JP2021028392A - Adhesive sheet - Google Patents

Abstract

To provide an adhesive sheet that can be used to grind a hard and brittle substrate during backgrinding of the hard and brittle substrate and that makes it possible to reduce pollution and achieve excellent productivity, grinding precision, and release.SOLUTION: This adhesive sheet comprises an adhesive layer. The thickness of the adhesive layer is 1-300 μm. The indentation hardness H (Pa) of the adhesive layer at 25°C and the thickness hA (μm) of the adhesive layer satisfy the relationship in the formula (1) defined by logH≥1.9385×loghA+4.2611.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adhesive sheet.

In recent years, white LED substrates, sapphire substrates used in electronic devices such as SOS (Silicon on Sapphire), cover glasses for smartphones and watches, silicon carbide substrates expected as power semiconductor substrates, gallium nitride substrates, and oxidation. Hard and brittle ceramic substrates such as gallium substrates, diamond substrates, silicon nitride substrates used as heat dissipation circuit substrate materials for power semiconductors, alumina substrates, and quartz substrates used for crystal transducers of glass and lenses (hereinafter collectively referred to as). There is an increasing need to accurately manufacture hard and brittle substrates. A typical example of a process for manufacturing such a substrate is a back grind process in which the back surface of the substrate (wafer) is ground to a desired thickness. In this process, a fixing material is used to fix the substrate. A wax or an adhesive sheet (back grind tape) is used as the coating. Among them, the adhesive sheet is less likely to contaminate the substrate than wax, and is also advantageously used from the viewpoint of productivity.

On the other hand, the substrate (hard and brittle substrate) has high hardness, and when grinding a high hardness substrate (hard and brittle substrate), fixed abrasive grains or free abrasive grains made of diamond or the like are subjected to a high load. It is necessary to rotate the grinder while pressing it against the (hard and brittle substrate) to thin the object to be ground. At this time, a high vertical pressure is applied to the fixing material, and in the conventional pressure-sensitive adhesive sheet, problems of grindability such as deformation of the pressure-sensitive adhesive layer and vibration of the object to be ground tend to occur. Further, the fixing material designed to solve these problems is heavily peeled, and when the object to be ground is peeled from the fixing material after the back grind process, the object to be ground is contaminated. As described above, when grinding a hard and brittle substrate, it is difficult to achieve both grindability and peelability with a conventional fixing material.

Japanese Unexamined Patent Publication No. 2011-151163

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is an adhesive sheet that can be used for grinding a hard and brittle substrate in a back grind process of a hard and brittle substrate, and has low contamination. An object of the present invention is to provide an adhesive sheet having excellent properties, productivity, grinding accuracy and peelability.

The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer is 1 μm to 300 μm, and the pressing hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and adhesion. The thickness h _A (μm) of the agent layer satisfies the relationship of the following formula (1).
logH ≧ 1.9385 × logh _A +4.2611 ・ ・ ・ (1)
In one embodiment, the shear adhesive strength at an environmental temperature of 25 ° C. when the adhesive surface of the adhesive sheet is attached to a silicon chip is 1.0 MPa or more.
In one embodiment, when the adhesive surface of the adhesive sheet is attached to SUS304BA, the peeling adhesive strength at an environmental temperature of 80 ° C. is 15 N / 20 mm or less.
In one embodiment, the indentation hardness H of the pressure-sensitive adhesive layer at 25 ° C. is 10 MPa to 1 GPa.
In one embodiment, the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive containing a base polymer, and the base polymer is a thermoplastic elastomer.
In one embodiment, the thermoplastic elastomer is a styrene-based elastomer or an ethylene-vinyl acetate-based elastomer.
In one embodiment, the pressure-sensitive adhesive further comprises a tack-imparting resin.
In one embodiment, the content of the tackifier resin is 1 part by weight to 350 parts by weight with respect to 100 parts by weight of the base polymer.
In one embodiment, it further comprises a substrate disposed on at least one side of the pressure-sensitive adhesive layer.
In one embodiment, another pressure-sensitive adhesive layer arranged on at least one side of the pressure-sensitive adhesive layer is further provided.
In one embodiment, the tensile elastic modulus of the substrate at 25 ° C. is 1 × 10 ⁷ Pa to 1 × 10 ^{10 Pa.}
In one embodiment, the pressure-sensitive adhesive sheet is used as a temporary fixing material during substrate processing in a semiconductor manufacturing process.
According to another aspect of the present invention, a method for grinding a substrate is provided. The method for grinding the substrate includes placing the substrate on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet provided with the pressure-sensitive adhesive layer, fixing the substrate, and then grinding the surface of the substrate opposite to the pressure-sensitive adhesive layer side. The thickness of the pressure-sensitive adhesive layer is 1 μm to 300 μm, and the indentation hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and the thickness h _A (μm) of the pressure-sensitive adhesive layer are of the following formula (1). Meet the relationship.
According to yet another aspect of the present invention, a method for manufacturing a substrate is provided. In this method of manufacturing a substrate, a grinding step of placing the substrate on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet provided with the pressure-sensitive adhesive layer, fixing the substrate, and then grinding the surface of the substrate opposite to the pressure-sensitive adhesive layer side is performed. The thickness of the pressure-sensitive adhesive layer is 1 μm to 300 μm, and the indentation hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and the thickness h _A (μm) of the pressure-sensitive adhesive layer are expressed by the following formula (1). Satisfy the relationship.

According to the present invention, there is provided an adhesive sheet that can be used for grinding a hard and brittle substrate in a back grinding process of a hard and brittle substrate, and is excellent in low contamination, productivity, grinding accuracy and peelability. can do.

(A), (b) and (c) are schematic cross-sectional views of the pressure-sensitive adhesive sheet according to one embodiment of the present invention.

A. Summary view of a pressure-sensitive adhesive sheet 1 (a) is a schematic sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention. The pressure-sensitive adhesive sheet 100 includes a pressure-sensitive adhesive layer 10. The pressure-sensitive adhesive sheet of the present invention may be composed of only the pressure-sensitive adhesive layer 10, and may further include any suitable layer in addition to the pressure-sensitive adhesive layer.

FIG. 1B is a schematic cross-sectional view of an adhesive sheet according to another embodiment of the present invention. The pressure-sensitive adhesive sheet 200 includes a pressure-sensitive adhesive layer 10 and a base material 20 arranged on at least one side of the pressure-sensitive adhesive layer 10. FIG. 1 (c) is a schematic cross-sectional view of an adhesive sheet according to still another embodiment of the present invention. The pressure-sensitive adhesive sheet 300 includes a pressure-sensitive adhesive layer 10 and another pressure-sensitive adhesive layer 30 arranged on at least one side of the pressure-sensitive adhesive layer 10. As shown in the illustrated example, the base material 20 may be arranged between the pressure-sensitive adhesive layer 10 and another pressure-sensitive adhesive layer 30, and although not shown, the base material is omitted and another adhesive is adhered to the pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet may be formed from the agent layer. Further, although not shown, the pressure-sensitive adhesive sheet is a layer other than the pressure-sensitive adhesive layer, which is an elastic layer (described later in item E) capable of imparting elasticity to the pressure-sensitive adhesive sheet and a separator which is detachably arranged on the pressure-sensitive adhesive layer. (F item described later) and the like may be further provided.

In the pressure-sensitive adhesive layer provided in the pressure-sensitive adhesive sheet of the present invention, the pressing hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and the thickness h _A (μm) of the pressure-sensitive adhesive layer have the relationship of the following formula (1). Fulfill. _{The thickness h A} of the pressure-sensitive adhesive layer is 1 μm to 300 μm.
logH ≧ 1.9385 × logh _A +4.2611 ・ ・ ・ (1)

In the present invention, the thickness h _A is set to 1 μm to 300 μm, and the indentation hardness H and the thickness h _A satisfy the above relationship to form the pressure-sensitive adhesive layer, whereby during grinding in the backgrinding step. It is possible to obtain an adhesive sheet that is not significantly deformed with respect to a load (that is, a load in the vertical direction and a load in the shear direction). Further, since the pressure-sensitive adhesive layer satisfying the above relationship becomes soft under high temperature (for example, 80 ° C. to 120 ° C.) while maintaining elastic deformation, the pressure-sensitive adhesive sheet of the present invention can be used after grinding the substrate. It can exhibit excellent peelability. The pressure-sensitive adhesive sheet of the present invention having such characteristics can be suitably used as a temporary fixing material at the time of substrate processing in a semiconductor manufacturing process, and can be particularly preferably used as a temporary fixing material at the time of grinding a hard and brittle substrate. More specifically, when grinding a hard and brittle substrate with high hardness, it is necessary to rotate the grinder while pressing it against the object to be ground (sapphire) with a high load, but as described above, it deforms with respect to the load during grinding. If a difficult adhesive sheet is used, the hard and brittle substrate can be ground with high accuracy. Further, since the pressure-sensitive adhesive sheet of the present invention is excellent in peelability, the pressure-sensitive adhesive layer component is unlikely to remain on the adherend during peeling, which is also useful as a temporary fixing material for a hard and brittle substrate. In one embodiment, a sapphire wafer is used as the hard and brittle substrate.

The indentation hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and the thickness h _A (μm) of the pressure-sensitive adhesive layer preferably further satisfy the relationship of the following formula (2), and the relationship of the following formula (2)'. It is more preferable to satisfy.
1.9385 x logh _A +9 ≥ logH ... (2)
1.9385 x logh _A +7 ≧ logH ・ ・ ・ ・ (2)'
If the indentation hardness H and the thickness h _A satisfy the above relationship, an adhesive sheet having better peelability can be obtained.

When the adhesive surface of the adhesive sheet of the present invention is attached to a silicon chip, the shear adhesive strength at an environmental temperature of 25 ° C. is preferably 1.0 MPa or more, more preferably 1.5 MPa or more, still more preferable. Is 2 MPa or more, particularly preferably 2.3 MPa or more, and most preferably 3 MPa or more. The upper limit of the shear adhesive strength at 25 ° C. environmental temperature is, for example, 8 MPa. In the present specification, the shear adhesive strength is determined by thermocompression bonding the surface of the pressure-sensitive adhesive layer as a bonding surface with a heat press machine at 100 ° C. and 0.1 MPa for 1 minute to fix the silicon chip, and manufactured by Nordson. The maximum breaking load is calculated from the load-displacement curve obtained by setting the measurement terminal at a height of 50 μm from the sticking surface using the damage4000 and applying an external force in the horizontal direction to the chip at a shear rate of 500 μm / sec. It can be measured by reading. When the target sample is a single-sided tape, the back surface of the base material (the surface opposite to the adhesive layer) is covered with a double-sided tape NO. At 585, it is attached to a predetermined base and fixed to perform the above measurement. The shear adhesive strength of the pressure-sensitive adhesive sheet can be adjusted by the type of pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer, the structure of the base polymer constituting the pressure-sensitive adhesive, the type and amount of additives added to the pressure-sensitive adhesive, and the like.

When the adhesive surface of the adhesive sheet of the present invention is attached to SUS304BA, the peeling adhesive force at an environmental temperature of 80 ° C. is preferably 15 N / 20 mm or less, more preferably 12 N / 20 mm or less, and further preferably. Is 10 N / 20 mm or less, and particularly preferably 8 N / 20 mm or less. Within such a range, an adhesive sheet that can be peeled off by heating can be obtained. By forming the pressure-sensitive adhesive layer having the peeling adhesive strength in the above range, it is possible to obtain a pressure-sensitive adhesive sheet having excellent peelability, less contaminated hard and brittle substrate (for example, sapphire wafer), and excellent productivity. .. In the present specification, the peeling adhesive force means that the adhesive surface (adhesive layer surface) of the adhesive sheet (20 mm width) is attached to SUS304BA with a hand roller to form a laminate, and then the laminate is preheated to 80 ° C. A sample was prepared by crimping with a heat press machine prepared for 1 minute at a pressure of 0.3 MPa, and the adhesive sheet was peeled off from SUS304BA under the conditions of a peeling angle of 180 ° and a peeling speed of 300 mm / min for measurement. Adhesive strength. When the pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet having no base material, the pressure-sensitive adhesive tape No. 2 manufactured by Nitto Denko KK is on the surface opposite to the pressure-sensitive adhesive layer surface. After the 315 is attached, the above sample can be prepared and the peeling adhesive strength can be measured. The peeling adhesive strength of the pressure-sensitive adhesive sheet can be adjusted by the type of pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer, the structure of the base polymer constituting the pressure-sensitive adhesive, the type and amount of additives added to the pressure-sensitive adhesive, and the like. ..

The adhesive sheet of the present invention is used for back grind process, resin sealing process, vapor deposition, sputtering and other substrate (wafer) back surface (grinding surface) processing process, dicing process, and breaking process while being attached to the work piece. It may be subjected to a single process or a combination process thereof.

The thickness of the pressure-sensitive adhesive sheet of the present invention is preferably 10 μm to 500 μm, and more preferably 20 μm to 300 μm.

According to another aspect of the present invention, there is provided a method for grinding a substrate using the pressure-sensitive adhesive sheet. This method includes, for example, placing a substrate on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, fixing the substrate, and then grinding the surface of the substrate opposite to the pressure-sensitive adhesive layer side. Any suitable method can be adopted for grinding the substrate. The grinding can be performed, for example, for the purpose of making the substrate a desired thickness. In one embodiment, a circular or olifra-shaped wafer may be used as the substrate. Further, as the substrate, for example, a hard and brittle substrate (wafer) such as a sapphire substrate (sapphire wafer) can be used.

According to yet another aspect of the present invention, there is provided a method for manufacturing a chip using the pressure-sensitive adhesive sheet. This manufacturing method includes, for example, a grinding step in which a substrate is placed on the pressure-sensitive adhesive layer of a pressure-sensitive adhesive sheet, fixed, and then the surface of the substrate opposite to the pressure-sensitive adhesive layer side is ground. As the substrate, for example, a circular or olifra-shaped wafer can be used. In addition, the manufacturing method may include any suitable step in addition to the grinding step. For example, a dicing process for cutting a substrate (wafer), a breaking process for dividing an object to be cut into chips after dicing, a processing process for the back surface (ground surface) of the chip such as vapor deposition and sputtering, and sealing for sealing the chip. It may include steps and the like. Examples of the chip include an LED chip having a hard and brittle wafer such as a sapphire wafer as a support.

B. Adhesive layer The adhesive layer contains an adhesive for imparting adhesiveness.

The indentation hardness H of the pressure-sensitive adhesive layer at 25 ° C. is preferably 10 MPa to 1 GPa, more preferably 12 MPa to 0.8 GPa, and further preferably 15 MPa to 0.4 GPa. Within such a range, an adhesive sheet capable of performing back grinding with excellent grinding accuracy can be obtained. Within such a range, an adhesive sheet capable of backgrinding a hard and brittle substrate (for example, a sapphire wafer) with excellent grinding accuracy can be obtained. The indentation hardness H is obtained by numerically processing the displacement-load hysteresis curve obtained by pressing a diamond Berkovich type (trigonal pyramidal type) probe perpendicularly to the surface of the pressure-sensitive adhesive layer with software (triboscan) attached to the measuring device. Obtained by doing. In the present specification, the indentation hardness H means an indentation speed of about 500 nm / sec and an indentation depth by a single indentation method at a predetermined temperature (25 ° C.) using a nanoindenter (Triboinder TI-950 manufactured by Hysiron Inc). The indentation hardness H measured under the measurement conditions of about 3000 nm. The pressing hardness H of the pressure-sensitive adhesive layer should be adjusted according to the type of pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer, the structure of the base polymer constituting the pressure-sensitive adhesive, the type and amount of additives added to the pressure-sensitive adhesive, and the like. Can be done.

The thickness of the pressure-sensitive adhesive layer is preferably 1 μm to 300 μm, more preferably 1 μm to 250 μm, further preferably 1 μm to 100 μm, and particularly preferably 1 μm to 50 μm.

B-1. Adhesive As the adhesive constituting the pressure-sensitive adhesive layer, any suitable pressure-sensitive adhesive can be used as long as the effects of the present invention can be obtained. Examples of the adhesive include thermoplastic elastomers, acrylic resins, silicone resins, vinyl alkyl ether resins, polyester resins, polyamide resins, urethane resins, fluorinated resins and the like as base polymers (adhesive resins). Examples thereof include adhesives. Preferably, the pressure-sensitive adhesive contains a thermoplastic resin as a base polymer. By using a thermoplastic resin, it is possible to easily obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer satisfying the above relational formula (1) and capable of exhibiting excellent peelability by heating. Preferably, an acrylic resin or a pressure-sensitive adhesive containing a thermoplastic elastomer is used as the base polymer, and the thermoplastic elastomer is more preferably used. As the thermoplastic elastomer, a styrene-based elastomer or an ethylene-vinyl acetate-based elastomer is preferably used, and a styrene-based elastomer is more preferably used. For example, if a styrene-based elastomer is used, the adhesiveness and indentation hardness H can be easily controlled by adjusting the styrene unit ratio.

Examples of styrene-based elastomers include styrene / butadiene copolymer (SB), styrene / isoprene copolymer (SI), styrene / isoprene / styrene block copolymer (SIS), and styrene / butadiene / styrene block copolymer (SBS). ), Styrene / isobutylene / styrene copolymer (SIBS), styrene / ethylene / butylene / styrene block copolymer (SEBS), styrene / ethylene / propylene block copolymer (SEP), styrene / ethylene / propylene / styrene block Examples thereof include copolymers (SEPS) and modified products thereof. Of these, SEBS, SBS, SIS, and SIBS are preferable. These copolymers are preferably block copolymers.

The content ratio of the styrene-derived structural unit in the styrene-based elastomer is preferably 10 parts by weight to 75 parts by weight, and more preferably 20 parts by weight to 70 parts by weight with respect to 100 parts by weight of the styrene-based elastomer. , More preferably 20 parts by weight to 50 parts by weight. Within such a range, it is possible to obtain an adhesive sheet that has appropriate elasticity and has excellent adhesiveness by forming an adhesive layer that enables backgrinding with excellent grinding accuracy. it can.

In one embodiment, the acid-modified styrene-based elastomer (preferably acid-modified SEBS, SBS, SIS or SIBS) is used as the styrene-based elastomer. Examples of the acid used for the acid denaturation include maleic acid, maleic anhydride and the like, and maleic acid denaturation is preferable. By using an acid-modified styrene-based elastomer, the molecular weight can be adjusted or a cross-linked structure can be formed by using a cross-linking agent (for example, an epoxy-based cross-linking agent) in combination, whereby the pressure-sensitive adhesive layer can be formed in a high temperature region. It can be configured to soften while maintaining elastic deformation, and the peeling force at high temperatures can be controlled. The acid value of the acid-modified styrene-based elastomer is preferably 5 mg (CH ₃ ONa) / g or more, more preferably 7 mg (CH ₃ ONa) / g or more, and further preferably 7 mg (CH ₃ ONa). / G to 25 (CH ₃ ONa) / g. The acid value here means the weight (mg) of _{sodium methoxide (CH 3} ONa) that neutralizes 1 g of the base polymer. The acid value of the base polymer can be measured according to JIS K0070: 1992.

The content ratio of the constituent unit derived from vinyl acetate in the ethylene-vinyl acetate-based elastomer is preferably 5 parts by weight to 50 parts by weight, more preferably 10 parts by weight, based on 100 parts by weight of the ethylene-vinyl acetate-based elastomer. Parts to 45 parts by weight. Within such a range, it is possible to obtain an adhesive sheet that has appropriate elasticity and has excellent adhesiveness by forming an adhesive layer that enables backgrinding with excellent grinding accuracy. it can.

As the acrylic resin, for example, an acrylic resin composed of one or more (meth) acrylic acid alkyl esters as a monomer component is used. Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, butyl (meth) acrylic acid, and (meth). ) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate , (Meta) 2-ethylhexyl acrylate, (meth) isooctyl acrylate, (meth) nonyl acrylate, (meth) isononyl acrylate, (meth) decyl acrylate, (meth) isodecyl acrylate, (meth) acrylate Undecyl, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate , (Meta) acrylic acid nonadecil, (meth) acrylic acid eicosyl and the like (meth) acrylic acid C1-20 alkyl esters. Of these, (meth) acrylic acid alkyl esters having a linear or branched alkyl group having 4 to 18 carbon atoms can be preferably used.

The acrylic polymer is a unit corresponding to other monomer components copolymerizable with the (meth) acrylic acid alkyl ester, if necessary, for the purpose of modifying cohesive force, heat resistance, crosslinkability, etc. May include. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; maleic anhydride and icotanic anhydride. Acid anhydride monomers such as; (meth) hydroxyethyl acrylate, (meth) hydroxypropyl acrylate, (meth) hydroxybutyl acrylate, (meth) hydroxyhexyl acrylate, (meth) hydroxyoctyl acrylate, (meth) Hydrolyl group-containing monomers such as hydroxydecyl acrylate, hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) methylmethacrylate; styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropan sulfonic acid. , (Meta) acrylamide propanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid and other sulfonic acid group-containing monomers; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (N-substituted) amide-based monomers such as (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; aminoethyl (meth) acrylate, N, N-dimethyl (meth) acrylate Aminoalkyl-based (meth) acrylate monomers such as aminoethyl and t-butylaminoethyl (meth) acrylate; alkoxyalkyl-based (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate. Monomers; Maleimide-based monomers such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-lauryl maleimide, N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide , N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide and other itaconimide-based monomers; N- (meth) acryloyloxymethylene succinimide, N- (meth) acurloyl-6-oxyhexamethylene succinimide, Succinimide-based monomers such as N- (meth) acryloyl-8-oxyoctamethylene succinimide; vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyro Vinyls such as lidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazin, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholin, N-vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam Monomer; Cyanoacrylate monomer such as acrylonitrile and methacrylonitrile; Epoxy group-containing acrylic monomer such as glycidyl (meth) acrylate; Polyethylene glycol (meth) acrylate, Polypropylene glycol (meth) acrylate, (meth) acrylic acid Glycol-based acrylic ester monomers such as methoxyethylene glycol and methoxypolypropylene glycol (meth) acrylate; heterocycles such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate and silicone (meth) acrylate, halogen atoms and silicon atoms. Acrylic acid ester-based monomers having the above; hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol Polyfunctional monomers such as di (meth) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate; isoprene, butadiene, Olefin-based monomers such as isobutylene; vinyl ether-based monomers such as vinyl ether and the like can be mentioned. These monomer components may be used alone or in combination of two or more.

The pressure-sensitive adhesive may optionally contain any suitable additive. Examples of the additive include tackifier resins, plasticizers, pigments, dyes, fillers, antioxidants, conductive materials, antistatic agents, ultraviolet absorbers, light stabilizers, release modifiers, softeners, and surfactants. Examples include agents, flame retardants, antioxidants, cross-linking agents and the like.

In one embodiment, the pressure-sensitive adhesive comprises a tack-imparting resin. In particular, when the pressure-sensitive adhesive contains a styrene-based elastomer, it is preferable to use the elastomer and the tackifier resin in combination. By using the tackifier resin in combination, a pressure-sensitive adhesive layer having excellent tackiness can be formed.

As the tackifier resin, any suitable tackifier resin can be used as long as the effects of the present invention can be obtained. Specific examples of the tackifier resin include rosin-based tackifier resins (for example, unmodified rosin, modified rosin, rosinphenol-based resin, rosin ester-based resin, etc.) and terpen-based tackifier resins (eg, terpene-based resin, terpenphenol). Rosin-based resin, styrene-modified terpene-based resin, aromatic-modified terpene-based resin, hydrogenated terpene-based resin), hydrocarbon-based tackifier resin (for example, aliphatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin, alicyclic group) Based hydrocarbon resin (for example, styrene resin, xylene resin, etc.), aliphatic / aromatic petroleum resin, aliphatic / alicyclic petroleum resin, hydrogenated hydrocarbon resin, kumaron resin, kumaron inden type Resins, etc.), phenol-based tackifier resins (eg, alkylphenol-based resins, xyleneformaldehyde-based resins, resoles, novolak, etc.), ketone-based tackifier resins, polyamide-based tackifier resins, epoxy-based tackifier resins, elastomeric tackifier resins And so on. Of these, a terpene-based tackifier resin, a rosin-based tackifier resin, or a hydrocarbon-based tackifier resin (preferably an alicyclic saturated hydrocarbon resin) is preferable. The tackifier resin may be used alone or in combination of two or more.

The content of the tackifier resin is preferably 0 parts by weight to 350 parts by weight, more preferably 1 part by weight to 350 parts by weight, and further preferably 1 part by weight to 100 parts by weight with respect to 100 parts by weight of the base polymer. It is 300 parts by weight, particularly preferably 20 parts by weight to 250 parts by weight. Within such a range, a pressure-sensitive adhesive layer having excellent adhesiveness can be formed. If the content of the tackifier resin is too large, the pressure-sensitive adhesive layer may become brittle.

In one embodiment, the pressure-sensitive adhesive comprises a surfactant. When a pressure-sensitive adhesive containing a surfactant is used, a light release layer is formed in the pressure-sensitive adhesive layer by segregation of the surfactant by heating, and a pressure-sensitive adhesive sheet having excellent peelability can be obtained.

As the above-mentioned surfactant, any suitable surfactant can be used as long as the effect of the present invention can be obtained. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. Of these, a nonionic surfactant, an anionic surfactant, and a cationic surfactant are preferably used, and more preferably a nonionic surfactant or a cationic surfactant is used. The above-mentioned surfactants can be used alone or in combination of two or more.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether; and polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; Solbitan fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, polyoxyethylene sorbitan monolaurate; polyoxyethylene glyceryl ether fatty acid esters; polyoxyelene-polyoxypropylene block copolymers; ethyl caprylate, ethyl caprate, laurin Methyl acid, butyl laurate, methyl myristate, isopropyl myristate, methyl palmitate, isopropyl palmitate, methyl stearate, butyl stearate, methyl behenate, butyl laurate, butyl stearate, isopropyl myristate, isopropyl palmitate Saturated fatty acid esters such as lauric acid amide, partimate amide, stearic acid amide, fatty acid amides such as behenic acid amide and the like.

In one embodiment, a phosphate ester compound is used as the surfactant (nonionic surfactant). Examples of the phosphoric acid ester compound include alkyl phosphoric acids such as isopropyl phosphoric acid and lauryl phosphoric acid; lipoxyalkylene alkyl ether phosphoric acid; and salts thereof. Of these, polyoxyalkylene alkyl ether phosphoric acid is preferable.

Examples of the counterion constituting the salt when the phosphoric acid ester compound is a salt include alkali metal, ammonium, and organic ammonium cations. Examples of the alkali metal include sodium, potassium, lithium and the like. Examples of the organic ammonium include alkylamines such as methylamine and ethylamine; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine.

Examples of polyoxyalkylene alkyl ether phosphoric acid include, for example, xyalkylene alkyl ether phosphoric acid, polyoxyethylene capryl ether phosphoric acid, polyoxyethylene decyl ether phosphoric acid, polyoxyethylene lauryl ether phosphoric acid, and polyoxyethylene. Examples thereof include tridecyl ether phosphoric acid, polyoxyethylene myristyl ether phosphoric acid, polyoxyethylene pentadecyl ether phosphoric acid, and polyoxyethylene stearyl ether phosphoric acid. When the polyoxyalkylene alkyl ether phosphoric acid is a salt, for example, sodium, potassium, barium, triethanolamine and the like are preferably selected as the counterions constituting the salt.

The number of moles of ethylene oxide added to the polyoxyalkylene alkyl ether phosphoric acid is preferably 1 to 20, more preferably 1 to 10, still more preferably 1 to 6, and particularly preferably 1 to 4.

Examples of the anionic surfactant include alkyl sulfates such as lauryl sulfate and octadecyl sulfate; fatty acid salts; alkylbenzene sulfonates such as nonylbenzene sulfonate and dodecylbenzene sulfonate; and dodecylnaphthalene sulfonate and the like. Naphthalene sulfonate; alkyldiphenyl ether disulfonate such as dodecyldiphenyl ether disulfonate; polyoxyethylene alkyl ether sulfate such as polyoxyethylene octadecyl ether sulfate, polyoxyethylene lauryl ether sulfate; polyoxyethylene laurylphenyl ether sulfate Polyoxyethylene alkylphenyl ether sulfate such as salt; polyoxyethylene styrenated phenyl ether sulfate; sulfosuccinate such as lauryl sulfosuccinate, polyoxyethylene lauryl sulfosuccinate, dioctyl sulfosuccinate (sodium dioctyl sulfosuccinate) Polyoxyethylene alkyl ether phosphate; polyoxyethylene alkyl ether sulfate; etc. When the anionic surfactant forms a salt, the salt is, for example, a metal salt such as a sodium salt, a potassium salt, a calcium salt, a magnesium salt (preferably a monovalent metal salt), an ammonium salt, or an amine salt. And so on.

Examples of the cationic surfactant include alkyltrimethylammonium chloride, stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, cowfat alkyltrimethylammonium chloride, behenyltrimethylammonium chloride, stearyltrimethylammonium bromide, and behenyltrimethyl bromide. Ammonium, distearyl dimethylammonium chloride, dicocoyl dimethylammonium chloride, dioctyldimethylammonium chloride, di (POE) oleylmethylammonium (2EO), benzalconium chloride, alkylbenzalconium chloride, alkyldimethylbenzalconium chloride, chloride Benzethonium, stearyldimethylbenzylammonium chloride, lanolin-derived quaternary ammonium salt, diethylaminoethylamide stearate, dimethylaminopropylamide stearate, amidopropyldimethylhydroxypropylammonium behenate chloride, stearoyl collaminoformylmethylpyridinium chloride, cetylpyridinium chloride, Tall chloride oil alkylbenzylhydroxyethyl imidazolinium, benzylammonium salt and the like can be mentioned.

A commercially available product may be used as the surfactant. Examples of commercially available surfactants include phosphate ester-based surfactants such as the trade name "Phosphanol RL210" manufactured by Toho Chemical Industry Co., Ltd .; the trade name "Exepearl IPP" manufactured by Kao Co., Ltd., Tokyo Kasei Kogyo Co., Ltd. Fatty acid ester-based surfactant such as methyl partimate manufactured by Tokyo Kasei Kogyo Co., Ltd .; Fatty acid amide-based surfactant such as stearic acid amide and lauric acid amide manufactured by Tokyo Kasei Kogyo Co., Ltd .; Fatty acid aminoalkylamide-based surfactant; trimethylammonium chloride-based surfactant such as Toho Kagaku Kogyo Co., Ltd. trade name "Catinal STC-70ET"; dimethylbenzylammonium chloride such as Sanyo Kasei Co., Ltd. trade name "Cation S" Surfactants; succinic acid anhydride-based surfactants such as Sanyo Kasei Kogyo's trade names "DSA" and "PDSA-DA"; Sanyo Kasei Kogyo's trade names "Sansepara 100" and other sodium sulfosuccinates Examples include surfactants.

In one embodiment, the surfactant has an alkyl group as a hydrophobic group. Preferably, a surfactant having a linear or branched (preferably linear) alkyl group having 5 to 20 carbon atoms (more preferably 8 to 18, still more preferably 10 to 18) is used. .. By using such a surfactant, it is possible to obtain an adhesive sheet capable of exhibiting excellent peelability at a high temperature without impairing the adhesiveness at room temperature.

The content of the surfactant is preferably 0.001 part by weight to 15 parts by weight, more preferably 0.01 part by weight to 10 parts by weight, still more preferably, based on 100 parts by weight of the base polymer. It is 0.1 part by weight to 8 parts by weight, and particularly preferably 1 part by weight to 5 parts by weight. Within such a range, an adhesive sheet capable of exhibiting excellent peelability even at a high temperature can be obtained.

The molecular weight of the surfactant is preferably 800 or less, more preferably 600 or less, and even more preferably 500 or less. The lower limit of the molecular weight of the surfactant is, for example, 150. Within such a range, an adhesive sheet capable of exhibiting excellent peelability even at a high temperature can be obtained.

In one embodiment, the pressure-sensitive adhesive comprises a cross-linking agent. If a cross-linking agent is contained, the cohesive force of the pressure-sensitive adhesive layer can be adjusted, and a pressure-sensitive adhesive sheet having excellent adhesiveness at room temperature and excellent peelability at high temperature can be obtained.

As the cross-linking agent, any suitable cross-linking agent can be used as long as the effects of the present invention can be obtained. Examples of the cross-linking agent include epoxy-based cross-linking agents, isocyanate-based cross-linking agents, melamine-based cross-linking agents, peroxide-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, metal chelate-based cross-linking agents, and metals. Examples thereof include salt-based cross-linking agents, carbodiimide-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, and amine-based cross-linking agents. Of these, an epoxy-based cross-linking agent is preferable.

Examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylene diamine, diglycidyl aniline, and 1,3-bis (N, N-glycidyl aminomethyl) cyclohexane (Mitsubishi Gas). Chemical Co., Ltd., trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (Kyoeisha Chemical Co., Ltd., trade name "Epolite 1600"), neopentyl glycol diglycidyl ether (Kyoeisha Chemical Co., Ltd., trade name " Epolite 1500NP "), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolite 40E "), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name" Epolite 70P "), polyethylene glycol diglycidyl ether (Japan Oil and fat company, product name "Epiol E-400"), polypropylene glycol diglycidyl ether (Japan Oil and Fat Co., product name "Epiol P-200"), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, product name "Denacol" EX-611 "), glycerol polyglycidyl ether (manufactured by Nagase ChemteX, trade name" Denacol EX-314 "), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase Chemtex, trade name" Denacol EX ") -512 "), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipate diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcin diglycidyl ether, bisphenol Examples thereof include −S—diglycidyl ether and epoxy resins having two or more epoxy groups in the molecule. The content of the epoxy-based cross-linking agent can be set to an arbitrary appropriate amount according to the desired adhesive strength, elasticity of the pressure-sensitive adhesive layer, etc., and is typically 0. It is 01 parts by weight to 10 parts by weight, more preferably 0.03 parts by weight to 5 parts by weight.

In addition, the pressure-sensitive adhesive layer may contain any suitable foaming agent. A foaming agent is an additive that can foam when heated. As the foaming agent, any suitable foaming agent is used as long as the effects of the present invention can be obtained. Typically, heat-expandable microspheres can be used as the foaming agent. When the pressure-sensitive adhesive sheet including the pressure-sensitive adhesive layer containing the heat-expandable microspheres is heated, the heat-expandable microspheres expand or foam to cause unevenness on the adhesive surface, and as a result, the adhesive strength is reduced or disappears. To do. Such an adhesive sheet can be easily peeled off by heating.

The foaming start temperature of the foaming agent is preferably 90 ° C. or higher, preferably 90 ° C. to 220 ° C., and more preferably 100 ° C. to 190 ° C. In the present specification, the foaming start temperature corresponds to, for example, the minimum temperature at which the adhesive strength of the pressure-sensitive adhesive layer becomes 10% or less of the normal adhesive strength of the pressure-sensitive adhesive layer (adhesive strength against a PET film at 23 ° C.). To do. The adhesive strength at this time means the adhesive strength measured by a method according to JIS Z 0237: 2000 (bonding conditions: 2 kg roller 1 reciprocation, peeling speed: 300 mm / min, peeling angle 180 °). The adhesive strength at the foaming start temperature (and the measurement sample after heating) is measured after the measurement sample is returned to room temperature (23 ° C.). When the foaming agent is a heat-expandable microsphere, the temperature at which the heat-expandable microsphere begins to expand corresponds to the foaming start temperature.

As the heat-expandable microsphere, any suitable heat-expandable microsphere can be used. As the heat-expandable microsphere, for example, a microsphere in which a substance that easily expands by heating is contained in an elastic shell can be used. Such heat-expandable microspheres can be produced by any suitable method, for example, a coacervation method, an interfacial polymerization method, or the like.

Examples of substances that easily expand by heating include propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, normal hexane, isohexane, heptane, octane, petroleum ether, methane halide, and tetraalkylsilane. Low boiling point liquids such as; azodicarboxylic amides gasified by thermal decomposition; and the like.

Examples of the substances constituting the shell include nitrile monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, and fumaronitrile; acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid. Carboxylic acid monomers such as citraconic acid; vinylidene chloride; vinyl acetate; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, (Meta) acrylic acid esters such as isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, β-carboxyethyl acrylate; styrene monomers such as styrene, α-methylstyrene, chlorostyrene; acrylamide, substituted acrylamide , Acrylate monomers such as methacrylicamide and substituted methacrylicamide; and the like. The polymer composed of these monomers may be a homopolymer or a copolymer. Examples of the copolymer include vinylidene chloride-methyl methacrylate-acrylonitrile copolymer, methyl methacrylate-acrylonitrile-methacrylonitrile copolymer, methyl methacrylate-acrylonitrile copolymer, and acrylonitrile-methacrylonitrile-itaconic acid. Examples include copolymers.

Commercially available products may be used as the heat-expandable microspheres. Specific examples of commercially available thermally expandable microspheres include the trade name "Matsumoto Microsphere" manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd. (grades: F-30, F-30D, F-36D, F-36LV, F-50, F-50D, F-65, F-65D, FN-100SS, FN-100SSD, FN-180SS, FN-180SD, F-190D, F-260D, F-2800D), trade name "EX" manufactured by Nippon Phillite Co., Ltd. "Pansel" (grades: 053-40, 031-40, 920-40, 909-80, 930-120), "Dieform" manufactured by Kureha Chemical Industry Co., Ltd. (grades: H750, H850, H1100, S2320D, S2640D, M330) , M430, M520), "Advancel" manufactured by Sekisui Chemical Co., Ltd. (grades: EML101, EMH204, EHM301, EHM302, EHM303, EM304, EHM401, EM403, EM501) and the like.

The average particle size of the heat-expandable microspheres before foaming the heat-expandable microspheres under an ambient temperature of 25 ° C. is preferably 50 μm or less, more preferably 1 μm to 50 μm, and further preferably. It is 3 μm to 35 μm, and particularly preferably 5 μm to 35 μm. By using the heat-expandable microspheres having an average particle size of 50 μm or less, the influence of the heat-expandable microspheres before foaming of the heat-expandable microspheres (that is, a situation where the adhesive layer requires adhesiveness) is affected. It is possible to obtain a pressure-sensitive adhesive sheet that is unlikely to occur on the surface of the pressure-sensitive adhesive layer, has high adhesion to an adherend, and has excellent adhesiveness. Within the above range, the larger the average particle size of the heat-expandable microspheres is, the more it expands during heating. Therefore, if the heat-expandable microspheres having the above range of average particle size are used, the adhesive sheet has excellent peelability. Can be obtained. The average particle size of the heat-expandable microspheres can be controlled, for example, by the conditions for polymerizing the heat-expandable microspheres (for example, the number of rotations of the stirring blade during polymerization and the polymerization temperature). Further, when a commercially available heat-expandable microsphere is used, it can be controlled by a classification treatment such as a mesh treatment, a filter treatment, or a centrifugation treatment. In the present specification, the average particle size is determined by observing the heat-expandable microspheres used or the heat-expandable microspheres taken out from the pressure-sensitive adhesive layer before heating with an optical microscope or an electron microscope. It can also be measured. Further, the average particle size can be measured by the particle size distribution measuring method in the laser scattering method. More specifically, the average particle size is determined by dispersing the thermally expandable microspheres to be used in a predetermined solvent (for example, water) and then using a particle size distribution measuring device (for example, trade name "SALD-2000J" manufactured by Shimadzu Corporation). ) Can be used for measurement.

The heat-expandable microspheres preferably have an appropriate strength that does not burst until the coefficient of thermal expansion is preferably 5 times or more, more preferably 7 times or more, and further preferably 10 times or more. When such a heat-expandable microsphere is used, the adhesive strength can be efficiently reduced by the heat treatment.

The content of the heat-expandable microspheres in the pressure-sensitive adhesive layer can be appropriately set according to the desired decrease in adhesive strength and the like. The content of the heat-expandable microspheres is preferably 20 parts by weight to 210 parts by weight, more preferably 30 parts by weight to 200 parts by weight, still more preferably 50 parts by weight, based on 100 parts by weight of the base polymer. Parts to 150 parts by weight. Within such a range, it is possible to obtain an adhesive sheet that exhibits good adhesiveness during backgrinding and can easily peel off the adherend during heating.

The content of the heat-expandable microspheres in the pressure-sensitive adhesive layer is preferably 5% by weight to 80% by weight, more preferably 10% by weight to 70% by weight, and further, with respect to the weight of the pressure-sensitive adhesive layer. It is preferably 15% by weight to 65% by weight. The content ratio of the heat-expandable microspheres is the volume filling rate of the heat-expandable microspheres obtained from X-ray CT analysis, SEM analysis, etc. (volume filling rate below the foaming start temperature (for example, 23 ° C.)) and thermal expansion. It can be calculated from the specific gravity of the sex microsphere and the specific gravity of the region other than the thermally expandable microsphere. In one embodiment, it can be calculated by estimating the specific gravity of the heat-expandable microsphere as 1 and the specific gravity of the region other than the heat-expandable microsphere as 1, and in this case, the heat-expandable microsphere The content ratio is in the above range.

The content of the heat-expandable microspheres in the pressure-sensitive adhesive layer is preferably 5% by volume to 80% by volume, more preferably 10% by volume to 70% by volume, and further, with respect to the volume of the pressure-sensitive adhesive layer. It is preferably 15% by volume to 65% by volume. The volume-based content ratio corresponds to the volume filling rate, and can be measured by X-ray CT analysis, SEM analysis, or the like as described above. More specifically, the volume filling factor can be measured by the following method.
<Measuring method of volume filling rate>
i) The sample is fixed to the holder with the adhesive layer of the adhesive sheet before heating facing up, and 1601 continuous transmission images are taken by X-ray CT at 0 to 180 °. X-ray CT is measured using ZEISS, Xradia 520 Versa, with a tube voltage of 40 kV, a tube current of 73 μA, and a pixel size of 0.3 μm / Pixel.
ii) Based on the obtained total transmission image, reconstruction is performed to create a tomographic image, and analysis software ImageJ. A three-dimensional reconstructed image (TIF stack image) and a reconstructed cross-sectional image (three-view view) are created using.
iii) Image processing is performed on the obtained three-dimensional reconstructed image (TIF stack image) to identify thermally expandable microspheres. From the identification result, the volume filling rate in the thickness direction, the volume of each foam, and the equivalent diameter of the sphere are calculated.
The thickness of the pressure-sensitive adhesive layer of each sample is measured by SEM cross-sectional observation, and the filling rate is calculated by taking the value excluding the bubble portion as the total volume.

As the foaming agent, an inorganic foaming agent or an organic foaming agent may be used. Examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, ammonium nitrite, sodium boron hydroxide, and various azides. Examples of the organic foaming agent include salt fluoride alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; and azo compounds such as azobisisobutyronitrile, azodicarboxylicamide, and barium azodicarboxylate. Hydrazine compounds such as paratoluenesulfonyl hydrazide, diphenylsulfone-3,3'-disulfonylhydrazide, 4,4'-oxybis (benzenesulfonylhydrazide), allylbis (sulfonylhydrazide); p-toluylenesulfonyl semicarbazide, 4, Semicarbazide compounds such as 4'-oxybis (benzenesulfonyl semicarbazide); triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; N, N'-dinitrosopentamethylenetetramine, N, N' Examples thereof include N-nitroso compounds such as −dimethyl-N, N ′ -dinitrosoterephthalamide; and the like.

C. Base material Examples of the base material include resin sheets, non-woven fabrics, paper, metal foils, woven fabrics, rubber sheets, foam sheets, and laminates thereof (particularly, laminates containing resin sheets). Examples of the resin constituting the resin sheet include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, and ethylene-. Vinyl acetate copolymer (EVA), polyamide (nylon), total aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyphenylene terephide (PPS), fluororesin, polyetheretherketone (PEEK) ) Etc. can be mentioned. Examples of the non-woven fabric include non-woven fabrics made of natural fibers having heat resistance such as non-woven fabrics containing Manila hemp; synthetic resin non-woven fabrics such as polypropylene resin non-woven fabrics, polyethylene resin non-woven fabrics and ester resin non-woven fabrics. Examples of the metal foil include copper foil, stainless steel foil, aluminum foil and the like. Examples of paper include Japanese paper and kraft paper. The base material may be a single layer or a multi-layer. When the base material has multiple layers, the composition of each layer may be the same or different.

The thickness of the base material can be set to an arbitrary appropriate thickness depending on the desired strength or flexibility, the purpose of use, and the like. The thickness of the base material is preferably 1000 μm or less, more preferably 1 μm to 1000 μm, further preferably 1 μm to 500 μm, particularly preferably 3 μm to 300 μm, and most preferably 5 μm to 250 μm.

The tensile elastic modulus of the base material at 25 ° C. is 1 × 10 ⁷ Pa to 1 × 10 ¹⁰ Pa, more preferably 5 × 10 ⁷ Pa to 5 × 10 ^{9 Pa.} Within such a range, an adhesive sheet capable of accurately grinding a hard and brittle substrate (for example, a sapphire wafer) can be obtained.

The base material may be surface-treated. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage impact exposure, ionizing radiation treatment, coating treatment with an undercoat agent, and the like.

Examples of the organic coating material include the materials described in "Plastic Hard Coat Material II (CMC Publishing, (2004))". Urethane-based polymers are preferably used, more preferably polyacrylic urethane, polyester urethane, or precursors thereof. This is because it is easy to apply and apply to the base material, and various types can be industrially selected and obtained at low cost. The urethane-based polymer is, for example, a polymer composed of a reaction mixture of an isocyanato monomer and an alcoholic hydroxyl group-containing monomer (for example, a hydroxyl group-containing acrylic compound or a hydroxyl group-containing ester compound). The organic coating material may contain a chain extender such as polyamine, an antioxidant, an oxidation stabilizer and the like as optional additives. The thickness of the organic coating layer is not particularly limited, but for example, about 0.1 μm to 10 μm is suitable, about 0.1 μm to 5 μm is preferable, and about 0.5 μm to 5 μm is more preferable.

D. Another Adhesive Layer As the other adhesive layer, any suitable adhesive layer can be formed. Examples of the adhesive forming another adhesive layer include rubber-based adhesives, acrylic-based adhesives, vinyl alkyl ether-based adhesives, silicone-based adhesives, polyester-based adhesives, polyamide-based adhesives, and urethane-based adhesives. Examples thereof include agents, fluorine-based pressure-sensitive adhesives, and styrene-diene block copolymer-based pressure-sensitive adhesives. The pressure-sensitive adhesive may contain known or commonly used additives such as plasticizers, fillers, surfactants, anti-aging agents, and tackifiers.

The thickness of the other pressure-sensitive adhesive layer is preferably 300 μm or less, more preferably 1 μm to 300 μm, and even more preferably 5 μm to 100 μm.

E. Elastic layer The pressure-sensitive adhesive sheet of the present invention may further include an elastic layer. The elastic layer can be placed on one side of the pressure-sensitive adhesive layer. If the pressure-sensitive adhesive sheet comprises a substrate, the elastic layer may be placed between the pressure-sensitive adhesive layer and the substrate. By providing the elastic layer, the followability to the adherend is improved.

The elastic layer contains a base polymer, and as the base polymer, a polymer exemplified as the base polymer constituting the pressure-sensitive adhesive layer can be used. In one embodiment, the elastic layer may contain natural rubber, synthetic rubber, synthetic resin and the like. Examples of the synthetic rubber and synthetic resin include nitrile-based, diene-based, and acrylic-based synthetic rubber; polyolefin-based, polyester-based thermoplastic elastomers; ethylene-vinyl acetate copolymer; polyurethane; polybutadiene; and soft polyvinyl chloride. Can be mentioned. The base polymer constituting the elastic layer may be the same as or different from the base polymer forming the pressure-sensitive adhesive layer. The elastic layer may be a foamed film formed from the base polymer. The foamed film can be obtained by any suitable method. The elastic layer and the pressure-sensitive adhesive layer can be distinguished by the difference in the base polymer.

The elastic layer may optionally contain any suitable additive. Examples of the additive include a cross-linking agent, a vulcanizing agent, a tackifier resin, a plasticizer, a softener, a filler, an anti-aging agent and the like. When a hard resin such as polyvinyl chloride is used as the base polymer, it is preferable to use a plasticizer and / or a softener in combination to form an elastic layer having desired elasticity.

The thickness of the elastic layer is preferably 3 μm to 200 μm, more preferably 5 μm to 100 μm. Within such a range, the above-mentioned function of the elastic layer can be fully exerted.

F. Separator The pressure-sensitive adhesive sheet of the present invention may further include a separator, if necessary. At least one surface of the separator is a peeling surface, and the separator may be provided to protect the pressure-sensitive adhesive layer. The separator can be composed of any suitable material.

G. Method for Producing Adhesive Sheet The adhesive sheet of the present invention can be produced by any suitable method. The pressure-sensitive adhesive sheet of the present invention is, for example, a method of applying a composition containing a pressure-sensitive adhesive directly on a base material (in the case of obtaining a pressure-sensitive adhesive sheet containing no base material, any suitable base material), or any suitable. Examples thereof include a method of transferring a coating layer formed by coating a composition containing an adhesive on a suitable substrate to the substrate. The composition containing the pressure-sensitive adhesive may contain any suitable solvent.

When the pressure-sensitive adhesive layer has the above-mentioned elastic layer, the elastic layer can be formed by, for example, applying a composition for forming the elastic layer on a base material or a pressure-sensitive adhesive layer.

Any suitable coating method can be adopted as the coating method for each of the above compositions. For example, each layer can be formed by applying and then drying. Examples of the coating method include a coating method using a multi-coater, a die coater, a gravure coater, an applicator, and the like. Examples of the drying method include natural drying and heat drying. The heating temperature for heat-drying can be set to any suitable temperature depending on the characteristics of the substance to be dried.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The evaluation method in the examples is as follows. In the following evaluation, an adhesive sheet from which the separator was peeled off was used. Further, in the examples, unless otherwise specified, "parts" and "%" are based on weight.

<Evaluation method>
In the following evaluation method, the pressure-sensitive adhesive layer (and another pressure-sensitive adhesive layer) was attached after the separator laminated on the adhesion surface was peeled off.
(1) Shear Adhesive Strength The adhesive sheet (size: 20 mm × 20 mm) obtained in Examples and Comparative Examples is attached to a predetermined base (for example, 20 mm × 20 mm silicon chip) on the surface opposite to the adhesive layer. It is attached and fixed, and a 5 mm × 5 mm silicon chip is placed on the surface of the adhesive layer of the adhesive sheet, and the silicon chip is thermocompression-bonded for 1 minute at 100 ° C. and 0.1 MPa with a heat press machine for evaluation. Samples were prepared. The adhesive sheet that does not have a separate adhesive layer can be fixed to the base by using double-sided tape No. 1 manufactured by Nitto Denko KK. 585 was used.
For the evaluation sample, a measurement terminal was set on the side surface of a 5 mm × 5 mm silicon chip at a height of 50 μm from the attachment surface using a Nordson load 4000 under an environmental temperature of 25 ° C., and a shear rate of 500 μm / sec. The maximum breaking load was read from the load-displacement curve obtained by applying an external force in the horizontal direction to the tip in 1., and this was used as the shear bond strength under an environmental temperature of 25 ° C.
Further, the shear adhesive strength was measured in the same manner as described above under an environmental temperature of 80 ° C.
Table 1 shows the average value of each of the three measurements.
(2) Pushing hardness A displacement-load hysteresis curve obtained by vertically pressing a diamond Berkovich type (triangular cone type) probe against the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples. , The indentation hardness H was measured by numerical processing with software (triboscan) attached to the measuring device. The indentation hardness H was measured by a single indentation method at 25 ° C. using a nanoindenter (Triboinder TI-950 manufactured by Hysiron Inc) under the measurement conditions of an indentation speed of about 500 nm / sec and an indentation depth of about 3000 nm. ..
Further, a value calculated by 1.9385 × loghA + 4.2611 was calculated from the indentation hardness H.
(3) Sapphire Grindability A heat press in which sapphire wafers having a thickness of 900 μm and a size of 4 inches are placed on the adhesive layer of the adhesive sheets obtained in Examples and Comparative Examples and then preheated to 90 ° C. It was crimped with a machine at a pressure of 1.0 MPa for 5 minutes. The adhesive sheet on which the sapphire wafer was fixed was set in a grinding machine DFG8540 manufactured by Disco Corporation, and ground until the wafer thickness became 120 μm. Grindability was evaluated based on the following criteria.
〇: Backside grinding is possible until the wafer thickness is 120 μm.
X: The wafer is cracked or the edge of the wafer is chipped before the thickness of the wafer reaches 120 μm. (Backside grinding is not possible)
(4) Peelability The adherend SUS304BA after the peeling adhesive strength evaluation of the adhesive sheet in (5) below at 80 ° C. was visually observed. The peelability was evaluated based on the following criteria.
〇: There is no residue of adhesive that has coagulated and broken on SUS304BA, and there is no sticking mark.
Δ: There is no residue of the adhesive that coagulated and fractured on SUS304BA, but a sticking mark can be confirmed.
X: Residue of adhesive that coagulated and fractured on SUS304BA can be confirmed.
(5) Peeling Adhesive Strength at 80 ° C. The adhesive sheets obtained in Examples and Comparative Examples are cut to a width of 20 mm, and the adhesive surface (adhesive layer surface) of the adhesive sheet is attached to SUS304BA with a hand roller to form a laminate. Was formed. Next, the laminate was pressure-bonded at a pressure of 0.3 MPa for 1 minute with a heat press machine preheated to 80 ° C. to prepare a sample. For the sample, the adhesive sheet was peeled off from SUS304BA under the conditions of a peeling angle of 180 ° and a peeling speed of 300 mm / min, and the adhesive strength was measured.
When the adhesive sheet is an adhesive sheet having no base material (Example 28), the adhesive tape No. 2 manufactured by Nitto Denko KK is on the surface opposite to the adhesive layer surface. After the 315 was attached, the above sample was prepared and the peeling adhesive strength was measured.
(6) Tensile Elastic Modulus of Base Material Using the base material (width 10 mm) used for the pressure-sensitive adhesive sheet as a sample, the tensile elasticity of a dynamic viscoelasticity measuring device (manufactured by TA Instrument, trade name "RSA-3") at 25 ° C. The rate was measured. The distance between the chucks was 20 mm, the measurement frequency was 1 Hz, the initial strain was 0.05%, and the temperature rising rate was 5 ° C./min (-20 ° C. to 100 ° C.).

[Production Example 1] Preparation of resin composition (I) Maleic acid-modified styrene / ethylene / butylene / styrene block copolymer (a) (SEBS: styrene moiety / ethylene / butylene moiety (weight ratio) = 20/80, acid Price: 10 (mg-CH ₃ ONa / g), manufactured by Asahi Kasei Chemicals, trade name "Tuftec M1943") 100 parts by weight, and terpenphenol-based tackifier resin (manufactured by Yasuhara Chemicals, trade name "YS Polystar T80", Softening point: 80 ° C.) 20 parts by weight, epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemicals, trade name "TETRAD-C"), 3 parts by weight, fatty acid ester-based surfactant (manufactured by Kao, trade name "Exepearl") The resin composition (I) (mixture) was prepared by mixing "IPP", molecular weight: 298.5, carbon number of alkyl group: 16) 3 parts by weight, and toluene as a solvent.

[Production Example 2-1] Preparation of resin composition (II-1) Maleic acid-modified styrene / ethylene / butylene / styrene block copolymer (b) (SEBS: styrene moiety / ethylene / butylene moiety (weight ratio) = 30 / 70, acid value: 10 (mg-CH ₃ ONa / g), manufactured by Asahi Kasei Chemicals, trade name "Tuftec M1913") 100 parts by weight and terpenphenol-based tackifier resin (manufactured by Yasuhara Chemicals, trade name "YS" 50 parts by weight of Polystar T80), 3 parts by weight of an epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemicals, trade name "TETRAD-C"), and a fatty acid ester-based surfactant (manufactured by Kao, trade name "Exepearl IPP" , Molecular weight: 298.5, Carbon number of alkyl group: 16) 3 parts by weight and toluene as a solvent were mixed to prepare a resin composition (II-1) (mixture).

[Production Example 2-2 to 10] Preparation of resin composition (II-2 to 10) Fatty acid ester-based surfactant (manufactured by Kao Corporation, trade name "Exepearl IPP", molecular weight: 298.5, number of carbon atoms of alkyl group : 16) Resin composition (II-2 to 10) in the same manner as in Production Example 2-1 except that the surfactant shown in Table 1 was used in the amount of addition shown in Table 1 instead of 3 parts by weight. ) Was prepared. The surfactants used are as follows.
Production Example 2-2 (resin composition (II-2)): phosphoric acid ester-based surfactant; manufactured by Toho Chemical Industry Co., Ltd., trade name "Phosphanol RL210", chemical formula: C ₂₂ H ₄₇ O ₅ P, alkyl Group carbon number: 18, molecular weight 422.57
Production Example 2-3 (resin composition (II-3)): fatty acid amide-based surfactant; manufactured by Tokyo Chemical Industry Co., Ltd., stearic acid amide, chemical formula: C ₁₈ H ₃₇ NO, alkyl group carbon number: 18, molecular weight : 283.49
Production Example 2-4 (resin composition (II-4)): fatty acid amide-based surfactant; manufactured by Tokyo Chemical Industry Co., Ltd., lauric acid amide, chemical formula: C ₁₂ H ₂₅ NO, alkyl group carbon number: 12, molecular weight 199.33
Production Example 2-5 (resin composition (II-5)): fatty acid aminoalkylamide-based surfactant; manufactured by Toho Chemical Industry Co., Ltd., trade name "Catinal MAPS", chemical formula: C ₂₃ H ₃₈ N ₂ O, alkyl group Carbon number: 18, molecular weight: 358.56
Production Example 2-6 (resin composition (II-6)): trimethylammonium chloride-based surfactant; manufactured by Toho Chemical Industry Co., Ltd., trade name "Catinal STC-70ET", chemical formula: C ₂₁ H ₄₆ ClN, alkyl group. Carbon number: 16, molecular weight: 348.04
Production Example 2-7 (resin composition (II-7)): dimethylbenzylammonium chloride-based surfactant; manufactured by Sanyo Chemical _{Industries, Ltd., trade name "cation S", chemical formula: C 26} H ₄₈ ClN, carbon number of alkyl group. : 18, molecular weight: 410.11
Production Example 2-8 (resin composition (II-8)): succinic anhydride-based surfactant; manufactured by Sanyo Chemical Industries, Ltd., trade name "DSA", chemical formula: C ₁₆ H ₂₆ O ₃ , carbon of alkyl group. Number: 12, molecular weight: 266.37
Preparation 2-9 (resin composition (II-9)): succinic acid anhydride surfactant; manufactured by Sanyo Chemical Industries, Ltd., trade name "PDSA-DA", chemical _formula: C _{19 H} 32 _{O 3,} an alkyl group Carbon number: 15, molecular weight: 308.45
Production Example 2-10 (resin composition (II-10)): sodium sulfosuccinate-based surfactant; manufactured by Sanyo Chemical Industries, Ltd., trade name "Sansepara 100", chemical formula: C ₂₀ H ₂₇ O ₇ SNa, alkyl group. Carbon number: 6, molecular weight: 434.48

[Production Example 3] Preparation of Resin Composition (III) Instead of the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals, trade name "YS Polystar T80"), the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals, product) The resin composition (III) was prepared in the same manner as in Production Example 2 except that the name “YS Polystar S145”, softening point: 145 ° C.) was used.

[Production Example 4] Preparation of Resin Composition (IV) 100 parts by weight of styrene / ethylene / butylene / styrene block copolymer (c) (unacid-modified product, manufactured by Asahi Kasei Chemicals Co., Ltd., trade name "Tuftec H1043"). 80 parts by weight of terpenphenol adhesive resin (Yasuhara Chemicals, trade name "YS Polystar T80"), 3 parts by weight of epoxy cross-linking agent (Mitsubishi Gas Chemicals, trade name "TETRAD-C"), and phosphorus 3 parts by weight of an acid ester-based surfactant (manufactured by Toho Chemical Industry Co., Ltd., trade name "Phosphanol RL210", molecular weight 422.57, number of carbon atoms of alkyl group: 18) and toluene as a solvent are mixed. Resin compositions (IV) (mixtures) were prepared.

[Production Example 5] Preparation of Resin Composition (V) With the exception of Production Example 4 in which the amount of the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals Co., Ltd., trade name "YS Polystar T80") is 20 parts by weight. The resin composition (V) was prepared in the same manner.

[Production Example 6] Preparation of Resin Composition (VI) Production Example 2 and the addition amount of the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals, trade name "YS Polystar T80") is 100 parts by weight. A resin composition (VI) was prepared in the same manner.

[Production Example 7] Preparation of Resin Composition (VII) Production Example 2 and the addition amount of the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals Co., Ltd., trade name "YS Polystar T80") is 125 parts by weight. A resin composition (VII) was prepared in the same manner.

[Production Example 8] Preparation of Resin Composition (VIII) Production Example 2 and the addition amount of the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals, trade name "YS Polystar T80") is 150 parts by weight. A resin composition (VIII) was prepared in the same manner.

[Production Example 9] Preparation of Resin Composition (IX) The amount of the terpene phenol-based tackifier resin (manufactured by Yasuhara Chemicals Co., Ltd., trade name "YS Polystar T80") is 200 parts by weight, and the thermal expansion is minute. Resin in the same manner as in Production Example 2, except that 100 parts by weight of spheres (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., trade name "Matsumoto Microsphere F-50D", foaming start temperature 120 ° C., average particle size 14 μm) were further added. The composition (IX) was prepared.

[Example 1]
100 parts by weight of acrylic resin (butyl acrylate-acrylic acid copolymer, butyl acrylate: acrylic acid (weight ratio) = 100: 5) and epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemicals, trade name "TETRAD-" C ") 3 parts by weight, fatty acid ester-based surfactant (manufactured by Kao, trade name" Exepearl IPP ", molecular weight: 298.5, number of carbon atoms of alkyl group: 16) 1 part by weight, and toluene as a solvent. Was mixed to prepare a resin composition (A). This resin composition (A) was applied onto a PET base material (thickness: 50 μm) so that the thickness after drying was 3 μm, and dried to form an adhesive layer. Further, a separator was bonded onto the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet having a layer structure of a PET base material / pressure-sensitive adhesive layer / separator. Table 2 shows the results of subjecting the obtained adhesive sheet to the above evaluations (1) to (5).

[Example 2]
The resin composition (I) prepared in Production Example 1 was applied onto a PET substrate (thickness: 50 μm) so as to have a thickness of 15 μm after drying, and dried to form an adhesive layer. Further, a separator was bonded onto the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet having a layer structure of a PET base material / pressure-sensitive adhesive layer / separator. Table 2 shows the results of subjecting the obtained adhesive sheet to the above evaluations (1) to (5).

[Example 3]
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer was 20 μm. Table 2 shows the results of subjecting the obtained adhesive sheet to the above evaluations (1) to (5).

[Example 4]
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer was 25 μm. Table 2 shows the results of subjecting the obtained adhesive sheet to the above evaluations (1) to (5).

[Examples 5 to 11]
Instead of the resin composition (I), the resin compositions shown in Table 2 (resin compositions (II-1) and (III) to (V) prepared in Production Examples 2-1 and 3 to 5) are used. A pressure-sensitive adhesive sheet was produced in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer was set to the thickness shown in Table 2. The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 2.

[Example 12]
100 parts by weight of ethylene-vinyl acetate copolymer resin (manufactured by Mitsubishi Chemical Company, trade name "EV-40W"), 3 parts by weight of epoxy-based cross-linking agent (manufactured by Mitsubishi Gas Chemical Company, trade name "TETRAD-C"), A resin composition obtained by mixing 3 parts by weight of a fatty acid ester-based surfactant (manufactured by Kao, trade name "EXPEPARIP IPP", molecular weight: 298.5, number of carbon atoms of alkyl group: 16) and toluene as a solvent. (B) was prepared. This resin composition (B) was applied onto a PET substrate (thickness: 50 μm) so as to have a thickness of 15 μm after drying, and dried to form an adhesive layer. Further, a separator was bonded onto the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive sheet having a layer structure of a PET base material / pressure-sensitive adhesive layer / separator. Table 3 shows the results of subjecting the obtained adhesive sheet to the above evaluations (1) to (5).

[Example 13]
Instead of the ethylene-vinyl acetate copolymer resin (manufactured by Mitsubishi Chemical Corporation, trade name "EV-40W"), an ethylene-vinyl acetate copolymer resin (manufactured by Mitsubishi Chemical Corporation, trade name "EV-150") was used. An adhesive sheet was obtained in the same manner as in Example 12 except. The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 3.

[Examples 14 to 25]
Instead of the resin composition (I), the resin compositions shown in Table 2 (resin compositions (VI) to (VIII) and (II-2) to (II-11) are used, and the thickness of the pressure-sensitive adhesive layer is shown. An adhesive sheet was produced in the same manner as in Example 2 except that the thickness was shown in 2. The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 3.

[Example 26]
Similar to Example 5 except that a polyolefin-based substrate (thickness: 80 μm) was used instead of the PET substrate (thickness: 50 μm) and the thickness of the pressure-sensitive adhesive layer was set to 20 μm. , Obtained an adhesive sheet. The obtained adhesive sheet was subjected to the above evaluation. The results are shown in Table 4.
As the polyolefin-based substrate, a propylene-based thermoplastic elastomer containing a propylene component and an ethylene-propylene rubber component (manufactured by Mitsubishi Chemical Co., Ltd., trade name "Zeras") is used as a T-die molding machine manufactured by Braco Co., Ltd. (set temperature: 230 ° C.). ), And a substrate obtained by molding into a film having a thickness of 80 μm was used.

[Example 27]
A polyolefin-based base material (manufactured by Okura Industrial Co., Ltd., trade name "NSO # 60", thickness: 60 μm) was used instead of the PET base material (thickness: 50 μm), and the thickness of the pressure-sensitive adhesive layer was 20 μm. An adhesive sheet was obtained in the same manner as in Example 5 except for the above. The obtained adhesive sheet was subjected to the above evaluation. The results are shown in Table 4.

[Example 28]
The resin composition (IX) prepared in Production Example 9 was applied onto a separator so that the thickness after drying was 40 μm, and dried to form an adhesive layer. Further, the pressure-sensitive adhesive layer on the separator and another separator were bonded together to prepare a pressure-sensitive adhesive sheet having a layer structure of a separator / pressure-sensitive adhesive layer / separator. Table 4 shows the results of subjecting the obtained adhesive sheet to the above evaluations (1) to (5).

[Comparative Example 1]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer was 30 μm. The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 5.

[Comparative Example 2]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 5 except that the thickness of the pressure-sensitive adhesive layer was 70 μm. The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 5.

[Comparative Example 3]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 8 except that the thickness of the pressure-sensitive adhesive layer was set to 200 μm. The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 5.

[Comparative Example 4]
Fatty acid ester-based surfactant (Kao Corporation, trade name "Exepearl IPP", molecular weight: 298.5, alkyl group carbon number: 16) Instead of 3 parts by weight, aromatic ester-based surfactant (manufactured by DIC) , Trade name "Monosizer W-700", molecular weight: 546.78, number of carbon atoms of alkyl group: 6), and the pressure-sensitive adhesive sheet was the same as in Example 1 except that the thickness of the pressure-sensitive adhesive layer was 10 μm. Got The obtained adhesive sheet was subjected to the above evaluations (1) to (5). The results are shown in Table 5.

10 Adhesive layer 20 Base material 30 Another adhesive layer 100, 200, 300 Adhesive sheet

Claims (14)

An adhesive sheet with an adhesive layer
The thickness of the pressure-sensitive adhesive layer is 1 μm to 300 μm.
The indentation hardness H (Pa) at 25 ° C. of the pressure-sensitive adhesive layer, the thickness _{h A} pressure-sensitive adhesive layer ([mu] m) but meets the relation of the following formula (1),
The thickness of the pressure-sensitive adhesive sheet is 10 μm to 500 μm.
Adhesive sheet.
logH ≧ 1.9385 × logh _A +4.2611 ・ ・ ・ (1) The adhesive sheet according to claim 1, wherein the shear adhesive strength at an environmental temperature of 25 ° C. when the adhesive surface of the adhesive sheet is attached to a silicon chip is 1.0 MPa or more. The adhesive sheet according to claim 1 or 2, wherein the peeling adhesive force at an environmental temperature of 80 ° C. when the adhesive surface of the adhesive sheet is attached to SUS304BA is 15 N / 20 mm or less. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the pressing hardness H of the pressure-sensitive adhesive layer at 25 ° C. is 10 MPa to 1 GPa. The pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive containing a base polymer.
The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the base polymer is a thermoplastic elastomer. The pressure-sensitive adhesive sheet according to claim 5, wherein the thermoplastic elastomer is a styrene-based elastomer or an ethylene-vinyl acetate-based elastomer. The pressure-sensitive adhesive sheet according to claim 5, wherein the pressure-sensitive adhesive further contains a pressure-sensitive adhesive resin. The pressure-sensitive adhesive sheet according to claim 7, wherein the content of the pressure-sensitive adhesive resin is 1 part by weight to 350 parts by weight with respect to 100 parts by weight of the base polymer. The pressure-sensitive adhesive sheet according to any one of claims 1 to 8, further comprising a base material arranged on at least one side of the pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet according to any one of claims 1 to 9, further comprising another pressure-sensitive adhesive layer arranged on at least one side of the pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet according to claim 9 or 10, wherein the tensile elastic modulus of the base material at 25 ° C. is 1 × 10 ⁷ Pa to 1 × 10 ^{10 Pa.} The pressure-sensitive adhesive sheet according to any one of claims 1 to 11, which is used as a temporary fixing material during substrate processing in a semiconductor manufacturing process. Including placing and fixing a substrate on the pressure-sensitive adhesive layer of a pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive layer, and then grinding the surface of the substrate opposite to the pressure-sensitive adhesive layer side.
The thickness of the pressure-sensitive adhesive layer is 1 μm to 300 μm.
The indentation hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and the thickness h _A (μm) of the pressure-sensitive adhesive layer satisfy the relationship of the following formula (1).
logH ≧ 1.9385 × logh _A +4.2611 ・ ・ ・ (1)
Substrate grinding method. A grinding step of placing a substrate on the pressure-sensitive adhesive layer of a pressure-sensitive adhesive sheet provided with the pressure-sensitive adhesive layer, fixing the substrate, and then grinding the surface of the substrate opposite to the pressure-sensitive adhesive layer side is included.
The thickness of the pressure-sensitive adhesive layer is 1 μm to 300 μm.
The indentation hardness H (Pa) of the pressure-sensitive adhesive layer at 25 ° C. and the thickness h _A (μm) of the pressure-sensitive adhesive layer satisfy the relationship of the following formula (1).
logH ≧ 1.9385 × logh _A +4.2611 ・ ・ ・ (1)
How to make chips.

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