JP7463147B2 - Adhesive Tape Roll - Google Patents

Description

The present invention relates to adhesive tape rolls, etc.

Adhesive tapes are used in various industrial fields because they can be easily bonded. In the construction field, adhesive tapes are used for temporary fixing of protective sheets and bonding of interior materials, in the automotive field for fixing interior parts such as seats and sensors, and for fixing exterior parts such as side moldings and side visors, and in the electrical and electronic field for module assembly and bonding of modules to housings. More specifically, adhesive tapes are widely used as surface protection tapes for temporarily protecting the surfaces of components such as optical devices, metal plates, painted metal plates, resin plates, and glass plates. In the manufacturing process of electronic devices such as semiconductor devices, adhesive tapes are attached to the adherends to protect or temporarily fix them in order to make them easier to handle and prevent damage during processing (for example, Patent Document 1, etc.).

Japanese Patent Application Laid-Open No. 5-32946

Adhesive tapes are usually shipped in the form of rolls. However, in this state, the adhesive layer may protrude from the sides due to winding stress during storage, and the protruding adhesive layers may adhere to each other, making it impossible to stably unwind the core side (blocking).

The inventors of the present invention have conducted research from the viewpoint of suppressing overhang of the adhesive layer in order to suppress blocking. In the course of their research, they have discovered that if there is no certain amount of overhang, the adhesive tape roll is prone to slippage due to vibrations and other factors that occur when it is transported.

Therefore, the objective of the present invention is to provide an adhesive tape and an adhesive tape roll that suppresses blocking while also suppressing winding slippage.

As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by an adhesive tape and an adhesive tape roll composed of the adhesive tape, which has a laminated structure including a substrate, an adhesive layer, and a cover film, and which has a laminated structure in this order, and in which, when the adhesive tape is pressurized at 2 kPa from the main surface direction, the length of the adhesive layer protruding from the end of the substrate is 20 μm or more, the gel fraction of the adhesive layer is 30% or more, and the thickness of the adhesive layer relative to the total thickness of the substrate and the cover film is 1.3 or less. Based on this finding, further research has led to the completion of the present invention.

That is, the present invention includes the following aspects:

Item 1. A long adhesive tape having a laminated structure including a substrate, an adhesive layer, and a cover film, the laminated structure being arranged in this order,
When the pressure-sensitive adhesive tape is pressed at 2 kPa in a direction along a main surface, a protruding length of the pressure-sensitive adhesive layer protruding from an end of the base material is 20 μm or more;
The pressure-sensitive adhesive layer has a gel fraction of 30% or more, and the thickness of the pressure-sensitive adhesive layer relative to the total thickness of the substrate and the cover film is 1.3 or less.
Adhesive tape.

Item 2. The adhesive tape according to item 1, in which the coefficient of dynamic friction between one surface and the other surface of the adhesive tape is 0.1 or more.

Item 3. The pressure-sensitive adhesive tape according to item 1 or 2, wherein the pressure-sensitive adhesive layer has a storage modulus G' at 23° C. of 5.0×10 ³ Pa or more and 2.0×10 ⁸ Pa or less.

Item 4. The adhesive tape according to any one of items 1 to 3, wherein the width of the adhesive tape is 50 to 1000 mm.

Item 5. An adhesive tape roll comprising the adhesive tape according to any one of items 1 to 4.

Item 6. The method includes a step of winding the adhesive tape into a roll,
the pressure-sensitive adhesive tape is a long-sized pressure-sensitive adhesive tape having a laminated structure including a substrate, a pressure-sensitive adhesive layer, and a cover film, the laminated structure being arranged in this order;
When the pressure-sensitive adhesive tape is pressed at 2 kPa in the main surface direction, the length of the pressure-sensitive adhesive layer protruding from the edge of the base material is 20 μm or more;
The pressure-sensitive adhesive layer has a gel fraction of 30% or more, and the thickness of the pressure-sensitive adhesive layer relative to the total thickness of the substrate and the cover film is 1.3 or less.
Item 6. A method for producing the adhesive tape roll according to item 5.

The present invention provides an adhesive tape and an adhesive tape roll that suppresses blocking while also suppressing winding slippage.

1 is a schematic diagram showing the length of the protruding portion of the adhesive layer protruding from the edge of the base material when the adhesive tape is pressed at 2 kPa from the main surface direction.

In this specification, the expressions "contain" and "include" include the concepts of "contain," "include," "consist essentially of," and "consist only of."

In this specification, "(meth)acrylic" refers to "acrylic" and "methacrylic". Thus, for example, (meth)acrylic acid includes acrylic acid and methacrylic acid, and (meth)acrylic acid esters include acrylic acid esters and methacrylic acid esters. The same applies to other compounds in which "(meth)acrylic" is used.

In one aspect, the present invention relates to a long adhesive tape having a laminated structure including a substrate, an adhesive layer, and a cover film, and in which these are arranged in this order, and in which, when the adhesive tape is pressurized at 2 kPa from the main surface direction, the length of the protruding portion of the adhesive layer protruding from the end of the substrate is 20 μm or more, the gel fraction of the adhesive layer is 30% or more, and the thickness of the adhesive layer relative to the total thickness of the substrate and the cover film is 1.3 or less (also referred to as the "adhesive tape of the present invention" in this specification), and an adhesive tape roll composed of the adhesive tape of the present invention (also referred to as the "adhesive tape roll of the present invention" in this specification). These will be described below.

(A) Substrate The substrate is not particularly limited as long as it contains a resin as a material. The substrate may contain components other than the resin as long as the effect of the present invention is not significantly impaired. In that case, the total amount of the resin in the substrate is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more, and is usually less than 100% by mass.

The resin constituting the substrate is not particularly limited, but examples thereof include polyolefin resins, polyester resins, ethylene-vinyl acetate copolymers, modified olefin resins, polyvinyl chloride resins, polyurethane resins, cycloolefin polymer resins, acrylic resins, polycarbonates, ABS (acrylonitrile-butadiene-styrene) resins, polyamides, polyurethanes, polyimides, and the like. Examples of the polyolefin resins include polyethylene and polypropylene. Examples of the polyester resins include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Examples of the modified olefin resins include ethylene-acrylic acid ester copolymers, and the like. Among these, polyester resins are preferred, and polyethylene terephthalate is more preferred.

The resin constituting the substrate may be a single type or a combination of two or more types.

The layer structure of the substrate is not particularly limited. The substrate may be composed of a single substrate, or may be a combination of two or more substrates.

The thickness of the substrate is not particularly limited as long as it satisfies the ratio of the thickness of the adhesive layer to the total thickness of the substrate and cover film described below, but is, for example, 10 μm or more and 250 μm or less. From the viewpoints of suppressing blocking, suppressing winding slippage, improving adhesive properties, etc., the thickness is preferably 15 μm or more, more preferably 20 μm or more, even more preferably 25 μm or more, and particularly preferably 30 μm or more, and is preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and particularly preferably 80 μm or less.

The substrate may be one that has been subjected to various surface treatments. Examples of surface treatments include surface activation treatments such as corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment. The surface treatment of the substrate may be performed on the side facing the adhesive polymer layer, or on the opposite side.

(B) Pressure-sensitive Adhesive Layer The pressure-sensitive adhesive layer is not particularly limited as long as it is a layer that contains a pressure-sensitive adhesive and satisfies the gel fraction described below.

The adhesive is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, polyolefin adhesives, polyester adhesives, vinyl alkyl ether adhesives, polyamide adhesives, rubber adhesives, silicone adhesives, and fluorine adhesives. Among these, acrylic adhesives are preferred from the viewpoint of ease of adjusting the adhesiveness after forming the adhesive layer.

Acrylic adhesives are obtained by polymerizing monomers in an adhesive composition that contains a (mono)acrylic ester as the main monomer component to form a (meth)acrylic copolymer.

The adhesive composition contains a (meth)acrylic acid ester (A) and a functional group-containing monomer (B) as monomer components.

The (meth)acrylic acid ester (A) is the main monomer component constituting the base polymer in the acrylic adhesive, and may be used alone or in combination of two or more (meth)acrylic acid esters. When (meth)acrylic acid esters are combined, the ratio of each (meth)acrylic acid ester may be selected as desired. The (meth)acrylic acid ester is preferably a (meth)acrylic acid ester having a hydrocarbon group with 1 to 15 carbon atoms.

Examples of the (meth)acrylic acid ester (A) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, and undecyl Examples of the (meth)acrylate include alkyl ester (meth)acrylates such as (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, and hexadecyl (meth)acrylate; (meth)acrylic acid esters having an alicyclic hydrocarbon group such as isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; and (meth)acrylic acid esters having an aromatic hydrocarbon group such as phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxydiethylene glycol (meth)acrylate.

Among the (meth)acrylic acid esters (A), alkyl ester (meth)acrylates are preferred from the viewpoint of being able to exhibit favorable adhesive properties as a semiconductor temporary fixing material, and alkyl ester (meth)acrylates having an alkyl group (preferably a branched alkyl group) with 2 to 12 carbon atoms (preferably 4 to 10, more preferably 6 to 10) are more preferred.

The content of the (meth)acrylic acid ester (A) is preferably 70 to 99% by mass, more preferably 75 to 95% by mass, and even more preferably 80 to 90% by mass, based on 100% by mass of the total amount of the monomer components of the (meth)acrylic copolymer.

Examples of the functional group-containing monomer (B) include carboxyl group-containing (meth)acrylates such as (meth)acrylic acid; hydroxyl group-containing (meth)acrylates; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate. Among these, acrylic acid and hydroxyl group-containing (meth)acrylates are preferred from the viewpoint of stable adhesiveness.

Examples of hydroxy group-containing (meth)acrylates include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. From the viewpoint of stable expression of adhesiveness, the number of carbon atoms in the alkyl of the hydroxyalkyl (meth)acrylate is preferably 2 to 6, and more preferably 2 to 3.

The functional group-containing monomer (B) may be used alone or in combination of two or more.

The content of the functional group-containing monomer (B) is preferably 1 to 30% by mass, more preferably 5 to 25% by mass, and even more preferably 10 to 20% by mass, relative to 100% by mass of the total amount of the monomer components of the (meth)acrylic copolymer.

To obtain a (meth)acrylic copolymer by copolymerizing a monomer mixture containing the above monomers, additives such as a polymerization regulator may be added to the monomer mixture as necessary, and a radical reaction may be carried out in the presence of a polymerization initiator. As a method for radically reacting the monomer mixture, i.e., a polymerization method, a conventionally known method may 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 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 of two or more.

The adhesive layer may consist of only an adhesive, but may also contain other components. The other components are not particularly limited, but may include, for example, a photopolymerization initiator, a thermal polymerization initiator, a gas generator, a radically polymerizable polyfunctional oligomer or monomer, a silicone compound, an inorganic filler, a tackifier, etc.

Examples of photopolymerization initiators include those that are activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal, and phosphine oxide derivative compounds. Other examples include bis(η5-cyclopentadienyl)titanocene derivative compounds, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. These photopolymerization initiators may be used alone or in combination of two or more.

Thermal polymerization initiators include those that decompose when heated and generate active radicals that initiate polymerization and curing. 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. Of these thermal polymerization initiators, commercially available ones are not particularly limited, but suitable examples include Perbutyl D, Perbutyl H, Perbutyl P, and Perpenta H (all manufactured by NOF Corporation). These thermal polymerization initiators may be used alone or in combination of two or more.

The polyfunctional oligomer or monomer is not particularly limited as long as it is radically polymerizable. By blending this, the photocuring property and the thermosetting property can be improved. The polyfunctional oligomer or monomer is preferably one having a molecular weight of 10,000 or less, and more preferably one having a molecular weight of 5,000 or less and having 2 to 20 radically polymerizable unsaturated bonds in the molecule so that the three-dimensional reticulation of the adhesive layer by heating or irradiation with light can be efficiently performed. Examples of polyfunctional oligomers or monomers include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, and the same methacrylates as those mentioned above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylates, and the same methacrylates as those mentioned above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The gas generating agent is not particularly limited as long as it generates gas by light irradiation or heating. When the adhesive layer containing such a gas generating agent is irradiated with light or heated, the adhesive component crosslinks and hardens, increasing the elastic modulus of the entire adhesive, and the gas generated in such a hard adhesive is released from the adhesive to the adhesive interface, peeling off at least a part of the adhesive surface, making peeling easier. From the viewpoint that the adhesive tape can exhibit heat resistance when the adhesive tape is used in a manufacturing method for electronic devices including a heating step, the gas generating agent is preferably one that generates gas by light irradiation. The gas generating agent is not particularly limited, but examples thereof include azide compounds, azo compounds, ketoprofen, tetrazole compounds, etc. Among them, ketoprofen and tetrazole compounds, which have excellent heat resistance, are preferable.

Since silicone compounds have excellent heat resistance, they prevent the adhesive from burning even when placed in a high-temperature environment of 200°C or more, and when peeled off, they bleed out to the interface with the adherend, making peeling easy. In a preferred embodiment of the present invention, it is preferable that the silicone compound has a functional group that can be crosslinked with the adhesive. In such a case, the silicone compound reacts chemically with the adhesive when irradiated with light or heated, and is incorporated into the adhesive, so that the silicone compound is less likely to adhere to the adherend and contaminate it. In addition, by blending a silicone compound, particularly a silicone compound having a functional group that can be crosslinked with the adhesive, into the adhesive layer, the effect of preventing adhesive residue on the adherend is also exhibited.

An example of an inorganic filler is fumed silica. By adding an inorganic filler, it is possible to increase the cohesive strength of the adhesive layer.

The adhesive layer may contain various polyfunctional compounds, such as isocyanate compounds, melamine compounds, and epoxy compounds, which are generally blended into adhesives, as desired, in order to adjust the cohesive strength of the adhesive. The adhesive layer may also contain known additives, such as antistatic agents, plasticizers, resins, surfactants, wax, and particulate fillers. These components may be used alone or in combination of two or more.

The content of the components other than the adhesive described above is, for example, 0 to 70% by weight, particularly 0 to 50% by weight, especially 0 to 30% by weight, and even more especially 0 to 10% by weight, relative to 100% by weight of the adhesive layer.

In the adhesive tape of the present invention, the gel fraction of the adhesive layer is 30% or more from the viewpoint of suppressing blocking, suppressing winding slippage, and being able to exhibit adhesive properties as a temporary fixing material. The gel fraction is preferably 40% or more, more preferably 50% or more, even more preferably 55% or more, and even more preferably 60% or more from the viewpoint of suppressing blocking, suppressing winding slippage, and being able to exhibit adhesive properties as a temporary fixing material. From the same viewpoint, the gel fraction is preferably 97% or less, more preferably 95% or less, even more preferably 92% or less, and even more preferably 90% or less. From the same viewpoint, the gel fraction is preferably 40 to 97%, more preferably 50 to 95%, even more preferably 55 to 92%, and even more preferably 60 to 90%.

The gel fraction is measured as follows: 0.1 g of the adhesive layer is scraped off from the obtained adhesive tape, immersed in 50 mL of ethyl acetate, and shaken in a shaker at 23°C and 200 rpm for 24 hours. After shaking, a metal mesh (mesh size #200) is used to separate the ethyl acetate and the adhesive layer that has absorbed the ethyl acetate and swollen. The separated adhesive layer is dried at 110°C for 1 hour. The weight of the adhesive layer including the dried metal mesh is measured, and the gel fraction is calculated using the following formula.

Gel fraction (wt%)=100×(W ₁ −W ₂ )/W ₀
(W ₀ : initial weight of the adhesive layer, W ₁ : weight of the adhesive layer including the metal mesh after drying, W ₂ : initial weight of the metal mesh).

In the adhesive tape of the present invention, the storage modulus G' of the adhesive layer at 23°C is preferably 5.0 x 10 ³ Pa or more and 2.0 x 10 ⁸ Pa or less, more preferably 5.0 x 10 4 Pa or more and 1.0 x 10 ⁷ Pa or less, and even more preferably 1.0 x 10 ⁵ Pa or more and 1.0 x 10 ⁶ Pa or less, from the viewpoints of suppressing blocking, suppressing winding slippage, and being able to express adhesive properties as ^a temporary fixing material.

The storage modulus is measured as follows: Using a dynamic viscoelasticity measuring device (IT Corporation, DVA-200), the dynamic viscoelasticity spectrum of the adhesive layer is measured under shear deformation at a measurement frequency of 10 Hz, and the storage modulus G' of the adhesive layer at 23°C is calculated.

The layer configuration of the adhesive layer is not particularly limited. The adhesive layer may be composed of a single adhesive layer, or may be composed of a combination of two or more adhesive layers.

The thickness of the adhesive layer is not particularly limited, as long as it satisfies the thickness of the adhesive layer relative to the total thickness of the substrate and cover film described below, but is, for example, 10 to 500 μm. From the viewpoints of suppressing blocking, suppressing winding slippage, and being able to exhibit adhesive properties as a temporary fixing material, the thickness is preferably 20 to 400 μm, more preferably 30 to 300 μm, even more preferably 40 to 200 μm, even more preferably 40 to 150 μm, and particularly preferably 40 to 120 μm.

(C) Cover film The cover film is not particularly limited as long as it contains resin as a material. The cover film may contain components other than resin as long as the effect of the present invention is not significantly impaired. In this case, the total amount of resin in the cover film is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more, and is usually less than 100% by mass.

The resin constituting the cover film is not particularly limited, but examples thereof include polyolefin resins, polyester resins, ethylene-vinyl acetate copolymers, modified olefin resins, polyvinyl chloride resins, polyurethane resins, cycloolefin polymer resins, acrylic resins, polycarbonates, ABS (acrylonitrile-butadiene-styrene) resins, polyamides, polyurethanes, polyimides, and the like. Examples of the polyolefin resins include polyethylene and polypropylene. Examples of the polyester resins include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). Examples of the modified olefin resins include ethylene-acrylic acid ester copolymers, and the like. Among these, polyester resins are preferred, and polyethylene terephthalate is more preferred.

The resin that constitutes the cover film may be a single type or a combination of two or more types.

The layer structure of the cover film is not particularly limited. The cover film may be composed of a single type of cover film, or may be composed of a combination of two or more types of cover films.

The thickness of the cover film is not particularly limited, but is within the range that satisfies the thickness of the adhesive layer relative to the total thickness of the substrate and cover film described below, and is, for example, 10 μm or more and 250 μm or less. From the viewpoints of blocking prevention, winding slippage prevention, and handling during the process, the thickness is preferably 12 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, still more preferably 25 μm or more, and particularly preferably 30 μm or more, and is preferably 200 μm or less, more preferably 175 μm or less, even more preferably 150 μm or less, still more preferably 125 μm or less, and particularly preferably 100 μm or less.

The cover film may be subjected to various surface treatments. Examples of surface treatments include surface activation treatments such as corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment. The cover film may also be subjected to a release treatment as necessary.

(D) Structure of the Adhesive Tape The adhesive tape of the present invention comprises the above-mentioned substrate, adhesive layer and cover film, and has a laminated structure in which these are arranged in this order (layer structure: substrate/adhesive layer/cover film).

The laminated structure may contain other layers. The other layers are not particularly limited as long as the effects of the present invention are not significantly impaired, and examples thereof include an anchor layer. The anchor layer can have the effect of increasing the adhesion between layers (for example, between the substrate and the pressure-sensitive adhesive layer).

The adhesive tape of the present invention may be composed of only a laminate structure (single-sided adhesive layer structure), or may contain other laminate structures in addition to the laminate structure. In a typical example of the latter case, the adhesive tape of the present invention includes a double-sided adhesive layer structure, i.e., a layer structure of (optionally a cover film/) adhesive layer/substrate/adhesive layer/cover film. It is preferable that the adhesive tape of the present invention has a single-sided adhesive layer structure, i.e., a layer structure of substrate/adhesive layer/cover film.

The adhesive tape of the present invention is a long adhesive tape. Here, "long" refers to a shape in which the long side is long enough to be rolled up, or a shape unwound from a roll. The short side of the adhesive tape of the present invention is the "width" of the adhesive tape.

From the viewpoint of easy handling during the process, etc., the width of the adhesive tape of the present invention is preferably 50 mm or more, more preferably 70 mm or more, even more preferably 100 mm or more, still more preferably 200 mm or more, particularly preferably 250 mm or more, and especially preferably 300 mm or more, and is preferably 1000 mm or less, more preferably 800 mm or less, even more preferably 700 mm or less, still more preferably 600 mm or less, particularly preferably 500 mm or less, and especially preferably 400 mm or less.
In the pressure-sensitive adhesive tape of the present invention, it is preferable that at least the widths of the substrate and the cover film are the same and that the edges are aligned.

In the adhesive tape of the present invention, the thickness of the adhesive layer relative to the total thickness of the substrate and the cover film is 1.3 or less from the viewpoints of suppressing blocking, suppressing winding slippage, and exhibiting adhesive properties as a temporary fixing material. When the thickness of the adhesive layer relative to the total thickness of the substrate and the cover film is in the above ratio, the adhesive layers are sufficiently separated from each other when rolled, preventing any protrusion that would cause a distance between them, and blocking can be suppressed. The thickness of the adhesive layer relative to the total thickness of the substrate and the cover film is preferably 0.1 to 1.3, more preferably 0.3 to 1.3, even more preferably 0.5 to 1.3, and even more preferably 0.8 to 1.3.

(E) Properties of the Adhesive Tape The adhesive tape of the present invention has the following property from the viewpoints of blocking suppression, winding slippage suppression, glue adhesion to the line during processing, etc.: when the adhesive tape is pressed from the main surface direction with 2 kPa, the length of the protruding part of the adhesive layer protruding from the edge of the base material is 20 μm or more. From the viewpoints of blocking suppression, winding slippage suppression, etc., the length of the protruding part is preferably 20 μm or more and 250 μm or less, more preferably 20 μm or more and 150 μm or less, even more preferably 20 μm or more and 100 μm or less, still more preferably 20 μm or more and 60 μm or less, and particularly preferably 20 μm or more and 40 μm or less.

The method for measuring the length of the protruding portion is as follows. The adhesive tape is cut to prepare a 10 cm square sample. The sample is placed between two 10 cm square copper plates (thickness 1 mm), and a 20 N weight is placed on the main surface of the sample via the copper plate, and the entire sample is pressurized (2 kPa pressure). In this state, the sample is left at 23°C and 50% RH for 24 hours. Thereafter, the length of the protruding portion of the adhesive layer protruding from the edge of the substrate is measured (see FIG. 1) by observing with an optical microscope while still under pressure. The measurement is performed at the center of each side (each of the four sides), and the maximum value is taken as the protruding portion length of the adhesive layer.
When the adhesive tape is made into a roll, if the protruding portion has the above-mentioned length at at least one end, the effect of suppressing winding slippage is excellent.

The pressure-sensitive adhesive tape of the present invention preferably has the following characteristic: the coefficient of dynamic friction between one surface and the other surface of the pressure-sensitive adhesive tape is 0.05 or more, from the viewpoints of blocking suppression, winding slippage suppression, ease of tape unwinding, etc. "One surface and the other surface" refers to, for example, the substrate surface and the cover film surface when the pressure-sensitive adhesive tape of the present invention has a single-sided pressure-sensitive adhesive layer structure, and the two cover film surfaces when the pressure-sensitive adhesive tape of the present invention has a double-sided pressure-sensitive adhesive layer structure. From the viewpoints of blocking suppression, winding slippage suppression, ease of tape unwinding, etc., the coefficient of dynamic friction is preferably 0.1 or more, more preferably 0.15 to 0.8, even more preferably 0.2 to 0.7, even more preferably 0.25 to 0.6, even more preferably 0.3 to 0.5, and particularly preferably 0.35 to 0.45.
The coefficient of dynamic friction can be adjusted by the resins constituting the substrate and cover film, surface treatment, and the like.

The dynamic friction coefficient is measured as follows: A dynamic friction test can be performed using a precision universal testing machine Autograph AG-ISHIMADZU at a test speed of 100 mm/min in accordance with JIS 7125.

(F) Manufacturing method of the pressure-sensitive adhesive tape The manufacturing method of the pressure-sensitive adhesive tape of the present invention is not particularly limited. The pressure-sensitive adhesive tape of the present invention can be manufactured, for example, by a method including a step of applying a mixture (pressure-sensitive adhesive composition) of each component of the pressure-sensitive adhesive layer, such as the pressure-sensitive adhesive (or monomer component), and a diluent added as necessary, onto a cover film, and attaching the obtained laminated sheet to one or both sides of another sheet including a substrate via the pressure-sensitive adhesive layer.

The diluent is not particularly limited, but examples thereof include esters such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, and ethyl butyrate; hydrocarbons such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; halogenated hydrocarbons such as dichloromethane, trichloroethane, trichloroethylene, tetrachloroethylene, and dichloropropane; alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, isobutyl alcohol, and diacetone alcohol; ethers such as diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, and cyclohexanone; polyols and derivatives thereof such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate. The diluent may be used alone or in combination of two or more types.

When a diluent is added, the mixing ratio is not particularly limited. From the viewpoint of coatability, etc., the mixing ratio is such that the solids concentration of the adhesive composition is, for example, 15 to 40% by mass, preferably 25 to 35% by mass.

The method for applying the adhesive composition is not particularly limited. For example, it can be applied using a conventional coater (gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, etc.).

After application, it is preferable to dry the coating. The drying temperature is, for example, 30 to 200°C, preferably 60 to 160°C, and more preferably 80 to 120°C. The drying time may vary depending on the drying temperature, but is, for example, 30 seconds to 15 minutes, preferably 1 minute to 10 minutes, and more preferably 3 minutes to 7 minutes.

(G) Adhesive Tape Roll The adhesive tape roll of the present invention can be obtained by a step of winding the adhesive tape of the present invention into a roll.

The width of the adhesive tape roll of the present invention is, for example, 50 mm or more and 1000 mm or less. From the viewpoint of the wafer size and substrate size generally used as a semiconductor temporary fixing material, the width is preferably 100 mm or more, more preferably 200 mm or more, and even more preferably 300 mm or more, and is preferably 700 mm or less, more preferably 500 mm or less, and even more preferably 400 mm or less.

(H) Uses The pressure-sensitive adhesive tape of the present invention constituting the pressure-sensitive adhesive tape roll of the present invention is not particularly limited in its use and can be used in various fields. In particular, it can be suitably used as a protective tape for electronic components for protecting electronic components such as semiconductor wafers (preferably surfaces having bumps or other irregularities).

The pressure-sensitive adhesive tape of the present invention can also be used for applications involving high-temperature treatment, such as fixing a wafer to a support plate in the TSV manufacturing process, or temporarily fixing a wafer or chip to a support plate or the like when passing the wafer or chip through a reflow furnace.

The adhesive tape of the present invention is suitable for use as a tape for fixing a support plate during high-temperature treatment, a fixing tape for both high-temperature treatment and back grinding, a fixing tape for both high-temperature treatment and dicing, and a tape for temporarily fixing semiconductor chips when individualized semiconductor chips are further treated at high temperatures.

The adhesive tape of the present invention is suitable as an adhesive tape for fixing a wafer to a support plate in order to facilitate handling of the wafer and prevent damage during wafer processing, including high-temperature processing. The present invention also includes a wafer processing method including a support plate fixing step of fixing the wafer to a support plate via the adhesive tape of the present invention, a wafer processing step of subjecting the surface of the wafer fixed to the support plate to a treatment involving heating at 200°C or higher, and a support plate peeling step of irradiating the wafer after the treatment with light to harden the adhesive layer and peel off the support plate from the wafer.

The support plate is not particularly limited, and examples thereof include a glass plate, a quartz glass plate, and a stainless steel plate. The process involving heating the surface of the wafer fixed to the support plate to 200°C or higher is not particularly limited, and examples thereof include chemical vapor deposition (CVD), reflow, and reactive ion etching (RIE).

The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

(1) Preparation of adhesive tape
(1-1) Example 1
(Preparation of Resin)
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared, and 85 parts by weight of 2-ethylhexyl acrylate as an alkyl (meth)acrylate ester, 10 parts by weight of hydroxyethyl methacrylate as functional group-containing monomers, 5 parts by weight of acrylic acid, 0.01 parts by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate were added to the reactor. 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, 1 hour and 2 hours after the start of polymerization, 1,1-bis(t
Then, 0.01 parts by weight of t-hexylperoxy)-3,3,5-trimethylcyclohexane was added at each time, and 0.05 parts by weight of t-hexylperoxypivalate was added 4 hours after the start of polymerization to continue the polymerization reaction. Then, 8 hours after the start of polymerization, an ethyl acetate solution of a functional group-containing (meth)acrylic polymer having a solid content of 30% by weight and a weight average molecular weight of 900,000 was obtained.

(Preparation of adhesive tape)
To 100 parts by weight of the resin solid content of the ethyl acetate solution of the obtained resin, 0.2 parts by weight of a photopolymerization initiator (Esacure One, manufactured by Nippon SiberHegner Co., Ltd.), 0.2 parts by weight of a crosslinking agent (Coronate L-45, manufactured by Tosoh Corporation), 10 parts by weight of a multifunctional acrylate (UN5500, manufactured by Negami Chemical Industries Co., Ltd.), 20 parts by weight of a silicone compound (EBECRYL350, manufactured by Daicel-Allnex Co., Ltd.), and 5 parts by weight of an inorganic filler (MT-10, manufactured by Tokuyama Corporation) were added and thoroughly mixed to obtain a pressure-sensitive adhesive composition. The ethyl acetate solution of the obtained pressure-sensitive adhesive composition was applied to the release-treated surface of a 50 μm-thick double-sided release-treated polyethylene terephthalate film (cover film, thickness 50 μm) with a comma coater so that the thickness of the dried film was 100 μm, and the mixture was dried at 110 ° C. for 5 minutes to form a pressure-sensitive adhesive layer. Next, a transparent polyethylene terephthalate film (substrate) having a thickness of 50 μm was attached to the adhesive layer, and then the adhesive layer was left to stand at 40° C. for 2 days to obtain an adhesive tape consisting of the substrate/adhesive layer/cover film.

The double-sided release-treated polyethylene terephthalate film used was NS-50-C (one-sided release treatment, thickness: 50 μm) manufactured by Nakamoto Packs, with the non-release-treated side treated with the same release treatment as the other side.

(1-2) Example 2
An adhesive tape (adhesive layer thickness: 100 μm, total thickness of substrate and cover film: 100 μm) was obtained in the same manner as in Example 1, except that the amount of crosslinking agent used was 0.6 parts by weight.

(1-3) Example 3
An adhesive tape (adhesive layer thickness: 100 μm, total thickness of substrate and cover film: 100 μm) was obtained in the same manner as in Example 1, except that the amount of crosslinking agent used was 2 parts by weight.

(1-4) Example 4
An adhesive tape (adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 1, except that a cover film (NS-50-C manufactured by Nakamoto Packs Co., Ltd.) having one side subjected to release treatment was used.

(1-5) Example 5
An adhesive tape (adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 2, except that a cover film with one side release treatment (NS-50-C manufactured by Nakamoto Packs Co., Ltd.) was used.

(1-6) Example 6
An adhesive tape (adhesive layer thickness: 100 μm, total thickness of substrate and cover film: 100 μm) was obtained in the same manner as in Example, except that a cover film having one side subjected to release treatment was used.

(1-7) Example 7
An adhesive tape (adhesive layer thickness: 50 μm, total thickness of substrate and cover film: 150 μm) was prepared in the same manner as in Example 4, except that the thickness of the dry film was 50 μm and the thickness of the substrate was 100 μm.
obtained.

(1-8) Example 8
An adhesive tape (adhesive layer thickness: 50 μm, total thickness of substrate and cover film: 150 μm) was obtained in the same manner as in Example 3, except that the thickness of the dry film was 50 μm and the thickness of the substrate was 100 μm.

(1-9) Example 9
An adhesive tape (adhesive layer thickness: 50 μm, total thickness of substrate and cover film: 150 μm) was obtained in the same manner as in Example 4, except that the thickness of the dry film was 50 μm and the thickness of the substrate was 100 μm.

(1-10) Example 10
An adhesive tape (adhesive layer thickness: 50 μm, total thickness of substrate and cover film: 150 μm) was obtained in the same manner as in Example 6, except that the thickness of the dry film was 50 μm and the thickness of the substrate was 100 μm.

(1-11) Example 11
An adhesive tape (adhesive layer thickness: 200 μm, total thickness of substrate and cover film: 150 μm) was obtained in the same manner as in Example 2, except that the thickness of the dry film was 200 μm and the thickness of the substrate was 100 μm.

(1-12) Example 12
An adhesive tape (adhesive layer thickness 250 μm, total thickness of substrate and cover film 250 μm) was obtained in the same manner as in Example 3, except that the thickness of the dry coating was 250 μm, the thickness of the substrate was 125 μm, and the thickness of the cover film was 125 μm.

(1-13) Example 13
An adhesive tape (adhesive layer thickness: 300 μm, total thickness of substrate and cover film: 250 μm) was obtained in the same manner as in Example 2, except that the thickness of the dry film was 300 μm, the thickness of the substrate was 125 μm, and the thickness of the cover film was 125 μm.

(1-14) Example 14
An adhesive tape (adhesive layer thickness: 100 μm, total thickness of substrate and cover film: 100 μm) was obtained in the same manner as in Example 1, except that the amount of inorganic filler was 0 part by weight.

(1-15) Example 15
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 1. Thereafter, light irradiation was performed using a high-pressure mercury lamp at a wavelength of 365 nm to achieve a dose of 500 mJ/ ^cm2 .

(1-16) Example 16
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 2, except that a substrate (NS-50-C, manufactured by Nakamoto Packs Co., Ltd.) having a release treatment applied to the side opposite the adhesive layer was used, and an ethyl acetate solution of the adhesive composition was applied so that the protruding portion length a was 60 μm.

(1-17) Example 17
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 2, except that a coating treatment (NK350: manufactured by Nippon Shokubai Co., Ltd.) was performed on the side of the substrate opposite the adhesive layer, and an ethyl acetate solution of the adhesive composition was applied so that the protruding portion length a was 20 μm.

(1-18) Example 18
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 2, except that a substrate (NS-50-MA, manufactured by Nakamoto Pax Co., Ltd.) having a release treatment applied to the side opposite the adhesive layer was used.

(1-19) Comparative Example 1
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 1, except that the amount of crosslinking agent used was 0.05 parts by weight.

(1-20) Comparative Example 2
To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution of the resin, 0.2 parts by weight of a photopolymerization initiator (Esacure One, manufactured by Nippon SiberHegner Co., Ltd.) and 0.2 parts by weight of a crosslinking agent (Coronate L-45, manufactured by Tosoh Corporation) were added and thoroughly mixed to obtain an adhesive tape (adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) in the same manner as in Example 1, except that an adhesive composition was used. Thereafter, light irradiation was performed with a high-pressure mercury lamp so that the wavelength of 365 nm was 500 mJ/ ^cm2 .

(1-21) Comparative Example 3
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 100 μm) was obtained in the same manner as in Example 1, except that the thickness of the substrate was 12 μm and the thickness of the cover film was 12 μm.

(1-22) Comparative Example 4
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 24 μm) was obtained in the same manner as in Example 3, except that the thickness of the substrate was 12 μm and the thickness of the cover film was 12 μm.

(1-23) Comparative Example 5
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 24 μm) was obtained in the same manner as in Example 1, except that the thickness of the substrate was 12 μm and the thickness of the cover film with one-sided release treatment was 12 μm.

(1-24) Comparative Example 6
An adhesive tape (tape width 100 mm, adhesive layer thickness 100 μm, total thickness of substrate and cover film 24 μm) was obtained in the same manner as in Example 3, except that the thickness of the substrate was 12 μm and the thickness of the cover film with one-sided release treatment was 12 μm.

(2) Evaluation
(2-1) Storage Modulus Measurement The dynamic viscoelasticity spectrum of the pressure-sensitive adhesive layer was measured under shear deformation at a measurement frequency of 10 Hz using a dynamic viscoelasticity measuring device (IT Corporation, DVA-200) to determine the storage modulus G' of the pressure-sensitive adhesive layer at 23°C.

(2-2) Gel Fraction Measurement 0.1 g of only the adhesive layer was scraped off from the obtained adhesive tape, immersed in 50 ml of ethyl acetate, and shaken for 24 hours at 23°C and 200 rpm in a shaker. After shaking, ethyl acetate and the adhesive layer that absorbed and swelled with ethyl acetate were separated using a metal mesh (opening #200 mesh). The separated adhesive layer was dried for 1 hour under conditions of 110°C. The weight of the adhesive layer including the dried metal mesh was measured, and the gel fraction was calculated using the following formula.

Gel fraction (wt%)=100×(W ₁ −W ₂ )/W ₀
(W ₀ : initial weight of the adhesive layer, W ₁ : weight of the adhesive layer including the metal mesh after drying, W ₂ : initial weight of the metal mesh).

(2-3) Dynamic friction coefficient measurement The measurements were performed using a precision universal testing machine Autograph AG-IS (Shimadzu) at a test speed of 100 mm/min, a total mass of the sliding piece of 200 g (1.96 N), a test piece size of 80 x 200 mm, and a contact area between the sliding piece and the test piece of 40 ^cm2 , in an environment of 23°C. The average load from the start of the relative slippage between the contact surfaces until 60 mm was taken as the dynamic friction force.
Dynamic friction coefficient μ ₀ = (F ₀ )/F _p
(μ ₀ : coefficient of kinetic friction, F ₀ : kinetic friction force (N), F _p : normal force generated by the mass of the sliding piece (=1.96 N)).

(2-4) Measurement of the protruding portion length The adhesive tape was cut to prepare a 10 cm square sample. The sample was placed between two 10 cm square copper plates (thickness 1 mm), and a 20 N weight was placed on the sample in the main surface direction via the copper plate, and pressure was applied (2 kPa pressure). In this state, it was left at 23°C and 50% RH for 24 hours. After leaving it, it was observed with an optical microscope while still under pressure, and the protruding portion length of the adhesive layer protruding from the edge of the substrate (see FIG. 1) was measured. The measurement was performed at the center of each side (each of the four sides), and the maximum value was taken as the protruding portion length of the adhesive layer.

(2-5) Evaluation of blocking The adhesive tape was cut to prepare a sample of 10 cm square. On a rigid plate, two of the samples were stacked so that the cover film of one sample and the substrate of the other sample faced each other. Another rigid plate was stacked on top of the sample, a 20N weight was placed on it (2 kPa pressure), and the sample was left at 23°C and 50% RH for 24 hours. After leaving the sample, the presence and degree of stringiness when peeling the two samples was visually observed, and blocking was evaluated according to the following criteria.
A: The film peels off cleanly and without any peeling from the cut sample.
B: Slight stickiness occurs when the cut sample is peeled off (the adhesive does not transfer).
C: Threading occurred on the sample, and the adhesive adhered to the side of the tape (adhesive transfer).

(2-6) Evaluation of Winding Misalignment The adhesive tape was cut to prepare a sample of 10 cm width x 50 cm. The sample was wound around a 3-inch ABS core with a winding misalignment of less than 0.5 mm to obtain a roll of adhesive tape. The roll was dropped from a height of 30 cm with the side facing sideways. After the drop, the winding position misalignment of the roll was measured, and the winding misalignment was evaluated according to the following criteria.
A: The length of the deviation is less than 1 mm.
B: The length of the deviation is 1.0 mm or more and less than 1.5 mm.
C: The length of the deviation is 1.5 to less than 2.0 mm.
D: The length of the deviation is 2 mm or more.

The results are shown in Tables 1 and 2.

Claims (6)

A long adhesive tape having a laminated structure including a substrate, an adhesive layer, and a cover film, the laminated structure being arranged in this order,
When the pressure-sensitive adhesive tape is pressed at 2 kPa in a main surface direction, a protruding length of the pressure-sensitive adhesive layer protruding from an end of the base material is 20 μm or more and 250 μm or less ,
The pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive as a pressure-sensitive adhesive,
The pressure-sensitive adhesive layer has a gel fraction of 30% or more ,
The thickness of the pressure-sensitive adhesive layer is 10 to 500 μm,
the pressure-sensitive adhesive layer has a storage modulus G' at 23°C of 5.0 x 10 ³ Pa or more and 2.0 x 10 ⁸ Pa or less;
The ratio of the thickness of the pressure-sensitive adhesive layer to the total thickness of the substrate and the cover film is 1.3 or less, and
The coefficient of dynamic friction between one surface and the other surface of the pressure-sensitive adhesive tape is 0.1 or more .
Adhesive tape. The pressure-sensitive adhesive tape according to claim 1 , wherein a dynamic friction coefficient between one surface and the other surface of the pressure-sensitive adhesive tape is 0.15 or more and 0.8 or less . 3. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer has a storage modulus G' at 23° C. of 5.0×10 ⁴ Pa or more and 1.0×10 ⁷ Pa or less . The adhesive tape according to any one of claims 1 to 3, wherein the width of the adhesive tape is 50 to 1000 mm. An adhesive tape roll comprising the adhesive tape according to any one of claims 1 to 4. The method includes a step of winding the adhesive tape according to any one of claims 1 to 4 into a roll.
A method for producing the adhesive tape roll according to claim 5.