WO2023234208A1 - Feuille adhésive - Google Patents

Feuille adhésive Download PDF

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Publication number
WO2023234208A1
WO2023234208A1 PCT/JP2023/019712 JP2023019712W WO2023234208A1 WO 2023234208 A1 WO2023234208 A1 WO 2023234208A1 JP 2023019712 W JP2023019712 W JP 2023019712W WO 2023234208 A1 WO2023234208 A1 WO 2023234208A1
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Prior art keywords
weight
parts
less
resin
adhesive layer
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PCT/JP2023/019712
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English (en)
Japanese (ja)
Inventor
宗重 中川
辰哉 小橋
彰規 田村
智雄 山口
逸大 畑中
Original Assignee
日東電工株式会社
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Priority claimed from JP2023012267A external-priority patent/JP2023177222A/ja
Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Publication of WO2023234208A1 publication Critical patent/WO2023234208A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/08—Macromolecular additives
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J125/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Adhesives based on derivatives of such polymers
    • C09J125/02—Homopolymers or copolymers of hydrocarbons
    • C09J125/04—Homopolymers or copolymers of styrene
    • C09J125/08—Copolymers of styrene
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J153/00—Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
    • C09J153/02—Vinyl aromatic monomers and conjugated dienes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

  • the present invention relates to a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing a styrenic block copolymer.
  • adhesives also referred to as pressure-sensitive adhesives, hereinafter the same
  • adhesives are widely used as a bonding means with good workability and high adhesive reliability in various industrial fields such as home appliances, automobiles, and office automation equipment.
  • a typical composition of such an adhesive includes a composition containing a polymer exhibiting rubber elasticity at room temperature and a tackifying resin.
  • Patent Document 1 describes an adhesive containing a styrene-isoprene block copolymer and a tackifying resin.
  • Patent Document 2 is a technical document regarding continuous kneading and coating of a solvent-free hot melt adhesive using a twin-screw extruder.
  • Non-Patent Document 1 is an academic paper on changes in the layer separation structure of an acrylic polymer (a blend of a diblock copolymer and a triblock copolymer) depending on hot melt coating conditions.
  • the adhesive strength of the adhesive changes depending on the material of the adherend and the surface shape of the adherend. For example, even if an adhesive exhibits good adhesion to non-polar materials, its adhesion to polar materials may be insufficient. Further, even if an adhesive exhibits high adhesive strength on a smooth surface, its adhesiveness may decrease on a rough surface due to insufficient tack, for example.
  • Patent Document 1 the adhesive force to the rough surface of a polypropylene plate, which is a substantially non-polar material, is investigated using an adhesive containing a styrene-isoprene block copolymer and a tackifying resin. Adhesion of polar materials to rough surfaces has not been investigated. Note that the adhesive used in Patent Document 1 is an adhesive formed from a solvent-based adhesive composition using an organic solvent.
  • an object of the present invention is to provide a pressure-sensitive adhesive sheet that can exhibit sufficient adhesion to polar rough surfaces and non-polar surfaces.
  • a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer contains a styrenic block copolymer and a tackifying resin. Further, the styrene content of the styrenic block copolymer is 10 to 22% by mass. Furthermore, the surface of the adhesive layer has a hardness of less than 0.15 MPa in a load/unload test by nanoindentation conducted at 23° C. and an indentation depth of 1 ⁇ m. Further, the amount of organic solvent remaining in the adhesive layer is less than 1000 ppm. According to the adhesive having the above composition and characteristics, it is a substantially solvent-free type with a residual amount of organic solvent of less than 1000 ppm, and can realize sufficient adhesion to both polar rough surfaces and non-polar surfaces.
  • the total amount of the tackifier resin in the adhesive layer is 70 to 140 parts by mass based on 100 parts by mass of the styrenic block copolymer.
  • the tackifying resin is at least one selected from the group consisting of terpene resins, rosin resins, styrene resins, and aromatic petroleum resins.
  • the effects of the technology disclosed herein are preferably achieved.
  • the content of the styrenic tackifier resin in the adhesive layer is 0 to 20 parts by mass based on 100 parts by mass of the styrenic block copolymer.
  • the content of the plasticizer in the adhesive layer is 0 to 20 parts by mass based on 100 parts by mass of the styrenic block copolymer. This can be achieved by either not including a plasticizer in the adhesive layer, or by designing the surface hardness of the adhesive layer to be less than a predetermined value by using a configuration in which a limited amount of plasticizer is used as described above. The effects of the technique disclosed in .
  • the content of the phenolic tackifier resin in the adhesive layer is less than 1 part by mass based on 100 parts by mass of the styrenic block copolymer.
  • FIG. 1 is a schematic cross-sectional view showing the configuration of a pressure-sensitive adhesive sheet (a double-sided pressure-sensitive adhesive sheet with a base material) according to an embodiment.
  • FIG. 3 is a schematic cross-sectional view showing the configuration of a pressure-sensitive adhesive sheet (substrate-less double-sided pressure-sensitive adhesive sheet) according to another embodiment. It is a typical sectional view showing the composition of an adhesive sheet (single-sided adhesive sheet with a base material) concerning other embodiments.
  • the term "adhesive” refers to a material that exhibits a soft solid (viscoelastic) state at a temperature around room temperature and has the property of easily adhering to an adherend under pressure.
  • the adhesive in the technology disclosed herein can also be understood as a solid content of the adhesive composition or a constituent component of the adhesive layer.
  • styrenic block copolymer means a polymer having at least one styrene block.
  • the above-mentioned styrene block refers to a segment (hard segment) containing styrene as the main monomer.
  • a segment consisting essentially of styrene is a typical example of the styrene block referred to herein.
  • styrene-isoprene block copolymer refers to a polymer having at least one styrene block and at least one isoprene block (a segment whose main monomer is isoprene).
  • styrene-isoprene block copolymers include copolymers with a triblock structure (triblock structure) having styrene blocks (hard segments) at both ends of an isoprene block (soft segment), one isoprene block and one Examples include copolymers with a diblock structure (diblock body) consisting of styrene blocks.
  • trim structure triblock structure
  • diblock body diblock body consisting of styrene blocks.
  • styrene-butadiene block copolymer refers to a polymer having at least one styrene block and at least one butadiene block (a segment whose main monomer is butadiene).
  • the "styrene content" of a styrenic block copolymer refers to the weight proportion of the styrene component to the total weight of the block copolymer.
  • the styrene content can be measured by NMR (nuclear magnetic resonance spectroscopy).
  • the proportion of diblock in the styrenic block copolymer (hereinafter sometimes referred to as “diblock ratio" or “diblock ratio”) is determined by the following method.
  • a styrene-based block copolymer was dissolved in tetrahydrofuran (THF), a total of four liquid chromatography columns (two stages each of Tosoh Corporation's GS5000H and G4000H) were connected in series, and THF was used as the mobile phase.
  • High performance liquid chromatography is performed at a temperature of 40° C. and a flow rate of 1 mL/min.
  • the peak area corresponding to the diblock body is measured from the obtained chart. Then, the diblock body ratio is determined by calculating the percentage of the peak area corresponding to the diblock body with respect to the entire peak area.
  • weight may be read as “mass”.
  • % by weight may be read as “% by mass”
  • parts by weight may be read as “parts by mass”.
  • the adhesive sheet disclosed herein includes an adhesive layer.
  • the above-mentioned pressure-sensitive adhesive sheet is, for example, a base material-less double-sided pressure-sensitive adhesive sheet comprising a first pressure-sensitive adhesive surface formed by one surface of the pressure-sensitive adhesive layer, and a second pressure-sensitive adhesive surface formed by the other surface of the pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive sheet disclosed herein may be in the form of a pressure-sensitive adhesive sheet with a base material, in which the pressure-sensitive adhesive layer is laminated on one or both sides of a support base material.
  • the supporting base material may be simply referred to as "base material".
  • adhesive sheet here includes what is called an adhesive tape, an adhesive label, an adhesive film, and the like.
  • the pressure-sensitive adhesive sheet disclosed herein may be in the form of a roll or a sheet. Alternatively, the adhesive sheet may be further processed into various shapes.
  • the adhesive sheet disclosed herein (which may be in a long form such as a tape) may be in the form of a double-sided adhesive sheet having the cross-sectional structure shown in FIG. 1, for example.
  • This double-sided adhesive sheet 1 includes a base material (for example, a plastic film) 15, and a first adhesive layer 11 and a second adhesive layer 12 supported on both sides of the base material 15, respectively. More specifically, the first adhesive layer 11 and the second adhesive layer 12 are provided on the first surface 15A and the second surface 15B (both non-peelable) of the base material 15, respectively. As shown in FIG.
  • the double-sided adhesive sheet 1 before use (before being attached to an adherend) is rolled into a spiral shape with the front surface 21A and the back surface 21B overlapped with a release liner 21 which is a release surface.
  • a release liner 21 which is a release surface.
  • the surface of the second adhesive layer 12 (second adhesive surface 12A) is released by the front surface 21A of the release liner 21, and the surface of the first adhesive layer 11 (first adhesive surface 11A) is peeled off.
  • the first adhesive surface 11A and the second adhesive surface 12A may be each protected by two independent release liners.
  • the technology disclosed herein is preferably applied to a double-sided pressure-sensitive adhesive sheet with a base material as shown in FIG. may also be applied.
  • the first adhesive surface 11A and the second adhesive surface 11B of the adhesive layer 11 without a base material are at least the surface (front surface) on the adhesive layer side.
  • the release liner 22 may be omitted and a release liner 21 having release surfaces on both sides may be used, and this and the adhesive layer 11 may be overlapped and spirally wound so that the second adhesive surface 11B is the release liner. It may be in a form in which it is protected by coming into contact with the back surface of 21.
  • the technology disclosed herein also provides a single-sided adhesive type base comprising a base material 15 and an adhesive layer 11 supported on a first surface (non-peelable surface) 15A of the base material, as shown in FIG. It can also be applied to the adhesive sheet 3 with material.
  • the pressure-sensitive adhesive sheet 3 before use is, for example, as shown in FIG. 3, the surface (adhesive surface) 11A of the pressure-sensitive adhesive layer 11 is a release liner in which at least the surface (front surface) on the pressure-sensitive adhesive layer side is a release surface. 21 protected form.
  • the release liner 21 may be omitted, the second surface 15B may be the release surface, and the first adhesive surface 11A may be the second surface of the base material 15 by winding the adhesive sheet 3 with the base material. It may be in a form in which it is protected by contacting the surface 15B.
  • the pressure-sensitive adhesive sheet disclosed herein has an adhesive surface, that is, the surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet, in a load-unloading test by nanoindentation conducted at 23° C. and an indentation depth of 1 ⁇ m.
  • One of its characteristics is that it has a hardness (nanoindentation hardness) of less than 15 MPa.
  • a substantially solvent-free adhesive having a predetermined composition specifically, a composition containing a styrenic block copolymer having a predetermined styrene content and a tackifying resin
  • a polar rough Sufficient adhesion can be achieved both to surfaces and to non-polar surfaces.
  • the nanoindentation hardness of the surface of the adhesive layer is preferably less than 0.10 MPa, more preferably less than 0.09 MPa, even more preferably less than 0.08 MPa, particularly preferably less than 0.07 MPa, and most preferably 0. It is less than .06 MPa, and may be less than 0.05 MPa.
  • the lower limit of the nanoindentation hardness may be, for example, 0.01 MPa or more, or 0.03 MPa or more, from the viewpoint of coexistence with other adhesive properties (cohesive force, etc.).
  • the adhesive sheet disclosed here is a double-sided adhesive sheet with a base material, at least one adhesive layer surface (preferably both surfaces) should have the above-mentioned nanoindentation hardness.
  • the nanoindentation hardness of the surface of the adhesive layer is determined by the composition of the adhesive layer (specifically, the type of styrenic block copolymer, chemical structure such as styrene content, molecular weight, etc.), the type of tackifier resin, etc. usage ratio, etc.), adhesive coating conditions (specifically, shear rate during coating, shear viscosity, back roll temperature, etc.), storage conditions after coating (specifically, heated storage, etc.), etc. It can be adjusted by Specifically, the nanoindentation hardness of the surface of the adhesive layer is measured by the method described in Examples below.
  • the adhesive layer may have a residual amount of organic solvent of less than 1000 ppm (the amount of organic solvent per 1 g of adhesive is less than 1000 ⁇ g (that is, less than 1000 ⁇ g/1 g of adhesive)).
  • the method for forming a solvent-free adhesive layer is appropriately set and adjusted (for example, by adjusting coating conditions, etc.).
  • the nanoindentation hardness By setting the nanoindentation hardness appropriately, the nanoindentation hardness of the surface of the adhesive layer can be made less than a predetermined value, and the effects of the technology disclosed herein can be preferably achieved.
  • the amount of organic solvent remaining in the adhesive layer may be less than 900 ppm, less than 800 ppm, less than 700 ppm, less than 600 ppm, and in some preferred embodiments, less than 500 ppm. It may be less than 400 ppm, less than 300 ppm, less than 200 ppm, or less than 100 ppm. In some embodiments, the amount of organic solvent remaining in the adhesive layer may be, for example, less than 90 ppm, less than 80 ppm, less than 70 ppm, less than 60 ppm, less than 50 ppm, or less than 40 ppm. , may be less than 30 ppm, may be less than 20 ppm, or may be less than 10 ppm.
  • Adhesives with such a small residual amount of organic solvent are preferable from the viewpoint of reducing environmental impact.
  • the adhesive layer in which the residual amount of organic solvent is less than a predetermined value may be formed from a substantially solvent-free adhesive composition (typically, a hot-melt adhesive composition). Therefore, in this specification, an adhesive (layer) in which the residual amount of organic solvent is less than 1000 ppm can be referred to as a solvent-free adhesive (layer) or even a hot-melt adhesive (layer).
  • the amount of organic solvent remaining in the adhesive layer is measured by the method described in Examples below.
  • the adhesive layer disclosed herein (in an embodiment having a first adhesive layer and a second adhesive layer, at least one adhesive layer; the same applies hereinafter unless otherwise specified) is made of a styrenic block copolymer.
  • the styrenic block copolymer refers to a block copolymer of styrene and a conjugated diene compound.
  • the conjugated diene compound include 1,3-butadiene and isoprene.
  • the styrenic block copolymer preferably contains at least one of a styrene-isoprene block copolymer and a styrene-butadiene block copolymer.
  • the styrenic block copolymer may include a hydride in which at least a portion thereof is hydrogenated (hydrogen atoms are added).
  • the above styrenic block copolymers can be used alone or in combination of two or more.
  • the proportion of styrene-isoprene block copolymer is 70% by weight or more, or the proportion of styrene-butadiene block copolymer is 70% by weight or more.
  • the total proportion of the styrene-isoprene block copolymer and the styrene-butadiene block copolymer is preferably 70% by weight or more.
  • substantially all (eg, 95-100% by weight) of the styrenic block copolymer is a styrene-isoprene block copolymer.
  • substantially all (eg, 95-100% by weight) of the styrenic block copolymer is a styrene-butadiene block copolymer. According to such a composition, the effects of the technology disclosed herein can be preferably exhibited.
  • the above styrenic block copolymer is a component that can be used as a base polymer of an adhesive.
  • the "base polymer" of an adhesive is the main component (i.e., more than 50% by weight of the rubbery polymer) of the rubbery polymer (polymer that exhibits rubber elasticity in the temperature range around room temperature) contained in the adhesive. component).
  • the styrene content of the styrenic block copolymer is 10 to 22% by weight.
  • the cohesive force of the styrene blocks also called hard segments
  • the adhesive has a surface hardness below a predetermined value. It is possible to obtain layers with improved adhesion to polar and non-polar surfaces, especially to polar rough surfaces.
  • the styrene content of the styrenic block copolymer is preferably more than 10% by weight, more preferably 12% by weight or more, and may be, for example, 14% by weight or more.
  • the styrene content is preferably less than 20% by weight, more preferably 18% by weight or less, and may be, for example, 16% by weight or less.
  • the above-mentioned styrene content refers to the styrene content in the entire (100% by weight) of the two or more types of styrenic block copolymers.
  • the adhesive layer disclosed herein has a styrene content of 10 to 22% by weight based on the entire styrenic block copolymer contained in the adhesive layer, and contains styrene to the extent that the effects of the invention are not impaired. It may contain less than 10% or more than 22% by weight of styrenic block copolymer.
  • the styrenic block copolymer may be in the form of a diblock, a triblock, a radial, a mixture thereof, or the like.
  • a styrene block is placed at the end of the polymer chain. This is because the styrene blocks placed at the ends of the polymer chains tend to aggregate to form styrene domains, thereby forming a pseudo crosslinked structure and improving the cohesiveness of the adhesive.
  • the styrenic block copolymer used in the technique disclosed herein has a diblock proportion of 30% by weight or more, from the viewpoint of reducing the hardness of the pressure-sensitive adhesive layer surface and improving adhesiveness to rough surfaces.
  • the diblock body ratio is more preferably 50% by weight or more (for example, more than 50% by weight), still more preferably 60% by weight or more, particularly preferably 65% by weight or more, and most preferably 70% by weight or more (for example, 75% by weight). (above) may be possible. Furthermore, from the viewpoint of cohesiveness and the like, a styrenic block copolymer having a diblock proportion of 90% by weight or less (more preferably 85% by weight or less, for example 80% by weight or less) can be preferably used.
  • a styrenic block copolymer with a diblock proportion of 60 to 85% by weight is preferred, A styrenic block copolymer of 70 to 85% by weight (for example, 70 to 80% by weight) is more preferred.
  • the adhesive layer disclosed herein contains a tackifying resin in addition to the styrenic block copolymer.
  • a tackifying resin can be used alone, or two or more types can be used in combination.
  • the tackifier resin is not particularly limited, and for example, petroleum-based tackifier resins or natural product-based tackifier resins can be used.
  • the petroleum-based tackifying resin is a compound derived from petroleum resources and has a chemical structure derived from petroleum resources, and has adhesive properties due to its compatibility with adhesives and chemical properties based on its chemical structure. It is intended to give.
  • natural product-based tackifying resins are compounds that contain components derived from natural products, and have a chemical structure derived from natural products. , which imparts adhesive properties.
  • one or more of petroleum-based tackifying resins and natural product-based tackifying resins are appropriately selected based on their chemical structures to achieve polar rough surface adhesion and non-polar surface adhesion. Adhesives with improved properties can be designed.
  • Examples of petroleum-based tackifying resins include aliphatic (C5-based) petroleum resins, aromatic (C9-based) petroleum resins, aliphatic/aromatic copolymer (C5/C9-based) petroleum resins, and styrene-based resins. , and their hydrogenated substances (for example, alicyclic petroleum resins obtained by hydrogenating aromatic petroleum resins).
  • Other examples of petroleum-based tackifying resins include coumaron-indene resin and dicyclopentadiene resin. Petroleum-based tackifying resins can be used alone or in combination of two or more.
  • styrenic resins include those whose main component is a homopolymer of styrene, those whose main component is a homopolymer of ⁇ -methylstyrene, those whose main component is a homopolymer of vinyltoluene, styrene, Copolymers whose main component is a copolymer containing two or more of ⁇ -methylstyrene and vinyltoluene in their monomer composition (for example, ⁇ -methylstyrene/styrene copolymers whose main component is an ⁇ -methylstyrene/styrene copolymer) polymer resins), etc.
  • coumaron-indene resin a resin containing coumaron and indene as monomer components constituting the skeleton (main chain) of the resin can be used.
  • monomer components other than coumaron and indene that may be included in the resin skeleton include styrene, ⁇ -methylstyrene, methylindene, and vinyltoluene.
  • Examples of natural product-based tackifying resins include terpene resins, rosin-based resins, and the like.
  • Terpene resins include unmodified terpene resins and modified terpene resins.
  • Rosin-based resins include rosin derivative resins.
  • Natural product-based tackifying resins can be used alone or in combination of two or more.
  • terpene resins examples include ⁇ -pinene polymers, ⁇ -pinene polymers, dipentene polymers, and the like.
  • modified terpene resins include those obtained by modifying the above-mentioned terpene resins (phenol modification, aromatic modification (for example, styrene modification), hydrogenation modification, hydrocarbon modification, etc.).
  • terpene phenol resins, aromatic-modified (for example, styrene-modified) terpene resins, hydrogenated terpene resins, and the like are exemplified.
  • the terpene phenolic resins may include hydrogenated terpene phenolic resins.
  • terpene phenol resin refers to a polymer containing terpene residues and phenol residues, including a copolymer of a terpene and a phenol compound (terpene-phenol copolymer resin) and a terpene homopolymer or copolymer. This is a concept that includes both terpene resins (terpene resins, typically unmodified terpene resins) and phenol-modified ones (phenol-modified terpene resins).
  • rosin-based resins include unmodified rosin (raw rosin) such as gum rosin, wood rosin, and tall oil rosin; rosin, disproportionated rosin, polymerized rosin, other chemically modified rosin, etc.);
  • rosin derivative resins include those obtained by esterifying unmodified rosin with alcohols (i.e., esterified products of rosin), and modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) with alcohols.
  • Rosin esters such as esterified products (i.e., esterified products of modified rosin); unsaturated fatty acid-modified rosin, which is obtained by modifying unmodified rosin or modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) with unsaturated fatty acids.
  • esterified products i.e., esterified products of modified rosin
  • unsaturated fatty acid-modified rosin which is obtained by modifying unmodified rosin or modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) with unsaturated fatty acids.
  • Rosin unsaturated fatty acid-modified rosin esters, which are rosin esters modified with unsaturated fatty acids; unmodified rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), unsaturated fatty acid-modified rosin or Rosin alcohols obtained by reducing the carboxyl group in saturated fatty acid-modified rosin esters; metal salts of rosins (especially rosin esters) such as unmodified rosin, modified rosin, and various rosin derivatives; rosin (especially rosin esters); Examples include rosin phenol resins obtained by adding phenol to rosin (rosin, various rosin derivatives, etc.) with an acid catalyst and thermally polymerizing the mixture.
  • the softening point of the tackifier resin used in the technology disclosed herein is usually higher than 40°C, and may be 60°C or higher.
  • the softening point of the tackifying resin is 80°C or higher (eg, greater than 80°C), preferably 100°C or higher (eg, greater than 100°C).
  • the upper limit of the softening point of the tackifying resin is not particularly limited, and is usually suitably 200°C or lower, and from the viewpoint of polar rough surface adhesion, preferably 180°C or lower, more preferably 170°C or lower (for example, 160°C or lower). °C or less), may be 140°C or less, or may be 120°C or less.
  • the softening point of the tackifying resin is defined as a value measured based on the softening point test method (ring and ball method) specified in JIS K5902 and JIS K2207. Specifically, the sample is melted as quickly as possible at the lowest possible temperature, and the sample is carefully filled into a ring placed on a flat metal plate, taking care not to form bubbles. After it has cooled down, use a slightly heated knife to cut off the raised part from the flat surface, including the top edge of the ring.
  • a supporter (ring stand) is placed in a glass container (heating bath) with a diameter of 85 mm or more and a height of 127 mm or more, and glycerin is poured into the container to a depth of 90 mm or more.
  • the steel ball (diameter 9.5 mm, weight 3.5 g) and the ring filled with the sample are immersed in glycerin without touching each other, and the temperature of the glycerin is maintained at 20 °C plus or minus 5 °C for 15 minutes. .
  • a steel ball is then placed in the center of the surface of the sample in the ring and placed in position on the support.
  • thermometer place a thermometer, set the center of the mercury bulb of the thermometer at the same height as the center of the ring, and heat the container.
  • the flame of the Bunsen burner used for heating should be halfway between the center of the bottom of the container and the edge to ensure even heating. Note that the rate at which the bath temperature increases after heating starts and reaches 40°C must be 5.0 plus or minus 0.5°C per minute.
  • the sample gradually softens and flows down from the ring, and the temperature at which it finally touches the bottom plate is read, and this is taken as the softening point.
  • the softening point is measured at two or more points at the same time, and the average value is used.
  • one or more types selected from terpene resins, rosin resins, styrene resins, and aromatic petroleum resins are used as the tackifier resin.
  • tackifier resins By selecting one or more appropriate tackifying resins from among the above tackifying resins, it is easy to obtain a pressure-sensitive adhesive having excellent adhesiveness to rough polar surfaces and non-polar surfaces.
  • a terpene resin is used as the tackifying resin.
  • the terpene resin is well compatible with the adhesive containing the styrenic block copolymer, and the effect of its addition can be suitably exhibited.
  • terpene resins are well compatible with the soft segments (segments whose main monomer is a conjugated diene compound) of styrenic block copolymers, and based on their softening points, terpene resins are It is thought that it imparts appropriate cohesive force to the segments.
  • adhesive properties such as polar rough surface adhesion and cohesive force can be achieved in a well-balanced manner.
  • polar rough surface adhesion and non-polar surface adhesion can be preferably achieved in a composition containing a terpene resin.
  • Terpene resins can be used alone or in combination of two or more.
  • the softening point of the terpene resin is usually higher than 40°C, and may be 60°C or higher. In some embodiments, the softening point of the terpene resin is higher than 80°C, from the viewpoint of cohesive force, preferably 90°C or higher, more preferably 95°C or higher, and 100°C or higher (for example, 100°C or higher).
  • the temperature is more preferably 110°C or higher (for example, higher than 110°C), particularly preferably 115°C or higher.
  • the upper limit of the softening point of the terpene resin is usually 200°C or lower, and from the viewpoint of rough surface adhesion, it is preferably 160°C or lower, more preferably 140°C or lower, and even if it is 120°C or lower. good.
  • the content of the terpene resin in the adhesive layer may be, for example, 1 part by weight or more, and 10 parts by weight, based on 100 parts by weight of the styrenic block copolymer.
  • the above is fine.
  • the content of the terpene resin is 20 parts by weight or more, and 30 parts by weight or more with respect to 100 parts by weight of the styrenic block copolymer.
  • the amount may be 40 parts by weight or more, or 50 parts by weight or more.
  • the content of the terpene resin relative to 100 parts by weight of the styrenic block copolymer is suitably less than 120 parts by weight, which improves adhesiveness (for example, rough surface adhesion) and cohesive force.
  • the amount is preferably 100 parts by weight or less, more preferably 80 parts by weight or less, may be 70 parts by weight or less, and may be 60 parts by weight or less.
  • the amount of the terpene resin per part by weight of the soft segment (segment whose main monomer is a conjugated diene compound) in the styrenic block copolymer is , for example, 0.1 part by weight or more, preferably 0.2 part by weight or more, may be 0.4 part by weight or more, may be 0.5 part by weight or more, or even 0.6 part by weight or more. good.
  • the amount of terpene resin per 1 part by weight of the soft segment of the styrenic block copolymer is suitably 1.5 parts by weight or less, which improves adhesion (e.g.
  • the amount is preferably 1.2 parts by weight or less, more preferably 1 part by weight or less, may be 0.8 parts by weight or less, and may be 0.75 parts by weight or less.
  • a rosin resin is used as the tackifying resin.
  • the rosin resin is well compatible with the adhesive containing the styrene block copolymer, and the effect of its addition can be suitably exhibited.
  • rosin-based resins usually have a high polarity region and a low polarity region in one molecule, and each segment (hard segment and soft segment) of the styrenic block copolymer. ), and is considered to contribute to improving adhesive properties (for example, achieving both adhesive properties such as rough surface adhesion and cohesive force) based on a compatibility effect different from that of terpene resins.
  • polar rough surface adhesion and non-polar surface adhesion can be preferably achieved in a composition containing a rosin-based resin.
  • the use of rosin resin is also advantageous in that it can improve adhesion to polar adherends such as metals.
  • One type of rosin resin can be used alone or two or more types can be used in combination.
  • the softening point of the rosin resin is usually higher than 40°C, and may be 60°C or higher. In some embodiments, the softening point of the rosin resin is higher than 80°C, and from the viewpoint of cohesive force, the softening point of the rosin resin is preferably 100°C or higher, and preferably 110°C or higher. The temperature is more preferably 130°C or higher, even more preferably 150°C or higher.
  • the upper limit of the softening point of the rosin resin is usually 200°C or lower, and from the viewpoint of rough surface adhesion, it is preferably 180°C or lower, and may be 170°C or lower.
  • the content of the rosin resin in the adhesive layer may be, for example, 1 part by weight or more, and 10 parts by weight or more, based on 100 parts by weight of the styrene block copolymer. It may be more than part by weight. In some preferred embodiments, from the viewpoint of effectively exhibiting the effect of adding the rosin resin, the content of the rosin resin based on 100 parts by weight of the styrene block copolymer is 20 parts by weight or more, and 30 parts by weight. or more, 40 parts by weight or more, or 50 parts by weight or more.
  • the content of the rosin resin based on 100 parts by weight of the styrenic block copolymer is suitably 120 parts by weight or less, which improves adhesiveness (for example, rough surface adhesion) and cohesive force.
  • the amount is preferably 100 parts by weight or less, more preferably 80 parts by weight or less, may be 70 parts by weight or less, may be 50 parts by weight or less, and may be 30 parts by weight or less.
  • the content of the rosin resin based on 100 parts by weight of the styrenic block copolymer may be 10 parts by weight or less, or 1 part by weight or less.
  • the technology disclosed herein can be implemented in an embodiment using an adhesive layer that does not substantially contain rosin resin.
  • the expression "the adhesive layer does not substantially contain a specific tackifying resin such as a rosin resin” means that no tackifying resin is intentionally added to the adhesive layer. This means that the content of the imparting resin is less than 0.1 part by weight (for example, 0 to 0.05 part by weight) based on 100 parts by weight of the styrenic block copolymer.
  • the tackifying resin includes a terpene resin and a rosin resin.
  • a terpene resin and a rosin resin together as the tackifying resin, it is possible to better achieve both polar rough surface adhesion and non-polar surface adhesion.
  • the ratio of the terpene resin to the rosin resin is not particularly limited.
  • the ratio (T/R) of the content of the terpene resin (T) to the content of the rosin resin (R) is, for example, 1/10 or more, and 1/5 or more on a weight basis. It may be 1/3 or more, 1/2 or more, 2/3 or more, or 1 or more.
  • the ratio (T/R) is greater than 1, may be 1.2 or more, may be 1.5 or more, may be 1.8 or more, may be 2 or more, It may be 2.5 or more.
  • the ratio (T/R) may be 10 or less, 5 or less, 3 or less, or 2 or less.
  • the total amount of terpene resin and rosin resin contained in the adhesive layer is not particularly limited, and an appropriate amount may be adopted to achieve the desired effect.
  • the total amount of the terpene resin and rosin resin may be, for example, 10 parts by weight or more, or 20 parts by weight or more, based on 100 parts by weight of the styrenic block copolymer.
  • the total amount of the terpene resin and rosin resin based on 100 parts by weight of the styrenic block copolymer is 30 parts by weight or more, more preferably 40 parts by weight or more, and even more preferably 50 parts by weight.
  • Parts by weight or more may be 70 parts by weight or more, and may be 80 parts by weight or more.
  • the total amount of the terpene resin and rosin resin based on 100 parts by weight of the styrenic block copolymer is suitably 140 parts by weight or less, preferably 120 parts by weight or less, and more preferably is 110 parts by weight or less, more preferably 100 parts by weight or less, particularly preferably 90 parts by weight or less, may be 80 parts by weight or less, or may be 70 parts by weight or less (for example, 60 parts by weight or less).
  • the tackifying resin includes a styrenic resin.
  • the styrene resin is well compatible with the adhesive containing the styrene block copolymer, and the effect of its addition can be suitably exhibited.
  • a styrene resin it is possible to improve the adhesive strength to a polar adherend based on the structure containing an aromatic ring. Further, by using a styrene resin, high cohesive force can be easily obtained.
  • styrenic resins have aromatic rings derived from styrene, so styrenic resins have domains formed by gathering hard segments of styrenic block copolymers (hereinafter referred to as "hard domains"). (also referred to as "styrene domain”).
  • hard domains also referred to as "styrene domain”
  • properties based on pseudo-crosslinking by the hard domain can be adjusted, such as improving adhesive strength to polar adherends and cohesive strength of adhesives. It is thought that this will effectively contribute to improvement.
  • the styrenic resins can be used alone or in combination of two or more.
  • the softening point of the styrenic tackifying resin is greater than 100°C.
  • the softening point of the styrenic tackifying resin is suitably 110°C or higher, preferably 125°C or higher, more preferably 135°C or higher, and may be, for example, 150°C or higher.
  • the upper limit of the softening point of the styrene-based tackifier resin is not particularly limited, and is usually suitably 200°C or lower, and from the viewpoint of rough surface adhesion, preferably 180°C or lower, more preferably 170°C or lower (e.g. 160°C or lower), may be 150°C or lower, or may be 140°C or lower.
  • the content of the styrene-based tackifying resin in the adhesive layer is not particularly limited, and an appropriate amount may be adopted to achieve the desired effect.
  • the content of the styrenic tackifying resin is less than 40 parts by weight based on 100 parts by weight of the styrenic block copolymer, and may be 35 parts by weight or less, and even 25 parts by weight or less. good. This makes it possible to achieve both rough surface adhesion and cohesive force in a well-balanced manner.
  • the content of the styrenic tackifying resin in the adhesive layer is 20 parts by weight or less (for example, 0 to 20 parts by weight) based on 100 parts by weight of the styrenic block copolymer, and From the viewpoint of improving rough surface adhesion and non-polar surface adhesion, it is more preferably 12 parts by weight or less, even more preferably 10 parts by weight or less, particularly preferably 8 parts by weight or less (for example, 6 parts by weight or less), and 3 The amount may be less than 1 part by weight, and the adhesive layer may be substantially free of styrenic tackifying resin.
  • the hardness of the surface of the adhesive layer can be appropriately controlled. Good adhesion to polar rough surfaces and non-polar surfaces can preferably be obtained.
  • the amount of the styrenic tackifying resin is 1.5 parts by weight per 1 part by weight of the hard segment (specifically, the styrene component) in the styrenic block copolymer. It is appropriate to use the following amount, and from the viewpoint of rough surface adhesion, it may be 1.0 part by weight or less, 0.8 part by weight or less, or 0.5 part by weight or less.
  • the amount of the styrenic tackifying resin per 1 part by weight of the hard segment (specifically, the styrene component) of the styrenic block copolymer may be 0 parts by weight or more, and the amount of the styrenic tackifying resin may be 0 parts by weight or more, From the viewpoint of exhibiting the effect of adding the resin, the amount is, for example, 0.01 part by weight or more, may be 0.05 part by weight or more, may be 0.1 part by weight or more, may be 0.2 part by weight or more, The amount may be 0.3 parts by weight or more.
  • the styrene-based tackifying resin is well compatible with the hard domain (typically, styrene domain) of the styrene-based block copolymer, and the styrene-based tackifying resin The effect of the addition of can be effectively exhibited.
  • the tackifying resin includes an aromatic petroleum resin.
  • the aromatic petroleum resin is a resin called a C9 petroleum resin, and is understood to have a chemical structure different from the above-mentioned styrene-based tackifying resin.
  • Aromatic petroleum resins are well compatible with adhesives containing styrenic block copolymers, and the effects of their addition can be suitably exhibited. Moreover, by using an aromatic petroleum resin, it is easy to obtain an appropriate cohesive force based on the chemical structure containing an aromatic ring.
  • aromatic petroleum resins have aromatic rings and are therefore easily compatible with hard domains (specifically, styrene domains) of styrenic block copolymers.
  • Aromatic petroleum resins can be used alone or in combination of two or more.
  • the softening point of the aromatic petroleum resin is greater than 100°C.
  • the softening point of the aromatic petroleum resin is suitably 110°C or higher, preferably 125°C or higher, more preferably 135°C or higher, and even more preferably 150°C or higher.
  • the upper limit of the softening point of the aromatic petroleum resin is not particularly limited, and is usually suitably 200°C or lower, and from the viewpoint of rough surface adhesion, preferably 180°C or lower, more preferably 170°C or lower (e.g. 160°C or lower), may be 150°C or lower, or may be 140°C or lower.
  • the content of the aromatic petroleum resin in the adhesive layer is not particularly limited, and an appropriate amount may be adopted to achieve the desired effect.
  • the content of the aromatic petroleum resin is more than 0 parts by weight, for example, 1 part by weight or more, or even 5 parts by weight or more, based on 100 parts by weight of the styrenic block copolymer. Often, it may be 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more (for example, 40 parts by weight or more). . Thereby, rough surface adhesion and cohesive force can be improved in a well-balanced manner.
  • the content of the aromatic petroleum resin relative to 100 parts by weight of the styrenic block copolymer is 70 parts by weight or less, and from the viewpoint of rough surface adhesion, the content is 60 parts by weight or less.
  • the amount may be 50 parts by weight or less, or 40 parts by weight or less.
  • the content of the aromatic petroleum resin relative to 100 parts by weight of the styrenic block copolymer may be 20 parts by weight or less, 10 parts by weight or less, or 1 part by weight or less. good.
  • the technology disclosed herein can be implemented in an embodiment using an adhesive layer that does not substantially contain aromatic petroleum resin.
  • the amount of aromatic petroleum resin per 1 part by weight of hard segment (specifically, styrene component) in the styrenic block copolymer is 10 parts by weight or less. From the viewpoint of rough surface adhesion, the amount may be 5 parts by weight or less, 4 parts by weight or less, or 3 parts by weight or less. In some embodiments, the amount of the aromatic petroleum resin may be 0 parts by weight or more based on 1 part by weight of the hard segment (specifically, the styrene component) of the styrenic block copolymer, and the amount of the aromatic petroleum resin may be 0 parts by weight or more.
  • the amount is, for example, 0.01 part by weight or more, may be 0.1 part by weight or more, may be 0.5 part by weight or more, may be 1 part by weight or more, and 1.
  • the amount may be 5 parts by weight or more.
  • the ratio of the total amount of terpene resin, rosin resin, styrene resin, and aromatic petroleum resin as tackifier resin to the total amount of tackifier resin contained in the adhesive layer is 50 It is preferable to make it more than % by weight.
  • a tackifier resin composition By employing such a tackifier resin composition, the effects of the technology disclosed herein are preferably exhibited. According to the technology disclosed herein, polar rough It is possible to form an adhesive with good surface adhesion and non-polar surface adhesion.
  • the proportion of the total amount of the terpene resin, rosin resin, styrene resin, and aromatic petroleum resin is more preferably 70% by weight or more, still more preferably 90% by weight or more, and particularly preferably 95% by weight. or more (for example, 99 to 100% by weight).
  • the total amount of terpene resin, rosin resin, styrene resin, and aromatic petroleum resin as tackifying resins contained in the adhesive layer is not particularly limited, and may be adjusted in an appropriate amount to achieve the desired effect. Can be adopted.
  • the total amount of the terpene resin, rosin resin, styrene resin, and aromatic petroleum resin is suitably 50 parts by weight or more based on 100 parts by weight of the styrenic block copolymer.
  • the amount may be 60 parts by weight or more, 65 parts by weight or more, preferably 70 parts by weight or more, more preferably 75 parts by weight or more, still more preferably 80 parts by weight or more, and 90 parts by weight or more.
  • the amount may be 100 parts by weight or more, 110 parts by weight or more, or 120 parts by weight or more.
  • the total amount of the terpene resin, rosin resin, styrene resin, and aromatic petroleum resin relative to 100 parts by weight of the styrenic block copolymer is less than 180 parts by weight, and 170 parts by weight.
  • An adhesive that can achieve excellent adhesion to rough polar surfaces and adhesion to non-polar surfaces by appropriately setting the amounts of terpene resin, rosin resin, styrene resin, and aromatic petroleum resin within the above ranges. can be preferably obtained.
  • Natural tackifier resin (A) Natural product-based tackifying resin (A) having a softening point of over 80° C. and containing no aromatic ring is used as the tackifying resin. Natural product-based tackifier resins having a molecular structure that does not contain aromatic rings and a softening point of over 80° C. are well compatible with adhesives containing styrenic block copolymers, and the effects of their addition can be suitably exhibited. By using the natural product-based tackifier resin (A), for example, sufficient high-temperature holding power can be easily obtained based on its softening point. Furthermore, by using a compound that does not contain an aromatic ring, rough surface adhesion tends to be easily obtained, and good storage stability is also likely to be obtained.
  • the natural product-based tackifier resin (A) among the above-mentioned natural product-based tackifier resins, those having a softening point exceeding 80°C and a molecular structure containing no aromatic ring may be used without particular restriction. I can do it.
  • terpene resins, modified terpene resins, rosin-based resins, rosin derivative resins, etc. having a softening point of over 80° C. can be used.
  • the natural tackifier resin (A) can be used alone or in combination of two or more.
  • a terpene resin is used as the natural tackifier resin (A).
  • a rosin resin is used as the natural tackifier resin (A).
  • the softening point of the natural product-based tackifying resin (A) is higher than 80°C.
  • the softening point of the natural tackifier resin (A) is preferably 90°C or higher, more preferably 100°C or higher (for example, over 100°C), and more preferably 110°C or higher (for example, over 100°C).
  • the temperature is more preferably 110°C or higher, and particularly preferably 115°C or higher.
  • the softening point of the natural tackifying resin (A) may be 120°C or higher, 140°C or higher, or 150°C or higher.
  • the upper limit of the softening point of the natural product-based tackifier resin (A) is not particularly limited, and is usually suitably 200°C or lower, and preferably 180°C or lower, more preferably 180°C or lower from the viewpoint of rough surface adhesion.
  • the temperature is 170°C or lower (for example, 160°C or lower), may be 140°C or lower, or may be 120°C or lower.
  • the natural product-based tackifying resin (A) includes the above-mentioned terpene resin as the tackifying resin (A1) and the above-mentioned rosin-based resin as the tackifying resin (A2).
  • a terpene resin and a rosin resin together as the tackifier resin (A)
  • the ratio of their usage is not particularly limited.
  • the ratio (A1/A2) of the content of the tackifier resin (A1) to the content of the tackifier resin (A2) is, for example, 1/10 or more, and 1/5 or more on a weight basis. It may be 1/3 or more, 1/2 or more, 2/3 or more, or 1 or more. In some preferred embodiments, the ratio (A1/A2) is greater than 1, may be 1.2 or more, may be 1.5 or more, may be 1.8 or more, may be 2 or more, It may be 2.5 or more. The ratio (A1/A2) may be 10 or less, 5 or less, 3 or less, or 2 or less.
  • the content of the above-mentioned natural product-based tackifying resin (A) in the adhesive layer is not particularly limited. , appropriate amounts may be employed to achieve the desired effect.
  • the content of the natural product-based tackifying resin (A) is more than 30 parts by weight and less than 140 parts by weight, and 35 to 130 parts by weight, based on 100 parts by weight of the styrenic block copolymer. It may be.
  • the content of the natural tackifying resin (A) is 40 to 120 parts by weight based on 100 parts by weight of the styrenic block copolymer. Thereby, rough surface adhesion and cohesive force can be improved in a well-balanced manner.
  • the content of the natural tackifying resin (A) based on 100 parts by weight of the styrene block copolymer may be 50 parts by weight or more, 70 parts by weight or more, 90 parts by weight or more, 100 parts by weight or more. It may be more than part by weight.
  • the content of the natural tackifying resin (A) based on 100 parts by weight of the styrene block copolymer is preferably 110 parts by weight or less, may be 90 parts by weight or less, and may be 80 parts by weight or less. The amount may be 60 parts by weight or less.
  • the tackifying resin includes a petroleum-based tackifying resin (B) having a softening point of over 100° C. and containing an aromatic ring.
  • a petroleum-based tackifying resin having a molecular structure containing an aromatic ring and a softening point of over 100° C. is well compatible with an adhesive containing a styrene-based block copolymer, and the effect of its addition can be suitably exhibited.
  • the petroleum-based tackifier resin (B) sufficient high-temperature holding power can be easily obtained based on the structure including an aromatic ring and the softening point.
  • the petroleum-based tackifier resin (B) since the petroleum-based tackifier resin (B) has an aromatic ring, the hard segments (segments whose main monomer is styrene) of the block copolymer are aggregated. formed hard domains). It is thought that the high softening point petroleum-based tackifying resin (B) is compatible with the hard domain, thereby improving the heat resistance of the pseudo-crosslinking caused by the hard domain, and contributing to the improvement of the high-temperature holding power of the adhesive. .
  • the petroleum-based tackifying resin (B) among the above-mentioned petroleum-based tackifying resins, those having a softening point exceeding 100°C and a molecular structure containing an aromatic ring can be used without particular limitation.
  • aromatic (C9-based) petroleum resins, aliphatic/aromatic copolymerized (C5/C9-based) petroleum resins, styrene-based resins, coumaron-indene resins, etc. with a softening point of over 100°C can be used. .
  • aromatic petroleum resins and styrene resins are preferred.
  • the petroleum-based tackifying resin (B) can be used alone or in combination of two or more.
  • the softening point of the petroleum-based tackifier resin (B) is higher than 100°C. From the viewpoint of high temperature holding power, the softening point of the petroleum-based tackifying resin (B) is suitably 110°C or higher, preferably 125°C or higher, more preferably 135°C or higher, and even more preferably 150°C or higher.
  • the upper limit of the softening point of the petroleum-based tackifying resin (B) is not particularly limited, and is usually suitably 200°C or lower, and from the viewpoint of rough surface adhesion, preferably 180°C or lower, more preferably 170°C or lower. °C or lower (for example, 160°C or lower), may be 150°C or lower, or may be 140°C or lower.
  • the content of the petroleum-based tackifying resin (B) in the adhesive composition (the total amount when two or more types are contained) is not particularly limited, Appropriate amounts may be employed to achieve the desired effect.
  • the content of the petroleum-based tackifying resin (B) is more than 0 parts by weight and less than 50 parts by weight, and 1 to 45 parts by weight, based on 100 parts by weight of the styrenic block copolymer. be.
  • the content of the petroleum-based tackifier resin (B) is 5 to 40 parts by weight based on 100 parts by weight of the styrenic block copolymer.
  • the content of the petroleum tackifying resin (B) based on 100 parts by weight of the styrene block copolymer may be 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more. The amount may be 30 parts by weight or more (for example, 35 parts by weight or more). Further, the content of the petroleum-based tackifying resin (B) based on 100 parts by weight of the styrene-based block copolymer may be 35 parts by weight or less, or 25 parts by weight or less, from the viewpoint of rough surface adhesion. .
  • the petroleum-based tackifying resin is based on 1 part by weight of the hard segment (specifically, the styrene component) in the styrenic block copolymer.
  • the amount of (B) is, for example, 0.01 part by weight or more, may be 0.05 part by weight or more, may be 0.1 part by weight or more, may be 0.2 part by weight or more, and may be 0.3 part by weight or more. It may be more than part by weight.
  • the amount of the petroleum-based tackifying resin (B) per 1 part by weight of the hard segment (specifically, the styrene component) of the styrenic block copolymer may be 0.5 part by weight or more, The amount may be 1 part by weight or more, or 1.5 parts by weight or more. In some embodiments, the amount of the petroleum-based tackifying resin (B) relative to 1 part by weight of the hard segment (specifically, the styrene component) of the styrenic block copolymer is suitably 10 parts by weight or less.
  • the amount may be 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, and suitably 2.7 parts by weight or less.
  • the amount may be 4 parts by weight or less, 1.8 parts by weight or less, or 1.5 parts by weight or less.
  • the amount of petroleum-based tackifying resin (B) per 1 part by weight of the hard segment (specifically, the styrene component) of the styrenic block copolymer is 1 part by weight from the viewpoint of rough surface adhesion.
  • the amount may be 0.0 part by weight or less, 0.8 part by weight or less, or 0.5 part by weight or less.
  • the petroleum-based tackifying resin (B) By setting the amount of the petroleum-based tackifying resin (B) within the above range, the petroleum-based tackifying resin (B) is well compatible with the domain (styrene domain) formed by the hard segments of the block copolymer. However, the effect of adding the petroleum-based tackifying resin (B) can be effectively exhibited.
  • the natural product-based tackifier resin (A) and the petroleum-based tackifier resin (B) are used together as the tackifier resin.
  • a natural product-based tackifier resin (A) and a petroleum-based tackifier resin (B) together the effects on the block copolymer based on the chemical structure differences of each tackifier resin can be used to It is easy to form a pressure-sensitive adhesive that has both surface adhesion and high-temperature holding power and has good storage stability.
  • the ratio of their use is not particularly limited.
  • the ratio (A/B) of the content of the natural product-based tackifier resin (A) to the content of the petroleum-based tackifier resin (B) is, for example, 0.5 or more on a weight basis, It is suitably 1 or more, preferably 2 or more, it may be 3 or more, it may be 4 or more, it may be 5 or more, it may be 6 or more. In some embodiments, the ratio (A/B) may be 8 or more, 10 or more, 12 or more, or 14 or more (for example, 15 or more). The ratio (A/B) is, for example, 20 or less, may be 16 or less, may be 12 or less, may be 10 or less, may be 8 or less, may be 6 or less, may be 4 or less. , 2 or less.
  • the adhesive layer may further contain a tackifier resin other than those mentioned above (other tackifier resins) to the extent that the effects of the present invention are not impaired.
  • other tackifier resins include aromatic modified terpene resins, terpene phenol resins, and rosin phenol resins. These are natural product-based tackifying resins containing aromatic rings.
  • Other examples of the other tackifier resins include aliphatic (C5-based) petroleum resins, alicyclic petroleum resins, and the like. These are petroleum-based tackifying resins that do not contain aromatic rings.
  • the tackifying resin includes a natural tackifying resin (A) and a petroleum tackifying resin (B)
  • the tackifying resin includes a natural tackifying resin (A) and a petroleum tackifying resin.
  • the content of the tackifier resin different from the resin (B) may be less than 30% by weight, and may be less than 10% by weight, based on the total amount of tackifier resin contained in the adhesive layer, and may be less than 3% by weight. % or less than 1% by weight.
  • the technology disclosed herein can be implemented in an embodiment in which the adhesive layer does not substantially contain a tackifying resin different from the natural product-based tackifying resin (A) and the petroleum-based tackifying resin (B). .
  • the technology disclosed herein does not rely on phenolic tackifying resins (e.g., terpene phenol resins), and can change the type and amount of tackifying resins other than phenolic tackifying resins. Based on this, it is possible to form an adhesive with good adhesion to polar rough surfaces and good adhesion to non-polar surfaces. While phenolic tackifier resins can contribute to improving adhesive properties, they tend to be a factor that accelerates deterioration of adhesives. Therefore, being able to achieve the desired adhesiveness without using a phenolic tackifying resin as an essential component is also significant in terms of obtaining excellent storage stability.
  • phenolic tackifying resins e.g., terpene phenol resins
  • the content of the phenolic tackifying resin can be less than 30% by weight, and may be less than 10% by weight, based on the total amount of tackifying resin contained in the adhesive layer. It may be less than 1% by weight, or less than 1% by weight.
  • the technique disclosed herein can be implemented in an embodiment in which the adhesive layer does not substantially contain a phenolic tackifying resin.
  • the content of the phenolic tackifier resin in the adhesive layer is preferably less than 30 parts by weight, more preferably less than 10 parts by weight, based on 100 parts by weight of the styrenic block copolymer.
  • the phenolic tackifier resin herein means a tackifier resin having a molecular structure containing a phenol skeleton, and includes terpene phenol resins, hydrogenated terpene phenol resins, phenol resins (alkyl phenol resins, xylene-formaldehyde resins, etc.) , rosin, phenolic resin, etc.
  • the total amount of tackifying resin in the adhesive layer is not particularly limited, and an appropriate amount may be adopted to achieve the desired effect.
  • the total amount of tackifier resin is more than 35 parts by weight, may be more than 45 parts by weight, suitably more than 50 parts by weight, based on 100 parts by weight of the styrenic block copolymer.
  • the amount may be 60 parts by weight or more, or 65 parts by weight or more.
  • the total amount of the tackifier resin is 70 parts by weight or more, more preferably 75 parts by weight or more, and still more preferably 80 parts by weight or more based on 100 parts by weight of the styrenic block copolymer.
  • the total amount of tackifier resin for 100 parts by weight of the styrenic block copolymer is less than 180 parts by weight, may be 170 parts by weight or less, and is 160 parts by weight or less (for example, 150 parts by weight). (below).
  • the total amount of the tackifier resin is 140 parts by weight or less, more preferably 120 parts by weight or less, even more preferably 100 parts by weight or less (e.g. (less than 100 parts by weight), particularly preferably at most 95 parts by weight, and may be at most 90 parts by weight.
  • the hardness of the surface of the adhesive layer is less than a predetermined value, and it is preferable to use an adhesive that has sufficient adhesion to rough polar surfaces and non-polar surfaces. can be formed.
  • the adhesive layer has a total amount of the styrenic block copolymer and the tackifying resin that is 50% of the total weight of the adhesive (i.e., the weight of the adhesive layer constituted by the adhesive).
  • the composition may account for more than 70% by weight, for example 70% by weight or more, or even 80% by weight or more.
  • the effects of the technology disclosed herein are preferably achieved in an embodiment that includes a pressure-sensitive adhesive layer having such a composition.
  • the total amount of the styrenic block copolymer and tackifier resin in the entire adhesive layer is 90% by weight or more, and may be 95% by weight or more (for example, 95 to 100% by weight).
  • the upper limit of the total amount of the styrenic block copolymer and tackifying resin in the entire adhesive layer may be 99% by weight or less from the viewpoint of adding other components such as plasticizers and anti-aging agents. It may be 98% by weight or less.
  • the adhesive layer disclosed herein may also contain a plasticizer.
  • a plasticizer in the adhesive, the adhesiveness to the adherend can be improved, and the rough surface adhesion can be improved.
  • the plasticizer in this specification refers to a material that is a liquid or a viscous fluid at room temperature (for example, 25°C), or has a softening point of 40°C or lower. The softening point can be measured by the same method as the method for measuring the softening point of the tackifier resin described above.
  • the type of plasticizer is not particularly limited, and depending on the adhesive composition (type of styrenic block copolymer, type of tackifying resin), etc., it may be selected from among those that can exert a plasticizing effect on the adhesive. things are selected.
  • plasticizers include liquid rubbers such as polybutene and polyisoprene, and process oils such as paraffinic oils and naphthenic oils.
  • a liquid resin such as a liquid terpene resin or a liquid rosin resin may be used.
  • Other examples of plasticizers include esters of higher fatty acids (higher fatty acid esters) such as stearic acid and palmitic acid, and fatty acid amides. Among them, liquid terpene resin and process oil are preferably used.
  • One kind of plasticizer can be used alone or two or more kinds can be used in combination.
  • the content of plasticizer in the adhesive layer is not particularly limited, and an appropriate amount may be adopted to achieve the desired effect.
  • the content of the plasticizer is more than 0 parts by weight, may be 1 part by weight or more, may be 3 parts by weight or more, and may be 5 parts by weight based on 100 parts by weight of the styrenic block copolymer. It may be more than one year.
  • the content of the plasticizer relative to 100 parts by weight of the styrenic block copolymer may be 10 parts by weight or more, or 15 parts by weight or more. The greater the amount of plasticizer used, the easier it is to improve rough surface adhesion.
  • the content of the plasticizer is 0 to 20 parts by weight based on 100 parts by weight of the styrenic block copolymer.
  • the adhesive layer does not contain a plasticizer or contains a plasticizer in a proportion of 20 parts by weight or less based on 100 parts by weight of the styrenic block copolymer.
  • the content of the plasticizer per 100 parts by weight of the styrenic block copolymer may be 16 parts by weight or less, 12 parts by weight or less, 8 parts by weight or less, or 6 parts by weight or less.
  • the amount may be 3 parts by weight or less, or 1 part by weight or less, and the adhesive layer does not need to contain substantially no plasticizer.
  • the expression "the adhesive layer does not substantially contain a plasticizer” means that a plasticizer is not intentionally added to the adhesive layer, and the content of the plasticizer is lower than that of the styrene block. This means that the amount is less than 0.1 part by weight (for example, 0 to 0.05 part by weight) based on 100 parts by weight of the polymer.
  • the adhesive layer disclosed herein may further contain an isocyanate compound.
  • an isocyanate compound By using an isocyanate compound, the cohesive force of the adhesive can be improved.
  • polyfunctional isocyanates referring to compounds having an average of two or more isocyanate groups per molecule, including those having an isocyanurate structure
  • polyfunctional isocyanate one or more selected from various isocyanate compounds (polyisocyanates) having two or more isocyanate groups in one molecule can be used. Examples of such polyfunctional isocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and the like.
  • the amount used is not particularly limited; ). Usually, it is appropriate to use 0.1 to 10 parts by weight of the isocyanate compound per 100 parts by weight of the styrenic block copolymer, and 0.1 to 5 parts by weight (typically 0.3 to 5 parts by weight). 3 parts by weight, for example 0.5 to 1 part by weight).
  • the adhesive layer may be substantially free of isocyanate compounds. Note that the expression "the adhesive layer does not substantially contain an isocyanate compound” means that the content of the isocyanate compound contained in the adhesive layer is less than 0.1% by weight (for example, 0 to 0.05% by weight). .
  • the adhesive layer disclosed herein may contain an anti-aging agent, if necessary.
  • the quality stability of adhesives can be improved by using anti-aging agents.
  • One type of anti-aging agent may be used alone, or two or more types may be used in combination.
  • Examples of anti-aging agents include phosphorus-based antioxidants, phenolic antioxidants (hindered phenol-based antioxidants, etc.), hindered amine-based antioxidants, aromatic amine-based antioxidants, sulfur-based antioxidants, etc. It will be done.
  • the amount of anti-aging agent contained in the adhesive layer disclosed herein can be, for example, approximately 20 parts by weight or less based on 100 parts by weight of the styrenic block copolymer.
  • the amount of the anti-aging agent may be, for example, 0.1 part by weight or more, 0.5 part by weight or more, or 1 part by weight or more, based on 100 parts by weight of the styrenic block copolymer. You can also use it as
  • the adhesive layer disclosed herein may contain leveling agents, crosslinking agents, crosslinking aids, fillers, colorants (pigments, dyes, etc.), antistatic agents, ultraviolet absorbers, light stabilizers, etc., as necessary. , may contain various additives common in the field of adhesives. Regarding such various additives, conventionally known additives can be used in a conventional manner. Further, the adhesive layer disclosed herein may contain one or more rubbery polymers other than the styrenic block copolymer as long as the effects of the present invention are not impaired.
  • the technology disclosed herein is based on an embodiment in which the adhesive layer does not substantially contain any rubbery polymer other than the styrenic block copolymer (for example, the content per 100 parts by weight of the styrenic block copolymer is 0 to 1 (parts by weight).
  • the adhesive layer may have a composition substantially free of chelate compounds.
  • the above-mentioned chelate compound refers to, for example, a chelate compound of an alkaline earth metal oxide and a resin (alkylphenol resin, etc.) having a functional group (hydroxyl group, methylol group, etc.) to which the oxide can coordinate. Point.
  • the technology disclosed herein can be preferably implemented in an embodiment in which the adhesive layer does not contain such a chelate compound at all, or the content of the chelate compound is 1% by weight or less. According to this embodiment, an adhesive with even more excellent adhesive strength can be realized.
  • the adhesive layer is such that the total amount of the styrenic block copolymer, tackifying resin, and plasticizer is the total weight of the adhesive (i.e., The composition may account for 90% by weight or more of the weight of the adhesive layer. For example, an embodiment may be preferably adopted in which the total amount is 90 to 99.8% by weight (typically, for example, 95 to 99.5% by weight) of the total weight of the adhesive.
  • the adhesive layer disclosed herein can be formed from an adhesive composition substantially free of organic solvents.
  • the expression that the pressure-sensitive adhesive composition does not substantially contain an organic solvent means that the amount of organic solvent in the pressure-sensitive adhesive composition is less than 1% by weight (for example, less than 0.1% by weight).
  • Such an adhesive composition may be a hot melt type adhesive composition.
  • a hot-melt pressure-sensitive adhesive composition is preferable from the viewpoint of productivity and reduction of environmental burden, since it can be coated in a heated molten state that does not substantially contain an organic solvent.
  • the method for forming the adhesive layer from the adhesive composition is not particularly limited, and any suitable known method can be employed.
  • the adhesive composition disclosed herein can be molded by a method such as a calendar method, a casting method, an inflation extrusion method, or a T-die extrusion method.
  • a hot melt coating method is used in forming the adhesive layer.
  • the adhesive composition is heated to a relatively high temperature (specifically 100°C or higher, for example 150 to 220°C). It is heated to a highly fluid molten state.
  • a relatively high temperature specifically 100°C or higher, for example 150 to 220°C.
  • the pressure-sensitive adhesive composition in a molten state due to the heating is extruded from the extruder die of the hot-melt coating device at an appropriate speed (coating speed) and coated.
  • the temperature during coating is usually approximately the same as the temperature during melting.
  • the extruder is not particularly limited, and for example, a known twin-screw extruder is preferably used.
  • the adhesive composition extruded from the die is continuously applied to the film (substrate or release liner) on the back roll.
  • the back roll is also referred to as a coating roll, and is a roll that is disposed on the opposite surface (non-coated surface) of the film-coated surface and has a function of feeding the film.
  • the pressure-sensitive adhesive composition is formed into a layer (also referred to as a film).
  • the layered adhesive composition may be further cured by crosslinking treatment such as irradiation with active energy rays such as ultraviolet rays. In this way, the adhesive layer is formed.
  • the layered adhesive composition may be stored and aged for a certain period of time (for example, 12 hours or more) under appropriate temperature conditions (for example, approximately 30 to 50°C), if necessary.
  • An adhesive formed by hot-melt coating as described above is also referred to as a hot-melt adhesive.
  • the hot-melt coating equipment equipped with the extruder is equipped with a feeder that mixes the adhesive composition, a back roll, a crosslinking section that performs the above-mentioned crosslinking process, and other mechanisms (filters, vents for degassing, etc.). ).
  • a back roll a roll whose temperature can be controlled (also referred to as a heating roll) is preferably used.
  • an adhesive layer having a desired surface hardness can be formed by setting coating conditions in addition to designing the adhesive composition.
  • the adhesive layer forming method specifically, a method including hot-melt coating
  • shear rate, shear viscosity, back roll temperature, etc. are adjusted during coating of the adhesive composition.
  • the hardness of the adhesive layer surface is less than a predetermined value.
  • the polymer in the pressure-sensitive adhesive composition may be oriented depending on the coating conditions, and the hardness of the surface of the formed pressure-sensitive adhesive layer may increase.
  • the stretching of the adhesive composition during coating is eased at a predetermined coating speed, and the adhesive composition is The orientation of the polymer is suppressed, and the hardness of the pressure-sensitive adhesive layer surface can be reduced.
  • the back roll temperature to an appropriate temperature in relation to the coating temperature and shear viscosity, the orientation of the polymer in the adhesive composition after coating is suppressed, and the surface of the adhesive layer is Hardness can be reduced.
  • the coating speed (shear rate) within an appropriate range, the shear viscosity can be adjusted, and a high-quality adhesive layer with a surface hardness less than a predetermined value can be formed.
  • the said shear rate is an apparent shear rate ⁇ [1/s], and is calculated
  • required from the formula: ⁇ 6Q/(Wh 2 );
  • Q [g/s] is the mass flow rate
  • h [m] is the die land gap
  • W is the die land width [m].
  • the shear rate during application of the adhesive composition is not particularly limited, but from the viewpoint of forming a high-quality adhesive layer and obtaining an appropriate shear viscosity, it is, for example, about 5000 to 50000 [1/s] ( More specifically, it can be set from a range of 8,000 to 50,000 [1/s]). By increasing the shear rate, the tack becomes stronger and rough surface adhesion can be improved.
  • the shear rate in the examples described below is also determined from the above.
  • the shear viscosity [Pa ⁇ s] is a value determined by the shear rate and temperature (coating temperature), and is measured using a measuring device (product name: ROSAND capillary rheometer RH7-2 manufactured by NETZSCH). Fill the sample (adhesive composition) into the device cylinder using The measured value is adopted.
  • the shear viscosity of the adhesive composition during application is not particularly limited, but may range from approximately 1 to 50 [Pa ⁇ s] (more specifically 3 to 30 [Pa ⁇ s]), for example. Can be set.
  • the shear viscosity in the examples described below is also determined from the above.
  • the back roll temperature of the hot-melt coating device when applying the adhesive composition is not particularly limited, but it is appropriate to set it to about 50°C or higher (for example, 50 to 120°C), and From the viewpoint of reducing the hardness of the surface of the agent layer, the temperature may be 60° C. or higher, 70° C. or higher, or 80° C. or higher (for example, 90° C. or higher) in some preferred embodiments.
  • the back roll temperature as described above can be obtained by using a roll whose temperature can be controlled.
  • a method may be adopted in which the adhesive layer is formed by a conventionally known method and conditions and then stored for a certain period of time in a state heated to a predetermined temperature or higher.
  • the orientation state of the polymer can be relaxed and the hardness of the surface of the adhesive layer can be reduced.
  • the temperature for heated storage it is appropriate to set the temperature for heated storage at 40°C or higher and lower than 100°C, and the temperature may be 50°C or higher, 60°C or higher, or 70°C or higher, The temperature may be 80°C or higher.
  • the period of heating storage is suitably 3 days or more, for example, 5 days or more, 6 days or more, or 7 days or more. Although there is no particular limit to the number of storage days, from the viewpoint of production efficiency, it is usually appropriate to keep it for 30 days or less (for example, 14 days or less), and it may be about 10 days or less.
  • the thickness of the adhesive layer is suitably about 4 ⁇ m or more (for example, 20 ⁇ m or more). In some embodiments, the thickness of the adhesive layer may be preferably 30 ⁇ m or more, more preferably 40 ⁇ m or more, and still more preferably 50 ⁇ m or more (for example, 60 ⁇ m or more).
  • a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer having such a thickness can exhibit excellent pressure-sensitive adhesive performance (for example, both rough surface adhesion and cohesive force).
  • the thickness of the adhesive layer is 80 ⁇ m or more, may be 100 ⁇ m or more (for example, more than 100 ⁇ m), may be 120 ⁇ m or more, or may be 140 ⁇ m or more. According to the pressure-sensitive adhesive layer having the above-mentioned thickness, excellent polar rough surface adhesion and non-polar surface adhesion are easily obtained. Further, the upper limit of the thickness of the adhesive layer can be, for example, approximately 1000 ⁇ m or less, may be 750 ⁇ m or less, may be 500 ⁇ m or less, or may be 400 ⁇ m or less. In some preferred embodiments, the thickness of the adhesive layer is approximately 300 ⁇ m or less, and may be 200 ⁇ m or less. In the case of a double-sided pressure-sensitive adhesive sheet with a base material, it is preferable that a pressure-sensitive adhesive layer of the above thickness is provided on each of both sides of the base material. The thickness of each adhesive layer may be the same or different.
  • ⁇ Base material> When applying the technology disclosed herein to a double-sided adhesive sheet with a base material or a single-sided adhesive sheet with a base material, examples of the base material include polypropylene film, ethylene-propylene copolymer film, polyester film, and polyvinyl chloride film.
  • plastic films such as; foam sheets made of foams such as polyurethane foam, polyethylene foam, and polychloroprene foam; various fibrous materials (natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon; Woven fabrics and non-woven fabrics (including papers such as Japanese paper and high-quality paper); Metal foils such as aluminum foil and copper foil; etc. It can be appropriately selected and used depending on the use of the pressure-sensitive adhesive sheet.
  • the above-mentioned plastic film (typically refers to a non-porous plastic film, and is a concept that is distinguished from woven fabric and non-woven fabric) can be either an unstretched film or a stretched (uniaxially stretched or biaxially stretched) film. is also available. Further, the surface of the base material on which the adhesive layer is provided may be subjected to surface treatment such as application of a primer or corona discharge treatment.
  • Nonwoven fabrics used as base materials include, for example, nonwoven fabrics made of pulps such as wood pulp, natural fibers such as cotton and linen; polyester fibers such as polyethylene terephthalate (PET) fibers, rayon, vinylon, acetate fibers, Examples include nonwoven fabrics made of chemical fibers (synthetic fibers) such as polyvinyl alcohol (PVA) fibers, polyamide fibers, polyolefin fibers, and polyurethane fibers; nonwoven fabrics made from a combination of two or more types of fibers of different materials; etc. .
  • PVA polyvinyl alcohol
  • preferred are nonwoven fabrics made of pulp or hemp (for example, hemp pulp), nonwoven fabrics made of PET fibers, etc. from the viewpoint of adhesive impregnation and repulsion resistance.
  • the use of a nonwoven fabric base material also contributes to improving the flexibility and hand tearability of the adhesive sheet.
  • nonwoven fabric nonwoven fabric base material
  • one having a basis weight of approximately 30 g/m 2 or less can be preferably employed.
  • a nonwoven fabric having such a basis weight is suitable for producing a pressure-sensitive adhesive sheet that is lightweight and has excellent adhesive performance.
  • a nonwoven fabric with a basis weight of less than 18 g/m 2 for example, 16 g/m 2 or less, typically 15 g/m 2 or less
  • the basis weight is preferably 10 g/m 2 or more (for example, 12 g/m 2 or more, typically 13 g/m 2 or more).
  • the bulk density (which can be calculated by dividing the basis weight by the thickness) of the nonwoven fabric base material is suitably approximately 0.20 g/cm 3 or more, and 0.25 g/cm 3 or more (for example, 0.30 g/cm 3 or more). 3 or more) is preferable, and approximately 0.50 g/cm 3 or less is appropriate, and 0.40 g/cm 3 or less (for example, 0.35 g/cm 3 or less) is preferable.
  • the base material itself has appropriate strength and good pressure-sensitive adhesive impregnation properties are obtained. From the viewpoint of repulsion resistance, it is particularly preferable to use a nonwoven fabric base material having a bulk density of about 0.25 to 0.40 g/cm 3 (for example, 0.30 to 0.35 g/cm 3 ).
  • the nonwoven fabric base material contains resin components such as starch (e.g., cationized starch), polyacrylamide, viscose, polyvinyl alcohol, urea formaldehyde resin, melamine formaldehyde resin, polyamide polyamine epichlorohydrin, etc. It is possible.
  • the resin component may function as a paper strength enhancer for the nonwoven fabric base material. By using such a resin component as necessary, the strength of the nonwoven fabric base material can be adjusted.
  • the nonwoven fabric base material may also contain additives that are common in the field of nonwoven fabric production, such as retention improvers, drainage agents, viscosity modifiers, and dispersants, as needed.
  • the thickness of the base material can be selected as appropriate depending on the purpose, but it is generally appropriate to set it to approximately 2 ⁇ m or more (typically 10 ⁇ m or more), and 500 ⁇ m or less (typically 200 ⁇ m or less). It is preferable that When a nonwoven fabric is used as the base material, it is appropriate that the thickness of the nonwoven fabric base material is approximately 150 ⁇ m or less. From the viewpoint of sufficiently impregnating the entire base material with the adhesive, the thickness is preferably 100 ⁇ m or less (for example, 70 ⁇ m or less). Further, in consideration of handling properties during production of the pressure-sensitive adhesive sheet, the thickness is preferably 10 ⁇ m or more (for example, 25 ⁇ m or more).
  • the thickness is preferably 30 ⁇ m or more (for example, 35 ⁇ m or more, typically 40 ⁇ m or more), and 60 ⁇ m or less (for example, 50 ⁇ m or less, typically 45 ⁇ m or less). is preferred.
  • a conventional release paper or the like can be used and is not particularly limited.
  • a release liner with a release treatment layer on the surface of a base material such as a plastic film or paper, or a release liner made of a low-adhesive material such as a fluoropolymer (polytetrafluoroethylene, etc.) or a polyolefin resin (polyethylene, polypropylene, etc.) etc. can be used.
  • the above-mentioned release treatment layer may be formed by surface-treating the above-mentioned base material with a release treatment agent such as silicone-based, long-chain alkyl-based, fluorine-based, molybdenum sulfide, or the like.
  • a release treatment agent such as silicone-based, long-chain alkyl-based, fluorine-based, molybdenum sulfide, or the like.
  • the total thickness of the adhesive sheet disclosed herein (including the thickness of the adhesive layer and the base material, but not including the thickness of the release liner) is not particularly limited, and is suitably approximately 1500 ⁇ m or less. It may be 1200 ⁇ m or less, 1000 ⁇ m or less (for example, less than 1000 ⁇ m), or 750 ⁇ m or less. In some preferred embodiments, the total thickness of the adhesive sheet is approximately 500 ⁇ m or less, may be 400 ⁇ m or less, may be 300 ⁇ m or less, and may be 200 ⁇ m or less, from the viewpoint of thinning, weight reduction, resource saving, etc. But that's fine.
  • the total thickness of the adhesive sheet is usually 10 ⁇ m or more, suitably 50 ⁇ m or more, and may be, for example, 70 ⁇ m or more.
  • the thickness of the pressure-sensitive adhesive sheet is 80 ⁇ m or more, may be 100 ⁇ m or more (for example, more than 100 ⁇ m), may be 120 ⁇ m or more, or may be 140 ⁇ m or more.
  • the technique disclosed herein can be preferably implemented in a pressure-sensitive adhesive sheet having a thickness within the above range.
  • the adhesive sheet disclosed herein has adhesion to flexible urethane foam measured at a tensile speed of 300 mm/min and a peel angle of 180 degrees in an environment of 23° C. and 50% RH. It is preferable that the force (adhesive force to urethane foam) is 3.0 N/10 mm or more. Since the surface of the urethane foam is a polar rough surface, the pressure-sensitive adhesive sheet exhibiting the above adhesive strength to the urethane foam can exhibit sufficient adhesiveness to the polar rough surface.
  • the adhesive force to the urethane foam is more preferably 3.5 N/10 mm or more, even more preferably 4.0 N/10 mm or more, particularly preferably 4.5 N/10 mm or more, and 5.0 N/10 mm or more.
  • /10mm or more is most preferable, and may be, for example, 5.5N/10mm or more.
  • the upper limit of the adhesive force to the urethane foam is not particularly limited, and may be, for example, about 10 N/10 mm or less.
  • Adhesive strength to urethane foam was measured by pressing a 2 kg roller back and forth once on the surface of a soft urethane foam as an adherend, leaving it for 30 minutes, and then applying it at a tensile speed of 300 mm/min and a peeling angle of 180 mm in accordance with JIS Z 0237. Measured under conditions of 30 degrees.
  • adherend flexible urethane foam
  • Color Foam (trade name: "ECS" (gray)) manufactured by INOAC Corporation or its equivalent product is used.
  • the above-mentioned flexible urethane foam (trade name "ECS" (gray)) has a density of 22 ⁇ 2 kg/m 3 and a hardness (according to D method specified in JIS K 6400-2 (2004)) of 107.9 ⁇ 22.6 N. polyether urethane foam. More specifically, the adhesive strength to urethane foam is measured by the method described in Examples below. In addition, when the adhesive sheet disclosed herein is a double-sided adhesive sheet with a base material, the above-mentioned adhesive strength to urethane foam is a property obtained for the adhesive layer surface having a hardness of less than 0.15 MPa. In such embodiments, the adhesion to urethane foam on each side may be the same or different.
  • the adhesive sheet disclosed herein has adhesive strength ( It is preferable that the adhesion force to PP is 15 N/10 mm or more. Since the above-mentioned PP is substantially non-polar, the pressure-sensitive adhesive sheet exhibiting the above-mentioned adhesion to PP can exhibit sufficient adhesion to non-polar surfaces. From the viewpoint of non-polar surface adhesiveness, the adhesive force to PP is more preferably 20 N/10 mm or more, even more preferably 25 N/10 mm or more, particularly preferably 28 N/10 mm or more, most preferably 30 N/10 mm or more, for example 32 N/10 mm or more. /10mm or more.
  • the upper limit of the adhesive force to PP is not particularly limited, and may be, for example, about 50 N/10 mm or less.
  • the adhesion to PP is measured by the method described in Examples below.
  • the adhesive sheet disclosed herein is a double-sided adhesive sheet with a base material
  • the above-mentioned adhesive strength to PP is a property that can be obtained at least on the adhesive layer surface having a hardness of less than 0.15 MPa. is preferred.
  • the adhesion to PP on each side may be the same or different.
  • the pressure-sensitive adhesive sheet disclosed herein preferably has a reduction rate of adhesive strength to PP after an aging test (post-aging test reduction rate) determined by the method described in the Examples below, which is 20% or less. .
  • a pressure-sensitive adhesive sheet that satisfies the above characteristics has excellent long-term quality stability and sufficient storage stability. It is particularly preferable that the pressure-sensitive adhesive sheet disclosed herein has a reduction rate of 10% or less after the aging test.
  • a method for manufacturing a pressure-sensitive adhesive sheet includes a step of forming an adhesive layer using an adhesive composition.
  • the adhesive layer can be formed, for example, by coating the adhesive composition onto a release liner or a substrate (film).
  • the step of forming the adhesive layer may include the step of heating the adhesive composition and applying it using an extruder. Conditions for applying the adhesive composition (shear rate, shear viscosity, back roll temperature, etc.) can be set based on the above explanation.
  • the method for producing an adhesive sheet may include a step of storing the formed adhesive layer under heating.
  • appropriate conditions can be set from among the above-mentioned temperatures and periods.
  • the pressure-sensitive adhesive composition or pressure-sensitive adhesive sheet disclosed herein can be used to bond parts (e.g., It is useful for fixing various parts in such products).
  • Example 1 100 parts of a styrene-isoprene block copolymer (manufactured by Nippon Zeon Co., Ltd., product name "Quintac 3520", styrene content 15%, diblock proportion 78%) and a terpene resin (Yasuhara Chemical Co., Ltd.) as a tackifying resin.
  • rosin resin product name "Pensel D160” manufactured by Arakawa Chemical Co., Ltd.
  • styrene resin product name "SA140” manufactured by Clayton
  • liquid terpene resin as a plasticizer product name: "YS Resin PX300N", manufactured by Yasuhara Chemical Co., Ltd.
  • an anti-aging agent product name: "IRGANOX CB612", manufactured by BASF Company
  • a pressure-sensitive adhesive composition is a mixture of the name "IRGAFOS 168" and the company's product name "IRGANOX 565" in a ratio of 2:1), which is heated and melted in a twin-screw extruder, and then cured.
  • a pressure-sensitive adhesive layer was formed by coating the release-treated surface of a 75- ⁇ m-thick PET film treated with a silicone release agent using a hot-melt coating method so that the subsequent pressure-sensitive adhesive layer thickness was 150 ⁇ m.
  • a release liner treated with a silicone release agent was attached to the surface of the resulting adhesive layer. In this way, a pressure-sensitive adhesive sheet according to this example (base material-less double-sided pressure-sensitive adhesive sheet with a release liner) was produced.
  • Coating conditions (coating speed and coating temperature) were set to achieve the shear rate and shear viscosity listed in Table 2.
  • the temperature of the roll (back roll, also referred to as coating roll) was set at 90° C., and the above-mentioned hot-melt coating was performed.
  • Adhesive compositions according to each example were prepared in the same manner as in Example 1, except that the adhesive composition was changed as shown in Tables 2 to 3, and using each adhesive composition, the adhesive compositions shown in Tables 2 to 3 were prepared.
  • Adhesive sheets according to each example were produced in the same manner as in Example 1, except that the coating conditions (shear rate, shear viscosity, and back roll temperature) were changed.
  • Example 10 after protecting both sides of the adhesive layer with a release liner, it was stored at 80°C for 7 days (equivalent to about 11 years in terms of room temperature) to promote relaxation and obtain an adhesive sheet. .
  • ⁇ Comparative example 8> The styrene-isoprene block copolymer, tackifier resin, and plasticizer shown in Table 3, the same kind and amount (3 parts) of anti-aging agent as in Example 1, and toluene as a solvent were mixed with stirring to form a solid. A 50% adhesive composition was prepared. The above adhesive composition was applied as a base material to a 75 ⁇ m thick silicone release treated surface and dried at 120° C. for 3 minutes to form a 75 ⁇ m thick adhesive layer.
  • a pressure sensitive adhesive sheet (substrate-less double-sided pressure sensitive adhesive sheet with a release liner and no base material) having a 150 ⁇ m thick pressure sensitive adhesive layer is obtained. Created.
  • ⁇ Evaluation method> (Nanoindentation hardness of adhesive layer surface)
  • the adhesive sheet double-sided adhesive sheet
  • the release liner covering one adhesive surface was peeled off
  • the exposed adhesive surface was fixed to a predetermined support to serve as a measurement sample.
  • the release liner covering the other adhesive surface was peeled off, and the exposed adhesive layer surface was unloaded by nanoindentation using a nanoindenter device (Triboindenter manufactured by Hysitron Inc.) under the following measurement conditions.
  • the said hardness is calculated
  • required from the formula: hardness [MPa] Pmax/A.
  • Pmax is the maximum load of the load curve and A is the projected contact area of the indenter.
  • ⁇ Indenter used Conical (spherical indenter, radius of curvature 10 ⁇ m)
  • ⁇ Measurement method Single indentation measurement
  • ⁇ Indentation depth 1000nm
  • ⁇ Pushing and pulling speed 2000 ⁇ m/s
  • ⁇ Measurement temperature Room temperature (23°C)
  • the other adhesive surface (surface to be measured) of the test piece was exposed, and the exposed adhesive surface of the test piece was pressed against the surface of the adherend by moving a 2 kg roller back and forth once. After leaving it in the same environment for 30 minutes, it was peeled off at 180 degrees using a tensile tester at a tensile speed of 300 mm/min according to JIS Z 0237, and its adhesive strength (adhesive strength to urethane foam) was measured [ N/10 mm]. If the adhesive force to urethane foam is 3.0 N/10 mm or more, it is judged that the adhesive has sufficient adhesion to a polar rough surface. In addition, when carrying out a measurement using a single-sided adhesive sheet as a test piece, the above-mentioned backing with PET film is not essential.
  • Adhesion to PP The release liner covering one adhesive side of the adhesive sheet (double-sided adhesive sheet) was peeled off, and it was pasted on a 50 ⁇ m thick PET film for backing. This lined adhesive sheet was cut into a size of 10 mm in width and 100 mm in length to prepare a test piece.
  • a 2 mm thick polypropylene (PP) resin plate product name "Kobe Polysheet PP-N-AN” manufactured by Showa Denko Materials Co., Ltd.
  • PP polypropylene
  • the other adhesive surface (surface to be measured) of the above test piece was exposed, and the exposed adhesive surface of the test piece was moved once with a 2 kg roller to the surface of the adherend. I crimped it. After leaving this in the same environment for 30 minutes, it was peeled off at 180° using a tensile tester at a tensile speed of 300 mm/min according to JIS Z 0237, and the adhesive strength (adhesive strength to PP) [N/10 mm ] was measured. If the adhesive force to PP is 15 N/10 mm or more, it is judged that the adhesive has sufficient adhesiveness to a non-polar surface. In addition, when carrying out a measurement using a single-sided adhesive sheet as a test piece, the above-mentioned backing with PET film is not essential.
  • the adhesive sheet was cut into a rectangular shape with a length of 30 cm and a width of 20 cm, including the release liner covering the adhesive surface, to prepare a sample for an aging test.
  • the sample was stored for 10 days in an air dryer maintained at 85°C. The samples were stored suspended in the dryer so as not to overlap each other.
  • the residual solvent in the adhesive (layer) was qualitatively and quantitatively analyzed by gas chromatography mass spectrometry (GC/MS) in accordance with JIS A 1901:2015.
  • the residual amount of organic solvents evaluated was 54 types shown in Table 1 (see https://www.mhlw.go.jp/new-info/kobetu/roudou/gyousei/anzen/dl/120815-01.pdf ).
  • the specific measurement conditions of GC/MS are as follows.
  • HSS head space sampler
  • the adhesive sheets according to Examples 1 to 10 had an adhesive layer containing a styrenic block copolymer with a styrene content of 10 to 22% and a tackifying resin.
  • the nanoindentation hardness of the surface of the adhesive layer was less than 0.15 MPa, and the amount of organic solvent remaining in the adhesive layer was less than 1000 ppm.
  • the adhesive sheets according to these examples achieved adhesive strength of 3.0 N/10 mm or more to urethane foam and 15 N/10 mm or more to PP, and both had sufficient adhesion to rough polar surfaces and adhesion to non-polar surfaces. had.
  • the nanoindentation hardness of the adhesive layer surface was 0.15 MPa or more, and at least one of the adhesive strength to urethane foam and the adhesive strength to PP was inferior.
  • Examples 1 to 10 and Comparative Examples 1 to 6 show that the nanoindentation hardness of the adhesive layer surface changes depending on the adhesive composition and coating conditions.
  • the shear rate during coating was By setting a higher coating temperature (specifically, a higher coating temperature), a predetermined shear viscosity range, and a higher back roll temperature, the nanoindentation hardness is lowered, and sufficient polar rough surface adhesion and non-concentration are achieved. Polar surface adhesion was obtained.
  • a higher coating temperature specifically, a higher coating temperature
  • a predetermined shear viscosity range specifically, a predetermined shear viscosity range, and a higher back roll temperature
  • Polar surface adhesion was obtained.
  • the above coating conditions suppressed the orientation of the styrenic block copolymer, making it possible to reduce the hardness of the adhesive layer surface to less than a predetermined value for a given adhesive composition.
  • Comparative Example 1 the shear rate and back roll temperature were lower than in Example 4, the nanoindentation hardness was relatively high, and sufficient polar rough surface adhesion was not obtained. Furthermore, from the comparison between Example 5 and Comparative Example 2, it can be seen that by setting the shear rate higher, the nanoindentation hardness of the adhesive layer surface can be reduced and the adhesion to polar rough surfaces can be improved. . Furthermore, from a comparison between Example 1 and Comparative Example 4, when the styrene content of the styrenic block copolymer exceeds 22%, the nanoindentation hardness of the adhesive layer surface increases, resulting in a polar rough surface and a non-porous surface.
  • Adhesive sheet 11 Adhesive layer, first adhesive layer 12 Second adhesive layer 15 Base material 21, 22 Release liner

Abstract

L'invention concerne une feuille adhésive qui peut présenter une adhérence suffisante à une surface polaire rugueuse et à une surface non polaire. L'invention concerne une feuille adhésive ayant une couche adhésive. La couche adhésive contient un copolymère séquencé à base de styrène et une résine tackifiante. La teneur en styrène dans le copolymère séquencé à base de styrène est de 10 à 22 % en masse. En outre, la surface de la couche adhésive a une dureté inférieure à 0,15 MPa dans un test d'élimination de charge au moyen d'une nano-indentation à une température de 23 °C et à une profondeur d'indentation de 1 µm. De plus, la quantité de solvant organique résiduel dans la couche adhésive est inférieure à 1 000 ppm.
PCT/JP2023/019712 2022-05-31 2023-05-26 Feuille adhésive WO2023234208A1 (fr)

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JP2022-088696 2022-05-31
JP2022088696 2022-05-31
JP2023012267A JP2023177222A (ja) 2022-05-31 2023-01-30 粘着シート
JP2023-012267 2023-01-30

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005074354A (ja) * 2003-09-02 2005-03-24 Denki Kagaku Kogyo Kk 塗工装置及び塗工方法
JP2012131978A (ja) * 2010-12-01 2012-07-12 Toyobo Co Ltd 粘着剤及び粘着フィルム
JP2014076960A (ja) * 2012-10-10 2014-05-01 Nichiban Co Ltd ホットメルト型粘着剤組成物及び経皮吸収貼付剤
JP2014114331A (ja) * 2012-12-06 2014-06-26 Nitto Lifetech Kk 粘着シート
JP2017190428A (ja) * 2016-04-15 2017-10-19 旭化成株式会社 粘接着剤組成物
JP2021161257A (ja) * 2020-03-31 2021-10-11 ニチバン株式会社 粘着剤組成物及びそれを用いた粘着テープ

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005074354A (ja) * 2003-09-02 2005-03-24 Denki Kagaku Kogyo Kk 塗工装置及び塗工方法
JP2012131978A (ja) * 2010-12-01 2012-07-12 Toyobo Co Ltd 粘着剤及び粘着フィルム
JP2014076960A (ja) * 2012-10-10 2014-05-01 Nichiban Co Ltd ホットメルト型粘着剤組成物及び経皮吸収貼付剤
JP2014114331A (ja) * 2012-12-06 2014-06-26 Nitto Lifetech Kk 粘着シート
JP2017190428A (ja) * 2016-04-15 2017-10-19 旭化成株式会社 粘接着剤組成物
JP2021161257A (ja) * 2020-03-31 2021-10-11 ニチバン株式会社 粘着剤組成物及びそれを用いた粘着テープ

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