JPH09127871A - Thermosensitive recording label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosensitive recording label which can deal with fast issuing and is advantageous for the cost and suitable for use in a circulation management by successively forming each specified first intermediate layer and second intermediate layer. SOLUTION: This label is produced by successively forming a thermosensitive recording layer, a first intermediate layer containing polyvinylalcohol, a second intermediate layer which is hardened by irradiation of a ionizing radiation-curing compd. with an ionizing radiation, and a release layer on one surface of a supporting body, forming an adhesive layer on the back surface, and then winding the product. By forming the release layer on the specified second intermediate layer, a uniform release layer can be formed with a small amt. of the coating material and good release property can be obtd. Since a linerless thermosensitive label has no release sheet, the adhesive layer touches the release layer on the thermosensitive recording layer face when the label is in a rolled state. However, by forming the first intermediate layer containing polyvinylalcohol, fog in the thermosensitive recording layer due to influences of the adhesive in the adhesive layer or decrease in the recording density can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording label in which a thermosensitive recording layer and a release layer are sequentially provided on one side of a support and an adhesive layer is provided on the back side.

[0002]

2. Description of the Related Art A heat-sensitive recording material in which a plurality of color-forming substances are brought into contact with each other by heat to obtain a recorded image is well known.
Since such a thermal recording medium is relatively inexpensive, the recording device is compact, and its maintenance is easy, it is used in a recording medium such as a facsimile machine and various computers, and in other wide fields. One of the fields of use thereof is, for example, a thermal recording label for a POS (point of sales) system. For conventional food label applications, it was sufficient to issue labels at a speed that did not delay the manual pasting work, but recently, with the spread of high-speed automatic pasting machines combined with devices such as belt conveyors, high speed There is a request for a thermal recording label that can be issued.

With the recent development of information processing technology and performance of recording equipment, the issuing speed of thermal recording labels is increasing, but in general, these thermal recording labels have a release paper on the back surface for the purpose of protecting the adhesive layer. Since the labels are affixed to each other, the winding diameter of the label is large, and the size of the thermal recording label that can be loaded in the recording device is limited.Therefore, the number of labels that can be issued in one winding is also limited. As a result, recording labels have to be replenished frequently as the recording speed increases. In addition, processing of the release paper generated at this time is also a problem. Also, from the viewpoint of cost, the ratio of the recording paper to the release paper is not small. Therefore, there is a strong demand for a heat-sensitive recording label that does not cause a problem even when used for distribution management, is adaptable to high-speed printing, and is advantageous in terms of environmental problems and cost.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording label suitable for distribution management, which can cope with high-speed issuance and is advantageous in terms of cost.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a thermosensitive recording label having a thermosensitive recording layer and a peeling layer sequentially provided on one side of a support and an adhesive layer on the backside of the support. The above problems are solved by sequentially providing a first intermediate layer containing polyvinyl alcohol and a second intermediate layer cured by irradiating an ionizing radiation-curable compound with an ionizing radiation on the heat-sensitive recording layer in between. At the same time, it was completed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a thermosensitive recording layer on one side of a support, a first intermediate layer containing polyvinyl alcohol,
A second intermediate layer, which is cured by irradiating the ionizing radiation-curable compound with ionizing radiation, and a release layer are sequentially provided,
A heat-sensitive recording label (linerless heat-sensitive recording label) that does not require release paper and has a pressure-sensitive adhesive layer provided on the back side, and in particular a second intermediate layer that is cured by irradiating an ionizing radiation-curable compound with ionizing radiation. By providing the release layer on top, a uniform release layer can be formed with a small coating amount, and good release aptitude can be obtained. In addition, since the linerless thermosensitive recording label has no release paper, the adhesive layer is in contact with the release layer on the side of the thermosensitive recording layer in the wound state, and the thermosensitive recording layer is provided on one side of the ordinary support. And a protective layer is sequentially provided, and the heat-sensitive recording layer is susceptible to the influence of the pressure-sensitive adhesive to cause fog on the background and a decrease in the recording density as compared with a normal heat-sensitive recording label in which a release paper is stacked on the pressure-sensitive adhesive layer on the back side. By providing the first intermediate layer containing polyvinyl alcohol, it is possible to obtain the effect of preventing the occurrence of background fog and reduction in recording density of the thermosensitive recording layer due to the influence of the adhesive in the adhesive layer.

The ionizing radiation-curable compound used in the second intermediate layer of the present invention is a compound which is cured by a polymerization reaction by irradiation energy such as X-rays, ultraviolet rays or electron beams. Ionizing radiation-curable compounds that are cured by ultraviolet rays or electron beams are preferred for their ease of use.

Specific examples of the ionizing radiation-curable compound which is cured by irradiation with ultraviolet rays or electron beams include the following. (a) Aliphatic, alicyclic, araliphatic polyhydric alcohol of dihydric to hexavalent alcohol and poly (meth) acrylate of polyalkylene glycol; (b) aliphatic, alicyclic, araliphatic, aromatic 2
Poly (meth) acrylate of polyhydric alcohol obtained by adding alkylene oxide to polyhydric alcohol of 6 to 6 valences; (c) poly (meth) acryloyloxyalkyl phosphate ester; (d) polyester poly (meth) acrylate; (e) epoxy poly (meth) acrylate; (f) polyurethane poly (meth) acrylate; (g) polyamide poly (meth) acrylate; (h) polysiloxane poly (meth) acrylate; (i) side chain and / or terminal To (meta)
(J) Prepolymers such as the modified oligoester (meth) acrylate described in (a) to (i) above, which have an acryloyloxy group.

As the monomer, (a) an ethylenically unsaturated monomer or a carboxyl group-containing monomer typified by a polycarboxylic acid or the like and a carboxylate group-containing alkali metal salt, ammonium salt, amine salt or the like Monomer: (b) Ethylenically unsaturated (meth) acrylamide or alkyl-substituted (meth) acrylamide, a sulfonic acid group-containing monomer represented by vinyl lactams such as N-vinylpyrrolidone, and alkali metal salts thereof. , Ammonium salt, amine salt and other sulfonate group-containing monomers; (d)
A hydroxyl-containing monomer represented by an ethylenically unsaturated ether or the like; (e) an amino-containing monomer such as dimethylaminoethyl (meth) acrylate-2-vinylpyridine; (f) 4
(G) alkyl ester of ethylenically unsaturated carboxylic acid; (h) nitrile group-containing monomer such as (meth) acrylonitrile; (i) styrene;
(j) esters of ethylenically unsaturated alcohols such as vinyl acetate and (meth) allyl acetate; (k) mono (meth) acrylates of alkylene oxide addition polymers of compounds containing active hydrogen; (l) polybasic acids An ester group-containing bifunctional monomer represented by a diester of a compound and an unsaturated alcohol;
(m) Bifunctional monomer consisting of diester of alkylene oxide addition polymer of active hydrogen-containing compound and (meth) acrylic acid; (n) bisacrylamide such as N, N-methylenebisacrylamide; (o) Difunctional monomers such as divinylbenzene, divinylethylene glycol, divinylsulfone, divinyl ether, divinyl ketone; (p) Ester group-containing polyfunctional monomer represented by polyester of polycarboxylic acid and unsaturated alcohol; q) A polyfunctional monomer comprising a polyester of an alkylene oxide addition polymer of a compound containing active hydrogen and (meth) acrylic acid; (r) a polyfunctional unsaturated monomer such as trivinylbenzene. Of course, two or more ionizing radiation-curable compounds as described above may be used in combination. As long as the desired effects of the present invention are not impaired, the resin may contain, for example, an acrylic resin, a silicone resin, an alkyd resin, a fluororesin, a butyral resin, or the like.

In the second intermediate layer, in addition to the above ionizing radiation-curable compound, calcium carbonate, barium carbonate, zinc carbonate, zinc oxide, aluminum oxide, titanium dioxide,
Inorganic pigments such as silicon dioxide, aluminum hydroxide, barium sulfate, talc, kaolin, clay, calcined clay, and colloidal silica, and pigments obtained by surface-treating these inorganic pigments with organic acids, styrene microballs, nylon powder,
Polyethylene powder, urea / formalin resin powder, cellulose acetate powder, polymethylmethacrylate powder, fluororesin powder, epoxy resin powder, benzoguanamine resin powder, organic starch such as raw starch particles, defoaming agent, leveling agent, lubricant, surfactant Additives such as plasticizers, ultraviolet absorbers, fluorescent dyes, coloring dyes, fluorescent pigments, and coloring pigments can also be added as appropriate.

The coating solution for the second intermediate layer, which contains the ionizing radiation-curable compound and, if necessary, the above-mentioned additives, is thoroughly mixed by a mixing stirrer, and then the gravure coater, the coater, the bar coater is applied on the first intermediate layer. Although it is applied by various known coating methods such as a curtain coater, the viscosity can be adjusted by heating the coating solution as necessary. Further, the coating amount is not particularly limited,
If it is less than 0.1 g / m ² , the effect of the present invention cannot be obtained, and if it exceeds 10 g / m ² , the recording sensitivity may decrease, so 0.1 to 10 g / m ² , more preferably 1 to 10 g / m ² .
It is adjusted within the range of about 5 g / m ² .

When the ionizing radiation is an electron beam, the amount of the electron beam applied is 0.1 to 15 Mrad, more preferably 0.5.
The range of about 10 Mrad is desirable. 0.1 Mrad
If it is less than 1, the resin component cannot be sufficiently cured, and 1
Excessive electron beam irradiation exceeding 5 Mrad may cause color development or discoloration of the thermosensitive recording medium, and may cause a decrease in paper strength when the support is paper. As an electron beam irradiation method, for example, a scanning method, a curtain beam method, a broad beam method, or the like can be adopted, and an accelerating voltage for irradiation is preferably about 100 to 300 kV.

When the ionizing radiation is ultraviolet rays, it is necessary to add a curing initiator to the coating liquid for the second intermediate layer in an amount of about 0.1 to 10% by weight based on the ionizing radiation curable compound.
Specific examples of the curing initiator include benzoyl alkyl ether and its derivatives, acetophenone and its derivatives, thioxanthone and its derivatives, and the like.

In the present invention, a first intermediate layer containing polyvinyl alcohol is provided between the heat-sensitive recording layer and the second intermediate layer. The polyvinyl alcohol used in the first intermediate layer is Specific examples thereof include fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol and other modified polyvinyl alcohol, and grafting of these polyvinyl alcohol and polyacrylamide. Examples include water-soluble copolymers.

In the first intermediate layer, in addition to polyvinyl alcohol, various water-soluble or water-dispersible polymer compounds such as binders, pigments, lubricants, surfactants such as sodium dioctylsulfosuccinate (dispersants, Wetting agents), antifoaming agents, and various auxiliaries such as water-soluble polyvalent metal salts such as potassium alum and aluminum acetate may be appropriately added. Further, in order to further improve the water resistance, a curing agent such as glyoxal, boric acid, dialdehyde starch, methylol urea, and an epoxy compound can be used in combination.

Specific examples of the binder comprising a water-soluble or water-dispersible polymer compound other than polyvinyl alcohol include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose,
Gelatin, casein, gum arabic, diisobutylene
Maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt, ethylene / acrylic acid copolymer salt, styrene / acrylic acid copolymer salt, styrene / butadiene copolymer emulsion, urea resin, melamine resin, Examples thereof include amide resins and polyurethane resins.

Specific examples of the pigment include, for example, calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, silicon dioxide, aluminum hydroxide, barium sulfate, talc, kaolin, clay, calcined kaolin, inorganic pigments such as colloidal silica, and styrene. Microballs, nylon powder, polyethylene powder, urea / formalin resin fillers, organic pigments such as raw starch particles, and the like,
Of these, kaolin and aluminum hydroxide are preferably used because they have high barrier properties and a small decrease in recording density.

Furthermore, the coating liquid for the first intermediate layer may contain microcapsules having a wall film made of polyurea or polyurethane-polyurea resin. The microcapsules may contain various solvents as core substances, as well as various solvents. A medium molecular polymer such as polybutene or liquid polybutadiene, an ultraviolet absorber, a fluorescent dye, a coloring dye, a release agent, an antioxidant and the like can be included.

The method for preparing the coating liquid for the first intermediate layer is not particularly limited. Generally, water is used as a dispersion medium, and polyvinyl alcohol and, if necessary, pigments, lubricants, surfactants and the like used with a stirrer. It is prepared by mixing and stirring.

The release layer is formed of a silicone compound which is cured by heat or an ionizing radiation-curable silicone compound which is cured by irradiation with ionizing radiation. The ionizing radiation-curable silicone compound requires heat energy during curing. Therefore, it is preferably used because there is little background fog in the heat-sensitive recording layer.

The ionizing radiation-curable silicone compound is preferably a silicone compound which is cured by irradiation with ultraviolet rays or electron beams. Specific examples thereof include a mixed composition of a mercapto group-containing organopolysiloxane and a vinyl group-containing organopolysiloxane, and acrylic. Group, methacrylic group or cinnamoyl group-containing organopolysiloxane composition, maleimide group or phenylmaleimide group-containing organopolysiloxane composition, mixed composition of azido group-containing organopolysiloxane and vinyl group-containing organopolysiloxane, thioacryl group, Examples thereof include a thiomethacryl group- or thiocinnamoyl group-containing organopolysiloxane composition, an acrylamide group, a methacrylamide group or a cinnamoylamide group-containing organopolysiloxane composition, and the like. Further, a mixed composition of an epoxy group-containing organopolysiloxane utilizing ultraviolet-initiated cationic polymerization and a diazonium Lewis acid salt as a photo-decomposition initiator can also be used.

When the composition is cured by irradiation with ultraviolet rays, it is necessary to add a curing initiator in the release layer coating liquid in an amount of about 0.1 to 10% by weight based on the ionizing radiation-curable compound. Specific examples of the curing initiator include benzoyl alkyl ether and its derivatives, acetophenone and its derivatives, thioxanthone and its derivatives, and the like.

The release layer is formed by applying the release layer coating liquid on the second intermediate layer by various known coating methods such as a gravure coater, a roll coater, a bar coater, and a curtain coater, and then curing the silicone compound. However, the viscosity can be adjusted by heating the coating liquid as needed. Further, there is no particular limitation on the coating weight, the peeling layer coating the coating amount of liquid is 0.5 to 10 g / m ² by dry weight, preferably adjusted in the range of about 1 to 5 g / m ² It

The heat-sensitive recording method applied to the heat-sensitive recording layer includes, for example, a combination of a leuco dye and a color former, a combination of a diazonium salt and a coupler, a combination of a chelate compound of a transition element such as iron and a color former, Examples thereof include a combination of an aromatic isocyanate compound and an imino compound, and a combination of a leuco dye and a color former is preferably used because of excellent color density and recording sensitivity. Hereinafter, the combination of the leuco dye and the color former will be described in detail.

Specific examples of leuco dyes include 3- (N-
Ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluoran,
3-dimethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di (n-butyl) amino-6-methyl-7-anilinoflu Oran, 3-diethylamino-7-
(O-Chlorophenylamino) fluorane, 3-diethylamino-7- (o-fluorophenylamino) fluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluorane, 3-diethylamino- 6
-Chloro-7-anilinofluorane, 3-pyrrolidino-
6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 2,2-bis {4- [6 '-(N-cyclohexyl-N-methylamino) -3 '-Methylspiro [phthalide-3,9'-xanthen-2'-ylamino] phenyl} propane, 3-
Diethylamino-7- (3′-trifluoromethylphenyl) aminofluorane, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3-
(4-Diethylamino-2-methylphenyl) -3-
(4-Dimethylaminophenyl) -6-dimethylaminophthalide, 3-diethylamino-7-dibenzylamino-benzo [a] fluorane, 3- (N-ethyl-Np)
-Tolyl) amino-7-N-methylanilinofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane,

3,3-bis [1- (4-methoxyphenyl) -1- (4-dimethylaminophenyl) ethylene-
2-yl] -4,5,6,7-tetrachlorophthalide,
3,3-bis [1- (4-methoxyphenyl) -1-
(4-pyrrolidinophenyl) ethylene-2-yl]-
4,5,6,7-tetrachlorophthalide, 3- [p-
(P-anilinoanilino) anilino] -6-methyl-7
-Chlorofluorane, 3- [p- (p-dimethylaminoanilino) anilino] -6-methyl-7-chlorofluorane, 3- [p- (p-dimethylaminoanilino) anilino] -6-methyl Fluoran, 3,6-bis (dimethylamino) fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide, 3'-phenyl-7-N-diethylamino-2,3,7-bis (dimethyl) Amino)-
10-benzoylphenothiazine, 3,3′-bis (4
-Diethylamino-2-ethoxyphenyl) -4-azaphthalide, 3- (Np-tolyl-N-ethylamino)
-6,8,8-Trimethyl-9-ethyl-8,9-dihydro- (3,2, e) pyridfluorane, 3-di (n-
Pentyl) amino-6,8,8-trimethyl-8,9-
Dihydro- (3,2, e) pyridfluorane, 3-di (n-butyl) amino-6,8,8-trimethyl-8,
9-dihydro- (3,2, e) pyridfluorane, 3-
[1,1-bis (p-diethylaminophenyl) ethylene-2-yl] -6-dimethylaminophthalide, 3-
(Pn-Butylaminoanilino) -6-methyl-7-
Chlorofluorane, 2-mesidino-8-diethylamino-benz [C] fluorane and the like can be mentioned. Of course, it is not limited to these, and two or more kinds may be used in combination.

Generally, many recorded images are black-colored. As such leuco dye, 3-di (n-butyl) amino-6-
Methyl-7-anilinofluorane is preferably used because it is excellent in recording density, recording sensitivity, storability and stability of uncolored portion. In recent years, due to the development of semiconductor laser light source readers, the use of dyes having absorption in the near-infrared region has been increasing. In this case, 3,7-bis (dimethylamino) -10-benzoylphenothiazine, 3 '-Phenyl-7-N-diethylamino-2,2'-spirology (2
H-1-benzopyran), 3,3-bis [1- (4-methoxyphenyl) -1- (4-dimethylaminophenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide , 3,3'-bis (4-diethylamino-
2-ethoxyphenyl) -4-azaphthalide, 3- (N
-P-Tolyl-N-ethylamino) -6,8,8-trimethyl-9-ethyl-8,9-dihydro- (3,2,2
e) Pyridfluorane has strong absorption in the near infrared region,
It is preferably used because the recorded image has high storability and the uncolored portion is stable.

The amount of these leuco dyes to be used cannot be limited because it depends on the coloring agent used. ~
Range of about 2 g / m ² , preferably 0.03 ~ 1 g /
Used in the range of about m ² .

Various materials are known for these coloring agents used in combination with leuco dyes.
4'-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-
Bis (4-hydroxyphenyl) -4-methylpentane, hydroquinone monobenzyl ether, benzyl 4-hydroxybenzoate, 4,4′-dihydroxybenzophenone, 2,4′-dihydroxybenzophenone, 4,
4'-dihydroxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, 4-hydroxy-4 '
-Isopropoxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 1,1-bis (4-hydroxyphenyl) -1-phenylethane,
1,4-bis [α-methyl-α- (4′-hydroxyphenyl) ethyl] benzene, 1,3-bis [α-methyl-α- (4′-hydroxyphenyl) ethyl] benzene, di (4- Hydroxy-3-methylphenyl) sulfide, 2,2′-thiobis (3-tert-octylphenol), 2,2′-thiobis (4-tert-octylphenol), 2,4-dihydroxy-2′-methoxybenzanilide, etc. Compounds of N, N'-di-m
-Thiourea compounds such as chlorophenylthiourea, N-
(P-Toluenesulfonyl) carbamoyl acid p-cumylphenyl ester, N- (p-toluenesulfonyl) carbamoyl acid p-benzyloxyphenyl ester, N
-(O-toluoyl) -p-toluenesulfoamide, N
-(P-toluenesulfonyl) -N '-(p-tolyl)
A compound having a —SO ₂ NH— bond in the molecule such as urea, p
-Zinc chlorobenzoate, zinc 4- [2- (p-methoxyphenoxy) ethyloxy] salicylate, 4- [3-
Examples are zinc salts of aromatic carboxylic acids such as (p-tolylsulfonyl) propyloxy] salicylic acid zinc and 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] salicylic acid. Among them, 4-hydroxy-4'-isopropoxydiphenyl sulfone and bis (3-allyl-
When 4-hydroxyphenyl) sulfone is used, it is preferably used because the general preservability of the recorded image is excellent.

The ratio of the leuco dye to the color-developing agent is appropriately selected according to the type of the leuco dye or the color-developing agent used and is not particularly limited, but generally 1 part by weight of the leuco dye is used. 1 to 10 parts by weight, preferably 2 to
About 5 parts by weight of the coloring agent is used.

A coating material for a heat-sensitive recording layer containing a leuco dye and a color developing agent generally uses water as a dispersion medium and finely separates the leuco dye and the color developing agent together or separately by a pulverizer such as a ball mill, an attritor or a sand mill. It is prepared by dispersing and adding a binder.

Specific examples of the binder include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, diisobutylene / maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt, Ethylene / acrylic acid copolymer salt, styrene / acrylic acid copolymer salt, styrene / butadiene copolymer emulsion, urea resin, melamine resin, amide resin, polyurethane resin, polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, etc. . Among these, polyvinyl alcohol is preferably used because it enhances the cohesive strength of the heat-sensitive recording layer.

Regarding the amount of these binders used,
Although it is not limited because it depends on the kind of the binder used, in the present invention, since the release layer coated on the thermosensitive recording layer must be retained, 20% or more of the total solids of the thermosensitive recording layer, preferably Is preferably 25% or more. When polyvinyl alcohol is used as the binder component, a thermosensitive recording layer that does not cause a problem in the release layer can be obtained by using 10% or more, preferably 15% or more of the total solid content of the thermosensitive recording layer.

If desired, various auxiliary agents can be added to these coating liquids, for example, dispersants such as sodium dioctylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate, and fatty acid metal salts. Waxes such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax and ester wax,
An antifoaming agent, a coloring dye, a pigment, a sensitizer, a storability improver and the like are appropriately added.

Specific examples of the pigment include kaolin,
Clay, calcium carbonate, calcined clay, calcined kaolin,
Examples thereof include inorganic pigments such as titanium oxide, diatomaceous earth, fine particulate anhydrous silica, and activated clay, and organic pigments such as styrene microballs, nylon powder, polyethylene powder, urea / formalin resin filler, and raw starch particles.

Specific examples of the sensitizer added to enhance the recording sensitivity include, for example, stearic acid amide, ethylenebisstearic acid amide, methylenebisstearic acid amide, N-methylolstearic acid amide, dibenzyl terephthalate, p. -Benzyl benzyloxybenzoate, phenyl 1-hydroxy-2-naphthoate, 2-naphthylbenzyl ether, m-terphenyl, dibenzyl oxalate, oxalate-di-p-methylbenzyl, oxalate-di-p-chloro Benzyl, a mixture of oxalic acid-di-p-methylbenzyl and oxalic acid-di-p-chlorobenzyl, di (p-methoxyphenoxyethyl) ether,
1,2-di (3-methylphenoxy) ethane, 1,2-
Di (4-methylphenoxy) ethane, 1,2-di (4-
Methoxyphenoxy) ethane, 1,2-di (4-chlorophenoxy) ethane, 1,2-diphenoxyethane, 1
-(4-Methoxyphenoxy) -2- (3-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, 1,4-di (phenylthio) butane, 1- (2-
Examples include naphthyloxy) -2-phenoxyethane and 1,3-di (naphthyloxy) propane. The amount of these sensitizers used is not particularly limited, but in general, the coloring agent 1
It is desirable to adjust the amount within the range of 4 parts by weight or less with respect to parts by weight.

Examples of the storability improver added to enhance the storability of a recorded image include the following.
2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-ethylidenebis (4,6-
Di-tert-butylphenol), 2-tert-butyl-6
-(3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 4,4 '
-Thiobis (2-methyl-6-tert-butylphenol), 1- [α-methyl-α- (4'-hydroxyphenyl) ethyl] -4- [α ', α'-bis (4 "-hydroxyphenyl) Ethyl] benzene, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-tris (2-methyl-)
4-hydroxy-5-tert-butylphenyl) butane,
4,4'-dihydroxy-3,3 ', 5,5'-tetramethyldiphenyl sulfone, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-
Hindered phenol compounds such as bis (4-hydroxy-3,5-dichlorophenyl) propane and 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 4,4′-diglycidyloxydiphenyl sulfone, Epoxy compounds such as 4-benzyloxy-4 ′-(2-methylglycidyloxy) diphenyl sulfone, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, N, N′-di-2-naphthyl Examples thereof include sodium p-phenylenediamine, sodium or polyvalent metal salt of 2,2′-methylenebis (4,6-di-tert-butylphenyl) phosphate, and bis (4-ethyleneiminocarbonylaminophenyl) methane. Among them, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane is preferably used because it has an excellent effect on water resistance and is less likely to cause background fog.
In addition, many of the dyes having absorption in the near infrared region are prone to fading due to light. However, when these dyes are used, N, N′-di-2-naphthyl-p-phenylenediamine is light-resistant. It is preferably used because it has an excellent effect of improving the properties.

The method for forming the heat-sensitive recording layer and the first intermediate layer is not particularly limited, and examples thereof include air knife coating, varibar blade coating, pure blade coating, rod blade coating, short dwell coating, curtain coating and die coating. The coating liquid for heat-sensitive recording layer is applied and dried on the support by a suitable coating method, and then the coating liquid for first intermediate layer is further applied and dried on the heat-sensitive recording layer. Further, the coating amount of the thermal recording layer coating liquid is 2 by dry weight.
˜12 g / m ² , preferably about 3 to 10 g / m ² , and the coating amount of the first intermediate layer coating liquid is 0.1 to 20 g / dry weight.
m ² , preferably adjusted in the range of about 0.5 to 10 g / m ² .

The adhesive contained in the adhesive layer is
Various well-known strongly tacky or removable ones can be used. Examples of the strong adhesive adhesive include acrylic adhesives obtained by copolymerizing monomers such as at least butyl acrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate, and natural rubber. Examples of the removable pressure-sensitive adhesive include a two-component cross-linking acrylic pressure-sensitive adhesive obtained by reacting an acrylic pressure-sensitive adhesive with a crosslinking agent having an epoxy group, or a styrene isoprene styrene block copolymer. Among them, the two-component cross-linking acrylic adhesive is easy to control the adhesive strength and removability, and almost no adhesive remains in the release layer, so that the residue of the adhesive adheres to the recording head during recording. This is preferable because it does not cause recording failure.

The pressure-sensitive adhesive layer is formed by coating the pressure-sensitive adhesive layer coating liquid on the back side of the support or on the release layer entirely or partially by various known coating methods such as gravure coater, roll coater, bar coater and curtain coater. It is formed by coating and drying.
The coating amount is not particularly limited, but the coating amount of the release layer coating liquid is a dry weight, and the coating amount of the pressure-sensitive adhesive layer is a dry weight of 3 to 50 g / m ² , preferably 5 to 3
It is adjusted in the range of about 0 g / m ² .

Further, in the present invention, since the first intermediate layer, the second intermediate layer and the peeling layer are provided on the thermosensitive recording layer, JIS K 5101 is provided between the support and the thermosensitive recording layer for the purpose of improving the recording sensitivity.
The oil absorption measured based on 80 to 300 cc / 10
It is preferable to provide an undercoat layer containing 0 g of the oil absorbing pigment. By providing the undercoat layer containing the oil-absorbing pigment in this range, not only the decrease in recording sensitivity is suppressed but also the image quality and whiteness are improved. Oil absorption is 8
If the pigment is less than 0 cc / 100 g, the effect of suppressing the decrease in recording sensitivity of the recorded image is insufficient, and the oil absorption is 300 cc.
If the pigment exceeds / 100 g, a clear recorded image cannot be obtained, and the surface strength of the recording material tends to decrease, which is not preferable.

The oil-absorbing pigment comprises 50 to 50% of the total solid content of the undercoat layer.
It is preferable that the content is about 98% by weight, preferably about 75 to 95% by weight. Specific examples of such oil-absorbing pigments include calcined clay, aluminum oxide, titanium oxide, magnesium carbonate, calcium carbonate,
Diatomaceous earth, amorphous silica, aluminum silicate, magnesium silicate, calcium silicate, sodium aluminosilicate, magnesium aluminosilicate, etc. having the above specific oil absorption amount, or a general pigment is physically or chemically treated to obtain the above specific Inorganic or organic pigments having an oil absorption amount, organic hollow particles, expandable polymers and the like can also be used, but calcined clay and amorphous silica are particularly preferably used because they have excellent heat insulating properties.

The undercoat layer is formed by a method of coating and drying a coating solution containing the above oil-absorbing pigment and a binder as main components and various additives, and examples of such binders include starches and celluloses. , Proteins, gum arabic, polyvinyl alcohol, styrene
Maleic anhydride copolymer salt, vinyl acetate / maleic anhydride copolymer salt, water-soluble polymers such as polyacrylate, styrene / butadiene copolymer emulsion, various emulsions such as acrylonitrile / butadiene copolymer emulsion, etc. Is appropriately selected and used.

The method of forming the undercoat layer is not particularly limited, and examples thereof include air knife coating, varibar blade coating, pure blade coating,
The undercoat layer coating solution is applied onto the support by a suitable coating method such as rod blade coating, short dwell coating, curtain coating, or die coating so that the dry weight is ² to ²⁰ g / m ^2, and the undercoat layer is formed. It is formed. Among them, pure blade coating and rod blade coating are excellent in recording image quality and are preferably used.

Further, a protective layer containing polyvinyl alcohol may be provided between the support and the pressure-sensitive adhesive layer, or smoothing treatment such as super calendering may be applied after coating each layer, but especially the second layer. First applied intermediate layer
Smoothing the surface of the intermediate layer is preferable in order to obtain a smooth and uniform release layer by applying a smooth second intermediate layer and a small amount of coating liquid for the release layer. Specifically, it is desirable that the surface of the first intermediate layer be adjusted to have a Beck's smoothness in the range of 500 seconds to 10000 seconds. Various other known techniques in the field of heat-sensitive recording medium production can be added as needed.

[0046]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted to such specific Examples. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively, unless otherwise specified.

Example 1 (1) Preparation of Liquid A Calcined clay [oil absorption: 110 ml / 100 g] 100
Of a 10% aqueous solution of polyvinyl alcohol and 100 parts of water were mixed and stirred to obtain a coating liquid for an undercoat layer.

(2) Formation of undercoat layer A solution A was applied and dried on one surface of a high-quality paper of 60 g / m ² so that the coating amount after drying was 9 g / m ^2, and then smoothed by a super calender. To form an undercoat layer.

(3) Preparation of Solution B A composition comprising 10 parts of 3-di- (n-butyl) amino-6-methyl-7-anilinofluorane, 5 parts of a 5% aqueous solution of methylcellulose and 40 parts of water was sand milled. The particles were pulverized with an average particle diameter of 1.0 μm.

(4) Preparation of liquid C A composition consisting of 30 parts of 4-hydroxy-4′-isopropoxydiphenyl sulfone, 5 parts of a 5% aqueous solution of methylcellulose and 80 parts of water has a mean particle diameter of 1.0 μm in a sand mill. Crushed until.

(5) Preparation of solution D A composition consisting of 20 parts of 1,2-di (3-methylphenoxy) ethane, 5 parts of a 5% aqueous solution of methylcellulose and 55 parts of water was sand milled to an average particle size of 1.0 μm. Crushed until

(6) Formation of thermosensitive recording layer 55 parts of solution B, 115 parts of solution C, 80 parts of solution D, 160 parts of 10% aqueous polyvinyl alcohol solution, 20 parts of 50% SBR latex and 17 parts of calcium carbonate were mixed and stirred. The amount of the obtained thermal recording layer coating liquid on the intermediate layer was 6 g after drying.
/ M ² to form a heat-sensitive recording layer.

(7) Formation of First Intermediate Layer 250 parts of 10% aqueous solution of polyvinyl alcohol modified with acetoacetyl group, kaolin [trade name: UW-90, EMC
Co., Ltd.] 70 parts, a composition comprising 6 parts of a 30% zinc stearate aqueous dispersion and 150 parts of water are mixed and stirred to obtain a coating solution for the intermediate layer, which has a coating amount after drying on the thermosensitive recording layer. 3 g /
After coating and drying so as to be m ² , the surface was smoothed by a super calendar to form a first intermediate layer. The Beck's smoothness of the surface of the first intermediate layer was 1200 seconds.

(8) Formation of Second Intermediate Layer An ionizing radiation-curable compound [trade name: GRANDIC EB 0227, which is cured by an electron beam on the first intermediate layer,
Dainippon Ink and Chemicals Co., Ltd.] dry coating amount 3g / m ²
And then 1.5M with an electron curtain type electron beam irradiation device [CB: 150 type, manufactured by ESI].
rad irradiation dose to cure the resin component and
An intermediate layer was formed.

(9) Formation of Release Layer Solventless ionizing radiation-curable silicone compound which is cured by electron beam [30 parts by weight of mercapto group-containing organopolysiloxane of 1.5 mol% and vinyl of 1.5 mol%] 100 parts by weight of a mixed composition consisting of 70 parts by weight of a group-containing organopolysiloxane, manufactured by Shin-Etsu Chemical Co., Ltd., and 3 parts by weight of a curing initiator (acetophenone) were mixed and stirred, and the coating amount of the release layer coating solution was 1. After coating so as to be 0 g / m ² ,
Ultraviolet rays were irradiated to form a release layer.

(10) Formation of adhesive layer After drying the acrylic emulsion adhesive on the back side of the support
Coating amount of 20g / m ^TwoAfter coating and drying so that
Then, a thermal recording label having no release paper was obtained.

Example 2 In the formation of the second intermediate layer of Example 1, an ionizing radiation-curable compound which is cured by an electron beam [trade name: GRANDI
CEB 0227, manufactured by Dainippon Ink and Chemicals, Inc.], an ionizing radiation curable compound [trade name: Dicure ROP varnish, manufactured by Dainippon Ink and Chemicals, Inc.] that is cured by ultraviolet rays is applied at a dry coating amount of 3 g / m ^2. After the application, the thermosensitive recording label without release paper was obtained in the same manner as in Example 1 except that the resin component was cured with an ultraviolet irradiation device to form the second intermediate layer.

Example 3 In the formation of the release layer of Example 1, a solventless ionizing radiation-curable silicone compound which was cured by electron beam [30 parts by weight of 1.5 mol% of the mercapto group-containing organopolysiloxane and 1 Mixed composition consisting of 70 parts by weight of vinyl group-containing organopolysiloxane of 0.5 mol%, manufactured by Shin-Etsu Chemical Co., Ltd.] 100 parts by weight, curing initiator (acetophenone)
Instead of 3 parts by weight, 100 parts by weight of an ionizing radiation-curable silicone compound [electron beam-curable acrylic modified silicone resin] which is cured by electron beam is used, and the coating amount is 1.0 g.
/ M ² was applied, and then a thermosensitive recording label without a release paper was obtained in the same manner as in Example 1 except that the release layer was formed by irradiating with an electron beam.

Example 4 In the formation of the pressure-sensitive adhesive layer of Example 1, 100 parts of epoxy was used instead of the acrylic emulsion pressure-sensitive adhesive for two-part cross-linking type acrylic pressure-sensitive adhesive [trade name: AE224, manufactured by Japan Synthetic Rubber Co., Ltd.]. One part of the cross-linking agent was added, mixed and stirred, 20 g / m ^{2 was} applied to the opposite surface of the heat-sensitive recording layer, dried, and then wound.
A heat-sensitive recording label without a release paper having a removable pressure-sensitive adhesive layer was obtained.

Comparative Example 1 A thermal recording label having no release paper was obtained in the same manner as in Example 1 except that the second intermediate layer was not provided in the formation of the thermal recording label of Example 1.

Comparative Example 2 A thermal recording label having no release paper was obtained in the same manner as in Example 1 except that the first intermediate layer was not provided in the formation of the thermal recording label of Example 1.

Comparative Example 3 In the formation of the thermosensitive recording label of Example 1, the first intermediate layer,
A heat-sensitive recording label having no release paper was obtained in the same manner as in Example 1 except that the second intermediate layer was not provided.

The thermal recording labels thus obtained were subjected to the following evaluation tests, and the results are shown in Tables 1 and 2.

[Evaluation] (1) [Coloring property] Each thermosensitive recording label was colored with applied energy: 0.5 mJ / dot using a thermosensitive recording evaluation device [trade name: TH-PMD, manufactured by Okura Electric Co., Ltd.]. The obtained recorded image was measured in a visual mode with a Macbeth densitometer [RD-914 type, manufactured by Macbeth Co.].

(2) [Whiteness] The whiteness of each thermosensitive recording label obtained was measured according to JIS P 8123.

(3) [Adhesive label suitability 1] The obtained thermosensitive recording label was peeled off, and the surface on which the adhesive had been applied was observed, and from the adhesive remaining and the surface condition, adhesive paper and release paper were prepared. The performance of was evaluated. Evaluation of Adhesive Label Suitability ⊚: There is no adhesive residue on the label surface, and there is no problem with the release layer. ◯: No adhesive residue was found on the label surface, and there were no printing problems. Also, there is no problem with the release layer. Δ: Slight scratches are seen on the release layer, and some printing defects are also seen. X: An adhesive residue is seen on the label surface. Also, the scratches on the release layer are severe.

[0067]

[Table 1]

[0068]

As is apparent from [Table 1], the heat-sensitive recording label of the present invention has good performance as a heat-sensitive recording paper and an adhesive paper, and also has suitability for high-speed recording equipment. It was an excellent heat-sensitive recording material suitable for distribution management, which does not require the treatment of.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41M 5/26 C09J 7/02 JJA C09J 7/02 JJA JKV JKV JLE JLE G09F 3/10 BG09F 3 / 10 B41M 5/18 F BE

Claims (4)

[Claims] 1. A thermosensitive recording label having a thermosensitive recording layer and a peeling layer sequentially provided on one side of a support and an adhesive layer on the backside of the support, wherein polyvinyl is provided on the thermosensitive recording layer between the thermosensitive recording layer and the peeling layer. A heat-sensitive recording label comprising a first intermediate layer containing alcohol and a second intermediate layer which is cured by irradiating an ionizing radiation-curable compound with ionizing radiation. 2. A heat-sensitive recording label according to claim 1, wherein the release layer is cured by irradiating an ionizing radiation-curable silicone compound with ionizing radiation. 3. An oil absorption (JIS K) between the support and the thermosensitive recording layer.
(Based on 5101) is 80 to 300 cc / 100 g, and an undercoat layer containing an oil absorbing pigment is provided.
Thermal recording label as described. 4. The heat-sensitive recording label according to claim 1, 2 or 3, wherein the pressure-sensitive adhesive layer contains a removable pressure-sensitive adhesive as a pressure-sensitive adhesive.