JP5162862B2 - Heat sensitive adhesive and heat sensitive adhesive material - Google Patents

Description

The present invention relates to a heat-sensitive adhesive and a heat-sensitive adhesive material.

  In recent years, labels such as physical distribution labels, price display labels, product display (barcode) labels, quality display labels, weighing display labels, and advertising labels (stickers) have been used in various fields. Various recording methods such as an ink jet recording method, a thermal recording method, and a pressure sensitive recording method are also used for displaying information on the label. Usually, the label before use has a structure in which an adhesive layer and release paper are laminated on the surface opposite to the information recording surface, and the release paper is peeled off from the adhesive layer when the label is applied to an object. The label can be easily attached simply by applying the pressure-sensitive adhesive layer to the object and applying pressure. However, a label having a general configuration is used by peeling the release paper, but the peeled release paper is discarded as garbage. The release paper is specially processed to weaken the adhesive strength with the pressure-sensitive adhesive, and is hardly reused. In most cases, the release paper is not collected and reused but discarded. Therefore, recently, a heat-sensitive adhesive material layer using a heat-sensitive adhesive that is non-tacky at normal temperature but develops tackiness by heating, and once sticked to heat, will remain sticky and adhesive after cooling. A label having The label having the heat-sensitive adhesive material layer is not only economical because the release paper is unnecessary, but also requires attention from the viewpoint of reducing the environmental load because it does not require the release paper.

  As described in Non-Patent Document 1, the basic structure of the heat-sensitive adhesive is composed of a thermoplastic resin and a heat-meltable substance such as a solid plasticizer and, if necessary, additives such as a tackifier. Become. Thermoplastic resins exhibit adhesive strength and adhesive strength, and hot-melt materials do not exhibit adhesive strength and adhesive strength. However, thermoplastic resins are mixed and heated with thermoplastic resins. The resin is melted and swollen or softened to facilitate the development of the adhesiveness of the thermoplastic resin. The tackifier functions to improve the tackiness. After the heat-meltable substance in the heat-sensitive adhesive is melted by heating, it is slowly recrystallized by cooling. Therefore, even after the heat source is removed, the adhesiveness can be maintained for a considerably long time. However, with conventional heat-sensitive adhesives, in labels and the like used for a long period of time, there is a case where a decrease in adhesive force with time after the development of adhesiveness becomes a problem.

  The heat-sensitive adhesive can be used for various applications. For example, a heat-sensitive adhesive in which a heat-sensitive adhesive layer made of a heat-sensitive adhesive is formed on the whole surface or a part of one side of a base material made of label paper. In addition to the materials and the heat-sensitive pressure-sensitive adhesive layer, it can be used for a heat-sensitive pressure-sensitive adhesive material in which a heat-sensitive color forming layer is provided on the opposite surface of the substrate. These heat-sensitive adhesive materials have been expected to be used as labels to be stuck on various food packaging wraps, so-called food POS labels. However, conventional heat-sensitive adhesives have hindered practical use because of insufficient adhesion to vinyl chloride wrap, polyolefin wrap, and the like.

  In order to solve such a problem, for example, in Patent Document 1 and Patent Document 2, as a thermoplastic resin, an ethylene-vinyl acetate copolymer having a glass transition point of 0 ° C. or higher, or a glass transition point of −5 is used. A heat-sensitive adhesive using a thermoplastic resin (excluding ethylene-vinyl acetate copolymer) having a temperature of ℃ or higher has been proposed. However, these heat-sensitive adhesives have a relatively good adhesive strength to a stainless steel plate, but the adhesive strength to vinyl chloride wrap, polyolefin wrap, etc. has not yet reached a practical level.

  Patent Document 3 discloses that a heat-sensitive adhesive layer is formed using a heat-sensitive recording material as a base material, dicyclohexyl phthalate as a heat-melting substance and a styrene-butadiene copolymer, and the surface smoothness of the heat-sensitive adhesive layer. A heat-sensitive adhesive material has been proposed in which an undercoat layer containing non-foamed hollow particles is further provided between the substrate and the heat-sensitive adhesive layer. Since this heat-sensitive adhesive material is provided with an undercoat layer, it is almost satisfactory in terms of preventing the background color development of the heat-sensitive color developing layer of the heat-sensitive recording material. Even in an environment where the resistance to blocking is about 40 ° C., it is still not sufficient.

  In Patent Document 4 and Patent Document 5, a heat-sensitive adhesive (delay tack adhesive) using benzophenone as a solid plasticizer has been proposed, but there is an adhesive force to a mirror surface such as polyolefin or glass, Adhesive strength against rough surfaces such as corrugated paper is weak, and there is a problem that the adhesive strength declines over time after pasting on corrugated paper, which is a major impediment to practical use for logistics such as courier service Yes. Moreover, there exists a problem that blocking generate | occur | produces in a 60 degreeC environment.

Patent Document 6 proposes a delayed tack paste using benzotriazole as a solid plasticizer. This is relatively excellent in blocking properties, and it can be adhered for a long period of time if it is attached to a material such as paper, glass, metal, or a so-called polyolefin resin material such as polypropylene or polyethylene as an adherend. Although the force persists, the adhesive force to a rough surface such as corrugated paper is weak, and after adhering to the corrugated paper, the adhesive strength is lowered over time, and the above problem cannot be solved.
JP-A-6-57226 JP-A-6-57233 JP-A-9-265260 JP 2003-206455 A JP 2002-38123 A Japanese Patent No. 3556414 "Adhesion Handbook" 12th edition, pages (131-135), published in 1970

  An object of the present invention is to provide a composition having a strong adhesive force against a rough surface adherend such as corrugated paper and having an excellent blocking resistance in view of the problems of the heat-sensitive adhesive material as described above. It is to provide a heat-sensitive adhesive material used.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a specific compound as a hot-melt material, and the present invention is based on this finding. It came to complete.

A first aspect of the present invention is a heat- sensitive adhesive containing a thermoplastic resin and a heat-meltable substance, wherein the thermoplastic resin is a natural rubber latex obtained by graft copolymerization with a vinyl monomer, a natural rubber latex, Polyvinyl acetate, methacrylate ester copolymer, acrylic acid ester-methacrylic acid ester copolymer, synthetic rubber, vinyl acetate-acrylic acid 2-ethylhexyl copolymer, vinyl acetate-ethylene copolymer, vinylpyrrolidone-styrene copolymer A resin selected from a polymer, a vinylpyrrolidone-acrylic acid ester copolymer, a styrene-acrylic copolymer, an acrylic acid ester copolymer, and a polyurethane resin, and the hot-melt material is benzylic acid or di-p- It is a heat-sensitive adhesive that is toluene tartaric acid. Furthermore, it is preferable that content of the heat-meltable substance in these heat-sensitive adhesives is 50 parts by mass or more and 600 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. Moreover, it is preferable that the heat-sensitive adhesive further contains a tackifier.

The second aspect of the present invention is a heat-sensitive adhesive material in which a heat-sensitive adhesive layer comprising the heat-sensitive adhesive of the first aspect is provided on the surface of a support. This heat-sensitive adhesive material is preferably provided with an intermediate layer containing fine hollow particles between the support and the heat-sensitive adhesive layer. This intermediate layer further preferably contains an acrylate copolymer having a glass transition temperature of less than -50 ° C. The heat-sensitive adhesive material is preferably provided with a heat-sensitive recording layer containing a leuco dye and a developer.

  According to the first aspect of the present invention, a heat-sensitive adhesive as a raw material for forming a heat-sensitive adhesive layer having a strong adhesive force even on a rough adherend such as corrugated cardboard and excellent in blocking resistance. Can be provided. Further, according to the second aspect of the present invention, it is possible to provide a heat-sensitive adhesive material that has a strong adhesive force even on a rough adherend such as corrugated cardboard and is excellent in blocking resistance.

  A first aspect of the present invention is a composition containing a thermoplastic resin and a heat-meltable substance, and benzyl having two hydrogen atoms at the α-position of α-hydroxycarboxylic acid substituted with phenyl groups as the heat-meltable substance. It is di-p-toluol tartaric acid in which two hydroxyl groups of acid or tartaric acid are esterified with p-toluic acid. Di-p-toluol tartaric acid may be D-form, L-form, racemate, or any mixture of D-form and L-form. For example, when the hot-melt material is di-p-toluol tartaric acid having two chiral carbon atoms, (R, R) -di-p-toluol tartaric acid ((+)-di-p-toluol-D- Tartaric acid), (S, S) -di-p-toluol tartaric acid, (R, S) -di-p-toluol tartaric acid, (racemic) di-p-toluol tartaric acid or a mixture of these optical isomers in any proportion But it may be.

  The composition of the present invention, when a heat-sensitive adhesive material is formed as a heat-sensitive adhesive, is melted by heating with a thermoplastic resin, which is a main component that imparts adhesive strength and adhesive strength by heating, and becomes a thermoplastic resin. The main active ingredient is a heat-meltable substance having an action of developing adhesiveness. The composition of the present invention, when used as a heat-sensitive adhesive layer of a heat-sensitive adhesive material, has a strong adhesive force to the adherend of the heat-sensitive adhesive material, particularly corrugated paper, and is difficult to peel off even after a long time, and It is a material with good blocking resistance.

  In particular, the content of the heat-meltable substance in the composition of the present invention is 50 to 600 parts by mass, preferably 100 to 550 parts by mass, with respect to 100 parts by mass of the thermoplastic resin. By setting the content of the heat-meltable substance to 50 parts by mass or more and 600 parts by mass or less, particularly 100 parts by mass or more and 550 parts by mass or less, the fusion of the thermoplastic resin is promoted during the heat treatment for bonding the heat-sensitive adhesive material. The effect is most effectively exhibited, and the adhesive force of the heat-sensitive adhesive material can be improved. In addition, even when combined with a resin having a low glass transition temperature (Tg), if the content of the heat-meltable substance is kept within the above range, it is difficult for the pressure-sensitive adhesive material to exhibit an adhesive force in a normal storage environment. , Blocking can be prevented.

  As the thermoplastic resin preferably used in the composition of the present invention, natural rubber latex, natural rubber latex, polyvinyl acetate, methacrylic acid ester copolymer, acrylic acid ester-methacrylic acid ester obtained by graft copolymerization with vinyl monomers are used. Copolymer, synthetic rubber, vinyl acetate-2-ethylhexyl acrylate copolymer, vinyl acetate-ethylene copolymer, vinyl pyrrolidone-styrene copolymer, vinyl pyrrolidone-acrylate copolymer, styrene-acrylic copolymer Examples include, but are not limited to, polymers, acrylic acid ester copolymers, polymer resins such as polyurethane resins, and the like. The content of the thermoplastic resin in the composition is preferably 10 to 60% by mass, more preferably 15 to 50% by mass. When the content of the thermoplastic resin is less than 10% by mass or more than 60% by mass, both are undesirable because the adhesive strength is lowered. In addition, when the content of the resin having a low glass transition temperature exceeds 60% by mass, an adhesive force is easily developed under a normal storage environment, and there is a risk that storage problems such as a decrease in blocking resistance may occur. .

  Further, when the composition of the present invention is used as a heat-sensitive adhesive, a rosin derivative (rosin, polymerized rosin, hydrogenated rosin and the like) that is a tackifier used in ordinary adhesives in order to improve adhesive strength Glycerin, esters with pentaerythritol, resin acid dimers, etc.), terpene resins, petroleum resins, phenol resins and xylene resins. By adding a tackifier, the adhesive strength when the composition of the present invention is used as a heat-sensitive adhesive can be improved.

  Examples of tackifiers that are particularly preferably used in the composition of the present invention include rosin derivatives (rosin, polymerized rosin, hydrogenated rosin and their esters with glycerin, pentaerythritol, etc., resin acid dimers, etc.), terpene resins (terpenes) Resin, aromatic modified terpene resin, terpene phenol resin, hydrogenated terpene resin). These tackifiers are compatible with the thermoplastic resin and the hot-melt material of the present invention, and the adhesive strength of the heat-sensitive adhesive is significantly improved. Moreover, the melting point or softening point of the tackifier in the heat-sensitive adhesive is preferably 80 ° C. or higher, more preferably 80 to 200 ° C. If it is less than 80 ° C., the adhesive force tends to be exhibited at a normal storage environment temperature, and storage defects such as a decrease in blocking resistance may occur. Moreover, the content of the tackifier in the heat-sensitive adhesive is preferably 5 to 30% by mass, and more preferably 5 to 20% by mass. If it is less than 5% by mass, the effect of improving the adhesive strength is reduced, and if it exceeds 30% by mass, the adhesive force is likely to be exhibited in a normal storage environment, and there is a possibility that storage problems such as a decrease in blocking resistance may occur. is there.

  In the composition of the present invention, in addition to the above components, in order to prevent blocking, inorganic substances such as titanium oxide, alumina, colloidal silica, kaolin and talc, stearic acid metal salts, paraffin, natural wax, synthetic wax, natural fats and oils are used. In addition, a dispersant, an antifoaming agent, a thickener, and the like can be used as necessary for organic substances such as polystyrene powder.

  The composition of the present invention can be formed by a conventionally known method. For example, first, the dispersion particle size of the hot-melt material is reduced by a dispersing machine such as a ball mill, an attritor, and a sand mill together with an aqueous solution containing a binder such as a nonionic surfactant or polyvinyl alcohol. After being pulverized and dispersed to 1 to 3 μm, it may be prepared by mixing with a thermoplastic resin and, if necessary, a tackifier and other additives. When pulverizing a hot-melt material, the hot-melt material is divided into small portions and put into an aqueous solution for pulverization and dispersion. First, the hot-melt material is coarsely pulverized, and then the desired particle size is obtained. In some cases, effective pulverization and dispersion can be achieved.

  The second aspect of the present invention is a heat-sensitive adhesive material in which a heat-sensitive adhesive layer comprising the composition of the first aspect is provided on the surface of a support. The composition of the first embodiment is prepared as an aqueous solution or dispersion, and this is applied to the surface of a support such as paper as a heat-sensitive adhesive coating solution, and dried to form a heat-sensitive adhesive layer. . It should be noted that the above heat-sensitive adhesive coating liquid and the composition obtained by applying this liquid to a support and drying are still the compositions of the first aspect of the present invention. The heat-sensitive adhesive material of the second aspect of the present invention has a strong adhesive force for a long time with respect to vinyl chloride wrap and polyolefin wrap, particularly cardboard paper, and also has good blocking resistance.

  The support used in the heat-sensitive adhesive material of the second aspect of the present invention is not particularly limited, and paper such as high-quality paper, art paper, and coated paper, and polyester films such as polyethylene terephthalate and polybutylene terephthalate other than paper A cellulose derivative film such as cellulose triacetate, a polyolefin film such as polypropylene or polyethylene, a plastic film such as a polystyrene film, or a film obtained by bonding them together can be used. In particular, a heat-sensitive adhesive material such as a heat-sensitive recording paper having a heat-sensitive recording layer formed on one side is a practical support for a heat-sensitive adhesive material.

  As a method of forming a heat-sensitive adhesive layer on a support, blade coating method, gravure coating method, gravure offset coating method, bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U comma Coating method, AKKU coating method, smoothing coating method, micro gravure coating method, reverse roll coating method, four or five roll coating method, dip coating method, falling curtain coating method, slide coating method, die coating method, etc. Examples thereof include a coating method or a method of coating and printing on a support using various printing machines such as flexo, letterpress, gravure and offset.

  Drying conditions during coating or printing must be dried within a temperature range in which the hot-melt material to be used does not melt. As a means for drying, in addition to hot air drying, a drying method using a heat source using infrared rays, microwaves, and high frequencies can be used.

When forming the heat-sensitive adhesive layer, the coating amount of the heat-sensitive adhesive composed of the composition of the first aspect of the present invention may be appropriately determined according to the purpose, but is usually a dry coating amount. The range may be 5 to 35 g / m ² , preferably 10 to 25 g / m ² . When the coating amount of the heat-sensitive adhesive layer is less than 5 g / m ² , sufficient adhesion may not be obtained when performing adhesion by heating. On the other hand, if it exceeds 35 g / m ² , the adhesion function is saturated, which is not economical.

  In the heat-sensitive adhesive material according to the second aspect of the present invention, an intermediate layer mainly composed of fine hollow particles and a binder can be provided between the support and the heat-sensitive adhesive layer. By providing the intermediate layer to obtain a heat insulating effect, it is possible to efficiently utilize the thermal energy at the time of thermal activation during bonding. Furthermore, in the case of a heat-sensitive adhesive material having a heat-sensitive color developing layer on the back side, it is difficult to transfer heat to the heat-sensitive color developing layer during heating for adhesion of the heat sensitive pressure-sensitive adhesive material, and it is possible to prevent background coloration of the heat sensitive color developing layer. it can.

  As an intermediate | middle layer, the foamable intermediate | middle layer using the non-foamable intermediate | middle layer using the micro hollow particle about 30-95% of the hollowness which makes a thermoplastic resin a wrinkle, and a foamable filler are mentioned. The fine hollow particles having a hollowness of about 30 to 95% using the thermoplastic resin used for the intermediate layer as a trap contain air and other gases inside, and are fine hollow particles in a foamed state. The average particle diameter (particle outer diameter) of the fine hollow particles is preferably 0.2 to 20 μm, more preferably 0.5 to 10 μm. When the average particle size is smaller than 0.2 μm, it is difficult to technically make it hollow, and the heat insulating effect is insufficient when formed as an intermediate layer. On the other hand, when the thickness is larger than 20 μm, the smoothness of the surface of the intermediate layer after coating and drying is lowered, so that the application of the heat-sensitive adhesive layer becomes non-uniform. A sticky adhesive must be applied. Therefore, it is desirable that such a fine hollow particle distribution has a particle size within the above range and a distribution spectrum with little variation.

  In this embodiment, fine hollow particles having a hollowness of 30% or more can be used, but those having a hollowness of 50% or more are more preferable. When the hollowness is less than 30%, the heat insulation effect is insufficient, so that heat energy is released to the outside through the support, and the heat utilization efficiency during the activation of the pressure-sensitive adhesive is deteriorated. The said hollowness here is ratio of the volume on the basis of the outer diameter of the hollow fine particles and the volume on the basis of the inner diameter.

  As described above, the fine hollow particles used in this embodiment are not particularly limited as long as they are made of a thermoplastic resin. As the thermoplastic resin, a copolymer resin mainly composed of vinylidene chloride and acrylonitrile is preferable. .

As a method for forming the non-foaming intermediate layer, the fine hollow particles described above may be dispersed in a dispersion medium such as water together with a binder, and this may be applied on a support and dried. In this case, the coating amount of the fine hollow particles is at least 1 g / m ² or more by dry mass, and more preferably about ² to 15 g / m ² . Further, the amount of the binder resin applied may be an amount sufficient to strongly bond the intermediate layer to the substrate, and is usually 10 to 70% by mass with respect to the total amount of the fine hollow particles and the binder resin. Good.

  The binder used when forming the non-foaming intermediate layer is appropriately selected from conventionally known water-soluble polymers and / or aqueous polymer emulsions. Specific examples thereof include water-soluble polymers such as polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylic acid. Ester copolymer, acrylamide / acrylic ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. Is mentioned. Also, as aqueous polymer emulsion, latex such as styrene / butadiene copolymer, styrene / butadiene / acrylic copolymer, vinyl acetate resin, vinyl acetate / acrylic acid copolymer, styrene / acrylic acid ester copolymer, Examples thereof include emulsions of acrylic acid ester copolymers and polyurethane resins. Among them, an acrylate copolymer having a Tg of less than -50 ° C, preferably less than -60 ° C is particularly preferable. When Tg is −50 ° C. or higher, the elasticity of the intermediate layer itself is lowered, the adhesiveness of the heat-sensitive adhesive material to the surface of the adherend is not sufficiently obtained, and the effect of improving the adhesive strength may be difficult to be exhibited.

  The foamable filler is a hollow plastic filler containing a thermoplastic resin as a base and containing a foaming agent of a low-boiling solvent inside, and various types are applied, but the particle diameter is in an unfoamed state. In this case, it is 2 to 50 μm, and in the foamed state, 10 to 100 μm, preferably 10 to 50 μm. Examples of the thermoplastic resin used as the plastic filler include polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, and copolymers thereof. Further, as the foaming agent contained in the bag, propane, butane, or a mixture thereof is generally used.

In order to form a foamable intermediate layer on the surface of the support, the foamable plastic filler described above is coated and dried on the support together with a binder and a dispersion medium, and then a thermal drum is brought into close contact with the coating surface, thereby the plastic filler. May be heated and foamed. The coating amount of the plastic filler is at least 1 g / m ² or more, preferably about ² to 5 g / m ² as the dry mass of the unfoamed filler. Moreover, the usage-amount of a binder should just be a quantity sufficient to make a foamable intermediate | middle layer bind | bond | bond with respect to a support body normally, Usually, it is 5-50 mass% with respect to the total amount of an unfoamed filler and a binder. is there. The heating foaming temperature is a temperature at which the thermoplastic resin constituting the filler ridge is softened. The expansion ratio is usually 2 to 4 times, preferably about 2 to 3 times, and is appropriately selected so as to achieve the above foaming.

  Since the surface of the foamable intermediate layer formed on the support is considerably uneven as described above, the surface of the foamable intermediate layer is smoothed by calendering after the foamable intermediate layer is formed (after heating and foaming). In addition, if necessary, one or a plurality of undercoat layers can be provided on the surface or the lower surface of the foamable intermediate layer.

  In the intermediate layer, a filler, a heat-fusible substance (sensitizer), a surfactant, and the like can be used in combination with the fine hollow particles or the foamable filler and the binder as necessary. In this case, examples of the filler include inorganic fine powders such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, and the like. Organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and the like. Examples of the heat fusible substance (sensitizer) include higher fatty acids or their In addition to esters, amides or metal salts, various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, p -Benzylbiphenyl and other thermofusible organic compounds such as those having a melting point of about 50 to 200 ° C.

  In the heat-sensitive adhesive material according to the second aspect of the present invention, a heat-sensitive recording layer mainly comprising a leuco dye and a developer is formed on the opposite surface of the support on which the heat-sensitive adhesive layer is formed. Can do. As the leuco dye used in this heat-sensitive recording layer, leuco dyes generally known in this type of leuco recording material can be used, for example, triphenylmethane, fluoran, phenothiazine, auramine, spiropyran, A leuco compound of a dye such as indinophthalide is preferably used. Specific examples of such leuco dyes include 3,3-bis (p-dimethylaminophenyl) phthalide and 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also called crystal violet lactone). 3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7 , 8-Benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane 3- (Np-tolyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- {N- (3'- Trifluoromethylphenyl) amino} -6-diethylaminofluorane, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-dibutyl Amino-7- (o-chloroanilino) fluorane, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-ani Linofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -5-methyl-7- ( , N-dibenzylamino) fluorane, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrospirane, 6'-bromo-3'-methoxy-benzoindolino-pyrospirane, 3- (2 ' -Hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy) -5'-nitrophenyl) phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl) phthalide, 3-diethylamino-6-methyl-7- (2 ′, 4′-dimethylanilino) fluorane, 3- (2′-methoxy-4′-dimethylaminophenyl) -3- (2′-hydroxy-4′-chloro) -5'-methylphenyl) phthalide, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro- 7- (N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5-chloro-7- (α-phenylethylamino) ) Fluorane, 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluorane, 3-diethylamino-5-methyl- 7- (α-phenylethylamino) fluorane, 3-diethylamino-7-piperi Nofluorane, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluorane, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo-7-α-naphthylamino -4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino-4 ', 5'-benzofluorane, 3-diethylamino-6-methyl-7- (2', 4'-dimethylanilino ) Fluorane, 3- (p-dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} phthalide, 3- (p-dimethylaminophenyl) -3- {1 , 1-Bis (p-dimethylaminophenyl) ethylene-2-yl} -6-dimethylaminophthalide, 3- (4′-dimethylamino-2′-methoxy) -3- (1 ″ -p -Dimethylaminophenyl-1 "-p-chlorophenyl-1", 3 "-butadiene-4" -yl) benzophthalide, 3- (4'-dimethylamino-2'-benzyloxy) -3- ( 1 ″ -p-dimethylaminophenyl-1 ″ -phenyl-1 ″, 3 ″ -butadiene-4 ″ -yl) benzophthalide, 3-dimethylamino-6-dimethylamino-fluorene-9-spiro- 3 ′-(6′-dimethylamino) phthalide, 3,3-bis {2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl} -4,5,6,7-tetrachlorophthalic acid 3-bis {1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl} -5,6-dichloro-4,7-dibromophthalide, bis (p-dimethylaminostyryl) -1- Naphthalenesulfonylmethane, 3- (N-methyl-N-propylamino) -6-methyl-7-anilidefluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3,6-bis (dimethylamino) fluorane spiro (9,3 ′)-6′-dimethylaminophthalide, 3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N- (2-ethoxypropyl) amino-6-methyl- 7-anilinofluorane, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino-4 ′, 5′-benzo Fluorane, 3-N-methyl-N-isobutyl-6-methyl-7-anilinofluorane, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane, etc. Can.

  Further, in the heat-sensitive recording layer in the heat-sensitive adhesive material of this aspect, various electron-accepting compounds as a developer, such as phenolic compounds, thiophenolic compounds, thiourea derivatives, organic acids and metal salts thereof, etc. Can be applied. Specific examples thereof include 4,4′-isopropylidenebisphenol, 3,4′-isopropylidenebisphenol, 4,4′-isopropylidenebis (o-methylphenol), 4,4′-secondary butylidenebisphenol, 4 , 4′-isopropylidenebis (o-tertiarybutylphenol), 4,4′-cyclohexylidenediphenol, 4,4′-isopropylidenebis (2-chlorophenol), 2,2′-methylenebis (4-methyl) -6-tertiarybutylphenol), 2,2'-methylenebis (4-ethyl-6-tertiarybutylphenol), 4,4'-butylidenebis (6-tertiarybutyl-2-methyl) phenol, 1,1,3 -Tris (2-methyl-4-hydroxy-5-tertiarybutylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4′-thiobis (6-tertiarybutyl-2-methyl) phenol, 4,4′-diphenolsulfone 4,2′-diphenolsulfone, 4-isopropoxy-4′-hydroxydiphenylsulfone, 4-benzyloxy-4′-hydroxydiphenylsulfone, 4,4′-diphenolsulfoxide, isopropyl P-hydroxybenzoate, P Benzyl hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,7-bis (4-hydroxyphenylthio) -3,5-dioxaheptane, 1,5-bis (4 -Hydroxyphenylthio) -3-oxaheptane, 1,3-bis (4-hydroxy Enylthio) -propane, 2,2′-methylenebis (4-ethyl-6-tertiarybutylphenol), 1,3-bis (4-hydroxyphenylthio) -2-hydroxypropane, N, N′-diphenylthiourea, N, N′-di (m-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, salicyl-o-chloroanilide, 2-hydroxy-3-naphthoic acid, antipyrine complex of zinc thiocyanate, 2-acetyl Zinc salt of oxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid, hydroxy naphthoic acid zinc, aluminum, calcium and other metal salts, bis- (4-hydroxyphenyl) Acetic acid methyl ester, bis- (4-hydroxyphenyl) acetic acid benzyl ester, 4- {β -(P-methoxyphenoxy) ethoxy} salicylic acid, 1,3-bis (4-hydroxycumyl) benzene, 1,4-bis (4-hydroxycumyl) benzene, 2,4'-diphenolsulfone, 3, 3'-diallyl-4,4'-diphenolsulfone, α, α-bis (4-hydroxyphenyl) -α-methyltoluenezinc thiocyanate antipyrine complex, tetrabromobisphenol A, tetrabromobisphenol S, 4,4 Examples include '-thiobis (2-methylphenol), 3,4-hydroxy-4'-methyl-diphenylsulfone, 4,4'-thiobis (2-chlorophenol), and the like.

  In order to form a heat-sensitive recording layer in the heat-sensitive adhesive material of this aspect, a leuco dye and a developer may be bonded and supported on a support. In this case, various conventional binders can be used as appropriate. Examples of such binders include polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, polyacrylic acid soda, polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer Water-soluble compounds such as acrylamide / acrylic acid ester / methacrylic acid terpolymers, styrene / maleic anhydride copolymer alkali salts, isobutylene / maleic anhydride copolymer alkali salts, polyacrylamide, sodium alginate, gelatin, casein, etc. In addition to functional polymers, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid ester, polybutyl methacrylate, vinyl chloride / acetic acid Cycloalkenyl copolymer, ethylene / emulsion and styrene / butadiene copolymer vinyl acetate copolymer, it can be mentioned latices such as styrene / butadiene / acrylic copolymer.

  Moreover, when forming a heat-sensitive recording layer in the heat-sensitive adhesive material of this aspect, various heat-fusible substances can be used as fillers. Specific examples of fillers include fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, zinc stearate, aluminum stearate, calcium stearate, zinc palmitate, zinc behenate and the like. Fatty acid metal salts, p-benzylbiphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, β-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, 1- Hydroxy-2-naphthoic acid methyl ester, diphenyl carbonate, terephthalic acid dibenzyl ester, terephthalic acid dimethyl ester, 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1 , 2-bis (phenoxy) ethane, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1,4-bis (phenoxy) butane, 1,4-bis (Phenoxy) -2-butene, 1,2-bis (4-methoxyphenylthio) ethane, dibenzoylmethane, 1,4-bis (phenylthio) butane, 1,4-bis (phenylthio) -2-butene, , 2-bis (4-methoxyphenylthio) ethane, 1,3-bis (2-vinyloxyethoxy) benzene, 1,4-bis (2-vinyloxyethoxy) benzene, p- (2-vinyloxyethoxy) Biphenyl, p-aryloxybiphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, 1,3-dibenzoyloxypropane, dibenzyl Sulfide, 1,1-diphenylethanol, 1,1-diphenylpropanol, p- (benzyloxy) benzyl alcohol, 1,3-diphenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-octadecylcarbamoyl Benzene, oxalic acid dibenzyl ester, 1,5-bis (p-methoxyphenyloxy) -3-oxapentane and the like can be mentioned.

  In the production of the heat-sensitive adhesive material having the heat-sensitive recording layer of the present invention, auxiliary additive components commonly used in ordinary heat-sensitive recording layers, such as surfactants and lubricants, can be used in combination. . In this case, examples of the lubricant include higher fatty acids and metal salts thereof, higher fatty acid amides, higher fatty acid esters, animal, vegetable, mineral, and petroleum-based waxes.

  In the production of the heat-sensitive adhesive material having the heat-sensitive recording layer of the present invention, an undercoat layer is provided between the support and the heat-sensitive recording layer, if necessary, and image reliability is provided on the heat-sensitive recording layer. For example, a protective layer mainly composed of a water-soluble resin may be provided for the purpose of improving the property. In this case, as the components constituting these layers, the above-described fine hollow particles, binder, filler, binder, thermofusible substance, surfactant and the like can be used.

  The heat-sensitive recording layer can be formed by a generally known method. For example, first, the leuco dye and the developer are separately pulverized and dispersed together with an aqueous binder solution by a dispersing machine such as a ball mill, an attritor, or a sand mill until the dispersed particle size becomes 1 to 3 μm, and a filler as required. In addition to the heat-fusible substance (sensitizer) dispersion, etc., a heat-sensitive recording layer coating solution is prepared by mixing in a predetermined formulation, and the above-mentioned known surface is formed on the opposite surface on which the heat-sensitive adhesive layer is formed on the support. A heat-sensitive recording layer can be formed by coating by a coating method.

  The heat-sensitive adhesive material of the present invention having a heat-sensitive recording layer can form a printed image on the heat-sensitive recording layer formed on the support, and further, the heat-sensitive adhesive layer is positioned on the heat-sensitive printer. Timing marks for detection can be printed and formed. As a printing method, the above-described printing machine or the like can be used.

  As the printing ink, for example, a UV curable ink is preferably used because it is excellent in productivity and the like. However, in UV drying, it is necessary to prevent the heat-sensitive adhesive material from sticking due to the heat generation, and a reflective cold mirror or a UV drying apparatus with a cooling device is effective.

  The heat-sensitive adhesive material of the second aspect of the present invention is produced in a sheet or tape shape larger than labels, tags, etc., and the sheet- or tape-shaped heat sensitive adhesive material is cut as necessary. Can be used. In this case, the sheet-like or tape-like heat-sensitive adhesive material may be preliminarily cut according to the size of the label, tag, or the like. This is advantageous in that the heat-sensitive adhesive material can be suitably used for various uses such as labels and tags.

  There is no restriction | limiting in particular as a shape of the heat sensitive adhesive material of this invention, A label form, a sheet form, a roll shape, a fanfold shape etc. are mentioned suitably. Since the heat-sensitive adhesive material of the present invention has good blocking resistance, even if the heat-sensitive adhesive material formed in the form of a label or sheet is stacked, it does not adhere and become unusable. Also, the heat-sensitive adhesive material formed in a roll shape can be suitably used without the roll being fixed during storage and becoming unusable from the roll during use.

  The adherend to which the heat-sensitive adhesive material of the present invention is affixed is not particularly limited, and its size, shape, structure, material, and the like can be appropriately selected according to the purpose. For example, polyolefins such as polyethylene and polypropylene, resin plates such as acrylic, polyethylene terephthalate (PET), polystyrene and nylon, metal plates such as SUS and aluminum, paper products such as envelopes and cardboard, polyolefin wraps, polyvinyl chloride Preferable examples include wraps made of polyethylene and non-woven fabric made of polyethylene (such as envelopes).

  Among these, corrugated paper has a rough surface, and it is generally difficult to apply a heat-sensitive adhesive material. However, the heat-sensitive adhesive material of the present invention can exhibit a strong adhesive force not only immediately after application but also after a long period of time. Therefore, even corrugated cardboard paper is advantageous in that it can be firmly adhered for a long time.

  The method for activating the heat-sensitive adhesive layer in the heat-sensitive adhesive material of the present invention (to make it stickable by exhibiting adhesiveness) is not particularly limited and can be appropriately selected according to the purpose. Examples include an activation method using hot air, an activation method using a hot roll, and an activation method using a thermal head. Among these, an activation method using a thermal head is preferable, and in this case, a heat-sensitive adhesive layer and a heat-sensitive adhesive layer of a heat-sensitive adhesive material are obtained by an apparatus in which a thermal activation unit using a thermal head is assembled to an existing thermal recording printer apparatus. Heating both surfaces of the recording layer almost simultaneously is advantageous in that recording on the heat-sensitive recording layer and activation of the heat-sensitive adhesive layer can be performed simultaneously.

[Example]
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The parts and% shown below are based on mass.
Example 1
A mixture having the following composition was dispersed using a sand mill so that the average particle size of the solid was 1.0 μm to prepare a hot-melt material dispersion [liquid A].
[Liquid A]
Benzyl acid 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts Heat-sensitive adhesive dispersion having the following composition [B1 solution ] Was produced.
[B1 solution]
20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C, nonvolatile content 50%)
[Liquid A] 100 parts [Liquid B1] was coated on the back of high-quality paper having a basis weight of 80 g / m ² to a dry mass of 16 g / m ² to prepare a heat-sensitive adhesive material. 1).

(Example 2)
A heat-sensitive adhesive material was prepared in the same manner as in Example 1 except that the heat-sensitive adhesive dispersion [B1 liquid] in Example 1 was changed to a heat-sensitive adhesive dispersion [B2 liquid] having the following composition.
[B2 liquid]
20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C, nonvolatile content 50%)
[Liquid A] 34 parts This heat-sensitive adhesive material was designated as heat-sensitive adhesive material (2).

(Example 3)
A heat-sensitive adhesive material was prepared in the same manner as in Example 1 except that the heat-sensitive adhesive dispersion [B1 liquid] in Example 1 was changed to a heat-sensitive adhesive dispersion [B3 liquid] having the following composition.
[B3 solution]
20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C, nonvolatile content 50%)
[Liquid A] 166 parts This heat-sensitive adhesive material was designated as heat-sensitive adhesive material (3).

Example 4
A heat-sensitive adhesive material was produced in the same manner as in Example 1 except that the heat-sensitive adhesive dispersion [B1 liquid] in Example 1 was changed to a heat-sensitive adhesive dispersion [B4 liquid] having the following composition.
[B4 solution]
20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C, nonvolatile content 50%)
[Liquid A] 30 parts This heat-sensitive adhesive material was designated as heat-sensitive adhesive material (4).

(Example 5)
A heat-sensitive adhesive material was prepared in the same manner as in Example 1 except that the heat-sensitive adhesive dispersion [B1 liquid] in Example 1 was changed to a heat-sensitive adhesive dispersion [B5 liquid] having the following composition.
[B5 solution]
20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C, nonvolatile content 50%)
[Liquid A] 170 parts This heat-sensitive adhesive material was designated as heat-sensitive adhesive material (5).

(Example 6)
A heat-sensitive adhesive material was prepared in the same manner as in Example 1 except that the heat-sensitive adhesive dispersion [Liquid B1] in Example 1 was changed to a heat-sensitive adhesive dispersion [Liquid C] having the following composition.
[C liquid]
20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C, nonvolatile content 50%)
Heat-meltable substance dispersion [Liquid A] 100 parts Terpene phenol resin (softening point 150 ° C., non-volatile content 53%) 10 parts This heat-sensitive adhesive material was used as a heat-sensitive adhesive material (6).

(Example 7)
<Preparation of intermediate layer coating solution>
A mixture having the following composition was stirred and dispersed to prepare an intermediate layer coating solution [solution D].
[Liquid D]
Micro hollow particles (acrylonitrile / vinylidene chloride / methyl methacrylate copolymer)
(Solid content concentration 41%, average particle size 3.6 μm, hollowness 90%) 14.6 parts styrene acrylic copolymer 21.7 parts (solid content concentration 55.4%, Tg-45 ° C.)
Surfactant Dapro W-77 (manufactured by Elementis Japan) 0.1 part Water 63.6 parts <Preparation of heat-sensitive adhesive material>
The intermediate layer coating solution [D solution] was dried on the back of 80 g / m ² single-sided coated paper, and then dried so as to have a mass of 5 g / m ² to provide an intermediate layer. On this intermediate layer, the heat-sensitive adhesive dispersion [B1 solution] described in Example 1 was applied and dried to a dry mass of 16 g / m ² to prepare a heat-sensitive adhesive material. It was set as material (7).

(Example 8)
A heat-sensitive adhesive material was prepared in the same manner as in Example 7 except that the intermediate layer coating solution [E solution] having the following composition was used instead of the intermediate layer coating solution [D solution].
[E liquid]
Micro hollow particles (acrylonitrile / vinylidene chloride / methyl methacrylate copolymer)
14.6 parts (solid content concentration 41%, average particle size 3.6 μm, hollowness 90%)
Acrylic ester copolymer 21.7 parts (solid content concentration 55.4%, Tg-65 ° C.)
Surfactant Dapro W-77 (manufactured by Elementis Japan) 0.1 part Water 63.6 parts This heat-sensitive adhesive material was used as a heat-sensitive adhesive material (8).

Example 9
<Adjustment of coating liquid for under layer>
A mixture having the following composition was stirred and dispersed to prepare an underlayer coating solution [F solution].
[F liquid]
Micro hollow particle dispersion Copolymer resin mainly composed of vinylidene chloride / acrylonitrile 30 parts (solid content concentration 32%, average particle size 3.0 μm, hollowness 92%)
10 parts of styrene / butadiene copolymer latex (Tg + 4 ° C, nonvolatile content 48%)
60 parts of water <Preparation of thermosensitive coloring layer solution>
A mixture having the following composition was dispersed using a sand mill so that the average particle diameter was about 1.5 μm to prepare a color developer dispersion [G1 liquid] and a developer dispersion [G2 liquid].
[G1 solution]
3-Di-n-butylamino-6-methyl-7-anilinofluorane 20 parts Polyvinyl alcohol (10% aqueous solution) 10 parts Water 70 parts [G2 solution]
4-Isopropoxy-4′-hydroxydiphenylsulfone 10 parts Polyvinyl alcohol (10% aqueous solution) 25 parts Calcium carbonate 15 parts Water 50 parts [Liquid H]
Next, 10 parts of [G1 liquid] and 80 parts of [G2 liquid] were mixed and stirred to prepare a thermosensitive coloring layer liquid [H liquid].
<Adjustment of protective layer solution>
A mixture having the following composition was pulverized and dispersed in a vertical sand mill so that the average particle size was 1 μm or less to prepare a protective layer primary dispersion [I1 liquid].
[I1 solution]
Aluminum hydroxide 20 parts Polyvinyl alcohol (10% aqueous solution) 20 parts Water 40 parts Using the above protective layer primary dispersion [I1 liquid], a protective layer liquid [I2 liquid] having the following composition was prepared.
[I2 liquid]
[Liquid I1] 10 parts Polyvinyl alcohol (10% aqueous solution) 20 parts Epichlorohydrin aqueous solution (nonvolatile content 12.5%) 5 parts Zinc stearate dispersion (nonvolatile content 30%) 2 parts <Preparation of thermosensitive adhesive material>
Under layer coating solution [F liquid], after drying mass on the surface of quality paper having a basis weight of 80 g / m ² was provided an under layer by coating and drying so as to 4g / m ^2. On this, the thermosensitive coloring layer solution [H solution] was applied and dried so as to have a mass of 5 g / m ² after drying to provide a thermosensitive coloring layer. Next, the protective layer solution [I2 solution] was applied onto the thermosensitive coloring layer so that the mass when dried was about 3 g / m ² and dried. Further, the surface of the protective layer was subjected to a supercalender treatment so that the Oken smoothness was 2000 seconds to obtain a thermal recording paper. A heat-sensitive adhesive layer was prepared by providing a heat-sensitive adhesive layer in the same manner as in Example 1 except that the heat-sensitive color-developing layer of the heat-sensitive recording paper was used instead of the back surface of the fine paper of Example 1, Was a heat-sensitive adhesive material (9).

(Example 10)
In Example 1, when preparing the hot melt material dispersion [liquid A], the hot melt material benzylic acid was changed to (+)-di-p-toluol-D-tartaric acid ((R, R) -di- A heat-sensitive adhesive material (10) was produced in the same manner as in Example 1 except that it was changed to p-toluol tartaric acid.

(Example 11)
In Example 2, except that benzylic acid, which is a hot-melting substance, was changed to (+)-di-p-toluol-D-tartaric acid when preparing the hot-melting substance dispersion [liquid A]. In the same manner, a heat-sensitive adhesive material (11) was produced.

(Example 12)
In Example 3, except that benzylic acid, which is a hot-melting substance, was changed to (+)-di-p-toluol-D-tartaric acid when preparing the hot-melting substance dispersion (liquid A). A heat-sensitive adhesive material (12) was produced in the same manner as described above.

(Example 13)
In Example 4, when preparing the hot melt material dispersion [Liquid A], the heat melt material benzyl acid was changed to (+)-di-p-toluol-D-tartaric acid. In the same manner as described above, a heat-sensitive adhesive material (13) was produced.

(Example 14)
Example 5 In Example 5, except that the hot-melting substance benzylic acid was changed to (+)-di-p-toluol-D-tartaric acid when preparing the hot-melting substance dispersion [Liquid A]. A heat-sensitive adhesive material (14) was produced in the same manner as described above.

(Example 15)
In Example 6, Example 6 was performed except that the hot-melt substance benzylic acid was changed to (+)-di-p-toluol-D-tartaric acid when preparing the hot-melt substance dispersion [liquid A]. A heat-sensitive adhesive material (15) was produced in the same manner as described above.

(Example 16)
In Example 7, when preparing the hot melt material dispersion [Liquid A], the heat melt material benzyl acid was changed to (+)-di-p-toluol-D-tartaric acid. A thermosensitive adhesive material (16) was produced in the same manner as described above.

(Example 17)
In Example 8, when preparing the hot melt material dispersion [solution A], the heat melt material benzyl acid was changed to (+)-di-p-toluol-D-tartaric acid. A heat-sensitive adhesive material (17) was produced in the same manner as described above.

(Example 18)
In Example 9, when preparing the hot melt material dispersion [liquid A], the hot melt material benzyl acid was changed to (+)-di-p-toluol-D-tartaric acid. A thermosensitive adhesive material (18) was produced in the same manner as described above.

(Comparative Example 1)
In Example 1, a heat-sensitive adhesive material was obtained in the same manner as in Example 1 except that the heat-meltable substance dispersion [liquid A] was replaced with a heat-meltable substance dispersion [liquid J] having the following composition. Was made.
[J liquid]
2- (2-Hydroxy-5-t-octylphenyl) -2H-benzotriazole
30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts The produced heat-sensitive adhesive material was combined with the heat-sensitive adhesive material (19). did.

(Comparative Example 2)
A heat-sensitive adhesive material was produced in the same manner as in Example 1, except that the heat-sensitive adhesive dispersion [liquid A] was replaced with a heat-meltable substance dispersion [liquid K] having the following composition.
[K liquid]
2- (3,5-di-t-pentyl-2-hydroxyphenyl) -2H-benzotriazole 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0 .15 parts Water 64.85 parts The produced heat-sensitive adhesive material was used as a heat-sensitive adhesive material (20).

(Comparative Example 3)
A heat-sensitive adhesive material was produced in the same manner as in Example 1, except that the heat-sensitive adhesive dispersion [liquid A] was replaced with a heat-meltable substance dispersion [liquid L] having the following composition.
[Liquid L]
5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) -2H-benzotriazole 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allylsulfone) Acid salt) 0.15 parts water 64.85 parts The produced heat-sensitive adhesive material was used as a heat-sensitive adhesive material (21).

(Comparative Example 4)
A heat-sensitive adhesive material was produced in the same manner as in Example 1, except that the heat-sensitive adhesive dispersion [liquid A] was replaced with a heat-meltable substance dispersion [liquid M] having the following composition.
[M liquid]
2-hydroxy-4-benzyloxybenzophenone 30.0 parts polyvinyl alcohol (30% aqueous solution) 5.0 parts surfactant (alkyl-allyl sulfonate) 0.15 parts water 64.85 parts produced thermosensitive adhesive material Was a heat-sensitive adhesive material (22).

(Comparative Example 5)
A heat-sensitive adhesive material was prepared in the same manner as in Example 1, except that the heat-sensitive adhesive dispersion [liquid A] was replaced with a heat-meltable substance dispersion [liquid N] having the following composition.
[N liquid]
2,4-Dihydroxybenzophenone 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts Heat-sensitive adhesive material prepared was heat sensitive The pressure-sensitive adhesive material (23) was obtained.

(Comparative Example 6)
A heat-sensitive adhesive material was produced in the same manner as in Example 1, except that the heat-sensitive adhesive dispersion [liquid A] was replaced with a heat-meltable substance dispersion [O liquid] having the following composition.
[O liquid]
2,2′-Dihydroxy-4,4′-dimethoxybenzophenone 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts Preparation The heat-sensitive adhesive material thus obtained was designated as a heat-sensitive adhesive material (24).

(Comparative Example 7)
A thermosensitive recording layer was prepared in the same manner as in Example 9 except that the hot-melt substance dispersion liquid [J liquid] prepared in Comparative Example 1 was used instead of the hot-melt substance dispersion liquid [A liquid] in Example 9. A heat-sensitive adhesive material was prepared, and this heat-sensitive adhesive material was used as a heat-sensitive adhesive material (25).

<Evaluation of heat-sensitive adhesive material>
1) Adhesive strength evaluation 2 minutes after sticking The heat-sensitive adhesive material (1) to the heat-sensitive adhesive material (25) prepared in the above Examples and Comparative Examples were cut into 40 mm × 150 mm rectangles, respectively. A label test piece was printed using a thermal printing apparatus TH-PMD manufactured by Okura Electric. The thermal activation head conditions in printing were: energy 0.5 mJ / dot, printing speed 4 ms / line, and platen pressure 6 kgf / B4. Next, the printed heat-sensitive adhesive material was affixed to the corrugated cardboard in the longitudinal direction with a rubber roller having a pressure of 2 kg. 2 minutes after application, the attached heat-sensitive adhesive material was peeled off from the cardboard paper under the conditions of a peel angle of 180 degrees and a peel speed of 300 mm / min. The adhesive strength at that time was measured with a force gauge, and the value obtained by reading and averaging the data at 0.1 second intervals was defined as the adhesive strength. The unit is gf / 40 mm. This test was conducted in a normal temperature environment (22 ° C., 65% RH), and for each thermal adhesive material, five test pieces were evaluated and the average values are shown in Table 1. In the adhesive evaluation,
○: 500 gf / 40 mm or more Δ: 100 gf / 40 mm to 500 gf / 40 mm
X: Less than 100 gf / 40 mm.

2) Evaluation of adhesive strength 30 days after application In the same manner as the evaluation of adhesive strength 2 minutes after application, a test piece of heat-sensitive adhesive label was prepared for each heat-sensitive adhesive material, printed and affixed to corrugated paper. . The cardboard paper to which the test piece was attached was stored for 30 days under the conditions of 40 ° C. and dry after being attached, and then the attached heat-sensitive adhesive material was peeled from the cardboard paper under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 mm / min. The adhesive strength at that time was measured with a force gauge, and the value obtained by reading and averaging the data at 0.1 second intervals was defined as the adhesive strength. The unit is gf / 40 mm. This test was conducted in a normal temperature environment (24 ° C., 65% RH). Five test pieces were evaluated for each heat-sensitive adhesive material, and the average value is shown in Table 1. In the adhesive strength evaluation, “◯”, “Δ”, and “X” are the same as the adhesive strength evaluation 2 minutes after the pasting.

3) Evaluation of blocking property A test piece of a heat-sensitive adhesive label was prepared in the same manner as in the above-described adhesive strength test for each heat-sensitive adhesive material in the same manner as the adhesive strength evaluation after 2 minutes of pasting. However, 10 test pieces were prepared for each heat-sensitive adhesive material. Place one test piece on the opposite side of the heat-sensitive adhesive layer of the other test piece made of the same heat-sensitive adhesive material, and pressurize at 60 ° C., Dry condition for 24 hours at a pressure of 200 g / cm ² did. Thereafter, the pressurization and heating were stopped and the sample was allowed to stand at room temperature, and then the two test pieces were peeled off. The blocking resistance at that time was evaluated according to the following ranking. For each heat-sensitive adhesive material, five sets of test pieces were evaluated and the average values are shown in Table 1.
<Blocking resistance evaluation score and qualitative evaluation>
10 (◎): The heat-sensitive adhesive material is caught by its own weight.

  9 (◎): The heat-sensitive adhesive material is slightly caught, but there is no peeling sound of the heat-sensitive adhesive material.

  8 (◯): The heat-sensitive adhesive material is caught and the heat-sensitive adhesive material has some peeling sound.

  7 (◯): There is a clear peeling sound of the heat-sensitive adhesive material.

  6 (Δ): Point-like transfer of the heat-sensitive adhesive material is observed on a part (30% or less) of the adhesive surface.

  5 (Δ): Point-like transfer of the heat-sensitive adhesive material is observed in the range of 30% to 50% of the adhesive surface.

  4 (Δ): Point-like transfer of the heat-sensitive adhesive material is observed at 50% or more of the adhesive surface.

  3 (x): peeling between layers of the heat-sensitive adhesive material is observed on a part (30% or less) of the adhesive surface.

  2 (x): peeling between layers of the heat-sensitive adhesive material is observed at 30% or more of the adhesive surface.

表１から判るように、本発明の感熱性粘着材料（１）乃至（１８）は、段ボール紙への貼付直後の接着強度だけでなく、長期間（３０日）保存後においても十分な接着強度を示している。また、ブロッキング性の評価においても、使用上問題のないランク８以上であり大半はランク１０と良好であった。裏側に感熱記録層を設けた感熱性粘着材料（９）及び（１８）においても十分な接着強度と耐ブロッキング性を示していた。また、微小中空粒子による中間層を設けた感熱性粘着材料（７）、（８）、（１６）及び（１７）については、段ボール紙への粘着特性及び耐ブロッキング性が特に優れていることを示している。さらに、ガラス転移温度が−５０度未満であるアクリル酸エステル共重合体を用いた中間層を設けた感熱性粘着材料（８）及び（１７）は特に接着強度が高いことが判る。

As can be seen from Table 1, the heat-sensitive adhesive materials (1) to (18) of the present invention have sufficient adhesive strength not only after adhesion to cardboard paper but also after storage for a long period (30 days). Is shown. Further, in the evaluation of blocking property, it was rank 8 or higher with no problems in use, and most of them were as good as rank 10. The heat-sensitive adhesive materials (9) and (18) provided with a heat-sensitive recording layer on the back side also showed sufficient adhesive strength and blocking resistance. In addition, the heat-sensitive adhesive material (7), (8), (16) and (17) provided with an intermediate layer of fine hollow particles is particularly excellent in adhesive properties to cardboard paper and blocking resistance. Show. Furthermore, it can be seen that the heat-sensitive adhesive materials (8) and (17) provided with an intermediate layer using an acrylic ester copolymer having a glass transition temperature of less than −50 ° C. have particularly high adhesive strength.

Although the embodiments and examples of the present invention have been specifically described above, the present invention is not limited to these embodiments and examples, and these embodiments and examples of the present invention are not limited thereto. Can be changed or modified without departing from the spirit and scope of the present invention.

  The heat-sensitive adhesive material of the present invention can be suitably used as various labels, particularly as a label for corrugated paper. The composition of the present invention is effective as a raw material for the heat-sensitive adhesive material of the present invention.

Claims (7)

A heat- sensitive adhesive containing a thermoplastic resin and a hot-melt material ,
The thermoplastic resin is a natural rubber latex, a natural rubber latex, a polyvinyl acetate, a methacrylic acid ester copolymer, an acrylic acid ester-methacrylic acid ester copolymer, a synthetic rubber, a vinyl acetate- 2-ethylhexyl acrylate copolymer, vinyl acetate-ethylene copolymer, vinyl pyrrolidone-styrene copolymer, vinyl pyrrolidone-acrylate copolymer, styrene-acryl copolymer, acrylate copolymer, and A resin selected from polyurethane resins,
The heat- sensitive adhesive is characterized in that the heat-meltable substance is benzyl acid or di-p-toluol tartaric acid. 2. The heat- sensitive adhesive according to claim 1, wherein the content of the hot-melt material is 50 parts by mass or more and 600 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. The heat-sensitive adhesive according to claim 1 or 2, further comprising a tackifier . The heat sensitive adhesive material which provided the heat sensitive adhesive layer which consists of a heat sensitive adhesive as described in any one of Claims 1 thru | or 3 on the surface of the support body.   The heat-sensitive adhesive material according to claim 4, wherein an intermediate layer containing fine hollow particles is provided between the support and the heat-sensitive adhesive layer.   The heat-sensitive adhesive material according to claim 5, wherein the intermediate layer further comprises an acrylate copolymer having a glass transition temperature of less than -50 ° C.   The heat-sensitive adhesive material according to any one of claims 4 to 6, further comprising a heat-sensitive recording layer containing a leuco dye and a developer.