TW201734166A - Adhesive sheet - Google Patents

Abstract

Provided is an adhesive sheet wherein an adhesive layer, which contains an adhesive resin and a tackifier, is directly laminated on a base. The adhesive layer of the adhesive sheet is composed of a multilayer structure that comprises at least a layer (X[beta]) having a surface ([beta]), which is directly laminated on the base, and a layer (X[alpha]) having an adhesive surface ([alpha]). Predetermined intensity ratios of the layer (X[alpha]) and the layer (X[beta]) as calculated from Raman spectra of the layer (X[alpha]) and the layer (X[beta]) obtained by means of Raman spectroscopy are regulated to be within specific ranges.

Description

Adhesive sheet

The present invention relates to adhesive sheets.

A general adhesive sheet is composed of a substrate, an adhesive layer formed on the substrate, and a release material provided on the adhesive layer as needed. When used, when the release material is provided, the adhesive sheet is peeled off. The release material abuts the surface of the exposed adhesive layer against the adherend and attaches it.

However, in such an adhesive sheet, in order to exhibit high adhesion to the adherend, an adhesive composition of a material for forming an adhesive layer contains an viscous agent together with an adhesive resin.

For example, Patent Document 1 discloses a heat-sensitive adhesive sheet obtained by coating a heat-sensitive adhesive on a substrate, the heat-sensitive adhesive containing an acrylic polymer having a carboxyl group and a specific amount of a tackifier or a solid. Plasticizers, and epoxy compounds.

Further, Patent Document 2 is an adhesive sheet which is laminated on a specific vinyl chloride resin sheet substrate and laminated with an adhesive layer containing an acrylic copolymer and a tackifier composed of a specific monomer.

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 08-060128

Patent Document 2: Japanese Patent Laid-Open No. Hei 10-017830

However, as described in Patent Documents 1 and 2, the adhesive sheet having the adhesive layer of the tackifier containing the oligomer component has a tendency to lower the adhesion between the substrate and the adhesive layer over time. The peeling occurs at the interface between the substrate and the adhesive layer.

According to the review by the present inventors, it has been found that the tackifier in the adhesive layer of the adhesive sheet is likely to be biased toward the side of the substrate due to the passage of time. In this case, the layer between the substrate and the adhesive layer is dense. The property is lowered, and the interface between the substrate and the adhesive layer is easily peeled off.

The present invention has been made in view of the above problems, and an object thereof is to provide an adhesive sheet which has good adhesion and maintains excellent interlayer adhesion between a substrate and an adhesive layer.

The present inventors have found that the following adhesive sheet can solve the above problems, and thus the present invention is completed by directly laminating an adhesive sheet comprising an adhesive layer of an adhesive resin and a tackifier on a substrate, the adhesive The coating layer is a multilayer structure of two or more layers, and the specific parameters indicating the distribution of the tackifier in each layer constituting the multilayer structure are adjusted to an appropriate range.

That is, the present invention provides the following [1] to [13].

[1] An adhesive sheet obtained by directly laminating an adhesive layer comprising an adhesive resin and a tackifier on a substrate, wherein the adhesive layer has at least a layer (Xα) and a layer (Xβ). The multilayer structure is composed of a layer (Xα) comprising an adhesive surface (α), the layer (Xβ) comprising a surface (β) directly laminated with the substrate, and a layer (Xα) and a layer (Xβ) ) meet the following requirements (I) and (II), (I): In the Raman spectrum of the layer (Xα) obtained by Raman spectroscopy, the intensity ratio I(Xα) of the layer (Xα) calculated by the following formula (1) is 0.30 to 20.00. , Element (II): In the Raman spectrum of the layer (Xβ) obtained by Raman spectroscopy, the intensity ratio of the layer (Xβ) calculated by the following formula (1) is higher than that of the layer (Xβ) (Xα). The intensity ratio is smaller than I(Xα), and the formula (1): the intensity ratio I = [the peak height derived from the peak of the above-mentioned tackifier] / [the peak height of the peak derived from the components other than the above-mentioned tackifier].

[2] The adhesive sheet according to [1] above, wherein the strength ratio I (Xβ) of the layer (Xβ) is from 0 to 15.0.

[3] The adhesive sheet according to the above [1] or [2], wherein the ratio of the intensity ratio I (Xβ) of the layer (Xβ) to the intensity ratio I(Xα) of the layer (Xα) [I(Xβ)/I (Xα)] is 0 to 0.90.

[4] The adhesive sheet according to any one of [1] to [3] wherein the layer (Xβ) forming material, that is, the composition (xβ), comprises the aforementioned adhesive resin, and substantially Does not contain the aforementioned tackifier.

[5] The adhesive sheet according to any one of the above [1] to [4] wherein the layer (Xα) forming material, that is, the composition (xα), comprises 100 parts by mass of the above-mentioned adhesive resin, and the mass of the tackifier 1 described above. More than one.

[6] The adhesive sheet according to any one of the above [1], wherein the adhesive layer is at least a plurality of layers (Xβ), a layer (Y1), and a layer (Xα). Construct.

[7] The adhesive sheet according to the above [6], wherein the intensity ratio I of the layer (Y1) calculated by the above formula (1) in the Raman spectrum of the layer (Y1) measured by Raman spectroscopy (Y1) is 0~15.0.

[8] The adhesive sheet of the above [6] or [7], wherein the layer (Y1) calculated by the above formula (1) in the Raman spectrum of the layer (Y1) obtained by Raman spectroscopy The ratio [I(Y1)/I(Xα)] of the intensity ratio I(Y1) to the intensity ratio I(Xα) of the layer (Xα) is 0 to 0.90.

[9] The adhesive sheet according to any one of the above [6] to [8] wherein the layer (Y1) is a layer containing fine particles.

[10] The adhesive sheet according to the above [9], wherein the composition (y1) which is a material for forming the layer (Y1) contains 15 to 100% by mass of the fine particles.

[11] The adhesive sheet according to [9] or [10] above, wherein the surface (?) of the layer (X?) has an amorphous concave portion.

[12] The adhesive sheet according to any one of the above [9], wherein the surface (α) of the layer (Xα) has a concave portion, and the concave portion is formed by simultaneously drying at least a layer (Xα). That is, the coating film (xα') composed of the composition (xα) and the coating film (y1') which is a composition (y1) which is a material forming the layer (Y1), and the adhesive agent In the process of forming the self-discipline of the layer, the self-formation of the disordered shape is naturally formed.

[13] The adhesive sheet according to any one of [1] to [12] wherein the tackifier comprises a rosin-based tackifier, a terpene-based tackifier, a styrene-based tackifier, and a source. One or more of the tackifiers from petroleum.

The adhesive sheet of the present invention has good adhesion while maintaining good interlayer adhesion between the substrate and the adhesive layer.

1, 1a, 1b‧‧‧ adhesive sheets

2‧‧‧Easy-adhesive adhesive sheets

11‧‧‧Substrate

12‧‧‧Adhesive layer

12a‧‧‧Surface (α)

12b‧‧‧Surface (β)

121‧‧‧ profile

13‧‧‧ recess

14‧‧‧flat surface

15‧‧‧Microparticles

50‧‧‧Laser illumination device

51‧‧‧Inspired laser

52‧‧‧Raman scattered light

Fig. 1 is a schematic cross-sectional view showing the adhesive sheet of an example of the structure of the adhesive sheet of the present invention.

Fig. 2 is a schematic cross-sectional view for explaining the operation of obtaining a Raman spectrum by Raman spectroscopy for each layer of the adhesive layer of the adhesive sheet.

Fig. 3 is a schematic cross-sectional view showing the attachable adhesive sheet as an example of the constitution of the easy-adhesive adhesive sheet in the same state of the present invention.

Fig. 4 is a schematic plan view showing the surface (α) when the adhesive layer of the easy-adhesive adhesive sheet of the present invention is observed from the surface (α) side.

Fig. 5 is a graph showing the relationship between the measurement position (distance from the surface (β)) and the intensity ratio I of the measurement position in the adhesive layer of the adhesive sheet produced in Example 1.

Fig. 6 is a rectangular view of an optional 8 mm long by 10 mm wide on the exposed surface (α) of the adhesive layer of the adhesive sheet prepared in Example 1 by using a digital microscope from the surface (α) side of the adhesive layer. A binarized image of the image of the enclosed area (D). And the black portion of the binarized image corresponds to a flat surface, and the white portion corresponds to a concave portion.

Fig. 7 is a arbitrarily selected rectangular shape of 8 mm long by 10 mm wide on the exposed surface (α) of the adhesive layer of the adhesive sheet prepared in Example 2, using a digital microscope from the surface (α) side of the adhesive layer. A binarized image of the image of the enclosed area (D). And the black portion of the binarized image corresponds to a flat surface, and the white portion corresponds to a concave portion.

Fig. 8 is a rectangular view of an optional 8 mm long by 10 mm wide on the exposed surface (α) of the adhesive layer of the adhesive sheet prepared in Example 3, using a digital microscope from the surface (α) side of the adhesive layer. A binarized image of the image of the enclosed area (D). And the black portion of the binarized image corresponds to a flat surface, and the white portion corresponds to a concave portion.

In the present invention, for example, "the YY containing the XX component as the main component" or the "YY mainly composed of the XX component" means that "the component having the highest content among the components contained in YY is the XX component". The content of the specific XX component described in the above is usually 50% by mass or more, preferably 65 to 100% by mass, more preferably 75 to 100% by mass, even more preferably the total amount (100% by mass) of YY. 85~100% by mass.

In the present invention, for example, "(meth)acrylic acid" means "acrylic acid". Other similar terms are the same as "methacrylic acid".

Further, in the case of a preferred numerical range (for example, a range of contents, etc.), the lower limit and the upper limit of the step are described as being independently combinable. For example, based on the description of "better 10~90, better 30~60", it is also possible to combine "better lower limit (10)" and "better upper limit (60)" to become "10~60". .

[Composition of the adhesive sheet of the present invention]

The adhesive sheet of the present invention is formed by directly laminating an adhesive layer containing an adhesive resin and a tackifier on a substrate, the adhesive layer being composed of a multilayer structure having at least a layer (Xα) and a layer (Xβ), the aforementioned The layer (Xα) contains an adhesive surface (α), and the aforementioned layer (Xβ) contains a surface (β) directly laminated with the aforementioned substrate.

First, the constitution of the adhesive sheet of the present invention will be described. Fig. 1 is a schematic cross-sectional view showing an example of the constitution of an adhesive sheet of the present invention.

As the adhesive sheet in the same state of the present invention, for example, as shown in Fig. 1(a), the adhesive sheet 1a of the adhesive layer 12 is directly laminated on the substrate 11. The adhesive sheet 12 of the adhesive sheet 1a of Fig. 1(a) is composed of a multilayer structure having two layers of a layer (Xα) and a layer (Xβ), and the layer (Xα) contains a layer attached to the adherend. The adhesive surface (α) 12a, the layer (Xβ) includes a surface (β) 12b directly laminated with the substrate 11 described above.

Further, in the same state of the present invention, as shown in FIG. 1(b), the layer (Xβ), the layer (Y1), and the layer (Xα) may be used as the substrate 11 side. The adhesive sheet 1b of the adhesive layer 12 formed by the three-layered multilayer structure in the order of lamination.

Further, from the viewpoint of handleability, the adhesive sheets 1a and 1b shown in Fig. 1 may be formed by laminating a release material on the adhesive surface (α) 12a of the adhesive layer 12.

Further, by forming each of the layers of the multilayer structure constituting the pressure-sensitive adhesive layer 12 into two adjacent layers, which are formed of mutually different compositions, the boundary between the two layers is formed.

For example, in the adhesive sheet 1a of Fig. 1(a), the composition (x?) which is a material for forming the layer (X?) is different from the composition (x?) which is a material for forming the layer (X?).

Further, in the adhesive sheet 1b of Fig. 1(b), the material for forming the layer (Y1), that is, the material for forming the composition (y1) and the layer (Xα), that is, the constituent material (xα) and the layer (Xβ) are formed. The object (xβ) is different. However, in the constitution of the adhesive sheet 1b, the composition (xα) and the composition (xβ) may be different from each other or may be the same.

Further, the adjacent two layers included in the multilayer structure may be in a state in which one of the boundaries of the two layers is partially mixed.

That is, in the adhesive layer 12 of the adhesive sheet 1a of Fig. 1(a), a state in which one of the boundaries of the layer (Xα) and the layer (Xβ) is partially mixed, and the adhesive of the adhesive sheet 1b of Fig. 1(b) The layer 12 may be in a state in which a boundary between the layer (Xα) and the layer (Y1) and at least one of the boundaries of the boundary between the layer (Y1) and the layer (Xβ) are partially mixed.

Also, based on the view of the adhesive sheet which is improved in burst resistance The layer (Y1) is preferably a layer containing fine particles.

The content of the fine particles in the layer (Y1) is preferably from 15 to 100% by mass, more preferably from 20 to 95% by mass, even more preferably from 25 to 90% by mass, based on the total mass (100% by mass) of the layer (Y1). More preferably 30 to 85% by mass, and even more preferably 35 to 80% by mass.

On the other hand, the layer (Xα) and the layer (Xβ) may contain fine particles, and the layer (Xα) and the layer (Xβ) are improved from the viewpoint of improvement in adhesion and adhesion between the substrate and the adhesive layer. The smaller the content of the microparticles contained in the ), the better.

The content of the microparticles in the layer (Xβ) and the layer (Xα) is independently independent of the total mass (100% by mass) of the layer (Xβ) or the layer (Xα), preferably less than 15% by mass, more preferably 0 to 13% by mass. %, more preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and even more preferably 0% by mass.

[Adhesive layer]

The adhesive sheet of the adhesive sheet of the present invention contains an adhesive resin and a tackifier, but preferably contains a crosslinking agent. Further, the adhesive layer may contain a general-purpose additive as needed within a range not impairing the effects of the present invention.

Further, from the viewpoint of being an adhesive sheet having improved burst resistance, the adhesive sheet of the adhesive sheet of the present invention preferably contains fine particles.

The adhesive sheet of the present invention preferably has an adhesive layer thickness of from 1 to 300 μm, more preferably from 5 to 150 μm, even more preferably from 10 to 75 μm.

The adhesive storage layer of the adhesive sheet of the present invention preferably has a shear storage elastic modulus at 100 ° C of 9.0 × 10 ³ Pa or more, more preferably 1.0 × 10 ⁴ Pa or more, and still more preferably 2.0 × 10 ⁴ Pa above.

Further, in the present invention, the shear storage elastic modulus at 100 ° C of the adhesive layer means a measurement value measured at a frequency of 1 Hz using a viscoelasticity measuring device (for example, a device name "DYNAMIC ANALYZER RDA II" manufactured by Rheometrics Co., Ltd.). .

The adhesive force of the surface (α) of the adhesive layer of the adhesive sheet of the present invention is preferably 0.5 N/25 mm or more, more preferably 2.0 N/25 mm or more, still more preferably 3.0 N/25 mm or more, and even more preferably 4.0. N/25mm or more, and even more preferably 7.0N/25mm or more.

Further, the value of the adhesive force of the adhesive sheet specifically means a value measured by the method described in the examples.

Hereinafter, each component contained in the adhesive layer of the adhesive sheet in the same state of the present invention will be described.

(adhesive resin)

The adhesive resin contained in the adhesive layer may be, for example, an acrylic resin, an urethane resin, a rubber resin, or a polyoxyn resin, as long as it has adhesiveness.

These adhesive resins may be used singly or in combination of two or more.

Among these, the adhesive resin preferably contains an acrylic resin and a rubber-based resin, and more preferably an acrylic resin, from the viewpoint of good adhesion properties and weather resistance.

Further, when the adhesive layer contains a crosslinking agent, the adhesive resin preferably contains a resin having a functional group, and more preferably contains an acrylic resin having a functional group.

The functional group is a group which is a starting point for crosslinking with a crosslinking agent, and examples thereof include a hydroxyl group, a carboxyl group, an epoxy group, an amine group, a cyano group, a ketone group, an alkoxyalkyl group, and the like, and are preferably a carboxyl group.

Further, the adhesive resin is preferably an ultraviolet non-curing adhesive resin, and more preferably an ultraviolet non-curing acrylic resin, from the viewpoint of maintaining good adhesion characteristics depending on the use environment.

Moreover, the "ultraviolet non-curing adhesive resin" means an adhesive resin which does not have a polymerizable functional group reactive with ultraviolet rays.

The mass average molecular weight (Mw) as the adhesive resin is usually 10,000 or more, preferably 10,000 to 2,000,000, more preferably 30,000 to 1.5 million, and even more preferably 50,000 to 1.3 million, and even more preferably 10 Ten thousand to 1.1 million.

The content of the adhesive resin in the adhesive layer is preferably 10% by mass or more, more preferably 20% by mass or more, more preferably 30% by mass or more, based on the total amount of the adhesive layer (100% by mass). It is 40% by mass or more, and preferably 99.9% by mass or less, more preferably 99.0% by mass or less.

In particular, in the adhesive layer having a fine particle content of less than 3% by mass, the content of the adhesive resin is preferably 50% by mass or more, more preferably 60% by mass or more based on the total amount of the adhesive layer (100% by mass). More preferably, it is 70% by mass or more, and preferably 99.9% by mass or less, more preferably 99.0% by mass or less.

In addition, in this specification, the term "total amount of adhesive layer" can be changed. It is read as "the amount of the active ingredient of the composition which is the material forming the adhesive layer". Further, the "active component of the composition" means a component other than the diluent solvent among the components of the composition.

(tackifier)

The tackifier used in the present invention is a component which assists in improving the adhesive property of the adhesive resin, and refers to an oligomer having a mass average molecular weight (Mw) of usually less than 10,000, which is different from the above adhesive resin.

The mass average molecular weight (Mw) of the tackifier is usually less than 10,000, but is preferably from 400 to 8,000, more preferably from 500 to 5,000, more preferably from 800 to 3,500.

The tackifier preferably contains at least one selected from the group consisting of a rosin-based tackifier, a terpene-based tackifier, a styrene-based tackifier, and a petroleum-based tackifier.

Further, these tackifiers may be used singly or in combination of two or more softening points or different structures.

Examples of the rosin tackifier include rosin-based resins such as rosin resins, rosin ester resins, and rosin-modified phenol resins, and hydrogenated rosin-based resins obtained by hydrogenating these rosin-based resins.

Examples of the terpene-based tackifiers include terpene resins such as terpene resins, aromatic modified terpene resins, and terpene phenol resins, and hydrogenated terpene resins such as hydrogenated these terpene resins. .

The styrene-based tackifier is exemplified by a styrene-based resin obtained by copolymerizing a styrene-based monomer such as α-methylstyrene or β-methylstyrene with an aliphatic monomer, and the like. Hydrogenation of vinyl resin A styrene resin or the like.

As a petroleum-derived tackifier, for example, a C5-based petroleum obtained by copolymerizing a C5 fraction such as pentene, isoprene, piperine, or 1,3-pentadiene which is formed by thermal cracking of petroleum brain is obtained. a hydrogenated petroleum resin of the resin and the C5-based petroleum resin; a C9-based petroleum resin obtained by copolymerization of a C9 fraction such as hydrazine or vinyl toluene which is formed by thermal cracking of a petroleum brain, and a hydrogenated petroleum resin of the C9-based petroleum resin. .

The softening point as the tackifier is preferably 80 ° C or more, more preferably 80 to 180 ° C, more preferably 83 to 170 ° C, and even more preferably 85 to 150 ° C.

Further, in the present invention, the "softening point" of the tackifier means a value measured in accordance with JIS K2531.

Further, when two or more kinds of the plurality of tackifiers are used, it is preferred to adjust the content ratio of the plurality of tackifiers so that the weighted average of the softening points of the plurality of tackifiers falls within the above range.

The tackifier content is preferably 1 part by mass or more, more preferably 1 to 200 parts by mass, more preferably 3 to 150 parts by mass, more preferably 100 parts by mass of the adhesive resin contained in the adhesive layer. 5 to 90 parts by mass.

(crosslinking agent)

The adhesive layer of the adhesive sheet of the present invention preferably contains a crosslinking agent, particularly as an adhesive resin, and more preferably contains the crosslinking agent together with a resin having a functional group.

Examples of the crosslinking agent include, for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent.

Further, these crosslinking agents may be used singly or in combination of two or more.

Examples of the isocyanate crosslinking agent include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; isophorone diisocyanate and hydrogenation. An alicyclic polyisocyanate such as diphenylmethane diisocyanate; and a uretide, isocyanurate body of the same, and a compound having a low molecular weight active hydrogen (ethylene glycol, propylene glycol, neopentyl glycol, An adduct of a reactant of trimethylolpropane, castor oil, or the like;

Examples of the epoxy crosslinking agent are, for example, ethylene glycol diglycidyl ether, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'- Tetraglycidyl-m-xylylenediamine, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine, and the like.

Examples of the aziridine-based crosslinking agent are, for example, diphenylmethane-4,4'-bis(1-aziridine carboxamide), trimethylolpropane tris-β-aziridine propionate, and four. Methyl hydroxymethyl methane tri-β-aziridine propionate, toluene-2,4-bis(1-aziridine carboxamide), tri-ethyl melamine, bis-m-xylylene-1- 2-methylaziridine), tri-1-(2-methylaziridine)phosphine, trimethylolpropane tri-β-(2-methylaziridine) propionate, and the like.

The metal chelate-based crosslinking agent is exemplified by a chelate compound in which the metal atom is aluminum, zirconium, titanium, zinc, iron, tin, or the like. However, it is preferred to form a concave portion on the surface (α) of the adhesive layer. Aluminum chelate crosslinking Agent.

Examples of the aluminum chelate crosslinking agent are, for example, aluminum diisopropoxide, monooleylacetate, monoisopropoxy aluminum bisacetoacetate, and monoisopropoxy aluminum. Ethyl monoethylacetate acetate, aluminum dilaurate, monolaurylacetate, diisopropoxy aluminum monostearyl acetate, diisopropoxide aluminum Stearyl ethyl acetate and the like.

When the crosslinking agent layer contains a crosslinking agent, the content of the crosslinking agent is preferably 0.01 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the adhesive resin contained in the adhesive layer. It is more preferably 0.3 to 7.0 parts by mass.

(general additive)

The adhesive layer of the adhesive sheet of the same state of the present invention may also contain a general-purpose additive used in general adhesives.

Examples of the general-purpose additive are, for example, an antioxidant, a softener (plasticizer), a rust preventive, a pigment, a dye, a retarder, a reaction accelerator, an ultraviolet absorber, and the like.

Further, these general-purpose additives may be used alone or in combination of two or more.

When the general-purpose additive is contained in the pressure-sensitive adhesive layer, the content of each of the general-purpose additives is preferably 0.0001 to 60 parts by mass, more preferably 0.001 to 50 parts by mass, per 100 parts by mass of the adhesive resin contained in the pressure-sensitive adhesive layer.

(microparticles)

The adhesive layer of the adhesive sheet in the same state of the present invention preferably contains fine particles based on the viewpoint of being an adhesive sheet having improved burst resistance.

By forming the adhesive layer containing fine particles, the shape maintaining property of the adhesive layer when the obtained adhesive sheet is attached to the adherend can be improved, and when the adhesive sheet is used at a high temperature, the occurrence of burst can be effectively suppressed. .

The average particle diameter of the fine particles is preferably from 0.01 to 100 μm, more preferably from 0.05 to 25 μm, still more preferably from 0.1 to 10 μm.

The fine particles are not particularly limited, and examples thereof include inorganic particles such as cerium oxide particles, oxidized metal particles, barium sulfate, calcium carbonate, magnesium carbonate, glass beads, and bentonite, and organic particles such as acrylic beads.

These fine particles may be used singly or in combination of two or more.

Among these fine particles, one or more selected from the group consisting of cerium oxide particles, oxidized metal particles and bentonite are preferred, and cerium oxide particles are more preferred.

The cerium oxide particles used in the same state of the present invention may be either dry cerium oxide or wet cerium oxide.

Further, the cerium oxide particles used in the same state of the present invention may be an organically modified cerium oxide surface-modified with an organic compound having a reactive functional group, or an inorganic surface treated with an inorganic compound such as sodium aluminate or sodium hydroxide. An organic-inorganic modified cerium oxide modified with cerium oxide, an organic-inorganic modified cerium oxide surface-treated with the organic compound and the inorganic compound, or an organic-inorganic hybrid material such as a decane coupling agent.

Further, the cerium oxide particles may be a mixture of two or more kinds.

As the oxidized metal particles, for example, selected from oxidation Also included in the particles of titanium, aluminum oxide, boehmite, chromium oxide, nickel oxide, copper oxide, titanium oxide, zirconium oxide, indium oxide, zinc oxide, and oxidized metals of the composite oxides thereof A sol particle formed by an oxidized metal.

Examples of the bentonite include, for example, montmorillonite, aluminum bentonite, sodium hectorite, saponite, saponite, nontronite, and zinc bentonite.

When the microparticles are contained in the adhesive layer, the content of the microparticles is preferably from 3 to 90% by mass, more preferably from 5 to 80% by mass, based on the total amount of the adhesive layer (100% by mass). It is 7 to 70% by mass, and more preferably 9 to 60% by mass.

<Layer composition of adhesive layer>

The adhesive sheet of the present invention has an adhesive layer composed of a multilayer structure having at least a layer (Xα) and a layer (Xβ), and the layer (Xα) and the layer (Xβ) satisfy the following requirements (I) and (II) By.

. (I): In the Raman spectrum of the layer (Xα) obtained by Raman spectroscopy, the intensity ratio I(Xα) of the layer (Xα) calculated by the following formula (1) is 0.30 to 20.00. .

. Element (II): In the Raman spectrum of the layer (Xβ) obtained by Raman spectroscopy, the intensity ratio of the layer (Xβ) calculated by the following formula (1) is higher than that of the layer (Xβ) (Xα). The intensity of the ) is smaller than I(Xα).

Formula (1): strength ratio I = [peak height derived from the peak of the above-mentioned tackifier] / [peak height of a peak derived from a component other than the above-mentioned tackifier].

In this specification, "by Raman spectroscopy The Raman spectrum obtained means a graph showing the relationship between the Raman shift and the Raman scattering intensity with the Raman scattering intensity as the vertical axis and the Raman shift as the horizontal axis.

As a method of specifically obtaining the Raman spectrum, as shown in FIG. 2, the surface (α) 12a and the surface (β) 12b of the adhesive layer 12 to be measured can be orthogonally adhered. The cross section 121 of the agent layer 12 is obtained by detecting the Raman scattered light 52 generated when the laser irradiation device 51 is vertically irradiated from the laser irradiation device 50 by a detector to obtain a Raman spectrum.

The "peak derived from a tackifier" in the above formula (1) means a peak generated by the presence of a tackifier in a Raman spectrum obtained by measuring a target layer by a Raman scattering spectrometry.

Similarly, the "peak derived from a component other than the tackifier" means a peak generated by the presence of a component other than the tackifier in the Raman spectrum obtained by measuring the target layer by the Raman scattering spectrometry as described above.

In addition, the "component other than the tackifier" means a component other than the tackifier contained in the adhesive layer, and is not only an adhesive resin but also a general-purpose additive such as a crosslinking agent to be added as needed.

However, the amount of the general-purpose additive such as a crosslinking agent is small compared with the adhesive resin. Therefore, when the adhesive layer formed of the adhesive composition excluding the tackifier is measured, the peak intensity derived from the general-purpose additive in the Raman spectrum observed is relatively weak compared with the peak derived from the adhesive resin. Therefore, the stronger peak in the Raman spectrum is substantially identical to the adhesive resin of the main component. Therefore, in fact, "the peak derived from a component other than the tackifier" can be considered to be derived from the peak of the adhesive resin.

Moreover, in the above formula (1), "the peak derived from the tackifier" and "Crests derived from components other than tackifiers" means peaks selected by the following (i) to (iv).

Further, a specific example method for calculating the "intensity ratio I of each layer" after measurement by Raman spectroscopy can be described in Examples to be described later.

(i) an adhesive sheet having an adhesive layer (a) formed of a composition containing a tackifying resin and a tackifier and containing a general-purpose additive such as a crosslinking agent as needed, as shown in FIG. The adhesive sheet 1 is also provided. Next, as shown in FIG. 2, the cross-section 121 of the adhesive layer (a) in the adhesive sheet is from the side of the surface (β) 12b toward the surface (α) 12a side, along the direction P, from 0.5 to 0.5 The range of 1 μm is selected to be shifted from the measurement position at regular intervals, and the excitation laser 51 is irradiated from the laser irradiation device 50 in the vertical direction, and the Raman spectrum (Ra) of the adhesive layer (a) at each measurement position is measured.

(ii) preparing an adhesive sheet of the adhesive layer (b) having a composition of the same composition and content as the composition of the material forming the adhesive layer (a) other than the "tackifier", for the adhesive layer The Raman spectrum (Rb) of the adhesive layer (b) was measured by Raman spectroscopy at any position on the cross section of (b) under the same conditions as in the above (i).

(iii) For Raman spectroscopy (Ra) and (Rb), a Raman scattering intensity ratio is calculated for each Raman shift. At this time, the Raman scattering intensity of the peak (p _a ) of the specific Raman shift (r) of the Raman spectrum (Ra) exceeds the peak (p _b ) of the same Raman shift (r) of the Raman spectrum (Rb). When the Raman scattering intensity is 10 times, the peak (p _a ) of the Raman spectrum (Ra) is judged as "the peak derived from the tackifier". The peak height calculated in the peak (p _a ) is "the height of the peak derived from the peak of the tackifier".

Further, in the case of (iii), when there is a complex peak, in the Raman spectrum (Ra), the peak having the strongest Raman scattering intensity in the peak is selected.

(iv) In the Raman spectrum (Ra), the other peak in the above (iii) which is not determined to be "the peak derived from the tackifier" is set to "the peak derived from the component other than the tackifier", and is calculated in the peak The peak height is "the peak height from the peak of the component other than the tackifier".

Further, in (iv), when there is a complex peak, in the Raman spectrum (Rb), the presence or absence of the tackifier in the peak is less affected by the Raman scattering intensity, and the Raman scattering intensity is stronger. The peak, but if it is the same degree, you can choose it.

Further, in the above (i), the boundary between the two adjacent layers is used for specifying the measurement site, and can be specified by an optical microscope image of the cross section 121 of the adhesive layer 12.

Further, the boundary line between the substrate 11 and the layer (Xβ) and the boundary line between the layer (Xα) and the air layer can be judged by an optical microscope image, and can also be based on a Raman spectrum obtained by Raman spectroscopy. It is judged by the presence or absence of a peak derived from the component forming the adhesive layer of the adhesive resin and the tackifier.

The Raman shift of "the peak derived from the tackifier" selected by the above (i) to (iv) can be specified to some extent by the type of tackifier as follows.

. Styrenic ^{tackifier: 3100cm -1, 1670cm -1, 1660cm} -1, 1650cm -1, 1600cm -1 ~ 1610cm -1, 1380cm -1, 1000cm -1

. Terpene-based ^{tackifier: 3100cm -1, 1670cm -1, 1660cm} -1, 1650cm -1, 1600cm -1 ~ 1610cm -1, 1380cm -1, 1000cm -1

. Rosin-based ^{tackifier: 1670cm -1, 1660cm -1, 1650cm} -1, 1600cm -1 ~ 1610cm -1, 1380cm -1

Based on the values of the "peak height from the peak of the tackifier" obtained by the above (i) to (iv) and the peak height of the peak derived from the component other than the tackifier, the above formula (1) can be used. The "intensity ratio I" of the individual measurement positions in the cross section 121 of the adhesive layer was calculated.

In the present invention, the "intensity ratio I of each layer" means an average value of the intensity ratios I of all the measurement positions included in the target layer. For example, the "intensity ratio I (Xβ) of the layer (Xβ)" means the average value of the intensity ratio I of all the measurement positions contained in the layer (Xβ). The same is true for the intensity ratio of the layer (Xα) to I(Xα) or the intensity ratio of the layer (Y1) to I(Y1).

In the above requirements (I) and (II), the Raman spectrum obtained by measuring each layer of the multilayer structure constituting the adhesive layer by Raman spectroscopy is indirectly expressed by the "intensity ratio I" calculated from the above formula (I). The ratio of the amount of tackifier present in the components other than the tackifier (mainly adhesive resin) contained in each measurement position.

That is, the "intensity ratio I of each layer" indicates an index of the degree of presence of the tackifier in the target layer, and the layer having a larger value means that the tackifier is more likely to exist in the layer.

As described above, the inventors of the present invention considered that the tackifier in the adhesive layer in the adhesive sheet may be easily biased toward the side of the substrate over time, in which case the adhesion between the substrate and the adhesive layer may be caused. reduce.

Therefore, the adhesive sheet of the present invention is such that the strength ratios I(Xα) and (Xβ) of the layer (Xα) and the layer (Xβ) constituting the adhesive layer satisfy the requirements (I) and (II). The type and content of the adhesive resin and the tackifier of the constituent layer (Xα) and the layer (Xβ) are appropriately adjusted.

For this reason, the adhesive sheet of the present invention can suppress the adhesion of the surface attached to the adherend due to the reduction of adhesion over time and exhibit excellent adhesion by satisfying the requirement (I).

Further, since the adhesive sheet of the present invention is designed to satisfy the requirement (II), it is difficult to bias the adhesive on the substrate side, so that the excellent interlayer adhesion between the substrate and the adhesive layer can be maintained for a long period of time.

In the present invention, as defined in the above requirement (I), the strength ratio I (Xα) of the layer (Xα) including the adhesive surface (α) is 0.30 to 20.00. By this range, it is possible to suppress the adhesion of the adhesive over time and to exhibit an excellent adhesive force, and at the same time, when it is temporarily attached to the adherend, the turbidity which can be suppressed by the adherend can be suppressed. .

Based on the above, the intensity ratio I(Xα) of the layer (Xα) specified by the above requirement (I) is preferably from 0.32 to 15.00, more preferably from 0.35 to 10.00, still more preferably from 0.40 to 8.00, and even more preferably 0.50~5.00, especially good 0.80~3.00.

Further, in the present invention, as defined by the above requirement (II), the intensity ratio I (Xβ) of the layer (Xβ) is smaller than the intensity ratio I (Xα) of the layer (Xα).

When the design layer (Xβ) and the layer (Xα) are satisfied as in the case of the requirement (II), it can be an adhesive sheet which can maintain excellent interlayer adhesion between the substrate and the adhesive layer for a long period of time.

Further, based on the above viewpoint, the intensity ratio I(Xβ) of the layer (Xβ) specified by the above requirement (II) is preferably from 0 to 15.0, more preferably from 0 to 10.0, still more preferably from 0 to 8.0, and furthermore. Good for 0~5.0, and better for 0~3.0, especially Good is 0~1.5.

In the present invention, the intensity ratio I (Xβ) of the layer (Xβ) is preferably 0. In the Raman spectrum of the layer (Xβ) obtained by Raman spectroscopy at the measurement position contained in the layer (Xβ) There is no "peak from the tackifier".

Further, based on the above viewpoint, the ratio [I(Xβ)/I(Xα)] of the intensity ratio I(Xβ) of the layer (Xβ) to the intensity ratio I(Xα) of the layer (Xα) is preferably 0 to 0.90. It is preferably 0 to 0.80, more preferably 0 to 0.70, and even more preferably 0 to 0.50.

The adhesive sheet as in the present invention may be an adhesive sheet 1b as shown in Fig. 1(b), and the adhesive layer 12 is at least layer (Xβ), layer (Y1) and layer (Xα) and in sequence. Adhesive sheets of laminated multilayer structures.

When the adhesive layer is a multilayer structure composed of a layer (Xβ), a layer (Y1), and a layer (Xα), it is more preferable that the layer (Xα) and the layer (Xβ) satisfy the above requirements (I) and (II). The simultaneous layer (Y1) satisfies at least one of the following requirements (III-1) and (III-2), and the better layer (Y1) satisfies both of the following requirements (III-1) and (III-2).

. Element (III-1): In the Raman spectrum of the layer (Y1) obtained by Raman spectroscopy, the intensity ratio I(Y1) of the layer (Y1) calculated by the above formula (1) is 0~ 15.0.

. (III-2): In the Raman spectrum of the layer (Y1) obtained by Raman spectroscopy, the intensity ratio I (Y1) of the layer (Y1) calculated by the above formula (1) is relative to the layer. The ratio [I(Y1)/I(Xα)] of the intensity ratio (Iα) of (Xα) is 0 to 0.90.

The above requirements (III-1) and (III-2) are the adhesive layer containing no surface (α) and The intermediate layer of the surface (β) is defined by the layer (Y1).

Moreover, the intensity ratio I(Y1) of the preferred layer (Y1) is greater than the intensity ratio I(Xβ) of the layer (Xβ), and the intensity ratio I(Y1) of the layer (Y1) is greater than the intensity ratio I of the layer (Xβ). (Xβ) and less than the intensity ratio I(Xα) of the layer (Xα).

By satisfying the requirement (III-1), it is possible to form an adhesive sheet which maintains the adhesion between the substrate and the adhesive layer for a long period of time.

Based on this point of view, the intensity ratio I(Y1) of the layer (Y1) specified by the requirement (III-1) is preferably 0 to 15.0, more preferably 0 to 10.0, and even more preferably 0 to 8.0. Good for 0~5.0, and better for 0~3.0, especially good for 0~1.5.

Further, by satisfying the requirement (III-2), it is possible to form an adhesive sheet which can maintain the adhesion between the substrate and the adhesive layer while maintaining the adhesion.

Based on this point of view, the ratio of the intensity ratio I(Y1) of the layer (Y1) specified by the requirement (III-2) to the intensity ratio I(Xα) of the layer (Xα) [I(Y1)/I(Xα) It is preferably 0 to 0.90, more preferably 0 to 0.85, still more preferably 0 to 0.80, and even more preferably 0 to 0.70.

Further, the above-mentioned "intensity ratio I of each layer" (specifically, "intensity ratio I (Xα) of layer (Xα)", "intensity ratio I (Xβ) of layer (Xβ)", and intensity ratio I of layer (Y1) The value of (Y1)") can be adjusted by appropriately selecting the component type or content of the adhesive resin, the tackifier, and the like in the composition which is the forming material of the target layer.

Hereinafter, the types and contents of the components contained in the composition which is a material for forming each layer will be described, and the adjustment of the "intensity ratio I of each layer" will be described. The agent is explained.

<layer (Xα) forming material, that is, composition (xα)>

In the same state of the present invention, based on the intensity ratio I(Xα) of the adjustment layer (Xα), it is easy to form a layer (Xα) satisfying the requirements (I) and (II), and the formation material of the layer (Xα) is a composition ( Xα) is preferably a composition containing 100 parts by mass of the adhesive resin and 1 part by mass or more of the tackifier.

In view of the above, the content of the tackifier in the composition (xα) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, based on 100 parts by mass of the adhesive resin in the composition (xα). More preferably, it is 10 mass parts or more, and still more preferably 15 mass parts or more.

And, based on the formation of the layer (Xα) satisfying the requirements (I) and (II), the value of the intensity ratio I(Xβ) of the layer (Xβ) and the intensity ratio I(Y1) of the layer (Y1) are adjusted. In the above preferred range, the content of the tackifier in the composition (xα) is preferably 400 parts by mass or less, more preferably 150 parts by mass, based on 100 parts by mass of the adhesive resin in the composition (xα). In the following, it is more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less, and particularly preferably 50 parts by mass or less.

The content of the adhesive resin in the composition (xα) is preferably based on the total amount of the active component (100% by mass) of the composition (xα), based on the fact that the strength ratio I of each layer is adjusted to the above preferred range. 25 mass% or more, more preferably 40 mass% or more, more preferably 50 mass% or more, still more preferably 60 mass% or more, and preferably 99 mass% or less, more preferably 97 mass% or less, and more Good is 95% by mass or less, and even better for 90 quality The amount is preferably 7% by mass or less, and particularly preferably 87% by mass or less.

Further, the composition (xα) preferably contains a crosslinking agent, and may contain the above-mentioned general-purpose additive within a range that does not affect the strength ratio I(Xα) of the layer (Xα) defined by the element (I).

Further, the composition (xα) may contain the above fine particles.

However, the content of the fine particles in the composition (xα) is usually less than 15% by mass, preferably 0 to 13% by mass, more preferably 0%, based on the total amount of the active ingredient (100% by mass) of the composition (xα). ~10% by mass, more preferably 0 to 5% by mass, and even more preferably 0% by mass.

The total content of the adhesive resin and the tackifier in the composition (xα) is preferably 70 to 100% by mass, more preferably 80%, based on the total amount of the active ingredient (100% by mass) of the composition (xα). ~99.9 mass%, more preferably 90-99.5 mass%, and even more preferably 95-99.0 mass%.

The tackifier in the composition (xα) is exemplified by the above, but is based on the viewpoint that the tackifier is prevented from moving toward a layer other than the layer (Xα), and the intensity ratio I of each layer is adjusted to the above preferred range. It is preferable to contain one or more selected from the group consisting of a rosin-based tackifier, a terpene-based tackifier, and a styrene-based tackifier, and more preferably one selected from the group consisting of a rosin-based tackifier and a terpene-based tackifier. the above.

The content of the tackifier selected from the group consisting of a rosin-based tackifier and a terpene-based tackifier is preferably 60% based on the total amount of the tackifier (100% by mass) of the composition (xα). 100% by mass, more preferably 70 to 100% by mass, still more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass.

As an adhesive resin in the composition (xα), based on excellent display From the viewpoint of adjusting the adhesion of the tackifier to the layer other than the layer (Xα) and adjusting the strength ratio I of each layer to the above preferred range, it is preferred to include an acrylic resin, more preferably an acrylic group having a functional group. Resin.

Further, as described above, the acrylic resin is preferably an ultraviolet non-curing acrylic resin.

The acrylic resin may be either a solvent type or an emulsion type.

The content of the acrylic resin is preferably from 25 to 100% by mass, more preferably from 50 to 100% by mass, even more preferably 70% based on the total amount of the adhesive resin (100% by mass) contained in the composition (xα). ~100% by mass, more preferably 80 to 100% by mass, and even more preferably 100% by mass.

The composition (xα) preferably contains an acrylic resin having a functional group and further contains a crosslinking agent.

The crosslinking agent is exemplified as the above-mentioned one, but it is preferably one or more selected from the group consisting of a metal chelate crosslinking agent, an epoxy crosslinking agent, and an aziridine crosslinking agent.

The content of the crosslinking agent is preferably 0.01 to 15 by mass based on 100 parts by mass of the adhesive resin (or the acrylic resin having a functional group or the acrylic copolymer (P) described later) contained in the composition (xα). The portion is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 7.0 parts by mass.

The acrylic resin is exemplified by, for example, a polymer having a constituent unit derived from an alkyl (meth)acrylate having a linear or branched alkyl group, and a composition derived from a (meth) acrylate having a cyclic structure. Unit of polymer, etc.

The mass average molecular weight (Mw) as the acrylic resin is preferably 5 10,000 to 1.5 million, more preferably 150,000 to 1.3 million, and more preferably 250,000 to 1.1 million, and even more preferably 350,000 to 900,000.

In the acrylic resin, it is preferred to have a carbon number derived from the viewpoint of exhibiting excellent adhesion, suppressing migration of the tackifier to a layer other than the layer (Xα), and adjusting the intensity ratio I of each layer to the above preferred range. a constituent unit (p1) of an alkyl (meth)acrylate (p1') (hereinafter also referred to as "monomer (p1')") of an alkyl group of 1 to 18 and a functional group-containing monomer (p2') (hereinafter also referred to as "acrylic copolymer (P)") as a constituent unit (p2) of "monomer (p2')" (hereinafter also referred to as "acrylic copolymer (P)").

Hereinafter, a preferred "acrylic copolymer (P)" in the acrylic resin will be described.

(acrylic copolymer (P))

The copolymerization form of the acrylic copolymer (P) is not particularly limited, and may be any of a block copolymer, a random copolymer, and a graft copolymer.

However, as described above, the acrylic copolymer (P) is preferably an ultraviolet non-curing type.

The method for synthesizing the acrylic copolymer (P) is not particularly limited, and for example, it can be solution-polymerized by dissolving a raw material monomer in a solvent in the presence of a polymerization initiator, a chain transfer agent, or the like, or in emulsification. In the presence of a solvent, a polymerization initiator, a chain transfer agent, a dispersant or the like, the raw material monomers are produced by a method of aqueous emulsion polymerization.

The carbon number of the alkyl group which the monomer (p1') has is preferably from 4 to 12, more preferably from 4 to 8, more preferably from the viewpoint of improving adhesion characteristics. 4~6.

As the monomer (p1'), for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, or (meth)acrylic acid 2- Ethylhexyl ester, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, and the like.

Among these, butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred, and butyl (meth)acrylate is more preferred.

The content of the constituent unit (p1) is preferably from 50 to 99.5% by mass, more preferably from 60 to 99% by mass, even more preferably 70% based on the total constituent unit (100% by mass) of the acrylic copolymer (P). ~97% by mass, and more preferably 80 to 95% by mass.

As the monomer (p2'), for example, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an epoxy group-containing monomer, an amine group-containing monomer, a cyano group-containing monomer, a ketone group-containing monomer, and an alkoxy group-containing group are exemplified. A decyl monomer or the like.

Among these, it is more preferably a carboxyl group-containing monomer.

The carboxyl group-containing monomer is exemplified by (meth)acrylic acid, maleic acid, fumaric acid, oriconic acid, etc., preferably (meth)acrylic acid.

The content of the constituent unit (p2) is preferably from 0.5 to 50% by mass, more preferably from 1 to 40% by mass, even more preferably 1.5, based on the total constituent unit (100% by mass) of the acrylic copolymer (P). ~30% by mass, and more preferably 2 to 20% by mass.

Further, the acrylic copolymer (P) may contain a constituent unit (p3) derived from a monomer (p3') other than the above monomers (p1') and (p2').

As the other monomer (p3'), for example, cyclohexyl (meth)acrylate, Benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate A (meth) acrylate, vinyl acetate, acrylonitrile, styrene or the like having a cyclic structure such as quinone imine (meth) acrylate.

The content of the constituent unit (p3) is preferably from 0 to 30% by mass, more preferably from 0 to 20% by mass, even more preferably 0 to the total constituent unit (100% by mass) of the acrylic copolymer (P). ~10% by mass, and more preferably 0 to 5% by mass.

Further, the above-mentioned monomers (p1') to (p3') may be used alone or in combination of two or more.

<layer (Xβ) forming material, that is, composition (xβ)>

In the same manner as in the present invention, the composition (xβ) which is a material for forming the layer (Xβ) is preferably a composition containing the above-mentioned adhesive resin and substantially containing no such tackifier.

The forming material of each layer, that is, the content of the tackifier in the composition, is one of the factors causing the strength ratio I of the target layer to rise. In other words, by making the layer (Xβ) a layer formed of a composition (xβ) which does not substantially contain a tackifier, the strength of the layer (Xβ) can be made lower than the value of I(Xβ), and it is easy to adjust to The above preferred range, and it is easy to form a layer (Xβ) which satisfies the requirement (II).

In the present specification, the term "substantially no viscosity-increasing agent" means the content of the tackifier, and the total amount of the active ingredient (100% by mass) of the target composition is less than 0.01% by mass (preferably not reached). 0.001% by mass, more preferably less than 0.0001% by mass).

Further, the composition (xβ) preferably contains a crosslinking agent, and may contain the above-mentioned general-purpose additive within a range that does not affect the value of the strength ratio I(Xβ) of the layer (Xβ).

Further, the composition (xβ) may contain the above fine particles.

However, the content of the fine particles in the composition (xβ) is usually less than 15% by mass, preferably 0 to 13% by mass, more preferably 0%, based on the total amount of the active ingredient (100% by mass) of the composition (xβ). ~10% by mass, more preferably 0 to 5% by mass, and even more preferably 0% by mass.

The content of the adhesive resin in the composition (xβ) is usually 65 mass% or more, preferably 70 mass% or more, more preferably 75, based on the total amount of the active component (100 mass%) of the composition (xβ). The mass% or more is more preferably 80% by mass or more, more preferably 85% by mass or more, and usually 100% by mass or less, preferably 99.9% by mass or less, more preferably 99.0% by mass or less.

Further, in the present invention, the strength ratio I (Xβ) of the layer (Xβ) is adjusted to the above preferred range, and when the layer (Xβ) satisfying the requirement (II) is satisfied, not only the composition of the layer (Xβ) but also the composition is considered. In the presence of the tackifier in (xβ), it is also necessary to review the components of the multilayer forming material, that is, the composition, by the migration of the tackifier contained in the other layers such as the suppressing layer (Xα).

In consideration of this point, for example, when the layer (Xα) contains a terpene-based tackifier, the adhesive resin in the composition (xβ) is preferably an acrylic resin.

In other words, the adhesive resin contained in the composition (xβ), which is a material for forming the layer (Xβ), is appropriately selected in accordance with the type of the tackifier contained in the layer (Xα), whereby the layer (Xα) can be suppressed. The adhesion of the tackifier can increase the strength of the layer (Xβ) The value of the ratio I(Xβ) is adjusted to be lower.

The acrylic resin contained in the adhesive (xβ) as the adhesive resin is preferably an acrylic resin having a functional group, more preferably an acrylic copolymer (P).

The details of the "acrylic resin", the "acrylic resin having a functional group", and the "acrylic copolymer (P)" are as described above.

The composition (xβ) preferably contains an acrylic resin having a functional group and a crosslinking agent, and more preferably contains an acrylic copolymer (P) and a crosslinking agent.

The cross-linking agent is exemplified as the above-mentioned one, and is preferably one or more selected from the group consisting of a metal chelate-based crosslinking agent, an epoxy-based crosslinking agent, and an aziridine-based crosslinking agent.

The content of the crosslinking agent is preferably 0.01 to 15 parts by mass, more preferably 0.1% by mass based on 100 parts by mass of the acrylic resin (or acrylic copolymer (P)) having a functional group contained in the composition (xβ). ~10 parts by mass, more preferably 0.3 to 7.0 parts by mass.

<Forming material of layer (Y1) is composition (y1)>

In the same state of the present invention, the composition (y1) which is a material for forming the layer (Y1) may be different from the composition (xα) and (xβ), but preferably satisfies the above requirement (III-1) and The composition of each component type and content is appropriately adjusted in the manner of (III-2).

Further, the adhesive layer contained in the composition (y1) which is a material for forming the layer (Y1) is appropriately selected in accordance with the type of the tackifier contained in the layer (Xα). The grease can also retain the tackifier from the layer (Xα) in the layer (Y1) and inhibit the migration to the layer (Xβ), and as a result, the intensity ratio of the layer (Xβ) can be adjusted to the value of I(Xβ). It is lower.

For example, when the layer (Xα) contains a terpene-based tackifier, the composition (y1) preferably contains an acrylic resin as an adhesive resin, more preferably an acrylic resin having a functional group, and more preferably an acrylic copolymer ( P).

Moreover, the details of the above-mentioned "acrylic resin", "acrylic resin having a functional group", and "acrylic copolymer (P)" are as described above.

When the composition (y1) contains an acrylic resin having a functional group or an acrylic copolymer (P) as an adhesive resin, it preferably contains a crosslinking agent.

The cross-linking agent is exemplified as the above-mentioned one, and is preferably one or more selected from the group consisting of a metal chelate-based crosslinking agent, an epoxy-based crosslinking agent, and an aziridine-based crosslinking agent.

The content of the crosslinking agent is preferably 0.01 to 15 parts by mass, more preferably 0.1% by mass based on 100 parts by mass of the acrylic resin (or acrylic copolymer (P)) having a functional group contained in the composition (y1). ~10 parts by mass, more preferably 0.3 to 7.0 parts by mass.

Further, the composition (y1) may contain the above-mentioned general-purpose additive insofar as it does not affect the value of the intensity ratio I(Y1) of the layer (Y1) or the intensity ratio I of the layer other than the layer (Y1).

Further, in the same state of the present invention, the layer (Y1) is preferably composed of fine particles 15 to 100 based on the viewpoint of being an adhesive sheet having improved burst resistance. A layer formed by the mass % of the composition (y1).

The composition (y1) may be a composition containing no fine particles and an adhesive, but preferably a composition containing fine particles and an adhesive resin.

The content of the fine particles in the composition (y1) is 15 to 100% by mass, preferably 20 to 95% by mass, more preferably 20%, based on the total amount of the active ingredient (100% by mass) of the composition (y1). 90% by mass, more preferably 30 to 85% by mass, and even more preferably 35 to 80% by mass.

Further, in the composition (y1) having a fine particle content of 100% by mass, the content of the adhesive resin and the tackifier was 0% by mass, and the content of the versatile additive to be added was also 0% by mass.

The content of the adhesive resin in the composition (y1) is preferably from 0 to 85% by mass, more preferably from 1 to 80% by mass, based on the total amount of the active ingredient (100% by mass) of the composition (y1). It is preferably 5 to 75% by mass, more preferably 10 to 70% by mass, and even more preferably 20 to 60% by mass.

In the composition (y1) containing an adhesive resin together with the fine particles, the tackifier content is preferably from 0 to 150 parts by mass, more preferably from 0 to 150 parts by mass, based on 100 parts by mass of the adhesive resin of the composition (y1). ~90 parts by mass, more preferably 0 to 60 parts by mass, more preferably 0 to 45 parts by mass, and still more preferably 0 to 10 parts by mass.

When the content of the tackifier in the composition (y1) is in the above range, the layer (Y1) satisfying the requirements (III-1) and (III-2) is easily formed. Further, the strength ratio I (Xβ) of the layer (Xβ) is easily adjusted to the above preferred range, and an adhesive layer containing the layer (Xβ) satisfying the requirement (II) can be formed.

In addition, the content of the tackifier contained in the composition (y1) of 100 parts by mass of the tackifier contained in the composition (xα) is preferably 0 to 100 parts by mass, more preferably 0 to 80 parts by mass, more preferably 0 to 65 parts by mass, and even more preferably 0 to 20 parts by mass.

[substrate]

The substrate to be used in the present invention is not particularly limited, and examples thereof include a paper substrate, a resin film or a sheet, a substrate obtained by laminating a paper substrate with a resin, and the like, and an adhesive sheet according to the present invention. Appropriate use.

Examples of the paper constituting the paper substrate are sheet paper, medium paper, fine paper, impregnated paper, coated paper, coated paper, sulfuric acid paper, cellophane, and the like.

Examples of the resin constituting the resin film or sheet are polyolefin resins such as polyethylene and polypropylene; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and the like. Vinyl resin; polyester resin such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate; polystyrene; acrylonitrile-butadiene-styrene Copolymer; cellulose triacetate; polycarbonate; urethane resin such as polyurethane, acrylic modified polyurethane; polymethylpentene; polyfluorene; polyether ether ketone Polyether oxime; polyphenylene sulfide; polyethylenimine-based resin such as polyether sulfimine or polyimine; polyamine-based resin; acrylic resin; fluorine-based resin.

The base material obtained by laminating the paper base material with a resin is exemplified by laminating the paper base material with a thermoplastic resin such as polyethylene.

Among these substrates, a resin film or a sheet is preferred, preferably The film or sheet made of a polyester resin is more preferably a film or sheet composed of polyethylene terephthalate (PET).

Further, when the adhesive sheet of the present invention is used for applications requiring heat resistance, it is preferably a film or sheet composed of a resin selected from the group consisting of polyethylene naphthalate and a polyimide resin, and is used for weather resistance. In the case of use, it is preferably a film or sheet composed of a resin selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, acrylic resin, and fluororesin.

The thickness of the substrate is appropriately set according to the use of the adhesive sheet of the present invention, but it is preferably from 5 to 1,000 μm, more preferably from 10 to 500 μm, even more preferably from 12 to 250 μm, from the viewpoint of handleability and economy. More preferably 15~150μm.

Further, the substrate may further contain various additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an anti-blocking agent, and a colorant.

Further, the substrate used in the present invention is preferably a non-air permeable substrate, and is preferably a substrate having a metal layer on the surface of the resin film or sheet, from the viewpoint of improving the burst resistance of the obtained pressure-sensitive adhesive sheet.

The metal contained in the metal layer is exemplified by a metal having a metallic luster such as aluminum, tin, chromium or titanium.

The method for forming the metal layer is, for example, a method of depositing the metal by a PVD method such as vacuum deposition, sputtering, or ion plating, or a method of attaching a metal foil made of the above metal using a general adhesive. However, it is preferably a method of vapor-depositing the above metal by a PVD method.

Furthermore, when a resin film or a sheet is used as a substrate, the base is used. From the viewpoint of improving the adhesion to the adhesive layer laminated on the resin film or sheet, a surface treatment or a primer treatment such as an oxidation method or a roughening method may be applied to the surface of the resin film or the sheet.

Examples of the oxidation method include, for example, a corona discharge method, a plasma discharge treatment, a chromic acid treatment (wet type), a hot air treatment, an ozone treatment, and an ultraviolet irradiation treatment. Examples of the unevenness method include a sandblasting method and a solvent treatment method.

[release material]

The release material used in the present invention is exemplified by a release sheet which has been subjected to release treatment on both sides, a release sheet which has been subjected to release treatment on one side, and the release agent is applied to a substrate for a release material.

Further, the release-treated surface is preferably a flat release material (for example, a release material having no emboss pattern).

The base material for the release material is, for example, the above-mentioned paper base material, resin film or sheet used as a base material of the adhesive sheet of the present invention, and a base material obtained by laminating a paper base material with a resin. .

Examples of the release agent include a rubber-based elastomer such as a polyfluorene-based resin, an olefin-based resin, an isoprene-based resin, and a butadiene-based resin, a long-chain alkyl-based resin, an alkyd-based resin, and a fluorine-based resin. Wait.

The thickness of the release material is not particularly limited, and is preferably from 10 to 200 μm, more preferably from 25 to 170 μm, still more preferably from 35 to 80 μm.

[Easy-adhesive adhesive sheet of the same state of the present invention]

As an adhesive sheet in the same state of the present invention, as shown in FIG. 3, it may be On the surface (α) of the layer (Xα) of the adhesive layer 12 of the multilayer structure, the easy-adhesive adhesive sheet 2 having the concave portion 13 and the flat surface 14 is present.

The concave portion 13 present on the surface (α) is responsible for releasing the "air accumulation" generated when the surface (α) is attached to the adherend to the outside as an air discharge passage. Therefore, the easy-adhesive adhesive sheet 2 having the concave portion 13 on the surface (α) can be excellent in air removal property.

Further, when the flat surface 14 which is present on the surface (α) is bonded to the adherend, the surface which is in direct contact with the adherend and adheres to the surface of the adherend adhesive sheet 2 is affected.

Fig. 4 is a view showing the surface of the surface (α) when the adhesive layer of the easy-adhesive adhesive sheet of the same state of the present invention is observed from the surface (α) side.

In the easy-adhesive adhesive sheet of the same state of the present invention, as shown in Fig. 4, the concave portion 13 existing on the surface (α) is preferably an amorphous concave portion, as compared with the viewpoint of the adhesive sheet having excellent air-removability. It is preferably a recess that can be visually recognized as an amorphous shape.

By the presence of the amorphous recess in the surface (α), even if the pressure from a certain direction is applied to collapse all the recesses 13, the path of the gas removal can be prevented from disappearing.

Further, in the easy-adhesive adhesive sheet of the same state of the present invention, as shown in Fig. 4, the flat surface 14 existing on the surface (α) is preferably an amorphous flat surface from the viewpoint of being an adhesive sheet excellent in adhesion characteristics. More preferably, it can be visually recognized as an amorphous flat surface.

In the present invention, "the shape is amorphous" means that it does not have A shape, such as a circle or an ellipse, which can be centered, and a shape such as a polygon, means that the shape is irregular, and each shape does not have a similar shape. Specifically, it corresponds to the recess 13 and flat shown in FIG. The shape of the face 14.

Here, the term "polygon" except for the shape of the amorphous shape means a pattern which can be plotted diagonally inside (not protruding to the outside), and the sum of the internal angles is 180 × n (degrees) (n) A figure surrounded by a straight line of natural numbers. The polygon also includes a shape in which the corner portion is curved in a curved shape.

Moreover, the judgment of whether the concave portion and the flat surface existing on the surface (α) are amorphous is in principle observed by a visual or digital microscope or an electron microscope (magnification: 30 to 100 times) from the surface (α). It is judged by the adhesive layer of the adhesive sheet.

However, it is also possible to select 1 to 10 regions on the surface (α) by an arbitrarily selected region of 8 mm long by 10 mm wide (D), and a visual or digital microscope from the surface (α) side (magnification: 30 to 100 times) It is judged by observing the shape of the concave portion or the flat surface existing in each selected region (D). In other words, if there is an amorphous concave portion or a flat surface in the selected region, it may be regarded as "an amorphous concave portion or a flat surface on the surface (α)".

Further, instead of the digital microscope, for example, an on-line sensing camera can be used to judge whether or not the concave portion and the flat surface are amorphous. By measuring on the line, it is also possible to have a product inspection product at the time of mass production.

In the easy-adhesive adhesive sheet of the same state of the present invention, the ratio of the area occupied by the flat surface of the surface (α) is preferably 20 to 95% with respect to 100% of the entire area of the surface (α). Good 30~90%, better It is 40~85%, and even better it is 45~80%.

In addition, the above-mentioned "area ratio of the area occupied by the flat surface" can be obtained by using a digital microscope (magnification: 30 to 100 times) to obtain an image of the surface (α), and image processing (binarization processing) of the image is calculated. .

Further, 1 to 10 regions may be selected on the surface (α) by an arbitrarily selected region (D) of 8 mm in length × 10 mm in width, and a digital microscope (magnification: 30 to 100 times) is used to obtain an image of the region. The value of the "area ratio of the area occupied by the flat surface" of each region is calculated from the image, and the average of the values of the selected one to ten regions is regarded as the surface (α) of the adhesive layer of the target adhesive sheet. "The proportion of the area occupied by the flat surface".

Further, instead of a digital microscope, for example, an on-line sensing camera can be used to measure the "area ratio of the area occupied by the flat surface" on the line.

In the adhesive-adhesive sheet which is in the same state of the present invention, it is preferable that the concave portion and the flat surface which are present on the surface (α) have a pressure based on the viewpoint of the adhesive sheet which is excellent in the balance of the air repellent property and the adhesive property. A pattern-shaped release material is formed.

Specifically, the concave portion and the flat surface existing on the surface (α) are preferably formed by self-forming of the adhesive layer. That is, it is preferred that the concave portion and the flat surface are formed as by-products in the formation of the adhesive layer during self-forming of the adhesive layer.

Further, the concave portion and the flat surface formed by the self-forming of the adhesive layer also become concave portions or flat surfaces which can be visually recognized as amorphous.

In particular, in the easy-adhesive adhesive sheet of the same state of the present invention, the concave portion and the flat surface in which the surface (α) exists are preferably made by sequentially a layer (Xβ) formed of the composition (xβ), a layer (Y1) formed of a composition (y1) containing 15 to 100% by mass of the fine particles, and a layer (Xα) formed of the above composition (xα) The laminated multilayer structure, that is, the adhesive layer is formed by self-forming.

In the present invention, the term "self-formation" means a phenomenon in which a disordered shape is naturally formed in the process of self-discipline formation of an adhesive layer, and more specifically, a material forming a self-adhesive layer is formed. The coating film is dry, and the shape of the disorder is naturally made in the process of self-discipline formation of the adhesive layer.

Further, in the process of self-forming of the adhesive layer 12 as in the adhesive-attachable adhesive sheet 2 shown in Fig. 3, the concave portion 13 is easily formed on the surface (α) 12a of the layer (Xα), and While the concave portion 13 is formed, the thickness of each layer is also likely to become more uneven.

The formation process of the adhesive layer and the recessed portion in which the thickness of each layer formed by self-forming of the adhesive layer is not uniform is considered as follows.

First, during the formation of at least two adhesive layers of different constituent components, shrinkage stress is generated inside the coating film by a step of drying a plurality of coating films formed of mutually different compositions, and the resin bonding strength is compared. In the weak portion, if the constituent components in the plurality of coating films move, cracks are generated on the surface (α). Therefore, it is considered that the thickness of each layer becomes uneven by the movement of the constituent components existing in the periphery to the moving portion of the constituent component, and the resin existing in the periphery of the cracked portion flows into the space temporarily generated by the crack. A recess is formed on the surface (α) of the adhesive layer.

That is, due to the formation of the concave portion while causing large-scale resin movement, Therefore, the thickness of each layer is made more uniform, and the layer (Xα), the layer (Y1), and the layer (Xβ) satisfying the above requirements are easily formed.

It is considered that after forming a two-layer coating film having different constituent components of the resin, the two coating films are simultaneously dried, and a shrinkage stress difference occurs inside the coating film during drying, so that the thickness of each layer becomes uneven, and surface (α) is easily generated. Cracked.

For example, on the surface (α) of the adhesive layer of the easy-adhesive adhesive sheet 2 shown in Fig. 3, there is a concave portion which is formed by simultaneously drying at least a layer (Xα) forming material ( The coating film (xα') formed of xα) and the coating film (y1') which is a composition (y1) which is a material forming the layer (Y1) are naturally made during the formation of the self-discipline of the adhesive layer. The formation of self-formation of disordered shapes.

From the viewpoint of forming the concave portion on the surface (α) and easily forming the layer (Xα), the layer (Y1), and the layer (Xβ) satisfying the above requirements, it is preferable to appropriately adjust the following matters. It is considered that a composite action due to such a problem is likely to form a concave portion, and it is easy to form a layer (Xα), a layer (Y1), and a layer (Xβ) satisfying the above requirements.

. The coating film forming material is a resin type, a constituent monomer, a molecular weight, and a content contained in the composition.

. The coating film forming material, that is, the type of the crosslinking agent and the type of the solvent contained in the composition.

. The coating film forming material is the viscosity of the composition and the solid content concentration.

. Film thickness formed (in the case of multiple layers, the thickness of each coating film)

. The drying temperature and drying time of the formed coating film.

The above matters are preferably considered in the resin contained in the formed coating film. It is set as appropriate in terms of fluidity and the like.

For example, when the fine particles are contained in the composition, the specific fluidity of the fine particles in the coating film can be maintained by adjusting the viscosity of the coating film formed of the composition containing a large amount of fine particles, and the coating film can be moderately suppressed (otherwise). Intermixing of coatings containing more resin). By such adjustment, in the coating film containing a large amount of resin, cracks are generated in the horizontal direction, and concave portions are easily formed, and the layer (Xα), the layer (Y1), and the layer (Xβ) satisfying the above requirements tend to be formed.

Moreover, in the above-mentioned matter, it is preferred to appropriately adjust the type, constituent monomer, molecular weight, and resin content of the resin so that the resin contained in the coating film containing a large amount of resin has moderate viscoelasticity.

That is, by making the hardness of the coating film (hardness determined by factors such as the viscoelasticity of the resin and the viscosity of the coating liquid) moderately hard, the shrinkage stress of the resin portion can be enhanced, the concave portion can be easily formed, and a layer satisfying the above requirements can be formed. (Xα), layer (Y1) and layer (Xβ).

The harder the hardness of the coating film is, the stronger the shrinkage stress is, and the concave portion tends to occur, but the coating suitability is lowered when it is too hard. Further, when the resin elasticity is excessively increased, the adhesive strength of the adhesive layer formed of the coating film tends to decrease. When considering this aspect, it is preferable to appropriately adjust the viscoelasticity of the resin.

Further, when the fine particles are contained in the composition or the coating film, it is considered that the degree of swelling of the thickness of the adhesive layer by the fine particles can be easily adjusted, or the self-forming force of the concave portion can be easily adjusted, and the result is easy. A concave portion is formed on the surface (α) to form a layer (Xα), a layer (Y1), and a layer (Xβ) satisfying the above requirements.

Furthermore, it is better to consider the formed coating film (or forming material as a group) The cross-linking speed of the product), the above matters are appropriately set.

That is, when the crosslinking speed of the coating film is too fast, the coating film is hardened before the concave portion is formed. Moreover, it also affects the crack size of the coating film.

The crosslinking speed of the coating film can be adjusted by appropriately setting the type of the crosslinking agent and the type of the solvent in the composition, that is, the drying time and drying temperature of the coating film.

<Easy strategy for easy surface (α) formation of amorphous recesses>

As a more specific strategy, it is easy to form an amorphous recess in the surface (α) during the self-forming of the adhesive layer by using the compositions (xα), (y1), and (xβ) which satisfy the following matters.

(1) Selection of adhesive resin in each composition

The compositions (xα), (y1), and (xβ) preferably contain an acrylic resin or a rubber-based resin as an adhesive resin, and more preferably contain an acrylic resin.

The acrylic resin preferably contains an acrylic resin having the above functional group, and more preferably contains the above acrylic copolymer (P). Further, the details of the acrylic resin, the acrylic resin having a functional group, and the acrylic copolymer (P) are as described above.

(2) Selection of crosslinking agent in each composition

The compositions (xα), (y1) and (xβ) preferably contain a crosslinking agent together with the acrylic resin (or acrylic copolymer (P)) having a functional group.

The crosslinking agent contained in the compositions (xα), (y1), and (xβ) preferably contains a metal chelate based on the viewpoint that the surface (α) of the adhesive layer is easily formed into an amorphous concave portion and a flat surface. One or more of the compound-based crosslinking agent, the epoxy-based crosslinking agent, and the aziridine-based crosslinking agent, more preferably a metal chelate-based crosslinking agent, and more preferably an aluminum chelate-based crosslinking agent Agent.

Further, from the viewpoint of easily forming an amorphous concave portion on the surface (α) of the adhesive layer, the composition (xα) which is a material for forming the layer (Xα) preferably contains a metal chelate crosslinking agent and an epoxy system. Crosslinker.

When the metal chelate-based crosslinking agent and the epoxy-based crosslinking agent are contained together, the content ratio of the metal chelate-based crosslinking agent and the epoxy-based crosslinking agent in the composition (xα) is [metal chelate compound system The crosslinking agent/epoxy crosslinking agent is preferably 10/90 to 99.5/0.5, more preferably 50/50 to 99.0/1.0, and even more preferably 65/35 to 98.5/1.5, in terms of mass ratio. Better still is 75/25~98.0/2.0.

(3) Selection of particles in the composition (y1)

The composition (y1) preferably contains cerium oxide particles as fine particles from the viewpoint that the surface (α) of the adhesive layer is easily formed into an amorphous concave portion.

The content of the cerium oxide particles in the composition (y1) is preferably from 15 to 100% by mass, more preferably from 20 to 95% by mass, based on the total amount of the active ingredient (100 mass) of the composition (y1), and further It is preferably 25 to 90% by mass, more preferably 30 to 85% by mass, and even more preferably 35 to 80% by mass.

The mass concentration of cerium oxide in the cerium oxide particles is preferably from 70 to 100% by mass, more preferably from 85 to 100% by mass, based on the total amount of the cerium oxide particles (100% by mass) in the composition (y1). , and better for 90~100 quality%.

Further, the volume average secondary particle diameter of the cerium oxide particles used in the same state of the present invention is based on the viewpoint of improving the air-removability and burst resistance of the adhesive sheet and forming a concave portion based on the surface (α) which is easy to adhere to the adhesive layer. The viewpoint of the flat surface is preferably from 0.5 to 10 μm, more preferably from 1 to 8 μm, still more preferably from 1.5 to 5 μm.

Further, in the present invention, the value of the volume average secondary particle diameter of the cerium oxide particles is a value obtained by measuring a particle size distribution by a Coulter counting method using a Multisizer 3 or the like.

Here, as the fine particles, by forming a plurality of particles such as cerium oxide particles and using the fine particles forming the secondary particles, it is easy to form the formed adhesive layer into a void-containing portion. The burst resistance of the adhesive sheet can be improved by the presence of voids in the adhesive layer.

The void portion also includes a void existing in the gap between the fine particles or a void existing in the secondary particle when the fine particles are secondary particles.

Further, even in the case where the adhesive layer is formed in the multilayer structure, that is, after the formation of the adhesive layer, there is a case where the adhesive resin flows into the void portion and the void disappears, and the adhesive layer is formed as a void-free portion.

However, even in the case where the void portion existing in the adhesive layer for a short period of time disappears, the easy-adhesive adhesive sheet of the same state of the present invention has air-removing property due to the presence of the concave portion on the surface (α) of the adhesive layer. Further, if fine particles are present in the adhesive layer, the burst resistance is also excellent.

(Quality retention rate of the adhesive layer)

The adhesive layer of the adhesive sheet having the same state of the present invention has a mass retention rate of preferably 3 to 90% by mass (more preferably 5 to 80% by mass, more preferably 5 to 80% by mass) after heating at 800 ° C for 30 minutes. 7 to 70% by mass, and more preferably 9 to 60% by mass).

When the mass retention rate is 3% by mass or more, it can be an adhesive sheet excellent in air release property and burst resistance. Further, in the production of the adhesive sheet of the present invention, it is easy to form a concave portion on the surface (α) of the adhesive layer. On the other hand, when the mass retention rate is 90% by mass or less, the adhesive layer can have high film strength, excellent water resistance and chemical resistance, and a flat surface can be easily formed on the surface (α) of the adhesive layer.

Moreover, the mass retention ratio can be regarded as indicating the content (% by mass) of the fine particles contained in the adhesive layer, and can be adjusted by changing the content of the fine particles contained in each composition.

<Microparticle distribution in the adhesive layer>

In the adhesive-attachable adhesive sheet of the same state of the present invention, the adhesive layer having the concave portion formed by self-forming in the adhesive layer has a tendency to be distributed as shown in Fig. 3: surface (α) The proportion of the fine particles 15 in the portion where the concave portion 13 exists is smaller than the ratio at which the fine particles 15 in the portion where the flat portion 14 exists on the surface (α).

It is considered that in the process of self-forming of the adhesive layer, when the concave portion is formed on the surface (α) of the adhesive layer, such a distribution is caused by the movement of the fine particles existing at the position where the concave portion is formed.

Further, the shape of the concave portion formed by the self-forming of the adhesive layer as described above can be adjusted to some extent by adjusting the drying condition or the component or content of the component in the composition of the adhesive layer. Different from the groove formed by using the embossed-type release material, it can be said that "it is impossible to reproduce the exact same shape".

Therefore, the shape of the concave portion 13 is likely to be amorphous, and the shape of the flat surface 14 is also amorphous by the surface (α) forming an amorphous concave portion.

[Method of Manufacturing Adhesive Sheet of the Present Invention]

The method for producing the adhesive sheet of the present invention is not particularly limited, and a coating film formed of each of the constituent materials of the adhesive layer of the multilayer structure can be formed on the substrate, and the coating film can be dried to form each layer. And manufacturing.

For example, as a method of producing the adhesive sheet 1a shown in Fig. 1(a), a composition is formed on the substrate 11 by using a composition (x?) to form a layer (X?), and then using the composition on the layer (X?). (xα) A method of producing the layer (Xα).

Further, in the above-described production method, after the coating film (xβ') composed of the composition (xβ) and the coating film (xα') formed of the composition (xα) are formed on the substrate 11, At the same time, the coating films are dried while forming a layer (Xβ) and a layer (Xα).

Further, in the adhesive sheet 1a shown in Fig. 1(a), a layer (X?) formed using the composition (x?) may be attached to the substrate 11, and the composition (x?) to be separately prepared may be applied to the release material. It is produced by forming the layer (Xα).

Further, as a method of producing the adhesive sheet 1b shown in Fig. 1(b), a composition (x?) is formed on the substrate 11 by using a composition (x?), and a composition is used on the layer (X?). (y1) A method of forming a layer (Y1) and forming a layer (Xα) on the layer (Y1) using the composition (xα).

Further, in the above-described method for producing the adhesive sheet 1b, a coating film (y1' formed by a coating film (xβ') composed of the composition (xβ) and a composition (y1) may be formed on the substrate 11. After the coating film (xα') formed of the composition (xα), the coating film is simultaneously dried to form a layer (Xβ), a layer (y1), and a layer (Xα).

Further, the layer (Xβ), the layer (y1), and the layer (Xα) may be formed separately, and then these may be attached in order.

When a coating film is formed, in order to form a coating film easily, it is preferable to further prepare a solvent in a composition which is a material for forming each layer, and to prepare a solution form of the composition.

Examples of such a solvent are water or an organic solvent.

The organic solvent is exemplified by, for example, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropanol, tert-butanol, second butanol, ethyl hydrazine. Acetone, cyclohexanone, n-hexane, cyclohexane, and the like. Further, these solvents may be used alone or in combination of two or more.

As a coating method on a substrate or on a release material, a conventional method can be used.

Further, as a method of forming the plurality of coating films, a method of sequentially forming another coating film may be formed on the formed coating film after forming one coating film.

The applicators used in the successive formation are exemplified by, for example, a spin coater, a spray coater, a bar coater, a knife coater, a roll coater, a knife roll coating. , squeegee applicator, gravure coater, curtain coater, die coater, and the like.

The applicator used for simultaneous coating with a multilayer coater is exemplified by, for example, a curtain coater, a die coater, etc., but among these, a die coater is preferred from the viewpoint of workability.

[Method for manufacturing easy-adhesive adhesive sheet in the same state of the present invention]

The method for producing the easily attachable adhesive sheet in the same state of the present invention is not particularly limited, but based on the viewpoint of productivity, and on the surface (α) of the adhesive layer, it is easier to form self-formation by the adhesive layer. The viewpoint of forming the concave portion and the flat surface formed by the formation is preferably a production method having at least the first aspect of the following steps (1A) and (2A), or at least the following steps (1B) and (2B) The manufacturing method of the second aspect.

The manufacturing method of the first aspect: a method for producing an easily attachable adhesive sheet having at least the following steps (1A) and (2A).

. Step (1A): a coating film (y1') formed on the substrate in accordance with a coating film (xβ') composed of the composition (xβ) and a composition (y1) containing 15% by mass or more of the fine particles. And a step of laminating and forming a coating film (xα') formed by the composition (xα); Step (2A): a step of simultaneously drying the coating film (xβ'), the coating film (y1'), and the coating film (xα') formed in the step (1A).

Manufacturing method of the second aspect: a method for producing an easily attachable adhesive sheet having at least the following steps (1B) and (2B).

. Step (1B): a layer formed of a composition (xβ) on a substrate (Xβ), the layer is formed in the order of the coating film (y1') composed of the composition (y1) containing 15% by mass or more of the fine particles, and the coating film (xα') formed of the composition (xα). The steps formed by the combination; Step (2B): a step of simultaneously drying the coating film (y1') and the coating film (xα') formed in the step (1B).

The details of the composition (xβ), the composition (y1), and the composition (xα) used in the step (1A) and the step (1B) are as described above.

Further, in the case of forming a coating film, in order to form a coating film easily, it is preferred to further prepare a solvent in the composition (xβ), (xα), and (y1) to prepare a solution form of the composition.

The solvent is exemplified by water or an organic solvent, and the organic solvent which can be used is as described above.

Further, as a method of forming the coating films (xβ'), (y1'), and (xα'), a method of sequentially forming each coating film may be employed, and from the viewpoint of productivity, a multilayer coater may be simultaneously coated. A method of forming a film.

The applicator used in the successive formation and the applicator used in the simultaneous coating with the multilayer coater are as described above.

(Manufacturing method of the first aspect)

In the step (1A), it is preferred to apply the above solvent to the composition (xβ), the composition (y1), and the composition (xα) to prepare a solution form of the composition, followed by coating.

The coating film (xβ'), the coating film (y1'), and the coating film (xα') may be formed by forming a coating film (xβ') on the substrate and then coating the coating film (xβ'). membrane (y1'), and further, a method of forming a coating film (xα') on the coating film (y1') by using the above-described applicator to form a coating film at the same time by using the above multilayer coater A method of (xβ'), a coating film (y1'), and a coating film (xα').

The coating amount of the coating film (xα'), the coating film (y1'), and the coating film (xβ') is preferably from 1.5 to 800 g/m ² , more preferably from the viewpoint of improving air removability and adhesion characteristics. 5~500g/m ² , more preferably 10~300g/m ² , and even more preferably 20~200g/m ² .

The coating amount of the coating film (y1') is preferably from 5 to 2,000, more preferably from 5 to 2,000, based on the viewpoint of improving the air removal property and the adhesion property with respect to the coating amount 100 of the coating film (xα'). 50~1500, and better 100~1000.

Further, in the step (1A), one or more coating films of the coating film (xβ'), the coating film (y1'), and the coating film (xα') are formed, and then the step (2A) may be performed before the step (2A). The pre-drying treatment does not allow the coating film to undergo a hardening reaction.

For example, after forming any coating film of the coating film (xβ'), the coating film (y1'), and the coating film (xα'), the pre-drying treatment may be performed each time, and the coating film (xβ') and the coating film may be formed. After the film (y1') is subjected to the above pre-drying step together, a coating film (xα') is formed.

In the step (1A), the drying temperature at the time of performing the pre-drying treatment is usually appropriately set within a temperature range in which the formed coating film is not cured, but preferably the drying temperature of the step (2A) is not reached. The specific drying temperature indicating that the drying temperature is "not up to step (2A)" is preferably from 10 to 45 ° C, more preferably from 10 to 34 ° C, still more preferably from 15 to 30 ° C.

The step (2A) is a step of simultaneously drying the coating film (xβ'), the coating film (y1'), and the coating film (xα') formed in the step (1A).

The drying temperature in this step is preferably from 35 to 200 ° C, preferably from 60 to 180 ° C, more preferably from 70 to 160 ° C, based on the viewpoint that the surface (α) of the adhesive layer is easily formed into a concave portion and a flat surface. More preferably 80~140 °C.

(Production method of the second aspect)

As a method of forming the layer (X?), a coating film (x?') composed of the composition (x?) can be formed on a substrate, and the coating film (x?') can be dried.

The drying temperature at this time is not particularly limited, and is preferably 35 to 200 ° C, more preferably 60 to 180 ° C, still more preferably 70 to 160 ° C, and even more preferably 80 to 140 ° C.

Further, in this aspect, it is not formed on the coating film (xβ') but in the order of the coating film (y1') and the coating film (xα') on the layer (Xβ) obtained after drying, and The first aspect described above is different.

In the step (1B), it is also preferred to mix the above solvent with the composition (y1) and the composition (xα) to prepare a solution form of the composition, followed by coating.

The coating film (y1') and the coating film (xα') may be formed by forming a coating film (x') on the coating layer (y1' after forming a coating film (y') on the layer (Xβ). Alternatively, the method of sequentially forming the applicator described above may be used to simultaneously form a coating film (y1') and a coating film (xα') by using the above multilayer coater.

The coating amount of the coating film (xα') and the coating film (y1'), and the ratio of the coating amount of the coating film (y1') to the coating amount 100 of the coating film (xα'), and the first The step (1A) of the manufacturing method of the aspect is the same.

Further, in the step (1B), after the coating film (y1') is formed or after the coating film (y1') and the coating film (xα') are formed, the step (2B) may be performed before the step (2B). The pre-drying treatment is performed to the extent that the coating film is subjected to a hardening reaction.

In the step (1B), the drying temperature at the time of performing the pre-drying treatment is usually appropriately set within a temperature range in which the formed coating film is not cured, but preferably the drying temperature of the step (2B) is not reached. The specific drying temperature indicating that the drying temperature is "not up to step (2B)" is preferably from 10 to 45 ° C, more preferably from 10 to 34 ° C, still more preferably from 15 to 30 ° C.

The step (2B) is a step of simultaneously drying the coating film (y1') and the coating film (xα') formed in the step (1B).

The drying temperature in this step is preferably from 35 to 200 ° C, more preferably from 60 to 180 ° C, and even more preferably from 70 to 160 ° C, from the viewpoint that the surface (α) of the adhesive layer is easily formed into a concave portion and a flat surface. More preferably 80~140 °C.

[Examples]

The present invention will be more specifically described by the following examples, but the present invention is not limited to the following examples. Moreover, the physical property values in the following production examples and examples are values measured by the following methods.

<mass average molecular weight (Mw)>

Using a gel permeation chromatography apparatus (product name "HLC-8020", manufactured by TOSOH Co., Ltd.), the measurement was carried out under the following conditions, and the values measured by standard polystyrene were used.

(measurement conditions)

. Pipe column: "TSK protection column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", "TSK gel G1000HXL" (both manufactured by TOSOH Co., Ltd.) are connected in sequence.

. Column temperature: 40 ° C

. Developing solvent: tetrahydrofuran

. Flow rate: 1.0mL/min

<Measurement of volume average secondary particle diameter of cerium oxide particles>

The volume average secondary particle diameter of the cerium oxide particles was determined by a Coulter counting method using a Multisizer 3 machine (manufactured by Beckman Coulter Co., Ltd.).

<Measurement of Thickness of Adhesive Layer>

The constant pressure thickness measuring device (model: "PG-02J" manufactured by TECLOCK Co., Ltd. was used according to standard specifications: JIS K6783, JIS Z1702, JIS Z1709).

Specifically, the value obtained by measuring the total thickness of the adhesive sheet to be measured and subtracting the thickness of the previously measured base material or the release sheet is referred to as "the thickness of the adhesive layer".

Manufacturing example x-1~x-5

(Preparation of solution of resin composition (xβ-1)~(xβ-3) and (xα-1)~(xα-2))

The type and the amount of the crosslinking agent and the tackifier described in Table 1 were added to the solution of the acrylic resin which is an adhesive resin of the type and solid content described in Table 1. Subsequently, the solution was diluted with the diluent solvent described in Table 1, and a solution (xβ-1) to (xβ-3) and (xα-1)~ (of the resin composition having the solid content concentration shown in Table 1) were prepared. Xα-2).

The details of the respective components described in Table 1 used for the preparation of the solutions (xβ-1) to (xβ-3) and (xα-1) to (xα-2) of the resin composition are as follows.

<Acrylic resin solution>

. Solution (i): a solid component containing an acrylic resin (xi) (acrylic copolymer having a constituent unit of a raw material monomer obtained by a source free BA/AA = 90/10 (% by mass), Mw: 470,000) A mixed solution of toluene and ethyl acetate having a concentration of 37.0% by mass.

. Solution (ii): an acrylic copolymer containing an acrylic resin (x-ii) (having a source of 2EHA/VAc/AA = 75/23/2 (% by mass) of a raw material monomer, Mw: A mixed solution of toluene and ethyl acetate having a solid concentration of 37.0% by mass.

. Solution (iii): acrylic copolymer containing an acrylic resin (x-iii) having a constituent unit of a raw material monomer having a source free of 2EHA/BA/VAc/AA=70/20/5/5 (% by mass) (Mw: 630,000), a mixed solution of toluene and ethyl acetate having a solid concentration of 33.5 mass%.

. Solution (iv): an acrylic copolymer containing an acrylic resin (x-iv) having a constituent unit of a raw material monomer derived from a source of free BA/AA/HEA=94/3/3 (% by mass), Mw: 1 million) solid concentration of 37.0 A mixture of toluene and ethyl acetate in an amount of %.

Further, the abbreviation of the constituent raw material monomers of the above acrylic copolymer is as follows.

. BA: n-butyl acrylate

. 2EHA: 2-ethylhexyl acrylate

. AA: Acrylic

. VAc: vinyl acetate

. HEA: Hydroxyethyl acrylate

<crosslinker>

. Al-based cross-linking agent: product name "M-5A", manufactured by Soken Chemical Co., Ltd., aluminum chelate-based crosslinking agent, solid content concentration = 4.95 mass%.

. Epoxy-based crosslinking agent: "TETRAD (registered trademark)-C" (product name, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was diluted with toluene to prepare a solution of an epoxy-based crosslinking agent having a solid concentration of 5 mass%.

<tackifier>

. Rosin ester type TF: rosin ester type tackifier, Mw: less than 10,000, softening point: 135 ° C

. Styrene TF: styrene tackifier, Mw: less than 10,000, softening point: 95 ° C

. Terpene TF: aromatic modified terpene tackifier, Mw: less than 10,000, softening point: 115 ° C

. Hydrogenated terpene TF: hydride of aromatic modified terpene tackifier, Mw: less than 10,000, softening point: 100 ° C

<dilution solvent>

. Mixed solvent (1): a mixed solvent of toluene/isopropyl alcohol (IPA) = 35/65 (mass ratio).

. Mixed solvent (2): a mixed solvent of ethyl acetate/IPA = 86/14 (mass ratio).

. Mixed solvent (3): a mixed solvent of toluene/IPA = 40/60 (mass ratio).

[Table 1]

Manufacturing example f-1

(modulation of fine particle dispersion (f-1))

An acrylic copolymer (Mw: 470,000) containing a solution (i) of the above acrylic resin (xi) (having a constituent unit derived from BA/AA = 90/10 (% by mass)) A mixed solution of toluene and ethyl acetate having a solid concentration of 37.0% by mass).

To 100 parts by mass of the solution (i) (solid content: 37.0% by mass), cerium oxide particles as fine particles (product name "NIPSIL E-200A", manufactured by TOSOH SILICA Co., Ltd., volume average secondary particle diameter: 3 μm) were added. 55.5 parts by mass (solid content: 55.5 parts by mass) and toluene were used to disperse the fine particles, and a fine particle dispersion liquid (f-1) containing a solid content concentration of 30% by mass of the acrylic resin (xi) and the ceria particles was prepared.

Manufacturing example y-1~y-3

(Preparation of coating liquid (y1') forming coating liquid (y-1) to (y-3)

A fine particle dispersion liquid, a solution of an acrylic resin, a crosslinking agent, a thickening agent, and a diluent solvent, which are described in Table 2, were added, and the coating film (y') for preparing the solid content concentration described in Table 2 was prepared. The coating liquid (y-1) to (y-3) of the composition.

Further, the details of the respective components described in Table 2 used for the preparation of the coating liquids (y-1) to (y-3) for forming the composition for coating film (y') are as follows.

<Microparticle dispersion>

. Dispersion liquid (f-1): A fine particle dispersion liquid (f-1) containing a solid content concentration of 30% by mass of the acrylic resin (x-i) and cerium oxide particles prepared in Production Example f-1.

<Acrylic resin solution>

. Solution (i): a solid component containing an acrylic resin (xi) (acrylic copolymer having a constituent unit of a raw material monomer obtained by a source free BA/AA = 90/10 (% by mass), Mw: 470,000) A mixed solution of toluene and ethyl acetate having a concentration of 37.0% by mass.

<crosslinker>

. Al-based cross-linking agent: product name "M-5A", manufactured by Soken Chemical Co., Ltd., aluminum chelate-based crosslinking agent, solid content concentration = 4.95 mass%.

<tackifier>

. Rosin ester type TF: rosin ester type tackifier, Mw: less than 10,000, softening point: 135 ° C

. Terpene TF: aromatic modified terpene tackifier, Mw: less than 10,000, softening point: 115 ° C

. Hydrogenated terpene TF: hydride of aromatic modified terpene tackifier, Mw: less than 10,000, softening point: 100 ° C

. Styrene TF: styrene tackifier, Mw: less than 10,000, softening point: 95 ° C

<dilution solvent>

. Mixed solvent (4): a mixed solvent (IPA/CHN=95/5 (mass ratio)) composed of IPA/CHN: isopropyl alcohol (IPA) and cyclohexanone (CHN).

[Table 2]

Examples 1 to 3, Comparative Example 1

(1) Formation of coating film

A polyethylene terephthalate (PET) film ("FNS MATT N50", manufactured by LINTEC Co., Ltd., 50 μm thick) having an aluminum vapor-deposited layer on one side was used as a substrate.

On the aluminum vapor-deposited layer of the PET film, a multilayer die coater (width: 250 mm) was used, and the production examples x-1 to x- described in Table 3 were simultaneously applied at the coating speeds shown in Table 3. The composition for forming a coating film (y1') prepared by any of the solutions (xβ-1) to (xβ-3) of the resin composition prepared in accordance with Table 3 and the production examples y-1 to y-3 described in Table 3 Solution (xα-1)~(xα) of any of the coating liquids (y-1) to (y-3) and the resin composition prepared in the production example x-4 to x-5 described in Table 3. In either of -2), a coating film (xβ'), a coating film (y1'), and a coating film (xα') are simultaneously formed.

Further, the coating amount of each solution (coating liquid) for forming the coating film (xβ'), the coating film (y1'), and the coating film (xα') is as shown in Table 3.

(2) Drying treatment

The formed coating film (xβ'), the coating film (y1'), and the coating film (xα') were simultaneously dried at a drying temperature of 100 ° C for 2 minutes to form a layer (Xβ), a layer (Y1), and a layer ( Xα) An adhesive layer of a multilayer structure in which layers are sequentially laminated. The thickness of the adhesive layer formed is shown in Table 3.

Next, on the surface (α) of the formed adhesive layer, a release film which is a release material (manufactured by LINTEC Co., Ltd., product name "SP-PET" The peeling-treated surface of 381011") was laminated in such a manner that the adhesive sheet attached to the substrate was produced.

Using the base adhesive sheet prepared in the examples and the comparative examples, the adhesive layer of the adhesive sheet and the characteristics of the adhesive sheet were calculated, measured, or observed by the following methods. These results are shown in Table 4.

<Method for Calculating the Intensity Ratio I of Each Layer constituting the Adhesive Layer>

The intensity ratio I of each layer constituting the adhesive layer was calculated by the following procedure.

(i) Determination of Raman spectroscopy (Ra)

The adhesive sheet with a base material prepared in the examples and the comparative examples was allowed to stand in an environment of 23 ° C and a relative humidity of 50% for 7 days, and was then placed in the same manner as the adhesive sheet 1 shown in Fig. 2 .

Next, a section 121 of the adhesive layer (hereinafter referred to as "adhesive layer (a)") in the adhesive sheet attached to the substrate is as shown in FIG. The side of the (β) 12b faces the surface (α) 12a side, and the measurement position is shifted at a certain interval from the range of 0.5 to 1 μm in the direction P, and the excitation Ray is irradiated from the laser irradiation device 50 in the vertical direction. Shot 51, and the Raman spectrum (Ra) of the adhesive layer (a) at each measurement position was measured.

Further, each measurement position is set based on an optical microscope image obtained by observing the cross section 121 of the adhesive layer 12 using an optical microscope built in the laser camera.

Further, the boundary between the two layers constituting the layer (Xβ), the layer (Y1), and the layer (Xα) of the adhesive layer (a) is the optical portion of the cross section 121 of the adhesive layer 12 used at the specified measurement position. The microscope image and the resulting Raman spectrum (Ra) are specified.

The apparatus used to determine the Raman spectrum and the measurement conditions are shown below.

. Laser irradiation device: manufactured by Thermo Fisher Scientific Co., Ltd., product name "Nicolet Almega XR"

. Laser wavelength: 532nm

. Aperture: 25μm pinhole

. Lens magnification: 50 times

. Output: 100%

. Exposure time: 2 seconds

. Number of exposures: 4 times

(ii) Determination of Raman spectroscopy (Rb)

For each of the examples and comparative examples, in addition to the tackifier, the adhesive layer (a) Formation Method Similarly, an adhesive sheet having an adhesive layer (b) containing no tackifier was produced.

Next, the Raman spectrum (Rb) of the adhesive layer (b) was measured by Raman spectroscopy at any position on the cross section of the adhesive layer (b) under the aforementioned measurement conditions.

(iii) Calculation of the peak height from the peak of the tackifier

For Raman spectroscopy (Ra) and (Rb), the Raman scattering intensity is compared for each Raman shift.

Specifically, the Raman scattering intensity of the peak (p _a ) of the specific Raman shift (r) of the Raman spectrum (Ra) exceeds the Raman of the same Raman shift (r) of the Raman spectrum (Rb). When the scattering intensity is 10 times, it is judged that the peak (p _a ) of the Raman spectrum (Ra) is "the peak derived from the tackifier". The peak height calculated in the peak (p _a ) is set to "the height of the peak derived from the peak of the tackifier".

Further, when there are a plurality of peaks, the peak of the Raman scattering intensity in the peak is selected in the Raman spectrum (Ra).

(iv) Calculation of the peak height of the peak derived from the component other than the tackifier

In the Raman spectrum (Ra), the other peaks in the above (iii) that are not judged as "peaks derived from tackifiers" are set as "peaks derived from components other than the tackifier", and the peak height calculated in the peaks Set to "peak height from the peak of the component other than the tackifier".

Further, when there are a plurality of peaks, the Raman spectrum (Rb) is selected, and one of the peaks is selected to have a small influence on the Raman scattering intensity due to the presence or absence of the tackifier and a strong Raman scattering intensity.

(v) Calculation of the intensity ratio I of each layer

Based on the values of the "peak height from the peak of the tackifier" obtained by the above (i) to (iv) and the peak height of the peak derived from the component other than the tackifier, the value is calculated by the above formula (1). The "intensity ratio I" of the measurement position in the section 121 of the adhesive layer is individual.

Fig. 5 is a graph showing the relationship between the measurement position (distance from the surface (β)) and the intensity ratio I of the measurement position in the adhesive layer of the adhesive sheet produced in the first embodiment.

Further, in the first embodiment, the peak having a Raman shift of 1000 cm ^{-1 is "} the peak derived from the tackifier", and the peak having the Raman shift of 1730 cm ^{-1 is "} the peak derived from the component other than the tackifier". .

Next, the average value of the intensity ratios I of all the measurement positions included in the layer (Xβ) is calculated as the "strength ratio I of the layer (Xβ)". Similarly, the average value of the intensity ratios I of all the measurement positions included in the layer (Y1) is calculated as the "strength ratio I of the layer (Y1)", and the average of the intensity ratios I of all the measurement positions contained in the layer (Xα) is calculated. The value is used as the intensity ratio I of the layer (Xα).

In the adhesive layer of the adhesive sheet prepared in the examples and the comparative examples, the "strength ratio of the layer (Xβ) I (Xβ)", the strength ratio of the layer (Y1) I (Y1), and the layer (Xα) The intensity ratio I(Xα)" is shown in Table 4.

Further, the ratio of the intensity ratio I(Xβ) of the layer (Xβ) to the intensity ratio I(Xα) of the layer (Xα) [I(Xβ)/I(Xα)]] and the layer (Y1) are also calculated. The ratio [I(Y1)/I(Xα)]] of the intensity ratio I(Y1) to the intensity ratio I(Xα) of the layer (Xα), which is also shown in Table 4.

<Observation of the state of the surface (α) of the adhesive layer>

The surface (α) of the adhesive layer of the adhesive sheet prepared in the examples and the comparative examples was arbitrarily selected from a region (D) surrounded by a rectangle having a length of 8 mm and a width of 10 mm, and was fabricated by a digital microscope (KYENCE Co., Ltd., Product name "Digital microscope VHX-1000", magnification: 50 times) The inside of the area (D) is observed from the surface (α) side (see stereoscopic view as needed) and photographed.

At the time of photographing, more specifically, the direction A is sequentially moved from the direction in which the flat surface is judged to be a flat surface from the direction A of FIG. 3, and the portion having the first focus is photographed as a flat surface.

Further, a digital microscope (magnification: 50 times) can be used to connect the arbitrarily selected ranges on the surface (α) to each other, and the image is connected by a digital microscope to obtain a connected image, and any of the obtained linked images can be obtained. Select an area surrounded by a rectangle of 8 mm long by 10 mm wide and set it as "image of area (D)".

Further, when it is impossible to judge whether or not the surface is a flat surface by visual observation of the image, the light-transmitting adherend having a smooth surface is attached to the surface of the adhesive layer by a rubber blade so as not to apply a load as much as possible (α). From the direction A of Fig. 3, the interface between the smooth surface of the light-transmitting adherend and the surface (α) 12a of the adhesive layer 12 was photographed, and the attached portion was judged to be a flat surface. An alkali-free glass (product name "EAGLE XG", manufactured by Corning Incorporated) was used for the light-transmitting property having a smooth surface.

Observe the image of the obtained area (D) and observe the presence or absence of the concave portion. Part shape and flat surface shape. The results are shown in Table 4.

<Measurement of the proportion of the area occupied by the flat surface existing in the area (D) >

The "area (D) image" obtained by the above-mentioned "observation of the state of the surface (α) of the adhesive layer" is subjected to automatic area measurement using the same digital microscope as described above, and is obtained in the region (D), respectively. The area of each flat surface that exists. The measurement results are shown in Table 4.

Further, in the automatic area measurement, the flat surface existing in the region (D) is binarized by a digital microscope and image processing visually visually necessary, and then the numerical value (area) of the obtained binarized image is measured. The area of each flat surface was measured separately. When there are a plurality of flat surfaces, the measurement of the area of each flat surface is performed. The ratio of the area of each flat surface obtained to the total area of the total area (D), that is, the area ratio (%) of the flat surface.

The automatic area measurement conditions are as follows.

(Automatic area measurement conditions)

. Extraction mode: brightness (missing noise is weak)

. Extraction area: Rectangularly drawn by a numerical value (rectangular) with a length of 8 mm × a width of 10 mm

. Shaping of the extraction area: removal of particles (removal area of 100 μm ² or less)

<Quality retention rate of adhesive layer of adhesive sheet>

From the adhesive sheets attached to the substrates prepared in the examples and the comparative examples, only the adhesive layer was obtained, and the quality of the adhesive layer before heating was measured. Next, the adhesion The agent layer was placed in Mafolu (product name "KDF-P90" manufactured by DENKEN CORPORATION), and heated at 800 ° C for 30 minutes.

Next, the mass of the adhesive layer after heating was measured, and the mass retention rate of the adhesive layer was calculated by the following formula. The calculated value of the mass retention rate is shown in Table 4.

The mass retention rate (%) of the adhesive layer = [the quality of the adhesive layer after heating] / [the quality of the adhesive layer before heating] × 100

<Interlayer adhesion between the substrate and the adhesive layer>

The adhesive sheet with the substrate prepared in the examples and the comparative examples was allowed to stand in an environment of 23 ° C and 50% RH (relative humidity) for 7 days, and attached to the adhered polycarbonate sheet (Mitsubishi Gas Chemical Co., Ltd. System, product name "YUPILON SHEET NF-2000VU"). After attaching, it was allowed to stand in an environment of 23 ° C and 50% RH (relative humidity) for 24 hours, and when the adhesive sheet attached to the substrate was slowly peeled off by hand, the substrate and the adhesive layer were evaluated by the following criteria. The adhesion between the layers. The evaluation results are shown in Table 4.

A: The interface between the adherend and the adhesive layer was peeled off, and no peeling was observed between the substrate and the adhesive layer, and the interlayer adhesion was excellent.

F: Peeling at the interface between the substrate and the adhesive layer, and the adhesion between the layers is poor.

<adhesion>

The substrate-attached adhesive sheets prepared in the examples and the comparative examples were allowed to stand in an environment of 23 ° C and 50% RH (relative humidity) for 7 days, and cut to a length of 25 mm × width. After the size of 300 mm, the surface (α) of the adhesive layer of the adhesive sheet was attached to a stainless steel plate (SUS304, No. 360 grinding) in the same environment to prepare a sample for adhesion measurement, and allowed to stand in the same environment for 24 hours.

After standing, the adhesion of each of the adhesive sheets attached to the substrate was measured by a 180° peeling method at a tensile speed of 300 mm/min based on JIS Z0237:2000. The results of the measurement of the adhesion are shown in Table 4.

<Air removal>

The adhesive sheet with a base material prepared in the examples and the comparative examples was grown to a thickness of 50 mm × a width of 50 mm, and then attached to the melamine coated plate of the adherend in such a manner as to generate air. Next, the presence or absence of air accumulation after pressing with a rubber blade was observed, and the air-removability of each adhesive sheet was evaluated by the following criteria. The evaluation results are shown in Table 4.

A: Air accumulation disappears and air removal is excellent.

F: Residual air is accumulated, and air removal is poor.

<Burst resistance>

The substrate-attached adhesive sheets prepared in the examples and the comparative examples were grown to a size of 50 mm × width 50 mm, and then attached to a polymethyl methacrylate plate having a length of 70 mm × a width of 150 mm and a thickness of 2 mm (Mitsubishi Co., Ltd., The product name "ACRYLITE L001") was strongly pressed with a rubber blade to prepare a test sample.

The test sample was allowed to stand at 23 ° C for 12 hours, and then allowed to stand in a hot air dryer at 80 ° C for 1.5 hours, and then allowed to stand in a hot air dryer at 90 ° C. The bursting state of each of the adhesive sheets was evaluated by visual observation of the state of occurrence of the burst after the heating was promoted for 1.5 hours. The evaluation results are shown in Table 4.

A: The burst was not confirmed at all.

B: Partial confirmation of bursting.

C: Fully confirmed to burst.

In the adhesive sheets produced in Examples 1 to 3, the adhesion between the substrate and the adhesive layer was excellent, and the adhesion was also good. On the other hand, the adhesive sheet produced in Comparative Example 1 was a result of poor adhesion between the substrate and the adhesive layer.

Figures 6-8 show the self-adhesive layer using a digital microscope. The surface (α) side is an image obtained by photographing the exposed surface (α) of the adhesive layer of the adhesive sheet produced in Examples 1 to 3 by an area surrounded by a rectangle having a length of 8 mm × a width of 10 mm (D). Binarized image. Further, the black portion of the binarized image corresponds to a flat surface, and the white portion corresponds to a concave portion. Further, the scales of the binary images of FIGS. 6 to 8 are 8 mm in length and 10 mm in width.

As is understood from Figs. 6 to 8, the adhesive sheets produced in Examples 1 to 3 were confirmed to have a plurality of amorphous concave portions and flat surfaces on the surface (α) of the adhesive layer. Therefore, the air release properties of the adhesive sheets are good.

Further, the adhesive sheets produced in Examples 1 to 3 were also excellent in burst resistance.

[Industrial availability]

The adhesive sheet of the same state of the present invention can be used for surface protection for identification, decoration, coating, metal sheet, etc., and can be used as an adhesive sheet having a large attachment area.

1a, 1b‧‧‧ adhesive sheets

11‧‧‧Substrate

12‧‧‧Adhesive layer

12a‧‧‧Surface (α)

12b‧‧‧Surface (β)

Claims (13)

An adhesive sheet obtained by directly laminating an adhesive layer comprising an adhesive resin and a tackifier on a substrate, the adhesive layer being composed of a plurality of layers having at least a layer (Xα) and a layer (Xβ) In the structure, the layer (Xα) includes an adhesive surface (α), and the layer (Xβ) includes a surface (β) directly laminated with the substrate, and the layer (Xα) and the layer (Xβ) satisfy The requirements (I) and (II), (I): In the Raman spectrum of the layer (Xα) obtained by Raman spectroscopy, the intensity ratio I(Xα) of the layer (Xα) calculated by the following formula (1) is 0.30 to 20.00. , (II): In the Raman spectrum of the layer (Xβ) obtained by Raman spectroscopy, the intensity ratio of the layer (Xβ) calculated by the following formula (1) is higher than that of the layer (Xβ) (Xα). The intensity ratio is smaller than I(Xα), and the formula (1): the intensity ratio I = [the peak height derived from the peak of the tackifier] / [the peak height of the peak derived from the component other than the tackifier). The adhesive sheet of claim 1, wherein the intensity ratio of the layer (Xβ) is 0 to 15.0. The adhesive sheet of claim 1 or 2, wherein the ratio of the intensity ratio I (Xβ) of the layer (Xβ) to the intensity ratio I(Xα) of the layer (Xα) [I(Xβ)/I(Xα)] is 0. ~0.90. The adhesive sheet of claim 1 or 2, wherein the layer (Xβ) forming material, that is, the composition (xβ), comprises the above-mentioned adhesive resin, and substantially does not contain the aforementioned tackifier. Such as the adhesive sheet of claim 1 or 2, wherein the formation of the layer (Xα) The material (xα) is 100 parts by mass of the above-mentioned adhesive resin and 1 part by mass or more with the above-mentioned tackifier. The adhesive sheet according to claim 1, wherein the adhesive layer is a multilayer structure in which at least a layer (Xβ), a layer (Y1), and a layer (Xα) are laminated at a time. In the Raman spectrum of the layer (Y1) obtained by Raman spectroscopy, the intensity ratio I(Y1) of the layer (Y1) calculated by the above formula (1) is 0~15.0. An adhesive sheet according to claim 6 or 7, wherein the intensity ratio of the layer (Y1) calculated by the above formula (1) in the Raman spectrum of the layer (Y1) measured by Raman spectroscopy is I (Y1) The ratio [I(Y1)/I(Xα)] of the intensity ratio I(Xα) to the layer (Xα) is 0 to 0.90. An adhesive sheet according to claim 6 or 7, wherein the layer (Y1) is a layer containing fine particles. The adhesive sheet of claim 9, wherein the composition (y1) which is a material for forming the layer (Y1) contains 15 to 100% by mass of the fine particles. The adhesive sheet of claim 9, wherein the surface (α) of the layer (Xα) has an indefinite concave portion. The adhesive sheet according to claim 9, wherein the surface (α) of the layer (Xα) has a concave portion which is formed by simultaneously drying a composition (xα) which is a material forming a layer (Xα). Xα') and the coating film (y1') which is a composition (y1) which is a material forming the layer (Y1), naturally forms a self-formation of disordered shape during the formation of the self-discipline of the adhesive layer. Former. An adhesive sheet according to claim 1 or 2, wherein the aforementioned tackifier package It contains at least one selected from the group consisting of a rosin-based tackifier, a terpene-based tackifier, a styrene-based tackifier, and a petroleum-based tackifier.