JP3507933B2 - Label for thermal recording - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat-sensitive recording label comprising a support and a heat-sensitive coloring layer on one side, and a heat-sensitive adhesive layer on the other side. The present invention relates to a linerless thermosensitive recording label containing a butadiene copolymer.

[0002]

2. Description of the Related Art In recent years, heat-sensitive recording labels have been used in a wide variety of fields, typified by the POS field. In thermal labels, release paper is usually attached to the surface via a pressure-sensitive adhesive layer. Is the actual situation. However,
Although such a thermal recording label is effective, it has many drawbacks. That is, the release paper has a larger area than the label itself, which is a product, and these release papers must be handled during use as well as during storage of the label for heat-sensitive recording. It must be post-treated after it has been removed from the label. Therefore,
From a recent ecological perspective, there is a problem that a large amount of waste is generated, and because the workability and productivity when attaching labels with coins are poor, the manufacturing cost associated with the use of release paper and the cost of the release paper itself It has problems such as high cost.

In order to solve these problems, a heat-sensitive recording label without a release paper is disclosed, for example, in Japanese Utility Model Publication 59.
No. 43979, No. 59-46265, Japanese Laid-Open Patent Publication No.
A linerless thermosensitive recording label has been proposed such as 0-54842 or the like in which a pressure-sensitive adhesive is microencapsulated, or a protective layer provided with a release agent layer for the pressure-sensitive adhesive. However, these have not been put to practical use because of their weak adhesive strength and the inability to print on the thermal surface. Further, a method of using a heat-sensitive adhesive as a functional adhesive is disclosed in JP-A-63-303387, JP-B-5-11.
No. 573 is proposed. However, these are inferior to the existing heat-sensitive labels in terms of blocking and the like. Further, the heat-sensitive adhesive obtained by these methods,
Although the adhesive strength to paper, PET film and the like is relatively good, the adhesive strength to adherends such as vinyl chloride wrap and polyethylene wrap used in the food POS field is weak and has not reached a practical level. Further, in the layer constitution not including the thermosensitive color developing layer, JP-A-63-152686 and JP-A-6-62 are used.
No. 57226, JP-A-6-57233, etc., a resin in an adhesive has been proposed in order to achieve both the adhesive strength and the blocking. However, in these as well, adhesion to an adherend such as vinyl chloride wrap or polyethylene wrap is proposed. The adhesive strength was not satisfactory.

[0004]

SUMMARY OF THE INVENTION In view of the present situation of the above-mentioned heat-sensitive recording label, an object of the present invention is to provide a heat-sensitive coloring layer on one side of the support and a heat-sensitive adhesive layer on the other side. In a linerless label provided with, a thermosensitive recording label having excellent adhesiveness to each adherend, particularly strong adhesiveness to vinyl chloride wrap or polyethylene wrap, and excellent blocking resistance in a wound state. It is in.

[0005]

According to the present invention, the following inventions are provided. (1) In a thermosensitive recording label having a thermosensitive coloring layer on one side of a support, and a thermosensitive adhesive layer which is normally non-adhesive and activates when heated to produce tackiness on the other side, the thermosensitive adhesive layer But
A thermosensitive recording label comprising a methylmethacrylate / butadiene copolymer, a tackifier and a solid plasticizer. (2) The heat-sensitive recording label according to (1), wherein the heat-sensitive adhesive layer further contains a styrene / acrylic copolymer. (3) Methyl methacrylate / in the heat-sensitive adhesive layer
The weight ratio of the butadiene copolymer and the styrene / acrylic copolymer is 1: 0.2 to 5 (2)
The heat-sensitive recording label described. (4) The heat-sensitive recording label according to (1), wherein the tackifier has a softening point or a melting point of 100 ° C. or higher. (5) The content of tackifier in the heat-sensitive adhesive layer is 3
The label for heat-sensitive recording according to (1), characterized in that the content is -30% by weight. (6) The content of the solid plasticizer in the heat-sensitive adhesive layer is 3
The heat-sensitive recording label according to (1), which is 0 to 70% by weight. (7) The heat-sensitive recording label according to (1), wherein a barrier layer is provided between the support and the heat-sensitive adhesive layer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Generally, a heat-sensitive adhesive has a function of polymer resin which is a main component for imparting an adhesive force and an adhesive force by heating and an action of causing the adhesive to exhibit an adhesive property by being melted by heating. It contains a solid plasticizer, a tackifier that improves tackiness, and the like. The heat-sensitive adhesive used in the present invention is an acrylic / butadiene copolymer used as the polymer resin. The following can be used as the acrylic monomer that can be copolymerized with butadiene of the acrylic / butadiene copolymer. Methacrylic acid ester represented by methylmethacrylate (hereinafter abbreviated as MMA), methacrylic acid, acrylic acid ester, acrylic acid, acrylonitrile, acrylamide, N-methylrollacrylamide, and the like. Among these acrylic / butadiene copolymers, MMA / butadiene copolymers are particularly preferable, and by using this, each adherend, particularly vinyl chloride wrap (PV wrap) or polyethylene wrap (PE
It has a strong adhesive force to wraps) and good blocking resistance.

Further, by using a styrene / acrylic copolymer in combination with the MMA / butadiene copolymer as the polymer resin, it is possible to achieve both better adhesive strength and blocking resistance. The following can be used as an acrylic monomer that can be copolymerized with styrene of the styrene / acrylic copolymer. Methacrylic acid ester,
Methacrylic acid, acrylic acid ester, acrylic acid, acrylonitrile, acrylamide, N-methylolamide and the like. The weight ratio of the acrylic / butadiene copolymer to the styrene / acrylic copolymer is preferably 1: 0.2 to 5, preferably 1: 0.3 to 3. If the ratio is less than 1: 0.2, the blocking resistance tends to decrease, and if it exceeds 1: 5, the adhesion to vinyl chloride wrap or polyethylene wrap decreases. Furthermore, the polymer resin used in combination is not limited to these, and it is also possible to use in combination with those exemplified below. Polyvinyl acetate, polybutyl methacrylate, vinyl oxide /
Vinylidene chloride copolymer, synthetic rubber, vinyl acetate / acrylic acid 2-ethylhexyl copolymer, vinyl acetate / ethylene copolymer, vinylpyrrolidone / styrene copolymer,
Polymer resins such as styrene / butadiene copolymer and vinylpyrrolidone / ethyl acrylate copolymer.

As the solid plasticizer used in the present invention, those exemplified below can be used but are not necessarily limited thereto. Diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dihydroabietyl phthalate, dimethyl isophthalate, sucrose benzoate, ethylene glycol dibenzoate, trimethylolethane tribenzoate, tribenzoic acid glyceride, pentabenzotribenzoate Trit, sucrose octaacetate, tricyclohexyl citrate, N-cyclohexyl-p-toluenesulfonamide and the like. The content of the solid plasticizer in the heat-sensitive adhesive is preferably 30 to 70% by weight, more preferably 35 to 65%. When the content of the solid plasticizer is less than 30% by weight or exceeds 70%, the adhesive strength is lowered in both cases.

As the tackifier used in the present invention, those exemplified below can be used, but they are not necessarily limited thereto. Rosin derivatives (rosin, polymerized rosin, hydrogenated rosin or esters thereof such as glycerin and pentaerythritol, resin acid dimer, etc.) Terpene resin system, petroleum resin system, phenol resin system, xylene resin system and the like. The melting point or softening point of the tackifier in the heat-sensitive adhesive is preferably 100 ° C or higher, more preferably 100.
~ 200 ° C. If it is less than 100, the blocking resistance decreases. The content of the tackifier in the heat-sensitive adhesive is preferably 3 to 30% by weight, more preferably 5 to 25% by weight. If it is less than 3% by weight, the adhesive strength will be lowered, and if it exceeds 30% by weight, the blocking property will be lowered.

In the heat-sensitive recording label of the present invention, the main component is fine hollow particles having an average particle size of 0.4 to 20 μm and a hollowness of 30% or more and made of a thermoplastic resin between the support and the heat-sensitive color forming layer. By providing a non-foaming heat insulating layer to
Improving the color development sensitivity by efficiently utilizing the thermal energy of the thermal head, and of the thermosensitive coloring layer by heat conversion of the light irradiation energy to the thermosensitive adhesive layer on the back surface necessary for activating the thermosensitive adhesive. It is possible to prevent background color development (background fog).

The fine hollow particles having a shell of a thermoplastic resin used in the present invention are those which already contain air or other gas and are already in a foamed state, and the average particle size thereof is Those having 0.4 to 20 μm can be used, but those having 0.5 to 10 μm are more preferable. When the average particle diameter (particle outer diameter) is smaller than 0.4 μm, there is a production problem such as difficulty in achieving an arbitrary hollowness, and there is a problem in terms of cost. Larger ones have lower surface smoothness after coating and drying, and thus have lower adhesion to the thermal head, poor dot reproducibility and lower sensitivity enhancement effect. Therefore,
It is desirable that such a particle distribution has a particle diameter within the above range and has a uniform distribution spectrum with little variation.

Further, the fine hollow particles having a shell of the thermoplastic resin used in the present invention can have a hollowness of 30% or more, and more preferably 50% or more. If the hollowness is less than 30%, the heat insulation is insufficient, so
The thermal energy from the thermal head is released to the outside of the thermal recording material through the support, and the color development sensitivity is not improved.
In addition, the heat insulating effect of heat energy of heat conversion due to light irradiation is small, the effect of activating the heat-sensitive adhesive is poor, and expression of adhesiveness is weakened. The hollowness referred to here is the ratio of the outer diameter to the inner diameter of the hollow particles and is represented by the following formula.

[Equation 1] The fine hollow particles used in the present invention have a thermoplastic resin as a shell as described above, and as the resin, a copolymer resin mainly containing vinylidene chloride and acrylonitrile is particularly preferable.

In order to provide a non-foaming heat insulating layer between the support and the thermosensitive color-developing layer, the above-mentioned fine hollow particles are dispersed in water together with a binder such as a well-known water-soluble polymer or aqueous polymer emulsion, and the support is used. It is obtained by coating on the surface and drying. In this case, the coating amount of the micro hollow particles is
At least 1 g, preferably 2 to 1 per 1 m ^{2 of} support
The amount of the binder resin applied may be such that the intermediate layer is strongly bound to the support, and is usually 2 to the total amount of the fine hollow particles and the binder resin.
It is 50% by weight.

In the present invention, the binder used when forming the non-foaming 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, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose,
Cellulose derivatives such as ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / Maleic anhydride copolymer alkali salt, polyacrylamide,
Examples thereof include sodium alginate, gelatin, casein and the like. Examples of the aqueous polymer emulsion include latex such as styrene / butadiene copolymer and styrene / butadiene / acrylic copolymer, vinyl acetate resin,
Examples thereof include emulsions of vinyl acetate / acrylic acid copolymer, styrene / acrylic acid ester copolymer, acrylic acid ester resin, polyurethane resin and the like. Incidentally, in the non-foaming heat insulating layer of the present invention, the fine hollow particles,
If necessary, auxiliary additives commonly used in this type of heat-sensitive recording material, such as a heat-fusible substance and a surfactant, can be used in combination with (optionally a pigment) and a binder. In this case, specific examples of the heat-fusible substance include various substances which will be shown later in relation to the thermosensitive coloring layer component.

In the heat-sensitive recording label of the present invention, the heat-activated adhesive permeates into the support side between the support and the heat-sensitive adhesive layer to prevent a decrease in the effective adhesive amount. A barrier layer may be provided for this purpose. Examples of the resin used in the barrier layer include, but are not limited to, the following resins. SB
Latex such as R, MBR, NBR, polyvinyl alcohol, cellulose derivative, starch and its derivative, carboxyl group-modified polyvinyl alcohol, polyacrylic acid and its derivative, styrene / acrylic acid copolymer and its derivative, poly (meth) acrylamide and Water-soluble polymer resins such as their derivatives, styrene / acrylic acid / acrylamide copolymers, amino group-modified polyvinyl alcohol, epoxy-modified polyvinyl alcohol, polyethyleneimine, isobutylene / maleic anhydride copolymers and their derivatives.

The barrier layer may contain a filler, and examples of the filler include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay and talc. In addition to surface-treated inorganic fine powders such as calcium and silica, there may be mentioned organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer and polystyrene resin.

Further, in the heat-sensitive recording label of the present invention, an infrared absorbing substance may be contained in the heat-sensitive adhesive layer and / or in the intermediate layer between the support and the heat-sensitive adhesive layer. it can. By including the infrared absorbing substance in these layers, when the pressure-sensitive adhesive layer is activated by irradiation with infrared light, the efficiency of conversion into heat energy can be increased, and the pressure-sensitive adhesive layer can be adhered. The effect of activating force can be further improved.

In a broad sense, the infrared absorbing material used in the present invention is an organic or inorganic substance that can effectively absorb a wavelength in the infrared region of 0.7 to 20 μm and convert light into heat. It is a compound. Specific examples of the above infrared absorbing substance are organic near infrared absorbing dyes, for example, cyanine dyes, azurenium dyes, pyrylium, thiopyrylium dyes, squarylium dyes, triarylmethane dyes, immonium, diimmonium dyes. Dye,
Thiol nickel complex salt type dye, phthalocyanine type dye,
Naphthalocyanine dye, anthraquinone dye, and triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, furfuryl acetate, bis (1-thio-2-phenolate) nickel-tetrabutylammonium, bis (1-thio-2) -Naft rate)
Nickel-tetrabutylammonium, 1,1'-diethyl-4,4'-quinocarbocyanine iodide,
1,1'-diethyl-6,6'-dichloro-4,4'-
Examples thereof include organic compounds such as quinotricarbocyanine iodide.

Further, graphite; metal oxides such as aluminum oxide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; olivine group, garnet group, pyroxene group, amphibole, mica group, feldspar group, Silicate minerals such as silica minerals and clay minerals; silicate compounds such as zinc silicate, magnesium silicate, calcium silicate and barium silicate; phosphate compounds such as zinc phosphate; nitrogen compounds such as trisilicon tetranitride and boron nitride. Barium sulfate, calcium sulfate,
Examples thereof include, but are not limited to, sulfate compounds such as strontium sulfate; carbonate compounds such as calcium carbonate, barium carbonate, magnesium carbonate, and zinc carbonate; and inorganic compounds such as nitrate compounds such as potassium nitrate.

Further, the infrared absorbing substance includes a dispersible near infrared absorbing substance which is generally insoluble in a solvent and a soluble near infrared absorbing substance which is soluble in a solvent. Generally, the dispersible near-infrared absorbing material is strongly colored such as black or black gray and is uniform over the entire near-infrared region as wide as 0.7 to 2.5 μm as compared with the soluble near-infrared absorbing material. Due to strong absorption, the efficiency of converting the absorbed near-infrared light into heat is high, and the stability of these functions over time is excellent. It is possible to make the heat-sensitive adhesive have tackiness by effectively utilizing the peculiar properties inherent to the dispersible near-infrared absorbing substance.

The dispersible near-infrared absorbing material used in the present invention has a property that it has a uniform strong absorption wavelength at a wavelength of 0.7 to 2.5 μm and can convert the light into heat. It is preferable to have one, but graphite is particularly preferable. As for graphite, natural graphite such as scaly graphite, granular graphite, lump graphite, and earth-crystal graphite, and artificial graphite exist depending on the production method and structure, but any of them can be used. These are preferably used in micronized much as infrared-absorbing material is available, it is preferable that the average particle child size and 2.0μm or less. The microparticulation method may be any of ordinary dry and wet pulverization methods and scientific methods such as dissolved colloids.

The above dispersible finely divided graphite is superior in absorption effect to any infrared absorbing substance or dye, and is excellent in the efficiency of conversion into heat, and thus exhibits excellent adhesiveness. Will be shown. When graphite is used as the dispersible near infrared absorbing material, from contamination of the coloring thermal surface, is preferably as small as possible, the content thereof is from 0.005 g / m ² of 0.3 g / m ² The range is preferably 0.01 g / m ² to 0.2 g / m ² . Dispersive near-infrared absorbing material 0.3
If it exceeds g / m ² , the heat-sensitive adhesive layer will be severely colored, the PCS of the thermal surface will be reduced when printed (due to the coloring of the background), contamination of the adherend, and a large amount of dispersive near-infrared light Since it is an absorbing substance, a large amount of infrared energy is taken in, which causes fog on the background of the thermal surface. If the dispersible near-infrared absorbing substance is less than 0.005 g / m ² , its efficiency is low in converting light energy into heat energy even by irradiation with infrared light, and the heat-sensitive adhesive strength is low. It is not activated and the adhesiveness of the heat-sensitive adhesive layer is not sufficiently expressed.

Next, the leuco dye as the color-forming agent used in the heat-sensitive color-forming layer of the heat-sensitive recording label of the present invention is applied alone or as a mixture of two or more kinds. As such a leuco dye, this type of heat-sensitive dye is used. What is applied to the material is arbitrarily applied, and for example, a leuco compound of a dye such as triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spirobilane-based, indolinophtalide-based dyes is preferably used. Specific examples of such leuco dyes include those shown below.
3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6
-Dimethylaminophthalide (also known as 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, 2- [3,6-bis (diethylamino) -9- (o
-Chloranilino) xanthyl benzoate lactam], 3
-Diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7
-(O-chloroanilino) fluorane, 3-di-n-butylamino-7- (o-chloroanilino) fluorane,
3-N-methyl-N, n-amylamino-6-methyl-
7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N, N -Diethylamino) -5-methyl-7- (N, N-dibenzylamino) fluorane, benzoylleucomethylene blue, 6'-chloro-8'-
Methoxy-benzoindolinose pyropyran, 6'-Promo-3'-methoxy-benzoindolinose pyropyran, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chloro Phenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-nitrophenyl) phthalide, 3- (2'-hydroxy-
4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl) phthalide, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2 '
-Hydroxy-4'-chloro-5'-methylphenyl)
Phthalide, 3- (N-ethyl-N-tetrahydrofurfuryl) amino-6-methyl-7-anilinofluorane,
3-N-ethyl-N- (2-ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3-N-methyl-N-isobutyl-6-methyl-7-anilinofluorane, 3- Morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7
-M-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylamino Fluorane, 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-piperidinofluorane, 2 -Chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluorane, 3
-(N-methyl-N-isopropylamino) -6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3,6-bis (dimethyl) Amino) fluorene spiro (9,3 ')-
6'-dimethylaminophthalide, 3- (N-benzyl-
N-cyclohexylamino) -5,6-benzo-7-α
-Naphthylamino-4'-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3
-Diethylamino-6-methyl-7-mesitidino-
4 ', 5'-benzofluorane, 3-N-methyl-N-
Isopropyl-6-methyl-7-anilinofluorane,
3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-
7- (2 ', 4'-dimethylanilino) fluorane and the like.

As the color developer used in the heat-sensitive color forming layer of the heat-sensitive recording label of the present invention, various electron-accepting compounds that cause the leuco dye to develop color upon contact, or oxidizing agents are used. Such a material is conventionally known, and specific examples thereof include the following. 4,
4'-isopropylidene diphenyl, 4,4'-isopropylidene bis (o-methylphenol), 4,4 '
-Sec-butylidenebisdenol, 4,4'-isopropylidenebis (2-tert-butylphenol),
Zinc p-nitrobenzoate, 1,3,5-tris (4-t
ert-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 monocalcium salt, 4,4'-cyclohexylidene diphenol, 4,4'-isopropylidenebis (2-
Chlorophenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4'-
Butylidene bis (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'-diphenol sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, 4-pentyloxy-4'-hydroxydiphenyl sulfone, 4,4 '
-Diphenol sulfoxide, isopropyl P-hydroxybenzoate, benzyl P-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, bis- (4-hydroxyphenyl)
Benzyl acetate, 1,3-bis (4-hydroxycumyl)
Benzene, 1,4-bis (4-hydroxycumyl) benzene, 2,4'-diphenol sulfone, 2,2'-diallyl-4,4'-diphenol sulfone, 3,4-dihydroxyphenyl-4 ' -Methyldiphenyl sulfone, 1-acetyloxy-2-naphthoate zinc, 2-acetyloxy-1-naphthoate zinc, 2-acetyloxy-3-naphthoate zinc, α, α-bis (4-hydroxyphenyl)- α-methyltoluene, antipyrine complex of zinc thiocyanate, tetrapromobisphenol A,
Tetrapromobisphenol S, 4,4'-thiobis (2-methylphenol), 4,4'-thiobis (2-
Chlorophenol) etc.

In the heat-sensitive color forming layer of the heat-sensitive recording label of the present invention, the amount of the developer is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, per 1 part by weight of the color forming agent. The color developer can be used alone or in combination of two or more kinds, and also in the case of the color developer, it can be applied alone or in combination of two or more kinds.

Preferred as the binder resin used in the thermosensitive coloring layer is a resin having a hydroxyl group or a carboxyl group in the molecule. Examples of such a resin include polyvinyl butyral, polyvinyl acetals such as polyvinyl acetoacetal, ethyl cellulose, cellulose acetate, cellulose acetate propionate, and cellulose derivatives such as cellulose acetate butyrate.
Examples thereof include epoxy resins, but are not limited to these. The binder resin may be used alone or as a mixture of two or more kinds.

The coating solution for the color forming layer may optionally contain various additives, such as fillers, surfactants and lubricants, which are used in ordinary heat-sensitive recording media for the purpose of improving coatability or color forming characteristics. Further, a pressure color-developing agent and the like can be used together within a range that does not impair the transparency of the recording medium. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, inorganic fine powder such as surface-treated calcium or silica, and urea. -Formalin resins, styrene / methacrylic acid copolymers, polystyrene resins, vinylidene chloride resins, and other organic fine powders can be mentioned. As the lubricant, higher fatty acids and metal salts thereof, higher fatty acid amides, higher fatty acid esters, Animal nature,
Various vegetable, mineral or petroleum waxes may be mentioned.

The support used in the present invention is not particularly limited, and not only paper but also polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate, polyolefin films such as polypropylene and polyethylene, polystyrene films. Alternatively full it <br/> Lum like by bonding these can also be used.

In the present invention, a protective layer may be provided on the thermosensitive coloring layer. The protective layer used in the present invention is important as a component of the present invention because it improves transparency, chemical resistance, water resistance, abrasion resistance, light resistance of a thermal recording label, and head matching with a thermal head. . The protective layer of the present invention includes a film formed mainly of a water-soluble resin or a hydrophobic resin, a film formed mainly of an ultraviolet curable resin or an electron beam curable resin, and the like.

As such a resin, in addition to a water-soluble resin,
Aqueous emulsion, hydrophobic resin and UV curable resin,
Further, an electron beam curable resin is included. Specific examples of the water-soluble resin include, for example, polyvinyl alcohol, modified polyvinyl alcohol, cellulose derivatives (methyl cellulose, methoxy cellulose, hydroxy cellulose, etc.),
Casein, gelatin, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, diisobutylene-maleic anhydride copolymer, polyacrylamide, modified polyacrylamide, methyl vinyl ether / maleic anhydride copolymer, carboxy modified polyethylene, polyvinyl alcohol / Examples include polyacrylamide block copolymers, melamine-formaldehyde resins, urea-formaldehyde resins, and the like.

As the resin for the aqueous emulsion or the hydrophobic resin, for example, polyvinyl acetate, polyurethane, styrene / butadiene copolymer, styrene / butadiene / acrylic copolymer, polyacrylic acid, polyacrylic ester, Examples thereof include vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, polyvinyl butyral, polyvinyl acetal, ethyl cellulose, ethylene / vinyl acetate copolymer and the like. 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.

Further, the ultraviolet curable resin is not particularly limited in kind as long as it is a monomer, oligomer or prepolymer which undergoes a polymerization reaction upon irradiation with ultraviolet light to be cured and becomes a resin, and various known resins can be used. The electron beam curable resin is also not particularly limited in type, but particularly preferable electron beam curable resins are mainly electron beam curable resins having a branched molecular structure of 5 or more functional groups having a polyester skeleton and silicon-modified electron beam curable resins. It is a component.

Inorganic and organic fillers and lubricants may be added to these protective layers in order to improve the head matching, as long as the surface smoothness is not deteriorated. The particle size of the filler in the present invention is preferably 0.3 μm or less. As the pigment in this case, the oil supply amount is 30 ml / 100 g
Above, preferably 80 ml / 100 g or more is selected. As these inorganic and / or organic pigments, one or more of the pigments commonly used for this type of thermal recording medium can be selected. Specific examples thereof include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, inorganic pigments such as surface-treated calcium and silica, and urea-formalin resin, Organic pigments such as styrene / methacrylic acid copolymers and polystyrene resins can be mentioned.

The coating method of the protective layer is not particularly limited and can be applied by a conventionally known method. The preferred protective layer thickness is 0.1 to 20 μm, more preferably 0.5 to 10 μm.
Is. If the protective layer is too thin, the function of the thermal recording label as a protective layer such as storability and head matching is insufficient, and if it is too thick, the thermal sensitivity of the thermal recording label decreases, and also in terms of cost. It is a disadvantage.

The recording method of the heat-sensitive recording label of the present invention is carried out by a hot pen, a thermal head, laser heating or the like depending on the purpose of use, but it is not particularly limited.

[0036]

EXAMPLES Next, the present invention will be described in more detail by way of examples. The parts and% shown below are based on weight.

Example 1 [Solution A] Color developer dispersion 3-dibenzylamino-6-methyl-7-anilinofluorane 20 parts Polyvinyl alcohol 10% aqueous solution 20 parts Water 60 parts [solution B] Developer dispersion liquid 4,4'-dihydroxybenzophenone 10 parts polyvinyl alcohol 10% aqueous solution of 25 parts of a mixture consisting of calcium carbonate 15 parts water 50 parts the above composition, an average particle child size respectively 2.
The liquids A and B were dispersed by using a sand mill so as to have a particle size of 0 μm or less. Next, [solution A] and [B
The liquid] was mixed and stirred so that the weight ratio of [Liquid A]: [Liquid B] = 1: 8 was obtained to obtain a coating liquid [Liquid C] for forming a thermosensitive color developing layer.
Next, the thermosensitive color forming layer-forming coating liquid [C liquid] is applied to the surface of 80 g / m ² of high-quality paper so as to have a dry weight of 5 g / m ² and dried to form a thermosensitive color forming layer. Further, a super calender treatment was performed so that the Beck's smoothness was 600 to 700 seconds to obtain a paper coated with a thermosensitive coloring layer. [D liquid] Heat-sensitive adhesive dispersion MMA / butadiene copolymer 16 parts (Takeda Yakuhin: 2M-36, concentration 47.5%) Styrene / acrylic copolymer 19 parts (Showa High Polymer: Polysol 4T- 2040, concentration 40%) Terpene resin (mp 120 ° C.) 10 parts Dicyclohexyl phthalate 25 parts Amine-based dispersant 2 parts Water 28 parts Mixture having the above composition so that the average particle size becomes 3.0 μm or less. Heat-sensitive adhesive dispersion liquid [D
Liquid] was applied to the back surface of the paper coated with the thermosensitive color developing layer so as to have a weight of 25 g / m ² after drying, and a sample of Example 1 was obtained.

Example 2 In Example 1, a carboxylated MMA / butadiene copolymer (Takeda Yakuhin Co., Ltd .: 2M-38, concentration 40%) was used as the same solid instead of the MMA / butadiene copolymer of [D liquid]. A sample of Example 2 was obtained in the same manner as in Example 1 except that the amount was used.

Example 3 In Example 1, an MMA / butadiene copolymer (manufactured by Takeda Yakuhin: 2M-36, concentration 47.5%) was used as the same solid in place of the styrene / acrylic copolymer of [D-liquid]. A sample of Example 3 was obtained in the same manner as in Example 1 except that the amount was used.

Example 4 Same as Example 1 except that the amounts of the MMA / butadiene copolymer component and the styrene / acrylic copolymer component of the [D liquid] used were 5 parts and 25 parts, respectively. The sample of Example 4 was obtained.

Example 5 Example 5 was conducted in the same manner as in Example 1 except that a terpene resin (mp 90 ° C.) was used in place of the terpene resin (mp 120 ° C.) in [D liquid]. I got a sample of.

Example 6 Example 6 was carried out in the same manner as in Example 1 except that the amount of the terpene resin (mp 120 ° C.) used in [D liquid] was changed to 20 parts.
I got a sample of.

Example 7 A sample of Example 7 was obtained in the same manner as in Example 1 except that the amount of dicyclohexyl phthalate used in [D liquid] was changed to 9 parts.

Example 8 [Solution E] Non-foaming heat-insulating layer-forming coating liquid Micro hollow particle dispersion (vinylidene chloride / acrylonitrile copolymer resin) (solid content concentration 32%, average particle diameter 5 μm, hollowness 90%) ) 30 parts Styrene / butadiene copolymer (concentration 50%) 10 parts Water 60 parts A mixture comprising the above composition is stirred and dispersed to prepare a non-foaming heat-insulating layer-forming coating liquid [E liquid], which is of high quality. After drying, the surface of the paper was coated and dried so that the weight became 5 g / m ² , to obtain a paper on which a non-foaming heat insulating layer had been coated. Using the above non-foaming heat-insulating layer-coated paper, the [C liquid] was applied onto the layer so as to have a weight of 5 g / m ² and dried to obtain a thermosensitive coloring layer-coated paper. Thereafter, a sample of Example 8 was obtained in the same manner as in Example 1.

Example 9 [F liquid] Barrier layer forming coating liquid 10% aqueous solution of polyvinyl alcohol 40 parts Aluminum hydroxide 12 parts Water 48 parts A mixture having the above composition is stirred and dispersed to form a barrier layer forming coating liquid [F Liquid] was prepared, and this was brought into contact with the base material under the heat-sensitive adhesive layer on the back surface of the thermosensitive coloring layer in Example 1,
A sample of Example 5 was obtained in the same manner as in Example 1 except that the weight was 2 g / m ² after drying.

Example 10 [G liquid] Phthalocyanine cobalt 5 parts Polyvinyl alcohol 10% aqueous solution 5 parts Water 90 parts [G liquid] having the above composition was dispersed using a sand mill so that the average particle diameter was 5 μm. [H liquid] Coating liquid for forming intermediate layer containing infrared absorbing substance Polyvinyl alcohol 10% aqueous solution 4 parts Aluminum hydroxide 44 parts Polyamide-epiclehydrin 10% aqueous solution 16 parts Phthalocyanine cobalt 5% dispersion [G liquid] 8 parts Water 28 parts The mixture having the above composition was stirred to prepare a coating liquid [H liquid] for forming an infrared absorbing substance-containing intermediate layer, and the coating dry weight was applied to the lower layer of the heat-sensitive adhesive layer on the back surface of the thermosensitive coloring layer in Example 1. A sample of Example 10 was obtained in the same manner as in Example 1 except that the intermediate layer was provided so that the amount was 2.5 g / m ² .

Example 11 A carbon dispersion (Volks Black PP-B manufactured by Sumika Color Co., Ltd.) was mixed with [D liquid] of Example 1 so that the dry weight ratio was 0.4%. A sample of Example 11 was obtained in the same manner as in Example 1.

Comparative Example 1 Instead of the MMA / butadiene copolymer component of [D-liquid] of Example 1, a styrene / acrylic copolymer (Showa High Polymer: Polyzol AT-2040, concentration 40%) was used as the same solid. A sample of Comparative Example 1 was obtained in the same manner as in Example 1 except that the amount was used.

Comparative Example 2 Instead of the MMA / butadiene copolymer component of [D liquid] of Example 1, a carboxylated styrene / acrylic copolymer (Takeda Yakuhin: SA-22, concentration 47%) was used as the same solid. A sample of Comparative Example 2 was obtained in the same manner as in Example 1 except that the amount was used.

With respect to the linerless thermosensitive recording label obtained as described above, the dynamic color density of the thermosensitive color developing layer, the adhesive strength due to light irradiation to the thermosensitive adhesive layer on the back side, and the thermosensitive color developing layer surface and the heat sensitive The following test was conducted and evaluated for the blocking resistance when brought into contact with the water-based pressure-sensitive adhesive layer, and the results are shown in the table. <Dynamic color density> Head power of 0.60 W / in a thermal printing experiment device with a thin film head manufactured by Matsushita Electronic Components Co., Ltd.
dot, 1 line recording time 10 msec / 1 line,
Printing was performed with a pulse width of 0.4 and 0.5 msec under a scanning line density of 8 × 7: 7 dot / mm, and the printing density was measured with a Macbeth densitometer RD-914. <Adhesiveness by light irradiation, background density> 3M Transp
so that the heat-sensitive adhesive layer on the back surface is irradiated with the light emitted from the arency-Maker (1350 W, halogen lamp).
It was attached to polyester and irradiated with light to measure the irradiation speed at which the pressure-sensitive adhesive layer was activated (the faster the irradiation speed, the shorter the activation time). Next, the activated sample was attached to an adherend (vinyl chloride wrap, polyethylene wrap), and its adhesive strength was evaluated according to the following ranks. <Evaluation Criteria> ◎: Strongly adhered ○: Adhered Δ: Slightly adhered ×: Not adhered <Blocking resistance> The thermosensitive coloring layer and the thermosensitive adhesive layer of the same sample were brought into contact with each other at 2 kg / cm ² 40 by pressure
After testing for 24 hours at 90 ° C. and 90% RH, the sample was peeled off after standing at room temperature, and the blocking resistance at that time was evaluated according to the following ranks. <Evaluation criteria> ◎: No blocking (no cracking sound) ○: No blocking (no cracking sound) △: Some blocking ×: Full blocking

[0051]

[Table 1]

[0052]

The linerless heat-sensitive recording label of the present invention contains the acrylic / butadiene copolymer, the tackifier and the solid plasticizer in the heat-sensitive adhesive layer.
It has a strong adhesive force to each adherend, particularly vinyl chloride wrap and polyethylene wrap, and also has excellent blocking resistance in a wound state.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C09J 133/02 C09J 133/04 133/04 133/06 133/06 G09F 3/02 F G09F 3/02 B41M 5/18 B 101F (56) References JP-A-7-164736 (JP, A) JP-A-62-115080 (JP, A) JP-A-1-165680 (JP, A) JP-A-63-89583 (JP, A) Kaihei 1-193381 (JP, A) JP 59-47212 (JP, A) JP 7-11229 (JP, A) JP 7-166137 (JP, A) JP 7-292344 ( JP, A) JP-B-45-7429 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G09F 3/00 C09J ⁷ /00-7/04

Claims (7)

(57) [Claims] 1. A thermosensitive recording label having a thermosensitive coloring layer on one side of a support, and a thermosensitive adhesive layer which is usually non-adhesive and activates when heated to produce tackiness on the other side, wherein the thermosensitive adhesive layer is a thermosensitive recording label. A label for heat-sensitive recording, wherein the agent layer contains a methylmethacrylate / butadiene copolymer, a tackifier and a solid plasticizer. 2. The label for heat-sensitive recording according to claim 1, wherein the heat-sensitive adhesive layer further contains a styrene / acrylic copolymer. 3. Methyl methacrylate in the heat-sensitive adhesive layer
The label for heat-sensitive recording according to claim 2, wherein the weight ratio of the rate / butadiene copolymer and the styrene / acrylic copolymer is 1: 0.2 to 5. 4. The softening point or melting point of the tackifier is 1
The label for heat-sensitive recording according to claim 1, which has a temperature of 00 ° C or higher. 5. The content of the tackifier in the heat-sensitive adhesive layer is 3 to 30% by weight.
The heat-sensitive recording label described. 6. The heat-sensitive recording label according to claim 1, wherein the content of the solid plasticizer in the heat-sensitive adhesive layer is 30 to 70% by weight. 7. The heat-sensitive recording label according to claim 1, further comprising a barrier layer provided between the support and the heat-sensitive adhesive layer.