Resin film and film laminate

Abstract

This invention provides a novel resin film and a film laminate equipped therewith, which have improved adhesion and reduced foreign matter, for use as components in the semiconductor CMP process. [Solution] A resin film comprising a base film having a resin layer A containing particles with an average particle size of 1 to 10 μm on at least one surface, wherein the arithmetic mean height (Sa) of the surface on the side with the resin layer A is 500 nm or more, and the ratio (Y2 / Y1) of the number of protrusions with a protrusion height of 0.5 μm or more and less than 2.5 μm (Y1) to the number of protrusions with a protrusion height of 2.5 μm or more (Y2) is 0.02 to 0.05.

Description

[Technical Field]

[0001] This invention relates to resin films and film laminates. [Background technology]

[0002] Traditionally, polyester films, particularly polyethylene terephthalate films and polyethylene naphthalate films, have excellent mechanical properties, heat resistance, and chemical resistance, and have been used in a variety of applications, including packaging, electronic components, electrical insulation, metal lamination, optical applications such as foldable displays, bendable displays, and rollable displays, touch panels, anti-reflective coatings, and glass shatterproof coatings.

[0003] In recent years, with the aim of increasing the density of semiconductor integrated circuits, miniaturization and multi-layer wiring have progressed, and consequently, the technology for flattening the unevenness of the wafer surface has become increasingly important. Chemical mechanical polishing (CMP) is generally used as a method for flattening the unevenness of the wafer surface. CMP is a method of polishing in which the surface to be polished of the wafer is pressed against the polishing surface of a polishing pad and polished using a slurry-like polishing agent (hereinafter referred to as slurry) in which abrasive particles are dispersed. It is known that polyester film is used as a support material for polishing pads. In this case, the adhesion between the polyurethane resin layer constituting the polishing pad and the polyester film is important, and as a measure to improve adhesion, it has been proposed to provide an adhesive layer between the two or an easy-adhesion layer on the surface of the polyester film (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-58984 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-81486

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] On the other hand, from the viewpoint of simplifying the manufacturing process, there is also a technical trend towards adhesive-free. In the case of adhesive-free, the adhesion between the polyurethane resin layer and the polyester film constituting the polishing pad may be insufficient, and further improvement is required. In addition, depending on the type of wafer product, stricter foreign matter management may be required.

[0006] The present invention has been made in view of the above circumstances, and its problem to be solved is to newly provide, for example, a resin film having an adhesion improving effect and capable of reducing foreign matter, and a film laminate provided with the same, as a member for a semiconductor CMP process.

MEANS FOR SOLVING THE PROBLEM

[0007] As a result of intensive studies by the present inventor in view of the above situation, it has been found that the above problems can be easily solved by a resin film having a specific configuration, and the present invention has been completed.

[0008] That is, the gist of the present invention provides the following [1] to

[20] .

[0009] [1] A base film having a resin layer A containing particles with an average particle diameter of 1 to 10 μm on at least one surface, wherein the arithmetic mean height (Sa) of the surface on the resin layer A side is 500 nm or more, and the ratio (Y2 / Y1) of the number of protrusions (Y1) with a protrusion height of 0.5 μm or more and less than 2.5 μm to the number of protrusions (Y2) with a protrusion height of 2.5 μm or more on the surface on the resin layer A side is 0.02 to 0.05. Resin film. [2] The resin film according to [1], wherein the particles are organic particles. [3] The number of protrusions (Y1) with a protrusion height of 0.5 μm or more and less than 2.5 μm on the surface on the resin layer A side is 1.2×10 5 pieces / mm2 The resin film according to [1] or [2] above, which is as described above. [4] The number of protrusions (Y2) with a protrusion height of 2.5 μm or more on the surface of the resin layer A side is 6 × 10 3 per mm 2 The resin film according to any one of [1] to [3] above, which is as described below. [5] The total number (Y1 + Y2) of the number of protrusions (Y1) with a protrusion height of 0.5 μm or more and less than 2.5 μm and the number of protrusions (Y2) with a protrusion height of 2.5 μm or more on the surface of the resin layer A side is 1.2 × 10 5 per mm 2 The resin film according to any one of [1] to [4] above, which is as described above. [6] The resin film according to any one of [1] to [6] above, wherein the base film is a polyester film. [7] The resin film according to [6] above, wherein the polyester film contains a titanium catalyst. [8] The resin film according to any one of [1] to [7] above, wherein the base film has a multilayer structure composed of at least two layers. [9] The resin film according to any one of [1] to [8] above, wherein the base film has a multilayer structure composed of a surface layer, an intermediate layer, and a surface layer.

[10] The resin film according to any one of [1] to [9] above, which has resin layers A on both surfaces of the base film.

[11] The resin film according to any one of [1] to

[10] above, wherein the maximum peak height (Sp) on the surface of the resin layer A side is 5000 nm or more.

[12] The resin film according to any one of [1] to

[11] above, wherein the amount of Si element detected from the resin film is 0.1 mass% or less.

[13] The resin film according to any one of [1] to

[12] above, wherein the glossiness at 60 degrees on the surface of the resin layer A side is 10% or less.

[14] The resin film according to any one of [1] to

[13] above, which has a resin layer B on the resin layer A on at least one surface.

[15] The resin film according to

[14] , wherein the resin layer B is formed from a resin composition comprising a binder resin (B) and a crosslinking agent (C).

[16] The resin film according to any one of [9] to

[15] above, wherein the intermediate layer contains recycled polyester resin.

[17] A resin film according to any of [1] to

[16] above, wherein the thickness of the base film is 25 to 5000 μm.

[18] A resin film according to any of [1] to

[17] above, which is a component for the CMP process.

[19] A film laminate comprising a resin film as described in any of [1] to

[18] above, and a polyurethane resin layer laminated on the surface of the resin film on the side of the resin layer A.

[20] A film laminate comprising the resin film described in

[14] or

[15] above and a polyurethane resin layer laminated on the resin layer B. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a resin film and a film laminate equipped therewith that have an adhesive-improving effect and can reduce foreign matter, for example, as a component for the CMP process of semiconductors, and thus have high industrial value. It is particularly suitable as a component for polishing pads in semiconductors. [Modes for carrying out the invention]

[0011] <Resin film> The resin film of the present invention comprises a resin layer A on at least one surface of a base film. Each constituent element will be described in detail below. [Base film] Examples of base films include resin films. Examples of resin films include those formed in the form of a film from resins such as polyethylene, polypropylene, cycloolefin polymer (COP), polyester, polystyrene, acrylic resin, polycarbonate, polyurethane, triacetylcellulose (TAC), polyvinyl chloride, polyethersulfone, polyamide, polyimide, and polyamideimide. Furthermore, if it is possible to form a film from these materials, it may also be a mixture of these materials (polymer blend) or a composite of constituent units (polymer).

[0012] Among the resin films exemplified above, polyester films using polyester as the resin are preferred. Polyester films are particularly preferred because they have excellent physical properties such as heat resistance, flatness, optical properties, and strength. The polyester film may have a single-layer structure or a multi-layer structure, and may have four or more layers in addition to two or three layers, as long as it does not exceed the gist of the present invention, and is not particularly limited. It is also preferable to have a multi-layer structure of two or more layers, giving each layer its own characteristics to achieve multi-functionality. In a multi-layer polyester film, it is preferable that the resin constituting each layer is polyester. Furthermore, other base films besides polyester film may also have a multilayer structure; however, in such cases, the resins constituting each layer should be appropriately selected from the resins described above.

[0013] A multilayer structure with two or more layers is preferably a three-layer structure having an intermediate layer and surface layers on both sides thereof. However, a multilayer substrate film with surface layers on both sides may have four or more layers, in which case, for example, there may be two or more intermediate layers. Alternatively, the multilayer structure may be a two-layer structure consisting of two surface layers without an intermediate layer.

[0014] The polyester used in polyester films is preferably obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, while examples of aliphatic glycols include ethylene glycol, diethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, and 1,4-cyclohexanedimethanol.

[0015] Examples of typical polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and polybutylene terephthalate. Such polyesters may be homopolymers that are not copolymerized. Alternatively, copolymerized polyesters of these materials may also be used. Specifically, these copolymerized polyesters may consist of a dicarboxylic acid (terephthalic acid or 2,6-naphthalenedicarboxylic acid) as the main component of the dicarboxylic acid component, and a diol (ethylene glycol or tetramethylene glycol) as the main component of the diol component. The copolymerized polyester is preferably such that 30 mol% or less, preferably 20 mol% or less of the dicarboxylic acid component is a dicarboxylic acid component other than the main component, and / or 30 mol% or less, preferably 20 mol% or less of the diol component is a diol component other than the main component. Furthermore, the polyester may be used alone, or it may be a mixture of two or more types. For example, homopolymers (homopolyesters) and copolymerized polyesters may be used in combination.

[0016] Polyesters can be obtained by conventionally known methods, such as directly obtaining low-degree-of-polymerization polyesters by reacting dicarboxylic acids and diols, or by reacting lower alkyl esters of dicarboxylic acids with diols using conventionally known transesterification catalysts, followed by a polymerization reaction in the presence of a polymerization catalyst. As the polymerization catalyst, known catalysts such as antimony compounds, germanium compounds, and titanium compounds may be used, but it is preferable to use an antimony compound in the polyester film that is zero or 100 ppm by mass or less as antimony, as this results in a film with reduced dullness.

[0017] Furthermore, it is also preferable to use a titanium compound as a catalyst. When a titanium catalyst is used, it is preferable from the viewpoint of film transparency and reduction of foreign matter generation because the amount of metal remaining in the film is small. When a titanium catalyst is used, the amount of titanium catalyst in the polyester film is preferably 6 to 80 ppm by mass, and more preferably 8 to 70 ppm by mass.

[0018] The resin constituting the base film may contain recycled resin. Using recycled resin can further reduce the environmental impact. The recycled resin may be resin that has been recycled from collected products, waste, etc., by a chemical recycling method involving chemical reactions, or it may be resin that has been recycled from collected products, waste, etc., by a physical recycling method (mechanical recycling). The recycled resin may be any of the above-mentioned resins, but from the viewpoint of recyclability, polyester resin (recycled polyester resin) is preferred.

[0019] Resins recycled by chemical recycling methods, in the case of polyester resins, can be obtained by depolymerizing discarded polyester resin, and then repolymerizing the resulting intermediate or monomer to synthesize polyester resin. The resin recycled by the physical recycling method can be obtained by collecting various resin products such as polyester resin products and scraps generated during the production process, sorting and washing as needed, then processing by melting and crushing, and then processing by granulation, micronization, pelletizing, flakeping, etc., to a form that can be used as a raw material, such as powder, granules, pellets, or flakes, and then using it as recycled resin. When using recycled resin, a portion of the resin constituting the base film may be recycled resin, or all of it may be recycled resin.

[0020] Furthermore, in the case of a multilayer structure, recycled resin may be used in either the intermediate layer or the surface layer, but it is preferable to use it in the intermediate layer, and it is more preferable to use recycled polyester resin in the intermediate layer. By using recycled polyester resin in the intermediate layer, the amount of recycled polyester resin used can be increased, and recyclability can be improved. Also, when using recycled polyester resin in the intermediate layer, a portion of the resin constituting the intermediate layer may be recycled polyester resin, or all of it may be recycled polyester resin.

[0021] The base film contains particles such that transparency is not impaired, and the surface on the resin layer A side, which will be described in detail later, is given a desired surface roughness (Sa) and maximum peak height (Sp). Furthermore, in the relationship between the protrusion height (X) and the number of protrusions (Y) on the surface on the resin layer A side, the ratio (Y2 / Y1) of the number of protrusions with a protrusion height of 0.5 μm or more and less than 2.5 μm (Y1) to the number of protrusions with a protrusion height of 2.5 μm or more (Y2) satisfies a specific ratio. The type of particles is not particularly limited as long as they can impart the above-mentioned properties. Specific examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide; and organic particles such as acrylic resin, styrene resin, urea resin, phenolic resin, epoxy resin, benzoguanamine resin, and copolymers thereof. Furthermore, precipitated particles obtained by precipitating and finely dispersing a portion of a metal compound such as a catalyst during the polyester manufacturing process can also be used. Among the inorganic particles, silica particles and calcium carbonate particles are particularly preferred because they are easily effective even in small amounts. Organic particles are preferred because they easily impart the above-mentioned properties, and among these, acrylic resin, styrene resin, or copolymers thereof are more preferred.

[0022] Furthermore, there are no particular restrictions on the shape of the particles used; spherical, lumpy, rod-shaped, flattened, etc., may be used. There are also no particular restrictions on their hardness, specific gravity, color, etc. Two or more types of these particles may be used in combination as needed.

[0023] Furthermore, the average particle size of the particles used is preferably in the range of 1 to 10 μm, more preferably in the range of 1 to 8 μm, more preferably in the range of 2 to 6 μm, and even more preferably in the range of 2 to 5 μm, from the viewpoint of creating an uneven surface on the film.

[0024] The base film has a resin layer constituting the surface of the base film that contains particles, and the particles in the resin layer have the average particle size described above. The resin layer containing such particles is preferably a resin layer (hereinafter also referred to as resin layer A) in which the arithmetic mean height (Sa) of the surface on which the resin layer is provided of the resin film described later is 500 nm or more, and the ratio (Y2 / Y1) of the number of protrusions with a protrusion height of 0.5 μm or more and less than 2.5 μm (Y1) to the number of protrusions with a protrusion height of 2.5 μm or more (Y2) is 0.02 to 0.05. In the present invention, by having a resin layer A with the above specific structure in the base film, it is possible to make a resin film that has an adhesive improvement effect and can reduce foreign matter.

[0025] If the resin layer A is a multilayer film, it constitutes the surface layer. If the resin layer A is a single-layer film, it is the resin layer that constitutes that single layer. By having particles of the average particle size described above, resin layer A imparts an appropriate adhesion-improving effect to the resin film and makes it easier to create irregularities on the surface of the resin film that are suitable as a support for polishing pads. Furthermore, when a polyurethane resin layer, described later, is laminated onto the resin film, it is preferable that resin layer A constitutes at least the surface of the base film on the side to which the polyurethane resin layer is laminated.

[0026] When the base film is a single layer, that single layer becomes the resin layer A, and the above-mentioned average particle size is contained in that single layer resin layer A. In the case of a single-layer film, the particle content in the polyester is preferably in the range of 0.1 to 20% by mass relative to 100% by mass of the total polyester constituting the base film (i.e., resin layer A). If the particle content is 0.1% by mass or more, the effect necessary for improving adhesion to resin layers such as polyurethane resin layers can be obtained. If it is 20% by mass or less, it becomes easier to appropriately control the number of protrusions on the surface of the resin film. The particle content is more preferably in the range of 1 to 17% by mass, even more preferably 3 to 15% by mass, and particularly preferably 5 to 10% by mass.

[0027] In the case of a multilayer film, it is preferable that at least one surface layer constituting the surface of the base film contains particles, and that the surface layer containing the particles is resin layer A, but it is preferable that both surface layers contain particles, and it is even more preferable that both surface layers containing particles are resin layer A. In addition, in the case of a multilayer film, it is also preferable to have a polyester film in which only the surface layer (for example, resin layer A) substantially contains particles, and the intermediate layer substantially does not contain particles. Note that substantially no particles means not only that there are no particles at all, but that there may be particles of a degree derived from the catalyst used in the synthesis of polyester, and the specific particle content may be, for example, less than 0.1% by mass or less than 0.05% by mass based on 100% by mass of polyester in the intermediate layer. In multilayer films, in order to appropriately control the number of protrusions relative to 100% by mass of polyester constituting the surface layer (resin layer A) and to contribute to improved adhesion, the particle content in resin layer A is preferably in the range of 0.1 to 20% by mass, more preferably 1 to 17% by mass, even more preferably 3 to 15% by mass, and particularly preferably 5 to 10% by mass. The average particle size is as described above. The above describes the particle content in polyester film, but the same applies when the base film is not polyester film. In that case, the particle content is the amount relative to 100% by mass of the resin constituting the base film in the case of a single-layer film, and the amount relative to 100% by mass of the resin constituting each layer, such as the surface layer, in the case of a multi-layer film.

[0028] The method for adding particles to a base film such as polyester is not particularly limited, and conventionally known methods can be employed. For example, the particles can be added at any stage in the production of polyester, but preferably at the esterification stage or after the completion of the transesterification reaction to proceed with the polycondensation reaction. Alternatively, the process can be carried out by blending a slurry of particles dispersed in ethylene glycol or water with the polyester raw material using a vented kneading extruder, or by blending dried particles with the polyester raw material using a kneading extruder.

[0029] In addition to the aforementioned particles and catalyst, conventionally known antioxidants, heat stabilizers, lubricants, antistatic agents, fluorescent whitening agents, dyes, pigments, ultraviolet absorbers, etc., may be added to the base film, such as polyester film, as needed.

[0030] The thickness of the polyester film (base film) is preferably in the range of 25 to 500 μm, more preferably 38 to 400 μm, even more preferably 50 to 350 μm, and even more preferably 75 to 300 μm, with a particularly preferred range of 100 to 200 μm.

[0031] Furthermore, the polyester film (base film) can be formed into a laminated structure using various conventionally known methods such as co-extrusion. In a multilayer film, the thickness of the outermost layer (surface layer) is preferably 2 μm or more, more preferably 3 μm or more, and preferably 1 / 8 or less of the total thickness, based on the thickness on only one side (i.e., the thickness of each surface layer). By using within the above range, as described above, it is possible to manufacture a polyester film having a polyester layer that substantially contains particles only in the surface layer, enabling the formation of sufficient irregularities and contributing to improved adhesion to the polyurethane resin layer.

[0032] The following will specifically describe the method for producing the polyester film used in the present invention. However, the method for producing the polyester film is not particularly limited to the following examples, as long as it satisfies the gist of the present invention. Generally, first, polyester chips dried by known methods or undried are supplied to a melt extruder and heated to a temperature above the melting point of each polymer to melt them. Next, the molten polymer is extruded from the die and rapidly cooled and solidified on a rotating cooling drum to a temperature below the glass transition temperature to obtain a substantially amorphous, unoriented sheet. In this case, in order to improve the flatness of the sheet, it is preferable to increase the adhesion between the sheet and the rotating cooling drum, and in the present invention, electrostatic application adhesion and / or liquid coating adhesion are preferably employed.

[0033] From the viewpoint of film strength, it is preferable to stretch the sheet obtained as described above in the biaxial direction to form a film. The stretching may be performed by sequential biaxial stretching or simultaneous biaxial stretching, but sequential biaxial stretching is preferred. Specifically regarding the stretching conditions, it is preferable to stretch the unstretched sheet by 2.0 to 4.5 times in the longitudinal direction at 70 to 145°C to form a longitudinally uniaxially oriented film, then stretch it by 3.0 to 6.5 times in the transverse direction at 90 to 160°C to form a biaxially oriented film, and then heat treat (heat set) at 210 to 260°C for 10 to 600 seconds. Furthermore, it is preferable to allow the sheet to relax by 1 to 10% in the longitudinal and / or transverse directions in the highest temperature zone of the heat treatment and / or the cooling zone at the heat treatment exit.

[0034] To ensure the arithmetic mean height (Sa) is above a certain value, it is important to control the heat-setting temperature to a sufficiently high temperature. A sufficiently high heat-setting temperature can improve Sa. This is thought to be due to the slight melting of the film surface at high temperatures during heat-setting, causing the protrusions formed by the particles to become more granular. If the heat-setting temperature is too low, Sa may be insufficient, which is unsuitable for this invention. On the other hand, if the heat-setting temperature is too high, film breakage may occur during film formation. The heat-setting temperature is preferably 210 to 260°C, more preferably 220 to 260°C, and even more preferably 230 to 255°C.

[0035] [Resin layer B] The resin film of the present invention may consist of the above-described base film alone, but it is preferable that a resin layer B is further laminated on one or both surfaces of the base film. It is preferable that the resin layer B is laminated on the resin layer A of the base film. In the present invention, by providing the resin layer B on the resin layer A, the adhesive improvement effect is more easily exhibited. Furthermore, when the base film is a multilayer film with resin layer A on both surfaces, or when the base film is a single-layer film, and both sides of the base film are composed of resin layer A, resin layer B may be laminated on both surfaces of the base film, or it may be laminated on only one surface.

[0036] <Various polymers> To form resin layer B, various polymers such as polyester resin, acrylic resin, urethane resin, and vinyl resin can be used to improve the appearance and transparency of the applied layer. In this specification, these polymers are sometimes referred to as binder resins. Among the various polymers, polyester resin, acrylic resin, urethane resin, and vinyl resin are preferred from the viewpoint of being able to easily control adhesion, and polyester resin, acrylic resin, or urethane resin are more preferred. The binder resin may be used alone or in combination of two or more types.

[0037] Polyester resins are primarily composed of polycarboxylic acids and polyhydroxy compounds, such as those listed below. Specifically, polycarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfisoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, monopotassium salt of trimellitic acid, and their ester-forming derivatives, while polyhydroxy compounds include For example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethylol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate, etc., can be used. From these compounds, one or more can be appropriately selected, and a polyester resin can be synthesized by a conventional polycondensation reaction.

[0038] Acrylic resin is a polymer composed of polymerizable monomers, including acrylic and methacrylic monomers (hereinafter, acrylic and methacrylic may be collectively abbreviated as (meth)acrylic). These can be homopolymers, copolymers, or copolymers with polymerizable monomers other than acrylic and methacrylic monomers.

[0039] Furthermore, polymers also include copolymers of these polymers with other polymers (e.g., polyester, polyurethane, etc.). Examples include block copolymers and graft copolymers. Alternatively, polymers (and sometimes mixtures of polymers) obtained by polymerizing polymerizable monomers in a polyester solution or polyester dispersion are also included. Similarly, polymers (and sometimes mixtures of polymers) obtained by polymerizing polymerizable monomers in a polyurethane solution or polyurethane dispersion are also included. In the same manner, polymers (and sometimes mixtures of polymers) obtained by polymerizing polymerizable monomers in other polymer solutions or dispersions are also included.

[0040] The polymerizable monomers mentioned above are not particularly limited, but some representative compounds include, for example, various carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid, and their salts; various hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutyl hydroxyl fumarate, and monobutyl hydroxyitaconate; methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and Examples include various alkyl(meth)acrylic acid esters such as uryl(meth)acrylate; various nitrogen-containing compounds such as (meth)acrylamide, diacetone acrylamide, N-methylolacrylamide, or (meth)acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, and vinyltoluene; various vinyl esters such as vinyl propionate and vinyl acetate; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane; phosphorus-containing vinyl monomers; various vinyl halides such as vinyl chloride and pyridene chloride; and various conjugated dienes such as butadiene.

[0041] Urethane resin is a polymer compound that contains urethane bonds within its molecule. Urethane resin is typically synthesized by the reaction of polyols and isocyanates. Examples of polyols include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds may be used individually or in combination.

[0042] Polycarbonate polyols are obtained from polyhydric alcohols and carbonate compounds by a de-alcoholization reaction. Examples of polyhydric alcohols include aliphatic polyhydric alcohols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 3,3-dimethylolheptane. Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Examples of polycarbonate-based polyols obtained from the reactions of these compounds include poly(1,6-hexylene) carbonate and poly(3-methyl-1,5-pentylene) carbonate.

[0043] Polyester polyols include polyhydric acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl Examples include those obtained from the reaction of ethyl-2,4-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamines, lactonediols, etc.

[0044] Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol.

[0045] Examples of polyisocyanate compounds used to obtain urethane resins include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylenediphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate; aliphatic diisocyanates having aromatic rings such as α,α,α',α'-tetramethylxylylene diisocyanate; aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and alicyclic diisocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl diisocyanate. These may be used individually or in combination of multiple types.

[0046] Chain extenders may be used when synthesizing urethane resins. There are no particular restrictions on the chain extender as long as it has two or more active groups that react with isocyanate groups. Generally, chain extenders having two hydroxyl groups or amino groups can be used.

[0047] Examples of chain extenders having two hydroxyl groups include glycols such as aliphatic glycols like ethylene glycol, propylene glycol, and butanediol; aromatic glycols like xylylene glycol and bishydroxyethoxybenzene; and ester glycols like neopentyl glycol hydroxypivalate. Furthermore, examples of chain extenders having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, and diphenylmethanediamine; aliphatic diamines such as ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine; and alicyclic diamines such as 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylidenecyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, and 1,3-bisaminomethylcyclohexane.

[0048] The urethane resin may use a solvent as a medium, but preferably water is used. Methods for dispersing or dissolving the urethane resin in water include forced emulsification using an emulsifier, self-emulsification by introducing hydrophilic groups into the urethane resin, or water-soluble methods. In particular, the self-emulsification type, in which ionic groups are introduced into the structure of the urethane resin to form an ionomer, is preferred because it offers excellent storage stability of the liquid and superior water resistance and transparency of the resulting resin layer B.

[0049] Furthermore, various ionic groups can be introduced, such as carboxyl groups, sulfonic acids, phosphoric acid, phosphonic acid, and quaternary ammonium salts, but carboxyl groups are preferred. Various methods can be used to introduce carboxyl groups into urethane resin at each stage of the polymerization reaction. For example, one method is to use a resin containing carboxyl groups as a copolymer component during prepolymer synthesis, or to use a component containing carboxyl groups as one component of polyols, polyisocyanates, or chain extenders. In particular, a method using a carboxyl group-containing diol to introduce a desired amount of carboxyl groups by adjusting the amount of this component added is preferred. For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butanoic acid, etc., can be copolymerized with the diol used in the polymerization of urethane resin. Furthermore, it is preferable that these carboxyl groups be in the form of salts obtained by neutralization with ammonia, amines, alkali metals, inorganic alkalis, etc. Ammonia, trimethylamine, and triethylamine are particularly preferred. In this polyurethane resin, the carboxyl groups that have been removed by the neutralizing agent during the drying process after coating can be used as crosslinking reaction sites by other crosslinking agents. This results in excellent stability in the liquid state before coating, and further improves the durability, solvent resistance, water resistance, and blocking resistance of the resulting resin layer B.

[0050] <Surfactants> Various conventionally known surfactants can be used to improve the dispersibility of each component, such as anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, anionic surfactants and nonionic surfactants are preferred when considering compatibility with polymers that can be used to form resin layer B. Alternatively, fluorine compounds can be used instead of these surfactants.

[0051] Examples of anionic surfactants include sulfonate-based surfactants such as sodium dodecylbenzenesulfonate, sodium alkylsulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylallyl ether sulfate, and ammonium polyoxyalkylene alkenyl ether sulfate, as well as sulfate ester-based surfactants, carboxylate-based surfactants such as sodium lauryl acid and potassium oleate, and phosphate-based surfactants such as alkyl phosphates, polyoxyethylene alkyl ether phosphates, and polyoxyethylene alkylphenyl ether phosphates. Among these, sulfonate-based surfactants are preferred from the viewpoint of good dispersibility.

[0052] Examples of nonionic surfactants include ether-type surfactants, which are formed by adding alkylene oxides such as ethylene oxide or propylene oxide to compounds having hydroxyl groups, such as higher alcohols or alkylphenols; ester-type surfactants, which are formed by ester bonding of polyhydric alcohols such as glycerin or sugars with fatty acids; ester-ether-type surfactants, which are formed by adding alkylene oxide to fatty acids or polyhydric alcohol fatty acid esters; and amide-type surfactants, which have hydrophobic and hydrophilic groups connected by amide bonds. Among these, ether-type surfactants are preferred when considering solubility in water and stability, and types with added ethylene oxide are even more preferred when considering ease of handling.

[0053] The amount of surfactant is preferably in the range of 0.01 to 0.5, more preferably 0.05 to 0.4, and even more preferably 0.1 to 0.3, based on a mass ratio of 1 for the binder resin.

[0054] <Crosslinking agent> In forming resin layer B, it is preferable to use various crosslinking agents to strengthen resin layer B in order to stabilize its properties such as adhesion. That is, it is preferable that resin layer B is formed from a resin composition containing the above-mentioned binder resin and crosslinking agent. In addition to the binder resin and crosslinking agent, the resin composition may also appropriately contain the above-mentioned surfactant and additives described later.

[0055] Conventionally known materials can be used as crosslinking agents, such as melamine compounds, epoxy compounds, oxazoline compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, and aziridine compounds. Among these, melamine compounds, epoxy compounds, isocyanate compounds, oxazoline compounds, carbodiimide compounds, and silane coupling compounds are preferred. Furthermore, from the viewpoint of maintaining appropriate water repellency and strengthening the release layer, melamine compounds, oxazoline compounds, and isocyanate compounds are preferred, with melamine compounds being particularly preferred. These crosslinking agents may be used individually or in combination of two or more.

[0056] Melamine compounds are compounds that have a melamine skeleton in their composition. For example, alkylolated melamine derivatives, compounds partially or completely etherified by reacting alkylolated melamine derivatives with alcohol, and mixtures thereof can be used. Suitable alcohols for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. The melamine compound may be a monomer, a polymer of two or more, or a mixture thereof. Considering the reactivity with various compounds, it is preferable that the melamine compound contains a hydroxyl group. Furthermore, compounds in which urea or the like is co-condensed with a portion of the melamine can also be used, and a catalyst can be used to increase the reactivity of the melamine compound.

[0057] Oxazoline compounds are compounds having an oxazoline group in their molecule, and polymers containing an oxazoline group are particularly preferred. These can be produced by polymerization of an addition-polymerizable oxazoline group-containing monomer alone or with other monomers. Examples of addition-polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. One or more of these can be used. Among these, 2-isopropenyl-2-oxazoline is preferred because it is readily available industrially. Other monomers are not limited as long as they are copolymerizable with addition-polymerizable oxazoline group-containing monomers, for example (meth)acrylic acid esters such as alkyl (meth)acrylates (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, and cyclohexyl groups); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and their salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; (meth)acrylamide, N-alkyl(meth)acrylamide Examples of unsaturated amides include lylamide, N,N-dialkyl(meth)acrylamide (alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, and cyclohexyl); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride; and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene. One or more of these monomers can be used.

[0058] The amount of oxazoline groups in the oxazoline compound is preferably in the range of 0.5 to 10 mmol / g, more preferably 1 to 9 mmol / g, even more preferably 3 to 8 mmol / g, and particularly preferably 4 to 6 mmol / g. Using the compound within this range makes it easier to adjust the water-repellent performance.

[0059] Isocyanate compounds are compounds having an isocyanate derivative structure, such as isocyanates or blocked isocyanates. Examples of isocyanates include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylenediphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; aliphatic isocyanates having aromatic rings such as α,α,α',α'-tetramethylxylylene diisocyanate; aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and alicyclic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylenebis(4-cyclohexyl isocyanate), and isopropylidene dicyclohexyl diisocyanate. Furthermore, polymers and derivatives of these isocyanates, such as biuretized, isocyanurateized, uretdioneized, and carbodiimide-modified products, are also mentioned. These may be used individually or in combination. Among the above isocyanates, aliphatic isocyanates or alicyclic isocyanates are more preferred than aromatic isocyanates in order to avoid yellowing due to ultraviolet light.

[0060] When used in the form of blocked isocyanates, examples of blocking agents include phenolic compounds such as bisulfites, phenol, cresol, and ethylphenol; alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol; active methylene compounds such as dimethyl malonate, diethyl malonate, methyl isobutanoylacetate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; lactam compounds such as ε-caprolactam and δ-valerolactam; amine compounds such as diphenylaniline, aniline, and ethyleneimine; acid amide compounds such as acetanilide and acetic acid amide; and oxime compounds such as formaldehyde, acetaldehyde oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime. These may be used individually or in combination of two or more. Among the above, isocyanate compounds blocked by active methylene compounds are particularly preferred from the viewpoint of being effective in reducing the transfer of the adhesive layer to the adherend.

[0061] Isocyanate compounds may be used individually or as mixtures or binders with various polymers. It is preferable to use mixtures or binders with polyester resins or urethane resins to improve the dispersibility and crosslinking properties of isocyanate compounds.

[0062] Epoxy compounds are compounds that have epoxy groups in their molecules. Examples include condensates of epichlorohydrin with hydroxyl or amino groups such as ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and bisphenol A. These include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, and glycidylamine compounds. Examples of polyepoxy compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris(2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. Examples of diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, and ethylene glycol. Examples of monoepoxy compounds include glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, monoepoxy compounds such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and glycidylamine compounds such as N,N,N',N'-tetraglycidyl-m-xylylenediamine and 1,3-bis(N,N-diglycidylamino)cyclohexane.

[0063] From the standpoint of having good various properties, polyether-based epoxy compounds are preferred among the above. Furthermore, in terms of the amount of epoxy groups, polyfunctional polyepoxy compounds with three or more functions are preferred over those with two functions.

[0064] Carbodiimide compounds are compounds that have one or more carbodiimide or carbodiimide derivative structures in their molecule. For better release layer strength and other reasons, polycarbodiimide compounds having two or more carbodiimide structures in their molecule are more preferable.

[0065] Carbodiimide compounds can be synthesized using conventionally known techniques, and generally, condensation reactions of diisocyanate compounds are employed. The diisocyanate compounds are not particularly limited and can be either aromatic or aliphatic. Specifically, examples include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

[0066] Furthermore, to the extent that the effects of the present invention are not impaired, surfactants may be added, or hydrophilic monomers such as polyalkylene oxides, quaternary ammonium salts of dialkylamino alcohols, and hydroxyalkyl sulfonates may be added to improve the water solubility and water dispersibility of the polycarbodiimide compounds.

[0067] Silane coupling compounds are organosilicon compounds that contain both an organic functional group and a hydrolysis group such as an alkoxy group within a single molecule. For example, epoxy group-containing compounds such as 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyl group-containing compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, styryl group-containing compounds such as p-styryltrimethoxysilane, p-styryltriethoxysilane, (meth)acrylic group-containing compounds such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)- Examples include amino group-containing compounds such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltriethoxysilane; isocyanurate group-containing compounds such as tris(trimethoxysilylpropyl)isocyanurate and tris(triethoxysilylpropyl)isocyanurate; and mercapto group-containing compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane.

[0068] Among the above compounds, epoxy group-containing silane coupling compounds, double bond-containing silane coupling compounds such as vinyl groups and (meth)acrylic groups, and amino group-containing silane coupling compounds are more preferred from the viewpoint of the strength of resin layer B.

[0069] These crosslinking agents are used in the design to improve the performance of resin layer B by reacting with them during the drying and film formation processes. It can be inferred that unreacted crosslinking agents, reacted compounds, or mixtures thereof are present in the formed resin layer B.

[0070] Furthermore, within the scope that does not impair the spirit of the present invention, the resin layer B may also contain various additives as needed, such as defoaming agents, coating properties improvers, thickeners, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, dyes, and pigments.

[0071] <Binder resin ratio> The binder resin content is preferably in the range of 3% by mass or more, more preferably 15% by mass or more, and even more preferably in the range of 25 to 99% by mass, as a percentage of the resin layer B (i.e., the non-volatile components of the resin composition). A content of 3% by mass or more provides sufficient film-forming properties. By setting it to 99% by mass or less, other components such as crosslinking agents can be incorporated into the resin layer B. A binder resin content of 40 to 80% by mass is more preferable. Furthermore, the amount of crosslinking agent blended in resin layer B (i.e., the non-volatile component of the resin composition) is not particularly limited, but it should be, for example, about 0.01 to 5, preferably 0.1 to 2, and more preferably 0.2 to 1.2 by mass ratio relative to the binder resin content.

[0072] The components in resin layer B can be analyzed by methods such as TOF-SIMS, ESCA, X-ray fluorescence, and IR.

[0073] The resin layer B has a mass of 0.005 to 0.3 g / m² per unit area. 2 It is preferable that it has a thickness such that the mass per unit area is 0.01 to 0.2 g / m².2 is more preferable, and 0.05 to 0.1 g / m 2 is even more preferable.

[0074] <Method for forming resin layer B> Examples of the method for forming the resin layer B include methods such as coating, transfer, and lamination. Considering the ease of forming the resin layer B, it is preferable to form it by coating.

[0075] As the method by coating, it may be formed by in-line coating performed within the process of manufacturing the base film, or it may be formed by off-line coating by coating the once-manufactured base film outside the system.

[0076] Specifically, in-line coating is a method of performing coating at an arbitrary stage from when the resin for forming the base film is melt-extruded until after stretching and heat-fixing and winding up. Usually, coating is performed on any of the unstretched sheet obtained by melting and rapid cooling, the uniaxially stretched film, the biaxially stretched film before heat-fixing, and the film before winding up after heat-fixing. Although not limited to the following, for example, in sequential biaxial stretching, a method of coating the uniaxially stretched film stretched particularly in the longitudinal direction (vertical direction) and then stretching in the lateral direction is desirable. According to such a method, since the film formation of the base film and the formation of the resin layer B can be performed simultaneously, there is an advantage in terms of manufacturing cost. Also, since stretching is performed after coating, the thickness of the resin layer B can be changed by the stretching ratio, and thin film coating can be performed more easily than off-line coating.

[0077] Also, by forming the resin layer B on the film before stretching, the resin layer B can be stretched together with the base film, whereby the resin layer B can be firmly adhered to the base film. Further, in the manufacture of a biaxially stretched polyester film, by stretching while gripping the film end with a clip or the like, the base film can be restrained in the longitudinal and lateral directions, and in the heat-fixing process, a high temperature can be applied while maintaining flatness without wrinkles. Therefore, because the heat treatment applied after coating can reach temperatures unattainable by other methods, the film-forming properties of resin layer B are improved, allowing for stronger adhesion between resin layer B and the substrate film, and furthermore, resulting in a stronger resin layer B. This is particularly effective for reacting with crosslinking agents to achieve stable adhesive performance.

[0078] The coating may be performed by applying a coating solution obtained by diluting a resin composition containing each component forming the resin layer B, specifically a binder resin, a crosslinking agent as needed, and other additives, with water or an organic solvent. For example, when formed by in-line coating, the coating solution is more preferably an aqueous solution or an aqueous dispersion. A small amount of organic solvent may be contained in the coating solution for purposes such as improving dispersibility in water and improving film-forming properties. Furthermore, only one type of organic solvent may be used, or two or more types may be used as appropriate. On the other hand, when providing resin layer B by offline coating, it is preferable to manufacture the product by coating a film with a liquid prepared by adjusting the solid content concentration of the above-mentioned series of compounds as a solution or dispersion in a solvent to approximately 0.1 to 80% by mass.

[0079] Conventional coating methods such as gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze coating, impregnation coating, kiss coating, spray coating, calender coating, and extrusion coating can be used.

[0080] The coated resin composition is preferably dried or cured to form resin layer B, but at least curing is preferable. The drying or curing conditions for forming resin layer B on the film are not particularly limited, but in the case of the coating method, the drying temperature of the solvent such as water used in the coating liquid is preferably in the range of 70 to 150°C, more preferably 80 to 130°C, and even more preferably 90 to 120°C. The drying time is approximately in the range of 3 to 200 seconds, preferably 5 to 120 seconds.

[0081] Furthermore, heat treatment and irradiation with active energy rays such as ultraviolet irradiation may be used in combination as needed. The surface of the base film, such as a polyester film on which the resin layer B is formed, may be subjected to a surface treatment such as corona treatment or plasma treatment in advance.

[0082] [Average surface roughness (arithmetic mean height; Sa) and maximum peak height (Sp) of the surface on side A of the resin layer] In the resin film of the present invention, the average surface roughness (Sa) of the surface on the resin layer A side is 500 nm or more. When Sa is 500 nm or more, an adhesion improvement effect is exhibited, resulting in good adhesion when laminating to a polyurethane resin layer, for example, as described later. From this viewpoint, it is even more preferable that the average surface roughness (Sa) of the surface on the resin layer A side be 700 nm or more. On the other hand, from the viewpoint of the adhesion of the polyester film, Sa is preferably 1200 nm or less, more preferably 1100 nm or less, and even more preferably 1000 nm or less.

[0083] Furthermore, the maximum peak height (Sp) of the surface on the resin layer A side of the resin film is preferably 4500 nm or more. Having an Sp of 4500 nm or more makes it easier to achieve better adhesion when laminating with other resin layers such as polyurethane resin layers. The maximum peak height (Sp) of the surface is more preferably 5000 nm or more, and even more preferably 5500 nm or more. On the other hand, for example, as a support for a polishing pad, from the viewpoint of not hindering polishing, the maximum peak height (Sp) is preferably 10,000 nm or less, more preferably 8,000 nm or less, and even more preferably 7,000 nm or less. Surface roughness (Sa, arithmetic mean height, ISO 25178 surface texture) is a parameter that extends Ra (arithmetic mean height of a line) to a surface, and represents the average of the absolute differences in height at each point relative to the average surface. Maximum peak height (Sp) is a three-dimensional extension of the two-dimensional maximum peak height (Rp), and is the maximum height from the surface where the height is 0 in the measurement area. Furthermore, Sa and Sp can be adjusted by the particle size and content of the particles contained in resin layer A. In addition, if resin layer B is provided, the values ​​can also be adjusted by the composition of resin layer B, such as its thickness.

[0084] [Protrusion height (X) and number of protrusions (Y)] The resin film of the present invention requires that the ratio (Y2 / Y1) of the number of protrusions with a height of 0.5 μm or more and less than 2.5 μm (Y1) to the number of protrusions with a height of 2.5 μm or more (Y2), determined from a distribution curve representing the relationship between the protrusion height (X) and the number of protrusions (Y) on the surface of the resin layer A, is between 0.02 and 0.05. If the ratio (Y2 / Y1) is less than 0.02, the adhesion improvement effect cannot be fully realized. Furthermore, when the ratio (Y2 / Y1) is within the above range, the surface is uniformly and moderately roughened, making it suitable as a support for polishing pads. Therefore, when used in polishing pads, it is possible to eliminate the need for abrasives, preventing abrasives from becoming foreign matter, and resulting in a resin film with minimal foreign matter generation. From the above perspective, the ratio (Y2 / Y1) is preferably 0.02 to 0.04.

[0085] The number of protrusions (Y1) is 1.0 × 10⁻⁶. 5 pieces / mm 2 Preferably, it is 1.2 × 10 5 pieces / mm 2 It is more preferable that the above be the case, 1.4 × 105 pieces / mm 2 It is even more preferable that the above conditions are met. By setting the number of protrusions (Y1) to a certain level or higher, it becomes easier to make it suitable for polishing, and also easier to obtain an adhesive improvement effect. Furthermore, the number of protrusions (Y1) is not particularly limited, but from the viewpoint of making it easier to keep Y2 / Y1 above a certain level, for example, 1.0 × 10 7 pieces / mm 2 The following is preferably 1.0 × 10 6 pieces / mm 2 The following is more preferable: 5.0 × 10 5 pieces / mm 2 The following applies:

[0086] The number of protrusions (Y2) is 6 × 10 3 pieces / mm 2 Preferably, it is 5.8 × 10 3 pieces / mm 2 It is more preferable that the following conditions apply: 5.0 × 10 3 pieces / mm 2 It is even more preferable that the following conditions are met: By keeping the number of protrusions (Y2) below a certain level, it becomes easier to ensure uniformity of the rough surface. Furthermore, the number of protrusions (Y2) is set to 5.0 × 10⁻¹⁰ to facilitate maintaining a constant Y2 / Y1 ratio. 2 pieces / mm 2 Preferably, it is 1.0 × 10 3 pieces / mm 2 It is more preferable that the above be the case, 2.0 × 10 3 pieces / mm 2 It is even more preferable that the above conditions are met.

[0087] Furthermore, the total number of protrusions (Y1 + Y2) of the above-mentioned number of protrusions (Y1) and number of protrusions (Y2) is 1.2 × 10⁻¹⁰ 5 pieces / mm 2 Preferably, it is 1.3 × 10 5 pieces / mm 2 It is more preferable that the above be the case, 1.4 × 10 5 pieces / mm 2It is even more preferable that the above is true. By setting the total number of protrusions (Y1 + Y2) to a certain level or higher, it becomes more suitable for polishing and also easier to obtain an improved adhesive effect. The total number (Y1 + Y2) is not particularly limited, but for example, 1.0 × 10 7 pieces / mm 2 The following is preferably 1.0 × 10 6 pieces / mm 2 The following is more preferable: 5.0 × 10 5 pieces / mm 2 The following applies:

[0088] Furthermore, the number of protrusions with a height of 0.5 μm or more and less than 2.5 μm (Y1), and the number of protrusions with a height of 2.5 μm or more (Y2) can be determined by using a surface shape measurement system to measure the surface irregularities on the resin layer A side of the resin film using optical interferometry, plotting the relationship between the protrusion height at 0.1 μm intervals and the number of protrusions at each protrusion height, representing it as a distribution curve, and obtaining the results from that distribution curve. Furthermore, the number of protrusions (Y1) and (Y2) can be adjusted by the shape, average particle size, and content of the particles contained in resin layer A. If resin layer B is provided, the number can also be adjusted by the composition of resin layer B, such as its thickness. It can also be adjusted by the stretching temperature, stretching ratio, and heat-fixing temperature.

[0089] [Glossiness] The resin film of the present invention preferably has a glossiness of 10% or less at 60 degrees on the surface of resin layer A. A glossiness of 10% or less results in a certain degree of unevenness on the surface of the resin film, which makes it easier to improve adhesion to other resin layers such as polyurethane resin layers. A glossiness of 9% or less is more preferable, and even more preferable is 8% or less. The glossiness is not particularly limited, but for example, it may be 1% or more, preferably 3% or more, and even more preferably 4% or more. A glossiness of less than or equal to the above upper limit and above the lower limit results in an appropriate uneven shape, making it suitable as a support for polishing pads.

[0090] The arithmetic mean height (Sa), maximum peak height (Sp), number of protrusions (Y1), (Y2), and glossiness mentioned above can be determined by measuring them on the surface of the resin film on the side where resin layer A is provided. Therefore, if a resin film has resin layer B on top of resin layer A, Sa, Sp, Y1, Y2, and glossiness should be measured on the surface of the resin film on which resin layer B is provided. If a resin film does not have resin layer B on top of resin layer A, Sa, Sp, Y1, Y2, and glossiness should be measured on the surface of the resin film composed of resin layer A. Furthermore, in the present invention, both surfaces of the base film are composed of resin layer A, and the arithmetic mean height (Sa), maximum peak height (Sp), ratio (Y1 / Y2), number of protrusions (Y1), (Y2), total number of protrusions (Y1+Y2), and glossiness are as described above on both surfaces of the resin film. Alternatively, only one surface of the base film may be composed of resin layer A, and the arithmetic mean height (Sa), maximum peak height (Sp), ratio (Y1 / Y2), number of protrusions (Y1), (Y2), total number of protrusions (Y1+Y2), and glossiness may be as described above on only one surface of the resin film.

[0091] [Si element amount] The resin film of the present invention preferably has a Si element content of 0.1 mass% or less. Having a Si element content of 0.1 mass% or less allows for proper prevention of wafer contamination by silicon elements from the resin film, even when used in semiconductor applications such as wafer polishing pads. More preferably, the Si element content is 0.05 mass% or less, and even more preferably 0.01 mass% or less. The lower limit of the Si element content is not particularly limited; it should be 0 mass% or more.

[0092] <Laminated film> The resin film of the present invention is used as a support film for supporting resin layers such as polyurethane resin layers. In this specification, a laminate in which a resin layer is further laminated on a resin film is referred to as a film laminate. The film laminate of the present invention preferably comprises the above-described resin film and a polyurethane resin layer on at least one surface of the resin film. The polyurethane resin layer is preferably laminated on the surface of the resin film on which resin layer A is provided. In the film laminate, the polyurethane resin layer may be laminated onto the resin film via an adhesive layer, but it is preferable that it be laminated onto the resin film without an adhesive layer. Examples of the adhesive layer include an adhesive layer formed from an adhesive agent. Since the surface of the resin layer A side of the resin film of the present invention has the specific surface shape described above, the polyurethane resin layer can be laminated onto the resin film with good adhesion even without using an adhesive layer.

[0093] If resin layer B is not provided on resin layer A, the polyurethane resin layer may be directly laminated on resin layer A. If resin layer B is laminated on resin layer A, the polyurethane resin layer may be laminated on resin layer B, and it is preferable that it be directly laminated on resin layer B.

[0094] The polyurethane resin constituting the polyurethane resin layer may be any known polyurethane resin, for example, any polyurethane resin that can be used as the abrasive surface of an abrasive pad. Examples of polyurethane resins include polymers of polyols such as polyester, polyether, and polycarbonate, and polyisocyanates such as diphenylmethane-4,4'-diisocyanate. In addition to the polyurethane resin, the polyurethane resin layer may also contain additives as appropriate. The polyurethane resin layer may have multiple air bubbles. Having multiple air bubbles in the polyurethane resin layer allows for the proper construction of the polishing surface of the polishing pad.

[0095] Furthermore, there are no particular restrictions on the method of forming the polyurethane resin layer, but methods include laminating a polyurethane resin layer, which is provided on a release substrate, to a resin film, or directly applying a coating liquid containing components for forming the polyurethane resin layer to the resin film. The method of applying the coating solution is not particularly limited and can be carried out by conventionally known methods, for example, by applying it with an applicator.

[0096] While the method of laminating using a release-type substrate is prone to trapping air bubbles and wrinkles during lamination, it has the advantage of not subjecting the final product, the laminated film, to heat or other processes. Direct application methods have the advantage of producing a uniform polyurethane resin layer, although they may require consideration of changes in film shrinkage due to the heat applied to the film for drying and curing during the formation of the polyurethane resin layer. Generally, the method for forming the polyurethane resin layer can be appropriately selected depending on the composition and purpose of the final product.

[0097] The polyurethane resin layer may have air bubbles as described above. In the coating method, there are no particular limitations on the method for forming air bubbles in the polyurethane resin layer, but examples include a method that incorporates a pore-forming agent such as a polyol or a cellulose derivative into the coating solution and utilizes solidification regeneration. When forming air bubbles by solidification regeneration, the air bubbles are typically elongated in the thickness direction and are expanded in diameter on the side opposite to the surface of the polyurethane resin layer (i.e., the resin film side). In this case, the air bubbles are preferably open on the surface of the polyurethane resin layer. The air bubbles may also be opened by grinding the surface of the polyurethane resin layer. Furthermore, in the bonding method, if the urethane resin layer contains air bubbles, for example, the urethane resin layer may be made of foam. Alternatively, a polyurethane resin layer containing air bubbles may be formed on a release substrate instead of a resin film using a method similar to the coating method described above, and this polyurethane resin layer may be bonded to the resin film.

[0098] (Thickness of the polyurethane resin layer) The thickness of the polyurethane resin layer (after drying) is preferably 1 to 100 μm, more preferably 5 to 80 μm, even more preferably 10 to 60 μm, and particularly preferably 20 to 50 μm. If the value is above the lower limit, sufficient adhesive strength is obtained, and if it is below the upper limit, it is easy to handle.

[0099] (Thickness of the film laminate) From the viewpoint of handling, the thickness of the film laminate is, for example, 550 μm or less, preferably 500 μm or less, more preferably 40 μm to 350 μm, even more preferably 40 μm to 300 μm, and even more preferably 50 μm to 250 μm.

[0100] In the above description, the film laminate was described as consisting of a resin film and a polyurethane resin layer. However, layers other than the resin film and polyurethane resin layer may also be provided. For example, a functional layer may be provided on the side of the resin film opposite to the side on which the polyurethane resin layer is laminated. Furthermore, in the above description of the film laminate, a configuration in which the polyurethane resin layer is provided on the surface of the resin film was shown. However, resin layers other than the polyurethane resin layer may also be provided.

[0101] <Application> The resin film of the present invention is useful, for example, as a film used as a support for polishing pads used in the CMP (Chemical Mechanical Polishing) process of semiconductors. It is also useful to use the film laminate of the present invention as a polishing pad. In the film laminate, the resin layer, such as a polyurethane resin layer laminated on the resin film, preferably constitutes the polishing surface of the polishing pad. As described above, the resin film of the present invention has a uniformly and moderately roughened surface, so that it can polish surfaces such as wafers without the use of abrasives. Therefore, it does not require the treatment to reduce foreign matter adhesion as in the conventional method, has good handling properties, and yet exhibits good adhesion to the urethane resin layer. [Examples]

[0102] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. The measurement and evaluation methods used in the present invention are as follows.

[0103] (1) Method for measuring the intrinsic viscosity of polyester 1 g of polyester was accurately weighed, dissolved in 100 ml of a phenol / tetrachloroethane mixed solvent (50 / 50 by mass ratio), and measured at 30°C.

[0104] (2) Average particle size (d 50 Measurement method for :μm The average particle size (average primary particle size) was defined as the 50% cumulative value (by mass) of the equivalent spherical distribution measured using a centrifugal sedimentation particle size distribution analyzer (SA-CP3 model, manufactured by Shimadzu Corporation).

[0105] (3) Distribution curve of the surface of resin layer A and measurement of the number of protrusions and their heights Using a surface topography system (Hitachi High-Tech Science Corporation's "VertScan" (registered trademark) R5500), the surface irregularities of a resin film (sample) in a 237.65 μm × 178.25 μm area were measured by optical interferometry. The relationship between the protrusion height at 0.1 μm intervals and the number of protrusions at each height was plotted and represented as a distribution curve. From the distribution curve, the number of protrusions with a height of 0.5 μm or more and less than 2.5 μm (Y1) and the number of protrusions with a height of 2.5 μm or more (Y2) were determined. In the examples and comparative examples, the casting surface of the resin film was used as the measurement surface.

[0106] (4) Glossiness The glossiness was measured by irradiating the film surface with light according to Method 3 (60° glossiness) of JIS Z-8741-1983. In the examples and comparative examples, the casting surface of the resin film was used as the measurement surface.

[0107] (5) Amount of Si element detected from resin film The film surface was measured using an X-ray fluorescence analyzer (XRF, Shimadzu EDX-8000) to perform quantitative analysis of the Si element. In the examples and comparative examples, the casting surface of the resin film was used as the measurement surface.

[0108] Examples and comparative examples are shown below, and the methods for producing the polyester used in the examples and comparative examples are as follows.

[0109] <Method for manufacturing homopolyester (A)> A homopolyester (A) was prepared, which contains terephthalic acid as a constituent unit derived from a carboxylic acid component and ethylene glycol as a constituent unit derived from a diol component, and has an intrinsic viscosity (IV) of 0.64 dl / g.

[0110] <Method for producing particle-containing polyester (B)> A homopolyester was prepared, which contains terephthalic acid as a constituent unit derived from a carboxylic acid component and ethylene glycol as a constituent unit derived from a diol component, and has an intrinsic viscosity (IV) of 0.82 dl / g. 10% by mass of (meth)acrylic acid ester / styrene copolymer particles with an average primary particle size of 4.1 μm were added to this polyester and kneaded using a vented twin-screw kneader to prepare particle-containing polyester (B).

[0111] <Method for producing particle-containing polyester (C)> A homopolyester was prepared, which contains terephthalic acid as a constituent unit derived from a carboxylic acid component and ethylene glycol as a constituent unit derived from a diol component, and has an intrinsic viscosity (IV) of 0.82 dl / g. 15% by mass of silica particles with an average primary particle size of 4.2 μm was added to this polyester and kneaded using a vented twin-screw kneader to prepare particle-containing polyester (C).

[0112] <Method for producing particle-containing polyester (D)> A particle-containing polyester D was prepared, which is a homopolyester containing terephthalic acid as a constituent unit derived from a carboxylic acid component and ethylene glycol as a constituent unit derived from a diol component, having an intrinsic viscosity (IV) of 0.62 dl / g and containing 0.6% by mass of silica particles with an average particle size of 2.3 μm.

[0113] <Method for producing copolymer polyester (E)> A copolymer polyester E (intrinsic viscosity (IV) 0.70 dl / g) was prepared, containing terephthalic acid and isophthalic acid as constituent units derived from dicarboxylic acids, with a terephthalic acid content of 78% by mass and an isophthalic acid content of 22% by mass, and ethylene glycol as a constituent unit derived from the diol component.

[0114] Example 1 Using a multilayer die with two types and three layers, the raw materials were a mixture of the aforementioned polyesters (B) and (E) in proportions of 80% and 20% by mass, respectively, as the front and back layers, and 100% by mass of polyester (A) as the intermediate layer. These materials were supplied to a vented twin-screw extruder, melted at 285°C, and co-extruded from the die. An unstretched sheet was obtained by cooling and solidifying on a cooling roll with a surface temperature set to 22°C using an electrostatic application adhesion method. Next, the film was stretched 3.0 times in the longitudinal direction at a film temperature of 90°C using the difference in roll peripheral speed, and then the following resin layer B composition was applied to one side of the film at a rate (after drying) of 0.5 g / m². 2 After coating the film in this manner, it was guided into a tenter, stretched 3.8 times in the transverse direction at 140°C, heat-treated at a main crystallization zone temperature of 245°C, and then relaxed by 3% in the transverse direction to obtain a biaxially oriented polyester film roll with a thickness of 188 μm. The resin layer B was provided on the film surface in contact with the cooling roll (i.e., the casting surface).

[0115] <Resin layer B composition> A composition obtained by mixing (a), (b), and (c) shown below in a ratio of 60 / 20 / 20 for the content of nonvolatile components. (a) Aqueous dispersion of aliphatic polycarbonate polyurethane resin (b) Oxazoline compounds Acrylic polymer EPOCLOSE having oxazoline groups and polyalkylene oxide chains (oxazoline group content = 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.) (c) Isocyanate compounds 1000 parts by mass of block polyisocyanate hexamethylene diisocyanate, prepared by the following method, was stirred at 60°C, and 0.1 parts by mass of tetramethylammonium caprylate was added as a catalyst. After 4 hours, 0.2 parts by mass of phosphoric acid was added to stop the reaction and obtain an isocyanurate-type polyisocyanate composition. 100 parts by mass of the obtained isocyanurate-type polyisocyanate composition, 42.3 parts by mass of methoxypolyethylene glycol with a number average molecular weight of 400, and 29.5 parts by mass of propylene glycol monomethyl ether acetate were charged and held at 80°C for 7 hours. Thereafter, the reaction solution temperature was maintained at 60°C, and 35.8 parts by mass of methyl isobutanoylacetate, 32.2 parts by mass of diethyl malonate, and 0.88 parts by mass of a 28% methanol solution of sodium methoxide were added and held for 4 hours. 58.9 parts by mass of n-butanol was added, and the reaction solution was maintained at 80°C for 2 hours. Subsequently, 0.86 parts by mass of 2-ethylhexyl acid phosphate was added to obtain blocked polyisocyanate.

[0116] Examples 2 and 3 and Comparative Examples 1 and 2 In Example 1, the resin film was manufactured in the same manner as in Example 1, except that the composition and manufacturing conditions of the resin film were changed as shown in Table 1.

[0117] Reference example A commercially available sand mat was used. The characteristics of the films of the above examples, comparative examples, and reference examples are shown in Table 1 below.

[0118] [Table 1]

[0119] The resin film of the present invention, as shown in Examples 1 to 3, exhibits a distribution curve of moderately roughened surface roughness, making it suitable as a support film for polishing pads in the CMP manufacturing process. Therefore, it is possible to provide a resin film that can polish surfaces such as wafers without using abrasives, thereby reducing foreign matter. Furthermore, as a measure to improve adhesion, it was found that adjusting the number of protrusions with a specific height in the formation of irregularities on the film surface contributes to improved adhesion. In addition, it is presumed that providing resin layer B between the polyurethane resin layer and resin layer A further contributes to improved adhesion. [Industrial applicability]

[0120] The resin film of the present invention is suitable as a support for polishing pads in the CMP manufacturing process, with the aim of improving adhesion to polyurethane resin layers and the like.

Claims

1. The substrate film comprises a resin layer A having a resin layer A containing particles with an average particle size of 1 to 10 μm on at least one surface, A resin film in which the arithmetic mean height (Sa) of the surface on the resin layer A side is 500 nm or more, and the ratio (Y2 / Y1) of the number of protrusions on the surface on the resin layer A side with a protrusion height of 0.5 μm or more and less than 2.5 μm (Y1) to the number of protrusions with a protrusion height of 2.5 μm or more (Y2) is 0.02 to 0.

05.

2. The resin film according to claim 1, wherein the particles are organic particles.

3. The number of protrusions (Y1) on the surface of the resin layer A with a height of 0.5 μm or more and less than 2.5 μm is 1.2 × 10 ５ pieces / mm ２ The resin film according to claim 1 is as described above.

4. The number of protrusions (Y2) on the surface of the resin layer A with a height of 2.5 μm or more is 6 × 10 ３ pieces / mm ２ The resin film according to claim 1, which is as follows:

5. The total number of protrusions on the surface of resin layer A, consisting of protrusions with a height of 0.5 μm or more and less than 2.5 μm (Y1) and protrusions with a height of 2.5 μm or more (Y2) (Y1 + Y2) is 1.2 × 10 ５ pieces / mm ２ The resin film according to claim 1 is as described above.

6. The resin film according to any one of claims 1 to 5, wherein the base film is a polyester film.

7. The resin film according to claim 6, wherein the polyester film contains a titanium catalyst.

8. The resin film according to any one of claims 1 to 5, wherein the base film has a multilayer structure consisting of at least two layers.

9. The resin film according to any one of claims 1 to 5, wherein the base film has a multilayer structure consisting of three layers: a surface layer, an intermediate layer, and a surface layer.

10. The resin film according to any one of claims 1 to 5, wherein the resin layer A is provided on both surfaces of the base film.

11. The resin film according to any one of claims 1 to 5, wherein the maximum peak height (Sp) of the surface on the resin layer A side is 5000 nm or more.

12. A resin film according to any one of claims 1 to 5, wherein the amount of Si element detected in the resin film is 0.1 mass% or less.

13. The resin film according to any one of claims 1 to 5, wherein the glossiness of the surface on the resin layer A side at 60 degrees is 10% or less.

14. A resin film according to any one of claims 1 to 5, comprising a resin layer B on the resin layer A on at least one surface.

15. The resin film according to claim 14, wherein the resin layer B is formed from a resin composition comprising a binder resin and a crosslinking agent.

16. The resin film according to claim 9, wherein the intermediate layer contains recycled polyester resin.

17. The resin film according to any one of claims 1 to 5, wherein the thickness of the base film is 25 to 500 μm.

18. A resin film according to any one of claims 1 to 5, which is a component for the CMP process.

19. A film laminate comprising a resin film according to any one of claims 1 to 5, and a polyurethane resin layer laminated on the surface of the resin film on the side of the resin layer A.

20. A film laminate comprising the resin film described in claim 14 and a polyurethane resin layer laminated on the resin layer B.

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