JP2015168711A - Pressure sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive sheet having appropriate adhesiveness to encapsulation resin and a semiconductor chip constituting a semiconductor package, easily peelable from the encapsulation resin and the semiconductor chip, and capable of preventing adhesive residue at peeling.SOLUTION: A pressure sensitive adhesive sheet has an adhesive layer. The contact angle of the adhesive layer surface to 4-tertiary butyl phenylglycidyl ether is 15° or more. The adhesive strength of the pressure sensitive adhesive sheet to polyethylene terephthalate at 23°C is 0.5 N/20 mm or more.

Description

  The present invention relates to an adhesive sheet.

  In recent years, miniaturization of semiconductor devices is required, and CSP (Chip Size / Scale Package) that forms a semiconductor package having the same size as a built-in semiconductor element has attracted attention as a semiconductor packaging technique. Among the CSPs, WLP (Wafer Level Package) is known as a semiconductor packaging technique for forming a particularly small and highly integrated package. WLP is a technique in which a plurality of semiconductor chips are collectively sealed with a sealing resin without using a substrate, and then individual semiconductor chips are cut and separated to obtain a semiconductor package. Generally, when semiconductor chips are collectively sealed, in order to prevent the movement of the semiconductor chips, a plurality of semiconductor chips are temporarily fixed with a predetermined temporary fixing material, and the plurality of semiconductor chips are collectively mounted on the temporary fixing material. To seal. Thereafter, when cutting and separating into individual semiconductor chips (after batch sealing and before or after cutting and separation), the temporary fixing material is peeled from the structure including the sealing resin and the semiconductor chip. As the temporary fixing material used in this way, a low-adhesive pressure-sensitive adhesive sheet is frequently used.

  However, when a conventional pressure-sensitive adhesive sheet is used, there is a problem in that an adhesive residue is generated in the structure when peeling from the structure including the sealing resin and the semiconductor chip. In particular, the adhesive residue at the peripheral portion of the semiconductor chip becomes prominent, and there is a problem that the adhesive residue causes a decrease in yield.

JP 2001-308116 A JP 2001-313350 A

  The present invention has been made to solve the above-described conventional problems. The object of the present invention is to have an appropriate adhesiveness to the sealing resin and the semiconductor chip constituting the semiconductor package, and the sealing An object of the present invention is to provide a pressure-sensitive adhesive sheet that can be easily peeled off from a resin and a semiconductor chip and hardly causes adhesive residue at the time of peeling.

The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer, and the contact angle of the surface of the pressure-sensitive adhesive layer with respect to 4-tertiarybutylphenylglycidyl ether is 15 ° or more, and the pressure-sensitive adhesive sheet has a 23 ° C. The adhesive strength with respect to polyethylene terephthalate is 0.5 N / 20 mm or more.
In one embodiment, sp value of the material which comprises the adhesive in the said adhesive layer is 7 (cal / cm < ³ >) ^<1/2 > -10 (cal / cm < ³ >) ^<1/2 >.
In one embodiment, the probe tack value of the pressure-sensitive adhesive layer is 50 N / 5 mmφ or more.
In one embodiment, the above-mentioned adhesive layer contains an acrylic adhesive.
In one embodiment, the acrylic pressure-sensitive adhesive contains an acrylic polymer having an alkyl ester having 4 or more carbon atoms in the side chain as a base polymer.
In one embodiment, the content rate of the structural unit which has a C4 or more alkyl ester in a side chain in the said acrylic polymer is 30 weight% with respect to all the structural units which comprise this acrylic polymer. That's it.
In one embodiment, the pressure-sensitive adhesive layer contains a rubber-based pressure-sensitive adhesive.
In one embodiment, the pressure-sensitive adhesive layer contains a silicone-based pressure-sensitive adhesive.
In one embodiment, the silicone-based pressure-sensitive adhesive includes a silicone rubber and a silicone resin as a base polymer, and a weight ratio of the silicone rubber to the silicone resin (rubber: resin) is 100: 0 to 100: 220. is there.
In one embodiment, the pressure-sensitive adhesive layer further includes thermally expandable microspheres.
In one embodiment, arithmetic surface roughness Ra of the said adhesive layer before heating the said thermally expansible microsphere is 500 nm or less.
In one embodiment, the pressure-sensitive adhesive sheet of the present invention is bonded to the bakelite plate on the entire outer surface of the pressure-sensitive adhesive layer at an environmental temperature of 23 ° C. and aged for 30 minutes at an environmental temperature of 40 ° C. When held for 2 hours while applying a load of 96 N, the deviation from the bakelite plate is 0.5 mm or less.
In one embodiment, the pressure-sensitive adhesive sheet of the present invention further includes a base material layer, and the pressure-sensitive adhesive layer is disposed on one side or both sides of the base material layer.
In one embodiment, the anchoring force of the base material layer and the pressure-sensitive adhesive layer is 6.0 N / 19 mm or more.

  According to the present invention, by providing an adhesive layer having a contact angle with respect to 4-tertiary butylphenyl glycidyl ether of 15 ° or more, appropriate adhesiveness to the sealing resin and the semiconductor chip constituting the semiconductor package is achieved. It is possible to obtain a pressure-sensitive adhesive sheet that can be easily peeled off from the sealing resin and the semiconductor chip and hardly causes adhesive residue at the time of peeling.

(A) is a figure explaining an example in the case of using the conventional adhesive sheet for manufacture of a semiconductor package. (B) is a figure explaining an example in the case of using the adhesive sheet of this invention for manufacture of a semiconductor package. (A) And (b) is a schematic sectional drawing of the adhesive sheet by one Embodiment of this invention. It is a schematic sectional drawing of the adhesive sheet by one Embodiment of this invention.

A. Outline of pressure-sensitive adhesive sheet The pressure-sensitive adhesive sheet of the present invention includes a pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet of the present invention may be composed of only the pressure-sensitive adhesive layer, and may further include any appropriate layer in addition to the pressure-sensitive adhesive layer. Examples of the layer other than the pressure-sensitive adhesive layer include a base material layer that can function as a support, and a separator that is detachably disposed on the pressure-sensitive adhesive layer. In addition to the pressure-sensitive adhesive layer, another pressure-sensitive adhesive layer may be further provided. The other pressure-sensitive adhesive layer may have a known configuration.

  The pressure-sensitive adhesive sheet of the present invention has an adhesive strength to polyethylene terephthalate at 23 ° C. of preferably 0.5 N / 20 mm or more, more preferably 0.5 N / 20 mm to 20 N / 20 mm, and still more preferably 0.5 N / 20 mm to 15 N / 20 mm. In one embodiment, the adhesive strength of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is reduced by heating or light irradiation. In this case, the adhesive force before reducing the adhesive force is 2.5 N / 20 mm to 20 N / 20 mm. In the present specification, “adhesive strength to polyethylene terephthalate” means that an adhesive sheet (width 20 mm × length 100 mm) is bonded to a polyethylene terephthalate film (thickness 25 μm) (bonding condition: 2 kg roller 1 (Reciprocating), after standing at an ambient temperature of 23 ° C. for 30 minutes, the sample is subjected to a tensile test (peeling speed: 300 mm / min, peeling angle 180 °) to measure the adhesive force.

  The adhesive strength of the adhesive sheet of the present invention to a silicone wafer (thickness 500 μm) at 23 ° C. is preferably 0.1 N / 20 mm to 4 N / 20 mm, more preferably 0.15 N / 20 mm to 3 N / 20 mm, Preferably it is 0.2N / 20mm-2 / 20mm. If it is such a range, the adhesive sheet with which the adhesive force with respect to a semiconductor chip and peelability were compatible can be obtained. The adhesive strength to the silicone wafer can also be measured by the same method as the above “adhesive strength to polyethylene terephthalate”.

  The pressure-sensitive adhesive strength of the pressure-sensitive adhesive sheet of the present invention to an epoxy resin sheet at 23 ° C. is preferably 0.1 N / 20 mm to 5 N / 20 mm, more preferably 0.3 N / 20 mm to 4 N / 20 mm, and still more preferably. It is 0.5N / 20mm-3 / 20mm. If it is such a range, the adhesive residue at the time of peeling from sealing resin (it mentions later for details) can be suppressed. The adhesive strength to the epoxy resin film can also be measured by the same method as the above “adhesive strength to polyethylene terephthalate”. In addition, as said epoxy-type resin film, the film comprised from sealing resin demonstrated by evaluation of the "standoff suppression effect" of an Example can be used, for example.

  The entire outer surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention (width 10 mm × length 150 mm) was bonded to a bakelite plate (width 10 mm × length 125 mm) at an ambient temperature of 23 ° C. When aged for 1 minute and then held for 2 hours while applying a load of 1.96 N, the deviation of the adhesive sheet from the bakelite plate is preferably 0.5 mm or less, more preferably 0.4 mm or less. . Here, “displacement of the pressure-sensitive adhesive sheet with respect to the bakelite plate” means the amount of movement of the pressure-sensitive adhesive sheet from the initial state based on the state before the aging (initial state). The pressure-sensitive adhesive sheet having a small misalignment is a pressure-sensitive adhesive sheet in which cohesive failure of the pressure-sensitive adhesive layer does not easily occur, and such a pressure-sensitive adhesive sheet is essentially a pressure-sensitive adhesive sheet that hardly causes adhesive residue. If it is such an adhesive sheet, the effect of this invention will become remarkable. The pressure-sensitive adhesive layer that hardly causes cohesive failure is formed, for example, by using the above acrylic pressure-sensitive adhesive (preferably a pressure-sensitive adhesive containing a cross-linked acrylic polymer as a base polymer) as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer. can do. In addition, a rubber-based pressure-sensitive adhesive is used as the pressure-sensitive adhesive, and more specifically includes a base polymer (rubber) constituting the rubber-based pressure-sensitive adhesive, a hydroxyl group-containing polyolefin, and a crosslinking agent that can react with the hydroxyl group of the hydroxyl group polyolefin. By using rubber-based pressure-sensitive adhesive (Rub1) and appropriately adjusting the blending amounts of the hydroxyl group-containing polyolefin and the cross-linking agent, a pressure-sensitive adhesive layer that hardly causes cohesive failure can be formed. Details will be described later.

  The thickness of the pressure-sensitive adhesive sheet of the present invention is preferably 3 μm to 300 μm, more preferably 5 μm to 150 μm, and still more preferably 10 μm to 100 μm.

B. Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer has a contact angle with respect to 4-tertiarybutylphenylglycidyl ether on the surface of 15 ° or more, more preferably 20 ° or more, and further preferably 30 ° to 100 °. Particularly preferably, the angle is 40 ° to 60 °.

  In the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention, the affinity for the sealing resin (for example, epoxy resin) used when sealing the semiconductor chip and the monomer component constituting the sealing resin is adjusted. Specifically, the pressure-sensitive adhesive layer is adjusted so that the affinity is low as long as appropriate adhesiveness can be expressed with respect to the sealing resin (and the semiconductor chip). The pressure-sensitive adhesive layer whose affinity is appropriately adjusted has a contact angle with respect to 4-tertiarybutylphenylglycidyl ether in the above range. By adjusting the affinity for the sealing resin and the monomer component constituting the sealing resin in this way, there is little adhesive residue, more specifically, the semiconductor and the resin that seals the semiconductor (or the resin) A pressure-sensitive adhesive sheet that can reduce the pressure-sensitive adhesive layer component adhering to the structure when adhered to a structure (FIG. 1) containing a precursor monomer and then peeled off can be obtained. The mechanism by which the adhesive residue is reduced by using the pressure-sensitive adhesive sheet of the present invention is considered as follows.

  FIG. 1A shows an example in which a conventional adhesive sheet 10 ′ is used for manufacturing a semiconductor package. The pressure-sensitive adhesive sheet 10 ′ has a pressure-sensitive adhesive layer, and the outer surface of the pressure-sensitive adhesive layer is used as a sticking surface. Conventionally, in the manufacture of a semiconductor package (CSP), first, a semiconductor chip 1 is attached on an adhesive sheet 10 '(ai). Thereafter, the semiconductor chip 1 is sealed, and a composition 2 ′ containing a monomer that becomes a precursor of the sealing resin 2 is applied (a-ii), and then the composition 2 ′ is cured (a -Iii). In addition, as said composition, the composition containing a naphthalene type bifunctional epoxy resin (epoxy equivalent: 144) is used, for example. Next, the adhesive sheet 10 ′ is peeled from the structure 20 including the semiconductor chip 1 and the sealing resin 2 before or after being individually cut and separated (in the illustrated example, before being cut and separated). (A-iv). When a conventional pressure-sensitive adhesive sheet is used, adhesive residue is likely to occur during peeling. In particular, adhesive residue is noticeable in the peripheral edge portion of the semiconductor chip 1. When the conventional adhesive sheet 10 ′ is used, the inventors of the present invention swell so that the adhesive layer of the adhesive sheet 10 ′ at the time of peeling surrounds the bottom of the semiconductor chip 1, and the adhesive sheet 10 ′ at the time of peeling is It has been found that a step (hereinafter also referred to as a standoff) due to the bottom side of the semiconductor chip 1 occurs in the adhesive layer. It is considered that the stress from the semiconductor chip 1 concentrates on the stand-off portion, causing cohesive failure of the adhesive layer, and as a result, the adhesive residue is generated.

  FIG.1 (b) shows an example in the case of using the adhesive sheet 10 of this invention for manufacture of a semiconductor package. The pressure-sensitive adhesive sheet 10 has a pressure-sensitive adhesive layer, and uses the outer surface of the pressure-sensitive adhesive layer as a sticking surface. In FIG. 1B, a structure including the semiconductor chip 1 and the sealing resin 2 on the adhesive sheet 10 by the same operation as that shown in FIG. 1A except that the adhesive sheet is changed. 20 is formed, and then the pressure-sensitive adhesive sheet 10 is peeled off. When the pressure-sensitive adhesive sheet 10 of the present invention is used, the standoff generated in the pressure-sensitive adhesive sheet 10 is extremely small (or does not occur), and adhesive residue is suppressed.

  In the conventional pressure-sensitive adhesive sheet 10 ′, the pressure-sensitive adhesive layer component is transferred to a composition containing a monomer that is a precursor of the sealing resin 2 or the sealing resin. As a result, the resin layer of the pressure-sensitive adhesive sheet 10 ′ is a semiconductor. It is considered that a raised standoff occurs so as to surround the bottom of the chip 1. The presence or absence of component transfer can be confirmed by spectroscopic analysis such as FT-IR. On the other hand, in the present invention, since the adhesive layer is adjusted in affinity for the sealing resin used when sealing the semiconductor chip and the monomer component constituting the sealing resin, the above components It is considered that the transition is suppressed and the standoff becomes extremely small (or does not occur), and as a result, the adhesive residue is suppressed. Hereinafter, in this specification, the sealing resin used when sealing the semiconductor chip and the monomer component constituting the sealing resin are collectively referred to as a sealing material.

The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive. The sp value of the material (polymer) constituting the pressure-sensitive adhesive is preferably 7 (cal / cm ³ ) ^1/2 to 10 (cal / cm ³ ) ^1/2 , more preferably 7 (cal / cm ³ ). ^{It is 1/2 to} 9.1 (cal / cm ³ ) ^1/2 , more preferably 7 (cal / cm ³ ) ^1/2 to 8 (cal / cm ³ ) ^1/2 . If it is such a range, it can form an adhesive layer which has appropriate adhesiveness and has low affinity with the sealing material and hardly causes standoff. A pressure-sensitive adhesive sheet having such a pressure-sensitive adhesive layer hardly causes adhesive residue. The material constituting the pressure-sensitive adhesive here refers to a base polymer contained in the pressure-sensitive adhesive (base polymer after cross-linking when cross-linked), rubber (rubber after cross-linking when cross-linked). Means a polymer such as a tackifier. In the present invention, at least the sp value of the base polymer (base polymer after crosslinking in the case of cross-linking) or rubber (cross-linked rubber in the case of cross-linking) which is the main component of the pressure-sensitive adhesive is within the above range. Preferably there is.

In one embodiment, the surface of the pressure-sensitive adhesive layer is contacted with 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane and placed in an environment at 50 ° C. for 2 hours. When the absorbance of the glycidyl group-derived peak is measured by -IR measurement, the absorbance ratio of the glycidyl group-derived peak is preferably 1.3 or less with respect to the absorbance of the glycidyl group-derived peak of the initial pressure-sensitive adhesive layer. More preferably, it is 1.1 or less, More preferably, it is 1.05 or less. The “initial pressure-sensitive adhesive layer” means a pressure-sensitive adhesive layer before contacting 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane. In another embodiment, the surface of the pressure-sensitive adhesive layer is contacted with 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane and placed in an environment of 50 ° C. for 2 hours, and the FT- When IR measurement (for example, attenuated total reflection method (ATR method)) is performed, the amount of increase from the initial pressure-sensitive adhesive layer with respect to absorbance at a wave number (near 850 cm ⁻¹ ) where a glycidyl group-derived peak is generated is preferably 0.00. 3 or less, more preferably 0.1 or less. Here, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane is an epoxy compound that can be a resin material for sealing a semiconductor chip. Even if the epoxy compound is brought into contact, if the pressure-sensitive adhesive layer in which the epoxy compound does not easily migrate as described above is formed, a pressure-sensitive adhesive sheet with less adhesive residue is obtained even when used for manufacturing a semiconductor package. be able to.

  The thickness of the pressure-sensitive adhesive layer is preferably 1 μm to 300 μm, more preferably 3 μm to 300 μm, further preferably 5 μm to 150 μm, further preferably 10 μm to 100 μm, and further preferably 10 μm to 50 μm. is there. As will be described later, when the pressure-sensitive adhesive layer contains thermally expandable microspheres, the thickness of the pressure-sensitive adhesive layer is preferably 3 μm to 300 μm, more preferably 5 μm to 150 μm, and 10 μm to 100 μm. Is more preferable. If it is such a range, the adhesive layer which is excellent in surface smoothness and adhesiveness can be formed. When the pressure-sensitive adhesive layer does not contain thermally expandable microspheres, the thickness of the pressure-sensitive adhesive layer is preferably 50 μm or less, more preferably 1 μm to 50 μm, and even more preferably 5 μm to 30 μm.

  The elastic modulus by the nanoindentation method at 25 ° C. of the pressure-sensitive adhesive layer is preferably less than 100 MPa, more preferably 0.1 MPa to 50 MPa, and further preferably 0.1 MPa to 10 MPa. If it is such a range, the adhesive sheet which has suitable adhesive force as an adhesive sheet which can be used for manufacture of a semiconductor package can be obtained. The elastic modulus by the nano-indentation method means that the load and indentation depth applied to the indenter when the indenter is pushed into the sample are continuously measured during loading and unloading, and the obtained load load minus indentation depth. It refers to the elastic modulus obtained from the height curve. In this specification, the elastic modulus by the nanoindentation method means an elastic modulus measured as described above under the measurement conditions of load: 1 mN, load / unloading speed: 0.1 mN / s, and holding time: 1 s.

  The tensile modulus at 25 ° C. of the pressure-sensitive adhesive layer is preferably less than 100 MPa, more preferably 0.1 MPa to 50 MPa, and still more preferably 0.1 MPa to 10 MPa. If it is such a range, the adhesive sheet which has suitable adhesive force as an adhesive sheet which can be used for manufacture of a semiconductor package can be obtained. The tensile modulus can be measured according to JIS K 7161: 2008.

  The probe tack value of the pressure-sensitive adhesive layer is preferably 50 N / 5 mmφ or more, more preferably 75 N / 5 mmφ or more, and further preferably 100 N / 5 mmφ or more. If it is such a range, it is excellent in the holding | maintenance property of a to-be-adhered body, for example, when a semiconductor chip is temporarily fixed, the unnecessary position shift of this semiconductor chip can be prevented. A method for measuring the probe tack value will be described later.

<Adhesive>
As an adhesive which comprises the said adhesive layer, as long as the effect of this invention is acquired, arbitrary appropriate adhesives may be used. Preferably, a pressure-sensitive adhesive containing a base polymer having an sp value in the above range is used. Examples of the pressure sensitive adhesive include acrylic pressure sensitive adhesive, rubber pressure sensitive adhesive, and silicone pressure sensitive adhesive. Among these, an acrylic pressure-sensitive adhesive can be preferably used. Moreover, you may use an active energy ray hardening-type adhesive as an adhesive.

(Acrylic adhesive)
Examples of the acrylic pressure-sensitive adhesive include, for example, an acrylic pressure-sensitive adhesive based on an acrylic polymer (homopolymer or copolymer) using one or more (meth) acrylic acid alkyl esters as monomer components. Etc.

  The acrylic polymer preferably has an alkyl ester having 4 or more carbon atoms as a side chain, more preferably an alkyl ester having 6 or more carbon atoms, and an alkyl ester having 8 or more carbon atoms. Is more preferable, it is particularly preferable to have an alkyl ester having 8 to 20 carbon atoms, and it is most preferable to have an alkyl ester having 8 to 18 carbon atoms. If an acrylic polymer having a long side chain is used, a pressure-sensitive adhesive layer having a low affinity with the sealing material can be formed. In the acrylic polymer, the content of the structural unit having an alkyl ester having 4 or more carbon atoms as a side chain is preferably 30% by weight or more with respect to all the structural units constituting the acrylic polymer. Preferably it is 50 weight% or more, More preferably, it is 70 weight%-100 weight%, Especially preferably, it is 80 weight%-100 weight%. If it is such a range, an adhesive layer with low affinity with a sealing material can be formed.

  The acrylic pressure-sensitive adhesive may contain a plurality of types of acrylic polymers, but the content ratio of the acrylic polymer having an alkyl ester having 4 or more carbon atoms in the side chain is based on 100 parts by weight of the total acrylic polymer. The amount is preferably 30 to 100 parts by weight, more preferably 70 to 100 parts by weight.

  Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, ( Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meth) acrylic acid Octyl, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) acrylic Undecyl acid, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Such as tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate ( Examples include (meth) acrylic acid C1-20 alkyl esters. Among them, preferred is a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 4 to 20 carbon atoms (more preferably 6 to 20, particularly preferably 8 to 18), and more preferably. Is 2-ethylhexyl (meth) acrylate.

  The acrylic polymer is a unit corresponding to another monomer component copolymerizable with the (meth) acrylic acid alkyl ester, if necessary, for the purpose of modifying cohesion, heat resistance, crosslinkability and the like. May be included. 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, itaconic anhydride Acid anhydride monomers such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, (meth) Hydroxyl group-containing monomers such as hydroxydecyl acrylate, hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate; styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide Sulfonic acid group-containing monomers such as 2-methylpropanesulfonic acid, (meth) acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalenesulfonic acid; (meth) acrylamide, N, N-dimethyl (meta ) (N-substituted) amide monomers such as acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; aminoethyl (meth) acrylate, (meth) acrylic (Meth) acrylic acid aminoalkyl monomers such as N, N-dimethylaminoethyl acid, t-butylaminoethyl (meth) acrylate; (meth) methacrylic acid (meth) acrylate, ) Alkoxy acrylate Rutile monomers; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octyl Itaconimide monomers such as itaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide; N- (meth) acryloyloxymethylenesuccinimide, N- (meth) acryloyl-6-oxyhexamethylene Succinimide monomers such as succinimide and N- (meth) acryloyl-8-oxyoctamethylenesuccinimide; vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyro Vinyl such as lidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, N-vinylcarboxylic amides, styrene, α-methylstyrene, N-vinylcaprolactam Cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, (meth) acrylic acid Glycol acrylic ester monomers such as methoxyethylene glycol and (meth) acrylic acid methoxypolypropylene glycol; (meth) acrylic acid tetrahydrofur Acrylic acid ester monomers having heterocycles such as ril, fluorine (meth) acrylate, silicone (meth) acrylate, halogen atoms, silicon atoms, etc .; hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate , (Poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa Polyfunctional monomers such as (meth) acrylates, epoxy acrylates, polyester acrylates, urethane acrylates; olefinic monomers such as isoprene, butadiene, isobutylene; And vinyl ether monomers such as vinyl ether. These monomer components may be used alone or in combination of two or more. Among these, a carboxyl group-containing monomer (particularly preferably acrylic acid) or a hydroxyl group-containing monomer (particularly preferably hydroxyethyl (meth) acrylate) is more preferable. The content of the structural unit derived from the carboxyl group-containing monomer is preferably from 0.1% by weight to 10% by weight, more preferably from 0.5% by weight to 5%, based on all the structural units constituting the acrylic polymer. % By weight, particularly preferably 1% by weight to 4% by weight. Further, the content of the structural unit derived from the hydroxyl group-containing monomer is preferably 0.1% by weight to 20% by weight, and more preferably 0.5% by weight with respect to all the structural units constituting the acrylic polymer. -10% by weight, particularly preferably 1% by weight to 7% by weight.

  The acrylic pressure-sensitive adhesive may contain any appropriate additive as required. Examples of the additive include a crosslinking agent, a tackifier, a plasticizer (for example, trimellitic acid ester plasticizer, pyromellitic acid ester plasticizer, etc.), a pigment, a dye, a filler, an antiaging agent, and a conductive agent. Examples thereof include materials, antistatic agents, ultraviolet absorbers, light stabilizers, release modifiers, softeners, surfactants, flame retardants, and antioxidants.

  As the crosslinking agent contained in the acrylic pressure-sensitive adhesive, for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide crosslinking agent, Examples of the metal chelate crosslinking agent, metal salt crosslinking agent, carbodiimide crosslinking agent, oxazoline crosslinking agent, aziridine crosslinking agent, and amine crosslinking agent. Of these, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferable.

  Specific examples of the isocyanate crosslinking agent contained in the acrylic adhesive include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic rings such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate. Aromatic isocyanates; aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd. Name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate trimer adduct (trade name "Coronate HL" manufactured by Nippon Polyurethane Industry Co., Ltd.), hexame Isocyanurate of diisocyanate (Nippon Polyurethane Industry Co., Ltd. under the trade name "Coronate HX") isocyanate adducts of the like; and the like. The content of the isocyanate-based crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.1 to 20 parts by weight with respect to 100 parts by weight of the base polymer. And more preferably 0.5 to 10 parts by weight.

  Examples of the epoxy crosslinking agent contained in the acrylic pressure-sensitive adhesive include N, N, N ′, N′-tetraglycidyl-m-xylenediamine, diglycidylaniline, and 1,3-bis (N, N— Glycidylaminomethyl) cyclohexane (trade name “Tetrad C” manufactured by Mitsubishi Gas Chemical Company), 1,6-hexanediol diglycidyl ether (trade name “Epolite 1600” manufactured by Kyoeisha Chemical Co., Ltd.), neopentyl glycol diglycidyl ether ( Kyoeisha Chemical Co., Ltd., trade name “Epolite 1500NP”), ethylene glycol diglycidyl ether (Kyoeisha Chemical Co., trade name “Epolite 40E”), propylene glycol diglycidyl ether (Kyoeisha Chemical Co., Ltd., trade name “Epolite 70P”) , Polyethylene glycol diglycidyl ether (Japan Product name "Epiol E-400" manufactured by Yushi Co., Ltd., polypropylene glycol diglycidyl ether (product name "Epiol P-200" manufactured by Nippon Oil & Fats Co., Ltd.), sorbitol polyglycidyl ether (product name "Denacol" manufactured by Nagase ChemteX Corporation) EX-611 "), glycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name" Denacol EX-314 "), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name" Denacol EX -512 "), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxy ester). Le) isocyanurate, resorcin diglycidyl ether, bisphenol -S- diglycidyl ether, epoxy resins having two or more epoxy groups in the molecule. The content of the epoxy-based crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.01 to 10 parts by weight with respect to 100 parts by weight of the base polymer. More preferably, it is 0.03 to 5 parts by weight.

  Any appropriate tackifier can be used as the tackifier contained in the acrylic pressure-sensitive adhesive. As the tackifier, for example, a tackifier resin is used. Specific examples of the tackifying resin include rosin tackifying resins (for example, unmodified rosin, modified rosin, rosin phenolic resin, rosin ester resin, etc.), terpene tackifying resins (for example, terpene resins, terpenes). Phenolic resin, styrene modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin), hydrocarbon tackifier resin (for example, aliphatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin, aromatic Hydrocarbon resins (eg, styrene resins, xylene resins), aliphatic / aromatic petroleum resins, aliphatic / alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, coumarone indenes Resin), phenolic tackifying resin (eg, alkylphenolic resin, xyleneformaldehyde resin, resole, resin) Racks, etc.), ketone-based tackifying resins, polyamide-based tackifying resins, epoxy-based tackifying resins, such as an elastomer-based tackifying resins. Among these, rosin-based tackifier resins, terpene-based tackifier resins, or hydrocarbon-based tackifier resins (such as styrene resins) are preferable. You may use a tackifier individually or in combination of 2 or more types. The addition amount of the tackifier is preferably 5 to 100 parts by weight, more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the base polymer.

  Preferably, as the tackifying resin, a resin having a high softening point or glass transition temperature (Tg) is used. If a resin with a high softening point or glass transition temperature (Tg) is used, a pressure-sensitive adhesive layer that can exhibit high adhesiveness even in a high temperature environment (for example, in a high temperature environment during processing at the time of semiconductor chip sealing, etc.) is formed. can do. The softening point of the tackifier is preferably 100 ° C to 180 ° C, more preferably 110 ° C to 180 ° C, and further preferably 120 ° C to 180 ° C. The glass transition temperature (Tg) of the tackifier is preferably 100 ° C to 180 ° C, more preferably 110 ° C to 180 ° C, and still more preferably 120 ° C to 180 ° C.

  Preferably, a low-polarity tackifier resin is used as the tackifier resin. If a low-polarity tackifying resin is used, a pressure-sensitive adhesive layer having a low affinity with the sealing material can be formed. Examples of the low-polarity tackifier resin include, for example, aliphatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aromatic hydrocarbon resins (for example, styrene resins, xylene resins, etc.), aliphatic Aromatic petroleum resins, aliphatic / alicyclic petroleum resins, and hydrocarbon-based tackifying resins such as hydrogenated hydrocarbon resins. Among them, a tackifier having 5 to 9 carbon atoms is preferable. This is because such a tackifier has a low polarity, is excellent in compatibility with an acrylic polymer, does not phase-separate in a wide temperature range, and can form a pressure-sensitive adhesive layer excellent in stability. .

  The acid value of the tackifying resin is preferably 40 or less, more preferably 20 or less, and still more preferably 10 or less. If it is such a range, an adhesive layer with low affinity with a sealing material can be formed. The hydroxyl value of the tackifying resin is preferably 60 or less, more preferably 40 or less, and still more preferably 20 or less. If it is such a range, an adhesive layer with low affinity with a sealing material can be formed.

(Rubber adhesive)
As the rubber-based pressure-sensitive adhesive, any appropriate pressure-sensitive adhesive can be used as long as the effects of the present invention are obtained. Examples of the rubber-based adhesive include natural rubber; polyisoprene rubber, butadiene rubber, styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene.・ Butadiene / styrene block copolymer (SBS) rubber, styrene / ethylene / butylene / styrene block copolymer (SEBS) rubber, styrene / ethylene / propylene / styrene block copolymer (SEPS) rubber, styrene / ethylene / propylene A rubber-based pressure-sensitive adhesive having a base polymer such as block copolymer (SEP) rubber, recycled rubber, butyl rubber, polyisobutylene rubber, or a modified rubber thereof is preferably used. These base polymers (rubbers) have a low sp value, and if the base polymer is used, an adhesive layer having a low affinity with the sealing material can be formed.

  As the base polymer constituting the rubber-based pressure-sensitive adhesive, polyisobutylene rubber, polyisoprene rubber or butyl rubber is particularly preferably used. By using these rubbers, it is possible to form a pressure-sensitive adhesive layer having excellent semiconductor chip retention at room temperature and excellent peelability. Moreover, an adhesive layer having low affinity with the sealing material can be formed.

  The base polymer that constitutes the rubber adhesive is styrene / ethylene / propylene block copolymer (SEP) rubber, styrene / ethylene / butylene / styrene block copolymer (SEBS) rubber, styrene / isoprene / styrene block copolymer A combined (SIS) rubber, a styrene / butadiene / styrene block copolymer (SBS) rubber, and a propylene rubber can also be preferably used. If these rubbers are used, a pressure-sensitive adhesive layer capable of exhibiting high adhesiveness can be formed even in a high-temperature environment (for example, in a high-temperature environment during processing at the time of semiconductor chip sealing or the like). In the base polymer (rubber) having a structural unit derived from styrene, the content ratio of the structural unit derived from styrene is preferably 15% by weight or more with respect to all the structural units in the base polymer.

  The rubber-based pressure-sensitive adhesive can contain any appropriate additive as required. Examples of the additive include a crosslinking agent, a vulcanizing agent, a tackifier, a plasticizer, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an antistatic agent, an ultraviolet absorber, a light stabilizer, and a release adjustment. Agents, softeners, surfactants, flame retardants, antioxidants and the like.

  Any appropriate tackifier is used as the tackifier contained in the rubber-based adhesive. As the tackifier, for example, a tackifier resin is used. Specific examples of the tackifying resin include rosin tackifying resins, rosin derivative resins, petroleum resins, terpene resins, ketone resins, and the like. The addition amount of the tackifier is preferably 5 to 100 parts by weight, more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the base polymer.

  Examples of the rosin resin contained in the rubber-based pressure-sensitive adhesive include gum rosin, wood rosin, tall rosin and the like. As the rosin resin, a stabilized rosin obtained by disproportionating or hydrogenating any appropriate rosin may be used. In addition, as a rosin resin, it was obtained by modifying a polymerized rosin, which is a polymer (typically a dimer) of any appropriate rosin, or any appropriate rosin (for example, modification with an unsaturated acid). Modified rosin may be used.

  Examples of the rosin derivative resin contained in the rubber-based pressure-sensitive adhesive include esterified products of the rosin resin, phenol-modified products of rosin resins, esterified products of phenol-modified rosin resins, and the like.

  Examples of the petroleum resin contained in the rubber-based pressure-sensitive adhesive include aliphatic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins, alicyclic petroleum resins, and hydrides thereof. .

  Examples of the terpene resin contained in the rubber adhesive include α-pinene resin, β-pinene resin, aromatic modified terpene resin, terpene phenol resin, and the like.

  Examples of the ketone-based resin contained in the rubber-based pressure-sensitive adhesive include ketone-based resins obtained by condensing ketones (for example, aliphatic ketones and alicyclic ketones) and formaldehyde.

  As a crosslinking agent contained in the said rubber-type adhesive, an isocyanate type crosslinking agent etc. are mentioned, for example. Examples of the vulcanizing agent contained in the rubber-based pressure-sensitive adhesive include thiuram vulcanizing agents, quinoid vulcanizing agents, and quinone dioxime vulcanizing agents. If the rubber-based adhesive contains a crosslinking agent and / or a vulcanizing agent, an adhesive layer that is highly cohesive and hardly causes adhesive residue can be formed. The total content of the crosslinking agent and the vulcanizing agent is typically 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the base polymer. is there.

  In one embodiment, a rubber-based pressure-sensitive adhesive (Rub1) containing the base polymer (rubber), a hydroxyl group-containing polyolefin, and a crosslinking agent a that can react with the hydroxyl group of the hydroxyl group polyolefin is used. In this rubber-based pressure-sensitive adhesive, the base polymer is not directly crosslinked, but entanglement between the base polymer and the crosslinked hydroxyl group-containing polyolefin occurs, and so-called pseudo crosslinking is performed. As a result, it is possible to form an adhesive layer that is highly cohesive and hardly retains adhesive. As the base polymer (rubber) used in this embodiment, the above synthetic rubber is preferably used. Moreover, as a crosslinking agent used for this embodiment, an isocyanate type crosslinking agent is used preferably.

  The blending amount of the hydroxyl group-containing polyolefin is preferably 0.5 parts by weight or more, more preferably 1 part by weight with respect to a total of 100 parts by weight of the base polymer (rubber), the hydroxyl group-containing polyolefin, and the crosslinking agent a. 0.0 part by weight or more. If it is such a range, a highly cohesive adhesive layer can be formed. Moreover, when an adhesive sheet is provided with a base material layer, the adhesiveness (throwing force) of a base material layer and an adhesive layer can be improved. That is, if the amount of the hydroxyl group-containing polyolefin is within the above range, an adhesive sheet with little adhesive residue can be obtained.

  The blending amount of the crosslinking agent a is preferably 0.5 parts by weight or more, more preferably 1 part with respect to 100 parts by weight in total of the base polymer (rubber), the hydroxyl group-containing polyolefin and the crosslinking agent a. 0.0 part by weight or more. If it is such a range, a highly cohesive adhesive layer can be formed. Moreover, when an adhesive sheet is provided with a base material layer, the adhesiveness (throwing force) of a base material layer and an adhesive layer can be improved. That is, when the blending amount of the crosslinking agent a is within the above range, an adhesive sheet with little adhesive residue can be obtained.

  As the hydroxyl group-containing polyolefin, a resin excellent in compatibility with the synthetic rubber is preferably used. Examples of the hydroxyl group-containing polyolefin include polyethylene polyol, polypropylene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, polyisoprene polyol, hydrogenated polyisoprene polyol, and the like. Among these, hydrogenated polyisoprene polyol, polyisoprene polyol, and polybutadiene polyol are preferable from the viewpoint of compatibility with the synthetic rubber.

  The number average molecular weight (Mn) of the hydroxyl group-containing polyolefin is preferably 500 to 500,000, more preferably 1,000 to 200,000, and still more preferably 1,200 to 150,000. The number average molecular weight can be measured according to ASTM D2503.

  The hydroxyl value (mgKOH / g) of the hydroxyl group-containing polyolefin is preferably 5 to 95, more preferably 10 to 80. The hydroxyl value can be measured according to JIS K1557: 1970.

(Silicone adhesive)
Any appropriate pressure-sensitive adhesive can be used as the silicone-based pressure-sensitive adhesive as long as the effects of the present invention can be obtained. As the silicone-based pressure-sensitive adhesive, for example, a silicone-based pressure-sensitive adhesive having a base polymer such as silicone rubber or silicone resin containing organopolysiloxane is preferably used. As the base polymer constituting the silicone-based pressure-sensitive adhesive, a base polymer obtained by crosslinking the above silicone rubber or silicone resin may be used. In the present specification, “silicone rubber” means a polymer (for example, viscosity 1000 Pa · s) in which diorganosiloxane (D unit) as a main component is linked in a straight chain, and “silicone resin” Means a polymer composed of triorganosyl hemioxane (M unit) and silicate (Q unit) as main components ("material design and functionalization of adhesive (film / tape)", Technical Information Association, published September 30, 2009).

  Examples of the silicone rubber include organopolysiloxane containing dimethylsiloxane as a structural unit. A functional group (for example, vinyl group) may be introduced into the organopolysiloxane as necessary. The weight average molecular weight of the organopolysiloxane is preferably 100,000 to 1,000,000, more preferably 150,000 to 500,000. The weight average molecular weight can be measured by GPC (solvent: THF).

Examples of the silicone resin include organopolysiloxanes containing at least one constituent unit selected from R ₃ SiO _1/2 constituent units, SiO ₂ constituent units, RSiO _3/2 constituent units, and R ₂ SiO constituent units. (R is a monovalent hydrocarbon group or a hydroxyl group).

The silicone rubber and silicone resin can be used in combination. The weight ratio of the silicone rubber to the silicone resin (rubber: resin) in the silicone adhesive is preferably 100: 0 to 100: 220, more preferably 100: 0 to 100: 180, and even more preferably 100: 10-100: 100. The silicone rubber and the silicone resin may be contained in the silicone-based pressure-sensitive adhesive as a simple mixture, or may be included in the silicone-based pressure-sensitive adhesive in a form in which the silicone rubber and the silicone resin are partially condensed. The rubber: resin ratio can also be determined from the ratio of the Q unit (resin) and the D unit (rubber) obtained by measuring the composition of the silicone adhesive by ²⁹ Si-NMR.

  The silicone-based pressure-sensitive adhesive may contain any appropriate additive as required. Examples of the additive include a crosslinking agent, a vulcanizing agent, a tackifier, a plasticizer, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an antistatic agent, an ultraviolet absorber, a light stabilizer, and a release adjustment. Agents, softeners, surfactants, flame retardants, antioxidants and the like.

  Preferably, the silicone pressure-sensitive adhesive contains a crosslinking agent. Examples of the crosslinking agent include a siloxane crosslinking agent and a peroxide crosslinking agent. Any appropriate crosslinking agent may be used as the peroxide-based crosslinking agent. Examples of the peroxide-based crosslinking agent include benzoyl peroxide, t-butyl peroxybenzoate, and dicumyl peroxide. Examples of the siloxane-based crosslinking agent include polyorganohydrogensiloxane. The polyorganohydrogensiloxane preferably has two or more hydrogen atoms bonded to silicon atoms. The polyorganohydrogensiloxane preferably has an alkyl group, a phenyl group, or a halogenated alkyl group as a functional group bonded to a silicon atom.

(Active energy ray-curable adhesive)
As the pressure-sensitive adhesive, an active energy ray-curable pressure-sensitive adhesive that can be cured (increased elastic modulus) by irradiation with active energy rays may be used. If an active energy ray-curable adhesive is used, an adhesive sheet that has low elasticity and high flexibility at the time of application and is easy to handle, and that can be peeled off can be reduced by irradiating active energy rays. Can be obtained. Examples of the active energy rays include gamma rays, ultraviolet rays, visible rays, infrared rays (heat rays), radio waves, alpha rays, beta rays, electron beams, plasma flows, ionizing rays, particle rays and the like. In the present specification, the term “pressure-sensitive adhesive layer” simply means a pressure-sensitive adhesive layer before the pressure-sensitive adhesive is cured and the pressure-sensitive adhesive force is reduced.

  Examples of the resin material constituting the active energy ray-curable pressure-sensitive adhesive include, for example, an ultraviolet curing system (by Kayo Kiyomi, General Technology Center, (1989)), photocuring technology (Technical Information Association (2000)), The resin material described in Unexamined-Japanese-Patent No. 2003-292916, patent 4151850, etc. is mentioned. More specifically, a resin material (R1) containing a polymer as a base material and an active energy ray reactive compound (monomer or oligomer), a resin material (R2) containing an active energy ray reactive polymer, and the like can be mentioned.

  Examples of the base polymer include natural rubber, polyisobutylene rubber, styrene / butadiene rubber, styrene / isoprene / styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, and nitrile rubber (NBR). Examples thereof include rubber polymers; silicone polymers; acrylic polymers. These polymers may be used alone or in combination of two or more. From the viewpoint of affinity with the sealing material, the polymer exemplified as the base polymer of the acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, or silicone-based pressure-sensitive adhesive can be preferably used as the base polymer.

  As said active energy ray reactive compound, the photoreactive monomer or oligomer which has a functional group which has carbon-carbon multiple bonds, such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, an acetylene group, is mentioned, for example. Specific examples of the photoreactive monomer or oligomer include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipenta Erythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, etc. (Meth) acryloyl group-containing compound; 2 to 5 mer of the (meth) acryloyl group-containing compound; and the like.

  Further, as the active energy ray-reactive compound, monomers such as epoxidized butadiene, glycidyl methacrylate, acrylamide, and vinyl siloxane; or oligomers composed of the monomers may be used. The resin material (R1) containing these compounds can be cured by high energy rays such as ultraviolet rays and electron beams.

  Furthermore, as the active energy ray-reactive compound, a mixture of an organic salt such as an onium salt and a compound having a plurality of heterocyclic rings in the molecule may be used. In the mixture, an organic salt is cleaved by irradiation with active energy rays (for example, ultraviolet rays and electron beams) to generate ions, which act as starting species to cause a ring opening reaction of the heterocyclic ring to form a three-dimensional network structure. Can do. Examples of the organic salts include iodonium salts, phosphonium salts, antimonium salts, sulfonium salts, and borate salts. Examples of the heterocyclic ring in the compound having a plurality of heterocyclic rings in the molecule include oxirane, oxetane, oxolane, thiirane, aziridine and the like.

  In the resin material (R1) containing the polymer as the base material and the active energy ray-reactive compound, the content ratio of the active energy ray-reactive compound is preferably 0.00 with respect to 100 parts by weight of the polymer as the base material. 1 to 500 parts by weight, more preferably 1 to 300 parts by weight, and even more preferably 10 to 200 parts by weight. If it is such a range, an adhesive layer with low affinity with a sealing material can be formed.

  The resin material (R1) containing the polymer as the base material and the active energy ray-reactive compound may contain any appropriate additive as necessary. Examples of the additive include an active energy ray polymerization initiator, an active energy ray polymerization accelerator, a crosslinking agent, a plasticizer, and a vulcanizing agent. Any appropriate initiator may be used as the active energy ray polymerization initiator depending on the type of active energy ray used. The active energy ray polymerization initiators may be used alone or in combination of two or more. In the resin material (R1) containing the polymer as the base material and the active energy ray-reactive compound, the content ratio of the active energy ray polymerization initiator is preferably 0.1 with respect to 100 parts by weight of the polymer as the base material. Parts by weight to 10 parts by weight, more preferably 1 part by weight to 5 parts by weight.

  As said active energy ray reactive polymer, the polymer which has a functional group which has carbon-carbon multiple bonds, such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, an acetylene group, is mentioned, for example. Specific examples of the polymer having an active energy ray reactive functional group include polymers composed of polyfunctional (meth) acrylates. The polymer composed of the polyfunctional (meth) acrylate preferably has an alkyl ester having 4 or more carbon atoms, more preferably has an alkyl ester having 6 or more carbon atoms, and an alkyl having 8 or more carbon atoms. More preferably, it has an ester, particularly preferably an alkyl ester having 8 to 20 carbon atoms, and most preferably an alkyl ester having 8 to 18 carbon atoms. If a polymer having a long side chain is used, a pressure-sensitive adhesive layer having a low affinity with the sealing material can be formed. In the polymer, the content of the structural unit having an alkyl ester having 4 or more carbon atoms as a side chain is preferably 30% by weight or more, more preferably 50% by weight with respect to all the structural units constituting the polymer. % Or more, more preferably 70% by weight to 100% by weight, and particularly preferably 80% by weight to 100% by weight. If it is such a range, an adhesive layer with low affinity with a sealing material can be formed.

  The resin material (R2) containing the active energy ray-reactive polymer may further contain the active energy ray-reactive compound (monomer or oligomer). Moreover, the resin material (R2) containing the said active energy ray reactive polymer may contain arbitrary appropriate additives as needed. The specific example of an additive is the same as that of the additive which can be contained in the resin material (R1) containing the polymer used as a base material, and an active energy ray reactive compound. In the resin material (R2) containing the active energy ray reactive polymer, the content ratio of the active energy ray polymerization initiator is preferably 0.1 parts by weight to 10 parts by weight with respect to 100 parts by weight of the active energy ray reactive polymer. More preferably, it is 1 to 5 parts by weight.

<Thermal expandable microsphere>
In one embodiment, the pressure-sensitive adhesive layer further includes thermally expandable microspheres. The pressure-sensitive adhesive sheet including the pressure-sensitive adhesive layer containing the heat-expandable microspheres is heated, whereby the heat-expandable microspheres expand or fire to cause unevenness on the adhesive surface, resulting in a decrease or disappearance of the adhesive force. To do. Such an adhesive sheet can be easily peeled off by heating.

  As the thermally expandable microsphere, any appropriate thermally expandable microsphere can be used as long as it is a microsphere that can expand or foam by heating. As the thermally expandable microsphere, for example, a microsphere in which a substance that easily expands by heating is encapsulated in an elastic shell can be used. Such thermally expandable microspheres can be produced by any appropriate method, for example, a coacervation method, an interfacial polymerization method, or the like.

  Examples of the material that easily expands when heated include propane, propylene, butene, normal butane, isobutane, isopentane, neopentane, normal pentane, normal hexane, isohexane, heptane, octane, petroleum ether, methane halide, tetraalkylsilane. And low-boiling-point liquids such as azodicarbonamide that is gasified by thermal decomposition.

  Examples of the substance constituting the shell include nitrile monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, fumaronitrile; acrylic acid, methacrylic acid, itaconic acid, maleic acid, 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, (Meth) 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 ; It includes polymer composed like; acrylamides, substituted acrylamides, methacrylamide, amide monomers such as substituted methacrylamide. 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, acrylonitrile-methacrylonitrile-itaconic acid copolymer. A polymer etc. are mentioned.

  An inorganic foaming agent or an organic foaming agent may be used as the thermally expandable microsphere. Examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, various azides and the like. Examples of the organic foaming agent include chlorofluorinated alkane compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate. Hydrazine compounds such as p-toluenesulfonyl hydrazide, diphenylsulfone-3,3′-disulfonyl hydrazide, 4,4′-oxybis (benzenesulfonyl hydrazide), allyl bis (sulfonyl hydrazide); p-toluylene sulfonyl 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, '- dimethyl -N, N'-dinitrosoterephthalamide; etc. N- nitroso compounds, and the like.

  A commercially available product may be used as the thermally expandable microsphere. Specific examples of commercially available thermally expandable microspheres are trade names “Matsumoto Microsphere” (grade: F-30, F-30D, F-36D, F-36LV, F-50, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.). F-50D, F-65, F-65D, FN-100SS, FN-100SSD, FN-180SS, FN-180SSD, F-190D, F-260D, F-2800D), trade names “Nippon Philite” "Expansel" (grade: 053-40, 031-40, 920-40, 909-80, 930-120), "Die Form" (grade: H750, H850, H1100, S2320D, S2640D, manufactured by Kureha Chemical Industry Co., Ltd.) M330, M430, M520), “ADVANCEL” manufactured by Sekisui Chemical Co., Ltd. (grade: EML101, EMH204, EHM3) 1, EHM302, EHM303, EM304, EHM401, EM403, EM501) and the like.

  The particle diameter of the thermally expandable microsphere before heating is preferably 0.5 μm to 80 μm, more preferably 5 μm to 45 μm, still more preferably 10 μm to 20 μm, and particularly preferably 10 μm to 15 μm. . Therefore, the particle size before heating of the thermally expandable microspheres is preferably 6 μm to 45 μm, more preferably 15 μm to 35 μm, in terms of the average particle size. The above particle diameter and average particle diameter are values obtained by the particle size distribution measurement method in the laser scattering method.

  The thermally expandable microsphere preferably has an appropriate strength that does not rupture until the volume expansion coefficient is preferably 5 times or more, more preferably 7 times or more, and even more preferably 10 times or more. When such a heat-expandable microsphere is used, the adhesive force can be efficiently reduced by heat treatment.

  The content ratio of the heat-expandable microspheres in the pressure-sensitive adhesive layer can be appropriately set according to the desired decrease in adhesive strength. The content ratio of the heat-expandable microspheres is, for example, 1 part by weight to 150 parts by weight, preferably 10 parts by weight to 130 parts by weight, and more preferably 100 parts by weight of the base polymer forming the pressure-sensitive adhesive layer. Is 25 to 100 parts by weight.

  When the pressure-sensitive adhesive layer contains thermally expandable microspheres, the arithmetic surface roughness Ra of the pressure-sensitive adhesive layer before the thermally expandable microspheres expand (that is, before heating) is preferably 500 nm or less, and more preferably Is 400 nm or less, more preferably 300 nm or less. If it is such a range, the adhesive sheet excellent in the adhesiveness with respect to a to-be-adhered body can be obtained. Thus, the pressure-sensitive adhesive layer having excellent surface smoothness is, for example, by setting the thickness of the pressure-sensitive adhesive layer in the above range, or by applying and transferring the pressure-sensitive adhesive layer to the separator when provided with another pressure-sensitive adhesive layer. Can be obtained. In addition, as demonstrated in said A term, when the adhesive sheet of this invention is further equipped with another adhesive layer, this another adhesive layer may contain the thermally expansible microsphere. Even in the case where another pressure-sensitive adhesive layer contains thermally expandable microspheres, the arithmetic surface roughness Ra of the pressure-sensitive adhesive layer is preferably within the above range.

  When the pressure-sensitive adhesive layer contains thermally expandable microspheres, the pressure-sensitive adhesive layer is composed of a base polymer having a dynamic storage elastic modulus at 80 ° C. in the range of 5 kPa to 1 MPa (more preferably 10 kPa to 0.8 MPa). It is preferable that the pressure-sensitive adhesive is included. With such a pressure-sensitive adhesive layer, a pressure-sensitive adhesive sheet having moderate pressure-sensitive adhesiveness before heating and having a pressure-sensitive adhesive force that is easily reduced by heating can be formed. The dynamic storage elastic modulus can be measured using a dynamic viscoelasticity measuring apparatus (for example, trade name “ARES” manufactured by Rheometrics) under measurement conditions of a frequency of 1 Hz and a heating rate of 10 ° C./min. .

C. Base material layer In one embodiment, the pressure sensitive adhesive sheet of the present invention is provided with a pressure sensitive adhesive layer and a base material layer. FIG. 2A is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention. The pressure-sensitive adhesive sheet 100 includes a pressure-sensitive adhesive layer 10 and a base material layer 30 disposed on one side of the pressure-sensitive adhesive layer 10. FIG. 2B is a schematic cross-sectional view of a pressure-sensitive 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 layer 30, and the pressure-sensitive adhesive layer 10 is disposed on both sides of the base material layer 30. The two pressure-sensitive adhesive layers may be the same pressure-sensitive adhesive layer or may be different pressure-sensitive adhesive layers. In addition, the structure which equips one side of a base material layer with the said adhesive layer, and equips another surface with another adhesive layer may be sufficient.

  When the adhesive sheet of this invention is equipped with a base material layer, the anchoring force of this base material layer and an adhesive layer becomes like this. Preferably it is 6.0 N / 19mm or more, More preferably, it is 15 N / 19mm or more.

  The anchoring force can be measured as follows. The anchoring force is (i) the surface opposite to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet having a width of 20 mm and a length of 150 mm (for example, in the case of a pressure-sensitive adhesive sheet having a base layer / pressure-sensitive adhesive layer configuration, the outer surface of the base layer) (Ii) A pressure-sensitive adhesive containing a polyester resin having a size of a width of 19 mm × a length of 150 mm on the outer surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet. An evaluation sheet (sheet having a peeling adhesive strength of 10 N / 20 mm to 20 N / 20 mm with respect to polyethylene terephthalate, for example, a product name “No. 315 tape” manufactured by Nitto Denko Corporation) is attached and evaluated. (Iii) It is obtained by measuring the peeling force between the base material layer and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet by a tensile test. In addition, said (i)-(iii) is performed under 23 degreeC environmental temperature. The tensile test conditions for measuring the peeling force are a peeling speed of 50 mm / min and a peeling angle of 180 °.

  As described above, the pressure-sensitive adhesive sheet having a high anchoring force between the base material layer and the pressure-sensitive adhesive layer is a pressure-sensitive adhesive sheet that is essentially difficult to leave glue, and if it is such a pressure-sensitive adhesive sheet, the effect of the present invention is remarkable. Become. When evaluated by the above method, peeling is not caused at the interface between the base material layer and the pressure-sensitive adhesive layer. For example, the pressure-sensitive adhesive sheet is preferably peeled between the SUS plate and the base material layer. A pressure-sensitive adhesive sheet having a high anchoring force can be obtained, for example, by using the rubber-based pressure-sensitive adhesive (Rub1) as a pressure-sensitive adhesive or adding an isocyanate-based crosslinking agent in the pressure-sensitive adhesive.

  Examples of the substrate layer include a resin sheet, a nonwoven fabric, paper, a metal foil, a woven fabric, a rubber sheet, a foamed sheet, and a laminate thereof (particularly, a laminate including a resin sheet). 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, ethylene- Vinyl acetate copolymer (EVA), polyamide (nylon), wholly aromatic polyamide (aramid), polyimide (PI), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), fluororesin, polyether ether ketone (PEEK) ) And the like. Examples of the nonwoven fabric include nonwoven fabrics made of natural fibers having heat resistance such as nonwoven fabrics including manila hemp; synthetic resin nonwoven fabrics such as polypropylene resin nonwoven fabrics, polyethylene resin nonwoven fabrics and ester resin nonwoven fabrics. Examples of the metal foil include copper foil, stainless steel foil, and aluminum foil. Examples of the paper include Japanese paper and kraft paper.

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

  The base material layer may be subjected to a surface treatment. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation treatment, and coating treatment with a primer.

  Examples of the organic coating material include materials described in Plastic Hard Coat Material II (CMC Publishing Co., (2004)). Preferably, a urethane-based polymer, more preferably polyacryl urethane, polyester urethane, or a precursor thereof is used. This is because coating and application to the base material are simple, and various industrial products can be selected and obtained at low cost. The urethane polymer is, for example, a polymer composed of a reaction mixture of an isocyanate 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 anti-aging agent, an oxidation stabilizer and the like as optional additives. Although the thickness of an organic coating layer is not specifically limited, For example, about 0.1 micrometer-10 micrometers are suitable, About 0.1 micrometer-5 micrometers are preferable, About 0.5 micrometer-5 micrometers are more preferable.

D. Elastic layer The pressure-sensitive adhesive sheet of the present invention may further comprise an elastic layer. FIG. 3 is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention. The pressure-sensitive adhesive sheet 300 further includes an elastic layer 40. The elastic layer 40 can be preferably disposed when the pressure-sensitive adhesive layer 10 includes the thermally expandable microspheres. Moreover, when the adhesive sheet 300 is provided with the base material layer 30, the elastic layer 40 may be arrange | positioned between the adhesive layer 10 and the base material layer 30 like the example of illustration, and the adhesive of a base material layer It may be provided on the side opposite to the agent layer. Two or more elastic layers 40 may be provided. FIG. 3 shows an example in which one elastic layer 40 is provided and the elastic layer 40 is disposed between the pressure-sensitive adhesive layer 10 and the base material layer 30. By providing the elastic layer 40, the followability to the adherend is improved. Further, when the pressure-sensitive adhesive sheet including the elastic layer 40 is heated at the time of peeling, deformation (expansion) in the surface direction of the pressure-sensitive adhesive layer is restricted, and deformation in the thickness direction is given priority. As a result, the peelability is improved.

  The elastic layer contains a base polymer, and the polymer exemplified as the base polymer constituting the pressure-sensitive adhesive layer can be used as the base polymer. The elastic layer may contain natural rubber, synthetic rubber, synthetic resin, or the like. Examples of the synthetic rubber and synthetic resin include nitrile, diene, and acrylic synthetic rubbers; thermoplastic elastomers such as polyolefins and polyesters; ethylene-vinyl acetate copolymers; polyurethanes; polybutadienes; 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 appropriate method. The elastic layer and the pressure-sensitive adhesive layer can be distinguished from each other by the difference in base polymer and / or the presence or absence of thermally expandable microspheres (the elastic layer does not include thermally expandable microspheres).

  The elastic layer may contain any appropriate additive as required. Examples of the additive include a crosslinking agent, a vulcanizing agent, a tackifier, a plasticizer, a softening agent, a filler, and an antiaging agent. When a hard resin such as polyvinyl chloride is used as the base polymer, it is preferable to form an elastic layer having desired elasticity by using a plasticizer and / or a softening agent in combination.

  The thickness of the elastic layer is preferably 3 μm to 200 μm, more preferably 5 μm to 100 μm. If it is such a range, the said function of an elastic layer can fully be exhibited.

  The tensile elastic modulus at 25 ° C. of the elastic layer is preferably less than 100 MPa, more preferably 0.1 MPa to 50 MPa, and further preferably 0.1 MPa to 10 MPa. If it is such a range, the said function of an elastic layer can fully be exhibited.

E. Separator The pressure-sensitive adhesive sheet of the present invention may further include a separator, if necessary. The separator has a release surface on at least one surface, and can be provided to protect the pressure-sensitive adhesive layer. The separator can be composed of any suitable material.

F. Manufacturing method of adhesive sheet The adhesive sheet of this invention can be manufactured by arbitrary appropriate methods. The pressure-sensitive adhesive sheet of the present invention is, for example, a method of directly applying a composition containing a pressure-sensitive adhesive on a base material layer (any appropriate base when a pressure-sensitive adhesive sheet not containing a base material layer is obtained), or any And a method of transferring a coating layer formed by coating a composition containing a pressure-sensitive adhesive onto a suitable substrate. The composition comprising an adhesive may comprise any suitable solvent.

  When forming an adhesive layer containing thermally expandable microspheres, the adhesive layer is formed by applying a composition containing thermally expandable microspheres, an adhesive, and any appropriate solvent to the base material layer. can do. Alternatively, after sprinkling the thermally expandable microspheres on the adhesive coating layer, using a laminator or the like, the thermally expandable microspheres are embedded in the adhesive to form an adhesive layer containing the thermally expandable microspheres. It may be formed.

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

  Arbitrary appropriate coating methods may be employ | adopted as a coating method of the said adhesive and each composition. For example, each layer can be formed by drying after coating. 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 in the case of heating and drying can be set to any appropriate temperature according to the characteristics of the substance to be dried.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The evaluation methods in the examples are as follows. In Examples, unless otherwise specified, “parts” and “%” are based on weight.

(1) Contact angle The pressure-sensitive adhesive sheet was placed on a slide glass with the pressure-sensitive adhesive layer facing upward, and the contact angle with respect to 4-tertiarybutylphenylglycidyl ether on the surface of the pressure-sensitive adhesive layer was measured.
On the surface of the pressure-sensitive adhesive layer, 2 μl of 4-tertiary butylphenyl glycidyl ether was dropped, and the contact angle after 5 seconds was measured (N = 5). The contact angle was measured using a contact angle meter (trade name “CX-A type” manufactured by Kyowa Interface Co., Ltd.) in an atmosphere of 23 ° C. and 50% RH.

(2) sp value The sp value of the polymer in the pressure-sensitive adhesive layer after the formation of the pressure-sensitive adhesive sheet is determined by the method of Fedors (Hideki Yamamoto, “Sp Value Basics / Applications and Calculation Methods”, Information Organization Publishing Co., Ltd., 2006). (April 3, published on pages 66-67). Specifically, the sp value is determined by the evaporation energy Δe (cal) of each atom or atomic group forming the polymer at 25 ° C. and the molar volume ΔV (cm ^{3 of} each atom or atomic group forming the polymer at 25 ° C. ) And the following formula.
Sp value = (ΣΔe / ΣΔv) ^1/2
Further, when the polymer is a copolymer, the SP value is calculated as the SP value of each homopolymer of each constituent unit constituting the copolymer, and each constituent unit is assigned to each of these SP values. It is calculated by adding the product of the mole fractions of
In the above case, the analysis method of each structural unit (polymer composition analysis) is performed by appropriately collecting only the pressure-sensitive adhesive layer from the pressure-sensitive adhesive sheet and immersing it in an organic solvent such as dimethylformamide (DMF), acetone, methanol, tetrahydrofuran (THF), etc. The solvent-soluble part obtained in this manner can be recovered and determined from gel filtration permeation chromatograph (GPC), nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), and mass spectrometry analysis methods.

(3) Adhesive force Through the double-sided adhesive tape (product name “No. 531” manufactured by Nitto Denko Corporation) on the entire surface opposite to the adhesive layer of the adhesive sheet (width 20 mm × length 140 mm), A SUS304 plate was attached using a 2 kg hand roller.
Next, a polyethylene terephthalate film (trade name “Lumirror S-10” manufactured by Toray Industries, Inc., thickness: 25 μm, width: 30 mm) was attached to the entire surface of the pressure-sensitive adhesive layer (temperature: 23 ° C., humidity: 65%). 2 kg roller 1 round trip).
The evaluation sample obtained as described above was subjected to a tensile test. As the tensile tester, a trade name “Shimadzu Autograph AG-120kN” manufactured by Shimadzu Corporation was used. After setting a sample for evaluation in a tensile tester, the sample was left at an ambient temperature of 23 ° C. for 30 minutes, and then a tensile test was started. The conditions for the tensile test were as follows: peeling angle: 180 °, peeling speed (pulling speed): 300 mm / min. The load when the pressure-sensitive adhesive sheet was peeled from the PET film was measured, and the maximum load at that time was defined as the pressure-sensitive adhesive force of the pressure-sensitive adhesive sheet.

(4) Throwing force Through the double-sided adhesive tape (Nitto Denko Corporation, trade name “No. 531”) on the entire surface opposite to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (width 20 mm × length 140 mm), A SUS304 plate (width 40 mm × length 120 mm) was attached using a 2 kg hand roller.
Subsequently, an evaluation sheet (Nitto Denko Corporation, trade name “No. 315 tape”, width 19 mm × length 150 mm) was attached (temperature: 23 ° C., humidity: 65%, 2 kg roller 1 round trip).
The evaluation sample obtained as described above was subjected to a tensile test. As the tensile tester, a trade name “Shimadzu Autograph AG-120kN” manufactured by Shimadzu Corporation was used. The conditions of the tensile test were as follows: peeling angle: 180 °, peeling speed (tensile speed): 50 mm / min. Grasp the above evaluation sheet, measure the load when peeling the adhesive layer from the base material layer of the adhesive sheet, the maximum load at that time was the anchoring force between the base material layer and the adhesive layer .

(5) Tack value Through the double-sided adhesive tape (Nitto Denko Corporation, trade name “No. 531”) on the entire surface opposite to the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (width 20 mm × length 50 mm), A slide glass (manufactured by Matsunami Glass Industry Co., Ltd., 26 mm × 76 mm) was attached using a 2 kg hand roller.
The probe tack value of the outer surface of the pressure-sensitive adhesive layer in the sample for evaluation obtained as described above was measured using a probe tack measuring device (trade name “TACKINES Model TAC-II” manufactured by RHESCA). The measurement conditions are as follows: probe processing speed (30 mm / min), test speed (test speed): 30 mm / min, contact load (Preload): 100 gf, contact holding time (press time): 1 second, probe area (Probe) Area): 5 mmφSUS.

(6) Holding power test Under an environmental temperature of 23 ° C., the entire outer surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (width 10 mm × length 150 mm) was baked on a bakelite plate (trade name “Tycolite FL-102” manufactured by Futamura Chemical Co., Ltd.) A 2 kg hand roller was attached to the central portion of 25 mm wide × 125 mm long × 2 mm thick.
The evaluation sample obtained as described above was allowed to stand for 30 minutes at an ambient temperature of 40 ° C. for aging, and then subjected to a tape creep tester (manufactured by Imada Seisakusho Co., Ltd., model / model no. )), A load of 1.96 N was applied, and this state was maintained and left for 2 hours.
The movement distance (deviation) of the pressure-sensitive adhesive sheet due to pressurization was measured with reference to the position before pressurization on the bakelite plate. A shorter moving distance indicates a higher holding force.

(7) Surface roughness The arithmetic surface roughness Ra of the pressure-sensitive adhesive layer surface of the pressure-sensitive adhesive sheet was measured according to JIS B0601. An optical surface roughness meter (manufactured by Veeco Metrology Group, trade name “Wyko NT9100”) was used as a measuring machine.

(8) Standoff suppression effect Naphthalene type bifunctional epoxy resin (DIC, trade name “HP4032D”, epoxy equivalent: 144) 100 parts by weight and phenoxy resin (Mitsui Chemicals, trade name “EP4250”) 40 weight 129 parts by weight of phenol resin (Maywa Kasei Co., Ltd., trade name “MEH-8000”), 1137 parts by weight of spherical silica (trade name “SO-25R”, manufactured by Admatechs), and dye (Orient Chemical Industries) 14 parts by weight of a product name “OIL BLACK BS” manufactured by the company, 1 part by weight of a curing catalyst (trade name “2PHZ-PW” manufactured by Shikoku Kasei Co., Ltd.), and 30 parts by weight of methyl ethyl ketone were mixed to obtain a resin solution A. (Solid content concentration: 23.6% by weight) was prepared.
A Si wafer (1 cm × 1 cm, thickness 500 μm) is placed on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, and the resin solution A is applied so as to cover and seal the Si wafer on the pressure-sensitive adhesive layer, (Coating size: 3 cm × 3 cm) The resin solution was cured by heating at 170 ° C. for 10 minutes to form a structure composed of a Si wafer and a sealing resin on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet.
After cooling, the adhesive sheet was peeled from the structure. About the adhesive sheet after peeling, the difference between the thickness of the part of the adhesive layer that was not in contact with the Si wafer and the thickness of the part of the adhesive layer that was in contact with the Si wafer was taken as the standoff amount.

(9) Adhesive residue The structure which consists of Si wafer and sealing resin was formed on the adhesive sheet like said (8), and the adhesive sheet was peeled from the structure after cooling. After peeling, the sticking surface of the structure was observed with a microscope (manufactured by Keyence Corporation, trade name “VHX-100”, magnification: 150 times), and the presence or absence of the adhesive layer component still attached to the structure was confirmed. . In Table 1, the case where there were less than 5 deposits having a particle size of 100 μm (in the case of an indefinite shape, the length of the longest side is 100 μm) was rated as ◯, and the case where it was 5 or more was marked as x.

[Example 1]
Acrylic copolymer as a base polymer (copolymer of 2-ethylhexyl acrylate and hydroxyethyl acrylate, 2-ethylhexyl acrylate structural unit: hydroxyethyl acrylate structural unit = 100: 5 (weight ratio)) and an isocyanate-based crosslinking agent ( Made by Nippon Polyurethane Co., Ltd., 1.5 parts by weight of the product name “Coronate L”, 10 parts by weight of terpene phenol-based tackifier resin (manufactured by Yashara Chemical Co., Ltd., product name “YS Polystar S145”) and 100 parts by weight of toluene are mixed. A composition for forming an adhesive layer was prepared.
The pressure-sensitive adhesive layer forming composition is applied to one side of a polytetrafluoroethylene film (trade name “Lumirror S10”, thickness 38 μm, manufactured by Toray Industries, Inc.) as a base material layer, and the base material layer and the pressure-sensitive adhesive layer A pressure-sensitive adhesive sheet composed of (thickness 10 μm) was obtained.

[Example 2]
Acrylic copolymer as base polymer (copolymer of 2-ethylhexyl acrylate, acrylic acid and trimethylolpropane acrylate, 2-ethylhexyl acrylate structural unit: acrylic acid structural unit: trimethylolpropane acrylate structural unit = 100: 3: 0 .03 (weight ratio)) 100 parts by weight, 0.5 parts by weight of an epoxy-based cross-linking agent (Mitsubishi Gas Chemical Co., Ltd., trade name “Tetrad C”), and terpene phenol-based tackifier resin (Yasuhara Chemical Co., Ltd., trade name) "YS Polystar S145") 10 parts by weight and 100 parts by weight of toluene were mixed to prepare a composition for forming an adhesive layer.
The pressure-sensitive adhesive layer forming composition is applied to one side of a polytetrafluoroethylene film (trade name “Lumirror S10”, thickness 38 μm, manufactured by Toray Industries, Inc.) as a base material layer, and the base material layer and the pressure-sensitive adhesive layer A pressure-sensitive adhesive sheet composed of (thickness 10 μm) was obtained.

[Example 3]
Addition reaction type silicone adhesive (trade name “Silicone Rubber SD-4580L” manufactured by Toray Industries, Inc., silicone rubber: silicone resin = 60: 40 (weight ratio)) and platinum catalyst (product manufactured by Toray Industries, Inc.) Name “SRX-212”) 0.5 parts by weight and 100 parts by weight of toluene were mixed to prepare a composition for forming an adhesive layer.
The pressure-sensitive adhesive layer-forming composition was applied to one side of a polyimide film (trade name “Kapton 200H”, thickness 50 μm, manufactured by Toray DuPont Co., Ltd.) as a base material layer, and the base material layer and the pressure-sensitive adhesive layer (10 μm ) Was obtained.

[Example 4]
100 parts by weight of polyisobutylene rubber (made by BASF Japan, trade name “Opanol B80”), 1.5 parts by weight of a hydroxyl group-containing polyolefin (made by Idemitsu Kosan Co., Ltd., trade name “Epol”), and an isocyanate crosslinking agent (Japan) 4 parts by weight of Polyurethane Industry Co., Ltd., trade name “Coronate L”) and 200 parts by weight of toluene were mixed to prepare an adhesive layer forming composition.
The pressure-sensitive adhesive forming composition was applied to one side of a polytetrafluoroethylene film (trade name “Lumirror S10”, thickness 38 μm, manufactured by Toray Industries, Inc.) as a base material layer, and the base material layer and the pressure-sensitive adhesive layer ( A pressure-sensitive adhesive sheet having a thickness of 10 μm) was obtained.

[Example 5]
30 parts by weight of thermally expandable microspheres (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., trade name “Matsumoto Microsphere F-50”) was further added to the composition for forming an adhesive layer, and the thickness of the adhesive layer was 40 μm. Except for the above, an adhesive sheet was obtained in the same manner as in Example 1.

[Example 6]
30 parts by weight of thermally expandable microspheres (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., trade name “Matsumoto Microsphere F-50”) was further added to the composition for forming an adhesive layer, and the thickness of the adhesive layer was 40 μm. Except for the above, an adhesive sheet was obtained in the same manner as in Example 2.

[Example 7]
30 parts by weight of thermally expandable microspheres (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., trade name “Matsumoto Microsphere F-50”) was further added to the composition for forming an adhesive layer, and the thickness of the adhesive layer was 40 μm. Except for the above, an adhesive sheet was obtained in the same manner as in Example 3.

[Example 8]
30 parts by weight of thermally expandable microspheres (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., trade name “Matsumoto Microsphere F-50”) was further added to the composition for forming an adhesive layer, and the thickness of the adhesive layer was 40 μm. Except for this, a pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4.

[Example 9]
In the same manner as in Example 1, a pressure-sensitive adhesive layer forming composition was prepared.
Acrylic copolymer (copolymer of ethyl acrylate, 2-ethylhexyl acrylate and hydroxyethyl acrylate, ethyl acrylate constitutional unit: 2-ethylhexyl acrylate constitutional unit: hydroxyethyl acrylate constitutional unit: 70: 30: 5: 6 (weight ratio) ) 100 parts by weight, 2 parts by weight of an isocyanate crosslinking agent (trade name “Coronate L”, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 100 parts by weight of toluene were mixed to prepare an elastic layer forming composition.
Acrylic copolymer (copolymer of ethyl acrylate, 2-ethylhexyl acrylate and hydroxyethyl acrylate, ethyl acrylate constitutional unit: 2-ethylhexyl acrylate constitutional unit: hydroxyethyl acrylate constitutional unit: 70: 30: 5: 6 (weight ratio) ) 100 parts by weight, 2 parts by weight of an isocyanate-based cross-linking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.), and a rosin phenol-based tackifier resin (manufactured by Sumitomo Bakelite Co., Ltd., trade name “Sumilide Resin PR-12603) ] 15 parts by weight, 35 parts by weight of thermally expandable microspheres (trade name “Matsumoto Microsphere F-50” manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) and 100 parts by weight of toluene are mixed to form another pressure-sensitive adhesive layer. A composition was prepared.
The pressure-sensitive adhesive layer forming composition is applied to one side of a PET film (trade name “Lumirror S10”, thickness 38 μm, manufactured by Toray Industries, Inc.) as a base material layer, and the pressure-sensitive adhesive layer (thickness) is formed on the base material layer. 10 μm). Moreover, the elastic layer forming composition was applied to the other surface of the PET film to form an elastic layer (thickness 10 μm) on the base material layer.
Separately, another pressure-sensitive adhesive layer forming composition was coated on another PET film to form another pressure-sensitive adhesive layer (thickness 35 μm). The other pressure-sensitive adhesive layer was transferred onto the elastic layer to obtain a pressure-sensitive adhesive sheet comprising pressure-sensitive adhesive layer / base material layer / elastic layer / other pressure-sensitive adhesive layer.

[Example 10]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 9 except that the pressure-sensitive adhesive layer forming composition obtained in Example 2 was used as the pressure-sensitive adhesive layer forming composition.

[Example 11]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 9 except that the pressure-sensitive adhesive layer forming composition obtained in Example 3 was used as the pressure-sensitive adhesive layer forming composition.

[Example 12]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 9 except that the pressure-sensitive adhesive layer forming composition obtained in Example 4 was used as the pressure-sensitive adhesive layer forming composition.

[Comparative Example 1]
100 parts by weight of acrylic copolymer (copolymer of methyl acrylate, 2-ethylhexyl acrylate and acrylic acid, methyl acrylate structural unit: 2-ethylhexyl acrylate structural unit: acrylic acid structural unit = 15: 85: 8 (weight ratio)) 3 parts by weight of an epoxy-based crosslinking agent (trade name “Tetrad C” manufactured by Mitsubishi Gas Chemical Company), 10 parts by weight of a terpene phenol-based tackifier resin (trade name “YS Polystar S145” manufactured by Yasuhara Chemical Co., Ltd.), toluene 100 parts by weight was mixed to prepare a pressure-sensitive adhesive layer forming composition.
The pressure-sensitive adhesive layer forming composition is applied to one side of a polytetrafluoroethylene film (trade name “Lumirror S10”, thickness 38 μm, manufactured by Toray Industries, Inc.) as a base material layer, and the base material layer and the pressure-sensitive adhesive layer A pressure-sensitive adhesive sheet composed of (thickness 10 μm) was obtained.

  As is apparent from Table 1, the pressure-sensitive adhesive sheet of the present invention includes a pressure-sensitive adhesive layer having a contact angle with respect to 4-tertiarybutylphenylglycidyl ether of 15 ° or more, that is, a pressure-sensitive adhesive having a low affinity for a sealing resin. By providing the agent layer, it is possible to obtain a pressure-sensitive adhesive sheet in which the occurrence of stand-off is small and the adhesive residue hardly occurs.

DESCRIPTION OF SYMBOLS 10 Adhesive layer 30 Base material layer 40 Elastic layer 100, 200, 300 Adhesive sheet

Claims (14)

An adhesive sheet comprising an adhesive layer,
The contact angle of the surface of the pressure-sensitive adhesive layer with respect to 4-tertiarybutylphenylglycidyl ether is 15 ° or more,
The adhesive strength of the adhesive sheet to polyethylene terephthalate at 23 ° C. is 0.5 N / 20 mm or more.
Adhesive sheet. The adhesive sheet of Claim 1 whose sp value of the material which comprises the adhesive in the said adhesive layer is 7 (cal / cm < ³ >) ^<1/2 > -10 (cal / cm < ³ >) ^<1/2 >.   The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the pressure-sensitive adhesive layer has a probe tack value of 50 N / 5 mmφ or more.   The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive.   The pressure-sensitive adhesive sheet according to claim 4, wherein the acrylic pressure-sensitive adhesive contains an acrylic polymer having an alkyl ester having 4 or more carbon atoms in the side chain as a base polymer.   The content ratio of the structural unit which has a C4 or more alkyl ester in a side chain in the said acrylic polymer is 30 weight% or more with respect to all the structural units which comprise this acrylic polymer. The pressure-sensitive adhesive sheet described in 1.   The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer contains a rubber-based pressure-sensitive adhesive.   The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer contains a silicone-based pressure-sensitive adhesive. The silicone-based pressure-sensitive adhesive contains a silicone rubber and a silicone resin as a base polymer,
The pressure-sensitive adhesive sheet according to claim 8, wherein a weight ratio of the silicone rubber to the silicone resin (rubber: resin) is 100: 0 to 100: 220.   The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer further comprises thermally expandable microspheres.   The pressure-sensitive adhesive sheet according to claim 10, wherein an arithmetic surface roughness Ra of the pressure-sensitive adhesive layer before heating the thermally expandable microspheres is 500 nm or less.   When the entire outer surface of the pressure-sensitive adhesive layer was bonded to a bakelite plate at an environmental temperature of 23 ° C., aged at an environmental temperature of 40 ° C. for 30 minutes, and then held for 2 hours while applying a load of 1.96 N, The pressure sensitive adhesive sheet according to any one of claims 1 to 11 whose gap with respect to a bakelite board is 0.5 mm or less. A base layer,
The pressure-sensitive adhesive layer is disposed on one side or both sides of the base material layer,
The pressure-sensitive adhesive sheet according to claim 1. The pressure-sensitive adhesive sheet according to claim 13, wherein the anchoring force between the base material layer and the pressure-sensitive adhesive layer is 6.0 N / 19 mm or more.

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