TWI611001B - Thermal peeling adhesive sheet - Google Patents

Abstract

The invention obtains a heat-peeling type adhesive sheet. Although it is a heat-peeling type adhesive sheet, it surely fixes the object to be processed during heat cutting. Of course, it prevents wafer shift caused by dicing and also prevents wafer spatter. Generated and excellent in thermal peelability.

A heat-peelable adhesive sheet having a heat-expandable adhesive layer containing heat-expandable microspheres, and the heat-expandable adhesive layer shears a polyethylene terephthalate film at 80 ° C. The force is 15 ~ 80N / cm ² .

Description

Thermal release type adhesive sheet

The present invention relates to a heat-peelable adhesive sheet used for temporary fixing in processing steps in the manufacture of electronic parts and the like.

Semiconductors and other fields have been promoting wafers with larger diameters (450 mm) and thinner thicknesses (less than 100 μm), and the demand for compound semiconductors that require attention when using LEDs, etc., has increased significantly.

In recent years, progress has been made in miniaturization or precision of electronic components. For example, with regard to ceramic capacitors, the size represented by 0603 size (0.6mm × 0.3mm) or 0402 size (0.4mm × 0.2mm) is less than 1mm. The size reduction has become remarkable, or the high capacity has been significantly increased by the use of a high-layer build-up that exceeds hundreds of layers.

Along with the above-mentioned miniaturization or refinement, the pre-fired sheet (green sheet) of ceramics, especially ceramic capacitors, is required to have high accuracy during processing.

For example, a ceramic capacitor is manufactured by the following steps.

(1) Internal electrode printing steps for green sheets

(2) Lamination steps

(3) Pressing step (pressing step)

(4) Cutting step

(5) roasting step

(After repeating the stacking step (2) and the pressing step (3) for a specific number of times, the process is shifted to the cutting step (4))

Among these steps, as aspects that should be paid special attention to during manufacturing, for example, the accuracy of internal electrode printing in the internal electrode printing step (1) of the green sheet, and the accuracy of electrode positioning in the lamination step (2) can be cited. Etc .; the accuracy of preventing the electrode position shift in the pressing step (3), etc., the reason for the electrode position shift is that the green sheet is deformed due to pressure and the electrode position is shifted; the cutting in the cutting step (4) Accuracy. Moreover, even if one of these steps has poor accuracy, the resulting product will also become a defective product, with which productivity is greatly reduced.

Regarding the internal electrode printing step (1), the laminating step (2), and the cutting step (4) of the green sheet among these steps, since mechanical accuracy is required, the accuracy can be improved by improving the device.

In addition, in step (4) as a cutting step, a heat-peelable adhesive sheet is widely used in order to improve cutting accuracy. Thereby, the green sheet can be firmly fixed during cutting, the adhesive force can be eliminated by heating after the cutting step, and the ceramic capacitor can be simply peeled from the sheet after the cutting is completed.

However, in recent years, in order to improve the cutting accuracy at the time of cutting processing, the following method has been widely used, and this method is to perform cutting in a state where the green sheet is softened by heating, especially during the cutting process.

In addition, the hot-release type adhesive sheet is required to have even higher green sheet retention even under a high temperature environment.

However, the current tape has a tendency that the holding property of the green sheet in a high-temperature environment is significantly deteriorated compared to the holding property of the green sheet at normal temperature, and sometimes the sufficient green sheet holding property cannot be obtained during the high-temperature die-cutting process, resulting in wafer spatter or chip Offset. As a result, processing becomes more difficult for small, highly integrated, and high-capacity wafers.

In view of this, there is a method of adding an adhesion-imparting resin to an adhesive to improve the adhesion and improve the retention of the object to the adhesive. Therefore, according to this method, the adhesion force is increased by adding an adhesion-imparting resin, and suppression of wafer spatter is sought. However, although Although the chip spatter frequency is slightly reduced, it has nothing to do with the leap improvement. If the amount of the adhesion-imparting resin is further increased to increase the adhesive force, it will be a result that when the wafer is peeled off, it is difficult to peel off because the adhesive layer has a sufficiently strong adhesive force. In addition, as a method for increasing the adhesion, there is also a method for reducing the amount of the crosslinking agent added. However, as a result, there are problems that the cohesiveness in a high-temperature environment is greatly reduced depending on the composition of the polymer or the crosslinked form, and the cohesive agent causes the cohesive failure to peel the cohesive agent together with the wafer.

In order to eliminate such a phenomenon, a method for temporarily fixing a green sheet cut using a non-thermally expandable releasable material as described in Patent Document 1 is also known, and a thermally expandable microballoon is also provided as described in Patent Document 2. A heat-peelable pressure-sensitive adhesive sheet made of a layered layer of a thermally expandable adhesive.

However, these known methods do not set the shear adhesion force of polyethylene terephthalate (hereinafter, also referred to as PET) to a specific range in an environment of 80 ° C. Moreover, the adhesive itself does not cause heating Those with good retention characteristics.

A method of using a heat-peelable pressure-sensitive adhesive sheet having a re-peelable pressure-sensitive adhesive composition using such a step is widespread, and these problems cannot be solved with respect to the heat-peelable pressure-sensitive adhesive sheet.

In the semiconductor field, the demand for compound semiconductors such as LEDs is rapidly expanding, and compound semiconductors are easily damaged due to small impacts. Care must be taken during processing such as back-grinding during wafer thinning or dicing steps during wafering. .

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2012-52038

[Patent Document 2] Japanese Patent Laid-Open No. 2008-266455

Generally, in order to improve the green sheet holding property and suppress the peeling of the wafer, a method of increasing the adhesive force of the tape is used. However, if the adhesion is simply improved, it cannot be achieved as described above. The peeling of the wafer is sufficiently suppressed, and good thermal peelability cannot be maintained.

In particular, the cutting method is a step of cutting by inserting a cutting knife approximately perpendicular to the surface of the green sheet and pulling it out from the green sheet in the same track. In order to suppress wafer peeling in such a dicing step, in most cases, the adhesive force is set to be high to oppose the force applied in the upward direction when the cutting blade is pulled out. However, it is known that the peeling of the wafer is mostly caused by the extent to which the thickness of the green sheet is offset from the surface of the knife in the horizontal direction at right angles to the surface of the knife when the cutting blade is inserted. Force, thereby causing peeling.

In view of the above background technology, the present invention intends to obtain a heat-peelable adhesive sheet. Although it is a heat-peelable adhesive sheet, it securely fixes a workpiece during thermal dicing, and of course prevents wafer displacement caused by dicing. , Can also prevent the occurrence of wafer spatter, and excellent thermal peelability.

In order to solve the above-mentioned problems, the present inventors have made intensive studies on the design of an adhesive with excellent shear adhesion at high temperatures, such as a small offset in the horizontal direction in a cutting step in a high temperature environment. As a result, the inventors have found that the following thermal peeling type adhesive sheet can suppress horizontal shift even under high temperature conditions, can significantly reduce wafer peeling, and can secure sufficient thermal peelability. This thermal peeling Type adhesive sheets are those having a thermally expandable adhesive layer containing thermally expandable microspheres, and the adhesive force of the thermally expandable adhesive layer to a polyethylene terephthalate film at 80 ° C is 15 ~ 80N / cm ² structure. In addition, it was found that by using a polymer having a heterocyclic skeleton introduced into the main chain or side chain as an adhesive, horizontal shifts can be suppressed at higher temperatures, and the chip can be reduced more significantly. It can be peeled off, and sufficient thermal peelability can be ensured.

That is, the present invention provides the following heat-peelable adhesive sheet.

The heat-peelable pressure-sensitive adhesive sheet of the present invention has a heat-expandable adhesive layer containing heat-expandable microspheres, and the shear-adhesive force of the heat-expandable adhesive layer to a polyethylene terephthalate film at 80 ° C It is 15 to 80 N / cm ² .

The thermally expandable adhesive layer preferably contains a polymer, and one of the monomers constituting the polymer is a monomer having a heterocyclic structure.

Moreover, it is preferable that the said monomer which has a heterocyclic structure has a heterocyclic structure of 5 member ring-7 member ring.

The monomer having a heterocyclic structure preferably has a heterocyclic structure containing nitrogen.

The monomer having a heterocyclic structure preferably has a maleimide structure.

In addition, it is preferable that the monomer having a heterocyclic structure contains a material selected from the group consisting of N-phenylcis-butenediamidoimine, N-cyclohexylcis-butenediamidoimine, and N- (4-aminophenyl). Maleicimide, N- (2-propenyloxyethyl) succinimide, N- (2-propenyloxyethyl) maleimide and N- (2- At least one of the group consisting of propylene ethoxyethyl) phthalimide.

Moreover, it is preferable that it is 1 to 30 weight% of the monomer which has the said heterocyclic structure with respect to the total weight of all the monomer components.

The polymer contained in the thermally expandable adhesive layer is preferably an acrylic copolymer.

The thermally expandable adhesive layer preferably contains at least one of an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent.

It is preferable that the thermally expandable adhesive layer contains at least one of a terpene phenol-based adhesion-imparting agent and a rosin phenol-based adhesion-imparting agent.

The heat-peelable adhesive sheet of the present invention is preferably used for processing electronic parts.

It is preferable that the above-mentioned electronic parts are processed for use in capacitors, inductors, coils, resistors or piezoelectric elements, oscillators, LEDs, semiconductors, or display devices.

Moreover, it is preferable that the above-mentioned electronic component processing is temporarily fixed in a cutting step.

According to the present invention, the heat-peeling type adhesive sheet exhibits the following effects: Processing such as dicing is performed in the state of the processed object, so that the diced wafer can be fixed, thereby preventing the occurrence of wafer spatter or offset.

1‧‧‧ support substrate

2‧‧‧ rubbery organic elastic layer

3‧‧‧ Thermally Expandable Adhesive Layer

4‧‧‧ diaphragm

Fig. 1 shows the constitution of a heat-peelable adhesive sheet of the present invention.

The invention provides a heat-peeling type adhesive sheet, which is provided with a heat-expandable adhesive layer containing heat-expandable microspheres, and the shear-adhesion force of the heat-expandable adhesive layer to PET under an environment of 80 ° C is 15-80N / cm ² .

It is particularly preferable to use a polymer having a heterocyclic skeleton introduced into the main chain or side chain as a constituent material of an adhesive. By containing a polymer with a heterocyclic skeleton introduced into the main chain or side chain, it is possible to further suppress horizontal shift even under high temperature conditions, which can significantly reduce wafer peeling and ensure sufficient heat. Peelability.

For this reason, it is predicted that the heterocyclic skeleton portion in the adhesive polymer may suppress the mobility of molecules related to the offset by the rigidity of the ring skeleton, and because the heterocyclic ring is a heterocyclic ring, the adhesive force is caused by polarization. The increase in the intermolecular force caused by these functions can be considered to be related to the improvement of shear adhesion in a high temperature environment.

FIG. 1 shows an example of a heat-peeling type adhesive sheet used in the present invention.

1 is a supporting substrate, 2 is a rubber-like organic elastic layer, 3 is a thermally expandable adhesive layer, and 4 is a separator (a smooth and peelable film). Here, in the present invention, three thermally expandable adhesive layers are necessary, and 1, 2, and 4 are arbitrarily selectable and may be optional. In addition, when 1, 2, and 4 are provided, as long as at least one side of 3 can be used as a bonding surface, it can be set in any order. Hereinafter, the heat-peelable adhesive sheet of the present invention will be described.

<Substrate>

The base material can be arbitrarily used as a support base for a heat-peelable double-sided adhesive tape or sheet. As the base material, for example, a plastic base material such as a plastic film or sheet, a non-woven fabric, a metal foil, paper, cloth, a rubber sheet such as a rubber base material, a foam such as a foamed sheet, Or such a laminated body (especially a laminated body of a plastic base material and other base materials or a laminated body of a plastic film (or sheet) with each other, etc.) and other suitable thin leaf bodies.

(Plastic base material)

As the base material, in particular, a plastic base material such as a plastic film or sheet can be preferably used. The material of the plastic-based substrate is not particularly limited, and generally includes polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate ( Polyesters such as PBT); olefin-based resins containing α-olefins as monomers, such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymers, and ethylene-ethyl acetate copolymers (EVA); polyfluorene Amines (nylon), fully aromatic polyamines (aromatic polyamines) and other amine-based resins; polyimide (PI), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), fluororesins, Polyetheretherketone (PEEK), etc. These raw materials can be used alone or in combination of two or more.

Specifically, as the polyethylene terephthalate (PET) film, Toray Co., Ltd. "Lumirror", Teijin Dupont Films Co., Ltd. "Teijin Tetoron Film" "Melinex", and Mitsubishi Resin Co., Ltd. "Diafoil" "As a polyethylene naphthalate (PEN) film, Teijin Dupont Films Co., Ltd." Teonex ", etc .; As a polyimide (PI) film, Toray-DuPont Co., Ltd." Kapton " , Kaneka Co., Ltd. "Apical", Ube Industrial Co., Ltd. "Upilex", etc .; as polypropylene (PP) film, Toray Co., Ltd. "Torayfan", Suntox Co., Ltd. "Suntox", Toyo Textile Co., Ltd. Company "PYLEN Film", etc .; Examples of polyvinyl chloride (PVC) film include Mitsubishi Resin Co., Ltd. "Altron", Achilles Co., Ltd. "Achilles type C +", etc .; As polyethylene (PE) film, Okura Industries Co., Ltd. "NSO", etc .; As a polyphenylene sulfide (PPS) film, Toray Co., Ltd. "TORELINA", etc .; As a fluorine film, Toray "Toyoflon" Co., Ltd., "Tedlar Film" by Dupont Co., Ltd., etc. Furthermore, in the case of using a plastic-based substrate as the substrate, the elongation can also be controlled by stretching treatment or the like. And other deformability.

(Non-woven)

As the non-woven fabric, a non-woven fabric using natural fibers having heat resistance can be preferably used, and among them, a non-woven fabric containing manila hemp is preferred. Examples of the synthetic resin nonwoven fabric include polypropylene resin nonwoven fabric, polyethylene resin nonwoven fabric, and ester resin nonwoven fabric.

(Metal foil)

The metal foil is not particularly limited. In addition to common metal foils such as copper foils, stainless steel foils, and aluminum foils, those containing various materials such as silver, iron, nickel, and chromium alloys having the following thicknesses can be used.

(paper)

The paper is not particularly limited, and generally, Japanese paper, kraft paper, cellophane, dorin paper, synthetic paper, and varnished paper can be used.

The thickness of the substrate can be appropriately selected according to strength, flexibility, purpose, etc., for example, it is usually 1000 μm or less (for example, 1 to 1000 μm), preferably 1 to 500 μm, further preferably 3 to 300 μm, and particularly preferably 5 to It is about 250 μm, but it is not limited to these. Furthermore, the substrate may have a single-layered form or a laminated form.

For the surface of the substrate, in order to improve the adhesion with the thermally expandable adhesive layer 3, conventional surface treatments such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, ionizing radiation treatment, etc. It is also possible to perform a coating treatment using a primer or the like by an oxidation treatment using a chemical method or a physical method.

<Thermal expansion adhesive layer>

The thermally expandable adhesive layer 3 contains an adhesive for imparting adhesion and thermally expandable microspheres for imparting thermal expansion. Therefore, after the adhesive sheet is adhered to the adherend, the thermally expandable adhesive layer 3 is heated at any time and the thermally expandable microspheres are foamed and / or expanded to reduce the thermally expandable adhesion. Agent layer 3 and adherend The adhesion area can be easily peeled off.

The thickness of the thermally expandable adhesive layer 3 is 3 to 300 μm, preferably 5 to 150 μm, and more preferably about 10 to 100 μm.

Furthermore, in terms of the balance between the moderate adhesion force before the heat treatment and the decrease in adhesion force after the heat treatment, a better adhesive is a drop of 5 kPa to 1 MPa at room temperature to 150 ° C with a dynamic elastic modulus. The inner polymer is used as the base pressure sensitive adhesive.

As an adhesive which comprises the thermally expandable adhesive layer 3, it is preferable that the foaming and / or expansion | expansion of a thermally expandable microsphere is not restrained as much as possible during heating. Examples of such adhesives include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, and urethanes. Ethyl-based adhesives, styrene-diene block copolymer-based adhesives, creep adhesives with improved creep properties obtained by blending hot-melt resins with a melting point of about 200 ° C or lower in these adhesives, radiation hardening Among known adhesives such as type adhesives, one kind or a combination of two or more kinds is appropriately selected and used (for example, refer to Japanese Patent Laid-Open No. 56-61468 and Japanese Patent Laid-Open No. 63-17981).

As the adhesive, an acrylic adhesive or a rubber-based adhesive can be preferably used, and an acrylic adhesive is particularly preferred. Examples of the acrylic pressure-sensitive adhesive include an acrylic polymer (homopolymer or copolymer) containing one or more alkyl (meth) acrylates as a monomer component as a base polymer. Adhesive.

Examples of the alkyl (meth) acrylate in the acrylic adhesive include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid. Isopropyl ester, butyl (meth) acrylate, isobutyl (meth) acrylate, second butyl (meth) acrylate, third butyl (meth) acrylate, amyl (meth) acrylate, ( Hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate Ester, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, Tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, cetyl (meth) acrylate, decyl (meth) acrylate C _1-20 alkyl (meth) acrylates, such as heptadecyl ester, octadecyl (meth) acrylate, undecyl (meth) acrylate, eicosyl (meth) acrylate, etc. (Preferably (meth) acrylic C _4-18 alkyl (linear or branched alkyl) ester) and the like.

Specific monomers constituting the acrylic polymer include, for example, methyl, ethyl, propyl, butyl, 2-ethylhexyl, isooctyl, isononyl, isodecyl, and dodecyl. , Lauryl, tridecyl, pentadecyl, cetyl, heptadecyl, octadecyl, undecyl, eicosyl, or acrylic acid having an alkyl group having a carbon number of 20 or less Acrylic alkyl esters such as methacrylic acid, acrylic acid, methacrylic acid, itaconic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-hydroxymethyl Acrylamide, acrylonitrile, methacrylonitrile, glycidyl acrylate, glycidyl methacrylate, vinyl acetate, styrene, isoprene, butadiene, isobutylene, vinyl ether, and the like.

Examples of the rubber-based adhesive include natural rubber and various synthetic rubbers (for example, polyisobutylene rubber, styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, and styrene). -Isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butene-styrene block copolymer ( (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) rubber, recycled rubber, butyl rubber, polyisobutylene, or the like Modified product, etc.) as a rubber-based adhesive for the base polymer.

In addition, in order to improve the shear adhesion under a high-temperature environment, it is preferable to include a monomer having a heterocyclic structure as a monomer copolymerizable with the monomer constituting the acrylic polymer. Monomers having a 5-membered ring to 7-membered ring heterocyclic structure are more suitable, and ideally have A heterocyclic structure having a nitrogen is used as such a heterocyclic structure. In addition, it is preferable to use a monomer having a heterocyclic structure having a glass transition temperature (Tg) of 25 ° C or higher, more preferably 40 ° C or higher, and even more preferably 80 ° C or higher when forming a homopolymer.

Specific examples include maleic anhydride and maleimide, such as thiophenes, furans, thianes, pyrrolidines, piperidines, and acrylimines.

These systems introduce a heterocyclic structure into the main chain or side chain by copolymerization with the monomers constituting the acrylic polymer described above, and exert a function of improving shearability under high temperature conditions.

Furthermore, in the present invention, monomers having a fluorene imine skeleton or a cis-butene difluorene imine structure are preferred, and monomers having a cis-butene difluorene imine structure are particularly preferred. Specifically, N-cyclohexyl-cis-butenedifluorene imine, N-phenyl-cis-butenedifluoreneimine, N- (4-aminophenyl) cis-butenedifluorene, N -N-substituted cis-butenedifluorene, such as (2-propenyloxyethyl) cis-butenedifluorene and N- (4-propenyloxybutyl) cis-butadieneimine And N- (2-propenyloxyethyl) succinimide, N- (2-propenyloxyethyl) phthalimide, N- (4-propenyloxybutyl) ) Acrylimines such as succinimide and N- (4-propenyloxybutyl) phthalimide. Particularly preferred are N-phenyl-cis-butene-diimide, N-cyclohexyl-cis-butene-diimide, N- (4-aminophenyl) -cis-butene-diimide, N- (2- Acrylic methoxyethyl) succinimide, N- (2-propylene ethoxyethyl) cis butene difluorene, and N- (2-propylene ethoxyethyl) phthalimide .

As for the monomer having a heterocyclic structure, in order to express the shear adhesion force under a high temperature environment, as a preferable content, it is 1 to 30% by weight, and more preferably 4 to 15% by weight, relative to the total weight of all monomer components. . By setting it to 1 to 30% by weight, the glass transition temperature (Tg) when forming an acrylic polymer does not become too high, it has sufficient adhesion at room temperature, and can improve shear under high temperature conditions Sexual Enhancement Function.

、乙烯基吡

、乙烯基吡咯、乙烯基咪唑、乙烯基

唑、乙烯基

啉、N-乙烯基羧醯胺類、苯乙烯、α-甲基苯乙烯、N-乙烯基己內醯胺等乙烯基系單體；丙烯腈、甲基丙烯腈等氰基丙烯酸酯單體；(甲基)丙烯酸縮水甘油酯等含環氧基之丙烯酸系樹脂系單 體；(甲基)丙烯酸聚乙二醇酯、(甲基)丙烯酸聚丙二醇酯、(甲基)丙烯酸甲氧基乙二醇酯、(甲基)丙烯酸甲氧基聚丙二醇酯等二醇系丙烯酸酯單體；(甲基)丙烯酸四氫糠酯、氟(甲基)丙烯酸酯、聚矽氧(甲基)丙烯酸酯等具有雜環、鹵素原子、矽原子等之丙烯酸酯系單體；己二醇二(甲基)丙烯酸酯、(聚)乙二醇二(甲基)丙烯酸酯、(聚)丙二醇二(甲基)丙烯酸酯、新戊二醇二(甲基)丙烯酸酯、季戊四醇二(甲基)丙烯酸酯、三羥甲基丙烷三(甲基)丙烯酸酯、季戊四醇三(甲基)丙烯酸酯、二季戊四醇六(甲基)丙烯酸酯、環氧丙烯酸酯、丙烯酸聚酯、丙烯酸胺甲酸乙酯等多官能單體；異戊二烯、丁二烯、異丁烯等烯烴系單體；乙烯基醚等乙烯基醚系單體等。該等單體成分可使用1種或2種以上。 In addition, the acrylic polymer may contain, as necessary, a monomer component corresponding to other monomer components copolymerizable with the alkyl (meth) acrylate in order to improve cohesion, heat resistance, and crosslinkability. unit. Examples of such monomer components include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and butylene acid. Monomers; anhydride monomers such as maleic anhydride, itaconic anhydride; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxy (meth) acrylate Hydroxyl-containing monomers such as hexyl ester, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate, etc. ; Styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, (Meth) acrylic acid oxynaphthalenesulfonic acid-containing monomers; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (methyl) ) (N-substituted) fluorenamine monomers such as acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide; (meth) acrylamine Ethyl ester, (meth) acrylic N, N-dimethylaminoethyl ester, tert-butylaminoethyl (meth) acrylate, and other (meth) acrylic acid amino alkyl ester-based monomers; methoxyethyl (meth) acrylate (Meth) acrylic alkoxyalkyl ester-based monomers such as ethoxyethyl (meth) acrylate, N-cyclohexyl-cis-butene difluorene imine, N-isopropyl-cis-butene difluorene Maleic monomers such as amines, N-lauryl maleimide, and N-phenyl maleimide diimide; N-methyl Ikonimine, N-ethyl Ikonimide, N-butyl Ikonimide, N-octyl Ikonimide, N-2-ethylhexyl Ikonimide, N-Cyclohexyl Ikonimide, N-Lauryl Ikonimine and other Ikonimide monomers; N- (meth) acryloxymethylene succinimide, N- (meth) acryl-6-oxyl Succinimide-based monomers such as hexamethylene succinimide, N- (meth) propenyl-8-oxyoctamethylene succinimide, vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperidine

Vinylpyridine

, Vinylpyrrole, vinylimidazole, vinyl

Azole, vinyl

Vinyl monomers such as phthaloline, N-vinylcarboxamides, styrene, α-methylstyrene, N-vinyl caprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile ; Epoxy-based acrylic resin monomers such as glycidyl (meth) acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, and methoxy (meth) acrylate Glycol acrylate monomers such as ethylene glycol esters and methoxypolypropylene glycol (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, and polysiloxane (meth) Acrylate monomers such as acrylate having a heterocyclic ring, halogen atom, silicon atom, 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, Multifunctional monomers such as dipentaerythritol hexa (meth) acrylate, epoxy acrylate, acrylic polyester, urethane acrylate; isoprene Olefin-based monomers such as olefin, butadiene, isobutylene; vinyl ether-based monomers such as vinyl ether and the like. These monomer components can be used alone or in combination of two or more.

In addition, the above-mentioned adhesive constituting the thermally expandable adhesive layer 3 may contain a crosslinking agent, an adhesion-imparting agent, a pigment, a dye, a filler, and an anti-aging agent in addition to a polymer component such as an adhesive component (base polymer). , Conductive agents, antistatic agents, ultraviolet absorbers, light stabilizers, peeling adjusters, softeners, surfactants, flame retardants, antioxidants and other appropriate additives.

(Crosslinking agent)

唑啉系交聯劑、氮丙啶系交聯劑、胺系交聯劑等，可較佳地使用異氰酸酯系交聯劑及環氧系交聯劑。 Examples of the crosslinking agent include, besides isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, and peroxide-based crosslinking agents, urea-based crosslinking agents and metal alkoxide-based crosslinking agents Crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, carbodiimide crosslinking agent,

The oxazoline-based cross-linking agent, aziridine-based cross-linking agent, and amine-based cross-linking agent can be preferably an isocyanate-based cross-linking agent or an epoxy-based cross-linking agent.

[Isocyanate-based crosslinking agent]

Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; cyclopentylene diisocyanate, cyclohexyl diisocyanate, isophor Cycloaliphatic isopropyl Cyanates; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane / toluene diisocyanate terpolymer plus Finished product (trade name Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane / hexamethylene diisocyanate terpolymer adduct (trade name Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), Isocyanate adducts such as isocyanurate of hexamethylene diisocyanate (trade name Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like. These compounds may be used singly or in combination of two or more kinds.

The compounding amount of the isocyanate-based crosslinking agent can be appropriately determined according to the situation of controlling the adhesion. 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, is prepared per 100 parts by weight of the base polymer.

[Epoxy crosslinking agent]

Examples of the epoxy-based crosslinking agent include N, N, N ', N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, and 1,3-bis (N, N-glycidyl). Glycerylaminomethyl) cyclohexane (product name "Tetrad C", manufactured by Mitsubishi Gas Chemical Co., Ltd.), 1,6-hexanediol diglycidyl ether (product name "Epolight 1600", Kyoeisha Chemical Co., Ltd.), neopentyl glycol diglycidyl ether (product name "Epolight 1500NP", manufactured by Kyoeisha Chemical Co., Ltd.), ethylene glycol diglycidyl ether (product name "Epolight 40E", Kyoeisha) Chemical Co., Ltd.), propylene glycol diglycidyl ether (product name "Epolight 70P", manufactured by Kyoeisha Chemical Co., Ltd.), polyethylene glycol diglycidyl ether (product name "EPIOL E-400", Japanese oils and fats Co., Ltd.), polypropylene glycol diglycidyl ether (product name "EPIOL P-200", manufactured by Japan Oil and Fat Co., Ltd.), sorbitol polyglycidyl ether (product name "DENACOL EX-611", Nagase Chemtex Corporation Co., Ltd.), glycerol polyglycidyl ether (product name "DENACOL EX-314", manufactured by Nagase Chemtex Co., Ltd.), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (product name "DENACOL EX-512", manufactured by Nagase Chemtex Co., Ltd.), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, Tris (2-hydroxyethyl) isocyanuric acid triglycidyl ester, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy having two or more epoxy groups in the molecule Department of resin and so on. These crosslinking agents may be used singly or in combination of two or more kinds.

The compounding amount of the epoxy-based crosslinking agent can be appropriately determined according to the situation of controlling the adhesion. 0.01 to 10 parts by weight, and preferably 0.03 to 5 parts by weight, are prepared per 100 parts by weight of the base polymer.

(Adhesion imparting agent)

The adhesion-imparting agent is not particularly limited, and can be appropriately selected from known adhesion-imparting resins. Specific examples of the adhesion-imparting resin include rosin-based adhesion-imparting resins (for example, unmodified rosin, modified rosin, rosin phenol-based resin, and rosin ester resin), and terpene-based adhesion-imparting resins. Resin (for example, terpene-based resin, terpene phenol-based resin, styrene-modified terpene-based resin, aromatic modified terpene-based resin, hydrogenated terpene-based resin), hydrocarbon-based adhesion-imparting resin (for example, aliphatic Hydrocarbon resin, aliphatic cyclic hydrocarbon resin, aromatic hydrocarbon resin (styrene resin, xylene resin, etc.), aliphatic / aromatic petroleum resin, aliphatic / alicyclic petroleum resin , Hydrogenated hydrocarbon resins, coumarone-based resins, coumarone-indene-based resins, etc.), phenol-based adhesion-imparting resins (for example, alkylphenol-based resins, xylene formaldehyde-based resins, soluble phenols, novolacs, etc.), Ketone-based adhesion-imparting resins, polyamide-based adhesion-imparting resins, epoxy-based adhesion-imparting resins, and elastic-system adhesion-imparting resins. The adhesion-imparting agent can be used alone or in combination of two or more. Among them, a rosin-based adhesion-imparting resin, a terpene-based adhesion-imparting resin, and a hydrocarbon-based adhesion-imparting resin (such as a styrene-based resin) can be preferably used. Particularly preferred are terpene phenol-based adhesion-imparting agents and rosin phenol-based adhesion-imparting agents.

The blending amount of the adhesion-imparting agent is relative to the basic polymerization of the heat-expandable adhesive layer. 100 parts by weight of the product is 5 to 100 parts by weight, and preferably 10 to 50 parts by weight.

Specific examples of the terpene phenol resin include "YS Polyster S145" and "Mighty Ace K140" manufactured by Yasuhara Chemical Co., Ltd., and "Tamanol 901" manufactured by Arakawa Chemical Co., Ltd., and Sumitomo as the rosin phenol resin. "Sumilite Resin PR-12603" manufactured by Bakelite Co., Ltd., "Tamanol 361" manufactured by Arakawa Chemical Co., Ltd., etc .; as the alkylphenol resin, "Tamanol 1010R" and "Tamanol 200N" manufactured by Arakawa Chemical Co., Ltd. can be cited. Examples of the alicyclic saturated hydrocarbon resin include "Arkon P-140" manufactured by Arakawa Chemical Co., Ltd. and the like.

(Plasticizer)

The plasticizer used in the present invention is not particularly limited, and for example, trimellitate-based plasticizer, pyromellitic-based plasticizer, polyester-based plasticizer, and adipic acid-based plasticizer can be used. As a plasticizer and the like, a trimellitate-based plasticizer and a pyromellitic-based plasticizer can be preferably used. The plasticizer may be used alone or in combination of two or more.

Specific examples of the trimellitate-based plasticizer include tris (n-octyl) trimellitate, tris (2-ethylhexyl) trimellitate, and tris trimellitate Trioctyl trimellitate, such as isooctyl ester, triisononyl trimellitate, triisodecyl trimellitate and the like. Examples of the pyromellitic acid-based plasticizer include tetraalkyl pyromellitic acid such as tetrakis (n-octyl) pyromellitic acid and tetra (2-ethylhexyl) pyromellitic acid ester. Esters, etc.

The compounding amount of the plasticizer can be appropriately determined according to the purpose, and 1 to 30 parts by weight, and preferably 1 to 20 parts by weight, are blended per 100 parts by weight of the base polymer.

(Thermally expandable microspheres)

The thermally expandable microsphere is not particularly limited, and may be appropriately selected from known thermally expandable microspheres, and may be used alone or in combination of two or more. As the thermally expandable microspheres, for example, it is only necessary that the microspheres containing the following substances are contained in a shell having elasticity, such as propane, propylene Olefin, butene, n-butane, isobutane, isopentane, neopentane, n-pentane, n-hexane, isohexane, heptane, octane, petroleum ether, halide of methane, tetraalkylsilane Low-boiling point liquid; Substances such as azomethoxamine which are thermally decomposed into gaseous form, which are easily vaporized and expanded by heating.

基酯、(甲基)丙烯酸環己酯、(甲基)丙烯酸苄酯、丙烯酸β-羧基乙酯之(甲基)丙烯酸酯；如苯乙烯、α-甲基苯乙烯、氯苯乙烯之苯乙烯單體；丙烯醯胺、經取代之丙烯醯胺、甲基丙烯醯胺、經取代之甲基丙烯醯胺之醯胺單體或該等之任意混合物等，於本發明中，只要包括熱熔融性物質或因熱膨脹而破壞之物質等即可。 The shell-forming substance that forms the thermally expandable microspheres may be composed of, for example, a polymer of a radically polymerizable monomer. Examples of the monomers include: nitrile monomers such as acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethoxyacrylonitrile, and fumaronitrile; such as acrylic acid, methacrylic acid, and Iran Carboxylic acid, maleic acid, fumaric acid, methyl maleic acid carboxylic monomers; vinylidene chloride; vinyl acetate; such as (meth) acrylate, (meth) Ethyl acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, third butyl (meth) acrylate, isopropyl (meth) acrylate

(Meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylate of β-carboxyethyl acrylate; such as styrene, α-methylstyrene, chlorostyrene Ethylene monomer; acrylamide, substituted acrylamide, methacrylamide, substituted acrylamide monomer, or any mixture of these, etc., in the present invention, as long as it includes heat A fusible substance or a substance which is destroyed by thermal expansion may be used.

The shell-forming substance can also be produced by copolymerization of one or more substances, and examples thereof include vinylidene chloride-methyl methacrylate-acrylonitrile copolymer and methyl methacrylate-acrylonitrile- Methacrylonitrile copolymer, methyl methacrylate-acrylonitrile copolymer, acrylonitrile-methacrylonitrile-Iconic acid copolymer, and the like. The thermally expandable microspheres can be produced by a conventional method such as a coacervation method or an interfacial polymerization method.

As such heat-expandable microspheres, for example, "Matsumoto Microsphere" (product names F-30, F-30D, F-36LV, F-50, F-50D, F-65, etc.) manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. can also be used. , F-65D, FN-100SS, FN-180SS, F-190D, F-260D, F-2800D), "Expancel" (product names 053-40, 031-40, 920-40) manufactured by Japan Fillite Co., Ltd. , 909-80, 930-120), "Daifoam" (product names H750, H850, H1100, S2320D, S2640D, M330, M430, M520) manufactured by Wu Yu Chemical Industry Co., Ltd., and "Advancell" (product names EML101, EMH204, EHM301, EHM302, EHM303, EM304, EHM401, EM403, EM501) and other commercially available products.

In addition, in the present invention, as the thermally expandable microspheres, other than the above may be used. Examples of such thermally expandable microspheres include various inorganic foaming agents and organic foaming agents. Typical examples of the inorganic foaming agent include ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydride, and various azides. In addition, as representative examples of the organic blowing agent, for example, water; chlorochloroalkane-based compounds such as trichloromonofluoromethane and dichloromonofluoromethane; azobisisobutyronitrile and azobiscarboxamide. , Azo compounds such as barium azodicarboxylate; p-toluenesulfonylhydrazine, diphenylphosphonium-3,3'-disulfonylhydrazine, 4,4'-oxybis (benzenesulfonylhydrazine), olefin Hydrazine compounds such as propyl bis (sulfohydrazine); hemicarbazide compounds such as p-toluenesulfonium hydrazine, 4,4'-oxybis (benzenesulfonyl hydrazine); 5-morpholinyl- Triazole compounds such as 1,2,3,4-thiatriazole; N, N'-dinitrosopentamethylenetetramine, N, N'-dimethyl-N, N'-dinitroso N-nitroso compounds such as p-xylylenediamine and the like.

As the thermally expandable microspheres, in order to efficiently reduce the adhesive force of the adhesive layer by heat treatment, it is preferable to have an appropriate strength not to break until the volume expansion rate becomes 5 times or more, especially 7 times or more, especially 10 times or more. By.

The compounding amount of the thermally expandable microspheres can be appropriately set according to the expansion ratio of the adhesive layer or the reduction of the adhesive force, etc., and is usually 1 to 150 parts by weight relative to 100 parts by weight of the base polymer forming the thermally expandable adhesive layer 2. It is preferably 10 to 130 parts by weight, and more preferably 25 to 100 parts by weight.

<Rubber-like organic elastic layer>

In the heat-peelable pressure-sensitive adhesive sheet shown in FIG. 1, in terms of imparting deformability to the heat-peelable pressure-sensitive adhesive sheet or improving peelability after heating, the support substrate 1 and thermal expansion properties A rubber-like organic elastic layer 2 is provided between the adhesive layers 3, and the rubber-like organic elastic layer 2 is a layer provided as needed, and may not necessarily be provided. As described above, by providing the rubber-like organic elastic layer 2, the heat-peelable pressure-sensitive adhesive sheet and the adherend (processed product) can be bonded to the heat-peelable pressure-sensitive adhesive sheet when the heat-expandable adhesive layer 3 is used. The surface of the heat-expandable adhesive layer 3 follows the surface shape of the adherend well to increase the bonding area. It is also possible to heighten the heat-peelable adhesive sheet from the adherend by heating (with high accuracy). The thermal expansion of the thermally expandable adhesive layer 3 is controlled to preferentially and uniformly expand the thermally expandable adhesive layer 3 in the thickness direction.

That is, the rubber-like organic elastic layer 2 has a function of providing a large bonding area by following the surface shape of the adherend when the heat-peelable adhesive sheet is adhered to the adherend; When the heat-peelable pressure-sensitive adhesive sheet peels off the adherend and heats the heat-expandable adhesive layer 3 to foam and / or expand, the restraint of foaming and / or expansion in the surface direction of the heat-peelable pressure-sensitive adhesive sheet is reduced. The formation of the undulating structure caused by the three-dimensional structure change of the thermally expandable adhesive layer 3 is promoted.

The rubber-like organic elastic layer 2 is preferably provided on the surface of the base material side of the thermally expandable adhesive layer 3 so as to overlap the thermally expandable adhesive layer 3. The rubber-like organic elastic layer 2 may be provided at a position other than between the base material and the thermally expandable adhesive layer 3. The rubber-like organic elastic layer 2 may also be present on one or both sides of the substrate.

The rubber-like organic elastic layer 2 may be an adhesive layer, and the material is not particularly limited. The adhesive and the like exemplified for the thermally expandable adhesive layer 3 may be preferably used as a constituent material. Examples of the adhesive include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, polysiloxane adhesives, polyester adhesives, polyamide adhesives, and urethanes. It is appropriately selected from a series of adhesives, styrene-diene block copolymer-based adhesives, adhesives with improved creep characteristics, radiation-curable adhesives, and the like.

More specifically, for example, a rubber-based adhesive containing natural rubber or synthetic rubber as a base polymer, and an acrylic polymer containing the following as a main component can be cited. Acrylic adhesives based on polymers: with methyl, ethyl, propyl, butyl, 2-ethylhexyl, isooctyl, isononyl, isodecyl, dodecyl, lauryl, Tridecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, undecyl, and eicosyl, usually acrylic or methacrylic acid having an alkyl group of 20 or less And other acrylic alkyl esters; acrylic acid, methacrylic acid, eicosanoic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-hydroxymethacrylamide , Acrylonitrile, methacrylonitrile, glycidyl acrylate, glycidyl methacrylate, vinyl acetate, styrene, isoprene, butadiene, isobutylene, vinyl ether, and the like.

The rubber-like organic elastic layer 2 may be formed of a natural rubber, a synthetic rubber, or a synthetic resin having rubber elasticity in addition to the adhesive. Examples of the synthetic resin include synthetic rubbers such as nitrile, diene, and acrylic resins; thermoplastic elastomers such as polyolefins and polyesters; ethylene-vinyl acetate copolymers, polyurethanes, Synthetic resins with rubber elasticity, such as polybutadiene and soft polyvinyl chloride. In addition, even if it is a rigid polymer in nature such as polyvinyl chloride, it can be used in combination with a formulation agent such as a plasticizer or a softener to express rubber elasticity.

In addition, the rubber-like organic elastic layer 2 containing these materials may be formulated with a cross-linking agent, an adhesion-imparting agent, a plasticizer, a filler, and anti-aging in the above-mentioned adhesive or synthetic resin in the same manner as the thermally expandable adhesive layer. Agents and other suitable additives.

The formation of the rubber-like organic elastic layer 2 can be performed, for example, in an appropriate manner: a method of applying a constituent material coating liquid containing a rubber-like organic elastic layer on the substrate 1 (coating method); A film of a film-like organic elastic layer forming agent, or a laminate film in which a layer including the above-mentioned rubbery organic elastic layer forming agent is formed on the thermally expansive adhesive layer 3 including one or more layers in advance (dry layer) Compression method); a method of co-extruding the resin composition containing the constituent material of the supporting substrate 1 and the resin composition containing the rubber-like organic elastic layer forming agent (co-extrusion method), and the like.

The rubber-like organic elastic layer 2 can also be formed by using a foamed film or the like having the above-mentioned components as its main body. Foaming can be performed by conventional methods, for example, by mechanical stirring, by using reaction to generate gas, by using foaming agent, by removing soluble substances, by spraying, or by forming coagulated foam. Method, sintering method, etc. The rubber-like organic elastic layer 2 may be a single layer, or may be composed of two or more layers.

The thickness of such a rubber-like organic elastic layer 2 is 3 to 200 μm, and preferably 5 to 100 μm. If it is in the range of 3 to 200 μm, it will not be too thin, and it can exhibit the function of providing a large bonding area by following the surface shape of the adherend of the heat-peelable adhesive sheet, and promoting the adhesive layer due to thermal expansion. 3 The function of generating the undulating structure caused by the change of the three-dimensional structure. Moreover, since the thickness is not thicker than necessary, it does not cause cohesive failure in the rubber-like organic elastic layer 2 after foaming.

(Adhesive layer)

In the heat-peelable pressure-sensitive adhesive sheet of the present invention, when a heat-peelable adhesive layer containing heat-expandable microspheres is provided on one side of the base material, another adhesive layer may be provided on the other side of the base material. Thereby, for example, during fixing an object to be fixed such as a cut of at least the object to be fixed, a heat-peelable adhesive sheet can be fixed to a separately prepared base for fixing the object.

At this time, the adhesive layer must also be stable against stimuli such as heat or vibration generated during processing such as cutting.

As this adhesive layer, the resin used for the said adhesive agent can be used as a base material, for example.

<Diaphragm>

In the heat-peelable pressure-sensitive adhesive sheet shown in FIG. 1, the separator 4 is used as a protective material for the surface (adhesive surface) of the heat-expandable adhesive layer 3. The separator 4 may be used as needed or need not be used. The separator 4 may be one in which both surfaces become the release surface, or one in which only one surface (single surface) is the release surface. Moreover, the separator 4 can be peeled off when an adhesive layer protected by the separator 4 is used.

As such a separator 4, a known or conventional release paper or the like can be used. Specifically, for example, a substrate having a release agent layer, such as a plastic film or paper, which is surface-treated with a release agent such as polysiloxane, long-chain alkyl-based, fluorine-based, or molybdenum sulfide can be used; including polytetrafluoroethylene, Low-adhesion base materials for fluorine-based polymers such as polyvinyl chloride trifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and vinyl chloride-vinylidene fluoride copolymer; including olefins Low-adhesion base materials of non-polar polymers such as resins (eg, polyethylene, polypropylene, etc.). Of course, in a substrate having a release agent layer, the surface of the release agent layer is a release surface, and in a low-adhesion substrate, the surface of the low-adhesion substrate is a release surface.

The separator 4 can be formed by a known or conventional method. The thickness and the like of the separator 4 are not particularly limited.

In the heat-peelable pressure-sensitive adhesive sheet, the heat-expandable adhesive layer 3 can be formed, for example, by a conventional method such as: using a solvent to prepare a coating solution containing an adhesive and heat-expandable microspheres, if necessary, and applying the solution A method for supporting a substrate 1 or a rubber-like organic elastic layer 2 formed on the substrate 1 in advance; applying the coating solution to an appropriate separator 4 (release paper, etc.) to form a thermally expandable adhesive layer and A method of transferring (transferring) the support substrate 1 or the rubber-like organic elastic layer 2. In this case, the thermally expandable adhesive layer 3 may be any of a single layer and a plurality of layers.

For the heat-peelable adhesive sheet, in order to suppress the peeling of the wafer during high-temperature dicing, it is preferable that the shear-adhesive force of the thermally expandable adhesive layer to the polyethylene terephthalate film (PET) at 80 ° C is 15 to 80 N / cm ² , preferably 20 to 70 N / cm ² . If the shear adhesive force under the environment of 80 ° C is 15N / cm ² to 80N / cm ² , the adherend can be sufficiently maintained without peeling off the wafer during high-temperature die-cutting processing. In addition, by subjecting the thermally expandable microspheres to foaming by applying heat treatment, the adherend can be reliably peeled off.

The heat treatment conditions of the adhesive sheet that can be easily peeled from the adherend vary from the surface state of the adherend or the reduction of the bonding area according to the type of thermally expandable microspheres, the heat resistance of the substrate or the adherend, or the heating method. Determined by other conditions, usually 100 1 to 90 seconds at ~ 250 ° C (hot plate, etc.) or 5 to 15 minutes at 100 to 250 ° C (hot air dryer, etc.).

(Method of using the heat-peelable adhesive sheet of the present invention)

The heat-peelable adhesive sheet of the present invention is used as an adhesive sheet for fixing (temporarily fixing) the electronic part on the substrate when the electronic part is specially processed (cut).

Examples of the electronic parts to be cut include electronic parts such as capacitors, inductors, coils, resistors or piezoelectric elements, oscillators, LEDs, semiconductors, or display devices, and are electronic parts that can be cut by any method.

Such an electronic component is fixed on a substrate by the adhesive force of the heat-peelable adhesive sheet of the present invention. Thereafter, the electronic component is cut by any method such as a cutting method using a cutting blade or a cutting method using a rotary blade, and then the heat-peelable adhesive sheet of the present invention is heated to foam the thermally expandable adhesive layer. In order to reduce the adhesion of the thermally expandable adhesive layer to the cut electronic parts, the cut electronic parts are picked up.

[Example]

In the examples of the present invention, various measurement methods and evaluation methods are as follows.

(Method for measuring glass transition temperature (Tg))

The measurement was performed using a DSC (differential scanning calorimeter) in accordance with JIS standards (JIS K 7121 (2012): a method for measuring the glass transition temperature of plastics).

In addition, when Tg is not displayed by thermal decomposition or the like by the above method, it is determined that the Tg of the polymer is 25 ° C or higher.

(Determination of DSC)

Measuring machine: Q200 by TA Instruments

Measurement speed: 10 ℃ / min

Ambient gas: N ₂ (50mL / min)

Sample weight: 3 ~ 4mg

(Measurement method of shear adhesion of polyethylene terephthalate film at 80 ° C)

A sample of a heat-peelable adhesive sheet having a width of 20 mm and a length of 140 mm was prepared. Furthermore, the adherend (PET # 100) was bonded to the sample with a bonding area of 10 mm × 10 mm (normal state) in accordance with JIS Z 0237 (2009), and it was set in a high-temperature tank with a preset temperature of 80 ° C. And placed on a tensile tester for 30 minutes. Thereafter, the load at the time of peeling the adherend: PET # 100 in the shearing direction at a peeling speed: 50 mm / min was set as a shear adhesive force (N / cm ² ).

(Method for measuring die-cutting and peeling wafers)

Laminated ceramic sheets (* 1) were adhered to the adhesive sheets (40mm × 40mm) obtained in the examples and comparative examples, and left to stand at 80 ° C for 5 minutes, and then cut into 0420 (0.4mm × 0.2 mm) wafer shape (* 2) (about 20,000 pieces). The number of wafers peeled during the die-cutting was evaluated.

<* 1 Laminated ceramic sheet manufacturing method>

100 parts by weight of barium titanate (manufactured by Sakai Chemical Industry Co., Ltd .: trade name "BT-03 / high-purity perovskite") and polyvinyl butyraldehyde (manufactured by Electrochemical Industry Co., Ltd .: trade name "PVB" ) 100 parts by weight (propylene glycol monoethyl ether dissolved product, 10% basis), bis (2ethylhexyl) phthalate (manufactured by J-PLUS Corporation: trade name "DOP"), 2 parts by weight 2 parts by weight of glycerol oleate (manufactured by Rikenvitamin Co., Ltd .: trade name "Rikemal 0-71-D (E)") and 80 parts by weight of toluene were stirred and mixed to prepare a coating liquid for producing a ceramic sheet. Then, the above coating liquid was applied to a membrane coated with a silicone release agent on one side so that the thickness after drying became about 50 μm, and the ceramic was peeled from the membrane after drying treatment at 80 ° C. for 5 minutes to obtain ceramics. Sheet. Ten ceramic sheets were laminated and pressed at a pressure of 300 kg / cm ² to obtain a laminated ceramic sheet.

<* 2 cutting conditions>

Cutting device manufacturer: UHT Corporation

Cutting temperature: 80 ℃

Cutting knife: thickness / 100μm, tip angle / 15 °

(Method for measuring heat peelability)

In the above manner, the ceramic sheet cut and cut on the thermally peelable sheet was put into a dryer at 130 ° C. for 10 minutes for heat treatment. After the heat treatment, the thermally peeled sheet was taken out, and when the wafer was peeled by turning the cut ceramic sheet face down, the number of wafers that had not been peeled off and remained on the thermally peeled sheet was evaluated.

(Example 1)

100 parts by weight of an acrylic copolymer polymer (ethyl acrylate: 2 ethylhexyl acrylate: hydroxyethyl acrylate = 55 parts by weight: 45 parts by weight: 5 parts by weight), and 1.5 parts by weight of an isocyanate-based crosslinking agent (Nippon Manufactured by Polyurethane Industry Co., Ltd .: trade name "Coronate L") and toluene are uniformly mixed and dissolved to prepare a coating liquid, and the coating liquid is applied to a supporting substrate (PET 100 μm so that the thickness after drying becomes 15 μm). ) And dried to obtain a rubbery organic elastic layer. Next, an acrylic copolymer polymer (ethyl acrylate: 2 ethylhexyl acrylate: hydroxyethyl acrylate: N-phenylcis butylene diimide) = 55 parts by weight: 45 parts by weight: 5 parts by weight: 8 parts by weight) 100 parts by weight, 1.5 parts by weight of an isocyanate-based cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name "Coronate L"), 30 parts by weight of thermally expandable microspheres (manufactured by Matsumoto Grease Pharmaceutical Co., Ltd .: product Name "Matsumoto Microsphere F-50D"), 20 parts by weight of rosin phenol resin (manufactured by Sumitomo Bakelite Co., Ltd .: trade name "Sumilite Resin PR-12603") and toluene were uniformly mixed and dissolved to prepare a coating solution. The coating solution is applied to a separator (substrate PET 38 μm) so that the thickness after drying becomes 40 μm, and dried to obtain a thermally expandable adhesive layer. After drying, it is bonded to a support substrate coated with a rubbery organic elastic layer. The rubber-like organic elastic layer side to obtain a heat-peelable adhesive sheet used in the present invention.

(Example 2)

100 parts by weight of an acrylic copolymer polymer (ethyl acrylate: 2 ethylhexyl acrylate: hydroxyethyl acrylate = 70 parts by weight: 30 parts by weight: 5 parts by weight), and 1 part by weight of an isocyanate-based crosslinking agent (Nippon Manufactured by Polyurethane Industry Co., Ltd .: trade name "Coronate L") and toluene are uniformly mixed and dissolved to prepare a coating liquid, and the coating liquid is applied to a support substrate (PET so that the thickness after drying becomes 20 μm). 100 μm) and dried to obtain a rubbery organic elastic layer. Next, an acrylic copolymer polymer (ethyl acrylate: 2 ethylhexyl acrylate: hydroxyethyl acrylate: N-cyclohexyl cis butene difluorene imine = 60 parts by weight: 40 parts by weight: 5 parts by weight: 7 parts by weight) 100 parts by weight, 1 part by weight of an isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name "Coronate L"), 60 parts by weight of terpene phenol resin (manufactured by Yasuhara Chemical Co., Ltd .: trade name " YS Polyster S145 "), 30 parts by weight of heat-expandable microspheres (manufactured by Matsumoto Oil and Fat Pharmaceutical Co., Ltd .: trade name" Matsumoto Microsphere F-50D ") and toluene were uniformly mixed and dissolved to prepare a coating liquid, and the coating was applied. The liquid was applied to a separator (substrate PET 38 μm) so that the thickness became 30 μm after drying, and dried to obtain a thermally expandable adhesive layer. After drying, the liquid was bonded to a rubber supporting a substrate coated with a rubbery organic elastic layer. Shape of the organic elastic layer side to obtain a heat-peelable pressure-sensitive adhesive sheet used in the present invention.

(Comparative example 1)

100 parts by weight of an acrylic copolymer polymer (butyl acrylate: acrylic acid = 95 parts by weight: 5 parts by weight) and 1 part by weight of an isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name "Coronate L") It was uniformly mixed and dissolved with toluene to prepare a coating liquid, and the coating liquid was applied to a support substrate (PET 100 μm) so that the thickness after drying became 15 μm, and dried to obtain a rubbery organic elastic layer. Next, 100 parts by weight of an acrylic copolymer polymer (butyl acrylate: acrylic acid = 95 parts by weight: 5 parts by weight) and 1.5 parts by weight of an isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name "Coronate L "),heat 30 parts by weight of swellable microspheres (made by Matsumoto Oil and Fat Pharmaceutical Co., Ltd .: trade name "Matsumoto Microsphere F-50D") are uniformly mixed with toluene and dissolved to prepare a coating liquid, and the coating liquid is dried to a thickness It is coated on a separator (substrate PET 38μm) in a 35 μm manner and dried to obtain a thermally expandable adhesive layer. After drying, it is bonded to the rubbery organic elastic layer side of the support substrate coated with the rubbery organic elastic layer. A heat-peeling type adhesive sheet was obtained.

(Comparative example 2)

100 parts by weight of an acrylic copolymer polymer (ethyl acrylate: 2ethylhexyl acrylate: hydroxyethyl acrylate = 70 parts by weight: 30 parts by weight: 5 parts by weight), and 1 part by weight of an isocyanate-based crosslinking agent ( Manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name "Coronate L") and toluene are uniformly mixed and dissolved to prepare a coating liquid, and the coating liquid is applied to a supporting substrate (15 μm after drying) PET (100 μm) and dried to obtain a rubbery organic elastic layer. Next, 100 parts by weight of an acrylic copolymer polymer (ethyl acrylate: 2ethylhexyl acrylate: hydroxyethyl acrylate = 70 parts by weight: 30 parts by weight: 5 parts by weight), and 0.4 part by weight of an isocyanate-based crosslinking agent (Manufactured by Nippon Polyurethane Industry Co., Ltd .: trade name "Coronate L"), 30 parts by weight of rosin phenol resin (manufactured by Sumitomo Bakelite Co., Ltd .: trade name "Sumilite Resin PR-12603"), 30 parts by weight of terpene phenol resin (Yasuhara Manufactured by Chemical Co., Ltd .: trade name "YS Polyster T160"), 30 parts by weight of thermally expandable microspheres (manufactured by Matsumoto Oil and Fat Pharmaceutical Co., Ltd .: trade name "Matsumoto Microsphere F-50D") and toluene are uniformly mixed and dissolved A coating solution was prepared, and the coating solution was applied to a separator (base material PET 38 μm) so that the thickness after drying became 35 μm, and dried to obtain a thermally expandable adhesive layer. The organic elastic layer supports the rubber-like organic elastic layer side of the substrate to obtain a heat-peelable adhesive sheet.

The heat-peelable adhesive sheet produced in Examples 1 to 2 and Comparative Examples 1 to 2 The properties and characteristics are shown in Table 1.

It can be seen that the heat-peelable adhesive sheet (Examples 1 to 2) of the present invention is superior to Comparative Example 1 in that it has excellent shear adhesion (N / cm ² ) under an environment of 80 ° C., and is easy to be heated by heating. The characteristics of ground peeling from the adherend. Moreover, it turns out that when a shear adhesive force is too high like the comparative example 2, thermal peelability is inferior.

The present invention has been described in detail, and the present invention has been described with reference to specific embodiments. The industry knows that various changes or modifications can be made without departing from the spirit and scope of the present invention.

This application is based on Japanese Patent Application 2013-042136 filed on March 4, 2013, the contents of which are incorporated herein by reference.

1‧‧‧ support substrate

2‧‧‧ rubbery organic elastic layer

3‧‧‧ Thermally Expandable Adhesive Layer

4‧‧‧ diaphragm

Claims (11)

A heat-peelable adhesive sheet comprising a heat-expandable adhesive layer containing heat-expandable microspheres, and the shear-adhesive force of the heat-expandable adhesive layer to a polyethylene terephthalate film at 80 ° C 15 to 80 N / cm ² ; the above-mentioned thermally expandable adhesive layer contains a polymer, and one of the monomers constituting the polymer is a monomer having a heterocyclic structure; it contains the above-mentioned Heterocyclic structure monomer 1% to 30% by weight. For example, the heat-peelable adhesive sheet of claim 1, wherein the monomer having a heterocyclic structure has a heterocyclic structure of 5 to 7 members. The heat-peeling type adhesive sheet according to claim 1, wherein the monomer having a heterocyclic structure has a heterocyclic structure containing nitrogen. The heat-peelable pressure-sensitive adhesive sheet according to claim 1, wherein the monomer having a heterocyclic structure has a maleimide structure. The heat-peelable pressure-sensitive adhesive sheet according to claim 1, wherein the monomer having a heterocyclic structure contains a material selected from the group consisting of N-phenylcis-butenedifluorene imine, N-cyclohexylcis-butenedifluorene imine, N- (4-Aminophenyl) maleimide, N- (2-propenyloxyethyl) succinimide, N- (2-propenyloxyethyl) maleimide At least one of the group consisting of imine and N- (2-propenyloxyethyl) phthalimide. The heat-peelable pressure-sensitive adhesive sheet according to claim 1, wherein the polymer contained in the thermally expandable adhesive layer is an acrylic copolymer. The heat-peelable adhesive sheet according to claim 1, wherein the thermally expandable adhesive layer contains at least one of an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent. The heat-peelable pressure-sensitive adhesive sheet according to claim 1, wherein the heat-expandable pressure-sensitive adhesive layer contains at least one of a terpene-based pressure-sensitive adhesive imparting agent and a rosin-based pressure-sensitive adhesive imparting agent. The heat-peeling type adhesive sheet according to any one of claims 1 to 8, which can be used for processing of electronic parts. The heat-peeling type adhesive sheet according to claim 9, wherein the electronic parts are processed for use in capacitors, inductors, coils, resistors or piezoelectric elements, oscillators, LEDs, semiconductors, or display devices. The heat-peeling type adhesive sheet according to claim 9, wherein the electronic part is processed to be temporarily fixed in the cutting step.