TWI686454B - Adhesive sheet, two-sided adhesive sheet and optical element - Google Patents

Abstract

The invention provides a double-sided adhesive sheet that maintains sufficient adhesion and makes a pattern of a conductive part invisible when applied to a conductive member with the conductive part disposed on a portion of a transparent support body, and the double-sided adhesive sheet provides favorable visibility of the image when used for bonding the conductive member to a display device. The invention relates to a double-sided adhesive sheet used for bonding of a conductive member with a conductive part disposed on a portion of a transparent support body and specifying the haze to be over 10% and less than 20%.

Description

Adhesive sheet, double-sided adhesive sheet and optical member

The present invention relates to a double-sided adhesive sheet for bonding a conductive member provided with a conductive portion on a transparent support, a cover glass, a display device, or the like. In addition, the present invention relates to an optical member in which the double-sided adhesive sheet is bonded to a conductive member.

Conventionally, in electrical products such as smartphones and tablet computers, for example, in order to provide a transparent support with a conductive member provided with a transparent electrode film such as indium tin oxide (ITO), a cover glass, a touch panel, and Two components such as a display device are bonded together, and double-sided adhesive sheets are widely used in the industry.

For example, Patent Document 1 proposes a pressure-sensitive adhesive sheet for metal surface sticking that does not corrode the metal surface, can be easily peeled from the metal surface during secondary processing, and has good transparency.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-077388

The conductive member usually has a structure in which ITO or the like is patterned on a transparent support. If the adhesive sheet described in Patent Document 1 is attached to such a conductive member, although the conductive portion does not corrode, there is a problem that the pattern of the conductive portion is visualized.

In order to solve this problem, the industry considers to prevent the pattern of the conductive portion from being visualized by adjusting the refractive index of the adhesive sheet. However, it is difficult to maintain the adhesive force while adjusting to the desired refractive index. In addition, for the adhesive sheet, it is necessary not only to prevent the pattern of the conductive portion from being visualized, but also to maintain good visibility of the screen when used for bonding the conductive member to the display device, but it is also difficult to balance both.

The object of the present invention is to provide a conductive member provided with a conductive part in a part of a transparent support, while maintaining sufficient adhesion, while making the pattern of the conductive part invisible, and when used in conductive members and A double-sided adhesive sheet with good visibility of the screen when the display device is attached, and an optical member provided with the double-sided adhesive sheet.

In order to solve the above problems, the inventors of the present invention conducted diligent studies and found that by specifying the haze of the double-sided adhesive sheet to be more than 10% and less than 20%, the following double-sided adhesive sheet is realized, which In the case of a conductive member, while maintaining sufficient adhesion, the pattern of the conductive portion is not visible, and the visibility of the screen is also good when used for bonding the conductive member to the display device. Specifically, the present invention has the following structure.

[1] A double-sided adhesive sheet for laminating a conductive member provided with a conductive portion in a part of a transparent support, and characterized in that the haze exceeds 10% and Less than 20%.

[2] The double-sided adhesive sheet according to [1], which is formed of an adhesive composition containing an acrylic polymer (A) and a crosslinking agent (B).

[3] The double-sided adhesive sheet according to [2], wherein the adhesive composition further contains light-diffusing fine particles (C).

[4] The double-sided adhesive sheet according to [2] or [3], wherein the adhesive composition contains 1 part by mass to 15 parts by mass of the light-diffusing fine particles (C) relative to 100 parts by mass of the acrylic polymer (A). Copies.

[5] The double-sided adhesive sheet according to [3] or [4], wherein the average particle diameter of the light-diffusing fine particles (C) is 0.1 μm to 20 μm.

[6] The double-sided adhesive sheet according to any one of [2] to [5], wherein the adhesive composition further contains an incompatible resin (D).

[7] The double-sided adhesive sheet according to any one of [2] to [6], wherein the adhesive composition contains 100 parts by mass of the acrylic polymer (A) and contains an incompatible resin (D) 1 ~50 parts by mass.

[8] A double-sided adhesive sheet with a release sheet having a release sheet on at least one adhesive area layer of the double-sided adhesive sheet according to any one of [1] to [7].

[9] A double-sided adhesive sheet with a release sheet, which is laminated with release sheets having different releasability from each other on both sides of the double-sided adhesive sheet according to any one of [1] to [7].

[10] An adhesive sheet with a transparent base material, which is used for bonding a conductive member provided with a conductive portion in a part of a transparent support, and includes any one of [1] to [7] The laminated structure in which one adhesive surface of the double-sided adhesive sheet is in contact with the transparent substrate layer.

[11] An adhesive sheet with a transparent base material, which is used for bonding of a conductive member provided with a conductive portion in a part of a transparent support, and includes sequentially having any of [1] to [7] The laminated structure of a double-sided adhesive sheet, a transparent base material layer, and a hard coat layer as described in one item, and an adhesive surface of the double-sided sheet is in contact with the transparent base material layer.

[12] An adhesive sheet with a transparent substrate, which is used for bonding a conductive member provided with a conductive portion in a part of a transparent support, and includes a transparent substrate layer in sequence, such as [1] to [7] The laminated structure of the double-sided adhesive sheet and the release sheet described in any one of the above, and one adhesive surface of the double-sided sheet is in contact with the transparent base material layer.

[13] An optical member that is bonded to any one of [1] to [7] on a conductive member provided with a conductive portion in a part of a transparent support, in contact with at least a portion of the conductive portion An adhesive surface of the double-sided adhesive sheet described in the item.

[14] An optical member in which a conductive member provided with a conductive part in part of a transparent support, a double-sided adhesive sheet according to any one of [1] to [7], and The optical member of the transparent base material layer, and at least a part of the conductive portion is in contact with the double-sided adhesive sheet.

[15] An optical member in which a conductive member in which a conductive part is provided on a part of a transparent support, a double-sided adhesive sheet according to any one of [1] to [7], transparent The base member layer and the hard-coated optical member, and at least a part of the conductive portion is in contact with the double-sided adhesive sheet.

According to the present invention, it is possible to realize a double-sided adhesive sheet which, when applied to a conductive member provided with a conductive portion in a part of a transparent support, maintains charging on one side On the one hand, the pattern of the conductive part is not visible, and the visibility of the screen is also good when used for the bonding of the conductive member and the display device.

In addition, if the double-sided adhesive sheet of the present invention is used, it is possible to obtain an optical member in which the conductive portion is not visible and the visibility of the screen is good when it is bonded to the display device.

10: Hard coating

11a, 11b: easy adhesion layer

12: Transparent substrate layer

13: Double-sided adhesive sheet

FIG. 1 is a schematic longitudinal cross-sectional view showing an example of an adhesive sheet with a transparent substrate of the present invention.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In addition, in this specification, the numerical range indicated by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

(1) Double-sided adhesive sheet

The double-sided adhesive sheet of the present invention is used for bonding a conductive member provided with a conductive portion in a part of a transparent support, and is characterized by a haze exceeding 10% and less than 20%. In addition, in the present invention, the "haze" refers to a value measured by a method according to JIS K7136. With regard to the haze value, in the case of the shape of the double-sided adhesive sheet, it is difficult to measure only the double-sided adhesive The haze value of the sheet (in the state without a peeling sheet), therefore, when laminated to a glass slide (model number: S9112) manufactured by Songlang Glass Co., Ltd. to make a laminate of the glass and the double-sided adhesive sheet of the present invention only The haze value is In the case of the shape of the transparent film adhesive sheet of the base material layer, it is the haze value when the transparent substrate layer of the glass and the transparent film adhesive sheet, the double-sided adhesive sheet, and the glass laminate are bonded.

If the double-sided adhesive sheet with a haze within the above range is attached to the conductive member in such a way as to be in contact with the conductive portion, since the haze exceeds 10%, the light incident into the double-sided adhesive sheet diffuses appropriately, and It is difficult to recognize the pattern of the electrode portion from the outside. In addition, the double-sided adhesive sheet has high transparency because the haze is less than 20%. Therefore, when the conductive member is bonded to the display device using the double-sided adhesive sheet, the display screen of the display device can be clearly recognized on the transparent support side of the conductive member. Further, for example, the haze of the double-sided adhesive sheet can be easily adjusted while ensuring the adhesive force by appropriately mixing the light-diffusing fine particles (C). Therefore, by specifying the haze in the above range, a double-sided adhesive sheet can be realized which, when applied to a conductive member, maintains sufficient adhesive force while making the pattern of the conductive portion invisible and is used for conducting electricity The visibility of the screen is also good when the member is attached to the display device. Here, the preferable range of the haze of the double-sided adhesive sheet is 12% to 18%, and the more preferable range is 14% to 16%.

[Adhesive composition]

The adhesive composition forming the double-sided adhesive sheet of the present invention is preferably an adhesive composition having transparency that does not reduce visibility, and as the base polymer of the adhesive composition, preferably an acrylic polymer (A). Thereby, a double-sided adhesive sheet excellent in adhesiveness can be obtained.

(Acrylic polymer (A))

As the acrylic polymer (A), it is preferable to use an acrylic monomer unit having a non-crosslinkable (meth)acrylate unit (a1) as a main component and containing a crosslinkable functional group therein ( a2) copolymer. In this specification, "unit" is a repeating unit (monomer unit) constituting a polymer.

The acrylic monomer unit (a2) having a crosslinkable functional group becomes a reaction point when the crosslinking agent (B) is used, and the adhesive force, cohesive force, and heat resistance can be controlled by crosslinking. The use amount of the acrylic monomer unit (a2) having a crosslinkable functional group in the acrylic polymer (A) is preferably calculated as the ratio of the total monomer mass constituting the copolymer 0.01% by mass to 20% by mass. It is more preferably 0.1% by mass to 15% by mass, and further preferably 0.5% by mass to 10% by mass. If the content of the crosslinkable acrylic monomer unit (a2) is equal to or higher than the lower limit of the above range, it will have sufficient crosslinkability, and if it is equal to or lower than the upper limit of the above range, the desired adhesion can be maintained Physical properties.

Examples of the non-crosslinkable (meth)acrylate unit (a1) constituting the acrylic polymer (A) include methyl (meth)acrylate, ethyl (meth)acrylate and propylene (meth)acrylate Ester, butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, (A (Alkyl) monomers such as isononyl acrylate, lauryl (meth) acrylate, isostearyl (meth) acrylate and other (meth) acrylate monomers, and these may be used in combination of two or more if necessary.

In addition, in the present invention, "(meth)acrylate" includes both "acrylate" and "methacrylate", and "(meth)acrylic acid" includes "acrylic acid" And "methacrylic acid".

In addition, the acrylic monomer unit (a2) having a crosslinkable functional group includes (meth)acrylic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, and fumaric acid. Carboxylic monomers such as oxalic anhydride, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, polyethylene glycol (methyl ) Hydroxy-containing monomers such as acrylates, (meth)acrylamide, morpholinylacrylamide, N,N-dimethylaminoethyl acrylate, N-third butylaminoethyl acrylate, etc. Epoxy groups such as amine group-containing (meth)acrylate, glycidyl (meth)acrylate and the like may be used in combination of two or more if necessary. In addition, when the conductive portion of the conductive member to which the double-sided adhesive sheet of the present invention is bonded is ITO, it is preferable to use a monomer having a functional group other than the carboxyl group-containing monomer, and acrylic having a crosslinkable functional group The ratio of the carboxyl group-containing monomer unit contained in the system monomer unit (a2) relative to the total mass of the acrylic system monomer unit (a2) is preferably 1% or less, more preferably 0.1% or less, and particularly preferably 0%. By setting the ratio of the carboxyl group-containing monomer unit contained in the acrylic monomer unit (a2) within the above range, the corrosion of the metal wiring of the conductive portion can be suppressed.

The acrylic polymer (A) may contain a monomer unit other than the non-crosslinkable (meth)acrylate unit (a1) and the acrylic monomer unit (a2) having a crosslinkable functional group, if necessary. As this other monomer, what is necessary is just to be a monomer copolymerizable with a non-crosslinkable (meth)acrylate and the acrylic monomer which has a crosslinkable functional group, For example, (meth)acrylonitrile, Vinyl acetate, styrene, vinyl chloride, vinyl pyrrolidone, vinyl pyridine, etc.

The content of other monomer units in the acrylic polymer (A) is preferably 0 mass % To 20% by mass, preferably 0% to 15% by mass.

The weight average molecular weight of the acrylic polymer (A) is preferably 100,000 to 2 million, and more preferably 300,000 to 1.5 million. If the weight average molecular weight is equal to or higher than the lower limit, sufficient durability can be ensured, and if the upper limit is not exceeded, sufficient followability of unevenness can be ensured. In addition, the weight average molecular weight of the acrylic polymer (A) is the value before crosslinking by the crosslinking agent (B). The weight average molecular weight is measured by size exclusion chromatography (SEC) and is determined on the basis of polystyrene.

When polymerizing the adhesive, for example, a solution polymerization method can be applied. The solution polymerization method may include an ion polymerization method or a radical polymerization method. Examples of the solvent used at this time include tetrahydrofuran, chloroform, ethyl acetate, toluene, hexane, acetone, and methyl ethyl ketone.

(Crosslinking agent (B))

In the case where the adhesive composition used in the present invention is a copolymer using a monomer having a functional group, the crosslinking treatment can be performed by blending a crosslinking agent (B).

Examples of the crosslinking agent (B) include isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds, and butylated melamine compounds. It is preferably selected in consideration of reactivity with the functional group used in the acrylic polymer (A).

Among these crosslinking agents (B), from the viewpoint of easily crosslinking the acrylic polymer (A), isocyanate compounds and epoxy compounds are preferred. Isocyanic acid Examples of the ester compound include toluene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol diglycidyl ether, and neopentyl glycol diglycidyl ether. Ether, 1,6-hexanediol diglycidyl ether, tetraglycidyl xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl) cyclohexane, trimethylol Propane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, etc.

In the adhesive composition, the content of the cross-linking agent (B) is appropriately selected according to the required adhesive properties, etc., and is not particularly limited. It is preferably 0.01 mass with respect to 100 mass parts of the acrylic polymer (A). Parts to 5 parts by mass, more preferably 0.03 parts to 3 parts by mass. If the content of the cross-linking agent (B) is equal to or greater than the lower limit value, the durability is excellent, and if it is equal to or less than the upper limit value, the adhesion to the adherend is excellent.

In addition, the content of the crosslinking agent (B) relative to the total mass of the adhesive composition is preferably 0.01% by mass to 5.0% by mass, and more preferably 0.02% by mass to 2.0% by mass.

The gel fraction of the cross-linked adhesive composition that has been cross-linked as described above is 20% to 98%, preferably 30% to 90%, and more preferably 40% to 80%. If the gel fraction is 20% or more, sufficient cohesion can be obtained, and if it is 98% or less, sufficient adhesion or wettability to the adherend can be obtained. In addition, the so-called gel fraction described here is expressed as a percentage of a value in which a specific amount of the adhesive composition is immersed in ethyl acetate or methyl acetate in an amount equal to or more than twice the mass of the adhesive composition. In a solvent such as benzene, after treating the impregnated material at 40°C for 24 hours, it is filtered through a 150-mesh wire mesh, and the dry weight of the residue from which the soluble components have been removed is divided by the mass of the adhesive composition before the impregnation Got.

(additive)

In the adhesive composition, in addition to mixing the acrylic polymer (A) and the crosslinking agent (B), when adjusting the haze of the double-sided adhesive sheet, it is also mixed with light-diffusing fine particles (C) And at least one of incompatible resins (D). The light-diffusing fine particles (C) and the incompatible resin (D) will be described in the column of [Adjustment of Haze] described later. In addition, other additives as described below may be added to the adhesive composition.

(i) UV absorber

The ultraviolet absorber can be selected from ultraviolet absorbers having a maximum absorption wavelength in the ultraviolet region, and it is preferable to use an ultraviolet absorber having a maximum absorption wavelength at a wavelength of 350 nm or more. Examples of the ultraviolet absorber having a maximum absorption wavelength at a wavelength of 350 nm or more include compounds represented by the following general formula (1) or (2).

In the above formula, R ¹ represents a hydrogen atom, a halogen atom, a C 1-4 alkoxy group, a nitro group or a cyano group, R ² represents a hydrogen atom or a C 1-8 alkyl group, and R ³ represents an alkyl group Department of structure.

In the above formula, R ⁴ , R ⁵ and R ⁶ are hydrogen atoms, hydroxyl groups, alkyl-based structures or halogen atoms, and R ⁴ , R ⁵ and R ^{6 are} not all hydrogen atoms.

The so-called alkyl-based structure includes a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and other substituents mainly composed of alkyl groups.

Among them, ultraviolet absorbers that can improve compatibility by introducing an alkyl group having a large molecular weight into the aromatic ring of the basic skeleton and show a liquid or oily state at 23°C can be used particularly preferably. Here, the expression of liquid or oily state at 23°C means that even if there is no dilution The release solvent is only a state where the ultraviolet absorber is also fluid.

The content of the ultraviolet absorber in the adhesive composition is preferably 0.5 to 8 parts by mass, more preferably 3 parts by mass relative to 100 parts by mass of the solid content of the adhesive composition (especially acrylic polymer). 8 parts by mass, more preferably 4 to 6 parts by mass. The content of the ultraviolet absorber in the adhesive composition is preferably adjusted so that the ultraviolet transmittance at 380 nm becomes less than 5%. If the content is 3 parts by mass or more, when the thickness of the double-sided adhesive sheet is 25 μm, the transmittance under light at a wavelength of 380 nm becomes 2% or less, so the laminated body using the double-sided adhesive sheet can be used outdoors or at high temperatures In the case of long-term use under severe conditions such as humidity, discoloration or rainbow unevenness caused by the birefringence interference of the laminate (especially the hard coat layer) can also be suppressed. In addition, if it is 8 parts by mass or less, the adhesive properties are not impaired, so it is preferable, and if it is 4 to 6 parts by mass, a transmittance of 2% or less can be obtained more stably, which is preferable. In the present invention, two or more ultraviolet absorbers may be used in combination.

(ii) Other additives

The additives added to the adhesive composition can preferably be exemplified by light stabilizers represented by hindered amine compounds. In addition, antioxidants represented by hindered phenol compounds are also preferably used. Antioxidants are generally classified into primary antioxidants called free radical chain terminators and secondary antioxidants that function as peroxide decomposers. Examples of the primary antioxidants include hindered phenol antioxidants, amine antioxidants, and lactone antioxidants. In addition, secondary antioxidants include phosphorus-based antioxidants and sulfur-based antioxidants.

These antioxidants may be used alone or in combination of two or more. In particular, when anticorrosion effect of ITO is expected, if a primary antioxidant and a secondary antioxidant are used together, the effect is easily obtained, which is preferable.

The content of these additives is preferably 0.03 to 1.5 parts by mass, and more preferably 0.05 to 1.0 parts by mass relative to 100 parts by mass of the acrylic polymer (A). If the content is above the lower limit, the ultraviolet absorbency when used for a long time under high temperature, low temperature, and humid environment can be reliably maintained, and if it is below the upper limit, the transmission at 380 nm can be further prevented The rate increases or the adhesive properties decrease.

The adhesive composition may optionally contain additives other than those mentioned above, such as silane coupling agent and metal corrosion inhibitor. Examples of the silane coupling agent include mercaptoalkoxysilane compounds (for example, mercapto-substituted alkoxy oligomers) and the like. As the metal anticorrosive agent, a type that prevents corrosion by forming a complex with a metal and forming a film on the metal surface is preferred, and a benzotriazole-based metal anticorrosive agent is particularly preferred.

[Adjustment of Haze]

The adjustment of the haze of the double-sided adhesive sheet is preferably carried out by (i) a method of mixing light-diffusing fine particles (C) in an amount of a desired haze in the adhesive composition, or (ii) ) A method of mixing the incompatible resin (D) in the adhesive composition in an amount necessary to achieve haze. In addition, it is also possible to adjust the haze of the double-sided adhesive sheet by combining the methods (i) and (ii). Hereinafter, each method will be described.

The haze of the double-sided adhesive sheet can be mixed in the adhesive composition by using Of the light-diffusing fine particles (C) as an additive, and the content of the light-diffusing fine particles (C) in the adhesive composition is changed to the above range.

The light-diffusing fine particles (C) may be fine particles having a function of diffusing light incident on the double-sided adhesive sheet, and may be organic fine particles or inorganic fine particles.

Examples of the inorganic fine particles include fine particles including silicon oxide, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, alumina, and titanium oxide.

As the organic fine particles, for example, resin particles containing the following components may be used: (meth)acrylic acid such as polystyrene resin, polyolefin resin such as polyethylene or polypropylene, polymethacrylate resin or polyacrylate resin, etc. Resin, epoxy resin, silicone resin, cross-linked polymer with a cross-linked structure formed in these resins, selected from ethylene, propylene, styrene, methyl methacrylate, benzoguanamine, formaldehyde, melamine , Butadiene and other two or more monomers copolymerized resin.

In addition, fine particles containing a silicon-containing compound having an inorganic and organic intermediate structure (for example, Tospearl series manufactured by Meitu Advanced Materials Japan Co., Ltd.) and the like can also be used as the light diffusion fine particles (C).

These light-diffusing fine particles (C) may be used alone or in combination of two or more. In addition, organic fine particles, inorganic fine particles, and fine particles having an inorganic and organic intermediate structure may be used in combination.

Among them, the light-diffusing fine particles (C) used in the present invention are preferably fine particles that do not excessively reduce the total light transmittance of the double-sided adhesive sheet, and are preferably acrylic particles or silicon oxide particles with high transparency.

The shape of the light-diffusing fine particles (C) is not particularly limited, and it is preferably spherical from the viewpoint of uniformly diffusing light.

In addition, the average particle diameter of the light-diffusing fine particles (C) is preferably 0.1 μm to 20 μm, more preferably 0.3 μm to 17 μm, and still more preferably 0.5 μm to 12 μm. Here, in this specification, the "average particle diameter" refers to an arithmetic average value, that is, a transmission electron microscope or a scanning electron microscope is used to measure the maximum length of a particle image of light-diffusing particles (Dmax: The maximum length of 2 points on the outline of the particle image) and the vertical length of the maximum length (DV-max: the shortest length between the two lines when the particle image is sandwiched between two lines parallel to the maximum length), The multiplied average value (Dmax×DV-max) ^{1/2 is} set as the particle size, and the particle size is measured for any 100 light-diffusing particles by this method, and the arithmetic average value is calculated. If the average particle diameter of the light-diffusing fine particles (C) is 20 μm or less, it tends to be difficult to feel the graininess or foreign body sensation when the double-sided adhesive sheet is visually recognized. If the average particle diameter is 0.1 μm or more, it is easy The tendency to adjust the haze of the double-sided adhesive sheet to the desired value.

The content of the light-diffusing fine particles (C) in the adhesive composition is preferably 1 to 15 parts by mass relative to 100 parts by mass of the acrylic polymer (A). If the content of the light-diffusing fine particles (C) in the adhesive composition is 15 parts by mass or less, it is easy to suppress the decrease in total light transmittance, and if it is 1 part by mass or more, it is easy to adjust to the desired haze Propensity.

Regarding the haze of the double-sided adhesive sheet, the type of the incompatible resin (D) in the adhesive composition can be changed by using the incompatible resin (D) mixed as an additive in the adhesive composition Or content, and adjust to the range. Here The incompatible resin refers to a resin with low compatibility with the acrylic polymer (A) of the base polymer. Specifically, when the acrylic polymer (A) and the incompatible resin are mixed, the resin whose haze increases according to the mixing amount is called an incompatible resin. Specifically, when the acrylic copolymer and the resin are mixed at 1:1, the resin whose haze becomes 20% or more is called an incompatible resin. If such an incompatible resin is used, the haze can be controlled within the range of 10% to 20% of the haze of the present invention.

Examples of incompatible resins include adhesion-imparting agents and styrene-based copolymer resins. Examples of the adhesion-imparting agent include rosin resins, terpene resins, terpene phenol resins, coumarone indene resins, styrene resins, xylene resins, phenol resins, and petroleum resins. Among them, the adhesion-imparting agent is preferably a terpene resin, more preferably an aromatic modified terpene resin, and further preferably an aromatic modified hydrogenated terpene resin. As the aromatic modified hydrogenated terpene resin, a tackifier (Anyuan Chemicals, K100) or the like can be used.

The content of the incompatible resin (D) in the adhesive composition with respect to 100 parts by mass of the acrylic polymer (A) is preferably 1 part by mass to 50 parts by mass, preferably 2 parts by mass to 30 parts by mass, It is more preferably 3 to 25 parts by mass, further preferably 5 to 20 parts by mass, and most preferably 8 to 15 parts by mass. In addition, the content will vary depending on the type of incompatible resin added. For example, it is preferable to use an aromatic modified hydrogenated terpene resin or a styrene-acrylic copolymer as the incompatible resin (D ), set to the above range. By setting the content of the incompatible resin (D) within the above range, the decrease in total light transmittance can be suppressed, and it can be easily adjusted to a desired haze.

In addition, the haze of the double-sided adhesive sheet can also be adjusted by using other adhesives having a composition or molecular weight, glass transition temperature (Tg) different from the main adhesive composition, and the like. Examples of such resins include acrylic adhesive compositions, urethane adhesive compositions or polyester adhesive compositions, rubber adhesive compositions, silicone adhesive compositions, etc. having different main compositions.

(Double-sided adhesive sheet with release sheet)

The double-sided adhesive sheet of the present invention can be obtained, for example, by applying an adhesive composition on a release sheet to form a coating film, and heating the coating film to obtain a cured product.

The release sheet is a sheet having releasability on at least one side. Examples of the release sheet include a peelable laminate sheet having a substrate for a release sheet and a release agent layer provided on one side of the substrate for the release sheet, or a polyolefin such as a polyethylene film or a polypropylene film as a low-polarity substrate membrane.

Paper and polymer films are used as the base material for the release sheet in the release laminate sheet. As the release agent constituting the release agent layer, for example, a general-purpose addition-type or condensation-type silicone-based release agent or a compound containing a long-chain alkyl group can be used. Additive silicone release agents with high reactivity can be used particularly well.

Specific examples of the silicone-based release agent include BY24-4527, SD-7220, etc. manufactured by Toray Dow Corning Silicone Corporation, or KS-3600, KS-774, X62-2600, etc. manufactured by Shin-Etsu Chemical Industry Co., Ltd. In addition, it is preferred that the silicone-based release agent contains a silicone resin as an organic silicon compound having SiO ₂ units and (CH ₃ ) ₃ SiO _1/2 units or CH ₂ =CH(H ₃ )SiO _1/2 units. . Specific examples of the silicone resin include BY24-843, SD-7292, SHR-1404, etc. manufactured by Toray Dow Corning Silicone Corporation, KS-3800, X92-183, etc. manufactured by Shin-Etsu Chemical Industry Co., Ltd.

Regarding the peeling sheet, in order to facilitate peeling, it is preferable that the peelability of one peeling sheet and the other peeling sheet are different from each other. That is, if the peelability from one peeling sheet is different from the peelability from another peeling sheet, it is easy to peel only the peeling sheet having high peelability first. In this case, it suffices to adjust the releasability of one release sheet and the other release sheet according to the bonding method or bonding sequence.

The application of the adhesive composition forming the double-sided adhesive sheet can be carried out using a known application device. Examples of the coating device include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, and a die lip Coater, die coater, curtain coater, etc.

The coating liquid contains a solvent. Examples of solvents include methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, n-hexane, n-butanol, methyl isobutyl ketone, methyl butyl ketone, ethyl butyl ketone, and cyclohexane Ketone, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, N-methyl-2-pyrrolidone, etc. These may be used alone or in combination of two or more.

The coating film can be heated using a known heating device such as a heating furnace or an infrared lamp.

[Thickness of double-sided adhesive sheet]

The thickness of the double-sided adhesive sheet is preferably 10 μm to 200 μm, and more preferably 20 μm to 100 μm. If the thickness of the double-sided adhesive sheet is 10 μm or more, sufficient adhesive force can be ensured, and even if it is used for a long time, it is not likely to swell or peel. In addition, if the thickness of the double-sided adhesive sheet is 200 μm or less, for example, when the double-sided adhesive sheet is cut to the size of the display device, the adhesive adheres to the cutting blade, etc., resulting in a defect rate. Advantages of upgrade failure.

(2) Adhesive sheet with transparent substrate

The adhesive sheet with a transparent base material of the present invention is used for bonding a conductive member provided with a conductive portion in a part of a transparent support, and includes the double-sided adhesive sheet of the present invention and an adhesive with the double-sided adhesive sheet Transparent substrate layer in surface contact. The transparent substrate layer may also contain a hard coat layer. In the case of laminating the transparent base material layer and the hard coat layer, it is preferable to provide an easy adhesion layer between the transparent base material layer and the hard coat layer. The aspect shown in FIG. 1 is an example of an adhesive sheet with a transparent substrate of the present invention, which is a double-sided adhesive sheet 13, an easily adhesive layer 11b, a transparent substrate layer 12, an easily adhesive layer 11a, and The hard coat layer 10 is formed by stacking.

Hereinafter, the transparent base material layer, the hard coat layer, and the easy-adhesion layer will be described.

[Transparent substrate layer]

The transparent base material layer functions as a base material that reinforces the adhesive sheet, or is used as an anti-scattering film or a decorative film of a conductive member using a glass base material. In addition, the transparent base material layer may be a layer having optical characteristics (a phase difference layer, etc.). That is, it may be a layer that also functions as an optical function in addition to its function as a base material that reinforces the diffusion adhesive layer.

The transparent base material layer contains a transparent material that transmits visible light, and for example, a film of transparent resin can be suitably used. Examples of the transparent resin film include polyethylene terephthalate (PET) film, polyethylene naphthalate film, polytrimethylene terephthalate film, and polybutylene terephthalate film. Ester film, Polypropylene naphthalate film, Polyethylene film, Polypropylene film, Cellophane, Diethyl cellulose film, Triethyl Acrylic cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, Polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyetheramide film, polyimide film, fluororesin film, polyamide film, acrylic resin film, etc. Among these, polyethylene terephthalate (PET) film can be preferably used from the viewpoint of excellent heat resistance.

The transparent substrate layer constituting the transparent substrate-attached adhesive sheet of the present invention may be a single layer or may include multiple layers. When including multiple layers, the transparent base material layer may contain different polyester resins.

The thickness of the transparent base material layer constituting the adhesive sheet with a transparent base material of the present invention is not particularly limited, and for example, it may be 10 μm or more, or may be selected within a range of 20 μm or more and 50 μm or more. The upper limit varies depending on the application, and for example, it can be selected within a range of 1 cm or less, 1 mm or less, and 300 μm or less.

The haze of the transparent base material layer constituting the adhesive sheet with a transparent base material of the present invention is preferably 5 or less, more preferably 3 or less, and still more preferably 1 or less.

[Hard coating]

The hard coat layer is a layer higher in hardness than the transparent substrate layer, and has a function of preventing scratches on the surface of the adhesive sheet with the transparent substrate.

The hard coat layer is preferably a layer having high hardness and transmitting visible light. In the case of a general hard coat layer, the centerline average roughness defined in JIS B 0601 is preferably 1 nm to 20 nm, and more preferably 10 nm or less. The centerline average roughness can be measured using, for example, an ultra-depth shape measuring microscope manufactured by Keyence Corporation.

The hard coat layer may be anti-reflection, anti-glare, or anti-watermark (in the laminated body of the touch panel module and the display device, in between When there is a structure with a gap, the touch panel module is in contact with the display device when the touch panel is operated, and the abnormality of the contacted part looks like being soaked by water. This abnormality is called a watermark. ) Functional layer. In the case of such a hard coat layer having an anti-glare function or an anti-floating watermark function, the centerline average roughness defined in JIS B 0601 is preferably 20 nm to 500 nm, and more preferably 50 nm to 300 nm. The centerline average roughness can be measured using, for example, an ultra-depth shape measuring microscope manufactured by Keyence Corporation, as described above.

The hard coat layer preferably contains a hard component for imparting hardness. Examples of the hard component include cross-linked polymers. Examples of the cross-linked polymer include monofunctional monomer polymers and polyfunctional monomer polymers. The polyfunctional monomer polymer is preferably a polymer of a polymerizable monomer including a polyfunctional monomer of 3 or more, and more preferably a polymer of a polymerizable monomer including a polyfunctional monomer of 4 or more. For example, a copolymer of a mixed monomer of a trifunctional or higher polyfunctional monomer and a bifunctional monomer may be preferably exemplified. In addition, the monomers referred to here also include oligomers.

The type of monomer that can be used to obtain the cross-linked polymer is not particularly limited, and for example, acrylic monomers can be preferably exemplified. Examples include dipropylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and polyethylene glycol (mass average molecular weight 600). (Meth) acrylate, propylene oxide modified neopentyl glycol di (meth) acrylate, modified bisphenol A bis (a Base) acrylate, tricyclodecane dimethanol di(meth)acrylate, polyethylene glycol (mass average molecular weight 400) di(meth)acrylate and other bifunctional (meth)acrylates, pentaerythritol tri(meth) Base) acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethoxytri(meth)acrylate, polyether tri(meth)acrylate, glycerol propoxytri( Trifunctional (meth)acrylates such as meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol ethoxytetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate , Propionic acid modified dipentaerythritol penta (meth) acrylate, di pentaerythritol monohydroxy penta (meth) acrylate, di pentaerythritol hexa (meth) acrylate and more than 4 functional (meth) acrylate.

The monomer or oligomer of the organic compound having a polymerizable unsaturated group may be thermosetting or active energy ray hardening.

In addition, the "(meth)acrylic acid" in this invention is a general term of acrylic acid and methacrylic acid.

The hard coat layer may also contain soft ingredients. If the hard coat layer contains a soft component, the occurrence of cracks and the like can be prevented. Examples of the flexible component include tricyclodecane methylol di(meth)acrylate, bisphenol F ethylene oxide modification di(meth)acrylate, bisphenol A ethylene oxide modification Di(meth)acrylate, isocyanuric acid ethylene oxide modified di(meth)acrylate, polypropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, etc. 2 Functional (meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylpropane propylene oxide modification Tri(meth)acrylate, trimethylpropane ethylene oxide modification Trifunctional (meth)acrylates such as tri(meth)acrylates, (meth)acrylate carbamates, polyester (meth)acrylates, polyethers (Meth) acrylate, etc.

In addition, the crosslinked polymer may contain inorganic particles and/or organic particles. If inorganic particles and/or organic particles are contained, it is preferable in terms of suppressing curing shrinkage of the coating film. Examples of the inorganic particles include inorganic oxide particles such as silicon oxide particles, titanium dioxide particles, zirconium oxide particles, aluminum oxide particles, tin dioxide particles, antimony pentoxide particles, and antimony trioxide particles. Examples of the organic particles include resin particles such as acrylic resin, polystyrene, polysiloxane, melamine resin, benzoguanamine resin, polytetrafluoroethylene, cellulose acetate, polycarbonate, and polyamide.

When inorganic particles are used, reactive inorganic oxide particles treated with a coupling agent may also be used. When organic particles are used, reactive organic oxide particles treated with a coupling agent may also be used. By treating with a coupling agent, the bonding force with the acrylic polymer can be improved. As a result, the surface hardness and scratch resistance can be improved, and further the dispersibility of the inorganic oxide particles and organic particles can be improved.

Examples of the coupling agent include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and γ-glycidoxypropane Trimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriethoxyaluminum, etc. These may be used alone or in combination of two or more. The processing amount of the coupling agent is preferably 0.1 to 20 parts by mass, and more preferably 1 to 10 parts by mass relative to 100 parts by mass of the inorganic oxide particles or organic particles.

The thickness of the hard coat layer is not particularly limited, for example, it can be set to 0.5 μm or more, It can also be selected within the range of 1.0 μm or more and 2.0 μm or more. The upper limit varies depending on the application, and for example, it can be selected within a range of 100 μm or less, 50 μm or less, and 20 μm or less.

[Easy adhesion layer]

The easy-adhesion layer is disposed between the transparent substrate layer and the hard coat layer, and has a function of adhering the layers to each other. In addition, the easy-adhesion layer can also be disposed between the double-sided adhesive sheet and the transparent substrate layer or hard coat layer.

The easy-adhesion layer preferably contains acrylic resin or polyester resin. Moreover, you may contain a urethane resin etc. as needed.

The acrylic resin used for the easy-adhesion layer is exemplified by the acrylic resin polymerized by the acrylic monomer shown below. For example, alkyl acrylate or alkyl methacrylate having a linear, branched, or cyclic alkyl group, a hydroxyl group-containing monomer, an epoxy group-containing monomer, and an amide group-containing group Monomers, etc., but not limited to these. In addition, these monomer components may be copolymerized using two or more kinds.

In addition, as the polyester-based resin, a polyester-based resin that is polycondensed with a polybasic acid component and a polyhydric alcohol component is exemplified. Examples of the polybasic acid used include terephthalic acid, isophthalic acid, and diphenylcarboxylic acid. In addition, the polyol component may include ethylene glycol, diethylene glycol, etc., but it is not limited to these. In addition, these monomer components may be copolymerized using two or more kinds.

The urethane-based resin is exemplified by a urethane-based resin obtained as a reaction product of a polyol compound and an isocyanate compound. Examples of the polyol compound used include polyester polyols, polyether diols, and polyacetal diols. another In addition, examples of the isocyanate compound include toluene diisocyanate, benzene diisocyanate, and the like, but are not limited thereto. In addition, two or more of these components may be reacted. Furthermore, if necessary, a chain length extender, a crosslinking agent, etc. can also be used.

In the easy-adhesion layer, in order to impart slippage or adjust the refractive index, particles may be added. Examples of the particles include inorganic pigments and organic fillers. Since the refractive index is relatively close to the resin of the easy-adhesion layer and high transparency can be obtained, it is preferable to use silicon oxide. In addition, particles used for the purpose of adjusting the refractive index of the easy-adhesion layer include alumina-silica composites, titanium oxide, zirconium oxide, zinc oxide, etc., but are not limited to these. In addition, two or more types of these particles may be used.

In the easy-adhesion layer, various additives such as antistatic agent, ultraviolet absorber, and plasticizer can be added as needed. In addition, in order to improve coating adaptability or reactivity, a surfactant or a pH adjusting agent may be added.

The thickness of the easy-adhesion layer is not particularly limited. For example, it can be set to 0.1 nm or more, or it can be selected within a range of 1 nm or more and 5 nm or more. The upper limit varies depending on the application, and for example, it can be selected within a range of 1 μm or less, 100 nm or less, and 50 nm or less.

The method for forming the easy-adhesion layer is not particularly limited. In the case where the polyester resin is used for the transparent base material layer, it is preferable to melt and extrude the polyester-based resin before forming the easy-to-form on the polyester-based resin sheet Adhesive layer. After being melted and extruded, the polyester resin sheet is stretched 3 times to 10 times in the longitudinal direction to form a longitudinally stretched polyester resin film, and corona discharge treatment is performed if necessary. The easy-adhesive layer is coated on at least one side thereof, and dried to form the easy-adhesive layer. Afterwards, by placing the film with an easily adhesive layer in the lateral direction Stretched 3 times to 10 times, and when forming a biaxially stretched polyester resin film, an easy-adhesion layer stretched in the transverse direction is formed at the same time.

In addition, as another method, the polyester-based resin and the resin for the easy-adhesion layer may be simultaneously extruded to form a laminated film, and the laminated film may be biaxially stretched by a factor of 9 to 100 by a known method. The formation of easy adhesion layer.

In addition, when laminating the adhesive layer or the hard coat layer, the surface treatment may be performed by a known method such as corona discharge treatment or flame treatment, if necessary.

[Peeling layer]

With regard to the adhesive sheet with a transparent base material of the present invention, a peeling layer may be formed on the side of the double-sided adhesive sheet opposite to the side on which the transparent base material layer or hard coat layer is formed. Since the adhesive sheet with a transparent substrate contains an adhesive, if it is exposed, it may adhere to an undesirable object, or the double-sided adhesive sheet itself may deteriorate. Therefore, in order to physically and chemically protect the double-sided adhesive sheet, a peeling layer may be provided in advance on the surface of the double-sided adhesive sheet, and the peeling layer is peeled off during use to expose the double-sided adhesive sheet, and then bonded to other members.

Examples of the peeling layer include a peeling layer in which a peeling agent such as silicone is applied to various plastic films to form a peeling agent layer, a polypropylene film monomer, etc., and a peeling layer that can be used as a peeling sheet for double-sided adhesive sheets can be used. .

In the adhesive sheet with a transparent substrate constructed in the above manner, the haze of the double-sided adhesive sheet exceeds 10% and is less than 20%. When applied to a conductive member, the double-sided adhesive sheet can provide sufficient adhesion It adheres to the conductive part side of the conductive member, and can make the pattern of the conductive part invisible. In addition, the adhesive sheet with transparent substrate When the display device is further provided on the side opposite to the side with the conductive member, the display screen of the display device can be well recognized on the transparent support side of the conductive member.

(3) Optical components

The optical member of the present invention is formed by bonding the double-sided adhesive sheet of the present invention to a conductive member provided with a conductive portion in a part of a transparent support. In this conductive member, the surface of the transparent support on which the conductive portion is not formed functions as a non-conductive portion. The double-sided adhesive sheet of the present invention is bonded in direct contact with at least a part of a conductive portion of a conductive member, preferably in direct contact with at least a part of a conductive portion and at least a part of a non-conductive portion. For the structure of the double-sided adhesive sheet, please refer to the column of (1) Double-sided adhesive sheet.

In addition, the optical member of the present invention may be an optical member configured by bonding an adhesive sheet with a transparent base material of the present invention to a conductive member provided with a conductive portion on a part of a transparent support. In other words, the optical member of the present invention can be bonded to the conductive member provided with the conductive portion in a part of the transparent support, and then on the side of the double-sided adhesive sheet opposite to the conductive member, At least one of the transparent substrate layer and the hard coating layer may be provided, and an easy adhesion layer may be further provided between the double-sided adhesive sheet and the transparent substrate layer or the hard coating layer, and between the transparent substrate layer and the hard coating layer . For the configuration of the transparent base material layer, the hard coat layer, and the easy-adhesion layer, refer to the description of the configuration of the transparent base material layer, hard coat layer, and easy-adhesion layer that constitute the adhesive sheet with a transparent base material.

Hereinafter, the transparent support and the conductive portion of the conductive member constituting the optical member will be described.

[Transparent Support]

As the transparent support of the conductive member, any support including a transparent material commonly used in optical members such as glass can be used. According to the application of the present invention, even if, for example, a transparent support including glass is damaged, the double-sided adhesive sheet can suppress the scattering of glass, thereby improving the safety of the product.

[Conducting Department]

The conductive portion is a layer containing a conductive material, and is formed on the transparent support in a pattern corresponding to the purpose of the conductive member.

Regarding the conductive portion, for example, when the optical member is applied to a surface type capacitive touch panel or the like, it is formed by having the following layers: a uniform layer having substantially uniform conductive properties in the in-plane direction; and The electrode layer is formed around the electrode layer in a pattern corresponding to the extraction electrode and the like. In addition, when this optical member is applied to a touch panel of a projection type electrostatic capacitance method, the conductive portion is formed as a conductive layer that regularly patterns conductive performance. In this projection type capacitive touch panel, the surface of the transparent support on which the conductive portion is not formed functions as a non-conductive portion for position detection. In addition, a protective film for preventing oxidation of the conductive film may be further formed on the conductive portion.

The conductivity of the conductive layer can be expressed by, for example, the surface resistance measured by the method described in JIS-K7194. In order to make an electrode plate for a touch panel, the surface resistance is preferably 1×10 ⁵ Ω/sq or less. 1×10 ³ Ω/sq or less. In addition, the surface resistance is preferably 0.1 Ω/sq or more. The range of the surface resistance of the conductive layer is preferably 0.1 Ω/sq to 1×10 ⁵ Ω/sq, more preferably 0.1 Ω/sq to 1×10 ³ Ω/sq.

On the other hand, for the non-conductive portion, in order to allow the touch panel to perform more accurate position detection, for example, it is preferable to set the surface resistance measured by the method described in JIS-K6911 to 1×10 ⁹ Ω/sq or more. It is preferably 1×10 ¹¹ Ω/sq or more and 1×10 ¹³ Ω/sq or less, and more preferably 1×10 ¹² Ω/sq or less, and the insulation is clearly performed. The range of the surface resistance of the non-conductive portion is preferably 1×10 ⁹ Ω/sq to 1×10 ¹³ Ω/sq, more preferably 1×10 ¹¹ Ω/sq to 1×10 ¹² Ω/sq.

As the material of the conductive portion, a known conductive substance can be applied. As the conductive substance, an inorganic material can also be used. Examples of the inorganic material include gold, silver, copper, aluminum, nickel, or cobalt, or indium-tin oxide (ITO), indium- Oxidation of metals such as zinc oxide (Indium Zinc Oxide, IZO), zinc oxide (Zinc Oxide, ZnO), or zinc-tin oxide (Zinc Tin Oxide, ZTO), or antimony-tin oxide (Antimony Tin Oxide, ATO) Thing. As the conductive substance, an organic conductor may be used. Examples of the organic conductor include conductive carbon materials such as conductive carbon nanotubes and graphene, and conductive polymers such as polythiophene and polyaniline, but are not limited thereto. For those.

Among them, as an inorganic-based material, ITO can be optimally used in terms of high reliability and excellent transparency and conductivity. In addition, in terms of having excellent flexibility and excellent transparency and conductivity, poly(3,4-ethylene di), which is a kind of polythiophene as an organic conductive polymer, can also be suitably used. Oxythiophene)-polystyrene sulfonic acid (Poly(3,4-ethylenedioxythiophene)/Poly(styrenesulfonate), PEDOT/PSS). PEDOT/PSS means a polymer in which PEDOT (a polymer of 3,4-ethylenedioxythiophene) and PSS (a polymer of styrenesulfonic acid) coexist Complex.

Compared with conductors with relatively good transparency like ITO or PEDOT/PSS, metals or conductive carbon materials have poor transparency. Therefore, when using metal or conductive carbon materials as the material of the conductive layer 2, it is preferable to use The metal or conductive carbon material used is nanowired and coated, or processed into a mesh to ensure transparency. Among them, since silver is the most excellent electrical conductor, it can be suitably used.

The thickness of the conductive portion must be set in consideration of the conductivity, transparency, etc. of the applied conductor, so although the thickness is not particularly limited, for example, it is preferably 30Å to 600Å in the case of a metal system. In the case of an oxide system or an organic system, the thickness is 80Å to 5000Å.

The conductive portion can be formed by a known method.

Specifically, the conductive portion can be formed by a method of providing a conductive layer on the transparent substrate by various printing methods, etc., or after a uniform conductive layer is formed, a part of it can be removed by etching or the like Conductive part. Examples of a method for forming a uniform conductive layer include vacuum deposition, sputtering, ion plating, spray pyrolysis, chemical plating, electroplating, coating, and combinations of these. law. From the viewpoint of the film formation rate, the formability of a large-area film, or productivity, the vacuum evaporation method or the sputtering method is preferred.

In order to improve adhesion, appropriate pretreatments such as corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, sputtering etching treatment, or primer treatment may be applied to the surface of the laminate before the formation of the conductive portion.

The optical member constructed in the above-mentioned manner has a haze After 10% and less than 20%, the double-sided adhesive sheet adheres to the conductive member with sufficient adhesive force, and makes the pattern of the conductive portion invisible. In addition, when bonding to the display device, the display screen of the display device can be well recognized on the transparent support side of the conductive member.

[Example]

The characteristics of the present invention will be described in more detail with examples and comparative examples below. The materials, usage amounts, ratios, processing contents, processing order, etc. shown in the following examples can be appropriately changed as long as they do not depart from the gist of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the specific examples shown below.

[1] Production of double-sided adhesive sheet

(Example 1 to Example 4)

Nitrogen was sealed in a reaction device equipped with a stirrer, thermometer, reflux cooler, dropping device, and nitrogen introduction tube, and then ethyl acetate as a solvent was injected. Next, 60% by mass of butyl acrylate (Butyl Acrylate, BA), 36% by mass of methyl acrylate (Methyl Acrylate, MA), and 4% by mass of 2-hydroxyethyl acrylate (2-Ethylhexyl Acrylate, 2EHA) were put into the reaction device. %, and put 0.1% by mass of azobisisobutyronitrile as a reaction initiator to perform a polymerization reaction, and then inject a solvent into the reaction liquid to obtain an acrylic polymer solution. To this acrylic polymer solution, 0.8 mass parts of a crosslinking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., (Cronade Coronate) L55E) was added at a ratio shown in Table 1 with respect to 100 mass parts of the solid content. And light diffusing particles (manufactured by Soken Chemical Co., Ltd., MX-1000 (average particle diameter: 10 μm)) to obtain the adhesive composition of Examples 1 to 4.

This adhesive composition was applied to the surface of the release agent layer of the first release sheet (Mitsubishi Resin Co., Ltd., MRV#50) by an applicator, and dried at 100°C for 2 minutes to obtain an adhesive layer (double Surface adhesive sheet). Next, the peeling agent layer side of the second peeling sheet (Mitsubishi Resin Co., Ltd., MRE#38) was overlapped with the adhesive layer, and bonded with a bonding machine. Thereby, a double-sided adhesive sheet having the first release sheet and the second release sheet was obtained. The coating amount of the adhesive layer after drying was 25 μm.

(Example 5 to Example 7)

The light-diffusing particles were changed to KMR-3TA (average particle diameter: 3 μm) manufactured by ZK Chemical Co., Ltd., and the number of added parts was changed to the ratio shown in Table 1, except that it was the same as in Example 1.

[2] Fabrication of adhesive sheet with transparent substrate layer

(Example 8 to Example 11)

The adhesive composition of Example 1 to Example 4 was applied on the surface of the release agent layer of the release sheet (Mitsubishi Resin Co., Ltd., MRE#38) by an applicator, and dried at 100° C. for 2 minutes to obtain Adhesive layer. Next, the easy-adhesive layer side of the transparent base material layer (manufactured by Toyobo Co., Ltd., A4100#100, PET film with easy-adhesive layer on one side) was overlapped with the adhesive layer, and bonded by a laminating machine, and The adhesive sheets with transparent substrates of Examples 8 to 11 were obtained. The coating amount of the adhesive layer after drying was 25 μm.

(Comparative Example 1 to Comparative Example 3)

The addition amount of the light-diffusing particles added to the adhesive composition was changed as shown in Table 1, except that a transparent substrate layer was prepared in the same manner as in Example 5. Adhesive sheet.

[Evaluation]

1. Haze

The second peeling sheet of the double-sided adhesive sheet of Examples 1 to 7 was peeled off, one side of the double-sided adhesive sheet was attached to a glass slide (model number: S9112) manufactured by Songlang Glass Co., Ltd., and the first peeling off Piece peeling. Moreover, the adhesive surface of the adhesive sheet with a transparent base material layer of Example 8-Example 11 and Comparative Example 1-Comparative Example 3 was bonded to the glass slide (model number: S9112) manufactured by Songlang Glass Co., Ltd. The haze of these patches was measured using NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd.

2. Non-visualization of conductive parts

An electrode member in which an ITO pattern is formed on a transparent support is prepared, and on this electrode member, the double-sided adhesive sheet of the laminate produced in each example and each comparative example is bonded in contact with the ITO pattern. When the laminates of Examples 1 to 7 are used, the peeling sheet is peeled off after bonding. Then, whether the ITO pattern is visible from the transparent support side of the electrode member is visually observed and evaluated based on the following criteria.

◎: ITO pattern is not recognized at all

○: ITO pattern is hardly seen

△: Recognize the ITO pattern

×: The ITO pattern is clearly recognized

3. Visibility of the picture

Electrode member of the bonded product used in the non-visual evaluation of the conductive part On the opposite side, a display device is further provided. Then, the screen was visually observed from the transparent support side of the electrode member, and the visibility of the screen was evaluated according to the following criteria.

○: Easy to see the picture

△: Slightly difficult to see the picture

×: Difficult to see the picture

The above evaluation results are shown in Table 1.

As shown in Table 1, the double-sided adhesive sheets of Examples 1 to 7 and the transparent substrate adhesive sheets of Examples 8 to 11 with haze exceeding 10% and less than 20% are made of ITO. The pattern is not visualized, and the visibility of the picture is also good. On the other hand, the adhesive sheets with a transparent base material layer of Comparative Example 1 and Comparative Example 2 with a haze of 10% or less did not make the ITO pattern invisible, and the transmission of Comparative Example 3 with a haze of 20% or more When the display device is installed, the adhesive sheet of the light base material layer has poor visibility of the screen.

(Example 12 to Example 13)

Except that the light-diffusing particles added to the adhesive composition were changed to incompatible resins, and the addition amount was changed as shown in Table 2, Example 12 and Example 13 were obtained in the same manner as Example 1 .

As shown in Table 2, in the double-sided adhesive sheet in which the incompatible resin is added to adjust the haze to more than 10% and less than 20%, the ITO pattern is not visible, and the visibility of the screen is also good.

10: Hard coating

11a, 11b: easy adhesion layer

12: Transparent substrate layer

13: Double-sided adhesive sheet

Claims (13)

A double-sided adhesive sheet is used for laminating a conductive member provided with a conductive part in a part of a transparent support, and is characterized in that the haze exceeds 10% and is less than 20%. The sheet is formed of an adhesive composition containing an acrylic polymer (A) and a crosslinking agent (B), and the adhesive composition further contains an incompatible resin (D), which is incompatible resin (D) It is a styrene acrylic copolymer and/or aromatic modified hydrogenated terpene. The double-sided adhesive sheet as described in item 1 of the patent application range, wherein the adhesive composition further contains light-diffusing fine particles (C). The double-sided adhesive sheet as described in item 1 of the patent application range, wherein the adhesive composition contains 1 to 15 parts by mass of light-diffusing fine particles (C) with respect to 100 parts by mass of the acrylic polymer (A). The double-sided adhesive sheet as described in item 2 of the patent application scope, wherein the average particle diameter of the light-diffusing fine particles (C) is 0.1 μm to 20 μm. The double-sided adhesive sheet as described in item 1 of the patent application scope, wherein the adhesive composition contains 1 part by mass to 50 parts by mass of the incompatible resin (D) relative to 100 parts by mass of the acrylic polymer (A) Quality parts. A double-sided adhesive sheet with a release sheet having a release sheet on at least one adhesive area layer of the double-sided adhesive sheet as described in any one of claims 1 to 5. A double-sided adhesive sheet with a release sheet, which has a releasable layer laminated on both sides of the double-sided adhesive sheet as described in any one of claims 1 to 5 Separate peeling pieces. An adhesive sheet with a transparent base material, which is used for bonding a conductive member provided with a conductive portion in a part of a transparent support, and includes any one of the patent application items 1 to 5 The laminated structure in which one adhesive surface of the double-sided adhesive sheet is in contact with the transparent substrate layer. An adhesive sheet with a transparent substrate, which is used for bonding a conductive member provided with a conductive part in a part of a transparent support, and includes any of the following items 1 to 5 of the patent application scope In one aspect, an adhesive surface of the double-sided adhesive sheet is laminated with a transparent substrate layer and a hard coat layer, and an adhesive surface of the double-sided adhesive sheet is in contact with the transparent substrate layer. An adhesive sheet with a transparent base material, which is used for bonding a conductive member provided with a conductive part in a part of a transparent support, and includes a transparent base material layer in sequence, such as patent application items 1 to The laminated structure of the double-sided adhesive sheet and the release sheet according to any one of item 5, and one adhesive surface of the double-sided adhesive sheet is in contact with the transparent base material layer. An optical member, which is attached to a conductive member provided with a conductive portion in a part of a transparent support, and is in contact with at least a portion of the conductive portion as in Patent Application Items 1 to 5 An adhesive surface of the double-sided adhesive sheet according to any one of the items. An optical member in which a conductive member provided with a conductive part in a part of a transparent support is sequentially laminated, a double-sided adhesive sheet as described in any one of items 1 to 5 of the patent application, and The optical member of the transparent substrate layer, and the guide At least a part of the electrical part is in contact with the double-sided adhesive sheet. An optical member in which a conductive member provided with a conductive part in part of a transparent support is laminated in sequence, such as the double-sided adhesive sheet described in any one of the patent application items 1 to 5, transparent The base member layer and the hard-coated optical member, and at least a part of the conductive portion is in contact with the double-sided adhesive sheet.

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