Classifications

• • 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
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/02—Non-macromolecular additives
  • C09J11/06—Non-macromolecular additives organic
• • 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
• • 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
• • 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
  • C09J133/062—Copolymers with monomers not covered by C09J133/06
  • C09J133/066—Copolymers with monomers not covered by C09J133/06 containing -OH groups
• • 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
  • C09J133/18—Homopolymers or copolymers of nitriles
  • C09J133/20—Homopolymers or copolymers of acrylonitrile
• • 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
  • C09J133/24—Homopolymers or copolymers of amides or imides
  • C09J133/26—Homopolymers or copolymers of acrylamide or methacrylamide
• • 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]
• • 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]
  • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • C09J7/385—Acrylic polymers

Definitions

• Adhesive tapes having an adhesive layer containing an adhesive have been widely used to fasten components in electronic components, vehicles, houses, and building materials (e.g., Patent Documents 1 to 3). Specifically, for example, adhesive tapes are used to adhere a cover panel for protecting the surface of a portable electronic device to a touch panel module or a display panel module, or to adhere a touch panel module to a display panel module.
• the present disclosure 1 relates to an adhesive tape having an adhesive layer, the adhesive layer containing a (meth)acrylic copolymer, the adhesive layer having a content of biological carbon of 30% or more, and satisfying at least one configuration selected from the group consisting of the following first configuration and the following second configuration:
• First configuration the pressure-sensitive adhesive layer has a water vapor permeability coefficient P of 11 g mm/( m2 day) or more, as calculated by the following formula (i):
• Present disclosure 2 is a pressure-sensitive adhesive tape of present disclosure 1 that satisfies the above first configuration.
• the present disclosure 3 is the pressure-sensitive adhesive tape of the present disclosure 2, wherein the (meth)acrylic copolymer contains at least one structural unit selected from the group consisting of a structural unit derived from n-heptyl (meth)acrylate and a structural unit derived from 2-octyl (meth)acrylate.
• the present disclosure 4 is a pressure-sensitive adhesive tape according to the present disclosure 2 or 3, wherein the (meth)acrylic copolymer contains at least one structural unit selected from the group consisting of structural units derived from hydroxyl group-containing monomers and structural units derived from nitrogen atom-containing monomers.
• the present disclosure 5 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, or 4, which satisfies the above-mentioned second configuration.
• the present disclosure 6 is the pressure-sensitive adhesive tape of the present disclosure 5, wherein the (meth)acrylic copolymer further contains a structural unit derived from a hydroxyl group-containing monomer.
• the present disclosure 7 is the pressure-sensitive adhesive tape according to the present disclosure 4 or 6, wherein the content of the structural unit derived from the hydroxyl group-containing monomer in the (meth)acrylic copolymer is 5% by mass or more and 30% by mass or less.
• the present disclosure 8 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, or 7, wherein the (meth)acrylic copolymer contains a structural unit derived from a (meth)acrylate containing carbon of biological origin.
• the present disclosure 9 is the pressure-sensitive adhesive tape of the present disclosure 8, wherein at least one structural unit selected from the group consisting of the structural unit derived from n-heptyl(meth)acrylate and the structural unit derived from 2-octyl(meth)acrylate contains biologically derived carbon.
• the present disclosure 10 is the pressure-sensitive adhesive tape of the present disclosure 4, 5, 6, 7, 8, or 9, wherein the constituent unit derived from the nitrogen atom-containing monomer includes a constituent unit derived from an amide group-containing monomer.
• the present disclosure 15 is the pressure-sensitive adhesive tape of the present disclosure 14, wherein the content of the structural unit derived from the isobornyl (meth)acrylate in the (meth)acrylic copolymer is 10% by mass or more and 45% by mass or less.
• the present disclosure 16 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15, wherein the (meth)acrylic copolymer has a weight average molecular weight (Mw) of 300,000 or more and 900,000 or less.
• the present disclosure 17 is the pressure-sensitive adhesive tape of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, wherein the pressure-sensitive adhesive layer contains a silane coupling agent.
• the content ratio of the constituent unit derived from the n-heptyl (meth)acrylate or the constituent unit derived from the 2-octyl (meth)acrylate in the (meth)acrylic copolymer can be calculated from the integrated intensity ratio of the hydrogen peak derived from the n-heptyl (meth)acrylate or the 2-octyl (meth)acrylate by performing mass spectrometry and 1 H-NMR measurement of the (meth)acrylic copolymer.
• the content ratio of the structural unit derived from isobornyl (meth)acrylate in the (meth)acrylic copolymer can be calculated from the integrated intensity ratio of the hydrogen peak derived from isobornyl (meth)acrylate by performing mass spectrometry and 1 H-NMR measurement of the (meth)acrylic copolymer.
• the content ratio of the structural unit derived from the hydroxyl group-containing monomer in the (meth)acrylic copolymer can be calculated from the integrated intensity ratio of the hydrogen peak derived from the hydroxyl group-containing monomer by subjecting the (meth)acrylic copolymer to mass spectrometry and 1 H-NMR measurement.
• the preferred lower limit of the content ratio of the constituent unit derived from the nitrogen atom-containing monomer in the (meth)acrylic copolymer is 5% by mass, and the preferred upper limit is 25% by mass.
• the content ratio of the constituent unit derived from the nitrogen atom-containing monomer is 5% by mass or more, the polarity of the pressure-sensitive adhesive layer becomes greater, and the water vapor transmission coefficient P of the pressure-sensitive adhesive layer can be easily adjusted to the above-mentioned range.
• whitening can be further suppressed, and the optical transparency becomes more excellent.
• the preferred lower limit of the total content ratio of the structural units derived from the hydroxyl group-containing monomer and the structural units derived from the nitrogen atom-containing monomer in the (meth)acrylic copolymer is 10% by mass, and the preferred upper limit is 30% by mass.
• the total content ratio of the structural units derived from the hydroxyl group-containing monomer and the structural units derived from the nitrogen atom-containing monomer is 10% by mass or more, the polarity of the pressure-sensitive adhesive layer becomes greater, and the water vapor transmission coefficient P of the pressure-sensitive adhesive layer can be easily adjusted to the above-mentioned range.
• the weight average molecular weight (Mw) of the (meth)acrylic copolymer is preferably 300,000 in lower limit and 900,000 in upper limit.
• Mw weight average molecular weight
• the weight average molecular weight of the (meth)acrylic copolymer is 300,000 or more, the cohesive force of the adhesive layer becomes larger, and the adhesive tape obtained has higher adhesive strength.
• the weight average molecular weight of the (meth)acrylic copolymer is 900,000 or less, the adhesive layer does not become too hard, and the adhesive tape obtained has higher adhesive strength.
• the viscosity of the (meth)acrylic copolymer-containing solution described later is unlikely to become too high, so that the smoothness of the adhesive tape obtained is improved, and the lamination property is more excellent.
• this measurement sample is supplied to a gel permeation chromatograph (for example, "2690 Separations Module” manufactured by Waters, etc.), and GPC measurement is performed under conditions of a sample flow rate of 1 mL/min and a column temperature of 40 ° C.
• the polystyrene-equivalent molecular weight of the (meth)acrylic copolymer is measured, and this value is taken as the weight average molecular weight of the (meth)acrylic copolymer.
• the preferred upper limit of the acid value of the (meth)acrylic copolymer is 5 mgKOH/g. By making the acid value of the (meth)acrylic copolymer 5 mgKOH/g or less, the metal corrosiveness of the obtained pressure-sensitive adhesive tape can be further suppressed.
• the more preferred upper limit of the acid value of the (meth)acrylic copolymer is 1 mgKOH/g.
• the lower limit of the acid value of the (meth)acrylic copolymer is not particularly limited, and may be 0 mgKOH/g.
• the (meth)acrylic copolymer can be obtained by polymerizing a monomer mixture as a raw material through a radical reaction in the presence of a polymerization initiator.
• the radical reaction method include living radical polymerization, free radical polymerization, etc. According to living radical polymerization, a copolymer having a more uniform molecular weight and composition can be obtained compared to free radical polymerization, and the generation of low molecular weight components and the like can be suppressed, so that the cohesive strength of the obtained pressure-sensitive adhesive layer becomes greater, and the adhesive strength of the obtained pressure-sensitive adhesive tape becomes higher.
• the method for polymerizing the monomer mixture may be a conventionally known method, such as solution polymerization (boiling point polymerization or constant temperature polymerization), UV polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc. Among these, solution polymerization and UV polymerization are preferred because the adhesive strength of the resulting adhesive tape is higher.
• solution polymerization is used as the method for polymerizing the above-mentioned monomer mixture, a (meth)acrylic copolymer-containing solution containing the above-mentioned (meth)acrylic copolymer is obtained.
• reaction solvents used in solution polymerization include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, diethyl ether, etc. These reaction solvents may be used alone or in combination of two or more.
• Examples of the polymerization initiator include organic peroxides, azo compounds, etc. Among them, organic peroxides are preferred from the viewpoints that the reaction temperature can be controlled and the molecular weight of the obtained (meth)acrylic polymer can be easily adjusted.
• organic peroxides examples include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, diisobutyryl peroxide, cumylperoxyneodecanoate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, di-sec- Butyl peroxydicarbonate, 1,1,3,3-tetramethylbut
• the azo compound examples include azobisisobutyronitrile and azobiscyclohexanecarbonitrile. These polymerization initiators may be used alone or in combination of two or more kinds.
• the polymerization initiator may be, for example, an organic tellurium polymerization initiator.
• the organic tellurium polymerization initiator is not particularly limited as long as it is one that is generally used in living radical polymerization, and may be, for example, an organic tellurium compound, an organic telluride compound, etc.
• the azo compound may also be used as the polymerization initiator in the living radical polymerization in order to accelerate the polymerization rate.
• the preferred lower limit of the solid content concentration of the (meth)acrylic copolymer-containing solution is 10% by mass, and the preferred upper limit is 80% by mass.
• the more preferred lower limit of the solid content concentration of the (meth)acrylic copolymer-containing solution is 20% by mass, and even more preferred lower limit is 30% by mass, and even more preferred upper limit is 70% by mass, and even more preferred upper limit is 65% by mass.
• solid content refers to the components in a solution other than the solvent.
• the viscosity of the (meth)acrylic copolymer-containing solution at 23° C. is preferably 500 mPa ⁇ s at its lower limit, and 12000 mPa ⁇ s at its upper limit. When the viscosity of the (meth)acrylic copolymer-containing solution at 23° C. is within this range, the adhesion of the resulting adhesive tape is more excellent.
• the viscosity of the (meth)acrylic copolymer-containing solution at 23° C. is more preferably 1000 mPa ⁇ s at its lower limit, and more preferably 2000 mPa ⁇ s at its upper limit, and more preferably 10000 mPa ⁇ s at its upper limit, and more preferably 8000 mPa ⁇ s at its upper limit.
• the viscosity of the (meth)acrylic copolymer-containing solution at 23° C. can be determined, for example, by the following method. That is, 400 mL of the (meth)acrylic copolymer-containing solution is weighed out into a 500 mL plastic cup, and the viscosity at 23° C. is determined by measuring the viscosity at 23° C. and 10 rpm using a Brookfield viscometer.
• a method for adjusting the viscosity of the (meth)acrylic copolymer-containing solution at 23°C to the above-mentioned range a method of adjusting the composition and weight average molecular weight of the (meth)acrylic copolymer, as well as the solids concentration and solvent of the (meth)acrylic copolymer-containing solution is preferred.
• the pressure-sensitive adhesive layer preferably further contains a silane coupling agent.
• a silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, ⁇ -methacryloxypropyltrimethoxysilane, ⁇ -methacryloxypropylmethyldimethoxysilane, ⁇ -glycidoxypropyltrimethoxysilane, ⁇ -glycidoxypropylmethyldimethoxysilane, ⁇ -glycidoxypropylmethyldiethoxysilane, ⁇ -glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, ⁇ -aminopropyltrimethoxysilane, ⁇ -aminopropyltriethoxysilane, ⁇ -aminopropyltriethoxysilane, ⁇ -aminopropyltrimethoxysilane, ⁇ -
• the pressure-sensitive adhesive layer preferably further contains a crosslinking agent.
• a crosslinking agent in the pressure-sensitive adhesive layer, crosslinking of the pressure-sensitive adhesive layer occurs, and the resulting pressure-sensitive adhesive tape has higher adhesive strength and also has improved adhesion to an adherend.
• the crosslinking agent include an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, an epoxy-based crosslinking agent, a metal chelate-type crosslinking agent, etc.
• At least one crosslinking agent selected from the group consisting of an isocyanate-based crosslinking agent, an aziridine-based crosslinking agent, and an epoxy-based crosslinking agent is preferred, and an isocyanate-based crosslinking agent is more preferred, because the pressure-sensitive adhesive tape has excellent adhesion to an adherend and excellent optical transparency even when exposed to a high-temperature and high-humidity environment.
• the content of the crosslinking agent is preferably 0.01 parts by mass at the lower limit and 7 parts by mass at the upper limit relative to 100 parts by mass of the (meth)acrylic copolymer.
• the content of the crosslinking agent being within this range, the shear storage modulus at 23°C of the pressure-sensitive adhesive layer described below is more likely to satisfy an appropriate range, and the adhesive strength of the obtained pressure-sensitive adhesive tape is further increased.
• the more preferred lower limit of the content of the crosslinking agent is 0.1 parts by mass, and the more preferred upper limit is 5 parts by mass.
• the content of the crosslinking agent refers to the amount of solid content of the crosslinking agent.
• the pressure-sensitive adhesive layer may further contain a crosslinking catalyst for promoting crosslinking by the crosslinking agent.
• the crosslinking catalyst include crosslinking catalysts for the isocyanate-based crosslinking agents, such as dibutyltin dilaurate, dibutyltin diacetate, and dioctyltin dilaurate.
• the content of the crosslinking catalyst is preferably 0.001 parts by mass, more preferably 0.01 parts by mass, and more preferably 3 parts by mass, and more preferably 1 part by mass, relative to 100 parts by mass of the (meth)acrylic copolymer.
• the above-mentioned adhesive layer may further contain a tackifier resin from the viewpoint of increasing the adhesive strength of the adhesive tape, but from the viewpoint of increasing optical transparency, it is preferable that the adhesive layer does not contain the above-mentioned tackifier resin.
• the adhesive layer may contain additives such as plasticizers, softeners, fillers, pigments, dyes, etc., as necessary.
• the preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 40% by mass, and the preferred upper limit is 95% by mass.
• the gel fraction of the pressure-sensitive adhesive layer is 40% by mass or more, the durability of the pressure-sensitive adhesive layer against the displacement or deformation of the adherend in a high-temperature and high-humidity environment is higher, and the adhesiveness of the obtained pressure-sensitive adhesive tape to the adherend is also improved.
• the gel fraction of the pressure-sensitive adhesive layer is 95% by mass or less, the pressure-sensitive adhesive layer does not become too hard, and the obtained pressure-sensitive adhesive tape has higher adhesive strength.
• the more preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 45% by mass, and even more preferred lower limit is 50% by mass, and the more preferred upper limit is 92.5% by mass, and even more preferred upper limit is 90% by mass.
• the gel fraction of the pressure-sensitive adhesive layer is measured by the following method. That is, first, the pressure-sensitive adhesive tape having the pressure-sensitive adhesive layer is cut into a flat rectangular shape of 20 mm x 40 mm to prepare a test piece, and the test piece is immersed in ethyl acetate at 23°C for 24 hours, then removed from the ethyl acetate and dried under the condition of 110°C for 1 hour. The mass of the test piece after drying is measured, and the gel fraction is calculated using the following formula (I).
• the test piece is not laminated with a release film for protecting the pressure-sensitive adhesive layer.
• the pressure-sensitive adhesive layer has a preferred lower limit of a shear storage modulus at 23° C. of 0.5 ⁇ 10 5 Pa, and a preferred upper limit of 3.0 ⁇ 10 6 Pa.
• the pressure-sensitive adhesive layer has a shear storage modulus at 23° C. within this range, the resulting pressure-sensitive adhesive tape has higher adhesive strength and is more improved in adhesion to the adherend.
• the pressure-sensitive adhesive layer has a more preferred lower limit of 0.7 ⁇ 10 5 Pa, an even more preferred lower limit of 0.9 ⁇ 10 5 Pa, an even more preferred lower limit of 1.0 ⁇ 10 5 Pa, and a particularly preferred lower limit of 2.0 ⁇ 10 5 Pa, and a more preferred upper limit of 2.0 ⁇ 10 6 Pa, an even more preferred upper limit of 1.0 ⁇ 10 6 Pa, and an even more preferred upper limit of 5.0 ⁇ 10 5 Pa.
• the shear storage modulus at 23° C. of the pressure-sensitive adhesive layer can be determined, for example, by the following method. That is, the adhesive constituting the adhesive layer is applied to the release-treated surface of a release-treated PET film so that the adhesive layer after drying has a thickness of 1000 ⁇ m, and then dried.
• the adhesive layers are stacked to form an adhesive layer having a thickness of 1000 ⁇ m.
• the dynamic viscoelasticity spectrum of the resulting adhesive layer having a thickness of 100 ⁇ m is measured using a dynamic viscoelasticity measuring device (e.g., "DVA-200" manufactured by IT Measurement and Control Co., Ltd.) under conditions of a shear direction, a frequency of 10 Hz, a temperature rise rate of 5° C./min, and a temperature range of -50° C. to 200° C., whereby the shear storage modulus at 23° C. can be obtained.
• a dynamic viscoelasticity measuring device e.g., "DVA-200” manufactured by IT Measurement and Control Co., Ltd.
• a method for adjusting the gel fraction of the pressure-sensitive adhesive layer and the shear storage modulus at 23°C of the pressure-sensitive adhesive layer to the above-mentioned ranges, a method of adjusting the composition and weight average molecular weight of the (meth)acrylic copolymer, and, if the crosslinking agent is used, the type and content of the crosslinking agent, is preferred.
• a preferred method for adjusting the acid value of the pressure-sensitive adhesive layer to the above range is to adjust the composition and acid value of the (meth)acrylic copolymer described above.
• the adhesive tape of the present invention may be a non-supported tape that does not have a substrate, or a supported tape that has a substrate.
• a non-supported tape that does not have a substrate is preferred.
• the adhesive tape of the present invention is a support tape having a substrate
• it may be a single-sided adhesive tape having the above-mentioned adhesive layer on one side of the substrate, or a double-sided adhesive tape having the above-mentioned adhesive layers on both sides of the substrate.
• the substrate is not particularly limited, and any conventionally known substrate can be used. However, in order to increase the content of biological carbon in the entire pressure-sensitive adhesive tape, it is preferable to use a substrate of biological origin.
• the biological substrate include films and nonwoven fabrics containing polyesters (PES) such as plant-derived polyethylene terephthalate (PET), polyethylene furanoate (PEF), polylactic acid (PLA), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).
• PET plant-derived polyethylene terephthalate
• PAF polyethylene furanoate
• PLA polylactic acid
• PTT polytrimethylene terephthalate
• PBT polybutylene terephthalate
• PBS polybutylene succinate
• Other examples include films and nonwoven fabrics containing plant-derived polyethylene (PE), polypropylene (PP), polyurethane (PU), triacetyl cellulose (TAC), cellulose, polyamide
• the substrate is preferably a film containing PES or a film containing PA.
• the substrate is preferably a film containing PA.
• the constituents of the film containing PA include nylon 11, nylon 1010, nylon 610, nylon 510, nylon 410, etc., which are made from castor oil, and nylon 56, etc., which are made from cellulose.
• a substrate made of recycled resources may be used.
• methods for recycling resources include collecting waste from packaging containers, home appliances, automobiles, construction materials, food, and other waste materials generated during manufacturing processes, and using the extracted materials again as raw materials by cleaning, decontamination, or decomposing them by heating or fermentation.
• substrates using the above-mentioned recycled resources include films and nonwoven fabrics made of PET, PBT, PE, PP, PA, and the like, which use recycled plastics re-resinized as raw materials.
• the collected waste materials may be burned and used as thermal energy for the production of substrates and their raw materials, or the oils and fats contained in the collected waste materials may be mixed with petroleum, fractionated, and refined, and used as raw materials.
• the substrate may be a foam substrate from the viewpoint of improving the compression characteristics.
• the foam base material is preferably a foam base material containing at least one selected from the group consisting of PE, PP, and PU, and from the viewpoint of achieving a high degree of both flexibility and strength, a foam base material containing PE is more preferable.
• the constituents of the foam base material containing PE include PE made from sugar cane.
• a preferred method for producing the foam base material is, for example, to prepare a foamable resin composition containing a PE resin containing PE derived from sugar cane and a foaming agent, and then foam the foaming agent when extruding the foamable resin composition into a sheet using an extruder, and crosslink the resulting polyolefin foam as necessary.
• the preferred lower limit of the thickness of the foam substrate is 50 ⁇ m, and the preferred upper limit is 5000 ⁇ m.
• the more preferred upper limit of the thickness of the foam substrate is 1000 ⁇ m, and the even more preferred upper limit is 300 ⁇ m.
• the adhesive tape of the present invention may have layers other than the adhesive layer and the substrate as long as the effects of the present invention are not impaired.
• the method for producing the pressure-sensitive adhesive tape of the present invention is not particularly limited, and the tape can be produced by a conventionally known production method.
• a solution of adhesive A is prepared by adding a solvent to the (meth)acrylic copolymer and, if necessary, a crosslinking agent, etc., and this solution of adhesive A is applied to the surface of a substrate, and the solvent in the solution is completely dried and removed to form an adhesive layer A.
• a release film is superimposed on the formed adhesive layer A with its release-treated surface facing the adhesive layer A.
• a release film other than the above release film is prepared, and a solution of adhesive B prepared in the same manner as above is applied to the release-treated surface of this release film, and the solvent in the solution is completely dried and removed to produce a laminated film in which adhesive layer B is formed on the surface of the release film.
• the obtained laminated film is superimposed on the back surface of the substrate on which adhesive layer A is formed, with adhesive layer B facing the back surface of the substrate to produce a laminate.
• a double-sided adhesive tape having adhesive layers on both sides of the substrate and the surfaces of the adhesive layers covered with release films can be obtained.
• two sets of laminate films may be prepared in a similar manner, and these laminate films may be superimposed on both sides of a substrate with the adhesive layer of the laminate film facing the substrate to produce a laminate.
• a double-sided adhesive tape having adhesive layers on both sides of the substrate and the surface of the adhesive layer covered with a release film may be obtained.
• the pressure-sensitive adhesive tape of the present invention preferably has a haze value (cloudiness) at room temperature (20° C. or higher and 25° C. or lower) (hereinafter, sometimes referred to as "initial haze value at room temperature") of less than 3.0%.
• a haze value at room temperature 20° C. or higher and 25° C. or lower
• the lower limit of the haze value at room temperature is not particularly limited, and the lower the value the better, and the haze value may be 0%.
• the haze value at room temperature can be measured, for example, in accordance with JIS K 7136:2000 using a haze meter (for example, "NDH 400" manufactured by Nippon Denshoku Industries Co., Ltd.).
• the pressure-sensitive adhesive tape of the present invention preferably has a haze value (cloudiness) of less than 3.0% at room temperature (20°C or more and 25°C or less) after standing for 500 hours in an environment of 65°C and 90% RH. Since the haze value at room temperature after standing for 500 hours in the above-mentioned environment of 65°C and 90% RH is less than 3.0%, the pressure-sensitive adhesive tape of the present invention can be suitably used for applications requiring optical transparency, such as adhesion of display panel modules, etc.
• the lower limit of the haze value at room temperature after standing for 500 hours in the above-mentioned environment of 65°C and 90% RH is not particularly limited, and the lower the haze value, the better, and it may be 0%.
• the haze value at room temperature after standing for 500 hours in the above-mentioned environment of 65° C. and 90% RH is measured by the following method. That is, first, two glass plates having a thickness of 0.7 mm, a width of 50 mm, and a length of 80 mm are used, and the glass plates are attached to both sides of an adhesive tape cut to the same size as the glass plates to prepare a test piece. Note that the test piece is not laminated with a release film for protecting the adhesive layer. Next, the obtained test piece is stored in an environment of 65° C. and 90% RH for 500 hours, and then the test piece temperature is returned to room temperature (20° C. or more and 25° C. or less) in an environment of 23° C. and 50% RH.
• the haze value of visible light at room temperature (20° C. or more and 25° C. or less) is measured using a haze meter (e.g., "NDH 400" manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7136:2000.
• a haze meter e.g., "NDH 400” manufactured by Nippon Denshoku Industries Co., Ltd.
• the pressure-sensitive adhesive tape of the present invention has a preferred lower limit of 10 N/25 mm, more preferably 15 N/25 mm, for the 180° peel strength against glass at 23° C.
• the upper limit of the 180° peel strength against glass at 23° C. is not particularly limited, and a higher value is more preferable, but the substantial upper limit is 50 N/25 mm.
• the 180° peel strength to glass at 23° C. is measured by the following method. That is, first, the adhesive tape is cut to a width of 25 mm x length of 75 mm to prepare a test piece.
• test piece is placed on a glass plate so that the adhesive layer faces the glass plate, and then a 2 kg rubber roller is moved back and forth on the test piece at a speed of 300 mm/min to bond it. Then, the test piece is aged at 23°C and 50% RH for 20 minutes to prepare a test sample. Under the conditions of 23°C and 50% RH, the test sample is peeled in the 180° direction at a pulling speed of 300 mm/min to measure the adhesive strength (N/25 mm).
• the adhesive tape is a non-support tape having no substrate or a double-sided adhesive tape having adhesive layers on both sides of the substrate
• the other surface of the adhesive layer (the side not being measured) is backed with a polyethylene terephthalate film having a thickness of 23 ⁇ m (for example, "FE2002" manufactured by Futamura Chemical Co., Ltd.) before being attached to the glass plate.
• the application of the adhesive tape of the present invention is not particularly limited, but it is preferably used for fixing electronic components or in-vehicle components.
• the adhesive tape of the present invention can be suitably used for adhesively fixing electronic components in large portable electronic devices, adhesively fixing in-vehicle components (e.g., in-vehicle panels), etc.
• the present invention can reduce the environmental impact and provide an adhesive tape that has excellent optical transparency even when exposed to high temperature and high humidity environments.
• ⁇ 2-octyl acrylate containing carbon derived from living organisms Ricinoleic acid derived from castor oil was fused with alkali to obtain a mixture containing sepacic acid and 2-octanol. The mixture was then separated from the sepacic acid by distillation to obtain 2-octanol containing carbon derived from living organisms. 2-octanol containing carbon derived from living organisms was esterified with acrylic acid (manufactured by Nippon Shokubai Co., Ltd.) to prepare 2-octyl acrylate.
• Example 44 A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1, except that the type and amount of the monomer constituting the (meth)acrylic copolymer were changed as shown in Table 5, and a polymerization initiator was used instead of azobisisobutyronitrile, and a polymerization initiator solution obtained by diluting a total of 0.51 parts by mass of 1,1-di(t-hexylperoxy)cyclohexane (manufactured by NOF Corp., "Perhexa HC”) and t-hexylperoxypivalate (manufactured by NOF Corp., "Perhexyl PV”) 10 times with ethyl acetate was added to a reaction vessel to obtain an acrylic copolymer-containing solution.
• a polymerization initiator obtained by diluting a total of 0.51 parts by mass of 1,1-di(t-hexylperoxy)cyclohexane (manufactured by NOF Corp
• Example 46 A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1, except that the type and amount of monomers constituting the (meth)acrylic copolymer were changed as shown in Table 5, and instead of azobisisobutyronitrile, a polymerization initiator was used, instead of azobisisobutyronitrile, and a polymerization initiator solution obtained by diluting a total of 0.82 parts by mass of 1,1-di(t-hexylperoxy)cyclohexane (NOF Corp., "Perhexa HC"), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (NOF Corp., "Perocta O"), and t-butyl peroxypivalate (NOF Corp., "Perbutyl PV”) 10 times with ethyl acetate was added to a reaction vessel to obtain a (meth)acrylic copolymer-containing solution.
• a polymerization initiator
• the visible light haze value at the initial room temperature was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., "NDH 400").
• the optical transparency of the adhesive tape was evaluated by rating it as follows: if the obtained haze value was less than 1.0%, it was rated as " ⁇ ", if it was 1.0% or more but less than 3.0%, it was rated as " ⁇ ", and if it was 3.0% or more, it was rated as " ⁇ ".
• Adhesive strength 180° peel strength against glass at 23°C
• One of the release PET films of the obtained adhesive tape was peeled off, and the tape was backed with a 23 ⁇ m thick PET film (manufactured by Futamura Chemical Co., Ltd., "FE2002"), and then cut into a width of 25 mm x length of 75 mm, and the other release PET film was peeled off to prepare a test piece.
• the test piece was placed on a glass plate so that the adhesive layer (the side to be measured) faced the glass plate, and then the test piece was laminated by moving a 2 kg rubber roller back and forth once at a speed of 300 mm/min.
• test piece was aged at 23°C and 50% RH for 20 minutes to prepare a test sample.
• the obtained test sample was peeled in the 180° direction under conditions of 23°C, 50% RH, and a tensile speed of 300 mm/min, and the 180° peel force (N/25 mm) was measured.
• the adhesive strength of the adhesive tape was evaluated as follows: if the 180° peel strength from glass at 23°C was 12 N/mm or more, it was marked " ⁇ "; if it was 8 N/mm or more but less than 12 N/mm, it was marked " ⁇ "; if it was less than 8 N/mm, it was marked " ⁇ ".
• the corrosion of the copper foil was judged as " ⁇ " when no corrosion of the copper foil was observed on either side of the copper foil, and " ⁇ " when corrosion was observed on at least one side of the copper foil, and the metal corrosiveness of the pressure-sensitive adhesive tape was evaluated. Even if the corrosion of the copper foil is judged to be "X", the pressure-sensitive adhesive tape of the present invention can be used without any problem depending on the application.
• a pressure-sensitive adhesive tape which can reduce the environmental load and has excellent optical transparency even when exposed to a high-temperature and high-humidity environment.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Adhesive Tapes (AREA)
• Adhesives Or Adhesive Processes (AREA)

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• 2023
  • 2023-12-26 KR KR1020247041640A patent/KR20250127704A/ko active Pending
  • 2023-12-26 JP JP2024502674A patent/JPWO2024143341A1/ja active Pending
  • 2023-12-26 WO PCT/JP2023/046597 patent/WO2024143341A1/ja not_active Ceased
  • 2023-12-26 CN CN202380051057.1A patent/CN119365556A/zh active Pending
  • 2023-12-27 TW TW112151039A patent/TW202436575A/zh unknown

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