WO2006077662A1

WO2006077662A1 - Retroreflective adhesive sheet

Info

Publication number: WO2006077662A1
Application number: PCT/JP2005/009389
Authority: WO
Inventors: Takashi Yoshioka; Hideyuki Kameya; Hitoshi Kainuma
Original assignee: Diatex Co., Ltd.
Priority date: 2005-01-19
Filing date: 2005-05-23
Publication date: 2006-07-27
Also published as: JPWO2006077662A1

Abstract

[PROBLEMS] To provide a retroreflective adhesive sheet that excels in tensile strength and ensures high hand tearability, realizing easy linear tearing by hand. [MEANS FOR SOLVING PROBLEMS] There is provided a retroreflective adhesive sheet characterized in that a material of cloth form produced by crossing tape-shaped filaments obtained by uniaxially drawing a thermoplastic resin with each other and an adhesive layer are sequentially superimposed on the backside of a burial type retroreflective sheet comprising a light refraction layer having retroreflective microparticles of ≤ 50 μm average particle diameter buried in a transparent binder resin of ≥ 80% elongation and, formed on the back surface thereof, a light reflection layer.

Description

Specification

Retroreflective adhesive sheet

Technical field

The present invention relates to a retroreflective adhesive sheet. More specifically, the present invention relates to a retroreflective adhesive sheet that is suitable for being used by being attached to clothing such as a hat, boots, or a sign board on a road or construction site.

Background art

[0002] In recent years, in order to improve safety, retroreflective sheets that shine brightly when light is applied to work clothes for workers, hats, boots and other clothing items, or sign boards on roads, construction sites, etc. It is widely done.

[0003] As these retroreflective sheets, those having a structure in which retroreflective fine particles such as glass fine particles are embedded in a transparent resin sheet such as acrylic resin are used, and these retroreflective sheets are also used. In order to increase the efficiency of the work of sticking the material to the object, a sheet having a pressure-sensitive adhesive layer formed on the back surface has been proposed (Patent Document 1, Patent Document 2).

[0004] The strong retroreflective sheet requires mechanical strength, and can be easily cut into a predetermined shape and size so that it can be cut and pasted appropriately according to the object outdoors. It is important that it must be freely cut by hand without using special tools.

[0005] However, the retroreflective sheet is a thermoplastic resin that joins glass fine particles and forms into a sheet. Since it is flexible and soft, it stretches when a tensile force acts. There is a problem that stress does not concentrate and it is difficult to create a break start point. Even if the break start point can be made, there is a problem that when cutting is advanced, the cutting line is bent and does not advance linearly, so it is difficult to cut into the expected shape. Therefore, there is a problem that the efficiency of the pasting work cannot be improved.

[0006] As a method for improving the tearability of a thermoplastic synthetic resin sheet, the present inventor has previously proposed laminating a woven fabric structure (Patent Document 3). By laminating the woven fabric structure, it is expected that when it is torn by hand, the breaking line proceeds along the warp or weft of the woven fabric structure, and as a result, it is cut linearly. . [0007] However, as a result of detailed investigations by the present researchers, the retroreflective sheet that is currently used generally has a straight line of fracture where the effect of improving hand tearability is small even when a woven fabric structure is laminated. It turned out to be easy.

Patent Document 1: JP-A-8-43615

Patent Document 2: JP 2002-243924

Patent Document 3: JP 2003-342539

Disclosure of the invention

Problems to be solved by the invention

[0008] The present invention provides a retroreflective pressure-sensitive adhesive sheet that has a great laminating effect of a woven fabric structure, is excellent in mechanical strength, and has good hand cutting ability, and can be easily cut linearly by hand. This is the issue.

Means for solving the problem

[0009] The present invention has been made as a result of intensive studies in order to solve the above-described problems. Specifically, retroreflective fine particles having an average particle size of 50 m or less are embedded in a transparent bonded resin. It is obtained by uniaxially stretching a thermoplastic resin on the back surface of an embedded retroreflective sheet having an optically refracting layer and a light reflecting layer formed on the back surface and having an elongation at break of 80% or more. The present invention provides a retroreflective pressure-sensitive adhesive sheet characterized in that a cloth-like body and an adhesive layer formed by crossing the tape-shaped filaments thus formed are sequentially laminated.

[0010] In addition, the present invention provides the above-described retroreflective adhesive sheet in which the binding resin forming the photorefractive layer is mainly composed of acrylic resin, and the retroreflective sheet is mainly composed of acrylic resin. The retroreflective adhesive sheet is provided by forming a surface layer made of polyester resin on the front surface of a photorefractive layer made of resin.

[0011] Further, the present invention provides a tape-like filament having a cloth-like body obtained by uniaxially stretching a thermoplastic resin, a warp fineness of 50 to 250 dtex, and a weft fineness of 200 to 400 dtex. The above retroreflective adhesive sheet formed by crossing, the above-mentioned retroreflective adhesive sheet whose tape-like striate is a polyolefin force, and the base layer on one side or both sides of the base layer where the tape-like striate is a polyolefin-based polymer force The above-mentioned retroreflective pressure-sensitive adhesive sheet in which a bonding layer having a lower melting point than that of a polyolefin polymer is laminated. It is to provide.

The invention's effect

[0012] Since the retroreflective adhesive sheet of the present invention has such a structure, it is easy to tear and hand-cut and can be easily attached to a sign board, etc., and has excellent mechanical strength and durability. A label is obtained. In particular, since a retroreflective sheet with an elongation of 80% or more is used, when tearing by hand, the tearing direction is not disturbed, but the material is torn linearly along the fabric yarn. Can be easily and linearly torn without needing to be cut, and the fractured surface is also cut beautifully, thus increasing the efficiency of the pasting operation.

Brief Description of Drawings

[0013] Fig. 1 is a longitudinal sectional view showing an example of the retroreflective adhesive sheet of the present invention.

[Fig. 2] An example of a cloth-like body is shown. (A) is a plan view and (B) is a longitudinal sectional view.

FIG. 3 is a longitudinal sectional view showing another example of a cloth-like body

[Fig.4] Longitudinal section showing an example of tape-like filaments

FIG. 5 is a longitudinal sectional view showing a production example of the retroreflective adhesive sheet of the present invention.

Explanation of symbols

1. Retroreflective adhesive sheet

2.Bonding resin

3. Retroreflective granules

4. Photorefractive layer

6.Surface layer

7.Light reflection layer

8. Retroreflective sheet

9. Tape-like striatum

10.Cloth body

11.Polyolefin layer

12.Adhesive layer

14.Base layer

15.Junction layer 16.Process sheet

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1, the retroreflective adhesive sheet 1 of the present invention comprises a photorefractive layer 4 in which retroreflective particles 3 having an average particle size of 50 m or less are embedded in a transparent binding resin 2. A tape obtained by uniaxially stretching a thermoplastic resin to a retroreflective sheet 8 having a light reflecting layer 7 formed on the back surface of the photorefractive layer 4 and an elongation at break of 80% or more. The cloth-like body 10 and the pressure-sensitive adhesive layer 12 formed by crossing the linear filaments 9a and 9b are sequentially laminated. Further, as a preferred embodiment, a retroreflective sheet 8 in which a surface layer 6 formed of a resin having an elongation of 80% or more is laminated on the surface of the photorefractive layer 4 can be used.

[0016] A retroreflective pressure-sensitive adhesive sheet with excellent hand cutting properties is obtained by making the retroreflective fine particles 3 have an average particle size of 50 m or less and a sealed retroreflective sheet structure embedded in the binding resin 2. Obtainable.

[0017] The bonded resin 2 fixes the retroreflective fine particles 3, and the material is not particularly limited. However, the bonded resin 2 should form a highly transparent sheet having an elongation of 80% or more. Synthetic resins that can be used are, for example, acrylic resins, polyester resins, alkyd resins, petitar resins, urethane resins and the like. In view of the suitability for forming a bonded resin layer in which acrylic resin and polyester resin are preferred in terms of weather resistance and processability, acrylic resin is most preferable.

[0018] By using a synthetic resin having an elongation at break of 80% or more, when the retroreflective sheet 8 is torn by hand, the break line extends linearly and a beautiful fracture surface can be obtained. . The elongation can be adjusted by selecting the molecular weight of the resin, the type of monomer and the amount added.

[0019] Additives such as a curing agent can be mixed with these resins, if necessary. Examples of the hardener include alkylated amino resins, alkylurea resins, and isocyanate cross-linking agents. Alkyl 匕 amino rosin is also preferred for the retroreflective point power.

[0020] It is desirable to form a surface layer 6 on the front side (upper side in FIG. 1) of the layer of the bonded resin 2. As the material for forming the surface layer 6, a material that forms a synthetic resin layer with an elongation of 80% or more and excellent in transparency is used. Acrylic resin, polyester resin, alkyd resin , Petital-based resin and urethane-based resin. The strength of weather resistance and transparency Considering the strength, elongation, and flexibility of the retroreflective sheet formed with acrylic resin and polyester resin, polyester resin is most preferable.

[0021] The polyester resin that forms the binding resin 2 or the surface layer 6 of the present invention is composed of a polyhydric alcohol such as ethylene glycol and propanediol, and an organic polybasic acid such as terephthalic acid. Polybasic acids include terephthalic acid, aromatic dicarboxylic acids such as isophthalic acid and naphthalene dicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, adipic acid, sebacic acid, It is possible to use aliphatic dicarboxylic acids such as azelaic acid, polyfunctional compounds composed of these derivatives, and the like.

[0022] In the present invention, a modified polyester resin in which the terminal carboxyl group of the polyester resin is modified with glycidyl acrylate can also be used in combination.

[0023] The synthetic resin forming the binding resin 2 or the surface layer 6 is generally used as a solution by dissolving in a suitable solvent. As a solvent for dissolving the synthetic resin, aromatics such as benzene, toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, or a mixed solvent thereof can be used.

[0024] In addition, additives such as a release agent can be blended with these fats and oils as necessary.

Examples of the release agent include silicon release agents and cellulose release agents.

[0025] The viscosity of the resin solution or the bonded resin 2 solution that forms the surface layer 6 when applied to the process sheet is 80 to 400 cP, preferably 90 to 350 cP, more preferably at the coating temperature. Is 10

0 ~ 300cP is preferred!

[0026] The thickness of the surface layer 6 is usually 10 μm to 100 μm, and is usually 15 μm to 60 μm, preferably 20 μm to 50 μm.

[0027] The thickness of the layer of the bonded resin 2 is a force determined in accordance with conditions such as the particle size of the retroreflective fine particles 3. In general, 15 111 to 100 111 is desirable, usually 18 111 to 60 111, preferably 2

0 m to 50 m.

[0028] A retroreflective fine particle 3 having a lens function is embedded in the binding resin 2. The retroreflective particles 3 are transparent and have a high refractive index, and are generally made of glass. Spherical fine particles are used. As glass, soda glass, quartz glass, borosilicate glass, bell glass, etc. can be widely used. In particular, a vitreous material having an optical refractive index of about 2.0 to 2.5 is desirable.

[0029] The average spherical diameter of the retroreflective fine particles 3 is 50 μm or less, preferably 20 μm to 45 μm. If the average spherical diameter of the retroreflective fine particles 3 is less than 20 m, the retroreflective property decreases, and if it exceeds 50 m, the hand-cut property of the retroreflective adhesive sheet 1 decreases.

[0030] Further, the retroreflective fine particles 3 can use a surface improver to improve the affinity with the binding resin 2, and as the surface improver, polyester resin modified polydimethylsiloxane, Examples include silicone surfactants and acrylic polymers, and polyester rosin-modified polydimethylsiloxane is preferred from the viewpoint of wettability and heat resistance.

A light reflecting layer 7 is formed on the back surface (lower surface in FIG. 1) of the layer of the binding resin 2. The light reflecting layer 7 is formed by vapor deposition, sputtering or plating of a metal thin film such as aluminum, gold, silver, tin, or nickel. In particular, an aluminum thin film that is inexpensive and has high light reflectance is suitable. When the light reflecting layer 7 is formed by vapor deposition or sputtering, the thickness of the metal layer is from 0.05 πι to 0. 5, preferably from 0.5 to πι to 0.15 m, and particularly preferably from 0.5 to 0.05 m. ~ 0.1 μm.

[0032] The retroreflective sheet 8 of the present invention can be prepared by the method shown in FIG. First, a resin solution for forming the surface layer 6 is applied to the process sheet 16. The process sheet 16 is not particularly limited as long as it has sufficient strength and is small in expansion and contraction when heat is applied, but a sheet of polyethylene terephthalate, polyimide, polysalt gel, etc. is suitable.

[0033] After drying the resin forming the coated surface layer 6, the bonded resin 2 forming the photorefractive layer 4 is applied over the surface layer 6. The binding resin 2 is formed by dividing it into two or more times, and a part thereof is first applied.

[0034] These coating methods are not particularly limited as long as they can be applied uniformly with a predetermined thickness, and there are methods such as reverse roll coating and comma direct coating.

Next, before the bonding resin 2 is cured, the retroreflective fine particles 3 are spread on the bonding resin 2. The temperature of the bonded resin 2 when spraying varies depending on the resin, but for example In the case of using krill-based resin, it is heated to 50 ° C to 150 ° C, preferably 70 ° C to 130 ° C, and particularly preferably 80 ° C to 120 ° C. It is good to make it easy to settle.

[0036] After the retroreflective fine particles 3 are dispersed, the heat treatment is performed to cure the resin. The curing temperature varies depending on the type of the resin and curing agent, but when acrylic resin is used as the bonded resin layer, it is preferably heated to 100 ° C or higher, preferably 100 ° C to 160 ° C.

[0037] Next, the remaining bonded resin 2 is further applied to embed the retroreflective fine particles 3. The bonding resin 2 is coated so that the bonding resin 2 on the upper part of the retroreflective fine particles 3 has a uniform thickness so that the top surface shape of the retroreflective fine particles 3 is reflected on the surface. It is desirable. The thickness of the binding resin 2 on the retroreflective fine particle 3 is determined in consideration of the refractive index of the resin so that the incident light beam is focused on the light reflecting layer 7, but usually the thickness is determined. 10 / ζ πι to 60 / ζ πι ゝ general range of 15 μm to 50 μm, and more preferably 20 μm to 40 μm.

[0038] Next, the binder resin 2 is cured by heat treatment. The curing temperature varies depending on the type of resin and curing agent, but when acrylic resin is used as bonded resin 2, it should be heated to 50 ° C to 160 ° C, preferably 70 ° C to 155 ° C! /.

When the bonded resin 2 is cured, a metal thin film is laminated on the photorefractive layer 4 formed by the bonded resin 2 to form the light reflecting layer 7. The light reflecting layer 7 can be formed by vapor deposition, sputtering, or the like. If the retroreflective sheet 8 is thus obtained, the process sheet 16 is peeled off. The extensibility of the retroreflective sheet 8 thus obtained is configured such that the elongation at break is 80% or more, preferably 90% or more, particularly preferably 100% or more. The elongation at break means the elongation at which the sheet breaks when the sheet is stretched, and it does not matter whether or not it is possible to destroy part of the structure of the light reflecting layer 7 or the like before that. To do.

[0040] As shown in FIG. 1, the obtained retroreflective sheet 8 is formed on a cloth-like body 10 formed by intersecting tape-like linear bodies 9 obtained by uniaxially stretching a thermoplastic resin. Laminated.

[0041] In the present invention, the cloth-like body 10 is a generic term for a flexible sheet-like body composed of the tape-like filaments 9, and is uniaxially stretched, such as tape, yarn, split yarn, etc. The tape-like filaments 9 are used to arrange plain fabrics, twills and other woven fabrics, or a large number of tape-like filaments 9 in one direction, and a number of tape-like filaments in a direction perpendicular thereto. It can be used as a cross-bonded cloth (sof) in which bodies 9 are juxtaposed and their intersections are joined. [0042] As shown in Fig. 4 (A), the tape-like filament 9 may be a single layer of crystalline resin, and as shown in Fig. 4 (B), the bonding layer 15 4 may be laminated on one side of the base layer 14, and the bonding layer 15 may be laminated on both sides of the base layer 14 as shown in FIG.

[0043] As a single layer of the tape-like filament 9 and a synthetic resin constituting the base layer 14 of the laminate, a resin having a large stretching effect, generally a crystalline resin, is used. High density polyethylene, polypropylene, ethylene-propylene block copolymer, polyolefins such as linear low density polyethylene, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyamide such as nylon 6, nylon 66, etc. Can be used

Of these, polyolefins such as high-density polyethylene, linear low-density polyethylene, and polypropylene are preferred because of their workability and economy. In particular, as a high-density polyethylene for which high-density polyethylene and linear low-density polyethylene are desired, those having a density of 0.930-0.970, preferably 0.940-0.960 are used.

[0045] The bonding layer 15 is formed by bonding the tape-like filaments 9 to a cloth-like shape, and bonding the tape-like filaments 9 or alternatively, the cloth-like member 10 and the retroreflective sheet 8 or a polyolefin layer 11 described later. A synthetic resin having a melting point lower than that of the synthetic resin constituting the base layer 14 and excellent in heat-fusibility is used.

[0046] Specifically, high pressure method low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, polyolefins such as ethylene 'propylene block copolymer, polyester resin such as polyethylene terephthalate, polybutylene terephthalate, etc. Nylon 6 and nylon 66 polyamide can be used, and a synthetic resin having a lower melting point than the base layer is selected in relation to the base layer synthetic resin.

[0047] An inorganic filler can be added to the thermoplastic resin forming the cloth-like body 10. As the types of inorganic fillers, known inorganic fillers can be used as synthetic resin additives. For example, talc, clay, my strength, calcium carbonate, barium sulfate, wollastonite, zeolite, hydroxide Aluminum, magnesium hydroxide, calcium silicate, etc. can be used. It is desirable to add inorganic filler together with acid-modified polyolefin [0048] By blending an inorganic filler, flame retardancy and hand cutting properties can be improved. The blending amount of the inorganic filler is 3 to 60% by weight, preferably 5 to 40% by weight.

[0049] Various additives may be added to the synthetic resin used as the base layer 14 or the bonding layer 15 depending on the purpose.

[0050] Specifically, organic phosphorus such as phenols and organic phosphites, acid-detering agents such as thioethers, light stabilizers such as hindered amines, benzophenones, benzotriazoles, benzoates, etc. UV absorbers such as non-ionic, cationic, and ionic anti-static agents; dispersants such as bisamides, waxes, and organometallic salts; amides, waxes, organometallic salts, Lubricants such as esters; Brominated organic, melamine, phosphoric acid, phosphoric ester, flame retardants such as antimony trioxide, magnesium hydroxide, red phosphorus; organic pigments; inorganic pigments; metal ions And inorganic and organic antibacterial agents.

[0051] These additives are appropriately combined and blended in any step of producing the material composition of the base layer 14 and the bonding layer 15. The additive may be mixed by mixing at a predetermined ratio using a kneading apparatus such as a conventional well-known twin screw extruder, Banbury mixer, kneader, or mixing roll, and melt-kneading the mixture. However, it is also possible to make a so-called master notch with a high concentration and dilute it before use.

[0052] When a laminated body is used as the tape-like linear body 9, as a means for forming a laminated film as the molding material, a film to be the base layer 14 and a film to be the bonding layer 15 are formed in advance. Means for making multiple layers using a dry laminating method or a heat laminating method, a method of coating the surface of the film to be the base layer 14 with a synthetic resin to be the bonding layer 15, a bonding layer to the film to be the previously formed base layer 14 15 Known means such as extrusion laminating or extrusion molding as a laminated film by multi-layer coextrusion method may be used as appropriate, but it is easy to mold, cost, and adhesion between each layer of the product From the standpoint of the light transmission property and the light transmission property, it is desirable to obtain a laminated body of the base layer 14 and the bonding layer 15 by a multilayer coextrusion method.

[0053] Further, as a means for stretching to form the tape-shaped filament 9, a film that becomes the base layer 14 is stretched in a uniaxial direction, and then a synthetic resin that becomes the bonding layer 15 is laminated, and this is slit into a tape shape. Shi Alternatively, it may be obtained by stretching in a uniaxial direction before or after slitting the laminated film in which the base layer 14 and the bonding layer 15 are laminated.

[0054] As the stretching method, stretching by a hot roll, stretching by a hot plate, stretching by a roll in a hot air furnace, and the like can be performed.

[0055] The draw ratio is 3 to 12 times, preferably about 5 to 10 times. The tape-like filament 9 has a fineness of 50 to 250 dtex, preferably 70 to 200 dtex, and weft. The yarn force is 00 to 400 dtex, preferably 230 to 360 dtex. The yarn width is 0.4 to 5. Omm, preferably 0.6 to 3.5 mm.

[0056] The tape-shaped filament (flat yarn) thus obtained can be split yarn by making a number of small cuts in the longitudinal direction. By using split yarn, texture and suppleness can be improved.

[0057] As shown in FIG. 2, the obtained tape-like filament 9 is plain weave, or is woven into a twill weave, a twill weave, a silk weave, a double weave, or the like, or as shown in FIG. In this way, a large number of tape-like filaments 9b are arranged in parallel, and tape-like filaments 9a are juxtaposed on top of each other, and the intersections are joined to form a cloth-like article 10 that is a cross-bonded cloth. Can do. In this case, the number of warps to be driven is greater than that of the weft.

The obtained cloth-like body 10 is laminated with the retroreflective sheet 8, and a pressure-sensitive adhesive layer 12 is formed on the other surface of the cloth-like body 10. Polyolefin is applied to one or both surfaces of the cloth-like body 10. It is desirable to laminate polyolefin layers l la and l ib made of film. Fig. 1 shows an example in which a polyolefin layer 1 la and 1 lb are formed on both sides of the cloth-like body 10!

[0059] As the laminated polyolefin layers 1 la and 1 lb, general polyolefin can be widely used. High pressure method low density polyethylene, linear low density polyethylene, high density polyethylene, ethylene propylene copolymer Polymers, ethylene / butyl acetate copolymer, and the like can be used. In particular, a high-pressure low-density polyethylene or a linear low-density polyethylene produced using a metalocene catalyst is preferred. The hand cutting property can be improved by forming a layer of polyolefin.

[0060] Further, acid-modified polyolefin and inorganic fillers can be added to these polyolefin layers lla and lib, and antioxidants, light stabilizers, ultraviolet absorbers, lubricants, flame retardants, Additives such as pigments can be added.

[0061] At least one of the polyolefin layers l la and l ib laminated on the cloth-like body 10 is preferably laminated on the cloth-like body 10 in advance by being melt-kneaded and formed into a film shape. In this case, it is preferable that the temperature of the laminated molten film is 130 to 220 ° C. higher than the melting point of the resin 10 of the cloth-like body 10. By laminating at a high temperature, the polyolefin is infiltrated into the cloth-like body 10 to fix the cloth-like tissue, so that the hand cutting property can be improved. The thickness of the polyolefin layer 11 laminated on the cloth-like body 10 is 10 to 60 μm, preferably 15 to 40 μm.

[0062] As the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer 12 of the present invention, those generally used as pressure-sensitive adhesives for pressure-sensitive adhesive tapes can be used, and examples thereof include acrylic resin-based pressure-sensitive adhesives and natural rubber. Rubber adhesives such as rubber and synthetic rubber, block copolymer adhesives such as styrene butadiene styrene block copolymers, styrene isoprene styrene block copolymers, and hydrogenated carotenates thereof, ethylene acetate butyl copolymer adhesives, Polyvinyl ether oil-based adhesives, silicone resin-based adhesives, etc. are mentioned, but among them durability is excellent in weather resistance, handling and little dirt on handling, acrylic resin-based adhesives are preferred ヽ. These pressure-sensitive adhesives may be used alone or in combination of two or more.

[0063] The form of these pressure-sensitive adhesives is not particularly limited. For example, a solvent-type pressure-sensitive adhesive, an emulsion-type pressure-sensitive adhesive, a hot-melt-type pressure-sensitive adhesive, a reactive pressure-sensitive adhesive, a photopolymerizable monomer-type pressure-sensitive adhesive. It may be in the form of a slip, etc.

[0064] Further, in these pressure-sensitive adhesives, a crosslinking agent such as a polyisocyanate compound, an aziridine compound, a metal chelate compound, or the like, as long as necessary, without inhibiting the present invention. Agent, coupling agent, filler, softener, plasticizer, surfactant, antioxidant (anti-aging agent), heat stabilizer, light stabilizer, ultraviolet absorber, colorant, antifoaming agent, flame retardant, One or more of various additives such as an antistatic agent may be added.

[0065] The pressure-sensitive adhesive layer 12 formed on the retroreflective pressure-sensitive adhesive sheet 1 is not particularly limited, but preferably has a thickness of 10 m to 0.5 mm. When the thickness of the pressure-sensitive adhesive layer 12 is less than 10 μm, the adhesiveness of the pressure-sensitive adhesive sheet 1 may be insufficient and the unevenness followability may be insufficient. Conversely, the thickness of the pressure-sensitive adhesive layer 12 exceeds 0.5 mm. And stickiness and adhesion are no longer that Despite the fact that it does not improve, the cost may increase.

[0066] The acrylic resin-based pressure-sensitive adhesive will be described in more detail. The acrylic resin-based pressure-sensitive adhesive is obtained by polymerizing a carboxyl group-containing monomer or a (meth) acrylic acid alkyl ester monomer. An acrylic polymer is used.

[0067] Specifically, the alkyl group preferably has a carbon number of about ˜12. Specifically, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) ) Atarylate, 2-ethyl hexyl (meth) acrylate, isonol (meth) acrylate, etc., n-butyl acrylate and 2-ethyl hexyl acrylate are particularly preferred.

[0068] Examples of the carboxyl group-containing monomer include monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and itaconic acid; dicarboxylic acids such as fumaric acid and maleic acid, and monoesters thereof. Of these carboxyl group-containing radical polymerizable monomers, acrylic acid and methacrylic acid are preferably used. The carboxyl group-containing polymerizable monomer is preferably about 3 to 20% by weight of the whole monomer.

[0069] The acrylic resin-based pressure-sensitive adhesive used in the present invention may be copolymerized with a small amount of a modifying component monomer for the purpose of adjusting the glass transition temperature, polarity and the like. Examples of such a monomer include methyl (meth) acrylate, ethyl (meth) acrylate, acrylamide, butyl acetate, styrene, acrylonitrile, burpyrrolidone, and the like.

[0070] In the acrylic polymer, a polyfunctional compound having two or more functional groups that react with a carboxyl group in the molecule, or a polyfunctional compound having one or more functional groups in the molecule. Individual monofunctional compounds can be blended. Examples of such functional group-containing compounds include isocyanate group-containing compounds, epoxy group (or glycidyl group) -containing compounds, aziridinyl group-containing compounds, metal complexes, melamine compounds, and the like. It can be illustrated.

[0071] The molecular weight of the pressure-sensitive adhesive is not particularly limited, but is preferably a resin having a weight average molecular weight of 100,000 or more, more preferably <300,000 to 1,000,000, and even more preferably. <Is preferably 500,000 to 1,000,000 rosin. Use of a resin having a molecular weight within the range and reacted with an appropriate curing agent such as an isocyanate cross-linking agent is most preferable because it can have both excellent adhesion and holding power. [0072] Further, a small amount of a plasticizer can be blended in the pressure-sensitive adhesive composition. The types of plasticizers to be blended are not limited. For example, low molecular plasticizers such as esters of aliphatic polyvalent carboxylic acids, esters of aromatic polyvalent carboxylic acids, phosphate esters, and polyester resin. Examples of the polymer plasticizer include aliphatic dibasic acid esters, with adipic acid diester being most preferred. The blending amount is preferably 4% by weight or less.

[0073] A benzotriazole compound can be added to the pressure-sensitive adhesive. Benzotriazole-based compounds are known to have an effect of preventing metal corrosion, and by incorporating this, discoloration due to metal corrosion can be more effectively prevented. The benzotriazole compound is preferably about 5% by weight or less if an effective amount is added.

[0074] Note that the surface to be coated with the pressure-sensitive adhesive layer 12 is subjected to physical treatment such as sandblasting or flame treatment or corona treatment on the surface in order to enhance the adhesion with the pressure-sensitive adhesive, if necessary. Chemical treatment such as plasma treatment or primer treatment can be applied.

[0075] Usually, the pressure-sensitive adhesive is dissolved and dispersed in an appropriate medium, and then coated on a substrate and dried to form the pressure-sensitive adhesive layer 12, or a process in which a release treatment is performed. What was dried after coating on paper is transferred onto a support to form a retroreflective adhesive sheet 1 on which an adhesive layer 12 is laminated. A well-known thing without a restriction | limiting in a coating means and a drying method is employable. Example

[0076] Hereinafter, the power of explaining the embodiments of the present invention The present invention is not limited to the embodiments.

[0077] Example 1

[Manufacture of retroreflective sheets]

A retroreflective sheet was prepared by the following procedures A to C.

[0078] A. Surface layer

100 parts by weight of polyester resin (Q-203, Mitsui Toatsu Chemical Co., Ltd.), 1 part by weight of polyester resin (P-647BC, Mitsui Toatsu Chemical Co., Ltd.), and 15 parts by weight of cellulose-based resin (CAB, Tokushiki) And 12 parts by weight of melamine cross-linking agent (Sanka Chemical Co., Ltd.-Power Rack MS-11) Furthermore, 40 parts by weight of methylisobutyl ketone and 15 parts by weight of toluene are mixed as a diluting solvent, and a mixed solution obtained by uniformly stirring and mixing is applied onto a polyester resin film having a thickness of about 75 m. The surface layer of polyester resin having a thickness of about 26 μm was formed by removing the portion.

[0079] B. Photorefractive layer

(bl) 100 parts by weight of acrylic resin (RS-3000 manufactured by Nitsuka Polymer Co., Ltd.) and 12 parts by weight of isocyanate cross-linking agent (Sumidur N-75 manufactured by Sumitomo Bayer Urethane Co., Ltd.), and methylisobutyl as a diluent solvent Apply 35 parts by weight of ketone and 8 parts by weight of toluene, and mix the mixture by stirring and mixing uniformly on the surface layer prepared in A above. A 40 μm tie layer was formed.

[0080] (b2) On this bonding layer, glass fine particles (K-43 manufactured by Nippon Electric Glass Co., Ltd.) having an average particle size of about 40 m and a refractive index of about 2.2 are dispersed so as to be dense in a single layer. Then, heat and pressure were applied to bond so that about 70% of the sphere diameter was buried in the bonded resin.

[0081] (b3) Next, 5.5 parts by weight of melamine-based cross-linking agent (Sanka Chemical Co., Ltd.-Power Rack MS-11) was added to 100 parts by weight of acrylic resin (RS-3000 manufactured by Nitsuka Polymer Co., Ltd.). In addition, 32 parts by weight of methylisobutyl ketone and 50 parts by weight of toluene were added as a diluting solution, and the mixture was stirred and mixed uniformly. The majority of the solvent was removed, and a transparent layer with a thickness of approximately 21 μm Formed. The last acrylic resin layer was coated so as to have a shape along the spherical surface of the retroreflective fine particles.

[0082] C. Light reflecting layer

Thereafter, aluminum was vapor-deposited thereon to form a light reflecting layer having a thickness of about 0.3 m.

[0083] [Production of cloth-like body]

High-density polyethylene (HY-433 manufactured by Nippon Polychem Co., Ltd.) was formed into a film by an inflation molding method, and the resulting film was slit using a laser. Next, after stretching 7 times on a hot plate at a temperature of 110 to 120 ° C, a 6% relaxation heat treatment was performed in a hot air circulating oven at a temperature of 120 ° C, and the yarn width was 0.85 mm and the fineness was 115 dtex. Wefts with warp and yarn width of 1.2 mm and fineness of 310 dtex were produced. [0084] The resulting weft using a water jet, 29 warps Z25. Was 4 mm, the weft 16 Z25. 4 mm, and plain weave woven fabric of basis weight 33gZm ^2.

[0085] On one side of the woven fabric, low-density polyethylene (LC-720 manufactured by Nippon Polychem Co., Ltd.) was extruded and laminated (laminate layer thickness 20 m), and the surface was subjected to corona discharge treatment to a wetting tension of 42 mNZm. .

[0086] [Lamination of retroreflective sheeting]

Apply a polyurethane anchor coating agent to the reflective layer side of the retroreflective sheet obtained above, and after drying, use low-density polyethylene (LC-720 manufactured by Nippon Polychem Co., Ltd.) at 280 ° C to be thicker than the T-die. It was melt-extruded into a 30-m film and laminated on the woven fabric side of the woven fabric with a single-sided polyethylene layer to obtain a composite sheet of retroreflective sheet Z woven fabric.

[0087] [Formation of pressure-sensitive adhesive layer]

On the corona discharge-treated surface of the above composite sheet, 100 parts by weight of a copolymer based on 2-ethylhexyl acrylate and vinyl acetate (AT D45 manufactured by Seiden Chemical Co., Ltd.) Isocyanate-based curing as a crosslinking agent An acrylic pressure-sensitive adhesive containing 2 parts by weight of an agent (Coronate L-45 manufactured by Nippon Polyurethane Co., Ltd.) was applied to a coating thickness (solid content basis) of 40 m. The evaluation results are shown in Table 1.

[0088] Example 2, Comparative Example 1

In Example 1, instead of the polyester resin layer of the surface layer, 100 parts by weight of acrylic resin (RS-1000 manufactured by Nitsuka Polymer Co., Ltd.), 15 parts by weight of cellulose resin (CAB manufactured by Tokushiki Co., Ltd.) Melamine-based crosslinking agent (Sanka Chemical Co., Ltd.-Power Lack MS-11) is blended, and 20 parts by weight of methylisobutyl ketone and 5 parts by weight of toluene are blended as a diluting solvent, and the mixture is stirred and mixed uniformly. A retroreflective adhesive sheet was obtained in the same manner as in Example 1 except that the blending solution was used. Table 1 shows the blending amounts of melamine-based crosslinking agents and the evaluation results for them.

[0089] Comparative Example 2

In Example 1, a retroreflective adhesive sheet was obtained in the same manner as in Example 1 except that glass fine particles (UB-34N HAC manufactured by Union Co., Ltd.) having an average particle size of about 57 μm were used.

[0090] Table 1 shows the results of the evaluation. [0091] Example 3

After forming the surface layer A in Example 1, on the surface layer produced in A, a red diagonal line with a width of 50 mm was printed by screen printing using a reflective sheet printing ink (red by Nitsuka Polymer). A recursive reflection-adhesive sheet was obtained in the same manner as in Example 1 except that two shades of red, white, and white were applied. There was no problem with printability.

[0092] Table 1 shows the results of evaluation of the obtained retroreflective adhesive sheet.

[0093] (Evaluation method)

1. Tensile strength: JIS Z-9117 Tensile speed 300mmZmin, 25mm width, 30mm between chucks

2. Tensile elongation: JIS Z-9117 Tensile speed 300mmZmin, 25mm width, 30 Omm between chucks

3. Hand cutting property: A cut surface of a test piece having a width of 100 mm and a length of 200 mm, which was torn by hand in the transverse direction, was visually observed.

[0094] ○: When it is torn by hand, it is cut straight and the cut part is beautiful.

△: A force that cuts straight when torn by hand.

Cracks in the retroreflective sheet occur

X: Retroreflective sheet tears diagonally when torn by hand

[0095] [Table 1]

Item Unit Example 1 Example 2 Comparative Example 1 Comparative Example 2 Example 3 Reflective sheet surface layer-polyester acrylic acrylic polyester polyester melamine crosslinker

Weight part 12 5 18 12 12 Directly added Retroreflective granules

m 40 40 40 57 40 Average particle diameter Reflective sheet elongation% 111 115 10 120 105 Reflective sheet

N / 25mm 213.2 190.5 200.6 215.8 Tensile strength Hand cutting ability-○ ○ △ X ○

N) O

Claims

The scope of the claims

[1] It has a photorefractive layer in which retroreflective particles having an average particle size of the following are embedded in a transparent bonded resin, and a light reflecting layer formed on the back surface thereof, and has an elongation at break of 80% A cloth-like body and an adhesive layer formed by crossing tape-like filaments obtained by uniaxially stretching thermoplastic resin are sequentially laminated on the back surface of the embedded retroreflective sheet as described above. Retroreflective adhesive sheet characterized by

[2] The retroreflective adhesive sheet according to [1], wherein the binder resin forming the photorefractive layer is made of a resin mainly composed of acrylic resin.

[3] The retroreflective adhesive according to claim 1 or 2, wherein the retroreflective sheet is formed by forming a surface layer made of polyester resin on the front side of a photorefractive layer made of resin mainly composed of acrylic resin. Sheet.

[4] A cloth-like body is obtained by uniaxially stretching a thermoplastic resin, and is formed by crossing tape-like filaments having a warp fineness of 50 to 250 decitus and a weft fineness of 200 to 400 dtex. The retroreflective adhesive sheet according to any one of claims 1 to 3.

[5] The retroreflective adhesive sheet according to [4], wherein the tape-like striate body is also polyolefin ink.

6. The tape-like striated body according to claim 5, wherein a bonding layer having a polyolefin polymer strength having a melting point lower than that of the base polyolefin polymer is laminated on one side or both sides of the base layer also having a polyolefin polymer strength. Retroreflective adhesive sheet.