JP2021155700A - Heat-peelable pressure sensitive adhesive tape - Google Patents

Abstract

To provide a heat-peelable pressure sensitive adhesive tape suitably used in a press step at high temperature or normal temperature for a long time and capable of significantly reducing the adhesiveness of an adhesive layer when further heated after use in the press step to easily peel the adhesive layer without a paste residue on an adherend.SOLUTION: In a heat-peelable pressure sensitive adhesive tape including a heat-expandable adhesive layer including an urethane based adhesive component and heat-expandable particles, the maximum expansion temperature of the heat-expandable particles is set to 170°C or more, and in the dynamic viscoelasticity measurement (a temperature of -60°C to 300°C, a heating rate of 10°C/minute and a frequency of 10 Hz) of the adhesive component, (1) a tanδ at the maximum expansion temperature of the heat-expandable particles is set to 0.120 or less and (2) a storage elastic modulus G' at 170°C is set to 30,000 Pa or more.SELECTED DRAWING: Figure 1

Description

The present invention can be suitably used in a pressing process at a high temperature or at room temperature for a long time in various manufacturing processes including a manufacturing process of electronic parts and semiconductor parts, and when further heated after use in the pressing process, the adhesiveness is improved. The present invention relates to a heat-removable adhesive tape that is significantly reduced and can be easily peeled off without adhesive residue.

In general, adhesive tapes having high heat resistance are widely used in manufacturing process applications for electronic parts and semiconductor parts. Highly heat-resistant adhesive tapes are widely used, for example, in heat treatment processes during the manufacture of electronic parts and semiconductor parts, for temporary fixing of members and parts, fixing during transportation, reinforcement, protection, masking, resin sealing, and the like. There is. In such applications, the adhesive tape is required to have a sufficiently high adhesive force to the adherend during use and to be easily peeled off without adhesive residue after use.

In recent years, in response to demands for thinner and smaller final products including electronic devices, parts have also become thinner and smaller. Adhesive tape may be used for the purpose of improving workability when it is difficult to process thin parts with low rigidity. For example, in the manufacturing process of a thin substrate such as a thin electronic circuit board, a double-sided adhesive tape is attached to a highly rigid transport plate by attaching an adhesive surface on one side to the adhesive surface on one side, and the thin substrate is attached to the adhesive surface on the opposite side. , Workability in mounting parts and processing members on a thin substrate can be improved. Processing of such a member includes, for example, a heat pressing step in which a semiconductor chip is placed on a thin substrate and sealed with a resin. The thin substrate, double-sided tape, and transfer plate completed after processing and mounting of the members are separated from each other, and the transfer plate is reused for processing the thin substrate as needed.
In the temporary fixing of the thin substrate with the adhesive tape described above, sufficiently strong adhesiveness is required during the processing process. On the other hand, if the load applied to the thin substrate when peeling the adhesive tape is large, the thin substrate will be damaged, so that the adhesiveness at the time of peeling the adhesive tape is required to be as low as possible. In addition, glass has been used as the material of the transport plate in the past. However, the transport plate made of glass may be easily deformed in a high temperature environment, or may have problems such as a coefficient of linear expansion significantly different from that of the product. Therefore, when used in a process with a stricter temperature than before, stainless steel (SUS), aluminum plate, metal such as copper plate, silicon, copper-clad laminate, etc. are often used as the material of the transport plate. There is.

In the manufacturing process of such a thin substrate, a single-sided adhesive tape using a highly rigid base material (for example, a resin film of 50 μm to 125 μm) is attached to the thin substrate instead of using a transport plate, so that the thin substrate can be manufactured. It is possible to improve workability in mounting parts and processing members. After the processing and mounting of the member is completed, the adhesive tape is peeled off from the thin substrate. Even in such usage, sufficiently strong adhesiveness is required during the processing process, while extremely low adhesiveness is required when the adhesive tape is peeled off.

Further, in recent years, electronic parts and semiconductor parts are required to have higher heat resistance than conventional ones, mainly for in-vehicle applications. Along with this, materials constituting parts (for example, resins that seal chips in semiconductor packages) are also required to have higher heat resistance. A resin having high heat resistance generally has a high heating temperature and a long heating time required for curing. Therefore, the adhesive tape used in the process of curing such a highly heat-resistant resin is also required to have high heat resistance.

Conventionally, Patent Documents 1 to 6 disclose adhesive tapes that have sufficient adhesiveness from the initial stage of attachment to an adherend to use in a manufacturing process, but the adhesiveness is significantly reduced by giving some external stimulus after use. Has been done.

Patent Document 1 shows excellent initial adhesive properties for semiconductor substrates and thin film substrates, and has excellent adhesiveness during manufacturing processes such as dicing, but the light-sensitive adhesive is cured by irradiation with ultraviolet rays and adheres. A photosensitive adhesive tape in which the force is significantly reduced and a method for producing the same are disclosed. However, the photoreactive component contained in the pressure-sensitive adhesive whose adhesive strength is lowered by such ultraviolet irradiation generally has low heat resistance, and may be unsuitable for use in a high-temperature manufacturing process. Further, such a light-sensitive adhesive cannot be used for a transport plate made of a material that does not transmit light, such as metal or silicon, as described above.

Patent Document 2 preferably prevents resin leakage in the sealing process, and also prevents peeling or breakage of the molded sealing resin or adhesive residue when the heat-resistant adhesive tape is peeled off. A heat-resistant adhesive tape capable of improving the yield is disclosed. The adhesive tape disclosed in Patent Document 2 has an ultraviolet curable adhesive layer, and the adhesive layer is irradiated with ultraviolet rays and further heated at 200 ° C. for 1 hour, and then the adhesive is measured in accordance with JISZ0237. The force is 1N / 19m or less. However, the adhesive tape disclosed in Patent Document 2 is irradiated with ultraviolet rays before the sealing step (that is, the heating step) with the sealing resin, and the adhesive strength is lowered by inducing a curing reaction by ultraviolet rays in the pressure-sensitive adhesive layer. It is used on the premise that the resin is injected and then heat-cured. That is, Patent Document 2 does not mention that the adhesive tape is easily peeled off by giving an external stimulus after the heating step. Like the adhesive tape of Patent Document 1, this adhesive tape cannot be used for a transport plate made of a material that does not transmit light, such as metal or silicon.

Patent Documents 3 to 6 disclose heat-release type pressure-sensitive adhesive sheets in which heat-expandable microspheres contained in the heat-expandable pressure-sensitive adhesive layer are foamed when heated to a predetermined temperature, and the adhesive strength is remarkably reduced.
The heat-peelable pressure-sensitive adhesive sheets disclosed in these patent documents have an pressure-sensitive adhesive layer (heat-expandable pressure-sensitive adhesive layer) containing heat-expandable microspheres as a foaming agent after achieving the purpose of adhering an article including an adherend. By heating, the adhesive force is reduced, and the adherend can be easily separated from the heat-release type adhesive sheet. The reduction in the adhesive force in the adhesive layer is mainly caused by foaming or expanding the adhesive layer by heating, changing the surface of the adhesive layer into an uneven shape, and reducing the adhesive area with the adherend.
The heat-removable pressure-sensitive adhesive sheets disclosed in these patent documents are not intended to be used in a high-temperature heating process for a long period of time. There is no mention of a technique for further heating and making it easy to peel off.
When these heat foam release type adhesive tapes are used in the high temperature and long time pressing process,
-The heat-expandable particles foam during pressing, which reduces the adhesion to the adherend during the process.
-The heat-expandable particles foam during pressing, and the dimensions of the heat-foaming release type adhesive tape itself or the dimensions specified by the heat-foaming release type adhesive tape change, causing processing problems.
-There is a risk that the adhesive component will be thermally deteriorated and the cohesive force will be reduced, causing problems such as adhesive residue on the adherend after foam peeling.

Patent Document 6 discloses a heat-release type adhesive tape that can prevent the pressure-sensitive adhesive from being deformed in the step of laminating and pressurizing a green sheet to cause a displacement of the heat-expandable pressure-sensitive adhesive layer in the ceramic capacitor manufacturing process. Has been done. It is considered that such a heat-removable adhesive tape can be suitably used for preventing misalignment in a pressing process at room temperature for a short time. However, Patent Document 6 describes the foam peeling property of the adhesive layer after being used in the pressing process at high temperature or at room temperature for a long time, the adhesive residue property on the adherend after peeling, and the high temperature pressing process. No mention is made of suppressing the foaming of heat-expandable particles. Further, the thermally expandable particles used in Examples 1 to 3 of Patent Document 6 are those that start expansion at 120 ° C., and are used in a process such as heat pressing at 170 ° C. for 1 hour, for example. In some cases, it is assumed that foaming may occur during hot pressing.

Japanese Unexamined Patent Publication No. 2001-139905 Japanese Unexamined Patent Publication No. 2012-46763 Japanese Unexamined Patent Publication No. 11-166164 JP-A-2007-246823 Japanese Unexamined Patent Publication No. 2016-155919 International Publication No. 2005/088787

An object of the present invention is an adhesive tape used in a pressurizing process of an adherend in various manufacturing processes including a manufacturing process of electronic parts and semiconductor parts, which is suitable for a pressing process at a high temperature or at a normal temperature for a long time. It is an object of the present invention to provide a heat-removable adhesive tape that can be used and is easily peeled off without adhesive residue on an adherend because the adhesiveness of the adhesive layer is remarkably reduced when further heated after use in a pressing step.

As a result of diligent studies to achieve the above object, the present inventors have found that a heat-release type pressure-sensitive adhesive tape having a heat-expandable pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component and heat-expandable particles satisfies the following requirements at a high temperature. However, it is suitable for use in the pressing process at room temperature for a long time, and it is very effective for easy peeling and adhesive residue when heated, and for suppressing the foaming of thermally expandable particles during high temperature pressing. I found it.
-The amount of the heat-expandable particles added to the pressure-sensitive adhesive component is within a specific range.
-The maximum expansion temperature of the thermally expandable particles is within a specific range.
-Various parameters in the dynamic viscoelasticity measurement of the adhesive component are in a specific range.
The present inventors have completed the present invention based on such new findings.

That is, the heat-release type pressure-sensitive adhesive tape according to the present invention is a heat-release type pressure-sensitive adhesive tape having a heat-expandable pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component and heat-expandable particles, and the heat-expandable pressure-sensitive adhesive layer is the pressure-sensitive adhesive component. A dynamic viscoelasticity measurement (temperature range) of the pressure-sensitive adhesive component, which contains 4 parts by mass or more of the heat-expandable particles with respect to 100 parts by mass, has a maximum expansion temperature of 170 ° C. or higher, and the heat-expandable particles have a maximum expansion temperature of 170 ° C. or more. At -60 ° C to 300 ° C, heating rate of 10 ° C / min, frequency 10 Hz), (1) tan δ at the maximum expansion temperature of the thermally expandable particles is 0.120 or less, and (2) storage elasticity G at 170 ° C. It is characterized in that'is 30,000 Pa or more.
The method for heat-pressing an adherend according to the present invention is as follows.
A method for heat-pressing an adherend having a temporarily fixed heat-release adhesive tape.
The process of temporarily fixing the above adhesive tape to the adherend, and
A step of heat-pressing the adherend to which the adhesive tape is temporarily fixed, and
A step of heating the adhesive tape temporarily fixed to the heat-pressed adherend to a temperature for peeling, and
A step of peeling the adhesive tape heated to the peeling temperature from the adherend,
It is characterized by having.

The heat-release type adhesive tape according to the present invention has a heat-expandable pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component and heat-expandable particles, the heat-expandable particles have a maximum expansion temperature in a specific range, and the pressure-sensitive adhesive component. Has specific physical properties in dynamic viscoelasticity measurement under specific conditions. Due to the structure and physical properties of these heat-expandable adhesive layers, the foaming of the heat-expandable particles contained in the pressure-sensitive adhesive layer is suppressed during the pressing process at high temperature or at room temperature for a long time, and further heating is performed after the pressing process. As a result, the adhesiveness of the heat-expandable adhesive layer is remarkably reduced, and it is possible to provide a heat-removable adhesive tape in which adhesive residue is less likely to occur on the adherend.

It is sectional drawing in the thickness direction which shows typically an example of the structure of the heat peeling type adhesive tape which concerns on this invention.

The heat-release adhesive tape according to the present invention has at least a heat-expandable adhesive layer.
[Thermal expansion adhesive layer]
The heat-expandable pressure-sensitive adhesive layer contains at least a pressure-sensitive adhesive component for imparting adhesiveness and heat-expandable particles (foaming agent) for imparting heat-expandability.
The heat-expandable pressure-sensitive adhesive layer contains 4 parts by mass or more of heat-expandable particles with respect to 100 parts by mass of the pressure-sensitive adhesive component.
The maximum expansion temperature of the heat-expandable particles is 170 ° C. or higher, and the pressure-sensitive adhesive component is measured in dynamic viscoelasticity (temperature range -60 ° C to 300 ° C., heating rate 10 ° C./min, frequency 10 Hz).
(1) the tan δ at the maximum expansion temperature of the thermally expandable particles satisfies 0.120 or less, and (2) the storage elastic modulus G'at 170 ° C. satisfies 30,000 Pa or more.

The maximum expansion temperature of the heat-expandable particles is a value obtained according to the measurement method described later.
If the maximum expansion temperature of the heat-expandable particles is less than 170 ° C., the following problems may occur.
-The heat-expandable particles expand (foam) during a long-term heat pressing process at a high temperature (for example, 170 ° C.), and the adhesion to the adherend decreases during the process. When the adhesion to the adherend is lowered, for example, in the cleaning process of parts, the cleaning liquid invades the interface between the adherend and the adhesive. In addition, there is a concern that the dimensions of the heat-expandable adhesive layer itself or the dimensions defined by the heat-expandable adhesive layer will change, causing problems in the processing of parts.
When the amount of the heat-expandable particles added to 100 parts by mass of the pressure-sensitive adhesive component is less than 4 parts by mass, the force generated by the expansion of the heat-expandable particles is not sufficient, and the surface of the pressure-sensitive adhesive layer is unlikely to change into an uneven shape. If it is desired to be thermally peeled off after pressing, the effect of reducing the adhesiveness may not be sufficiently obtained.
When the tan δ of the pressure-sensitive adhesive component at the maximum expansion temperature of the heat-expandable particles is higher than 0.120, that is, when the viscosity term of the pressure-sensitive adhesive component is significantly higher than the elastic term, the maximum expansion of the heat-expandable particles causes The generated force is easily dissipated as heat. That is, the surface of the adhesive layer is unlikely to change into an uneven shape due to the force generated by the expansion of the generated heat-expandable particles. As a result, the adhesive force from the adherend is unlikely to be reduced.
If the storage elastic modulus G'of the pressure-sensitive adhesive component at 170 ° C. is less than 30,000 Pa, the heat-expandable particles may foam during pressing at a high temperature for a long time.
Further, when the storage elastic modulus G'of the pressure-sensitive adhesive component is less than 30,000 Pa, the cohesive force of the heat-expandable pressure-sensitive adhesive layer is also weak, so that when the pressure-sensitive adhesive layer is peeled off after use in a high-temperature environment, adhesive remains easily on the adherend.

[Adhesive component]
The pressure-sensitive adhesive component meets the requirements for specific parameters in dynamic viscoelasticity measurements (temperature range −60 ° C. to 300 ° C., heating rate 10 ° C./min, frequency 10 Hz).
That is, the tan δ at the maximum expansion temperature of the heat-expandable particles is 0.120 or less, preferably 0.001 or more and 0.120 or less, more preferably 0.001 or more and 0.110 or less, and particularly preferably 0.001 or more and 0. It is 100 or less.
Further, the storage elastic modulus G'at 170 ° C. is 30,000 Pa or more, preferably 30,000 Pa or more and 1,000,000 Pa or less, more preferably 40,000 Pa or more and 1,000,000 Pa or less, and particularly preferably 50,000 Pa. It is 1,000,000 Pa or less.

The adhesive component has the above-mentioned characteristics from, for example, acrylic adhesive, rubber adhesive, silicone adhesive, polyester adhesive, polyamide adhesive, urethane adhesive, and fluorine adhesive. The pressure-sensitive adhesive can be appropriately selected and used. The pressure-sensitive adhesive can be used alone or in combination of two or more.

In the present invention, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive can be particularly preferably used as the pressure-sensitive adhesive.

The type of the acrylic pressure-sensitive adhesive is not particularly limited, and various known acrylic pressure-sensitive adhesives containing an acrylic copolymer as a main component can be used. As the acrylic copolymer, for example, an acrylic copolymer obtained by copolymerizing a (meth) acrylic acid ester, a carboxyl group-containing monomer, and other monomers if necessary can be used. Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth). Examples thereof include acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, and lauryl (meth) acrylate. Specific examples of the carboxyl group-containing monomer include (meth) acrylic acid, itaconic acid, crotonic acid, (maleic anhydride) maleic acid, fumaric acid, 2-carboxy-1-butene, 2-carboxy-1-pentene, and 2-carboxy. Examples thereof include -1-hexene and 2-carboxy-1-heptene. Specific examples of other monomers include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate, acrylonitrile, styrene, and 2-methylolethylacrylamide. , Vinyl acetate, acryloylmorpholine and the like.

Examples of the acrylic copolymer include a (meth) acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms (A1) and a (meth) acrylic acid having an alkyl group having 1 to 3 carbon atoms. Acrylic polymer (A) having a hydroxyl group and a carboxyl group, which contains an alkyl ester (A2), a carboxyl group-containing monomer (A3), a hydroxyl group-containing monomer (A4) and, if necessary, another monomer (A5) as constituents. ) Is preferable. The components (A1), (A2), (A3), (A4) and (A5) can be used independently of one kind of component or in combination of two or more kinds of components.

Specific examples of the (meth) acrylic acid alkyl ester (A1) having an alkyl group having 4 to 12 carbon atoms include n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Examples thereof include octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, and lauryl (meth) acrylate. Further, as the (meth) acrylic acid alkyl ester monomer (A2) having an alkyl group having 1 to 3 carbon atoms, the number of carbon atoms of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and the like can be increased. A (meth) acrylic acid alkyl ester having 1 to 3 alkyl groups may be used. The sum of the component amounts of the (meth) acrylic acid alkyl ester (A1) and (A2) is preferably 50% by mass or more in 100% by mass of all the constituents (monomer unit) of the acrylic copolymer (A). , More preferably 60% by mass or more, and particularly preferably 70% by mass or more.

Specific examples of the carboxyl group-containing monomer (A3) include (meth) acrylic acid, itaconic acid, crotonic acid, (maleic anhydride), fumaric acid, 2-carboxy-1-butene, 2-carboxy-1-pentene, and the like. Examples thereof include 2-carboxy-1-hexene and 2-carboxy-1-heptene. The blending amount of the carboxyl group-containing monomer (A3) is preferably 0.5 to 15% by mass, more preferably 1 to 1%, based on 100% by mass of all the constituents (monomer units) of the acrylic copolymer (A). It is selected from the range of 12% by mass, particularly preferably 1 to 10% by mass.

Specific examples of the hydroxyl group-containing monomer (A4) include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. The blending amount of the hydroxyl group-containing monomer (A4) is preferably 0.05 to 15% by mass, more preferably 0.07, based on 100% by mass of all the constituents (monomer units) of the acrylic copolymer (A). It is selected from the range of ~ 12% by mass, particularly preferably 0.1 to 10% by mass.

As the other monomer (A5), vinyl acetate and acryloylmorpholine are preferable. When vinyl acetate is added, the blending amount thereof is preferably selected from the range of 0.1 to 10% by mass in 100% by mass of the constituent components (monomer unit) of the acrylic copolymer (A). When acryloylmorpholine is added, the blending amount thereof is selected from the range of 0.1 to 10% by mass, preferably 0.1 to 10% by mass, based on 100% by mass of all the constituents (monomer units) of the acrylic copolymer (A). NS.

The acrylic copolymer (A) may further contain a monomer other than each of the above-exemplified monomers as a constituent component.

As the acrylic pressure-sensitive adhesive, a cross-linking agent having reactivity with the functional group of the acrylic copolymer is generally used. As the cross-linking agent, for example, isocyanate compounds, acid anhydrides, amine compounds, epoxy compounds, metal chelates, aziridine compounds, and melamine compounds can be used. If necessary, one of these cross-linking agents or a combination of two or more thereof can be used.
The amount of the cross-linking agent to be blended is usually in the range of 0.1 to 15 parts by mass, more preferably 0.3 to 12 parts by mass, and particularly preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the acrylic copolymer. Is selected from.

Acrylic adhesives include rosin-based, terpene-based, petroleum-based, kumaron-inden-based, pure monomer-based, phenol-based, xylene-based tackifier resins, mineral oils such as paraffin-based process oils, and polyesters, if necessary. Plasticizers; Softeners containing vegetable oils, etc .; Add at least one of anti-aging agents such as aromatic secondary amines, monophenols, bisphenols, polyphenols, benzimidazoles, rosins, etc. May be good. Further, the saturated hydrocarbon resin may be blended with the acrylic pressure-sensitive adhesive.

The acrylic pressure-sensitive adhesive may further contain at least one of additives such as a silane coupling agent and an antioxidant, if necessary.

As the silane coupling agent, a silane coupling agent containing a glycidyl group is particularly preferable. Specific examples include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. , Tris- (trimethoxysilylpropyl) isocyanurate and the like. One of these may be used, or two or more thereof may be used in combination. The blending amount of the silane coupling agent is preferably 0.01 to 0.5 parts by mass, more preferably 0.02 to 0.5 parts by mass, particularly based on 100 parts by mass of the acrylic copolymer (A). It is preferably selected from the range of 0.03 to 0.3 parts by mass.

As the antioxidant, a hindered phenolic antioxidant is particularly preferable. The blending amount of the antioxidant is preferably selected from the range of 0.01 to 1 part by mass, more preferably 0.02 to 0.7 parts by mass with respect to 100 parts by mass of the acrylic copolymer (A). NS.

In order to satisfy the above parameters with the acrylic pressure-sensitive adhesive, for example, increasing the theoretical Tg of the acrylic copolymer can be mentioned. Since an acrylic copolymer having a high theoretical Tg generally has a high cohesive force between the polymers, the storage elastic modulus G'in a high temperature environment tends to be high. Moreover, since G'in a high temperature environment is high, tan δ in a relatively high temperature environment is also relatively low. The theoretical Tg can be generally calculated by the FOX formula, but the theoretical Tg also increases by increasing the ratio of the (A2) component, the (A3) component, the (A4) component, and the (A5) component in the entire acrylic copolymer. ..
Another method is to increase the weight average molecular weight (Mw) of the acrylic copolymer. When the weight average molecular weight (Mw) is high, the cohesive force between the polymers is generally high and the fluidity is low, so that the storage elastic modulus G'in a high temperature environment is high and the tan δ in a high temperature environment is also low.
Further, it is preferable that the amount of the cross-linking agent added for bonding the acrylic copolymers to each other is large. When the amount of the cross-linking agent added is large, a three-dimensional network is formed more strongly by cross-linking the acrylic copolymers, and as a result, G'is high and tan δ is low even in a high temperature environment.

The type of the rubber-based pressure-sensitive adhesive is not particularly limited, and various known rubber-based pressure-sensitive adhesives containing a rubber component as a main component can be used. Specific examples of the rubber component include butyl rubber, polyisobutylene rubber, isoprene rubber, styrene-isobutylene-styrene block copolymer, styrene-isoprene block copolymer, styrene-butadiene rubber, styrene-isoprene-styrene block copolymer, and the like. Synthetic rubber such as styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-propylene block copolymer; natural rubber Can be mentioned. One kind of rubber component may be used, or two or more kinds of rubber components may be used in combination. Butyl rubber is generally a rubber containing a copolymer of isobutylene and 1 to 3% by mass of isoprene as a main component.

When a rubber-based pressure-sensitive adhesive is used for the pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer preferably contains a saturated hydrocarbon resin together with the rubber-based pressure-sensitive adhesive. The saturated hydrocarbon resin is a hydrocarbon resin having no unsaturated bond, and is a component for improving the adhesiveness of the pressure-sensitive adhesive layer.

The type of saturated hydrocarbon resin is not particularly limited, and for example, various alicyclic or aliphatic saturated hydrocarbon resins known as tackifiers can be used. One kind of saturated hydrocarbon resin may be used, or two or more kinds of saturated hydrocarbon resins may be used in combination. In particular, an alicyclic saturated hydrocarbon resin is preferable, and a hydrocarbon resin whose unsaturated bond is eliminated by hydrogenation treatment is more preferable. Hydrogenated petroleum resin is a commercially available saturated hydrocarbon resin. Hydrogenated petroleum resin is a resin obtained by hydrogenating petroleum resin (for example, aromatic petroleum resin, aliphatic petroleum resin, copolymerized petroleum resin of alicyclic component and aromatic component, etc.). Is. Of these, hydrogenated petroleum resins (alicyclic saturated hydrocarbon resins) obtained by hydrogenating aromatic petroleum resins are preferable. This hydrogenated petroleum resin is available as a commercially available product (for example, Alcon (trade name, registered trademark in Japan) P-100 manufactured by Arakawa Chemical Industry Co., Ltd.). The blending amount of the saturated hydrocarbon resin is preferably selected from the range of 0.01 to 100 parts by mass, more preferably 0.1 to 80 parts by mass with respect to 100 parts by mass of the pressure-sensitive adhesive component. The higher the content of the saturated hydrocarbon resin, the better the adhesiveness.

In order to satisfy the above parameters with a rubber-based pressure-sensitive adhesive, for example, the molecular weight of the rubber component may be increased to increase the cohesive force of the pressure-sensitive adhesive component. Further, even if the rubber component is vulcanized with sulfur or resin to form a stronger three-dimensional network by cross-linking the rubber components, G'in a high temperature environment can be increased and tan δ can be decreased.

Specific examples of the silicone-based pressure-sensitive adhesive used in the present invention include silicone raw rubber (a long-chain polymer of polydimethylsiloxane having a structure composed of _{D unit [(CH 3} ) _{2 SiO]) and MQ resin (M unit). Examples} thereof include a pressure-sensitive adhesive containing [(CH ₃ ) ₃ SiO _1/2 ] and a polymer of a silicone resin having a three-dimensional structure having a structure consisting of a Q unit [SiO 4/2]. Such a pressure-sensitive adhesive containing silicone raw rubber and MQ resin is superior in adhesiveness to silicone raw rubber alone. Further, by changing the ratio of the silicone raw rubber and the MQ resin in the adhesive, it is possible to control the basic adhesive physical properties such as adhesive force, holding force, and tack. Furthermore, the adhesive physical characteristics can be controlled by changing the ratio of the M unit to the Q unit of the MQ resin and changing the molecular weight. Silicone-based adhesives are roughly classified into addition-curing type and peroxide-curing type according to their curing mechanism.

The addition-curable silicone-based pressure-sensitive adhesive contains, for example, a main agent made of a silicone raw rubber containing an alkenyl group, an MQ resin, and a cross-linking agent made of a polyorganosiloxane containing a SiH group. Then, it is cured by heating under a platinum catalyst and causing a cross-linking reaction. The silicone raw rubber containing an alkenyl group is typically a polyorganosiloxane having at least two alkenyl groups (for example, vinyl groups) bonded to a silicon atom in one molecule. The polyorganosiloxane containing a SiH group is typically a polyorganosiloxane having at least two hydrogen atoms bonded to a silicon atom in one molecule.

The peroxide-curable silicone-based pressure-sensitive adhesive contains, for example, a main agent made of silicone raw rubber containing no alkenyl group and an MQ resin. Then, a peroxide such as benzoyl peroxide is added as a curing agent, the solvent is removed, and then the mixture is heated at a high temperature to cure.

The silicone-based pressure-sensitive adhesive may be a blend of two or more types of silicone-based pressure-sensitive adhesives for the purpose of improving various properties. However, it is necessary to appropriately select the type and amount of the silicone-based pressure-sensitive adhesive to be blended so as not to impair the effects of the invention.

Satisfaction of the above pressure-sensitive adhesive parameters with a silicone-based pressure-sensitive adhesive can be achieved, for example, by appropriately adjusting the ratio of silicone rubber and silicone resin. Specifically, the ratio of silicone rubber to silicone resin (based on mass) is preferably in the range of 30/70 to 90/10. When the ratio of the silicone rubber is less than this range, the cohesive force in a high temperature environment tends to be weakened, so that the storage elastic modulus G'is also low and the tan δ is high. On the other hand, if the ratio of silicone rubber is large, it is difficult to develop sufficient initial adhesive force and it is difficult to adhere to the adherend.
Further, in the case of an addition-curable silicone-based adhesive, the bond between the silicone components is controlled by adjusting the alkenyl group content and the amount of the cross-linking agent of the raw silicone rubber, and as a result, the storage elastic modulus G'and tan δ are controlled. It is possible to do. When the alkenyl group content and the amount of the cross-linking agent of the silicone raw rubber are increased, the sufficient storage elastic modulus G'at high temperature tends to increase, and the tan δ tends to decrease.
In the case of a peroxide-curable silicone-based pressure-sensitive adhesive, the storage elastic modulus G'and tan δ can be controlled by the amount of peroxide added. When the amount of peroxide added is increased, the sufficient storage elastic modulus G'at high temperature tends to increase, and tan δ tends to decrease.

Each of the pressure-sensitive adhesives described above may further contain at least one other component, if necessary. Specific examples include solvents such as toluene; additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, conductivity improvers, and thermal conductivity improvers; carbon black, calcium oxide, etc. Examples thereof include fillers or pigments such as magnesium oxide, silica, zinc oxide and titanium oxide.

[Thermal expandable particles]
As the heat-expandable particles, heat-expandable particles having a maximum expansion temperature of 170 ° C. or higher are preferably used. The heat-expandable particles can be used alone or in combination of two or more.
As the heat-expandable particles, known heat-expandable microspheres can be appropriately selected, and microencapsulated heat-expandable particles are preferable. Examples of such thermally expandable particles include those in which a gasifying agent such as a liquid low boiling point hydrocarbon such as isobutane, propane, or pentane is wrapped in a thermoplastic polymer shell (shell). When such heat-expandable particles are heated, the polymer shell softens, and the contained liquid low-boiling-point hydrocarbon gasifies and expands at that pressure. Examples of the material for forming the thermoplastic polymer shell include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethylmethacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone.

Examples of the thermally expandable particles having a maximum expansion temperature of 170 ° C. or higher include the series of the product name "Matsumoto Microsphere" manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd. (for example, "Matsumoto Microsphere FN-180 SSD" as the product name. , "Matsumoto Microsphere FN-180SD", "Matsumoto Microsphere FN-180D", "Matsumoto Microsphere FN-190SD", "Matsumoto Microsphere F-190D", "Matsumoto Microsphere F-260D" ) And other commercially available products can be preferably used.

In order to obtain the desired effect in the present invention, thermally expandable particles having a maximum expansion temperature of 170 ° C. or higher, particularly preferably 180 ° C. or higher and 320 ° C. or lower can be preferably used.

In the present invention, the maximum expansion temperature of the heat-expandable particles can be determined by using a thermal analyzer TMA (TMA7100, manufactured by Hitachi High-Tech Science Corporation). The maximum expansion temperature of the heat-expandable particles was analyzed in a compression mode (load: 0.05 N, heating rate: 10 ° C./min) by placing the heat-expandable particles in a 5 mmφ aluminum pan, covering it with an inner lid. When, it is the temperature at which the expansion of the thermally expandable particles is maximized. For convenience, this temperature was defined as TFmax. When heated to a temperature higher than the maximum expansion temperature, the gas inside the thermally expandable particles permeates the polymer shell, so that the shrinkage generally proceeds without bursting.

In addition, since the adhesive force of the heat-expandable adhesive layer is efficiently and stably reduced by the heat treatment, the heat-expandable particles having a volume expansion coefficient of 5 times or more can be preferably used.

The blending amount of the heat-expandable particles is 4 parts by mass or more, preferably 5 parts by mass or more, more preferably 5 parts by mass or more and less than 100 parts by mass with respect to 100 parts by mass of the resin component contained in the heat-expandable adhesive layer. Particularly preferably, it can be appropriately set from the range of 7 parts by mass or more and less than 80 parts by mass, more preferably 10 parts by mass or more and 50 parts by mass, depending on the desired initial adhesiveness, lowering of peeling force after foaming, and the like. ..

The heat-expandable particles may have reduced foamability when exposed to a high-temperature and high-humidity environment such as a temperature of 65 ° C. and a relative humidity of 80%. Therefore, it is desirable that the heat-removable adhesive tape using the heat-expandable particles should be stored away from a high-temperature and high-humidity environment. Further, in order to maintain the thermal exfoliation property even in a state where the foamability is lowered, the blending amount of the thermally expandable particles is preferably 7 parts by mass or more with respect to 100 parts by mass of the resin component contained in the thermally expandable adhesive layer. ..

The average particle size of the heat-expandable particles can be appropriately selected depending on the thickness of the heat-expandable adhesive layer and the like. The average particle size of the heat-expandable particles having a shape such as a microsphere can be selected from, for example, preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 1 μm or more and 50 μm or less. Thermally expandable particles having a target average particle size can be selected from commercially available products and used. Alternatively, the particle size of the heat-expandable particles may be adjusted in the process of producing the heat-expandable particles, or may be performed by a known method (for example, classification) for commercially available heat-expandable particles. .. In order to obtain the smoothness of the heat-expandable adhesive layer, it is preferable that the particle sizes of the heat-expandable particles are uniform.

The thickness of the heat-expandable adhesive layer is not particularly limited, but can be selected from, for example, preferably in the range of 5 μm to 200 μm, more preferably 10 μm to 150 μm, and particularly preferably 15 μm to 100 μm.

As a method for foaming the heat-expandable particles in the heat-expandable adhesive layer, a known heat-expansion method can be appropriately selected and adopted. Specifically, as the heat treatment for expanding the heat-expandable particles, for example, a heating means such as a hot plate, a hot air dryer, or an infrared heater can be appropriately used. The heating temperature during the heat treatment may be equal to or higher than the foaming start temperature of the heat-expandable particles in the heat-expandable adhesive layer, but the heat treatment conditions are appropriately set depending on the heating means, the material of the adherend, the heat capacity, and the like. can.

[Layer structure of heat-removable adhesive tape]
The layer structure of the heat-removable adhesive tape according to the present invention includes a layer structure consisting of only a heat-expandable adhesive layer having no other layers, and a layer structure consisting of a heat-expandable adhesive layer and other layers. Can be mentioned. The heat-release type adhesive tape composed of only the heat-expandable adhesive layer is a heat-release type adhesive tape having a plurality of different heat-expandable adhesive layers even if it is a heat-release type adhesive tape composed of a single layer of the heat-expandable adhesive layer. There may be.
Examples of other layers used as necessary include a base material, a release liner and the like.
Examples of the form of the heat-release type adhesive tape having at least one of the base material and the release liner include the following forms.
(1) A heat-removable adhesive tape having a heat-expandable adhesive layer on both sides of a base material.
(2) A heat-removable adhesive tape having a heat-expandable adhesive layer on only one side of the base material.
(3) A heat-release type adhesive tape having a heat-expandable adhesive layer on one surface of a base material and a non-heat-expandable adhesive layer (adhesive layer having no thermal expansion) on the other surface.
(4) A heat-release type adhesive tape having a heat-expandable adhesive layer on the release liner.
(5) A heat-release type adhesive tape having a heat-expandable adhesive layer and a non-heat-expandable adhesive layer on a release liner in this order.
When the heat-expandable adhesive layers are formed on both sides of the base material, at least one of the heat-expandable adhesive layers may have the above-mentioned characteristics according to the present invention. The heat-expandable pressure-sensitive adhesive layer and the non-heat-expandable pressure-sensitive adhesive layer, which are different from the heat-expandable pressure-sensitive adhesive layer according to the present invention, may be selected so as to obtain the desired functions and effects of the heat-releaseable pressure-sensitive adhesive tape. Further, in the case of the above-mentioned forms (1) to (3), a release liner may be provided on the heat-expandable adhesive layer or the non-heat-expandable adhesive layer.

[Other layers]
[Base material]
The base material can be used as a member of a heat-removable adhesive tape, for example, as a support for a heat-expandable adhesive layer or the like. The base material is not particularly limited, but known films, non-woven fabrics, foams, cloths, papers, and combinations thereof can be used. A film-like base material that can easily obtain thickness uniformity in the manufacturing process of a thin substrate is preferable. In particular, a resin film having heat resistance required in the usage environment is preferable. Specific examples thereof include polyesters such as polyimide (PI), polyetheretherketone (PEEK), polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyamideimide (PAI), and poly. Examples thereof include resin films such as ether sulfone (PES) and polytetrafluoroethylene (PTFE). These films can be used as a single layer or a laminated film having two or more layers. The laminated film may include one or more combinations of a plurality of layers made of different materials.
As the heat-resistant resin film, a polyimide film having excellent dimensional stability at high temperatures is particularly preferable.
The thickness of the base material is not particularly limited, but can be selected from a range of preferably 1 μm or more and 200 μm or less, more preferably 2 μm or more and 150 μm or less, and particularly preferably 2 μm or more and 125 μm or less.

If necessary, an easy-adhesion treatment may be applied to the surface of the base material on which the pressure-sensitive adhesive layer is provided. Examples of the easy-adhesion treatment include a primer treatment, a corona treatment, an etching treatment, a plasma treatment, and a sandblast treatment. From these, one kind or a combination of two or more kinds can be selected.

If necessary, the base material may be surface-treated such as antistatic. Examples of the antistatic treatment include treatment with an antistatic agent such as a cationic surfactant, an anionic surfactant, and a nonionic surfactant. Further, the base material may be colored by printing, kneading, or the like, if necessary.

[Non-thermally expandable adhesive layer]
The pressure-sensitive adhesive for forming the non-thermally expandable pressure-sensitive adhesive layer is not particularly limited, and the pressure-sensitive adhesive exemplified above in the description of the heat-expandable pressure-sensitive adhesive layer can be similarly used. As the pressure-sensitive adhesive, for example, known pressure-sensitive adhesives such as acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, polyester-based pressure-sensitive adhesive, polyamide-based pressure-sensitive adhesive, and urethane-based pressure-sensitive adhesive can be used. These adhesives can be used alone or in combination of two or more. The non-heat-expandable adhesive layer contains at least one additive such as a tackifier, a coloring pigment, an antioxidant, an antioxidant, an antistatic agent, a cross-linking agent, and a silane coupling agent. May be good.

The thickness of the non-thermally expandable adhesive layer can be selected from, for example, preferably 200 μm or less, more preferably 1 μm or more and 150 μm or less, and particularly preferably 1 μm or more and 100 μm or less. The method for forming the non-thermally expandable adhesive layer is the same as that for the heat-expandable adhesive layer (for example, a method of applying on a base material, a method of applying on a release liner to form an adhesive layer, and then this. Is transferred onto a substrate, etc.).

[Peeling liner]
As the release liner, a known release paper or the like can be used. The release liner is used as a protective material for the heat-expandable adhesive layer, and is peeled off when the heat-release type adhesive sheet is attached to the adherend. Examples of the release liner include a plastic film (for example, PET film) surface-treated with a release agent such as silicone-based, long-chain alkyl-based, and fluorine-based, a base material having a release layer such as paper, and a fluorine-based resin (for example). A low adhesive base material made of a non-polar polymer such as polytetrafluoroethylene) or an olefin resin (for example, polyethylene, polypropylene, etc.) may be used.

An embodiment of a heat-release adhesive tape having a base material and a release liner as other layers will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view in the thickness direction showing an embodiment of the heat-removable adhesive tape according to the present invention. The heat-release type pressure-sensitive adhesive sheet 1 shown in FIG. 1 has a base material 2, a heat-expandable pressure-sensitive adhesive layer 3, and a release liner 4. The two heat-expandable adhesive layers 3 may be the same or different. The two release liners 4 may also be the same release liner or different release liners.

The heat-removable pressure-sensitive adhesive sheet 1 shown in FIG. 1 has the form of a double-sided pressure-sensitive adhesive tape having two heat-expandable pressure-sensitive adhesive layers 3 formed on both sides of the base material 2. In the form of the double-sided adhesive tape, at least one of the two adhesive layers may be the heat-expandable adhesive layer according to the present invention. For example, in the form of a double-sided adhesive tape, at least one of the two adhesive layers 3 is a heat-expandable adhesive layer according to the present invention, and the other is a heat-expandable adhesive layer other than the heat-expandable adhesive layer according to the present invention. It may be a layer or an adhesive layer having no thermal expansion property (non-thermal expansion adhesive layer).

[Manufacturing method of heat-removable adhesive tape]
The heat-release type adhesive tape composed of a heat-expandable adhesive layer is obtained by applying a layer-forming composition material containing a resin component and heat-expandable particles on a base material for forming a heat-expandable pressure-sensitive adhesive layer, and heating the coating layer. It can be produced by peeling the heat-expandable adhesive layer formed by causing a cross-linking reaction from the base material for forming the heat-expandable adhesive layer.
The heat-release type adhesive tape having a heat-expandable adhesive layer on a base material or a release liner as a constituent member of the heat-release type adhesive tape is based on, for example, a layer-forming composition material containing a resin component and heat-expandable particles. It can be produced by applying it on a material or a release liner and causing a cross-linking reaction in the coating layer by heating to form a heat-expandable adhesive layer. Further, a layer-forming composition material containing a resin component and heat-expandable particles is applied onto a release liner (for example, a silicone-treated PET film), and heating causes a cross-linking reaction in the coated layer to cause a cross-linking reaction on one side of the base material. Alternatively, a heat-removable adhesive tape can be formed by transferring to both sides. It is important that the heating temperature for cross-linking is sufficiently lower than the foaming start temperature of the heat-expandable particles. For forming the coating layer, for example, a known coating device such as a roll coater, a die coater, or a lip coater can be used. When heating after coating, the solvent in the layer-forming material can be removed as well as the cross-linking reaction by heating. When the heat-expandable adhesive layer is formed by transfer, it is preferable to laminate with a heated roll or the like in order to improve the adhesion between the base material and the heat-expandable adhesive layer and further obtain the smoothness of the surface.

The heat-removable adhesive tape according to the present invention can be suitably used for heat-pressing an adherend to which the heat-removable adhesive tape is temporarily fixed.
One form of the method of using the heat-removable adhesive tape according to the present invention in the heat pressing treatment of the adherend is
The process of temporarily fixing the adhesive tape having the above configuration to the adherend,
A step of heat-pressing the adherend to which the adhesive tape is temporarily fixed, and
A step of heating the adhesive tape temporarily fixed to the heat-pressed adherend to a temperature for peeling, and
A step of peeling the adhesive tape heated to the peeling temperature from the adherend,
Have.
One form of the heat pressing treatment method for the adherend using such a usage method is
A method for heat-pressing an adherend having a temporarily fixed heat-release adhesive tape.
The process of temporarily fixing the heat-removable adhesive tape having the above configuration to the adherend, and
A step of heat-pressing the adherend to which the adhesive tape is temporarily fixed, and
A step of heating the adhesive tape temporarily fixed to the heat-pressed adherend to a temperature for peeling, and
A step of peeling the adhesive tape heated to the peeling temperature from the adherend,
Have.
The forms of temporary fixing of the heat-removable adhesive tape to the adherend include temporary fixing between the adherends, temporary fixing during transportation of the adherend, reinforcement, protection or masking of the adherend, and temporary fixing to the adherend. Includes resin encapsulation and the like.
Further, as the heat pressing process, a heat pressing process in the manufacturing process of electronic parts / semiconductor parts can be mentioned.
Conditions of the heat pressing step in which the heat-release adhesive tape according to the present invention can be preferably used include a temperature of 120 to 240 ° C., a time of 5 minutes to 10 hours, and a pressure of 5 to 40 kgf / cm ² .

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following description, "part" is a mass part.

<Preparation example of acrylic copolymer>
An acrylic copolymer having the composition shown in Table 1 was polymerized. The compounding ratio of each component in Table 1 shows the ratio when the total of the components A1 to A5 is 100 parts. For reference, the theoretical Tg and weight average molecular weight (Mw) of each acrylic copolymer are also shown in Table 1. The theoretical Tg is a value calculated by the formula of FOX, and can be adjusted by appropriately selecting the composition of the acrylic monomer. The weight average molecular weight (Mw) is a value obtained by measuring the molecular weight of the acrylic copolymer in terms of standard polystyrene by the GPC method with the following measuring devices and conditions.
・ Equipment: LC-2000 series (manufactured by JASCO Corporation)
-Column: Shodex KF-806M x 2, Shodex KF-802 x 1-Eluent: tetrahydrofuran (THF)
・ Flow velocity: 10 mL / min ・ Column temperature: 40 ° C
・ Injection amount: 100 μL
・ Detector: Refractive index meter (RI)
-Measurement sample: A solution in which an acrylic polymer is dissolved in THF to prepare a solution having an acrylic polymer concentration of 0.5% by mass, and dust is removed by filtration through a filter.
The weight average molecular weight (Mw) is the type and amount of the polymerization initiator (for example, 0.1 part by mass of lauryl peroxide with respect to 100 parts by mass of the acrylic monomer) and the type of chain transfer agent when polymerizing the acrylic copolymer. It can be adjusted by appropriately selecting the amount (for example, 0.1 part by mass of n-dodecanethiol with respect to 100 parts by mass of the acrylic monomer), the polymerization initiation concentration (for example, 50% by mass), and the like.

The abbreviations in Table 1 indicate the following compounds.
"2-EHA": 2-ethylhexyl acrylate "BA": n-butyl acrylate "MA": methyl acrylate "EA": ethyl acrylate "AA": acrylic acid "4-HBA": 4-hydroxybutyl acrylate "2-" HEA ": 2-Hydroxyethyl acrylate" VAc ": Vinyl acetate" ACMO ": Acryloylmorpholin

<Examples 1 to 12 and Comparative Examples 1 to 8: Preparation of heat-removable acrylic adhesive tape>
As shown in Table 2, a cross-linking agent (component B), an antioxidant (component C), and a silane coupling agent (component) are used with respect to 100 parts of the solid content of the acrylic copolymer (component A) obtained in Table 1. D) and toluene (diluting solvent) were mixed at a predetermined compounding ratio (mass basis) to obtain a pressure-sensitive adhesive composition. Further, a foaming agent (component F) was mixed with 100 parts of the pressure-sensitive adhesive component at the blending ratio (mass basis) shown in Table 2 to prepare a heat-expandable pressure-sensitive adhesive composition.

This heat-expandable pressure-sensitive adhesive composition was applied onto a PET film having a thickness of 50 μm that had been subjected to a silicone mold release treatment. Next, the diluting solvent was removed and dried at 90 to 100 ° C., and a cross-linking reaction was carried out to form a heat-expandable pressure-sensitive adhesive layer. This heat-expandable pressure-sensitive adhesive layer was bonded to both sides of a polyimide film having a thickness of 12 μm and transferred. Further, laminating was performed at a temperature of 100 ° C. using a tabletop laminating machine. Then, it was cured at 40 ° C. for 3 days to obtain a double-sided heat-peeling type adhesive tape.
The heat-expandable pressure-sensitive adhesive composition was applied so that the thickness of the pressure-sensitive adhesive layer on one side after lamination was 50 μm. The thickness of the obtained double-sided adhesive tape is 112 μm.

The abbreviations in Table 2 indicate the following components.
"B1": Epoxy-based cross-linking agent (manufactured by Soken Chemical Co., Ltd., trade name E-5XM, solid content concentration 5%)
"B2": Isocyanate-based cross-linking agent (manufactured by Tosoh Corporation, trade name Coronate L-45E, solid content concentration 45%)
"C1": Antioxidant (manufactured by BASF, trade name Irganox 1010)
"D1": Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403, solid content concentration 10%)
"F1": Thermally expandable microcapsules (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., trade name Matsumoto Microsphere FN-180 SSD, maximum expansion temperature 192 ° C)
"F2": Thermally expandable microcapsules (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., trade name Matsumoto Microsphere FN-100 SSD, maximum expansion temperature 162 ° C)

<Example 13: Preparation of heat-removable silicone-based adhesive tape>
First, two types of prototypes (I and II) of an addition-curable silicone-based pressure-sensitive adhesive stock solution were prepared. In these prototypes, the storage elastic modulus G after curing is measured by the method described later by appropriately changing the mixing ratio of MQ resin to the raw silicone rubber, the MQ resin type, the amount of the alkenyl group of the raw silicone rubber, and the amount of the cross-linking agent. ', This is a prototype of a pressure-sensitive adhesive adjusted so that tan δ shows various values. In Example 13, of these prototypes, an addition-curable silicone-based pressure-sensitive adhesive having a storage elastic modulus G'at 170 ° C. of 125,770 Pa and a tan δ of 0.053 at the maximum expansion temperature of the heat-expandable particles F1. The undiluted solution (I) was selected.
100 parts of additive-curing silicone adhesive stock solution (I) with a solid content concentration of 50% by mass, 25 parts of toluene as a diluting solvent, and platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 1.25 as a curing catalyst. A silicone-based pressure-sensitive adhesive composition containing a portion was prepared. Further, 15 parts of heat-expandable microcapsules F1 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., trade name Matsumoto Microsphere FN-180 SSD, maximum expansion temperature 192 ° C.) were mixed as a foaming agent to prepare a heat-expandable pressure-sensitive adhesive composition.

This heat-expandable pressure-sensitive adhesive composition is applied to one side of a primer-treated polyimide (PI) film having a thickness of 50 μm so that the thickness of the pressure-sensitive adhesive layer after drying is 50 μm, and is placed in a drying furnace. It was dried at 120 ° C. for 2 minutes to remove the solvent and heat-cured to form a heat-expandable pressure-sensitive adhesive layer. Then, as a release liner, a polyethylene terephthalate (PET) film having a thickness of 50 μm treated with a fluorine-substituted alkyl-modified silicone resin was attached to an adhesive layer to obtain a heat-release type single-sided adhesive tape.

<Comparative Example 9: Fabrication of Heat-Removable Silicone Adhesive Tape>
In Comparative Example 9, an addition-curable silicone-based pressure-sensitive adhesive stock solution (II) having a storage elastic modulus G'at 170 ° C. of 39,749 Pa and a tan δ of 0.532 at the maximum expansion temperature of the heat-expandable particles F1 was selected. ..
100 parts of additive-curing silicone adhesive stock solution (II) with a solid content concentration of 50% by mass, 25 parts of toluene as a diluting solvent, and platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 1.25 as a curing catalyst. A silicone-based pressure-sensitive adhesive composition containing a portion was prepared. Further, 15 parts of heat-expandable microcapsules F1 (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., trade name Matsumoto Microsphere FN-180 SSD, maximum expansion temperature 192 ° C.) were mixed as a foaming agent to prepare a heat-expandable pressure-sensitive adhesive composition. A heat-peeling type single-sided adhesive tape was obtained in the same manner as in Example 13 except for the above.

The heat-removable adhesive tapes obtained in Examples 1 to 13 and Comparative Examples 1 to 9 were evaluated by the following methods. The results are shown in Tables 3-1 to 3-4.

(A) [Dynamic viscoelasticity measurement of adhesive composition]
Regarding the acrylic pressure-sensitive adhesive composition, from the formulation shown in Table 2, the solid content of the acrylic copolymer (A) obtained in Table 1 was 100 parts without containing the heat-expandable microcapsules (F). Then, the cross-linking agent (B), the antioxidant (C), and the silane coupling agent (D) were added and mixed to prepare a pressure-sensitive adhesive composition for preparing a sample for measurement.
Regarding the silicone-based pressure-sensitive adhesive composition, a pressure-sensitive adhesive composition for preparing a sample for measurement was prepared in the same manner as in Example 13 and Comparative Example 9 except that the heat-expandable microcapsules (F) were not contained.

Each pressure-sensitive adhesive composition as a sample for measurement is used independently, and in the case of an acrylic pressure-sensitive adhesive composition, the thickness after drying is 50 μm on a PET film having a thickness of 50 μm that has been subjected to silicone mold release treatment. Was applied to. Next, the solvent was removed and dried at 90 to 100 ° C., and a cross-linking reaction was carried out to form a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layers were laminated to form a laminate having a thickness of 2 mm, which was further cured at 40 ° C. for 3 days to prepare a sample for measurement. In the case of the silicone-based pressure-sensitive adhesive composition, it was applied on a polyethylene terephthalate (PET) film having a thickness of 50 μm, which had been mold-released with a fluorine-substituted alkyl-modified silicone resin, so as to have a thickness of 50 μm after drying. Then, it was dried in a drying oven at 120 ° C. for 2 minutes to remove the solvent, and heat-cured to form a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layers were laminated to form a laminated body having a thickness of 2 mm, which was used as a measurement sample.

A sample for measurement is sandwiched between parallel disks (φ8 mm), and a temperature rise rate of 10 ° C./min is applied using a dynamic viscoelasticity measuring device (manufactured by Rheometric Scientific, device name RDAIII) while applying shear strain at a frequency of 10 Hz. Then, the storage elastic modulus (G') and the loss elastic modulus (G ″) are measured in the range of −50 ° C. to 300 ° C.
From the storage elastic modulus (G') and the loss elastic modulus (G "), the loss tangent tan δ is calculated by the following formula.
tan δ = modulus of loss (G ”) / modulus of storage (G ′)
Table 3-1 shows the measured values of the storage elastic modulus (G') at 23 ° C. and 170 ° C. and tan δ at the maximum expansion temperature TFmax ° C.

(B) Measurement of TFmax The maximum expansion temperature (TFmax) of the thermally expandable particles was measured by the method described above.

[Evaluation of acrylic double-sided heat-removable adhesive tape]
(C) [Initial peeling force of copper foil, initial peeling force of heat-peeling adhesive tape against copper plate]
The samples (double-sided adhesive tape) according to Examples 1 to 12 and Comparative Examples 1 to 8 cut into a width of 10 mm and a length of 90 mm are subjected to a copper plate having a thickness of 0.7 mm, a width of 25 mm, and a length of 125 mm (assuming a transport plate). ) And the glossy surface of a copper foil having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm (assuming a substrate product, an electrolytic copper foil manufactured by Fukuda Metal Co., Ltd.), and these were bonded together. A roller coated with a rubber layer weighing 2 kg was reciprocated once at a speed of 300 mm / min for crimping, and left to stand in an environment of 23 ° C. for 20 to 40 minutes. Then, using a tensile tester, the force required to peel the copper foil from the tape was measured at an angle of 90 ° at a speed of 300 mm / min in an environment of 23 ° C. Then, a tensile tester was used to measure the force required to peel the tape from the copper plate at a speed of 300 mm / min at an angle of 90 °.

(D) [Peeling force of copper foil when heat peeling treatment, peeling force of heat peeling type adhesive tape against copper plate]
The samples (double-sided adhesive tape) according to Examples 1 to 12 and Comparative Examples 1 to 8 cut into a width of 10 mm and a length of 90 mm are subjected to a copper plate having a thickness of 0.7 mm, a width of 25 mm, and a length of 125 mm (assuming a transport plate). ) And a thickness of 35 μm, a width of 10 mm, and a length of 90 mm (assuming a substrate product), and these were bonded together. A roller coated with a rubber layer weighing 2 kg was reciprocated once at a speed of 300 mm / min for crimping, and then heated in a dryer at 200 ° C. for 3 minutes. After allowing to cool at 23 ° C. for 1 hour or more, the force required to peel the copper foil from the tape at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the glue on the adherend was measured. The presence or absence of the residue was visually confirmed. Next, the force required to peel the tape from the copper plate was measured at a speed of 300 mm / min at an angle of 90 ° using a tensile tester, and the presence or absence of adhesive residue on the adherend was visually confirmed.

The peeling force and adhesive residue after the heat peeling treatment were judged according to the following criteria.
(Copper foil peeling force when heat peeling treatment)
A: The peeling force was spontaneously peeled off during heating, or the peeling force was less than 20% of the initial peeling force (good).
B: The peeling force was 20% or more of the initial peeling force (defective).
(Remaining adhesiveness of copper foil when heat-peeled)
A: There was no adhesive residue (good).
B: There was adhesive residue (defective).
(Peeling force of heat-peeling adhesive tape against copper plate when heat-peeling treatment)
A: The peeling force was spontaneously peeled off during heating, or the peeling force was less than 20% of the initial peeling force (good).
B: The peeling force was 20% or more of the initial peeling force (defective).
(Remaining adhesiveness of copper plate when heat-peeled)
A: There was no adhesive residue (good).
B: There was adhesive residue (defective).

(E) [Suppression of foaming during high-temperature long-time pressing]
With respect to Examples 1 to 12 and Comparative Examples 2, 3, 7, and 8 which were good in the evaluation of (d) above (all were evaluated as A), the suppression of foaming during high-temperature long-time pressing was evaluated as follows. bottom.
The samples (double-sided adhesive tape) according to Examples 1 to 12 and Comparative Examples 2, 3, 7, and 8 cut into a width of 10 mm and a length of 90 mm were subjected to a copper plate having a thickness of 0.7 mm, a width of 25 mm, and a length of 125 mm. It was placed between a transport plate) and a copper foil having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm (assuming a substrate product), and these were bonded together. After crimping by reciprocating once at a speed of 300 mm / min with a roller coated with a rubber layer weighing 2 kg, the temperature is 170 ° C. and the pressure applied to the entire test piece is 26 kg / cm ^{2 using a heating press.} Pressurized for 1 hour. At this time, in order to apply pressure uniformly, a silicone rubber sheet (IS-825, hardness 50 °, manufactured by Irumagawa Rubber Co., Ltd.) having a thickness of 1 mm, a width of 25 mm, and a length of 125 mm was laid under the copper plate, and the width was 10 mm. The same silicone rubber sheet cut to a length of 90 mm was placed on a test piece, sandwiched and pressed. After allowing to cool at 23 ° C. for 1 hour or more, the tape was peeled off from the copper foil and the copper plate, the presence or absence of foaming was visually confirmed, and the obtained results were evaluated according to the following criteria.
A: The heat-expandable adhesive layer did not foam during the hot press (good).
B: The heat-expandable adhesive layer foamed during hot pressing (defective).

(F) [Peeling force of copper foil when heat-peeling treatment after high-temperature long-time pressing, peeling force of heat-peeling adhesive tape against copper plate]
Compared to the examples and comparative examples that were good in the evaluation of (e) above, the peeling force of the copper foil when heat-peeling treatment was performed after pressing at a high temperature for a long time, and the heat-peeling adhesive tape on the copper plate. The peeling force was evaluated as follows.
The samples (double-sided adhesive tape) described in Examples 1 to 12 and Comparative Example 2 cut into a width of 10 mm and a length of 90 mm were used as a copper plate (assuming a transport plate) having a thickness of 0.7 mm, a width of 25 mm, and a length of 125 mm. It was placed between copper foils (assuming a substrate product) having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm, and these were bonded together. A roller coated with a rubber layer weighing 2 kg reciprocates once at a speed of 300 mm / min for crimping, and then using a heating press machine, the temperature is 170 ° C. and the pressure applied to the entire test piece is 26 kg / cm ^2. Pressurized for 1 hour. At this time, in order to apply pressure uniformly, a silicone rubber sheet (IS-825, hardness 50 °, manufactured by Irumagawa Rubber Co., Ltd.) having a thickness of 1 mm, a width of 50 mm, and a length of 125 mm was laid under the copper plate, and the width was 10 mm. The same silicone rubber sheet cut to a length of 90 mm was placed on a test piece, sandwiched and pressed. After allowing to cool at 23 ° C. for 1 hour or more, the mixture was further heated in a dryer at 200 ° C. for 3 minutes. After allowing to cool at 23 ° C. for 1 hour or more, the force required to peel the copper foil from the tape at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the glue on the adherend was measured. The presence or absence of the residue was visually confirmed. Next, the force required to peel the tape from the copper plate at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the presence or absence of adhesive residue on the adherend was visually confirmed.

The peeling of the copper foil and the peeling of the tape against the copper plate were evaluated according to the following criteria.
(Copper foil peeling force when heat peeling treatment)
A: The peeling force was spontaneously peeled off during heating, or the peeling force was less than 20% of the initial peeling force (good).
B: The peeling force was 20% or more of the initial peeling force (defective).
(Remaining adhesiveness of copper foil when heat-peeled)
A: There was no adhesive residue (good).
B: There was adhesive residue (defective).
(Peeling force of heat-peeling adhesive tape against copper plate when heat-peeling treatment)
A: The peeling force was spontaneously peeled off during heating, or the peeling force was less than 20% of the initial peeling force (good).
B: The peeling force was 20% or more of the initial peeling force (defective).
(Remaining adhesiveness of copper plate when heat-peeled)
A: There was no adhesive residue (good).
B: There was adhesive residue (defective).

[Evaluation of silicone-based heat-release type single-sided adhesive tape]
(G) [Initial peeling force of copper foil]
The samples described in Example 13 and Comparative Example 9 cut into a width of 10 mm and a length of 90 mm (single-sided adhesive tape, assuming reinforcement during transportation) were subjected to a glossy surface of a copper foil having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm. It was attached to (assuming a substrate product, electrolytic copper foil manufactured by Fukuda Metal Co., Ltd.). A roller coated with a rubber layer weighing 2 kg was reciprocated once at a speed of 300 mm / min for crimping, and left to stand in an environment of 23 ° C. for 20 to 40 minutes. Then, using a tensile tester, the force required to peel the copper foil from the tape was measured at an angle of 90 ° at a speed of 300 mm / min in an environment of 23 ° C. At this time, the base material side of the single-sided adhesive tape was fixed to the SUS plate with a paper double-sided adhesive tape (No. 778 manufactured by Teraoka Seisakusho Co., Ltd.) for measurement.

(H) [Peeling force of copper foil when heat peeling treatment]
The samples described in Example 13 and Comparative Example 9 cut into a width of 10 mm and a length of 90 mm (single-sided adhesive tape, assuming reinforcement during transportation) were subjected to a glossy surface of a copper foil having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm. It was attached to (assuming a substrate product, electrolytic copper foil manufactured by Fukuda Metal Co., Ltd.). A roller coated with a rubber layer weighing 2 kg was reciprocated once at a speed of 300 mm / min for crimping, and then heated in a dryer at 200 ° C. for 3 minutes. After allowing to cool at 23 ° C for 1 hour or more, the force required to peel the copper foil from the tape at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the adhesive residue on the adherend was measured. The presence or absence of was visually confirmed. Next, the force required to peel the tape from the copper plate at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the presence or absence of adhesive residue on the adherend was visually confirmed. At this time, the base material side of the single-sided adhesive tape was fixed to the SUS plate with a paper double-sided adhesive tape (No. 778 manufactured by Teraoka Seisakusho Co., Ltd.) for measurement.

The peeling force and adhesive residue after the heat peeling treatment were judged according to the following criteria.
(Copper foil peeling force when heat peeling treatment)
A: The peeling force was spontaneously peeled off during heating, or the peeling force was less than 20% of the initial peeling force (good).
B: The peeling force was 20% or more of the initial peeling force (defective).
(Remaining adhesiveness of copper foil when heat-peeled)
A: There was no adhesive residue (good).
B: There was adhesive residue (defective).

(I) [Suppression of foaming during high-temperature long-time pressing]
With respect to the example in which the evaluation of (h) was good (all were evaluated as A), the suppression of foaming during high temperature and long-time pressing was evaluated as follows.
The sample according to Example 13 cut into a width of 10 mm and a length of 90 mm (single-sided adhesive tape, assuming reinforcement during transportation) is subjected to a glossy surface of a copper foil having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm (a substrate product). Assumed, it was attached to an electrolytic copper foil manufactured by Fukuda Metal Co., Ltd.). A roller coated with a rubber layer weighing 2 kg reciprocates once at a speed of 300 mm / min for crimping, and then using a heating press machine, the temperature is 170 ° C. and the pressure applied to the entire test piece is 26 kg / cm ^2. Pressurized for 1 hour. At this time, in order to apply pressure uniformly, a silicone rubber sheet (IS-825, hardness 50 °) having a thickness of 1 mm, a width of 25 mm and a length of 125 mm is placed under a copper plate having a thickness of 0.7 mm, a width of 25 mm and a length of 125 mm. , Made by Irumagawa Rubber Co., Ltd.), and the same silicone rubber sheet cut to a width of 10 mm and a length of 90 mm was placed on a test piece, sandwiched and pressed. After allowing to cool at 23 ° C. for 1 hour or more, the tape was peeled off from the copper foil and the copper plate, the presence or absence of foaming was visually confirmed, and the obtained results were evaluated according to the following criteria.
A: The heat-expandable adhesive layer did not foam during the hot press (good).
B: The heat-expandable adhesive layer foamed during hot pressing (defective).

(J) [Peeling force of copper foil when heat peeling treatment is performed after pressing at high temperature for a long time]
With respect to the example (evaluation A) which was good in the evaluation of (h) above, the peeling force of the copper foil when heat peeling treatment was performed after pressing at a high temperature for a long time was evaluated as follows.
The sample according to Example 13 cut into a width of 10 mm and a length of 90 mm (single-sided adhesive tape, assuming reinforcement during transportation) is subjected to a glossy surface of a copper foil having a thickness of 35 μm, a width of 10 mm, and a length of 90 mm (a substrate product). Assumed, it was attached to an electrolytic copper foil manufactured by Fukuda Metal Co., Ltd.). A roller coated with a rubber layer weighing 2 kg reciprocates once at a speed of 300 mm / min for crimping, and then using a heating press machine, the temperature is 170 ° C. and the pressure applied to the entire test piece is 26 kg / cm ^2. Pressurized for 1 hour. At this time, in order to apply pressure uniformly, a silicone rubber sheet (IS-825, hardness 50 °) having a thickness of 1 mm, a width of 25 mm and a length of 125 mm is placed under a copper plate having a thickness of 0.7 mm, a width of 25 mm and a length of 125 mm. , Made by Irumagawa Rubber Co., Ltd.), and the same silicone rubber sheet cut to a width of 10 mm and a length of 90 mm was placed on a test piece, sandwiched and pressed. After allowing to cool at 23 ° C. for 1 hour or more, the mixture was further heated in a dryer at 200 ° C. for 3 minutes. After allowing to cool at 23 ° C. for 1 hour or more, the force required to peel the copper foil from the tape at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the glue on the adherend was measured. The presence or absence of the residue was visually confirmed. Next, the force required to peel the tape from the copper plate at an angle of 90 ° at a speed of 300 mm / min was measured using a tensile tester, and the presence or absence of adhesive residue on the adherend was visually confirmed. At this time, the base material side of the single-sided adhesive tape was fixed to the SUS plate with a paper double-sided adhesive tape (No. 778 manufactured by Teraoka Seisakusho Co., Ltd.) for measurement.

The peeling of the copper foil was evaluated according to the following criteria.
(Copper foil peeling force when heat peeling treatment)
A: The peeling force was spontaneously peeled off during heating, or the peeling force was less than 20% of the initial peeling force (good).
B: The peeling force was 20% or more of the initial peeling force (defective).
(Remaining adhesiveness of copper foil when heat-peeled)
A: There was no adhesive residue (good).
B: There was adhesive residue (defective).

[Evaluation results]
As is clear from the evaluation results in Tables 3-2 to 3-4, in Examples 1 to 13 that satisfy the requirements of the present invention, further heat peeling treatment is performed even after undergoing a high-temperature and long-time hot pressing step. It was easy to peel off, and good results were obtained with less adhesive residue on the adherend. Furthermore, the foaming of the heat-expandable particles was suppressed even during the hot press.

In Comparative Example 1, since the heat-expandable particles were not contained in the first place, they were not easily peeled off even by the heat peeling treatment.
In Comparative Example 2, if the heat press treatment was not performed, the heat peeling treatment was performed to make the peeling easy. However, since the amount of the foaming agent added to the pressure-sensitive adhesive component is less than 4 parts, the peeling force against the copper foil assuming the substrate product member is sufficiently reduced when the heat peeling treatment is performed after hot pressing at a high temperature for a long time. The effect was not obtained.

In Comparative Example 3, if the heat press treatment was not performed, the heat peeling treatment was performed to make the peeling easy. On the other hand, since the maximum expansion temperature of the heat-expandable particles is less than 170 ° C., the expansion of the heat-expandable particles could not be suppressed during a hot press at a high temperature for a long time.

In Comparative Examples 4 to 6 and Comparative Example 9, since the tan δ of the pressure-sensitive adhesive component at the maximum expansion temperature of the heat-expandable particles is higher than 0.120, after the heat peeling treatment without pressing at a high temperature for a long time. It did not peel off easily.

In Comparative Examples 7 to 8, the tan δ of the pressure-sensitive adhesive component at the maximum expansion temperature of the heat-expandable particles is lower than 0.120. do. However, since the storage elastic modulus G'at 170 ° C. is lower than 30,000 Pa, the expansion of the thermally expandable particles could not be suppressed during the hot pressing at a high temperature for a long time.

For example, Patent Document 6 defines the range of the storage elastic modulus G'of the heat-expandable adhesive layer at a relatively low temperature such as 23 ° C. or 95 ° C., and there is a possibility that it can be preferably used in that range. However, as is clear from the above evaluation results shown in Tables 3-2 to 3-4, even if the storage elastic modulus G'at room temperature is high, the storage elastic modulus at high temperature (for example, 170 ° C.) is not necessarily G. 'Is not always high. Therefore, in the technique disclosed in Patent Document 6, the position is less likely to shift in the pressing process at room temperature for a short time (for example, room temperature, 3 MPa, 3 seconds, 100 times as in the examples), and further heating is easy. Although it is considered to be suitable for applications such as peeling, it is necessary to satisfy each parameter specified in the present invention when it is used in a high temperature and long time pressing process. Further, Examples 1 to 3 described in Patent Document 6 are low-temperature expansion type heat-expandable particles (according to the examples in the specification of Patent Document 6, firing is started at 120 ° C. and foam peeling is performed at 130 ° C. ) Is used, and it can be assumed that the foaming of the heat-expandable particles cannot be suppressed when the heat press treatment is performed at a high temperature (for example, 170 ° C.).

The heat-removable adhesive tape of the present invention is usefully used in manufacturing processes of electronic parts and semiconductor parts, for example, in processes requiring high-temperature heating such as temporary fixing of parts, fixing during transportation, reinforcement, protection, masking, and resin sealing. can. In particular, it is very useful in a process such as a curing process of a sealing resin, which requires easy peeling without adhesive residue after a high-temperature and long-time pressing process.

Claims (13)

A heat-release adhesive tape having a heat-expandable pressure-sensitive adhesive layer containing a pressure-sensitive adhesive component and heat-expandable particles.
The heat-expandable adhesive layer contains 4 parts by mass or more of the heat-expandable particles with respect to 100 parts by mass of the pressure-sensitive adhesive component.
The maximum expansion temperature of the thermally expandable particles is 170 ° C. or higher.
In the dynamic viscoelasticity measurement of the pressure-sensitive adhesive component (temperature range -60 ° C to 300 ° C, heating rate 10 ° C / min, frequency 10 Hz), (1) tan δ at the maximum expansion temperature of the heat-expandable particles is 0.120. Below, and (2) the storage elastic modulus G'at 170 ° C. is 30,000 Pa or more, and
A heat-removable adhesive tape characterized in that the pressure-sensitive adhesive component is a urethane-based pressure-sensitive adhesive. The heat-release type adhesive tape according to claim 1, wherein the heat-expandable particles are contained in an amount of 5 parts by mass or more with respect to 100 parts by mass of a resin component contained in the heat-expandable adhesive layer. The heat-release type adhesive tape according to claim 1, wherein the heat-expandable particles are contained in a ratio of 7 parts by mass or more and less than 80 parts by mass with respect to 100 parts by mass of the resin component contained in the heat-expandable adhesive layer. The heat-removable adhesive tape according to claim 1, wherein the maximum thermal expansion temperature of the heat-expandable particles is 180 ° C. or higher and 320 ° C. or lower. The heat-removable adhesive tape according to claim 1, wherein the tan δ is 0.001 or more and 0.110 or less, and the storage elastic modulus G'is 40,000 Pa or more and 1,000,000 Pa or less. The heat-removable adhesive tape according to claim 1, wherein the heat-expandable adhesive layer is provided on at least one side of the base material. The heat-removable adhesive tape according to claim 1, which has the heat-expandable adhesive layer on both sides of the base material. The heat-removable adhesive tape according to claim 6 or 7, wherein the base material is a resin film. The heat-removable adhesive tape according to claim 8, wherein the base material is a polyimide film. The heat-removable adhesive tape according to claim 1, which is used for temporarily fixing the adherend to the adherend in the heat pressing step. The hot pressing step includes a hot pressing step of a temperature of 120 to 240 ° C., a time of 5 minutes to 10 hours, and a pressure of 5 to 40 kgf / cm ² , and is heated from the adherend by heating for peeling after the hot pressing step. The heat-removable adhesive tape according to claim 10, wherein the peeling force is remarkably reduced. It is a method of using the heat-release type adhesive tape in the heat pressing process of the adherend.
The step of temporarily fixing the heat-removable adhesive tape according to claim 1 to the adherend, and
A step of heat-pressing the adherend to which the adhesive tape is temporarily fixed, and
A step of heating the heat-release type adhesive tape temporarily fixed to the heat-pressed adherend to a temperature for peeling, and
A step of peeling the heat-peeling type adhesive tape heated to the peeling temperature from the adherend,
A method of using a heat-removable adhesive tape, which comprises. The method for using a heat-release adhesive tape according to claim 12, wherein the heat-pressing step includes a heat-pressing step at a temperature of 120 to 240 ° C., a time of 5 minutes to 10 hours, and a pressure of 5 to 40 kgf / cm ^2.

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