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
  • 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
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/08—Macromolecular additives
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • 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
  • 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 an adhesive tape that can be used in the manufacturing of various products such as electronic devices.
• Adhesive tape is widely used in the manufacturing of various products such as electronic devices and automobiles.
• the adhesive tape is usually required to maintain excellent adhesive strength for a long period of time regardless of the influence of water, heat, or the like.
• adhesive tapes used in the manufacturing of portable electronic devices and the fixing of automobile interior parts which are often touched by humans, retain excellent adhesive strength even when sweat or sebum adheres to them, for example. It is required to have excellent so-called oil resistance, which is possible.
• Examples of the adhesive tape having excellent chemical resistance include (meth) acrylic acid alkyl ester (A1) having an alkyl group having 4 to 12 carbon atoms, 50 to 90% by mass, and a carboxyl group-containing monomer (A2) 3 to 20. Weight%, hydroxyl group-containing monomer (A3) 3 to 20% by mass, and (meth) acrylic acid alkyl ester (A4) having an alkyl group having 1 to 3 carbon atoms (A4) 3 to 15% by mass as a constituent component.
• Adhesive tapes obtained using these materials are known (see, for example, Patent Document 1).
• the frame has been narrowed from the viewpoint of effective use of the screen and design, and the width of the adhesive tape has also been narrowed accordingly (for example, 0.5 to 1.0 mm). ). Therefore, for example, in the technique described in Patent Document 1, the base material is easily stretched, and there is a concern that a problem may occur during processing. In addition, when the bubbles become large, the bubble diameter becomes larger than the tape width, and the waterproof performance is lost. There is a risk that it will end up.
• the adhesive tape with a narrowed width has a small adhesive area, it adheres when it comes into contact with substances such as sweat, sebum, and alcohol, even if the amount of adhesion is small, as compared with the adhesive tape with a wide width. It is particularly susceptible to the effects of a decrease in force over time, and higher oil resistance is required.
• the problem to be solved by the present invention is to provide an adhesive tape which can maintain excellent adhesive force for a long period of time and has excellent impact resistance even when sweat, sebum, etc. adhere to it. be.
• the present inventor has one or more types other than a carboxyl group-containing monomer having a specific content, a hydroxyl group-containing monomer having a specific content, a carboxyl group-containing monomer having an average carbon atom number of less than 4, and a hydroxyl group-containing monomer.
• An acrylic copolymer in which an alkyl (meth) acrylate monomer and an alicyclic monomer are selected and combined with the alkyl (meth) acrylate monomer and an acrylic pressure-sensitive adhesive containing a cross-linking agent, and a viscoelastic material layer containing hollow particles or bubbles are formed. It has been found that the above-mentioned problems can be solved if the adhesive tape is provided.
• the acrylic copolymer comprises an acrylic pressure-sensitive adhesive containing an acrylic copolymer and a cross-linking agent and a viscoelastic material layer containing hollow particles or bubbles
• the acrylic copolymer is: (A) Carboxylic group-containing monomer and (B) Hydroxy group-containing monomer and (C)
• One or more selected from the group consisting of alkyl (meth) acrylate monomers and alicyclic monomers other than (A) and (B) is contained as a constituent component, and the monomer of (C) is said. It relates to an adhesive tape having an average number of carbon atoms of less than 4.
• the adhesive tape of the present invention has good initial adhesive strength, does not easily swell even when sweat or sebum adheres to it, maintains excellent adhesive strength for a long period of time, and has excellent impact resistance. Has.
• the pressure-sensitive adhesive tape of the present invention comprises an acrylic pressure-sensitive adhesive containing an acrylic copolymer and a cross-linking agent, and a viscoelastic material layer containing hollow particles or bubbles.
• One or more selected from the group consisting of alkyl (meth) acrylate monomers and alicyclic monomers other than (A) and (B) is contained as a constituent component, and the monomer of (C) is said.
• the present invention relates to an adhesive tape having an average carbon atom number of less than 4 calculated from the following formula.
• Average number of carbon atoms [ ⁇ Total (X) of the product of the molar ratio (mol%) of the alkyl (meth) acrylate monomer to the (C) and the number of carbon atoms of the alkyl group of the alkyl (meth) acrylate monomer. ) ⁇ + ⁇ Total (Y) ⁇ / 100 of the product of the molar ratio (mol%) of the alicyclic monomer to the (C) and the number of carbon atoms of the alicyclic group of the alicyclic monomer.
• a so-called base material-less adhesive tape composed of the viscoelastic body layer has the adhesive layer directly or via another layer on one side or both sides of the viscoelastic body layer. Adhesive tape and the like can be mentioned.
• the viscoelastic body layer and the pressure-sensitive adhesive layer may each have a single structure or a multi-layer structure of two or more layers. Further, a supporting base material or an adhesive layer may be arranged on one side or both sides of the viscoelastic body layer.
• the pressure-sensitive adhesives constituting each layer may have the same or different composition such as resin composition and additives.
• the acrylic pressure-sensitive adhesive used for the viscoelastic body layer includes a carboxyl group-containing monomer (A), a hydroxyl group-containing monomer (B), an alkyl (meth) acrylate monomer other than (A) and (B), and an alicyclic monomer.
• Acrylic copolymer (C) composed of a copolymer containing one or more selected from the above group as a constituent component is used as a base polymer, and a tackifier resin, a cross-linking agent, or the like is added to the base polymer as necessary.
• a (meth) acrylic pressure-sensitive adhesive containing the agent can be used.
• Examples of the (A) carboxyl group-containing monomer that can be used in the production of the acrylic copolymer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, (meth) acrylic acid dimer, crotonic acid, and ethylene oxide-modified amber. Acid acrylates and the like can be used, and among them, it is preferable to use acrylic acid as a copolymerization component in order to exhibit even better oil resistance against sweat, sebum, alcohol and the like.
• the total amount of (A) to (C) used in producing the acrylic copolymer and the total amount of other vinyl monomers other than (A) to (C) described later (hereinafter, acrylic monomer).
• the content of the carboxyl group-containing monomer with respect to the total amount) is not particularly limited, but is preferably in the range of 2 to 30% by mass, more preferably in the range of 4.1 to 25% by mass, and 5.3 to 20% by mass. This is particularly preferable for exhibiting even more excellent oil resistance and impact resistance against sweat, sebum, alcohol and the like.
• Examples of the (B) hydroxyl group-containing monomer that can be used in the production of the acrylic copolymer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
• a hydroxyl group-containing (meth) acrylate such as 6-hydroxyhexyl (meth) acrylate can be used.
• the content of the hydroxyl group-containing monomer with respect to the total amount of the acrylic monomers that can be used in producing the acrylic copolymer is not particularly limited, but is preferably in the range of 0.01 to 1.0% by mass, preferably 0.01 to 1.0%.
• the range of 0.85% by mass is more preferable, 0.02 to 0.7% by mass is further preferable, and 0.03 to 0.5% by mass is particularly preferable, and 0.04 to 0.3 by mass. It is even more preferably mass%, and even more preferably 0.05 to 0.2 mass%. Within the above range, it is easy to develop even better oil resistance against sweat, sebum and the like.
• the alkyl (meth) acrylate monomer of (C) is a (meth) acrylate having an alkyl group at the ester terminal.
• the alkyl group contained in the alkyl (meth) acrylate monomer may be a straight chain or a branched chain.
• Examples of the alkyl (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth) acrylate.
• N-Hexyl (meth) acrylate N-Hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isostearyl (meth) acrylate, etc.
• Examples thereof include (meth) acrylate having 1 to 18 atoms, and one or more of these can be used, but it is preferable to use two or more of them.
• a (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms it is preferable to use a (meth) acrylate monomer having 1 to 10 carbon atoms.
• the alicyclic monomer (C) has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and has an alicyclic structure-containing group.
• the "alicyclic structure-containing group” refers to a substituent containing at least one alicyclic structure, and may be hereinafter referred to as an alicyclic group.
• the alicyclic group include a hydrocarbon having an alicyclic structure and a hydrocarbon oxy group.
• Examples of the alicyclic monomer include isobornyl (meth) acrylate and cyclohexyl (meth) acrylate.
• the average number of carbon atoms calculated from the following formula of one or more selected from the group consisting of the alkyl (meth) acrylate monomer and the alicyclic monomer of (C) is less than 4, but 2.1. It is preferably in the range of ⁇ 3.9, more preferably in the range of 2.5 to 3.8, and more preferably in the range of 2.6 to 3.8 or less, 2.7 to 3 It is particularly preferably in the range of 6.6. In particular, when n-butyl acrylate and at least one of methyl acrylate and ethyl acrylate are used in the above range to have a good initial adhesive strength and sweat, sebum, alcohol, etc. are attached. However, it does not swell easily and can maintain excellent adhesive strength and impact resistance for a long period of time.
• the average number of carbon atoms is calculated as follows. For the alkyl (meth) acrylate monomer contained as (C), the product of the number of carbon atoms of each alkyl group and the mole fraction (mol%) of the alkyl (meth) acrylate monomer in (C) is calculated. Similarly, for the alicyclic monomer contained as (C), the product of the number of carbon atoms of each alicyclic group and the molar fraction (mol%) of the alicyclic monomer in (C) is calculated.
• the total of the products calculated for each alkyl (meth) acrylate monomer and alicyclic monomer contained in (C) is selected from the group consisting of the alkyl (meth) acrylate monomer and alicyclic monomer of (C).
• the alkyl (meth) acrylate monomer having an alkyl group having A carbon atoms is a (mol%) and the alkyl having carbon atoms B is.
• Average number of carbon atoms [ ⁇ Total (X) of the product of the mole fraction (mol%) of the alkyl (meth) acrylate monomer with respect to (C) and the number of carbon atoms of the alkyl group of the alkyl (meth) acrylate monomer. ) ⁇ / 100]
• the alkyl (meth) acrylate monomer having an alkyl group having an carbon atom number A is a (mol%)
• the alkyl (meth) acrylate monomer having an alkyl group having a carbon atom number B is a (mol%).
• the amount is preferably 70% by mass or more, more preferably 79 to 98% by mass, and even more preferably 84 to 95.7% by mass.
• vinyl monomers other than (A) to (C) can be used, and as the other vinyl monomers, a vinyl monomer having an amide group and a monomer having a sulfonic acid group can be used.
• Vinyl ether monomer, monomer having an alkoxy group, macromonomer having a radically polymerizable vinyl group in the molecule, and the like can be used.
• the amount used should be appropriately selected so that it does not easily swell even when sweat, sebum, alcohol, etc. adhere to it, and excellent adhesive strength and impact resistance are realized over a long period of time. Just do it.
• the content of the other vinyl monomer with respect to the total amount of the acrylic monomer that can be used in producing the acrylic copolymer is relative to the total amount of the acrylic monomer that can be used in producing the acrylic copolymer. 2 to 15% by mass is preferable, and 2.5 to 10% by mass is more preferable.
• the acrylic copolymer can be obtained by copolymerizing with a known polymerization method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, or an emulsion polymerization method, but the solution polymerization method is used because of the water resistance of the pressure-sensitive adhesive. Or a lumpy polymerization method is preferable, and when n-butyl acrylate, methyl acrylate, or ethyl acrylate among the alkyl (meth) acrylate monomer and alicyclic monomer of the above (C) is used as a main component, a solution is used from the viewpoint of safety.
• the polymerization method is preferable.
• the polymerization initiation method is a thermal initiation method using a peroxide-based thermal polymerization initiator such as benzoyl peroxide or lauroyl peroxide, or an azo-based thermal polymerization initiator such as azobisisobutylnitrile, or an acetophenone-based, benzoin ether-based, or benzyl polymerization method.
• a peroxide-based thermal polymerization initiator such as benzoyl peroxide or lauroyl peroxide
• an azo-based thermal polymerization initiator such as azobisisobutylnitrile
• an acetophenone-based, benzoin ether-based or benzyl polymerization method.
• the starting method by ultraviolet irradiation using a ketal-based, acylphosphine oxide-based, benzoin-based, or benzophenone-based photopolymerization initiator, or the method by electron beam irradiation can be arbitrari
• the weight average molecular weight in terms of standard polystyrene measured by gel permeation chromatography is preferably 400,000 or more, and preferably 450,000 to 3 million. More preferably, it is 500 to 2 million in order to exhibit further excellent oil resistance against sweat, sebum, alcohol and the like.
• the measurement of the molecular weight by the GPC method is a standard polystyrene conversion value measured by using a GPC device (HLC-8320GPC) manufactured by Tosoh Corporation, and the measurement conditions are as follows.
• the viscoelastic body layer of the adhesive tape of the present invention preferably has a temperature of ⁇ 40 ° C. to 5 ° C., which indicates a peak value of loss tangent (tan ⁇ ) at a frequency of 1 Hz.
• the temperature is more preferably ⁇ 35 ° C. to 3 ° C., and further preferably ⁇ 25 ° C. to 0 ° C.
• the viscoelastic body layer is composed of a mixture or laminate of pressure-sensitive adhesive compositions having different compositions and there are a plurality of peak values of loss tangent (tan ⁇ ), any one of them may be within the above range. It is preferable that the peak values on the low temperature side are within the above range, and it is more preferable that all the peak values are within the above range.
• a viscoelasticity tester manufactured by TA Instruments Japan, trade name: ARES G2
• ARES G2 was used to form a pressure-sensitive adhesive layer with a thickness of about 2 mm.
• a test piece is sandwiched between parallel disks made of stainless steel having a diameter of 8 mm, which is a measuring unit of the above, and the storage elastic modulus (G') and the loss elastic modulus (G ”) from -60 ° C. to 150 ° C. are measured at a frequency of 1 Hz.
• the viscoelastic body layer shall contain hollow particles or air bubbles.
• the viscoelastic body layer has even better oil resistance and resistance to sweat, sebum, alcohol, etc. by applying the acrylic copolymer and forming a hollow structure by containing hollow particles or bubbles. It can be an adhesive tape that has both impact resistance.
• a form containing hollow particles is preferable from the viewpoint of oil resistance and impact resistance, and it is particularly preferable to use hollow particles made of glass or thermoplastic resin.
• the hollow particles if they are made of a thermoplastic resin, the impact resistance can be further improved, and as the hollow particles made of a thermoplastic resin, the thermoplastic resin is used as the outer shell and carbon such as heptane, hexane, or isobutane is inside the outer shell. It is particularly preferable to use thermally expandable microcapsules in which a thermoplastic agent such as a saturated hydrocarbon having a number of 4 to 7 is encapsulated.
• the heat-expandable microcapsules can be appropriately expanded by heating and used, and since the thickness accuracy of the viscoelastic base material and the ease of manufacturing are easy, the use of pre-expanded heat-expandable microcapsules is preferable.
• the hollow particles made of a thermoplastic resin are preferably one obtained by polymerizing a vinyl monomer having a glass transition temperature of a homopolymer of 80 ° C., preferably 100 ° C. or higher as the thermoplastic resin constituting the outer shell, and acrylonitrile or metaacrylonitrile.
• a thermoplastic resin containing methyl methacrylate as a main component is more preferable in exhibiting even more excellent oil resistance and impact resistance against sweat, sebum, alcohol and the like.
• the average particle size of the hollow particles is preferably equal to or less than the thickness of the viscoelastic body layer, preferably 90% or less, and more preferably 20 to 50% with respect to the thickness of the viscoelastic body layer. Within the above range, 150 ⁇ m or less is preferable, 10 to 90 ⁇ m is more preferable, and 20 to 60 ⁇ m is particularly preferable because sufficient impact resistance can be obtained without impairing the initial adhesion.
• the average particle size of the hollow particles is, for example, a 50% average particle size performed using a laser light scattering type particle size distribution measuring device.
• the true specific gravity of the hollow particles is not particularly limited, but in consideration of the mechanical strength and uniform dispersibility of the hollow particles, 0.01 to 0.50 g / cm 3 , preferably 0.01 to 0.30 g / cm 3 , More preferably selected from the range of 0.02 to 0.20 g / cm 3.
• the amount of hollow particles used in the viscoelastic body layer is preferably 5 to 60% by volume, more preferably 15 to 45% by volume, based on the total amount of the pressure-sensitive adhesive used in the viscoelastic body layer. Within this range, sufficient impact resistance can be obtained, and the tensile strength of the viscoelastic body layer becomes strong, so that excellent punching suitability can be obtained.
• a stirrer such as a mixer or a dissolver can be adopted as an arbitrary dispersion method as long as the effects of the present invention are not impaired.
• the apparent density of the viscoelastic body layer is not particularly limited, but 0.50 to 1.1 g / cm 3 , preferably 0. It is 60 to 1.0 g / cm 3 , more preferably 0.7 to 1.0 g / cm 3 .
• the apparent density was measured according to JIS K6767. A viscoelastic body layer (thickness has been measured) cut into a rectangle of 4 cm ⁇ 5 cm is prepared for about 15 cm for 3 minutes, and its mass is measured to determine the apparent density.
• acrylic pressure-sensitive adhesive that can be used in the present invention, one containing a tack-imparting resin can be used in order to obtain a pressure-sensitive adhesive sheet having even better adhesiveness.
• tackifier resin examples include a rosin-based tackifier resin, a polymerized rosin-based tackifier resin, a polymerized rosin ester-based tackifier resin, a rosinphenol-based tackifier resin, a stabilized rosin ester-based tackifier resin, and a disproportionate rosin ester.
• a system-based adhesive-imparting resin, a hydrogenated rosin ester-based adhesive-imparting resin, a terpene-based adhesive-imparting resin, a terpene-phenol-based adhesive-imparting resin, a petroleum resin-based adhesive-imparting resin, a (meth) acrylate resin-based adhesive-imparting resin, etc. can be used. ..
• the softening point of the tackifier resin is not particularly specified, but is 30 to 180 ° C., preferably 40 ° C. to 140 ° C.
• the content of the pressure-sensitive adhesive resin is not particularly limited as long as the temperature indicating the peak value of the loss tangent (tan ⁇ ) at a frequency of 1 Hz of the viscoelastic body layer is within the range of ⁇ 40 ° C. to 5 ° C., but the acrylic pressure-sensitive adhesive.
• the resin solid content in the agent is 50 parts by mass or less with respect to 100 parts by mass, it is preferably 35 parts by mass or less in order to exhibit further excellent oil resistance against sweat, sebum and the like. It is more preferable that the content is in the range of parts by mass or less.
• two or more kinds of the tackifier resin may be used in combination.
• the viscoelastic body layer is crosslinked with a cross-linking agent in order to have even more excellent cohesive force.
• a cross-linking agent As an index of the degree of cross-linking of the pressure-sensitive adhesive layer, the value of the gel fraction for measuring the insoluble content after immersing the pressure-sensitive adhesive layer in toluene for 24 hours is used.
• the gel fraction is preferably in the range of 20% by mass to 90% by mass, more preferably 30% by mass to 80% by mass, and further preferably 30% by mass to 70% by mass, both cohesiveness and adhesiveness are good. Is.
• cross-linking agent a cross-linking agent conventionally known or commonly used in the field of acrylic pressure-sensitive adhesives can be used.
• an isocyanate-based cross-linking agent an epoxy-based cross-linking agent, a metal chelate-based cross-linking agent, an aziridine-based cross-linking agent, an oxazoline-based cross-linking agent and the like can be used.
• a cross-linking agent which is easy to use by mixing with the previously produced acrylic copolymer or a solution thereof and capable of rapidly advancing the cross-linking reaction, and specifically, isocyanate.
• a system-based cross-linking agent or an epoxy-based cross-linking agent may be used alone or in combination of two or more.
• isocyanate-based cross-linking agent for example, tolylene diisocyanate, naphthylene-1,5-diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane-modified tolylene diisocyanate and the like can be used.
• Trimethylolpropane-modified tolylene diisocyanate is preferably used.
• epoxy-based cross-linking agent examples include N, N'-(cyclohexane-1,3-diylbismethylene) bis (diglycidylamine), N, N, N', N'-tetraglycidyl-1,3-benzenedi. (Methyleneamine) and the like are preferable.
• the amount of the cross-linking agent used is not particularly limited as long as it can be adjusted to the gel content, but is preferably 0.001 part by mass to 5.0 parts by mass with respect to 100 parts by mass of the resin solid content in the acrylic pressure-sensitive adhesive, but sweat. It is more preferably 0.01 part by mass to 4.3 parts by mass in order to exhibit further excellent oil resistance against oil and skin oil.
• the acrylic pressure-sensitive adhesive it is preferable to use a coating liquid containing a solvent in order to maintain its good coating workability and the like.
• a solvent for example, toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, hexane and the like can be used.
• the ratio of ethyl acetate to the total solvent components is preferably 70% by mass or more, more preferably 90% by mass or more.
• the solid content concentration (acrylic resin) is not particularly limited, but is preferably 10 to 80% by mass.
• the viscoelastic body layer may be colored in order to exhibit designability, light shielding property, hiding property, light reflection property, and light resistance in the adhesive tape.
• the colorants can be used alone or in combination of two or more.
• the viscoelastic body layer is colored black.
• Black colorants include carbon black, graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite, magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, and composite oxidation.
• a physical black dye, an anthraquinone organic black dye, or the like can be used. Of these, carbon black is preferable from the viewpoint of cost, availability, and insulation.
• the viscoelastic body layer When imparting design and light reflectivity to the adhesive tape, the viscoelastic body layer is colored white.
• White colorants include titanium oxide, zinc oxide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, calcium oxide, tin oxide, barium oxide, cesium oxide, yttrium oxide, magnesium carbonate, calcium carbonate, barium carbonate, zinc carbonate.
• Inorganic white colorants such as titanium, mica, gypsum, white carbon, diatomaceous soil, bentonite, lithopon, zeolite, sericite, and organics such as silicone resin particles, acrylic resin particles, urethane resin particles, and melamine resin particles.
• a white colorant or the like can be used.
• aluminum oxide, zinc oxide, and calcium carbonate are preferable from the viewpoint of cost, availability, and color tone.
• a plasticizer an antioxidant, a leveling agent, a flame retardant such as aluminum hydroxide or magnesium hydroxide, an antioxidant, particles or fibers made of glass or plastic.
• Metal powder, fillers such as metal compounds, conductive fillers, heat conductive fillers, and other known additives may be optionally contained in the resin.
• the viscoelastic body layer used for the pressure-sensitive adhesive sheet of the present invention in order to maintain appropriate followability and cushioning property, the above addition is made to 100 parts by mass of the resin solid content in the acrylic pressure-sensitive adhesive constituting the viscoelastic body layer.
• the total amount of the agents is preferably in the range of 0.1% by mass to 10% by mass, and more preferably in the range of 1% by mass to 7% by mass.
• the thickness of the viscoelastic body layer constituting the adhesive tape of the present invention is 20 ⁇ m to 500 ⁇ m in order to have even better oil resistance against sweat, sebum, etc. and to contribute to the thinning of electronic devices and the like. It is preferable to use one having a thickness in the range of 25 ⁇ m to 400 ⁇ m, more preferably one having a thickness in the range of 25 ⁇ m to 400 ⁇ m, and one having a thickness in the range of 30 ⁇ m to 300 ⁇ m. More preferred. By setting the thickness of the viscoelastic body layer within the above range, it is possible to exhibit suitable adhesive force and impact resistance for an adherend having an uneven shape, a 3D shape, and a rough surface.
• the viscoelastic body layer a layer in which a plurality of layers (preferably two or three layers) are laminated is preferable.
• a viscoelastic body layer having a thickness of 90 ⁇ m or more is prepared from the coating liquid of the acrylic pressure-sensitive adhesive, an adhesive having a thickness of less than 90 ⁇ m is prepared in order to prevent appearance defects due to foaming of a solvent generated during drying. It is preferable to stack the sheets.
• a plurality of viscoelastic body layers are laminated to form as described above, it is easy to obtain an adhesive tape having impact resistance. It is considered that this is because when the viscoelastic body layer is a laminated body of a plurality of layers, the hollow particles in the viscoelastic body layer are likely to be uniformly dispersed.
• the viscoelastic body layer in the present invention with the above-mentioned viscoelastic properties and the like, even when sweat, sebum or the like adheres to the layer while maintaining the properties of the conventional adhesive tape as a base material. It can be used as a layer that also has adhesive properties that maintain excellent adhesive strength.
• the carboxyl group-containing monomer is composed of (A), the hydroxyl group-containing monomer (B), and the alkyl (meth) acrylate monomer and the alicyclic monomer other than (A) and (B).
• the base polymer is an acrylic copolymer (C) composed of a copolymer containing one or more selected from the above group as a constituent component, and if necessary, a tackifier resin, a cross-linking agent, etc. may be used.
• a (meth) acrylic pressure-sensitive adhesive containing an additive can be used.
• Examples of the (A) carboxyl group-containing monomer that can be used in the production of the acrylic copolymer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, (meth) acrylic acid dimer, crotonic acid, and ethylene oxide-modified amber. Acid acrylates and the like can be used, and it is particularly preferable to use acrylic acid as a copolymerization component in order to exhibit even better oil resistance and impact resistance against sweat, sebum, alcohol and the like.
• the total amount of (A) to (C) used in producing the acrylic copolymer and the total amount of other vinyl monomers other than (A) to (C) described later (hereinafter, acrylic monomer).
• the content of the carboxyl group-containing monomer with respect to the total amount) is not particularly limited, but is preferably in the range of 2 to 30% by mass, more preferably in the range of 4.1 to 25% by mass, and 5.3 to 20% by mass. This is particularly preferable for exhibiting even more excellent oil resistance and impact resistance against sweat, sebum, alcohol and the like.
• Examples of the (B) hydroxyl group-containing monomer that can be used in the production of the acrylic copolymer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
• a hydroxyl group-containing (meth) acrylate such as 6-hydroxyhexyl (meth) acrylate can be used.
• the content of the hydroxyl group-containing monomer with respect to the total amount of the acrylic monomers that can be used in producing the acrylic copolymer is not particularly limited, but is preferably in the range of 0.01 to 1.0% by mass, preferably 0.01 to 1.0%.
• the range of 0.85% by mass is more preferable, 0.02 to 0.7% by mass is further preferable, and 0.03 to 0.5% by mass is particularly preferable, and 0.04 to 0.3 by mass. It is even more preferably mass%, and even more preferably 0.05 to 0.2 mass%. Within the above range, it is easy to develop even better oil resistance against sweat, sebum and the like.
• the alkyl (meth) acrylate monomer of (C) is a (meth) acrylate having an alkyl group at the ester terminal.
• the alkyl group contained in the alkyl (meth) acrylate monomer may be a straight chain or a branched chain.
• Examples of the alkyl (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth) acrylate.
• Examples thereof include (meth) acrylates having a number of 1 to 18, and one or more of these can be used, but it is preferable to use two or more of them.
• a (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms it is preferable to use a (meth) acrylate monomer having 1 to 10 carbon atoms.
• the alicyclic monomer (C) has a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and has an alicyclic structure-containing group.
• the "alicyclic structure-containing group” refers to a substituent containing at least one alicyclic structure, and may be hereinafter referred to as an alicyclic group.
• the alicyclic group include a hydrocarbon having an alicyclic structure and a hydrocarbon oxy group.
• Examples of the alicyclic monomer include isobornyl (meth) acrylate and cyclohexyl (meth) acrylate.
• the average number of carbon atoms of one or more selected from the group consisting of the alkyl (meth) acrylate monomer and the alicyclic monomer of (C) is less than 4, but 2.1 to 3.9.
• the range is preferably in the range of 2.5 to 3.8, more preferably in the range of 2.6 to 3.8 or less, and more preferably in the range of 2.7 to 3.6. It is particularly preferable to have.
• n-butyl acrylate and at least one of methyl acrylate and ethyl acrylate are used in the above range to have a good initial adhesive strength and sweat, sebum, alcohol, etc. are attached. However, it does not swell easily and can maintain excellent adhesive strength and impact resistance for a long period of time.
• the average number of carbon atoms possessed by one or more selected from the group consisting of the alkyl (meth) acrylate monomer and the alicyclic monomer of (C) is calculated as follows. For the alkyl (meth) acrylate monomer contained as (C), the product of the number of carbon atoms of each alkyl group and the mole fraction (mol%) of the alkyl (meth) acrylate monomer in (C) is calculated. Similarly, for the alicyclic monomer contained as (C), the product of the number of carbon atoms of each alicyclic group and the molar fraction (mol%) of the alicyclic monomer in (C) is calculated.
• the total of the products calculated for each alkyl (meth) acrylate monomer and alicyclic monomer contained in (C) is selected from the group consisting of the alkyl (meth) acrylate monomer and alicyclic monomer of (C).
• the alkyl (meth) acrylate monomer having an alkyl group having A carbon atoms is a (mol%) and the alkyl having carbon atoms B is.
• Average number of carbon atoms [ ⁇ Total (X) of the product of the mole fraction (mol%) of the alkyl (meth) acrylate monomer with respect to (C) and the number of carbon atoms of the alkyl group of the alkyl (meth) acrylate monomer. ) ⁇ / 100]
• the alkyl (meth) acrylate monomer having an alkyl group having an carbon atom number A is a (mol%)
• the alkyl (meth) acrylate monomer having an alkyl group having a carbon atom number B is a (mol%).
• the amount is preferably 70% by mass or more, more preferably 79 to 98% by mass, and even more preferably 84 to 95.7% by mass.
• vinyl monomers other than (A) to (C) can be used, and as the other vinyl monomers, a vinyl monomer having an amide group and a monomer having a sulfonic acid group can be used.
• Vinyl ether monomer, monomer having an alkoxy group, macromonomer having a radically polymerizable vinyl group in the molecule, and the like can be used.
• the amount used should be appropriately selected so that it does not easily swell even when sweat, sebum, alcohol, etc. adhere to it, and excellent adhesive strength and impact resistance are realized over a long period of time. Just do it.
• the content of the other vinyl monomer is preferably 2 to 15% by mass, more preferably 2.5 to 10% by mass, based on the total amount of the acrylic monomer that can be used in producing the acrylic copolymer. preferable.
• the acrylic copolymer can be obtained by copolymerizing with a known polymerization method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, etc., but the solution polymerization method is used because of the water resistance of the pressure-sensitive adhesive. Or a lumpy polymerization method is preferable, and when n-butyl acrylate, methyl acrylate, or ethyl acrylate among the alkyl (meth) acrylate monomers of the above (C) is used as a main component, the solution polymerization method is preferable from the viewpoint of safety.
• a known polymerization method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, etc.
• the solution polymerization method is used because of the water resistance of the pressure-sensitive adhesive.
• a lumpy polymerization method is preferable, and when n-
• the polymerization initiation method is a thermal initiation method using a peroxide-based thermal polymerization initiator such as benzoyl peroxide or lauroyl peroxide, or an azo-based thermal polymerization initiator such as azobisisobutylnitrile, or an acetophenone-based, benzoin ether-based, or benzyl polymerization method.
• a peroxide-based thermal polymerization initiator such as benzoyl peroxide or lauroyl peroxide
• an azo-based thermal polymerization initiator such as azobisisobutylnitrile
• an acetophenone-based, benzoin ether-based or benzyl polymerization method.
• the starting method by ultraviolet irradiation using a ketal-based, acylphosphine oxide-based, benzoin-based, or benzophenone-based photopolymerization initiator, or the method by electron beam irradiation can be arbitrari
• the weight average molecular weight in terms of standard polystyrene measured by gel permeation chromatography is preferably 400,000 or more, and preferably 450,000 to 3 million. More preferably, it is 500 to 2 million in order to exhibit further excellent oil resistance against sweat, sebum, alcohol and the like.
• the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape of the present invention preferably has a temperature at which the peak value of loss tangent (tan ⁇ ) at a frequency of 1 Hz is ⁇ 40 ° C. to 5 ° C.
• the temperature is more preferably ⁇ 35 ° C. to 3 ° C., and further preferably ⁇ 25 ° C. to 0 ° C.
• the viscoelastic body layer is composed of a mixture or laminate of pressure-sensitive adhesive compositions having different compositions and there are a plurality of peak values of loss tangent (tan ⁇ ), any one of them may be within the above range. It is preferable that the peak values on the low temperature side are within the above range, and it is more preferable that all the peak values are within the above range.
• the hollow structure may be introduced as the pressure-sensitive adhesive layer contains hollow particles or air bubbles like the viscoelastic body layer.
• both sides The hollow structure may be introduced into the adhesive layer of the above, and the hollow structure is introduced into the adhesive layer on the side to be attached to the first adherend, and the adhesive layer on the side to be attached to the second and subsequent adherends is A configuration that does not introduce a hollow structure may be used.
• the introduction of the hollow structure is preferably in the form of containing hollow particles from the viewpoint of chemical resistance and impact resistance, and it is particularly preferable to use hollow particles made of glass or thermoplastic resin.
• the hollow particles if they are made of a thermoplastic resin, the impact resistance can be further improved, and as the hollow particles made of a thermoplastic resin, the thermoplastic resin is used as the outer shell and carbon such as heptane, hexane, or isobutane is inside the outer shell. It is particularly preferable to use thermally expandable microcapsules in which a thermoplastic agent such as a saturated hydrocarbon having a number of 4 to 7 is encapsulated.
• the heat-expandable microcapsules can be appropriately expanded by heating and used, and since the thickness accuracy of the viscoelastic base material and the ease of manufacturing are easy, the use of pre-expanded heat-expandable microcapsules is preferable.
• the hollow particles made of a thermoplastic resin are preferably one obtained by polymerizing a vinyl monomer having a glass transition temperature of a homopolymer of 80 ° C., preferably 100 ° C. or higher as the thermoplastic resin constituting the outer shell, and acrylonitrile or metaacrylonitrile.
• a thermoplastic resin containing methyl methacrylate as a main component is more preferable in exhibiting even more excellent oil resistance and impact resistance against sweat, sebum, alcohol and the like.
• the average particle size of the hollow particles is preferably equal to or less than the thickness of the pressure-sensitive adhesive layer, preferably 90% or less, more preferably 50% or less, and more preferably 20 to 40% with respect to the thickness of the pressure-sensitive adhesive layer. preferable. Within the above range, 100 ⁇ m or less is preferable, 10 to 80 ⁇ m is preferable, and 20 to 60 ⁇ m is preferable because sufficient impact resistance can be obtained without impairing the initial adhesion.
• the average particle size of the hollow particles is, for example, a 50% average particle size performed using a laser light scattering type particle size distribution measuring device.
• the true specific gravity of the hollow particles is not particularly limited, but in consideration of the mechanical strength and uniform dispersibility of the hollow particles, 0.01 to 0.50 g / cm 3 , preferably 0.01 to 0.30 g / cm. 3 , more preferably selected from the range of 0.02 to 0.20 g / cm 3.
• the amount of hollow particles used in the viscoelastic body layer is preferably 5 to 60% by volume, more preferably 15 to 45% by volume, based on the total amount of the pressure-sensitive adhesive used in the viscoelastic body layer. Within this range, sufficient impact resistance can be obtained, and the tensile strength of the viscoelastic body layer becomes strong, so that excellent punching suitability can be obtained.
• a stirrer such as a mixer or a dissolver can be adopted as an arbitrary dispersion method as long as the effect of the present invention is not impaired.
• the apparent density of the pressure-sensitive adhesive layer is not particularly limited, but 0.50 to 1.1 g / cm 3 , preferably 0.60, because it is easy to achieve both impact resistance and excellent adhesion to the adherend. It is ⁇ 1.0 g / cm 3 , more preferably 0.7 ⁇ 1.0 g / cm 3 .
• the apparent density was measured according to JIS K6767. Prepare an adhesive layer (thickness has been measured) cut into a rectangle of 4 cm ⁇ 5 cm for about 15 cm for 3 minutes, and measure the mass to determine the apparent density.
• acrylic pressure-sensitive adhesive that can be used in the present invention, one containing a tack-imparting resin can be used in order to obtain a pressure-sensitive adhesive sheet having even better adhesiveness.
• tackifier resin examples include a rosin-based tackifier resin, a polymerized rosin-based tackifier resin, a polymerized rosin ester-based tackifier resin, a rosinphenol-based tackifier resin, a stabilized rosin ester-based tackifier resin, and a disproportionate rosin ester.
• a system-based adhesive-imparting resin, a hydrogenated rosin ester-based adhesive-imparting resin, a terpene-based adhesive-imparting resin, a terpene-phenol-based adhesive-imparting resin, a petroleum resin-based adhesive-imparting resin, a (meth) acrylate resin-based adhesive-imparting resin, etc. can be used. ..
• the softening point of the tackifier resin is not particularly specified, but is 30 to 180 ° C., preferably 40 ° C. to 140 ° C.
• the content of the tackifier resin is not particularly limited as long as the temperature indicating the peak value of loss tangent (tan ⁇ ) at a frequency of 1 Hz is within the range of ⁇ 40 ° C. to 5 ° C., but the resin solid in the acrylic pressure-sensitive adhesive.
• it is 50 parts by mass or less with respect to 100 parts by mass, it is preferably 35 parts by mass or less, and it is in the range of 25 parts by mass or less in order to exhibit further excellent oil resistance against sweat, sebum and the like. Is more preferably the content of.
• two or more kinds of the tackifier resin may be used in combination.
• the pressure-sensitive adhesive layer it is crosslinked with a cross-linking agent in order to have even more excellent cohesive force.
• a cross-linking agent As an index of the degree of cross-linking of the pressure-sensitive adhesive layer, the value of the gel fraction for measuring the insoluble content after immersing the pressure-sensitive adhesive layer in toluene for 24 hours is used.
• the gel fraction is preferably in the range of 20% by mass to 90% by mass, more preferably 30% by mass to 80% by mass, and further preferably 30% by mass to 70% by mass, both cohesiveness and adhesiveness are good. Is.
• cross-linking agent a cross-linking agent conventionally known or commonly used in the field of acrylic pressure-sensitive adhesives can be used.
• an isocyanate-based cross-linking agent an epoxy-based cross-linking agent, a metal chelate-based cross-linking agent, an aziridine-based cross-linking agent, an oxazoline-based cross-linking agent, and the like can be used.
• a cross-linking agent which is easy to use by mixing with the previously produced acrylic copolymer or a solution thereof and capable of rapidly advancing the cross-linking reaction, and specifically, isocyanate.
• a system-based cross-linking agent or an epoxy-based cross-linking agent may be used alone or in combination of two or more.
• isocyanate-based cross-linking agent for example, tolylene diisocyanate, naphthylene-1,5-diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, trimethylolpropane-modified tolylene diisocyanate and the like can be used.
• Trimethylolpropane-modified tolylene diisocyanate is preferably used.
• epoxy-based cross-linking agent examples include N, N'-(cyclohexane-1,3-diylbismethylene) bis (diglycidylamine), N, N, N', N'-tetraglycidyl-1,3-benzenedi. (Methyleneamine) and the like are preferable.
• the amount of the cross-linking agent used is not particularly limited as long as it can be adjusted to the gel content, but is preferably 0.001 part by mass to 5.0 parts by mass with respect to 100 parts by mass of the resin solid content in the acrylic pressure-sensitive adhesive, but sweat. It is more preferably 0.01 part by mass to 4.3 parts by mass in order to exhibit further excellent oil resistance against oil and skin oil.
• the acrylic pressure-sensitive adhesive it is preferable to use one containing a solvent in order to maintain its good coating workability and the like.
• a solvent for example, toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, hexane and the like can be used.
• the ratio of ethyl acetate to the total solvent components is preferably 70% by mass or more, more preferably 90% by mass or more.
• the acrylic pressure-sensitive adhesive may be colored in order to exhibit designability, light-shielding property, concealing property, light reflection property, and light resistance in the pressure-sensitive adhesive tape.
• the colorants can be used alone or in combination of two or more.
• the adhesive layer is colored black.
• Black colorants include carbon black, graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite, magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, and composite oxidation.
• a physical black dye, an anthraquinone organic black dye, or the like can be used. Of these, carbon black is preferable from the viewpoints of cost, availability, insulating property, heat resistance to withstand the temperature of the step of extruding the foamable polyolefin resin composition and the heat foaming step.
• the adhesive layer When imparting design and light reflectivity to the adhesive tape, the adhesive layer is colored white.
• White colorants include titanium oxide, zinc oxide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, calcium oxide, tin oxide, barium oxide, cesium oxide, yttrium oxide, magnesium carbonate, calcium carbonate, barium carbonate, zinc carbonate.
• Inorganic white colorants such as titanium, mica, gypsum, white carbon, diatomaceous soil, bentonite, lithopon, zeolite, sericite, and organics such as silicone resin particles, acrylic resin particles, urethane resin particles, and melamine resin particles.
• a white colorant or the like can be used.
• aluminum oxide, zinc oxide, and calcium carbonate are preferable from the viewpoint of cost, availability, and color tone.
• the pressure-sensitive adhesive layer may contain a plasticizer, an antioxidant, a leveling agent, a flame retardant such as aluminum hydroxide or magnesium hydroxide, an antioxidant, glass or plastic particles or fibers, or a metal, if necessary.
• the resin may optionally contain known additives such as powders, fillers such as metal compounds, conductive fillers, and thermally conductive fillers.
• the acrylic pressure-sensitive adhesive used for the pressure-sensitive adhesive layer of the present invention the above addition is made to 100 parts by mass of the resin solid content in the acrylic pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer in order to maintain appropriate followability and cushioning property.
• the total amount of the agent is preferably 0.1% by mass to 10% by mass, preferably 1% by mass to 7% by mass.
• the average particle size of the additive is preferably not less than or equal to the thickness of the pressure-sensitive adhesive layer, preferably 90% or less, more preferably 50% or less, and 20 to 40% of the initial thickness of the pressure-sensitive adhesive tape. It is preferable because it has little effect on adhesion.
• the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive tape of the present invention has an even better oil resistance against sweat, sebum, etc., and is in the range of 1 ⁇ m to 200 ⁇ m in order to contribute to thinning of electronic devices and the like. It is preferable to use one having a thickness, more preferably one having a thickness in the range of 10 ⁇ m to 140 ⁇ m, and even more preferably one having a thickness in the range of 10 ⁇ m to 100 ⁇ m.
• the adhesive tape of the present invention may contain a supporting base material.
• a resin base material for example, a resin base material, a foam base material, a non-woven fabric base material, a cloth, paper, a metal foil, or the like can be used. Above all, it is preferable to use a resin base material.
• the resin base material include polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyolefins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and loss tangent (tan ⁇ ) at a frequency of 1 Hz such as polymethylmethacrylate.
• a film or sheet obtained by using poly (meth) acrylate, polyurethane, polyamide, polyimide or the like having a peak temperature of 50 ° C. or higher can be used.
• the thickness of the supporting base material is appropriately selected depending on the intended purpose, but is preferably 1 to 500 ⁇ m, and usually 2 to 200 ⁇ m is particularly preferable.
• surface treatment such as corona treatment, flame treatment, plasma treatment, hot air treatment, ozone / ultraviolet treatment, and application of an easy-adhesion treatment agent is performed. It may have been done.
• good adhesion can be obtained by setting the wetting index with the wetting reagent to 36 mN / m or more, preferably 40 mN / m, and more preferably 48 mN / m.
• the supporting base material may be subjected to a treatment (blending of pigment, printing, vapor deposition of metal, etc.) for enhancing designability, hiding property, and light-shielding property.
• the pressure-sensitive adhesive composition for the viscoelastic body layer is previously applied to the surface of a release liner and dried to form the viscoelastic body layer, and one side or both sides thereof is formed.
• the pressure-sensitive adhesive composition is applied to the surface of the release liner and dried (direct method), or the surface of the release liner is coated with the pressure-sensitive adhesive composition and dried to form a pressure-sensitive adhesive layer.
• a method (transfer method) of producing by transferring the pressure-sensitive adhesive layer to one side or both sides of the viscoelastic body layer can be mentioned.
• the adhesive tape of the present invention may be stored in the form of a sheet or a roll with a release film laminated on the surface of the adhesive layer.
• the thickness of the adhesive tape of the present invention is not particularly limited, but it has a thickness of 40 ⁇ m or more in addition to having further excellent oil resistance against sweat, sebum, etc. and excellent impact resistance. It is preferable to use one having a thickness in the range of 80 ⁇ m to 900 ⁇ m, more preferably one having a thickness in the range of 90 ⁇ m to 500 ⁇ m, and further preferably one having a thickness in the range of 100 ⁇ m to 400 ⁇ m. It is more preferable to use one having the thickness of.
• the adhesive tape of the present invention has good initial adhesive strength, does not easily swell even when sweat or skin oil adheres to it, maintains excellent adhesive strength for a long period of time, and has excellent impact resistance.
• Double-sided tape used for bonding housings that make up electronic devices such as portable electronic terminals and tablet PCs, labels that impart design to the surface of the housing, waterproof tape, and medical treatment because of its resilience resistance. It can be suitably used in various fields such as adhesive tapes for devices.
• thermoplastic resin manufactured by Matsumoto Yushi Seiyaku Co., Ltd., acrylonitrile copolymer, average particle size 30 ⁇ m
• Vernock D-40 manufactured by DIC Co., Ltd., adduct of tolylene diisocyanate and trimetyl propane, non-volatile
• a pressure-sensitive adhesive composition (P-1) was obtained by blending 0.8 parts by mass of 40% by mass, hereinafter D-40).
• Adjustment example 7 1.30 parts by mass of hollow glass particles (Glass Bubbles K-15, manufactured by 3M, average particle size 60 ⁇ m, density 0.15 g / cm3) in 100 parts by mass of the acrylic copolymer (A-1) solution. After blending and uniformly dispersing, 0.8 parts by mass of D-40 was blended to obtain a pressure-sensitive adhesive composition (P-7).
• Adjustment example 8 Weight by the same method as in Adjustment Example 1 except that n-butyl acrylate is changed to 74.9 parts by mass, acrylic acid is changed to 10 parts by mass, methyl acrylate is changed to 15 parts by mass, and 4-hydroxybutyl acrylate is changed to 0.1 parts by mass.
• An acrylic copolymer (A-2) solution solid content concentration 26%) having an average molecule of 750,000 and an average carbon atom number of 3.3 saturated hydrocarbon groups contained in the alkyl acrylate monomer was obtained.
• Adjustment example 9 Weight average by the same method as in Adjustment Example 1 except that n-butyl acrylate is changed to 59.9 parts by mass, acrylic acid is changed to 10 parts by mass, methyl acrylate is changed to 30 parts by mass, and 4-hydroxybutyl acrylate is changed to 0.1 parts by mass.
• Adjustment example 10 Weight average by the same method as in Adjustment Example 1 except that n-butyl acrylate is changed to 59.9 parts by mass, acrylic acid is changed to 5 parts by mass, methyl acrylate is 35 parts by mass, and 4-hydroxybutyl acrylate is changed to 0.1 parts by mass.
• Example 1 The pressure-sensitive adhesive composition (P-1) obtained in Adjustment Example 1 was applied to a release-treated surface of a release liner (a polyethylene terephthalate film having a thickness of 75 ⁇ m on one side), and the thickness after drying was 66 ⁇ m. And dried at 90 ° C. for 3 minutes to prepare one viscoelastic body layer.
• two viscoelastic body layers were prepared by applying and drying the pressure-sensitive adhesive composition (P-1) to a thickness of 67 ⁇ m after drying. Next, the exposed surfaces of the two viscoelastic body layers were laminated, and then laminated with a roll having a linear pressure of 5 kg / cm from the upper surface of the release liner.
• the release liner on one side is peeled off, another viscoelastic body layer is laminated on the exposed surface and bonded, and then laminated at room temperature with a roll having a linear pressure of 5 kg / cm from the upper surface of the release liner. did. This was aged in an environment of 40 ° C. for 48 hours to obtain an adhesive tape (T-1) having a thickness of 200 ⁇ m.
• Adhesive tapes (T-2 to T-10) having a thickness of 200 ⁇ m were operated in the same manner as in Example 1 except that the adhesive compositions (P-2 to P-10) obtained in Adjustment Examples 2 to 10 were used. ) was obtained.
• a pressure-sensitive adhesive composition (Q-1) was obtained by blending 0.8 parts by mass of D-40 with 100 parts by mass of the acrylic copolymer (A-1) solution.
• “Comparison adjustment example 4" The weight average molecular weight was 870,000 in the same manner as in Adjustment Example 1 except that the mixture was changed to 75 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of methyl acrylate, 10 parts by mass of acrylic acid, and 5.0 parts by mass of 2-hydroxyethyl acrylate.
• An acrylic copolymer (B-3) solution solid content concentration 26%) having an average carbon atom number of 6.5 as a saturated hydrocarbon group contained in the alkyl acrylate monomer was obtained.
• Example 1 A double-sided adhesive tape (U-1) having a thickness of 200 ⁇ m was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (Q-1) was used instead of the pressure-sensitive adhesive composition (P-1). ..
• Example 2 A double-sided adhesive tape (U-2) having a thickness of 200 ⁇ m was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (Q-2) was used instead of the pressure-sensitive adhesive composition (P-1). ..
• Example 3 A double-sided adhesive tape (U-3) having a thickness of 200 ⁇ m was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition (Q-3) was used instead of the pressure-sensitive adhesive composition (P-1). ..
• Example 11 The pressure-sensitive adhesive composition (P-1) obtained in Adjustment Example 1 is applied to a release-treated surface of a release liner (a polyethylene terephthalate film having a thickness of 75 ⁇ m on one side), and the thickness after drying is 100 ⁇ m. And dried at 90 ° C. for 3 minutes to prepare one viscoelastic body layer.
• two pressure-sensitive adhesive layers were prepared by applying and drying the pressure-sensitive adhesive composition (Q-1) to a thickness of 50 ⁇ m after drying. Next, after laminating the viscoelastic body layer and one of the pressure-sensitive adhesive layers, they were laminated with a roll having a linear pressure of 5 kg / cm from the upper surface of the release liner.
• the release liner on the viscoelastic body layer side is peeled off, another adhesive layer is laminated on the exposed surface and bonded, and then a roll with a linear pressure of 5 kg / cm is used from the upper surface of the release liner.
• Example 12 An adhesive tape (T-12) having a thickness of 200 ⁇ m was obtained by the same operation as in Example 10 except that the thickness of the viscoelastic body layer was 60 ⁇ m and the thickness of the pressure-sensitive adhesive layer was 70 ⁇ m.
• the patch was left in an atmosphere of 23 ° C. and 50% RH for 24 hours, and then left in an atmosphere of 60 ° C. and 90% RH for 24 hours. Then, it was left at 23 ° C. and 50% RH for 24 hours.
• the glass plate was pushed from the hole of the polycarbonate plate of the pasted object with a probe made of SUS having a diameter of 7 mm at a speed of 5 mm / min, and the strength (G1) at which the glass plate was peeled off was measured.
• the glass plate was pushed from the hole of the polycarbonate plate of the pasted object with a probe having a diameter of 7 mm at a speed of 5 mm / min, and the strength (G2) at which the glass plate was peeled off was measured.
• Adhesive retention rate (%) (G2 / G1) x 100
• the average number of carbon atoms is the average number of carbon atoms of the saturated hydrocarbon group of the alkyl (meth) acrylate monomer used.
• Examples 1 to 12 of the present invention have good properties in all of adhesive strength (push strength), oil resistance (adhesive strength retention rate), and impact resistance. In particular, even a narrow tape having a width of 1 mm has good oil resistance. On the other hand, in Comparative Examples 1 to 5, it can be seen that any one or more of the above characteristics are inferior.

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