WO2022210638A1 - Pressure-sensitive adhesive tape - Google Patents

Pressure-sensitive adhesive tape Download PDF

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Publication number
WO2022210638A1
WO2022210638A1 PCT/JP2022/015265 JP2022015265W WO2022210638A1 WO 2022210638 A1 WO2022210638 A1 WO 2022210638A1 JP 2022015265 W JP2022015265 W JP 2022015265W WO 2022210638 A1 WO2022210638 A1 WO 2022210638A1
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WO
WIPO (PCT)
Prior art keywords
pressure
sensitive adhesive
meth
adhesive layer
weight
Prior art date
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PCT/JP2022/015265
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French (fr)
Japanese (ja)
Inventor
徳之 内田
Original Assignee
積水化学工業株式会社
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Application filed by 積水化学工業株式会社 filed Critical 積水化学工業株式会社
Priority to CN202280008379.3A priority Critical patent/CN116670249A/en
Priority to JP2022534685A priority patent/JPWO2022210638A1/ja
Publication of WO2022210638A1 publication Critical patent/WO2022210638A1/en

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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
    • C09J133/00—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 only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/08—Homopolymers or copolymers of acrylic acid esters
    • 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
    • C09J133/00—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 only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/10—Homopolymers or copolymers of methacrylic acid esters
    • 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
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • 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 adhesive tapes.
  • Patent Literature 1 describes a re-peelable pressure-sensitive adhesive tape for packaging having, on at least one surface of a base material, a pressure-sensitive adhesive layer made of a specific pressure-sensitive adhesive containing a plasticizer.
  • Such an adhesive tape is desired to be easily peelable without damaging the adherend, but if the adhesive strength is too low, the tape will peel during use.
  • the adhesive tape may not adhere sufficiently to the adherend.
  • the stickiness to a non-smooth surface can be improved by increasing the thickness of the pressure-sensitive adhesive layer, in general, the thicker the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape, the higher the adhesive strength. For this reason, it has been difficult to obtain a pressure-sensitive adhesive layer that can be sufficiently attached to an adherend and that can be easily peeled off from the adherend while having a certain thickness or more.
  • An object of the present invention is to provide a pressure-sensitive adhesive tape which has excellent sticking properties to non-smooth surfaces such as paper and which can be easily peeled off without damaging the adherend.
  • the present invention is a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer has a shear storage elastic modulus of 1 ⁇ 10 4 Pa or more and 5 ⁇ 10 4 Pa or less at 23° C. and 1 Hz, and 180°
  • the adhesive tape has an adhesive strength of 0.3 N/25 mm or more and 0.7 N/25 mm or less and a thickness of 30 ⁇ m or more.
  • the present inventors have found that in a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer with a thickness of 30 ⁇ m or more, the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is adjusted to a specific relatively low range, and the pressure-sensitive adhesive layer Consideration was given to adjusting the 180° tack to a specific, relatively low range.
  • the present inventors have found that such an adhesive tape has an adhesive layer having a certain thickness or more, has excellent adhesion to non-smooth surfaces such as paper, and can be easily applied without damaging the adherend.
  • the inventors have found that the film can be peeled off easily, and have completed the present invention.
  • the adhesive tape of the present invention is an adhesive tape having an adhesive layer.
  • the pressure-sensitive adhesive layer has a shear storage modulus at 23° C. and 1 Hz with a lower limit of 1 ⁇ 10 4 Pa and an upper limit of 5 ⁇ 10 4 Pa. If the shear storage elastic modulus is 1 ⁇ 10 4 Pa or more, the shape can be sufficiently retained even if the pressure-sensitive adhesive layer has a certain thickness or more. When the shear storage elastic modulus is 5 ⁇ 10 4 Pa or less, the pressure-sensitive adhesive layer easily conforms to a non-smooth surface such as paper, thereby improving the sticking property.
  • the preferred lower limit of the shear storage modulus is 1.5 ⁇ 10 4 Pa
  • the preferred upper limit is 4 ⁇ 10 4 Pa
  • the more preferred lower limit is 1.7 ⁇ 10 4 Pa
  • the more preferred upper limit is 3 ⁇ 10 4 Pa.
  • a more preferable lower limit is 2 ⁇ 10 4 Pa.
  • the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz can be measured, for example, using a viscoelastic spectrometer (DVA-200, manufactured by IT Keisoku Kogyo Co., Ltd.), etc., using a simple heating mode with a heating rate of 5° C. It can be obtained as the storage elastic modulus at 23°C when the dynamic viscoelasticity spectrum is measured from -40 to 140°C under the condition of 1 Hz/min.
  • the shape of the measurement sample at this time is not particularly limited, for example, the pressure-sensitive adhesive layer can be measured as a rectangular shape with a thickness of 1 mm, a length of 10 mm and a width of 6 mm.
  • the pressure-sensitive adhesive layer has a 180° adhesive strength with a lower limit of 0.3 N/25 mm and an upper limit of 0.7 N/25 mm.
  • the 180° adhesive strength is 0.3 N/25 mm or more, the adhesive layer has appropriate adhesive strength, and the sticking property to non-smooth surfaces such as paper is improved. If the 180° adhesive strength is 0.7 N/25 mm or less, the adhesive strength of the adhesive layer is sufficiently low, so that it can be easily peeled without damaging the adherend during peeling (re-peeling). .
  • a preferred lower limit of the 180° adhesive strength is 0.35 N/25 mm, a preferred upper limit is 0.65 N/25 mm, a more preferred lower limit is 0.4 N/25 mm, and a more preferred upper limit is 0.6 N/25 mm.
  • the 180° adhesive strength of the adhesive layer can be measured by the following method. Adhesive tape pre-cut to a width of 25 mm and a length of 10 cm is pasted on a polyethylene terephthalate plate of 50 mm in width, 12.5 cm in length and 2 mm in thickness (for example, product name PET-6010 manufactured by Takiron C.I., or equivalent). A sample for measurement is obtained by combining and reciprocating a 2 kg roller once.
  • the obtained measurement sample for example, using an autograph (manufactured by Shimadzu Corporation) or the like, according to JIS Z0237: 2009, polyethylene at a tensile speed of 300 mm / min under an environment of a temperature of 23 ° C. and a relative humidity of 50%.
  • a peeling test is performed by peeling the adhesive tape off the terephthalate plate in the direction of 180°, and the 180° adhesive strength (N/25 mm) is measured.
  • the shear storage modulus at 23 ° C. and 1 Hz of the pressure-sensitive adhesive layer and the 180 ° adhesive strength to the above ranges, for example, the composition and molecular weight (weight average molecular weight) of the base polymer contained in the pressure-sensitive adhesive layer (Mw)), etc., and a method of adjusting the degree of cross-linking (gel fraction) of the pressure-sensitive adhesive layer.
  • the adhesive layer is not particularly limited, and examples thereof include an acrylic adhesive layer, a rubber-based adhesive layer, a urethane-based adhesive layer, a silicone-based adhesive layer, and the like.
  • an acrylic pressure-sensitive adhesive layer containing a (meth)acrylic polymer is preferable from the viewpoints of easy adjustment of molecular weight, degree of crosslinking, etc., and excellent heat resistance, weather resistance, cost, and the like.
  • the (meth)acrylic polymer is a polymer containing structural units derived from (meth)acrylic monomers.
  • the (meth)acrylic monomer is not particularly limited, and examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and pentyl (meth)acrylate.
  • a (meth)acrylic acid ester having an alkyl group having 12 or more carbon atoms and having a glass transition temperature (Tg) of 0° C. or less when made into a homopolymer (hereinafter referred to as “(meth)acrylic acid ester (a)” is also preferred). That is, the (meth)acrylic polymer preferably contains a structural unit derived from the (meth)acrylic acid ester (a). Further, a (meth)acrylic acid ester (hereinafter referred to as "(meth) ) Also referred to as “acrylic acid ester (b)”.) is also preferably used in combination.
  • the (meth)acrylic polymer further contains structural units derived from the (meth)acrylic ester (b) in addition to the structural units derived from the (meth)acrylic ester (a). is more preferable.
  • the (meth)acrylic polymer contains a structural unit having an alkyl group with a relatively long carbon chain
  • the pressure-sensitive adhesive layer has a shear storage modulus at 23°C and 1 Hz and a 180° adhesive strength. is easily adjusted within the above range.
  • the pressure-sensitive adhesive layer has improved sticking property to a non-smooth surface such as paper, and can be easily peeled off (re-peeled) without damaging the adherend.
  • the glass transition temperature (Tg) of the (meth)acrylic acid ester (a) and the (meth)acrylic acid ester (b) is not particularly limited as long as it is 0° C. or lower. From the viewpoint of adjusting the shear storage modulus of and the 180° adhesive strength to a more preferable range, the preferable lower limit is -80°C and the preferable upper limit is -5°C. A more preferable lower limit of the glass transition temperature (Tg) is -70°C, and a more preferable upper limit is -10°C.
  • the glass transition temperature (Tg) of the homopolymer is determined by differential scanning calorimetry (T ⁇ Can be measured using a device such as A Instruments Co., Ltd.). More specifically, it is possible to use the value obtained in the 2nd run when the measurement is performed under the conditions of a temperature increase rate of 10° C./min under a nitrogen atmosphere.
  • the (meth)acrylic acid ester (a) is not particularly limited, and among the above-mentioned (meth)acrylic monomers, for example, lauryl acrylate (Tg is ⁇ 23° C. when converted to a homopolymer), lauryl methacrylate (homo Tg when converted to a polymer is -65°C). Further examples include isomyristyl acrylate (Tg of -56°C when converted to a homopolymer), isostearyl acrylate (Tg of -18°C when converted to a homopolymer), and the like.
  • lauryl acrylate from the group consisting of lauryl acrylate, lauryl methacrylate and isostearyl acrylate, since the shear storage modulus at 23 ° C. and 1 Hz of the pressure-sensitive adhesive layer and the 180 ° adhesive force are easily adjusted to more preferable ranges. At least one selected is preferred. Furthermore, lauryl acrylate is more preferred.
  • the content of the structural unit derived from the (meth)acrylic acid ester (a) in the (meth)acrylic polymer is not particularly limited, but the preferred lower limit is 40% by weight.
  • the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer are easily adjusted within the above ranges.
  • the pressure-sensitive adhesive layer has improved sticking property to a non-smooth surface such as paper, and can be easily peeled off (re-peeled) without damaging the adherend.
  • a more preferable lower limit for the content of the structural unit is 45% by weight.
  • the upper limit of the content of the structural unit is not particularly limited, but the upper limit is preferably 90% by weight, and the upper limit is more preferably 80% by weight.
  • the (meth)acrylic acid ester (b) is not particularly limited, and among the above-mentioned (meth)acrylic monomers, for example, 2-ethylhexyl acrylate (Tg is ⁇ 70° C. when converted to a homopolymer), octyl acrylate (Tg of -65°C when homopolymerized) and the like. Furthermore, isononyl acrylate (Tg is -58°C when converted to homopolymer), isodecyl acrylate (Tg is -62°C when converted to homopolymer), and the like. Among them, 2-ethylhexyl acrylate is preferable because the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz can easily be adjusted to a more preferable range.
  • the content of the structural unit derived from the (meth)acrylic acid ester (b) in the (meth)acrylic polymer is not particularly limited. From the viewpoint of adjusting the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer to more preferable ranges, the preferable lower limit of the content of the structural unit is 20% by weight, and the preferable upper limit is 60. A more preferable lower limit is 30% by weight, and a more preferable upper limit is 50% by weight.
  • the (meth)acrylic polymer preferably further contains a structure derived from a crosslinkable functional group-containing monomer. Since the (meth)acrylic polymer contains a structure derived from the crosslinkable functional group-containing monomer, the cohesive force of the pressure-sensitive adhesive layer can be adjusted by cross-linking of the crosslinkable functional group. It becomes easy to adjust the adhesive strength of the layer to the above range, and it becomes easy to adjust the shear storage elastic modulus at 23° C. and 1 Hz to the above range. As a result, the adhesion of the pressure-sensitive adhesive layer to a non-smooth surface such as paper is further improved, and the adhesive layer can be easily peeled off (re-peeled) without damaging the adherend.
  • the crosslinkable functional group may or may not be crosslinked, but is more preferably crosslinked. However, even if the structure remains uncrosslinked, the cohesive force of the pressure-sensitive adhesive layer increases due to the interaction between the functional groups.
  • crosslinkable functional group-containing monomers examples include monomers containing carboxyl groups, hydroxyl groups, epoxy groups, double bonds, triple bonds, amino groups, amide groups, nitrile groups, and the like. These crosslinkable functional group-containing monomers may be used alone, or two or more of them may be used in combination. Among them, at least one selected from the group consisting of carboxyl group-containing monomers and hydroxyl group-containing monomers is preferable. Hydroxyl group-containing monomers are more preferable because the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz can be easily adjusted to the above range by cross-linking with an isocyanate-based cross-linking agent.
  • the crosslinkable functional group-containing monomer may further contain an alkyl group, an ether group, a carbonyl group, an ester group, a carbonate group, an amide group, a urethane group, or the like.
  • Examples of the carboxyl group-containing monomer include (meth)acrylic acid-based monomers such as (meth)acrylic acid.
  • Examples of the hydroxyl group-containing monomer include 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. Glycidyl (meth)acrylate etc. are mentioned as said epoxy-group-containing monomer.
  • Examples of the double bond-containing monomer include allyl (meth)acrylate, hexanediol di(meth)acrylate, and the like.
  • Examples of the triple bond-containing monomer include propargyl (meth)acrylate.
  • Examples of the amide group-containing monomer include (meth)acrylamide.
  • the content of the structure derived from the monomer having the crosslinkable functional group is not particularly limited. From the viewpoint of adjustment, the preferable lower limit of the content of the structural unit is 0.1% by weight, and the preferable upper limit is 30% by weight. A more preferable lower limit of the content of the structural unit is 0.5% by weight, and a more preferable upper limit is 25% by weight.
  • the content of the structure derived from the hydroxyl group-containing monomer is not particularly limited, but the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is adjusted to a more preferable range.
  • the preferable lower limit of the content of the structural unit is 1% by weight, and the preferable upper limit is 20% by weight.
  • a more preferable lower limit to the content of the structural unit is 3% by weight, and a more preferable upper limit is 10% by weight.
  • a monomer mixture containing the (meth)acrylic monomer, the crosslinkable functional group-containing monomer, etc. is radically reacted in the presence of a polymerization initiator, and copolymerized.
  • a polymerization method a conventionally known method is used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, and the like.
  • the weight average molecular weight (Mw) of the (meth)acrylic polymer is not particularly limited, but the preferred upper limit is 1,000,000.
  • the weight average molecular weight (Mw) is 1,000,000 or less, the shear storage elastic modulus at 23° C. and 1 Hz of the pressure-sensitive adhesive layer is easily adjusted to the above range, and the pressure-sensitive adhesive layer has a non-smooth surface such as paper. The sticking property against is further improved.
  • a more preferable upper limit of the weight average molecular weight (Mw) is 950,000, and a further preferable upper limit is 900,000.
  • the lower limit of the weight-average molecular weight (Mw) is not particularly limited, the preferred lower limit is 400,000, and the more preferred lower limit is 500,000, from the viewpoint of adhesive strength, shape retention property, etc. of the pressure-sensitive adhesive layer.
  • the weight average molecular weight of the (meth)acrylic polymer can be determined, for example, by GPC (Gel Permeation Chromatography) in terms of standard polystyrene. More specifically, for example, using “2690 Separations Module” manufactured by Waters as a measuring instrument, "GPC KF-806L” manufactured by Showa Denko as a column, and ethyl acetate as a solvent, a sample flow rate of 1 mL/min, and a column temperature of 40°C. can be measured under the conditions of
  • the pressure-sensitive adhesive layer may contain a tackifying resin.
  • the tackifying resin include rosin ester-based resins, hydrogenated rosin-based resins, terpene-based resins, terpene phenol-based resins, coumarone-indene-based resins, alicyclic saturated hydrocarbon-based resins, C5-based petroleum resins, and C9-based resins. petroleum resins, C5-C9 copolymer petroleum resins, and the like. These tackifying resins may be used alone or in combination of two or more.
  • the content of the tackifying resin is not particularly limited, it is preferable that the tackifying resin is not contained from the viewpoint of easier peeling without damaging the adherend during peeling (re-peeling).
  • the preferred upper limit is 10 parts by weight with respect to 100 parts by weight of the resin (for example, (meth)acrylic polymer) that is the main component of the adhesive layer.
  • the content of the tackifier resin is 10 parts by weight or less, the adherend can be easily peeled without damaging the adherend during peeling (re-peeling).
  • the pressure-sensitive adhesive layer contains a cross-linking agent to form a cross-linked structure between the main chains of the resin (for example, the (meth)acrylic polymer, the tackifier resin, etc.) constituting the pressure-sensitive adhesive layer.
  • the cross-linking agent is not particularly limited, and examples thereof include an isocyanate-based cross-linking agent, an aziridine-based cross-linking agent, an epoxy-based cross-linking agent, and a metal chelate-type cross-linking agent.
  • the (meth)acrylic polymer contains a structural unit derived from the hydroxyl group-containing monomer, the shear storage modulus of the pressure-sensitive adhesive layer at 23° C.
  • the content of the cross-linking agent is preferably 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight, relative to 100 parts by weight of the resin (for example, the (meth)acrylic polymer) that is the main component of the pressure-sensitive adhesive layer. Parts by weight are more preferred.
  • the pressure-sensitive adhesive layer may further contain an inorganic filler such as fumed silica. By blending the inorganic filler, the cohesive force of the pressure-sensitive adhesive layer can be increased.
  • the pressure-sensitive adhesive layer may further contain known additives such as plasticizers, resins, surfactants, waxes and fine particle fillers. These additives may be used alone, or two or more of them may be used in combination.
  • the gel fraction of the pressure-sensitive adhesive layer is not particularly limited, but the preferred lower limit is 85% by weight and the preferred upper limit is 95% by weight.
  • the preferred lower limit is 85% by weight or more
  • the 180° adhesive strength of the pressure-sensitive adhesive layer is easily adjusted to the above range, and when peeling (re-peeling), the adherend is more easily peeled without damaging the adherend. be able to.
  • the gel fraction is 95% by weight or less, the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is easily adjusted to the above range, and the pressure-sensitive adhesive layer is attached to a non-smooth surface such as paper. Better adhesion.
  • a more preferable lower limit of the gel fraction is 86% by weight, a more preferable upper limit is 94% by weight, a still more preferable lower limit is 87% by weight, and a further preferable upper limit is 93% by weight.
  • the gel fraction of the adhesive layer can be measured by the following method. Only 0.1 g of the adhesive layer (adhesive composition) is taken out from the adhesive tape, immersed in 50 mL of ethyl acetate, and shaken with a shaker at 200 rpm and a temperature of 23° C. for 24 hours.
  • a metal mesh (#200 mesh) is used to separate the ethyl acetate and the pressure-sensitive adhesive composition that has absorbed and swollen the ethyl acetate.
  • the adhesive composition after separation is dried at 110° C. for 1 hour.
  • the weight of the pressure-sensitive adhesive composition containing the metal mesh after drying is measured, and the gel fraction of the pressure-sensitive adhesive layer is calculated using the following formula.
  • Gel fraction (% by weight) 100 x (W 1 - W 2 )/W 0 (W 0 : initial weight of adhesive composition, W 1 : weight of adhesive composition containing metal mesh after drying, W 2 : initial weight of metal mesh)
  • the lower limit of the thickness of the pressure-sensitive adhesive layer is 30 ⁇ m.
  • the shear storage modulus at 23° C. and 1 Hz of the pressure-sensitive adhesive layer and the 180° pressure-sensitive adhesive strength are adjusted within the above ranges, so that the pressure-sensitive adhesive tape has a certain thickness or more. While having an agent layer, it has excellent sticking property to non-smooth surfaces such as paper, and can be easily peeled off without damaging the adherend. In addition, when the thickness of the pressure-sensitive adhesive layer is reduced, the followability is deteriorated, so that the sticking property of the pressure-sensitive adhesive layer to the adherend may be deteriorated.
  • a preferable lower limit of the thickness of the pressure-sensitive adhesive layer is 40 ⁇ m, and a more preferable lower limit is 50 ⁇ m.
  • the upper limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, the upper limit is preferably 200 ⁇ m, more preferably 150 ⁇ m, from the viewpoint of the adhesive strength, shape retention property, etc. of the pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive tape of the present invention may be a non-support type that does not have a substrate, but it is preferably a support type that has a substrate.
  • the adhesive tape of the present invention may be a single-sided adhesive tape having an adhesive layer only on one side of the substrate, or a double-sided adhesive tape having an adhesive layer on both sides of the substrate. Although good, it is preferably a single-sided adhesive tape having an adhesive layer on only one side of the substrate.
  • the substrate is not particularly limited, and examples of materials for the substrate include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, poly Arylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, liquid crystal polymer and the like.
  • polyethylene terephthalate and polyethylene naphthalate are preferable because of their excellent heat resistance.
  • the thickness of the base material is not particularly limited, but a preferable lower limit is 5 ⁇ m and a preferable upper limit is 188 ⁇ m. When the thickness of the base material is within the above range, the pressure-sensitive adhesive tape can have appropriate stiffness and excellent handleability.
  • a more preferable lower limit of the thickness of the substrate is 12 ⁇ m, and a more preferable upper limit thereof is 125 ⁇ m.
  • the pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer having a certain thickness or more by adjusting the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer within the above ranges. While having such properties, it has excellent sticking property to non-smooth surfaces such as paper, and can be easily peeled off without damaging the adherend. As a method for adjusting the shear storage modulus at 23° C.
  • the composition of the base polymer contained in the pressure-sensitive adhesive layer a method of adjusting the molecular weight (weight average molecular weight (Mw)) and the like, and a method of adjusting the degree of crosslinking (gel fraction) of the pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive layer contains a (meth)acrylic polymer, and the (meth)acrylic polymer contains 40% by weight or more of structural units derived from the (meth)acrylic acid ester (a) described above, It is particularly preferable that the pressure-sensitive adhesive layer has a weight average molecular weight of 1,000,000 or less, a gel fraction of 85% by weight or more and 95% by weight or less, and a thickness of 30 ⁇ m or more.
  • a pressure-sensitive adhesive tape having such a pressure-sensitive adhesive layer is also one aspect of the present invention. In such a pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer, the (meth)acrylic polymer, etc. are preferably the same as those described above.
  • the shear storage modulus at is adjusted to the above range. That is, the pressure-sensitive adhesive layer preferably has a shear storage modulus of 1 ⁇ 10 4 Pa or more and 5 ⁇ 10 4 Pa or less at 23° C. and 1 Hz.
  • the use of the pressure-sensitive adhesive tape of the present invention is not particularly limited.
  • the adhesive tape which is excellent in the stickiness with respect to non-smooth surfaces, such as paper, and can be peeled easily, without damaging an adherend can be provided.
  • Example 1 Preparation of (meth)acrylic polymer A reactor equipped with a thermometer, a stirrer and a condenser was charged with 52 parts by weight of ethyl acetate, and after the atmosphere was replaced with nitrogen, the reactor was heated to initiate reflux. After 30 minutes from the boiling of ethyl acetate, 0.08 part by weight of azobisisobutyronitrile was added as a polymerization initiator. To this, 47.2 parts by weight of 2-ethylhexyl acrylate, 47.5 parts by weight of lauryl acrylate, 5 parts by weight of 4-hydroxybutyl acrylate and 0.3 parts by weight of acrylic acid were added dropwise evenly and gradually over 1 hour and 30 minutes. reacted.
  • a viscoelastic spectrometer manufactured by IT Keisoku & Co., Ltd., DVA-200 was used, and a temperature increase rate of 5 ° C./min in a simple temperature increase mode and a condition of 1 Hz- A dynamic viscoelastic spectrum was measured from 40 to 140°C.
  • the storage elastic modulus at 23°C was defined as the shear storage elastic modulus at 23°C and 1 Hz of the pressure-sensitive adhesive layer.
  • Examples 2 to 12, Comparative Examples 1 to 11 A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1, except that the composition and weight average molecular weight of the (meth)acrylic polymer, and the amount of the cross-linking agent were changed as shown in Tables 1 and 2.
  • the cross-linking agent Coronate HX (manufactured by Tosoh Corporation), which is an isocyanate-based cross-linking agent, and Tetrad C (manufactured by Mitsubishi Gas Chemical Company, Inc.), which is an epoxy-based cross-linking agent, were also used.
  • Adhesiveness evaluation on non-smooth surfaces Adhesive tapes were attached to the paper surface of Campus Notebook (manufactured by Kokuyo Co., Ltd.) and Japanese paper (Ryuun pattern, manufactured by Kokuyo Co., Ltd.), and crimped by reciprocating a 2 kg roller once. . When only the adhesive tape part is grabbed and lifted, both the notebook paper and Japanese paper are lifted together with the adhesive tape. A case where neither the paper nor the Japanese paper was lifted and the adhesive tape was peeled off was evaluated as x.
  • BA butyl acrylate 2-EHA: 2-ethylhexyl acrylate LA: lauryl acrylate LMA: lauryl methacrylate ISTA: isostearyl acrylate 4-HBA: 4-hydroxybutyl acrylate AAc: acrylic acid
  • the adhesive tape which is excellent in the stickiness with respect to non-smooth surfaces, such as paper, and can be peeled easily, without damaging an adherend can be provided.

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  • Organic Chemistry (AREA)
  • Adhesive Tapes (AREA)
  • Adhesives Or Adhesive Processes (AREA)

Abstract

An objective of the present invention is to provide a pressure-sensitive adhesive tape that has excellent adhesiveness to a non-smooth surface such as paper and can be easily peeled off without damaging the adherend. The present invention provides a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer having a shear storage elastic modulus of 1 × 104 Pa to 5 × 104 Pa at 23°C and 1 Hz, a 180° adhesive strength of 0.3-0.7 N/25 mm, and a thickness of 30 μm or more.

Description

粘着テープAdhesive tape
本発明は、粘着テープに関する。 The present invention relates to adhesive tapes.
従来から、電子部品、車輌、住宅及び建材において部品を固定する際に、粘着テープが広く用いられている。また、例えば包装用途等において、使用後に剥離（再剥離）することを前提とした微粘着テープが用いられている。特許文献１には、可塑剤を含有する特定の粘着剤からなる粘着剤層を基材の少なくとも片面に有してなる再剥離包装用粘着テープが記載されている。 2. Description of the Related Art Adhesive tapes have been widely used for fixing parts in electronic parts, vehicles, houses and building materials. In addition, for example, in packaging applications, etc., a slightly adhesive tape is used on the premise that it will be peeled off (removed) after use. Patent Literature 1 describes a re-peelable pressure-sensitive adhesive tape for packaging having, on at least one surface of a base material, a pressure-sensitive adhesive layer made of a specific pressure-sensitive adhesive containing a plasticizer.
特開平１０－０４６１１８号公報JP-A-10-046118
このような粘着テープには、被着体を破損することなく容易に剥離できることが望まれるが、粘着力が低すぎるとそもそも使用中に剥離してしまう。特に被着体の表面が非平滑面（粗面）である場合には、粘着テープが被着体に充分に貼りつくことができないことがあった。
粘着剤層を厚くすることで非平滑面への貼りつき性を向上させることも考えられるが、一般に粘着テープにおいては、粘着剤層の厚みが厚くなると粘着力が高くなる。このため、一定以上の厚みを有しながら、被着体に充分に貼りつくことができ、かつ、被着体から容易に剥離できる粘着剤層を得ることは困難であった。また、仮に粘着剤層の厚みを保ったまま粘着力を低くしようとすると、粘着剤層の凝集力を高めることが考えられる。しかし、ベースポリマーの分子量を上げたり、粘着剤層の架橋度を高くしたりすると、紙等の表面の平滑性が低い被着体に対して貼りつき性が悪化することがあった。 Such an adhesive tape is desired to be easily peelable without damaging the adherend, but if the adhesive strength is too low, the tape will peel during use. In particular, when the surface of the adherend is non-smooth (rough), the adhesive tape may not adhere sufficiently to the adherend.
Although it is conceivable that the stickiness to a non-smooth surface can be improved by increasing the thickness of the pressure-sensitive adhesive layer, in general, the thicker the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape, the higher the adhesive strength. For this reason, it has been difficult to obtain a pressure-sensitive adhesive layer that can be sufficiently attached to an adherend and that can be easily peeled off from the adherend while having a certain thickness or more. Further, if an attempt is made to reduce the adhesive force while maintaining the thickness of the adhesive layer, it is conceivable that the cohesive force of the adhesive layer will be increased. However, when the molecular weight of the base polymer is increased or the degree of cross-linking of the pressure-sensitive adhesive layer is increased, the sticking property to an adherend having a low surface smoothness such as paper may deteriorate.
本発明は、紙等の非平滑面に対する貼りつき性に優れ、被着体を破損することなく容易に剥離できる粘着テープを提供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive adhesive tape which has excellent sticking properties to non-smooth surfaces such as paper and which can be easily peeled off without damaging the adherend.
本発明は、粘着剤層を有する粘着テープであって、上記粘着剤層は、２３℃、１Ｈｚでのせん断貯蔵弾性率が１×１０４Ｐａ以上、５×１０４Ｐａ以下であり、１８０°粘着力が０．３Ｎ／２５ｍｍ以上、０．７Ｎ／２５ｍｍ以下であり、厚みが３０μｍ以上である粘着テープである。
以下に本発明を詳述する。 The present invention is a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer has a shear storage elastic modulus of 1×10 4 Pa or more and 5×10 4 Pa or less at 23° C. and 1 Hz, and 180° The adhesive tape has an adhesive strength of 0.3 N/25 mm or more and 0.7 N/25 mm or less and a thickness of 30 µm or more.
The present invention will be described in detail below.
本発明者は、厚みが３０μｍ以上の粘着剤層を有する粘着テープにおいて、粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率を特定の比較的低い範囲に調整し、かつ、粘着剤層の１８０°粘着力を特定の比較的低い範囲に調整することを検討した。本発明者は、このような粘着テープであれば、一定以上の厚みを有する粘着剤層を有しながら、紙等の非平滑面に対する貼りつき性に優れ、被着体を破損することなく容易に剥離できることを見出し、本発明を完成させるに至った。 The present inventors have found that in a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer with a thickness of 30 μm or more, the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is adjusted to a specific relatively low range, and the pressure-sensitive adhesive layer Consideration was given to adjusting the 180° tack to a specific, relatively low range. The present inventors have found that such an adhesive tape has an adhesive layer having a certain thickness or more, has excellent adhesion to non-smooth surfaces such as paper, and can be easily applied without damaging the adherend. The inventors have found that the film can be peeled off easily, and have completed the present invention.
本発明の粘着テープは、粘着剤層を有する粘着テープである。上記粘着剤層は、２３℃、１Ｈｚでのせん断貯蔵弾性率の下限が１×１０４Ｐａ、上限が５×１０４Ｐａである。
上記せん断貯蔵弾性率が１×１０４Ｐａ以上であれば、上記粘着剤層が一定以上の厚みを有していても充分に形状を保持することができる。上記せん断貯蔵弾性率が５×１０４Ｐａ以下であれば、上記粘着剤層が紙等の非平滑面に対しても追従しやすくなり、貼りつき性が向上する。上記せん断貯蔵弾性率の好ましい下限は１．５×１０４Ｐａ、好ましい上限は４×１０４Ｐａであり、より好ましい下限は１．７×１０４Ｐａ、より好ましい上限は３×１０４Ｐａであり、更に好ましい下限は２×１０４Ｐａである。
なお、粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率は、例えば、粘弾性スペクトロメーター（アイティー計測制御社製、ＤＶＡ－２００）等を用い、単純昇温モードの昇温速度５℃／分、１Ｈｚの条件で－４０～１４０℃の動的粘弾性スペクトルを測定した時の２３℃における貯蔵弾性率として得ることができる。このときの測定用サンプルの形状は特に限定されないが、例えば、粘着剤層を厚み１ｍｍ、縦１０ｍｍ、横６ｍｍの長方形の形状として測定することができる。 The adhesive tape of the present invention is an adhesive tape having an adhesive layer. The pressure-sensitive adhesive layer has a shear storage modulus at 23° C. and 1 Hz with a lower limit of 1×10 4 Pa and an upper limit of 5×10 4 Pa.
If the shear storage elastic modulus is 1×10 4 Pa or more, the shape can be sufficiently retained even if the pressure-sensitive adhesive layer has a certain thickness or more. When the shear storage elastic modulus is 5×10 4 Pa or less, the pressure-sensitive adhesive layer easily conforms to a non-smooth surface such as paper, thereby improving the sticking property. The preferred lower limit of the shear storage modulus is 1.5×10 4 Pa, the preferred upper limit is 4×10 4 Pa, the more preferred lower limit is 1.7×10 4 Pa, and the more preferred upper limit is 3×10 4 Pa. A more preferable lower limit is 2×10 4 Pa.
The shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz can be measured, for example, using a viscoelastic spectrometer (DVA-200, manufactured by IT Keisoku Kogyo Co., Ltd.), etc., using a simple heating mode with a heating rate of 5° C. It can be obtained as the storage elastic modulus at 23°C when the dynamic viscoelasticity spectrum is measured from -40 to 140°C under the condition of 1 Hz/min. Although the shape of the measurement sample at this time is not particularly limited, for example, the pressure-sensitive adhesive layer can be measured as a rectangular shape with a thickness of 1 mm, a length of 10 mm and a width of 6 mm.
上記粘着剤層は、１８０°粘着力の下限が０．３Ｎ／２５ｍｍ、上限が０．７Ｎ／２５ｍｍである。
上記１８０°粘着力が０．３Ｎ／２５ｍｍ以上であれば、上記粘着剤層が適度な粘着力を有し、紙等の非平滑面に対する貼りつき性が向上する。上記１８０°粘着力が０．７Ｎ／２５ｍｍ以下であれば、上記粘着剤層の粘着力が充分に低いため、剥離（再剥離）時には被着体を破損することなく容易に剥離することができる。上記１８０°粘着力の好ましい下限は０．３５Ｎ／２５ｍｍ、好ましい上限は０．６５Ｎ／２５ｍｍであり、より好ましい下限は０．４Ｎ／２５ｍｍ、より好ましい上限は０．６Ｎ／２５ｍｍである。
なお、粘着剤層の１８０°粘着力は、以下の方法により測定することができる。
予め幅２５ｍｍ、長さ１０ｃｍにカットした粘着テープを、幅５０ｍｍ、長さ１２．５ｃｍ、厚さ２ｍｍのポリエチレンテレフタレート板（例えば、タキロンシーアイ社製、品名ＰＥＴ－６０１０、又はその同等品）に貼り合わせ、２ｋｇローラーを１往復させることで測定用サンプルを得る。得られた測定用サンプルについて、例えば、オートグラフ（島津製作所社製）等を用い、ＪＩＳ　Ｚ０２３７：２００９に準じて、温度２３℃、相対湿度５０％の環境下で３００ｍｍ／ｍｉｎの引張速度でポリエチレンテレフタレート板に対し１８０°方向に粘着テープを引き剥がす剥離試験を行い、１８０°粘着力（Ｎ／２５ｍｍ）を測定する。 The pressure-sensitive adhesive layer has a 180° adhesive strength with a lower limit of 0.3 N/25 mm and an upper limit of 0.7 N/25 mm.
When the 180° adhesive strength is 0.3 N/25 mm or more, the adhesive layer has appropriate adhesive strength, and the sticking property to non-smooth surfaces such as paper is improved. If the 180° adhesive strength is 0.7 N/25 mm or less, the adhesive strength of the adhesive layer is sufficiently low, so that it can be easily peeled without damaging the adherend during peeling (re-peeling). . A preferred lower limit of the 180° adhesive strength is 0.35 N/25 mm, a preferred upper limit is 0.65 N/25 mm, a more preferred lower limit is 0.4 N/25 mm, and a more preferred upper limit is 0.6 N/25 mm.
The 180° adhesive strength of the adhesive layer can be measured by the following method.
Adhesive tape pre-cut to a width of 25 mm and a length of 10 cm is pasted on a polyethylene terephthalate plate of 50 mm in width, 12.5 cm in length and 2 mm in thickness (for example, product name PET-6010 manufactured by Takiron C.I., or equivalent). A sample for measurement is obtained by combining and reciprocating a 2 kg roller once. For the obtained measurement sample, for example, using an autograph (manufactured by Shimadzu Corporation) or the like, according to JIS Z0237: 2009, polyethylene at a tensile speed of 300 mm / min under an environment of a temperature of 23 ° C. and a relative humidity of 50%. A peeling test is performed by peeling the adhesive tape off the terephthalate plate in the direction of 180°, and the 180° adhesive strength (N/25 mm) is measured.
上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力を上記範囲に調整する方法として、例えば、上記粘着剤層に含まれるベースポリマーの組成、分子量（重量平均分子量（Ｍｗ））等を調整する方法、上記粘着剤層の架橋度（ゲル分率）を調整する方法等が挙げられる。 As a method for adjusting the shear storage modulus at 23 ° C. and 1 Hz of the pressure-sensitive adhesive layer and the 180 ° adhesive strength to the above ranges, for example, the composition and molecular weight (weight average molecular weight) of the base polymer contained in the pressure-sensitive adhesive layer (Mw)), etc., and a method of adjusting the degree of cross-linking (gel fraction) of the pressure-sensitive adhesive layer.
上記粘着剤層は特に限定されず、例えば、アクリル粘着剤層、ゴム系粘着剤層、ウレタン粘着剤層、シリコーン系粘着剤層等が挙げられる。なかでも、分子量、架橋度等を調整しやすく、耐熱性、耐候性、コスト等に優れる観点から、（メタ）アクリル系ポリマーを含有するアクリル粘着剤層が好ましい。 The adhesive layer is not particularly limited, and examples thereof include an acrylic adhesive layer, a rubber-based adhesive layer, a urethane-based adhesive layer, a silicone-based adhesive layer, and the like. Among them, an acrylic pressure-sensitive adhesive layer containing a (meth)acrylic polymer is preferable from the viewpoints of easy adjustment of molecular weight, degree of crosslinking, etc., and excellent heat resistance, weather resistance, cost, and the like.
上記（メタ）アクリル系ポリマーは、（メタ）アクリル系モノマーに由来する構成単位を含有するポリマーである。
上記（メタ）アクリル系モノマーは特に限定されず、例えば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ペンチル（メタ）アクリレート、ヘキシル（メタ）アクリレート、ヘプチル（メタ）アクリレート、オクチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、２－エチルへキシル（メタ）アクリレート、ノニル（メタ）アクリレート、イソノニル（メタ）アクリレート、デシル（メタ）アクリレート、ラウリル（メタ）アクリレート、イソミリスチル（メタ）アクリレート、ステアリル（メタ）アクリレート、イソステアリル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート等が挙げられる。これらの（メタ）アクリル系モノマーは単独で用いられてもよく、２種以上が併用されてもよい。なお、「（メタ）アクリル」とは、アクリル又はメタクリルを意味し、「（メタ）アクリレート」とは、アクリレート又はメタクリレートを意味する。 The (meth)acrylic polymer is a polymer containing structural units derived from (meth)acrylic monomers.
The (meth)acrylic monomer is not particularly limited, and examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and pentyl (meth)acrylate. , hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate ) acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate and the like. These (meth)acrylic monomers may be used alone, or two or more of them may be used in combination. In addition, "(meth)acryl" means acryl or methacryl, and "(meth)acrylate" means acrylate or methacrylate.
なかでも、炭素数１２以上のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度（Ｔｇ）が０℃以下である（メタ）アクリル酸エステル（以下、「（メタ）アクリル酸エステル（ａ）」ともいう。）が好ましい。即ち、上記（メタ）アクリル系ポリマーは、上記（メタ）アクリル酸エステル（ａ）に由来する構成単位を含有することが好ましい。
また、更に、炭素数８以上、１２未満のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度（Ｔｇ）が０℃以下である（メタ）アクリル酸エステル（以下、「（メタ）アクリル酸エステル（ｂ）」ともいう。）を併用することも好ましい。即ち、上記（メタ）アクリル系ポリマーは、上記（メタ）アクリル酸エステル（ａ）に由来する構成単位に加えて、更に、上記（メタ）アクリル酸エステル（ｂ）に由来する構成単位を含有することがより好ましい。
上記（メタ）アクリル系ポリマーがこれらの比較的炭素鎖の長いアルキル基を有する構成単位を含有することで、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力が上記範囲に調整されやすくなる。これにより、上記粘着剤層は、紙等の非平滑面に対する貼りつき性がより向上し、剥離（再剥離）時には被着体を破損することなくより容易に剥離することができる。 Among them, a (meth)acrylic acid ester having an alkyl group having 12 or more carbon atoms and having a glass transition temperature (Tg) of 0° C. or less when made into a homopolymer (hereinafter referred to as “(meth)acrylic acid ester (a)” is also preferred). That is, the (meth)acrylic polymer preferably contains a structural unit derived from the (meth)acrylic acid ester (a).
Further, a (meth)acrylic acid ester (hereinafter referred to as "(meth) ) Also referred to as “acrylic acid ester (b)”.) is also preferably used in combination. That is, the (meth)acrylic polymer further contains structural units derived from the (meth)acrylic ester (b) in addition to the structural units derived from the (meth)acrylic ester (a). is more preferable.
When the (meth)acrylic polymer contains a structural unit having an alkyl group with a relatively long carbon chain, the pressure-sensitive adhesive layer has a shear storage modulus at 23°C and 1 Hz and a 180° adhesive strength. is easily adjusted within the above range. As a result, the pressure-sensitive adhesive layer has improved sticking property to a non-smooth surface such as paper, and can be easily peeled off (re-peeled) without damaging the adherend.
上記（メタ）アクリル酸エステル（ａ）及び上記（メタ）アクリル酸エステル（ｂ）のガラス転移温度（Ｔｇ）は０℃以下であれば特に限定されないが、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力をより好ましい範囲に調整する観点から、好ましい下限は－８０℃、好ましい上限は－５℃である。上記ガラス転移温度（Ｔｇ）のより好ましい下限は－７０℃、より好ましい上限は－１０℃である。
なお、ホモポリマーとしたときのガラス転移温度（Ｔｇ）は、重量平均分子量（Ｍｗ）が５０００～１００万程度又は重合度が５０～１万程度のホモポリマーについて、例えば、示差走査熱量測定（ティー・エイ・インスツルメント社製）等を用いて測定することができる。より詳細には、窒素雰囲気下、昇温速度１０℃／分の条件で測定を行った際に２ｎｄ　ｒｕｎで得られる値を用いることができる。 The glass transition temperature (Tg) of the (meth)acrylic acid ester (a) and the (meth)acrylic acid ester (b) is not particularly limited as long as it is 0° C. or lower. From the viewpoint of adjusting the shear storage modulus of and the 180° adhesive strength to a more preferable range, the preferable lower limit is -80°C and the preferable upper limit is -5°C. A more preferable lower limit of the glass transition temperature (Tg) is -70°C, and a more preferable upper limit is -10°C.
The glass transition temperature (Tg) of the homopolymer is determined by differential scanning calorimetry (T・Can be measured using a device such as A Instruments Co., Ltd.). More specifically, it is possible to use the value obtained in the 2nd run when the measurement is performed under the conditions of a temperature increase rate of 10° C./min under a nitrogen atmosphere.
上記（メタ）アクリル酸エステル（ａ）は特に限定されず、上述した（メタ）アクリル系モノマーのなかでは、例えば、ラウリルアクリレート（ホモポリマーとしたときのＴｇが－２３℃）、ラウリルメタクリレート（ホモポリマーとしたときのＴｇが－６５℃）等が挙げられる。更に、イソミリスチルアクリレート（ホモポリマーとしたときのＴｇが－５６℃）、イソステアリルアクリレート（ホモポリマーとしたときのＴｇが－１８℃）等が挙げられる。なかでも、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力がより好ましい範囲に調整されやすくなることから、ラウリルアクリレート、ラウリルメタクリレート及びイソステアリルアクリレートからなる群より選択される少なくとも１種が好ましい。更に、ラウリルアクリレートがより好ましい。 The (meth)acrylic acid ester (a) is not particularly limited, and among the above-mentioned (meth)acrylic monomers, for example, lauryl acrylate (Tg is −23° C. when converted to a homopolymer), lauryl methacrylate (homo Tg when converted to a polymer is -65°C). Further examples include isomyristyl acrylate (Tg of -56°C when converted to a homopolymer), isostearyl acrylate (Tg of -18°C when converted to a homopolymer), and the like. Among them, from the group consisting of lauryl acrylate, lauryl methacrylate and isostearyl acrylate, since the shear storage modulus at 23 ° C. and 1 Hz of the pressure-sensitive adhesive layer and the 180 ° adhesive force are easily adjusted to more preferable ranges. At least one selected is preferred. Furthermore, lauryl acrylate is more preferred.
上記（メタ）アクリル系ポリマー中、上記（メタ）アクリル酸エステル（ａ）に由来する構成単位の含有量は特に限定されないが、好ましい下限が４０重量％である。上記構成単位の含有量が４０重量％以上であれば、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力が上記範囲に調整されやすくなる。これにより、上記粘着剤層は、紙等の非平滑面に対する貼りつき性がより向上し、剥離（再剥離）時には被着体を破損することなくより容易に剥離することができる。上記構成単位の含有量のより好ましい下限は４５重量％である。
上記構成単位の含有量の上限は特に限定されないが、好ましい上限は９０重量％、より好ましい上限は８０重量％である。 The content of the structural unit derived from the (meth)acrylic acid ester (a) in the (meth)acrylic polymer is not particularly limited, but the preferred lower limit is 40% by weight. When the content of the structural unit is 40% by weight or more, the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer are easily adjusted within the above ranges. As a result, the pressure-sensitive adhesive layer has improved sticking property to a non-smooth surface such as paper, and can be easily peeled off (re-peeled) without damaging the adherend. A more preferable lower limit for the content of the structural unit is 45% by weight.
The upper limit of the content of the structural unit is not particularly limited, but the upper limit is preferably 90% by weight, and the upper limit is more preferably 80% by weight.
上記（メタ）アクリル酸エステル（ｂ）は特に限定されず、上述した（メタ）アクリル系モノマーのなかでは、例えば、２－エチルへキシルアクリレート（ホモポリマーとしたときのＴｇが－７０℃）、オクチルアクリレート（ホモポリマーとしたときのＴｇが－６５℃）等が挙げられる。更に、イソノニルアクリレート（ホモポリマーとしたときのＴｇが－５８℃）、イソデシルアクリレート（ホモポリマーとしたときのＴｇが－６２℃）等が挙げられる。なかでも、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率がより好ましい範囲に調整されやすくなるため、２－エチルへキシルアクリレートが好ましい。 The (meth)acrylic acid ester (b) is not particularly limited, and among the above-mentioned (meth)acrylic monomers, for example, 2-ethylhexyl acrylate (Tg is −70° C. when converted to a homopolymer), octyl acrylate (Tg of -65°C when homopolymerized) and the like. Furthermore, isononyl acrylate (Tg is -58°C when converted to homopolymer), isodecyl acrylate (Tg is -62°C when converted to homopolymer), and the like. Among them, 2-ethylhexyl acrylate is preferable because the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz can easily be adjusted to a more preferable range.
上記（メタ）アクリル系ポリマー中、上記（メタ）アクリル酸エステル（ｂ）に由来する構成単位の含有量は特に限定されない。上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力をより好ましい範囲に調整する観点から、上記構成単位の含有量の好ましい下限は２０重量％、好ましい上限は６０重量％であり、より好ましい下限は３０重量％、より好ましい上限は５０重量％である。 The content of the structural unit derived from the (meth)acrylic acid ester (b) in the (meth)acrylic polymer is not particularly limited. From the viewpoint of adjusting the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer to more preferable ranges, the preferable lower limit of the content of the structural unit is 20% by weight, and the preferable upper limit is 60. A more preferable lower limit is 30% by weight, and a more preferable upper limit is 50% by weight.
上記（メタ）アクリル系ポリマーは、更に、架橋性官能基含有モノマーに由来する構造を含有することが好ましい。
上記（メタ）アクリル系ポリマーが上記架橋性官能基含有モノマーに由来する構造を含有することで、架橋性官能基の架橋によって上記粘着剤層の凝集力を調整することができるため、上記粘着剤層の粘着力を上記範囲に調整しやすくなり、また、２３℃、１Ｈｚでのせん断貯蔵弾性率を上記範囲に調整しやすくなる。これにより、上記粘着剤層の紙等の非平滑面に対する貼りつき性がより向上し、剥離（再剥離）時には被着体を破損することなくより容易に剥離することができるようになる。上記架橋性官能基は架橋されていても架橋されていなくてもよいが、架橋されていることがより好ましい。ただし、架橋されていない構造のままであったとしても、官能基間の相互作用により上記粘着剤層の凝集力が高まる。 The (meth)acrylic polymer preferably further contains a structure derived from a crosslinkable functional group-containing monomer.
Since the (meth)acrylic polymer contains a structure derived from the crosslinkable functional group-containing monomer, the cohesive force of the pressure-sensitive adhesive layer can be adjusted by cross-linking of the crosslinkable functional group. It becomes easy to adjust the adhesive strength of the layer to the above range, and it becomes easy to adjust the shear storage elastic modulus at 23° C. and 1 Hz to the above range. As a result, the adhesion of the pressure-sensitive adhesive layer to a non-smooth surface such as paper is further improved, and the adhesive layer can be easily peeled off (re-peeled) without damaging the adherend. The crosslinkable functional group may or may not be crosslinked, but is more preferably crosslinked. However, even if the structure remains uncrosslinked, the cohesive force of the pressure-sensitive adhesive layer increases due to the interaction between the functional groups.
上記架橋性官能基含有モノマーとしては、例えば、カルボキシル基、水酸基、エポキシ基、二重結合、三重結合、アミノ基、アミド基、ニトリル基等を含有するモノマーが挙げられる。これらの架橋性官能基含有モノマーは単独で用いられてもよく、２種以上が併用されてもよい。なかでも、カルボキシル基含有モノマー及び水酸基含有モノマーからなる群より選択される少なくとも１種が好ましい。イソシアネート系架橋剤による架橋によって上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率を上記範囲に調整しやすいことから、水酸基含有モノマーがより好ましい。
なお、上記架橋性官能基含有モノマーは、更に、アルキル基、エーテル基、カルボニル基、エステル基、カーボネート基、アミド基、ウレタン基等を含んでいてもよい。 Examples of the crosslinkable functional group-containing monomers include monomers containing carboxyl groups, hydroxyl groups, epoxy groups, double bonds, triple bonds, amino groups, amide groups, nitrile groups, and the like. These crosslinkable functional group-containing monomers may be used alone, or two or more of them may be used in combination. Among them, at least one selected from the group consisting of carboxyl group-containing monomers and hydroxyl group-containing monomers is preferable. Hydroxyl group-containing monomers are more preferable because the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz can be easily adjusted to the above range by cross-linking with an isocyanate-based cross-linking agent.
The crosslinkable functional group-containing monomer may further contain an alkyl group, an ether group, a carbonyl group, an ester group, a carbonate group, an amide group, a urethane group, or the like.
上記カルボキシル基含有モノマーとしては、（メタ）アクリル酸等の（メタ）アクリル酸系モノマーが挙げられる。上記水酸基含有モノマーとしては、４－ヒドロキシブチル（メタ）アクリレート、２－ヒドロキシエチル（メタ）アクリレート等が挙げられる。上記エポキシ基含有モノマーとしては、グリシジル（メタ）アクリレート等が挙げられる。上記二重結合含有モノマーとしては、アリル（メタ）アクリレート、ヘキサンジオールジ（メタ）アクリレート等が挙げられる。上記三重結合含有モノマーとしては、プロパルギル（メタ）アクリレート等が挙げられる。上記アミド基含有モノマーとしては、（メタ）アクリルアミド等が挙げられる。 Examples of the carboxyl group-containing monomer include (meth)acrylic acid-based monomers such as (meth)acrylic acid. Examples of the hydroxyl group-containing monomer include 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. Glycidyl (meth)acrylate etc. are mentioned as said epoxy-group-containing monomer. Examples of the double bond-containing monomer include allyl (meth)acrylate, hexanediol di(meth)acrylate, and the like. Examples of the triple bond-containing monomer include propargyl (meth)acrylate. Examples of the amide group-containing monomer include (meth)acrylamide.
上記（メタ）アクリル系ポリマー中、上記架橋性官能基を有するモノマーに由来する構造の含有量は特に限定されないが、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率をより好ましい範囲に調整する観点から、上記構成単位の含有量の好ましい下限は０．１重量％、好ましい上限は３０重量％である。上記構成単位の含有量のより好ましい下限は０．５重量％、より好ましい上限は２５重量％である。
また、上記（メタ）アクリル系ポリマー中、上記水酸基含有モノマーに由来する構造の含有量は特に限定されないが、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率をより好ましい範囲に調整する観点から、上記構成単位の含有量の好ましい下限は１重量％、好ましい上限は２０重量％である。上記構成単位の含有量のより好ましい下限は３重量％、より好ましい上限は１０重量％である。 In the (meth)acrylic polymer, the content of the structure derived from the monomer having the crosslinkable functional group is not particularly limited. From the viewpoint of adjustment, the preferable lower limit of the content of the structural unit is 0.1% by weight, and the preferable upper limit is 30% by weight. A more preferable lower limit of the content of the structural unit is 0.5% by weight, and a more preferable upper limit is 25% by weight.
In the (meth)acrylic polymer, the content of the structure derived from the hydroxyl group-containing monomer is not particularly limited, but the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is adjusted to a more preferable range. From the point of view, the preferable lower limit of the content of the structural unit is 1% by weight, and the preferable upper limit is 20% by weight. A more preferable lower limit to the content of the structural unit is 3% by weight, and a more preferable upper limit is 10% by weight.
上記（メタ）アクリル系ポリマーを得るには、上記（メタ）アクリル系モノマー、上記架橋性官能基含有モノマー等を含むモノマー混合物を、重合開始剤の存在下にてラジカル反応させ、共重合すればよい。上記モノマー混合物をラジカル反応させる方法、即ち、重合方法としては、従来公知の方法が用いられ、例えば、溶液重合（沸点重合又は定温重合）、乳化重合、懸濁重合、塊状重合等が挙げられる。 In order to obtain the (meth)acrylic polymer, a monomer mixture containing the (meth)acrylic monomer, the crosslinkable functional group-containing monomer, etc. is radically reacted in the presence of a polymerization initiator, and copolymerized. good. As a method of radically reacting the monomer mixture, that is, a polymerization method, a conventionally known method is used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, and the like.
上記（メタ）アクリル系ポリマーの重量平均分子量（Ｍｗ）は特に限定されないが、好ましい上限が１００万である。上記重量平均分子量（Ｍｗ）が１００万以下であれば、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率が上記範囲に調整されやすくなり、上記粘着剤層の紙等の非平滑面に対する貼りつき性がより向上する。上記重量平均分子量（Ｍｗ）のより好ましい上限は９５万、更に好ましい上限は９０万である。
上記重量平均分子量（Ｍｗ）の下限は特に限定されないが、上記粘着剤層の粘着力、形状保持性等の観点から、好ましい下限は４０万、より好ましい下限は５０万である。
なお、（メタ）アクリル系ポリマーの重量平均分子量は、例えば、ＧＰＣ（Ｇｅｌ　Ｐｅｒｍｅａｔｉｏｎ　Ｃｈｒｏｍａｔｏｇｒａｐｈｙ：ゲルパーミエーションクロマトグラフィ）法により標準ポリスチレン換算にて求めることができる。より具体的には、例えば、測定機器としてＷａｔｅｒｓ社製「２６９０　Ｓｅｐａｒａｔｉｏｎｓ　Ｍｏｄｕｌｅ」、カラムとして昭和電工社製「ＧＰＣ　ＫＦ－８０６Ｌ」、溶媒として酢酸エチルを用い、サンプル流量１ｍＬ／ｍｉｎ、カラム温度４０℃の条件で測定することができる。 The weight average molecular weight (Mw) of the (meth)acrylic polymer is not particularly limited, but the preferred upper limit is 1,000,000. When the weight average molecular weight (Mw) is 1,000,000 or less, the shear storage elastic modulus at 23° C. and 1 Hz of the pressure-sensitive adhesive layer is easily adjusted to the above range, and the pressure-sensitive adhesive layer has a non-smooth surface such as paper. The sticking property against is further improved. A more preferable upper limit of the weight average molecular weight (Mw) is 950,000, and a further preferable upper limit is 900,000.
Although the lower limit of the weight-average molecular weight (Mw) is not particularly limited, the preferred lower limit is 400,000, and the more preferred lower limit is 500,000, from the viewpoint of adhesive strength, shape retention property, etc. of the pressure-sensitive adhesive layer.
The weight average molecular weight of the (meth)acrylic polymer can be determined, for example, by GPC (Gel Permeation Chromatography) in terms of standard polystyrene. More specifically, for example, using "2690 Separations Module" manufactured by Waters as a measuring instrument, "GPC KF-806L" manufactured by Showa Denko as a column, and ethyl acetate as a solvent, a sample flow rate of 1 mL/min, and a column temperature of 40°C. can be measured under the conditions of
上記粘着剤層は、粘着付与樹脂を含有してもよい。
上記粘着付与樹脂として、例えば、ロジンエステル系樹脂、水添ロジン系樹脂、テルペン系樹脂、テルペンフェノール系樹脂、クマロンインデン系樹脂、脂環族飽和炭化水素系樹脂、Ｃ５系石油樹脂、Ｃ９系石油樹脂、Ｃ５－Ｃ９共重合系石油樹脂等が挙げられる。これらの粘着付与樹脂は単独で用いてもよいし、２種以上を併用してもよい。 The pressure-sensitive adhesive layer may contain a tackifying resin.
Examples of the tackifying resin include rosin ester-based resins, hydrogenated rosin-based resins, terpene-based resins, terpene phenol-based resins, coumarone-indene-based resins, alicyclic saturated hydrocarbon-based resins, C5-based petroleum resins, and C9-based resins. petroleum resins, C5-C9 copolymer petroleum resins, and the like. These tackifying resins may be used alone or in combination of two or more.
上記粘着付与樹脂の含有量は特に限定されないが、剥離（再剥離）時に被着体を破損することなくより容易に剥離できる観点から、上記粘着付与樹脂は含有しないことが好ましい。上記粘着付与樹脂を含有する場合は、上記粘着剤層の主成分となる樹脂（例えば、（メタ）アクリル系ポリマー）１００重量部に対する好ましい上限は１０重量部である。上記粘着付与樹脂の含有量が１０重量部以下であると、剥離（再剥離）時に被着体を破損することなくより容易に剥離できる。 Although the content of the tackifying resin is not particularly limited, it is preferable that the tackifying resin is not contained from the viewpoint of easier peeling without damaging the adherend during peeling (re-peeling). When the tackifying resin is contained, the preferred upper limit is 10 parts by weight with respect to 100 parts by weight of the resin (for example, (meth)acrylic polymer) that is the main component of the adhesive layer. When the content of the tackifier resin is 10 parts by weight or less, the adherend can be easily peeled without damaging the adherend during peeling (re-peeling).
上記粘着剤層は、架橋剤を含有することにより上記粘着剤層を構成する樹脂（例えば、上記（メタ）アクリル系ポリマー、上記粘着付与樹脂等）の主鎖間に架橋構造が形成されていることが好ましい。
上記架橋剤は特に限定されず、例えば、イソシアネート系架橋剤、アジリジン系架橋剤、エポキシ系架橋剤、金属キレート型架橋剤等が挙げられる。なかでも、上記（メタ）アクリル系ポリマーが上記水酸基含有モノマーに由来する構成単位を含有する場合、水酸基との架橋によって上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率を上記範囲に調整しやすいことから、イソシアネート系架橋剤が好ましい。
上記架橋剤の含有量は、上記粘着剤層の主成分となる樹脂（例えば、上記（メタ）アクリル系ポリマー）１００重量部に対して０．０１～１０重量部が好ましく、０．１～７重量部がより好ましい。 The pressure-sensitive adhesive layer contains a cross-linking agent to form a cross-linked structure between the main chains of the resin (for example, the (meth)acrylic polymer, the tackifier resin, etc.) constituting the pressure-sensitive adhesive layer. is preferred.
The cross-linking agent is not particularly limited, and examples thereof include an isocyanate-based cross-linking agent, an aziridine-based cross-linking agent, an epoxy-based cross-linking agent, and a metal chelate-type cross-linking agent. Among them, when the (meth)acrylic polymer contains a structural unit derived from the hydroxyl group-containing monomer, the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is adjusted to the above range by crosslinking with the hydroxyl group. An isocyanate-based cross-linking agent is preferred because it is easy to use.
The content of the cross-linking agent is preferably 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight, relative to 100 parts by weight of the resin (for example, the (meth)acrylic polymer) that is the main component of the pressure-sensitive adhesive layer. Parts by weight are more preferred.
上記粘着剤層は、更に、ヒュームドシリカ等の無機フィラーを含有してもよい。上記無機フィラーを配合することにより、上記粘着剤層の凝集力を高めることができる。 The pressure-sensitive adhesive layer may further contain an inorganic filler such as fumed silica. By blending the inorganic filler, the cohesive force of the pressure-sensitive adhesive layer can be increased.
上記粘着剤層は、更に、可塑剤、樹脂、界面活性剤、ワックス、微粒子充填剤等の公知の添加剤を含有してもよい。これらの添加剤は単独で用いられてもよく、２種以上が併用されてもよい。 The pressure-sensitive adhesive layer may further contain known additives such as plasticizers, resins, surfactants, waxes and fine particle fillers. These additives may be used alone, or two or more of them may be used in combination.
上記粘着剤層のゲル分率は特に限定されないが、好ましい下限が８５重量％、好ましい上限が９５重量％である。上記ゲル分率が８５重量％以上であれば、上記粘着剤層の１８０°粘着力が上記範囲に調整されやすくなり、剥離（再剥離）時には被着体を破損することなくより容易に剥離することができる。上記ゲル分率が９５重量％以下であれば、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率が上記範囲に調整されやすくなり、上記粘着剤層の紙等の非平滑面に対する貼りつき性がより向上する。上記ゲル分率のより好ましい下限は８６重量％、より好ましい上限は９４重量％であり、更に好ましい下限は８７重量％、更に好ましい上限は９３重量％である。
なお、粘着剤層のゲル分率は、以下の方法により測定することができる。
粘着テープから粘着剤層（粘着剤組成物）のみを０．１ｇ取り出し、酢酸エチル５０ｍＬ中に浸漬し、振とう機で温度２３度、２００ｒｐｍの条件で２４時間振とうする。振とう後、金属メッシュ（目開き＃２００メッシュ）を用いて、酢酸エチルと酢酸エチルを吸収し膨潤した粘着剤組成物を分離する。分離後の粘着剤組成物を１１０℃の条件下で１時間乾燥させる。乾燥後の金属メッシュを含む粘着剤組成物の重量を測定し、下記式を用いて粘着剤層のゲル分率を算出する。
ゲル分率（重量％）＝１００×（Ｗ１－Ｗ２）／Ｗ０
（Ｗ０：初期粘着剤組成物重量、Ｗ１：乾燥後の金属メッシュを含む粘着剤組成物重量、Ｗ２：金属メッシュの初期重量） The gel fraction of the pressure-sensitive adhesive layer is not particularly limited, but the preferred lower limit is 85% by weight and the preferred upper limit is 95% by weight. When the gel fraction is 85% by weight or more, the 180° adhesive strength of the pressure-sensitive adhesive layer is easily adjusted to the above range, and when peeling (re-peeling), the adherend is more easily peeled without damaging the adherend. be able to. When the gel fraction is 95% by weight or less, the shear storage modulus of the pressure-sensitive adhesive layer at 23° C. and 1 Hz is easily adjusted to the above range, and the pressure-sensitive adhesive layer is attached to a non-smooth surface such as paper. Better adhesion. A more preferable lower limit of the gel fraction is 86% by weight, a more preferable upper limit is 94% by weight, a still more preferable lower limit is 87% by weight, and a further preferable upper limit is 93% by weight.
In addition, the gel fraction of the adhesive layer can be measured by the following method.
Only 0.1 g of the adhesive layer (adhesive composition) is taken out from the adhesive tape, immersed in 50 mL of ethyl acetate, and shaken with a shaker at 200 rpm and a temperature of 23° C. for 24 hours. After shaking, a metal mesh (#200 mesh) is used to separate the ethyl acetate and the pressure-sensitive adhesive composition that has absorbed and swollen the ethyl acetate. The adhesive composition after separation is dried at 110° C. for 1 hour. The weight of the pressure-sensitive adhesive composition containing the metal mesh after drying is measured, and the gel fraction of the pressure-sensitive adhesive layer is calculated using the following formula.
Gel fraction (% by weight) = 100 x (W 1 - W 2 )/W 0
(W 0 : initial weight of adhesive composition, W 1 : weight of adhesive composition containing metal mesh after drying, W 2 : initial weight of metal mesh)
上記粘着剤層の厚みは、下限が３０μｍである。
本発明の粘着テープは、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力が上記範囲に調整されていることで、このように一定以上の厚みを有する粘着剤層を有しながら、紙等の非平滑面に対する貼りつき性に優れ、被着体を破損することなく容易に剥離することができる。なお、上記粘着剤層の厚みが薄くなると、追従性が低下するため、上記粘着剤層の被着体に対する貼りつき性が低下することがある。上記粘着剤層の厚みの好ましい下限は４０μｍ、より好ましい下限は５０μｍである。
上記粘着剤層の厚みの上限は特に限定されないが、上記粘着剤層の粘着力、形状保持性等の観点から、好ましい上限は２００μｍ、より好ましい上限は１５０μｍである。 The lower limit of the thickness of the pressure-sensitive adhesive layer is 30 μm.
In the pressure-sensitive adhesive tape of the present invention, the shear storage modulus at 23° C. and 1 Hz of the pressure-sensitive adhesive layer and the 180° pressure-sensitive adhesive strength are adjusted within the above ranges, so that the pressure-sensitive adhesive tape has a certain thickness or more. While having an agent layer, it has excellent sticking property to non-smooth surfaces such as paper, and can be easily peeled off without damaging the adherend. In addition, when the thickness of the pressure-sensitive adhesive layer is reduced, the followability is deteriorated, so that the sticking property of the pressure-sensitive adhesive layer to the adherend may be deteriorated. A preferable lower limit of the thickness of the pressure-sensitive adhesive layer is 40 µm, and a more preferable lower limit is 50 µm.
Although the upper limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, the upper limit is preferably 200 µm, more preferably 150 µm, from the viewpoint of the adhesive strength, shape retention property, etc. of the pressure-sensitive adhesive layer.
本発明の粘着テープは、基材を有さないノンサポートタイプであってもよいが、基材を有するサポートタイプであることが好ましい。サポートタイプの場合、本発明の粘着テープは、基材の片面のみに粘着剤層を有する片面粘着テープであってもよいし、基材の両面に粘着剤層を有する両面粘着テープであってもよいが、基材の片面のみに粘着剤層を有する片面粘着テープであることが好ましい。 The pressure-sensitive adhesive tape of the present invention may be a non-support type that does not have a substrate, but it is preferably a support type that has a substrate. In the case of the support type, the adhesive tape of the present invention may be a single-sided adhesive tape having an adhesive layer only on one side of the substrate, or a double-sided adhesive tape having an adhesive layer on both sides of the substrate. Although good, it is preferably a single-sided adhesive tape having an adhesive layer on only one side of the substrate.
上記基材は特に限定されず、上記基材の材料としては、例えば、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリアセタール、ポリアミド、ポリカーボネート、ポリフェニレンエーテル、ポリブチレンテレフタレート、超高分子量ポリエチレン、シンジオタクチックポリスチレン、ポリアリレート、ポリサルフォン、ポリエーテルサルフォン、ポリフェニレンサルファイド、ポリエーテルエーテルケトン、ポリイミド、ポリエーテルイミド、フッ素樹脂、液晶ポリマー等が挙げられる。なかでも、耐熱性に優れることから、ポリエチレンテレフタレート、ポリエチレンナフタレートが好ましい。 The substrate is not particularly limited, and examples of materials for the substrate include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, poly Arylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, liquid crystal polymer and the like. Among them, polyethylene terephthalate and polyethylene naphthalate are preferable because of their excellent heat resistance.
上記基材の厚みは特に限定されないが、好ましい下限は５μｍ、好ましい上限は１８８μｍである。上記基材の厚みが上記範囲内であることにより、適度なコシがあって、取り扱い性に優れる粘着テープとすることができる。上記基材の厚みのより好ましい下限は１２μｍ、より好ましい上限は１２５μｍである。 The thickness of the base material is not particularly limited, but a preferable lower limit is 5 μm and a preferable upper limit is 188 μm. When the thickness of the base material is within the above range, the pressure-sensitive adhesive tape can have appropriate stiffness and excellent handleability. A more preferable lower limit of the thickness of the substrate is 12 μm, and a more preferable upper limit thereof is 125 μm.
本発明の粘着テープは、上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力が上記範囲に調整されていることで、一定以上の厚みを有する粘着剤層を有しながら、紙等の非平滑面に対する貼りつき性に優れ、被着体を破損することなく容易に剥離することができる。
上記粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率、及び、１８０°粘着力を上記範囲に調整する方法としては、上述したように、例えば、上記粘着剤層に含まれるベースポリマーの組成、分子量（重量平均分子量（Ｍｗ））等を調整する方法、上記粘着剤層の架橋度（ゲル分率）を調整する方法等が挙げられる。なかでも、上記粘着剤層が（メタ）アクリル系ポリマーを含有し、該（メタ）アクリル系ポリマーが上述した（メタ）アクリル酸エステル（ａ）に由来する構成単位を４０重量％以上含有し、重量平均分子量が１００万以下であり、上記粘着剤層のゲル分率が８５重量％以上、９５重量％以下であり、厚みが３０μｍ以上であることが特に好ましい。このような粘着剤層を有する粘着テープもまた、本発明の１つである。このような本発明の粘着テープにおいて、上記粘着剤層、上記（メタ）アクリル系ポリマー等は、上述したものと同様であることが好ましく、なかでも特に、上記粘着剤層は、２３℃、１Ｈｚでのせん断貯蔵弾性率が上記範囲に調整されていることが好ましい。即ち、上記粘着剤層は、２３℃、１Ｈｚでのせん断貯蔵弾性率が１×１０４Ｐａ以上、５×１０４Ｐａ以下であることが好ましい。 The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer having a certain thickness or more by adjusting the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer within the above ranges. While having such properties, it has excellent sticking property to non-smooth surfaces such as paper, and can be easily peeled off without damaging the adherend.
As a method for adjusting the shear storage modulus at 23° C. and 1 Hz and the 180° adhesive strength of the pressure-sensitive adhesive layer within the above ranges, for example, the composition of the base polymer contained in the pressure-sensitive adhesive layer , a method of adjusting the molecular weight (weight average molecular weight (Mw)) and the like, and a method of adjusting the degree of crosslinking (gel fraction) of the pressure-sensitive adhesive layer. Among them, the pressure-sensitive adhesive layer contains a (meth)acrylic polymer, and the (meth)acrylic polymer contains 40% by weight or more of structural units derived from the (meth)acrylic acid ester (a) described above, It is particularly preferable that the pressure-sensitive adhesive layer has a weight average molecular weight of 1,000,000 or less, a gel fraction of 85% by weight or more and 95% by weight or less, and a thickness of 30 μm or more. A pressure-sensitive adhesive tape having such a pressure-sensitive adhesive layer is also one aspect of the present invention. In such a pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer, the (meth)acrylic polymer, etc. are preferably the same as those described above. It is preferable that the shear storage modulus at is adjusted to the above range. That is, the pressure-sensitive adhesive layer preferably has a shear storage modulus of 1×10 4 Pa or more and 5×10 4 Pa or less at 23° C. and 1 Hz.
本発明の粘着テープの用途は特に限定されないが、例えば、包装用途等において、使用後に剥離（再剥離）することを前提とした微粘着テープとして好適に用いられる。 The use of the pressure-sensitive adhesive tape of the present invention is not particularly limited.
本発明によれば、紙等の非平滑面に対する貼りつき性に優れ、被着体を破損することなく容易に剥離できる粘着テープを提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the adhesive tape which is excellent in the stickiness with respect to non-smooth surfaces, such as paper, and can be peeled easily, without damaging an adherend can be provided.
以下に実施例を挙げて本発明の態様を更に詳しく説明するが、本発明はこれら実施例のみに限定されない。 EXAMPLES The aspects of the present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.
（実施例１）
（１）（メタ）アクリル系ポリマーの調製
温度計、攪拌機、冷却管を備えた反応器に酢酸エチル５２重量部を入れて、窒素置換した後、反応器を加熱して還流を開始した。酢酸エチルが沸騰してから、３０分後に重合開始剤としてアゾビスイソブチロニトリル０．０８重量部を投入した。ここに２－エチルヘキシルアクリレート４７．２重量部、ラウリルアクリレート４７．５重量部、４－ヒドロキシブチルアクリレート５重量部及びアクリル酸０．３重量部を１時間３０分かけて、均等かつ徐々に滴下し反応させた。滴下終了３０分後にアゾビスイソブチロニトリル０．１重量部を添加し、更に５時間重合反応させ、反応器内に酢酸エチルを加えて希釈しながら冷却することにより、（メタ）アクリル系ポリマーの溶液を得た。
得られた（メタ）アクリル系ポリマーについて、測定機器としてＷａｔｅｒｓ社製「２６９０　Ｓｅｐａｒａｔｉｏｎｓ　Ｍｏｄｕｌｅ」、カラムとして昭和電工社製「ＧＰＣ　ＫＦ－８０６Ｌ」、溶媒として酢酸エチルを用い、サンプル流量１ｍＬ／ｍｉｎ、カラム温度４０℃の条件で重量平均分子量を測定した。 (Example 1)
(1) Preparation of (meth)acrylic polymer A reactor equipped with a thermometer, a stirrer and a condenser was charged with 52 parts by weight of ethyl acetate, and after the atmosphere was replaced with nitrogen, the reactor was heated to initiate reflux. After 30 minutes from the boiling of ethyl acetate, 0.08 part by weight of azobisisobutyronitrile was added as a polymerization initiator. To this, 47.2 parts by weight of 2-ethylhexyl acrylate, 47.5 parts by weight of lauryl acrylate, 5 parts by weight of 4-hydroxybutyl acrylate and 0.3 parts by weight of acrylic acid were added dropwise evenly and gradually over 1 hour and 30 minutes. reacted. 0.1 part by weight of azobisisobutyronitrile was added 30 minutes after the completion of dropping, and the polymerization reaction was continued for 5 hours. A solution of
For the obtained (meth)acrylic polymer, the measuring instrument "2690 Separations Module" manufactured by Waters, the column "GPC KF-806L" manufactured by Showa Denko Co., Ltd., the solvent ethyl acetate, the sample flow rate 1 mL / min, the column The weight average molecular weight was measured at a temperature of 40°C.
（２）粘着テープの製造
得られた（メタ）アクリル系ポリマーの溶液に、（メタ）アクリル系ポリマー１００重量部に対して、イソシアネート系架橋剤としてコロネートＬ－４５（東ソー社製）を固形分が０．８重量部となるように加えて更に充分に撹拌し、粘着剤溶液を得た。得られた粘着剤溶液を、乾燥皮膜の厚さが３０μｍになるようにアプリケーターを用いて基材としての厚み１００μｍのポリエチレンテレフタレート（ＰＥＴ）フィルム上に塗工し、１１０℃で３分間乾燥させることで粘着テープを得た。 (2) Production of adhesive tape Into the obtained (meth)acrylic polymer solution, Coronate L-45 (manufactured by Tosoh Corporation) as an isocyanate cross-linking agent is added to 100 parts by weight of the (meth)acrylic polymer as a solid content. was added so as to be 0.8 parts by weight, and the mixture was sufficiently stirred to obtain an adhesive solution. The obtained pressure-sensitive adhesive solution is applied onto a polyethylene terephthalate (PET) film having a thickness of 100 μm as a substrate using an applicator so that the dry film has a thickness of 30 μm, and dried at 110° C. for 3 minutes. got the adhesive tape.
（３）ゲル分率の測定
粘着テープから粘着剤層（粘着剤組成物）のみを０．１ｇ取り出し、酢酸エチル５０ｍＬ中に浸漬し、振とう機で温度２３度、２００ｒｐｍの条件で２４時間振とうした。振とう後、金属メッシュ（目開き＃２００メッシュ）を用いて、酢酸エチルと酢酸エチルを吸収し膨潤した粘着剤組成物を分離した。分離後の粘着剤組成物を１１０℃の条件下で１時間乾燥させた。乾燥後の金属メッシュを含む粘着剤組成物の重量を測定し、下記式を用いて粘着剤層のゲル分率を算出した。
ゲル分率（重量％）＝１００×（Ｗ１－Ｗ２）／Ｗ０
（Ｗ０：初期粘着剤組成物重量、Ｗ１：乾燥後の金属メッシュを含む粘着剤組成物重量、Ｗ２：金属メッシュの初期重量） (3) Gel fraction measurement Take out 0.1 g of only the adhesive layer (adhesive composition) from the adhesive tape, immerse it in 50 mL of ethyl acetate, and shake it with a shaker at a temperature of 23 degrees and 200 rpm for 24 hours. I did. After shaking, ethyl acetate and the adhesive composition swollen by absorbing ethyl acetate were separated using a metal mesh (#200 mesh opening). The adhesive composition after separation was dried at 110° C. for 1 hour. The weight of the adhesive composition containing the dried metal mesh was measured, and the gel fraction of the adhesive layer was calculated using the following formula.
Gel fraction (% by weight) = 100 x (W 1 - W 2 )/W 0
(W 0 : initial weight of adhesive composition, W 1 : weight of adhesive composition containing metal mesh after drying, W 2 : initial weight of metal mesh)
（４）１８０°粘着力の測定
予め幅２５ｍｍ、長さ１０ｃｍにカットした粘着テープを、幅５０ｍｍ、長さ１２．５ｃｍ、厚さ２ｍｍのポリエチレンテレフタレート板（タキロンシーアイ社製、品名ＰＥＴ－６０１０）に貼り合わせ、２ｋｇローラーを１往復させることで測定用サンプルを得た。得られた測定用サンプルについて、オートグラフ（島津製作所社製）を用い、ＪＩＳ　Ｚ０２３７：２００９に準じて、温度２３℃、相対湿度５０％の環境下で３００ｍｍ／ｍｉｎの引張速度でポリエチレンテレフタレート板に対し１８０°方向に粘着テープを引き剥がす剥離試験を行い、１８０°粘着力（Ｎ／２５ｍｍ）を測定した。 (4) Measurement of 180° Adhesive Strength A polyethylene terephthalate plate having a width of 50 mm, a length of 12.5 cm, and a thickness of 2 mm (PET-6010, product name: PET-6010, manufactured by Takiron C.I. Co., Ltd.) was cut from an adhesive tape that had been cut to a width of 25 mm and a length of 10 cm. , and a 2 kg roller was reciprocated once to obtain a sample for measurement. Using Autograph (manufactured by Shimadzu Corporation), the obtained measurement sample was subjected to a polyethylene terephthalate plate at a tensile speed of 300 mm / min in an environment of 23 ° C. and 50% relative humidity in accordance with JIS Z0237: 2009. A peeling test was conducted by peeling off the adhesive tape in the 180° direction, and the 180° adhesive strength (N/25 mm) was measured.
（５）せん断貯蔵弾性率の測定
粘着テープについて、粘弾性スペクトロメーター（アイティー計測制御社製、ＤＶＡ－２００）を用い、単純昇温モードの昇温速度５℃／分、１Ｈｚの条件で－４０～１４０℃の動的粘弾性スペクトルを測定した。２３℃における貯蔵弾性率を、粘着剤層の２３℃、１Ｈｚでのせん断貯蔵弾性率とした。 (5) Measurement of shear storage elastic modulus For the adhesive tape, a viscoelastic spectrometer (manufactured by IT Keisoku & Co., Ltd., DVA-200) was used, and a temperature increase rate of 5 ° C./min in a simple temperature increase mode and a condition of 1 Hz- A dynamic viscoelastic spectrum was measured from 40 to 140°C. The storage elastic modulus at 23°C was defined as the shear storage elastic modulus at 23°C and 1 Hz of the pressure-sensitive adhesive layer.
（実施例２～１２、比較例１～１１）
（メタ）アクリル系ポリマーの組成及び重量平均分子量、並びに、架橋剤の量を表１～２に示したとおりに変更したこと以外は実施例１と同様にして、粘着テープを得た。架橋剤としては、イソシアネート系架橋剤であるコロネートＨＸ（東ソー社製）、エポキシ系架橋剤であるテトラッドＣ（三菱ガス化学社製）も用いた。 (Examples 2 to 12, Comparative Examples 1 to 11)
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1, except that the composition and weight average molecular weight of the (meth)acrylic polymer, and the amount of the cross-linking agent were changed as shown in Tables 1 and 2. As the cross-linking agent, Coronate HX (manufactured by Tosoh Corporation), which is an isocyanate-based cross-linking agent, and Tetrad C (manufactured by Mitsubishi Gas Chemical Company, Inc.), which is an epoxy-based cross-linking agent, were also used.
＜評価＞
実施例及び比較例で得られた粘着テープについて下記の評価を行った。結果を表１～２に示した。 <Evaluation>
The adhesive tapes obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 1-2.
（１）被着体の破損評価
キャンパスノート（コクヨ社製）の紙面に粘着テープを貼りつけ、２０分間静置した。静置後、高速剥離試験機（テスター産業社製）を用い、５０Ｍ／ｍｉｎの引張速度で１８０°方向に粘着テープを引き剥がす剥離試験を行った。ノートの紙面の表面が破れなかった場合を〇、破れた場合を×とした。なお、比較例１１では、粘着剤層が凝集破壊し、ノートの紙面に粘着剤残渣が残り、剥離できなかった。 (1) Evaluation of Damage to Adherend An adhesive tape was attached to the paper surface of Campus Note (manufactured by Kokuyo Co., Ltd.) and allowed to stand for 20 minutes. After standing still, using a high-speed peeling tester (manufactured by Tester Sangyo Co., Ltd.), a peeling test was performed in which the adhesive tape was peeled off in a 180° direction at a tensile speed of 50 M/min. When the surface of the notebook paper was not torn, it was evaluated as ◯, and when it was torn, it was evaluated as ×. In Comparative Example 11, cohesive failure occurred in the adhesive layer, leaving an adhesive residue on the paper surface of the notebook, and the notebook could not be peeled off.
（２）非平滑面に対する貼りつき性評価
キャンパスノート（コクヨ社製）の紙面及び和紙（コクヨ社製、流雲柄）に粘着テープをそれぞれ貼りつけ、２ｋｇローラーを１往復させることで圧着させた。粘着テープ部分のみを掴んで持ち上げ、粘着テープとともにノートの紙も和紙も持ち上がった場合を◎、粘着テープとともにノートの紙は持ち上がったが、和紙は持ち上がらず粘着テープが剥がれた場合を〇、ノートの紙も和紙も持ち上がらず粘着テープが剥がれた場合を×とした。 (2) Adhesiveness evaluation on non-smooth surfaces Adhesive tapes were attached to the paper surface of Campus Notebook (manufactured by Kokuyo Co., Ltd.) and Japanese paper (Ryuun pattern, manufactured by Kokuyo Co., Ltd.), and crimped by reciprocating a 2 kg roller once. . When only the adhesive tape part is grabbed and lifted, both the notebook paper and Japanese paper are lifted together with the adhesive tape. A case where neither the paper nor the Japanese paper was lifted and the adhesive tape was peeled off was evaluated as x.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
ＢＡ：ブチルアクリレート
２－ＥＨＡ：２－エチルヘキシルアクリレート
ＬＡ：ラウリルアクリレート
ＬＭＡ：ラウリルメタクリレート
ＩＳＴＡ：イソステアリルアクリレート
４－ＨＢＡ：４－ヒドロキシブチルアクリレート
ＡＡｃ：アクリル酸 BA: butyl acrylate 2-EHA: 2-ethylhexyl acrylate LA: lauryl acrylate LMA: lauryl methacrylate ISTA: isostearyl acrylate 4-HBA: 4-hydroxybutyl acrylate AAc: acrylic acid
本発明によれば、紙等の非平滑面に対する貼りつき性に優れ、被着体を破損することなく容易に剥離できる粘着テープを提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the adhesive tape which is excellent in the stickiness with respect to non-smooth surfaces, such as paper, and can be peeled easily, without damaging an adherend can be provided.

Claims (9)

  1. 粘着剤層を有する粘着テープであって、
    前記粘着剤層は、２３℃、１Ｈｚでのせん断貯蔵弾性率が１×１０４Ｐａ以上、５×１０４Ｐａ以下であり、１８０°粘着力が０．３Ｎ／２５ｍｍ以上、０．７Ｎ／２５ｍｍ以下であり、厚みが３０μｍ以上である
    ことを特徴とする粘着テープ。     An adhesive tape having an adhesive layer,
    The pressure-sensitive adhesive layer has a shear storage modulus of 1×10 4 Pa or more and 5×10 4 Pa or less at 23° C. and 1 Hz, and a 180° adhesive strength of 0.3 N/25 mm or more and 0.7 N/25 mm. below and having a thickness of 30 μm or more.
  2. 前記粘着剤層は、（メタ）アクリル系ポリマーを含有し、
    前記（メタ）アクリル系ポリマーは、炭素数１２以上のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度が０℃以下である（メタ）アクリル酸エステルに由来する構成単位を４０重量％以上含有し、重量平均分子量が１００万以下であり、
    前記粘着剤層は、ゲル分率が８５重量％以上、９５重量％以下である
    ことを特徴とする請求項１記載の粘着テープ。     The pressure-sensitive adhesive layer contains a (meth)acrylic polymer,
    The (meth)acrylic polymer has 40 structural units derived from a (meth)acrylic acid ester having an alkyl group having 12 or more carbon atoms and a glass transition temperature of 0° C. or lower when homopolymerized. % by weight or more, the weight average molecular weight is 1 million or less,
    2. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer has a gel fraction of 85% by weight or more and 95% by weight or less.
  3. 前記炭素数１２以上のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度が０℃以下である（メタ）アクリル酸エステルは、ラウリルアクリレート、ラウリルメタクリレート及びイソステアリルアクリレートからなる群より選択される少なくとも１種を含有することを特徴とする請求項２記載の粘着テープ。 The (meth)acrylic acid ester having an alkyl group having 12 or more carbon atoms and having a glass transition temperature of 0° C. or less when converted into a homopolymer is selected from the group consisting of lauryl acrylate, lauryl methacrylate and isostearyl acrylate. 3. The pressure-sensitive adhesive tape according to claim 2, comprising at least one selected.
  4. 前記炭素数１２以上のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度が０℃以下である（メタ）アクリル酸エステルは、ラウリルアクリレートを含有することを特徴とする請求項３記載の粘着テープ。 3. The (meth)acrylic acid ester having an alkyl group of 12 or more carbon atoms and having a glass transition temperature of 0° C. or lower when homopolymerized contains lauryl acrylate. Adhesive tape as described.
  5. 前記（メタ）アクリル系ポリマーは、更に、炭素数８以上、１２未満のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度が０℃以下である（メタ）アクリル酸エステルに由来する構成単位を含有することを特徴とする請求項２、３又は４記載の粘着テープ。 The (meth)acrylic polymer further has an alkyl group having 8 or more carbon atoms and less than 12 carbon atoms, and is derived from a (meth)acrylic acid ester having a glass transition temperature of 0 ° C. or less when converted to a homopolymer. 5. The pressure-sensitive adhesive tape according to claim 2, 3 or 4, comprising a structural unit which
  6. 前記（メタ）アクリル系ポリマーは、水酸基含有モノマーに由来する構成単位を１重量％以上含有することを特徴とする請求項１、２、３、４又は５記載の粘着テープ。 6. The pressure-sensitive adhesive tape according to claim 1, 2, 3, 4 or 5, wherein the (meth)acrylic polymer contains 1% by weight or more of structural units derived from a hydroxyl group-containing monomer.
  7. 前記粘着剤層は、イソシアネート架橋剤を含有することを特徴とする請求項１、２、３、４、５又は６記載の粘着テープ。 7. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer contains an isocyanate cross-linking agent.
  8. 粘着剤層を有する粘着テープであって、
    前記粘着剤層は、（メタ）アクリル系ポリマーを含有し、
    前記（メタ）アクリル系ポリマーは、炭素数１２以上のアルキル基を有し、かつ、ホモポリマーとしたときのガラス転移温度が０℃以下である（メタ）アクリル酸エステルに由来する構成単位を４０重量％以上含有し、重量平均分子量が１００万以下であり、
    前記粘着剤層は、ゲル分率が８５重量％以上、９５重量％以下であり、厚みが３０μｍ以上である
    ことを特徴とする粘着テープ。     An adhesive tape having an adhesive layer,
    The pressure-sensitive adhesive layer contains a (meth)acrylic polymer,
    The (meth)acrylic polymer has 40 structural units derived from a (meth)acrylic acid ester having an alkyl group having 12 or more carbon atoms and a glass transition temperature of 0° C. or lower when homopolymerized. % by weight or more, the weight average molecular weight is 1 million or less,
    The pressure-sensitive adhesive tape, wherein the pressure-sensitive adhesive layer has a gel fraction of 85% by weight or more and 95% by weight or less and a thickness of 30 μm or more.
  9. 前記粘着剤層は、２３℃、１Ｈｚでのせん断貯蔵弾性率が１×１０４Ｐａ以上、５×１０４Ｐａ以下であることを特徴とする請求項９記載の粘着テープ。
     

          The pressure-sensitive adhesive tape according to claim 9, wherein the pressure-sensitive adhesive layer has a shear storage modulus of 1 x 104 Pa or more and 5 x 104 Pa or less at 23°C and 1 Hz.
PCT/JP2022/015265 2021-04-02 2022-03-29 Pressure-sensitive adhesive tape WO2022210638A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005314513A (en) * 2004-04-28 2005-11-10 Nitto Denko Corp Adhesive composition, and surface-protective film obtained by using the same
JP2009057394A (en) * 2006-08-30 2009-03-19 Dic Corp Repeelable self-adhesive sheet
JP2013122036A (en) * 2011-11-10 2013-06-20 Nitto Denko Corp Self-adhesive sheet
JP2015214677A (en) * 2014-04-23 2015-12-03 日本合成化学工業株式会社 Adhesive composition, adhesive and adhesive sheet

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005314513A (en) * 2004-04-28 2005-11-10 Nitto Denko Corp Adhesive composition, and surface-protective film obtained by using the same
JP2009057394A (en) * 2006-08-30 2009-03-19 Dic Corp Repeelable self-adhesive sheet
JP2013122036A (en) * 2011-11-10 2013-06-20 Nitto Denko Corp Self-adhesive sheet
JP2015214677A (en) * 2014-04-23 2015-12-03 日本合成化学工業株式会社 Adhesive composition, adhesive and adhesive sheet

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