JP7739145B2 - Method for manufacturing processed thin glass, adhesive film, and adhesive film with thin glass - Google Patents

Description

The present invention relates to a method for manufacturing processed thin glass, an adhesive film, and an adhesive film with thin glass.

Flexible displays, particularly those that can be bent, are attracting attention as cover glass for smartphones and tablets. As a flexible display material, ultra-thin glass substrates (thin glass) are attracting particular attention due to their advantages over organic materials such as transparent polyimide, such as their low oxygen permeability and transparency.

Patent Document 1 discloses a method for producing an organic electroluminescence panel, in which a thin glass substrate having a thickness of 10 to 150 μm is temporarily fixed to a support plate via a double-sided pressure-sensitive adhesive tape having, on at least one side of a base layer, a heat-peelable pressure-sensitive adhesive layer containing heat-expandable microspheres that begin to expand and/or foam at a temperature higher than the vacuum deposition temperature, and electrodes are formed on the thin glass substrate.
However, as shown in the manufacturing method of an organic electroluminescence panel in Patent Document 1, since the thin glass substrate is very fragile as described above, if the thin glass substrate is transported alone, the thin glass substrate may be "cracked" or "chipped" during transportation, resulting in a decrease in yield.

International Publication No. 2010/004703

In recent years, coating and inkjet processing have increasingly been used on thin glass substrates to form polymer layers to prevent cracking, or functional layers to provide adhesion to the smartphone body or other components. However, even in these processes, transporting the thin glass substrate alone can result in cracks or chips occurring in the thin glass substrate during transport, resulting in reduced yields.

Furthermore, when fixing thin glass to a support via a self-releasing tape containing heat-expandable microspheres in the adhesive layer, the size of the foam spheres needs to be a certain ratio to the total thickness of the adhesive layer in order to achieve sufficient heat-releasing properties. However, self-releasing tape has some unevenness in thickness, hardness, and waviness, which can create voids between the support and the thin glass, preventing uniform temporary fixation. Furthermore, the presence of voids can cause the cleaning liquid to seep into these voids during wet cleaning after the coating or inkjet process, contaminating the thin glass.

In other words, the present invention aims to temporarily fix thin glass to a support using double-sided tape, thereby preventing the occurrence of voids between the support and the thin glass when the thin glass is processed or transported, and to temporarily fix the thin glass uniformly. Furthermore, the present invention aims to prevent contamination of the thin glass when a functional layer is formed on the thin glass by inkjet processing, coating, or other methods.

As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by using an adhesive film having an intermediate layer provided between an adhesive resin layer containing heat-expandable microspheres and a substrate layer, and have thus completed the present invention.
That is, the present invention can be shown as follows.

[1] A substrate layer,
an adhesive resin layer (A) provided on the first surface side of the base material layer;
an adhesive resin layer (B) provided on the second surface side of the base material layer;
and an intermediate layer (C) provided between at least one of the adhesive resin layer (A) and the base material layer and the adhesive resin layer (B) and the base material layer,
preparing an adhesive film containing heat-expandable microspheres in at least one of an adhesive resin layer (A) and an adhesive resin layer (B);
a step of attaching the adhesive film to a support via an adhesive resin layer (B);
a step of temporarily fixing a thin glass to a surface of the adhesive resin layer (A);
processing the thin glass;
A method for producing processed thin glass, comprising:
[2] The step of preparing the adhesive film includes:
The method for producing processed thin glass according to [1], further comprising the step of preparing an adhesive film including the intermediate layer (C) between the adhesive resin layer containing the heat-expandable microspheres and the substrate layer.
[3] The method according to [1] or [2], wherein the intermediate layer (C) is crosslinkable by heat and/or light.
[4] The manufacturing method according to any one of [1] to [3], wherein the thickness of the thin glass is 1 μm to 200 μm.
[5] The manufacturing method according to any one of [1] to [4], wherein the step of processing the thin glass is selected from inkjet processing on the thin glass, gravure printing, screen printing, spray coating, dispenser coating, air spray, electrostatic coating, roll coating, brush coating, roller brush coating, and dip coating.
[6] The method according to any one of [1] to [5], wherein the heat-expandable microspheres include microspheres having a shell encapsulating a substance that expands upon gasification.
[7] An adhesive film used to temporarily fix thin glass and process the thin glass,
a substrate layer;
an adhesive resin layer (A) provided on the first surface side of the base material layer;
an adhesive resin layer (B) provided on the second surface side of the base material layer;
and an intermediate layer (C) provided between at least one of the adhesive resin layer (A) and the base material layer and the adhesive resin layer (B) and the base material layer,
An adhesive film comprising at least one of an adhesive resin layer (A) and an adhesive resin layer (B) containing heat-expandable microspheres.
[8] The pressure-sensitive adhesive film according to [7], further comprising the intermediate layer (C) between the pressure-sensitive adhesive resin layer containing the heat-expandable microspheres and the substrate layer.
[9] The pressure-sensitive adhesive film according to [7] or [8], wherein the intermediate layer (C) is crosslinkable by heat or/and light.
[10] The adhesive film according to any one of [7] to [9], wherein the thickness of the thin glass is 1 μm to 200 μm.
[11] The pressure-sensitive adhesive film according to any one of [7] to [10], wherein the heat-expandable microspheres include microspheres having a shell encapsulating a substance that expands upon gasification.
[12] An adhesive film with thin glass, comprising an adhesive film and a thin glass having a thickness of 1 μm to 200 μm,
The adhesive film is
a substrate layer;
an adhesive resin layer (A) provided on the first surface side of the base material layer;
an adhesive resin layer (B) provided on the second surface side of the base material layer;
and an intermediate layer (C) provided between at least one of the adhesive resin layer (A) and the base material layer and the adhesive resin layer (B) and the base material layer,
at least one of the adhesive resin layer (A) and the adhesive resin layer (B) contains heat-expandable microspheres;
The adhesive film with the thin glass is formed by temporarily fixing the thin glass to the surface of the adhesive resin layer (A).
[13] The adhesive film with a thin glass sheet according to [12], further comprising the intermediate layer (C) between the adhesive resin layer containing the heat-expandable microspheres and the substrate layer.

The method for producing processed thin glass of the present invention uses an adhesive film comprising an adhesive resin layer containing heat-expandable microspheres and a substrate layer. By providing an intermediate layer, the formation of voids between the support and the thin glass can be suppressed. This allows the thin glass to be uniformly temporarily fixed to the support when the thin glass is processed, and also prevents contamination of the processed thin glass.

1 is a cross-sectional view schematically showing an example of a method for manufacturing processed thin glass according to the present embodiment. 1 is a cross-sectional view schematically showing an example of a method for manufacturing processed thin glass according to the present embodiment. 1 is a cross-sectional view schematically illustrating an example of a method for manufacturing processed thin glass according to the present embodiment. 1 is a cross-sectional view schematically illustrating an example of a method for manufacturing processed thin glass according to the present embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In all the drawings, the same components are denoted by the same reference numerals and the description thereof will be omitted where appropriate. Also, the drawings are schematic diagrams and do not necessarily correspond to the actual dimensional ratios.
In the specification, unless otherwise specified, the expression "A to B" regarding a numerical range means from A to B. For example, 1 to 5% means from 1% to 5%.
In the present specification, "(meth)acrylic" means acrylic, methacrylic, or both acrylic and methacrylic.

The method for producing processed thin glass of this embodiment includes the steps of: preparing an adhesive film comprising a substrate layer, an adhesive resin layer (A) provided on a first surface of the substrate layer, an adhesive resin layer (B) provided on a second surface of the substrate layer, and an intermediate layer (C) provided between the adhesive resin layer (A) and the substrate layer and/or between the adhesive resin layer (B) and the substrate layer, the adhesive film containing heat-expandable microspheres in at least one of the adhesive resin layer (A) and the adhesive resin layer (B);
a step of attaching the adhesive film to a support via an adhesive resin layer (B);
a step of temporarily fixing a thin glass to a surface of the adhesive resin layer (A);
and processing the thin glass.
According to the manufacturing method for processed thin glass of this embodiment, it is possible to suppress the occurrence of voids between the support and the thin glass, so that the thin glass can be uniformly temporarily fixed to the support when processing the thin glass, resulting in excellent workability of the thin glass and further preventing contamination of the thin glass.

The manufacturing method for processed thin glass of this embodiment will be explained below using first to fourth embodiments.

[First embodiment]
The method for producing processed thin glass of this embodiment includes the following steps as shown in FIGS.
Step a: An adhesive film 10 is prepared, comprising a substrate layer 12, an adhesive resin layer 14 containing heat-expandable microspheres a and provided on the first surface 12a of the substrate layer 12, an adhesive resin layer 16 provided on the second surface 12b of the substrate layer 12, and an intermediate layer 18 provided between the adhesive resin layer 14 and the substrate layer 12 (FIG. 1(a)).
Step b: The adhesive film 10 is attached to the support 20 via the adhesive resin layer 16 (FIG. 1(a)).
Step c: A thin glass 30 is temporarily fixed to the surface of the adhesive resin layer 14 (FIG. 1(b)).
Step d: The thin glass 30 is processed (FIG. 1(c)).

According to the manufacturing method of processed thin glass of this embodiment, the occurrence of voids between the adhesive resin layer 14 and the thin glass 30 can be suppressed, so that the thin glass can be uniformly temporarily fixed to the support 12 when processing the thin glass, and further, contamination of the processed thin glass can be prevented.
Furthermore, the presence of the intermediate layer 18 allows the thin glass 30 to be uniformly attached to the surface of the layer 14, and the thin glass 30 can be positioned relative to the support 20, resulting in excellent workability of the thin glass 30. Furthermore, since the thin glass 30 is attached to the surface of the layer 14, the processed thin glass can be peeled off stress-free in a subsequent process.

(Step a)
In this step, an adhesive film 10 having a laminated structure as shown in Fig. 1(a) is prepared. In this embodiment, the adhesive film 10 is used to process the temporarily fixed thin glass.

(Base material layer 12)
The base layer 12 constituting the pressure-sensitive adhesive film 10 is a layer provided for the purpose of improving the properties of the pressure-sensitive adhesive film 10 such as ease of handling, mechanical properties, and heat resistance.
The base layer 12 is not particularly limited, but may be, for example, a resin film.

The resin constituting the resin film can be any known thermoplastic resin. Examples include one or more selected from the following: polyolefins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamides such as nylon-6, nylon-66, and polymethaxylene adipamide; polyacrylate; polymethacrylate; polyvinyl chloride; polyvinylidene chloride; polyimide; polyetherimide; ethylene-vinyl acetate copolymer; polyacrylonitrile; polycarbonate; polystyrene; ionomer; polysulfone; polyethersulfone; and polyphenylene ether.

Among these, from the viewpoint of an excellent balance of transparency, mechanical strength, price, etc., one or more selected from polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyimide are preferred, and at least one selected from polyethylene terephthalate and polyethylene naphthalate is more preferred.

The substrate layer 12 may be a single layer or two or more layers.
Furthermore, the form of the resin film used to form the base layer 12 may be a stretched film or a uniaxially or biaxially stretched film, but from the viewpoint of improving the mechanical strength of the base layer 12, a uniaxially or biaxially stretched film is preferred.

From the viewpoint of obtaining good film properties, the thickness of the base layer 12 is preferably 1 μm or more and 500 μm or less, more preferably 5 μm or more and 300 μm or less, and even more preferably 10 μm or more and 250 μm or less.
The substrate layer 12 may be subjected to a surface treatment to improve adhesion to other layers, such as corona treatment, plasma treatment, undercoat treatment, or primer coat treatment.

(Adhesive resin layer 14)
The adhesive film 10 according to this embodiment includes an adhesive resin layer 14 on the first surface 12a side of the base layer 12. The adhesive resin layer 14 is a layer that comes into contact with the surface of the thin glass sheet 30 to temporarily fix the thin glass sheet 30 during, for example, the processing step of the thin glass sheet.
The adhesive resin layer 14 contains heat-expandable microspheres a and is a heat-peelable adhesive resin layer, which allows the thin glass 30 to be easily peeled off from the adhesive film 10 by heating.

Thermal-expandable microspheres (a) can be, for example, microencapsulated blowing agents. Examples of such thermally expandable microspheres include microspheres in which a substance that easily gasifies and expands upon heating, such as isobutane, propane, or pentane, is encapsulated within an elastic shell. Examples of materials that make up the shell include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone. Thermally expandable microspheres can be produced by, for example, coacervation or interfacial polymerization.

The content of the heat-expandable microspheres a can be appropriately set depending on the expansion ratio and adhesive strength reduction of the adhesive resin layer 14, and is not particularly limited. For example, the content is 1 part by mass or more and 150 parts by mass or less, preferably 10 parts by mass or more and 130 parts by mass or less, and more preferably 12 parts by mass or more and 100 parts by mass or less, per 100 parts by mass of the adhesive resin (A1) in the adhesive resin layer 14.
It is preferable to design the temperature at which gas is generated or the temperature at which the heat-expandable microspheres thermally expand to be higher than 150°C or higher than 170°C.

Examples of the adhesive resin (A1) that constitutes the adhesive resin layer 14 include (meth)acrylic resin (a), urethane resin, silicone resin, polyolefin resin, polyester resin, polyamide resin, fluorine resin, and styrene-diene block copolymer resin. Among these, (meth)acrylic resin (a) is preferred.

The (meth)acrylic adhesive resin (a) used in the adhesive resin layer 14 may be, for example, a copolymer containing a (meth)acrylic acid alkyl ester monomer unit (a1) and a monomer unit (a2) having a functional group capable of reacting with a crosslinking agent.
In this embodiment, the (meth)acrylic acid alkyl ester means an acrylic acid alkyl ester, a methacrylic acid alkyl ester, or a mixture thereof.

The (meth)acrylic adhesive resin (a) according to this embodiment can be obtained, for example, by copolymerizing a monomer mixture containing a (meth)acrylic acid alkyl ester monomer (a1) and a monomer (a2) having a functional group capable of reacting with a crosslinking agent.

Examples of monomer (a1) that forms the (meth)acrylic acid alkyl ester monomer unit (a1) include (meth)acrylic acid alkyl esters having an alkyl group containing approximately 1 to 12 carbon atoms. (Meth)acrylic acid alkyl esters having an alkyl group containing 1 to 8 carbon atoms are preferred. Specific examples include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. These may be used alone or in combination of two or more.

In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the (meth)acrylic acid alkyl ester monomer unit (a1) is preferably 10% by mass or more and 98.9% by mass or less, more preferably 50% by mass or more and 97% by mass or less, and even more preferably 85% by mass or more and 95% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

Examples of the monomer (a2) that forms the monomer (a2) having a functional group reactive with a crosslinking agent include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, and tert-butylaminoethyl methacrylate. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like. These may be used alone or in combination of two or more.
In the (meth)acrylic adhesive resin (a) according to the present embodiment, the content of the monomer unit (a2) is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is 100% by mass.

The (meth)acrylic adhesive resin (a) according to this embodiment may further contain, in addition to the monomer unit (a1) and the monomer unit (a2), a bifunctional monomer unit (a3) or a specific comonomer unit having surfactant properties (hereinafter referred to as a polymerizable surfactant).
The polymerizable surfactant has the property of copolymerizing with the monomers (a1), (a2) and (a3), and also acts as an emulsifier when emulsion polymerization is carried out.

Examples of the monomer (a3) that forms the bifunctional monomer unit (a3) include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and, for example, diacrylates or acrylates having both terminals. or dimethacrylates whose main chain structure is propylene glycol type (for example, NOF Corporation's trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol type (for example, NOF Corporation's trade names: ADT-250, ADT-850), or a mixture of these (for example, NOF Corporation's trade names: ADET-1800, ADPT-4000).

In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the monomer unit (a3) is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 15% by mass or less, even more preferably 0.1% by mass or more and 20% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

Examples of polymerizable surfactants include those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aqualon RN-10, RN-20, RN-30, RN-50, etc.), those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of the ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: Aqualon HS-10, HS-20, HS-1025, etc.), and sulfosuccinic acid diesters with a polymerizable double bond in the molecule (manufactured by Kao Corporation; trade names: Latemul S-120A, S-180A, etc.).

In the (meth)acrylic adhesive resin (a) according to this embodiment, the content of the polymerizable surfactant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 20% by mass or less, even more preferably 0.1% by mass or more and 15% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less, when the sum of all monomer units in the (meth)acrylic adhesive resin (a) is taken as 100% by mass.

The (meth)acrylic adhesive resin (a) according to this embodiment may further contain, as necessary, a monomer unit formed from a monomer having a polymerizable double bond, such as vinyl acetate, acrylonitrile, or styrene.

The polymerization reaction mechanism of the (meth)acrylic adhesive resin (a) according to the present embodiment may be radical polymerization, anionic polymerization, cationic polymerization, etc. Taking into consideration the production cost of the (meth)acrylic adhesive resin (a), the influence of functional groups of the monomers, the influence of ions on the surface of electronic components, etc., polymerization by radical polymerization is preferred.
When polymerizing by radical polymerization reaction, the radical polymerization initiator may be benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butylperoxy-2-hexanoate, t-butyl peroxy Examples of the peroxide include organic peroxides such as 2-ethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, t-butyl peroxide, and di-t-amyl peroxide; inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate; and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 4,4'-azobis-4-cyanovaleric acid.

When polymerization is carried out by emulsion polymerization, among these radical polymerization initiators, inorganic peroxides such as water-soluble ammonium persulfate, potassium persulfate, and sodium persulfate, and azo compounds having a carboxyl group in the molecule such as water-soluble 4,4'-azobis-4-cyanovaleric acid are preferred. Considering the influence of ions on the surface of electronic components, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferred, and azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferred.

The adhesive resin layer 14 according to this embodiment preferably further contains, in addition to the adhesive resin (A1), a crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule.
The crosslinking agent (A2) having two or more crosslinkable functional groups in one molecule is used to react with the functional groups of the adhesive resin (A1) to adjust the adhesive strength and cohesive strength.
Examples of such crosslinking agents (A2) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate; and trimethylolpropane-tri-β-aziridinylpropionate. aziridine compounds such as tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine compounds such as hexamethoxymethylolmelamine. These may be used alone or in combination of two or more.
Among these, it is preferable to contain one or more compounds selected from the group consisting of epoxy compounds, isocyanate compounds, and aziridine compounds.

The content of the crosslinking agent (A2) is usually preferably within a range such that the number of functional groups in the crosslinking agent (A2) is not greater than the number of functional groups in the adhesive resin (A1). However, if necessary, an excess amount of the crosslinking agent (A2) may be contained in cases where new functional groups are generated by the crosslinking reaction or where the crosslinking reaction is slow.
The content of the crosslinking agent (A2) in the adhesive resin layer 14 is preferably 0.1 parts by mass or more and 10 parts by mass or less, and more preferably 0.5 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the adhesive resin (A1).

From the viewpoint of improving adhesion to the support substrate, the adhesive resin layer 14 according to this embodiment preferably contains a tackifier resin in addition to the adhesive resin (A1). Incorporating a tackifier resin into the adhesive resin layer 14 is preferred because it facilitates adjustment of adhesion to the support substrate at around room temperature. Tackifier resins preferably have a softening point of 100°C or higher. Specific examples of tackifier resins include rosin-based resins such as rosin derivatives that have been treated with esterification or the like; terpene-based resins such as α-pinene, β-pinene, dipentene, and terpene phenol; natural rosins such as gum-based, wood-based, and tall oil-based rosins; hydrogenated, disproportionated, polymerized, or maleated natural rosins; petroleum resins; and coumarone-indene resins.

Among these, those with a softening point in the range of 100 to 160°C are more preferred, and those in the range of 120 to 150°C are particularly preferred. Using a tackifier resin with a softening point within this range not only reduces contamination and adhesive residue on the support substrate, but also enables improved adhesion to the support substrate in working environments. Furthermore, using a polymerized rosin ester-based tackifier resin not only reduces contamination and adhesive residue on the support substrate, but also improves adhesion to the support substrate in environments of 80 to 130°C, and in the case of a heat-expandable adhesive containing heat-expandable microspheres, it enables easier peeling from the support substrate after the heat-expandable microspheres expand.

The blending ratio of the tackifier resin is not particularly limited, and may be selected as appropriate so as to adjust the elastic modulus of the adhesive resin layer 14 within the desired predetermined numerical range. However, in terms of the elastic modulus and initial peel strength of the adhesive resin layer 14, a blending ratio of 1 to 100 parts by mass per 100 parts by mass of adhesive resin (A1) is preferred. When the blending ratio of the tackifier resin is equal to or greater than the lower limit per 100 parts by mass of adhesive resin (A1), adhesion to the support substrate during operation tends to be improved. On the other hand, when the blending ratio is equal to or less than the upper limit, attachment to the support substrate at room temperature tends to be improved. In terms of adhesion to the support substrate and attachment at room temperature, a blending ratio of the tackifier resin of 2 to 50 parts by mass per 100 parts by mass of adhesive resin (A1) is even more preferred. Furthermore, the acid value of the tackifier resin is preferably 30 or less. When the acid value of the tackifier resin is equal to or less than the upper limit, adhesive residue on the support substrate tends to be less likely to be left during peeling.

The adhesive resin layer 14 may contain additives such as plasticizers as other components. The total content of the adhesive resin (A1), crosslinking agent (A2), and tackifier resin in the adhesive resin layer 14 is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entire adhesive resin layer 14 is taken as 100% by mass. Furthermore, when the adhesive resin layer 14 is composed of a heat-expandable adhesive, the total content of the adhesive resin (A1), crosslinking agent (A2), tackifier resin, gas-generating component, and heat-expandable microspheres in the adhesive resin layer 14 is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entire adhesive resin layer 14 is taken as 100% by mass.

The adhesive resin layer 14 may be a single layer or multiple layers. For example, by laminating two or more layers that expand to different degrees upon heating to form the adhesive resin layer 14, it is possible to change the adhesiveness/thermal releasability between one side and the other side of the adhesive resin layer 14.
The thickness of the adhesive resin layer 14 is, for example, preferably 5 μm or more and 300 μm or less, and more preferably 20 μm or more and 150 μm or less.

The average particle size _D50 of the heat-expandable microspheres a is, for example, preferably from 1 μm to 47 μm, more preferably from 5 μm to 27 μm. Furthermore, the particle size _D99.9 of the heat-expandable microspheres a is preferably from 20 μm to 300 μm, more preferably from 30 μm to 180 μm. In this embodiment, the average particle size _D50 of the heat-expandable microspheres a is larger than the thickness of the adhesive resin layer 14, or the particle size _D99.9 is larger than the thickness of the adhesive resin layer 14.
When a high-hardness support 20 and a high-hardness thin glass sheet 30 are laminated on both sides of the adhesive film 10, the particle size of the heat-expandable microspheres a affects the formation of voids between the thin glass sheet 30 and the adhesive resin layer 14. The adhesive film 10 of this embodiment includes the intermediate layer 18 between the substrate layer 12 and the adhesive resin layer 14. Even if the particle size of the heat-expandable microspheres a exceeds the thickness of the adhesive resin layer 14, the formation of voids between the thin glass sheet 30 and the adhesive resin layer 14 can be suppressed. This allows the thin glass sheet 30 to be uniformly temporarily fixed during processing and prevents contamination of the thin glass sheet 30.
The adhesive resin layer may be composed of multiple layers, including an adhesive resin layer 14 containing heat-expandable microspheres a and another adhesive resin layer having the same composition as layer 14 but excluding the heat-expandable microspheres a. In this embodiment, even if the average particle diameter _D50 of the heat-expandable microspheres a is greater than T/2 or the average particle diameter _D99.9 of the heat-expandable microspheres a is greater than T/2, where T is the total thickness of the adhesive resin layer, the intermediate layer 18 can still provide the above-mentioned effects.
The average particle size of the heat-expandable microspheres a can be measured using a general particle shape/particle size analyzer, such as Microtrac MT3000II, FPIA-3000, or Mastersizer 3000E.

The adhesive resin layer 14 can be formed, for example, by applying an adhesive coating liquid onto the intermediate layer 18, or by transferring the adhesive resin layer 14 formed on a separator onto the intermediate layer 18.
The adhesive coating liquid can be applied by conventional coating methods such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coater method, a comma coater method, or a die coater method. The drying conditions for the applied adhesive are not particularly limited, but it is generally preferable to dry the applied adhesive at a temperature range of 80 to 200°C for 10 seconds to 10 minutes. It is more preferable to dry the applied adhesive at 80 to 170°C for 15 seconds to 5 minutes. To sufficiently promote the crosslinking reaction between the crosslinker and the adhesive, the adhesive coating liquid may be heated at 40 to 80°C for about 5 to 300 hours after drying.

The base material layer 12 and the adhesive resin layer 14 may be formed by co-extrusion molding, or may be formed by laminating a film-like base material layer 12 and a film-like adhesive resin layer 14 together.
The base material layer 12, the intermediate layer 18, and the adhesive resin layer 14 may be formed by co-extrusion molding, or may be formed by laminating (stacking) the film-like base material layer 12, the film-like intermediate layer 18, and the film-like adhesive resin layer 14.

(Adhesive resin layer 16)
The adhesive resin layer 16 is a layer provided on the second surface 12b side, which is opposite to the first surface 12a of the base layer 12. The adhesive resin layer 16 is a layer that comes into contact with the surface of the support 20 (described later) during the thin glass processing step, for example, to temporarily fix the "adhesive film with thin glass attached."

The adhesive resin layer 16 usually contains an adhesive resin (B1).
Examples of the adhesive resin (B1) include (meth)acrylic adhesive resins (b), silicone adhesive resins, urethane adhesive resins, olefin adhesive resins, and styrene adhesive resins.
Among these, the (meth)acrylic adhesive resin (b) is preferred from the viewpoint of facilitating adjustment of adhesive strength.

The adhesive resin layer 16 may be a radiation-crosslinkable adhesive resin layer whose adhesive strength can be reduced by radiation. When the radiation-crosslinkable adhesive resin layer is irradiated with radiation, crosslinking occurs, significantly reducing the adhesive strength, making it easier to peel the adhesive film 10 from the thin glass. Examples of radiation include ultraviolet rays, electron beams, and infrared rays.
The radiation crosslinkable adhesive resin layer is preferably an ultraviolet crosslinkable adhesive resin layer.

The (meth)acrylic adhesive resin (b) used in the adhesive resin layer 16 may be, for example, a copolymer containing a (meth)acrylic acid alkyl ester monomer unit (b1) and a monomer unit (b2) having a functional group capable of reacting with a crosslinking agent.
In this embodiment, the (meth)acrylic acid alkyl ester means an acrylic acid alkyl ester, a methacrylic acid alkyl ester, or a mixture thereof.

The (meth)acrylic adhesive resin (b) according to this embodiment can be obtained, for example, by copolymerizing a monomer mixture containing a (meth)acrylic acid alkyl ester monomer (b1) and a monomer (b2) having a functional group capable of reacting with a crosslinking agent.

Examples of the monomer (b1) that forms the (meth)acrylic acid alkyl ester monomer unit (b1) include (meth)acrylic acid alkyl esters having an alkyl group containing approximately 1 to 12 carbon atoms. (Meth)acrylic acid alkyl esters having an alkyl group containing 1 to 8 carbon atoms are preferred. Specific examples include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. These may be used alone or in combination of two or more.

In the (meth)acrylic adhesive resin (b) according to this embodiment, the content of the (meth)acrylic acid alkyl ester monomer unit (b1) is preferably 10% by mass or more and 98.9% by mass or less, more preferably 50% by mass or more and 97% by mass or less, and even more preferably 85% by mass or more and 95% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass.

Examples of the monomer (b2) that forms the monomer (b2) having a functional group reactive with a crosslinking agent include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid, itaconic acid monoalkyl ester, mesaconic acid monoalkyl ester, citraconic acid monoalkyl ester, fumaric acid monoalkyl ester, maleic acid monoalkyl ester, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, and tert-butylaminoethyl methacrylate. Preferred are acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, and the like. These may be used alone or in combination of two or more.
In the (meth)acrylic adhesive resin (b) according to the present embodiment, the content of the monomer unit (b2) is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is 100% by mass.

The (meth)acrylic adhesive resin (b) according to this embodiment may further contain, in addition to the monomer unit (b1) and the monomer unit (b2), a bifunctional monomer unit (b3) or a specific comonomer unit having surfactant properties (hereinafter referred to as a polymerizable surfactant).
The polymerizable surfactant has the property of copolymerizing with the monomers (b1), (b2) and (b3), and also acts as an emulsifier when emulsion polymerization is carried out.

Examples of the monomer (b3) that forms the bifunctional monomer unit (b3) include allyl methacrylate, allyl acrylate, divinylbenzene, vinyl methacrylate, vinyl acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tetraethylene glycol di(meth)acrylate, and, for example, diacrylates or acrylates having both ends or dimethacrylates whose main chain structure is propylene glycol type (for example, NOF Corporation, trade names: PDP-200, PDP-400, ADP-200, ADP-400), tetramethylene glycol type (for example, NOF Corporation, trade names: ADT-250, ADT-850), or a mixture of these (for example, NOF Corporation, trade names: ADET-1800, ADPT-4000).

In the (meth)acrylic adhesive resin (b) according to this embodiment, the content of the monomer unit (b3) is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 15% by mass or less, even more preferably 0.1% by mass or more and 20% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less, when the total of all monomer units in the (meth)acrylic adhesive resin (b) is taken as 100% by mass.

Examples of the polymerizable surfactant include those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: AQUALON RN-10, RN-20, RN-30, RN-50, etc.), those in which a polymerizable 1-propenyl group has been introduced into the benzene ring of an ammonium salt of a sulfate ester of polyoxyethylene nonylphenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; trade names: AQUALON HS-10, HS-20, HS-1025, etc.), and sulfosuccinic acid diesters having a polymerizable double bond in the molecule (manufactured by Kao Corporation; trade names: Latemul S-120A, S-180A, etc.).
In the (meth)acrylic adhesive resin (b) according to the present embodiment, the content of the polymerizable surfactant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 15% by mass or less, even more preferably 0.1% by mass or more and 20% by mass or less, and particularly preferably 0.1% by mass or more and 5% by mass or less, when the sum of all monomer units in the (meth)acrylic adhesive resin (b) is 100% by mass.

The (meth)acrylic adhesive resin (b) according to this embodiment may further contain, as necessary, a monomer unit formed from a monomer having a polymerizable double bond, such as vinyl acetate, acrylonitrile, or styrene.

The polymerization reaction mechanism of the (meth)acrylic adhesive resin (b) according to the present embodiment may be radical polymerization, anionic polymerization, cationic polymerization, etc. Taking into consideration the production cost of the (meth)acrylic adhesive resin (b), the influence of functional groups of the monomer, the influence of ions on the surface of electronic components, etc., polymerization by radical polymerization is preferred.
When polymerizing by radical polymerization reaction, the radical polymerization initiator may be benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 3,3,5-trimethylhexanoyl peroxide, di-2-ethylhexyl peroxydicarbonate, methyl ethyl ketone peroxide, t-butyl peroxyphthalate, t-butyl peroxybenzoate, di-t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butylperoxy-2-hexanoate, t-butyl peroxy Examples of the peroxide include organic peroxides such as 2-ethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, t-butyl peroxide, and di-t-amyl peroxide; inorganic peroxides such as ammonium persulfate, potassium persulfate, and sodium persulfate; and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 4,4'-azobis-4-cyanovaleric acid.

When polymerization is carried out by emulsion polymerization, among these radical polymerization initiators, inorganic peroxides such as water-soluble ammonium persulfate, potassium persulfate, and sodium persulfate, and azo compounds having a carboxyl group in the molecule such as water-soluble 4,4'-azobis-4-cyanovaleric acid are preferred. Considering the influence of ions on the surface of electronic components, azo compounds having a carboxyl group in the molecule such as ammonium persulfate and 4,4'-azobis-4-cyanovaleric acid are more preferred, and azo compounds having a carboxyl group in the molecule such as 4,4'-azobis-4-cyanovaleric acid are particularly preferred.

In addition to the adhesive resin (B1), the adhesive resin layer 16 according to this embodiment preferably further contains a crosslinking agent (B2) having two or more crosslinkable functional groups per molecule.

The crosslinking agent (B2) having two or more crosslinkable functional groups in one molecule can be used to adjust the adhesive strength and cohesive strength by reacting with the functional groups of the adhesive resin (B1).
Examples of such crosslinking agents (B2) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcinol diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate triadduct of trimethylolpropane, polyisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate; and trimethylolpropane-tri-β-aziridinylpropionate. aziridine compounds such as tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate; tetrafunctional epoxy compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane; and melamine compounds such as hexamethoxymethylolmelamine. These may be used alone or in combination of two or more.
Among these, it is preferable to contain one or more compounds selected from the group consisting of epoxy compounds, isocyanate compounds, and aziridine compounds.

The content of the crosslinking agent (B2) is usually preferably within a range in which the number of functional groups in the crosslinking agent (B2) is not greater than the number of functional groups in the adhesive resin (B1). However, if necessary, an excess amount of the crosslinking agent (B2) may be contained in cases where new functional groups are generated by the crosslinking reaction or where the crosslinking reaction is slow.
The content of the crosslinking agent (B2) in the adhesive resin layer 16 is preferably 0.1 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the adhesive resin (B1), from the viewpoint of improving the balance between the heat resistance and adhesion of the adhesive resin layer 16.

The adhesive resin layer 16 may contain other components such as additives such as plasticizers and tackifying resins. When the adhesive resin layer 16 is a radiation-crosslinked adhesive resin layer, it may contain various additives for radiation crosslinking. The total content of the adhesive resin (B1) and crosslinking agent (B2) in the adhesive resin layer 16, when the entire adhesive resin layer 16 is taken as 100% by mass, is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. This further reduces adhesive residue on the support 20 when the adhesive film 10 is peeled from the support 20.

The adhesive resin layer 16 may be a single layer or multiple layers.
The thickness of the adhesive resin layer 16 is not particularly limited, but is preferably, for example, 1 μm or more and 100 μm or less, and more preferably 3 μm or more and 50 μm or less.

The adhesive resin layer 16 can be formed, for example, by applying an adhesive to the base layer 12. The adhesive may be dissolved in a solvent and applied as a coating liquid, or may be applied as a water-based emulsion, or the liquid adhesive may be directly applied.
Among these, an aqueous emulsion coating liquid is preferred. Examples of the aqueous emulsion coating liquid include a coating liquid obtained by dispersing a (meth)acrylic adhesive resin (b), a silicone adhesive resin, a urethane adhesive resin, an olefin adhesive resin, a styrene adhesive resin, or the like in water.

A pressure-sensitive adhesive coating solution dissolved in an organic solvent may also be used. There are no particular restrictions on the organic solvent, and it may be appropriately selected from known solvents taking into account solubility and drying time. Examples of organic solvents include esters such as ethyl acetate and methyl acetate; ketones such as acetone and MEK; aromatic solvents such as benzene, toluene, and ethylbenzene; linear or cyclic aliphatic solvents such as heptane, hexane, and cyclohexane; and alcohols such as isopropanol and butanol. Ethyl acetate and toluene are preferred as organic solvents. These solvents may be used alone or in combination of two or more.

The adhesive coating solution can be applied using conventional coating methods such as roll coating, reverse roll coating, gravure roll coating, bar coating, comma coating, and die coating. There are no particular restrictions on the drying conditions for the applied adhesive, but it is generally preferable to dry it for 10 seconds to 10 minutes at a temperature range of 80 to 200°C. It is even more preferable to dry it for 15 seconds to 5 minutes at a temperature range of 80 to 170°C. To fully promote the crosslinking reaction between the crosslinker and adhesive, the adhesive coating solution may be heated at 40 to 80°C for approximately 5 to 300 hours after drying is complete.

The base material layer 12 and the adhesive resin layer 14 or intermediate layer 18 may be formed by co-extrusion molding, or may be formed by laminating a film-like base material layer 12 and a film-like adhesive resin layer 14. In the examples described below, the adhesive film is manufactured by first forming the adhesive resin layer 14 on the surface of a separator (release film), and then bonding the adhesive resin layer 14 to other layers.

(Intermediate layer 18)
The pressure-sensitive adhesive film 10 according to this embodiment has an intermediate layer 18 that can be crosslinked by an external stimulus between the substrate layer 12 and the pressure-sensitive adhesive resin layer 14 .
The intermediate layer 18 absorbs the irregularities on the surface of the adhesive resin layer 14 caused by the heat-expandable microspheres a and suppresses the formation of voids between the support 12 and the thin glass 30, thereby enabling the thin glass to be uniformly temporarily fixed during processing and preventing contamination of the thin glass. Furthermore, the presence of the intermediate layer 18 allows the thin glass 30 to be positioned relative to the support 20, improving the workability of the thin glass 30.
Furthermore, the intermediate layer 18 can be cross-linked and hardened by an external stimulus, thereby increasing the elastic modulus of the intermediate layer 18. This allows the thin glass 30 to be more accurately positioned relative to the support 20 during processing, making the thin glass 30 even more easily processable.
The external stimulus may be, for example, heat or light.
The intermediate layer 18 can also be described as an irregularity-absorbing resin layer 18 due to its function.

The resin constituting the intermediate layer 18 is not particularly limited as long as it exhibits irregularity absorbency, and for example, a thermoplastic resin is preferred. Specifically, one or more resins selected from the group consisting of polyolefin resins, polystyrene resins, and (meth)acrylic resins are more preferred. From another perspective, resins having a Shore D hardness of preferably 50 or less, more preferably 40 or less, according to ASTM D-2240 Shore D hardness are preferred.
Even when the resin constituting the intermediate layer 18 is not a thermoplastic resin, it is preferable that the intermediate layer 18 has the same unevenness absorbability as described above.

The intermediate layer 18 preferably contains a resin, a crosslinking agent, and an initiator that generates active chemical species in response to an external stimulus. By including these components in the intermediate layer 18, the intermediate layer 18 can be more effectively crosslinked in response to an external stimulus, and the elastic modulus of the intermediate layer 18 can be further improved. This makes it possible to prevent the intermediate layer from softening due to heat in the process of sealing the electronic components with a sealing material, and as a result, it is possible to further prevent the electronic components from sinking into the PSA film 10 due to the pressure of the sealing material.
Depending on the chemical structure and reactivity of the resin and cross-linking agent, the intermediate layer 18 may be cross-linked (cured) by an external stimulus even if it does not necessarily contain an initiator.

The resin that can be used to form the intermediate layer 18 is not particularly limited, but preferred examples include the resin described above as the adhesive resin (A1) in the adhesive resin layer 14.

Other resins that can be used to form the intermediate layer 18 are not particularly limited, and examples thereof include olefin-based resins such as ethylene-α-olefin copolymers containing ethylene and an α-olefin having 3 to 20 carbon atoms, high-density ethylene resins, low-density ethylene resins, medium-density ethylene resins, very-low-density ethylene resins, linear low-density polyethylene (LLDPE) resins, propylene (co)polymers, 1-butene (co)polymers, 4-methylpentene-1 (co)polymers, ethylene-cyclic olefin copolymers, ethylene-α-olefin-cyclic olefin copolymers, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-aromatic vinyl copolymers, and ethylene-α-olefin-aromatic vinyl copolymers; ethylene-unsaturated carboxylic anhydride copolymers, ethylene-α-olefin-unsaturated carboxylic anhydride copolymers, and olefin-based resins such as ethylene-α-olefin-unsaturated carboxylic anhydride copolymers. ethylene-carboxylic acid anhydride copolymers such as ethylene-epoxy-containing unsaturated compound copolymers and ethylene-α-olefin-epoxy-containing unsaturated compound copolymers; ethylene-(meth)acrylic acid ester copolymers such as ethylene-ethyl (meth)acrylate copolymer, ethylene-methyl (meth)acrylate copolymer, ethylene-propyl (meth)acrylate copolymer, ethylene-butyl (meth)acrylate copolymer, ethylene-hexyl (meth)acrylate copolymer, ethylene-2-hydroxyethyl (meth)acrylate copolymer, ethylene-2-hydroxypropyl (meth)acrylate copolymer, and ethylene-glycidyl (meth)acrylate copolymer; ethylene-(meth)acrylic acid copolymer, ethylene-maleic acid copolymer, ethylene-fumaric acid copolymer, ethylene - Ethylene-ethylenically unsaturated acid copolymers such as crotonic acid copolymer; ethylene-vinyl ester copolymers such as ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butyrate copolymer, and ethylene-vinyl stearate copolymer; ethylene-styrene copolymers, etc.; unsaturated carboxylic acid ester (co)polymers such as (meth)acrylic acid ester (co)polymers; ionomer resins such as ethylene-metal acrylate copolymer and ethylene-metal methacrylate copolymer; urethane-based resins; silicone-based resins; acrylic acid-based resins; methacrylic acid-based resins; cyclic olefin (co)polymers; α-olefin-aromatic vinyl compound-aromatic polyene copolymers; ethylene-α-olefin-aromatic vinyl compound; aromatic polyene copolymers; ethylene-aromatic vinyl compound-aromatic polyene copolymers; styrene-based One or more materials selected from the group consisting of resins; acrylonitrile-butadiene-styrene copolymers; styrene-conjugated diene copolymers; acrylonitrile-styrene copolymers; acrylonitrile-ethylene-α-olefin-non-conjugated polyene-styrene copolymers; acrylonitrile-ethylene-α-olefin-conjugated polyene-styrene copolymers; methacrylic acid-styrene copolymers; ethylene terephthalate resins; fluororesins; polyester carbonates; polyvinyl chloride; polyvinylidene chloride; polyolefin-based thermoplastic elastomers; polystyrene-based thermoplastic elastomers; polyurethane-based thermoplastic elastomers; 1,2-polybutadiene-based thermoplastic elastomers; trans-polyisoprene-based thermoplastic elastomers; chlorinated polyethylene-based thermoplastic elastomers; liquid crystalline polyesters; and polylactic acid can be used.
The intermediate layer 18 may include only one resin, or may include two or more resins.

The cross-linking agent that can be contained in the intermediate layer 18 is not particularly limited, and may be any agent that undergoes a cross-linking reaction due to chemical species generated from an initiator.
Preferred crosslinking agents include polyfunctional (meth)acrylate compounds, more specifically urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate.

Examples of the crosslinking agent include various monomers or oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based.
The amount of the crosslinking agent is, for example, 5 parts by mass or more and 500 parts by mass or less, preferably 40 parts by mass or more and 150 parts by mass or less, per 100 parts by mass of the resin (base polymer) such as a (meth)acrylic polymer.

From another perspective, the intermediate layer 18 may contain one or more crosslinking agents (A2) that can be contained in the aforementioned adhesive resin layer (A). Specifically, the intermediate layer 18 may contain an isocyanate-based compound. When such a crosslinking agent is used, the amount thereof is, for example, 0.01 to 5 parts by weight, preferably 0.01 to 3 parts by weight, per 100 parts by weight of the resin (base polymer).

The initiator (an initiator that generates active chemical species in response to an external stimulus) that can be contained in the intermediate layer 18 is not particularly limited as long as it is capable of crosslinking the resin and/or crosslinking agent in the intermediate layer 18 by heat or light. Considering that other layers may not have high light transmittance and that light may be blocked by electronic components, the initiator is preferably an initiator that generates active chemical species by heat.
The chemical species generated from the initiator may be appropriately selected based on the functional groups possessed by the resin and/or the crosslinking agent, and is typically a radical or a cation.

Examples of the initiator include aromatic ketones, onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, azo compounds, etc. These may be used alone or in combination of two or more.
Among these, azo compounds or organic peroxides are preferred in terms of availability, ease of handling, etc., and organic peroxides are more preferred.

Commercially available initiators include V-70, V-65, V-601, V-59, V-40, VF-096, V-30, VAm-110, and VAm-111 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), Niper BW, Niper BMT, Perloyl TCP, Perloyl L, Perloyl 355, Perloyl SA, Perhexa HC, Perbutyl 355, Perbutyl D, Perbutyl L, Perbutyl ND, Perocta O, Perhexyl D, Perhexyl O, and Perhexyl PV (all manufactured by NOF Corp.), Trigonox 36-C75, Laurox, Perkadox L-W75, Perkadox CH-50L, Trigonox TMBH, Kayacumen H, Kayabutyl H-70, Perkadox BC-FF, and Kayahexa Examples include AD, Perkadox 14, Kayabutyl C, Kayabutyl D, Perkadox 12-XL25, Trigonox 22-N70 (22-70E), Trigonox D-T50, Trigonox 423-C70, Kayaester CND-C70, Trigonox 23-C70, Trigonox 257-C70, Kayaester P-70, Kayaester TMPO-70, Trigonox 121, Kayaester O, Kayaester HTP-65W, Kayaester AN, Trigonox 42, Trigonox F-C50, Kayabutyl B, Kayacarbon EH, Kayacarbon I-20, Kayacarbon BIC-75, Trigonox 117, and Kayalene 6-70 (all manufactured by Kayaku Akzo Co., Ltd.).

When the intermediate layer 18 contains an initiator, the amount thereof is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the resin (base polymer) such as a (meth)acrylic polymer. Furthermore, from the viewpoint of storage stability, the amount is preferably 15 parts by mass or less, more preferably 5 parts by mass or less.

In the pressure-sensitive adhesive film 10 according to this embodiment, the lower limit of the storage modulus E' at 60°C of the intermediate layer 18 before crosslinking is preferably 1.0 x ¹⁰³ Pa or more, and more preferably 5.0 x 103 Pa or more, in order to further suppress sinking of electronic components into the pressure-sensitive adhesive film during the sealing process of the electronic components.
In addition, in the adhesive film 10 according to this embodiment, the upper limit of the storage modulus E' at 60°C of the intermediate layer 18 before crosslinking is preferably 1.0 x 10 ⁶ Pa or less, and more preferably 5.0 x 10 5 Pa or less, in order to effectively absorb the unevenness on the chip surface and to prevent deterioration of the absorption of unevenness over time due to springback of the ^resin .
The storage modulus E' at 60°C of the intermediate layer 18 before crosslinking can be controlled within the above range, for example, by controlling the types and blending ratios of the components constituting the roughness-absorbing resin layer (C).

In the pressure-sensitive adhesive film 10 according to this embodiment, the lower limit of the storage modulus E' at 125°C of the intermediate layer (C') obtained by crosslinking the intermediate layer 18 is preferably 1.0 x 10 ⁶ Pa or more, and more preferably 5.0 x 10 ⁶ Pa or more, since this can further suppress sinking of electronic components into the pressure-sensitive adhesive film during the sealing process of the electronic components.
In the adhesive film 10 according to this embodiment, one of the intermediate layers (C')
The upper limit of the storage modulus E' at 25°C is preferably 1.0 x 10 ⁹ Pa or less, and more preferably 1.0 x 10 ⁸ Pa or less, from the viewpoint of further suppressing displacement of electronic components during the sealing step.
The storage modulus E' of the intermediate layer (C') at 125°C can be controlled within the above range by, for example, controlling the types and blending ratios of the components constituting the intermediate layer 18.
Here, whether or not the crosslinking process of the intermediate layer 18 is complete can be determined, for example, by determining that the crosslinking is complete when the storage modulus E' of the intermediate layer 18 no longer increases even after the crosslinking process.

The thickness of the intermediate layer 18 is not particularly limited as long as it is thick enough to absorb the irregularities on the surface of the adhesive resin layer 14, but for example, it is preferably 10 μm or more and 1000 μm or less, more preferably 20 μm or more and 900 μm or less, even more preferably 30 μm or more and 800 μm or less, and particularly preferably 50 μm or more and 700 μm or less.

The method for forming the intermediate layer 18 is not particularly limited, and the same method as for the adhesive resin layer (A) and the adhesive resin layer (B) can be used.

(Other layers)
The pressure-sensitive adhesive film 10 according to this embodiment may further include, for example, an easy-adhesion layer between the layers, as long as the effect of this embodiment is not impaired.

(Step b)
In this step, as shown in FIG. 1( a ), an adhesive film 10 is attached onto a support 20 via an adhesive resin layer 16 .
Specifically, first, the adhesive film 10 is attached to the support 20 so that the adhesive resin layer 16 faces the support 20. A protective film called a separator may be attached to the adhesive resin layer 16, and the protective film can be peeled off, allowing the exposed surface of the adhesive resin layer 16 to be attached to the surface of the support 20.
The support 20 may be, for example, a quartz substrate, a glass substrate, or a SUS substrate.

(Step c)
In this step, as shown in FIG. 1(b), a thin glass 30 is attached to the surface of the adhesive resin layer 14 and temporarily fixed thereon.
The thin glass 30 may be divided into a plurality of pieces as shown in FIG. 1(b), or may be a single sheet of thin glass.

A sheet of thin glass can be attached to the surface of the adhesive resin layer 14 by, for example, sequentially unwinding the thin glass from a roll, placing it on the surface of the adhesive resin layer 14, and temporarily fixing it thereto.
Methods for attaching multiple pieces of thin glass to the surface of the adhesive resin layer 14 include, for example, a method of sequentially unwinding the thin glass from a roll, placing it on the surface of the adhesive resin layer 14, and then dicing the thin glass; a method of sequentially unwinding multiple pieces of thin glass attached to a roll of thin glass with a resin film, placing the thin glass on the surface of the adhesive resin layer 14, and then peeling the resin film from the thin glass with the resin film; or a method of sequentially placing multiple pieces of thin glass that have been diced.
The thickness of the thin glass is preferably 1 μm or more and 200 μm or less, and more preferably 10 μm or more and 150 μm or less.

(Step d)
In this step, as shown in FIG. 1(c), the thin glass 30 is processed to obtain processed thin glass.
The processing method of the thin glass 30 is selected from inkjet processing, gravure printing, screen printing, spray coating, dispenser coating, air spray, electrostatic coating, roll coating, brush coating, roller brush coating, and dip coating on the thin glass 30.

Inkjet printing allows printing by spraying ink directly onto the thin glass 30 .
Gravure printing can accurately and beautifully express minute shades of light and shade, and is excellent in speed, so that it can print (apply) onto a large amount of thin glass 30 at one time.

By using screen printing, ink can be printed (applied) onto the thin glass 30 by passing it through the precise mesh of a screen mask made of synthetic fibers such as polyester, or a "screen mesh" woven from stainless steel or various metal fibers, using pressure from a squeegee or similar tool.

Spray coating applies high pressure to the desired polymer solution, ink, etc., spraying it from a special nozzle, atomizing it, and applying it to the thin glass 30, allowing the desired polymer layer to be formed or printed on the thin glass 30.

By using an air spray, a desired polymer solution, ink, or the like can be atomized with compressed air and applied to the thin glass 30, thereby forming a desired polymer layer or printing on the thin glass 30.
In electrostatic coating, atomized polymer solution or ink is negatively charged, and the thin glass 30 is positively charged and attracted by electrical attraction, allowing the desired polymer layer to be formed or printed on the thin glass 30.

In roll coating, a polymer solution, ink, etc. is coated onto the thin glass 30 from a rotating roll, allowing the desired polymer layer to be formed or printed on the thin glass 30.

By brushing, a desired polymer solution, ink, or the like can be spread with a brush, and a desired polymer layer can be formed or printed on the thin glass 30 .
By applying the roller brush, the desired polymer solution, ink, etc. can be spread with the roller brush, and the desired polymer layer can be formed or printed on the thin glass 30.
By dip coating, the thin glass 30 can be immersed in a polymer solution, ink, or the like, to form or print a desired polymer layer on the thin glass 30 .

In each process, a heating step may be carried out to dry the coating film, etc. at a predetermined temperature and harden the resin, etc.

If the intermediate layer 18 is photocurable, it is preferable to photo-cure the intermediate layer 18 in advance by irradiating UV light from above the glass 10 before the step d of processing the thin glass 30. If the intermediate layer 18 is thermosetting, the intermediate layer 18 can be cured by heating, such as in a drying step, in the step d of processing the thin glass 30.
It is preferable that the heating in the drying step etc. in step d is performed at a temperature at which the processed thin glass temporarily fixed to the surface of the adhesive resin layer 14 does not peel off.

In this embodiment, the intermediate layer 18 is provided on the adhesive film 10, thereby preventing the formation of voids between the support 20 and the thin glass 30. Therefore, when processing the thin glass 30, the thin glass 30 can be uniformly temporarily fixed to the support 20, resulting in excellent processability, and further preventing contamination of the processed thin glass by cleaning solutions and the like used in processing.
After step d, the processed thin glass can be heated at a predetermined temperature and peeled off from the surface of the adhesive resin layer 14. The processed thin glass can also be described as functional thin glass because it is given functionality by the processing described above.
In this embodiment, since the adhesive resin layer 14 containing the heat-expandable microspheres a is attached to the processed thin glass, the adhesive film 10 can be easily peeled off from the processed thin glass.

Applications of processed thin glass include smartphone cover glass, water vapor and oxygen barrier layers for organic EL devices, flexible lighting, and cover glass for various sensors.

In this embodiment, it is also possible to obtain an adhesive film with thin glass by providing thin glass 30 having a thickness of 1 μm to 200 μm on the adhesive film 10 without attaching the adhesive film 10 to the support 20.
Specifically, the adhesive film with thin glass is an adhesive film 10 comprising a base layer 12, an adhesive resin layer 14 containing heat-expandable microspheres a and provided on a first surface 12a of the base layer 12, an adhesive resin layer 16 provided on a second surface 12b of the base layer 12, and an intermediate layer 18 provided between the adhesive resin layer 14 and the base layer 12,
A thin glass 30 having a thickness of 1 μm to 200 μm is temporarily fixed to the surface of the adhesive resin layer 14 .
This prevents the thin glass 30 from cracking or chipping when it is transported, and the adhesive resin layer 16 of the adhesive film with thin glass attached can be attached to the support 20 at the destination, allowing the thin glass 30 to be processed.

Second Embodiment
The method for producing processed thin glass of this embodiment includes the following steps as shown in FIGS.
Step a: An adhesive film 10 is prepared, comprising a substrate layer 12, an adhesive resin layer 14 provided on the first surface 12a of the substrate layer 12, an adhesive resin layer 16 containing heat-expandable microspheres a provided on the second surface 12b of the substrate layer 12, and an intermediate layer 18 provided between the adhesive resin layer 16 and the substrate layer 12 (FIG. 2(a)).
Step b: The adhesive film 10 is attached to the support 20 via the adhesive resin layer 16 (FIG. 2(a)).
Step c: A thin glass 30 is temporarily fixed to the surface of the adhesive resin layer 14 (FIG. 2(b)).
Step d: The thin glass 30 is processed (FIG. 2(c)).

In this embodiment, the adhesive resin layer 16 contains heat-expandable microspheres a, and an intermediate layer 18 is provided between the adhesive resin layer 16 and the base layer 12. Other than this, the second embodiment is the same as the first embodiment, and therefore will not be described further.

In this embodiment, the adhesive resin layer 16 containing heat-expandable microspheres a is attached to the support 20, allowing the adhesive film with the thin glass to be easily peeled off from the support 20. The intermediate layer 18 absorbs irregularities on the surface of the adhesive resin layer 16 caused by the heat-expandable microspheres a, thereby preventing the formation of voids between the adhesive resin layer 16 and the support 20. Furthermore, the intermediate layer 18 absorbs irregularities on the surface of the adhesive resin layer 14 caused by the heat-expandable microspheres a, preventing the formation of voids between the adhesive resin layer 14 and the thin glass 30. Since the formation of voids can be prevented in this way, the thin glass 30 can be temporarily fixed uniformly during processing, resulting in excellent processability and preventing contamination of the processed thin glass by cleaning solutions, etc.

In this embodiment, it is also possible to obtain an adhesive film with thin glass by providing thin glass 30 having a thickness of 1 μm to 200 μm on the adhesive film 10 without attaching the adhesive film 10 to the support 20.
Specifically, the adhesive film with thin glass is an adhesive film 10 comprising a base layer 12, an adhesive resin layer 14 provided on a first surface 12a of the base layer 12, an adhesive resin layer 16 containing heat-expandable microspheres a provided on a second surface 12b of the base layer 12, and an intermediate layer 18 provided between the adhesive resin layer 16 and the base layer 12,
A thin glass 30 having a thickness of 1 μm to 200 μm is temporarily fixed to the surface of the adhesive resin layer 14 .
This prevents the thin glass 30 from cracking or chipping when it is transported, and the adhesive resin layer 16 of the adhesive film with thin glass attached can be attached to the support 20 at the destination, allowing the thin glass 30 to be processed.

[Third embodiment]
The method for manufacturing processed thin glass of this embodiment includes the following steps as shown in FIGS.
Step a: An adhesive film 10 is prepared, comprising a substrate layer 12, an adhesive resin layer 14 containing heat-expandable microspheres a and provided on the first surface 12a of the substrate layer 12, an adhesive resin layer 16 provided on the second surface 12b of the substrate layer 12, and an intermediate layer 18 provided between the adhesive resin layer 16 and the substrate layer 12 (FIG. 3(a)).
Step b: The adhesive film 10 is attached to the support 20 via the adhesive resin layer 16 (FIG. 3(a)).
Step c: A thin glass 30 is temporarily fixed to the surface of the adhesive resin layer 14 (FIG. 3(b)).
Step d: The thin glass 30 is processed (FIG. 3(c)).

This embodiment is the same as the first embodiment except that an intermediate layer 18 is provided between the adhesive resin layer 16 and the base layer 12, so further explanation will be omitted.

In this embodiment, the intermediate layer 18 absorbs the irregularities on the surface of the adhesive resin layer 14 caused by the heat-expandable microspheres a, maintaining the smoothness of the surface of the adhesive resin layer 14 and suppressing the formation of voids between the adhesive resin layer 14 and the thin glass 30. This allows the thin glass 30 to be temporarily fixed uniformly during processing, resulting in excellent processability and preventing contamination of the processed thin glass by cleaning solutions, etc. Furthermore, because the thin glass 30 is attached to the surface of the layer 14, the processed thin glass can be peeled off stress-free in subsequent processes.

In this embodiment, it is also possible to obtain an adhesive film with thin glass by providing thin glass 30 having a thickness of 1 μm to 200 μm on the adhesive film 10 without attaching the adhesive film 10 to the support 20.
Specifically, the adhesive film with thin glass is an adhesive film 10 comprising a base layer 12, an adhesive resin layer 14 containing heat-expandable microspheres a and provided on a first surface 12a of the base layer 12, an adhesive resin layer 16 provided on a second surface 12b of the base layer 12, and an intermediate layer 18 provided between the adhesive resin layer 16 and the base layer 12,
A thin glass 30 having a thickness of 1 μm to 200 μm is temporarily fixed to the surface of the adhesive resin layer 14 .
This prevents the thin glass 30 from cracking or chipping when it is transported, and the adhesive resin layer 16 of the adhesive film with thin glass attached can be attached to the support 20 at the destination, allowing the thin glass 30 to be processed.

[Fourth embodiment]
The method for manufacturing processed thin glass of this embodiment includes the following steps as shown in FIGS.
Step a: An adhesive film 10 is prepared, comprising a substrate layer 12, an adhesive resin layer 14 provided on the first surface 12a of the substrate layer 12, an adhesive resin layer 16 containing heat-expandable microspheres a provided on the second surface 12b of the substrate layer 12, and an intermediate layer 18 provided between the adhesive resin layer 16 and the substrate layer 12 (FIG. 4(a)).
Step b: The adhesive film 10 is attached onto the support 20 via the adhesive resin layer 16 (FIG. 4(a)).
Step c: A thin glass 30 is temporarily fixed to the surface of the adhesive resin layer 14 (FIG. 4(b)).
Step d: The thin glass 30 is processed (FIG. 4(c)).

This embodiment is the same as the first embodiment except that the adhesive resin layer 16 contains heat-expandable microspheres a, so further explanation will be omitted.

In this embodiment, the adhesive resin layer 16 containing heat-expandable microspheres a is attached to the support 20, allowing the adhesive film with the thin glass to be easily peeled off from the support 20. The intermediate layer 18 absorbs irregularities on the surface of the adhesive resin layer 16 caused by the heat-expandable microspheres a, thereby preventing the formation of voids between the adhesive resin layer 16 and the support 20. Furthermore, the intermediate layer 18 absorbs irregularities on the surface of the adhesive resin layer 14 caused by the heat-expandable microspheres a, preventing the formation of voids between the adhesive resin layer 14 and the thin glass 30. Since the formation of voids can be prevented in this way, the thin glass 30 can be temporarily fixed uniformly during processing, resulting in excellent processability and preventing contamination of the processed thin glass by cleaning solutions, etc.

In this embodiment, it is also possible to obtain an adhesive film with thin glass by providing thin glass 30 having a thickness of 1 μm to 200 μm on the adhesive film 10 without attaching the adhesive film 10 to the support 20.
Specifically, the adhesive film with thin glass is an adhesive film 10 comprising a substrate layer 12, an adhesive resin layer 14 provided on a first surface 12a of the substrate layer 12, an adhesive resin layer 16 containing heat-expandable microspheres a provided on a second surface 12b of the substrate layer 12, and an intermediate layer 18 provided between the adhesive resin layer 16 and the substrate layer 12,
A thin glass 30 having a thickness of 1 μm to 200 μm is temporarily fixed to the surface of the adhesive resin layer 14 .
This prevents the thin glass 30 from cracking or chipping when it is transported, and the adhesive resin layer 16 of the adhesive film with thin glass can be attached to the support 20 at the destination, allowing the thin glass 30 to be processed.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted as long as they do not impair the effects of the present invention.
For example, in FIGS. 1 and 2, the intermediate layer 18 can be provided on both the first surface 12a side and the second surface 12b side of the base material layer 12.

10 adhesive film 12 base layer 12a first surface 12b second surface 14 adhesive resin layer 16 adhesive resin layer 18 intermediate layer 20 support 30 thin glass a heat-expandable microspheres

Claims (13)

a substrate layer;
an adhesive resin layer (A) provided on the first surface side of the base material layer;
an adhesive resin layer (B) provided on the second surface side of the base material layer;
and an intermediate layer (C) provided between at least one of the adhesive resin layer (A) and the base material layer and the adhesive resin layer (B) and the base material layer,
preparing an adhesive film containing heat-expandable microspheres in at least one of an adhesive resin layer (A) and an adhesive resin layer (B);
a step of attaching the adhesive film to a support via an adhesive resin layer (B);
a step of temporarily fixing a thin glass to a surface of the adhesive resin layer (A);
processing the thin glass;
A method for producing processed thin glass, comprising:
the intermediate layer (C) contains a resin, a crosslinking agent, and an initiator that generates an active chemical species in response to an external stimulus;
The method for producing processed thin glass, wherein the crosslinking agent contains a polyfunctional (meth)acrylate compound . The step of preparing the adhesive film includes:
The method according to claim 1, further comprising the step of preparing a pressure-sensitive adhesive film having the intermediate layer (C) between the pressure-sensitive adhesive resin layer containing the heat-expandable microspheres and the substrate layer. The manufacturing method described in claim 1 or 2, wherein the intermediate layer (C) is crosslinkable by heat and/or light. The manufacturing method described in any one of claims 1 to 3, wherein the thickness of the thin glass is 1 μm to 200 μm. The manufacturing method described in any one of claims 1 to 4, wherein the process of processing the thin glass is selected from inkjet processing, gravure printing, screen printing, spray coating, dispenser coating, air spray, electrostatic coating, roll coating, brush coating, roller brush coating, and dip coating onto the thin glass. The manufacturing method described in any one of claims 1 to 5, wherein the heat-expandable microspheres include microspheres having a shell encapsulating a substance that expands upon gasification. An adhesive film used to temporarily fix thin glass and process the thin glass,
a substrate layer;
an adhesive resin layer (A) provided on the first surface side of the base material layer;
an adhesive resin layer (B) provided on the second surface side of the base material layer;
and an intermediate layer (C) provided between at least one of the adhesive resin layer (A) and the base material layer and the adhesive resin layer (B) and the base material layer,
at least one of the adhesive resin layer (A) and the adhesive resin layer (B) contains heat-expandable microspheres;
the intermediate layer (C) contains a resin, a crosslinking agent, and an initiator that generates an active chemical species in response to an external stimulus;
The adhesive film , wherein the crosslinking agent contains a polyfunctional (meth)acrylate compound . The adhesive film according to claim 7, further comprising the intermediate layer (C) between the adhesive resin layer containing the heat-expandable microspheres and the substrate layer. The pressure-sensitive adhesive film according to claim 7 or 8, wherein the intermediate layer (C) is crosslinkable by heat and/or light. The adhesive film according to any one of claims 7 to 9, wherein the thickness of the thin glass is 1 μm to 200 μm. The adhesive film according to any one of claims 7 to 10, wherein the heat-expandable microspheres include microspheres having a shell encapsulating a substance that expands upon gasification. An adhesive film with thin glass, comprising a thin glass having a thickness of 1 μm to 200 μm on an adhesive film,
The adhesive film is
a substrate layer;
an adhesive resin layer (A) provided on the first surface side of the base material layer;
an adhesive resin layer (B) provided on the second surface side of the base material layer;
and an intermediate layer (C) provided between at least one of the adhesive resin layer (A) and the base material layer and the adhesive resin layer (B) and the base material layer,
at least one of the adhesive resin layer (A) and the adhesive resin layer (B) contains heat-expandable microspheres;
The thin glass is temporarily fixed to the surface of the adhesive resin layer (A) ,
the intermediate layer (C) contains a resin, a crosslinking agent, and an initiator that generates an active chemical species in response to an external stimulus;
The crosslinking agent comprises a polyfunctional (meth)acrylate compound . The adhesive film with thin glass according to claim 12, comprising the intermediate layer (C) between the adhesive resin layer containing the heat-expandable microspheres and the substrate layer.