JPH1152862A - Tacky adhesive label for thermosensitive recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tacky adhesive label which is a tacky adhesive label for thermosensitive recording not requiring release paper, is stable in peeling force, is light, is excellent in a tacky adhesive characteristic and has excellent recording characteristics as thermosensitive recording paper. SOLUTION: The release agent layer of the tacky adhesive label for thermosensitive recording obtd. by providing the front surface side of a base with a thermosensitive recording layer contg. basic dyes and coloring agents, then the release layer and providing the rear surface side with a tacky adhesive layer is the release agent layer formed by using at least >=1 kind of the polysiloxane selected from a polysiloxane contg. an epoxy group, polysiloxane contg. a 1-propenyl ether group and polysiloxane having a vinyl ether group, polymerizing this polysiloxane by irradiation with radiations and curing the same. In addition, the tacky adhesive layer thereof is a tacky adhesive layer formed by applying a styrene-butadiene-acrylic copolymer latex having a glass transition temp. of -60 to -20 deg.C as a main component and drying the coating. More preferably, the gel content of the styrene-butadiene-acrylic copolymer latex constituting the tacky adhesive layer is 30 to 100%.

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 pressure-sensitive adhesive label utilizing a color development reaction between a colorless or light-colored basic dye and a color former, and more particularly to a heat-sensitive recording pressure-sensitive adhesive label which does not require a release paper. The present invention relates to a pressure-sensitive adhesive label which has excellent adhesive properties, especially excellent adhesive properties at low temperatures, adhesiveness to a non-polar surface such as polyethylene, and excellent recording properties as heat-sensitive recording paper.

[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 and the like are used. In addition, the surface base material, such as fine paper, kraft paper, art paper, coated paper, cast coated paper, thermal recording paper, ink jet recording paper, paper base such as thermal transfer image receiving paper, film,
Sheets such as synthetic paper and metal foil are used.

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 the recording material is melt-contacted by heat to record. In order to obtain an image, a recording layer containing both of them is provided on a support, which is well known in the art.

The heat-sensitive recording paper is relatively inexpensive, and the recording equipment is compact and easy to maintain, so that it is used not only as a recording medium for facsimile machines and various computing equipment but also in a wide range of fields. For example, with the expansion of POS (point of sales) systems at retail stores and the like, the number of cases used as an adhesive label for barcode printing is increasing.

[0006] The pressure-sensitive adhesive label for heat-sensitive recording generally has a pressure-sensitive adhesive layer provided on the back surface of the heat-sensitive recording paper and then a release sheet, but has the following problems. First, there is a problem of the discharged release sheet. Specifically, a large amount of release sheet is discharged after recording by a label printer and attaching the label to the adherend. This release sheet not only disturbs the labeling work, but also cannot be recycled and pulped in a normal waste paper recovery facility, and is currently incinerated or landfilled.

Next, there is a problem that the roll length of the label becomes short because there is an unnecessary release sheet in use. General thermal adhesive labels are laminated with thermal recording paper, an adhesive, and a release sheet, and the paper thickness is increased.Therefore, the winding length of the thermal recording adhesive label that can be built into the label printer is limited. There is also a problem that the size of the heat-sensitive recording pressure-sensitive adhesive label must be changed frequently or the roll of the heat-sensitive recording pressure-sensitive adhesive label must be replaced.

[0008] From the problem of discarding the release sheet, it is conceivable to remove the release sheet from the heat-sensitive recording pressure-sensitive adhesive label. In this regard, a release agent layer is provided on the heat-sensitive recording pressure-sensitive adhesive label, and the tape is finished. Method (Tokuhei 4-15)
No. 110) has been proposed. A method for producing the above-mentioned pressure-sensitive adhesive label for heat-sensitive recording, comprising a UV-curable or EB curable at ordinary temperature on a recording surface of a general heat-sensitive recording paper.
Apply a curable non-solvent type or emulsion type release agent, cure it to form a release agent layer, and then apply an adhesive directly to the top surface of the release agent layer or the back surface of the support to dry and adhere. It is manufactured by forming an agent layer and finishing it into a tape shape.

However, when a solvent-type pressure-sensitive adhesive is applied during the formation of the pressure-sensitive adhesive layer, the solvent in which the pressure-sensitive adhesive is dissolved penetrates through the release agent layer or from the back surface of the support to reach the heat-sensitive recording layer. And there is a problem that the heat-sensitive recording layer is colored. Further, when applying a hot-melt pressure-sensitive adhesive, the hot-melt pressure-sensitive adhesive is heated and melted at a temperature of 100 ° C. or higher, so that there is a problem that the heat-sensitive recording layer develops color in response to heat.

Further, when a polyacrylate copolymer-based emulsion-type pressure-sensitive adhesive is used, it is possible to form a pressure-sensitive adhesive layer, but the adhesiveness at a low temperature or the adhesiveness to a non-polar surface such as polyethylene. Are inferior to rubber-based and urethane-based adhesives.

In the case of a general heat-sensitive recording pressure-sensitive adhesive label, when stored in a roll, a release sheet, a pressure-sensitive adhesive layer, a support, a heat-sensitive recording layer, then a release sheet, a pressure-sensitive adhesive layer , The support, the heat-sensitive recording layer ... overlap, between the pressure-sensitive adhesive layer and the heat-sensitive recording layer, the support and
There is a release sheet, and the effect of the adhesive on the heat-sensitive recording layer is slight.

However, in the case of the heat-sensitive recording pressure-sensitive adhesive label without the release sheet, when stored in a roll,
From the bottom in order, the pressure-sensitive adhesive layer, the support, the heat-sensitive recording layer, the release agent, and then the pressure-sensitive adhesive layer, the support, the heat-sensitive recording layer, the release agent layer, etc. are overlapped, and between the pressure-sensitive adhesive layer and the heat-sensitive recording layer One is a support, and the other is a release agent layer. The release agent layer is usually 0.1 to 0.1 in terms of the performance of the release agent and the price.
Since 5.0 g / m ^{2 is} applied and the film is very thin, the influence of the adhesive on the heat-sensitive recording layer is great. In particular, in the case of a polyacrylate copolymer-based pressure-sensitive adhesive, there is a problem in that components in the pressure-sensitive adhesive penetrate into the heat-sensitive recording layer and lower the sensitivity of the heat-sensitive recording layer.

In order to solve the above-mentioned problems, when an adhesive other than an acrylic resin-based adhesive is used as the adhesive used for the adhesive layer, the peeling force increases depending on the type of the selected release agent. In some cases, the support may be torn without peeling, or the heat-sensitive recording layer of the inner label may be peeled. When a release agent layer is formed using a polysiloxane containing a mercapto group, a vinyl group, or an acrylic group, heavy release occurs when an adhesive other than an acrylic resin-based adhesive is used.

The heat-sensitive recording adhesive label according to the present invention comprises:
Since printing is performed while the roll-shaped label is peeled off by the printer, if the peeling force becomes heavy, a running trouble in the printer occurs, resulting in printing trouble and running failure.

In the pressure-sensitive adhesive label for thermal recording according to the present invention, the release agent layer not only has a function as a release agent, but also has the same functions as general thermal recording paper such as running property to a thermal printer and sticking. You have to balance them. In particular, when the release agent layer is formed, the curability of the release agent and the adhesion to the thermosensitive recording paper may be deteriorated depending on the release agent selected.

[0016] Glassine paper and polyethylene laminated paper, which are general base papers for release paper, hardly inhibit the curing of the release agent, but heat-sensitive recording paper contains components which inhibit the curing of the release agent. is there. The pressure-sensitive adhesive label for heat-sensitive recording according to the present invention, since the release agent layer is in direct contact with the heating element of the thermal printer to perform printing, when the curability of the release agent is poor, the peeling force of the pressure-sensitive label is increased. In addition, the release agent peels off and accumulates as residue in the heating element, causing printing defects such as residue removal.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording adhesive label which eliminates the above-mentioned problems and which does not require a release paper. An object of the present invention is to provide an adhesive label which is excellent and has excellent recording characteristics as a heat-sensitive recording paper.

[0018]

As a result of intensive studies in view of the present situation, the present inventor has found that a heat-sensitive recording layer containing a basic dye and a colorant and a release agent layer are provided on the surface side of a support. In a pressure-sensitive adhesive label for thermal recording, wherein a pressure-sensitive adhesive layer is provided on the back side, the release agent layer has a polysiloxane containing an epoxy group, a polysiloxane containing a 1-propenyl ether group, and a polysiloxane having a vinyl ether group. A release agent layer that is polymerized and cured by irradiation with at least one kind of polysiloxane selected from siloxane, and that the pressure-sensitive adhesive layer has, as a main component, a glass transition temperature of −60 ° C. to − It has been found that all of the above-mentioned problems can be solved by forming a pressure-sensitive adhesive layer by applying and drying a styrene-butadiene-acrylic copolymer latex at 20 ° C. The has been completed. If necessary,
It is of course possible to provide a release agent layer on the heat-sensitive recording layer via a protective layer, and to provide a pressure-sensitive adhesive layer on the back side of the support via an undercoat layer.

Further, since a printer for a heat-sensitive recording adhesive label that does not require a release paper performs recording while peeling off the label from the winding of the pressure-sensitive adhesive label, if the peeling force of the heat-sensitive recording pressure-sensitive adhesive label is heavy, the printer cannot be used. Running troubles may occur. By setting the gel content of the styrene-butadiene-acrylic copolymer latex constituting the pressure-sensitive adhesive layer of the heat-sensitive recording adhesive label to 30% or more, the peeling force of the heat-sensitive recording pressure-sensitive adhesive label becomes lighter, It has been found that running troubles are completely eliminated, and a more favorable pressure-sensitive adhesive label for thermal recording can be obtained.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the present invention relates to a release agent constituting an adhesive label for heat-sensitive recording, wherein the release agent has a polysiloxane containing an epoxy group, a polysiloxane containing a 1-propenyl ether group, and a vinyl ether group. A specific effect can be obtained by using at least one or more polysiloxanes selected from polysiloxanes to form a release agent layer which is polymerized by irradiation with radiation and cured.

The above-mentioned epoxy group, 1-propenyl ether group and vinyl ether group contained in the polysiloxane are functional groups, and a radical polymerization reaction is caused by radicals generated by irradiating ultraviolet rays or electron beams to cure. Alternatively, a strong acid generated by ultraviolet rays or the like causes a cationic polymerization reaction to be caused to cure.

The polysiloxane containing an epoxy group has an organopolysiloxane as a basic skeleton and is not particularly limited as long as it is a compound having an epoxy group. The polysiloxane having a 1-propenyl ether group is not particularly limited as long as it is a compound having an organopolysiloxane as a basic skeleton and having a 1-propenyl ether group. The polysiloxane having a vinyl ether group has an organopolysiloxane as a basic skeleton, and is not particularly limited as long as it is a compound having a vinyl ether group.

From the viewpoint of suppressing coloring of the heat-sensitive recording layer due to heating, curling of the support, and the like, it is desirable not to involve a drying step, and a solventless type 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. Also, in the release agent, if necessary, other radiation curable resin, photopolymerization initiator, dye, pigment, wetting agent, defoaming agent,
Various auxiliaries such as a dispersant, an antistatic agent, a leveling agent, and a lubricant can be appropriately added within a range not to impair the desired effect.

The method of applying the release agent is not particularly limited, and ordinary application means such as a bar coater, a multi-stage roll coater, an air knife coater, a gravure coater, and an offset gravure coater are appropriately used. The application amount of the release agent is appropriately adjusted in the range of 0.1 to 5.0 g / m ² .

As the ultraviolet irradiation device used in the present invention, there are, for example, 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 30W / c output
m or more lamps are often used in parallel.

The electron beam irradiating apparatus used in the present invention has an accelerating voltage of 100 to 100 in terms of penetrating power and curability.
An electron beam accelerator of 0 kV, preferably 100 to 300 kV is used, and the amount of the irradiated electron beam is 0.5 to 2 in terms of absorbed dose.
It is desirable to adjust within a range of about 0 Mrad. 0.5
If it is less than Mrad, a sufficient irradiation effect cannot be obtained.
Irradiation exceeding ad 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. In the electron beam irradiation step, a synthetic resin film, a metal layer, a metal drum, or the like can be closely attached to the protective layer, and the release agent layer can be cured while transferring its 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 or carbon dioxide is performed to reduce the oxygen concentration to 600 ppm or less, preferably 400 ppm. The irradiation is preferably performed in an atmosphere controlled below.

As described above, in the present invention, the pressure-sensitive adhesive constituting the heat-sensitive recording pressure-sensitive adhesive label needs to be a styrene-butadiene-acrylic copolymer latex pressure-sensitive adhesive. That is, by making the pressure-sensitive adhesive a styrene-butadiene-acrylic copolymer latex pressure-sensitive adhesive as a main component, the adhesion to a non-polar surface such as polyethylene is improved,
In addition, a decrease in sensitivity of the heat-sensitive recording layer can be prevented.
Further, by setting the glass transition temperature to -60 to -20C, the adhesiveness at low temperatures can be improved. When the glass transition temperature is higher than −20 ° C., the adhesiveness at low temperature is deteriorated, and when the glass transition temperature is lower than −60 ° C., the cohesive force is reduced, and the performance as an adhesive such as the displaced label is shifted. Worsens.

The styrene-butadiene-acrylic copolymer latex pressure-sensitive adhesive is obtained by copolymerizing a styrene monomer, a butadiene monomer, and a (meth) acrylate monomer. The transition temperature can be adjusted. However, if the content ratio of the (meth) acrylic acid ester is too large, the sensitivity of the heat-sensitive recording layer in the heat-sensitive recording label is reduced.
It is desirable to be within the range.

Specific examples of the (meth) acrylate monomer include acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate. Monomers, methacrylate monomers such as methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, monomers containing a glycidyl group such as glycidyl acrylate and glycidyl methacrylate, acrylonitrile, methacryloyl Examples include unsaturated nitrile monomers such as nitriles, and monomers containing an amide group such as acrylamide, N-methylolacrylamide, and methacrylamide.

Further, an olefin monomer other than a styrene monomer, a butadiene monomer, and an acrylate monomer can be contained, and specific examples of such a monomer include, for example, isoprene and the like. Examples include conjugated double bond-containing monomers, aromatic vinyl monomers such as α-methylstyrene, vinyltoluene and dimethylstyrene, and unsaturated carboxylic acids such as fumaric acid and itaconic acid. These monomers are usually contained in an amount of 30% by weight as long as the effects of the present invention are not inhibited.
It can be used by adjusting the glass transition temperature by the ratio of these monomers, styrene monomer and butadiene monomer.

The method for producing the copolymer in the present invention is not particularly limited. For example, a known emulsion polymerization method such as continuous emulsion polymerization and batch emulsion polymerization can be employed. Additives used in general emulsion polymerization, such as a chain transfer agent, a polymerization initiator, an electrolyte, and a chelating agent, can be appropriately used. Further, the polymerization temperature can be either high or low. In addition, it is preferable to use as little additives as possible or to use those produced without using an emulsifier, and by using such a copolymer, it is possible to minimize the influence on the heat-sensitive recording layer. .

As the emulsifier, for example, an amphoteric surfactant, an anionic surfactant or a nonionic surfactant can be used. As the amphoteric surfactant, for example, a carboxylate, a sulfate, a sulfonate or the like as an anion portion, an amine salt as a cation portion,
Specific examples include those having a quaternary ammonium salt and the like, and specific examples include lauryl betaine, stearyl betaine, lauryl-β-alanine, stearyl-β-alanine and the like.

Examples of the anionic surfactant include higher alcohol sulfates, alkylbenzene sulfonates, and aliphatic sulfonates. Specific examples include sodium dodecylbenzene sulfonate, sodium lauryl sulfate, and the like. And sodium dodecyl diphenyl ether disulfonate.

Further, nonionic surfactants include:
For example, alkyl ether type, alkyl ester type, alkyl aryl ether type and the like of ordinary polyethylene glycol are exemplified.
0) Oxyethylene C5 to C30 alkyl esters, poly (polymerization degree 1 to 30) oxyethylene C1 to C20 alkylphenyl ether and the like. These emulsifiers can be used alone or in combination of two or more.

The amount of these emulsifiers is usually 0.05 to 5 parts by weight based on 100 parts by weight of the monomer compound.

Examples of the polymerization initiator include inorganic polymerization initiators represented by persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; cumene hydroperoxide; diisopropylbenzene peroxide; Hydroperoxides such as peroxides, peroxides such as benzoyl peroxide and lauryl peroxide, organic polymerization initiators represented by azo compounds such as azobisisobutyronitrile, and the above polymerization initiators and sulfuric acid A redox-based polymerization initiator obtained by combining with a reducing agent such as ferrous iron is exemplified. These initiators can be used alone or in combination of two or more.

The amount of these polymerization initiators is not particularly limited, but is 0.1 to 5 parts by weight based on 100 parts by weight of the monomer compound.

Examples of the chain transfer agent include α-methylstyrene dimer, terpinolene and 2,6-di-t-
Phenol compounds such as butyl-4-methylphenol and styrenated phenol; aryl compounds such as aryl alcohol; vinyl ether compounds such as α-benzyloxystyrene, α-benzyloxyacrylonitrile and α-benzyloxyacrylamide; acrolein; Acrolein, aldehyde compounds such as benzoaldehyde, toluene, triphenylmethane, aromatic compounds such as pentaphenylethane, t-dodecyl mercaptan, n-octyl mercaptan such as mercaptan compounds, xanthogen compounds such as dimethyl xanthogen disulfide, Thiuram compounds such as tetramethylthiuram sulfide, thioglycolic acid (ester) compounds such as thioglycolic acid and octyl thioglycolate, dichloromethane, Romometan, carbon tetrachloride,
Examples thereof include halogenated hydrocarbon compounds such as 1,1,1-trichlorotoluene and alcohol compounds such as t-crotyl alcohol. These chain transfer agents can be used alone or in combination of two or more.

The amount of the chain transfer agent to be used is usually 0.01 to 20 parts by weight based on 100 parts by weight of the monomer compound.

In the present invention, by setting the gel content of the styrene-butadiene-acrylic copolymer latex pressure-sensitive adhesive in the pressure-sensitive adhesive layer of the heat-sensitive recording pressure-sensitive adhesive label to 30% or more, even better effects can be obtained. The gel content is
The copolymer was cast on a glass plate with a frame and air-dried at room temperature to produce a film having a thickness of about 1 mm.
g) The sample of g) is immersed in 100 ml of toluene at room temperature for 48 hours, and the residue obtained by filtration through a 300-mesh wire gauze is measured after drying, and can be expressed in terms of% by weight based on the sample. .

The gel content can be controlled by adjusting the type and proportion of the monomers used, the polymerization method, and the additives used in the emulsion polymerization.

The styrene-butadiene-acrylic copolymer latex pressure-sensitive adhesive used as the pressure-sensitive adhesive in the present invention may include various additives such as tackifiers, thickeners, wetting agents, leveling agents, defoamers, etc., if necessary. Auxiliaries can be used as appropriate.

Further, the pressure-sensitive adhesive of the present invention comprises a styrene-butadiene-acrylic copolymer latex pressure-sensitive adhesive as a main component of the solid content, and styrene-butadiene-pressure as another component.
It is in the form of an emulsion containing an additive used for producing an acrylic copolymer and various auxiliaries as optional components, and the emulsion solid content concentration as an adhesive may be 20 to 80%. preferable. Solid concentration 2
If it is less than 0% or more than 80%, there is a problem that it is difficult to control the amount of application when applying the pressure-sensitive adhesive with various coating apparatuses. Further, it is preferable that the solid content concentration is appropriately adjusted to a concentration suitable for a coating apparatus to be used.

The coating amount of the pressure-sensitive adhesive of the present invention is 5% by dry weight.
~50g / m ² is preferred. More preferably, 10 to 30
g / m ² . Incidentally, if the coating amount is less than 5 g / m ² , sufficient adhesiveness cannot be obtained when used as a label, while if it exceeds 50 g / m ² , there is a problem that the adhesiveness is saturated and the economic efficiency is poor.

The method of applying the pressure-sensitive adhesive of the present invention to a support includes brush coating, spray coating, screen printing, gravure printing, offset printing, letterpress printing, Meyer bar coater, kiss roll coater, lip coater, and direct roll coater. This is performed by various coating apparatuses such as an offset roll coater, a gravure roll coater, a reverse roll coater, a rod coater, a blade coater, and an air knife coater. Drying can be performed by a conventional method combined with the above-described apparatus for performing coating. In the drying, the drying is performed by appropriately adjusting the drying temperature so that the heat-sensitive recording layer provided on the support does not develop color.

The heat-sensitive recording paper of the present invention is not particularly limited, and may be used on a support such as high-quality paper (acid paper, neutral paper), synthetic paper, film, or coated paper which is generally used as a heat-sensitive recording base paper. A heat-sensitive recording sheet provided with a heat-sensitive recording layer and, if necessary, an intermediate layer is used. As the heat-sensitive recording layer, a recording layer utilizing a color reaction between a basic dye and a color former generally used for heat-sensitive recording paper can be used. In addition, the intermediate layer, for the purpose of improving the storage stability of the record, imparting printability in the case of performing printing immediately before providing the release agent layer, improving the adhesiveness and film formability of the release agent layer, One or two or more intermediate layers can be provided. Also,
Super calender processing may be performed for the purpose of improving image quality and image density.

In the present invention, a release agent layer is provided on the recording surface of the heat-sensitive recording paper by the above-mentioned method, and then an adhesive layer is formed on the back surface, but migration of adhesive components and the like into the support is prevented. An undercoat layer can be provided if necessary to provide a sufficient adhesive effect.

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 which does not require a release paper, and has an adhesive property, especially at a low temperature and on a non-polar surface such as polyethylene. This is a heat-sensitive recording pressure-sensitive adhesive label having excellent adhesive properties and excellent recording characteristics as heat-sensitive recording paper.

[0050]

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% indicate "parts by weight" and "% by weight" unless otherwise specified. Test methods not particularly described are JIS standard (P), ISO standard (TC
6), TAPPI test method, JAPAN TAPPI paper pulp test method specified measurement method, or according to the method.

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.

"Manufacture 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.

Preparation of Solution C 20 parts of 1,2-di (3-methylphenoxy) ethane 5
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 a 10% acetoacetyl group-modified polyvinyl alcohol aqueous solution, 100 parts of kaolin (trade name: UW-90, manufactured by EMC), 30 parts of a 30% zinc stearate dispersion,
And a composition composed of 100 pieces 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 recording layer was formed. On the recording layer, solution D was applied and dried so that the applied amount after drying was 5 g / m ^2, and after forming a protective layer, a super calender treatment was performed to produce a thermosensitive recording paper.

[Formation of Release Agent Layer] An ultraviolet-curable silicone resin containing an epoxy group (trade name: using an offset gravure coater) on the protective layer of the thermal recording paper.
1.5 g of UV-9300, manufactured by Toshiba Silicone Co., Ltd.)
/ M ² and an ultraviolet irradiation device (trade name:
Using Rapid Cure, manufactured by Ushio Electric Co., Ltd., the composition was cured by irradiating ultraviolet rays at an irradiation dose of 200 mj / cm ² to obtain a thermosensitive recording paper having a release agent layer.

"Production of pressure-sensitive adhesive label" A styrene-butadiene-acrylic copolymer latex having a monomer composition shown in Table 1: monomer composition-1 was dried on the back of the thermosensitive recording paper having the above-mentioned release agent layer. Coating and drying with a reverse roll coater so that the weight becomes 25 g / m ² , forming an adhesive layer (water content of the adhesive layer 1.2%), finishing in a roll form,
An adhesive label for thermal recording of the present invention was produced.

[0059]

[Table 1]

The glass transition temperature was measured using a scanning calorimeter (manufactured by Seiko Instruments Inc., SCC-5020) at a temperature rising rate of 10 ° C./min and a starting temperature of −100 ° C.

Example 2 In "Production of pressure-sensitive adhesive label" of Example 1, styrene-
Butadiene-acrylic copolymer latex: Roll-shaped in the same manner as in Example 1 except that styrene-butadiene-acrylic copolymer latex: monomer composition-2 was used instead of monomer composition-1. An adhesive label for thermal recording was manufactured.

Example 3 In Example 1, "Production of adhesive label",
Butadiene-acrylic copolymer latex: Roll-shaped in the same manner as in Example 1 except that styrene-butadiene-acrylic copolymer latex: monomer composition-3 was used instead of monomer composition-1. An adhesive label for thermal recording was manufactured.

Example 4 In the “Formation of a release agent layer” in Example 1, instead of curing using an ultraviolet irradiation apparatus, an electron beam irradiation apparatus (trade name: Electron Curtain CB-15) was substituted with nitrogen.
Roll, thermosensitive recording adhesive in the same manner as in Example 1 except that curing was performed by irradiating an electron beam of 4 Mrad under the conditions of an acceleration voltage of 175 kV and an irradiation current of 20 mA. Label was manufactured.

Example 5 In Example 1 "Formation of a release agent layer", a polysiloxane containing a vinyl ether group synthesized by the following method was used, and bis (dodecylphenyl) was used as a photopolymerization initiator.
A roll-shaped pressure-sensitive adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that iodonium hexafluoroantimonate was added.

"Synthesis of polysiloxane" In a nitrogen atmosphere, potassium acetate and a platinum catalyst were added to 1,4-butanediol divinyl ether, and a polysiloxane represented by the following general structural formula (Chemical Formula 1) was added dropwise with stirring. Then, by heating and reacting, a polysiloxane containing a vinyl ether group represented by the following general structural formula (Formula 2) was synthesized.

[0066]

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[0067]

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Example 6 In "Formation of a release agent layer" in Example 1, a polysiloxane containing a vinyl ether group synthesized by the following method was used, and bis (dodecylphenyl) was used as a photopolymerization initiator.
A roll-shaped pressure-sensitive adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that iodonium hexafluoroantimonate was added.

"Synthesis of polysiloxane" In a nitrogen atmosphere, potassium acetate and a platinum catalyst were added to 1,4-butanediol di-1-propenyl ether, and the mixture was stirred with stirring to form a polysiloxane represented by the above general formula (Chemical Formula 1). Siloxane was added dropwise, and the mixture was heated and reacted to synthesize a polysiloxane containing a 1-propenyl ether group.

Example 7 In Example 1, synthetic paper (trade name: FP) was used as a support.
Except for using H-80, manufactured by Oji Yuka Synthetic Paper Co., Ltd., an adhesive label for heat-sensitive recording was produced in the same manner as in Example 1.

Comparative Example 1 In the “Formation of a release agent layer” in Example 1, instead of the ultraviolet-curable silicone resin containing an epoxy group, an ultraviolet-curable silicone containing a mercapto group (trade name:
BY-24-551A, 75 parts by Dow Corning Toray Silicone Co., Ltd.), and a UV-curable silicone containing a vinyl group (trade name: BY-24-551)
B, manufactured by Dow Corning Toray Silicone Co., Ltd.) 2
A roll-shaped heat-sensitive recording pressure-sensitive adhesive label was produced in the same manner as in Example 1 except that 5 parts of the mixture was used.

Comparative Example 2 A roll-shaped heat-sensitive recording pressure-sensitive adhesive label 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] A radiation-curable silicone containing an acrylic group (trade name: X) was formed on the protective layer of the heat-sensitive recording paper by using an offset gravure coater.
-62-7213, manufactured by Shin-Etsu Chemical Co., Ltd.) at an amount of 1.5 g / m ^2, and using an electron beam irradiation apparatus (trade name: Electron Curtain CB-150, manufactured by ESI) which was subjected to nitrogen substitution. Acceleration voltage 175kV, irradiation current 20mA
Curing was performed by irradiating 4 Mrad of electron beam under the conditions described above to obtain a thermosensitive recording paper having a release agent layer.

Comparative Example 3 Instead of the styrene-butadiene-acrylic copolymer latex of Example 1: monomer composition-1, the styrene-butadiene-acrylic copolymer latex shown in Table 1: monomer composition- A roll-shaped pressure-sensitive adhesive label for thermal recording was produced in the same manner as in Example 1 except that No.4 was used.

Comparative Example 4 In Example 1, "Production of pressure-sensitive adhesive label",
Butadiene-acrylic copolymer latex: In the same manner as in Example 1 except that an acrylic emulsion adhesive (trade name: L-145, manufactured by Nippon Carbide Industry Co., Ltd.) was used instead of monomer composition-1. Then, a roll-shaped heat-sensitive recording adhesive label was produced.

The following evaluations were performed on the 11 types of heat-sensitive recording pressure-sensitive adhesive labels thus obtained, and the results are shown in Tables 2 and 3. In addition, the evaluation method of each evaluation item is as follows.

[Adhesiveness] The adhesive label for heat-sensitive recording was adhered to a stainless steel plate and a polyethylene sheet. After 2 hours, the adhesive force was measured at an angle of 180 ° at a speed of 0.3 m / min. Judged by. ◎: Adhesive strength is 1000 g / 25 mm or more, the substrate is completely broken at the time of measuring the adhesive strength, and the adhesive strength is particularly excellent. : The adhesive strength is 800 g / 25 mm or more, and the substrate is partially broken at the time of measuring the adhesive strength. C: Adhesive strength of 400 g / 25 mm or more, which has no practical problem. X: Adhesive strength of 150 g / 25 mm or more, but easily peelable. XX: Adhesive force of less than 150 g / 25 mm and hardly adhered.

[Low-Temperature Adhesion] The pressure-sensitive adhesive label for thermal recording stored at -15 ° C. was adhered to a stainless steel plate at -15 ° C., and after 2 hours at -15 ° C., 0.1 ° at 180 °. 3
The adhesive strength was measured at a speed of m / min, and judged based on the following criteria. ◎: Adhesive force is 1000 g / 25 mm or more, the substrate is completely broken during the adhesive force measurement, and the adhesive force is particularly excellent. : The adhesive strength is 800 g / 25 mm or more, and the substrate is partially broken at the time of measuring the adhesive strength. C: Adhesive strength of 400 g / 25 mm or more, which has no practical problem. X: Adhesive strength of 150 g / 25 mm or more, but easily peelable. XX: Adhesive force of less than 150 g / 25 mm and hardly adhered.

[Recording Density] A pressure-sensitive adhesive label for thermal recording was prepared by using a commercially available printer (trade name: Prodigy Plus).
Recording was performed with a LINERLESS (manufactured by DATAMAX), and the maximum color density of the obtained recorded image was measured using a Macbeth densitometer (trade name: RD-914, using filter visual,
Macbeth).

[Roll Preserved Recording Density] After the roll-shaped pressure-sensitive adhesive label for thermal recording was treated at 40 ° C. and 90% RH for 7 days, recording was performed with a test printer equipped with a thermal head, and the recorded image obtained was obtained. Was measured with a Macbeth densitometer (trade name: RD-914, using filter visual, manufactured by Macbeth).

[Peeling Force] A roll-shaped pressure-sensitive adhesive label for heat-sensitive recording was peeled at a peeling speed of 0.3 m / min and 10 m / mi.
Under the test conditions of n, the peeling force (g / 5 cm) when the pressure-sensitive adhesive label for thermal recording was peeled was measured.

[0082]

[Table 2]

[0083]

[Table 3]

From Tables 2 and 3, Examples 1 to 7 were obtained.
In the above, polysiloxane containing an epoxy group, 1-
A release agent layer which is polymerized and cured by irradiation or the like using at least one kind of polysiloxane selected from polysiloxane having a propenyl ether group and polysiloxane having a vinyl ether group, and has a glass transition temperature of A heat-sensitive adhesive label using a styrene-butadiene-acrylic copolymer-based latex at -60 ° C to -20 ° C as an adhesive has a low peeling force, an adhesive property to a non-polar polyethylene sheet, and a low temperature. Had good adhesion.

Further, as compared with Comparative Example 4 in which an acrylic resin emulsion was used as an adhesive, the roll storage recording density was such that a heat-sensitive adhesive label using a styrene-butadiene-acrylic copolymer latex as an adhesive was: High recording density was obtained. Further, Example 2 and Example 3
It can be seen that the peeling force was further reduced because a styrene-butadiene-acrylic copolymer latex having a gel content of 30% or more was used as an adhesive.

[0086]

As described above, the heat-sensitive recording pressure-sensitive adhesive label obtained by the present invention is a heat-sensitive recording pressure-sensitive adhesive label which does not require a release paper, and has a pressure-sensitive adhesive property, especially at a low temperature and on a non-polar surface such as polyethylene. It is an adhesive label having excellent adhesiveness to paper, light peeling power, and excellent recording characteristics as heat-sensitive recording paper.

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Claims (2)

[Claims] 1. A heat-sensitive recording pressure-sensitive adhesive label comprising: a heat-sensitive recording layer containing a basic dye and a colorant on the surface side of a support; a release agent layer; and a pressure-sensitive adhesive layer on the back side. The release agent layer is polymerized by irradiation with at least one kind of polysiloxane selected from an epoxy group-containing polysiloxane, a 1-propenyl ether group-containing polysiloxane, and a vinyl ether group-containing polysiloxane, The cured release agent layer, and the pressure-sensitive adhesive layer has a glass transition temperature of -60 as a main component.
A pressure-sensitive adhesive label for heat-sensitive recording, which is a pressure-sensitive adhesive layer coated and dried with a styrene-butadiene-acrylic copolymer latex at a temperature of from -20 ° C to -20 ° C. 2. The styrene-butadiene-acrylic copolymer latex constituting the pressure-sensitive adhesive layer has a gel content of 3
The heat-sensitive recording pressure-sensitive adhesive label according to claim 1, which is 0 to 100%.