JP2001066991A - Thermal tacky adhesive label and its thermal activation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printable label which has good tacky adhesive power to an adherend and has excellent blocking resistance by providing the surface of a pressure sensitive tacky adhesive layer with a sealing layer which contains a hot meltable material compatible with the pressure sensitive tacky adhesive layer at the time of heat impression and having a melting point higher than a specific temperature and which itself does not develop tacky adhesiveness at the time of heat impression. SOLUTION: A base is provided with the pressure sensitive tacky adhesive layer and the surface of this pressure sensitive tacky adhesive layer is provided with the sealing layer which contains the hot meltable material compatible with the pressure sensitive tacky adhesive layer at the time of heat impression and having the melting point of >=50 deg.C and which itself does not develop the tacky adhesiveness at the time of heat impression. A thermoplastic resin and/or a tackifier is incorporated into this sealing layer. Various kinds of pressure sensitive tacky adhesives used in this field are usable as the pressure sensitive tacky adhesive to be used in this pressure sensitive tacky adhesive layer. More specific examples include polyvinyl acetate, vinyl acetate/ ethylene copolymer, vinyl acetate/acrylate copolymer, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive label that does not require a release paper, and more particularly to a heat-adhesive label that does not require a release paper and develops adhesiveness by heat.

[0002]

2. Description of the Related Art In recent years, thermosensitive recording labels having adhesive properties have been used in a wide range of fields such as the POS field, and these labels usually have a release paper attached on a pressure-sensitive adhesive layer. Is common. However, although such a thermosensitive recording label having adhesiveness is useful,
On the other hand, it has many disadvantages. That is, since the release paper is peeled off when the label is attached to the article and discarded, it is a waste of resources and a waste of space of the wound body, and therefore leads to an increase in cost. Also, when attaching a label to an article, the operation of peeling off the release paper is troublesome.

[0003] In order to solve these problems, there have been proposed some thermal recording labels having adhesiveness without using release paper. For example, Japanese Utility Model Laid-Open No. 59-43979
No., 59-46265, 60-60484
In No. 2 etc., a microcapsule of an adhesive is provided, and a release layer for the adhesive is provided on a protective layer provided on the heat-sensitive recording layer in order to isolate (block or seal) the protective layer during winding. In addition, linerless thermal recording labels have been proposed. However, these thermal recording labels that do not use release paper have problems such as low adhesive strength and the inability to print on the surface of the thermal recording layer, and have not been put to practical use.

A method using a heat-sensitive adhesive (thermal adhesive) as a functional adhesive is disclosed in Japanese Patent Laid-Open No. 63-30338.
No. 7, Japanese Utility Model Publication No. 5-115773, which is particularly inferior in adhesiveness as compared with existing thermal recording labels. In addition, the heat-sensitive adhesive obtained by these methods has relatively good adhesive strength to paper, PET film, and the like, but the vinyl wrap (P) used in the food POS field is used.
(VC wrap) and polyethylene wrap (PE wrap) have low adhesive strength and have not reached a practical level.

Further, simple thermal adhesive labels having no heat-sensitive recording layer are disclosed in JP-A-63-152686, JP-A-6-57226, JP-A-6-57233, and the like. On the other hand, the heat-adhesive label uses a material having high adhesiveness when heated. Therefore, even when wound and stored, depending on the storage temperature, part of the adhesiveness is exhibited, and the front and back surfaces stick together, causing blocking.

In order to prevent this blocking, it is necessary to control the adhesiveness. In order to solve this, it is necessary to use an appropriate resin for the adhesive in order to achieve both the adhesive strength and the blocking ability. Although proposals have been made, the adhesive strength and blocking properties have not yet been completely achieved, and when blocking is prevented, the adhesive strength eventually becomes weaker, and the adhesive strength to the adherend such as polyvinyl chloride wrap or polyethylene wrap and blocking. The fact is that a heat-adhesive label that balances properties has not yet been developed as a simple label or a label for thermal recording.

Japanese Patent Application Laid-Open No. 9-20079 discloses a technique for achieving both the adhesive strength and the blocking property, in which the pressure-sensitive adhesive layer is activated by heat on the pressure-sensitive adhesive layer for the purpose of preventing blocking at the time of winding. A thermal recording label provided with a barrier layer is disclosed. In this label, the adhesiveness is sufficiently strong because of the pressure-sensitive adhesive, and furthermore, the seal layer itself exhibits the adhesiveness when heat is applied, so the adhesiveness is strong, but the function of the seal layer is not sufficient and blocking occurs. Therefore, in order to satisfy the blocking resistance, it is necessary to increase the thickness of the barrier layer, but in such a case, the adhesiveness at the time of applying heat is insufficient, and the adhesive strength to PVC wrap and polyethylene wrap becomes insufficient, and It is difficult to achieve both blocking and adhesion.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive adhesive layer and a seal layer (one side of a support) on one side of a support in view of the current state of the above-mentioned heat-sensitive recording label or a mere heat-adhesive label. A shielding layer) and, if necessary, a linerless label provided with a thermosensitive recording on the other side of the support,
Adhesive strength to each adherend, especially strong to PVC wrap, polyethylene wrap, etc., and good blocking properties, it is possible to print on the surface of the thermosensitive recording layer, moreover, the rising properties of thermosensitive recording of thermosensitive recording, An object of the present invention is to provide a heat-adhesive label (including a label for heat-sensitive recording) whose sensitivity is maintained at a conventional level.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a heat-sensitive recording layer is provided on the surface of the support as necessary, and the heat-sensitive recording layer is formed on the back surface of the support. Among those provided with a pressure-sensitive adhesive layer and a specific sealing layer (shielding layer) in that order, the sealing layer is only compatible with the pressure-sensitive adhesive layer when heat is applied, and does not itself exhibit adhesiveness when heat is applied. As a result, it was found that the above object was achieved, and the present invention was completed.

According to the present invention, first, a pressure-sensitive adhesive layer is provided on a support, and has a melting point on the pressure-sensitive adhesive layer that is compatible with the pressure-sensitive adhesive layer when heat is applied. A heat-adhesive label is provided, which comprises a seal layer containing a heat-meltable substance at 50 ° C. or higher and not exhibiting adhesiveness when heat is applied.

Second, there is provided the first heat-adhesive label, wherein the seal layer contains at least 70% by weight or more of a heat-fusible substance having a melting point of 50 ° C. or more.

Third, there is provided the above-mentioned first or second thermo-adhesive label, characterized in that the seal layer contains a thermoplastic resin and / or a tackifier.

Fourth, the heat-sensitive adhesive label according to any one of the first to third aspects, wherein a heat-sensitive recording layer is provided on the surface of the support opposite to the pressure-sensitive adhesive layer. Is done.

Fifthly, a thin film resistor is provided on a ceramic substrate, and a surface on the thin film resistor side of a heating means having a protective film provided on a surface of the thin film resistor; A heat-sensitive adhesive label, wherein the heat-sensitive adhesive label is brought into contact with the sealing layer to develop the pressure-sensitive adhesive layer.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The heat-adhesive label of the present invention is obtained by sequentially laminating a pressure-sensitive adhesive layer and a seal layer (shielding layer) on a support, and the seal layer does not necessarily exhibit adhesiveness when heat is applied.
Compatible with the pressure-sensitive adhesive layer, homogenized in the pressure-sensitive adhesive layer,
Any material may be used as long as it is integrated, so that the adhesiveness can be sufficiently developed by applying heat.

Therefore, since the seal layer in the present invention is formed without exhibiting adhesiveness when heat is applied, the material and the adhesiveness when heated can be made not too strong, and blocking can be prevented. Since it is not heat-adhesive, the range of materials to be selected is widened, and the adhesive strength to PVC wrap and polyethylene wrap is also sufficient. In addition, since the pressure-sensitive adhesive layer does not exhibit tackiness during storage during storage, printing on the heat-sensitive recording layer is also possible.

The label for heat-sensitive recording of the present invention is provided with a heat-sensitive recording layer mainly composed of a colorless or light-colored leuco dye and a developer on the surface of a support, and a pressure-sensitive adhesive layer on the back of the support. And a release paper on which the seal layer (a seal layer containing a heat-meltable substance which is usually solid, thermally melted by heat and compatible with the pressure-sensitive adhesive layer) is sequentially provided. . After the heat-sensitive recording label of the present invention is subjected to heat-sensitive recording, heat is applied to the pressure-sensitive adhesive layer and the seal layer by heating the seal layer with a thin-film resistor heater such as a thermal head in order to develop the adhesiveness by applying heat. Are compatible with each other, and the adhesive force of the pressure-sensitive adhesive is obtained. Here, the adhesive strength is particularly strong against polyvinyl chloride wrap or polyethylene wrap, etc., and usually there is no surface stickiness due to the sealing layer, so that the blocking property can be improved, the blocking resistance is not too strong, and the blocking resistance on the surface of the heat-sensitive recording layer is further improved. Because there is no conventional silicon processing or the like, printability is also excellent.

As the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer in the present invention, various pressure-sensitive adhesives used in this field can be appropriately used. Specific examples thereof include polyvinyl acetate, vinyl acetate / ethylene copolymer, vinyl acetate / acrylate copolymer, vinyl acetate / maleate copolymer, ethylene / acrylic acid copolymer, epoxy resin, and phenol. Emulsions such as resins, starch, gelatin, casein, polyvinyl alcohol, carboxycellulose, cellulose derivatives such as methylcellulose and hydroxyethylcellulose, and water-soluble resins such as polyvinylpyrrolidone, and the like, but the present invention is not limited thereto. Absent.

The amount of the pressure-sensitive adhesive applied is 5 to 3 on a dry basis.
5 g / m ^2, preferably preferably set to 10 to 25 g / m ^2.

In the present invention, the seal layer which is heat-melted by heating is made of a substance (a heat-meltable substance having a melting point of 50 ° C. or more) which is compatible with the main pressure-sensitive adhesive layer when heat is applied. Become. A specific example of this substance is a plasticizer which is solid at normal temperature. The seal layer may further contain a thermoplastic resin if necessary, and may further contain a tackifier to enhance the adhesion.

As the plasticizer which is solid at room temperature (hereinafter referred to as "solid plasticizer"), the following substances can be used, but not limited thereto. Diphenyl phthalate, Dihexyl phthalate, Dicyclohexyl phthalate, Dihydroabiethyl phthalate, Dimethyl isophthalate, Sucrose benzoate, Ethylene glycol dibenzoate, Trimethylolethane tribenzoate, Glyceride tribenzoate, Pentaery tetrabenzoate Plasticizers that are solid at room temperature, such as Trit, sucrose octaacetate, tricyclohexyl citrate, and N-cyclohexyl-p-trisulfonamide.

As the tackifier contained in the seal layer in the present invention, the following substances can be used, but the present invention is not necessarily limited thereto. Rosin derivatives (rosin, polymerized rosin, hydrogenated rosin or esters thereof such as glycerin pentaerythritol, resin acid dimer, etc.), terpene resin, petroleum resin, phenol resin, xylene resin and the like.

As the thermoplastic resin contained in the seal layer in the present invention, a natural rubber latex obtained by graft-copolymerizing a vinyl monomer is used. A natural rubber latex obtained by graft copolymerization of a methacrylate monomer can be used. Further, a natural rubber latex obtained by graft copolymerization of a methacrylate monomer, in particular, a natural rubber latex grafted by methyl methacrylate monomer can be used.

As the vinyl-based monomer to be graft-copolymerized with the natural rubber, those exemplified below can be used, but are not necessarily limited thereto. For example, a carboxyl group adduct, a methacrylic ester, a hydroxyl group adduct, vinyl acetate, acrylonitrile, acrylamide, glycidyl methacrylate and the like can be mentioned, and these can be used alone or in combination.

If necessary, the polymer resin may be used in combination with the following substances. Polyvinyl acetate, polybutyl methacrylate, synthetic rubber, vinyl acetate /
Acrylic acid / 2-ethylhexyl copolymer, vinyl acetate / ethylene copolymer, vinylpyrrolidone / styrene copolymer, styrene / butadiene copolymer, vinylpyrrolidone / ethyl acrylate copolymer, acrylic / butadiene copolymer, Polymeric resin such as styrene / acrylic copolymer.

The mixing ratio of the solid plasticizer and the thermoplastic resin is 950 to 70: 5 to 30, preferably 90 to 80:10 to 20 by weight. The ratio of the solid plasticizer to the tackifier is 100 to 70: 5 by weight.
-30, preferably 90-80: 10-20. The coating amount of this seal layer is 1 to 20 g / m ^{2 on} a dry basis,
Preferably it is ² to 15 g / m ² . The ratio of the coating amount between the pressure-sensitive adhesive layer and the sealing layer is determined by the dry adhesion amount (g / m2).
^{In 2} ), the ratio is preferably 2: 1 or less, preferably 2.5: 1.0 or less.

The leuco dyes (color formers) used in the heat-sensitive recording layer of the present invention are used alone or as a mixture of two or more kinds. Such leuco dyes are applied to this kind of heat-sensitive recording material. The following are optionally used, but are not limited thereto. For example,
Leuco compounds of dyes such as triphenylmethane, fluoran, phenothiazine, auramine, spiropyran and indolinophthalide are preferably used. Specific examples of such leuco dyes include, for example, those shown below.

3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminephthalide (also known as crystal violet lactone), 3,3-bis (P-dimethylaminophenyl) -6-diethylaminophthalide,
3,3-3-bis (p-diethylaminophenyl) -6
-Chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-
Chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-dimethylamino-7-methylfluorane,
3-diethylamino-7,8-benzfluoran, 3-
Diethylamino-6-methyl-7-chlorofluoran,
3- (Np-tolyl-N-ethylamino) -6-methyl-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 2- [N- (3'- Trifluoromethylphenyl) amino] -6-diethylaminofluoran, 2- [3,6-bis (diethylamine) -9- (o-chloroanilino) xanthylbenzoate lactam], 3-diethylamino-6-methyl-7-
(M-trichloromethylanilino) fluoran, 3-diethylamino-7- (o-chloroanilino) fluoran, 3-di-n-butylamino-7- (o-chloroanilino) fluoran, 3-N-methyl-Nn -Amylamino-6-methyl-7-anilinofluoran, 3-N-
Methyl-N-cyclohexylamino-6-methyl-7-
Anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) fluoran, benzoylleucomethylene blue ,
6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-3'-methoxy-benzoindolino-spiropyran, 3- (2'-hydroxy-
4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3-
(2 ′ methoxy-5′-nitrophenyl) phthalide, 3
-(2'-methoxy-4'-dimethylaminophenyl)
-3- (2'-hydroxy-4'-chloro-5'-methylphenyl) phthalide, 3- (N-ethyl-N-tetrahydrofurfuryl) amino-6-methyl-7-anilinofluoran, 3- N-ethyl-N- (2-ethoxypropyl) amino-6-methyl-7-anilinofluoran;
3-N-methyl-N-isobutyl-6-methyl-7-anilinofluoran, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7-m-trifluoro Methylanilinofluoran, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino) fluoran, 3
-Pyrrolidino-7- (di-p-chlorophenyl) methylaminofluoran, 3-diethylamino-5-chloro-
7- (α-phenylethylamino) fluoran, 3-
(N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluoran, 3-diethylamino-7-
(O-methoxycarbonylphenylamino) fluoran, 3-diethylamino-5-methyl-7- (α-phenylethylamino) fluoran, 3-diethylamino-
7-piperidinofluoran, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluoran, 3- (N-methyl-N-isopropylamino) -6-methyl-7- Anilinofluoran, 3-di-
n-butylamino-6-methyl-7-anilinofluoran, 3,6-bis (dimethylamino) fluoranspiro (9,3 ′)-6′-dimethylaminophthalide, 3-
(N-benzyl-N-cyclohexylamino) -5,6
-Benzo-7-α-naphthylamino-4′-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino-6-methyl-7-
Mesitidino-4 ', 5'-benzofluoran, 3-N-
Methyl-N-isopropyl-6-methyl-7-anilinofluoran, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluoran, 3-diethylamino-
6-methyl-7- (2 ', 4'-dimethylanilino) fluoran and the like.

As the color developer used in the heat-sensitive recording layer of the present invention, various electron-accepting compounds capable of forming a color by contacting the leuco dye under heat, a solvent or the like, or an oxidizing agent are used. Such a device is conventionally known, and specific examples thereof include the following, but are not limited thereto.

4,4'-isopropylidene diphenol, 4,4'-isopropylidenebis (o-methylphenol), 4,4'-secondarybutylidenebisphenol 4,4'-isopropylidenebis (2-tertiary- Butylphenol), zinc p-nitrobenzoate,
1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid, 2,2- (3,4'-dihydroxydiphenyl) propane, bis (4-hydroxy-3 -Methylphenyl)
Sulfide, 4- [β- (p-methoxyphenoxy) ethoxy] salicylic acid, 1,7-bis (4-hydroxyphenylthio) -3,5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -5-oxapentane, phthalic acid monobenzyl ester monocalcic acid,
4,4'-cyclohexylidenediphenol, 4,4 '
-Isopropylidenebis (2, -chlorophenol),
2,2′-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (6
-Tert-butyl-2-methyl) phenol, 1,
1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4 ′ -Thiobis (6-tert-butyl-2-methyl) phenol, 4,4'-diphenolsulfone, 4-isopropoxy-4'-hydroxydiphenylsulfone, 4-benzyloxy-4'-hydroxydiphenylsulfone, 4,4 ' -Diphenol sulfoxide, isopropyl p-hydroxybenzoate, p
Benzyl-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,3-bis (4-hydroxyphenylthio) -propane, N, N′-diphenylthiourea, N,
N′-di (m-chlorophenyl) thiourea, salicylanilide, methyl bis- (4-hydroxyphenyl) acetate, benzyl bis- (4-hydroxyphenyl) acetate,
Benzyl 1,3-bis (4-hydroxyphenyl) acetate, 1,3-bis (4-hydroxycumyl) benzene,
1,4-bis (4-hydroxycumyl) benzene, 2,
4'-diphenol sulfone, 2,2'-diallyl-
4,4'-diphenolsulfone, 3,4-dihydroxyphenyl-4'-methyldiphenylsulfone, zinc 1-acetyloxy-2-naphthoate, zinc 2-acetyloxy-1-naphthoate, 2-acetyloxy- Zinc 3-naphthoate, α, α-bis (4-hydroxyphenyl) -α-methyltoluene, antipyrine complex of zinc thiocyanate, tetrabromobisphenol A, tetrabromobisphenol S, 4,4′-thiobis (2-methyl Phenol), 4,4'-thiobis (2-chlorophenol) and the like.

In the heat-sensitive recording layer of the present invention, the color developer is used in an amount of 1 to 20 parts by weight, preferably 2 to 2 parts by weight, based on 1 part by weight of the color former.
10 parts by weight. These color formers and developers can be used alone or in combination of two or more.

Preferred as the binder resin used in the heat-sensitive recording layer is a resin having a hydroxyl group or a carboxyl group in the molecule. Such resins include, for example, polyvinyl butyral, polyvinyl acetals such as polyvinyl acetoacetal, ethyl cellulose, cellulose acetate, cellulose acetate propionate, cellulose derivatives such as cellulose acetate butyrate, and epoxy resins. It is not limited. These binder resins are used alone or in combination of two or more.

In the heat-sensitive recording layer of the present invention, a heat-fusible substance can be used alone or in combination of two or more as an auxiliary additive component, if necessary. Examples of the heat-fusible substance include, besides higher fatty acids or their esters, amides or metal salts,
Various waxes, condensates of aromatic carboxylic acids and amines, phenyl benzoate, higher linear glycols,
Dialkyl 3,4-epoxy-hexahydrophthalate,
50 to 2 such as higher ketones and other heat-fusible organic compounds
Examples include those having a melting point of about 00 ° C., but are not limited thereto.

When the heat-sensitive recording layer according to the present invention is obtained, additional components commonly used in this type of heat-sensitive recording medium, such as fillers, surfactants, and the like, if necessary, together with a leuco dye, a developer and a binder resin. A lubricant, a pressure coloring inhibitor and the like can be used in combination as long as the transparency of the heat-sensitive recording layer is not impaired.

In this case, as a filler, for example, inorganic fine powder such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, surface-treated calcium and silica, etc. Besides, organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin and vinylidene chloride resin can be mentioned. As a lubricant, higher fatty acids and metal salts thereof, higher fatty acid amides,
Examples include higher fatty acid estil, various animal, vegetable, mineral or petroleum waxes.

The heat-sensitive recording layer is prepared by uniformly dispersing or dissolving a color former, a color developer, and a binder resin in a solvent, applying the resultant to a support made of high quality paper or film, and drying. The coating method is not particularly limited. The dispersed particle size of the heat-sensitive recording layer coating solution is preferably 10 μm or less, and 5 μm
Is more preferably 1 μm or less. The thickness of the heat-sensitive recording layer depends on the composition of the heat-sensitive recording layer and the use of the heat-adhesive label, but is about 1 to 50 μm, preferably 3 to 20 μm.
m.

The recording method of the heat-sensitive recording layer of the present invention is not particularly limited depending on the purpose of use, such as a hot pen, a thermal head, and laser heating.

The support used in the present invention is not particularly limited. For example, paper, cloth, film, and transparent materials include polyester films such as polyethylene terephthalate and polybutylene terephthalate, and cellulose derivatives such as cellulose triacetate. It is common to use a film, a polyolefin film such as polypropylene or polyethylene, a polystyrene film, or a transparent film obtained by laminating these.

In the present invention, a protective layer can be provided on the heat-sensitive recording layer. The protective layer used in the present invention improves the transparency of the heat-sensitive recording layer, chemical resistance, water resistance, abrasion resistance, light resistance and durability against a thermal head, corrosion resistance, and improvement of so-called head matching properties such as lubricity. Therefore, it is important as a component of the present invention. The protective layer includes a film formed mainly of a water-soluble resin or a hydrophobic resin, a film mainly formed of an ultraviolet curable resin or an electron beam curable resin, and the like. Such resins include, in addition to water-soluble resins, aqueous emulsions, hydrophobic resins, ultraviolet curable resins, and electron beam curable resins.

Specific examples of the water-soluble resin include polyvinyl alcohol, modified polyvinyl alcohol, cellulose derivatives (eg, methylcellulose, methoxycellulose, hydroxycellulose), casein, gelatin,
Polyvinyl pyrrolidone, styrene-maleic anhydride copolymer, diisobutylene-maleic anhydride copolymer, polyacrylamide, modified polyacrylamide, methyl vinyl ether-maleic anhydride copolymer, carboxy-modified polyethylene, polyvinyl alcohol / acrylamide block copolymer Coalescence, melamine-formaldehyde resin,
Urea-formaldehyde resin and the like.

Examples of the resin or hydrophobic resin for the aqueous emulsion include polyvinyl acetate, polyurethane,
Styrene / butadiene copolymer, styrene / butadiene / acrylic copolymer, polyacrylic acid, polyacrylate, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, polyvinyl butyral, polyvinyl acetal, methyl cellulose, ethyl cellulose,
Examples include an ethylene / vinyl acetate copolymer.

Further, copolymers of these resins and silicon segments are also preferably used. These may be used alone or as a mixture, and if necessary, a curing agent may be added to cure the resin.

The type of the ultraviolet-curable resin is not particularly limited as long as it is a monomer, oligomer or prepolymer that undergoes a polymerization reaction upon irradiation with ultraviolet light and cures to become a resin, and various known ones can be used.

The type of the electron beam-curable resin is not particularly limited. Particularly preferred electron beam-curable resins include an electron beam-curable resin having a penta-functional or more branched pentafunctional molecular structure and a silicon-modified electron beam. It is mainly composed of a cured resin.

In order to improve head matching, an inorganic and / or organic filler or a lubricant can be added to the protective layer within a range that does not reduce the surface smoothness. The particle size of the filler is preferably 0.3 μm or less. In this case, a filler having an oil supply amount of 30 ml / 100 or more, preferably 80 ml / 100 g or more is selected.

As these inorganic and / or organic fillers, one or more of pigments commonly used in this type of heat-sensitive recording medium can be selected. Specific examples include calcium carbonate, silica, zinc oxide, titanium oxide,
Inorganic pigments such as aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, and organic pigments such as urea-formalin resin, styrene / methacrylic acid copolymer, and polystyrene resin. be able to. As the lubricant, those described in the description of the heat-sensitive recording layer can be used.

The coating method of the protective layer is not particularly limited, and can be applied by a conventionally known method. The preferred thickness of the protective layer is 0.1-20 μm, more preferably 0.5-10 μm.
μm. If the thickness of the protective layer is too thin, the function as a protective layer such as the storage stability and head matching of the heat-adhesive label is insufficient, and if it is too thick, the thermal sensitivity of the heat-sensitive recording layer decreases, and cost is reduced. Is also disadvantageous.

In the present invention, a heat insulating layer (under layer) is provided between the support and the pressure-sensitive adhesive layer and / or between the support and the heat-sensitive recording layer, if necessary. By providing this heat insulating layer, the thermal energy efficiency of the thermal head can be improved, and the thermal activation temperature can be lowered. Further, when the pressure-sensitive adhesive layer is thermally activated, the coloring of the heat-sensitive recording layer on the opposite side can be blocked. The heat insulating layer may be used together with the fine hollow particles and the binder, if necessary, with a pigment, and with auxiliary additives commonly used in this type of heat-sensitive recording material, for example, a heat-fusible substance, a filler, a surfactant, and the like. it can. In this case, as a specific example of the heat-fusible substance, the same substance as the heat-fusible substance described in the description of the heat-sensitive recording layer is used.

Examples of the resin used in the non-foamable heat insulating layer in the present invention include the following compounds, but are not necessarily limited thereto. SBR, MBR,
Latex such as NBR and polyvinyl alcohol, cellulose derivatives, starch and derivatives thereof, carboxyl group-modified polyvinyl alcohol, polyacrylic acid and derivatives thereof, styrene / acrylic acid copolymer and derivatives thereof, poly (meth) acrylamide and derivatives thereof, Water-soluble polymer resins such as styrene / acrylic acid / acrylamide copolymer, amino group-modified polyvinyl alcohol, epoxy-modified polyvinyl alcohol, polyethyleneimine, isobutylene / maleic anhydride copolymer and derivatives thereof.

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, and surface-treated calcium and silica. In addition, organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, and polystyrene resin can be mentioned.

As the heat insulating layer in the present invention, a non-foamable heat insulating layer using fine hollow particles having a hollowness of 30% or more or a porous pigment having a shell of a thermoplastic resin and a foaming heat insulating layer using a foamable filler are used. However, it is preferably a non-foamable heat insulating layer.

The fine hollow particles having a hollowness of 30% or more, which are formed of a thermoplastic resin as a shell and used for the heat insulating layer of the present invention, contain air or other gas inside, and are already in a foamed state. Particles having a number average particle size of 2.0 to 20 μm.
Are more preferred. If the number average particle diameter (particle outer diameter) is smaller than 2.0 μm, there is a problem in production such as difficulty in obtaining an arbitrary hollowness, and there is a problem in cost, and conversely, 20 μm. When the size is larger, the smoothness of the surface after coating and drying is reduced, so that the adhesion to the thermal head is reduced, the dot reproducibility is deteriorated, and the effect of improving sensitivity is reduced. Therefore, it is desirable that such a particle distribution has a uniform distribution spectrum with little variation as well as a particle diameter in the above-mentioned range.

The plastic spherical hollow particles used in the present invention may have a hollowness of 30% or more, and more preferably 50% or more. This hollowness is 30%
In the case of less than one, the thermal energy from the thermal head is released through the support to the outside of the thermo-adhesive label due to insufficient heat insulating property, the color sensitivity is not improved, and the heat energy of the heat conversion by light irradiation is not improved. The heat insulating effect is small, the effect of activating the pressure-sensitive adhesive is inferior, and the expression of adhesiveness is weakened.

Here, the hollowness is a ratio of the outer diameter to the inner diameter of the hollow particles, and is expressed by the following equation.

(Equation 1)

The hollow microparticles used in the present invention have a shell made of a thermoplastic resin as described above. The thermoplastic resin is preferably a copolymer resin mainly containing vinylidene chloride and acrylonitrile. . Further, as other porous pigments used in the heat insulating layer of the present invention,
There are organic pigments such as urea-formaldehyde resin and inorganic pigments such as shirasu earth, but not limited thereto.

Between and / or between the support and the thermosensitive recording layer
To provide a non-foamable heat-insulating layer between the body and the pressure-sensitive adhesive layer
Is a known water-soluble polymer, an aqueous high
Dispersed in water with a binder such as molecular emulsion,
This is obtained by applying this to the support surface and drying.
It is. In this case, the coating amount of the fine hollow particles is 1 m
^TwoAt least 1 g, preferably about 2 to 15 g
Yes, and the amount of binder resin applied is non-foamable heat insulating layer
May be used in such an amount as to bind strongly to the support.
2 to 5 based on the total amount of the small hollow particles and the binder resin
0% by weight.

In the present invention, the binder used for forming the non-foamable heat insulating 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, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and the like.
Cellulose derivatives such as ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / Maleic anhydride copolymer alkali salt, polyacrylamide,
Sodium alinate, gelatin, casein and the like can be mentioned.

As the aqueous polymer emulsion,
Latex such as styrene / butadiene copolymer, styrene / butadiene copolymer, styrene / butadiene / acrylic copolymer, vinyl acetate resin, vinyl acetate / acrylic acid copolymer, styrene / acrylic ester copolymer, acrylic Emulsions such as acid ester resins and polyurethane resins are exemplified.

[0060]

Next, the present invention will be described in more detail with reference to examples. In addition, all the parts and% shown below are based on weight.

Example 1 (Solution A) Dye dispersion 3-dibenzylamino-6-methyl-7-anilinofluoran 20 parts Polyvinyl alcohol 10% aqueous solution 20 parts Water 60 parts (Solution B) Dispersion 4,4'-dihydroxybenzophenone 10 parts Polyvinyl alcohol 10% aqueous solution 25 parts Calcium carbonate 15 parts Water 50 parts A mixture having the above composition has an average particle diameter of 2.
(Solution A) and (Solution B) were prepared by dispersing using a sand mill so as to be 0 μm or less. Next, (A solution) and (B
The liquid was mixed and stirred such that the weight ratio of (liquid A) :( liquid B) = 1: 8 to obtain a thermosensitive recording layer forming liquid (liquid C). The heat-sensitive recording layer forming liquid (liquid C) was dried at an amount of 5 g / m ^2.
After coating and drying on the surface of a high-quality paper having a basis weight of 80 g / m ² to provide a heat-sensitive recording layer, a super calender treatment is further performed so that the peck smoothness is 600 to 700 seconds. A recording layer-formed paper was obtained.

Next, a polyvinyl acetate emulsion as a pressure-sensitive adhesive was applied on the back surface of the paper on which the heat-sensitive recording layer was formed so as to have a dry adhesion amount of 18 g / m ² and dried to form a pressure-sensitive adhesive layer. A pressure-sensitive adhesive sheet was obtained.

(D Solution) Solid Plasticizer Dispersion Dicyclohexyl Phthalate (Melting Point: 60 ° C.) 40 Parts Amine Dispersant 8 Parts Water 52 Parts A mixture having the above composition was adjusted so that the average particle diameter was 3.0 μm or less. The mixture was dispersed using a ball mill to obtain a solid plasticizer dispersion liquid (D liquid). Next, a sealing layer dispersion liquid (liquid E) was obtained using (liquid D) with the following composition. Methyl methacrylate graft copolymerized natural rubber latex (50% solution; thermoplastic resin) (methyl methacrylate / natural rubber = 20/100) 30 parts Solid plasticizer dispersion liquid (D liquid) 170 parts Seal layer dispersion obtained from above The liquid (E liquid) was applied and dried on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet so that the dry adhesion amount was 25 g / m ² , to obtain a linerless heat-adhesive label.

Example 2 A thermo-adhesive label was prepared by removing the heat-sensitive recording layer from Example 1, and a sample of Example 2 was obtained.

Example 3 The natural rubber latex grafted with methyl methacrylate graft copolymer of Example E (Solution E) was used.
A sample of Example 3 was obtained in the same manner as in Example 1 except that the number of parts was changed to 10 parts.

Example 4 The procedure of Example 1 was repeated except that 30 parts of the methyl methacrylate graft copolymerized natural rubber latex of (E liquid) was changed to 30 parts of a 50% aqueous dispersion of a tackifier: terpene resin. A sample of Example 4 was obtained in the same manner as in Example 1.

Example 5 5 of the terpene resin of Example 4
A sample of Example 5 was obtained in the same manner as in Example 4, except that the 0% aqueous dispersion was changed from 30 parts to 10 parts.

Example 6 A sample of Example 6 was obtained in the same manner as in Example 1 except that 35 parts of a 50% aqueous dispersion of a terpene resin was added to (E solution) of Example 1.

Comparative Example 1 A solid plasticizer dispersion liquid (D liquid) was removed from (E liquid) of Example 1, and 35 parts of a 50% aqueous terpene resin dispersion was added to this (E liquid). In the same manner as in Example 1, a sample of Comparative Example 1 was obtained.

Subsequently, these Examples 1 to 6 and Comparative Example 1
The evaluation (coloring sensitivity, adhesiveness, blocking property) of the sample (heat-adhesive label) obtained in was performed. Table 1 shows the results.

Coloring sensitivity (rise characteristics): A thermal printing device having a thin film head manufactured by Matsushita Electronic Components Co., Ltd.
Head power 0.60 W / dot, 1 line recording time 10
msec / 11ine, scanning line density 8 × 7: 7dot /
mm, pulse width 0.4 msec, 0.5 ms
ec, and the print density is measured using a Macbeth densitometer RD-9.
Measured at 14.

Adhesion: A label sample prepared for the test and a thermal printing apparatus having a thin film head manufactured by Matsushita Electronic Parts Co., Ltd. were left at room temperature (20 ° C., 60% RH) for 1 hour or more. Head power 0.60 W / dot, 1 line recording time 10 msec / 11ine, scanning line density 8 ×
7: pulse width 0.5 mse under the condition of 7 dots / mm
c to activate the pressure-sensitive adhesive layer, and apply it to the adherend (PVC).
Wrap, PE wrap) and evaluated the adhesive strength according to the following rank. ◎: Strongly adhered ○: Adhered △: Slightly adhered

Blocking property: A heat-sensitive coloring layer and a pressure-sensitive adhesive layer of the same sample were brought into contact with each other, tested under a pressure of ² kg / cm ² at 40 ° C. and 90% RH for 24 hours, and then left at room temperature. Thereafter, the sample was peeled off, and the blocking property at that time was evaluated according to the following rank. ◎: No blocking occurred (no peeling sound) ○: No blocking occurred (no peeling sound) △: Slight blocking occurred

[0074]

[Table 1]

[0075]

According to the heat-sensitive adhesive label of the present invention, a pressure-sensitive adhesive layer is provided on a support, and the heat-sensitive adhesive layer has a melting point on the pressure-sensitive adhesive layer that is compatible with the pressure-sensitive adhesive layer when heat is applied. Contains a heat-fusible substance of 50 ° C or higher, and has a configuration in which a seal layer (shielding layer) that does not exhibit adhesiveness when heat is applied has a strong adhesive force to a wrap film, and also has an anti-blocking property. It has excellent properties and can be printed on the back layer (back side of support, heat-sensitive recording layer).

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroshi Yamada 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2H026 AA07 AA28 BB01 FF29 4J004 AA04 AA05 AA06 AA07 AA09 AA10 AA12 AA13 AB01 CC02 CC05 CD01 CE01 DB01 FA01 FA05

Claims (5)

[Claims] 1. A pressure-sensitive adhesive layer is provided on a support, and is compatible with the pressure-sensitive adhesive layer when heat is applied on the pressure-sensitive adhesive layer.
A heat-adhesive label comprising a heat-fusible substance having a melting point of 50 ° C. or higher, and having a sealing layer which does not exhibit adhesiveness when heat is applied. 2. The heat-adhesive label according to claim 1, wherein the seal layer contains at least 70% by weight of a heat-fusible substance having a melting point of 50 ° C. or higher. 3. The sealant according to claim 1, wherein the seal layer contains a thermoplastic resin and / or a tackifier.
The heat-adhesive label as described. 4. A heat-sensitive recording layer is provided on the surface of the support opposite to the pressure-sensitive adhesive layer.
Or the heat-adhesive label according to 3. 5. A thin film resistor is provided on a ceramic substrate,
A surface of the heating means provided with a protective film on the surface of the thin-film resistor is contacted with the surface of the thin-film resistor on the side of the thin-film resistor, and the sealing layer of the heat-adhesive label according to any one of claims 1 to 4, to form a pressure-sensitive adhesive layer. A method for thermally activating a thermo-adhesive label, which is characterized by exhibiting adhesiveness.