JPH10315621A - Adhesive label for thermal recording - Google Patents

Abstract

(57) [Problem] To provide a heat-sensitive recording pressure-sensitive adhesive label which does not require a release paper even when used under severe conditions, with little decrease in coloring ability even during long-term storage. is there. Kind Code: A1 Abstract: A thermosensitive recording layer is provided on one side of a support, a first intermediate layer, a second intermediate layer, and a release layer are sequentially provided, and a pressure-sensitive adhesive layer is provided on the back side. In the pressure-sensitive adhesive label, as one means for solving the above-mentioned problem, the present invention includes a water-resistant agent contained in at least one of the heat-sensitive recording layer, the first intermediate layer, and the second intermediate layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording adhesive label utilizing a color-forming reaction between a leuco dye and a color former.

[0002]

2. Description of the Related Art Thermal recording media utilizing a color-forming reaction between a leuco dye and a color former are well known. Such a thermosensitive recording medium is relatively inexpensive, has a compact recording device, and is easy to maintain. Therefore, it is used in recording media such as facsimile machines and various computers, and in a wide variety of fields. For example, a thermosensitive recording medium is used as a recording medium for a POS (point of sales) system. The thermosensitive recording medium for a POS system has a thermosensitive recording layer formed on at least one side of a support, and an adhesive layer formed on the back side of the support. Applications such as industrial and industrial use are expanding.

Further, with the recent development of information processing technology and the performance of recording equipment, it has become possible to record at higher speeds on pressure-sensitive adhesive labels for heat-sensitive recording. A release paper is attached for the purpose of protection, which increases the diameter of the heat-sensitive recording pressure-sensitive adhesive label. Further, the size of the heat-sensitive recording pressure-sensitive adhesive label that can be loaded into a recording device is limited, so that one roll is required. The number of adhesive labels that can be issued is reduced, and the recording adhesive labels must be frequently replaced with an increase in recording speed. In addition, the treatment of the release paper generated at this time is also a problem, and the ratio of the release paper to the recording adhesive label is not small in terms of cost. Therefore, there is a strong demand for a thermosensitive recording adhesive label which does not cause any problem even when used for distribution management, can be adapted to high-speed issuance, and is advantageous in terms of environmental measures and cost.

By the way, since the pressure-sensitive adhesive label for heat-sensitive recording which does not require a release paper has no release paper due to its constitution, when it is wound up, the pressure-sensitive adhesive layer comes into contact with the release layer on the heat-sensitive recording surface. The heat-sensitive recording layer is more susceptible to the effect of the pressure-sensitive adhesive than the heat-sensitive recording pressure-sensitive adhesive label, and the color-forming ability of the heat-sensitive recording layer decreases after long-term storage, or the adhesion between the intermediate layer and the release layer is insufficient. In particular, when exposed to high-temperature and high-humidity conditions, there is a problem that a part of the release layer is peeled off and adheres to the pressure-sensitive adhesive layer.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive for heat-sensitive recording which requires little release paper even when used under severe conditions with little decrease in color-forming ability even during long-term storage. Provide labels.

[0006]

A roll-shaped release paper in which a heat-sensitive recording layer, a first intermediate layer, a second intermediate layer, and a release layer are sequentially provided on one side of a support, and an adhesive layer is provided on the back side. In an unnecessary heat-sensitive recording pressure-sensitive adhesive label, as one means for solving the above problems, the present invention includes a water-resistant agent in at least one of a heat-sensitive recording layer, a first intermediate layer, and a second intermediate layer. It is to let.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION At least one of a heat-sensitive recording layer, a first intermediate layer and a second intermediate layer is used in order to suppress a decrease in the coloring ability of the heat-sensitive recording layer due to a pressure-sensitive adhesive as a main component in the pressure-sensitive adhesive layer. Characterized in that it contains a waterproofing agent, especially the first
It is preferable to include a waterproofing agent in the intermediate layer.

When at least one of the first intermediate layer and the second intermediate layer contains a water-soluble adhesive excellent in film formability,
It is preferable that the second intermediate layer contains a water-soluble adhesive excellent in film formability, which has a strong effect of suppressing a decrease in the coloring ability of the heat-sensitive recording layer.

The water-resistant agent contained in at least one of the heat-sensitive recording layer, the first intermediate layer and the second intermediate layer is used as an adhesive for the heat-sensitive recording layer, the first intermediate layer or the second intermediate layer. There is no particular limitation as long as it is a waterproofing agent for the water-soluble adhesive. As such a waterproofing agent,
For example, glyoxal, glutaraldehyde, formalin, dimethylol urea, boric acid, borax, dialdehyde starch, adipic dihydrazide, polyamide epichlorohydrin resin, polyamide urea formaldehyde resin, adipic hydrazide, melamine / formaldehyde resin, ammonium carbonate Zirconium and the like can be mentioned. The amount used is not particularly limited, but it is about 0.1 to 15% by weight, preferably about 0.3 to 10% by weight, based on the total solids of the layer to which the waterproofing agent is added.

The water-soluble adhesive used for the heat-sensitive recording layer, the first intermediate layer or the second intermediate layer includes, for example, starches, hydroxyethyl cellulose, methyl cellulose, and the like.
Carboxymethylcellulose, gelatin, casein, gum arabic, completely (partially) saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, co-polymerization of hydrophobic monomer and ethylenically unsaturated carboxylic acid Polymer salts and the like can be mentioned.

In the present invention, the first intermediate layer and the second intermediate layer are provided on the heat-sensitive recording layer for the purpose of preventing the components of the pressure-sensitive adhesive in the pressure-sensitive adhesive layer from migrating into the heat-sensitive recording layer. When the first intermediate layer contains a water-soluble adhesive having an acid value of 40 to 80, the effect is remarkably obtained. The amount used is not particularly limited, but is at least 5% by weight, preferably about 20 to 80% by weight, based on the total solids of the first intermediate layer. The acid value in the present invention means 1 g of a water-soluble adhesive.
Means the number of mg of potassium hydroxide required to neutralize

The water-soluble adhesive having an acid value of 40 to 80 includes, for example, styrene, ethylene, methyl acrylate,
Hydrophobic monomers such as methyl methacrylate, ethyl acrylate and ethyl methacrylate, and ethylenic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, 2-methacryloyloxysuccinic acid, and 2-methacryloyloxyethylsuccinic acid Copolymers with unsaturated carboxylic acids are mentioned. Among them, a copolymer of styrene and an ethylenically unsaturated carboxylic acid, particularly a copolymer of styrene and acrylic acid, is excellent in the effect of suppressing a decrease in the color developing ability of the heat-sensitive recording layer. The carboxylic acid of the copolymer is used in a state neutralized with an alkali such as sodium hydroxide, potassium hydroxide, ammonium hydroxide or the like so that the acid value becomes about 40 to 80, preferably about 40 to 65. If the acid value is less than 40, the effect of suppressing a decrease in the coloring ability of the heat-sensitive recording layer is reduced. If the acid value is more than 80, background fog may occur in the heat-sensitive recording layer. As for the ratio between the hydrophobic monomer and the unsaturated carboxylic acid, the unsaturated carboxylic acid is about 10 to 80 mol% based on the hydrophobic monomer.

Further, the first intermediate layer has an average particle diameter of 0.1 to
The pigment having a thickness of 3 μm is 40 to 70 with respect to the total solid content of the first interlayer.
The content by weight has an effect of improving the barrier property to the pressure-sensitive adhesive in the pressure-sensitive adhesive layer. Specific examples of such pigments include, for example, calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, amorphous silica, aluminum hydroxide, barium sulfate, talc, kaolin, clay, calcined kaolin, styrene microballs, nylon powder, polyethylene powder. And a urea-formalin resin filler. Among them, the use of kaolin or aluminum hydroxide is preferable because of its high barrier property and small decrease in recording density.

The adhesive label for heat-sensitive recording which does not require a release paper is provided with a release layer as an uppermost layer, so that when the recording is performed by a recording device, the release layer comes into contact with the thermal head. Therefore, the release layer and the second
If the adhesion to the intermediate layer is insufficient, the release layer is peeled off and adheres to the thermal head, causing a recording failure. In the present invention, the second intermediate layer is provided on the first intermediate layer in order to improve the adhesion of the release layer. However, when the acetoacetyl group-modified polyvinyl alcohol is contained in the second intermediate layer, the effect is large. . The amount used is not particularly limited, but is at least 5% by weight, preferably about 20 to 80% by weight, based on the total solids of the second intermediate layer.

The second intermediate layer may be used in combination with various known water-soluble resins and pigments exemplified in the first intermediate layer as long as the desired effects of the present invention are not impaired. The content of 30 to 70% by weight based on the total solid content of the layer has the effect of improving the adhesion between the second intermediate layer and the release layer. If the content of the pigment is less than 30% by weight, the above effects cannot be sufficiently obtained. If the content is more than 70% by weight, the silicone resin penetrates into the barrier layer at the time of coating the release layer, thereby impairing the releasability or causing adhesion. Even if the barrier property to the agent is improved, the barrier property to the solvent or the plasticizer may be reduced.

In the present invention, the heat-sensitive recording layer, the first intermediate layer, the second intermediate layer, and the release layer are sequentially provided on one side of the support. Is unnecessary. Since at least the release layer is formed after providing the heat-sensitive recording layer, an ultraviolet-curable or electron-beam-curable silicone resin is preferably used as the resin used for the release layer because no thermal curing is required.

Specific examples of these silicone resins include a mixed composition of a mercapto group-containing organopolysiloxane and a vinyl group-containing organopolysiloxane, an acrylic group, a methacryl group or a cinnamoyl group-containing organopolysiloxane composition, a maleimide group or Phenylmaleimide group-containing organopolysiloxane composition, azide group-containing organopolysiloxane and vinyl group-containing organopolysiloxane, thioacryl group, thiomethacryl group or thiocinnamoyl group-containing organopolysiloxane composition, acrylamide group, methacryl Amide group or cinnamoylamide group-containing organopolysiloxane composition, etc., and epoxy group-containing organopolysiloxane utilizing ultraviolet-initiated cationic polymerization and photodecomposition initiator Mixed composition of diazonium Lewis acid salts can also be used. In the case of ultraviolet curing, a curing initiator is required. Specific examples of such a curing initiator include benzoyl alkyl ether and its derivatives, acetophenone and its derivatives, thioxanthone and its derivatives, and the like.

The pressure-sensitive adhesive and the removable pressure-sensitive adhesive used in the adhesive layer are not particularly limited, and include, for example, natural rubber and acrylic resin-based pressure-sensitive adhesives. Examples of the removable pressure-sensitive adhesive include styrene isoprene Styrene block copolymers and the like are preferably used because they have a high cohesion even at a low molecular weight, but more preferably a two-part crosslinkable acrylic pressure-sensitive adhesive. This type is used in combination with an appropriate crosslinking agent such as an epoxy derivative, so that when applied to an adhesive label, crosslinking of the adhesive has not progressed,
Since the adhesive soaks into the adhesive label support to some extent, the adhesive strength of the appropriate adhesive to the adhesive label is obtained, and the cohesive force increases due to the progress of crosslinking of the adhesive over time, and the removability is improved. Will occur. In this type, it is easy to control the adhesive strength and removability by selecting the type of acrylic used and the crosslinking agent.

Various known leuco dyes and colorants can be used in the heat-sensitive recording layer. Examples of the leuco dye include the following. 3,3
Blue-coloring dyes such as -bis (p-dimethylaminophenyl) -6-dimethylaminophthalide and 3-diethylamino-7-dibenzylamino-benzo [a] fluoran;
Green coloring such as-(N-ethyl-N-p-tolyl) amino-7-N-methylanilinofluoran, 3-diethylamino-7-anilinofluoran, 3-diethylamino-7-dibenzylaminofluoran, etc. Sex dye, 3,6-bis (diethylamino) fluoran-γ-anilinolactam, 3-cyclohexylamino-6-chlorofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-7- Red-coloring dyes such as chlorofluorane, 3-dimethylamino-6-methyl-7
-Anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-di (nbutyl) amino-6-methyl-7-anilinofluoran, 3-di (n
-Pentyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-7- (m-trifluoromethyl) anilinofluoran, 3-diethylamino-7-
(O-fluorophenylamino) fluoran, 3-di (n-butyl) amino-7- (o-fluorophenylamino) fluoran, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilino Fluoran, 3- (N
-Ethyl-N-tetrahydrofurfurylamino) -6
Methyl-7-anilinofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-dibutylamino-6-methyl-7-m-toluidinofluoran,
3- (N-methyl-N-cyclohexyl) amino-6
Methyl-7-anilinofluoran, 3- (N-ethyl-
N-isobutyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-p-
Ethoxyanilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-piperidino-6
Black-color-forming dyes such as methyl-7-anilinofluoran;
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-dimethylaminoanilino) anilino-6-methyl-7-chlorofluoran, 3-p- (p-chloroanilino) anilino-6
Dyes having an absorption wavelength in the near infrared region, such as methyl-7-chlorofluorane and 3,6-bis (dimethylamino) fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide; Of course, it is not limited to these,
Also, two or more kinds can be used in combination. The use amount of these leuco dyes is not particularly limited, but is preferably about 5 to 35% by weight based on the heat-sensitive recording layer.

Examples of the coloring agent include 4,4'-isopropylidenediphenol, 4,4'-cyclohexylidenediphenol, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 4-hydroxy Benzyl benzoate, 2,4′-dihydroxydiphenyl sulfone,
4,4′-dihydroxydiphenylsulfone, 4-hydroxy-4′-isopropoxydiphenylsulfone, bis (3-allyl-4-hydroxyphenyl) sulfone,
4-hydroxy-4'-methyldiphenyl sulfone, 4
-Hydroxyphenyl-4'-benzyloxyphenylsulfone, 3,4-dihydroxyphenyl-4'-methylphenylsulfone, 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) Phenolic compounds such as sulfide, 2,2′-thiobis (3-tert-octylphenol), 2,2′-thiobis (4-tert-octylphenol), and 4,4′-bis (p-tolylsulfonylaminocarbonylamino) Diphenyllmethane, N- (p-
Tolylsulfonyl) -N '- (p-tolyl) having a -SO ₂ NH- bond in the molecule, such as urea, 4- [2-
Aromatics such as (p-methoxyphenoxy) ethyloxy] zinc salicylate, 4- [3- (p-tolylsulfonyl) propyloxy] zinc salicylate, 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] zinc salicylate Examples thereof include zinc salts of carboxylic acids.

The ratio of the leuco dye to the colorant is appropriately selected according to the type of the leuco dye and the colorant used, and is not particularly limited. 1 to 8 parts by weight, preferably 2 to 5 parts by weight
A colorant of about parts by weight is used.

In the present invention, a preservability improver for improving the storage stability of the recorded image and a sensitizer for improving the recording sensitivity can be used in combination. Specific examples of such a preservability improver include, for example, 2,2′-methylenebis (4
-Methyl-6-tert-butylphenol), 2,2'-
Methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-tert-
Butylphenol), 4,4'-butylidenebis (6-
tert-butyl-m-cresol), 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 (3-methylphenol), 2,2
-Bis (4-hydroxy-3,5-dibromophenyl)
Hindered phenol compounds such as propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, and 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane; Glycidyloxybenzene, 4,4′-diglycidyloxydiphenylsulfone, 4-benzyloxy-4 ′-(2-methylglycidyloxy) diphenylsulfone, diglycidyl terephthalate, cresol novolak epoxy resin, phenol novolak epoxy resin, bisphenol Epoxy compounds such as A-type epoxy resin, N, N'-di-2-naphthyl-p-phenylenediamine, metal salts of 2,2'-methylenebis (4,6-di-tert-butylphenyl) phosphate, and the like. Can be

Specific examples of the sensitizer include, for example, stearic acid amide, ethylenebisstearic acid amide, behenic acid amide, methylenebisstearic acid amide, N-methylol stearic acid amide, dibenzyl terephthalate,
Dimethyl terephthalate, benzyl p-benzyloxybenzoate, 2-naphthylbenzyl ether, m-terphenyl, p-benzylbiphenyl, p-tolylbiphenyl ether, 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, p −
Acetotoluidide, p-acetophenethidide, N-acetoacetyl-p-toluidine, di (β-biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1-isopropylphenyl-2-phenylethane, dioxalate -P-chlorobenzyl ester, di-p-methylbenzyl oxalate, dibenzyl oxalate and the like. The amounts of these storage improvers and sensitizers are not particularly limited, but are generally about 0.1 to 4 parts by weight per 1 part by weight of the color former.

The heat-sensitive recording layer generally uses water as a dispersion medium,
A leuco dye, a color former, and if necessary, a sensitizer, a preservability improver, and the like are used together or separately by a pulverizer such as a ball mill, an attritor, a sand mill, or the like.
After pulverizing to a thickness of about 2 to 2 μm, a thermosensitive recording layer coating solution prepared by adding the following adhesive is coated on a support and dried.

Examples of the adhesive added to the coating solution for the heat-sensitive recording layer include starches, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, and the like.
Gelatin, casein, gum arabic, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, diisobutylene / maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt, ethylene -Acrylic acid copolymer salts, styrene / acrylic acid copolymer salts, styrene / butadiene-based latex, urethane-based latex, acrylic latex, and the like. The amount of the adhesive used is 5 to the heat-sensitive recording layer.
About 35% by weight.

Further, various known auxiliaries can be added to the coating solution for the heat-sensitive recording layer. As the auxiliary agent, for example, kaolin, clay, calcium carbonate, calcined clay, calcined kaolin, amorphous silica, aluminum hydroxide, urea / formalin resin filler and other pigments having a volume average particle diameter of 3 μm or less, sodium dioctyl sulfosuccinate, dodecyl Surfactants such as sodium benzenesulfonate, sodium lauryl alcohol sulfate, and sulfone-modified polyvinyl alcohol; lubricants such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax, and ester wax;
And an antifoaming agent, a fluorescent dye, a coloring dye and the like are appropriately added.

The method for forming the heat-sensitive recording layer and the first and second intermediate layers is not particularly limited, and includes, for example, bar coating, burbar blade coating, gravure coating, rod blade coating, short dwell coating, curtain coating, die coating, and the like. The coating solution for the heat-sensitive recording layer and the coating solutions for the first and second intermediate layers are sequentially coated and dried on the support to form the heat-sensitive recording layer and the first and second intermediate layers.

The support is appropriately selected from paper, plastic film, synthetic paper, nonwoven fabric and the like. The coating amount of the coating solution for the heat-sensitive recording layer is 2 to 2% by dry weight.
12 g / m ^2, preferably 3 to 10 g / m ² approximately, the coating amount of the first and second intermediate layer coating liquid for dry weight 0.5 to 10 g / m ^2, preferably 1.0~5g / M ²
It is about.

The method for forming the release layer and the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include the same methods as those for forming the heat-sensitive recording layer and the first and second intermediate layers. The coating amount of the coating liquid for the release layer is 0.5 to 20 g by dry weight.
/ M ^2, preferably from 1 to 10 g / m ² approximately, the coating amount of the adhesive layer is 3 to 50 g / m ² by dry weight, preferably 5 to
It is about 30 g / m ² . The release layer and the pressure-sensitive adhesive layer are respectively applied to the entire surface of the back surface side of the support on the second intermediate layer. For example, the pressure-sensitive adhesive layer may be partially applied. In this case, the release layer can be applied only to the portion where the pressure-sensitive adhesive layer is applied or to the entire surface. As for the method of forming the pressure-sensitive adhesive layer, a method in which the pressure-sensitive adhesive layer is directly applied to the back surface of the recording material, or a method in which the pressure-sensitive adhesive layer is coated on the release layer and transferred to the back surface of the wound recording material, is also possible.

Further, it is possible to apply a smoothing treatment such as super calendering after coating each layer. In particular, to smooth the surface of the second intermediate layer to which the release layer is applied, a smooth release Necessary for obtaining layers. It is desirable that the surface of the second intermediate layer has a Beck smoothness of 500 seconds or more. Further, if necessary, an intermediate layer may be provided between the support and the pressure-sensitive adhesive layer to further enhance the preservability and impart a strong gloss. Furthermore, an undercoat layer containing an organic or inorganic oil-absorbing pigment as a main component is provided between the support and the thermosensitive recording layer, a perforated label is formed on a sleeping label for thermosensitive recording, and an adhesive is printed by a printing method. Various other known techniques in the field of heat-sensitive recording medium production, such as part coating excluding the edge portion and the perforated portion, can be added as necessary.

[0031]

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. Parts and% in Examples are parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 Preparation of Coating Liquid for Undercoat Layer 100 parts of calcined clay (trade name: Ansilex, manufactured by EC, oil absorption 110 ml / 100 g), 1 part of 40% aqueous solution of sodium polyacrylate, solid concentration 48% Of styrene-butadiene-based latex, 50 parts 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.

Preparation of Solution A 10 parts of 3-di (n-butyl) amino-6-methyl-7-anilinofluoran, 5% aqueous solution of methylcellulose 5
Part A and 40 parts of water were pulverized with a sand mill until the average particle diameter became 1.0 μm to obtain a liquid A.

Preparation of Solution B 30 parts of bis (3-allyl-4-hydroxyphenyl) sulfone, 5 parts of a 5% aqueous solution of methylcellulose and 8 parts of water
The composition consisting of 0 parts was sand-milled to an average particle size of 1.0
The solution B was obtained by pulverizing the mixture to a thickness of μm.

Preparation of Solution C A composition comprising 20 parts of 1,2-di (3-methylphenoxy) ethane, 5 parts of a 5% aqueous solution of methylcellulose and 55 parts of water is pulverized by a sand mill until the average particle diameter becomes 1.0 μm. Thus, solution C was obtained.

Preparation of Coating Solution for Heat Sensitive Recording Layer 55 parts of solution A, 115 parts of solution B, 80 parts of solution C, polyvinyl alcohol (trade name: PVA-210, manufactured by Kuraray Co., Ltd.)
160 parts of 0% aqueous solution, 20 parts of styrene / butadiene latex having a solid concentration of 50%, and light calcium carbonate 1
The composition of 7 parts was mixed and stirred to obtain a coating solution for a heat-sensitive recording layer.

Preparation of Coating Liquid for First Intermediate Layer 200 parts of a 20% aqueous solution of ammonium salt of styrene / acrylic acid copolymer (acid value: 45), 4 parts of glyoxal
1 part of 0% aqueous solution and polyvinyl alcohol [trade name:
Of PVA-105, manufactured by Kuraray Co., Ltd.] was mixed and stirred to obtain a first intermediate layer coating liquid.

Preparation of Coating Solution for Second Intermediate Layer Acetoacetyl-modified polyvinyl alcohol [trade name: Gosefimer Z-200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.]
400 parts of a 10% aqueous solution of colloidal silica [trade name:
Snowtex C, Nissan Chemical Co., Ltd.] 20% aqueous dispersion 1
00 parts, 60 parts of a 50% aqueous dispersion of kaolin (trade name: UW-90, manufactured by EC) and 30% of zinc stearate
The composition comprising 1 part of the aqueous dispersion was mixed and stirred to obtain a second intermediate layer coating liquid.

Preparation of Coating Liquid for Release Layer Solvent-free UV-curable silicone [a mixed composition comprising 30 parts by weight of 1.5 mol% of a mercapto group-containing organopolysiloxane and 70 parts of 1.5 mol% of a vinyl group-containing organopolysiloxane] , Shin-Etsu Chemical Co., Ltd.] and 3 parts of a curing initiator (acetophenone) were mixed and stirred to obtain a coating liquid for a release layer.

Preparation of Adhesive Label for Thermal Recording On one side of neutral paper-made high-quality paper having a basis weight of 64 g / m ² ,
The coating amount after drying the undercoat layer coating solution, the heat-sensitive recording layer coating solution, the first intermediate layer coating solution and the second intermediate layer coating solution is 9 g /
An undercoat layer, a heat-sensitive recording layer, a first intermediate layer, and a second intermediate layer were sequentially formed by coating and drying to obtain m ² , 6 g / m ² , 4 g / m ^2, and 2 g / m ² . Next, a coating solution for a release layer is applied at 1 g / m ² on the second intermediate layer, and then a release layer is formed by irradiating ultraviolet rays.
% Of an acrylic resin-based pressure-sensitive adhesive latex was applied and dried so that the coated amount after drying was 20 g / m ² to form a pressure-sensitive adhesive layer, and then wound up to obtain a heat-sensitive recording pressure-sensitive adhesive label without a release paper. . After forming the undercoat layer, the heat-sensitive recording layer and the second intermediate layer, each was subjected to a super calender treatment.

Example 2 In the preparation of the coating solution for the first intermediate layer in Example 1, styrene-acrylic acid was used instead of 200 parts of a 20% aqueous solution of ammonium salt of styrene-acrylic acid copolymer (acid value: 45). An adhesive label for heat-sensitive recording was obtained in the same manner as in Example 1 except that 200 parts of a 20% aqueous solution of a sodium salt of a copolymer (acid value: 60) was used.

Example 3 In the preparation of the coating solution for the first intermediate layer in Example 1, styrene / maleic acid was used instead of 200 parts of a 20% aqueous solution of ammonium salt of styrene / acrylic acid copolymer (acid value: 45). An adhesive label for heat-sensitive recording was obtained in the same manner as in Example 1, except that 200 parts of a 20% aqueous solution of an ammonium salt of a copolymer (acid value: 95) was used.

Example 4 In the preparation of the coating solution for the first intermediate layer of Example 1, ethylene / acrylic acid was used instead of 200 parts of a 20% aqueous solution of ammonium salt of styrene / acrylic acid copolymer (acid value: 45). A thermosensitive recording adhesive label was obtained in the same manner as in Example 1, except that 200 parts of a 20% aqueous solution of an ammonium salt of a copolymer (acid value: 36) was used.

Example 5 In the preparation of the coating solution for the first intermediate layer in Example 1, 10 parts of dimethylol urea (trade name: papyrol J-001, manufactured by Showa Denko KK) was used instead of 1 part of a 40% aqueous solution of glyoxal. A thermosensitive recording adhesive label was obtained in the same manner as in Example 1 except that 5 parts of a 5% aqueous dispersion was used.

Example 6 The procedure of Example 1 was repeated, except that 9 parts of a 5% borax aqueous solution was used instead of 1 part of a 40% aqueous glyoxal solution in the preparation of the coating solution for the first intermediate layer in Example 1. Thus, an adhesive label for thermal recording was obtained.

Example 7 In the preparation of the second intermediate layer coating solution of Example 1, a 10% aqueous solution of acetoacetyl-modified polyvinyl alcohol was used.
Instead of 0 parts, a 10% aqueous solution 40 of completely saponified polyvinyl alcohol (trade name: PVA-110, manufactured by Kuraray Co., Ltd.)
A thermosensitive recording adhesive label was obtained in the same manner as in Example 1 except that 0 part was used.

Example 8 Example 1 was repeated except that 1 part of a 40% aqueous solution of glyoxal was added in the preparation of the second intermediate layer coating solution of Example 1.
In the same manner as in the above, an adhesive label for thermal recording was obtained.

Example 9 In the preparation of the coating solution for the heat-sensitive recording layer of Example 1, a polyamide urea formaldehyde resin
% Aqueous solution was added, and in the preparation of the coating solution for the first intermediate layer, an adhesive label for heat-sensitive recording was obtained in the same manner as in Example 1, except that 1 part of a 40% aqueous solution of glyoxal was not added. .

Comparative Example 1 In the preparation of the heat-sensitive recording adhesive label of Example 1, the first
Except that the intermediate layer was not provided, a heat-sensitive recording adhesive label was obtained in the same manner as in Example 1.

Comparative Example 2 In the preparation of the heat-sensitive recording adhesive label of Example 1,
Except that the intermediate layer was not provided, a heat-sensitive recording adhesive label was obtained in the same manner as in Example 1.

Comparative Example 3 An adhesive label for heat-sensitive recording was obtained in the same manner as in Example 1, except that 1 part of a 40% aqueous solution of glyoxal was not added in the preparation of the first intermediate layer coating liquid of Example 1. .

The following evaluation test was performed on the thus obtained pressure-sensitive adhesive label for heat-sensitive recording, and the results are shown in [Table 1].

[Coloring property] Thermal evaluation machine [Product name: TH-P]
MD, manufactured by Okura Electric Co., Ltd.] and applied energy 0.50 mJ
/ Dot to color each thermosensitive recording adhesive label, and measure the color density of the obtained recorded image with a Macbeth densitometer [RD-914].
Type, manufactured by Macbeth Corporation] in the visual mode.

[Deterioration of Coloring Resistance] As a test for accelerating long-term preservation during winding, each of the obtained heat-sensitive recording pressure-sensitive adhesive labels was laminated and adhered so that the pressure-sensitive adhesive layer came on the release layer surface. After leaving for 24 hours under the conditions of 50 ° C. and 95% RH, the color development was measured in the same manner as described above.

[Adhesion of Release Layer] The release layer surface of each of the obtained heat-sensitive recording adhesive labels was rubbed with a fingertip, and the adhesion of the release layer was visually evaluated. Evaluation criteria A: The release layer surface did not peel off and there was no fogging. ：: The surface of the release layer is not peeled, but is slightly clouded. ×: The release layer surface is peeled off.

[Plasticizer resistance] Polypropylene pipe (4
0 mmφ), a vinylidene chloride wrap film (trade name: KMA-W, manufactured by Mitsui Toatsu Chemicals, Inc.) is wound three times, and each of the heat-sensitive recording adhesive labels recorded in the above-mentioned evaluation test of [coloring property]. Was sandwiched so that the recording surface was on the outside, and a vinylidene chloride wrap film was further wound three times thereon and allowed to stand at room temperature for one day. Then, the color density of the recording portion was measured with a Macbeth densitometer (visual mode). .

[Water resistance] The adhesive label for thermal recording recorded in the evaluation test of the above [coloring property] was placed in tap water at 20 ° C.
The color density after immersion and standing for 4 hours was measured with a Macbeth densitometer (visual mode) to evaluate the water resistance.

[0058]

[Table 1]

[0059]

As is clear from Table 1, the pressure-sensitive adhesive label for heat-sensitive recording of the present invention does not decrease the coloring property of the recording layer even under conditions of high temperature and high humidity, and can be adapted to high-speed printing. The heat-sensitive recording pressure-sensitive adhesive label was suitable for use in distribution management, which was excellent in suitability and required no release paper, which was advantageous in terms of cost.

Claims (7)

[Claims] 1. A peeling method in which a heat-sensitive recording layer containing a leuco dye and a coloring agent, a first intermediate layer, a second intermediate layer, and a release layer are sequentially provided on one side of a support, and an adhesive layer is provided on the back side. In a roll of heat-sensitive adhesive label that does not require paper, the heat-sensitive recording layer,
A pressure-sensitive adhesive label for thermal recording, characterized in that at least one of the intermediate layer and the second intermediate layer contains a waterproofing agent. 2. The heat-sensitive recording pressure-sensitive adhesive label according to claim 1, wherein a water-proofing agent is contained in the first intermediate layer. 3. The heat-sensitive recording pressure-sensitive adhesive label according to claim 1, wherein a water-soluble adhesive is contained in the second intermediate layer. 4. The heat-sensitive recording adhesive label according to claim 3, wherein the water-soluble adhesive is acetoacetyl-modified polyvinyl alcohol. 5. The heat-sensitive recording pressure-sensitive adhesive label according to claim 1, wherein the first intermediate layer contains a water-soluble adhesive having an acid value of 40 to 80. 6. The heat-sensitive recording adhesive label according to claim 5, wherein the water-soluble adhesive having an acid value of 40 to 80 is a copolymer of styrene and an ethylenically unsaturated carboxylic acid. 7. The heat-sensitive recording adhesive label according to claim 6, wherein the ethylenically unsaturated carboxylic acid is acrylic acid.