JPH10273631A - Adhesive label for thermal recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tacky label for heat sensitive recording not requiring a releasing paper, excellent in adhesion characteristics especially at a low temperature and those to a non-polar surface such as a polyethylene, and also in recording characteristics and preserving property for a heat sensitive recording. SOLUTION: This tacky label for heat sensitive recording provided with a heat sensitive recording layer containing a basic dyestuff and a color developing agent and a releasing agent layer consecutively at the one side surface of a supporting material, and an adhesive layer at another surface is obtained by containing a styrene-butadiene copolymer having (-)60-(-)20 deg.C glass transition temperature as a main component in the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive label for heat-sensitive recording which does not require a release paper, and has excellent adhesive properties, in particular, low temperature and excellent adhesion to non-polar surfaces such as polyethylene, and recording for heat-sensitive recording. The present invention relates to an adhesive label having excellent properties and storability.

[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.

As the surface substrate, for example, heat-sensitive recording paper is used. This heat-sensitive recording paper utilizes a color-forming reaction between a colorless or light-colored basic dye and an organic or inorganic colorant. It is well known that a recording layer containing both of them is provided on a support so that a recording image is obtained by bringing a coloring material into contact with heat. In general, heat-sensitive recording paper is relatively inexpensive, and its recording equipment is compact and easy to maintain, so that it is used not only as a recording medium for facsimile equipment and various computing equipment but also in a wide range of fields. For example, as one of the application fields, POS (point of service) of retail stores and the like is used.
ales) With the expansion of systemization, the cases used as adhesive labels are increasing.

[0004] The heat-sensitive recording pressure-sensitive adhesive label is generally provided with a pressure-sensitive adhesive layer on the back surface of the heat-sensitive recording paper and then provided with a release sheet, but after recording with a label printer and attaching the label to an adherend, A large amount of release sheet was discharged. 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. 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 roll of the thermosensitive recording adhesive label must be frequently replaced.

[0005] In view of the problem of discarding the release sheet, it is conceivable to remove the release sheet from the heat-sensitive recording adhesive label. In this regard, a release agent layer is provided on the heat-sensitive recording adhesive label and the tape is finished. Method (Tokuhei 4-15)
No. 110) has been proposed. A method for producing the above-mentioned heat-sensitive recording pressure-sensitive adhesive label, comprising applying a UV-curable or EB-curable release agent which can be cured at room temperature on a recording surface of general thermal recording paper, and curing the applied release agent. It is manufactured by forming a pressure-sensitive adhesive layer by applying a pressure-sensitive adhesive to the upper surface of the release agent layer or the back surface of the support, and then finishing it into a tape shape. However, when forming the pressure-sensitive adhesive layer, when applying a solvent-type pressure-sensitive adhesive, the solvent dissolving the pressure-sensitive adhesive through the release agent layer,
Alternatively, there is a problem in that it penetrates from the back surface of the support, reaches the heat-sensitive recording layer, and causes the heat-sensitive recording layer to develop color. Also,
When applying a hot-melt type pressure-sensitive adhesive, the hot-melt type pressure-sensitive adhesive is heated and melted at a temperature of 100 ° C. or higher.

Further, when an acrylic emulsion type pressure-sensitive adhesive is used, a pressure-sensitive adhesive layer can be formed, but the adhesion at a low temperature or the adhesion to a non-polar surface such as polyethylene is based on rubber or urethane. Is inferior to adhesives such as Further, in the case of a general heat-sensitive recording pressure-sensitive adhesive label, when stored in a roll, in order from the bottom, a release sheet, a pressure-sensitive adhesive layer, a support, a heat-sensitive recording layer, then a release sheet, a pressure-sensitive adhesive layer, a support. The support and the release sheet are present between the pressure-sensitive adhesive layer and the heat-sensitive recording layer, and the effect of the pressure-sensitive adhesive on the heat-sensitive recording layer is slight.

However, in the case of the above-mentioned heat-sensitive recording pressure-sensitive adhesive label, when stored in a roll, the pressure-sensitive adhesive layer, the support, the heat-sensitive recording layer, the release agent, then the pressure-sensitive adhesive layer, the support, The heat-sensitive recording layer and the release agent layer overlap in this order. Between the pressure-sensitive adhesive layer and the heat-sensitive recording layer, one is a support and the other is a release agent layer. This release agent layer is usually used in an amount of 0.1 to 5.0 g / g from the viewpoint of the performance and cost of the release agent.
The pressure-sensitive adhesive has a great effect on the heat-sensitive recording layer because it is applied on the order of m ² and is a very thin film. In particular, in the case of an acrylic emulsion-type pressure-sensitive adhesive, there is a problem that components in the pressure-sensitive adhesive penetrate into the heat-sensitive recording layer and lower the sensitivity of the heat-sensitive recording layer.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an adhesive label for heat-sensitive recording which does not require a release paper, which solves the above-mentioned problems of the prior art, and has an adhesive property, especially an adhesive property at a low temperature, and a non-polarity such as polyethylene. Provided is a heat-sensitive recording pressure-sensitive adhesive label which has excellent adhesion to a surface and is excellent in recording characteristics and preservability for heat-sensitive recording utilizing a color development reaction between a colorless or light-colored basic dye and a color former. It is in.

[0009]

The pressure-sensitive adhesive label for thermal recording according to the present invention is provided with a heat-sensitive recording layer containing a basic dye and a coloring agent on one side of a support, and a release agent layer sequentially on one side, and an adhesive on the other side. In a heat-sensitive recording pressure-sensitive adhesive label provided with a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer has a glass transition temperature of -60 to
It is characterized by containing a styrene-butadiene copolymer at -20 ° C. In the heat-sensitive recording adhesive label of the present invention, the styrene-butadiene copolymer preferably has a gel content of 30 to 100%.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies on the above problems, the present inventors have found that a heat-sensitive recording layer containing a basic dye and a colorant and a release agent layer are sequentially provided on the surface of a support. Further, in the heat-sensitive recording pressure-sensitive adhesive label having a pressure-sensitive adhesive layer provided on the back side of the support, a styrene-butadiene copolymer having a glass transition temperature in a specific range is used as a pressure-sensitive adhesive component of the pressure-sensitive adhesive layer. By using the coalesce as the main component, the adhesiveness of the pressure-sensitive adhesive layer to a nonpolar surface such as polyethylene can be improved, and the sensitivity of the heat-sensitive recording layer can be prevented from lowering. They have found that they can be made favorable, and have completed the present invention. If necessary, a release agent layer may be provided on the heat-sensitive recording layer via a protective layer, and an adhesive layer may be provided on the back side of the support via an undercoat layer.

In the present invention, a latex of a styrene-butadiene copolymer is used as the pressure-sensitive adhesive constituting the heat-sensitive recording pressure-sensitive adhesive label, and the copolymer has a glass transition temperature of -60 to -20 ° C. Range, preferably in the range of -55 to -35 ° C. When the glass transition temperature is higher than −20 ° C., the adhesiveness at a low temperature is reduced, and when the glass transition temperature is lower than −60 ° C., the cohesive force is reduced, so that the performance as an adhesive such as the displaced label is shifted. Tends to be inadequate.

The styrene-butadiene copolymer latex is obtained by copolymerizing a styrene monomer and a butadiene monomer as main components, and the glass transition temperature can be easily adjusted by the mixing ratio of the two. It is possible.
Further, the glass transition temperature can be adjusted by appropriately mixing an olefin monomer other than the styrene monomer and the butadiene monomer. Specific examples of such olefin monomers include, for example, conjugated double bond-containing monomers such as isoprene, α-methylstyrene, vinyltoluene, aromatic vinyl monomers such as dimethylstyrene,
Methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, 2
-Contains acrylate monomers such as hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, methacrylate monomers such as 2-hydroxypropyl methacrylate, and glycidyl groups such as glycidyl acrylate and glycidyl methacrylate. Monomers, acrylonitrile, unsaturated nitrile monomers such as methacrylonitrile, acrylamide, N-methylolacrylamide,
Examples include monomers containing an amide group such as methacrylamide. These monomers can be used in an amount of about 0 to 50% by weight based on the total amount of the styrene monomer and the butadiene monomer as long as the effects of the present invention are not impaired.

The method for producing the styrene-butadiene copolymer latex in the present invention is not particularly limited. For example, a known emulsion polymerization method such as continuous emulsion polymerization or batch emulsion polymerization is employed, and the polymerization temperature is appropriately adjusted. Adjusted. In the polymerization mixture, additives used in general emulsion polymerization such as various known emulsifiers, chain transfer agents, polymerization initiators, electrolytes, and chelating agents are appropriately used as long as the original purpose of the present invention is not impaired. it can. If these additives are used excessively, the obtained copolymer latex may have a particularly bad influence on the heat-sensitive recording layer, and it is necessary to pay close attention to the amount of the additives used.

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, for example, sulfates of higher alcohols, alkyl benzene sulfonates, aliphatic sulfonates, and the like.Specifically, sodium dodecylbenzene sulfonate, sodium lauryl sulfate, dodecyl diphenyl ether disulfone Acid sodium and the like. Further, examples of the nonionic surfactant include, for example, alkyl ether type, alkyl ester type, and alkyl aryl ether type of ordinary polyethylene glycol, and specifically,
Examples thereof include poly (polymerization degree 1 to 30) oxyethylene C5 to C30 alkyl esters, and poly (polymerization degree 1 to 30) oxyethylene C1 to C20 alkyl phenyl ether. 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 per 100 parts by weight of the monomer compound.
Used by weight.

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, benzoyl peroxide, peroxides such as 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 preferably about 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 generally 0.1 to 20 parts by weight based on 100 parts by weight of the monomer compound.

Furthermore, 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. In the present invention, by setting the gel content of the styrene-butadiene copolymer in the pressure-sensitive adhesive layer of the heat-sensitive recording pressure-sensitive adhesive label to 30 to 100%, 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.

The gel content was determined by casting the copolymer on a glass plate with a frame, air-drying at room temperature to produce a film having a thickness of about 1 mm, and preparing a predetermined amount (about 0.3 g) of the sample. 100m
After immersing in 1 l of toluene at room temperature for 48 hours, the residue obtained by filtration through a 300-mesh wire gauze was dried, and its weight was measured and shown as a percentage by weight based on the sample. The gel content can be easily controlled by adjusting the type and mixing ratio of the monomers used, the polymerization method, the additives used for emulsion polymerization, and the like.

The styrene-butadiene copolymer latex used as the pressure-sensitive adhesive in the present invention may optionally contain a tackifier, a thickener, a wetting agent, a leveling agent,
Various auxiliaries such as an antifoaming agent can be appropriately used.

The pressure-sensitive adhesive of the present invention comprises a styrene-butadiene-based copolymer latex as a main component of a solid component, an additive for producing a styrene-butadiene-based copolymer as another component, and an optional component. The emulsion is in the form of an emulsion containing various auxiliaries. The solid concentration of the emulsion as an adhesive is preferably 20 to 80%. If the solid content is less than 20% 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,
The dry weight is preferably 5 to 50 g / m ² . More preferably, it is 10 to 30 g / m ² . By the way, application amount is 5g / m
^If it is less than 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 for 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 sheet of the present invention is not particularly limited, and is generally used as a base paper for heat-sensitive recording on a support such as high-quality paper (including acidic paper and neutral paper), synthetic paper, film, and coated paper. In addition, a heat-sensitive recording sheet provided with a heat-sensitive recording layer and, if necessary, an intermediate layer (protective 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 in a heat-sensitive recording sheet can be used. Further, the intermediate layer (protective layer) improves the storage stability of the record, imparts printability when printing is performed immediately before providing the release agent layer, or improves the adhesiveness and film formability of the release agent layer. For this purpose, one or more intermediate layers (protective layers) can be provided. Further, for the purpose of improving image quality and image density, a super calender process may be performed.

In the present invention, a release agent layer is provided on the recording surface of the heat-sensitive recording sheet by the above-described 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. If necessary, an undercoat layer can be provided to ensure a sufficient adhesive effect.

Regarding the release agent provided on the heat-sensitive recording layer,
There is no particular limitation, as long as it is a substance having releasability from the pressure-sensitive adhesive layer, and a known silicone-based or non-silicone-based release agent can be used. Specific examples include a solvent thermosetting silicone resin, a solventless thermosetting silicone resin, an emulsion thermosetting silicone resin, a solventless ultraviolet curing silicone resin, a solventless electron beam curing silicone resin, a solvent fluorine resin, Solvent ultraviolet curable fluororesin, solventless electron beam curable fluororesin, long-chain aliphatic hydrocarbon compounds, and the like. Among these, a silicone resin is preferably used, and not only is the releasability stable, but also a head residue during thermal recording hardly adheres. Considering that the coloring of the heat-sensitive recording layer is not induced when the release agent is cured, it is preferable to use a solventless UV-curable release agent or a solventless electron beam-curable release agent.

In the release agent, other radiation-curable resins, photopolymerization initiators, dyes, pigments, wetting agents, defoamers, dispersants, antistatic agents, leveling agents, lubricants, etc., if necessary. The various auxiliary agents described above can be appropriately added within a range not to impair the desired effect. The method for applying the release agent is not particularly limited, and for example, a usual coating means such as a bar coater, a multi-stage roll coater, an air knife coater, a gravure coater, and an offset gravure coater is 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. During electron beam irradiation, if the oxygen concentration is high, the curing of the release agent is hindered.
Substitution with an inert gas such as nitrogen, helium, carbon dioxide or the like is performed to reduce the oxygen concentration to 600 ppm or less, preferably 40 ppm or less.
Irradiation is preferably performed in an atmosphere controlled to 0 ppm or less.

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, particularly a low temperature and an adhesive property to a non-polar surface such as polyethylene. This is a heat-sensitive recording pressure-sensitive adhesive label which is excellent in heat resistance and has excellent recording characteristics and storage stability for heat-sensitive recording applications.

[0029]

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 "%" indicate "parts by weight" and "% by weight" unless otherwise specified.

Example 1 "Preparation of support" Softwood bleached kraft pulp (CSF 550 ml) 2
5 parts, hardwood bleached kraft pulp (CSF 560m)
l) To a pulp slurry containing 75 parts, talc was added so that the paper ash content was 5.0%, and a rosin size as a sizing agent was 1.5% based on the absolutely dried pulp, and aluminum sulfate was added. 0% was added to obtain a stock. This stock is made into a fourdrinier multi-cylinder cylinder dryer paper machine,
It was treated with a column 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.

"Preparation of heat-sensitive recording paper" Preparation of solution A 10 parts of 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-phenylaminofluoran 5 parts of a 5% aqueous methylcellulose solution and 40 parts of water Was pulverized with a sand mill until the average particle diameter became 3 μm. Solution B Preparation A composition comprising 30 parts of 4-hydroxy-4'-isopropyloxydiphenylsulfone, 5 parts of a 5% aqueous methylcellulose solution, 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
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. D solution preparation 10% acetoacetyl group-modified polyvinyl alcohol aqueous solution 200 parts, kaolin (trade name: UW-90, manufactured by EMC) 100 parts, 30% zinc stearate dispersion 30 parts,
And a composition comprising 100 parts of water were mixed and stirred to obtain a coating liquid for a protective layer. A liquid 55 was applied on the surface of the support obtained above.
Part, 115 parts of liquid B, 80 parts of liquid C, 80 parts of a 10% aqueous solution of polyvinyl alcohol, and 35 parts of calcium carbonate, and the coating liquid obtained by mixing and drying was applied in an amount of 6 g / m 2 after drying.
^Then, the recording layer was formed by coating and drying to obtain ² . Liquid D was applied onto the recording layer and dried 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 prepare a thermosensitive recording paper.

"Formation of release agent layer" 1.5 g of an ultraviolet-curable silicone resin (trade name: UV-9300, manufactured by Toshiba Silicone Co., Ltd.) on the protective layer of the heat-sensitive recording paper using an offset gravure coater. / M ^2, and an irradiation dose of 200 mJ / cm using an ultraviolet irradiation device (trade name: Rapid Cure, manufactured by Ushio Electric Co., Ltd.).
² so as to ultraviolet perform cured by irradiation, was obtained a heat-sensitive recording paper having a release agent layer.

[Preparation of adhesive label] Having the above-mentioned release agent layer
As shown in Table 1 on the back of the thermosensitive recording paper,
Styrene-butadiene latex (monomer composition-
1) 25 g / m2 in dry weight ^TwoReverse ro
Apply and dry with an adhesive coater to form an adhesive layer (adhesive layer
Of 1.2%), and finished in a roll shape to obtain the feeling of the present invention.
An adhesive label for thermal recording was produced.

[0034]

[Table 1]

Example 2 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive
Except that the styrene-butadiene-based latex (monomer composition-2) shown in Table 1 was used, the same as in Example 1,
A roll-shaped adhesive label for heat-sensitive recording was produced.

Example 3 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive was
Except that the styrene-butadiene-based latex (monomer composition-3) shown in Table 1 was used, the same as in Example 1,
A roll-shaped adhesive label for heat-sensitive recording was produced.

Example 4 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive
Except that the styrene-butadiene-based latex (monomer composition-4) shown in Table 1 was used, the same as in Example 1,
A roll-shaped adhesive label for heat-sensitive recording was produced.

Example 5 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive
Except for using the styrene-butadiene-based latex (monomer composition-5) shown in Table 1, in the same manner as in Example 1,
A roll-shaped adhesive label for heat-sensitive recording was produced.

Example 6 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive was
In the same manner as in Example 1 except that the styrene-butadiene-based latex (monomer composition-6) shown in Table 1 was used,
A roll-shaped adhesive label for heat-sensitive recording was produced.

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

Comparative Example 1 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive
Acrylic emulsion adhesive (trade name: TS-172)
7, a roll-shaped pressure-sensitive adhesive label for heat-sensitive recording was produced in the same manner as in Example 1 except that Nippon Carbide Industry Co., Ltd. was used.

Comparative Example 2 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive
In the same manner as in Example 1 except that the styrene-butadiene-based latex (monomer composition-7) shown in Table 1 was used,
A roll-shaped adhesive label for heat-sensitive recording was produced.

Comparative Example 3 In the production of the pressure-sensitive adhesive label of Example 1, the pressure-sensitive adhesive
In the same manner as in Example 1 except that the styrene-butadiene-based latex (monomer composition-8) shown in Table 1 was used,
A roll-shaped adhesive label for heat-sensitive recording was produced.

Evaluation The pressure-sensitive adhesive labels for heat-sensitive recording obtained in the above Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 2. [Adhesiveness] Adhesive label for thermal recording was prepared according to JIS Z 02
Adhere to stainless steel plate and polyethylene sheet according to 37, and after 30 minutes, 0.3 m / m at 180 ° angle
The adhesive strength was measured at the speed of "in" and judged according to the following criteria. ◎: 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. ：: Adhesion force of 800 g / 25 mm or more, 1000 g / 2
It is less than 5 mm and the substrate is partially broken when measuring the adhesive strength. ′ ': Adhesive strength of 400 g / 25 mm or more, 800 g / 2
Less than 5 mm, no problem in practical use Δ: Adhesion force of 150 g / 25 mm or more, 400 g / 25
Less than mm and easily peels off. C: Adhesive strength of less than 150 g / 25 mm and hardly adhered.

[Low Temperature Adhesion] The 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 an angle of 180 °. 3
The adhesive strength was measured at a speed of m / min, and judged based on the following criteria. ◎: 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. ：: Adhesion force of 800 g / 25 mm or more, 1000 g / 2
It is less than 5 mm and the substrate is partially broken when measuring the adhesive strength. ′ ': Adhesive strength of 400 g / 25 mm or more, 800 g / 2
Less than 5 mm, no problem in practical use Δ: Adhesion force of 150 g / 25 mm or more, 400 g / 25
Less than mm and easily peels off. C: Adhesive strength of less than 150 g / 25 mm and hardly adhered.

[Recording Density] An adhesive label for thermal recording was recorded by a test printer equipped with a thermal head, and the maximum color density of the obtained recorded image was measured using a Macbeth densitometer (trade name:
RD-914, manufactured by Macbeth, using a visual filter).

[Roll-preserved recording density] A roll-shaped pressure-sensitive adhesive label for heat-sensitive recording was prepared by (1) 60 ° C. and (2) 40 ° C., 9
After processing for 7 days under 0% RH conditions, recording was performed with a test printer equipped with a thermal head, and the maximum color density of the obtained recorded image was measured using a Macbeth densitometer (trade name: RD-914, trade name).
Macbeth, using a visual filter).

[Peeling Force] A roll-shaped heat-sensitive recording adhesive label was subjected to (1) a peeling speed of 0.3 m / min and (2) 10
Under the test conditions of m / min, the peeling force (g / 5 cm) when the heat-sensitive recording adhesive label was peeled was measured.

[0049]

[Table 2]

As can be seen from Table 2, in Examples 1 to 7, the heat-sensitive recording adhesive label using a styrene-butadiene copolymer latex having a glass transition temperature of -60 to -20 ° C. as an adhesive has a non-polar surface. Was good at a low temperature and good at a low temperature. Further, regarding the roll storage recording density, Comparative Example 1 using an acrylic resin emulsion as an adhesive was used.
In comparison with the pressure-sensitive adhesive label for thermal recording using a styrene-butadiene copolymer latex as a pressure-sensitive adhesive, a higher recording density was obtained. Further, in Examples 3 to 6, it can be seen that since the styrene-butadiene copolymer latex having a gel content of 30% or more was used as an adhesive, the peeling force was further reduced.

[0051]

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 an adhesive property, especially an adhesive property at a low temperature, and a non-polar surface such as polyethylene. It has become possible to provide an adhesive label for heat-sensitive recording which is excellent in adhesiveness and excellent in recording characteristics and storage stability as heat-sensitive recording paper.

Claims (2)

[Claims] 1. A heat-sensitive recording pressure-sensitive adhesive label comprising a support in which a heat-sensitive recording layer containing a basic dye and a colorant and a release agent layer are sequentially provided on one surface and a pressure-sensitive adhesive layer is provided on the other surface. And a pressure-sensitive adhesive label for heat-sensitive recording, wherein the pressure-sensitive adhesive layer contains, as a main component, a styrene-butadiene-based copolymer having a glass transition temperature of -60 to -20 ° C. 2. The heat-sensitive recording adhesive label according to claim 1, wherein the styrene-butadiene copolymer has a gel content of 30 to 100%.