JP3487182B2 - Adhesive sheet for thermal recording - Google Patents

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 sheet which utilizes a color-forming reaction between an electron-donating compound and an electron-accepting compound, and in particular, a heat-sensitive recording pressure-sensitive adhesive sheet suitable for distribution control and requiring no release paper It is about.

[0002]

2. Description of the Related Art A heat-sensitive recording material utilizing a color reaction between an electron-donating compound and an electron-accepting compound by heat is well known. Since such a thermal recording medium is relatively inexpensive, the recording device is compact, and its maintenance is easy, it is used in a recording medium such as a facsimile machine and various computers, and in a wide range of fields other than that. One of the fields of use thereof is, for example, a heat-sensitive recording adhesive sheet or a heat-sensitive recording tag for a POS (point of sales) system.

Further, due to the recent development of information processing technology and performance of recording equipment, it has become possible to record on a heat-sensitive adhesive sheet at a higher speed than before, but the adhesive layer is protected on the back surface of these adhesive sheets. Since the release paper is attached for the purpose, the roll diameter of the heat-sensitive recording pressure-sensitive adhesive sheet becomes large, and the size of the heat-sensitive recording pressure-sensitive adhesive sheet that can be loaded in the recording device is limited. The number of pressure-sensitive adhesive sheets also decreases, and as the recording speed increases, the heat-sensitive recording pressure-sensitive adhesive sheets must be replaced frequently. Further, the treatment of the release paper that occurs at this time is also a problem, and the ratio of the release paper to the pressure-sensitive adhesive sheet for recording is not small in terms of cost.

Thermosensitive recording adhesive sheets which do not use release paper are disclosed in JP-A-60-54842 and JP-A-1-28058.
No. 4, JP-A No. 2-165989, and JP-A No. 5-15989.
It is proposed in Japanese Patent No. 8541 and Japanese Patent Application Laid-Open No. 6-222717. However, recently, the opportunities for severe use in distribution management applications such as delivery adhesive sheets and aviation baggage tags have increased, and rolls of thermal recording adhesive sheets that do not use release paper have a release layer surface and an adhesive layer surface. If the adhesion of the release layer to the barrier layer is insufficient because of contact, there is a drawback that a part of the release layer is peeled off and adhered to the adhesive layer when particularly strong adhesive force is required. is there. A heat-sensitive recording pressure-sensitive adhesive sheet that does not require release paper and contains a styrene-butadiene-based resin emulsion-polymerized with an emulsifier in order to enhance the adhesion of the release layer to the barrier layer.
Although it is described in Japanese Patent Laid-Open No. 100537, further improvement in adhesion is required. Further, when exposed to high temperature and high humidity conditions, the components of the pressure-sensitive adhesive permeate from the surface of the peeling layer to the heat-sensitive recording layer, resulting in a decrease in color forming ability.

Therefore, the adhesive for heat-sensitive recording has no problem even when used under severe conditions such as distribution management, is adaptable to high-speed printing, has excellent recording suitability, and is advantageous in terms of cost. Sheets are strongly requested.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure-sensitive adhesive sheet for heat-sensitive recording which does not require release paper and has excellent adhesion of the release layer to the barrier layer and excellent recording density and recording runnability. It is in.

[0007]

[Means for Solving the Problems] A pressure-sensitive adhesive sheet for heat-sensitive recording which does not require release paper, in which a heat-sensitive recording layer, a barrier layer and a release layer are sequentially provided on one side of a support and an adhesive layer is provided on the back side. As one means for solving the problems, the present invention is to contain a self-emulsion-polymerized acrylic resin and polyvinyl alcohol in the barrier layer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a barrier layer containing a self-emulsion-polymerized acrylic resin as an aqueous resin and polyvinyl alcohol is formed on a thermosensitive recording layer, and then a release layer is formed on the barrier layer. By doing so, the releasing effect of the release layer on the adhesive layer is enhanced, and at the same time, the adhesiveness of the release layer to the barrier layer is excellent. A usual resin emulsion-polymerized by using an emulsifier, that is, a latex has a drawback that the emulsifier in the latex significantly lowers the adhesion of the release layer to the barrier layer.

Although the amount of the self-emulsion-polymerized acrylic resin used is not particularly limited, it is 1 with respect to the total solid amount of the barrier layer.
If it is less than 0% by weight, the adhesion of the release layer to the barrier layer may be insufficient, and if it exceeds 50% by weight, the components of the pressure-sensitive adhesive may permeate into the recording layer and the coloring ability may be deteriorated. About 10 to 50% by weight is particularly preferable. Also, the amount of polyvinyl alcohol used is not particularly limited, but if it is less than 10 wt% with respect to the total solid amount of the barrier layer, the release effect of the release layer on the adhesive layer may not be enhanced, and 80 wt% If it exceeds, the adhesion of the release layer to the barrier layer may not be sufficient, and about 10 to 80% by weight is particularly preferable. As the adhesive strength of the adhesive layer to the release layer,
0.5 according to the 180 ° peeling method described in JIS Z 0237
It is preferably about 10 to 10 g / cm.

The self-emulsion polymerized acrylic resin is a hydrophobic acrylic resin such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. The system monomers are (meth) acrylic acid, itaconic acid, maleic acid,
2-Aminoethyl (meth) acrylate, 2- (N-dimethylamino) ethyl (meth) acrylate, (meth)
It is obtained by a radical polymerization method after emulsifying with a hydrophilic monomer such as 2-hydroxyethyl acrylate or glycidyl (meth) acrylate. In particular, a nonionic self-emulsion-polymerized acrylic resin is preferable. The molecular weight of the self-emulsion-polymerized acrylic resin is 10,000 to 10
It is about 0,000.

As the polyvinyl alcohol used for the barrier layer, there are partially (fully) saponified polyvinyl alcohols having a degree of polymerization of about 300 to 3000 and various modified polyvinyl alcohols. Among them, acetoacetyl modified polyvinyl alcohols and diacetones are preferred. Modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, and silicon-modified polyvinyl alcohol are particularly preferred for exhibiting the effects of the present invention.

The barrier layer is a thermosensitive recording solution prepared by mixing and stirring a self-emulsion-polymerized acrylic resin latex, a polyvinyl alcohol aqueous solution, and optionally the following auxiliary agents in water as a medium. It is formed by coating and drying on the layer.

As an auxiliary agent that can be added to the coating liquid for the barrier layer, colloidal silica, calcium carbonate, zinc oxide, aluminum oxide, aluminum hydroxide, kaolin, pigments such as urea-formalin resin filler, zinc stearate and steer. Calcium phosphate, polyethylene wax,
Examples thereof include carnauba wax, waxes such as paraffin wax and ester wax, polyamide epoxy resins, urea-formalin resins, melamine-formalin resins, curing agents such as chitosan, fluorescent dyes and coloring dyes. Above all,
Curing agents such as polyamide epoxy resin, urea-formalin resin, melamine-formalin resin and chitosan are highly effective in improving the adhesion of the release layer to the barrier layer. The solid amount is not particularly limited, but is preferably about 0.5 to 20% by weight based on the total solid amount of the barrier layer.

In the present invention, the heat-sensitive recording layer, the barrier layer and the release layer are sequentially provided on one side of the support, so that the release paper is not required even if the adhesive layer is provided on the back side of the support. Since at least the peeling layer is formed after providing the heat-sensitive recording layer, the peeling layer is coated with a coating liquid for a peeling layer containing an ultraviolet ray or electron beam curable silicone compound as a main component on the barrier layer, and then the ultraviolet ray or electron beam is applied. It is preferable to irradiate with and cure to form the surface because fog on the background is less likely to occur.

Specific examples of these silicone compounds include a mixed composition of a mercapto group-containing organopolysiloxane and a vinyl group-containing organopolysiloxane, an acrylic group, a methacrylic group or a cinnamoyl group-containing organopolysiloxane composition, a maleimide group or Phenylmaleimide group-containing organopolysiloxane composition, mixed composition of azido group-containing organopolysiloxane and vinyl group-containing organopolysiloxane, thioacryl group, thiomethacryl group or thiocinnamoyl group-containing organopolysiloxane composition, acrylamide group, methacryl group Examples thereof include an amide group- or cinnamoylamide group-containing organopolysiloxane composition, and an epoxy group-containing organopolysiloxane utilizing UV-initiated cationic polymerization and photodegradation-initiated And the like can also be used in the mixed composition of the diazonium Lewis acid salt. In the case of UV curing, a curing initiator is required. Specific examples of the curing initiator include benzoyl alkyl ether and its derivatives, acetophenone and its derivatives, thioxanthone and its derivatives, and the like.

The pressure-sensitive adhesive and the removable pressure-sensitive adhesive used in the pressure-sensitive adhesive layer are not particularly limited, and examples of the pressure-sensitive adhesive include natural rubber and acrylic resin-based pressure-sensitive adhesives. For example, a styrene-isoprene-styrene block copolymer or the like is preferably used because it has a high cohesive force even with a low molecular weight, but a two-component cross-linking acrylic pressure-sensitive adhesive is more preferable. When this type is used in combination with an appropriate cross-linking agent such as an epoxy derivative, since the pressure-sensitive adhesive is not cross-linked, the pressure-sensitive adhesive penetrates into the support, so that the adhesive strength of the pressure-sensitive adhesive to the support is improved. When the pressure-sensitive adhesive is obtained, and the crosslinking of the pressure-sensitive adhesive progresses with time, the cohesive force is increased, and removability comes to occur. Further, in this type, it is easy to control the adhesive strength and removability by selecting the type of acrylic used and the crosslinking agent.

The heat-sensitive recording method utilizing the color reaction of the electron-donating compound and the electron-accepting compound to which the present invention is applied includes, for example, a combination of a leuco dye and a color former, a combination of a diazonium salt and a coupler, Iron, a combination of a transition element such as cobalt and a chelate compound, a combination of an aromatic isocyanate compound and an imino compound, and the like,
A combination of a leuco dye and a color-developing agent is preferably used because of its excellent color density. Hereinafter, the pressure-sensitive adhesive sheet for a heat-sensitive recording layer using a leuco dye and a coloring agent will be described in detail.

Various known leuco dyes and coloring agents can be used. Specific examples of leuco dyes include:
For example: 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-methylphenyl)
Blue-coloring dye such as -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (N-ethyl-)
N-p-tolyl) amino-7-N-methylanilinofluorane, 3-diethylamino-7-anilinofluorane, 3-diethylamino-7-dibenzylaminofluorane, and other green-coloring dyes, 3-cyclohexyl Amino-6
-Chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane, rhodamine (o-chloroanilino) lactam, 3-diethylamino-6,8-dimethylfluorane, etc. Red coloring dye, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluorane,
3- (N-methyl-N-cyclohexyl) amino-6-
Methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di (n-
Butyl) amino-6-methyl-7-anilinofluorane, 3-di (n-pentyl) amino-6-methyl-7-
Anilinofluorane, 3-diethylamino-7- (o-
Chlorophenylamino) fluorane, 3-di (n-butyl) amino-7- (o-fluorophenylamino) fluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluorane, 3 -(N-ethyl-N
-Tetrahydrofurfurylamino) -6-methyl-7-
Black coloring dyes such as anilinofluorane, 3-diethylamino-6-chloro-7-anilinofluorane and 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3
-Bis [1- (4-methoxyphenyl) -1- (4-dimethylaminophenyl) ethylene-2-yl] -4,
5,6,7-Tetrachlorophthalide, 3-p- (p-dimethylaminoanilino) anilino-6-methyl-7-chlorofluorane, 3-p- (p-chloroanilino) anilino-6-methyl- 7-chlorofluorane, 3,6-bis (dimethylamino) fluorene-9-spiro-3'-
Dyes having an absorption wavelength in the near infrared region such as (6′-dimethylamino) phthalide are of course not limited to these, and two or more kinds can be used in combination.

Specific examples of the coloring agent include, for example, 4,4 '.
-Isopropylidenediphenol, 4,4'-cyclohexyl
Xylidene diphenol, 2,2-bis (4-hydroxy)
Cyphenyl) -4-methylpentane, hydroquinone mono
Benzyl ether, benzyl 4-hydroxybenzoate,
2,4'-dihydroxydiphenyl sulfone, 4,4 '
-Dihydroxydiphenyl sulfone, 4-hydroxy-
4'-isopropoxydiphenyl sulfone, bis (3-
Allyl-4-hydroxyphenyl) sulfone, 4-hydr
Roxy-4'-methyldiphenyl sulfone, bis (p-
Hydroxyphenyl) butyl acetate, bis (p-hydroxy)
Cyphenyl) methyl acetate, 1,1-bis (4-hydroxy)
Cyphenyl) -1-phenylethane, 1,4-bis [α
-Methyl-α- (4'-hydroxyphenyl) ethyl]
Benzene, 1,3-bis [α-methyl-α- (4'-hi
Phenolic properties such as droxyphenyl) ethyl] benzene
Compound, N- (p-tolylsulfonyl) carbamoyl acid
p-cumylphenyl ester, N- (o-tolyl) -p
-Tolylsulfoamide, 4,4'-bis (Np-tri
Lesulfonylaminocarbonylamino) diphenylmethane
-SO in the molecule such as ₂Having an NH-bond, p-q
Zinc lolobenzoate, 4- [2- (p-methoxyphenoxy)
Si) Ethyloxy] zinc salicylate, 4- [3- (p-
Tolylsulfonyl) propyloxy] zinc salicylate,
5- [p- (2-p-methoxyphenoxyethoxy) qua
Mil] zinc salts of aromatic carboxylic acids such as salicylic acid
You can

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

The heat-sensitive recording layer may contain a storability improver for increasing the storage stability of the recorded image and a sensitizer for increasing the recording sensitivity. Specific examples of such a shelf stability improver include 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,
2'-ethylidene bis (4,6-di-tert-butylphenol), 4,4'-thiobis (2-methyl-6-tert)
-Butylphenol), 4-4'-butylidene bis (6
-Tert-butyl-m-cresol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4)
-Hydroxy-5-cyclohexylphenyl) butane,
4,4'-thiobis (3-methylphenol), 2,2
-Bis (4-hydroxy-3,5-dibromophenyl)
Propane, hindered phenol compounds such as 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,4-diglycidyloxybenzene, 4,4 ′
-Epoxy compounds such as diglycidyloxydiphenyl sulfone, 4-benzyloxy-4 '-(2-methylglycidyloxy) diphenyl sulfone, diglycidyl terephthalate, cresol novolac type epoxy resin, phenol novolac type epoxy resin, and bisphenol A type epoxy resin Etc.

Specific examples of the sensitizer include stearic acid amide, methylenebisstearic acid amide, dibenzyl terephthalate, benzyl p-benzyloxybenzoate, 2-naphthylbenzyl ether, m-terphenyl, p-benzylbiphenyl. , P-tolylbiphenyl ether, di (p-methoxyphenoxyethyl) ether, 1,2-di (3-methylphenoxy) ethane, 1,
2-di (4-methylphenoxy) ethane, 1,2-di (4-methoxyphenoxy) ethane, 1,2-di (4-
Chlorophenoxy) ethane, 1,2-diphenoxyethane, 1- (4-methoxyphenoxy) -2- (3-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, 1,4-di (phenylthio) butane, p −
Acetotoluidide, p-acetophenetidide, N-acetoacetyl-p-toluidine, di (β-biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1-isopropylphenyl-2-phenylethane, dioxalate. Examples include -p-chlorobenzyl ester, oxalic acid di-p-methylbenzyl ester, and oxalic acid dibenzyl ester. The amount of these preservative-improving agents and sensitizers used is not particularly limited, but it is generally desirable to adjust the amount to 4 parts by weight or less per 1 part by weight of the color developing agent.

The heat-sensitive recording layer generally uses water as a dispersion medium,
Leuco dye, color former, sensitizer, storability improver, etc. together or separately, ball mill, attritor,
The average particle size is 2μ with a stirring and crushing machine such as a sand mill.
After being finely dispersed so as to have a particle size of m or less, a thermosensitive recording layer coating liquid prepared by adding an adhesive is applied on a support and dried.

Specific examples of the adhesive added to the heat-sensitive recording coating liquid include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, and acetoacetyl. Group-modified polyvinyl alcohol, silicon polyvinyl alcohol, diisobutylene-maleic anhydride copolymer salt, styrene-maleic anhydride copolymer salt, ethylene-acrylic acid copolymer salt, styrene-acrylic acid copolymer salt, urea resin , Melamine resin, amide resin, polyurethane latex, styrene-butadiene latex and the like. The amount of the adhesive used is about 5 to 30% by weight based on the total solid content of the thermosensitive recording layer.

Further, various auxiliary agents can be added to the heat-sensitive recording layer coating liquid, if necessary. For example, kaolin,
Light (heavy) calcium carbonate, calcined kaolin, titanium oxide, magnesium carbonate, aluminum hydroxide, amorphous silica, pigments such as urea-formalin resin filler, sodium dioctyl sulfosuccinate, sodium dodecylbenzene sulfonate, sodium lauryl alcohol sulfate Surfactants such as fatty acid metal salts, waxes such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax and ester wax, defoaming agents and coloring dyes.

The method for forming the heat-sensitive recording layer and the barrier layer is not particularly limited, and examples thereof include air knife coating, varibar blade coating, pure blade coating, gravure coating, rod blade coating, short dwell coating, curtain coating and die coating. After coating and drying the coating liquid for heat-sensitive recording layer by a suitable coating method of
Further, the coating liquid for the barrier layer is formed on the thermosensitive recording layer by a method such as coating and drying. As the support, paper (neutral paper,
Acidic paper), plastic film, synthetic paper, non-woven fabric, metal vapor deposition, etc. are appropriately selected and used. Also,
The coating amount of the heat-sensitive recording layer coating liquid is 2 to 12 g / m on a dry weight basis.
² , preferably about 3 to 7 g / m ² , and the coating amount of the coating liquid for the barrier layer is 0.5 to 10 g / m ^{2 on a} dry weight basis, preferably 1
It is about 5 g / m ² .

The method for forming the peeling layer and the adhesive layer is not particularly limited, and the same method as the method for forming the heat-sensitive recording layer and the barrier layer can be used. The coating amount of the release layer is 0.3 to 7 g / m ² in solid amount, preferably 0.5 to 5
It is about g / m ² . Further, the coating amount of the adhesive layer is 3 to 50 g / m ^{2 in} solid amount, preferably about 5 to 30 g / m ² . The release layer and the pressure-sensitive adhesive layer are coated on the barrier layer or the entire back surface of the support, but they may be partially coated. Further, as a method for forming the adhesive layer, a method of forming the adhesive layer on the release layer, winding it, and transferring it to the back surface side of the support is also possible.

Further, it is also possible to carry out smoothing treatment such as super calendering after forming each layer. The surface of the barrier layer preferably has a Bekk smoothness of 500 seconds or more. If necessary, a barrier layer may be provided between the support and the pressure-sensitive adhesive layer to further improve the storage stability, or an undercoat layer containing an organic or inorganic oil-absorbing pigment as a main component between the support and the recording layer. If necessary, various other well-known techniques in the field of heat-sensitive recording material manufacturing, such as the provision of perforations, perforation on the adhesive sheet, and part coating of the adhesive by printing method excluding the edges and perforations, etc. It can be added.

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show a weight part and weight%, respectively.

Example 1 Preparation of Coating Liquid for Undercoat Layer 100 parts of calcined clay [trade name: Ansilex, manufactured by EMC, oil absorption amount 110 ml / 100 g], 1 part of 40% aqueous solution of sodium polyacrylate, solid concentration 48% 14 parts of the styrene-butadiene latex, 50 parts of a 10% aqueous solution of polyvinyl alcohol, and 100 parts of water were mixed and stirred to obtain a coating liquid for undercoat layer.

Preparation of solution A 3-di (n-butyl) amino-6-methyl-7-anilinofluorane 10 parts, 5% aqueous solution of methylcellulose 5
Parts of the composition and 40 parts of water were pulverized with a sand mill until the average particle size became 1.0 μm.

Preparation of solution B A composition consisting of 30 parts of 4-hydroxy-4'-isopropoxydiphenyl sulfone, 5 parts of a 5% aqueous solution of methylcellulose and 80 parts of water was pulverized with a sand mill until the average particle diameter became 1.0 μm. .

Preparation of liquid C A composition consisting of 20 parts of 1,2-di (3-methylphenoxy) ethane, 5 parts of a 5% aqueous solution of methylcellulose and 55 parts of water was ground by a sand mill until the average particle diameter became 1.0 μm. did.

Formation of Undercoat Layer The undercoat layer coating solution is applied to one side of 64 g / m ² of neutral paper (support) so that the coating amount after drying is 9 g / m ² and dried to form the undercoat layer. Formed.

Formation of thermal recording layer. Heat-sensitive obtained by mixing and stirring 55 parts of A solution, 115 parts of B solution, 80 parts of C solution, 160 parts of 10% aqueous solution of polyvinyl alcohol, 20 parts of styrene-butadiene latex having a solid concentration of 50% and 17 parts of light calcium carbonate. The thermosensitive recording layer was formed by coating and drying the coating liquid for a recording layer on the above-mentioned undercoat layer so that the coating amount after drying was 6 g / m ² .

Formation of Barrier Layer 10% of acetoacetyl-modified polyvinyl alcohol (trade name: Gocefimer Z200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
Aqueous solution 500 parts and nonionic self-emulsion polymerized acrylic latex [trade name: Dicknard RT2
2, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] 80
Part and kaolin [Product name: UW-90, manufactured by EC]
The coating liquid for the barrier layer obtained by mixing and stirring 80 parts of 50% aqueous dispersion of the above was coated on the thermosensitive recording layer at a coating amount of 3 g /
After coating and drying so as to be m ² , the surface was smoothed by a super calender to form a barrier layer.

Formation of Release Layer Solventless UV curable silicone compound [1.5 mol%
30 parts of mercapto group-containing organopolysiloxane and 1.5 mol% vinyl group-containing organopolysiloxane 70
Mixed composition consisting of parts, manufactured by Shin-Etsu Chemical Co., Ltd.] 100 parts,
A coating amount of 1.0 g / m 2 of the release layer coating liquid obtained by mixing and stirring 3 parts of a curing initiator (acetophenone) was applied on the barrier layer.
After coating so as to be ² , the ultraviolet ray was irradiated to form a release layer.

Formation of adhesive layer An acrylic resin type adhesive emulsion for strong adhesion is applied on the back side of the support so that the coating amount after drying is 20 g / m ² and dried to form an adhesive layer, which is then wound up. A heat-sensitive recording adhesive sheet having no release paper was obtained.

Example 2 In the formation of the barrier layer of Example 1, acetoacetyl-modified polyvinyl alcohol [trade name: Gocefimer Z
-200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.], 10% aqueous solution 50
Instead of 0 part, diacetone-modified polyvinyl alcohol [trade name: D polymer D-3480, manufactured by Unitika Ltd.]
A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 500 parts of a 10% aqueous solution of 10% of was used.

Example 3 In the formation of the barrier layer of Example 1, acetoacetyl-modified polyvinyl alcohol [trade name: Gocefimer Z
-200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.], 10% aqueous solution 50
A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 500 parts of a 10% aqueous solution of carboxy-modified polyvinyl alcohol (trade name: Gohsenal T215: manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was used instead of 0 part. .

Example 4 In the formation of the barrier layer of Example 1, acetoacetyl-modified polyvinyl alcohol [trade name: Gocefimer Z
-200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] 10% aqueous solution 40
Instead of 0 part, 10% of silicon-modified polyvinyl alcohol (trade name: R polymer R1130: manufactured by Kuraray Co., Ltd.)
A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 300 parts of the aqueous solution was used.

Example 5 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] In the same manner as in Example 1 except that 80 parts of a nonionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RT14, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] was used in place of An adhesive sheet for heat-sensitive recording was obtained.

Example 6 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] Instead of 80%, a nonionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RT22-2, solid concentration 40%, Dainippon Ink and Chemicals, Inc.] was used except that 80 parts was used. A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1.

Example 7 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] The same as in Example 1 except that 80 parts of an anionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RT22-3, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] was used instead of To obtain a heat-sensitive recording pressure-sensitive adhesive sheet.

Example 8 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] Example 1 except that 80 parts of a weak anion type self-emulsion-polymerized acrylic latex [trade name: Dicknard RT22-4, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] was used in place of In the same manner, a thermosensitive recording adhesive sheet was obtained.

Example 9 In the formation of the barrier layer of Example 1, 80 parts of nonionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] In the same manner as in Example 1 except that 80 parts of nonionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RS292, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] was used in place of An adhesive sheet for heat-sensitive recording was obtained.

Example 10 In the formation of the barrier layer of Example 3, in the coating liquid for the barrier layer,
Further, a heat-sensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 80 parts of a 12.5% aqueous solution of an epoxy polyamide resin [trade name: WS570, manufactured by Nippon PMC] was added.

Example 11 In the formation of the barrier layer of Example 4, in the barrier layer coating liquid,
Epoxy polyamide resin [Product name: Euramine P-
5600, manufactured by Mitsui Chemicals, Inc.] A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 30 parts of a 30% aqueous solution was added.

Example 12 In the formation of the barrier layer of Example 4, in the barrier layer coating liquid,
Furthermore, 10% of chitosan (trade name: OTS, manufactured by Kuraray Co., Ltd.)
A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 80 parts of an aqueous solution was added.

Example 13 In the formation of the barrier layer of Example 1, acetoacetyl-modified polyvinyl alcohol [trade name: Gocefimer Z
-200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] 10% aqueous solution 40
Instead of 0 part, a 10% aqueous solution 3 of partially saponified polyvinyl alcohol (trade name: PVA-210, manufactured by Kuraray Co., Ltd.)
A heat-sensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts was used.

Comparative Example 1 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] Instead of acetoacetyl modified polyvinyl alcohol [trade name: Gocefimer Z-20
0, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.] was used to obtain a thermosensitive recording pressure-sensitive adhesive sheet in the same manner as in Example 1 except that 320 parts of a 10% aqueous solution was used.

Comparative Example 2 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion-polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] Instead of emulsion-polymerized styrene-
A thermosensitive recording pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 67 parts of butadiene-based latex [trade name: L-1571, solid concentration 48%, manufactured by Asahi Kasei Kogyo Co., Ltd.] was used.

Comparative Example 3 In the formation of the barrier layer of Example 1, 80 parts of a nonionic self-emulsion polymerized acrylic latex [trade name: Dicknard RT22, solid concentration 40%, manufactured by Dainippon Ink and Chemicals, Inc.] Instead of colloidal silica-containing anionic styrene-acrylic latex [trade name:
Movinyl 8021, solid concentration 45%, Hoechst Synthetic Co., Ltd.] was used in the same manner as in Example 1 except that 71 parts were used to obtain a heat-sensitive adhesive sheet.

The heat-sensitive recording pressure-sensitive adhesive sheet thus obtained was subjected to the following evaluation tests, and the results are shown in Table 1.

[Coloring property] Thermosensitive evaluation machine [Product name: TH-P
MD, manufactured by Okura Electric Co., Ltd., and applied energy 0.50
Each thermosensitive recording pressure-sensitive adhesive sheet was recorded at mJ / dot, and the density of the recording portion was measured in a visual mode with a Macbeth densitometer [RD-914 type, manufactured by Macbeth Co.].

[Adhesive Force of Adhesive Layer to Release Layer] Each of the obtained pressure-sensitive adhesive recording sheets was formed into a strip having a width of 5 cm and a length of 10 cm, and the release layer surface and the adhesive layer surface were bonded together at 10 kgf / cm ² . After pressurization, 1 described in JIS Z0237
The adhesive strength was measured according to the 80 ° peeling method.

[Adhesion of Release Layer to Barrier Layer] The release layer surface of each of the obtained heat-sensitive adhesive sheets was strongly rubbed with a fingertip 20 times, and the adhesion of the release layer to the barrier layer was visually evaluated. Evaluation criteria *: The surface of the release layer is not peeled at all. ⊚: The surface of the release layer peels off very slightly. ◯: The surface of the release layer is slightly peeled off. Δ: The surface of the release layer is slightly peeled off. X: The surface of the release layer is peeled off.

[Abrasion resistance of lees to thermal head] After printing with the above [color development], the state of the lees produced on the thermal head was visually judged. Evaluation criteria ⊚: No adhesion of lees was observed on the thermal head. ◯: A slight amount of residue was observed on the thermal head. X: A considerable amount of lees are observed on the thermal head.

[0059]

[Table 1]

[0060]

As shown in [Table 1], the pressure-sensitive adhesive sheet for heat-sensitive recording of the present invention, which does not require release paper, has excellent adhesion of the release layer to the barrier layer, and recording sensitivity and recording runnability. It has an excellent effect.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI B41M 5/18 101E (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/26 C09J 7/02 C09J 105 / 08 C09J 129/04 C09J 133/00

Claims (5)

(57) [Claims] 1. A heat-sensitive recording layer, a barrier layer, and one surface side of a support,
In the pressure-sensitive adhesive sheet for heat-sensitive recording that does not require release paper and is provided with a release layer in sequence and an adhesive layer is provided on the back side, the barrier layer contains a self-emulsion-polymerized acrylic resin and polyvinyl alcohol. Adhesive sheet for heat-sensitive recording. 2. The adhesive for heat-sensitive recording according to claim 1, wherein the polyvinyl alcohol in the barrier layer is at least one selected from acetoacetyl-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol and silicon-modified polyvinyl alcohol. Sheet. 3. The pressure-sensitive adhesive for heat-sensitive recording according to claim 1, wherein the barrier layer further contains at least one selected from polyamide epoxy resin, urea-formalin resin, melamine-formalin resin and chitosan as a curing agent. Sheet. 4. The barrier layer contains a self-emulsion-polymerized acrylic resin in an amount of 10 to 50% by weight, based on the total solid amount of the barrier layer, and polyvinyl alcohol, based on the total solid amount of the barrier layer. The heat-sensitive recording pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive sheet contains -80% by weight. 5. The release layer is a layer obtained by applying a release layer coating liquid containing an ultraviolet ray or electron beam curable silicone compound as a main component onto the barrier layer and then irradiating the barrier layer with ultraviolet rays or an electron beam to cure. The heat-sensitive recording pressure-sensitive adhesive sheet according to claim 1.