TWI845807B - Remove the adhesive tape again - Google Patents

Abstract

The present invention provides a re-peelable adhesive tape with excellent gripping power between the adhesive layer and the substrate. The re-peelable adhesive tape of the present invention sequentially comprises a substrate, a base coating layer including an adhesive resin and a filler, and an adhesive layer. The re-peelable adhesive tape has a protrusion in which at least a portion of the filler protrudes from the base coating layer toward the adhesive layer, and the interface between the base coating layer and the adhesive layer has a concave-convex surface.

Description

Remove the adhesive tape again

The present invention relates to a re-peelable adhesive tape.

In recent years, as wafers have become thinner, adhesive tapes have been used as supporting materials in various semiconductor manufacturing processes. In semiconductor manufacturing processes, the materials used for adhesives and substrates have also diversified due to the different properties required in each step. As a result, it is sometimes impossible to ensure sufficient grip between the substrate and the adhesive. As a method of improving the grip on the substrate, a solution of forming a base coating on the substrate has been proposed (for example, patent documents 1 to 3). However, there is a problem that sufficient grip cannot be ensured, and the base coating itself cannot be formed.

In addition, in terms of easy re-peeling, an adhesive tape using an active energy ray-hardening adhesive has been proposed. The active energy ray-hardening adhesive hardens and shrinks the double bonds of the material contained in the adhesive by irradiating the active energy ray. Among them, the adhesive using a side chain double bond-introduced polymer tends to have poor grip on the substrate due to the hardening and shrinkage of the polymer itself, and sometimes produces adhesive residue on the adherend during peeling. In particular, when the side chain of the polymer has a long carbon chain substituent, there is a problem of further poor grip. [Prior art literature] [Patent literature]

[Patent Document 1] Japanese Patent Publication No. 2005-231119 [Patent Document 2] Japanese Patent Publication No. 2009-224375 [Patent Document 3] Japanese Patent Publication No. 2012-214585

[The problem the invention is trying to solve]

The present invention is completed to solve the above-mentioned previous problems, and its purpose is to provide a re-peelable adhesive tape with excellent gripping force between the adhesive layer and the substrate. [Technical means to solve the problem]

The re-peelable adhesive tape of the present invention sequentially comprises a substrate, a primer layer including an adhesive resin and a filler, and an adhesive layer. The re-peelable adhesive tape has a protrusion in which at least a portion of the filler protrudes from the primer layer toward the adhesive layer, and the interface between the primer layer and the adhesive layer has a concave-convex surface. In one embodiment, the filler is at least one selected from the group consisting of silicon dioxide, aluminum oxide, and calcium carbonate. In one embodiment, the adhesive resin is a urethane resin. In one embodiment, the adhesive layer comprises an active energy ray-curing adhesive. In one embodiment, the base polymer of the active energy ray-curing adhesive is a side chain double bond-introducing acrylic resin. In one embodiment, more than 50% of the side chains of the side chain double bond-introducing acrylic resin are substituents with a carbon number of 8 or more. In one embodiment, the adhesive layer further includes an isocyanate crosslinking agent. In one embodiment, the height of the protrusion is more than 1 μm. In one embodiment, the protrusion exists at more than 10/mm. In one embodiment, the average particle size of the filler is 0.2 μm to 2.0 μm. In one embodiment, the gripping force of the adhesive layer is more than 2 N/50 mm. In one embodiment, the substrate comprises at least one resin selected from the group consisting of polyethylene terephthalate resins, polyethylene naphthalate resins and polyolefin resins. In one embodiment, the re-peelable adhesive tape is used for semiconductor processing. [Effect of the invention]

According to the present invention, a re-peelable adhesive tape having excellent gripping power between the adhesive layer and the substrate can be provided. The re-peelable adhesive tape of the present invention has a protrusion in which at least a portion of the filler protrudes from the base coating layer toward the adhesive layer, and the interface between the base coating layer and the adhesive layer has a concave-convex surface. As a result, the contact surface area between the base coating layer and the adhesive layer becomes larger, and the affinity between the functional groups of the adhesive contained in the adhesive layer and the filler can be improved. Furthermore, the reactivity with the crosslinking agent at the interface between the base coating layer and the adhesive layer can also be improved. As a result, the gripping power can be improved. Therefore, even when an adhesive containing a side chain double bond-introducing polymer is used, it is possible to prevent the paste residue from remaining on the adherend.

A. Overall structure of the re-peelable adhesive tape Figure 1 is a schematic cross-sectional view of a re-peelable adhesive tape of one embodiment of the present invention. The re-peelable adhesive tape 100 of the present invention sequentially comprises a substrate 10, a primer layer 20 comprising an adhesive resin and a filler, and an adhesive layer 30. The re-peelable adhesive tape 100 comprises a filler in the primer layer, and has a protrusion 40 in which at least a portion of the filler protrudes from the primer layer 20 to the adhesive layer 30. The protrusion 40 provides a concave-convex interface between the primer layer 20 and the adhesive layer 30. Therefore, the contact surface area between the primer layer 20 and the adhesive layer 30 becomes larger, so the reaction performance at the interface between the primer layer and the adhesive layer can be improved. As a result, the gripping force can be improved.

FIG. 2 is a cross-sectional SEM photograph of a re-peeled adhesive tape in one embodiment of the present invention. FIG. 2(a) is a photograph taken at a magnification of 2000 times, FIG. 2(b) is a photograph taken at a magnification of 5000 times, and FIG. 2(c) is a photograph taken at a magnification of 10000 times. In the SEM photographs taken at any magnification, the presence of protrusions of the filler contained in the base coating layer protruding toward the adhesive layer can be confirmed. In one embodiment, a filler with a wide particle size distribution range is used as a filler. By using such a filler, bumps and depressions can also be generated between the fillers. Therefore, more protrusions can be formed at the interface between the adhesive layer and the base coating layer (for example, FIG. 2(a) and FIG. 2(b)). It can also be confirmed that by including fillers with smaller particle sizes, fine concavities and convexities are also formed at the interface between the base coating layer and the adhesive layer (for example, FIG. 2(c) ).

The height of the protrusion is preferably greater than 1 μm, more preferably greater than 1.2 μm, and further preferably greater than 1.5 μm. By making the height of the protrusion within the above range, the contact surface area between the base coating layer and the adhesive layer becomes larger, and the gripping performance is improved. The height of the protrusion only needs to match the thickness of the base coating layer and the adhesive layer, and be adjusted to a value that can prevent dents on the substrate when the re-peel adhesive tape is made into a roll, for example, less than 5.0 μm. In this specification, the height of the protrusion refers to the distance between the flat portion of the interface between the base coating layer and the adhesive layer and the highest portion of the filler. The height of the protrusion can be measured by any appropriate method. For example, the adhesive tape can be cut and then peeled off by any appropriate method to make a cross section, and the cross section can be confirmed and measured using a scanning electron microscope.

The re-peelable adhesive tape preferably has more than 10 protrusions per mm in the cross section, more preferably more than 15 protrusions per mm, and even more preferably more than 20 protrusions per mm. By making the protrusions within the above range, the gripping performance of the re-peelable adhesive tape is improved. The more protrusions, the better, for example, less than 150 protrusions per mm. In this specification, the number of protrusions refers to the number of protrusions per unit length of the cross section produced by cutting by any appropriate method. The number of protrusions can be measured by any appropriate method. In this specification, a cross section is prepared by cutting and then peeling off the adhesive tape using any appropriate method, and the number of protrusions within a range of 250 μm is measured at three random locations on the cross section. The average value of the number of protrusions at the three locations is converted into mm units, and the resulting value is set as the number of protrusions.

The thickness of the re-peelable adhesive tape can be set to any appropriate value according to the intended use, etc. The thickness of the re-peelable adhesive tape is preferably 25 μm to 800 μm, more preferably 30 μm to 600 μm, and further preferably 30 μm to 450 μm.

B. Adhesive layer As the adhesive composition forming the adhesive layer, any appropriate adhesive can be used. The re-peelable adhesive tape of the present invention has excellent gripping power. Therefore, even an adhesive with high adhesion can be appropriately used.

In one embodiment, the adhesive layer includes an active energy ray-hardening adhesive. The active energy ray-hardening adhesive has low elasticity and high flexibility when attached, excellent operability, and excellent adhesion. On the other hand, when peeling is required, the adhesive force is reduced by irradiating the active energy ray, and a re-peelable adhesive tape that can be easily peeled off can be obtained. In addition, the active energy ray-hardening adhesive has a problem of poor grip on the substrate due to hardening and shrinkage of the double bond, and there is a problem of adhesive residue on the adherend when peeling. The re-peelable adhesive of the present invention can exert excellent gripping power even when the adhesive layer includes an active energy ray curing adhesive. Examples of active energy rays include gamma rays, ultraviolet rays, visible rays, infrared rays (heat rays), radio frequency waves, alpha rays, beta rays, electron beams, plasma streams, ionizing radiation, and particle beams. Ultraviolet rays are preferred.

As the active energy ray-curable adhesive, any appropriate adhesive may be used. For example, an adhesive obtained by adding a UV-curable monomer and/or oligomer to any appropriate adhesive such as an acrylic adhesive, a rubber adhesive, a silicone acrylic adhesive, or a polyvinyl ether adhesive, or an adhesive obtained by using a polymer having a carbon-carbon double bond in the side chain (hereinafter also referred to as a side chain double bond-introduced polymer) as a base polymer.

As the UV-curable monomer and oligomer, any appropriate monomer or oligomer can be used. As the UV-curable monomer, for example, there can be mentioned: (meth) urethane acrylate, trihydroxymethylpropane tri(meth) acrylate, tetrahydroxymethylmethane tetra(meth) acrylate, pentaerythritol tri(meth) acrylate, pentaerythritol tetra(meth) acrylate, dipentaerythritol monohydroxy penta(meth) acrylate, dipentaerythritol hexa(meth) acrylate, 1,4-butanediol di(meth) acrylate, etc. As the radiation-curable oligomer, there can be mentioned urethane oligomers, polyether oligomers, polyester oligomers, polycarbonate oligomers, polybutadiene oligomers, etc. As the oligomer, it is preferred to use one with a molecular weight of about 100 to 30,000. The monomers and oligomers may be used alone or in combination of two or more.

The monomer and/or oligomer can be used in any appropriate amount according to the type of adhesive used. For example, relative to 100 parts by weight of the base polymer constituting the adhesive, it is preferably used in an amount of 5 to 500 parts by weight, and more preferably 40 to 150 parts by weight.

In one embodiment, the adhesive layer preferably includes an active energy ray-hardening adhesive containing a side chain double bond-introducing polymer. The active energy ray-hardening adhesive containing a side chain double bond-introducing polymer requires a better grip on the substrate because the polymer itself hardens and shrinks. By providing the above-mentioned re-peelable adhesive tape with a protrusion, it is possible to prevent the adhesive residue on the adherend even when using an active energy ray-hardening adhesive containing a side chain double bond-introducing polymer.

When using an adhesive containing a polymer having a side chain double bond introduced, a polymer having a polymerizable carbon-carbon double bond in the side chain and having adhesiveness can be used as a base polymer. Examples of such polymers include polymers having polymerizable carbon-carbon double bonds introduced into resins such as (meth)acrylic resins, vinyl alkyl ether resins, silicone acrylic resins, polyester resins, polyamide resins, urethane resins, and styrene-diene block copolymers. Preferably, a (meth)acrylic resin having polymerizable carbon-carbon double bonds introduced into a (meth)acrylic resin (hereinafter also referred to as a side chain double bond introduced acrylic resin) is used. By using the (meth) acrylic polymer, the storage modulus and tensile modulus of the adhesive layer can be easily adjusted, and an adhesive tape having an excellent balance between adhesion and release properties can be obtained. In addition, "(meth) acrylic" refers to acrylic acid and/or methacrylic acid.

Any appropriate (meth)acrylic resin can be used as the (meth)acrylic resin. Examples of the (meth)acrylic resin include polymers obtained by polymerizing a monomer composition containing one or more esters of acrylic acid or methacrylic acid having a linear or branched alkyl group.

The straight chain alkyl group or branched chain alkyl group is preferably an alkyl group having 30 or less carbon atoms, more preferably an alkyl group having 1 to 20 carbon atoms, and still more preferably an alkyl group having 4 to 18 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, pentyl, isopentyl, hexyl, heptyl, cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, octadecyl, and dodecyl.

In one embodiment, preferably, more than 50 mol% of the side chains of the side chain double bond-introduced acrylic resin have a substituent with a carbon number of 8 or more. Acrylic resins having long-chain substituents with a carbon number of 8 or more on the side chains can prevent the adhesive residue on the adherend. On the other hand, the adhesion of acrylic resins having long-chain substituents with a carbon number of 8 or more on the side chains to the substrate may further become a problem. According to the present invention, even in the case where more than 50 mol% of the side chains are long-chain substituents with a carbon number of 8 or more, the substrate and the adhesive layer can have excellent adhesion. Therefore, it is possible to take into account the gripping properties of the substrate and the adhesive layer and prevent the adhesive residue on the adherend. More preferably, 60 mol% or more of the side chains of the side chain double bond-introduced acrylic resin have a substituent with a carbon number of 8 or more, and more preferably, 70 mol% or more of the side chains of the side chain double bond-introduced acrylic resin have a substituent with a carbon number of 8 or more.

The monomer composition forming the (meth)acrylic resin may contain any other appropriate monomers. Examples of other monomers include: carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 1-hydroxyoctyl (meth)acrylate. Monomers containing a hydroxyl group such as 12-hydroxylauryl ester, (4-hydroxymethylcyclohexyl) methyl acrylate, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether; monomers containing a sulfonic acid group such as styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, (meth)sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid; monomers containing a phosphate group such as 2-hydroxyethylacryloyl phosphate, and the like. By including a monomer containing a functional group, a (meth)acrylic resin that can easily introduce a polymerizable carbon-carbon double bond can be obtained. The content ratio of the monomer containing a functional group is preferably 4 to 30 parts by weight, and more preferably 6 to 20 parts by weight, relative to 100 parts by weight of all monomers in the monomer composition.

As other monomers, multifunctional monomers can be used. By using multifunctional monomers, the cohesive force, heat resistance, adhesion, etc. of the adhesive can be improved. In addition, since the low molecular weight components in the adhesive layer are reduced, an adhesive tape that is not easy to contaminate the adherend can be obtained. As multifunctional monomers, for example: hexanediol (meth) acrylate, (poly)ethylene glycol di(meth) acrylate, (poly)propylene glycol di(meth) acrylate, neopentyl glycol di(meth) acrylate, pentaerythritol di(meth) acrylate, trihydroxymethylpropane tri(meth) acrylate, pentaerythritol tri(meth) acrylate, dipentaerythritol hexa(meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, (meth) acrylate urethane, etc. can be cited. The content ratio of the multifunctional monomer is preferably 1 to 100 parts by weight, and more preferably 5 to 50 parts by weight, relative to 100 parts by weight of all monomers in the monomer composition.

The weight average molecular weight of the (meth)acrylic resin is preferably 300,000 or more, more preferably 500,000 or more, and further preferably 800,000 to 3,000,000. If it is within this range, the permeation of low molecular weight components can be prevented, and a low-staining adhesive tape can be obtained. The molecular weight distribution (weight average molecular weight/number average molecular weight) of the (meth)acrylic resin is preferably 1 to 20, and more preferably 3 to 10. By using a (meth)acrylic resin with a narrow molecular weight distribution, the permeation of low molecular weight components can be prevented, and a low-staining adhesive tape can be obtained. In addition, the weight average molecular weight and the number average molecular weight can be determined by gel permeation chromatography (solvent: tetrahydrofuran, polystyrene conversion).

The polymer having a polymerizable carbon-carbon double bond in the side chain can be obtained by any appropriate method. For example, it can be obtained by reacting a resin obtained by any appropriate polymerization method with a compound having a polymerizable carbon-carbon double bond (e.g., condensation reaction, addition reaction). Specifically, when a (meth)acrylic resin is used, the polymer can be obtained by polymerizing a (meth)acrylic resin (copolymer) having a structural unit derived from a monomer containing any appropriate functional group in any appropriate solvent, and then reacting the functional group of the acrylic resin with a compound having a polymerizable carbon-carbon double bond capable of reacting with the functional group. The amount of the compound having a polymerizable carbon-carbon double bond to be reacted is preferably 4 to 30 parts by weight, more preferably 4 to 20 parts by weight, relative to 100 parts by weight of the above resin. As the solvent, any appropriate solvent can be used, for example, various organic solvents such as ethyl acetate, methyl ethyl ketone, toluene, etc.

When the resin and the compound having a polymerizable carbon-carbon double bond are reacted as described above, the resin and the compound having a polymerizable carbon-carbon double bond preferably have functional groups that can react with each other. Examples of the combination of functional groups include carboxyl/epoxy, carboxyl/aziridine, hydroxyl/isocyanate, etc. Among the combinations of functional groups, the combination of hydroxyl and isocyanate is preferred in terms of easy tracking of the reaction.

Examples of the compound having a polymerizable carbon-carbon double bond include 2-isocyanatoethyl methacrylate, methacrylic acid isocyanate, 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), m-isopropenyl-α,α-dimethylbenzyl isocyanate, and the like.

B-1. Additives The above-mentioned active energy ray-curing adhesive may contain any appropriate additives as needed. Examples of such additives include: photopolymerization initiators, crosslinking agents, catalysts (e.g., platinum catalysts), adhesion agents, plasticizers, pigments, dyes, fillers, anti-aging agents, conductive materials, ultraviolet absorbers, light stabilizers, stripping regulators, softeners, surfactants, flame retardants, solvents, etc.

In one embodiment, the active energy ray-curable adhesive preferably includes a photopolymerization initiator. Any appropriate initiator can be used as the photopolymerization initiator.

The photopolymerization initiator can be used in any appropriate amount. The content of the photopolymerization initiator is preferably 0.1 to 10 parts by weight, and more preferably 0.3 to 7 parts by weight, relative to 100 parts by weight of the above-mentioned UV-curable adhesive. When the content of the photopolymerization initiator is less than 0.1 parts by weight, there is a risk that the adhesive may not be sufficiently cured when irradiated with active energy rays. When the content of the photopolymerization initiator exceeds 10 parts by weight, the storage stability of the adhesive may be reduced, and precipitation and outgassing to the surface of the adhesive layer may increase.

In one embodiment, the active energy ray-curable adhesive further includes a crosslinking agent. Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, chelating agent crosslinking agents, and melamine crosslinking agents. The content ratio of the crosslinking agent is preferably 0.01 to 10 parts by weight, more preferably 0.02 to 7 parts by weight, and further preferably 0.025 to 5 parts by weight, relative to 100 parts by weight of the base polymer included in the active energy ray-curable adhesive. The softness of the adhesive layer can be controlled according to the content ratio of the crosslinking agent. When the content of the crosslinking agent is less than 0.01 parts by weight, the adhesive is in a sol-like state and there is a risk that the adhesive layer cannot be formed. When the content of the crosslinking agent exceeds 10 parts by weight, there is a risk that the adhesion to the adherend is reduced and the adherend cannot be fully protected.

In one embodiment, it is preferred to use an isocyanate crosslinking agent. An isocyanate crosslinking agent is preferred in that it can react with a variety of functional groups. It is particularly preferred to use a crosslinking agent having three or more isocyanate groups. By using an isocyanate crosslinking agent as the crosslinking agent and setting the content ratio of the crosslinking agent to the above range, an adhesive layer having excellent releasability after heating and significantly less paste residue can be formed.

The thickness of the adhesive layer can be set to any appropriate value. The thickness of the adhesive layer is preferably 4 μm to 500 μm, more preferably 5 μm to 400 μm, and further preferably 5 μm to 330 μm. By setting the thickness of the adhesive layer to the above range, sufficient adhesion to the adherend can be exerted, and the burying property of the bumps and the sufficient burying property of the concave and convex can be exerted.

The gripping force of the adhesive layer (adhesion of the adhesive layer to the substrate) is preferably 2 N/50 mm or more, more preferably 3 N/50 mm or more, and further preferably 5 N/50 mm or more. The higher the gripping force of the adhesive layer, the better. In this specification, the gripping force of the adhesive layer refers to the peeling force (gripping force) when the adhesive layer is irradiated with active energy rays to harden the adhesive layer, an adhesive tape is attached to the hardened adhesive layer, and the adhesive is peeled off by T-type peeling at a tensile speed of 300 mm/minute. Furthermore, when using this measurement method, when the adhesive layer contains a large amount of peeling agent, the gripping force value may be lower.

C. Base coating layer The base coating layer includes an adhesive resin and a filler. By making the base coating layer include a filler, at least a portion of the filler has a protrusion protruding from the base coating layer toward the adhesive layer. By having the protrusion, the contact surface area between the base coating layer and the adhesive layer becomes larger, and as a result, the gripping force can be improved.

C-1. Adhesive resin As the adhesive resin, any appropriate resin can be used. For example, urethane resins, polyester resins, and acrylic resins can be cited. It is preferred to use urethane resins. As urethane resins, specifically, polyacrylic urethane, polyester urethane, or their precursors can be cited. The reason is that it is easier to coat and apply on the substrate, and a variety of materials can be selected industrially and can be obtained at a low price. The urethane polymer is, for example, a polymer of a reaction mixture of an isocyanate monomer and an alcoholic hydroxyl-containing monomer (such as a hydroxyl-containing acrylic compound or a hydroxyl-containing ester compound). Furthermore, the adhesive resin may or may not contain a structure derived from an aromatic compound in the molecule.

C-2. Filler Any appropriate filler can be used as a filler. For example, metal oxides such as silicon dioxide, aluminum oxide, calcium carbonate, titanium oxide, magnesium oxide, and zinc oxide, talc, etc. are exemplified. It is preferred to use at least one selected from the group consisting of silicon dioxide, aluminum oxide, and calcium carbonate. Since these fillers have hydroxyl groups on the surface, they have a higher affinity with the functional groups contained in the adhesive, and when an isocyanate crosslinking agent is used, the reactivity with the isocyanate crosslinking agent is also good, so the gripping force can be further improved. Only one filler can be used, or two or more fillers can be used in combination.

The average particle size of the filler is preferably 0.2 μm to 2.0 μm, more preferably 0.2 μm to 1.5 μm, and even more preferably 0.2 μm to 1.2 μm. By setting the average particle size within the above range, it is possible to prevent the opposite side of the base coating from being dented against the base film when the re-peelable adhesive tape is rolled into a roll.

In one embodiment, the wider the particle size distribution of the filler, the better. By using a filler with a wider particle size distribution, including particles with a particle size substantially larger than the average particle size, the height of the protrusion can be made sufficient. In addition, by increasing the particle size deviation between the fillers, a step difference is also generated between the fillers, and as a result, the unevenness at the interface between the adhesive layer and the base coating layer increases, and the contact surface area can be increased. As a result, the gripping performance can be further improved. As a method of widening the particle size distribution of the filler, any appropriate method can be used. For example, a filler with a large particle size deviation can be used, and two or more fillers with different particle sizes can be mixed and used.

As the filler, for example, a filler having a particle size distribution of 0.01 μm to 10 μm can be used, preferably a filler having a particle size distribution of 0.05 μm to 7 μm, and more preferably a filler having a particle size distribution of 0.08 μm to 5 μm. The particle size distribution of the filler can be measured by any appropriate method. For example, image analysis method, Coulter method, extension sedimentation method, laser diffraction scattering method, etc. can be cited.

As the filler, any filler of appropriate shape can be used. For example, spherical, flat, random, etc. can be cited. From the viewpoint of improving the stability of the base coating layer forming composition, spherical fillers can be appropriately used. The shape of the filler can be used alone or in combination of two or more.

The content of the filler is preferably 10 to 65 parts by weight, more preferably 12 to 60 parts by weight, and further preferably 15 to 60 parts by weight relative to 100 parts by weight of the adhesive resin. By making the content of the filler within the above range, the gripping performance is improved.

The primer layer can be formed by any appropriate method. For example, it can be formed by applying a primer layer forming composition containing a binder resin and a filler to a substrate. In addition to the binder resin and the filler, the primer layer forming composition can further contain any appropriate additives such as a crosslinking agent.

The thickness of the primer layer can be set to any appropriate value. The thickness of the primer layer is preferably 1.0 μm to 4.0 μm, more preferably 1.2 μm to 3.0 μm, and further preferably 1.5 μm to 2.5 μm. In addition, the primer layer can be one layer or two or more layers. When there are two or more layers, as long as at least the layer in contact with the adhesive layer contains an adhesive resin and a filler, the other layers can be formed only of an adhesive resin.

D. Substrate The substrate may be composed of any appropriate resin. Examples of the resin include: low-density polyethylene, linear polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolymer polypropylene, polybutene, polymethylpentene and other polyolefins; ethylene-vinyl acetate copolymers, ionic polymer resins, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random, alternating) copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, polyurethane, polyethylene naphthalate and other polyesters; polyimide, polyether ketone, polystyrene, polyvinyl chloride, polyvinylidene chloride, fluororesins, silicone resins, cellulose resins and crosslinked products thereof. Preferably, at least one resin selected from the group consisting of polyethylene terephthalate resins, polyethylene naphthalate resins and polyolefin resins is used. By using these resins, the gripping performance can be further improved.

The thickness of the substrate is preferably 12 μm to 210 μm, more preferably 17.5 μm to 150 μm, and further preferably 25 μm to 100 μm. Within this range, a removable adhesive tape having appropriate rigidity, easy pasting operation, and excellent operability can be obtained.

In order to improve the adhesion and retention of the base coating, the surface of the substrate may be subjected to any surface treatment. Examples of the surface treatment include chemical treatment such as corona treatment and plasma treatment, physical treatment, and coating treatment.

E. Method for manufacturing re-peelable adhesive tape Re-peelable adhesive tape can be manufactured by any appropriate method. For example, it can be obtained by the following method: an adhesive solution (active energy ray curing adhesive) is applied to a separator film, dried to form an adhesive layer on the separator film, and then attached to a substrate with a primer layer formed thereon. Alternatively, the re-peelable adhesive tape can be obtained by applying the above-mentioned adhesive solution on a substrate with a primer layer formed thereon and drying it. As the coating method of the adhesive solution, various methods such as rod coating, air knife coating, gravure coating, gravure reverse coating, reverse roll coating, die lip coating, mold coating, dip coating, offset printing, flexographic printing, screen printing, etc. can be used. As the drying method, any appropriate method can be used. In one embodiment, the above-mentioned adhesive layer can be formed by any appropriate curing treatment.

The primer layer can be formed by any appropriate method. For example, it can be formed by applying a primer layer forming composition containing an adhesive resin and a filler to a substrate and drying the composition. As the coating method, the same method as the case of forming the above-mentioned adhesive layer by coating can be used.

F. Application The re-peelable adhesive tape can be used for any appropriate purpose. For example, it can be used in the processing steps of semiconductors and LEDs. In one embodiment, the re-peelable adhesive tape can be appropriately used for semiconductor processing purposes. Specifically, it can be appropriately used as a dicing tape, back grinding tape, masking tape, etc. Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are by weight unless otherwise specified.

[Production Example 1] Preparation of acrylic polymer 1 with side chain double bond introduction 12 parts of 2-methacryloyloxyethyl isocyanate (MOI) and a copolymer obtained by polymerization using 100 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of 2-hydroxyethyl acrylate (HEA), and 25 parts of acrylonitrile (ACMO) were subjected to an addition reaction to obtain acrylic polymer 1.

[Production Example 2] Preparation of acrylic polymer 2 with side chain double bond introduction 40 parts of MOI and a copolymer obtained by polymerization using 100 parts of ethyl acrylate (EA), 100 parts of butyl acrylate (BA), and 40 parts of HEA were subjected to an addition reaction to obtain acrylic polymer 2.

[Production Example 3] Preparation of acrylic polymer 3 with side chain double bond introduction 12 parts of 2-methacryloyloxyethyl isocyanate (MOI) and a copolymer obtained by polymerizing 88.8 parts of 2-ethylhexyl acrylate (2EHA) and 11.2 parts of 2-hydroxyethyl acrylate (HEA) were subjected to an addition reaction to obtain acrylic polymer 3.

[Example 1] 100 parts by weight of an acrylic polymer 1, 3 parts by weight of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name CORONATE L) and 7 parts by weight of a photopolymerization initiator (manufactured by IGM Resins B.V., trade name: omnirad 651) were mixed to obtain an adhesive layer forming composition 1. A two-component urethane ink containing no aromatic dicarboxylic acid component was gravure printed in a thickness of 1 μm on a substrate (polyethylene naphthalate film, thickness 25 μm, manufactured by Teijin Co., Ltd., trade name: TEONEX Q51C) subjected to a corona treatment. Next, 60 parts by weight of aluminum oxide (ADMATECHS, trade name: ADMAFINE AO-502, average particle size: 0.2 μm to 0.3 μm) was mixed into 100 parts by weight of a polyester urethane resin containing no aromatic dicarboxylic acid component to prepare a filler-containing primer layer forming composition 1. The obtained filler-containing primer layer forming composition 1 was applied to a thickness of 2 μm to form a filler-containing primer layer. Separately, an adhesive layer forming composition 1 was applied to a polyethylene terephthalate separator film having a thickness of 38 μm to a thickness of 20 μm. Then, an adhesive layer is attached to the base coating layer containing the filler and the adhesive layer is transferred to obtain a re-peelable adhesive tape.

[Example 2] As a substrate, a polyolefin film with a thickness of 150 μm (manufactured by ACHILLES, trade name: POVIC) was used. A removable adhesive tape was obtained in the same manner as in Example 1 except that the above-mentioned method was used.

[Example 3] Except for using acrylic polymer 2, adhesive layer forming composition 2 is obtained in the same manner as in Example 1. Using the above adhesive layer forming composition 2 and using a polyethylene terephthalate film (manufactured by Toray Industries, trade name: Lumirror ES-10) with a thickness of 100 μm as a substrate, a re-peelable adhesive tape is prepared in the same manner as in Example 1 except that.

[Example 4] Except for using acrylic polymer 3, an adhesive layer forming composition 3 is obtained in the same manner as in Example 1. Except for using the obtained adhesive layer forming composition 3, a re-peelable adhesive tape is obtained in the same manner as in Example 1.

[Example 5] 16 parts by weight of silica (manufactured by ADMATECHS, trade name: ADMAFINE SO-C4, average particle size: 0.9 μm to 1.2 μm) was mixed with 100 parts by weight of a polyester urethane resin containing no aromatic dicarboxylic acid component to prepare a filler-containing primer-forming composition 2. Using the obtained filler-containing primer-forming composition 2, and using the polyethylene terephthalate film used in Example 3 as a substrate, a re-peelable adhesive tape was obtained in the same manner as in Example 1 except that the polyethylene terephthalate film used in Example 3 was used as a substrate.

[Example 6] A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that an adhesive layer was used to form composition 3 and a primer layer containing a filler was used to form composition 2.

[Example 7] A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that an adhesive layer was used to form composition 2, a primer layer containing a filler was used to form composition 2, and the polyethylene naphthalate film used in Example 3 was used as a substrate.

[Example 8] A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that an adhesive layer was used to form composition 2, a primer layer containing a filler was used to form composition 2, and the polyolefin film used in Example 2 was used as a substrate.

[Example 9] 100 parts by weight of an acrylic copolymer (monomer composition ratio: BA 100 parts, EA 30 parts, acrylic acid 100 parts, HEA 1 part) as a base polymer was mixed with 80 parts by weight of a multifunctional oligomer (acrylic urethane, manufactured by Nippon Gosei Kagaku Co., Ltd., trade name: UV-1700TL), 3 parts by weight of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name: CORONATE L), and 7 parts by weight of a photopolymerization initiator (manufactured by IGM Resins B.V., trade name: omnirad 651) to obtain an adhesive layer forming composition 4. A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that the obtained adhesive layer forming composition 4 was used.

[Example 10] A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that the adhesive layer was used to form the composition 4, the polyethylene terephthalate film used in Example 3 was used as the substrate, and the primer layer was used to form the composition 2.

[Example 11] A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that the polyolefin film used in Example 2 was used as the substrate.

(Comparative Example 1) A two-component urethane ink containing no aromatic dicarboxylic acid components was gravure-printed to a thickness of 1 μm on a substrate (polyethylene terephthalate film with a thickness of 100 μm (manufactured by Toray Industries, trade name: Lumirror ES-10)). Subsequently, a polyester urethane resin containing no aromatic dicarboxylic acid components was applied to a thickness of 2 μm to form a base coating layer. A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that the above was performed.

(Comparative Example 2) A re-peelable adhesive tape was obtained in the same manner as in Example 1 except that an adhesive layer was transferred to the corona-treated surface of the substrate without forming a base coat layer.

<Evaluation> The following evaluation was performed using the re-peelable adhesive tapes obtained in the embodiments and comparative examples. The results are shown in Table 1. 1. Height of protrusions and number of fillers For the re-peelable adhesive tapes obtained in the embodiments and comparative examples, a cross section was made using an ion polishing device (manufactured by Leica, product name: EMTIC 3X). The produced cross section was confirmed using a scanning electron microscope (SEM) at a magnification range of 500 to 5000 times, and the height of the protrusions and the number of protrusions (the number per unit length of the cross section of the re-peelable adhesive tape) were measured. The measurement was performed randomly at three locations within a length range of 250 μm. The height of the protrusion is set as the distance between the flat part of the interface between the base coating layer and the adhesive layer and the highest part of the filler. Figure 3 is a schematic diagram illustrating a method for measuring the height of the protrusion. The height is set as the distance from the highest part of the protrusion 40 to the interface between the base coating layer 20 and the adhesive layer 30 (double arrow in the example). The number of fillers is converted into the number per 1 mm, and the average value of three places is set as the number of fillers. Furthermore, for samples where the filler falls off when the cross-section is made, the cavity portion formed by the fall-off is measured as the height and number of the filler. 2. Grip The substrate used in each embodiment and comparative example is subjected to corona treatment. Next, the filler-containing primer-forming composition used in each embodiment was applied to the corona-treated surface of the substrate in a thickness of 3 μm to form a primer. Thereafter, the adhesive-forming composition used in each embodiment and comparative example was applied to the primer in a thickness of 20 μm to form an adhesive layer, thereby obtaining an evaluation sample. The evaluation sample was irradiated with 460 mJ/cm ² of ultraviolet light using a high-pressure mercury lamp to harden the adhesive layer, and then, a cutter was used to cut a cut in the adhesive layer in a direction perpendicular to the peeling direction. After that, an adhesive tape (manufactured by Nitto Denko, trade name: BT-315) was attached to the hardened adhesive layer and heated at 50°C for 48 hours. Then, the peeling force (gripping force) was measured by T-type peeling at a tensile speed of 300 mm/min using a TENSILON tester (manufactured by A&D, trade name: RTG-1210). Furthermore, although it is the peeling force (gripping force) between the substrate and the base coating, when the gripping force is high, the peeling occurs first between the adhesive layer and the adhesive tape. At this time, the gripping force is set to 8.0 N/50 mm or more. If the gripping force is 3.0 N/50 mm or more, the gripping property is good.

[Table 1] filler Substrate Protrusion height Number of protrusions Grip strength (N/50 mm) Grip Embodiment 1 Alumina 25 μm PEN 1.9 μm 217.4pcs/mm 8.0 or above good Embodiment 2 Alumina 150 μm PO 1.9 μm 217.4pcs/mm 8.0 or above good Embodiment 3 Alumina 100 μm PET 1.3 μm 72.5pcs/mm 8.0 or above good Embodiment 4 Alumina 25 μm PEN 1.3 μm 72.5pcs/mm 3.0 good Embodiment 5 Silicon Dioxide 100 μm PET 3.3 μm 25.9pcs/mm 8.0 or above good Embodiment 6 Silicon Dioxide 25 μm PEN 3.3 μm 25.9pcs/mm 8.0 or above good Embodiment 7 Silicon Dioxide 100 μm PET 3.3 μm 25.9pcs/mm 8.0 or above good Embodiment 8 Silicon Dioxide 150 μm PO 3.3 μm 25.9pcs/mm 8.0 or above good Embodiment 9 Alumina 25 μm PEN 1.3 μm 72.5pcs/mm 8.0 or above good Embodiment 10 Silicon Dioxide 100 μm PET 3.3 μm 25.9pcs/mm 8.0 or above good Embodiment 11 Alumina 150 μm PO 1.3 μm 72.5pcs/mm 8.0 or above good Comparison Example 1 without 100 μm PET - - 0.2 Unable to use Comparison Example 2 without 25 μm PEN - - 0.2 Unable to use [Industrial Availability]

The re-peelable adhesive tape of the present invention can be suitably used in semiconductor processing applications.

10: Base material 20: Base coating 30: Adhesive layer 40: Protrusion 100: Peel off adhesive tape

FIG1 is a schematic cross-sectional view of a re-peelable adhesive tape according to one embodiment of the present invention. FIG2 is a cross-sectional SEM photograph of a re-peelable adhesive tape according to one embodiment of the present invention. FIG2(a) is a photograph taken at a magnification of 2000 times, FIG2(b) is a photograph taken at a magnification of 5000 times, and FIG2(c) is a photograph taken at a magnification of 10000 times. FIG3 is a schematic diagram illustrating a method for measuring the height of a protrusion in a re-peelable adhesive tape according to the present invention.

10: Base material

20: Base coating

30: Adhesive layer

40: protrusion

100: Peel off the adhesive tape again

Claims (13)

A re-peelable adhesive tape comprises a substrate, a primer layer including an adhesive resin and a filler, and an adhesive layer in sequence. The re-peelable adhesive tape has a protrusion in which at least a portion of the filler protrudes from the primer layer toward the adhesive layer. The interface between the primer layer and the adhesive layer has a concave-convex surface. The re-peelable adhesive tape of claim 1, wherein the filler is at least one selected from the group consisting of silicon dioxide, aluminum oxide, and calcium carbonate. The re-peelable adhesive tape of claim 1, wherein the adhesive resin is a urethane resin. The removable adhesive tape of claim 1, wherein the adhesive layer comprises an active energy ray-hardening adhesive. The re-peelable adhesive tape of claim 4, wherein the base polymer of the active energy ray-curing adhesive is a side chain double bond-introduced acrylic resin. The re-peelable adhesive tape of claim 5, wherein at least 50 mol% of the side chains of the side chain double bond-introduced acrylic resin are substituents having at least 8 carbon atoms. The re-peelable adhesive tape of claim 1, wherein the adhesive layer further comprises an isocyanate crosslinking agent. As in claim 1, the re-peelable adhesive tape, wherein the height of the protrusion is greater than 1 μm. As in claim 1, the re-peelable adhesive tape, wherein the number of the protrusions is greater than 10/mm. The re-peelable adhesive tape of claim 1, wherein the average particle size of the filler is 0.2 μm to 1.2 μm. The re-peelable adhesive tape of claim 4, wherein the gripping force of the adhesive layer is greater than 2 N/50 mm. The re-peelable adhesive tape of claim 1, wherein the substrate comprises at least one resin selected from the group consisting of polyethylene terephthalate resins, polyethylene naphthalate resins and polyolefin resins. The re-peelable adhesive tape of claim 1 is used for semiconductor processing purposes.