JP2016151544A - Stress light emission sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stress light emission sheet that exhibits improved light emission properties, and more specifically, a stress light emission sheet that can realize such a sharp light emission as lightning when a stress is applied.SOLUTION: In the stress light emission sheet, the Gurley rigidity based on JAPAN TAPPI No.40 is not larger than 1.55 mN and is preferably not larger than 0.40 mN, the sheet density is 10 g/m2 to 100 g/m2, and the thickness is 10 μm to 250 μm. The stress light emission sheet is bendable and is deformable, and the bent part of the sheet emits light when the sheet is bent or is deformed.SELECTED DRAWING: None

Description

  The present invention relates to a stress light-emitting sheet that emits light by applying a mechanical external force such as pressure.

  In recent years, materials that emit light when mechanical external forces such as pressure, frictional force, and impact force are applied have been developed. A material that emits light by applying such a mechanical external force is called a stress-stimulated luminescent material.

  JP-A-2003-253261 proposes a sheet containing a stress-stimulated luminescent material (see Patent Document 1).

JP 2003-253261 A

  However, the conventional sheet containing the stress-stimulated luminescent material is inferior in luminescent properties, and in particular, the light emission upon application of stress tends to be in a blurred state.

  An object of the present invention is to provide a stress-stimulated luminescent sheet having improved luminescent properties, particularly a stress-stimulated luminescent sheet capable of realizing sharp light emission like lightning when stress is applied.

  The present invention relates to JAPAN TAPPI No. The Gurley rigidity based on 40 is related with the stress light emission sheet | seat which is 1.55 mN or less.

  The Gurley stiffness is preferably 0.40 mN or less.

The stress-stimulated luminescent sheet of the present invention preferably has a basis weight of 10 to 100 g / m ² .

  The stress-stimulated luminescent sheet of the present invention preferably has a thickness of 10 to 250 μm.

  The stress-stimulated luminescent sheet of the present invention can be refracted and it is preferable that the refracted portion emits light when refracting. Moreover, it is preferable that a plurality of the refraction portions are formed during the refraction deformation, and the relative positions of the plurality of refraction portions are variable.

  The stress luminescent sheet of the present invention is preferably reversibly deformable.

  The stress luminescent sheet of the present invention preferably includes a base material layer and a stress luminescent layer. The stress-stimulated luminescent layer preferably contains at least one kind of stress luminescent material fine particles and at least one binder polymer. And the said base material layer may contain the stress luminescent material.

  The base material layer may be a film, a nonwoven fabric, or paper.

  It is preferable that light emitted from the stress-stimulated luminescent layer can be transmitted through the base material layer.

  The stress-stimulated luminescent sheet of the present invention can further include at least one adhesive layer. In this case, the outermost layer may be the adhesive layer.

  The stress-stimulated luminescent sheet of the present invention has excellent luminescent properties. In particular, the stress-stimulated luminescent sheet of the present invention can realize sharp light emission like lightning when stress is applied.

  As a result of intensive studies, the inventors of the present invention are able to realize sharp light emission like lightning when stress is applied to the stress light emitting sheet by controlling the Gurley stiffness of the stress light emitting sheet. The present invention has been completed.

  Thus, the stress-stimulated luminescent sheet of the present invention has a JAPAN TAPPI No. The Gurley stiffness according to 40 is 1.55 mN or less.

  Hereinafter, the stress-stimulated luminescent sheet of the present invention will be described in detail.

  The stress-stimulated luminescent sheet of the present invention includes at least one stress-stimulated luminescent material. The term “stress luminescent material” is a material that emits light by an externally applied force, and is synonymous with “stress luminescent material” or “stress luminescent material”. That is, the stress-stimulated luminescent material has a property that the material itself emits light upon receiving a force applied from the outside, and the luminescence intensity changes in proportion to the force.

  The kind of the stress luminescent material contained in the stress luminescent sheet of the present invention is not particularly limited, and a conventionally known stress luminescent material can be used.

The stress-stimulated luminescent material has a basic structural formula such as, for example, europium-added strontium aluminate, similar to the inorganic phosphorescent material. However, the difference from the inorganic phosphorescent material is that it has a highly structured structure such as how to give lattice defects to Sr. By adding an element serving as the emission center into the controlled inorganic crystal skeleton, a stress emission phenomenon with high emission intensity is exhibited. Examples of stress luminescent materials include strontium aluminate (SrAl ₂ O ₄ : Eu, luminescent in green) added with europium as an element of luminescent center, and zinc sulfide (ZnS: Mn, yellow-green) added with manganese as luminescent center. Luminescence), a composite semiconductor crystal having a coexistence structure of a wurtzite structure and a zinc-blende structure disclosed in JP-A-2004-43656, strontium and aluminum disclosed in JP-A-2004-059746 Examples thereof include composite metal oxides, and barium composite oxides disclosed in JP-A No. 2006-124725. In addition, it is preferable to use the strontium aluminate that emits light in a green region of 500 to 600 nm, which has particularly high human visibility in the visible light region, because it can be easily confirmed with the naked eye.

  The stress-stimulated luminescent material is preferably in the form of fine particles, and can have a particle diameter of, for example, about 1 to 1000 nm, preferably 5 to 500 nm, and more preferably about 10 to 200 nm.

  In the present invention, a single type of stress luminescent material can be used, but two or more different types of stress luminescent material may be used.

  The stress-stimulated luminescent sheet of the present invention can include, for example, at least one stress-stimulated luminescent material and at least one binder polymer. Preferably, the stress-stimulated luminescent sheet of the present invention can be a resin-based sheet comprising fine particles of at least one stress-stimulated luminescent material and a matrix of at least one binder polymer.

  The kind of the binder polymer is not particularly limited. For example, various thermoplastic resins and / or thermosetting resins can be used, but polyurethane resin, polyester resin, polycarbonate resin, polyolefin resin, At least one selected from the group consisting of ethylene / vinyl acetate copolymer resin, styrene / butadiene copolymer resin, polyvinyl chloride resin, polyvinylidene chloride resin, nylon resin, polyamide resin, polyvinyl alcohol, and fluorine resin. It is preferable to use it.

  The stress light-emitting sheet of the present invention includes polyurethane resin, polyester resin, polycarbonate resin, polyolefin resin, ethylene / vinyl acetate copolymer resin, styrene / butadiene copolymer resin, polyvinyl chloride resin, polyvinylidene chloride resin, and nylon resin. In the case of including at least one binder polymer selected from the group consisting of polyamide resin, polyvinyl alcohol, and fluorine-based resin, external force can be efficiently transmitted to the stress-stimulated luminescent material, and vivid stress luminescence can be realized. be able to.

  As the binder polymer, a polyurethane resin and / or a polyester resin is more preferable, a thermoplastic polyurethane resin is still more preferable, and a polyester-based polyurethane is particularly preferable.

  Polyurethane resins, in particular thermoplastic polyurethane resins, can be obtained, for example, by reacting a polyisocyanate such as diisocyanate with a polyol such as diol and, if necessary, a chain extender.

  Examples of the diisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate (HMDI) and 2,2,4-trimethylhexamethylene diisocyanate; 1,4-cyclohexane diisocyanate, dicycloalkylmethane-4,4′-diisocyanate, isophorone diisocyanate (IPDI). And alicyclic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate (TDI), diphenylmethane-4,4′-diisocyanate (MDI), and araliphatic diisocyanates such as xylylene diisocyanate. As the diisocyanate, a compound in which an alkyl group (for example, a methyl group) is substituted on the main chain or ring may be used. Diisocyanate can be used individually or in combination of 2 or more types.

Examples of the diol, a polyester diol [aliphatic dicarboxylic acid component (such as C _4-12 aliphatic dicarboxylic acids such as adipic acid), an aliphatic diol component (ethylene glycol, propylene glycol, butanediol, such as neopentyl glycol C _{2- 12} aliphatic diol), _{C 4-12} polyester diols obtained from a lactone or the like) such as a lactone component (.epsilon.-caprolactone (aliphatic polyester diols), such as poly (ethylene adipate), poly (1,4-butylene Adipate), poly (1,6-hexylene adipate), poly-ε-caprolactone, etc.], polyether diol [aliphatic polyether diol such as polyethylene glycol, poly (oxytrimethylene) glycol, polypropylene glycol, polytetra Poly (oxy C _2-4 alkylene) glycols such as methylene ether glycol (PTMG), block copolymers of these poly (oxyalkylene) glycols (polyoxyethylene-polyoxypropylene block copolymers, etc.); aromatic poly Ether diols, for example, alkylene oxide adducts of aromatic diols such as bisphenol A-alkylene oxide adducts (C _2-4 alkylene oxide adducts such as ethylene oxide and propylene oxide)]; polyester ether diols (of diol components) Polyester diols using the above polyether diols as part); polycarbonate diols and the like can be used. These diols can be used alone or in combination of two or more. Of these diols, polyester diols and polyether diols (polytetramethylene ether glycol, etc.) (for example, polyester diols) are often used. Polyester diol is preferred.

Examples of chain extenders include glycols [short chain glycols such as C _2-10 alkane diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol; bishydroxyethoxybenzene (BHEB ) Etc.], and other diamines [aliphatic diamines such as C _2-10 alkylene diamines such as ethylene diamine, trimethylene diamine, tetramethylene diamine and hexamethylene diamine; alicyclic diamines such as isophorone diamine; Aromatic diamines such as range amines] can also be used. A chain extender can be used individually or in combination of 2 or more types.

  Among thermoplastic polyurethane resins, in particular, diol [diol having polyester units or polyether units (polyester diol, polyether diol, etc.)], diisocyanate, and glycols as chain extenders (short chain glycols, etc.) And thermoplastic polyurethane elastomers obtained using This thermoplastic polyurethane elastomer has a hard segment (hard block) composed of a polyurethane of glycols and diisocyanate, a polyether diol [an aliphatic polyether diol such as poly (oxyethylene) glycol, etc.], a polyester diol (fat Soft segment (soft block) composed of a polyester diol, etc.). The polyurethane elastomer includes, for example, a polyester urethane elastomer, a polyester ether urethane elastomer, a polyether urethane elastomer, a polycarbonate urethane elastomer, etc., depending on the type of the soft segment. Of the polyurethane elastomers, polyester urethane elastomers, polyester ether urethane elastomers, polyether urethane elastomers and the like are preferable. In addition, the molecular weight (or weight average molecular weight) of the said polyether (polyoxyalkylene glycol) can be selected from the range of about 100-10,000, for example, Preferably it is 300-6,000 (for example, 300-5,000). ), More preferably about 500 to 4,000 (for example, 500 to 3,000).

  Examples of the polyurethane resin include a one-pack type and a two-pack type, but a two-pack type is preferable. As the two-pack type, for example, “Samprene IB” (manufactured by Sanyo Chemical Industries), “Olestar Q” (manufactured by Mitsui Chemicals), “Chris Bon” (manufactured by DIC), “Nipporan” (Nippon Polyurethane Industry Co., Ltd.) etc. "Coronate HL" (Nippon Polyurethane Industry Co., Ltd.), "Sumijour N" (Suika Bayer Urethane Co., Ltd.) aliphatic polyfunctional isocyanate What was hardened | cured with can be used suitably.

  Polyester resins include curable resins such as unsaturated polyester resins, thermoplastic resins such as PET (polyethylene terephthalate), PBT (polybutylene terephthalate), and PEN (polyethylene naphthalate), or (poly) urethane modified Mention may be made of modified polyester resins such as polyester resins.

  When a thermoplastic resin such as a thermoplastic polyester resin is used, its glass transition temperature is preferably 100 ° C. or lower, more preferably 50 ° C. or lower, still more preferably 20 ° C. or lower, even more preferably 0 ° C. or lower, − 10 degrees C or less is still more preferable, and -30 degrees C or less is still more preferable.

  The “elongation” of the binder polymer is preferably 60% or more, more preferably 100% or more, still more preferably 150% or more, still more preferably 200% or more, and still more preferably 400% or more and 900% or less.

  The tensile strength of the binder polymer is preferably 20 MPa or more, more preferably 30 MPa or more, still more preferably 40 MPa or more, and even more preferably 50 MPa or more.

  The stress-stimulated luminescent sheet of the present invention includes, for example, fine particles of at least one stress-stimulated luminescent material, as well as polyurethane resin, polyester resin, polycarbonate resin, polyolefin resin, ethylene / vinyl acetate copolymer resin, and styrene / butadiene copolymer resin. , At least one binder polymer selected from the group consisting of polyvinyl chloride resin, polyvinylidene chloride resin, nylon resin, polyamide resin, polyvinyl alcohol, fluorine resin, petroleum oil such as methyl ethyl ketone, acetone, gasoline, etc. It is manufactured by a method of dissolving and dispersing in an organic solvent such as a system solvent, applying the obtained paint on a substrate, then removing the organic solvent by drying, etc., and peeling the obtained sheet from the substrate. Can do.

  The paint can be applied using a known coating technique. Examples of known coating techniques include, but are not limited to, rod coaters, bar coaters, air knife coaters, blade coaters, gravure coaters, die coaters, curtain coaters, and gate roll coaters.

  The compounding weight ratio of the stress luminescent material fine particles: binder polymer contained in the stress luminescent sheet of the present invention is not particularly limited, but is preferably 1: 100-3: 1, and 1: 50-3: 1. More preferably, 1:20 to 3: 1 is even more preferable, and 1: 2 to 3: 1 is even more preferable.

  The stress-stimulated luminescent sheet of the present invention is made of JAPAN TAPPI No. The Gurley stiffness according to 40 is 1.55 mN or less. The Gurley stiffness is preferably 0.40 mN or less.

  The JAPAN TAPPI No. of the stress luminescent sheet of the present invention. The Gurley stiffness according to 40 can be controlled, for example, by the type and amount of the stress-stimulated luminescent material contained in the sheet. When the stress-stimulated luminescent sheet of the present invention contains a binder polymer, in addition to the type and blending amount of the stress-stimulated luminescent material contained in the sheet, it is also possible to control the type and blending amount of the binder polymer. The Gurley stiffness of the stress luminescent sheet can be controlled.

  Since the stress-stimulated luminescent sheet of the present invention has the specific Gurley stiffness range described above, it can be deformed manually. Therefore, the stress light-emitting sheet of the present invention can emit light by applying a mechanical external force to the stress light-emitting sheet of the present invention by human power.

  For example, the stress-stimulated luminescent sheet of the present invention can be refracted and deformed by hand, and mechanical external force can be easily concentrated on the refracted portion. And since the stress light emission sheet | seat of this invention has said specific Gurley rigidity range, it can form the geometrical shape in which a refracted part contains at least a straight line. For this reason, the stress-stimulated luminescent sheet of the present invention can realize sharp light emission like lightning when stress is applied. Thus, the stress-stimulated luminescent sheet of the present invention has excellent luminescent properties.

  Conventionally, the relationship between the light emission characteristics of the stress light-emitting sheet and the Gurley stiffness of the sheet is not known, and the light emission characteristics of the stress light-emitting sheet can be controlled by setting the Gurley rigidity of the sheet to a specific range. It was not even recognized. Moreover, in order to realize light emission like lightning when stress is applied, the stress luminescent sheet JAPAN TAPPI No. It was not recognized at all that the Gurley stiffness according to 40 should be 1.55 mN or less. Therefore, the stress-stimulated luminescent sheet of the present invention has high technical significance.

  The stress-stimulated luminescent sheet of the present invention can be refracted and deformed by human power as described above, but it is preferable that the refracted portion emits light during the refractive deformation. By concentrating external force on the refraction site and forming a geometric shape including at least a straight line, the stress emission including at least a linear light emission site can be realized.

  In the stress-stimulated luminescent sheet of the present invention, it is preferable that a plurality of the refraction portions are formed at the time of the refraction deformation, and the relative positions of the plurality of refraction portions are variable. In this case, the stress-stimulated luminescent sheet of the present invention can be crumpled or instantaneously deformed, and at this time, the relative position of the refracting part varies in a short time, so that The position fluctuates in a short time (for example, 1 to 2 seconds), and in the dark, it is possible to realize a light emission form as if lightning runs. The external force applied to the stress light-emitting sheet of the present invention for lightning-like light emission is preferably small, but the external force applied to the stress-light-emitting sheet of the present invention may be large as long as it emits lightning. Therefore, it is preferable that the stress light-emitting sheet of the present invention has a small degree of refractive deformation for lightning-like light emission, but the stress light-emitting sheet of the present invention may have a high degree of refractive deformation as long as it emits lightning. In particular, it is preferable that the stress-stimulated luminescent sheet of the present invention causes sharp refractive deformation such that a crease is generated in the sheet during refractive deformation. Thereby, lightning-like light emission becomes easier.

  The stress-stimulated luminescent sheet of the present invention does not need to return to its original shape when an external force is removed, and may maintain a deformed state, but is preferably reversibly deformable. Thereby, even if it deform | transforms crumpled by hand, the stress light-emitting sheet | seat of this invention can return to the original shape. Note that it is not necessary to completely return to the original shape, and a part of the refractive deformation such as a fold may remain in a part.

Stress-luminescent sheet of the present invention preferably has a basis weight of 10 to 100 g / ^{m 2,} more preferably having a basis weight of 20~90g / ^{m 2,} having a basis weight of 30 to 80 g / ^{m 2} Even more preferred.

  The stress-stimulated luminescent sheet of the present invention preferably has a thickness of 10 to 250 μm, more preferably has a thickness of 15 to 125 μm, and still more preferably has a thickness of 20 to 100 μm.

  The stress-stimulated luminescent sheet of the present invention may be a single layer or a laminate including a base material layer and a stress-stimulated luminescent layer. In this case, the JAPAN TAPPI No. Preferably, the Gurley stiffness according to 40 is 1.55 mN or less, and the Gurley stiffness is 0.40 mN or less.

  When the stress-stimulated luminescent sheet of the present invention includes a base layer and a stress-stimulated luminescent layer, the stress-stimulated luminescent layer preferably contains at least one kind of stress-stimulated luminescent material particles and at least one binder polymer. As the stress-stimulated luminescent material and the binder polymer, for example, those described above can be used.

  The material of the base material layer is not particularly limited, and various inorganic or organic materials can be used alone or in combination. Examples of the inorganic material include transparent or translucent glass such as heat resistant glass, metal oxide such as indium tin oxide (ITO), metal, clay, ceramics, and carbon. Examples of organic materials include polyethylene resins, polypropylene resins, polycarbonate resins, (meth) acrylic resins, polyethylene terephthalate resins, saturated polyester resins, polyamide resins, ABS resins, polyvinyl chloride and other thermoplastic resins, and And thermosetting resins such as phenol resin, urethane resin, melamine resin, urea resin, and epoxy resin. In view of heat resistance, inorganic materials are preferable, and in terms of flexibility, organic materials are preferable.

  The base material layer may be at least partly composed of fibers. As the fiber, fibers made of various inorganic or organic materials described above can be used. For example, glass fibers, carbon fibers, various resin fibers, and the like can be used.

  The base material layer can be in the form of, for example, a film, a nonwoven fabric, or paper. In particular, it is preferable to use a film having high heat resistance as the substrate. For example, a film made of cellophane, polypropylene, polyester, polyethylene terephthalate, nylon, polyvinyl alcohol, polyvinyl chloride, polycarbonate or the like can be used as the film. Is more preferable.

  The base material layer may be subjected to various treatments as necessary. For example, corona discharge treatment, primer coating treatment, embossing treatment, installation of a transparent colored layer, and the like can be appropriately performed.

  The base material layer may contain a stress luminescent material. In this case, it is preferable to mix and knead the stress-stimulated luminescent material in the material constituting the base material layer, and to form, for example, a film, non-woven fabric or paper by a conventionally known method.

  The method for providing the stress-stimulated luminescent layer on the base material layer is not particularly limited. For example, the single-layer stress luminescent sheet of the present invention may be laminated on the base material layer. Also, fine particles of at least one stress luminescent material, and, for example, polyurethane resin, polyester resin, polycarbonate resin, polyolefin resin, ethylene / vinyl acetate copolymer resin, styrene / butadiene copolymer resin, polyvinyl chloride resin, At least one binder polymer selected from the group consisting of polyvinylidene chloride resin, nylon resin, polyamide resin, polyvinyl alcohol, fluorine resin, organic solvent such as petroleum solvent such as methyl ethyl ketone, acetone, gasoline, etc. It can also be produced by a method in which the obtained paint is applied onto the base material layer and then the organic solvent is removed by drying or the like.

  The paint can be applied using a known coating technique. Examples of known coating techniques include, but are not limited to, rod coaters, bar coaters, air knife coaters, blade coaters, gravure coaters, die coaters, curtain coaters, and gate roll coaters.

  The compounding weight ratio of the stress-stimulated luminescent material contained in the stress-stimulated luminescent layer is not particularly limited, but is preferably 1: 100-3: 1, more preferably 1: 50-3: 1. : 20 to 3: 1 is even more preferable, and 1: 2 to 3: 1 is even more preferable.

  The stress-stimulated luminescent layer of the laminated stress-stimulated luminescent sheet of the present invention comprises a polyurethane resin, a polyester resin, a polycarbonate resin, a polyolefin resin, an ethylene / vinyl acetate copolymer resin, a styrene / butadiene copolymer resin, a polyvinyl chloride resin, When at least one binder polymer selected from the group consisting of vinylidene chloride resin, nylon resin, polyamide resin, polyvinyl alcohol, and fluorine resin is included, external force can be efficiently transmitted to the stress luminescent material. Vivid stress light emission can be realized.

  As the binder polymer, a polyurethane resin and / or a polyester resin is preferable, a thermoplastic polyurethane resin is preferable, and a polyester polyurethane is particularly preferable. Specifically, what was already described about the single layer type stress light emitting sheet of the present invention can be used.

  In the multi-layer stress-stimulated luminescent sheet of the present invention, it is preferable that light emitted from the stress-stimulated luminescent layer can be transmitted through the base material layer. Thereby, it is possible to effectively utilize the light emission of the stress light emitting layer, and the base material layer can be arranged facing the outside. There is no need to be exposed to the outside world.

  The laminated stress light emitting sheet of the present invention can further include at least one adhesive layer, and in particular, can include a heat-weldable layer as the adhesive layer. It is preferable that the outermost layer of the laminated type stress-emitting sheet is the adhesive layer, and more preferably a heat-weldable layer. The heat-weldable layer has a property of being melted by heating. For example, when the stress-luminescent sheet of the present invention is used for threads and anti-counterfeit paper, the stress-luminescent layered product can be firmly fixed to the paper.

  Further, since the stress luminescent material is generally weak against water, the stress luminescent material in the stress luminescent layer can be protected from moisture in the outside by the adhesive layer. Therefore, when the adhesive layer is formed, vivid light emission can be maintained over a longer period.

  The material of the adhesive layer, particularly the heat-weldable layer, is not particularly limited as long as it has a property of melting by heat. As the material of the adhesive layer, for example, a heat-sensitive adhesive in which a thermoplastic resin is dispersed in an organic solvent can be used.

  Thermoplastic resins include those used as base resins for conventional heat-sensitive adhesives such as vinyl acetate polymer, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polyethylene, polyvinyl butyral, polyamide, and acrylic resin. Plastic resins can be widely used, but among these, an ethylene-vinyl acetate copolymer can be suitably used from the viewpoint of thermal adhesiveness and ease of dispersion in an organic solvent, and further contains vinyl acetate. An ethylene-vinyl acetate copolymer in an amount of 5 to 30% by weight is preferred.

  The organic solvent is not particularly limited as long as it can disperse the thermoplastic resin, and organic solvents that are conventionally used as solvents for heat-sensitive adhesives such as toluene, ethyl acetate, methyl ethyl ketone, and acetone can be widely used. May be used. Among these, in particular, when the thermoplastic resin is an ethylene-vinyl acetate copolymer, a mixed solvent of toluene and ethyl acetate can be preferably used from the viewpoint of ease of dispersion. The mixing ratio of toluene and ethyl acetate is not particularly limited, but is preferably mixed at a weight ratio (toluene / ethyl acetate) of 60/40 to 80/20.

  Examples of the method for dispersing the thermoplastic resin in the organic solvent include a mechanical pulverization method and a precipitation method from a solution. Examples of the method by mechanical pulverization include a method of pulverizing and dispersing in a solvent using a pulverizer having strong dispersion power. Examples of the method for precipitating from a solution include a method in which an organic solvent that does not dissolve the resin is added to a solution in which the thermoplastic resin to be dispersed is dissolved, and the resin is precipitated and dispersed. Among these, the method by mechanical pulverization can be suitably used because of easy control of the particle size of the dispersed thermoplastic resin.

  The thermoplastic resin is preferably contained in a proportion of 3 to 20 parts by weight with respect to 100 parts by weight of the heat-sensitive adhesive, and is preferably dispersed so that the average particle diameter of the thermoplastic resin is about 10 to 50 μm.

  The heat-sensitive adhesive preferably contains a solid plasticizer in order to improve heat sensitivity. Examples of the solid plasticizer include diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dihydroabiethyl phthalate, dimethyl isophthalate, sucrose benzoate, ethylene glycol dibenzoate, trimethylolethane tribenzoate, and tribenzoyl glyceride tribenzoate. , Pentaerythritol tetrabenzoate, sucrose octaacetate, tricyclohexyl citrate, N-cyclohexyl-p-toluenesulfonamide and the like.

  Moreover, in order to improve adhesive performance, you may contain a tackifier. Examples of the tackifier include terpene resin, aliphatic petroleum resin, aromatic petroleum resin, coumarone-indene resin, styrene resin, phenol resin, terpene-phenol resin, rosin derivative (rosin, polymerized rosin, hydrogenated rosin. And esters thereof with glycerin, pentaerythritol, etc., resin acid dimers, etc.).

The application method is not particularly limited, and it can be applied using various blade coaters, roll coaters, air knife coaters, bar coaters, gravure coaters, curtain coaters, etc., but is applied using a gravure coater for excellent productivity. It is preferable to do. The coating amount of the adhesive layer, the range of 1.0 to 5.0 g / ^{m 2} is preferred.

  In the multi-layer stress-stimulated luminescent sheet of the present invention, the binder polymer contained in the stress-stimulated luminescent layer is preferably immiscible or low-affinity in the organic solvent in the adhesive layer. Thereby, even when an adhesive layer is formed on the surface of the stress light emitting layer, it is possible to avoid or reduce the outflow of the binder polymer from the stress light emitting layer.

  The stress-stimulated luminescent sheet according to the present invention can realize light emission as sharp as lightning runs in the dark at the time of deformation. Therefore, the stress-stimulated light emitting sheet of the present invention can be used to visualize the distortion of a building due to an earthquake or the like by sticking it to the outer surface of the building, or by sticking it to the surface of a sidewalk, for example for a pedestrian or bicycle passing through the surface. This is useful for visualizing distortions, such as visualizing the existence even at night.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely using an Example and a comparative example, the scope of the present invention is not limited to an Example.

[Example 1]
40 parts by mass of softwood bleached kraft pulp and 60 parts by weight of hardwood bleached kraft pulp were 380 ml C.I. S. F. The paper strength enhancer (trade name “Polystron 117”, manufactured by Arakawa Chemical Industries, Ltd.) 0.4 parts by mass, the sizing agent (trade name “Size Pine GF”, Arakawa Chemical Industries ( Co., Ltd.) 1.0 parts by mass and 2.0 parts by mass of a sulfuric acid band were added to prepare a paper material, and a substrate (paper) having a basis weight of 30 g / m ² was made using a long net paper machine. As a coating layer containing a stress-stimulated luminescent material on one side of this base material, strontium aluminate (SrAl ₂ O ₄ : Eu) powder added with europium as the luminescent center is made of polyvinyl alcohol (trade name “Kuraray Poval 117”, Kuraray). And a light-emitting stress sheet coated with 13 g / m ^{2 on} the surface of the substrate with an air knife coater.

[Example 2]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that the basis weight of the substrate was 60 g / m ² .

[Example 3]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that the basis weight of the substrate was 64 g / m ² .

[Example 4]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that the basis weight of the substrate was 75 g / m ² .

[Example 5]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that the basis weight of the substrate was 81 g / m ² .

[Example 6]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that a non-woven fabric having a basis weight of 25 g / m ² (trade name “Marix” manufactured by Unitika Ltd.) was used as the substrate.

[Example 7]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that a non-woven fabric having a basis weight of 50 g / m ² (trade name “Terramac” manufactured by Unitika Ltd.) was used as the substrate.

[Example 8]
Polyurethane resin (trade name “Samprene IB” manufactured by Sanyo Chemical Industries, Ltd.) and isocyanate-based curing agent (product) using strontium aluminate (SrAl ₂ O ₄ : Eu) powder with europium added as the luminescent center. The product was dispersed in toluene together with the name “Coronate” manufactured by Nippon Polyurethane Industry Co., Ltd. to obtain a dispersion. A transparent PET film having a basis weight of 25 g / m ² (trade name “Tetron Film” manufactured by Teijin DuPont Co., Ltd.) is prepared as a base material, and a dispersion liquid is applied on the base material in an amount of 13 g / m ² with a gravure coater. Coating was performed to obtain a stress luminescent sheet.

[Example 9]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that a transparent polyethylene film having a basis weight of 58 g / m ² (trade name “Polyfilm” manufactured by Ishijima Chemical Industries, Ltd.) was used as the substrate.

[Comparative Example 1]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that the basis weight of the substrate was 90 g / m ² .

[Comparative Example 2]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 1 except that the basis weight of the substrate was 100 g / m ² .

[Comparative Example 3]
A stress-stimulated luminescent sheet was prepared in the same manner as in Example 8, except that a transparent PET film having a basis weight of 165 g / m ² (trade name “Tetron Film” manufactured by Teijin DuPont Co., Ltd.) was used as the substrate.

  The stress-stimulated luminescent sheet thus obtained was cut into 15 cm square, and the luminescent properties were evaluated by the following methods. The evaluation results are shown in Table 1.

[Light emission by scratch]
The stress-stimulated luminescent sheet, which was allowed to stand for 5 minutes in a light place, was placed under the dark curtain, and external pressure was applied from the surface by scratching (scratching or scratching) the surface of the stress-stimulated luminescent layer with a nail. Luminescence generated by this was visually evaluated according to the following criteria.
Emission is clearly observed with the naked eye: ○
Slight luminescence is observed even with the naked eye: △
What is not observed at all with the naked eye: ×

[Light emission by refraction deformation]
A stress-stimulated light-emitting sheet that was allowed to stand for 5 minutes in a bright place was placed under the dark curtain, and both ends of the sheet were held with both hands, and both hands were moved up, down, left, and right to cause instantaneous refractive deformation of the sheet. Luminescence generated by this was evaluated according to the following criteria evaluated visually, and Δ or more was regarded as acceptable.
A number of lightning-like luminescence easily occurs during refraction deformation: ○
By increasing the applied external force and increasing the degree of refractive deformation, lightning-like light emission occurs: △
Those that do not emit light even when the applied external force is increased to increase the degree of refraction deformation, or those that emit light that is unclear and blurry (not lightning-like): ×

The following can be seen from the results in Table 1.
(1) Light emission by scratch was confirmed in any of the samples of Examples 1 to 9 and Comparative Examples 1 to 3 regardless of sheet physical properties.
(2) About the sheet | seat of Examples 1-9, irrespective of the kind of sheet | seat base material, the sharp refraction | bending deformation | transformation was produced and stress came to concentrate on some stripes. As a result, a lot of lightning-like light emission was generated, which was clearer than the light emission by scratch.
(3) Among them, for the sheets of Examples 1-2 and 6-9, lightning-like light emission was easily generated without applying excessive stress.
(4) About the sheet | seat of Comparative Examples 1-3, refractive deformation became loose and stress came to disperse | distribute to the whole sheet | seat. For this reason, the light emission is generally blurred, and lightning-like light emission as in Examples 1 to 9 was not confirmed.
(5) Comparison of Examples 1 to 9 and Comparative Examples 1 to 3 revealed that the stiffness of the sheet is important for generating lightning-like light emission. In order to show lightning-like light emission due to refractive deformation, the Gurley stiffness (stiffness) of the sheet needs to be 1.55 mN or less, and in order to easily generate lightning-like light emission, the sheet Gurley stiffness ( The stiffness is required to be 0.40 mN or less.

Claims (14)

  JAPAN TAPPI No. The stress light emission sheet | seat whose Gurley rigidity based on 40 is 1.55 mN or less.   The stress-stimulated luminescent sheet according to claim 1, wherein the Gurley stiffness is 0.40 mN or less. The stress-stimulated luminescent sheet according to claim 1, having a basis weight of 10 to 100 g / m ² .   The stress-stimulated luminescent sheet according to any one of claims 1 to 3, having a thickness of 10 to 250 µm.   The stress-stimulated luminescent sheet according to any one of claims 1 to 4, which can be refracted and emits light at a refracting portion during the refracting deformation. During the refraction deformation,
A plurality of the refraction parts are formed,
The stress-stimulated luminescent sheet according to claim 5, wherein the relative positions of the plurality of refractive portions vary.   The stress-stimulated luminescent sheet according to claim 5 or 6, which is reversibly deformable.   The stress-stimulated luminescent sheet according to claim 1, comprising a base material layer and a stress-stimulated luminescent layer. The stress-stimulated luminescent layer comprises at least one stress-stimulated luminescent material particulate; and
The stress-stimulated luminescent sheet according to claim 8, comprising at least one binder polymer.   The stress-stimulated luminescent sheet according to claim 8 or 9, wherein the base material layer contains a stress-stimulated luminescent material.   The stress light-emitting sheet according to any one of claims 8 to 10, wherein the base material layer is a film, a nonwoven fabric, or paper.   The stress-stimulated luminescent sheet according to any one of claims 8 to 11, wherein light emitted from the stress-stimulated luminescent layer can pass through the base material layer.   The stress-stimulated luminescent sheet according to any one of claims 8 to 12, further comprising at least one adhesive layer.   The stress-stimulated luminescent sheet according to claim 13, wherein the outermost layer is the adhesive layer.