JPH10237398A - Adhesive label for thermal recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject adhesive label excellent in both chemical resistance and water resistance, and requiring no release sheet. SOLUTION: This adhesive label for thermal recording is obtained by providing a tack agent layer on the reverse side of a support and a thermal recording layer containing a basic dye and color agent and a releasing layer on the surface of the support so as to represent the releasant layer as the face layer. In this case, the releasant layer consists of a releasant comprising 100 pts.wt. of a mixture. the main ingredient, of a mercapto group-bearing silicon compound and vinyl group-bearing silicon compound and 1-100 pts.wt. of an organic compound, a second ingredient, bearing acrylic, methacrylic or cinnamoyl group, which is a resin layer cured by UV or electron beam irradiation.

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 colorless or pale-colored basic dye and a coloring agent, and more particularly to a heat-sensitive recording sheet having excellent recording characteristics and requiring no release paper. The present invention relates to an adhesive label for use.

[0002]

2. Description of the Related Art Adhesive labels have been used as labels, stickers, stickers, patches and the like for a wide range of applications such as commercial use, office use, and home use. This adhesive label is generally formed by laminating a surface substrate, an adhesive, and a release paper. As the release paper, one obtained by applying a release agent such as a silicone compound or a fluorine compound to a base paper for release paper such as high-density paper such as glassine paper, clay-coated paper, or polyethylene laminated paper is used. As the pressure-sensitive adhesive, a solvent-type pressure-sensitive adhesive, an emulsion-type pressure-sensitive adhesive, a hot-melt-type pressure-sensitive adhesive, or the like is used. In addition, surface base materials include paper base materials such as high-quality paper, kraft paper, art paper, coated paper, cast coated paper, thermal recording paper, ink jet recording paper, thermal transfer image receiving paper, film, synthetic paper, metal foil, and the like. And the like.

On the other hand, the heat-sensitive recording paper used as the surface base material utilizes a color-forming reaction between a colorless or light-colored basic dye and an organic or inorganic coloring agent, and heat-contacts a coloring material to form a recorded image. Recording papers in which a recording layer containing both of them is provided on a support so as to obtain them are well known. This heat-sensitive recording paper is relatively inexpensive, has a compact recording device, and is easy to maintain, so that it is used not only as a recording medium for facsimile machines and various computing devices but also in a wide range of fields. For example, as one of the fields of use, POS (point of point) of retail stores and the like is used.
sales) With the expansion of systemization, the cases used as adhesive labels are increasing.

This thermosensitive recording paper is required to have a stable recorded image. Therefore, a method of applying an aqueous emulsion of a resin having a film forming ability and chemical resistance on a recording layer (Japanese Patent Laid-Open No. 54-128347). And a method of applying a water-soluble polymer compound such as polyvinyl alcohol (Jpn.
-125354) or a method of providing a resin layer cured by irradiating an electron beam (Japanese Patent Application Laid-Open No. 62-1987).
279980) has been proposed, but a heat-sensitive recording paper having further excellent chemical resistance and water resistance has been demanded.

[0005] In general, the pressure-sensitive adhesive label for heat-sensitive recording is provided with an adhesive layer on the back surface of the heat-sensitive recording paper and then provided with a release sheet. However, printing is performed by a label printer, and the label is attached to an adherend. After that, a large amount of release sheet was discharged. This release sheet not only disturbs the labeling work, but also because it is difficult to perform the re-pulp treatment of the release sheet with ordinary waste paper recovery equipment, it is presently incinerated or landfilled. . In addition, the thermal recording paper, adhesive and release sheet are laminated when used, and the paper thickness is increased, so the winding length of the thermal recording adhesive label that can be built into the label printer is limited, and the label printer must be enlarged or There is also a problem that the winding of the heat-sensitive recording adhesive label must be frequently replaced.

[0006] Due to such a problem of the release sheet being discarded, a heat-sensitive recording adhesive label using no release sheet is, for example, provided with a release agent layer on the heat-sensitive recording layer of the heat-sensitive recording adhesive label and finished in a tape shape. Method (Tokuhei 4-1511)
No. 0) has been proposed. It is also described that a type to which heat is not applied when forming a release agent layer, that is, a type that cures with an electron beam or ultraviolet rays, is suitable (Japanese Patent Publication No. 4-15110). However, when a mixture of a silicone compound having a mercapto group and a silicone compound having a vinyl group is used as a release agent of a type that is cured by an electron beam or ultraviolet light, a normal release sheet is applied to a base sheet for release sheet, It is possible to produce a release sheet by curing by irradiating with a ray, etc., but when applying the mixture of the silicone compound on a thermosensitive recording paper and curing by irradiating the radiation, in the thermosensitive recording layer, or There are problems such as that the components in the protective layer inhibit the curing of the silicone compound or deteriorate the adhesion to the heat-sensitive recording layer or the protective layer.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat-sensitive recording pressure-sensitive adhesive label which is excellent in chemical resistance and water resistance, and which does not require a release sheet.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the present situation, and as a result, have found that a support, an adhesive layer is provided on the back surface of the support, and a basic dye is provided on the surface of the support. A heat-sensitive recording layer containing a colorant and a release agent layer containing a release agent,
In a heat-sensitive recording pressure-sensitive adhesive label provided with a release agent layer as the outermost layer, the release agent layer is mainly composed of a mixture of a silicone compound having a mercapto group and a silicone compound having a vinyl group, and acrylic is used as an additive. Group, a methacrylic group, or an organic compound having a cinnamoyl group, a release agent containing 1 to 100 parts by weight based on 100 parts by weight of the mixture of the silicone compound, and cured by irradiating ultraviolet rays or electron beams. It has been found that all of the above-mentioned problems can be solved by using a heat-sensitive recording adhesive label characterized by being a resin layer, and the present invention has been completed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method in which a mixture of a silicone compound having a mercapto group and a silicone compound having a vinyl group as a main component and an organic compound having an acrylic group, a methacryl group, or a cinnamoyl group are formed on a thermosensitive recording paper. A specific effect can be obtained by applying a mixture to which the compound has been added and curing it by irradiating ultraviolet rays or electron beams.

This is because the mercapto group and vinyl group in the silicone compound are functional groups, which are cured by a radical polymerization reaction caused by radicals generated by irradiation with ultraviolet rays or electron beams. If an organic compound having an acrylic group, or a methacrylic group, or a cinnamoyl group is not added, the functional groups in the silicone compound activated by the generated radicals are very unstable, so that the polymerization for curing does not proceed. In addition, there is a large tendency to return to the original silicone compound,
Therefore, curing becomes worse. By mixing an organic compound having an acryl group, a methacryl group, or a cinnamoyl group in a mixture of these silicone compounds, to stabilize radicals generated by these organic compounds,
It is considered that the polymerization proceeds promptly, and as a result, the curing occurs favorably.

The silicone compound having a mercapto group is not particularly limited as long as it has an organopolysiloxane as a basic skeleton and has a mercapto group. In addition, the silicone compound having a vinyl group has an organopolysiloxane as a basic skeleton, and is not particularly limited as long as it is a compound having a vinyl group. Preferably, no process is involved, and for this purpose, a solvent-free one is preferred.
The viscosity of the resin is preferably about 10 to 10,000 cps in consideration of the impregnation of the resin into the heat-sensitive recording layer and the uniformity of the coated surface.

A silicone compound having a mercapto group,
And an organic compound having an acryl group, a methacryl group, or a cinnamoyl group, which is added to a mixture containing a silicone compound having a vinyl group as a main component, as long as it is polymerized by radicals generated by ultraviolet irradiation or electron beam irradiation. There is no particular limitation, and a radical polymerizable monofunctional monomer, a radical polymerizable polyfunctional monomer, a radical polymerizable oligomer, or a mixture thereof is used. It is particularly preferable that the organic compound having an acrylic group, a methacryl group, or a cinnamoyl group is a silicone compound because it has a function as a release agent. The silicone compound having an acryl group, a methacryl group, or a cinnamoyl group is not particularly limited as long as it is an organic compound having an organopolysiloxane as a basic skeleton and having an acryl group, a methacryl group, or a cinnamoyl group, respectively.

A silicone compound having a mercapto group,
And an organic compound having an acryl group, a methacryl group, or a cinnamoyl group, which is added to a mixture containing a silicone compound having a vinyl group as a main component, in an amount of 1 to 100 parts by weight based on 100 parts by weight of the mixture of the silicone compound.
It is necessary to adjust and add within the range of parts by weight, and it is desirable to add the compound in the range of 3 to 70 parts by weight. If the content is less than 1% by weight, the curing of the mixture of the silicone compounds due to irradiation is poor, and the desired effect cannot be obtained. In addition, when the amount is more than 100 parts by weight, curing by radiation irradiation occurs, but when used after finishing the adhesive label, the peeling force at the time of peeling the adhesive label becomes heavy, and the original function as the release agent layer is achieved. It causes adverse effects such as disappearance.

In the coating liquid having such a release agent, a photopolymerization initiator, a dye, a pigment, a wetting agent,
Various auxiliaries such as an antifoaming agent, a dispersant, an antistatic agent, a leveling agent, and a lubricant can be appropriately added as long as the desired effect is not impaired. The release agent is applied by a known application means and then cured by irradiating ultraviolet rays or electron beams to form a release agent layer.

As a coating means, for example, a bar coater, a multi-stage roll coater, an air knife coater, a gravure coater, an offset gravure coater or the like can be used as appropriate. The coating amount of the release agent is 0.1 to 3 g / m
Adjusted in ² ranges.

Examples of the ultraviolet irradiation device include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and the like, and an ozone-less type having little ozone. Generally, a plurality of lamps having an output of 30 W / cm or more are often used in parallel.

The electron beam irradiating apparatus may have an accelerating voltage of 100 to 1000 kV, preferably 1
It is desirable to use an electron beam accelerator of 00 to 300 kV and to adjust the amount of the irradiated electron beam in the range of about 0.5 to 20 Mrad in terms of absorbed dose. If it is less than 0.5 Mrad, a sufficient irradiation effect cannot be obtained, and irradiation exceeding 20 Mrad is not preferable because it may deteriorate the base material. As an electron beam irradiation method, for example, a scanning method, a curtain beam method, a broad beam method, or the like is employed. Also, in the step of electron beam irradiation, a synthetic resin film, a metal pad or a metal drum, etc.
The release agent layer can be cured while transferring the shape. At the time of electron beam irradiation, if the oxygen concentration is high, the curing of the release agent is hindered. Therefore, replacement with an inert gas such as nitrogen, helium, carbon dioxide or the like is performed to reduce the oxygen concentration to 6%.
Irradiation is preferably performed in an atmosphere controlled to 00 ppm or less, preferably 400 ppm or less.

The heat-sensitive recording paper used in the present invention is not particularly limited, and is generally used as a base paper for heat-sensitive recording, such as a high-quality paper (acid paper, neutral paper), a film, a synthetic paper, or a coated paper. An example in which a heat-sensitive recording layer is provided can be given. If necessary, an undercoat layer having an oil-absorbing pigment, a hollow pigment, or the like may be provided between the support and the heat-sensitive recording layer. Further, for the purpose of improving image quality and image density, a super calender process may be performed. A protective layer may be provided on the surface of the heat-sensitive recording layer to protect the recording layer.

The pressure-sensitive adhesive used in the present invention is not particularly limited.
Various pressure-sensitive adhesives such as a solvent-type pressure-sensitive adhesive, an emulsion-type pressure-sensitive adhesive, and a hot-melt-type pressure-sensitive adhesive can be used. The method of providing the pressure-sensitive adhesive layer is a method of applying and drying the pressure-sensitive adhesive on the release layer provided on the heat-sensitive recording layer or the protective layer, and transferring it to the base paper surface when finishing the winding, or direct heat-sensitive recording A method of applying and drying an adhesive on the back surface of the paper, or a method of using a process paper, applying and drying the adhesive on the process paper, transferring the heat-sensitive recording paper to the back surface, and peeling the process paper can be used. If necessary, an undercoat layer can be provided on the back surface of the support, if necessary, in order to prevent migration of the pressure-sensitive adhesive component and the like into the support and to ensure a sufficient adhesive effect.

The method for applying the pressure-sensitive adhesive is not particularly limited, either, and roll coaters, reverse roll coaters, knife coaters, bar coaters, air knife coaters, die coaters, slot die coaters,
Apply using a gear in die coater, etc., if necessary,
The adhesive layer is formed by drying or irradiating with radiation such as ultraviolet rays or electron beams. Here, the ultraviolet or electron beam irradiation device used for curing the pressure-sensitive adhesive is the same device as that used for curing the release agent layer, and curing is performed in the same manner under the same curing conditions.

The amount of the adhesive applied is 5 to 5 on a dry weight basis.
0 g / m ^2, it is preferably adjusted in the range of about 10 to 25 g / m ^2. By the way, when the application amount of the pressure-sensitive adhesive is less than 5 g / m ² , the adhesive performance is excessively reduced, and when it exceeds 50 g / m ² , the wool is deteriorated or the necessity is reduced for economic reasons.

The heat-sensitive recording pressure-sensitive adhesive label of the present invention obtained as described above is a heat-sensitive recording pressure-sensitive adhesive label excellent in chemical resistance and water resistance and requiring no release sheet.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the scope of the present invention.
In the examples, parts and% are unless otherwise specified.
"Parts by weight" and "% by weight" are shown.

Example 1 "Manufacture of support" Softwood bleached kraft pulp (C.S.
F. Talc was added to a pulp slurry containing 25 parts of 550 ml) and 75 parts of hardwood bleached kraft pulp (CSF 560 ml) so that the paper ash content was 5.0%. Was added to 1.5% of absolutely dry pulp and 2.0% of aluminum sulfate to obtain a stock. This stock was paper-made by a fourdrinier multi-cylinder cylinder drier paper machine and processed by a 4-stage super calender to obtain a support of 58 g / m ² . The size of the 20% aqueous ethyl alcohol solution of the support was 10 seconds.

"Production of thermosensitive recording paper" Preparation of solution A 10 parts of 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-phenylaminofluoran 5 parts of 5% methylcellulose aqueous solution and 40 parts of water Was pulverized with a sand mill until the average particle diameter became 3 μm.

Preparation of Solution B A composition comprising 30 parts of 4-hydroxy-4'-isopropyloxydiphenylsulfone, 5 parts of a 5% aqueous solution of methylcellulose and 80 parts of water was pulverized by a sand mill until the average particle diameter became 3 μm.

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

Preparation of Solution D 200 parts of 10% acetoacetyl group-modified polyvinyl alcohol aqueous solution, 100 parts of kaolin (trade name: UW-90, manufactured by EMC), 30 parts of 30% zinc stearate dispersion liquid,
And 100 parts of water were mixed and stirred to obtain a coating liquid for a protective layer.

On the surface of the obtained support, 55 parts of solution A, B
A coating liquid obtained by mixing and stirring 115 parts of the liquid, 80 parts of the liquid C, 80 parts of a 10% aqueous solution of polyvinyl alcohol, and 35 parts of calcium carbonate is applied and dried so that the coating amount after drying is 6 g / m ^2. Thus, a heat-sensitive recording layer was formed. Liquid D was coated and dried on the heat-sensitive recording layer so that the coating amount after drying was 5 g / m ^2, and after forming a protective layer, a super calender treatment was performed to produce a heat-sensitive recording paper.

"Formation of release agent layer" A radiation-curable silicone resin containing a mercapto group (trade name: BY-24)
551A, Toray Dow Corning Silicone Co., Ltd.), 75 parts, a vinyl group-containing radiation-curable silicone resin (trade name: BY-24-551B, Toray Dow Corning Silicone Co., Ltd.), 25 parts, 10 parts of methylolpropane triacrylate were mixed and stirred to obtain a coating liquid for a release agent layer. This release agent layer coating solution was applied to the protective layer of the heat-sensitive recording paper so as to have a coating weight of 1.5 g / m ² using an offset gravure coater, and then was applied to an ultraviolet irradiation device (trade name: Rapid Cure, Ushio Electric Co., Ltd.). (Manufactured by Co., Ltd.), and cured by irradiating ultraviolet rays so that the irradiation dose was 160 mj / cm ² , to obtain a thermosensitive recording paper having a release agent layer.

[Production of pressure-sensitive adhesive label] An acrylic emulsion pressure-sensitive adhesive (trade name: L-145, manufactured by Nippon Carbide Industry Co., Ltd.) is applied to the back surface of the heat-sensitive recording paper having the release agent layer in a dry weight of 25 g / m ^2. The coating was dried using a reverse roll coater to form an adhesive layer (water content of the adhesive layer was 1.2%), thereby producing an adhesive label for heat-sensitive recording of the present invention.

Example 2 An electron beam irradiation device (trade name: Electron Curtain CB-15) was replaced with nitrogen in the "Formation of Release Agent Layer" in Example 1 in place of curing using an ultraviolet irradiation device.
0, manufactured by ESI) under the conditions of an acceleration voltage of 175 kV and an irradiation current of 20 mA.
An adhesive label for heat-sensitive recording was obtained in the same manner as in Example 1 except that the curing was performed.

Example 3 An adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that the release agent layer was formed by the following method in "Formation of release agent layer" in Example 1. "Formation of release agent layer" 75 parts of a radiation-curable silicone resin containing mercapto groups (trade name: BY-24-551A, manufactured by Dow Corning Toray Silicone Co., Ltd.),
25 parts of a radiation-curable silicone resin containing a vinyl group (trade name: BY-24-551B, manufactured by Dow Corning Toray Silicone Co., Ltd.) and a silicone resin containing an acrylic group (trade name: X-62-2) 8013,
(Shin-Etsu Chemical) 20 parts were mixed and stirred to obtain a coating solution for a release agent layer. This release agent layer coating liquid was applied onto the protective layer of the thermosensitive recording paper at 1.5 g / m 2 using an offset gravure coater.
The coating is ^2, the electron beam irradiation apparatus was purged with nitrogen (trade name: Electron Curtain CB-0.99, ES
I), an acceleration voltage of 175 kV and an irradiation current of 20 kV.
The composition was cured by irradiating 4 Mrad of electron beam under the condition of mA to produce a thermosensitive recording paper having a release agent layer.

Example 4 In Example 1, synthetic paper (trade name: FP) was used as a support.
Except for using H-80), an adhesive label for thermal recording was produced in the same manner as in Example 1.

Comparative Example 1 A pressure-sensitive adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that a release agent layer was formed by the following method in "Formation of a release agent layer" in Example 1. "Formation of release agent layer" 75 parts of a radiation-curable silicone resin containing a mercapto group (trade name: BY-24-551A, manufactured by Dow Corning Toray Silicone Co., Ltd.),
25 parts of a radiation-curable silicone resin containing a vinyl group (trade name: BY-24-551B, manufactured by Dow Corning Toray Silicone Co., Ltd.) was mixed and stirred to obtain a coating liquid for a release agent layer. This release agent layer coating solution was applied to the protective layer of the heat-sensitive recording paper so as to have a coating weight of 1.5 g / m ² using an offset gravure coater, and then was applied to an ultraviolet irradiation device (trade name: Rapid Cure, Ushio Electric Co., Ltd.). (Manufactured by Co., Ltd.), and cured by irradiating ultraviolet rays so that the irradiation dose was 160 mj / cm ² , to obtain a thermosensitive recording paper having a release agent layer.

Comparative Example 2 An adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that the release agent layer was formed by the following method in "Formation of a release agent layer" of Example 1. "Formation of release agent layer" 75 parts of a radiation-curable silicone resin containing mercapto groups (trade name: BY-24-551A, manufactured by Dow Corning Toray Silicone Co., Ltd.),
25 parts of a radiation-curable silicone resin containing a vinyl group (trade name: BY-24-551B, manufactured by Dow Corning Toray Silicone Co., Ltd.) was mixed and stirred to obtain a coating liquid for a release agent layer. This release agent layer coating liquid was applied on the protective layer of the thermal recording paper by using an offset gravure coater for 1.5 hours.
g / m ^2, and nitrogen-substituted electron beam irradiation apparatus (trade name: Electron Curtain CB-15)
(Manufactured by ESI Co., Ltd.) under the conditions of an acceleration voltage of 175 kV and an irradiation current of 20 mA, followed by curing by irradiation with an electron beam of 4 Mrad to produce a thermosensitive recording paper having a release agent layer.

Comparative Example 3 An adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that the release agent layer was formed by the following method in "Formation of a release agent layer" in Example 1. "Formation of release agent layer" 75 parts of a radiation-curable silicone resin containing mercapto groups (trade name: BY-24-551A, manufactured by Dow Corning Toray Silicone Co., Ltd.),
25 parts of a vinyl group-containing radiation-curable silicone resin (trade name: BY-24-551B, manufactured by Dow Corning Toray Silicone Co., Ltd.) and 0.5 part of trimethylolpropane triacrylate are mixed and stirred, and a release agent is used. This was used as a layer coating liquid. This release agent layer coating solution was applied to a protective layer of a thermosensitive recording paper at 1.5 g / m ² using an offset gravure coater, and nitrogen-substituted electron beam irradiation apparatus (trade name: Electron curtain CB-
150, manufactured by ESI) using an acceleration voltage of 175 kV,
The composition was cured by irradiating 4 Mrad of an electron beam under the conditions of an irradiation current of 20 mA to produce a thermosensitive recording sheet having a release agent layer.

Comparative Example 4 An adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that the release agent layer was formed by the following method in "Formation of a release agent layer" in Example 1. "Formation of release agent layer" 75 parts of a radiation-curable silicone resin containing mercapto groups (trade name: BY-24-551A, manufactured by Dow Corning Toray Silicone Co., Ltd.),
25 parts of a vinyl-containing radiation-curable silicone resin (trade name: BY-24-551B, manufactured by Dow Corning Toray Silicone Co., Ltd.) and 120 parts of trimethylolpropane triacrylate are mixed and stirred to form a release agent layer. It was a coating liquid. This release agent layer coating solution was applied to a protective layer of a thermosensitive recording paper at 1.5 g / m ² using an offset gravure coater, and nitrogen-substituted electron beam irradiation apparatus (trade name: Electron curtain CB-
150, manufactured by ESI), using an acceleration voltage of 175 kV,
The composition was cured by irradiating 4 Mrad of an electron beam under the conditions of an irradiation current of 20 mA to produce a thermosensitive recording sheet having a release agent layer.

The following evaluations were performed on the eight kinds of pressure-sensitive adhesive labels for heat-sensitive recording thus obtained, and the results are shown in Table 1. In addition, the evaluation method of each evaluation item is as follows.

[Recording Density] An adhesive label for thermal recording is recorded by a test printer equipped with a thermal head, and the maximum color density of the obtained recorded image is measured by a Macbeth densitometer (trade name:
(RD-914, Filter Visual / Macbeth)
Was measured.

[Water resistance] The recording density after immersing the heat-sensitive recording medium obtained in the measurement of the recording density in warm water of 40 ° C. for 24 hours was measured with a Macbeth densitometer.

[Chemical resistance] About 0.1 ml each of dioctyl phthalate (DOP) and edible oil was dropped on the recorded image from the heat-sensitive recording surface side of the heat-sensitive recording medium obtained by measuring the recording density.
The recording density after standing at 40 ° C. for 24 hours was measured with a Macbeth densitometer.

[Removal resistance to white spots]
After treatment at 0 ° C. for 3 weeks, recording was performed with a test printer equipped with a thermal head, and the resulting recorded image was visually judged for white spots. The evaluation criteria for the recording image quality were as follows. ：: No white spots are observed. Δ: White spots are slightly observed, but at a level that does not cause any practical problem. X: The white spot is remarkable.

[Silicone Curability] The silicone layer of the heat-sensitive recording pressure-sensitive adhesive label was strongly rubbed with a finger, and the degree of haze of the silicone layer was visually determined. When the silicone layer is not sufficiently cured, the silicone layer becomes cloudy when rubbed, and the degree of hardening of the silicone layer can be determined by observing the degree of the cloudiness. The evaluation criteria were as follows. ：: No fogging is observed. Δ: Some clouding is observed. X: Clouding is remarkable.

[Silicone Adhesion] The silicone layer of the heat-sensitive recording adhesive label was strongly rubbed with a finger to determine whether or not the silicone layer was peeled off. When the adhesion between the silicone layer and the heat-sensitive recording layer is poor, the silicone layer peels off when rubbed, so that the adhesion of the silicone layer can be observed. In addition,
The evaluation criteria were as follows. ：: The silicone layer does not peel off. X: The silicone layer peels off.

[Peel force] The same pressure-sensitive adhesive label for heat-sensitive recording was adhered on the silicone layer of the pressure-sensitive adhesive for heat-sensitive recording, and subjected to a pressure treatment (0.5 kg / cm ² ) for 24 hours. × 5cm sample is prepared and INT
Peeling speed 0.3m / with ESCO Model 2001
The peeling force (g) when the film was peeled at a tensile angle of 180 degrees under the test conditions of minutes was measured.

[0047]

[Table 1]

From Table 1, in Examples 1, 2 and 4, a mixture of a silicone compound containing a mercapto group and a silicone compound containing a vinyl group on a heat-sensitive recording paper contains an acrylic group. Adhesive labels for thermal recording coated with a release agent mixed with an organic compound are not only excellent in water resistance, chemical resistance and white spot resistance, but also have good curing properties of the release agent and good adhesion to the heat-sensitive recording layer. The adhesive label for heat-sensitive recording was very excellent with a light peeling force. Further, as can be seen from Example 3, by using an organic compound containing an acrylic group in the above-mentioned release agent and a silicone compound containing an acrylic group, the water resistance is further improved, and at the same time, the peeling force is reduced, and It was an excellent heat-sensitive recording adhesive sheet. In Comparative Examples 1, 2 and 3, a mixture of a silicone compound containing a mercapto group and a silicone compound containing a vinyl group was used as a release agent applied on a thermal recording paper. No compound is added, or the added amount is less than the specified amount, so the water resistance, chemical resistance, poor whitening resistance are poor, and the curability of the release agent, the adhesion to the heat-sensitive recording layer is poor. You can see that there is. In Comparative Example 4, since the amount of the organic compound containing an acryl group added to the mixture of the silicone compound as the release agent was larger than the specified amount, the water resistance and the chemical resistance were good, but the release force was high. Therefore, the original function as the release agent layer was deteriorated.

[0049]

As described above, the heat-sensitive recording pressure-sensitive adhesive label obtained by the present invention does not require a release sheet, and is excellent in water resistance and chemical resistance.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09K 3/00 G09F 3/10 H G09F 3/10 B41M 5/18 B 101E 5/26

Claims (2)

[Claims] 1. A support, a pressure-sensitive adhesive layer on a back surface of the support,
On the surface of the support, a heat-sensitive recording layer containing a basic dye and a colorant and a release agent layer containing a release agent, in a heat-sensitive recording adhesive label provided such that the release agent layer is the outermost layer, The release agent layer is mainly composed of a mixture of a silicone compound having a mercapto group and a silicone compound having a vinyl group, and an organic compound having an acrylic group, a methacryl group, or a cinnamoyl group as an additive.
1 to 100 parts by weight of the silicone compound mixture
A pressure-sensitive adhesive label for heat-sensitive recording, comprising a release agent containing 100 parts by weight, wherein the resin layer is a resin layer cured by irradiating an ultraviolet ray or an electron beam. 2. The heat-sensitive recording adhesive label according to claim 1, wherein the organic compound having an acryl group, a methacryl group or a cinnamoyl group is a silicone compound.