Silicone-based graft copolymer, pressure-sensitive adhesive composition, pressure-sensitive adhesive tape, and method for manufacturing semiconductor device

Abstract

A purpose of the present invention is to provide a silicone-based graft copolymer able to form a pressure-sensitive adhesive layer which is unlikely to delaminate even if subjected to a high temperature heat treatment and which can increase adhesion and suppress contamination of an adherend. Another purpose of the present invention is to provide: a pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape that contain the silicone-based graft copolymer; and a method for producing a semiconductor device. The present invention is a silicone-based graft copolymer which has a structure derived from a polar functional group-containing monomer and a structure derived from a silicone macromonomer, has a glass transition temperature, as measured using differential scanning calorimetric measurements, of 30ºC or lower, and has a 5% weight loss temperature, as measured at a temperature increase rate of 10ºC / min using a device for simultaneously measuring differential heat and thermogravimetric weight, of 300ºC or higher.

Description

[Technical Field]

[0001] The present invention relates to a silicone graft copolymer, a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape each containing the silicone graft copolymer, and a method for producing a semiconductor device. [Background technology]

[0002] In recent years, adhesive tapes have been used in various industrial fields. In the construction field, double-sided adhesive tapes are used for temporary fixing of protective sheets and bonding of interior materials, in the automotive field for fixing interior components such as seats and sensors, and for fixing exterior components such as side moldings and side visors, and in the electrical and electronic field for assembling modules and bonding modules to housings. Specifically, double-sided adhesive tapes are used for assembly in, for example, portable electronic devices (e.g., mobile phones, personal digital assistants, etc.) equipped with image display devices or input devices. More specifically, double-sided adhesive tapes are used for bonding cover panels for protecting the surfaces of portable electronic devices to touch panel modules or display panel modules, or for bonding touch panel modules to display panel modules. Such double-sided adhesive tapes are punched into shapes such as picture frames and placed around display screens (e.g., Patent Documents 1 and 2). Double-sided adhesive tapes are also used for fixing vehicle components (e.g., in-vehicle panels) to vehicle bodies. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-242541 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-258274 Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the application of the adhesive tape, it may be necessary to perform a high-temperature heat treatment process while the adhesive tape is attached to the adherend, and then peel the adhesive tape off. For example, in the manufacturing process of semiconductor chips, various high-temperature heat treatment processes are performed while a semiconductor wafer is adhered to a support plate and reinforced with a double-sided adhesive tape, and then the semiconductor wafer is peeled off from the support plate. Here, if the adhesive tape is over-adhered by the high-temperature heat treatment process, it may become difficult to peel the semiconductor wafer from the support plate, or adhesive may remain on the surface of the semiconductor wafer during peeling. To address this, a silicone compound is blended into the adhesive layer as a peeling aid. By blending a silicone compound, over-adhesion can be prevented by the silicone compound bleed-out from the adhesive layer.

[0005] However, conventional silicone compounds may have difficulty in sufficiently suppressing adhesion enhancement depending on the type of adherend. Conventional silicone compounds have low polarity and therefore low affinity with highly polar substances. Therefore, when the adherend is highly polar, such as a semiconductor wafer, the silicone compound that bleeds out onto the adhesive tape surface cannot remain on the surface and diffuses from the interface with the adherend. This reduces the amount of silicone compound present at the interface between the adhesive tape and the adherend, making it difficult to sufficiently suppress adhesion enhancement. In particular, when a heat treatment process at 200°C or higher is involved, the silicone compound becomes more mobile due to heat, which makes it more likely for the silicone compound to separate from the interface with the adherend, resulting in increased adhesion enhancement. Furthermore, silicone compounds that bleed out onto the surface of the adhesive tape may contaminate the adherend, and if the adherend, such as a semiconductor wafer, is contaminated after the adhesive tape has been peeled off, problems may arise when the adherend is subjected to a subsequent manufacturing process. Therefore, it is required that the silicone compound that bleeds out onto the surface of the adhesive tape remains at the interface with the adherend, sufficiently suppressing adhesion enhancement, while not contaminating the adherend.

[0006] Furthermore, while adhesive tapes need to suppress increased adhesion, they also need to have high adhesive strength when applied (hereinafter, the adhesive strength when applied is referred to as initial adhesive strength) and not peel off even when subjected to a high-temperature heat treatment process. However, for the reasons mentioned above, conventional silicone compounds cannot suppress increased adhesion unless they are used in large quantities, and there is also the problem that using a large amount of silicone compound reduces the initial adhesive strength and causes the adhesive tape to peel off when subjected to a high-temperature heat treatment process.

[0007] In view of the above-mentioned current situation, an object of the present invention is to provide a silicone-based graft copolymer capable of forming a pressure-sensitive adhesive layer that is resistant to peeling even when subjected to a high-temperature heat treatment step, and that can enhance adhesion and suppress contamination of the adherend. Another object of the present invention is to provide a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape containing the silicone-based graft copolymer, as well as a method for manufacturing a semiconductor device. [Means for solving the problem]

[0008] The present invention provides a silicone graft copolymer having a structure derived from a polar functional group-containing monomer and a structure derived from a silicone macromonomer, which has a glass transition temperature of 30°C or lower as measured using differential scanning calorimetry, and a 5% weight loss temperature of 300°C or higher as measured using a simultaneous thermogravimetry and differential thermal analyzer at a heating rate of 10°C / min. The present invention will be described in detail below.

[0009] The silicone graft copolymer of the present invention has a structure derived from a polar functional group-containing monomer and a structure derived from a silicone macromonomer, and preferably further has a structure derived from a monomer containing a functional group crosslinkable with the polar functional group. When the silicone graft copolymer of the present invention has polar functional groups, when used in a pressure-sensitive adhesive tape, it is likely to gather at the interface with a highly polar adherend, thereby suppressing increased adhesion at high temperatures and further increasing the initial adhesive strength. The silicone graft copolymer that gathers at the interface with the adherend can be crosslinked via the polar functional groups with the pressure-sensitive adhesive component directly or, if necessary, via a crosslinking agent, and fixed at the interface with the adherend. This means that the silicone moiety is also fixed at the interface with the adherend, suppressing increased adhesion at high temperatures and also suppressing contamination of the adherend. Furthermore, if the silicone graft copolymer of the present invention has a functional group that can crosslink with a polar functional group, it can bond with the polar functional group of another silicone graft copolymer. By bonding (self-crosslinking) between silicone graft copolymers, the elastic modulus of the pressure-sensitive adhesive layer increases, making it possible to further suppress increased adhesion at high temperatures and also to suppress adhesive residue.

[0010] The polar functional group-containing monomer is not particularly limited as long as it has a polar functional group. Examples of the polar functional group include a hydroxyl group, a carboxyl group, an amide group, and an epoxy group. Examples of the hydroxyl group-containing monomer include 4-hydroxybutyl (meth)acrylate, hydroxypropyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Examples of the carboxyl group-containing monomer include (meth)acrylic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, and β-carboxyethyl (meth)acrylate. Examples of the amide group-containing monomer include acrylamide, hydroxyethyl acrylamide, isopropyl acrylamide, and dimethylaminopropyl acrylamide. Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate. Among these, hydroxyl group-containing monomers are preferred because they tend to accumulate at the interface with highly polar adherends. When a crosslinking agent is used, a carboxyl group-containing monomer is preferred because crosslinking with the pressure-sensitive adhesive component is easily formed via the crosslinking agent. Furthermore, because of excellent heat resistance and weather resistance, a hydroxyl group-containing (meth)acrylate monomer or a carboxyl group-containing (meth)acrylate monomer is more preferred, and a hydroxyl group-containing (meth)acrylate monomer is even more preferred.

[0011] The content of the structure derived from the polar functional group-containing monomer in the silicone graft copolymer of the present invention is preferably 0.1% by weight or more and 30% by weight or less. By having the content of the structure derived from the polar functional group-containing monomer within the above range, adhesion can be enhanced and contamination of the adherend can be further suppressed at high temperatures. From the viewpoint of further enhancing adhesion and further suppressing contamination of the adherend at high temperatures, the lower limit of the content of the structure derived from the polar functional group-containing monomer is more preferably 0.3 wt%, even more preferably 0.5 wt%, even more preferably 0.7 wt%, and particularly preferably 1 wt%. The upper limit of the content of the structure derived from the polar functional group-containing monomer is more preferably 20 wt%, even more preferably 18 wt%, even more preferably 15 wt%, even more preferably 12 wt%, even more preferably 10 wt%, even more preferably 8 wt%, and particularly preferably 5 wt%.

[0012] The monomer containing a functional group crosslinkable with the polar functional group is not particularly limited as long as it has a functional group crosslinkable with the polar functional group. Examples of the functional group crosslinkable with the polar functional group include an isocyanate group when the polar functional group is a hydroxyl group, and an epoxy group when the polar functional group is a carboxyl group. Examples of isocyanate group-containing monomers include 2-isocyanatoethyl (meth)acrylate. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate. Among these, isocyanate group-containing monomers are preferred because they can crosslink with hydroxyl group-containing monomers that tend to accumulate at the interface with highly polar adherends. Blocked isocyanate group-containing monomers in which a protecting group, as described below, is bonded to the isocyanate group are more preferred. Furthermore, blocked isocyanate group-containing (meth)acrylic monomers are even more preferred because of their excellent heat resistance and weather resistance.

[0013] The monomer containing a functional group capable of crosslinking with the polar functional group preferably has a protecting group bonded to the functional group capable of crosslinking with the polar functional group. The monomer containing the functional group crosslinkable with the polar functional group has a protecting group bonded to the functional group crosslinkable with the polar functional group, thereby preventing unintended self-crosslinking reactions. Conventionally known protecting groups can be used as appropriate for the protecting group depending on the functional group crosslinkable with the polar functional group. For example, when the functional group crosslinkable with the polar functional group is a carboxy group, examples of the protecting group include a vinyl ether group, and when the functional group crosslinkable with the polar functional group is an isocyanate group, examples of the protecting group include a pyrazole group. Among these, a protecting group that is cleaved by heat is preferred because it can initiate a self-crosslinking reaction during a heat treatment step. Examples of protecting groups that are cleaved by heat include a pyrazole group, a phenol group, an oxime group, a lactam group, and a vinyl ether group.

[0014] In the silicone graft copolymer of the present invention, the content of the structure derived from the monomer containing a functional group crosslinkable with the polar functional group is preferably 0.1% by weight or more and 20% by weight or less. By setting the content of the structure derived from a monomer containing a functional group crosslinkable with a polar functional group within the above range, adhesion can be enhanced and contamination of the adherend can be further suppressed at high temperatures. From the viewpoint of further enhancing adhesion and further suppressing contamination of the adherend at high temperatures, the lower limit of the content of the structure derived from a monomer containing a functional group crosslinkable with a polar functional group is more preferably 0.3 wt%, even more preferably 0.5 wt%, even more preferably 0.7 wt%, and particularly preferably 1 wt%. The upper limit of the content of the structure derived from a monomer containing a functional group crosslinkable with a polar functional group is more preferably 10 wt%, even more preferably 8 wt%, and even more preferably 5 wt%.

[0015] The silicone macromonomer may be any monomer having a siloxane bond, such as an acrylic monomer having a siloxane bond or a styrene monomer having a siloxane bond. Among these, an acrylic monomer having a siloxane bond is preferred because of its excellent heat resistance and weather resistance. Examples of the acrylic monomer having a siloxane bond include monomers having a structure represented by the following general formula (1) or (2):

[0016] [ka]

[0017] Here, R represents a (meth)acryloyl group-containing functional group, and X and Y each independently represent an integer of 0 or more, and usually an integer of 5000 or less, particularly 500 or less.

[0018] The content of the structure derived from the silicone macromonomer in the silicone graft copolymer of the present invention is preferably 1% by weight or more and 90% by weight or less. By keeping the content of the structure derived from the silicone macromonomer within the above range, it is possible to further suppress the increase in adhesion at high temperatures. From the viewpoint of further suppressing the increase in adhesion at high temperatures, the lower limit of the content of the structure derived from the silicone macromonomer is more preferably 5 wt %, even more preferably 10 wt %, and even more preferably 80 wt %, and even more preferably 60 wt %.

[0019] When the polar functional group-containing monomer is a hydroxyl group-containing monomer and the monomer containing a functional group crosslinkable with the polar functional group is an isocyanate group-containing monomer, it is preferable that the equivalent ratio of the hydroxyl group to the isocyanate group (hydroxyl group / isocyanate group) is 0.1 or more and 10 or less. By setting the ratio of hydroxyl groups to isocyanate groups within the above range, the self-crosslinking reaction proceeds efficiently, further improving the elastic modulus of the pressure-sensitive adhesive layer at the interface with the adherend and reducing adhesive residue on the adherend. From the perspective of further reducing adhesive residue on the adherend, the equivalent ratio of the hydroxyl groups to the isocyanate groups is more preferably 0.2 or more, even more preferably 0.4 or more, more preferably 4 or less, and even more preferably 2.5 or less.

[0020] The silicone graft copolymer of the present invention may have a structure derived from a monomer other than the polar functional group-containing monomer, the monomer containing a functional group crosslinkable with the polar functional group, and the silicone macromonomer. Examples of the other monomers include (meth)acrylic acid alkyl esters. Examples of the (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, and isostearyl (meth)acrylate. Examples of the other monomers include cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and polypropylene glycol mono(meth)acrylate.

[0021] The silicone graft copolymer of the present invention has an upper limit of 30°C for the glass transition temperature (Tg) measured using differential scanning calorimetry. If the glass transition temperature is 30°C or lower, the silicone graft copolymer is less likely to adhere to the adherend, thereby preventing contamination of the adherend. The upper limit of the glass transition temperature is preferably 10°C, and more preferably -10°C. There is no particular restriction on the lower limit of the glass transition temperature, and although the lower the better, the substantial lower limit is about -80°C. The glass transition temperature can be measured using a 5 mg sample of silicone graft copolymer placed in an aluminum sample container (e.g., Hitachi High-Tech Science's Al autosampler sample container, φ6.8) under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min). The measurement can be performed using a differential scanning calorimeter (e.g., Hitachi High-Tech Science's SII Exstar 6000 / DSC 6220) from -100°C to 100°C at a heating rate of 10°C / min, and the value obtained from the first run can be used.

[0022] Although the method for adjusting the glass transition temperature to the above range is not particularly limited, it is preferable to select and use a monomer that lowers the glass transition temperature of the copolymer. Among the other monomers described above, examples of monomers that lower the glass transition temperature of the copolymer include n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. Among them, 2-ethylhexyl acrylate is preferred because it has a particularly large effect of lowering the glass transition temperature of the copolymer.

[0023] The silicone graft copolymer of the present invention has a 5% weight loss temperature (T d5 ) is 300°C. If the 5% weight loss temperature is 300°C or higher, the heat resistance of the silicone graft copolymer increases and it becomes less likely to decompose even at high temperatures. Therefore, when used in an adhesive tape, the amount of outgassing is reduced even at high temperatures, making the adhesive tape less likely to peel. The lower limit of the 5% weight loss temperature is preferably 305°C, more preferably 320°C, and even more preferably 350°C. There are no particular limitations on the upper limit of the 5% weight loss temperature, and a higher temperature is preferable, but the practical upper limit is about 400°C. The 5% weight loss temperature can be measured by the following method. A 10 mg sample of silicone graft copolymer is placed in a platinum sample container (e.g., Hitachi High-Tech Science Corporation, Pt open-type sample container, φ5.2, H2.5 mm) and measured under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min). For the measurement, a differential thermal and thermogravimetric simultaneous analyzer (e.g., Hitachi High-Tech Science Corporation, TG-DTA; STA7200) is used. The sample is heated from 25°C at a heating rate of 10°C / min, and the weight loss is measured. The weight loss rate is calculated from the obtained weight loss amount and the weight before heating, and the temperature at which the weight loss rate reaches 5% is defined as the 5% weight loss temperature.

[0024] The method for adjusting the 5% weight loss temperature to fall within the above range is not particularly limited, but it is preferable to select and use a monomer with high heat resistance and to reduce the amount of low-molecular-weight components described below. Of the other monomers mentioned above, acrylates are more preferable than methacrylates as the monomer with high heat resistance, and examples include n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. Of these, 2-ethylhexyl acrylate is preferred because the ester bond is relatively stable.

[0025] The silicone graft copolymer of the present invention preferably has a silicon element content of 1% by weight or more and 30% by weight or less. A silicon content of 1 wt% or more can further suppress increased adhesion, and a silicon content of 30 wt% or less can further increase initial adhesive strength and make the adhesive tape less likely to peel even at high temperatures. From the viewpoint of further suppressing increased adhesion and further improving initial adhesive strength, the silicon content is more preferably 3 wt% or more, even more preferably 5 wt% or more, more preferably 25 wt% or less, and even more preferably 20 wt% or less.

[0026] The silicon element content can be measured by the following method. One gram of a silicone graft copolymer sample is weighed into a platinum crucible, sulfuric acid is added, and the mixture is heated to 450°C on a hot plate to ash. The ash is melted using a mixed melting agent of sodium carbonate and boric acid, and water is added to dissolve the mixture by heating. After that, a hydrochloric acid solution is added to adjust the pH. The silicon content of this solution is measured using an ICP emission spectrometer (e.g., OPTIMA 8300, manufactured by PerkinElmer Japan) to determine the silicon content of the silicone graft copolymer.

[0027] The silicone graft copolymer of the present invention preferably has a weight-average molecular weight of 400,000 or less. When the molecular weight of the silicone graft copolymer is within the above range, the mobility of the silicone graft copolymer is improved, allowing it to concentrate more at the interface with the adherend, thereby further suppressing increased adhesion. From the viewpoint of further suppressing increased adhesion, the weight-average molecular weight is more preferably 200,000 or less, and even more preferably 100,000 or less. There are no particular restrictions on the lower limit of the weight-average molecular weight, but it is preferably 5,000 or more, as this facilitates crosslinking with the pressure-sensitive adhesive component and suppresses contamination of the adherend. The weight-average molecular weight can be determined, for example, by GPC using a polystyrene standard. Specifically, the measurement can be performed using a Water's "2690 Separations Module" measuring instrument, a Showa Denko "GPC KF-806L" column, tetrahydrofuran as the mobile phase, a sample flow rate of 1 mL / min, and a column temperature of 40°C.

[0028] The silicone graft copolymer of the present invention is not particularly limited in the content of components having a weight-average molecular weight of 3000 or less as measured by gel permeation chromatography (hereinafter also referred to as "low molecular weight components"), but a preferred upper limit of the total amount of the silicone graft copolymer is 10 wt%. If the content of the low molecular weight components is 10 wt% or less, the amount of outgassing derived from the silicone graft copolymer is further reduced, and when used in an adhesive tape, the adhesive tape becomes less likely to peel even at high temperatures. A more preferred upper limit of the content of the low molecular weight components is 5 wt%, an even more preferred upper limit is 3 wt%, and an even more preferred upper limit is 1 wt%. There is no particular limit on the lower limit of the content of the low molecular weight components, and a value closer to 0 wt% is preferred because the adhesive tape becomes less likely to peel even at high temperatures. The method for adjusting the content of the low-molecular-weight component to fall within the above range is not particularly limited, and may be achieved by adjusting the type, composition, physical properties, polymerization method, etc. of the silicone graft copolymer. Among these, it is preferable to produce the silicone graft copolymer by solution polymerization (boiling point polymerization or constant temperature polymerization).

[0029] The content of low molecular weight components can be measured by the following method. The tetrahydrofuran solution of the silicone graft copolymer is filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The resulting filtrate is fed to a gel permeation chromatograph (e.g., Waters, 2690 Separations Model) and subjected to GPC measurement at a sample flow rate of 1 mL / min and a column temperature of 40°C. The polystyrene-equivalent molecular weight of the silicone graft copolymer is measured, and the content and molecular weight of low-molecular-weight components are determined. For example, a GPC KF-806L (Showa Denko) is used as the column, tetrahydrofuran is used as the mobile phase, and a differential refractometer is used as the detector.

[0030] The method for producing the silicone graft copolymer of the present invention is not particularly limited, and it can be obtained by radical polymerization of the polar functional group-containing monomer, the silicone macromonomer, and, if necessary, other monomers in a solvent. The polymerization method for the radical polymerization can be a conventionally known method, such as solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, etc. Among these, solution polymerization (boiling point polymerization or constant temperature polymerization) is preferred.

[0031] The silicone graft copolymer of the present invention may be used in any application, but it can be suitably used as a release aid for pressure sensitive adhesives. Such a pressure-sensitive adhesive composition containing the silicone graft copolymer of the present invention, a pressure-sensitive adhesive component having a functional group crosslinkable with the silicone graft copolymer, and a crosslinking agent also constitutes one aspect of the present invention.

[0032] The pressure-sensitive adhesive composition of the present invention contains a silicone graft copolymer, a pressure-sensitive adhesive component having a functional group capable of crosslinking with the silicone graft copolymer, and a crosslinking agent. The pressure-sensitive adhesive component of the pressure-sensitive adhesive composition of the present invention has a functional group capable of crosslinking with a silicone-based graft copolymer, so that when the composition is used in a pressure-sensitive adhesive tape, the silicone-based graft copolymer that has gathered at the interface with the adherend can be crosslinked with the pressure-sensitive adhesive component directly, or if necessary, via a crosslinking agent, and fixed at the interface with the adherend, thereby preventing contamination of the adherend. Furthermore, the pressure-sensitive adhesive composition of the present invention contains a crosslinking agent, which increases the cohesive strength of the pressure-sensitive adhesive layer, improving initial adhesive strength and making the composition less susceptible to peeling even at high temperatures.

[0033] The content of the silicone graft copolymer in the pressure-sensitive adhesive composition of the present invention is preferably 0.1 to 20 parts by weight per 100 parts by weight of the pressure-sensitive adhesive component. When the content of the silicone graft copolymer in the pressure-sensitive adhesive composition of the present invention is 0.1 parts by weight or more, adhesion enhancement at high temperatures can be further suppressed. When the content of the silicone graft copolymer is 20 parts by weight or less, clouding of the pressure-sensitive adhesive composition can be suppressed, and processes using light, such as alignment, can be performed through the pressure-sensitive adhesive composition. From the viewpoint of further suppressing adhesion enhancement and clouding at high temperatures, the content of the silicone graft copolymer is more preferably 1 part by weight or more, even more preferably 5 parts by weight or more, more preferably 15 parts by weight or less, even more preferably 10 parts by weight or less, and even more preferably 8 parts by weight or less.

[0034] The pressure-sensitive adhesive component is not particularly limited as long as it has a functional group capable of crosslinking with the silicone-based graft copolymer, and may be either a non-curing pressure-sensitive adhesive or a curing pressure-sensitive adhesive. When the pressure-sensitive adhesive component is a curing pressure-sensitive adhesive, the pressure-sensitive adhesive composition of the present invention may further contain a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator, or may not contain a polymerization initiator. The non-curable pressure-sensitive adhesive is not particularly limited, and examples thereof include rubber-based pressure-sensitive adhesives, adhesive (meth)acrylic polymers, vinyl alkyl ether-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, styrene-diene block copolymer-based pressure-sensitive adhesives, etc. The curable pressure-sensitive adhesive is not particularly limited, and examples thereof include curable adhesive (meth)acrylic polymers, etc. The structure of the pressure-sensitive adhesive component is not particularly limited, and may be a random copolymer or a block copolymer.

[0035] The pressure-sensitive adhesive component is preferably an adhesive (meth)acrylic polymer. When the pressure-sensitive adhesive component is an adhesive (meth)acrylic polymer, heat resistance and weather resistance are improved, and the pressure-sensitive adhesive component can be used on a wide range of adherends. The adhesive (meth)acrylic polymer is preferably a curable adhesive (meth)acrylic polymer. Examples of the curable adhesive (meth)acrylic polymer include polymerizable polymers. By using the polymerizable polymer, the adhesive layer can be cured by light (ultraviolet) irradiation, heat, or the like. The polymerizable polymer is more preferably a polymerizable polymer having a radically polymerizable unsaturated bond in the molecule. The method for producing the polymerizable polymer having a radically polymerizable unsaturated bond in the molecule is not particularly limited, and examples thereof include a method in which a monomer having a radically polymerizable unsaturated bond is used when synthesizing the polymer. Another example is a method in which a compound having a radically polymerizable unsaturated bond (hereinafter also referred to as an "unsaturated bond-containing compound") is reacted with a functional group present in the polymer that can crosslink with the silicone-based graft copolymer or other polar functional group.

[0036] The above-mentioned adhesive (meth)acrylic polymer is not particularly limited as long as it uses a monomer containing a functional group crosslinkable with the above-mentioned silicone-based graft copolymer as a raw material monomer and has a structural unit derived from the monomer containing a functional group crosslinkable with the above-mentioned silicone-based graft copolymer. Examples of raw material monomers that can be used other than the monomer containing a functional group crosslinkable with the above-mentioned silicone-based graft copolymer include (meth)acrylic acid alkyl esters having an alkyl group with 1 to 13 carbon atoms, (meth)acrylic acid alkyl esters having an alkyl group with 13 to 18 carbon atoms, and functional monomers. Examples of (meth)acrylic acid alkyl esters having 1 to 13 carbon atoms in the alkyl group include 2-ethylhexyl acrylate, butyl acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. Examples of (meth)acrylic acid alkyl esters having 13 to 18 carbon atoms in the alkyl group include tridecyl methacrylate and stearyl (meth)acrylate. Examples of the functional monomers include hydroxyalkyl (meth)acrylate, glycerin dimethacrylate, glycidyl (meth)acrylate, 2-methacryloyloxyethyl isocyanate, (meth)acrylic acid, itaconic acid, maleic anhydride, crotonic acid, maleic acid, and fumaric acid. Of these, 2-ethylhexyl acrylate is preferred.

[0037] The functional group crosslinkable with the silicone graft copolymer is not particularly limited and can be appropriately selected depending on the functional group possessed by the silicone graft copolymer. For example, when the functional group possessed by the silicone graft copolymer is a hydroxyl group, an isocyanate group, a blocked isocyanate group, or an epoxy group can be mentioned. When the functional group possessed by the silicone graft copolymer is a carboxyl group, an epoxy group, an isocyanate group, or a blocked isocyanate group can be mentioned. When the functional group possessed by the silicone graft copolymer is an isocyanate group, an hydroxyl group can be mentioned. When the functional group possessed by the silicone graft copolymer is an epoxy group, an carboxyl group can be mentioned. As the monomer having a hydroxyl group or a carboxyl group, which is the raw material for the adhesive (meth)acrylic polymer, the same one as the polar functional group-containing monomer in the silicone graft copolymer of the present invention described above can be used.

[0038] The content of the structural unit derived from the monomer containing a functional group capable of crosslinking with the silicone graft copolymer in the adhesive (meth)acrylic polymer is not particularly limited. From the viewpoint of increasing the cohesive strength and adhesive strength to the adherend, the content of the structural unit derived from the monomer containing a functional group capable of crosslinking with the silicone graft copolymer is preferably 1% by weight or more and 20% by weight or less.

[0039] In addition, when the adhesive (meth)acrylic polymer is the curable adhesive (meth)acrylic polymer, the content of the structural unit derived from the monomer containing a functional group crosslinkable with the silicone graft copolymer means the content after reaction with the unsaturated bond-containing compound described below. That is, when the adhesive (meth)acrylic polymer is the curable adhesive (meth)acrylic polymer, the crosslinkable functional group in the structural unit derived from the monomer containing a functional group crosslinkable with the silicone graft copolymer may be partially consumed when reacting with the unsaturated bond-containing compound. The crosslinkable functional group reacts with the unsaturated bond-containing compound to introduce a radically polymerizable unsaturated bond, thereby obtaining a curable adhesive (meth)acrylic polymer. However, since the crosslinkable functional group remains partially unconsumed, the resulting curable adhesive (meth)acrylic polymer can have structural units derived from the monomer containing a functional group crosslinkable with the silicone graft copolymer. The content of constituent units derived from monomers containing functional groups crosslinkable with the silicone graft copolymer before reaction with the unsaturated bond-containing compound is not particularly limited, but is preferably 5% by weight or more and 40% by weight or less from the viewpoints of improving adhesion to the adherend, crosslinking with the silicone graft copolymer, and reaction with the unsaturated bond-containing compound.

[0040] The unsaturated bond-containing compound is not particularly limited and can be appropriately selected depending on the functional group present in the polymer that is crosslinkable with the silicone graft copolymer or other polar functional groups. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is a carboxy group, a compound having an epoxy group and a radically polymerizable unsaturated bond, or a compound having an isocyanate group and a radically polymerizable unsaturated bond is used. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is a hydroxyl group, a compound having an isocyanate group and a radically polymerizable unsaturated bond is used. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is an epoxy group, a compound having a carboxy group and a radically polymerizable unsaturated bond, or a compound having an amide group and a radically polymerizable unsaturated bond is used. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is an amino group, a compound having an epoxy group and a radically polymerizable unsaturated bond is used. Among these, from the viewpoint of reactivity, it is preferred that the functional group present in the polymer that is crosslinkable with the silicone graft copolymer or the other polar functional group is a carboxyl group or a hydroxyl group, and that the unsaturated bond-containing compound is a compound having an isocyanate group and a radically polymerizable unsaturated bond.

[0041] The compound having an isocyanate group and a radically polymerizable unsaturated bond is not particularly limited, and examples thereof include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, etc. By using the compound having an isocyanate group and a radically polymerizable unsaturated bond, it is possible to obtain a curable adhesive (meth)acrylic polymer in which a radically polymerizable unsaturated bond is introduced into the side chain of a polymer (particularly a hydroxyl group-containing polymer).

[0042] When the adhesive (meth)acrylic polymer is the curable adhesive (meth)acrylic polymer, the content of the structural unit having a radically polymerizable unsaturated bond in the curable adhesive (meth)acrylic polymer is not particularly limited, but the lower limit is preferably 1% by weight, and the upper limit is preferably 20% by weight. The lower limit of the content of the structural unit is more preferably 3% by weight, and the upper limit is more preferably 18% by weight, and the even more preferably lower limit is 5% by weight, and the even more preferably upper limit is 15% by weight.

[0043] The weight-average molecular weight of the adhesive (meth)acrylic polymer is not particularly limited, but is preferably from 200,000 to 2,000,000. When the weight-average molecular weight of the adhesive (meth)acrylic polymer is within the above range, the adhesive strength to the adherend can be increased. The weight-average molecular weight can be determined, for example, by GPC using a polystyrene standard. Specifically, the measurement can be performed using a Water's "2690 Separations Module" measuring instrument, a Showa Denko "GPC KF-806L" column, ethyl acetate as a solvent, a sample flow rate of 1 mL / min, and a column temperature of 40°C.

[0044] The above-mentioned adhesive (meth)acrylic polymer may have a structural unit derived from another modifying monomer. Examples of the other modifying monomers include vinyl carboxylate esters such as vinyl acetate and vinyl propionate, and acrylonitrile. Other examples include aromatic vinyl compounds such as styrene, substituted styrenes (e.g., α-methylstyrene), and vinyltoluene. Other examples include aromatic ring-containing (meth)acrylates such as aryloxyalkyl (meth)acrylates (e.g., phenyl (meth)acrylate, phenoxyethyl (meth)acrylate), and arylalkyl (meth)acrylates (e.g., benzyl (meth)acrylate). Other examples include various monomers used in general (meth)acrylic polymers, such as macromonomers having a radically polymerizable vinyl group at the end of a monomer obtained by polymerizing a vinyl group, and amide group-containing monomers. These other modifying monomers may be used alone or in combination of two or more.

[0045] The adhesive (meth)acrylic polymer can be obtained by subjecting a raw material monomer mixture to a radical reaction in the presence of a polymerization initiator. As a method for subjecting the raw material monomer mixture to a radical reaction, i.e., a polymerization method, a conventionally known method can be used, such as solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, etc. The polymerization initiator is not particularly limited, and examples thereof include organic peroxides and azo compounds. Examples of the organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxylaurate. Examples of the azo compounds include azobisisobutyronitrile and azobiscyclohexanecarbonitrile. These polymerization initiators may be used alone or in combination.

[0046] The above-mentioned adhesive (meth)acrylic polymer may be obtained by living radical polymerization. Living radical polymerization is a polymerization in which a molecular chain grows without being hindered by side reactions such as termination reactions or chain transfer reactions. Living radical polymerization can produce polymers with more uniform molecular weights and compositions than, for example, free radical polymerization, and can suppress the generation of low-molecular-weight components, etc., so that the resulting pressure-sensitive adhesive composition can be prevented from increasing adhesion at high temperatures, while also making the pressure-sensitive adhesive composition less susceptible to peeling to the extent that unintended peeling does not occur.

[0047] The living radical polymerization is not particularly limited as long as it is a commonly used one, and examples thereof include the TERP method, the RAFT method, the NMP method, etc. As the initiator, an organic tellurium compound is used in the TERP method, a RAFT agent is used in the RAFT method, and a nitroxide compound is used in the NMP method, and these are used in combination with a radical polymerization initiator as necessary.

[0048] Examples of the organic tellurium compound include 2-methyl-2-n-butyltellanyl-propionic acid, (methyltellanyl-methyl)benzene, 1-chloro-4-(methyltellanyl-methyl)benzene, 1-hydroxy-4-(methyltellanyl-methyl)benzene, and 1-phenoxycarbonyl-4-(2-methyltellanyl-propyl)benzene. Examples of RAFT agents include S-cyanomethyl-S-dodecyltrithiocarbonate, 2-cyano-2-propyl dithiobenzoate, S-(2-cyano-2-propyl)-S-dodecyltrithiocarbonate, and 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid. Examples of nitroxide compounds include di-tert-butyl-nitroxide, 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl, tetramethyl-isoindoline-1-oxyl, tetraethyl-isoindoline-1-oxyl, N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)]nitroxide, and 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide.

[0049] In the living radical polymerization, an azo compound may be used in addition to the initiator in order to accelerate the polymerization rate. The azo compound is not particularly limited as long as it is one that is generally used in radical polymerization. Examples of the azo compound include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, 4,4' -Azobis(4-cyanovaleric acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis{2-methyl-N-[1,1'-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2 '-Azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2'-azobis(2,4,4-trimethylpentane), etc. These azo compounds may be used alone or in combination of two or more.

[0050] In the living radical polymerization, a dispersion stabilizer may be used, such as polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, ethyl cellulose, poly(meth)acrylic acid, poly(meth)acrylic acid ester, and polyethylene glycol.

[0051] As the method for the living radical polymerization, a conventionally known method can be used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization. When a polymerization solvent is used in the living radical polymerization, the polymerization solvent is not particularly limited. Examples of the polymerization solvent that can be used include nonpolar solvents such as hexane, cyclohexane, octane, toluene, and xylene, and highly polar solvents such as water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, and N,N-dimethylformamide. These polymerization solvents may be used alone or in combination of two or more. The polymerization temperature is preferably 0 to 110°C from the viewpoint of polymerization rate.

[0052] The crosslinking agent is not particularly limited, and examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, etc. Among these, epoxy-based crosslinking agents are preferred because they further increase the cohesive strength of the pressure-sensitive adhesive components.

[0053] The content of the crosslinking agent in the pressure-sensitive adhesive composition of the present invention is preferably 0.1 wt% or more and 20 wt% or less. By including the crosslinking agent in this range, the pressure-sensitive adhesive components can be appropriately crosslinked, thereby further increasing the initial adhesive strength and making the pressure-sensitive adhesive tape less likely to peel even at high temperatures. From the viewpoint of further increasing the initial adhesive strength, the lower limit of the content of the crosslinking agent is more preferably 0.5 wt%, even more preferably 1 wt%, and even more preferably 15 wt%, and even more preferably 10 wt%.

[0054] When the pressure-sensitive adhesive component is the curable adhesive (meth)acrylic polymer, the pressure-sensitive adhesive composition of the present invention may further contain a polymerization initiator. Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator. Among them, a thermal polymerization initiator is preferred because the pressure-sensitive adhesive composition can be cured by the heat of the heat treatment step, eliminating the need for a separate step of curing the pressure-sensitive adhesive composition, and curing is possible even when used on an adherend that does not transmit light.

[0055] Examples of the photopolymerization initiator include those activated by irradiation with ultraviolet light having a wavelength of 200 to 410 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds, benzoin ether compounds, ketal derivative compounds, phosphine oxide derivative compounds, bis(η5-cyclopentadienyl)titanocene derivative compounds, alkylphenone compounds, benzophenone, Michler's ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. Examples of the acetophenone derivative compounds include methoxyacetophenone. Examples of the benzoin ether compounds include benzoin propyl ether and benzoin isobutyl ether. Examples of the ketal derivative compounds include benzyl dimethyl ketal and acetophenone diethyl ketal. Commercially available alkylphenone compounds include Omnirad 184, Omnirad 651, Omnirad 369, Omnirad 2959, and Omnirad 907 (all manufactured by IGM Resins). Commercially available phosphine oxide derivative compounds include Omnirad TPO H and Omnirad 819. These photopolymerization initiators may be used alone or in combination of two or more.

[0056] The thermal polymerization initiator is not particularly limited, and examples thereof include those that decompose when heated to generate active radicals that initiate a polymerization reaction. Specific examples include dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoyl, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, and di-t-butyl peroxide. These thermal polymerization initiators may be used alone or in combination of two or more.

[0057] The content of the polymerization initiator is not particularly limited and is determined appropriately depending on the types of the curable adhesive (meth)acrylic polymer and the polymerization initiator. A preferred lower limit is 0.1 parts by weight, a preferred upper limit is 10 parts by weight, a more preferred lower limit is 1 part by weight, and a more preferred upper limit is 8 parts by weight, relative to 100 parts by weight of the curable adhesive (meth)acrylic polymer.

[0058] The pressure-sensitive adhesive composition of the present invention may contain a polymerization initiator as described above, but it is more preferable that the pressure-sensitive adhesive component is the curable adhesive (meth)acrylic polymer and does not contain a polymerization initiator. In recent years, various environmental regulations have designated some compounds in polymerization initiators as targets of restriction. Because the pressure-sensitive adhesive composition of the present invention contains the silicone-based graft copolymer, it is resistant to peeling even when subjected to a high-temperature heat treatment process, and can suppress enhanced adhesion and contamination of the adherend. Furthermore, because the pressure-sensitive adhesive composition of the present invention contains the silicone-based graft copolymer, even if it is cured only by cleavage of unsaturated double bonds and polymerization reaction in a high-temperature heat treatment process (i.e., even without containing a polymerization initiator), its adhesive strength decreases and it can be easily peeled off after the process is completed.

[0059] The pressure-sensitive adhesive composition of the present invention may contain, as necessary, known additives such as a gas generating agent that generates gas in response to stimulation, an inorganic filler, a heat stabilizer, an antioxidant, an antistatic agent, a plasticizer, a resin, and a wax.

[0060] The pressure-sensitive adhesive composition of the present invention preferably does not contain an emulsifier. By not containing an emulsifier, the heat resistance of the pressure-sensitive adhesive composition is improved and the pressure-sensitive adhesive composition is less likely to decompose even at high temperatures. As a result, when the pressure-sensitive adhesive composition is used in a pressure-sensitive adhesive tape, the amount of outgassing is further reduced even at high temperatures, making the pressure-sensitive adhesive tape more difficult to peel.

[0061] In order to prevent the pressure-sensitive adhesive composition of the present invention from containing the emulsifier, it is preferable not to use the emulsifier when obtaining the silicone-based graft copolymer of the present invention and the pressure-sensitive adhesive component (adhesive polymer). To achieve this, for example, solution polymerization or the like may be employed as the polymerization method when obtaining the silicone-based graft copolymer of the present invention and the pressure-sensitive adhesive component (adhesive polymer). The content of the emulsifier can be determined, for example, by measuring the pressure-sensitive adhesive composition using a liquid chromatography mass spectrometer (e.g., NEXCERA manufactured by Shimadzu Corporation and Exactive manufactured by Thermo Fisher Scientific). More specifically, an ethyl acetate solution of the pressure-sensitive adhesive composition is filtered through a filter (material: polytetrafluoroethylene, pore size: 0.2 μm). Approximately 10 μL of the obtained filtrate is injected and analyzed using the liquid chromatography mass spectrometer under the following conditions. The content of the emulsifier can be determined from the area ratio of the peak corresponding to the emulsifier to the total. It is preferable to prepare samples of each emulsifier type with a known content in the pressure-sensitive adhesive composition, and create a calibration curve showing the relationship between the emulsifier content and the peak area ratio for analysis. Column: Thermo Fisher Scientific, Hypersil GOLD (2.1 x 150 mm) Mobile phase: acetonitrile Column temperature: 40℃ Flow rate: 1.0mL / min Ionization method: ESI Capillary temperature: 350℃ The absence of an emulsifier in the pressure-sensitive adhesive composition of the present invention means that the content of the emulsifier in the pressure-sensitive adhesive composition of the present invention, as measured using a liquid chromatography mass spectrometer, is 3% by weight or less, preferably 1% by weight or less, more preferably 0.5% by weight or less, and even more preferably 0.1% by weight or less.

[0062] The method for producing the pressure-sensitive adhesive composition of the present invention is not particularly limited, and the composition can be obtained, for example, by adding the silicone-based graft copolymer, the crosslinking agent, and, if necessary, other additives to a solution of the pressure-sensitive adhesive components produced by the method described above, and mixing them.

[0063] The pressure-sensitive adhesive composition of the present invention can be used to produce a pressure-sensitive adhesive tape. Such an adhesive tape having a substrate and an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer contains the silicone graft copolymer of the present invention, also constitutes one aspect of the present invention.

[0064] The pressure-sensitive adhesive tape of the present invention has a substrate. The material constituting the substrate is preferably a heat-resistant material. Examples of the heat-resistant material include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyimide, polyetherimide, fluororesin, and liquid crystal polymer. Among these, polyethylene naphthalate is preferred because of its excellent heat resistance.

[0065] The thickness of the substrate is not particularly limited, but the lower limit is preferably 15 μm, more preferably 25 μm, even more preferably 40 μm, and even more preferably 50 μm, and the upper limit is preferably 250 μm, more preferably 125 μm, even more preferably 100 μm, and even more preferably 75 μm. When the substrate has a thickness within this range, the pressure-sensitive adhesive tape can be made excellent in handleability.

[0066] The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer laminated on at least one surface of the substrate. The adhesive constituting the adhesive layer can be the same as that used in the adhesive composition of the present invention.

[0067] The thickness of the pressure-sensitive adhesive layer is not particularly limited, but preferably has a lower limit of 3 μm and an upper limit of 100 μm. When the thickness of the pressure-sensitive adhesive layer is within the above range, it can adhere to the support with sufficient adhesive strength. From the same viewpoint, the lower limit of the thickness of the pressure-sensitive adhesive layer is more preferably 5 μm, even more preferably 10 μm, and even more preferably 20 μm, and the upper limit is more preferably 80 μm, even more preferably 60 μm, and even more preferably 50 μm.

[0068] The method for producing the pressure-sensitive adhesive tape of the present invention is not particularly limited, and a conventionally known method can be used. For example, the pressure-sensitive adhesive tape can be produced by applying a solution of the pressure-sensitive adhesive composition to a film that has been subjected to a release treatment, drying the applied solution to form a pressure-sensitive adhesive layer, and laminating the resulting layer to a substrate.

[0069] The application of the pressure-sensitive adhesive tape of the present invention is not particularly limited, but it can be suitably used in the processing of semiconductor wafers or semiconductor chips. In particular, the pressure-sensitive adhesive tape of the present invention is resistant to peeling even when subjected to a high-temperature heat treatment process, and is capable of suppressing increased adhesion and contamination of the adherend at high temperatures. Therefore, it is more suitably used as a protective tape for protecting an adherend in the production of products that involve a high-temperature treatment process, such as semiconductor devices. Examples of high-temperature treatment processes for semiconductor devices include high-temperature treatment processes at 150°C or higher, particularly 180°C or higher, and especially 200°C or higher. The upper temperature limit of the high-temperature treatment process is not particularly limited, and is, for example, 350°C.

[0070] The adhesive tape of the present invention is resistant to peeling even when subjected to a high-temperature heat treatment process, and is capable of suppressing increased adhesion and contamination of the adherend at high temperatures. Therefore, it is particularly suitable for use as a protective tape that is attached to a ring frame and a semiconductor wafer to protect the semiconductor wafer during the processing process of the semiconductor wafer. FIG. 1 schematically shows an example of a semiconductor wafer processing step using the adhesive tape of the present invention. In the semiconductor wafer processing step shown in FIG. 1, an adhesive tape 2 of the present invention is attached to a ring frame 1 and a semiconductor wafer 3 (FIG. 1(a)). Then, the semiconductor wafer 3 is diced to obtain semiconductor chips 4 (FIG. 1(b)). Note that while FIG. 1 illustrates a processing step for a semiconductor wafer having bumps (electrodes), the use of the adhesive tape of the present invention is not limited to such a step. Also, while FIG. 1 illustrates a step for dicing a semiconductor wafer to obtain semiconductor chips, the use of the adhesive tape of the present invention is not limited to such a step.

[0071] A method for manufacturing a semiconductor device, which comprises a step of processing a semiconductor wafer or semiconductor chip using the pressure-sensitive adhesive tape of the present invention, also constitutes one aspect of the present invention. The method for producing a semiconductor device of the present invention is not particularly limited as long as it includes a step of processing a semiconductor wafer or semiconductor chip using the pressure-sensitive adhesive tape of the present invention, but it preferably includes a step of processing a semiconductor wafer as shown in Fig. 1. That is, the method for producing a semiconductor device of the present invention preferably includes a step of attaching the pressure-sensitive adhesive tape of the present invention to a ring frame and a semiconductor wafer, and a step of dancing the semiconductor wafer to obtain a semiconductor chip. [Effects of the Invention]

[0072] According to the present invention, it is possible to provide a silicone-based graft copolymer capable of forming a pressure-sensitive adhesive layer that is resistant to peeling even when subjected to a high-temperature heat treatment step, and that can enhance adhesion and suppress contamination of an adherend. Furthermore, according to the present invention, it is possible to provide a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape containing the silicone-based graft copolymer, as well as a method for manufacturing a semiconductor device. [Brief explanation of the drawings]

[0073] [Figure 1] 1A to 1C are diagrams schematically illustrating an example of a semiconductor wafer processing step using the pressure-sensitive adhesive tape of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0074] The following examples will explain the present invention in more detail, but the present invention is not limited to these examples.

[0075] (Preparation of Acrylic Polymer) 6.38 g (50 mmol) of polymerization initiator was suspended in 50 mL of tetrahydrofuran (THF), and 34.4 mL (55 mmol) of a 1.6 mol / L n-butyllithium / hexane solution was slowly added dropwise at room temperature. The reaction solution was stirred until the metallic tellurium completely disappeared. 10.7 g (55 mmol) of ethyl 2-bromoisobutyrate was added to the reaction solution at room temperature and stirred for 2 hours. After the reaction was completed, the solvent was concentrated under reduced pressure, followed by vacuum distillation to obtain ethyl 2-methyl-2-n-butyltellanylpropionate as a yellow oil. In an argon-purged glove box, 45.7 μL of the prepared ethyl 2-methyl-2-n-butyltellanyl propionate, 10 mg of 2,2'-azobis(2,4-dimethylvaleronitrile), and 0.5 mL of ethyl acetate were added to a reaction vessel, which was then sealed and removed from the glove box. Next, while argon gas was flowing into the reaction vessel, a raw material monomer mixture was added to the reaction vessel. The raw material monomer mixture consisted of 100 parts by weight of 2-ethylhexyl acrylate (2EHA), 3 parts by weight of acrylic acid (Aac), and 0.1 parts by weight of 2-hydroxyethyl acrylate (HEA). Furthermore, 68.7 g of ethyl acetate was added as a polymerization solvent, and the polymerization reaction was carried out at 60°C for 20 hours to obtain a solution containing the adhesive component. The raw materials used were as follows: Polymerization initiator: Tellurium, metallic tellurium, 40 mesh, manufactured by Aldrich n-Butyllithium / hexane solution: Aldrich 2,2'-Azobis(2,4-dimethylvaleronitrile): Wako Pure Chemical Industries, Ltd.

[0076] Next, the obtained solution containing the adhesive component was diluted 50 times with tetrahydrofuran (THF), and the resulting diluted solution was filtered through a polytetrafluoroethylene filter with a pore size of 0.2 μm. The obtained filtrate was then fed to a gel permeation chromatograph for GPC measurement. The polystyrene-equivalent molecular weight of the adhesive component was measured to determine the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn). The results were Mw: 899,000, and Mw / Mn: 1.78. The measuring equipment and conditions were as follows: Gel permeation chromatograph: e2695 Separations Module (Waters) Detector: Differential refractometer (2414, Waters) Column: GPC KF-806L (Showa Denko) Standard sample: STANDRAD SM-105 (Showa Denko) Mobile phase: tetrahydrofuran Sample flow rate: 1 mL / min Column temperature: 40℃

[0077] (Preparation of Curable Adhesive Acrylic Polymer) A reactor equipped with a thermometer, stirrer, and condenser was prepared, and the raw material monomer mixture was added to the reactor. The raw material monomer mixture consisted of 79 parts by weight of 2-ethylhexyl acrylate (2EHA), 1 part by weight of acrylic acid (Aac), and 20 parts by weight of 2-hydroxyethyl acrylate (HEA). Furthermore, 80 parts by weight of ethyl acetate was added as a polymerization solvent. The reactor was heated to initiate reflux. Subsequently, 0.05 parts by weight of V-60 (2,2'-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as a polymerization initiator to initiate polymerization under reflux. Two hours after the start of polymerization, 0.15 parts by weight of V-60 (2,2'-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added again. The polymerization reaction was carried out under reflux for 8 hours from the start of polymerization, yielding a polymer-containing solution. A reaction vessel was charged with 100 parts by weight of the obtained polymer, 10 ppm of hydroquinone, and 40 parts by weight of ethyl acetate, and heated to 60° C. Subsequently, 8 parts by weight of 2-methacryloyloxyethyl isocyanate (MOI) was added dropwise to the reaction vessel over 60 minutes, and the mixture was allowed to react at 60° C. for a further 120 minutes, yielding a solution containing a pressure-sensitive adhesive component (boiling point free radical polymerized acrylic polymer, Mw: 601,000, Mw / Mn: 5.3).

[0078] (Preparation of Silicone-Based Graft Copolymer (Synthesis Example 1)) A reactor equipped with a thermometer, stirrer, and condenser was prepared. 89 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of silicone macromonomer, 1 part by weight of acrylamide, 0.6 parts by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate were added to the reactor, and the reactor was heated to initiate reflux. Next, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane was added as a polymerization initiator to initiate polymerization under reflux. Next, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane was added at 1 hour and 2 hours after the start of polymerization, and 0.05 parts by weight of t-hexylperoxypivalate was added at 4 hours after the start of polymerization to continue the polymerization reaction. Then, 8 hours after the start of polymerization, a silicone graft copolymer (Synthesis Example 1) (Mw: 60,000, Mw / Mn: 2.4) was obtained.

[0079] The glass transition temperature of the silicone graft copolymer (Synthesis Example 1) was determined as follows. A 5 mg sample of the silicone graft copolymer (Synthesis Example 1) placed in an aluminum sample container (Hitachi High-Tech Science Corporation, Al autosampler sample container, φ6.8) was measured for glass transition temperature under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min). The measurement was performed using a differential scanning calorimetry (Hitachi High-Tech Science Corporation, SII Exstar 6000 / DSC 6220) from -100°C to 100°C at a heating rate of 10°C / min to determine the glass transition temperature (value from the first run) of the silicone graft copolymer (Synthesis Example 1).

[0080] Furthermore, the 5% weight loss temperature of the silicone graft copolymer (Synthesis Example 1) was determined as follows. A 10 mg sample of the silicone graft copolymer (Synthesis Example 1) placed in a platinum sample container (Hitachi High-Tech Science Corporation, Pt open-type sample container, φ5.2, H2.5 mm) was measured for its 5% weight loss temperature under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min). The measurement was performed using a simultaneous differential thermal and thermogravimetric analyzer (Hitachi High-Tech Science Corporation, TG-DTA; STA7200) by heating the sample from 25°C at a heating rate of 10°C / min, and measuring the weight loss. The weight loss rate was calculated from the resulting weight loss and the weight before heating, and the temperature at which the weight loss rate reached 5% was defined as the 5% weight loss temperature.

[0081] Furthermore, the silicon element content of the silicone graft copolymer (Synthesis Example 1) was determined as follows. A measurement sample of 1 g of the silicone graft copolymer (Synthesis Example 1) was weighed into a platinum crucible, sulfuric acid was added, and the mixture was heated to 450°C on a hot plate to be incinerated. The ash was melted using a mixed melting agent of sodium carbonate and boric acid, and water was added and the mixture was dissolved by heating. After that, a hydrochloric acid solution was added to adjust the pH. The silicon content of this solution was measured using an ICP emission spectrometer (OPTIMA 8300, manufactured by PerkinElmer Japan) to determine the silicon content in the silicone graft copolymer (Synthesis Example 1).

[0082] Furthermore, the content of low molecular weight components in the silicone graft copolymer (Synthesis Example 1) was determined as follows. A tetrahydrofuran solution of the silicone graft copolymer (Synthesis Example 1) was filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The resulting filtrate was fed to a gel permeation chromatograph (Waters, 2690 Separations Model) and subjected to GPC measurement at a sample flow rate of 1 mL / min and a column temperature of 40°C. The polystyrene-equivalent molecular weight of the silicone graft copolymer (Synthesis Example 1) was measured, and the content and molecular weight of low-molecular-weight components were determined. A GPC KF-806L (Showa Denko KK) column was used, tetrahydrofuran was used as the mobile phase, and a differential refractometer was used as the detector.

[0083] (Preparation of Silicone-Based Graft Copolymers (Synthesis Examples 2 to 19)) Silicone graft copolymers (Synthesis Examples 2 to 19) were obtained in the same manner as in the preparation of the silicone graft copolymer (Synthesis Example 1), except that the monomer compositions were as shown in Table 1.

[0084] (Preparation of Silicone-Based Graft Copolymer (Synthesis Example 20)) A reactor equipped with a thermometer, stirrer, dropping funnel, and condenser was prepared. 90 parts by weight of ion-exchanged water, 10 parts by weight of emulsifier (Eleminol JS-20, Sanyo Chemical Industries, Ltd.), and 0.1 parts by weight of ammonium persulfate were added to the reactor, and the mixture was saturated with nitrogen gas. 80 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of silicone macromonomer, 10 parts by weight of 4-hydroxybutyl acrylate, 0.6 parts by weight of lauryl mercaptan, and 60 parts by weight of ion-exchanged water were mixed in a pipeline mixer to obtain a suspension with an oil droplet diameter of 0.5 μm or less. The internal temperature of the reactor was raised to 80°C, 0.4 parts by weight of ammonium persulfate was added, and the dropwise addition of the suspension was initiated 5 minutes later. The dropwise addition of the suspension took 2 hours, and the polymerization reaction was continued for another 2 hours. Four hours after the start of polymerization, the mixture was cooled and the pH was adjusted to 8-9 with ammonia to obtain a silicone graft copolymer (Synthesis Example 20).

[0085] [Table 1]

[0086] 2EHA: 2-(ethylhexyl) acrylate BA: n-butyl acrylate ISTA: Isostearyl acrylate MA: methyl acrylate STA: Stearyl acrylate IBOA: Isobornyl acrylate MMA: Methyl methacrylate M2EHA: 2-(ethylhexyl) methacrylate Silicone macromonomer: one-terminated methacryloyl-modified polydimethylsiloxane (Shin-Etsu Chemical Co., Ltd., weight-average molecular weight 4600) AAc: acrylic acid AAm: acrylamide 4HBA: 4-hydroxybutyl acrylate AOI-BP: 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl acrylate

[0087] Example 1 To 100 parts by weight of the solid content of the obtained adhesive component-containing solution, 5 parts by weight of a silicone-based graft copolymer (Synthesis Example 1) as a release aid and 3.0 parts by weight of an epoxy-based crosslinker were added to obtain an adhesive composition solution. The adhesive composition solution was then applied with a doctor knife to the release-treated surface of a polyethylene terephthalate film whose surface had been subjected to a release treatment so that the dry film thickness was 40 μm, and the film was dried by heating at 110°C for 5 minutes to obtain an adhesive layer. The obtained adhesive layer was bonded to the corona-treated surface of a 25 μm-thick transparent polyethylene naphthalate film that had been corona-treated on one side, to obtain an adhesive tape. The following crosslinking agents were used: Epoxy crosslinking agent: Tetrad C, manufactured by Mitsubishi Gas Chemical Company, Inc.

[0088] (Examples 2 to 23, Comparative Examples 1 to 8) Pressure-sensitive adhesive tapes were obtained in the same manner as in Example 1, except that the types and blending amounts of the release aids and the types and blending amounts of the crosslinking agents used were as shown in Tables 2 and 3. The following release aids and isocyanate-based crosslinking agents were used. Silicone oil: KF-96-10cs, manufactured by Shin-Etsu Chemical Co., Ltd. Epoxy-modified silicone oil: X-22-163C, manufactured by Shin-Etsu Chemical Co., Ltd. Silicone oil graft copolymer: Cymac US-270, manufactured by Toagosei Co., Ltd. Isocyanate crosslinking agent: Coronate L45, manufactured by Nippon Polyurethane Co., Ltd. Thermal polymerization initiator: Perbutyl O, manufactured by NOF Corporation Photopolymerization initiator: Omnirad369, manufactured by IGM Resins

[0089] <Evaluation> The pressure-sensitive adhesive tapes obtained in the examples and comparative examples were evaluated by the following methods. The results are shown in Tables 2 and 3.

[0090] (1) Measurement of initial adhesive strength and adhesive strength after heating The adhesive tape was cut into a 25 mm width to obtain a test specimen. The adhesive layer of the obtained test specimen was placed on a glass plate (large slide glass with white edge polished No. 2, manufactured by Matsunami Glass Industrial Co., Ltd.). Next, a 2 kg rubber roller was rolled back and forth on the test specimen at a speed of 300 mm / min to bond the test specimen to the glass plate. The test specimen was then left to stand at 23°C for 1 hour to prepare a test sample. After standing, the test sample was subjected to a tensile test in the 180° direction at a peel rate of 300 mm / min in accordance with JIS Z0237:2009 to measure the initial adhesive strength. Next, the test sample prepared in the same manner as above was subjected to a heat treatment at 220°C for 2 hours. After cooling, a tensile test in the 180° direction was performed in the same manner as above, and the adhesive strength after heating was measured. The initial adhesive strength and the adhesive strength after heating were evaluated according to the following criteria. In Example 18, since the adhesive layer was a photocurable type, an ultra-high pressure mercury lamp was irradiated from the glass plate side at 20 mW / cm before the heat treatment. 2 The light was irradiated for 150 seconds at an intensity of 1.

[0091] Initial adhesive strength ◎: Initial adhesive strength is 1.0N / 25mm or more ○: Less than 1.0N / 25mm, 0.10N / 25mm or more △: Less than 0.10N / 25mm

[0092] Adhesive strength after heating ◎: Adhesive strength after heating is less than 0.3N / 25mm ○: 0.3N / 25mm or more, less than 0.6N / 25mm △: 0.6N / 25mm or more, less than 1.0N / 25mm ×:1.0N / 25mm or more

[0093] (2) Evaluation of delamination resistance (high temperature resistance) and contamination The adhesive tape was cut into a width of 25 mm to obtain a test piece. Under an environment of room temperature 23°C and relative humidity 50%, the adhesive layer of the obtained test piece was placed on a glass plate (large slide glass with white edge polished No. 2, manufactured by Matsunami Glass Industrial Co., Ltd.) and adhered using a 2 kg rubber roller at a speed of 10 mm / min. The obtained laminate was subjected to a heat treatment once at 280°C for 60 minutes. After cooling, the state of the laminate was visually observed. Note that in Example 18, since the adhesive layer is a photocurable type, an ultra-high pressure mercury lamp was irradiated from the glass plate side at 20 mW / cm before the heat treatment. 2 The light was irradiated for 150 seconds at an intensity of 1. The delamination resistance (delamination resistance (high temperature)) was evaluated according to the following criteria. ○: Test piece did not peel off from glass plate after heat treatment ×: After heat treatment, the test piece peeled off from the glass plate.

[0094] After the test piece was peeled off from the glass plate, the glass plate was visually observed and the staining was evaluated according to the following criteria. ◎: No residue on the glass plate ○: Residue is present on part of the glass plate (less than 10% of the test piece area) ×: Residue is present on most of the glass plate (wider than 10% of the test piece area)

[0095] [Table 2]

[0096] [Table 3] [Industrial Applicability]

[0097] According to the present invention, it is possible to provide a silicone-based graft copolymer capable of forming a pressure-sensitive adhesive layer that is resistant to peeling even when subjected to a high-temperature heat treatment step, and that can enhance adhesion and suppress contamination of an adherend. Furthermore, according to the present invention, it is possible to provide a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape containing the silicone-based graft copolymer, as well as a method for manufacturing a semiconductor device. [Explanation of symbols]

[0098] 1 ring frame 2 adhesive tapes 3. Semiconductor wafers 4. Semiconductor chips

Claims

1. a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, a structure derived from an alkyl acrylate ester, and a structure derived from a monomer containing a functional group crosslinkable with the polar functional group; the composition contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, The weight average molecular weight is 5,000 or more and 200,000 or less, The glass transition temperature is -80°C or higher and 30°C or lower, and the 5% weight loss temperature is 300°C or higher and 400°C or lower, The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) and a temperature rise rate of 10°C / min from -100°C to 100°C, The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) at a heating rate of 10°C / min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating. Silicone graft copolymer.

2. 2. The silicone graft copolymer according to claim 1, wherein the polar functional group-containing monomer is a hydroxyl group-containing monomer.

3. 3. The silicone graft copolymer according to claim 1, wherein the silicon content is from 1 to 30% by weight.

4. 4. The silicone graft copolymer according to claim 1, wherein the monomer containing a functional group capable of crosslinking with a polar functional group has a protecting group bonded to the functional group capable of crosslinking with the polar functional group.

5. 5. The silicone graft copolymer of claim 1, wherein the content of components having a weight average molecular weight of 3,000 or less as measured by gel permeation chromatography is 10% by weight or less.

6. 6. A pressure-sensitive adhesive composition comprising the silicone graft copolymer according to claim 1, 2, 3, 4 or 5, a pressure-sensitive adhesive component having a functional group capable of crosslinking with said silicone graft copolymer, and a crosslinking agent.

7. A pressure-sensitive adhesive composition comprising a silicone-based graft copolymer, a pressure-sensitive adhesive component having a functional group capable of crosslinking with the silicone-based graft copolymer, and a crosslinking agent, the silicone graft copolymer has a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, and a structure derived from an alkyl acrylate; the silicone graft copolymer contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, has a weight average molecular weight of 5,000 or more and 200,000 or less, a glass transition temperature of −80° C. or more and 30° C. or less, and a 5% weight loss temperature of 300° C. or more and 400° C. or less; The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) and a temperature rise rate of 10°C / min from -100°C to 100°C, The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) at a heating rate of 10°C / min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating. Pressure-sensitive adhesive composition.

8. 8. The pressure-sensitive adhesive composition according to claim 6, wherein the pressure-sensitive adhesive component having a functional group capable of crosslinking with the silicone graft copolymer is a curable pressure-sensitive adhesive (meth)acrylic polymer.

9. The pressure-sensitive adhesive composition according to claim 8, which does not contain a polymerization initiator.

10. 8. The pressure-sensitive adhesive composition according to claim 6, wherein the content of the silicone graft copolymer is 0.1 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the pressure-sensitive adhesive component.

11. 6. An adhesive tape comprising a substrate and an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer contains the silicone graft copolymer according to claim 1.

12. The adhesive tape according to claim 11, which is used in the processing of semiconductor wafers or semiconductor chips.

13. An adhesive tape having a substrate and an adhesive layer laminated on at least one surface of the substrate, the adhesive tape being used in a processing step of a semiconductor wafer or semiconductor chip, the pressure-sensitive adhesive layer contains a silicone-based graft copolymer, the silicone graft copolymer has a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, and a structure derived from an alkyl acrylate; the silicone graft copolymer contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, has a weight average molecular weight of 5,000 or more and 200,000 or less, a glass transition temperature of −80° C. or more and 30° C. or less, and a 5% weight loss temperature of 300° C. or more and 400° C. or less; The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) and a temperature rise rate of 10°C / min from -100°C to 100°C, The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) at a heating rate of 10°C / min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating. Adhesive tape.

14. 14. The adhesive tape according to claim 12, which is attached to a ring frame and a semiconductor wafer to be used as a protective tape for protecting the semiconductor wafer during processing steps of the semiconductor wafer.

15. A method for manufacturing a semiconductor device, comprising the step of processing a semiconductor wafer or a semiconductor chip using the adhesive tape according to claim 11.

16. 16. A method for manufacturing a semiconductor device according to claim 15, comprising the steps of: attaching the adhesive tape according to claim 11 to a ring frame and a semiconductor wafer; and dicing the semiconductor wafer to obtain semiconductor chips.

17. A method for manufacturing a semiconductor device, comprising a process for processing a semiconductor wafer or a semiconductor chip using an adhesive tape, The pressure-sensitive adhesive tape has a substrate and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate, the pressure-sensitive adhesive layer contains a silicone-based graft copolymer, the silicone graft copolymer has a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, and a structure derived from an alkyl acrylate; the silicone graft copolymer contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, has a weight average molecular weight of 5,000 or more and 200,000 or less, a glass transition temperature of −80° C. or more and 30° C. or less, and a 5% weight loss temperature of 300° C. or more and 400° C. or less; The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) and a temperature rise rate of 10°C / min from -100°C to 100°C, The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL / min) at a heating rate of 10°C / min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating. A method for manufacturing a semiconductor device.

Images