JP2013100510A - Impact absorbing adhesive sheet and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact absorbing adhesive sheet which never adversely affects display characteristics and is excellent in yield, and a method for producing the same.SOLUTION: The impact absorbing adhesive sheet includes an impact absorbing adhesive layer including an impact absorbing layer. The side surfaces of the impact absorbing adhesive layer are tapered, and the taper angle of the tapered surfaces is set to 65° or more. The method for producing the impact absorbing adhesive sheet includes the step of cutting the impact absorbing adhesive layer including the impact absorbing layer by irradiation of a laser beam. The cut surface of the impact absorbing adhesive layer is tapered, and the taper angle of the tapered surface is set to 65° or more.

Description

  The present invention relates to an impact-absorbing pressure-sensitive adhesive sheet and a method for producing the same. More specifically, the present invention relates to an impact-absorbing pressure-sensitive adhesive sheet used for an image display device such as a liquid crystal display device and a manufacturing method thereof.

  In the liquid crystal display device, it is indispensable to dispose polarizing plates on both sides of the glass substrate on which the liquid crystal panel surface is formed because of its image forming method. In general, a polarizing plate is used in which a polarizer protective film is bonded to both sides of a polarizer. For the purpose of optical compensation of a liquid crystal panel, an optical compensation film such as a retardation film is also disposed between a polarizing plate and the glass substrate.

  In order to prevent the glass substrate from being broken by an external impact, it is disclosed that an impact-absorbing pressure-sensitive adhesive layer is provided on the viewing side of the glass substrate (see Patent Document 1). The arrangement of the shock-absorbing pressure-sensitive adhesive layer has been proposed, for example, between the viewing side of the polarizing plate and between the polarizing plate and the glass substrate.

  In mobile devices such as mobile phones, a protective layer formed from a plastic sheet or the like is usually provided on the viewing side of the liquid crystal display. In order to prevent damage to the liquid crystal display due to external impact, a space (air layer) is provided between the liquid crystal display and the protective layer. However, there is a problem that reflection occurs at the interface between the protective layer and the air layer and at the interface between the air layer and the liquid crystal display, resulting in a decrease in visibility. Therefore, the above-described impact-absorbing pressure-sensitive adhesive layer is used in place of the air layer for the purpose of improving visibility and further reducing the thickness of the plastic sheet (mobile device) while ensuring impact resistance.

  By the way, the impact-absorbing pressure-sensitive adhesive layer is usually cut according to the size of the applied optical element. However, the shock-absorbing pressure-sensitive adhesive layer typically has a thickness of several hundred microns in order to obtain practically sufficient impact resistance performance. Accordingly, there is a problem in that the cut surface can be deformed at the time of cutting, which adversely affects the display characteristics of the image display device. On the other hand, cutting with high yield is also desired.

JP 2005-173462 A

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide an impact-absorbing pressure-sensitive adhesive sheet excellent in yield without adversely affecting display characteristics and a method for producing the same. It is in.

  The shock-absorbing pressure-sensitive adhesive sheet of the present invention has a shock-absorbing pressure-sensitive adhesive layer including a shock-absorbing layer, the side surface of the shock-absorbing pressure-sensitive adhesive layer is a tapered surface, and the taper angle of the tapered surface is 65 ° or more. .

  In another embodiment, the impact-absorbing pressure-sensitive adhesive sheet of the present invention includes a base material and a plurality of impact-absorbing pressure-sensitive adhesive pieces arranged side by side on one side of the base material. The side surface of the agent piece is a tapered surface, and the taper angle of the tapered surface is 65 ° or more.

  In a preferred embodiment, the plurality of impact-absorbing pressure-sensitive adhesive pieces are arranged side by side with a space on one side of the base material, and the distance between the side lower end and the side lower end of adjacent shock-absorbing adhesive pieces is 30 μm or more. .

  In another aspect of the present invention, a method for producing an impact-absorbing pressure-sensitive adhesive sheet is provided. The method for producing the shock-absorbing pressure-sensitive adhesive sheet of the present invention includes a step of irradiating a laser beam to the shock-absorbing pressure-sensitive adhesive layer including the shock-absorbing layer, and cutting the shock-absorbing pressure-sensitive adhesive layer as a tapered surface. The taper angle of the taper surface is set to 65 ° or more.

  In preferable embodiment, the distance of the cut surface of a shock absorption adhesive layer and a cut surface is at least 30 micrometers or more.

  In a preferred embodiment, the laser beam includes light having a wavelength of at least 400 nm or less and / or 1.5 μm or more.

In a preferred embodiment, the laser is a CO ₂ laser.

  In a preferred embodiment, an impact-absorbing pressure-sensitive adhesive sheet having a base material and a plurality of impact-absorbing pressure-sensitive adhesive pieces including a shock-absorbing layer arranged on one side of the base material is produced.

  According to the present invention, it is possible to provide an impact-absorbing pressure-sensitive adhesive sheet excellent in yield without adversely affecting display characteristics.

(A)-(c) is a schematic sectional drawing of the impact-absorbing adhesive sheet by preferable embodiment of this invention. (A)-(b) is a schematic sectional drawing of the impact-absorbing adhesive sheet by preferable embodiment of this invention.

  Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.

A. Overall Configuration FIG. 1A is a schematic cross-sectional view of an impact-absorbing pressure-sensitive adhesive sheet 100 according to a preferred embodiment of the present invention. The shock-absorbing pressure-sensitive adhesive sheet 100 has a shock-absorbing pressure-sensitive adhesive layer 10 including a shock-absorbing layer. The shock absorbing adhesive sheet 100 includes a first separator (base material) 21 disposed on one side of the shock absorbing adhesive layer 10 and a second separator disposed on the other side of the shock absorbing adhesive layer 10. And a separator 22. FIG.1 (b) is a schematic sectional drawing of the impact-absorbing adhesive sheet 200 by another preferable embodiment of this invention. The shock-absorbing pressure-sensitive adhesive sheet 200 has a shock-absorbing pressure-sensitive adhesive layer 10 including a shock-absorbing layer. The shock absorbing adhesive sheet 200 includes a first separator (base material) 21 disposed on one side of the shock absorbing adhesive layer 10 and a second separator disposed on the other side of the shock absorbing adhesive layer 10. The separator 22, the polarizing plate 30 disposed between the shock absorbing adhesive layer 10 and the first separator 21, and the adhesive layer 40 disposed between the polarizing plate 30 and the first separator 21. Also have. FIG.1 (c) is a schematic sectional drawing of the impact-absorbing adhesive sheet 300 by another preferable embodiment of this invention. The shock-absorbing pressure-sensitive adhesive sheet 300 has a shock-absorbing pressure-sensitive adhesive layer 10 including a shock-absorbing layer. The shock-absorbing pressure-sensitive adhesive sheet 300 includes a separator (base material) 20 disposed on one side of the shock-absorbing pressure-sensitive adhesive layer 10, a polarizing plate 30 disposed on the other side of the shock-absorbing pressure-sensitive adhesive layer 10, and an impact. It further has a support layer 50 disposed between the absorbent pressure-sensitive adhesive layer 10 and the separator 20, and a pressure-sensitive adhesive layer 40 disposed between the support layer 50 and the separator 20.

  As shown in FIGS. 1A to 1C, the impact-absorbing pressure-sensitive adhesive sheet of the present invention may further have any appropriate layer (film). Although not shown, the impact-absorbing pressure-sensitive adhesive sheet of the present invention may further include any appropriate optical compensation layer. The type, number, arrangement, and the like of such an optical compensation layer can be appropriately selected according to the purpose. In addition, for example, in the form shown in FIG. 1C, a surface treatment layer may be provided on the side of the polarizing plate 30 where the shock absorbing adhesive layer 10 is not formed. Details of each layer will be described later.

  FIG. 2A is a schematic cross-sectional view of an impact-absorbing pressure-sensitive adhesive sheet 400 according to another preferred embodiment of the present invention. The impact-absorbing pressure-sensitive adhesive sheet 400 includes a first separator (base material) 21 and impact-absorbing pressure-sensitive adhesive pieces 10 ′, 10 ′, and 10 ′ arranged in parallel on one side of the first separator 21. The impact-absorbing pressure-sensitive adhesive sheet 400 further includes a second separator 22 disposed on the side where the first separator 21 is not disposed in each impact-absorbing pressure-sensitive adhesive piece 10 ′. FIG. 2B is a schematic cross-sectional view of an impact-absorbing pressure-sensitive adhesive sheet 500 according to another preferred embodiment of the present invention. The shock-absorbing pressure-sensitive adhesive sheet 500 includes a first separator (base material) 21 and shock-absorbing pressure-sensitive adhesive pieces 10 ′, 10 ′, and 10 ′ arranged in parallel on one side of the first separator 21. The shock-absorbing pressure-sensitive adhesive sheet 500 includes a second separator 22 disposed on the side where the first separator 21 of each shock-absorbing pressure-sensitive adhesive piece 10 ′ is not disposed, the shock-absorbing pressure-sensitive adhesive piece 10 ′ and the first. The polarizing plate 30 disposed between the separator 21 and the pressure-sensitive adhesive layer 40 disposed between the polarizing plate 30 and the first separator 21 are further included. As shown in FIGS. 2A to 2B, by providing a plurality of impact-absorbing pressure-sensitive adhesive pieces on one side of the base material, workability at the time of stacking on an optical element or the like can be improved. Furthermore, it can be excellent in yield.

B. Shock absorbing adhesive layer (Shock absorbing adhesive piece)
The side surfaces 11 and 11 of the impact-absorbing pressure-sensitive adhesive layer 10 (impact-absorbing pressure-sensitive adhesive piece 10 ′) are tapered surfaces. The taper angle of the taper surface is 65 ° or more, and the closer to 90 °, the better. With such a configuration, the display characteristics of the image display apparatus are not adversely affected, and the yield can be excellent. Preferably it is 75 ° or more, more preferably 80 ° or more. By having such a taper angle, it can be excellent in peelability from the separator (base material). As a result, the workability at the time of stacking on the optical element can be excellent. In the present specification, the “tapered surface” includes a case where the side surface is substantially tapered. “Substantially tapered” means that the side surface is not smooth within a range that does not adversely affect the display characteristics of the image display device. The “taper angle” is θ shown in FIGS. 1 and 2, and is calculated from the extension width x from the upper surface of the lower surface of the shock absorbing adhesive layer (shock absorbing pressure sensitive adhesive piece) and the thickness y of the shock absorbing pressure sensitive adhesive layer. Is the value to be

  Preferably, the plurality of shock-absorbing pressure-sensitive adhesive pieces 10 ′ are arranged side by side with a space on one side of the base material 21. The interval (distance between the side surface 11 and the side surface 11) between the adjacent shock-absorbing pressure-sensitive adhesive pieces 10 'and 10' can be set to any appropriate value depending on the configuration of the shock-absorbing pressure-sensitive adhesive sheet. The distance L1 between the side upper end 11a and the side upper end 11a is preferably 70 μm or more, more preferably 90 to 230 μm, and particularly preferably 110 to 170 μm. The distance L2 between the side lower end 11b and the side lower end 11b is preferably 30 μm or more, more preferably 30 to 120 μm, and particularly preferably 30 to 60 μm. When the distance between the adjacent impact-absorbing pressure-sensitive adhesive pieces is in such a range, the peelability from the substrate can be excellent, and the workability at the time of stacking on the optical element can be excellent. Further, the side surfaces of the adjacent impact-absorbing pressure-sensitive adhesive layers can be prevented from re-bonding, the taper surface can be kept good, and the display characteristics of the image display device can be excellent. On the other hand, the yield can be excellent.

  In the form shown in FIG. 2A, the distance L3 between the side surface upper ends 22a of the adjacent second separators 22 is preferably 80 μm or more, more preferably 100 to 350 μm, and particularly preferably 120 to 310 μm. In the form shown in FIG. 2B, the distance L4 between the side surface upper ends 22a of the adjacent second separators 22 is preferably 80 μm or more, more preferably 100 to 410 μm, and particularly preferably 120 to 370 μm. Moreover, the distance L5 between the side surface lower ends 40a of the adjacent pressure-sensitive adhesive layers 40 is preferably 30 μm or more, more preferably 30 to 100 μm, and particularly preferably 30 to 50 μm.

  The side surface 11 of the impact-absorbing pressure-sensitive adhesive piece 10 ′ is a tapered surface and satisfies the taper angle, and further, the interval between adjacent shock-absorbing pressure-sensitive adhesive pieces 10 ′ and 10 ′ can satisfy the above range. Therefore, the peelability can be remarkably improved. As a result, workability can be remarkably improved.

  The impact-absorbing pressure-sensitive adhesive layer 10 (shock-absorbing pressure-sensitive adhesive piece 10 ') includes at least a shock-absorbing layer. Hereinafter, the shock absorbing layer will be described.

B-1. Shock Absorbing Layer The shock absorbing layer can be formed of any appropriate pressure-sensitive adhesive. Specific examples include acrylic pressure-sensitive adhesives containing (meth) acrylic polymers. As a monomer which comprises a (meth) acrylic-type polymer, (meth) acrylic-acid alkylester is mentioned, for example. Specific examples of the (meth) acrylic acid alkyl ester include butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth) acrylate. , Isononyl (meth) acrylate, allyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like.

  The (meth) acrylic polymer is preferably obtained by copolymerizing the above (meth) acrylic acid alkyl ester and a hydroxyl group-containing monomer. Specific examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxy (meth) acrylate. Hydroxyalkyl (meth) acrylates such as hexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) -methyl acrylate , (Meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol and the like.

  Any suitable polymerization initiator may be used when the (meth) acrylic polymer is polymerized. Specific examples of the polymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, methoxyacetophenone, 2,2-dimethoxy- Acetophenone-based photopolymerization initiators such as 2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1 Etc.

  In the polymerization, a crosslinking agent may be added. As a crosslinking agent, polyfunctional (meth) acrylate is mentioned, for example. Specific examples of polyfunctional (meth) acrylates include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate , Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) ) Acrylate and the like.

The dynamic storage elastic modulus G ′ at 20 ° C. of the shock absorbing layer is preferably 1 × 10 ⁷ Pa or less, and more preferably 1 × 10 ^{3 to} 7 × 10 ⁶ Pa. This is because an excellent shock absorbing ability can be obtained.

  The thickness of the shock absorbing layer is preferably 100 to 1000 μm, more preferably 100 to 600 μm. If the thickness is less than 100 μm, there is a possibility that sufficient impact absorbing ability cannot be obtained. On the other hand, when the thickness exceeds 1000 μm, a problem of visibility tends to occur.

  In addition, as the said shock absorption layer, you may employ | adopt the glass crack prevention adhesive layer of Unexamined-Japanese-Patent No. 2005-173462, for example.

B-2. Other Layers The shock absorbing pressure-sensitive adhesive layer (shock absorbing pressure-sensitive adhesive piece) may further include an undercoat layer disposed on one side or both sides of the shock absorbing layer. By providing the undercoat layer, the adhesive property of the shock absorbing layer to the adherend can be improved. Any appropriate material can be adopted as a material for forming the undercoat layer. As a specific example, an undercoat layer formed by crosslinking an adhesive composition will be described.

  The pressure-sensitive adhesive composition preferably contains a (meth) acrylic polymer and an isocyanate compound. The (meth) acrylic polymer refers to a polymer or copolymer synthesized from an acrylate monomer and / or a methacrylate monomer (referred to herein as (meth) acrylate). When the (meth) acrylic polymer is a copolymer, the arrangement state of the molecules is not particularly limited, and may be a random copolymer, a block copolymer, or a graft copolymer. It may be a coalescence. A preferred molecular arrangement state is a random copolymer.

  The (meth) acrylic polymer is obtained, for example, by homopolymerizing or copolymerizing alkyl (meth) acrylate. The alkyl group of the alkyl (meth) acrylate may be linear, branched or cyclic. Carbon number of the alkyl group of the alkyl (meth) acrylate is preferably about 1 to 18, more preferably 1 to 10.

  Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, t-butyl ( (Meth) acrylate, n-pentyl (meth) acrylate, iso-pentyl (meth) acrylate, n-hexyl (meth) acrylate, iso-hexyl (meth) acrylate, n-heptyl (meth) acrylate, iso-heptyl (meth) Acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, n-nonyl (meth) acrylate, iso-nonyl (meth) acrylate, lauryl (meth) acrylate, Lil (meth) acrylate, cyclohexyl (meth) acrylate one bets. These can be used alone or in combination of two or more. When combining 2 or more types, the average carbon number of the alkyl group of the alkyl (meth) acrylate is preferably 3-9.

  The (meth) acrylic polymer may be a copolymer of the alkyl (meth) acrylate and a hydroxyl group-containing (meth) acrylate. In this case, the carbon number of the alkyl group of the alkyl (meth) acrylate is preferably 1 to 8, more preferably 2 to 8, particularly preferably 2 to 6, and most preferably 4 to 6. The alkyl group of the alkyl (meth) acrylate may be linear or branched.

  Specific examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3 -Hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 3-hydroxy-3-methylbutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 7-hydroxy Heptyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) Methyl acrylate. These can be used alone or in combination of two or more.

  The number of carbon atoms of the hydroxyalkyl group of the hydroxyl group-containing (meth) acrylate is preferably equal to or more than the number of carbon atoms of the alkyl group of the alkyl (meth) acrylate. Furthermore, the carbon number of the hydroxyalkyl group of the hydroxyl group-containing (meth) acrylate is preferably 2-8, more preferably 4-6. Thus, by adjusting the carbon number, the reactivity with an isocyanate compound described later can be excellent. For example, when 4-hydroxybutyl (meth) acrylate is used as the hydroxyl group-containing (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate or butyl is used as the alkyl (meth) acrylate. (Meth) acrylate is preferably used.

  The copolymerization amount of the hydroxyl group-containing (meth) acrylate is preferably 0.01 to 10 mol%, more preferably 0.1 to 10 mol%, particularly preferably 0.2 to 5 mol%, most preferably 0.00. 3 to 1.1 mol%. If it is the amount of copolymerization of the said range, the undercoat which is excellent in adhesiveness, durability, and stress relaxation property can be obtained.

  The (meth) acrylic polymer can be obtained by copolymerizing other components in addition to the alkyl (meth) acrylate and the hydroxyl group-containing (meth) acrylate. Other components include, but are not limited to, (meth) acrylic acid, benzyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, (meth) acrylamide, acetic acid Vinyl, (meth) acrylonitrile and the like are preferably used. The copolymerization amount of the other components is preferably 100 parts by weight or less, more preferably 50 parts by weight or less with respect to 100 parts by weight of the alkyl (meth) acrylate.

  The weight average molecular weight (Mw) of the (meth) acrylic polymer is preferably 1 million or more, more preferably 1.2 million to 3 million, and particularly preferably 1.2 million to 2.5 million.

  Examples of the isocyanate compound include 2,4- (or 2,6-) tolylene diisocyanate, xylylene diisocyanate, 1,3-bis (isocyanate methyl) cyclohexane, hexamethylene diisocyanate, norbornene diisocyanate, chlorophenylene diisocyanate, tetramethylene. Isocyanate monomers such as diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, trimethylolpropane xylene diisocyanate, hydrogenated diphenylmethane diisocyanate; adduct isocyanate compounds obtained by adding these isocyanate monomers to polyhydric alcohols such as trimethylolpropane; isocyanurate compounds; burettes Type compound; furthermore any suitable polyether polyol All or a polyester polyol, acrylic polyol, polybutadiene polyol, isocyanate urethane prepolymer type obtained by addition reaction of polyisoprene polyol and the like, can be used in combination thereof either singly or in.

  A commercial item can be used as it is as the isocyanate compound. Examples of commercially available isocyanate compounds include Takenate series (trade name “D-110N, 500, 600, 700, etc.”) manufactured by Mitsui Takeda Chemical Co., Ltd. Name “L, MR, EH, HL, etc.”) and the like.

  An appropriate amount of the isocyanate compound may be set according to the purpose. For example, the blending amount is preferably 0.1 to 1.5 parts by weight, more preferably 0.3 to 1.0 parts by weight, particularly preferably 0.4 to 100 parts by weight of the (meth) acrylic polymer. -0.8 parts by weight. By setting the blending amount of the isocyanate compound in the above range, moderate stress relaxation properties and excellent thermal stability can be exhibited. Furthermore, the adhesiveness can be improved even in a harsh (high temperature, high humidity) environment.

  The pressure-sensitive adhesive composition may further contain various additives without departing from the object of the present invention. Examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, ultraviolet absorbers, flame retardants, colorants, antistatic agents, compatibilizers, crosslinking agents, coupling agents, and additives. Examples thereof include a sticky agent and a pigment.

  An appropriate amount of the other additive may be set according to the purpose. The blending amount is preferably more than 0 and 5 parts by weight or less with respect to 100 parts by weight of the (meth) acrylic polymer.

  The thickness of the undercoat layer can be set to any appropriate value. Preferably it is 1-50 micrometers, More preferably, it is 10-30 micrometers, Most preferably, it is 20-25 micrometers.

C. Polarizing plate The polarizing plate 30 typically includes a polarizer and a protective film disposed on at least one side of the polarizer.

C-1. Polarizer Any appropriate polarizer may be adopted as the polarizer according to the purpose. For example, dichroic substances such as iodine and dichroic dyes are adsorbed on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. And polyene-based oriented films such as a uniaxially stretched product, a polyvinyl alcohol dehydrated product and a polyvinyl chloride dehydrochlorinated product. Among these, a polarizer obtained by adsorbing a dichroic substance such as iodine on a polyvinyl alcohol film and uniaxially stretching is particularly preferable because of its high polarization dichroic ratio. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

  A polarizer uniaxially stretched by adsorbing iodine to a polyvinyl alcohol film can be produced by, for example, dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. . If necessary, it may contain boric acid, zinc sulfate, zinc chloride, or the like, or may be immersed in an aqueous solution such as potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. By washing the polyvinyl alcohol film with water, not only can the surface of the polyvinyl alcohol film be cleaned and the anti-blocking agent can be washed, but also the effect of preventing unevenness such as uneven dyeing can be obtained by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

C-2. Protective film Any appropriate film that can be used as a protective film for a polarizing plate may be employed as the protective film. Specific examples of the material that is the main component of such a film include cellulose resins such as triacetylcellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, Examples thereof include transparent resins such as polysulfone, polystyrene, polynorbornene, polyolefin, acrylic, and acetate. In addition, thermosetting resins such as acrylic, urethane, acrylic urethane, epoxy, and silicone, or ultraviolet curable resins are also included. In addition to this, for example, a glassy polymer such as a siloxane polymer is also included. Moreover, the polymer film as described in Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007) can also be used. As a material for this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in the side chain For example, a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer can be mentioned. The polymer film may be an extruded product of the resin composition, for example. TAC, polyimide resin, polyvinyl alcohol resin, and glassy polymer are preferable, and TAC is more preferable.

  The protective film is preferably transparent and has no color. Specifically, the thickness direction retardation value is preferably −90 nm to +90 nm, more preferably −80 nm to +80 nm, and most preferably −70 nm to +70 nm.

  As the thickness of the protective film, any appropriate thickness can be adopted as long as the above-mentioned preferable thickness direction retardation is obtained. Specifically, the thickness of the protective film is preferably 5 mm or less, more preferably 1 mm or less, particularly preferably 1 to 500 μm, and most preferably 5 to 150 μm.

  The polarizer and the protective film are laminated through any suitable pressure-sensitive adhesive layer or adhesive layer.

  For example, in FIG.1 (c), the surface treatment layer may be provided in the protective film provided in the upper side (the side in which the impact-absorbing adhesive layer 10 is not formed) of a polarizer as needed. Specific examples of the surface treatment layer include a hard coat treatment layer, an antireflection treatment layer, an anti-sticking treatment layer, and an antiglare treatment layer.

D. Support Layer The support layer 50 can typically be formed of a plastic film. Further, the support layer may be a single layer of a plastic film or a laminate of plastic films. The plastic film can be formed of any suitable material that can be used as an optical film. Specific examples include norbornene resins, polycarbonate resins, cellulose resins, (meth) acrylic resins, polyester resins, nylon resins, and the like. The support layer may be a plastic film that has been stretched.

The dynamic storage elastic modulus G ′ at 20 ° C. of the support layer is preferably 2 × 10 ⁸ Pa or more, more preferably 2 × 10 ⁸ to 1 × 10 ¹¹ Pa, and particularly preferably 5 × 10 ⁸ to 1 ×. 10 ¹⁰ Pa. By having such a dynamic storage elastic modulus G ′, the self-supporting property can be excellent. As a result, a polarizing plate with an impact-absorbing pressure-sensitive adhesive layer that is more excellent in reworkability and can more effectively suppress the generation of bubbles can be obtained.

  The thickness of the support layer can be set to any appropriate value. Preferably it is 5-500 micrometers, More preferably, it is 10-200 micrometers, Most preferably, it is 10-100 micrometers. By having such a thickness, the self-supporting property can be excellent. As a result, a polarizing plate with an impact-absorbing pressure-sensitive adhesive layer that is more excellent in reworkability and can more effectively suppress the generation of bubbles can be obtained.

  The support layer may be optically isotropic or optically anisotropic (birefringent). When the support layer has optical isotropy, the obtained polarizing plate with an impact-absorbing pressure-sensitive adhesive layer can be used without substantially affecting the display characteristics of the liquid crystal display device. When the support layer has optical anisotropy, the support layer can also function as an optical compensation layer. When the support layer has optical anisotropy, its optical characteristics (for example, Δnd, Rth) can be appropriately set according to the driving mode of the liquid crystal cell to be compensated. In the present specification, the term “optically isotropic” includes a case where the optically isotropic property is included. “Substantially optically isotropic” means that Δnd is less than 10 nm and the absolute value of Rth is less than 10 nm.

E. Adhesive Layer As a material for forming the adhesive layer 40, any appropriate adhesive can be adopted. As a specific example, the undercoat layer described in the above section B-2 can be employed.

F. Separator (base material)
The separators (base materials) 20, 21, and 22 are typically provided with a support base and a peelability provided on at least one side of the support base (the side on which the shock absorbing pressure-sensitive adhesive layer is disposed). Including layers. By appropriately selecting the type and coating amount of the release agent that forms the later-described peelability-imparting layer, the release force of the separator can be easily adjusted.

  Any appropriate plastic film can be adopted as the support substrate. Further, the support substrate may be a single layer of a plastic film or a laminate of plastic films. The plastic film can be formed of any appropriate material as long as it can function as a separator. Specific examples include nylons; halogen-containing polymers such as polyvinyl chloride; polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate (PET). Among these, a polyester film is preferable from the viewpoint of punching processability. Moreover, as a material of a support base material, the thing which does not contain the component used as catalyst poison with respect to the said peelability provision layer (for example, silicone resin) is preferable. In addition, metal vapor deposition may be given to the surface of a support base material.

  The said peelability provision layer may be formed with arbitrary appropriate release agents. Specific examples include silicone-based release agents such as condensation-type and addition-type thermosetting silicone release agents, radiation-curable silicone release agents such as ultraviolet rays and electron beams, etc .; fluorine-containing esters of (meth) acrylic acid; Fluorine release agent containing an acrylic copolymer obtained by polymerizing an alkyl ester of (meth) acrylic acid having an alkyl group having 8 or less carbon atoms; having a long-chain alkyl group having 12 to 22 carbon atoms A long-chain alkyl release agent comprising an acrylic copolymer obtained by polymerizing an alkyl ester of (meth) acrylic acid and an alkyl ester of (meth) acrylic acid having an alkyl group having 8 or less carbon atoms ( JP-B-29-3144, JP-B-29-7333) and the like. Among these, a silicone release agent is preferable.

  As the peelability-imparting layer, for example, a release layer described in JP-A-2004-346093 may be employed.

  The thickness of the separator is typically about 15 to 100 μm, preferably about 30 to 100 μm.

G. Manufacturing Method The manufacturing method of the impact-absorbing pressure-sensitive adhesive sheet of the present invention includes a step of irradiating the impact-absorbing pressure-sensitive adhesive layer including the impact-absorbing layer with laser light and cutting it. Typically, a method of producing a laminate by laminating an impact-absorbing pressure-sensitive adhesive layer and each of the desired layers (films), and then cutting the laminate by irradiating it with laser light (for example, by laser ablation) Is adopted. Arbitrary appropriate methods may be employ | adopted for the lamination | stacking order and the lamination | stacking method of said each layer (film). This will be specifically described below.

  The impact-absorbing pressure-sensitive adhesive sheet shown in FIG. 2A is prepared by laminating a first separator (base material), a shock-absorbing pressure-sensitive adhesive layer and a second separator in this order, It can be obtained by irradiating a laser beam from the side where the substrate is not disposed (second separator side) and cutting the laminate until it reaches the substrate (half cut). The shock-absorbing pressure-sensitive adhesive sheet shown in FIG. 2B is a laminate in which a first separator (base material), a pressure-sensitive adhesive layer, a polarizing plate, a shock-absorbing pressure-sensitive adhesive layer, and a second separator are laminated in this order. Can be obtained by irradiating a laser beam from the side where the substrate of the laminate is not disposed (second separator side) and cutting the laminate until it reaches the substrate (half cut) ). The impact-absorbing pressure-sensitive adhesive sheets shown in FIGS. 1 (a) and (b) can be obtained by further cutting the impact-absorbing pressure-sensitive adhesive sheets shown in FIGS. 2 (a) and (b), respectively. That is, it can be obtained by cutting a portion of the first separator (base material) 21 where the impact-absorbing pressure-sensitive adhesive piece 10 'is not formed. Arbitrary appropriate methods can be employ | adopted for the cutting method of the 1st separator (base material) 21. FIG.

  The impact-absorbing pressure-sensitive adhesive sheet shown in FIG. 1 (c) was prepared by laminating a separator (base material), a pressure-sensitive adhesive layer, a support layer, a shock-absorbing pressure-sensitive adhesive layer, and a polarizing plate in this order, It can be obtained by irradiating the laminate with laser light and completely cutting it (full cut). In the case of full cut, the irradiation direction of the laser beam can be appropriately changed according to the type of layer to be formed. Thus, a desired impact-absorbing pressure-sensitive adhesive sheet can be obtained by adjusting the cutting depth.

  In the case of the half cut or the full cut, it is preferable to cut so that the distance between the cut surfaces of the adjacent impact-absorbing pressure-sensitive adhesive layers is at least 30 μm or more. That is, in the case of half-cutting, as shown in FIG. 2, after cutting, it is preferable to cut so that the distance L2 between the side lower end 11b and the side lower end 11b of adjacent shock absorbing pressure-sensitive adhesive pieces is 30 μm or more. More preferably, it is 30-120 micrometers, Most preferably, it is 30-60 micrometers. The cut surfaces can be prevented from re-bonding, and the workability at the time of stacking on the optical element can be improved. Furthermore, it can be excellent in yield. When the distance between the cut surface and the cut surface is in such a range, the obtained impact-absorbing pressure-sensitive adhesive sheet can be excellent in releasability from the base material and can be excellent in workability at the time of lamination to an optical element. . In addition, it is possible to prevent the adjacent cut surfaces from being re-fused, the taper surface is kept good, and the display characteristics of the image display device can be excellent. On the other hand, the yield can be excellent.

  The laser light preferably includes light having a wavelength of at least 400 nm or less and / or 1.5 μm or more. More preferably, it contains light having a wavelength of 2 to 30 μm, particularly preferably 8 to 12 μm. This is because the material for forming each layer (film) including the impact-absorbing pressure-sensitive adhesive layer can efficiently absorb laser light and can be cut well. As a result, the desired taper angle and the distance between the side surfaces (cut surfaces) can be easily achieved.

Any appropriate laser can be adopted as the laser. Specific examples include a gas laser such as a CO ₂ laser and an excimer laser; a solid laser such as a YAG laser; and a semiconductor laser. A CO ₂ laser is preferable. This is because the CO ₂ laser light can include light having the above-described preferable wavelength. Further, the CO ₂ laser has a wide range of application of irradiation output conditions, can easily control the cutting depth, can easily achieve the desired taper angle, and can be excellent in cut surface. Moreover, the distance between the cut surfaces can be easily achieved, and recutting of the cut surfaces can be suppressed. Furthermore, it can be excellent in productivity.

Arbitrary appropriate conditions can be employ | adopted for irradiation conditions (output conditions, moving speed, frequency | count) of a laser beam according to a cutting object, cutting depth, etc. The output condition is typically 10 to 800 W when a CO ₂ laser is used. Preferably it is 10-200W, More preferably, it is 10-100W. When the CO ₂ laser is used, the moving speed is typically 50 to 700 mm / second, preferably 100 to 500 mm / second. The number of times is typically 1 to 2 times.

H. Usage Method Any appropriate method can be adopted as the usage method of the impact-absorbing pressure-sensitive adhesive sheet of the present invention. Typically, there is a method in which the substrate (separator) is peeled off and the peeled surface is attached to the optical element surface.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. Unless otherwise indicated, parts and% in the examples are based on weight.

[Production Example 1: Production of shock absorbing layer]
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, an ultraviolet irradiation device and a stirring device, 83.6 parts of 2-ethylhexyl acrylate, 16.4 parts of 4-hydroxybutyl acrylate, 2,2 as a photopolymerization initiator 0.05 parts of dimethoxy-2-phenylacetophenone (“Irgacure-651” manufactured by Ciba Specialty Chemicals) and 1-hydroxycyclohexyl phenyl ketone (“Irgacure Ir-184” manufactured by Ciba Specialty Chemicals) 0 .05 parts was added and polymerized by irradiating with ultraviolet rays to obtain an acrylic polymer / monomer mixture having a polymerization rate of 10%. Next, with respect to 100 parts of this mixed solution, 0.2 part of trimethylpropane triacrylate as a crosslinking agent and 1-hydroxycyclohexyl phenyl ketone (“Irgacure Ir-184” manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator. ] 0.15 part was mixed and the coating liquid was obtained.
The coating solution obtained above is applied onto a base material (polyester separator having a thickness of 100 μm, “PET Sepa MRF” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.), and the upper surface is peeled more than the base material. Was covered with a light base material (polyester separator with a thickness of 75 μm, “PET Sepa MRN” manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) to obtain a laminate. The obtained laminate was cooled at −15 ° C., and irradiated with an ultraviolet ray of 4,000 mJ / cm ² by an ultraviolet lamp to cause photopolymerization to produce a 204 μm-thick impact absorbing layer. The obtained shock absorbing layer had a dynamic storage elastic modulus G ′ at 20 ° C. of 1 × 10 ⁵ Pa.

[Production Example 2: Production of undercoat layer]
In a four-necked flask equipped with a condenser, stirring blade and thermometer, 100 parts of butyl acrylate, 5 parts of acrylic acid, 0.1 part of 4-hydroxybutyl acrylate and 0.2 part of benzoyl peroxide are added to 100 parts of ethyl acetate. And the mixture was reacted at 60 ° C. for 7 hours to obtain an acrylic polymer solution having a solid content of 40%. To 100 parts of the solid content of this acrylic polymer solution, add 1 part of an isocyanate compound (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) with a solid content, and further add ethyl acetate, and a primer with a solid content of 30%. A solution was prepared. The obtained primer solution was applied on a substrate (polyester separator having a thickness of 38 μm) by a reverse roll coating method, dried at 150 ° C. for 3 minutes to volatilize the solvent, and an undercoat layer was produced. The thickness of the obtained undercoat layer after drying was 23 μm.

[Example 1]
The base material (“PET Sepa MRN”) on one side of the shock absorbing layer obtained above was peeled, and the undercoat layer obtained above and the first separator (base material) were laminated in this order on the peeled surface. . Next, the base material (“PET Sepa MRF”) on the other side of the shock absorbing layer was peeled, and the undercoat layer obtained above and the second separator were laminated in this order on the peeled surface. As the first separator, a 75 μm thick PET film (trade name “MDAR” manufactured by Toyo Metallizing Co., Ltd.) was used. As the second separator, a 75 μm thick PET film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name “MRV”) was used. In this way, a laminate A having a configuration of a first separator (75 μm) / impact absorbing adhesive layer (250 μm) / second separator (75 μm) was produced.

The laminate A obtained above is irradiated with laser light with a CO ₂ laser (trade name “SILAS-SAM (SPL2305 type)” manufactured by Kajitani Industry Co., Ltd.), and the second separator and the shock absorbing adhesive layer are cut (half The impact-absorbing pressure-sensitive adhesive sheet as shown in FIG. The dimension of the obtained impact-absorbing pressure-sensitive adhesive piece was 40 mm long × 30 mm wide. Cutting with laser light was performed under the conditions of an output of 50 W, a moving speed of 400 mm / second, a focus of 66 mm, and a single irradiation. The focus means the distance from the outermost surface of the laser lens to the surface of the laminate (second separator).

[Example 2]
An impact-absorbing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the focus was 64 mm.

Example 3
An impact-absorbing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the output was 25 W and the moving speed was 200 mm / second.

Example 4
An impact-absorbing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the output was 25 W, the moving speed was 200 mm / second, and the focus was 64 mm.

Example 5
An impact-absorbing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the output was 25 W, the moving speed was 200 mm / second, and the focus was 62 mm.

Example 6
The base material (“PET Sepa MRN”) on one side of the shock absorbing layer obtained above was peeled off, the undercoat layer obtained above on this peeled surface, a polarizing plate having a thickness of 100 μm (trade name, manufactured by Nitto Denko Corporation) : TEG1465DUHC), the undercoat layer obtained above, and the first separator (base material) were laminated in this order. Next, the base material (“PET Sepa MRF”) on the other side of the shock absorbing layer was peeled, and the undercoat layer obtained above and the second separator were laminated in this order on the peeled surface. As the first separator and the second separator, the same separators as in Example 1 were employed. Thus, the laminate B having the configuration of the first separator (75 μm) / adhesive layer (23 μm) / polarizing plate (100 μm) / impact absorbing adhesive layer (250 μm) / second separator (75 μm) Produced.

The laminate B obtained above is irradiated with CO ₂ laser light, and the second separator, the shock absorbing adhesive layer, the polarizing plate and the adhesive layer are cut (half cut), and shown in FIG. Such an impact-absorbing pressure-sensitive adhesive sheet was prepared. The dimension of the obtained impact-absorbing pressure-sensitive adhesive piece was 40 mm long × 30 mm wide. Cutting with laser light was performed under the conditions of an output of 75 W, a moving speed of 400 mm / second, a focus of 66 mm, and a number of irradiations of one time.

Example 7
The base material (“PET Sepa MRN”) on one side of the shock absorbing layer obtained above is peeled off, and the undercoat layer obtained in the above, the support layer, the undercoat layer obtained in the above, and the separator (Substrate) was laminated in this order. Next, the base material (“PET Sepa MRF”) on the other side of the shock absorbing layer is peeled, and the undercoat layer and the polarizing plate (product name: TEG1465DUHC, manufactured by Nitto Denko Corporation) obtained above are peeled off on this peeled surface. Laminated in order. As the separator, a 75 μm thick PET film (manufactured by Toyo Metallizing Co., Ltd., trade name “MDAR”) was used. As a support layer, a substantially optically isotropic film (thickness 60 μm, dynamic storage elastic modulus G ′ = 2 × 10 ⁹ Pa, Δnd [590] = 5 nm, Rth [590] = 7 nm, Nippon Zeon Product name: ZEONOR ZF-14) was used. In this way, a laminate C having a configuration of separator (75 μm) / adhesive layer (23 μm) / support layer (60 μm) / shock absorbing adhesive layer (250 μm) / polarizing plate (100 μm) was produced.

The laminate C obtained above was irradiated with CO ₂ laser light, and the laminate C was cut (full cut) to produce an impact-absorbing pressure-sensitive adhesive sheet as shown in FIG. The dimensions of the impact-absorbing pressure-sensitive adhesive layer of the impact-absorbing pressure-sensitive adhesive sheet were 40 mm long × 30 mm wide. Cutting with laser light was performed under the conditions of an output of 100 W, a moving speed of 400 mm / second, a focus of 66 mm, and an irradiation frequency of once.

[Comparative Example 1]
Except that the laser beam was irradiated using a UV laser (Electro Scientific Industries, Inc., trade name “5330”), the output was 20 W, and the moving speed was 2 mm / second, the same as in Example 1. A shock absorbing adhesive sheet was prepared.

[Comparative Example 2]
An impact-absorbing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that cutting was performed using a continuous automatic cutter (super cutter, tip angle 45 ° double-edged blade).

[Comparative Example 3]
An impact-absorbing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that cutting was performed using the water jet method. The cutting conditions were: water extrusion pressure: 350 MPa, tip diameter (water extrusion diameter): φ0.1 mm, moving speed: 2 mm / second.

The impact-absorbing pressure-sensitive adhesive sheets obtained in each example and each comparative example are summarized in Table 1. The obtained impact-absorbing pressure-sensitive adhesive sheet was evaluated by the following method.
1. Measurement of taper angle (about Examples 1 to 5)
The value obtained by measuring the extension width of the shock absorbing pressure-sensitive adhesive piece from the second separator (L6 in FIG. 2A), the thickness of the shock-absorbing pressure-sensitive adhesive piece, and the thickness of the second separator The taper angle was calculated from the total (325 μm).
(About Example 6)
The value obtained by measuring the extending width of the pressure-sensitive adhesive layer from the second separator (L7 in FIG. 2B), the thickness of the pressure-sensitive adhesive layer, the thickness of the polarizing plate, and the thickness of the shock-absorbing pressure-sensitive adhesive piece And the total thickness of the second separator (448 μm), the taper angle was calculated.
(About Example 7)
The value obtained by measuring the extending width of the separator from the polarizing plate (L8 in FIG. 1 (c)), the thickness of the separator, the thickness of the pressure-sensitive adhesive layer, the thickness of the support layer, and the thickness of the shock-absorbing pressure-sensitive adhesive piece And the total thickness of the polarizing plate (508 μm), the taper angle was calculated.
2. Evaluation of Cut Surface The cut surface (side surface) of the shock absorbing pressure-sensitive adhesive layer (shock absorbing pressure-sensitive adhesive piece) was observed with a microscope.
<Evaluation results>
◯: Smooth ×: Swelling, unevenness, etc. occurred About re-fusion It was observed whether or not adjacent impact pressure-sensitive adhesive layers (impact-absorbing pressure-sensitive adhesive pieces) were re-fused during or after cutting.
<Evaluation results>
○: Re-fusion did not occur ×: Re-fusion occurred
4). Evaluation of peelability The separator (base material) was peeled off from the obtained impact-absorbing pressure-sensitive adhesive sheet or 10 impact-absorbing pressure-sensitive adhesive pieces. At that time, it was evaluated whether it was easy to peel off or the presence or absence of glue chips (a part of the impact-absorbing pressure-sensitive adhesive layer (impact-absorbing pressure-sensitive adhesive piece) adhered to the separator).
<Evaluation results>
○: Excellent peelability ×: Inferior peelability

  As is apparent from Table 1, Examples 1 to 7 had a taper angle of 65 ° or more and excellent yield. Moreover, the cut surface was smooth and formed a tapered surface. On the other hand, in Comparative Example 1, although the cut surface was generally smooth, the lower end portions of the side surfaces of the adjacent impact adhesive pieces were re-fused to form a tapered surface. Therefore, the taper angle could not be measured. In Comparative Example 2, the taper angle was substantially 90 °, but the adjacent impact adhesive pieces were re-fused. In Comparative Example 3, half-cutting (cutting only the second separator and the shock-absorbing pressure-sensitive adhesive layer) was not possible, and full-cutting (cutting the first separator was also cut). In addition, the cut surfaces were re-fused. Therefore, the taper angle could not be measured. In Comparative Example 2 and Comparative Example 3, the cut surfaces were re-fused to form a tapered surface.

  Examples 1 to 3 and Examples 6 to 7 were particularly excellent in peelability. In Example 4 and Example 5 in which the taper angle was relatively small, the impact-absorbing pressure-sensitive adhesive piece and the second separator were not peeled together, but only the second separator was peeled off. . Comparative Example 1 was re-fused as described above, and it was difficult to peel off and chipping occurred, resulting in poor peelability. In Comparative Example 2 and Comparative Example 3, the degree of re-fusion between the cut surfaces was large, and the peelability could not be evaluated. Except for Comparative Examples 1 and 3, the productivity was excellent. In particular, Examples 1-2 and Examples 6-7 were excellent in productivity.

  The impact-absorbing pressure-sensitive adhesive pieces obtained in Example 1 and Comparative Example 1 were used for mobile phone images. As a result, compared with Comparative Example 1, Example 1 was superior in visibility.

  The impact-absorbing pressure-sensitive adhesive sheet of the present invention is suitably used for an image display device such as a liquid crystal display device.

10 Shock Absorbing Adhesive Layer 10 ′ Shock Absorbing Adhesive Piece 20 Separator (Base Material)
21 First separator (base material)
22 Second separator 30 Polarizing plate 40 Adhesive layer 50 Support layer 100 Impact absorbing adhesive sheet 200 Impact absorbing adhesive sheet 300 Impact absorbing adhesive sheet 400 Impact absorbing adhesive sheet 500 Impact absorbing adhesive sheet

Claims (1)

Having a shock-absorbing pressure-sensitive adhesive layer including a shock-absorbing layer;
The impact-absorbing pressure-sensitive adhesive sheet, wherein the side surface of the shock-absorbing pressure-sensitive adhesive layer is a tapered surface, and the taper angle of the tapered surface is 65 ° or more.

Images