mol/g, and the urethane in the adhesive sheet is used. The ester bond concentration is 0 to 150×10 ^-6 mol/g.

The hydroxyl group concentration of the adhesive sheet and the adhesive sheet of the above total concentration of urethane bond of the ester is preferably ^{100 × 10 -6 ~ 750 × 10} -6 mol / g.

The solubility parameter of the cured product of the curable resin composition is preferably from 17.5 to 18.5 (J/cm ³ ) ^1/2 .

The curable resin composition preferably contains a curable oligomer (A) having an addition polymerizable unsaturated double bond and a low molecular weight polymerizable compound (B) having an addition polymerizable unsaturated double bond, and Either or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) have a hydroxyl group.

Either or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) may have a urethane bond.

The curable resin composition preferably contains a curable oligomer (A) having an addition polymerizable unsaturated double bond, a low molecular weight polymerizable compound (B) having an addition polymerizable unsaturated double bond, and does not have a non-curable oligomer (C) having a polymerizable unsaturated double bond, and the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) At least one of them has a hydroxyl group. The above curable oligomer (A), the above low At least one of the molecular weight polymerizable compound (B) and the non-curable oligomer (C) may have a urethane bond.

The adhesive sheet with a protective film of the present invention has the adhesive sheet of the present invention and a peelable protective film covering at least one surface of the adhesive sheet.

According to the transparent surface material with an adhesive layer of the present invention, when the adherend and the transparent surface material are bonded via the adhesive layer, the bubbles remaining at the interface between the adherend and the adhesive layer can be quickly disappeared.

According to the method for producing a transparent surface material with an adhesive layer according to the present invention, when the adhesive composition and the transparent surface material are bonded together via the adhesive layer, the bubbles remaining at the interface between the adhesive composition and the adhesive layer can be quickly formed. The disappearing transparent surface material with adhesive layer.

The display device of the present invention is capable of suppressing air bubbles from remaining on the interface between the display panel and the adhesive layer.

According to the method of manufacturing a display device of the present invention, a display device capable of suppressing the remaining bubbles at the interface between the display panel and the adhesive layer can be produced with good productivity.

According to the adhesive sheet of the present invention, when the adhesive sheet is attached to the adherend, the bubbles remaining at the interface between the adhesive and the adhesive sheet can be quickly disappeared.

1‧‧‧Transparent surface material with adhesive layer

2‧‧‧Transparent surface material with adhesive layer

3‧‧‧Display device

10‧‧‧Transparent surface material

12‧‧‧Lighting Printing Department

14‧‧‧Adhesive layer

15‧‧‧堰

16‧‧‧Protective film

18‧‧‧First composition

20‧‧‧layer of partially hardened

22‧‧‧Unhardened

24‧‧‧Area

26‧‧‧First composition

28‧‧‧Unloading plate

30‧‧‧ Dispenser

32‧‧‧feed screw

34‧‧‧feed screw

36‧‧‧Support surface material

38‧‧‧Reducing device

40‧‧‧Adsorption pad

42‧‧‧Upper platen

44‧‧‧Unloading plate

46‧‧‧ cylinder

48‧‧‧vacuum pump

50‧‧‧ display panel

52‧‧‧Transparent substrate

54‧‧‧Transparent substrate

56‧‧‧Liquid layer

58‧‧‧Polar plate

60‧‧‧Soft printed wiring board

62‧‧‧Mouth coating machine

64‧‧‧LED light source

M1, M2‧‧‧ bubbles

Fig. 1 is a cross-sectional view showing a first embodiment of a transparent surface material with an adhesive layer of the present invention.

Fig. 2 is a cross-sectional view showing a second embodiment of the transparent surface material with an adhesive layer of the present invention.

Fig. 3 is a plan view for explaining a step (α1) in the production of the transparent surface material with an adhesive layer according to the first embodiment.

Fig. 4 is a cross-sectional view for explaining the step (α1) in the production of the transparent surface material with the adhesive layer of the first embodiment.

Fig. 5 is a cross-sectional view for explaining a step (β1) in the production of the transparent surface material with an adhesive layer according to the first embodiment.

Fig. 6 is a plan view for explaining a step (α21) in the production of the transparent surface material with an adhesive layer according to the second embodiment.

Fig. 7 is a cross-sectional view for explaining a step (α21) in the production of the transparent surface material with an adhesive layer according to the second embodiment.

Fig. 8 is a plan view for explaining a step (α22) in the production of the transparent surface material with an adhesive layer according to the second embodiment.

Fig. 9 is a cross-sectional view for explaining a step (α22) in the production of the transparent surface material with an adhesive layer according to the second embodiment.

Fig. 10 is a cross-sectional view for explaining a step (β2) in the production of the transparent surface material with an adhesive layer according to the second embodiment.

Figure 11 is a cross-sectional view showing an example of a display device of the present invention.

Fig. 12 is a perspective view showing the state of air bubbles in the interface between the display panel and the adhesive layer when the transparent surface material and the display panel are bonded via the adhesive layer.

Fig. 13 is a graph showing the relationship between the concentration of hydroxyl groups in the adhesive layer in Examples 1 to 3 and the defoaming time.

Fig. 14 is a graph showing the relationship between the total of the hydroxyl group concentration and the urethane bond concentration in the adhesive layer in Examples 1 to 3 and the defoaming time.

Fig. 15 is a graph showing the relationship between the concentration of the hydroxyl group in the adhesive layer in Examples 4 to 6 and the defoaming time.

Fig. 16 is a graph showing the relationship between the total of the hydroxyl group concentration and the urethane bond concentration in the adhesive layer in Examples 4 to 6 and the defoaming time.

The following terms are used throughout this specification and the scope of the patent application.

The so-called "transparent" in transparent surface material means the following pattern, that is, the surface material and the display surface. After the display surface of the panel is bonded via the adhesive layer without air bubbles and/or voids, the entire or a part of the display image of the display panel is not visually deformed by optical deformation. Therefore, even if a part of the light incident from the display panel to the face material is absorbed or reflected by the face material, or the visible light transmittance of the face material is low due to a change in optical phase or the like, the optical component can be visually recognized by the face material. The display image of the display panel can be referred to as "transparent".

The "liquid curable resin composition" means that the curable resin composition is in a liquid state without containing a solvent.

The "cured material of the curable resin composition" means a case where the curable resin composition is cured until the storage shear modulus at 35 ° C is the target of the storage layer at 35 ° C.

The term "partially cured product" means a case where the curable resin composition is cured until the storage shear modulus at 35 ° C is 1 / 200 to 1 / 5 of the storage shear modulus of the adhesive layer at 35 ° C.

The "oligomer" means a compound having a molecular chain containing a repeating structural unit (oxyalkylene unit, diene unit, etc.) and having a number average molecular weight of 1,000 to 100,000.

The "low molecular weight polymerizable compound" means a compound having an addition polymerizable unsaturated double bond having a molecular weight of 600 or less.

The term "(meth) acrylate" means acrylate or methacrylate.

"Viscosity" is a value measured using an E-type viscometer at 25 °C.

The "number average molecular weight of the curable oligomer (A)" is a polystyrene-equivalent number average molecular weight determined by gel permeation chromatography (hereinafter referred to as GPC). In the case where a peak of an unreacted low molecular weight component (monomer or the like) occurs in GPC, the number average molecular weight is determined by excluding the peak.

"The number average molecular weight of non-hardening oligomers (C1)" is based on the following formula. The value calculated from the hydroxyl value A (KOH mg/g) measured in JIS K 1557-1:2007 and the hydroxyl number B in one molecule of the non-curable oligomer (C).

‧ Non-curable oligomer (C) number average molecular weight = 56.1 × B × 1000 / A

The "solubility parameter of the adhesive layer" (hereinafter also referred to as the SP value) is a solubility parameter of the cured product of the curable resin composition calculated using the calculation formula of Fedors. For the specific calculation method, refer to the following documents.

Yamamoto Hideki, "SP value basis ‧ application and calculation method", company information agency.

Regarding the "storage modulus of the adhesive layer (or crucible) at 35 ° C", a rheometer (manufactured by Anton Paar, module rheometer Physica MCR-301) was used to determine the measurement axis and the light transmittance. The gap between the sheets is the same as the thickness of the adhesive layer (or crucible), and the uncured curable resin composition is disposed in the gap, and heat or light necessary for hardening is applied to the uncured curable resin composition, and the measurement frequency is The storage shear modulus of the hardening process was measured at 1 Hz, and the measured value under the hardening condition when the adhesive layer (or enamel) was formed was set as the storage shear modulus of the adhesive layer (or 堰).

<Transparent surface material with adhesive layer>

The transparent surface material with an adhesive layer of the present invention has a transparent surface material and an adhesive layer formed on the surface of the transparent surface material and comprising a cured product of the curable resin composition for forming an adhesive layer. The adhesive layer may be formed on at least one surface of the transparent surface material, or may be formed on both sides of the transparent surface material.

The transparent surface material with an adhesive layer of the present invention may have a frame-like shape that surrounds the adhesive layer in a state of being in contact with the periphery of the adhesive layer, as needed.

The transparent surface material of the adhesive layer of the present invention may also have a peelable protective film covering the surface of the adhesive layer as needed.

(transparent surface material)

As a form of a transparent surface material, the image display surface provided in the display panel is mentioned. Protecting the protection panel of the display panel on the side (viewing side); protecting the protection panel of the coordinate input device on the contact side (viewing side) of the coordinate input device such as the touch panel; and forming a touch in the display device with the touch panel A substrate with a transparent electrode attached to the panel portion.

As a transparent surface material, a glass plate or a transparent resin board is mentioned. In terms of high transparency to the emitted or reflected light from the display panel, the glass plate is of course the best, but has light resistance, low birefringence, high planar precision, and surface damage resistance. In terms of high mechanical strength, it is also optimal as a glass plate. In the production process described below, a glass plate is also preferred in terms of sufficiently transmitting light that hardens the photocurable resin composition.

Examples of the material of the glass plate include a glass material such as soda lime glass, and a high-permeability glass (also referred to as white glass) having a lower iron content and less blue light. For added safety, tempered glass can also be used. Especially in the case of using a thin glass plate, it is preferred to use a glass plate which has been subjected to chemical strengthening. The material of the transparent resin sheet is a resin material (polycarbonate, polymethyl methacrylate or the like) having high transparency.

For the transparent surface material, in order to improve the adhesion to the adhesive layer, a surface treatment can also be performed. Examples of the surface treatment method include a method of treating the surface of a transparent surface material with a decane coupling agent, a method of forming a thin film of cerium oxide by an oxidizing flame of a flame burner, and the like.

(adhesive layer)

The adhesive layer is a layer of a transparent resin obtained by curing a curable resin composition for forming a liquid adhesive layer.

The concentration of the hydroxyl group in the adhesive layer is 100×10 ^-6 to 600×10 ^-6 mol/g, preferably 250×10 ^-6 to 550×10 ^-6 mol/g, more preferably 300×10 ^-6 to 500. ×10 ^-6 mol/g. When the concentration of the hydroxyl group in the adhesive layer is 100 × 10 ^-6 mol/g or more, the adhesion between the adhesive layer and the transparent surface material, and the adhesion between the adhesive layer and the adherend (display panel or the like) become good.

In particular, when the concentration of the hydroxyl group in the adhesive layer is 250 × 10 ^-6 mol/g or more, in the case where the bonding of the transparent surface material with the adhesive layer and the adherend (display panel or the like) fails, in order to reuse When the transparent surface material with the adhesive layer is peeled off from the adherend by the adhesive composition, the adhesive layer is less likely to aggregate and break, and it is difficult for one part of the adhesive layer to remain on the adherend. When the adhesive layer is less likely to remain in the adhesive composition, the applied composition cannot be reused.

When the concentration of the hydroxyl group in the adhesive layer is 600×10 ^-6 mol/g or less, when the transparent surface material with the adhesive layer is attached to the adherend, the bubbles remaining at the interface between the adhesive and the adhesive layer may be Disappeared quickly.

The concentration of the hydroxyl group in the adhesive layer is calculated from the raw materials of the first composition such as the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) described below. The concentration of the hydroxyl group in the medium and the blending ratio of each raw material were determined.

The hydroxyl group concentration of the curable oligomer (A) and the non-curable oligomer (C) was determined by calculating the molar ratio of the raw material at the time of synthesizing the oligomer. The hydroxyl group concentration of the low molecular weight polymerizable compound (B) was determined from the molecular weight and the number of functional groups by calculation.

The concentration of the hydroxyl group in the adhesive layer can be adjusted in each of the raw materials of the first composition such as the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) described below. The hydroxyl group concentration and the blending ratio of each raw material were adjusted to the above range.

The concentration of the urethane bond in the adhesive layer is 0 to 150 × 10 ^-6 mol / g, preferably 30 × 10 ^-6 to 95 × 10 ^-6 mol / g, more preferably 50 × 10 ^-6 ~ 90 × 10 ^-6 mol / g. In particular, if the concentration of the urethane bond in the adhesive layer is 30×10 ^-6 mol/g or more, when the transparent surface material of the adhesive layer is peeled off from the adherend, the adhesive layer is hard to be agglomerated and destroyed, and adhered. It is difficult for a part of the layer to remain on the adherend. When the concentration of the urethane bond in the adhesive layer is 150×10 ^-6 mol/g or less, the transparent surface material with the adhesive layer adheres to the adherend and remains on the adhesive layer and the adhesive layer. The bubbles at the interface can disappear quickly.

Further, in terms of the disappearance of the bubble, the adhesive layer preferably has no urethane bond, and when the curing rate of the curable oligomer (A) is to be made faster, the adhesive layer is more It is preferred to have a urethane bond.

The concentration of the urethane bond in the adhesive layer is calculated from the following first, such as the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C). The concentration of the urethane bond in each raw material of the composition and the blending ratio of each raw material were determined.

The urethane bond concentration of the curable oligomer (A) and the non-curable oligomer (C) is calculated from the molar ratio of the raw material at the time of synthesizing the oligomer. The urethane bond concentration of the low molecular weight polymerizable compound (B) is determined from the molecular weight and the number of functional groups by calculation.

The concentration of the urethane bond in the adhesive layer can be adjusted by adjusting the first composition such as the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) described below. The concentration of the urethane bond in each raw material and the blending ratio of each raw material are adjusted to the above range.

In the case where the curable oligomer (A1), the low molecular weight polymerizable compound (B1), and the non-curable oligomer (C1) are combined, the curable oligomer (A1) can be adjusted. The concentration of the urethane bond contained and the blending ratio of each raw material are adjusted to the above range.

The concentration of the hydroxyl group in the adhesive layer and the concentration of the urethane bond in the adhesive layer are preferably 100 × 10 ^-6 to 750 × 10 ^-6 mol / g, more preferably 250 × 10 ^-6 to 600 × 10 ^-6 mol/g. If the total concentration of the hydroxyl groups in the adhesive layer and the concentration of the urethane bond in the adhesive layer are 100×10 ^-6 mol/g or more, the hardening oligomer (A) has a faster curing speed and an adhesive layer. The adhesion to the transparent surface material and the adhesion between the adhesive layer and the adherend (display panel, etc.) become good.

In particular, when the total concentration of the hydroxyl groups in the adhesive layer and the concentration of the urethane bond in the adhesive layer are 250 × 10 ^-6 mol/g or more, the transparent surface material of the adhesive layer is peeled off from the adherend. The adhesive layer is difficult to aggregate and damage, and it is difficult for a part of the adhesive layer to remain on the adherend. When the total concentration of the hydroxyl groups in the adhesive layer and the concentration of the urethane bond in the adhesive layer are 600×10 ^-6 mol/g or less, when the transparent surface material with the adhesive layer is attached to the adherend, The bubbles remaining at the interface between the adherend and the adhesive layer can be further quickly disappeared.

The solubility parameter of the adhesive layer (i.e., the cured product of the curable resin composition for forming an adhesive layer) is preferably from 17.5 to 18.5 (J/cm ³ ) ^1/2 , more preferably from 18.0 to 18.45 (J/cm ³ ) ^{1/. 2} . If the solubility parameter of 17.5 (J / cm ^{3) 1/2} or more, the adhesion between the adhesive layer and the transparent plate, and the adhesive layer is affixed to the compound (a display panel) The adhesiveness becomes good. When the solubility parameter is 18.5 (J/cm ³ ) ^1/2 or less, when the transparent surface material with the adhesive layer is bonded to the adherend, the bubbles remaining at the interface between the adhesive and the adhesive layer can be further rapidly formed. The land disappears.

The storage shear modulus of the adhesive layer at 35 ° C is preferably from 1 × 10 ³ to 300 × 10 ³ Pa, more preferably from 1 × 10 ³ to 100 × 10 ³ Pa, and still more preferably from 1 × 10 ³ to 50 ×10 ³ Pa. If the storage shear modulus is 1 × 10 ³ Pa or more, the shape of the adhesive layer can be maintained. Moreover, even when the thickness of the adhesive layer is relatively thick, the thickness of the adhesive layer can be uniformly maintained as a whole, and when the transparent surface material with the adhesive layer is bonded to the display panel, the interface between the display panel and the adhesive layer is difficult. Create bubbles. When the storage shear modulus is 300 × 10 ³ Pa or less, the adhesive layer can exhibit good adhesion when it is bonded to the display panel.

Moreover, since the cured product of the first composition constituting the adhesive layer has relatively high molecular mobility, the display panel and the transparent surface material with the adhesive layer are bonded together under a reduced pressure environment, and then returned to the atmospheric pressure environment. At the time, the volume of the bubble becomes the pressure due to the pressure in the bubble (that is, the pressure in the decompressed state of the reduced pressure environment) and the pressure applied to the adhesive layer (that is, the atmospheric pressure when placed in the atmospheric pressure environment). It is easy to reduce, and the gas in the bubble whose volume is reduced is easily dissolved in the adhesive layer and absorbed by the adhesive layer.

The thickness of the adhesive layer is preferably from 0.03 to 2 mm, more preferably from 0.1 to 0.8 mm. When the thickness of the adhesive layer is 0.03 mm or more, the adhesive layer can effectively absorb the impact or the like caused by a force from the side of the transparent surface material, and can protect the display panel or the like. Further, in the method of manufacturing a display device, even if foreign matter that does not exceed the thickness of the adhesive layer is mixed between the display panel and the transparent surface material of the adhesive layer, the thickness of the adhesive layer does not largely change, and the light transmission property is affected. less.

When the thickness of the adhesive layer is 2 mm or less, it is difficult for the bubbles to remain in the adhesive layer, and the thickness of the entire display device does not need to be thick. The method of adjusting the thickness of the adhesive layer to be applied to the surface of the transparent surface material, the method of adjusting the supply amount of the curable resin composition for forming the adhesive layer on the surface of the transparent surface material, and the method of adjusting the thickness of the crucible.

(curable resin composition for forming an adhesive layer)

The curable resin composition for forming an adhesive layer is not particularly limited as long as it can form an adhesive layer. The curable resin composition for forming an adhesive layer is preferably in terms of the adhesion between the adhesive layer and the transparent face material or the adherend, and the speed at which the bubbles remaining at the interface between the adherend and the adhesive layer disappear. The following first composition can be mentioned.

(first composition)

The first composition contains a curable oligomer (A) having an addition polymerizable unsaturated double bond, a low molecular weight polymerizable compound (B) having an addition polymerizable unsaturated double bond, and optionally having no A non-curable oligomer (C) having a polymerizable unsaturated double bond added thereto.

When the non-curable oligomer (C) is not contained, either or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) have a hydroxyl group. Either or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) may have a urethane bond.

When the non-curable oligomer (C) is contained, at least one of the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) has a hydroxyl group. At least one of the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) may have a urethane bond.

The first composition may be a photocurable resin composition or a thermosetting resin composition. The first composition is preferably a photocurable resin composition which is further cured with a photopolymerization initiator (D) in terms of being cured at a low temperature and having a high curing rate. Further, when the first composition is a photocurable resin composition, the curing does not require a high temperature, and thus the damage of the display panel or the like due to the high temperature is also small.

In the first composition, additives may also be formulated as needed.

About the curable oligomer (A):

The addition polymerizable unsaturated double bond of the curable oligomer (A) is preferably an acryloxy group or a methacryloxy group in terms of the hardenability of the first composition, and particularly preferably Acryloxy.

The viscosity of the curable oligomer (A) is preferably from 1 to 800 Pa s, more preferably from 2 to 600 Pa s. When the viscosity of the curable oligomer (A) is within the above range, the viscosity of the first composition is easily adjusted to the following range.

The curable oligomer (A) may be used alone or in combination of two or more.

As the curable oligomer (A), in terms of the hardenability of the first composition and the mechanical properties of the adhesive layer, it is preferred to formulate a number average molecular weight of 1,000 to 100,000, and addition polymerization unsaturated double The average number of bonds is 1.8 to 4 of the curable oligomer (A1).

The curable oligomer (A) is preferably formulated in such a manner that the bubbles remaining at the interface between the adherend and the adhesive layer can be further quickly disappeared and the display unevenness of the display device is suppressed. A curable oligomer (A2) having an average molecular weight of 1,000 to 20,000 and an average of addition polymerizable unsaturated double bonds of 0.5 to 1.

As the curable oligomer (A), a curable oligomer (A1) and a curable oligomer (A2) are more preferably formulated.

Hardening oligomer (A1):

The curable oligomer (A1) has a number average molecular weight of 1,000 to 100,000, preferably 10,000 to 80,000. When the number average molecular weight of the curable oligomer (A1) is within the above range, it is easy to adjust the viscosity of the first composition to the following range, and it is easy to form an adhesive layer in which display unevenness is suppressed.

The average number of addition polymerizable unsaturated double bonds of the curable oligomer (A1) is from 1.8 to 4, preferably 1.8, in terms of the hardenability of the first composition and the mechanical properties of the adhesive layer. ~3.

As the curable oligomer (A1), it is usually preferred that the number of addition polymerizable unsaturated double bonds in one molecule is 2 to 4, but when the curable oligomer (A1) is produced, an addition is produced. The case where the number of polymerizable unsaturated double bonds is less than 2 by-products. Therefore, the average number of addition polymerizable unsaturated double bonds of the curable oligomer (A1) is set to 1.8 to 4 as a by-product.

The curable oligomer (A1) is preferably a polyoxyalkylene chain or a polydiene chain, and more preferably a polyoxyalkylene chain, in terms of flexibility and heat and humidity resistance. .

Examples of the curable oligomer (A1) having a polydiene chain include an ester of a maleic anhydride adduct of a polyisoprene polymer and 2-hydroxyethyl methacrylate (Kuraray Co., Ltd.) Manufactured, UC102 (number average molecular weight: 17,000, average of addition polymerizable unsaturated double bonds: 2), UC203 (number average molecular weight: 35,000, average of addition polymerizable unsaturated double bonds: 3), UC- 1 (number average molecular weight: about 25,000)), a (meth) acrylate type oligomer of a polybutadiene skeleton, or the like.

The curable oligomer (A1) may be used alone or in combination of two or more.

The curable oligomer (A1) is preferably a curable oligomer (A11) or a curable oligomer (A12) described below in terms of flexibility. The curable oligomer (A12) is as follows.

Curable oligomer (A11): Acrylic acid obtained by reacting a polyol with a polyisocyanate to obtain a prepolymer having an isocyanate group at the terminal, and reacting the isocyanate group of the prepolymer with the following monomer (a1) A urethane oligomer.

Monomer (a1): a monomer having a molecular weight of from 125 to 600 and having one or more acryloxy groups and having one reactive group with an isocyanate group.

Examples of the monomer (a1) include a group having an active hydrogen (hydroxy group, an amine group, etc.) and a monomer having an acryloxy group.

Specific examples of the monomer (a1) include a hydroxyalkyl acrylate having a hydroxyalkyl group having 2 to 6 carbon atoms (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy acrylate). Butyl ester, 4-hydroxybutyl acrylate, etc.).

The monomer (a1) is preferably a hydroxyalkyl acrylate having a hydroxyalkyl group having 2 to 4 carbon atoms.

The monomer (a1) may be used alone or in combination of two or more.

Specific examples of the polyhydric alcohol include polyoxyalkylene polyols (polyoxyethylene glycol, polyoxypropylene polyol, etc.), polyester polyols, and polycarbonate polyols. As the polyol, from the viewpoint of flexibility, a polyoxyalkylene polyol is preferable, and a polyoxypropylene polyol is more preferable.

Further, in terms of improving the compatibility of the first composition with other components, a polyoxyalkylene polyol having an oxygen-extended propyl group and an oxygen-extended ethyl group is further preferred. Further, in terms of easily obtaining a cured product having high flexibility in a low temperature region, it is particularly preferred to have a polyoxyalkylene group having a polyoxyalkylene chain containing only an oxygen-extended ethyl group and an oxygen-extended propyl group. Polyol.

The number average molecular weight of the polyol is preferably 4,000 or more, and more preferably 8,000 or more in terms of lowering the concentration of the urethane bond in the first composition. The number average molecular weight of the polyol is preferably 45,000 or less, and more preferably 35,000 or less, from the viewpoint that the viscosity of the first composition is in the following range.

The polyol may be used alone or in combination of two or more.

The polyisocyanate is preferably at least one diisocyanate selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and non-yellowing aromatic diisocyanates.

Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, and 2,4,4-trimethyl-hexamethylene diisocyanate. .

Examples of the alicyclic polyisocyanate include isophorone diisocyanate and methylene bis(4-cyclohexyl isocyanate).

As the non-yellowing aromatic diisocyanate, benzodimethyl diisocyanate may be mentioned. Ester and the like.

The polyisocyanate may be used alone or in combination of two or more.

In the reaction of a polyol and a polyisocyanate, the ratio of the number of moles of the isocyanate group to the number of moles of the hydroxyl group (isocyanate group / hydroxyl group) is preferably 1/1 or more and 1.8/1 or less, more preferably 1.05/1. Above and below 1.5/1. When the isocyanate group/hydroxy group is in the above range, the viscosity of the first composition is easily adjusted to the following range.

The method of adjusting the average number of the addition polymerizable unsaturated double bonds of the curable oligomer (A11) to 1.8 to 4 is to adjust the blending of the raw materials used for the production of the curable oligomer (A11). The method of the ratio can be exemplified by the following methods (i) and (ii).

(i) When the addition of the polymerizable unsaturated double bond is an average of 1.8 to 2 of the curable oligomer (A11):

The method is as follows: a polyol having an average number of hydroxyl groups of 1.8 to 2 and a polyisocyanate having an average number of isocyanate groups of 2 are obtained, and a prepolymer having an average number of isocyanate groups of 1.8 to 2 is obtained, and then The monomer (a11) having an addition polymerizable unsaturated double bond and one hydroxyl group in one molecule is reacted so that the isocyanate group/hydroxyl molar ratio becomes 1/1.

(ii) When the addition of the polymerizable unsaturated double bond is 2 to 4 in the case of the curable oligomer (A11):

In the following method, a polyol having an average number of hydroxyl groups of 2 and a polyisocyanate having an average number of isocyanate groups of 2 are reacted to obtain a prepolymer having an average number of isocyanate groups of 2, and then having 1 molecule; The monomer (a12) having one hydroxyl group and having one or more addition polymerizable unsaturated double bonds is 1/1 of the isocyanate group/hydroxyl molar ratio and the average number of addition polymerizable unsaturated double bonds Become a 2~4 way of reaction.

The curable oligomer (A12) is an oligomer described below.

The curable oligomer (A12): an urethane urethane oligomer obtained by reacting a polyol with a compound having one of an isocyanate group and an addition polymerizable double bond.

As the polyol, it can be used in the same manner as the user of the curable oligomer (A11). By.

As a compound having one of an isocyanate group and an addition polymerizable double bond, for example, a compound represented by CH ₂ =C(R)C(O)OR ¹ -NCO (wherein R is a hydrogen atom or a methyl group) is preferable. , R ¹ is an alkylene group having 1 to 6 carbon atoms). As such a compound, Karenz MOI (registered trademark) (manufactured by Showa Denko Co., Ltd., R is a methyl group, the carbon number of R ¹ is 2), Karenz AOI (registered trademark) (manufactured by Showa Denko, R is a hydrogen atom) , the carbon number of R ¹ is 2) and the like.

Hardening oligomer (A2):

The curable oligomer (A2) has a number average molecular weight of 1,000 to 20,000, preferably 2,000 to 10,000. When the number average molecular weight of the curable oligomer (A2) is in this range, it is easy to form an adhesive layer which is easy to adjust the viscosity of the first composition to the following range.

When the curable oligomer (A) contains the curable oligomer (A2), the viscosity of the first composition can be easily adjusted to the following range. Since the curable oligomer (A2) does not substantially have a hydroxyl group, it does not adversely affect the disappearance of the bubble, and the viscosity of the first composition can be adjusted.

Examples of the addition polymerizable unsaturated double bond of the curable oligomer (A2) include an acryloxy group and a methacryloxy group. The addition polymerizable unsaturated double bond of the curable oligomer (A2) is preferably an acryloxy group or a methyl group in terms of a faster curing rate and an adhesive layer having a higher transparency. The propylene oxime group has a small difference in reactivity between the curable oligomer (A2) and the addition polymerizable unsaturated double bond of the low molecular weight polymerizable compound (B), and forms a homogeneous adhesive layer. Especially preferred is propylene oxime.

The average number of the addition polymerizable unsaturated double bonds of the curable oligomer (A2) is from 0.5 to 1, preferably 0.7, in terms of the hardenability of the first composition and the mechanical properties of the adhesive layer. ~1. When the number of addition polymerizable unsaturated double bonds exceeds 1, the crosslinkable oligomer is formed, and the storage shear modulus of the cured product of the curable resin composition is easily improved. Therefore, the stress applied to the display panel attached to the adhesive layer becomes large, and is likely to occur. The display device is unevenly displayed.

Further, the fluidity of the adhesive layer is lost, so that bubbles which are generated at the interface between the adhesive layer and the display panel at the time of bonding tend to remain. Therefore, it is preferred to select a raw material for production of the curable oligomer (A2) so that the number of the addition polymerizable unsaturated double bonds is not more than one.

The curable oligomer (A2) may be used alone or in combination of two or more.

The curable oligomer (A2) is preferably a curable oligomer (A21) described below in terms of flexibility.

Curable oligomer (A21): a single obtained by reacting a monool with a polyisocyanate to obtain a prepolymer having an isocyanate group at only one end, and reacting the isocyanate group of the prepolymer with the monomer (a1) Acryl acrylate oligomer.

The monomer (a1) and the polyisocyanate used for the production of the curable oligomer (A21) are the same as those of the user of the curable oligomer (A11), and the preferred embodiment is also the same. The monool may be the same as the user of the curable oligomer (A11) except for the number of hydroxyl groups, and the preferred embodiment is also the same. The number of preferred hydroxyl groups of the monool is 0.5 to 1 in a molecule, and more preferably 0.7 to 1.

The method of adjusting the average number of addition polymerizable unsaturated double bonds of the curable oligomer (A21) to 0.5 to 1 is to adjust the blending of raw materials used for the production of the curable oligomer (A21). The method of the ratio is, for example, the following methods (iii) and (iv).

(iii) is a method in which a monool and a diisocyanate are reacted in a ratio of an isocyanate group/hydroxyl molar ratio of 1/1 to 2/1 to obtain a prepolymer having an average number of isocyanate groups of 0.5 to 1. Thereafter, it is reacted in such a manner that the molar ratio of the monomer (a1) to the isocyanate group/isocyanate group is 1/1.

(iv) a method in which a monool and a compound having one each of an acryloxy group and an isocyanate group in one molecule are reacted at a ratio of a mole ratio of an isocyanate group to a hydroxyl group of 1/2 to 1/1. The compound having an average of propylene decyloxy groups of 0.5 to 1 is obtained.

Regarding the low molecular weight polymerizable compound (B):

The molecular weight of the low molecular weight polymerizable compound (B) is 600 or less, preferably 140 to 400. The smaller the molecular weight of the low molecular weight polymerizable compound (B), the better the adhesion between the adhesive layer and the transparent surface material, and the adhesion between the adhesive layer and the adherend (display panel or the like). When the molecular weight of the low molecular weight polymerizable compound (B) is 140 or more, the volatilization of the low molecular weight polymerizable compound (B) in the production of the transparent surface material or the display device with the adhesive layer can be suppressed by the following method.

The number of addition polymerizable unsaturated double bonds of the low molecular weight polymerizable compound (B) is preferably from 1 to 3, more preferably from 1 to 2. The low molecular weight polymerizable compound (B) is preferably one in which a compound having an addition polymerizable unsaturated double bond is used in combination, and a compound having an addition polymerizable unsaturated double bond is two or more.

Examples of the addition polymerizable unsaturated double bond of the low molecular weight polymerizable compound (B) include an acryloxy group and a methacryloxy group. The addition polymerizable unsaturated double bond of the low molecular weight polymerizable compound (B) is preferably an acryloxy group or a methyl group in terms of a faster curing rate and an adhesive layer having a higher transparency. The propylene oxime group is particularly preferably an acryloxy group in terms of a faster curing rate.

The low molecular weight polymerizable compound (B) may be used alone or in combination of two or more.

Low molecular weight polymerizable compound (B1):

As the low molecular weight polymerizable compound (B), the adhesion between the adhesive layer and the transparent surface material, the adhesion between the adhesive layer and the adherend (display panel, etc.) are improved, and the adhesive layer is easily obtained. In terms of the dispersion stabilizing effect of the non-curable oligomer (C1), it is preferred to formulate a low molecular weight polymerizable compound having an addition polymerizable unsaturated double bond and a hydroxyl group bonded to a carbon atom ( B1).

The number of hydroxyl groups of the low molecular weight polymerizable compound (B1) is in terms of the adhesion between the adhesive layer and the transparent face material or the adherend, and the rate of disappearance of the bubbles remaining at the interface between the adherend and the adhesive layer. Preferably, it is 1 or 2, and particularly preferably 1.

As the low molecular weight polymerizable compound (B1) having one hydroxyl group, (A) 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl methacrylate , phenyl glycidyl ether acrylate, and the like.

Examples of the low molecular weight polymerizable compound (B1) having two hydroxyl groups include glycerin monoacrylate and 2,3-dihydroxypropyl acrylate.

The low molecular weight polymerizable compound (B1) is preferably a methacrylic acid hydroxyalkyl group having a hydroxyalkyl group having 3 to 8 carbon atoms in terms of adhesion between the adhesive layer and the transparent surface material or the adherend. Ester (2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, etc.) or phenyl glycidyl ether acrylate, more preferably phenyl glycidyl ether acrylate.

The low molecular weight polymerizable compound (B1) may be used alone or in combination of two or more.

Low molecular weight polymerizable compound (B2):

The low molecular weight polymerizable compound (B) may be a low molecular weight polymerizable compound (B2) having an addition polymerizable unsaturated double bond and having no hydroxyl group.

About non-hardening oligomer (C):

The non-curable oligomer (C) is one which does not react with the curable oligomer (A) or the low molecular weight polymerizable compound (B) during curing of the first composition. The non-curable oligomer (C) may or may not have a hydroxyl group.

The non-curable oligomer (C) may be used alone or in combination of two or more.

If the non-curable oligomer (C) is contained in the first composition, the fluidity of the first composition is improved, and the storage shear modulus of the adhesive layer is lowered. Therefore, the non-hardening oligomer (C) contributes to shortening of the adhesive surface and adhesion when the transparent surface material of the adhesive layer is bonded to the adherend after being placed in an atmosphere under reduced pressure. The time necessary for the bubbles at the interface of the layer to disappear.

Further, the non-curable oligomer (C) can suppress the stress applied to the transparent surface material when the first composition is applied to the surface of the transparent surface material and the first composition is cured.

The non-curable oligomer (C) can exhibit the above effects in a small amount, but it is caused by the fact that when the ruthenium is present, the non-curable oligomer (C) is diffused from the adhesive layer to the ruthenium, and thus The deformation (for example, the step) in the interface between the adhesive layer and the crucible causes the generation or residual of the bubble when it is bonded to the adherend. Therefore, the non-curable oligomer (C) is preferably used in the range of the following amounts.

Non-hardening oligomer (C1):

The non-curable oligomer (C) is preferably formulated in terms of adhesion between the adhesive layer and the transparent surface material, and adhesion between the adhesive layer and the adherend (display panel or the like). Non-hardening oligomer (C1).

The average number of hydroxyl groups of the non-curable oligomer (C1) is preferably 0.8 to 3 in terms of compatibility and the rate of disappearance of bubbles remaining at the interface between the adherend and the adhesive layer. It is 1.8~2.3.

The number average molecular weight of each of the hydroxyl groups of the non-curable oligomer (C1) is preferably from 400 to 8,000, more preferably from 600 to 5,000. When the number average molecular weight of each of the hydroxyl groups is 400 or more, the polarity of the non-curable oligomer (C1) becomes too high, and the curable oligomer (A) and the low molecular weight polymerizable compound (B) are easily obtained. Good compatibility with other non-hardening oligomers (C).

When the number average molecular weight of each of the hydroxyl groups is 8,000 or less, the hardening is easily obtained by the interaction between the hydroxyl group derived from the low molecular weight polymerizable compound (B1) and the hydroxyl group of the non-hardenable oligomer (C1). The dispersion stabilizing effect of the non-hardening oligomer (C1) in the subsequent adhesive layer. For this interaction, it is presumed to be related to hydrogen bonding.

The non-hardening oligomer (C1) may be used alone or in combination of two or more.

Examples of the non-curable oligomer (C1) include high molecular weight polyols and the like. The non-curable oligomer (C1) is preferably a polyoxyalkylene polyol, a polyester polyol, a polycarbonate polyol, or a polybutadiene polyol in terms of flexibility and compatibility. .

Further, in the curable oligomer (A), a polyoxyalkylene polyol is used as a raw material. In the case of the ureic acid urethane, the non-curable oligomer (C1) is more preferably a polyoxyalkylene polyol in terms of compatibility.

Examples of the polyoxyalkylene polyol include polyoxyalkylene glycols such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene glycol, and polyoxytetramethylene glycol.

As the non-curable oligomer (C1), a polyoxyalkylene polyol is preferable, and a polyoxyalkylene polyol is preferable in terms of the fact that the storage shear modulus of the adhesive layer is likely to be low. Further, as the non-curable oligomer (C1), a polyoxyalkylene polyol having an oxygen-extended propyl group and an oxygen-extended ethyl group can also be used.

Non-hardening oligomer (C2):

The non-curable oligomer (C) may be further formulated with a non-curable oligomer (C2) having no hydroxyl group.

The number average molecular weight of the non-curable oligomer (C2) is preferably from 1,000 to 8,000. When the number average molecular weight of the non-curable oligomer (C2) is 1,000 or more, the non-curable oligomer (C2) hardly escapes. When the number average molecular weight of the non-curable oligomer (C2) is 8,000 or less, it becomes easy to adjust the viscosity of the first composition to the following range.

Examples of the non-curable oligomer (C2) include a compound in which a hydroxyl group of the non-curable oligomer (C1) is substituted with a group which is not reactive with an acryloyl group, a polydiene having a high molecular weight, and the like. Examples of the polydiene include polybutadiene, polyisoprene, a hydrogenated product of polybutadiene, and polybutene. Examples of the compound in which the hydroxyl group of the non-curable oligomer (C1) is substituted with a group having no reactivity with the acryloyl group may, for example, be an alkoxide of a polyoxyalkylene polyol, a monocarboxylate or an oxiranide. Compounds, esterates, and the like.

Regarding the combination of the curable oligomer (A) and the non-curable oligomer (C):

The curable oligomer (A) and the non-hardening oligomer are stabilized in terms of stabilizing the mixed state of the first composition before hardening and suppressing the separation of the non-curable oligomer (C) from the adhesive layer ( C) is preferably a molecular chain having the same structure or a similar structure.

Specifically, it is preferred to use a compound having a hydroxyl group (hereinafter, it is described as having a hydroxyl group) The compound is used as a raw material of the curable oligomer (A), and the same hydroxyl group-containing compound is used as the non-curable oligomer (C).

In the first composition, the curable oligomer (A) is an urethane urethane oligomer synthesized by using a polyoxyalkylene polyol and a polyisocyanate as a raw material, in terms of compatibility. Preferably, the non-curing oligomer (C) is a polyoxyalkylene polyol.

That is, when a hydroxyl group-containing compound which is convenient as a raw material of the curable oligomer (A) is not the same as a hydroxyl group-containing compound used as the non-hardenable oligomer (C), the hydroxyl group-containing compound It is preferred that the molecular chain has a structure in which a molecular unit has a common structural unit (oxyalkylene unit, diene unit, etc.) and the like, and the polarity is the same. When the curable oligomer (A) and the non-curable oligomer (C) have the same molecular structure, the compatibility of the non-curable oligomer (C) in the first composition is further improved.

A preferred combination of the hydroxyl group-containing compound used as a raw material of the curable oligomer (A) and the hydroxyl group-containing compound used as the non-curable oligomer (C) is exemplified. The combination described.

The combination is as follows, that is, the curable oligomer (A) is a polyoxypropyl propyl polyol in which one part of an oxygen-extended propyl group is substituted by an oxygen-extended ethyl group, and an acrylic acid carboxylic acid synthesized using a polyisocyanate as a raw material. Ester oligomer; non-curable oligomer (C) is a polyoxypropyl propylene polyol having no oxygen-extended ethyl group, and the molecular weight of each hydroxyl group is smaller than that of the curable oligomer (A) A polyoxyl extended propylene polyol of an alcohol.

The combination of the curable oligomer (A) and the non-curable oligomer (C) is particularly preferably the combination described below.

The combination is as follows, that is, the curable oligomer (A) is obtained by reacting a polyoxyalkylene glycol having an oxygen-extended propyl group and an oxygen-extended ethyl group with a polyisocyanate to obtain a prepolymer having an isocyanate group at the terminal. An urethane urethane oligomer obtained by reacting with the monomer (a1); the non-curable oligomer (C) is the same as the user of the curable oligomer (A), and has an oxygen extension a polyoxyalkylene glycol having a propyl group and an oxygen-extended ethyl group, or a polyoxypropylene having an oxygen-extended propyl group A diol which is a polyoxypropylene diol having a molecular weight smaller than that of the diol used in the curable oligomer (A).

About photopolymerization initiator (D):

Examples of the photopolymerization initiator (D) include an acetophenone system, a ketal system, a benzoin system, a benzoin ether system, a phosphine oxide system, a benzophenone system, and a 9-oxosulfuric acid. Photopolymerization initiators such as lanthanum and lanthanide. As the photopolymerization initiator (D), a phosphine oxide system or a 9-oxosulfurate is preferred. The photopolymerization initiator is preferably a phosphine oxide system in terms of suppressing coloration after photopolymerization.

About additives:

Examples of the additive include a polymerization inhibitor, a photocuring accelerator, a chain transfer agent, a light stabilizer (a UV absorber, a radical scavenger, etc.), an antioxidant, a flame retardant, and an adhesion improver (a decane coupling agent). Etc.), pigments, dyes, etc. As the additive to be added to the first composition, a polymerization inhibitor and a light stabilizer are preferred. In particular, the storage stability of the first composition can be improved by containing a polymerization inhibitor in an amount smaller than that of the polymerization initiator, and the molecular weight of the cured product of the first composition can also be adjusted.

Examples of the polymerization inhibitor include hydroquinone (2,5-di-t-butyl hydroquinone, etc.), catechol (p-butyl catechol, etc.), and hydrazine. A polymerization inhibitor such as an anthraquinone, a phenothiazine or a hydroxytoluene.

Examples of the light stabilizer include an ultraviolet absorber (such as a benzotriazole system, a benzophenone system, and a salicylate system), a radical scavenger (hindered amine), and the like.

Examples of the antioxidant include hindered phenol-based, phosphorus-based, and sulfur-based compounds.

About the blending ratio of each raw material:

The ratio of the low molecular weight polymerizable compound (B) in the first composition is preferably from 1 to 80 in the total (100% by mass) of the curable oligomer (A) and the low molecular weight polymerizable compound (B). The mass% is more preferably 3 to 70% by mass.

When the ratio of the low molecular weight polymerizable compound (B1) is at least the above lower limit value, the storage stability of the first composition becomes good, and the adhesion between the adhesive layer and the transparent surface material and adhesion are obtained. The adhesion between the layer and the adherend (display panel, etc.) becomes good.

The ratio of the low molecular weight polymerizable compound (B2) is preferably 50% by mass in the total (100% by mass) of the curable oligomer (A) and the low molecular weight polymerizable compound (B) in the first composition. Hereinafter, it is more preferably 40% by mass or less.

Further, in the synthesis of the curable oligomer (A11) or the curable oligomer (A21), the monomer (a1) which reacts with the isocyanate group of the prepolymer is used as a part of the curable oligomer (A). It exists and is therefore not included in the ratio of the low molecular weight polymerizable compound (B). On the other hand, in the synthesis of the curable oligomer (A11) or the curable oligomer (A21) or after the synthesis, a low molecular weight polymerizable compound as a diluent is added as needed (wherein, unlike the prepolymer) When the reactant is a low molecular weight polymerizable compound (B), the low molecular weight polymerizable compound is contained in the ratio of the low molecular weight polymerizable compound (B).

In the case where the first composition contains the non-curable oligomer (C), the ratio of the non-curable oligomer (C) is preferably from 1 to 60% by mass in the first composition (100% by mass). When the ratio of the non-curable oligomer (C) is at least the above lower limit value, bubbles are less likely to remain between the adhesive layer and the adherend. When the ratio of the non-curable oligomer (C) is at most the above upper limit value, the protective film is easily peeled off from the adhesive layer as long as the adhesive layer is sufficiently cured.

When the first composition contains the non-curable oligomer (C), the total of the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-hardenable oligomer (C) (100) In the mass%), the curable oligomer (A) is preferably 6 to 80% by mass, the low molecular weight polymerizable compound (B) is 3 to 70% by mass, and the non-curable oligomer (C) is 1 to 1. 60% by mass; more preferably, the curable oligomer (A) is 6 to 60% by mass, the low molecular weight polymerizable compound (B) is 3 to 55% by mass, and the non-curable oligomer (C) is 1 to 60%. quality%.

The amount of the photopolymerization initiator (D) in the first composition is preferably 0.01 to 10 parts by mass based on 100 parts by mass of the total of the curable oligomer (A) and the low molecular weight polymerizable compound (B). The mass part is more preferably 0.1 to 5 parts by mass.

Regarding the amount of the additive in the first composition, relative to the curable oligomer (A) The total amount of the low molecular weight polymerizable compound (B) is 100 parts by mass, preferably 10 parts by mass or less, more preferably 5 parts by mass or less.

Regarding the viscosity of the first composition:

The viscosity of the first composition is preferably from 0.05 to 50 Pa‧s, more preferably from 1 to 20 Pa‧s. If the viscosity of the first composition is 0.05 Pa‧s or more, the coating shape of the first composition is maintained when the adhesive layer is formed. When the viscosity of the first composition is 50 Pa‧s or less, the first composition is easily supplied to the surface of the transparent surface material, and the productivity of the transparent surface material with the adhesive layer is good.

(weir)

The oxime system is a part of a transparent resin obtained by coating and curing a curable resin composition for forming a liquid.

By the fact that the periphery of the adhesive layer has flaws, the peripheral portion of the adhesive layer is prevented from expanding outward and the thickness of the peripheral portion is reduced, so that the thickness of the entire adhesive layer can be kept uniform. By making the thickness of the entire adhesive layer uniform, it is preferable to prevent the bubbles from remaining at the interface in the bonding with the adherend (for example, a display panel or the like).

In the case of flaws, the thickness of the crucible is slightly thicker than the thickness of the adhesive layer. Even if the surface of the adhesive layer is not flat, the thickness of the adhesive layer is not necessarily the same. In at least a portion of the region where the adhesive layer is close to the adhesive layer, it is preferable that the thickness of the adhesive layer is slightly thicker than the thickness of the adhesive layer.

The thickness of the crucible is preferably substantially equal to the average thickness of the adhesive layer removed from the region where the crucible is adjacent to the adhesive layer, or as described above, is thicker than the thickness of the adhesive layer by 0.005 to 0.05 mm, more preferably 0.01 to 0.03 thick. Mm.

The area on the outer side of the image display area of the display panel is relatively narrow, so that the width of the crucible is preferably narrowed. The width of the crucible is preferably 0.5 to 2 mm, more preferably 0.8 to 1.6 mm.

The storage shear modulus at 35 ° C is preferably greater than the storage shear modulus of the adhesive layer at 35 ° C. If the storage shear modulus of the crucible is larger than the storage shear modulus of the adhesive layer, the laminate is bonded to the transparent surface material of the adhesive layer, even at the peripheral portion of the adhesive layer. There are bubbles remaining at the interface between the laminate and the adhesive layer, and the bubbles are difficult to open to the outside, and are easily become independent bubbles.

Therefore, when the adherend is bonded to the transparent surface material of the adhesive layer in a reduced pressure environment and then returned to the atmospheric pressure environment, the pressure in the bubble (ie, the decompressed state of the reduced pressure environment) The pressure is reduced by the pressure applied to the pressure of the adhesive layer (i.e., the atmospheric pressure when returned to the atmospheric pressure environment), and the volume of the bubble is reduced, so that the bubble easily disappears.

Moreover, by making the storage shear modulus of the crucible larger than the storage shear modulus of the adhesive layer, the thickness of the crucible is slightly larger than the thickness of the adhesive layer in at least a portion of the region close to the adhesive layer, and is easy A transparent face material with an adhesive layer is produced.

(curable resin composition for bismuth formation)

Examples of the curable resin composition for forming a crucible include a composition comprising a polyfluorene oxide resin (organopolyoxyalkylene oxide), a urethane oligomer, and an urethane acrylate oligomer.

The curable resin composition for forming a crucible preferably has a composition of an oligomer (F) and a monomer (G) (hereinafter referred to as a second composition) in terms of flexibility and curing rate. .

(second composition)

The second composition may be a photocurable resin composition or a thermosetting resin composition. The second composition is preferably a photocurable resin composition which is further cured with a photopolymerization initiator (E) in terms of curing at a low temperature and a faster curing rate. Further, when the second composition is a photocurable resin composition, the curing does not require a high temperature, and thus the damage of the display panel caused by the high temperature is also small.

Further, the same composition as the first composition may be used as the second composition. In this case, in the following step (α21), the second composition is applied to the peripheral portion of the surface of the transparent surface material, and semi-hardened to form a crucible.

In the second composition, additives may also be formulated as needed.

Further, in order to maintain the distance between the transparent face material and the display panel, spacer particles having a specific particle diameter may be blended in the second composition.

About oligomer (F):

The oligomer (F) is a compound having an addition polymerizable unsaturated double bond and having a number average molecular weight of 30,000 to 100,000.

Examples of the addition polymerizable unsaturated double bond of the oligomer (F) include an acryloxy group and a methacryloxy group. The addition polymerizable unsaturated double bond of the oligomer (F) is preferably an acryloxy group or a methacryloxy group in terms of a faster curing rate and a higher transparency. base. Further, the difference in reactivity between the oligomeric (F) and the monomer (G) addition polymerizable unsaturated double bond becomes small, and in terms of homogenization, it is particularly preferable to be an oligomer ( F) The addition polymerizable unsaturated double bond is an acryloxy group, and the addition polymerizable unsaturated double bond of the monomer (G) is a methacryloxy group.

The oligomer (F) has a number average molecular weight of 30,000 to 100,000, preferably 40,000 to 80,000, more preferably 50,000 to 65,000. When the number average molecular weight of the oligomer (F) is within the above range, the viscosity of the second composition is easily adjusted to the following range.

The average number of the addition polymerizable unsaturated double bonds of the oligomer (F) is preferably from 1.8 to 4 in terms of the hardenability of the second composition and the mechanical properties of the crucible.

Examples of the oligomer (F) include a urethane oligomer having a urethane bond, a poly(meth) acrylate of a polyoxyalkylene polyol, and a polycondensation of a polyester polyol. (Meth) acrylate, etc.

It is preferred to use a polyol and a polyisocyanate in terms of broadly adjusting the mechanical properties of the crucible after hardening, the adhesion to the transparent face material, and the like by molecular design of the urethane chain or the like. The urethane oligomer synthesized by the raw material is more preferably an oligomer (F1) obtained by the following synthesis method. As the polyol, a polyoxyalkylene polyol is more preferable.

Oligomer (F1):

Since the oligomer (F1) having a number average molecular weight of 30,000 to 100,000 is highly viscous, it is difficult to synthesize by a usual method, and it is difficult to mix with the monomer (G) even if it can be synthesized.

Therefore, it is preferred to synthesize the oligomer (F1) by a synthesis method using the monomer (G) (the monomer (G1) and the monomer (G2) described below), and the obtained product is directly used as the first The second composition is further used as a second fat composition by diluting the obtained product with the monomer (G) (monomer (G1) to monomer (G3) or the like described below).

Monomer (G1): a monomer having an addition polymerizable unsaturated double bond in the monomer (G) and having no reaction with an isocyanate group.

Monomer (G2): a monomer having an addition polymerizable unsaturated double bond and having a group reactive with an isocyanate group in the monomer (G).

Monomer (G3): a monomer having an addition polymerizable unsaturated double bond and having a hydroxyl group in the monomer (G).

The oligomer (F1) is obtained by the following synthesis method.

A method for reacting an isocyanate group of the prepolymer with a monomer (G2) after reacting a polyol with a polyisocyanate to obtain a prepolymer having an isocyanate group in the presence of a monomer (G1) used as a diluent .

The polyhydric alcohol may be the same as the polyol exemplified in the first composition. The polyol may be the same as the first composition, or may be the same as the first composition, preferably the same as the first composition. Further, in terms of improving the compatibility of the second composition with other components, a polyoxyalkylene polyol having an oxygen-extended propyl group and an oxygen-extended ethyl group is further preferred.

The polyol may be used alone or in combination of two or more.

The polyisocyanate may be the same as the polyisocyanate exemplified in the first composition. The polyisocyanate may be the same as the first composition, or may be the same as the first composition, preferably the same as the first composition.

The polyisocyanate may be used alone or in combination of two or more.

About monomer (G):

The monomer (G) is a compound having an addition polymerizable unsaturated double bond and having a molecular weight of from 125 to 600.

Examples of the addition polymerizable unsaturated double bond of the monomer (G) include an acryloxy group and a methacryloxy group. The addition polymerizable unsaturated double bond as the monomer (G) is preferably an acryloxy group or a methacryloxy group in terms of a faster curing rate and a higher transparency. . Further, the difference in reactivity between the oligomeric (F) and the monomer (G) addition polymerizable unsaturated double bond becomes small, and in terms of homogenization, it is particularly preferable to be an oligomer ( F) The addition polymerizable unsaturated double bond is an acryloxy group, and the addition polymerizable unsaturated double bond of the monomer (G) is a methacryloxy group.

The molecular weight of the monomer (G) is from 125 to 600, preferably from 140 to 400, more preferably from 150 to 350. When the molecular weight of the monomer (G) is 125 or more, volatilization of the monomer (G) in the production of the display device can be suppressed. When the molecular weight of the monomer (G) is 600 or less, the solubility of the monomer (G) to the high molecular weight oligomer (F) can be improved, and the viscosity adjustment as the second composition can be preferably carried out.

The monomer (G) may also be included in the monomer (G1) used as a diluent in the synthesis method of the oligomer (F1). Further, the monomer (G) may contain an unreacted monomer (G2) used in the synthesis method of the oligomer (F1).

Further, in terms of the adhesion between the transparent face material and the crucible or the solubility of the additive, the monomer (G) preferably contains the monomer (G3).

Monomer (G1):

Examples of the monomer (G1) include an alkyl (meth)acrylate having an alkyl group having 8 to 22 carbon atoms (n-dodecyl (meth)acrylate, n-octadecyl (meth)acrylate. a base ester, a benzalkonium (meth)acrylate, etc., a (meth) acrylate having an alicyclic hydrocarbon group ((meth)acrylic acid) Alkyl ester, adamantyl (meth)acrylate, etc.).

Monomer (G2):

Examples of the monomer (G2) include monomers having an active hydrogen (hydroxy group, an amine group, etc.) and an addition polymerizable unsaturated double bond. Specific examples of the monomer (G2) include a hydroxyalkyl (meth)acrylate having a hydroxyalkyl group having 2 to 6 carbon atoms (2-hydroxyethyl (meth)acrylate, (meth)acrylic acid) 2-hydroxypropyl ester, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.). The monomer (G2) is preferably a hydroxyalkyl acrylate having a hydroxyalkyl group having 2 to 4 carbon atoms.

Monomer (G3):

As the monomer (G3), a hydroxy methacrylate having a hydroxyl group of 1 to 2 and a carbon number of 3 to 8 (2-hydroxypropyl methacrylate or 2-hydroxybutyl methacrylate) is preferred. , 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, etc.), particularly preferably 2-hydroxybutyl methacrylate.

About photopolymerization initiator (E):

Examples of the photopolymerization initiator (E) include an acetophenone system, a ketal system, a benzoin system, a benzoin ether system, a phosphine oxide system, a benzophenone system, and a 9-oxosulfuric acid. Photopolymerization initiators such as lanthanum and lanthanide. The photopolymerization initiator (E) is preferably an acetophenone-based, ketal-based or benzoin-based photopolymerization initiator. In the case of performing hardening using visible light of a short wavelength, a phosphine oxide-based photopolymerization initiator is more preferable in terms of absorption of a wavelength region. By using two or more kinds of photopolymerization initiators (E) having different wavelength domains, the hardening time can be further shortened or the surface hardenability of tantalum can be improved.

About additives:

The additive is the same as those listed in the first composition. As the additive to be added to the second composition, a polymerization inhibitor and a light stabilizer are preferred. In particular, the storage stability of the second composition can be improved by containing a polymerization inhibitor in an amount smaller than that of the polymerization initiator, and the molecular weight of the cured product of the second composition can also be adjusted.

About the blending ratio of each raw material:

The ratio of the monomer (G) in the second composition is preferably from 15 to 50% by mass, more preferably from 20 to 50% by mass, based on the total of the oligomer (F) and the monomer (G) (100% by mass). ~45 mass%, further preferably 25-40 mass%. When the ratio of the monomer (G) is 15% by mass or more, the curability of the second composition and the adhesion between the transparent surface material and the crucible are improved. When the ratio of the monomer (G) is 50% by mass or less, the viscosity of the second composition is easily adjusted to 500 Pa‧s or more.

Further, in the synthesis of the oligomer (F1), the monomer (G2) which reacts with the isocyanate group of the prepolymer is partially present as one of the oligomers (F), and thus is not contained in the monomer (G). In the proportion. On the other hand, in the synthesis of the oligomer (F1), the monomer (G1) used as the diluent and the monomer (G) added after the synthesis of the oligomer (F1) are contained in the monomer (G). In the proportion.

The amount of the photopolymerization initiator (E2) in the second composition is preferably 0.01 to 10 parts by mass, more preferably 100 to 10 parts by mass, based on 100 parts by mass of the total of the oligomer (F) and the monomer (G). It is 0.1 to 5 parts by mass.

The total amount of the additives in the second composition is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less based on 100 parts by mass of the total of the oligomer (F) and the monomer (G).

Regarding the viscosity of the second composition:

The viscosity of the second composition is preferably from 500 to 3,000 Pa s, more preferably from 800 to 2,500 Pa s, and still more preferably from 1,000 to 2,000 Å s. When the viscosity of the second composition is 500 Pa ‧ or more, the shape of the crucible before curing can be maintained for a relatively long period of time, and the height of the crucible before curing can be sufficiently maintained. If the viscosity of the second composition is 3,000 Pa‧s or less, the crucible before hardening can be formed by coating.

Further, even if the viscosity of the second composition is less than 500 Pa s, in the case where the second composition is a photocurable resin composition, the second combination after the light irradiation is irradiated by the light immediately after application. The viscosity of the substance may be the above preferred range. In terms of easiness of coating, it is preferred that the viscosity at the time of coating of the second composition is less than 500 Pa‧s, and more preferably 200 Pa‧s or less.

(protective film)

For the protective film, it is required not to be in close contact with the adhesive layer. Therefore, as the protective film, a film having a relatively low adhesion to an adhesive layer such as polyethylene, polypropylene or a fluorine-based resin is preferable.

In the production method described below, when the protective surface film is bonded to the surface material, the protective film is required to be bonded to the support surface material. Therefore, in this case, as the protective film, a self-adhesive protective film having an adhesive surface on one side of the base film having relatively low adhesion is preferable.

The adhesive force of the adhesive surface of the protective film is preferably 0.01 to 0.1 N, more preferably 0.02 to 0.06 N in the test body of 50 mm width in the 180-degree peeling test at a peeling speed of 300 mm/min of the acrylic sheet. . When the adhesive force is at least the above lower limit value, it can be bonded to the support surface material. When the adhesive force is at most the above upper limit value, it is easy to peel off the protective film from the support surface material.

The thickness of the protective film varies depending on the resin to be used. However, when a relatively soft film such as polyethylene or polypropylene is used, the thickness of the protective film is preferably 0.04 to 0.2 mm, more preferably 0.06 to 0.1 mm. When the thickness of the protective film is at least the above lower limit value, deformation of the protective film can be suppressed when the protective film is peeled off from the adhesive layer. When the thickness of the protective film is at most the above upper limit value, the protective film is easily bent at the time of peeling, and it is easy to peel off the protective film from the adhesive layer.

[First Embodiment]

Fig. 1 is a cross-sectional view showing a first embodiment of a transparent surface material with an adhesive layer of the present invention.

The transparent surface material 1 with an adhesive layer has a transparent surface material 10, a light-shielding printing part 12 (light-shielding part) formed in the peripheral part of the surface of the transparent surface material 10, and the transparent surface material formed in the side in which the light-shielding printing part 12 was formed. A layered adhesive layer 14 on the surface of 10, and a peelable protective film 16 covering the surface of the adhesive layer 14.

After the transparent surface material 1 with the adhesive layer is peeled off the protective film 16, the transparent surface of the adhesive layer is adhered The material 1 is bonded to the display panel, whereby the display device can be manufactured.

(transparent surface material)

The transparent surface material 10 is provided on the image display surface side (that is, the viewing side) of the display panel described below to protect the display panel.

In the transparent surface material 10, in order to increase the contrast of the display image, an antireflection layer may be provided on the surface opposite to the side on which the adhesive layer 14 is formed. Further, it is also possible to color a part or the whole of the transparent face material 10, or to polish a part or the whole of the surface of the transparent face material 10 to form a glass shape to scatter light, or on the surface of the transparent face material 10. A part or the whole is formed with fine irregularities or the like to refract or reflect the transmitted light. Further, a colored film, a light-scattering film, a light-refractive film, a light-reflecting film, or the like may be bonded to one or a part of the surface of the transparent surface material 10.

The shape of the transparent face material 10 is preferably rectangular in the sense of being externally fitted to the display device. Depending on the shape of the display device, it is also possible to use a transparent face material that covers the entire shape of the display surface of the display panel and has a curved shape.

The size of the transparent surface material 10 may be appropriately set in accordance with the shape of the display device. The thickness of the transparent surface material 10 is preferably 0.5 to 25 mm in terms of mechanical strength and transparency in the case of a glass plate. . For applications such as television receivers and PC monitors used in indoors, the thickness of the transparent face material 10 is preferably 1 to 6 mm in terms of weight reduction of the display device, and is used in public display applications installed outdoors. The thickness of the transparent face material 10 is preferably 3 to 20 mm. In the case of using chemically strengthened glass, the thickness of the glass plate is preferably about 0.5 to 1.5 mm in terms of strength. In the case of a transparent resin sheet, it is preferably 2 to 10 mm.

(shading printing department)

The light-shielding printing unit 12 is invisible from the side of the transparent surface material 10 except for the image display area of the display panel described below, and concealed the wiring member or the like connected to the display panel. The light-shielding printing portion 12 may be formed on the surface on the side where the adhesive layer 14 is formed or the side opposite thereto. Reduce shading printing In terms of the parallax of the portion 12 and the image display region, it is preferable that the light-shielding portion 12 is formed on the surface on the side where the adhesive layer 14 is formed. In the case where the transparent surface material 10 is a glass plate, when the light-shielding printing portion 12 is printed using a ceramic containing a black pigment, the light-shielding property is high, which is preferable.

When the wiring member or the like on the display panel is a structure that is not visible from the side of the viewing display panel, or is concealed by another member such as a casing of the display device, or is transparent to the bonded body and the adhesive layer other than the display panel When the face material 1 is bonded, there is a case where the light-shielding printing portion 12 is not formed on the transparent surface material 10.

(adhesive layer)

The adhesive layer 14 is a layer containing a transparent resin obtained by hardening the above first composition.

(protective film)

As the protective film 16, a film having a relatively low adhesion to an adhesive layer such as polyethylene, polypropylene or a fluorine-based resin described above can be used.

[Second Embodiment]

Fig. 2 is a cross-sectional view showing a second embodiment of the transparent surface material with an adhesive layer of the present invention.

The transparent surface material 2 with an adhesive layer has a transparent surface material 10, a light-shielding printing part 12 (light-shielding part) formed in the peripheral part of the surface of the transparent surface material 10, and the transparent surface material formed in the side in which the light-shielding printing part 12 was formed. The layered adhesive layer 14 on the surface of the 10 surrounds the frame-shaped cymbal 15 of the adhesive layer 14 and the peelable protective film 16 covering the surface of the adhesive layer 14 in a state of being in contact with the peripheral edge of the adhesive layer 14.

After the transparent surface material 2 of the adhesive layer is peeled off from the protective film 16, the transparent surface material 2 with the adhesive layer is bonded to the display panel, whereby a display device can be manufactured.

The same configurations as those in the first embodiment are denoted by the same reference numerals and will not be described.

(weir)

堰15 is a part comprising a transparent resin obtained by hardening the above second composition.

(Other embodiments)

The transparent surface material of the adhesive layer of the present invention may have a transparent surface material and an adhesive layer, and the concentration of the hydroxyl group and the concentration of the urethane bond in the adhesive layer may be within a specific range, and is not limited to the illustration. example.

(Mechanism)

With respect to the transparent surface material of the adhesive layer of the present invention described above, the concentration of the hydroxyl group in the adhesive layer is 600×10 ^-6 mol/g or less, and the concentration of the urethane bond in the adhesive layer is 150×10 ^{− When the amount is 6} mol/g or less, when it is bonded to the adherend (display panel or the like), the bubbles remaining at the interface between the adherend and the adhesive layer can be quickly disappeared. Further, since the concentration of the hydroxyl group in the adhesive layer is 100 × 10 ^-6 mol/g or more, the adhesion between the adhesive layer and the transparent surface material and the adhesion between the adhesive layer and the adherend are improved.

<Method of Manufacturing Transparent Surface Material with Adhesive Layer>

The method for producing a transparent surface material with an adhesive layer of the present invention has the following step (α), the following step (β), and the following step (γ). The order of the following step (α), the following step (β), and the following step (γ) is preferred.

(α) A step of supplying a liquid curable resin composition to the surface of the transparent surface material, and partially curing the curable resin composition as necessary to obtain a partially cured product.

(β) A step of covering the surface of the curable resin composition or the partially cured product with a protective film as needed.

(γ) A step of curing the curable resin composition or the partially cured product to form an adhesive layer.

The method for producing a transparent surface material with an adhesive layer according to the present invention can be classified into a method for producing a transparent surface material having no adhesive layer (for example, a transparent surface material with an adhesive layer according to the first embodiment), and a method for producing the same. A method for producing a transparent surface material with an adhesive layer (for example, a transparent surface material with an adhesive layer according to the second embodiment).

[Manufacturing method of transparent surface material without adhesive layer]

Examples of the method for producing a transparent surface material having an adhesive layer without a crucible include a method of the following step (α1), the following step (β1), and the following step (γ1).

(α1) The liquid curable resin composition for forming an adhesive layer is supplied to the surface of the transparent surface material in a layered manner, and the curable resin composition for forming an adhesive layer to be applied to the surface of the transparent surface material is partially cured. A step of forming a layer of a partially cured product.

(β1) A step of covering the surface of the portion of the cured portion with a protective film as needed.

(γ1) A step of further hardening the layer of the partially cured product to form an adhesive layer.

(step (α1))

The step (α1) may be the step (α1a) described below or may be the step (α1b) described below. The periphery of the curable resin composition for forming an adhesive layer, and the area of the device necessary for curing, and the periphery of the curable resin composition for forming an adhesive layer which can be supplied to the surface of the transparent surface material can be suppressed. In the aspect in which the portion is expanded outward and the thickness of the peripheral portion is reduced, the step (α1a) is preferred.

(α1a) The liquid curable resin composition for forming an adhesive layer is supplied to the surface of the transparent surface material in a layered manner, and the curable resin composition for forming an adhesive layer to be applied to the surface of the transparent surface material is partially hardened. The step of forming a layer of partially hardened material.

(α1b) The liquid curable resin composition for forming an adhesive layer is supplied to the surface of the transparent surface material in a layered manner, and a layer of the curable resin composition for forming an adhesive layer is formed, and then the curable resin for forming the adhesive layer is formed. The step of partially curing the layer of the composition to form a layer of partially cured.

The supply of the curable resin composition for forming an adhesive layer is performed using a die coater, a knife coater, or the like.

The curing of the curable resin composition for forming an adhesive layer is carried out by irradiating ultraviolet rays or short-wavelength visible light from a light source (ultraviolet lamp, high-pressure mercury lamp, UV-LED, etc.) in the case of a photocurable resin composition. . The light irradiation can be carried out in the air or under the supply of nitrogen. Light irradiation is preferably a hardening tree formed from a supply adhesive layer The side of the lipid composition is carried out.

The curing of the curable resin composition for forming an adhesive layer is carried out by heating in the case of a thermosetting resin composition.

The layer of partially cured material is stored at 35 ° C. The storage modulus of the target is 1/200 to 1/5 of the storage shear modulus at 35 ° C. When the storage shear modulus of the layer of the partially cured product at 35 ° C is at least the above lower limit, the shape of the layer of the partially cured product is not deformed when the protective film is superposed. When the storage shear modulus of the layer of the partially cured product at 35 ° C is not more than the above upper limit, the adhesion to the protective film is sufficiently high.

(Step (β1))

In the step (β1), a protective film is superposed on the surface of the partially cured layer, and the surface of the partially cured layer is covered with a protective film.

The superposition can be carried out under atmospheric pressure, or can be carried out under a reduced pressure atmosphere as in the following step (β2).

Preferably, after the overlapping, the shape of the layer of the partially cured product is gradually pressed from the end of the layer of the partially cured product so as not to be deformed. A crimping machine can also be used for crimping.

(step (γ1))

In the step (γ1), the layer of the partially cured product is further hardened to form an adhesive layer.

The hardening of the layer of the partially cured product is carried out by irradiating ultraviolet rays or short-wavelength visible light from a light source (ultraviolet lamp, high-pressure mercury lamp, UV-LED, etc.) in the case of the photocurable resin composition. The light irradiation can be carried out in the air or under the supply of nitrogen. Light irradiation is preferably performed from the side of the protective film.

The hardening of the layer of the partially cured product is carried out by heating in the case of the thermosetting resin composition.

[Method for Producing Transparent Surface Material with Adhesive Layer According to First Embodiment]

Hereinafter, an example of a method of producing the transparent surface material 1 with an adhesive layer according to the first embodiment will be specifically described with reference to the drawings.

(step (α1))

In the step (α1), as shown in FIG. 3 and FIG. 4, the transparent surface material 10 placed on the conveying device (not shown) is moved at a constant speed in the direction of the arrow in the figure. The slit coater 62 disposed so as to extend in a direction orthogonal to the moving direction of the transparent face material 10 linearly ejects the liquid first composition 18 onto the surface of the transparent surface material 10. At this time, both ends of the linear first composition 18 are placed on the light-shielding printing portion 12. The first composition 18 is supplied in a layered manner so as to cover the entire surface of the light transmitting portion of the transparent surface material 10 and the inner edge side of the light shielding printing portion 12 together with the movement of the transparent surface material 10.

The first composition 18 is supplied in a layered manner, and linear light (ultraviolet light or short-wavelength visible light) is irradiated from the linear LED light source 64 to supply the first composition 18 to the surface of the transparent surface material 10. The layer 20 of the partially cured product is formed by hardening to form a partially cured product, and the linear LED light source 64 is opposite to the die coater 62 on the flow side below the moving direction of the transparent face material 10, and the longitudinal direction and the moving direction of the transparent face material 10 Orthogonal configuration.

(Step (β1))

In the step (β1), as shown in Fig. 5, the protective film 16 is superposed on the surface of the layer 20 of the partially cured product under atmospheric pressure, and the end of the layer 20 of the partially cured product is used using a bonding machine (not shown). The protective film 16 is slowly crimped, and the surface of the layer 20 of the partially cured product is covered with the protective film 16.

(step (γ1))

In the step (γ1), the layer 20 of the partially cured product is irradiated with light (ultraviolet rays or short-wavelength visible light) from the side of the protective film 16 to further harden the layer 20 of the partially cured product to form the adhesive layer 14, thereby obtaining the figure. A transparent face material 1 with an adhesive layer as shown in FIG.

[Manufacturing method of transparent surface material with adhesive layer attached]

Examples of the method for producing a transparent surface material having an adhesive layer with a crucible include the following steps (α21), the following step (α22), the following step (β2), the following step (γ21), and the following steps. (γ22) method.

(α21) A step of forming a frame-shaped ridge on the peripheral portion of the surface of the transparent surface material.

(α22) A step of supplying a curable resin composition for forming an adhesive layer to a region surrounded by the crucible.

(β2) The protective surface material of the protective film is laminated on the surface of the layer of the curable resin composition for forming an adhesive layer so as to be in contact with the surface of the layer of the curable resin composition for forming an adhesive layer. In the above, a step of obtaining a layered body of a layer of a curable resin composition for forming an adhesive layer by a transparent surface material, a protective film, and a crucible is obtained.

(γ21) A step of forming a layer of the curable resin composition for forming an adhesive layer to form an adhesive layer in a state where the layered body is placed under a pressure environment higher than the step (β2).

After the step (γ21) (γ22), the step of supporting the face material from the protective film is removed.

(Step (α21))

First, in the step (α21), a liquid curable resin composition for forming a crucible is applied to the peripheral portion of the surface of the transparent surface material to form a crucible.

The coating is performed using a printing machine, a dispenser, or the like. The crucible may be in an unhardened state or a partially hardened semi-hardened state. The partial hardening of the crucible is carried out by irradiation of light in the case where the curable resin composition for forming a crucible is a photocurable composition. For example, ultraviolet light or short-wavelength visible light is irradiated from a light source (ultraviolet lamp, high-pressure mercury lamp, UV-LED, etc.) to partially cure the photocurable resin composition.

(Step (α22))

After the step (α21), a liquid curable resin composition for forming an adhesive layer is supplied to the region surrounded by the crucible in the step (α22).

The supply amount of the curable resin composition for forming an adhesive layer is set such that the space formed by the enamel, the transparent surface material, and the protective film is filled with the curable resin composition for forming an adhesive layer, and There is a specific spacing between the transparent face material and the protective film (ie, the adhesive layer is of a specific thickness). In this case, it is preferable to consider the volume reduction caused by the hardening shrinkage of the curable resin composition for forming an adhesive layer in advance. Therefore, the component is preferably The thickness of the curable resin composition for forming an adhesive layer is slightly thicker than the specific thickness of the adhesive layer.

The supply method is a method in which a transparent surface material is placed horizontally, and a curable resin composition for forming an adhesive layer is formed in a dot shape, a line shape or a planar shape by a supply mechanism such as a dispenser or a die coater. supply.

(Step (β2))

After the step (α22), the transparent surface material supplied with the curable resin composition for forming an adhesive layer is placed in a decompression device in a step (β2), and is formed on the fixed support disk in the decompression device by an adhesive layer. The transparent facestock was horizontally placed with the face of the curable resin composition facing up.

A movement support mechanism that can move up and down is provided in an upper portion of the decompression device, and a support surface material (glass plate or the like) is attached to the movement support mechanism. A protective film is attached to the surface of the lower side of the support surface material.

The support face material is placed above the transparent face material and is not in contact with the curable resin composition for forming an adhesive layer. In other words, the curable resin composition for forming an adhesive layer on the transparent surface material is opposed to the protective film attached to the surface of the support surface material without being in contact with each other.

After the transparent surface material and the support surface material are placed at a specific position, the inside of the pressure reducing device is decompressed to a specific pressure reducing environment. After the inside of the decompression device becomes a specific decompression environment, the support surface material supported by the movement support mechanism is moved downward, and the support surface material with the protective film is brought into contact with the surface of the protective film to form the curable resin for the adhesive layer formation. The manner of the composition is superimposed on the first composition on the transparent facestock. Hereinafter, the overlap is referred to as a laminate.

By laminating, the curable resin composition for forming an adhesive layer is sealed on the surface of the transparent surface material, the surface of the protective film attached to the support surface material, and the space surrounded by the crucible.

When the film is overlapped, the curable resin composition for forming an adhesive layer is spread by supporting the weight of the face material, the pressure of the self-moving support mechanism, and the like, and the adhesive layer is filled in the space. The curable resin composition is formed to form an uncured adhesive layer. Thereafter, when exposed to a higher pressure environment in the step (?21), an uncured adhesive layer having little or no bubbles is formed.

The reduced pressure environment at the time of overlap is preferably 1 kPa or less, more preferably 10 to 300 Pa, and still more preferably 15 to 100 Pa. When the pressure-reducing environment is extremely low pressure, each component (curable compound, photopolymerization initiator, polymerization inhibitor, chain transfer agent, light stabilizer, etc.) contained in the curable resin composition for forming an adhesive layer is caused. The impact of adverse effects. For example, if the decompression environment is extremely low pressure, there is a case where the components are vaporized, and it takes time to provide a reduced pressure environment.

The time from the time when the transparent surface material and the support surface material are overlapped until the pressure-reducing environment is released is not particularly limited, and the pressure-reducing environment can be immediately released after sealing the adhesive layer-forming curable resin composition. After the adhesive layer is sealed with the curable resin composition, the reduced pressure state is maintained for a specific period of time.

(Step (γ21))

After the reduced pressure environment in the step (β2) is released, the step (γ21) is placed in a pressure environment higher than the step (β2). As a pressure environment higher than the step (β2), a pressure environment of 50 kPa or more is preferable.

When the laminated body is placed in a pressure environment higher than the step (β2), the transparent surface material and the supporting surface material are pressed in the direction in which they are adhered by the rising pressure. Therefore, if air bubbles are present in the sealed space in the laminated body, the uncured adhesive layer flows toward the air bubbles, and the entire sealed space is uniformly filled by the uncured adhesive layer.

The time from the time when the laminated body is placed in the pressure environment higher than the step (β2) until the hardening of the uncured adhesive layer (hereinafter referred to as the high-pressure holding time) is not particularly limited. When the laminate is taken out from the decompression device and moved to the curing device, and the process before the hardening is started in an atmospheric pressure environment, the time required for the process becomes the high pressure holding time.

Therefore, the uncured adhesive layer can be immediately hardened when there is no bubble in the sealed space of the laminate before being placed in the atmospheric pressure environment, or when the bubble disappears during the above process. When it takes time until the bubble disappears, the laminate is held under a pressure environment higher than the step (β2) until the bubble disappears. Further, even if the high-pressure holding time is long, there is usually no problem, and therefore, the high-voltage holding time can be lengthened in addition to other necessity in the process. The high-pressure holding time may be longer than one day, but in terms of production efficiency, it is preferably within 6 hours, more preferably within 1 hour, and particularly preferably 10 in terms of further improving production efficiency. Within minutes.

Then, the adhesive layer and the crucible are formed by hardening the uncured adhesive layer and the uncured or semi-hardened crucible. In this case, the hardening of the unhardened or semi-hardened crucible can be carried out simultaneously with the hardening of the uncured adhesive layer, and the unhardened or semi-hardened crucible can be hardened before the hardening of the uncured adhesive layer.

The uncured adhesive layer and the uncured or semi-hardened enamel are hardened by irradiation with light when the photocurable composition is contained. For example, ultraviolet light or short-wavelength visible light is irradiated from a light source (ultraviolet lamp, high-pressure mercury lamp, UV-LED, etc.) to cure the photocurable resin composition. a case where a light-shielding printing portion is formed on a peripheral portion of the transparent surface material, or an anti-reflection layer is provided on the transparent surface material, and the ultraviolet ray is not transmitted through the anti-reflection layer or the transparent resin film on which the anti-reflection layer is formed or is disposed on the anti-reflection layer. In the case of an adhesive layer or the like between the film and the transparent face material, light is irradiated from the side of the support face material.

(Step (γ22))

In the step (γ22), by removing the supporting surface material from the protective film, an adhesive layer having a sufficient adhesive force is formed in advance on the transparent surface material, and the bubble generation in the interface between the transparent surface material and the adhesive layer is sufficiently obtained. A transparent surface material with an adhesive layer that is suppressed.

[Method for Producing Transparent Surface Material with Adhesive Layer According to Second Embodiment]

Hereinafter, an example of a method of producing the transparent surface material 2 with an adhesive layer according to the second embodiment will be specifically described with reference to the drawings. The manufacturing system sequentially performs the following α21, α22, β2, Each step of γ21, γ22.

(Step (α21))

As shown in FIGS. 6 and 7, the second composition is applied along the light-shielding printing portion 12 of the peripheral portion of the transparent surface material 10 by a dispenser (not shown) to form an unhardened crucible 22.

(Step (α22))

Then, as shown in FIGS. 8 and 9, the first composition 26 is supplied to the rectangular region 24 surrounded by the unhardened crucible 22 of the transparent surface material 10. The supply amount of the first composition 26 is set in advance to the first composition 26 as long as the space sealed by the unhardened crucible 22, the transparent surface material 10, and the protective film 16 (see FIG. 10) is sealed. Filled.

Regarding the supply of the first composition 26, the transparent surface material 10 is horizontally placed on the lower pressure plate 28 as shown in Figs. 8 and 9, and the dispenser 30 is moved in the horizontal direction. The composition 26 is supplied in a line shape, a belt shape, or a dot shape.

The dispenser 30 is horizontally movable over the entire range of the region 24 by means of a known horizontal moving mechanism comprising a pair of feed screws 32 and a feed orthogonal to the feed screw 32. Screw 34. Instead of the dispenser 30, a die coater can also be used.

(Step (β2))

Then, as shown in FIG. 10, the transparent surface material 10 and the support surface material 36 with the protective film 16 are carried in the pressure reduction device 38. A pressure plate 42 having a plurality of adsorption pads 40 is disposed on the upper portion of the pressure reducing device 38, and a lower pressure plate 44 is disposed at the lower portion. The upper platen 42 is movable in the up and down direction by the air cylinder 46.

The support surface material 36 is attached to the adsorption pad 40 with the surface on which the protective film 16 is bonded facing downward. The transparent face material 10 is fixed to the lower platen 44 with the surface on which the first composition 26 is supplied facing upward.

Then, the air in the decompression device 38 is sucked by the vacuum pump 48. After the ambient pressure in the decompression device 38 reaches a reduced pressure environment of, for example, 15 to 100 Pa, the support surface 36 is sucked and held by the adsorption pad 40 of the upper platen 42, and the cylinder 46 is operated downward. The standby transparent face material 10 is lowered. Then, the transparent surface material 10 and the support surface material 36 with the protective film 16 are overlapped by the unhardened crucible 22. Thus, the laminated body in which the uncured adhesive layer containing the first composition 26 is sealed by the transparent surface material 10, the protective film 16, and the unhardened crucible 22 is held, and the laminated body is held for a specific period of time under a reduced pressure environment.

(Step (γ21))

Then, after the inside of the decompression device 38 is, for example, an atmospheric pressure environment, the laminated body is taken out from the decompression device 38. When the laminated body is placed in an atmospheric pressure environment, the surface on the side of the transparent surface material 10 on the side of the laminated body and the surface on the side of the supporting surface material 36 are pressed by the atmospheric pressure, and the transparent surface material 10 and the supporting surface material 36 are placed in the sealed space. The uncured adhesive layer is pressurized. By this pressure, the uncured adhesive layer in the sealed space flows, and the entire sealed space is uniformly filled by the uncured adhesive layer.

Then, from the side of the support surface material 36 to the unhardened crucible 22 and the uncured adhesive layer, light (ultraviolet light or short-wavelength visible light) is irradiated to harden the unhardened crucible 22 and the uncured adhesive layer inside the laminated body. The adhesive layer 14 and the crucible 15 are formed.

(Step (γ22))

Then, the support face material 36 is peeled off from the protective film 16, whereby the transparent face material 2 with the adhesive layer shown in Fig. 2 is obtained.

(Other embodiments)

The method for producing the transparent surface material with an adhesive layer of the present invention is a method for producing the transparent surface material with an adhesive layer of the present invention, and the method is not limited to the method as long as it has the steps (α) and (γ). An example of a method for producing a transparent face material with an adhesive layer.

For example, the peripheral edge portion of the protective film of the transparent surface material with the adhesive layer may be hermetically bonded to the transparent surface material over the entire circumference under reduced pressure. Specifically, the peripheral edge portion of the protective film 16 of the transparent surface material 1 with the adhesive layer shown in FIG. 1 may be applied to the transparent surface material 10 over the entire circumference under reduced pressure conditions (side surface, The lower surface, the upper surface, and the like) are hermetically joined. Thereby, the adhesive layer 14 is hermetically wrapped by the protective film 16, so that it can be confirmed The external air is prevented from entering the adhesive layer 14.

Further, the transparent surface material with the adhesive layer may be sealed in a sealed body containing a film having gas barrier properties under reduced pressure. Thereby, it is also possible to prevent the outside air from being mixed into the adhesive layer.

(Mechanism)

The method for producing a transparent surface material with an adhesive layer of the present invention described above, which is a method for producing a transparent surface material with an adhesive layer of the present invention, and has the steps (α) and (γ), and thus When the film is bonded to the adherend, the transparent surface material of the adhesive layer which remains in the bubble at the interface between the adhesive composition and the adhesive layer can be quickly disappeared.

<display device>

Figure 11 is a cross-sectional view showing an example of a display device of the present invention.

The display device 3 includes a display panel 50 and a transparent face material 2 attached to an adhesive layer of the display panel 50 so as to be in contact with the display panel 50 with the adhesive layer 14.

The display device 3 includes a transparent surface material 10, a display panel 50, a transparent surface material 10, and an adhesive layer 14 sandwiched between the display panel 50, a crucible 15 surrounding the adhesive layer 14, and a display connected to the display panel 50 for display. The flexible printed wiring board 60 (FPC) of the driving IC in which the panel 50 operates.

(display panel)

As shown in FIG. 11, the display panel 50 is an example of a liquid crystal panel having a color filter, and a transparent substrate 52 provided with a color filter and a transparent substrate 54 provided with a TFT (Thin-film transistor). The liquid crystal layer 56 is attached and held by a pair of polarizing plates 58.

The surface of the joint between the display panel 50 and the adhesive layer 14 may be subjected to surface treatment in order to improve adhesion to the adhesive layer 14. The surface treatment may be performed only on the peripheral portion, or the entire surface of the surface material may be performed. As a method of surface treatment, a method of treating with a primer or the like by low-temperature processing may be mentioned.

Regarding the thickness of the display panel 50, the case of the liquid crystal panel that operates by the TFT The thickness of the display panel 50 is usually about 0.4 to 4 mm. In the case of the EL panel, the thickness of the display panel 50 is usually about 0.2 to 3 mm.

(shape)

Regarding the shape of the display panel 50, it is generally rectangular. The transparent face material 10 and the display panel 50 may be substantially equal in size, and the transparent face material 10 may be made larger than the display panel 50 in relation to the other housings accommodating the display device. Further, conversely, the transparent face material 10 may be made smaller than the display panel 50 in accordance with the configuration of the other casings.

(Other embodiments)

The display device of the present invention is not limited to the illustrated example as long as it is a transparent surface material to which the adhesive layer of the present invention is attached to the display panel.

For example, the display panel is not limited to the liquid crystal panel shown in FIG.

The display panel is characterized in that at least one of the transparent electrodes is sandwiched between the electrodes, or between the substrate and the transparent substrate having a plurality of pairs of electrodes formed in the same plane, and optical characteristics are changed by external electrical signals. Display material. Depending on the type of display material, there are liquid crystal panels, EL panels, plasma panels, electronic ink panels, and the like.

Further, the display panel has a structure in which at least one of the transparent substrates is bonded to the face material, and is disposed such that the transparent substrate side is in contact with the adhesive layer. At this time, in some of the display panels, an optical film such as a polarizing plate or a retardation film is provided on the outermost layer side of the transparent substrate on the side in contact with the adhesive layer. In this case, the adhesive layer serves to bond the optical film on the display panel to the transparent face material.

(Mechanism)

In the display device of the present invention described above, the transparent surface material to which the adhesive layer of the present invention is attached is attached to the display panel. Therefore, it is possible to suppress the air bubbles from remaining on the interface between the display panel and the adhesive layer.

<Method of Manufacturing Display Device>

When manufacturing the display device of the present invention, the transparent surface material of the adhesive layer of the present invention is peeled off After leaving the protective film (protective material), the display panel and the transparent surface material with the adhesive layer are overlapped and adhered in such a manner that the adhesive layer contacts the display panel.

The method of manufacturing the display device may be a method including the steps S1 and S2 shown below.

(Step S1: Protective film peeling step)

In this step, the protective film is peeled off from the transparent face material of the adhesive layer covered by the protective film. The peeling of the protective film can be carried out in the atmosphere or under reduced pressure. After the protective film is peeled off, the transparent surface material with the adhesive layer can be exposed to the atmosphere without being exposed to the atmosphere before the transparent surface material of the adhesive layer is transferred to the inside of the reduced pressure container used in the step S2. In the case of storage in an environment, it is preferred to carry out the peeling of the protective film in a reduced pressure environment.

Among them, in the case of production equipment and the like, it is actually difficult to carry out the peeling of the protective film in a reduced pressure environment. In this case, there is no particular problem even if the peeling of the protective film is carried out in the atmosphere. In the case where the pressure-reducing container is not required to be prepared in the protective film peeling step, it is preferred to carry out the peeling of the protective film in the atmosphere. After the peeling of the protective film, it is preferred to proceed to the next step S2 quickly.

(Step S2: lamination step)

In this step, in the bonding apparatus, the display panel and the transparent surface material with the adhesive layer are bonded together in such a manner that the adhesive layer is in contact with the display panel. In this case, it is preferable that the display panel and the transparent surface material with the adhesive layer are bonded together under a reduced pressure environment in the pressure reduction container of the bonding apparatus. It is difficult to generate bubbles at the interface between the display panel and the adhesive layer by bonding under a reduced pressure environment. After the pressure reduction environment was maintained for a predetermined period of time inside the decompression container, the reduced pressure environment was released and the pressure was normal pressure.

The pressure reducing environment at the time of bonding is preferably 20 kPa or less, more preferably 15 to 0.5 kPa, still more preferably 10 to 0.2 kPa. When the degree of pressure reduction is less than or equal to the above upper limit, bubbles are less likely to remain, and when the degree of pressure reduction is at least the lower limit, a large-scale pressure reducing device is not required.

Regarding the time from the time when the display panel and the transparent surface material with the adhesive layer are overlapped until the decompression environment is released, it is preferable that the production efficiency is short. For example, it is preferably within 1 minute, more preferably within 10 seconds.

After the display panel is bonded to the transparent surface material to which the adhesive layer is attached, the adhesive layer may be irradiated again with light or heated, thereby promoting the hardening of the adhesive layer and stabilizing the hardened state of the adhesive layer.

When the transparent surface material to which the adhesive layer is attached is flexible, it may be bonded by attaching the surface of the transparent surface material with the adhesive layer to the surface on which the adhesive layer is formed to be convex. When the transparent surface material of the layer is bent, the transparent surface material with the adhesive layer is gradually superposed on the display panel from one end side to the other end side. According to this method, the gas existing in the space between the transparent surface material of the adhesive layer and the display panel is extruded from the one end side to the other end side, and the gas is bonded to the interface between the display panel and the adhesive layer. Create bubbles.

(Mechanism)

As shown in FIG. 12, the transparent surface material 2 with an adhesive layer is bonded to the display panel 50, and the bubbles M1 and M2 which are the sealed spaces are formed at the interface between the display panel 50 and the adhesive layer 14, but The bubbles M1, M2 generated immediately after the bonding are substantially disappeared after a certain period of time.

The inventors of the present invention have estimated that the mechanism of the disappearance of the bubble generated immediately after the bonding is as follows. In the process of shrinking the volume of the bubble, it is considered that there are three processes of P1, P2, and P3.

(Process P1: shrinking by the volume of the bonded differential pressure)

Process P1 is a method in which a display panel and a transparent surface material with an adhesive layer are bonded together under a reduced pressure environment, and after returning to a normal pressure environment, a pressure in a bubble in a decompressed state is generated, and a pressure is applied from the outside to the adhesive layer. The differential pressure of the pressure (i.e., the atmospheric pressure when returning to the atmospheric pressure environment), the process of reducing the volume of the bubble due to the differential pressure. The period of the process P1 is, for example, about several seconds. That is, the volume of the bubble is urgent after a few seconds from the time when the pressure is restored to the atmospheric environment. 遽 Zoom out.

(Process P2: the volume caused by the absorption of gas in the bubble by the adhesive layer is reduced)

The process P2 is a process in which the gas sealed in the bubble is absorbed and dissolved by the adhesive layer in contact with the bubble, whereby the volume of the bubble is reduced. The period of the process P2 is, for example, several minutes to several ten minutes. The volume of the bubble in the process P2 is reduced at a slower rate than the volume of the bubble in the process P1.

(Process P3: volume reduction caused by diffusion of gas into the adhesive layer)

The process P3 is accompanied by a process in which the gas dissolved in the adhesive layer in the process P2 diffuses from the periphery of the bubble to the outside thereof, so that the gas in the bubble is reabsorbed by the adhesive layer in contact with the bubble and is dissolved again, whereby the volume of the bubble is reduced.

That is, the concentration of the gas remaining in the bubble through the process P2 and the concentration of the gas dissolved in the adhesive layer around the bubble are substantially balanced. However, at this time, the concentration of the gas dissolved in the adhesive layer around the bubble and the concentration of the gas in the adhesive layer away from the bubble become a non-equilibrium state, so that the gas dissolved in the adhesive layer diffuses further outward from the bubble.

Through this process, the gas in the bubble is reabsorbed by the adhesive layer in contact with the bubble and dissolved again. The period of the process P3 is, for example, several hours or more. The rate at which the volume of the bubble in the process P3 is reduced depends on the diffusion speed of the gas in the adhesive layer, and therefore is slower than the volume of the bubble in the process P2. Through the process P3, the bubbles almost completely disappear.

As described above, immediately after the transparent surface material 2 with the adhesive layer is bonded to the display panel 50, air bubbles are generated at the interface between the display panel 50 and the adhesive layer 14 (M1, M2 in Fig. 12).

As a result of research by the inventors of the present invention, it has been found that in the case of the transparent surface material of the prior adhesive layer, it is necessary to have a long time for the bubble to disappear in the case of long-term storage after the production, but the adhesive layer according to the present invention is used. The transparent surface material disappears in a short time even when it is used for bonding to the bonded body after a long period of time after manufacture.

In the case of using the transparent face material with the adhesive layer of the present invention, the bubble is short The reason for disappearing in time can be estimated as follows.

As described above, the concentration of the hydroxyl group in the adhesive layer of the transparent surface material of the adhesive layer of the present invention is 600×10 ^-6 mol/g or less, and the concentration of the urethane bond in the adhesive layer is 150×10 ^-6 mol. /g below. Therefore, the cohesive force of the adhesive layer is weak, and diffusion of gas into the adhesive layer becomes easy. Thereby, the processes P2 and P3 become faster, and as a result, the remaining bubbles disappear in a short time.

(Other embodiments)

The manufacturing method of the display device of the present invention is a method for manufacturing the display device of the present invention, as long as the display panel and the transparent surface material with the adhesive layer are overlapped and adhered to the display panel in an adhesive layer under a reduced pressure environment. The method is not limited to the above-described manufacturing method.

For example, in the above-described manufacturing method, in the manufacturing step of the transparent surface material with an adhesive layer according to the second embodiment, the adhesive layer is placed under reduced pressure, whereby the gas content of the adhesive layer is reduced, and The step of reducing the gas content of the adhesive layer under reduced pressure may be any time before the step of bonding the transparent surface material of the adhesive layer to the adherend.

Further, various modifications can be added without departing from the spirit of the invention.

For example, the transparent surface material with an adhesive layer can also be attached to a coordinate input device such as a touch panel.

Moreover, the transparent surface material may also be a substrate with a transparent electrode constituting the touch panel portion in the display device with the touch panel. An adhesive layer may be formed on both surfaces of the substrate with the transparent electrode, or the transparent surface material and the display panel may be bonded to each other via a substrate with a transparent electrode on which the adhesive layer is formed on both sides.

<adhesive sheet>

The adhesive sheet of the present invention contains a cured product of a curable resin composition for forming an adhesive sheet.

The adhesive sheet of the present invention may be optionally applied to one or both sides of the adhesive sheet. An adhesive sheet with a protective film attached to a peelable protective film.

The adhesive sheet is such that the adhesive layer in the transparent face material of the above-mentioned adhesive layer exists alone without a transparent face material. Therefore, the characteristics and materials of the adhesive sheet, and the preferred embodiment are the same as those of the above-mentioned adhesive layer, and detailed description thereof will be omitted.

The adhesive sheet can be produced, for example, by using a protective film or a support surface material with a protective film instead of the transparent face material, and by the same manufacturing method as that of the transparent face material to which the adhesive layer is attached.

In the adhesive sheet of the present invention as described above, the concentration of the hydroxyl group in the adhesive sheet layer is 600 × 10 ^-6 mol/g or less, and the concentration of the urethane bond in the adhesive sheet is 150 × 10 ^-6 mol/g. In the following, when it is bonded to the adherend (transparent surface material, display panel, etc.), the bubbles remaining at the interface between the adherend and the adhesive sheet can be quickly disappeared. Further, since the concentration of the hydroxyl group in the adhesive sheet is 100 × 10 ^-6 mol/g or more, the adhesion between the adhesive sheet and the adherend (for example, a transparent surface material, a display panel, etc.) is improved.

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples.

Examples 1, 2, 4, and 5 are examples, and examples 3 and 6 are comparative examples.

The transparent surface material, the adherend, the protective surface material with a protective film, the curable oligomer (A), the non-hardening oligomer (C), the first composition, and the second composition system in each example Produced as follows.

(transparent surface material)

Transparent surface material (1):

In the peripheral portion of the surface of one of the soda lime glass sheets having a length of 240 mm, a width of 190 mm, and a thickness of 1.3 mm, the light-shielding portion is formed by printing using an ink containing a black pigment so that the light-transmitting portion has a length of 218 mm and a width of 168 mm. It is formed into a frame shape to produce a transparent face material (1).

Transparent surface material (2):

In the peripheral portion of the surface of one of the soda lime glass sheets having a length of 100 mm, a width of 100 mm, and a thickness of 1.3 mm, the light-shielding portion is printed by using a black pigment-containing ink so that the light-transmitting portion has a length of 85 mm and a width of 85 mm. It is formed into a frame shape to produce a transparent face material (2).

(attached)

Admixture (1):

A polarizing plate (manufactured by Polatechno Co., Ltd., KN-18240T) having an adhesive layer was attached to one surface of a soda lime glass plate having a length of 220 mm, a width of 170 mm, and a thickness of 1.1 mm to prepare a laminate (1) in place of the liquid crystal panel.

Attached compound (2):

A polarizing plate (manufactured by Polatechno Co., Ltd., KN-18240T) having an adhesive layer was attached to one surface of a soda lime glass plate having a length of 90 mm, a width of 90 mm, and a thickness of 2 mm to prepare a laminate (2) in place of the liquid crystal display panel.

(with protective film support surface)

A protective film having a length of 130 mm, a width of 130 mm, and a thickness of 0.75 mm (manufactured by Mitsui Chemicals Tohcello Co., Ltd., PURETECT (registered trademark) VLH-9) was attached to a glass having a length of 100 mm and a width of 100 mm so that the adhesive surface of the protective film was in contact with the glass. One side of the supporting surface material of the soda lime glass plate having a thickness of 2 mm is used to produce a supporting surface material with a protective film.

(curable oligomer (A))

UA-1:

The bifunctional polypropylene glycol (the number average molecular weight calculated from the hydroxyl value: 18,000) and the isophorone diisocyanate are mixed at a molar ratio of 4:5, in the presence of a catalyst of a tin compound, at 70 ° C The reaction was carried out to obtain a prepolymer, and 2-hydroxyethyl acrylate was added to the prepolymer by a prepolymer and 2-hydroxyethyl acrylate to a molar ratio of approximately 1:2, which was reversed at 70 ° C. In this way, an urethane urethane oligomer (hereinafter referred to as UA-1) is obtained.

The average number of addition polymerizable unsaturated double bonds of UA-1 was 2, the number average molecular weight was about 73,000, and the viscosity at 25 ° C was about 250 Pa‧s.

UA-2

An urethane urethane oligomer (hereinafter referred to as UA-2) was obtained by the same method as UA-1 except that a bifunctional polypropylene glycol (a number average molecular weight calculated from a hydroxyl value: 10,000) was used. .

The average number of addition polymerizable unsaturated double bonds of UA-2 was 2, the number average molecular weight was about 41,000, and the viscosity at 25 ° C was about 250 Pa‧s.

UA-3

The urethane amide oligomerization was obtained by the same method as UA-1, using a 2-functional polypropylene glycol having a molecular end modified with ethylene oxide (a number average molecular weight calculated from a hydroxyl value: 4000). (hereinafter referred to as UA-3).

The average number of addition polymerizable unsaturated double bonds of UA-3 was 2, the number average molecular weight was about 17,300, and the viscosity at 25 ° C was about 250 Pa‧s.

UA-4

A bifunctional polypropylene glycol having a molecular end modified with ethylene oxide (a number average molecular weight calculated from a hydroxyl value: 4000), and a hexamethylene diisocyanate mixed at a molar ratio of 6:7, followed by an acrylic acid The ester (manufactured by Osaka Organic Chemical Industry Co., Ltd., IBXA) was diluted, and reacted at 70 ° C in the presence of a tin catalyst to obtain a prepolymer. 2-hydroxyethyl acrylate was added to the obtained prepolymer in such a manner that the prepolymer and 2-hydroxyethyl acrylate were 1:2 in molar ratio, and reacted at 70 ° C to obtain 30% by mass. Acrylic The ester-diluted urethane urethane oligomer (UA-4) (hereinafter referred to as UA-4).

The average number of addition polymerizable unsaturated double bonds of UA-4 was 2, the number average molecular weight was 55,000, and the viscosity at 60 ° C was 580 Pa‧s.

UA-5

The monofunctional polypropylene glycol (the number average molecular weight calculated from the hydroxyl value: 10000) is mixed with 2-propenyloxyethyl isocyanate to a molar ratio of 1:1 in the presence of a catalyst of a tin compound. The reaction was carried out at 70 ° C to obtain an urethane acrylate oligomer (hereinafter referred to as UA-5).

The average number of addition polymerizable unsaturated double bonds of UA-5 was 1, the number average molecular weight was about 10,100, and the viscosity at 25 ° C was about 7 Pa ‧ s.

UA-6

An urethane urethane oligomer (hereinafter referred to as UA-6) was obtained by the same method as UA-3 except that a monofunctional polypropylene glycol (a number average molecular weight calculated from a hydroxyl value: 5000) was used. .

UA-6 has a hardening base of 1, a number average molecular weight of about 5,100, and a viscosity at 25 ° C of about 3 Pa ‧ s.

(non-hardening oligomer (C))

Non-hardening oligomer (1):

2-functional polypropylene glycol modified with ethylene oxide at the end of the molecule (quantitative average molecular weight calculated from hydroxyl value: 4000), and trifunctional polypropylene glycol modified with ethylene oxide at the molecular end (calculated from hydroxyl value) The number average molecular weight: 6200) was mixed in a mass ratio of 1:1 to obtain a non-hardening oligomer (1).

(first composition)

First composition (1):

20 parts by mass of UA-1 as the component (A), 32.5 parts by mass of UA-5, and 32.5 parts by mass of UA-6, and phenyl glycidyl ether acrylate as component (B) (Kyoeisha Chemical Co., Ltd.) 15 parts by mass of the epoxy ester M-600A) was uniformly mixed, and then, as a component (D), bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide ( 0.3 parts by mass of 2,5-di-t-butyl hydroquinone (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.) manufactured by BASF Corporation, IRGACURE (registered trademark) 819), and antioxidant (BASF) 1 part by mass of the company, PUR68) was uniformly dissolved in 100 parts by mass of the mixture and mixed, and thereafter, the polypropylene glycol which was methylated at the end of the component (C) (the number average molecular weight calculated from the hydroxyl value: 1200) was obtained. 42.9 parts by mass of the mixture was uniformly dissolved in 100 parts by mass of the mixture and mixed to obtain a first composition (1).

The viscosity of the first composition (1) at 25 ° C was 3.2 Pa ‧ s. The concentration of the hydroxyl group in the first composition (1) is 471×10 ^-6 mol/g, the concentration of the urethane bond is 85×10 ^-6 mol/g, and the concentration of the hydroxyl group and the concentration of the urethane bond are combined. The ratio was 556 × 10 ^-6 mol/g, and the SP value was 18.2 (J/cm ³ ) ^1/2 . Since the hydroxyl group and the urethane bond were not reacted at the time of hardening, the hydroxyl group concentration and the urethane bond concentration after hardening did not change.

Further, the method for determining the hydroxyl group concentration is obtained by calculating the molar concentration of the hydroxyl group contained in the components (A), (B), and (C). Specifically, in the first composition (1), the phenyl glycidyl ether acrylate of the component (B) has a hydroxyl group and a hydroxyl group concentration of 0.0045 mol/g. The components (A), (B), and (C) were mixed at the above-mentioned blending amount, and calculated to have a hydroxyl group concentration contained in the components (A), (B), and (C), and were 471 × 10 ^-6 mol/g.

Further, the urethane bond concentration was determined by calculating the molar concentration of the urethane bond contained in the components (A), (B), and (C). Specifically, in the first composition (1), UA-1, UA-5, and UA-6 of the component (A) contain a urethane bond, and each has a molar concentration of 19 × 10 ^-6 mol. /g, 44 × 10 ^-6 mol / g, 22 × 10 ^-6 mol / g. The components (A), (B), and (C) are mixed at the above-mentioned blending amount, and are calculated as the urethane bond concentration contained in the components (A), (B), and (C) to be 85 × 10 ^{- 6} mol/g.

First composition (2):

20 parts by mass of UA-2 as the component (A), 32.5 parts by mass of UA-5, and 32.5 parts by mass of UA-6, and phenyl glycidyl ether acrylate as component (B) (Kyoeisha Chemical Co., Ltd.) 15 parts by mass of the epoxy resin M-600A) was uniformly mixed, and then 3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Corporation, IRGACURE (registered trademark) 184), 2,5-di-t-butyl hydroquinone (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.) 1 part by mass of 0.04 parts by mass and an antioxidant (manufactured by BASF Corporation, PUR68) were uniformly dissolved in 100 parts by mass of the mixture and mixed, and thereafter, the polypropylene glycol which was methylated at the end of the component (C) was used ( 66.7 parts by mass of the number average molecular weight calculated from the hydroxyl value: 1200) was uniformly dissolved in 100 parts by mass of the mixture and mixed to obtain the first composition (2).

The viscosity of the first composition (2) at 25 ° C was 1.5 Pa ‧ s. The concentration of the hydroxyl group in the first composition (2) is 398 × 10 ^-6 mol / g, the concentration of the urethane bond is 85 × 10 ^-6 mol / g, and the concentration of the hydroxyl group and the concentration of the urethane bond are combined. The ratio was 483 × 10 ^-6 mol/g, and the SP value was 18.2 (J/cm ³ ) ^1/2 . Since the hydroxyl group and the urethane bond were not reacted at the time of hardening, the hydroxyl group concentration and the urethane bond concentration after hardening did not change.

First composition (3):

25.7 parts by mass of polyisoprene methacrylate (manufactured by Kuraray Co., Ltd., UC203) as the component (A), and 7.7 parts by mass of dicyclopentenyloxyethyl methacrylate as the component (B), 2.6 parts by mass of 2-hydroxypropyl acrylate, 54.1 parts by mass of polybutadiene (Polyoil 110 manufactured by Evonik Degussa Co., Ltd.) as component (C), and 1-hydroxy-cyclohexyl-phenyl group as component (D) - 1.8 parts by mass of ketone (manufactured by BASF Corporation, IRGACURE (registered trademark) 184), and 0.4 parts by mass of 2,4,6-trimethylbenzimidyldiphenylphosphine oxide (manufactured by LAMBSON Co., Ltd., SPEEDCURE TPO) The first composition (3) is obtained by uniformly mixing.

The viscosity of the first composition (3) at 25 ° C was 2.5 Pa ‧ s. The hydroxyl group concentration in the first composition (3) is 220×10 ^-6 mol/g, the urethane bond concentration is 0 mol/g, and the total of the hydroxyl group concentration and the urethane bond concentration is 220×10 ^{− 6} mol/g, SP value is 18.0 (J/cm ³ ) ^1/2 . The hydroxyl group did not react upon hardening, so the hydroxyl group concentration after hardening did not change.

First composition (4):

40 parts by mass of UA-3 as the component (A), and 40 parts by mass of methyl 2-hydroxybutyl methacrylate (Lightester HOB, manufactured by Kyoeisha Chemical Co., Ltd.) as a component (B) 20 parts by mass of n-dodecyl acrylate was uniformly mixed to obtain bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide as component (D) (manufactured by BASF Corporation, IRGACURE ( Registered trademark) 819) 0.5 parts by mass, 0.04 parts by mass of 2,5-di-tert-butyl hydroquinone (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.), and antioxidant (manufactured by BASF Corporation, IRGANOX (registered) 0.3 parts by mass of the trademark) 1010) was uniformly dissolved in 100 parts by mass of the mixture. Then, 42.9 parts by mass of the non-curable oligomer (1) as the component (C) was uniformly dissolved in 100 parts by mass of the mixture and mixed to obtain a first composition (4).

The viscosity of the first composition (4) at 25 ° C was 3.0 Pa ‧ . The concentration of the hydroxyl group in the first composition (4) is 1925 × 10 ^-6 mol / g, the concentration of the urethane bond is 161 × 10 ^-6 mol / g, and the concentration of the hydroxyl group and the concentration of the urethane bond are combined. It is 2086 × 10 ^-6 mol/g, and the SP value is 20.3 (J/cm ³ ) ^1/2 . Since the hydroxyl group and the urethane bond were not reacted at the time of hardening, the hydroxyl group concentration and the urethane bond concentration after hardening did not change.

First composition (5):

50 parts by mass of UA-4 as the component (A) and 50 parts by mass of 4-hydroxybutyl acrylate as the component (B) are uniformly mixed to obtain 1-hydroxy-cyclohexyl-benzene as the component (D). 3 parts by mass of a base-ketone (manufactured by BASF Corporation, IRGACURE (registered trademark) 184), and 0.04 parts by mass of 2,5-di-t-butyl hydroquinone (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.), and One part by mass of the antioxidant (manufactured by BASF Corporation, PUR68) was uniformly dissolved in 100 parts by mass of the mixture. Then, 150 parts by mass of the non-curable oligomer (1) as the component (C) was uniformly dissolved in 100 parts by mass of the mixture and mixed to obtain a first composition (5).

The viscosity of the first composition (5) at 25 ° C was 5.9 Pa ‧ s. The concentration of the hydroxyl group in the first composition (5) is 1850×10 ^-6 mol/g, the concentration of the urethane bond is 74×10 ^-6 mol/g, and the concentration of the hydroxyl group and the concentration of the urethane bond are combined. The value was 1924 × 10 ^-6 mol/g, and the SP value was 19.6 (J/cm ³ ) ^1/2 . Since the hydroxyl group and the urethane bond were not reacted at the time of hardening, the hydroxyl group concentration and the urethane bond concentration after hardening did not change.

(second composition)

Second composition (1):

55 parts by mass of UA-4 as the component (F) and 45 parts by mass of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., 4HBA) as the component (G) were uniformly mixed to obtain a mixture. 3.0 parts by mass of bis(2,4,6-trimethylbenzylidene) which is 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Corporation, IRGACURE (registered trademark) 184) as component (E) 0.5 parts by mass of phenylphosphine oxide (manufactured by BASF Corporation, IRGACURE (registered trademark) 819) and 0.04 mass of 2,5-di-t-butyl hydroquinone (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.) 0.3 parts by mass of the antioxidant and the antioxidant (manufactured by BASF Corporation, IRGANOX (registered trademark) 1010) were uniformly mixed in 100 parts by mass of the mixture to obtain a base composition. 25 parts by mass of the non-curable oligomer (1) was uniformly dissolved in 75 parts by mass of the base composition to obtain a second composition (1). The viscosity of the second composition (1) at 25 ° C was 60 Pa‧s.

(example 1)

Production of transparent surface material with adhesive layer (1):

The first composition (1) was uniformly applied to the surface of the transparent surface material (1) which was moved at a constant speed by a die coater at a thickness of 400 μm, and was disposed on the downstream side of the die coater. The LED light source illuminates the ultraviolet light to form a layer of partially cured material.

A protective film (manufactured by Mitsui Chemicals Tohcello Co., Ltd., PURETECT (registered trademark) VLH-9) of a relatively transparent surface material (1) was laminated on the surface of the layer of the partially cured product.

A high-pressure mercury light source (manufactured by USHIO Electric Co., Ltd., UVC-05016S1TA01, irradiation intensity: 100 mW/cm ² ) disposed on the side of the protective film is irradiated with ultraviolet rays to completely harden the layer of the partially cured product, thereby obtaining an adhesive layer protected by the protective film. Transparent surface material (1).

The irradiation intensity was measured using an illuminometer (manufactured by USHIO Electric Co., Ltd., ultraviolet intensity meter Unimeter UIT-101).

In Example 1, the storage shear elastic modulus of the partially cured layer at 35 ° C became 700. Pa, the storage shear modulus of the adhesive layer at 35 ° C became 5300 Pa.

(Example 2)

Production of transparent surface material with adhesive layer (2):

A transparent face material (2) having an adhesive layer protected by a protective film was obtained in the same manner as in Example 1 except that the first composition (2) was used instead of the first composition (1).

In Example 2, the storage shear modulus of the partially cured layer at 35 ° C was 60 Pa, and the storage shear modulus of the adhesive layer at 35 ° C was 3000 Pa.

(Example 3)

Production of transparent face material with adhesive layer (3):

A transparent face material (3) having an adhesive layer protected by a protective film was obtained in the same manner as in Example 1 except that the first composition (5) was used instead of the first composition (1).

In Example 3, the storage shear modulus of the partially cured layer at 35 ° C was 900 Pa, and the storage shear modulus of the adhesive layer at 35 ° C was 4600 Pa.

(Defoaming test 1)

Under normal pressure, the transparent surface material (1) with the adhesive layer peels off the protective film. Using the adhesive pad and the electrostatic chuck, the transparent face material (1) with the adhesive layer is held on the upper platen in the pressure reducing device of the lifting device provided with a pair of platens with the face of the adhesive layer facing downward.

Adhesive layer (1) is adhered to the adhesive layer of the polarizing plate of the adhesive composition (1) and the transparent surface material (1) of the adhesive layer on the pressure plate under the lifting device in the decompression device. The transparent surface material (1) with the adhesive layer was placed in the same direction as the center position of the polarizing plate, and was held at a distance of 30 mm from the transparent surface material (1) to which the adhesive layer was attached.

The decompression device was set to a sealed state, and the exhaust gas was evacuated until the pressure in the decompression device became about 100 Pa for 10 minutes. Then, temporarily return to normal pressure and keep it for 1 minute. Then, the pressure is reduced until the pressure in the decompression device becomes about 10 Pa, and after holding for 1 minute, the upper and lower pressure plates are brought close to each other by the lifting device in the decompression device, and the polarized film attached to the adherend (1) is attached. The plate and the transparent surface material (1) with the adhesive layer are carried out at a pressure of 2 kPa via the adhesive layer. Crimp and hold for 10 seconds. The electrostatic chuck was destaticized to separate the adherend (1) from the upper platen, and the inside of the pressure reducing device was returned to atmospheric pressure in about 20 seconds to obtain an analog display device.

Immediately after the simulation display device and the transparent surface material (1) with the adhesive layer were laminated, it was found that the adhesive layer adhered to the polarizing plate of the adhesive composition (1) and the transparent surface material (1) with the adhesive layer was adhered. There are a lot of tiny bubbles in the interface. An analog display device was placed to measure the time until the bubble disappeared (defoaming time). The results are shown in Table 1 as Example 1. The defoaming time was set as the average of the results of the three samples.

(Defoaming test 2)

An anti-foaming time was measured by preparing an analog display device in the same manner as the defoaming test 1 except that the transparent surface material (2) with an adhesive layer was used instead of the transparent surface material (1) to which the adhesive layer was attached. The results are shown in Table 1 as Example 2.

(Defoaming test 3)

An anti-foaming time was measured by preparing an analog display device in the same manner as the defoaming test 1 except that the transparent surface material (3) with an adhesive layer was used instead of the transparent surface material (1) to which the adhesive layer was attached. The results are shown in Table 1 as Example 3.

(90 degree peel test)

The protective film and the adhesive layer of the transparent surface materials (1) to (3) with the adhesive layer protected by the protective film are cut into a cut having a width of 25 mm and a length of about 90 mm. One end of the long side was peeled off by about 30 mm, and attached to an adhesion measuring instrument (manufactured by Shimadzu Corporation, Autograph), and subjected to a 90-degree peeling test. The results of each are shown in Table 1 as Examples 1 to 3. Further, the peeling speed was 60 mm/min. The criteria for judgment are as follows:

○: Interface peeling (no adhesive layer remained on the glass side).

×: Aggregation failure (the adhesive layer is broken during the peeling, and the adhesive layer remains in both the glass and the protective film).

[Table 1]

The graph of the hydroxyl group concentration and the defoaming time in the adhesive layers in Examples 1 to 3 is shown in Fig. 13. The graph of the total of the hydroxyl group concentration and the urethane bond concentration in the adhesive layer in Examples 1 to 3 and the defoaming time is shown in Fig. 14 . It can be seen that there is a correlation between the concentration of the hydroxyl group and the concentration of the urethane bond in the adhesive layer and the defoaming time.

In addition, the unit of the hydroxyl group concentration on the horizontal axis in FIG. 13 and the total of the hydroxyl group concentration and the urethane bond concentration on the horizontal axis in FIG. 14 are mol/(g×10 ⁶ ).

(Example 4)

Production of transparent surface material (4) with adhesive layer:

The second composition (1) was applied to the entire circumference at a position of about 25 mm from the outer periphery of the transparent face material (2) by a dispenser to have a width of about 1 mm and a coating thickness of about 0.6 mm. The LED light source attached to the device illuminates the ultraviolet rays to form a semi-hardened crucible.

The first composition (1) was supplied to a plurality of portions in the region inside the crucible so that the total mass was 2.5 g using a dispenser. During the supply of the first composition (1), there is no damaged portion such as a breach, and the shape of the semi-hardened crucible is maintained.

The transparent face material (2) is horizontally placed on the lower platen in the decompression device provided with the lifting device of the pair of platens in such a manner that the surface of the first composition (1) is coated upward. The support surface material with the protective film is held in the pressure reducing device on the upper platen with the surface of the protective film 16 facing downward. The pressure was exhausted until the pressure in the pressure reducing device became about 10,000 Pa, and was maintained in this state for 1 minute. Thereafter, the upper and lower pressure plates are brought close by the lifting device in the decompression device, and the transparent surface material (2) and the supporting surface material with the protective film are separated by the first composition (1) to 2 The pressure of kPa was crimped and held for 10 seconds to fit. After the bonding, the inside of the decompression device was returned to the atmospheric pressure environment, and a laminate in which the opaque adhesive layer containing the first composition (1) was sealed with the transparent surface material (2), the protective film, and the crucible was obtained.

The high-pressure mercury light source (irradiation intensity: 100 mW/cm ² ) disposed on the support surface material side was irradiated with ultraviolet rays for 20 seconds to harden the semi-hardened crucible and the uncured adhesive layer to form an adhesive layer. The thickness of the adhesive layer after hardening is 0.4 mm, which is substantially uniform.

Thereafter, the transparent surface material (4) with the adhesive layer protected by the protective film is obtained by peeling off the supporting surface material.

In Example 4, the storage shear modulus of the adhesive layer at 35 ° C became 7000 Pa.

(Example 5)

Production of transparent surface material with adhesive layer (5):

A transparent face material (5) having an adhesive layer protected by a protective film was obtained in the same manner as in Example 4 except that the first composition (3) was used instead of the first composition (1).

In Example 5, the storage shear modulus of the adhesive layer at 35 ° C became 10,500 Pa.

(Example 6)

Production of transparent surface material (6) with adhesive layer:

A laminate was obtained in the same manner as in Example 4 except that the first composition (4) was used instead of the first composition (1).

A chemical lamp (FL15BL, irradiation intensity: 2 mW/cm ² manufactured by Nippon Electric Co., Ltd.), which is disposed on the side of the support surface material, is irradiated with ultraviolet rays for 10 minutes to harden the semi-hardened crucible and the uncured adhesive layer. Adhesive layer. The thickness of the adhesive layer after hardening is 0.4 mm, which is substantially uniform.

Thereafter, the transparent surface material (6) to which the adhesive layer is protected by the protective film is obtained by peeling off the supporting surface material.

In Example 6, the storage shear modulus of the adhesive layer at 35 ° C was 181,000 Pa.

(Defoaming test 4)

Under normal pressure, the protective film is peeled off by the transparent surface material (4) attached to the adhesive layer. Using the adhesive pad and the electrostatic chuck, the transparent face material (4) with the adhesive layer is held on the upper platen in the pressure reducing device of the lifting device provided with a pair of platens with the face of the adhesive layer facing downward.

The adhesive layer (2) is adhered to the adhesive layer of the polarizing plate of the adhesive composition (2) and the transparent surface material (4) of the adhesive layer on the pressure plate under the lifting device in the decompression device. The transparent surface material (4) with the adhesive layer was placed in the same direction as the center position of the polarizing plate, and was held at a distance of 30 mm from the transparent surface material (4) to which the adhesive layer was attached.

The pressure-reducing device is sealed, and the pressure is reduced until the pressure in the pressure-reducing device is about 10,000 Pa. After holding for 1 minute, the upper and lower pressure plates are brought close to each other by the lifting device in the pressure reducing device, and the pressure is applied to the surface. The polarizing plate of the adhesive composition (2) and the transparent surface material (4) with the adhesive layer were pressure-bonded via the adhesive layer at a pressure of 2 kPa for 10 seconds. The electrostatic chuck was destaticized to separate the adherend (2) from the upper platen, and the inside of the pressure reducing device was returned to atmospheric pressure in about 20 seconds to obtain an analog display device.

Immediately after the simulation display device and the transparent surface material (4) with the adhesive layer were laminated, it was found that the polarizing plate attached to the adhesive composition (2) and the transparent surface material (4) adhered to the adhesive layer were adhered. A large number of fine bubbles appear at the interface of the layer. An analog display device was placed to measure the time until the bubble disappeared (defoaming time). The results are shown in Table 2 as Example 4. The defoaming time was set as the average of the results of the three samples.

(Defoaming test 5)

An analog display device was produced in the same manner as the defoaming test 4 except that the transparent surface material (5) with an adhesive layer was used instead of the transparent surface material (4) to which the adhesive layer was attached, and the defoaming time was measured. The results are shown in Table 2 as Example 5.

(Defoaming test 6)

An analog display device was produced in the same manner as the defoaming test 4 except that the transparent surface material (6) with an adhesive layer was used instead of the transparent surface material (4) to which the adhesive layer was attached, and the defoaming time was measured. The results are shown in Table 2 as Example 6.

(90 degree peel test)

The protective film and the adhesive layer of the transparent surface materials (4) to (6) with the adhesive layer protected by the protective film are cut into a cut having a width of 25 mm and a length of about 90 mm. One end of the long side was peeled off by about 30 mm, and attached to an adhesion measuring instrument (Autograph manufactured by Shimadzu Corporation), and subjected to a 90-degree peeling test. The results are shown in Table 2 as Examples 4 to 6. Further, the peeling speed was 60 mm/min. The judgment criteria are as follows.

○: Interface peeling (no adhesive layer remained on the glass side).

×: Aggregation failure (the adhesive layer is broken during the peeling, and the adhesive layer remains in both the glass and the protective film).

The graph of the hydroxyl group concentration and the defoaming time in the adhesive layers in Examples 4 to 6 is shown in Fig. 15. The graph of the total of the hydroxyl group concentration and the urethane bond concentration in the adhesive layer in Examples 4 to 6 and the defoaming time is shown in Fig. 16 . It can be seen that there is a correlation between the concentration of the hydroxyl group in the adhesive layer and the concentration of the urethane bond and the defoaming time.

(Example 7)

Production of adhesive sheet with protective film (1):

The first composition (1) was continuously applied to a polyethylene terephthalate (PET) film which was subjected to release treatment at a surface speed by a die coater at a thickness of 500 μm (the first base) After the surface of the product (Purex (registered trademark)) was produced by Teijin Co., Ltd., the PET film (second substrate) having a higher mold release property than the first substrate (People's Purex (registered trademark)) was used for the surface. From the first substrate side, ultraviolet rays were irradiated from a high-pressure mercury light source (manufactured by USHIO Electric Co., Ltd., UVC-05016S1TA01, irradiation intensity: 1500 mJ/cm ² ) to completely cure the first composition (1), thereby obtaining adhesion with a protective film. Sheet (1). The storage shear modulus of the adhesive sheet at 35 ° C was 5300 Pa.

(Defoaming test 7)

With respect to the above-mentioned pressure-sensitive adhesive sheet with a protective film, the second substrate of the pressure-sensitive adhesive sheet (1) with a protective film was peeled off under normal pressure and subjected to a defoaming test. An anti-foaming time was measured in the same manner as in the defoaming test 1 except that the adhesive sheet (1) with a protective film was used instead of the transparent surface material (1) to which the adhesive layer was attached. Defoaming time is good.

INDUSTRIAL APPLICABILITY According to the present invention, when the adherend and the transparent surface material are bonded together via the adhesive layer, the bubbles remaining at the interface between the adherend and the adhesive layer rapidly disappear, and there are no defects such as bubbles. The transparent surface material with the adhesive layer attached. The transparent surface material with the adhesive layer is useful as a protective plate for a display panel, a protective plate for a coordinate input device, a substrate with a transparent electrode for a coordinate input device, and the like.

The entire disclosure of Japanese Patent Application No. 2014-085423, the entire disclosure of which is hereby incorporated by reference in its entirety in its entirety in its entirety in

1‧‧‧Transparent surface material with adhesive layer

10‧‧‧Transparent surface material

12‧‧‧Lighting Printing Department

14‧‧‧Adhesive layer

16‧‧‧Protective film

Claims (18)

A transparent surface material with an adhesive layer having a transparent surface material and an adhesive layer formed on the hard surface of at least one surface of the transparent surface material comprising a curable resin composition, wherein the concentration of the hydroxyl group in the adhesive layer is 100× 10 ^-6 ~ 600 × 10 ^-6 mol / g, the concentration of the urethane bond in the above adhesive layer is 0 ~ 150 × 10 ^-6 mol / g. The transparent surface material of the adhesive layer of claim 1, wherein the concentration of the hydroxyl group in the adhesive layer and the concentration of the urethane bond in the adhesive layer are 100×10 ^-6 to 750×10 ^-6 mol/ g. The transparent surface material of the adhesive layer of claim 1 or 2, wherein the solubility parameter of the adhesive layer is 17.5 to 18.5 (J/cm ³ ) ^1/2 . The transparent surface material with an adhesive layer according to any one of claims 1 to 3, wherein the curable resin composition contains a curable oligomer (A) having an addition polymerizable unsaturated double bond, and has an additive Any one or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) having a polymerizable unsaturated double bond and a low molecular weight polymerizable compound (B), and the curability Either or both of the oligomer (A) and the above low molecular weight polymerizable compound (B) may have a urethane bond. The transparent surface material with an adhesive layer according to any one of claims 1 to 3, wherein the curable resin composition contains a curable oligomer (A) having an addition polymerizable unsaturated double bond, and has addition polymerization. a low molecular weight polymerizable compound (B) having an unsaturated double bond, and a non-curable oligomer (C) having no addition polymerizable unsaturated double bond, and the above curable oligomer (A) and the above-mentioned low At least one of the molecular weight polymerizable compound (B) and the non-curable oligomer (C) has a hydroxyl group. At least one of the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curable oligomer (C) may have a urethane bond. The transparent surface material of the adhesive layer according to any one of claims 1 to 5, which further has a peelable protective film covering the surface of the adhesive layer. A method for producing a transparent face material with an adhesive layer, which is a method for producing a transparent face material with an adhesive layer according to any one of claims 1 to 6, and having the following step (α) and the following steps (γ) (α) a step of supplying the curable resin composition in a liquid form to the surface of the transparent surface material, and partially curing the curable resin composition to form a partially cured product, if necessary; (γ) hardening the hardened material The step of forming the above-mentioned adhesive layer by curing the resin composition or the above-mentioned partial cured product. The method for producing a transparent surface material with an adhesive layer according to claim 7, further comprising the step (β) of: (β) covering the surface of the curable resin composition or the partially cured product with a protective film. The method for producing a transparent surface material with an adhesive layer according to claim 8, wherein the step (α) is the following step (α1), the step (β) is the following step (β1), and the step (γ) is lower Step (γ1): (α1) The liquid curable resin composition is supplied to the surface of the transparent surface material in a layered manner, and the curable resin composition supplied to the surface of the transparent surface material is partially partially a step of hardening to form a layer of a partially cured product; (β1) a step of covering a surface of the partially cured layer with a protective film; and (γ1) a step of further hardening the layer of the partially cured product to form the adhesive layer. The method for producing a transparent face material with an adhesive layer according to claim 8, wherein the above step (α) In the following step (α21) and the following step (α22), the above step (β) is the following step (β2), and the above step (γ) is the following step (γ21) and the following step (γ22): (α21) a step of forming a frame-shaped crucible on a peripheral portion of the surface of the transparent surface material; (α22) a step of supplying the curable resin composition to a region surrounded by the crucible; (β2) in a decompressing environment, attaching The support surface material of the protective film is superposed on the layer of the curable resin composition so that the protective film is in contact with the surface of the layer of the curable resin composition, and the layer of the curable resin composition is obtained by the transparent surface. a step of forming a laminate of the above-mentioned protective film and the above-mentioned ruthenium seal; (γ21) hardening a layer of the curable resin composition in a state where the laminate is placed under a pressure environment higher than the above step (β2) And the step of forming the adhesive layer; (γ22) after the step (γ21), the step of peeling the support surface material from the protective film. A display device comprising: a display panel; and a transparent surface material with an adhesive layer according to any one of claims 1 to 5, wherein the adhesive layer is attached to the display panel so that the adhesive layer contacts the display panel. A method of manufacturing a display device, which is the method of manufacturing the display device of claim 11, and contacting the display panel and the transparent surface material of the adhesive layer with the adhesive layer on the display panel under a reduced pressure environment The way overlaps and fits. An adhesive sheet comprising a cured product of a curable resin composition, wherein a concentration of a hydroxyl group in the adhesive sheet is 100×10 ^-6 to 600×10 ^-6 mol/g, and the urethane in the adhesive sheet The ester bond concentration is 0 to 150×10 ^-6 mol/g. The adhesive sheet of claim 13, wherein the total concentration of the hydroxyl groups in the adhesive sheet and the concentration of the urethane bond in the adhesive sheet is 100 × 10 ^-6 to 750 × 10 ^-6 mol/g. The adhesive sheet of claim 13 or 14, wherein the hardening property of the curable resin composition has a solubility parameter of 17.5 to 18.5 (J/cm ³ ) ^1/2 . The adhesive sheet according to any one of claims 13 to 15, wherein the curable resin composition comprises a curable oligomer (A) having an addition polymerizable unsaturated double bond, and an addition polymerizable unsaturated double The low molecular weight polymerizable compound (B) of the bond, and one or both of the curable oligomer (A) and the low molecular weight polymerizable compound (B) have a hydroxyl group, and the curable oligomer (A) And either or both of the above low molecular weight polymerizable compounds (B) may have a urethane bond. The adhesive sheet according to any one of claims 13 to 15, wherein the curable resin composition contains a curable oligomer (A) having an addition polymerizable unsaturated double bond, and has an addition polymerizable unsaturated double bond. The low molecular weight polymerizable compound (B) and the non-curable oligomer (C) having no addition polymerizable unsaturated double bond, and the curable oligomer (A) and the low molecular weight polymerizable compound ( B) and at least one of the non-curable oligomers (C) having a hydroxyl group, the curable oligomer (A), the low molecular weight polymerizable compound (B), and the non-curing oligomer (C) At least one of them may also have a urethane bond. An adhesive sheet with a protective film, comprising: the adhesive sheet according to any one of claims 13 to 17; and a peelable protective film covering at least one surface of the adhesive sheet.