JP5141074B2 - Impact-resistant adhesive layer, impact-resistant adhesive laminate, and display device - Google Patents

Description

  The present invention relates to an impact-resistant adhesive layer, an impact-resistant adhesive laminate, and a display device. More specifically, the present invention relates to an impact-resistant adhesive layer and an impact-resistant adhesive laminate excellent in adhesiveness and impact resistance, and a display device excellent in visibility.

  In recent years, flat display panels such as a liquid crystal display panel (LCD) and a plasma display panel (PDP) have been used as display panels. A flat display panel is usually a laminate in which a plurality of films are laminated. For example, in an LCD, an optical film such as a polarizing plate, a retardation plate, a viewing angle widening film, and a brightness improving film is usually laminated on the surface of a liquid crystal panel. And each layer which comprises a planar display panel is bonded together by the adhesive layer normally formed with various adhesives.

  Patent Document 1 describes an optical film with a pressure-sensitive adhesive in which an optical film is laminated on a glass cracking-proof pressure-sensitive adhesive layer having a dynamic storage elastic modulus at 20 ° C. in a specific range. Patent Document 1 describes that acrylic, rubber-based, polyester-based, and silicone-based pressure-sensitive adhesives can be used as the pressure-sensitive adhesive that forms the glass cracking-preventing pressure-sensitive adhesive layer. Patent Document 1 describes that the above-mentioned pressure-sensitive adhesive can be a heat-crosslinking pressure-sensitive adhesive and a photo-crosslinking pressure-sensitive adhesive such as an ultraviolet ray or an electron beam.

  Patent Document 2 contains an initial polymer (A) composed of a copolymer of a specific acrylate monomer and another vinyl monomer, and a (meth) acrylic monomer (B), and has a glass transition point in a specific range. An acrylic syrup resin composition is described. Patent Document 2 describes that the composition is cured by irradiation with ultraviolet rays or electron beams, and can be used as various pressure-sensitive adhesive sheets.

  Patent Document 3 includes a transparent layer including a scattering prevention layer having a specific shear modulus, two or more types of crack prevention layers having different shear modulus, and a transparent pressure-sensitive adhesive layer (such as an acrylic pressure-sensitive adhesive layer). An impact relaxation laminate is described.

  Patent Document 4 describes a pressure-sensitive adhesive sheet that has a base material layer and a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer includes an acrylic pressure-sensitive adhesive and is a laminate having a specific shear modulus.

  Patent Document 5 includes a transparent filter layer selected from at least a transparent adhesive layer and an acrylic adhesive material and having a specific thickness and Young's modulus, and a display filter having specific physical properties and a display device using the same Is described.

  Patent Document 6 describes a glass crack preventing laminate having a glass crack preventing adhesive layer having a specific storage elastic modulus.

JP 2004-271935 A JP 2005-240044 A JP 2002-23649 A JP-A-9-33723 International Publication No. 2002/074532 JP 2005-173462 A

  It is known that a glass plate or the like constituting a flat display panel is not very viscoelastic and easily breaks when pressed or hit. A laminate in which a glass plate or the like and another layer such as a polarizing plate are directly bonded together with an adhesive layer cannot be said to have sufficient strength. As a method for increasing the strength of the laminated body and preventing the laminated body from being damaged, a method of further providing a shock absorbing layer can be considered. However, the method of separately providing a shock absorbing layer requires a step of separately providing a shock absorbing layer. Therefore, it has been desired to develop an adhesive layer that has excellent adhesiveness and impact resistance.

  When applying a shock absorbing layer to a display panel, maintaining the visibility of the display panel is also important. On the other hand, the filter for a display of the said patent document 5 aims at preventing damage, such as a crack of a display with respect to an impact. In Patent Document 5, there is no technical knowledge about the influence on the visibility of the display panel when an impact is applied to the display panel.

  The present invention has been made in view of the above circumstances. An object of the present invention is to provide an impact-resistant adhesive layer excellent in adhesiveness and impact resistance and an impact-resistant adhesive laminate including the impact-resistant adhesive layer. Another object of the present invention is to provide a display device with excellent visibility.

The present invention is as follows.
(1) The tensile elastic modulus E ′ is 0.46 to 0.9 MPa, the thickness t is 50 μm or more, and the ratio (t / E ′) between the tensile elastic modulus and the thickness is greater than 400 and less than 900. An impact-resistant adhesive layer ,
The impact-resistant adhesive layer contains (A) acrylic syrup, (B) acrylic monomer, (C) silane coupling agent, (D) urethane (meth) acrylate, and (E) a photopolymerization initiator. An impact-resistant adhesive layer, which is an impact-resistant adhesive layer formed by radiation-curing a liquid adhesive composition .
( 2 ) The impact-resistant adhesive layer according to the above ( 1 ), wherein the (B) acrylic monomer contains at least one acrylic monomer having a cyclic structure in the molecule.
( 3 ) The impact-resistant adhesive laminate comprising the impact-resistant adhesive layer described in (1) or (2) above and another layer laminated on at least one surface of the impact-resistant adhesive layer. .
( 4 ) The impact-resistant adhesive laminate according to the above ( 3 ), wherein at least one of the other layers is an optical film.
( 5 ) A display device comprising, on the display panel surface, any one of the impact-resistant adhesive layer described in (1) or (2) and the impact-resistant adhesive laminate described in ( 3 ) or ( 4 ). .

  The impact-resistant adhesive layer of the present invention and the impact-resistant adhesive laminate of the present invention are excellent in adhesiveness and impact resistance (including impact absorption) by having the above-described configuration. The display device of the present invention has excellent visibility due to the above configuration.

(1) Impact-resistant adhesive layer The impact-resistant adhesive layer of the present invention (hereinafter referred to as “the adhesive layer of the present invention”) has a tensile elastic modulus E ′ of 0.46 to 0.9 MPa and a thickness t of 50 μm or more. And an impact-resistant adhesive layer having a ratio (t / E ′) of the tensile elastic modulus to the thickness of more than 400 and less than 900, wherein the impact- resistant adhesive layer comprises (A) acrylic syrup, (B Impact-resistant adhesive formed by radiation-curing a radiation curable liquid adhesive composition containing an acrylic monomer, (C) a silane coupling agent, (D) urethane (meth) acrylate, and (E) a photopolymerization initiator. It is a layer .

  As described above, Patent Document 5 and the like describe that it is possible to prevent breakage of a display panel such as glass breakage using an impact adhesive layer. However, when an impact is applied to a display panel having an impact adhesive layer, the impact adhesive layer is usually deformed. This deformation affects the visibility of the display panel, such as light leakage and distortion in the displayed image. That is, when an impact is applied to a display panel having an impact adhesive layer, the visibility of the display panel may be reduced even if breakage such as glass breakage can be prevented. Further, the visibility of a display panel having an impact adhesive layer is not a property determined only by the impact absorbability, but also a property determined by the degree of restoration from deformation of the impact adhesive layer caused by the impact. And since the adhesion layer of this invention has the said structure, while being excellent in impact absorptivity, the deformation | transformation by an impact can be decompress | restored rapidly and the visibility of the display panel with respect to an impact can be improved.

  The thickness t of the pressure-sensitive adhesive layer of the present invention is 50 μm or more, preferably 80 μm or more, more preferably 100 μm or more, more preferably 150 μm or more, and particularly preferably 180 μm or more. When the t is less than the above range, the impact resistance of the adhesive layer is lowered. As a result, when the pressure-sensitive adhesive layer of the present invention is used in a display device, the visibility of the display panel against impact is reduced, which is not preferable.

  The upper limit of the thickness t is not particularly limited. The upper limit of the thickness t can be appropriately set as necessary. The upper limit of the thickness t is usually 1000 μm, preferably 900 μm, more preferably 800 μm, and more preferably 750 μm. It is preferable for the upper limit of t to be in the above range since the impact resistance is good.

The tensile elastic modulus E ′ of the pressure-sensitive adhesive layer of the present invention is 0.46 to 0.9 MPa. When the above E ′ is within the above range, the flexibility of the pressure-sensitive adhesive layer of the present invention can be maintained within an appropriate range. As a result, it is preferable because the impact resistance can be enhanced and the visibility of the display panel against the impact can be enhanced.

  The above E ′ can be appropriately adjusted by changing, for example, the type, amount, structure and the like of the component constituting the adhesive layer of the present invention. For example, when the pressure-sensitive adhesive layer of the present invention is composed of a polymer, the above E ′ can be adjusted to a desired range by appropriately selecting the type and blending amount of the monomer constituting the polymer. Further, by appropriately selecting the degree of crosslinking of the polymer, E ′ can be adjusted to a desired range. The degree of crosslinking can be adjusted, for example, by appropriately selecting the conditions such as the amount of the crosslinking agent, the amount of the photopolymerization initiator, and the illuminance and the amount of light during the photopolymerization. Examples of the method for increasing the degree of crosslinking include methods such as increasing the amount of the crosslinking material, decreasing the amount of the photopolymerization initiator, decreasing the illuminance, and increasing the amount of light. On the other hand, as a method of reducing the degree of crosslinking, for example, a method reverse to the above can be mentioned.

  In the pressure-sensitive adhesive layer of the present invention, the ratio (t / E ′) between E ′ and t is greater than 400 and less than 900, preferably 420 to 880, more preferably 450 to 800, and more preferably 500 to 800. . Here, the unit of t / E ′ is (micron / MPa). If t / E 'is less than the above range, the ability to absorb impact is inferior and impact resistance is lowered, which is not preferable. Further, if t / E 'exceeds the above range, the deformation caused by the impact is not restored well, and the impact resistance is lowered, which is not preferable. As described later, the pressure-sensitive adhesive layer of the present invention can have a multilayer structure composed of two or more layers. When the pressure-sensitive adhesive layer of the present invention has a multilayer structure composed of two or more layers that are directly laminated without including other layers, t / E ′ is the total value of t / E ′ of each layer. And Moreover, when the adhesion layer of this invention is laminated | stacked through another layer between layers, let the thickest adhesion layer in those adhesion layers be an impact-resistant adhesion layer.

  The adhesive layer of the present invention is not particularly limited in the material, shape, and structure as long as the above requirements are satisfied. For example, the pressure-sensitive adhesive layer of the present invention is usually a solid material such as a sheet or film, but may be a gel or a sealed liquid. The pressure-sensitive adhesive layer of the present invention may have a single-layer structure or a multilayer structure composed of two or more layers having the same or different materials or physical properties. Examples of the adhesive layer of the present invention having a multilayer structure include an adhesive layer having two or more layers having different t and / or E ′.

  The pressure-sensitive adhesive layer of the present invention can be applied to various uses that require stickiness. The pressure-sensitive adhesive layer of the present invention can be used for display devices such as display panels (flat panel displays and the like) for electronic and electric devices. That is, the adhesive layer of the present invention can be used as an impact resistant adhesive layer for display devices or an impact resistant adhesive layer for display panels of electronic / electrical equipment.

  There is no limitation in particular in the transparency of the adhesion layer of this invention. Since the adhesive layer of the present invention can be applied to uses other than display devices such as display panels, it may be opaque. When the pressure-sensitive adhesive layer of the present invention is used for a display device such as a display panel, it is preferably transparent from the viewpoint of the visibility of the display panel. Specifically, for example, the total light transmittance is preferably 90% or more, particularly 91% or more, and more preferably 92% or more under the conditions of 25 ° C. and 0.5 mm thickness. The total light transmittance can be measured at 25 ° C. using a BYK-Gardner Gmbh model (haze-gard plus).

  Moreover, when using the adhesive layer of this invention for display apparatuses, such as a display panel, it can be set as the adhesive layer which has the transparency excellent in the wide temperature range from a viewpoint of the visibility of a display panel. Specifically, for example, the pressure-sensitive adhesive layer of the present invention is transparent at −100 to 150 ° C., preferably −80 to 130 ° C., more preferably −50 to 120 ° C. (total light transmittance at 0.5 mm thickness is 90% or more, preferably 91% or more, more preferably 92% or more).

  Furthermore, when the pressure-sensitive adhesive layer of the present invention has a multilayer structure having two or more layers, the refractive index of each layer is almost the same (usually within ± 10%, preferably within ± 5%, more preferably within ± 3%). ). Having this configuration is preferable because the visibility of the display panel can be improved.

  The 180 ° peel adhesive strength of the adhesive layer of the present invention is usually 0.1 N / 25 mm or more, preferably 0.1 to 10 N / 25 mm, more preferably 0.5 to 10 N / 25 mm when measured at 25 ° C. More preferably, it is 0.8-10N / 25mm, Most preferably, it can be set to 1-8N / 25mm. It is preferable for the adhesive layer of the present invention that the 180 ° peel adhesive strength is in the above-mentioned range since the adhesiveness is excellent. Moreover, the adhesive layer of this invention is excellent also in rework property simultaneously by making 180 degree peeling adhesive force into the said range.

The pressure-sensitive adhesive layer of the present invention has a ratio (T / F) of the time T (μs) from the generation of impact stress to the first peak and the impact stress F (kN) at the first peak of 180 or less, preferably 150. Hereinafter, it is more preferably 100 or less, more preferably 70 or less, and particularly preferably 1 to 50. For the measurement of T and F, for example, an LC-20KNG702 compression load cell (rated capacity 20 kN, rated output 1160 × 10 ⁻⁶ strain) manufactured by Nikkei Denso is fixed on a hard and stable horizontal surface such as a stone table. A 5 cm square sample film is fixed to the upper center, and 530 to 550 g of steel balls are dropped from a height of 10 cm at room temperature. The stress and time at that time are obtained by connecting the load cell, the NEC Seiei AS2102 type dynamic strain meter, the NEC Sanei company AP11-103 type high-speed DC amplifier, and the NEC Sanei company RA1200 type thermal dot recorder. Measure (see Japanese Patent No. 3706105).

The pressure-sensitive adhesive layer is formed, for example, by curing a radiation-curable liquid pressure-sensitive adhesive composition (hereinafter simply referred to as “pressure-sensitive adhesive composition”) that is cured by irradiation with radiation and has a property that the cured product has adhesiveness. be able to. Examples of the pressure-sensitive adhesive composition include acrylic, rubber-based, polyester-based, and silicone-based pressure-sensitive adhesive compositions. From the viewpoints of transparency and durability, in the present invention, an acrylic pressure-sensitive adhesive composition is used as the pressure-sensitive adhesive composition. The “liquid” includes not only liquid such as solution but also semi-solid such as gel.

Adhesive composition of the acrylic is (meth) as a main component acrylic acid or its alkyl ester, Ru composition der showing an adhesive polymerized by irradiation with radiation such as ultraviolet rays.

Examples of the acrylic adhesive composition include (A) acrylic syrup, (B) acrylic monomer, (C) silane coupling agent, (D) urethane (meth) acrylate, and (E) photopolymerization initiator. A pressure-sensitive adhesive composition containing at least one of them can be mentioned. Examples of the pressure-sensitive adhesive composition include (A) acrylic syrup, (B) acrylic monomer, (C) silane coupling agent, (D) urethane (meth) acrylate, and (E) photopolymerization initiator. And an adhesive composition containing at least one of the above. In the present invention, the pressure-sensitive adhesive composition contains (A) acrylic syrup, (B) acrylic monomer, (C) silane coupling agent, (D) urethane (meth) acrylate, and (E) photopolymerization initiator. An adhesive composition is used .

  The (A) acrylic syrup is a composition containing an acrylic polymer obtained by polymerizing an acrylic monomer and, if necessary, another monomer. In the present invention, the previously prepared (A) acrylic syrup may be added to the adhesive composition. Moreover, in this invention, an acryl-type monomer and another monomer as needed may be superposed | polymerized, this may be said (A) acrylic syrup, and another component may be added to this and it may be set as an adhesive composition.

  Examples of the acrylic monomer include (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid annealed ester, (meth) acrylic acid alkoxyalkyl, polyvalent acrylic acid ester, and alicyclic alcohol. The methacrylic acid ester of this is mentioned. The acrylic monomers may be used alone or in combination of two or more. As said acrylic monomer, the acrylic monomer and (meth) acrylic acid which have a (meth) acrylic-acid alkylester as a main component are preferable.

  As said acrylic monomer, the 1 type (s) or 2 or more types of a monofunctional acrylic monomer and a polyfunctional acrylic monomer can be used, for example.

  Specific examples of the monofunctional acrylic monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and amyl. (Meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (Meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, Dicyclopentanyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4- Hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, Zir (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) Examples include acrylate, methoxypolypropylene glycol (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and 7-amino-3,7-dimethyloctyl (meth) acrylate. The said monofunctional acrylic monomer may be used individually by 1 type, and may use 2 or more types. Among these, it is preferable to use at least one of acrylic acid and methacrylic acid because an adhesive composition that forms an adhesive layer excellent in adhesive strength can be obtained. Moreover, it is preferable to use at least one of ethyl acrylate, butyl acrylate, octyl acrylate, and 2-ethylhexyl acrylate because an adhesive composition that forms an adhesive layer having adhesive strength in a wide temperature range can be obtained.

  Specific examples of the polyfunctional acrylic monomer include trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, Ethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, tricyclodecanediyldimethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate Bisphenol A diglycidyl ether end (meth) acrylic acid addition, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri ( Di (meth) acrylate of diol which is an adduct of bisphenol A ethylene oxide or propylene oxide, (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate , Di (meth) acrylate of diol which is an adduct of hydrogenated bisphenol A ethylene oxide or propylene oxide, and (meth) acrylate to diglycidyl ether of bisphenol A Epoxy obtained by adding relations (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, and cyclohexane dimethanol di (meth) acrylate. The said polyfunctional acrylic monomer may be used individually by 1 type, and may use 2 or more types. In the pressure-sensitive adhesive composition containing the polyfunctional acrylic monomer, the polyfunctional acrylic monomer is considered to act as a cross-linking material (note that this explanation is not intended to limit the polyfunctional acrylic monomer in any way). Therefore, the elasticity modulus of the adhesion layer obtained from the said adhesion composition can be adjusted by adjusting the addition amount of the said polyfunctional acrylic monomer suitably.

  Specific examples of the other monomer include N-vinylpyrrolidone, N-vinylcaprolactam, vinylimidazole, vinylpyridine, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, Examples include hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and t-octyl (meth) acrylamide. It is done. One of these other monomers may be used alone, or two or more thereof may be used. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition containing the other monomer is preferable because it has excellent adhesive strength.

  There is no limitation in particular in the polymerization reaction which obtains the said acrylic polymer. The polymerization reaction can be performed, for example, by using a polymerization initiator that generates radicals by heat or light.

  The viscosity of the (A) acrylic syrup is usually 1000 to 100000 cps, preferably 2000 to 95000 cps, more preferably 3000 to 90000 cps, and more preferably 10,000 to 90000 cps. This viscosity is a viscosity measured with a B-type viscometer at 25 ° C. The weight average molecular weight of the acrylic polymer contained in the acrylic syrup (A) is usually 500,000 to 3,000,000, preferably 500,000 to 2,500,000, more preferably 600,000 to 2,000,000, more preferably 70. 10,000 to 1.8 million. It is preferable for the viscosity and the weight average molecular weight to be in the above ranges since application is easy and the adhesiveness and impact resistance of the resulting adhesive layer can be improved.

  The (A) acrylic syrup may contain not only the acrylic polymer but also the acrylic monomer such as (meth) acrylic acid alkyl ester. When the (A) acrylic syrup contains the acrylic monomer, the viscosity of the (A) acrylic syrup can be adjusted to an appropriate range. As a result, the application and handling of the (A) acrylic syrup is easy, which is preferable. There is no limitation in particular in the method of containing the said acrylic monomer. The (A) acrylic syrup containing the acrylic monomer can be usually obtained by stopping the reaction before the reaction rate reaches 100% in the polymerization reaction for obtaining the acrylic polymer. The (A) acrylic syrup obtained by this method is a mixture of the acrylic polymer and the unreacted acrylic monomer.

  There is no limitation in particular about content of the said acrylic polymer contained in said (A) acrylic syrup. The content ratio of (A-1) the acrylic polymer and (A-2) the acrylic monomer in the (A) acrylic syrup is 100 masses of the total amount of (A-1) and (A-2). %, (A-1) is 1% by mass or more, preferably 3% by mass or more, and more preferably 5 to 60% by mass. When the content of (A-1) is within the above range, the impact resistance and adhesiveness of the adhesive layer obtained from the adhesive composition are improved, and the viscosity of the (A) acrylic syrup is within an appropriate range. It is preferable because it can be easily handled in production.

  As said (B) acrylic monomer, the said acrylic monomer is mentioned, for example. The said (B) acrylic monomer may be used individually by 1 type, and may use 2 or more types. The (B) acrylic monomer may be the same monomer as the acrylic monomer constituting the acrylic polymer contained in the (A) acrylic syrup, or may be a different monomer.

  As the (B) acrylic monomer, an acrylic monomer containing at least one acrylic monomer having a cyclic structure in the molecule can be used. The use of the acrylic monomer is preferable because it can enhance the resilience to the impact and maintain the visibility of the display panel while maintaining excellent impact absorbability. Specific examples of the acrylic monomer having a cyclic structure in the molecule include, for example, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, and cyclododecyl (meth) acrylate. , Tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate It is done. Among these, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate are preferable from the viewpoint of availability and low cost. Moreover, as said (B) acrylic monomer, using 1 type, or 2 or more types of the acrylic monomer which has a cyclic structure in the said molecule | numerator, and 1 type or 2 or more types of the acrylic monomer which does not have this structure is used. it can.

  The content of the (B) acrylic monomer can be selected according to the type and content of each component. The content of the (B) acrylic monomer is usually 1 to 80% by mass, preferably 2 to 75% by mass, out of a total of 100% by mass of the content of the (A) acrylic syrup and the (B) acrylic monomer. More preferably, it is 3-70 mass%, More preferably, it is 5-65 mass%.

  Moreover, when the said (B) acrylic monomer contains 2 or more types of acrylic monomers, content of each acrylic monomer can be made into various ranges as needed. The content can be selected according to the type and content of each component. For example, when the total amount of the (B) acrylic monomer is 100% by mass, the content of the acrylic monomer as the main component (the component having the highest content) is usually 30 to 90% by mass, preferably 35 to 85% by mass. %, More preferably 40 to 80% by mass. More specifically, for example, the (B) acrylic monomer includes an acrylic monomer having a cyclic structure in the molecule such as tetrahydrofurfuryl acrylate, an alkyl acrylate such as 2-ethylhexyl acrylate, and a hydroxyl group such as 4-hydroxybutyl acrylate. In the case of containing the containing acrylic monomer, the content of the main component acrylic monomer (acrylic monomer having a cyclic structure in the molecule or hydroxyl group-containing acrylic monomer) can be within the above range.

［式（１）において、Ｘはアクリロイル基、グリシジル基、メルカプト基又はハロゲン基であり、Ｒ^１は２価の有機基であり、Ｒ^２は炭化水素基である。］ As said (C) silane coupling agent, the compound represented by following formula (1) is mentioned, for example.

[In Formula (1), X is an acryloyl group, a glycidyl group, a mercapto group, or a halogen group, R ¹ is a divalent organic group, and R ² is a hydrocarbon group. ]

  X is a functional group selected from the group consisting of an acryloyl group, a glycidyl group, a mercapto group, and a halogen group. Among these, an acryloyl group and a mercapto group are particularly preferable in terms of expressing high adhesiveness.

If R ¹ is a divalent organic group, the structure is not limited. For example, the carbon number of R ¹ is usually 1 to 20, preferably 1 to 18, more preferably 2 to 15, and more preferably 3 to 12. R ¹ may have a linear structure or a branched structure. Furthermore, R ¹ may be a saturated organic group (such as a saturated alkyl group), an unsaturated organic group (such as an unsaturated alkyl group), or an alicyclic or aromatic organic group. Specific examples of R ¹ include a methylene group, an ethylene group, an n-propylene group, an n-butylene group, a cyclohexyl group, and a benzyl group.

If R ² is a hydrocarbon group, the type and structure are not particularly limited. Usually, the carbon number of R ² is 1 to 10, preferably 1 to 8, more preferably 1 to 6, and more preferably 1 to 4. R ² may have a linear structure or a branched structure. Further, R ¹ may be a saturated hydrocarbon group, an unsaturated hydrocarbon group, or an alicyclic or aromatic hydrocarbon group. In the above formula (1), R ² may be the same group or different groups.

  More specifically, examples of the hydrocarbon group include (1) methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, and n-octyl group. Group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group A linear or branched alkyl group such as a group, n-nonadecyl group, n-eicosyl group, i-propyl group, i-butyl group, sec-butyl group, t-butyl group, and t-dodecyl group, (2) cyclopentyl Group, cyclobutyl group, cyclopentyl group, and cyclohexyl group, norbornyl group, norbornyl group, tricyclodecanyl group, tetracyclododecyl group, adamantyl group, methyl group Bridged alicyclic groups such as mantyl group, ethyladamantyl group, and butyladamantyl group, (3) alkenyl groups such as vinyl group and propenyl group, (4) phenyl group, toluyl group, benzyl group, methylbenzyl group, xylyl group Aryl groups such as a group, mesityl group, naphthyl group, and anthryl group, and (5) heteroaryl groups such as a pyridyl group, an imidazolyl group, a morpholinyl group, a piperidinyl group, and a pyrrolidinyl group. Among these, an alkyl group having 1 to 3 carbon atoms (methyl group, ethyl group, n-propyl group, i-propyl group) is preferable.

In the formula (1), R ¹ and R ² may further have other functional groups or atoms in the structure. Examples of other functional groups include thiol groups, hydroxyl groups, ether groups, thioether groups, sulfinyl groups, sulfonyl groups, carbonyl groups, carboxyl groups, carboxylic anhydride groups, nitrile groups, and amide groups. Examples of the atoms include various heteroatoms (oxygen atoms, nitrogen atoms, sulfur atoms, etc.) and halogen atoms (fluorine atoms, chlorine atoms, iodine atoms, etc.). The above-mentioned other functional groups or atoms may be only one kind or may contain two or more kinds. The number of the other functional groups or atoms is not particularly limited, and may be one or may include two or more.

  Specific examples of the compound represented by the above formula (1) include 3- (meth) acryloxypropyltrialkoxysilane, 3-glycidoxypropyltrialkoxysilane, vinyltrialkoxysilane, tetraalkoxysilane, 3 -Mercaptopropyltrialkoxysilane and 3-chloropropyltrialkoxysilane. In these, the silane coupling agent which has a C1-C2 alkoxysilyl group is preferable. In particular, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, and 3-mercaptopropyltrialkoxysilane are preferable in terms of developing high adhesiveness.

  Content of the said (C) silane coupling agent can be selected according to the kind of each said component, content, etc. The content of the (C) silane coupling agent is usually 0.05 to 5 parts by mass, preferably 0 with respect to 100 parts by mass in total of the contents of the (A) acrylic syrup and the (B) acrylic monomer. 0.1 to 3 parts by mass, more preferably 0.2 to 2 parts by mass, and more preferably 0.3 to 1.5 parts by mass. It is preferable that the content of the (C) silane coupling agent is in the above range because the adhesiveness is improved by suppressing the reaction rate of the pressure-sensitive adhesive and the unreacted monomer remaining. .

  The (D) urethane (meth) acrylate is preferably urethane (meth) acrylate obtained by reacting diisocyanate, hydroxyl group-containing (meth) acrylate, and diol. As this reaction, for example, (1) a method in which diol, diisocyanate and hydroxyl group-containing (meth) acrylate are charged together and reacted, (2) a method in which diol and diisocyanate are reacted, and then a hydroxyl group-containing (meth) acrylate is reacted. , (3) a method of reacting diisocyanate and hydroxyl group-containing (meth) acrylate, and then reacting with diol, and (4) reacting diisocyanate and hydroxyl group-containing (meth) acrylate, then reacting with diol, and finally hydroxyl group-containing The method of making (meth) acrylate react is mentioned.

  The (D) urethane (meth) acrylate is a diol and a diisocyanate such that the diol is preferably contained in one molecule as a repeating unit of 2 or more molecules, more preferably 3 or more in one molecule. The reaction rate is adjusted to react. Specifically, for example, the molar ratio of the diisocyanate is adjusted to be 1.5 mol or less with respect to 1 mol of the diol. The ratio of the hydroxyl group-containing (meth) acrylate is preferably adjusted to 1.0 to 1.5 equivalents with respect to the excess isocyanate equivalent calculated from the molar ratio of the diol and the diisocyanate.

  Examples of the diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, and m-phenylene diisocyanate. P-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 1,6- Hexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, bis (2-isocyanate ethyl) ) Fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, and 2,5 (or 6) -bis (Isocyanatemethyl) -bicyclo [2.2.1] heptane and the like. Among these, 2,4-tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and methylene bis (4-cyclohexyl isocyanate) which are aliphatic compounds are particularly preferable. By using an aliphatic compound for the diisocyanate component, yellowing during heating can be suppressed. When seeking better yellowing at the time of heating, it is preferable to use isophorone diisocyanate or methylene bis (4-cyclohexyl isocyanate). The said diisocyanate may be used individually by 1 type, and may use 2 or more types.

  Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) ) Acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 1,6-hexanediol Mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethanedi (meth) acrylate, pentaerythritol tri (meth) acrylate Examples thereof include compounds obtained by addition reaction of (meth) acrylic acid with glycidyl group-containing compounds such as acrylate, dipentaerythritol penta (meth) acrylate, alkyl glycidyl ether, allyl glycidyl ether, and glycidyl (meth) acrylate. it can. Of these hydroxyl group-containing (meth) acrylates, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like are particularly preferable. The said hydroxyl-containing (meth) acrylate may be used individually by 1 type, and may use 2 or more types.

  Specific examples of the diol include aliphatic polyether diol, cyclic polyether diol, polyester diol, polycarbonate diol, and polycaprolactone diol.

  Specific examples of the aliphatic polyether diol include, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, and polydecamethylene glycol, or two or more ion-polymerizable cyclic compounds. And polyether diol obtained by ring-opening copolymerization.

  Examples of the ion polymerizable cyclic compound include ethylene oxide, propylene oxide, 1,2-butylene oxide, butene-1-oxide, isobutene oxide, 3,3-bischloromethyloxetane, tetrahydrofuran, 2-methyltetrahydrofuran, 3- Methyltetrahydrofuran, dioxane, trioxane, tetraoxane, cyclohexene oxide, styrene oxide, epichlorohydrin, glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl carbonate, butadiene monooxide, isoprene monooxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, Cyclic rings such as butyl glycidyl ether and benzoic acid glycidyl ester Ether compounds, and the like.

  Further, a polyether diol obtained by ring-opening copolymerization of the above ion-polymerizable cyclic compound with cyclic imines such as ethyleneimine, cyclic lactone acids such as β-propiolactone and glycolic acid lactide, or dimethylcyclopolysiloxanes. Can also be used.

  Specific combinations of the two or more ion-polymerizable cyclic compounds include, for example, tetrahydrofuran and propylene oxide, tetrahydrofuran and 2-methyltetrahydrofuran, tetrahydrofuran and 3-methyltetrahydrofuran, tetrahydrofuran and ethylene oxide, propylene oxide and ethylene oxide, butene- Examples thereof include terpolymers of 1-oxide and ethylene oxide, tetrahydrofuran, butene-1-oxide, ethylene oxide, and the like. The ring-opening copolymer of these ion-polymerizable cyclic compounds may be bonded at random or may be bonded in a block form. Among these, at least one diol selected from the group consisting of polypropylene glycol, polybutylene glycol, a copolymer of 1,2-butylene oxide and ethylene oxide and a copolymer of propylene oxide and ethylene oxide is used. Is preferred.

  Examples of commercially available products of the above aliphatic polyether diol include (1) PPG-400, PPG1000, PPG2000, PPG3000, EXCENOL720, 1020, 2020, PREMINOL PML S-X4001, PML S-4003, PML S-X4004, PML. S-X4008, PML S-X4011, PML S-X4016, and NPML-4002A (above, manufactured by Asahi Glass Urethane Co., Ltd.), (2) EO / BO500, EO / BO1000, EOBO / 2000, EO / BO3000, and EO / BO4000 (Above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), (3) PTMG650, PTMG1000, and PTMG2000 (above, manufactured by Mitsubishi Chemical Corporation), (4) PEG1000, Unisafe DC1100, and DC1800 (above, (Manufactured by the present oil and fat company), (5) PPTG2000, PPTG1000, PTG400, and PTGL2000 (above, manufactured by Hodogaya Chemical Co., Ltd.), and (6) Z-3001-4, Z-3001-5, PBG2000A, and PBG2000B (above, Daiichi Kogyo Seiyaku Co., Ltd.).

  Examples of the cyclic polyether diol include bisphenol A alkylene oxide addition diol, bisphenol F alkylene oxide addition diol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol A alkylene oxide addition diol, hydrogenated bisphenol. Alkylene oxide addition diol of F, alkylene oxide addition diol of hydroquinone, alkylene oxide addition diol of naphthohydroquinone, alkylene oxide addition diol of anthrahydroquinone, 1,4-cyclohexanediol and its alkylene oxide addition diol, tricyclodecane diol, tricyclo Decanedimethanol, pentacyclopentadecanediol, and pentacyclopentadecane dimeta Lumpur, and the like. Among these, alkylene oxide addition diol of bisphenol A, alkylene oxide addition diol of hydrogenated bisphenol A, and tricyclodecane dimethanol are preferable.

  Examples of commercially available cyclic polyether polyols include Uniol DA400, DA700, DA1000, and DB400 (manufactured by NOF Corporation), N1162 (Daiichi Kogyo Seiyaku Co., Ltd.), and tricyclodecane dimethanol ( Mitsubishi Chemical Corporation).

  Examples of the polyester diol include a polyester diol obtained by reacting a diol with a diacid base. Examples of the diol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, and 3-methyl. Examples include -1,5-pentanediol, 1,9-nonanediol, and 2-methyl-1,8-octanediol. Examples of the dibasic acid include phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, and sebacic acid.

  As a commercial item of the said polyester diol, Curapol P-2010, PMIPA, PKA-A, PKA-A2, and PNA-2000 (above, the Kuraray company make) are mentioned, for example.

  Examples of the polycarbonate diol include polytetrahydrofuran polycarbonate and 1,6-hexanediol polycarbonate. Examples of commercially available polycarbonate diols include DN-980, 981, 982, 983 (manufactured by Nippon Polyurethane Co., Ltd.), PC-8000 (manufactured by PPG, USA), and PC-THF-CD (manufactured by BASF). Is mentioned.

  Examples of the polycaprolactone diol include ε-caprolactone, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol, 1,6-hexanediol, Examples thereof include polycaprolactone diol obtained by reacting diols such as neopentyl glycol, 1,4-cyclohexanedimethanol, and 1,4-butanediol. As these diols, Plaxel 205, 205AL, 212, 212AL, 220, 220AL (manufactured by Daicel) can be obtained as a commercial product.

  The number average molecular weight of the diol is preferably 300 to 15,000, more preferably 1000 to 12000, and particularly preferably 2000 to 12000.

  Many other diols other than those described above can also be used. Examples of such other diols include ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, and dicyclopentadiene. Dimethylol compound, tricyclodecane dimethanol, β-methyl-δ-valerolactone, hydroxy-terminated polybutadiene, hydroxy-terminated hydrogenated polybutadiene, castor oil-modified polyol, polydimethylsiloxane-terminated diol compound, and polydimethylsiloxane carbitol-modified diol Etc.

  The number average molecular weight of these other diol components is 300 to 5000, preferably 300 to 2000, and more preferably 300 to 1000.

  It is also possible to use a diamine together with the diol component. Examples of such diamines include diamines such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, paraphenylenediamine, and 4,4'-diaminodiphenylmethane, diamines containing heteroatoms, and polyether diamines.

  In the (D) urethane (meth) acrylate, urethane (meth) acrylate obtained by reacting 2 mol of a hydroxyl group-containing (meth) acrylate compound with respect to 1 mol of diisocyanate can also be blended. As such urethane (meth) acrylate, for example, a reaction product of hydroxyethyl (meth) acrylate and 2,4-tolylene diisocyanate, hydroxyethyl (meth) acrylate and 2,5 (or 6) -bis (isocyanate methyl)- Bicyclo [2.2.1] heptane reactant, hydroxyethyl (meth) acrylate and isophorone diisocyanate reactant, hydroxypropyl (meth) acrylate and 2,4-tolylene diisocyanate reactant, hydroxypropyl (meth) acrylate And a reaction product of isophorone diisocyanate.

  Content of the said (D) urethane (meth) acrylate can be selected according to the kind of each said component, content, etc. The content of the (D) urethane (meth) acrylate is usually 0.1 to 50 parts by weight, preferably 100 parts by weight in total of the contents of the (A) acrylic syrup and the (B) acrylic monomer. 0.5-40 mass parts, More preferably, it is 1-35 mass parts, More preferably, it is 5-35 mass parts. It is preferable that the content of the (D) urethane (meth) acrylate is within the above range because the degree of crosslinking becomes sufficient and the adhesive force can be increased.

  Specific examples of the (E) photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2 -Hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxyl Cantonal, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino - propan-1-one, and 2,4,6-trimethylbenzoyl diphenylphosphine oxide.

  Specifically as a commercial item of the said (E) photoinitiator, Irgacure 184,369,651,500,907, CGI1700, CGI1750, CGI1850, and CG24-61 (above, Ciba Specialty Chemicals make ), Lucirin LR8728 (manufactured by BASF), Darocur 1116, 1173 (manufactured by Merck), and Ubekrill P36 (manufactured by UCB). The said (E) photoinitiator may be used individually by 1 type, and may use 2 or more types.

  The content of the (E) photopolymerization initiator can be selected according to the type and content of each component. The content of the (E) photopolymerization initiator is usually 0.1 to 15 parts by mass, preferably 0 with respect to 100 parts by mass in total of the contents of the (A) acrylic syrup and the (B) acrylic monomer. 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and more preferably 0.5 to 5 parts by mass. When the content of the (E) photopolymerization initiator is within the above range, the adhesive layer is sufficiently cured and excellent in adhesiveness, and the molecular weight of the component contained in the adhesive layer is increased to improve the durable adhesiveness. Is preferable.

  It is preferable to add a photosensitizer to the (E) photopolymerization initiator as necessary. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylamino. An isoamyl benzoate is mentioned. As a commercial item of the said photosensitizer, Ubekrill P102, 103, 104, and 105 (above, the product made from UCB) etc. are mentioned, for example.

  The said adhesive composition may contain the 1 type (s) or 2 or more types of other components as needed, as long as the performance is not impaired. Examples of other components include pigments, dyes, lubricants, softeners, photosensitizers, antioxidants, antioxidants, stabilizers such as heat stabilizers, weathering agents, metal deactivators, UV absorbers, Stabilizers such as light stabilizers, copper damage inhibitors, antibacterial and antifungal agents, dispersants, plasticizers, crystal nucleating agents, flame retardants, tackifiers, foaming aids, crosslinking agents, co-crosslinking agents, vulcanization Agents, vulcanization aids, foaming agents, colorants such as titanium oxide and carbon black, and metal powders such as ferrite. These may be used alone or in combination of two or more.

  Examples of the other components include inorganic fibers (glass fibers and metal fibers), organic fibers (carbon fibers and aramid fibers), composite fibers, inorganic whiskers such as potassium titanate whiskers, glass beads, glass balloons, Glass flake, asbestos, mica, calcium carbonate, talc, silica, calcium silicate, hydrotalcite, kaolin, diatomaceous earth, graphite, pumice, evo powder, cotton floc, cork powder, barium sulfate, fluororesin, polymer beads, etc. And fillers such as polyolefin wax, cellulose powder, rubber powder and wood powder, low molecular weight polymers, silane coupling agents, and titanium coupling agents. These may be used alone or in combination of two or more.

The pressure-sensitive adhesive composition may contain a compound having a phosphite group and a phenol group represented by the following formula (5) in order to suppress yellowing due to ultraviolet rays or heating.
(R ⁹ O) _n P (OR ¹⁰ ) _3-n (5)
(In formula (5), n represents an integer of 1 to 3, R ⁹ represents an organic group having a phenolic hydroxyl group, and R ¹⁰ represents an organic group that may contain a phosphorus atom.)

R ⁹ and R ¹⁰ may have an element other than carbon. Examples of elements other than carbon include nitrogen, sulfur, oxygen, halogen and phosphorus. The R ⁹ and R ¹⁰ may be a cyclic organic group in which two or more of the R ⁹ and R ¹⁰ are connected.

Examples of R ⁹ include hydroxyphenyl optionally substituted with 1 to 3 alkyl groups, alkoxy groups, or halogen atoms on the benzene or naphthalene ring, and hydroxynaphthyl or hydroxyphenylalkyl groups. As the above-mentioned R ^10, for example, an alkyl group, an aryl group, and aralkyl group, and the like. Examples of the aryl group include an alkyl group, an alkoxy group, and a phenyl or naphthyl group which may be substituted with a halogen atom. Examples of the arylalkyl group include an alkyl group, an alkoxy group, and a phenylalkyl group which may be substituted with a halogen atom. Moreover, as described above, the R ⁹ and the R ¹⁰ may be linked.

In the case where R ¹⁰ contains a phosphorus atom, 2 to 4 phosphites having a phenolic hydroxyl group are bonded to a divalent to tetravalent alkane residue or a divalent to tetravalent aromatic hydrocarbon residue. There are cases. In the above formula (5), when R ⁹ is 2 or more, each R ⁹ may be the same group or different groups. Similarly, if a said R ¹⁰ is 2 or more, each R ¹⁰ together may be the same group or a different group.

  Specific examples of the compound having a phosphite group and a phenolic hydroxyl group represented by the above formula (5) include 2-methyl-4-hydroxyphenyl diethyl phosphite and 2-t-butyl-4-hydroxy. Phenyldiethylphosphite, 2,5-di-t-butyl-4-hydroxyphenyldiethylphosphite, bis (2,5-di-t-butyl-4-hydroxyphenyl) ethylphosphite, tris (2,5- Di-t-butyl-4-hydroxyphenyl) phosphite, tetrakis (2,5-di-t-butyl-4-hydroxyphenyl) -2,5-di-t-butyl-hydroxyquinonediyl-phosphite It is done.

As the compound having a phosphite group and a phenolic hydroxyl group represented by the above formula (5), a compound represented by the following formula (6) or (7) is particularly preferable. Examples of commercially available compounds having a phosphite group and a phenolic hydroxyl group include “Sumilyzer GP” (manufactured by Sumitomo Chemical Co., Ltd.).

  The content of the compound having a phosphite group and a phenolic hydroxyl group represented by the above formula (5) is preferably 0.1 to 10% by mass, more preferably 0.00%, based on the total amount of the pressure-sensitive adhesive composition. It is 1-5 mass%, Most preferably, it is 0.1-3 mass%.

  The pressure-sensitive adhesive composition can contain a dialkylaminobenzoic acid ester in order to reduce the tack after curing. Specific examples of the dialkylaminobenzoic acid ester include dialkylaminobenzoic acid alkyl esters such as methyl, ethyl, propyl, butyl, and isoamyl esters of dialkylaminobenzoic acid. Here, as an alkyl group of a dialkylamino group, a C1-C6 thing is preferable. The ester residue is preferably an alkyl group having 1 to 6 carbon atoms. The dialkylamino group and the carboxyl group of the dialkylaminobenzoic acid are preferably bonded to the para position on the benzene ring. Of these, ethyl p-dimethylaminobenzoate is particularly preferred.

  Specific examples of commercially available products of the dialkylaminobenzoate include Kayacure EPA, Kayacure DMBI (manufactured by Nippon Kayaku Co., Ltd.), and the like.

  The content of the dialkylaminobenzoic acid ester is preferably 0.05 to 5% by mass with respect to the total amount of the radiation curable liquid pressure-sensitive adhesive composition, more preferably from the viewpoint of curability of the end face. It is 1-3 mass%, Most preferably, it is 0.2-1 mass%.

  The pressure-sensitive adhesive composition can contain an aromatic thiol compound in order to improve the heat and moisture resistance. Specifically, for example, an aromatic heterocyclic compound having a mercapto group is preferable as the aromatic thiol compound. More specifically, examples of the aromatic thiol compound include mercaptobenzoxazole, mercaptobenzothiazole, and 1-phenyl-5-mercapto-1H-tetrazole.

  Specific examples of commercially available aromatic thiol compounds include Noxeller M, Noxeller MP, Nocrack MB, Nocrack MMB (manufactured by Ouchi Shinsei Chemical Co., Ltd.), Accel M, Antage MB (and Kawaguchi). Chemicals), Sunseller M and Sunseller MG (above, manufactured by Sanshin Chemical Co., Ltd.), Soxinol M and Sumilyzer MB (above, manufactured by Sumitomo Chemical Co., Ltd.), and the like.

  As for content of the said aromatic thiol compound, 0.01-5 mass% is preferable with respect to the whole quantity of the said adhesive composition from a heat-and-moisture resistant point, More preferably, it is 0.05-4 mass%.

  The pressure-sensitive adhesive composition can contain an antioxidant in order to improve thermal stability and color stability. There is no limitation in particular in the kind of the said antioxidant. Specific examples of the antioxidant include a hindered phenol having a structure in which a methyl group and a hydrocarbon group having 1 to 8 carbon atoms are bonded to carbon atoms on both sides of a carbon atom to which a phenol hydroxyl group is bonded. A type antioxidant can be preferably used.

  Specific examples of the hindered phenol-type antioxidant include benzenepropanoic acid-3,5-bis (1,1-dimethylethyl) -4-hydroxy, ethylenebis (oxyethylene) bis [3- (5 -Tert-butyl-4-hydroxy-m-tolyl) propionate], 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1, 1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol-bis {3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate} , And 2,2-thio-diethylenebis {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate}. That.

  As a commercial item of the said hindered phenol type antioxidant, Irganox 245 and 1035 (above, the product made by Ciba Specialty Chemicals) and Sumilizer GA-80 (made by Sumitomo Chemical Co., Ltd.) are mentioned, for example.

  The content of the hindered phenol-type antioxidant is preferably 0.01 to 3% by mass, more preferably 0.03 to 3% by mass with respect to the total amount of the adhesive composition, from the viewpoint of thermal stability and color stability. 1 mass%, More preferably, it is 0.05-0.5 mass%.

  When preparing the said adhesive composition, a deaeration process can be performed as needed. The degassing step is a step of reducing the amount of dissolved oxygen from the pressure-sensitive adhesive composition. By performing the degassing step, when the pressure-sensitive adhesive composition is cured by radiation, the radiation irradiation side and the opposite side of the pressure-sensitive adhesive composition can be cured with good balance.

  The degassing method for the pressure-sensitive adhesive composition is not particularly limited as long as the amount of dissolved oxygen can be reduced from the pressure-sensitive adhesive composition. Examples of the degassing method include vacuum degassing by reducing the pressure of the reaction vessel containing the adhesive composition, and reducing the amount of dissolved oxygen by dissolving an inert gas such as nitrogen and helium in the adhesive composition. Inert gas bubbling, ultrasonic degassing by applying ultrasonic waves, and contacting the above adhesive composition with a thin film such as a hollow fiber, the gas concentration between the inside and outside of the thin film with one space separating the membrane as a vacuum state Thin film deaeration that deaerates the difference as a driving force can be mentioned. In the case of vacuum degassing, for example, the pressure-sensitive adhesive composition can be degassed by stirring under reduced pressure at room temperature (20 to 30 ° C.) at −0.09 MPaG for 1 hour.

      There is no particular limitation on the amount of dissolved oxygen contained in the pressure-sensitive adhesive composition after the degassing step. The amount of dissolved oxygen contained in the pressure-sensitive adhesive composition after the degassing step is preferably 90% or less of the saturated oxygen amount, more preferably 85% or less, more preferably 80% or less, and particularly preferably 10 to 75%. . By setting the amount of dissolved oxygen in the above range, when the pressure-sensitive adhesive composition is cured by radiation, the radiation irradiation side and the opposite side of the pressure-sensitive adhesive composition can be cured in a balanced manner. As a result, an impact resistant adhesive layer having an excellent balance between adhesiveness and impact resistance can be obtained, which is preferable.

  There is no limitation in particular in the method of forming the adhesion layer of this invention. Usually, it can form by apply | coating the solution or semisolid agent containing the component which comprises the adhesion layer of this invention to a base layer, and making it harden | cure. For example, the pressure-sensitive adhesive layer of the present invention can be formed by applying the above pressure-sensitive adhesive composition to a base layer and then curing it by irradiating with radiation.

  There are no particular limitations on the material, type, and configuration of the base layer. As a member which comprises the said base layer, the glass plate of arbitrary materials, various resin (especially transparent resin), a functional member, etc. are mentioned, for example. These contents will be described later.

  There is no particular limitation on the method of applying the solution or semi-solid agent containing the components constituting the pressure-sensitive adhesive layer of the present invention, for example, the pressure-sensitive adhesive composition to the base layer. Examples of the coating method include a solvent casting method and a spin coating method, in addition to a method of coating with a roll coater. In addition, the said application | coating is not only the method of apply | coating the said solution or semi-solid agent to the said base layer artificially, but the said solution or semi-solid agent is dripped on the surface of the said base layer, and another member is then the surface of the said base layer. A method of spreading the solution or the semi-solid agent over the entire surface of the base layer.

  When forming the adhesive layer of this invention using the said adhesive composition, the said adhesive composition is normally hardened | cured by irradiating a radiation. The kind of the radiation is not particularly limited as long as the pressure-sensitive adhesive composition can be cured. Examples of the radiation include active energy rays such as visible light, ultraviolet rays, electron beams, and X-rays. The radiation is preferably light (visible light or ultraviolet light). As the ultraviolet ray source, known irradiation devices such as a mercury arc, a carbon arc, a low pressure mercury lamp, a medium / high pressure mercury lamp, a metal halide lamp, a chemical lamp, and a book light lamp can be used.

There is no particular limitation on the irradiation condition of the radiation. When ultraviolet rays are used as the radiation, the wavelength range of the ultraviolet rays is usually 150 to 500 nm, preferably 180 to 460 nm, and more preferably 200 to 400 nm. The peak irradiance of the ultraviolet, 50~1000mW / cm ^2, preferably 50 to 800 mW / cm ^2, more preferably 50~700mW / cm ^2, more preferably, to 50~600mW / cm ^2. Furthermore, the integrated light quantity of the ultraviolet light 100 to 2000 mJ / cm ^2, preferably 150~1500mJ / cm ^2, more preferably 200~1300mJ / cm ^2, more preferably, to 250~1000mJ / cm ^2.

The conditions for the ultraviolet irradiation are preferably low illuminance and large integrated light quantity. That is, it is preferable to irradiate ultraviolet rays with low illuminance for a long time. Specifically, for example, the conditions of the ultraviolet irradiation, the peak irradiance of the ultraviolet is 50~1000mW / cm ^2, and the accumulated light quantity of the ultraviolet light may be a condition of 100 to 2000 mJ / cm ^2. The preferable conditions for the ultraviolet irradiation can be the conditions in which the peak illuminance of the ultraviolet light is 50 to 800 mW / cm ² and the cumulative amount of the ultraviolet light is 150 to 1500 mJ / cm ² . More preferable conditions for the ultraviolet irradiation may be a condition in which the peak illuminance of the ultraviolet light is 50 to 700 mW / cm ² and the accumulated light amount of the ultraviolet light is 200 to 1300 mJ / cm ² . The preferable conditions for the ultraviolet irradiation may be a condition in which the peak illuminance of the ultraviolet light is 50 to 600 mW / cm ² and the accumulated light amount of the ultraviolet light is 250 to 1000 mJ / cm ² . By making the peak illuminance and integrated light quantity of the ultraviolet ray within the above ranges, the adhesive layer of the adhesive layer of the present invention has a good balance of impact resistance and impact resistance, and the adhesive layer of the present invention has impact resistance and radiation curability. Since it can raise, it is preferable.

  The irradiation with the radiation can be performed in an oxygen-free atmosphere substituted with an inert gas such as nitrogen gas. The irradiation with the radiation can also be performed in an air atmosphere. When irradiation with the radiation is performed in an air atmosphere, the adhesiveness of the impact-resistant adhesive layer on the radiation irradiation surface side can be increased.

  Specifically, for example, the method for producing the pressure-sensitive adhesive layer of the present invention includes a degassing step of degassing the pressure-sensitive adhesive composition, and a coating step of applying the pressure-sensitive adhesive composition degassed by the degassing step to the base layer surface And a curing step of curing the radiation-curable liquid pressure-sensitive adhesive composition applied in the application step by irradiating with radiation.

(2) Impact-resistant adhesive laminate The impact-resistant adhesive laminate of the present invention (hereinafter simply referred to as “adhesive laminate”) is formed on the impact-resistant adhesive layer of the present invention and at least one surface of the impact-resistant adhesive layer. Other layers provided.

  There are no particular limitations on the material, shape, and structure of the other layers. As said other layer, a glass plate, various resin (transparent resin, a resin film, etc.) and a functional member are mentioned, for example. Specific examples of the other layer include a protective film layer that protects the adhesive layer of the present invention and a functional layer that is composed of various functional materials and is disposed in various display devices.

  Examples of the glass constituting the glass plate include borosilicate glass, aluminosilicate glass, and aluminoborosilicate glass, and low alkali glass and alkali-free glass in which the alkali metal content of these glasses is reduced. In addition, silica glass and soda lime glass can be used.

  Specific examples of the resin include polycarbonate resins, acrylic resins such as polymethyl methacrylate, 1,2-polybutadiene resins, polyvinyl chloride resins, cyclic olefin copolymers, modified norbornene resins, norbornene. Resin, alicyclic acrylic resin, amorphous polyolefin such as polycyclohexylethylene, amorphous fluororesin, polystyrene resin, transparent ABS resin, polyethylene terephthalate, polyethylene naphthalate, amorphous copolyester, polyarylate, poly Methylpentene, polysulfone, polyethersulfone, polyetherimide, cellulose acetate, allyl diglycol carbonate resin, ethylene-vinyl acetate copolymer (EVA, usually containing 3% by mass or more vinyl acetate units), poly Styrene and polyolefin resins such as polypropylene, (. Excluding EVA) vinyl ester resins, amorphous polyamide resins, urethane resins, epoxy resins, unsaturated polyester resins, and silicon resins. Of these, resins such as polycarbonate resins, acrylic resins, and polyester resins are preferable. In particular, the resin is preferably transparent.

  The protective film layer can be provided on at least one surface of the exposed surface of the pressure-sensitive adhesive layer of the present invention. For example, it can be provided on both exposed surfaces of the pressure-sensitive adhesive layer of the present invention. Moreover, it can provide in the surface of one side of the exposed surface of the adhesion layer of this invention. The said protective film layer can be peeled from the adhesion layer of this invention. By having the said protective film layer, the adhesion laminated body of this invention can prevent the damage of the adhesion layer before use. Moreover, the adhesion laminated body of this invention which has the said protective film layer can peel easily the said protective film layer at the time of use, and can obtain a laminated body easily by sticking on the surface of another to-be-adhered body.

  There is no particular limitation on the material, shape, and structure of the protective film layer. Specifically, as the material of the protective film layer, for example, polyester such as PET (polyethylene terephthalate), polyamide, polyimide, polyolefin, polycarbonate, acrylic resin, resin such as fluororesin, or resin is impregnated into paper. The resin-impregnated paper obtained by (1) is mentioned. The protective film layer may be transparent or may not be transparent. The shape of the protective film layer may be a sheet or a film. Furthermore, the protective film layer may have a single layer structure or a laminate of two or more layers. Further, in the pressure-sensitive adhesive laminate of the present invention, when there are two or more protective film layers, each protective film layer may be a protective film layer having the same material, shape and structure, and a protective film layer having a different material, shape or structure. You may use together.

  A release layer can be provided between the protective film layer and the adhesive layer of the present invention. By having the release layer, the pressure-sensitive adhesive laminate of the present invention can easily peel the protective film layer. The method for providing the release layer is not particularly limited. For example, the release layer can be provided by applying a release coating agent to the surface of the protective film layer. There is no particular limitation on the type of the release coating agent. Specific examples of the release coating agent include silicon coating agents, inorganic coating agents, fluorine coating agents, and organic-inorganic hybrid coating agents. The pressure-sensitive adhesive laminate of the present invention provided with the release layer can usually be obtained by forming the pressure-sensitive adhesive layer of the present invention on the surface of the release layer after providing the release layer on the surface of the protective film layer.

  As said functional layer, the optical film comprised with various resin films is mentioned, for example. Specific examples of the functional layer include, for example, an ultraviolet cut plate, a polarizing plate (including various films constituting the polarizing plate), an array substrate, a color filter, a viewing angle widening film, an anti-reflection film, an anti-glare film, and a transparent conductive material. 1 type, or 2 or more types, such as a film | membrane, retardation film, an electromagnetic wave absorption film, an infrared rays absorption film, and a film for touchscreens, are mentioned. Moreover, as various films which comprise the said polarizing plate, a polarizing film, a substrate film, a protective film, etc. are mentioned. If said other layer is a polarizing plate, LCD can be manufactured by bonding the adhesion laminated body of this invention and a liquid crystal display panel through the adhesion layer of this invention.

  The pressure-sensitive adhesive laminate of the present invention only needs to include the pressure-sensitive adhesive layer of the present invention and another layer provided on at least one surface of the pressure-sensitive adhesive layer, and can have various structures as necessary. . The pressure-sensitive adhesive laminate of the present invention can be configured to have another layer on one exposed surface of the pressure-sensitive adhesive layer of the present invention (see FIG. 1). Moreover, the adhesion laminated body of this invention can be set as the structure which has another layer in both the exposed surfaces of the adhesion layer of this invention (refer FIG. 2). Furthermore, the pressure-sensitive adhesive layer and the other layers of the present invention may each be a single layer or a multilayer structure of two or more layers. When the impact adhesive layer of the present invention has a multilayer structure of two or more layers, the configuration, thickness and physical properties of each adhesive layer may be the same or different. When the other layer has a multilayer structure of two or more layers, the type, configuration, thickness, and physical properties of each other layer may be the same or different.

  The pressure-sensitive adhesive laminate of the present invention is illustrated in FIGS. FIG. 1 is a laminate including another layer on one exposed surface of the pressure-sensitive adhesive layer of the present invention. In the laminate A1 of FIG. 1, the protective film layer 2 including the adhesive layer 1 and the release layer 21 of the present invention is laminated. Moreover, FIG.2 and FIG.3 is a laminated body which equips both the exposed surfaces of the adhesion layer of this invention with another layer. The laminated body 2 of FIG. 2 is a structure which has the protective film layer 2 provided with the peeling layer 21 on both surfaces of the adhesion layer 1 of this invention. 3 has a protective film layer 2 provided with a release layer 21 on one surface of the pressure-sensitive adhesive layer 1 of the present invention, and a structure having a functional layer 3 such as a polarizing plate on the other surface. It is.

  The pressure-sensitive adhesive laminate of the present invention can be produced, for example, by forming the impact-resistant pressure-sensitive adhesive layer of the present invention on at least one surface of the other layer. In the laminate A1 of FIG. 1, for example, the pressure-sensitive adhesive composition is applied to the surface of the other layer (protective film layer 2), and then the pressure-sensitive adhesive composition is cured by irradiation with radiation. It can be obtained by forming the layer 1. 2 is applied to the surface of the first other layer (protective film layer 2), then cured by irradiation with radiation, and then formed. The second other layer (protective film layer 2 ′) can be bonded to the surface of the adhesive layer 1 thus obtained.

  In addition, in the pressure-sensitive adhesive laminate A2 of the present invention shown in FIG. 2, the pressure-sensitive adhesive composition is applied to the surface of the first other layer (protective film layer 2), and then is in contact with the applied pressure-sensitive adhesive composition. The second other layer (protective film layer 2 ′) is disposed, and then the pressure-sensitive adhesive composition is cured by irradiation with radiation to form the pressure-sensitive adhesive layer 1 of the present invention. Furthermore, in the pressure-sensitive adhesive laminate A2 of the present invention shown in FIG. 2, the pressure-sensitive adhesive composition is dropped onto the surface of the first other layer (protective film layer 2), and then the first other layer (protective film). By disposing the second other layer (protective film layer 2 ′) on the surface of the layer 2), the adhesive composition is spread over the entire surface of the first other layer (protective film layer 2). Thereafter, the pressure-sensitive adhesive composition can be cured by irradiation to form the pressure-sensitive adhesive layer 1 of the present invention.

  The pressure-sensitive adhesive laminate of the present invention can be used for display devices such as display panels (flat panel display etc.) such as electronic / electrical equipment. That is, the pressure-sensitive adhesive laminate of the present invention can be used as an impact-resistant adhesive laminate for display devices or an impact-resistant adhesive laminate for display panels of electronic / electrical equipment.

  The pressure-sensitive adhesive laminate of the present invention is preferably transparent from the viewpoint of the visibility of display contents on the display panel. Specifically, for example, the total light transmittance can be 90% or more, preferably 91% or more, and more preferably 92% or more, at 25 ° C. and 0.5 mm thickness.

(3) Display device The display device of the present invention comprises the adhesive layer or the adhesive laminate of the present invention on the display panel surface.

  Examples of the display device of the present invention include display panels (flat panel displays and the like) such as electronic and electrical equipment. Specific examples of the display device of the present invention include a display device including an LCD panel, a plasma display panel (PDP), an organic EL display panel, a field emission display panel, and an electronic paper display panel.

  Hereinafter, the present invention will be specifically described with reference to examples. In addition, this invention is not restrict | limited at all by these Examples. Further, “%” and “part” in the examples are based on mass unless otherwise specified.

(1) Preparation of radiation curable liquid adhesive composition The following materials were used as raw materials. And the radiation curable liquid adhesive composition (A1)-(A6) was prepared with the method as described below. Table 1 shows the compositions and ratios (parts) of the pressure-sensitive adhesive compositions (A1) to (A6).

(A) Acrylic syrup, trade name “BA-6” manufactured by Shinsetsu Kogyo Co., Ltd. (viscosity: 80000 cps, composition; acrylic acid / butyl acrylate = 6/94, polystyrene equivalent molecular weight of polymer in syrup; 1.7 million, molecular weight dispersion) (Mw / Mn: 3.1, solid content concentration: 16%)
Product name “2EHA-10” (manufactured by Shinseng Industries Co., Ltd., viscosity: 60000 cps, composition: acrylic acid / 2-ethylhexyl acrylate = 10/90, polystyrene equivalent molecular weight of polymer in syrup; 1,200,000 , Molecular weight dispersion Mw / Mn: 2.8, solid content concentration: 22%)

(B) Acrylic monomer Tetrahydrofurfuryl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, and acrylic acid

(C) Silane coupling agent 3-methacryloxypropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane

(D) Urethane acrylate, product name “Ebecryl 270” manufactured by Daicel UCB

(E) Photopolymerization initiator 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide

<Adhesive composition (A1)>
Into a reaction vessel with an internal volume of 1 liter substituted with nitrogen, 350 g of acrylic syrup (trade name “BA-6”, manufactured by Shinsetsu Kogyo Co., Ltd.), 262.5 g of tetrahydrofurfuryl acrylate (manufactured by Osaka Organic Industry Co., Ltd.), 2-ethylhexyl 87.5 g of acrylate, 70 g of urethane acrylate (manufactured by Daicel UCB, trade name “Ebecryl 270”), 7 g of 3-methacryloxypropyltrimethoxysilane (trade name “KBM-503”, manufactured by Shin-Etsu Chemical Co., Ltd.), 1-hydroxy 10.5 g of cyclohexyl phenyl ketone (product name “IRGACURE184” manufactured by Ciba Specialty Chemicals) and 7 g of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (product name “Optomer SP246” manufactured by Asahi Denka Kogyo Co., Ltd.) Was introduced. Subsequently, it stirred at room temperature for 3 hours and obtained the adhesion composition (A1).

  Thereafter, the pressure in the reaction vessel was reduced, and vacuum deaeration was performed while stirring the pressure-sensitive adhesive composition (A1). The dissolved oxygen content of the adhesive composition (A1) after 1 hour of vacuum degassing was 71% of the saturated oxygen content. Moreover, the weight reduction of the said adhesive composition (A1) was 1%.

<Adhesive composition (A2)>
Into a reaction vessel with an internal volume of 1 liter substituted with nitrogen, 504 g of acrylic syrup (“2EHA-10”), 35 g of 2-ethylhexyl acrylate, 140 g of isobornyl acrylate, 21 g of acrylic acid, 7 g of 3-mercaptopropyltrimethoxysilane (Shin-Etsu) Chemical Industry Co., Ltd., trade name “KBM-503”), urethane acrylate (“Ebecryl 270”) 70 g, 1-hydroxycyclohexyl phenyl ketone (“IRGACURE184”) 21 g, and bis (2,4,6-trimethylbenzoyl) phenylphosphine 1.4 g of oxide (manufactured by Ciba Specialty Chemicals, trade name “IRGACURE819”) was added. Subsequently, it stirred at room temperature for 3 hours and obtained the adhesion composition (A-2).

  Thereafter, the pressure in the reaction vessel was reduced, and vacuum deaeration was performed while stirring the pressure-sensitive adhesive composition (A2). The dissolved oxygen content of the pressure-sensitive adhesive composition (A2) after 1 hour of vacuum degassing was 70% of the saturated oxygen content. Moreover, the weight reduction of the said adhesive composition (A2) was 1%.

<Adhesive composition (A3)>
Into a reaction vessel having an internal volume of 1 liter purged with nitrogen, 350 g of acrylic syrup (“2EHA-10”), 350 g of 2-ethylhexyl acrylate, 7 g of 3-mercaptopropyltrimethoxysilane (“KBM-503”), urethane acrylate (“ 140 g of Ebecryl 270 "), 21 g of 1-hydroxycyclohexyl phenyl ketone (" IRGACURE184 "), and 1.4 g of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide. Subsequently, it stirred at room temperature for 3 hours and obtained the adhesion composition (A3).

  Thereafter, the pressure in the reaction vessel was reduced, and vacuum deaeration was performed while stirring the pressure-sensitive adhesive composition (A3). The dissolved oxygen content of the pressure-sensitive adhesive composition (A3) after 1 hour of vacuum degassing was 72% of the saturated oxygen content. Moreover, the weight reduction of the said adhesive composition (A3) was 1%.

<Adhesive composition (A4)>
A pressure-sensitive adhesive composition (A4) was obtained in the same manner as the pressure-sensitive adhesive composition (A3) using 210 g of the urethane acrylate (“Ebecryl 270”). Thereafter, the reaction vessel was depressurized and vacuum deaeration was performed while stirring. The dissolved oxygen content of the adhesive composition (A4) after 1 hour of vacuum degassing was 71% of the saturated oxygen content. Moreover, the weight reduction of the said adhesive composition (A4) was 1%.

<Adhesive composition (A5)>
Using 14 g of the urethane acrylate (“Ebecryl 270”), a pressure-sensitive adhesive composition (A5) was obtained in the same manner as the pressure-sensitive adhesive composition (A3). Thereafter, the reaction vessel was depressurized and vacuum deaeration was performed while stirring. The dissolved oxygen content of the pressure-sensitive adhesive composition (A5) after 1 hour of vacuum degassing was 73% of the saturated oxygen content. Moreover, the weight reduction of the said adhesive composition (A5) was 1%.

<Adhesive composition (A6)>
Using 7 g of the urethane acrylate (“Ebecryl 270”), a pressure-sensitive adhesive composition (A6) was obtained in the same manner as the pressure-sensitive adhesive composition (A3). Thereafter, the reaction vessel was depressurized and vacuum deaeration was performed while stirring. The dissolved oxygen content of the pressure-sensitive adhesive composition (A6) after 1 hour of vacuum degassing was 73% of the saturated oxygen content. Moreover, the weight reduction of the said adhesive composition (A6) was 1%.

  In addition, the dissolved oxygen amount of the said adhesive composition (A1)-(A6) was measured with the following method.

  500 g of the above-mentioned adhesive compositions (A1) to (A6) are put into a reaction vessel having an internal volume of 1 liter substituted with dry air, then supplied with dry air, and stirred at room temperature for 1 hour to saturate the above composition. An oxygen solution was made. The dry air was supplied while confirming with a pressure gauge so that the pressure in the reaction vessel was maintained at 1 atm. And the saturated oxygen amount (display value of a DO meter) of the saturated oxygen solution of the said composition was measured using DO meter for organic solvents (The product made from Central Science Co., Ltd., brand name "UC-12-SOL"). Next, using the DO meter, the amount of saturated oxygen (indicated value on the DO meter) of the composition deaerated in vacuum was measured. Based on these displayed values, the dissolved oxygen amount (%) was calculated from the following calculation formula.

Dissolved oxygen amount (%) = A / B
A: Display value of DO meter after vacuum deaeration B: Display value of DO meter of saturated oxygen solution

  Using a coater, a thermosetting acrylic adhesive (trade name “HT-6537L” manufactured by Shinseng Industries Co., Ltd.) with a thickness of 100 μm and a PET film with a release coat (trade name “Purex A71” manufactured by Teijin DuPont) It was applied to. Next, after drying the pressure-sensitive adhesive in a drying furnace, a cover PET film (trade name “MRF” manufactured by Mitsubishi Chemical Corporation) was pasted and cured at room temperature for 2 weeks. By this method, an acrylic adhesive film (A7) having a thickness of 25 μm was obtained.

(2) Production of impact-resistant adhesive layer As a base layer, a polyester film with a release coat having a thickness of 100 μm (trade name “Purex A71” manufactured by Teijin DuPont) was used. And the said adhesive composition (A1)-(A6) was apply | coated to the said peeling coat surface of the said base layer. The adhesive compositions (A1) to (A6) were applied by a bar coater. A metal halide lamp (manufactured by Eye Graphics) was used as an ultraviolet ray source. The peak irradiance 170 mW / cm ^2, under conditions of integrated quantity of light 500 mJ / cm ^2, was irradiated with ultraviolet rays coated the adhesive composition (A1) ~ (A6). The adhesive compositions (A1) to (A6) were cured by this ultraviolet irradiation, and the impact-resistant adhesive layers of Examples 1 to 7 and Comparative Examples 1 to 6 were produced.

  Further, after curing the pressure-sensitive adhesive composition (A1), one or two layers of the acrylic pressure-sensitive adhesive film (A7) are laminated on the surface of the formed impact-resistant pressure-sensitive adhesive layer. Manufactured.

  E ′ of each impact-resistant adhesive layer of Examples 1 to 9 and Comparative Examples 1 to 6 was measured using a dynamic viscoelasticity measuring device (trade name “RSA-II”) manufactured by TA Instruments at a measurement temperature of 25 ° C. It measured by the method of measurement frequency 1Hz. Tables 2 and 3 show E ′ (MPa) and t (μm) of the impact-resistant adhesive layers of Examples 1 to 9 and Comparative Examples 1 to 6, respectively.

(3) Evaluation The impact-resistant adhesive layers of Examples 1 to 9 and Comparative Examples 1 to 6 and the polarizing plate (trade name “Sumikaran SQ-1832A”, manufactured by Sumitomo Chemical Co., Ltd.) serving as a functional layer were bonded together. An impact-resistant adhesive laminate was obtained. The impact-resistant adhesive layer was bonded so that the ultraviolet irradiation surface was in contact with the polarizing plate. Next, the PET film with a release coat was peeled from the impact-resistant adhesive laminate. Then, the impact-resistant adhesive layers of Examples 1 to 9 and Comparative Examples 1 to 6 are bonded to a non-alkali glass plate (product name “# 1737” manufactured by Corning) with a thickness of 0.7 mm and 4 inches square. A sample for evaluation was prepared.

  Using these evaluation samples, the peak force, peak time, and impact resistance height were measured by the methods described below. The results are shown in Tables 2 and 3.

  A dynamometer (product name: 9255B, rated capacity 200 kN) manufactured by Kistler was fixed on a hard and stable horizontal surface such as marble. The sample for evaluation was fixed to the center of the dynamometer, and a 550 g steel ball was dropped from a height of 10 cm at room temperature. The stress and time at that time were measured using the dynamometer, Kistler charge meter (product name: 5015A), MeasurementComputing analog-digital converter (PC-CARD-DAS16 / 16), and IBM personal computer ( The peak force (kN) and the peak time (μs) were measured by connecting and measuring the product name: Thinkpad T43).

  As shown in FIG. 4, an acrylic plate 61 having a thickness of 1 mm (“Clarex” manufactured by Nitto Jushi Kogyo Co., Ltd.) was placed on a base 62 made of marble or the like. The evaluation samples A of Examples 1 to 9 and Comparative Examples 1 to 6 were placed so that the alkali-free glass plate 4 was in contact with the acrylic plate 61. Subsequently, the iron ball 7 (diameter 5 cm, mass 550 g) was freely dropped from the predetermined height onto each of the evaluation samples A and collided. Thereafter, the presence or absence of appearance defects such as cracks and dents in the sample A for evaluation was visually confirmed. And the lowest value was calculated | required as an impact-resistant height (cm) in the height when the crack or external appearance defect of the sample A for evaluation produced.

(Effect of Example)
In Examples 1 to 9 having the adhesive layer of the present invention, the impact-resistant height was 50 cm or more. From these results, it can be seen that Examples 1 to 9 have excellent impact absorbability and a high restoring force against impact, and can improve the visibility of the display panel.

  Example 5 using an acrylic monomer (2-ethylhexyl acrylate) having no cyclic structure in the molecule as the component (b), and an acrylic monomer (tetrahydrofurfuryl acrylate or isobornyl acrylate) having a cyclic structure in the molecule 2) and 4), both have the same t, but in Examples 2 and 4, E ′ is small and t / E ′ is large. In Examples 2 and 4, the peak force and the peak time are similar to those in Example 5, but the impact resistance height is large. A similar trend is observed in comparison with Examples 3 and 6. From this result, when an acrylic monomer having a cyclic structure in the molecule is used as the component (b), the resilience to impact is enhanced while maintaining excellent shock absorption, and the visibility of the display panel is enhanced. You can see that

  Comparative Examples 1 and 3 have an adhesive layer having t / E 'less than the lower limit. Comparative Examples 1 and 3 have the same peak time and peak force as those of Examples 1 to 9, but the impact resistance height is low. This result shows that Comparative Examples 1 and 3 have a low ability to absorb the impact, and thus the impact resistance is not sufficient. On the other hand, Comparative Examples 2, 4 and 5 have an impact-resistant adhesive layer in which t / E ′ exceeds the upper limit. In Comparative Examples 2 and 4, the peak time is long, but the peak force and the impact resistance height are low. Further, the peak force of Comparative Example 5 is larger than those of Comparative Examples 2 and 4, which is about the same as Examples 1 to 9, but the peak time is short and the impact resistance height is low. This result indicates that in Comparative Examples 2, 4, and 5, the deformation caused by the impact does not return well, the display panel visibility is lowered, and the impact resistance is not sufficient.

  Comparative Example 6 has an adhesive layer where t is outside the scope of the present invention. In Comparative Example 6, the peak force is large, but the peak time is short and the impact resistance height is low. This result shows that the impact resistance is not sufficient because the ability to absorb the impact is low as in Comparative Examples 1 and 3.

  The pressure-sensitive adhesive layer and pressure-sensitive adhesive laminate of the present invention can be applied to various uses that require pressure-sensitive adhesiveness and impact resistance. For example, the pressure-sensitive adhesive layer and pressure-sensitive adhesive laminate of the present invention can be applied to glass for automobiles, glass for building materials, bulletproof glass, etc., in addition to the above-described display devices such as electronic and electric devices.

It is a schematic cross section for demonstrating an example of the impact-absorbing laminated body of this invention. It is a schematic cross section for demonstrating an example of the impact-absorbing laminated body of this invention. It is a schematic cross section for demonstrating an example of the impact-absorbing laminated body of this invention. It is a schematic diagram for demonstrating the impact resistance test of a present Example. It is the graph which plotted t and E 'of Examples 1-9 and Comparative Examples 1-6.

Explanation of symbols

  A: Sample for evaluation, A1, A2, A3; Impact-resistant adhesive laminate, 1; Impact-resistant adhesive layer, 2, 2 '; Protective film layer, 21; Release layer, 3; Functional layer, 4; 61; Acrylic plate, 62; Base, 7; Iron ball.

Claims (5)

Impact resistance with a tensile elastic modulus E ′ of 0.46 to 0.9 MPa, a thickness t of 50 μm or more, and a ratio of the tensile elastic modulus to the thickness (t / E ′) of more than 400 and less than 900 An adhesive layer ,
The impact-resistant adhesive layer contains (A) acrylic syrup, (B) acrylic monomer, (C) silane coupling agent, (D) urethane (meth) acrylate, and (E) a photopolymerization initiator. An impact-resistant adhesive layer, which is an impact-resistant adhesive layer formed by radiation-curing a liquid adhesive composition . The (B) acrylic monomers, impact adhesive layer according to claim 1 further comprising at least one acrylic monomer having a cyclic structure in the molecule. And impact adhesive layer according to claim 1 or 2, wherein the impact pressure-sensitive adhesive laminate which comprises a further layer which is laminated on at least one surface of The impact adhesive layer. The impact-resistant adhesive laminate according to claim 3 , wherein at least one of the other layers is an optical film. A display device comprising the impact-resistant adhesive layer according to claim 1 or 2 and the impact-resistant adhesive laminate according to claim 3 or 4 on a display panel surface.

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