JP2006342208A - Heat-sensitive adhesive and adhesive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-sensitive adhesive and a heat-sensitive adhesive material solving drawbacks seen in conventional heat-sensitive adhesives and excellent in tackiness to rough surfaces such as of corrugated boards and blocking resistance, particularly, to provide such a heat-sensitive adhesive and a heat-sensitive adhesive material causing no peeling off corrugated boards with the lapse of time. <P>SOLUTION: The heat-sensitive adhesive essentially comprising a thermoplastic material and a hot-melt material that melts on heating, wherein the hot-melt material includes a polymeric hot-melt material that is obtained by copolymerization between, as the essential components, (a) at least one benzophenone-based monomer selected from the compounds of the formula(1) and (b) a vinyl monomer copolymerizable therewith. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat-sensitive pressure-sensitive adhesive and a heat-sensitive pressure-sensitive adhesive material that are non-tacky at normal temperature but exhibit tackiness upon heating and that remain tacky even after the tackiness is developed.

  In recent years, adhesive materials for labels have been used as labels for logistics labels, price display labels, product display (barcode) labels, quality display labels, weighing display labels, advertising labels (stickers), etc. That is increasing. There are various recording methods such as an inkjet recording method, a thermal recording method, and a pressure sensitive recording method. Conventionally, a general pressure-sensitive adhesive sheet having a structure in which a pressure-sensitive adhesive layer and release paper are laminated on the surface opposite to the information recording surface of a label can be simply attached by simply peeling off the release paper at the time of bonding. Because it is widely used.

  However, the adhesive material having a general configuration is used by peeling the release paper, but the peeled release paper is hardly collected and reused, and is almost always disposed of. Therefore, in recent years, a heat-sensitive adhesive material that does not exhibit adhesiveness at room temperature and does not require a release paper has attracted attention.

  In addition, as described in “Adhesion Handbook”, 12th edition, pages (131-135), published in 1980, published by Polymer Publishing Co., Ltd. (Non-Patent Document 1), Is a material containing a heat-meltable substance such as a thermoplastic resin and a solid plasticizer and, if necessary, a tackifier. Thermoplastic resins impart adhesive strength and adhesive strength, and hot-melt materials are solid at room temperature (24 ° C), so they do not impart plasticity to resins, but melt by heating to swell the resin. Alternatively, it is softened to develop adhesiveness. The tackifier also works to improve the tackiness. Since the hot-melt material in the heat-sensitive adhesive is slowly crystallized after being melted by heating, the adhesiveness is maintained for a long time even after the heat source is removed. However, the conventional heat-sensitive adhesive has a problem that the adhesive strength after the development of adhesiveness decreases with time.

  In order to solve such a problem, for example, in JP-A-6-57226 (Patent Document 1) and JP-A-6-57233 (Patent Document 2), the glass transition point is 0 as a thermoplastic resin. It has been proposed to use an ethylene-vinyl acetate copolymer having a glass transition temperature of -5 ° C or higher, or a thermoplastic resin having a glass transition point of -5 ° C or higher (excluding an ethylene-vinyl acetate copolymer). However, although the adhesive strength to a stainless steel plate or the like has a relatively good result, the adhesive strength to a vinyl chloride wrap, a polyolefin wrap, or the like has not yet reached a practical level.

  The use of the heat-sensitive adhesive is not particularly limited, but for example, a pressure-sensitive adhesive material in which a layer made of a heat-sensitive adhesive is provided on one side of the base material, and in addition to the heat-sensitive pressure-sensitive adhesive layer, heat-sensitive color development on the other side of the base material A heat-sensitive adhesive material provided with a layer can be mentioned. These are expected to be used for so-called food POS, in which various food products are packaged in wraps and pasted on the wraps.

  However, conventional heat-sensitive adhesives have insufficient adhesion to vinyl chloride wrap, polyolefin wrap, and the like, which hinders the practical application of heat-sensitive adhesive materials themselves. Japanese Patent Application Laid-Open No. 9-265260 (Patent Document 3) discloses a heat-sensitive adhesive material in which an undercoat layer containing non-foamed hollow particles is provided between a base material and a heat-sensitive color developing layer. A heat-sensitive adhesive using dicyclohexyl acid as a solid plasticizer has been proposed. Since this thermosensitive adhesive material is provided with an undercoat layer, it is at a level that is almost satisfactory in terms of improving the thermal sensitivity of the thermosensitive coloring layer and preventing the background coloring of the thermosensitive coloring layer that may occur during thermal activation. Regarding the blocking property that occurs when the materials are overlapped, it occurs at about 40 ° C. and does not reach a practical level.

  JP-A-2003-206455 (Patent Document 4) and JP-A-2002-38123 (Patent Document 5) propose a heat-sensitive adhesive (delay tack-type adhesive) using benzophenone as a solid plasticizer. However, although it has adhesion to mirror surfaces such as polyolefin and glass, adhesion to rough surfaces such as corrugated cardboard is weak, and there is a problem that the adhesive strength decreases over time after pasting on cardboard etc. This is a major impediment to practical use for logistics. Moreover, there exists a problem that blocking generate | occur | produces in a 60 degreeC environment.

  Japanese Patent No. 3556414 (Patent Document 6) proposes a delayed tack paste using benzotriazole as a solid plasticizer. This is relatively excellent in blocking properties, and a long-term stable adhesive force can be maintained if the adherend is made of a material such as paper, glass or metal, or a so-called polyolefin resin such as polypropylene or polyethylene. However, the adhesive strength to rough surfaces such as corrugated cardboard is weak, and there is a problem that the adhesive strength decreases with time after being attached to corrugated cardboard. Yes.

JP-A-6-57226 JP-A-6-57233 JP-A-9-265260 JP 2003-206455 A JP 2002-38123 A Japanese Patent No. 3556414 "Adhesion Handbook" 12th edition, pages (131-135), published in 1970

  An object of the present invention is to provide a heat-sensitive pressure-sensitive adhesive and a heat-sensitive pressure-sensitive adhesive material that overcome the drawbacks found in conventional heat-sensitive pressure-sensitive adhesives and are excellent in adhesion to rough surfaces such as cardboard and blocking resistance. In particular, it is to provide a heat-sensitive adhesive and a heat-sensitive adhesive material that do not peel off over time on cardboard.

As a result of intensive studies in order to solve the above problems, the present inventors have found that the above problems can be solved by using a compound represented by the following general formula. It came to completion.
That is, the said subject is solved by following (1)-(7) of this invention.
(1) “At least one benzophenone-based monomer selected from the following formula (1) in a heat-sensitive adhesive mainly comprising at least a thermoplastic resin and a heat-meltable material that melts when heated: A heat-sensitive adhesive comprising a polymer hot-melt material obtained by polymerizing (a) and a copolymerizable vinyl monomer (b) as an essential component.

（式（１）中、Ｒ^１１は水素原子、炭素数１〜６のアルキル基又はアルコキシル基を示す。Ｒ^１２は炭素数１〜１０のアルキレン基又はオキシアルキレン基を示し、ｍ^１は０又は１を示す。Ｒ^１３は水素原子又は低級アルキル基を示す。Ｘ^１はエステル結合、アミド結合、エーテル結合、またはウレタン結合を示す。）」；
（２）「該高分子熱溶融性物質が熱可塑性樹脂（粘着剤）１００部に対し、５０〜５００部含有されることを特徴とする前記第（１）項に記載の感熱性粘着剤」；
（３）「該感熱性粘着剤中に、さらに粘着付与剤を含有することを特徴とする前記第（１）項又は第（２）項に記載の感熱性粘着剤」；
（４）「前記第（１）項乃至第（３）項のいずれかに記載の感熱性粘着剤からなる層を基材の片面に設けてなることを特徴とする感熱性粘着材料」；
（５）「前記基材の該感熱性粘着剤層の反対面にロイコ染料と顕色剤を主成分とする感熱記録層が設けられたことを特徴とする前記第（４）に記載の感熱性粘着材料」；
（６）「該感熱性粘着剤層と基材との間に、微小中空粒子とバインダーを主成分とする中間層が設けられたことを特徴とする前記第（４）項又は第（５）項に記載の感熱性粘着材料」；
（７）「ラベル状、シート状、及びロール状のいずれかである前記第（４）項乃至第（６）項のいずれかに記載の感熱性粘着材料」。

(In Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group. R ¹² represents an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group, and m ¹ is 0 or And R ¹³ represents a hydrogen atom or a lower alkyl group, and X ¹ represents an ester bond, an amide bond, an ether bond, or a urethane bond.
(2) "The heat-sensitive adhesive according to (1) above, wherein the polymer hot-melt material is contained in an amount of 50 to 500 parts per 100 parts of thermoplastic resin (adhesive)". ;
(3) "The heat-sensitive adhesive according to item (1) or (2), wherein the heat-sensitive adhesive further contains a tackifier";
(4) “Thermosensitive adhesive material, wherein a layer made of the thermosensitive adhesive according to any one of the items (1) to (3)” is provided on one side of the substrate ”;
(5) The thermosensitive recording material according to (4), wherein a thermosensitive recording layer mainly comprising a leuco dye and a developer is provided on the opposite surface of the thermosensitive adhesive layer of the substrate. Adhesive material ";
(6) The item (4) or (5), wherein an intermediate layer mainly comprising fine hollow particles and a binder is provided between the heat-sensitive adhesive layer and the substrate. The heat-sensitive adhesive material according to item ";
(7) “The heat-sensitive adhesive material according to any one of (4) to (6)”, which is any one of a label shape, a sheet shape, and a roll shape.

  ADVANTAGE OF THE INVENTION According to this invention, the heat-sensitive adhesive and heat-sensitive adhesive label which overcome the fault seen in the conventional heat-sensitive adhesive, the adhesiveness with respect to a cardboard, especially the adhesiveness with time, and were excellent in blocking resistance were improved. Is provided.

  A heat-sensitive adhesive is generally a thermoplastic resin, which is a main component that imparts adhesive strength and adhesive strength by heating, and a polymer thermomeltable substance (co-polymer) that melts by heating and develops adhesive properties in the adhesive. Polymer) as a main component.

The heat-sensitive adhesive of the present invention is obtained by copolymerizing the following monomers (a) and (b) as essential components in a heat-sensitive adhesive comprising a thermoplastic resin and a heat-meltable substance. In addition, by containing a high-molecular heat-meltable substance (copolymer), the adherence to each adherend, particularly cardboard, is strong and difficult to peel off over time, and the blocking resistance is improved.
Monomer (a): at least one monomer selected from benzophenone monomers represented by the formula (1).

（式（１）中、Ｒ^１１は水素原子、炭素数１〜６のアルキル基又はアルコキシル基を示す。Ｒ^１２は炭素数１〜１０のアルキレン基又はオキシアルキレン基を示し、ｍ^１は０又は１を示す。Ｒ^１３は水素原子又は低級アルキル基を示す。Ｘ^１はエステル結合、アミド結合、エーテル結合、又はウレタン結合を示す。）

(In Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group. R ¹² represents an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group, and m ¹ is 0 or .X ¹ .R ¹³ is showing a hydrogen atom or a lower alkyl group represented by 1 illustrates an ester bond, an amide bond, an ether bond, or urethane bond.)

As described above, the monomer (a) used in the present invention is at least one selected from benzophenone monomers represented by the formula (1).
In the formula (1), examples of the alkyl group having 1 to 6 carbon atoms (R ¹¹ ) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a s-butyl group, a t-butyl group, and a pentyl group. A hexyl group, preferably an alkyl group having 1 to 4 carbon atoms (more preferably 1 to 2 carbon atoms). Moreover, as a C1-C6 alkoxyl group (R < ¹¹ >), a methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. are mentioned, for example, Preferably it is C1-C4 (more preferably 1-2). Of the alkoxyl group. R ¹¹ is preferably a hydrogen atom.

R ¹¹ may be substituted at any site in the benzene ring substituted with a hydroxyl group, and the preferred substitution position of R ¹¹ is the 3-position or 5-position.

In Formula (1), examples of the alkylene group having 1 to 10 carbon atoms (R ¹² ) include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and an octane group. Examples thereof include a methylene group and a decamethylene group, preferably an alkylene group having 1 to 6 carbon atoms (more preferably an alkylene group having 1 to 4 carbon atoms). Examples of the oxyalkylene group having 1 to 10 carbon atoms (R ¹² ) include an oxymethylene group, an oxyethylene group, and an oxypropylene group.

R ¹² may be substituted at any position in the benzene ring substituted with a hydroxyl group, and the preferred substitution position of R ¹² is the 4-position or 5-position, and the 4-position is particularly preferred.

As a lower alkyl group (R < ¹³ >), a C1-C4 alkyl group is mentioned, for example, Specifically, a C1-C4 alkyl group is mentioned among the said exemplary alkyl groups.

X ¹ represents an ester bond, an amide bond, an ether bond, or a urethane bond. Specifically, —COO—, —OCO—, —NHCO—, —CONH—, —O—, —NHCOO—, — COONH- etc.

m ¹ represents 0 or 1, for example, when m ¹ is 0, it means that X ¹ is directly bonded to a benzene ring substituted with a hydroxyl group without R ^12. is doing. That is, when m ¹ is 0, it means that R ¹² does not exist. On the other hand, when m ¹ is 1, it means that R ¹² is present, for example, that X ¹ is bonded to R ¹² .

  Examples of the benzophenone monomer (a) represented by the formula (1) include 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, and 2-hydroxy-4- (2-acryloyloxy). ) Ethoxybenzophenone, 2-hydroxy-4- (2-methacryloyloxy) ethoxybenzophenone, 2-hydroxy-4- (2-methyl-2-acryloyloxy) ethoxybenzophenone and the like.

The monomer (a) is a known material, and is disclosed in, for example, JP-A Nos. 2003-40937, 2002-363226, 2005-42019 and others. Moreover, it is marketed, for example, can obtain from one company oil and fat industry Co., Ltd., for example. Furthermore, the monomer (a) is a copolymer having a 2-hydroxybenzophenone skeleton and a functional group (hydroxyl group, carboxyl group, amino group, etc.) and a functional group (hydroxyl group, carboxyl group, amino group, etc.). It can be prepared by reacting and bonding a vinyl compound (acrylic acid, methacrylic acid, etc.) (ester bond, amide bond, ether bond, urethane bond, etc.).
The said monomer (a) can be used individually or in combination of 2 or more types.

  The copolymerizable vinyl monomer (b) is not particularly limited as long as it is copolymerizable with the monomer (a), and can be used alone or in combination of two or more. By copolymerizing the polymerizable vinyl monomer (b) with the monomer (a), compatibility with the thermoplastic resin is improved, and stability over time is improved. In addition, the molecular weight of the polymer can be easily adjusted by including the polymerizable vinyl monomer (b) in the hot-melt material.

  The copolymerizable vinyl monomer (b) can be used within a range that does not impair the effects of the present invention. For example, the polymerization amount thereof is 20 to 80% by mass, preferably 25 to 25% with respect to the whole polymer. It is 70 mass%, Most preferably, it is the range of 30-60 mass%.

  Examples of the copolymerizable vinyl monomer (b) that can be used in the present invention include carboxylic acid monomers such as acrylic acid, methacrylic acid, and maleic anhydride; styrene monomers such as styrene and α-methylstyrene; methyl acrylate Acrylate monomers such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate; methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxy Methacrylic acid ester monomers such as ethyl methacrylate and benzyl methacrylate: Vinyl acetate monomers such as vinyl acetate; α, β-unsaturated polybasic acid monoalkyl esters, α, β-unsaturated polybasic acid dialkyl esters, etc. Polybasic acid ester Nomers; alkyl vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; alkoxy polyethylene glycol (n = 1 to 20) (meth) acrylic acid ester and phenoxy polyethylene glycol (n = 1 to 20) (meth) acrylic acid ester It is done. Among these, acrylic acid ester monomers and methacrylic acid ester monomers are preferable, and -C1-4 alkyl esters of acrylic acid and methacrylic acid are particularly preferable.

The value of the weight average molecular weight (Mw) of the polymer hot-melt material (copolymer) is preferably in the range of 1,000 to 100,000, more preferably in the range of 1,000 to 10,000. When the weight average molecular weight (Mw) is less than 1,000, the polymer heat-melting substance (polymer) is likely to bleed out from the thermoplastic resin after being attached to the corrugated cardboard substrate, and the adhesive strength with time decreases. To do. On the other hand, when the weight average molecular weight (Mw) is larger than 100,000, the compatibility between the polymer hot-melt material (copolymer) and the thermoplastic resin is lowered, so that the initial adhesive force is lowered.
In addition, a mass average molecular weight is a polystyrene conversion molecular weight by gel permeation chromatography (GPC).

  The polymer hot-melt material (copolymer) of the present invention can be produced by a conventionally known polymerization method such as a solution polymerization method, a suspension polymerization method or an emulsion polymerization method. For example, when preparing by a solution polymerization method, monomer components (monomer (a) and polymerizable vinyl monomer (b)) are added to an organic solvent such as ethyl acetate, methyl ethyl ketone, and dimethylformamide, and polymerization is performed in the presence of a polymerization initiator. It can be prepared by performing. The organic solvent and polymerization initiator used in the solution polymerization are not particularly limited, and widely known ones can be used.

  Moreover, when preparing by an emulsion polymerization method, it can prepare by emulsifying said monomer component using an emulsifier as needed, and performing emulsion polymerization in presence of a polymerization initiator. The emulsifier and polymerization initiator used in the emulsion polymerization are not particularly limited, and widely known ones can be used.

Two or more kinds of the polymer hot-melting substances (copolymers) may be mixed and used.
In the heat-sensitive adhesive of the present invention, the content of the compound that is a heat-meltable substance in the heat-sensitive adhesive is 50 to 500 parts, more preferably 100 to 400 parts, relative to 100 parts of the adhesive. Used in When the content of the above compound, which is a heat-meltable substance, is 500 parts or more with respect to 100 parts of the pressure-sensitive adhesive, the adhesive force may be lowered. In addition, when combined with a low Tg resin, if the content of the above-mentioned general formula compound is less than 50 parts relative to 100 parts of the pressure-sensitive adhesive, there are problems in storage such as an adhesive force appearing at a normal storage environment temperature. .

  Examples of the thermoplastic resin preferably used in combination with the heat-sensitive adhesive of the present invention include natural rubber latex, natural rubber latex, polyvinyl acetate, acrylic acid ester copolymer, and methacrylic acid ester copolymer that are graft copolymerized with vinyl monomers. Polymer, acrylic ester-methacrylic ester copolymer, synthetic rubber, vinyl acetate-acrylic acid 2-ethylhexyl copolymer, vinyl acetate-ethylene copolymer, vinyl pyrrolidone-styrene copolymer, vinyl pyrrolidone-acrylic ester Examples thereof include polymer resins such as copolymers and styrene-acrylic copolymers, but are not limited thereto.

  The content of the thermoplastic resin in the heat-sensitive adhesive is preferably 10 to 60% by weight, more preferably 15 to 50% by weight. When the content of the thermoplastic resin is less than 10% by weight or more than 60% by weight, both are undesirable because the adhesive strength is lowered. On the other hand, when the content of the low Tg resin exceeds 60% by weight, there are problems in storage, such as an adhesive force appearing at a normal storage environment temperature.

  Furthermore, in order to improve the adhesive strength of heat-sensitive adhesives, rosin derivatives (rosin, polymerized rosin, hydrogenated rosin and their glycerin, pentaerythritol, etc.) that are tackifiers used in general adhesives for the above components Ester, resin acid dimer, etc.), terpene resin, petroleum resin, phenol resin and xylene resin can be used.

  Examples of tackifiers that are particularly preferably used in the heat-sensitive adhesive of the present invention include rosin derivatives (rosin, polymerized rosin, hydrogenated rosin and esters thereof with glycerin, pentaerythritol, etc., resin acid dimers, etc.), terpene resins (Terpene resin, aromatic modified terpene resin, terpene phenol resin, hydrogenated terpene resin). These tackifiers are compatible with the thermoplastic resin and the hot-melt material of the present invention, and the adhesive strength of the heat-sensitive adhesive is significantly improved.

  Moreover, the melting point or softening point of the tackifier in the heat-sensitive adhesive is preferably 80 ° C or higher, more preferably 80 to 200 ° C. When the temperature is less than 80 ° C., storage defects (decrease in blocking resistance) occur at normal storage environment temperatures. The content of the tackifier in the heat-sensitive adhesive is preferably 5 to 30% by weight, more preferably 5 to 20% by weight. If it is less than 5% by weight, the adhesive strength is reduced, and if it exceeds 30% by weight, storage problems (decrease in blocking resistance) occur at temperatures in a normal storage environment.

  In the heat-sensitive adhesive of the present invention, in addition to the above components, in order to prevent blocking, inorganic substances such as titanium oxide, alumina, colloidal silica, kaolin, talc, stearic acid metal salts, paraffin, natural wax, synthetic wax, Organic substances such as natural fats and oils, polystyrene powder, and the like can be further used, if necessary, dispersants, antifoaming agents, thickeners and the like.

  By applying the heat-sensitive adhesive of the present invention to one surface of a substrate, a heat-sensitive adhesive material having strong adhesive strength against vinyl chloride wrap and polyolefin wrap, particularly cardboard, and good blocking resistance can be obtained.

  The drying conditions for coating or printing on the support must be dried within a temperature range in which the hot-melt material to be used does not melt. As a means for drying, in addition to hot air drying, a drying method using a heat source using infrared rays, microwaves, and high frequencies can be used.

The coating amount of the heat-sensitive adhesive layer, dry coating amount in the normal 2~35g / ^{m 2,} and preferably applied in the range of 5 to 25 g / ^{m 2.} When the coating amount of the heat-sensitive adhesive layer is less than 2 g / m ² , sufficient adhesion cannot be obtained when performing adhesion by heating. On the other hand, if it exceeds 35 g / m ² , the adhesion function is saturated, which is not economical.

  In the heat-sensitive recording layer of the present invention, a heat-sensitive recording layer mainly composed of a leuco dye and a developer can be formed on the substrate.

  As the leuco dye used in the heat-sensitive recording layer of the present invention, a leuco dye known in this type of leuco recording material is generally applied. For example, triphenylmethane, fluorane, phenothiazine, auramine, spiropyran And leuco compounds of dyes such as indolinophthalide are preferably used.

  Specific examples of such leuco dyes include 3,3-bis (p-dimethylaminophenyl) phthalide and 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also called crystal violet lactone). 3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7 , 8-Benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane 3- (Np-tolyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- {N- (3'- Trifluoromethylphenyl) amino} -6-diethylaminofluorane, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-dibutyl Amino-7- (o-chloroanilino) fluorane, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-ani Linofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -5-methyl-7- N, N-dibenzylamino) fluorane, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrospirane, 6'-bromo-3'-methoxy-benzoindolino-pyrospirane, 3- (2 '-Hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'- Methoxy-5′-nitrophenyl) phthalide, 3- (2′-hydroxy-4′-diethylaminophenyl) -3- (2′-methoxy-5′-methylphenyl) phthalide, 3-diethylamino-6-methyl-7 -(2 ', 4'-dimethylanilino) fluorane, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2′-hydroxy-4′-chloro-5′-methylphenyl) phthalide, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7-trifluoromethylanilinofur Oran, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5- Chlor-7- (α-phenylethylamino) fluorane, 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) Fluorane, 3-diethylamino-5-methyl-7- (α-phenylethylamino) fluorane 3-diethylamino-7-piperidinofluorane, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluorane, 3- (N-benzyl-N-cyclohexylamino) -5 6-Benzo-7-α-naphthylamino-4′-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino-4 ′, 5′-benzofluorane, 3-diethylamino-6-methyl-7- (2 ′, 4′-dimethylanilino) fluorane, 3- (p-dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} phthalide, 3- (p -Dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} -6-dimethylaminophthalide, 3- (4'-dimethyl) Ruamino-2′-methoxy) -3- (1 ″ -p-dimethylaminophenyl-1 ″ -p-chlorophenyl-1 ″, 3 ″ -butadiene-4 ″ -yl) benzophthalide, 3- (4′-dimethylamino) -2'-benzyloxy) -3- (1 "-p-dimethylaminophenyl-1" -phenyl-1 ", 3" -butadiene-4 "-yl) benzophthalide, 3-dimethylamino-6-dimethylamino- Fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide, 3,3-bis {2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl} -4,5,6 , 7-tetrachlorophthalide, 3-bis {1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl} -5,6-dichloro-4,7-dibromophthalide, bis (p-dimethyl) Ruaminostyryl) -1-naphthalenesulfonylmethane, 3- (N-methyl-N-propylamino) -6-methyl-7-anilidefluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3 , 6-Bis (dimethylamino) fluorane spiro (9,3 ')-6'-dimethylaminophthalide, 3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N- ( 2-Ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl- 7-mesitidino-4 ′, 5′-benzofluorane, 3-N-methyl-N-isobutyl-6-methyl-7-anilinofluorane, 3-N-ethyl It can be mentioned N- isoamyl-6-methyl-7-anilinofluoran, and the like.

  In the heat-sensitive recording layer of the present invention, various electron-accepting compounds such as phenolic compounds, thiophenolic compounds, thiourea derivatives, organic acids, and metal salts thereof can be applied as color developers. it can.

  Specific examples thereof include 4,4′-isopropylidenebisphenol, 3,4′-isopropylidenebisphenol, 4,4′-isopropylidenebis (o-methylphenol), 4,4′-secondary butylidenebisphenol, 4 , 4′-isopropylidenebis (o-tertiarybutylphenol), 4,4′-cyclohexylidenediphenol, 4,4′-isopropylidenebis (2-chlorophenol), 2,2′-methylenebis (4-methyl) -6-tertiarybutylphenol), 2,2'-methylenebis (4-ethyl-6-tertiarybutylphenol), 4,4'-butylidenebis (6-tertiarybutyl-2-methyl) phenol, 1,1,3 -Tris (2-methyl-4-hydroxy-5-tertiary butylphenol L) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4′-thiobis (6-tertiarybutyl-2-methyl) phenol, 4,4 ′ -Diphenol sulfone, 4,2'-diphenol sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, 4-benzyloxy-4'-hydroxydiphenyl sulfone, 4,4'-diphenol sulfoxide, P-hydroxybenzoic acid Isopropyl acid, benzyl P-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,7-bis (4-hydroxyphenylthio) -3,5-dioxaheptane, 1,5 -Bis (4-hydroxyphenylthio) -3-oxaheptane, 1,3 Bis (4-hydroxyphenylthio) -propane, 2,2′-methylenebis (4-ethyl-6-tertiarybutylphenol), 1,3-bis (4-hydroxyphenylthio) -2-hydroxypropane, N, N '-Diphenylthiourea, N, N'-di (m-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, salicyl-o-chloroanilide, 2-hydroxy-3-naphthoic acid, zinc thiocyanate Antipyrine complex, zinc salt of 2-acetyloxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid, zinc of hydroxynaphthoic acid, metal salts such as aluminum and calcium, bis- (4-Hydroxyphenyl) acetic acid methyl ester, bis- (4-hydroxyphenyl) acetic acid Benzyl ester, 4- {β- (p-methoxyphenoxy) ethoxy} salicylic acid, 1,3-bis (4-hydroxycumyl) benzene, 1,4-bis (4-hydroxycumyl) benzene, 2,4 ′ -Diphenolsulfone, 3,3'-diallyl-4,4'-diphenolsulfone, antipyrine complex of α, α-bis (4-hydroxyphenyl) -α-methyltoluenethiocyanate, tetrabromobisphenol A, tetra Examples include bromobisphenol S, 4,4′-thiobis (2-methylphenol), 3,4-hydroxy-4′-methyl-diphenylsulfone, 4,4′-thiobis (2-chlorophenol), and the like.

  In order to form the heat-sensitive recording layer of the present invention, a leuco dye and a developer may be bonded and supported on a substrate. In this case, various conventional binders can be used as appropriate.

  Examples of such binders include polyvinyl alcohol, starch, and derivatives thereof, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, and acrylamide / acrylate esters. Polymer, acrylamide / acrylic ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. In addition to water-soluble polymers, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid ester, polybutyl methacrylate, vinyl chloride / vinegar Vinyl copolymer, ethylene / emulsion and styrene / butadiene copolymer vinyl acetate copolymer, can be mentioned latices such as styrene / butadiene / acrylic copolymer.

Further, when the heat-sensitive recording layer is formed according to the present invention, various heat-fusible substances can be used as fillers.
Specific examples thereof include fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, fatty acids such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate and zinc behenate. Metal salts, p-benzylbiphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, β-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, 1-hydroxy 2-naphthoic acid methyl ester, diphenyl carbonate, terephthalic acid dibenzyl ester, terephthalic acid dimethyl ester, 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1, 2-bis (phenoxy) ethane, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1,4-bis (phenoxy) butane, 1,4-bis ( Phenoxy) -2-butene, 1,2-bis (4-methoxyphenylthio) ethane, dibenzoylmethane, 1,4-bis (phenylthio) butane, 1,4-bis (phenylthio) -2-butene, 1, 2-bis (4-methoxyphenylthio) ethane, 1,3-bis (2-vinyloxyethoxy) benzene, 1,4-bis (2-vinyloxyethoxy) benzene, p- (2-vinyloxyethoxy) biphenyl , P-aryloxybiphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, 1,3-dibenzoyloxypropane, dibenzyldi Rufide, 1,1-diphenylethanol, 1,1-diphenylpropanol, p- (benzyloxy) benzyl alcohol, 1,3-diphenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-octadecylcarbamoyl Benzene, oxalic acid dibenzyl ester, 1,5-bis (p-methoxyphenyloxy) -3-oxapentane and the like can be mentioned.

  In the present invention, auxiliary additives commonly used in this type of heat-sensitive recording layer, such as surfactants and lubricants, can be used in combination as required. In this case, examples of the lubricant include higher fatty acids and metal salts thereof, higher fatty acid amides, higher fatty acid esters, various animal, vegetable, mineral or petroleum waxes.

  In the present invention, for example, a water-soluble resin is used for the purpose of providing an undercoat layer between the base material and the heat-sensitive recording layer or improving the image reliability on the heat-sensitive recording layer, if necessary. A protective layer having a main component can also be provided. In this case, as the components constituting these layers, the above-mentioned fillers, binders, thermofusible substances, surfactants and the like can be used. Furthermore, when the protective layer and the protective layer are not provided, a printed image can be formed directly on the heat-sensitive recording layer. For example, UV curable ink is used as the printing ink.

  The heat-sensitive recording layer of the present invention can be formed by a generally known method. For example, first, the leuco dye and the developer are separately pulverized and dispersed together with an aqueous binder solution by a dispersing machine such as a ball mill, an attritor, or a sand mill until the dispersed particle size becomes 1 to 3 μm, and a filler as required. A heat-sensitive recording layer can be formed by preparing a heat-sensitive recording layer coating solution by mixing with a thermofusible substance (sensitizer) dispersion and the like and applying the mixture to a substrate.

  By applying the heat-sensitive adhesive of the present invention on various substrates, a heat-sensitive adhesive material can be obtained. As described above, an intermediate layer or a heat-sensitive color development between the substrate and the heat-sensitive adhesive layer. In the case of the pressure-sensitive adhesive material provided with a layer, an undercoat layer can be provided between the substrate and the thermosensitive coloring layer. When these intermediate layers and / or undercoat layers are provided, it is preferable that they have heat insulation properties. By providing such a layer, the thermal sensitivity of the thermosensitive coloring layer is improved, and the thermosensitive coloring layer when thermally activated. It is possible to prevent the color development of the background and to efficiently use the thermal energy at the time of thermal activation. Hereinafter, when the intermediate layer and / or the undercoat layer is heat-insulating, it is referred to as a heat-insulating layer. Examples of the heat insulating layer include a non-foaming heat insulating layer using fine hollow particles having a hollowness of about 30 to 95% or a porous pigment and a foaming heat insulating layer using a foaming filler.

  The fine hollow particles having a hollowness of about 30 to 95%, which uses the thermoplastic resin used for the heat insulating layer as a soot, contain air or other gas inside, and are fine hollow particles already in a foamed state. The average particle diameter of the fine hollow particles is preferably 0.2 to 20 μm, more preferably 0.5 to 10 μm. When this average particle diameter (particle outer diameter) is smaller than 0.2 μm, it is difficult to technically make it hollow and the role of the heat insulating layer becomes insufficient.

  On the other hand, if the size is larger than 20 μm, the smoothness of the surface after coating and drying is lowered, so that the coating of the heat-sensitive adhesive layer becomes non-uniform. Must be applied. Therefore, it is desirable that the distribution of such fine hollow particles has a uniform distribution spectrum with little variation while the particle diameter is in the above range.

Further, in the present invention, fine hollow particles having a hollowness of 30% or more can be used, but those having a hollowness of 50% or more are more preferable. Those having a hollowness of less than 30% are not desirable because the heat insulating property is insufficient, so that heat energy is released to the outside through the base material, and the heat efficiency during the activation of the pressure-sensitive adhesive is deteriorated.
The said hollowness here is ratio of the volume on the basis of the outer diameter of the hollow fine particles and the volume on the basis of the inner diameter.

  As described above, the hollow microparticles used in the present invention are made of a thermoplastic resin, and the thermoplastic resin is preferably a copolymer resin mainly composed of vinylidene chloride and acrylonitrile.

  Examples of the porous pigment used in the heat insulating layer of the present invention include organic pigments such as urea formaldehyde resin and inorganic pigments such as shirasu earth, but are not necessarily limited thereto.

In order to form the non-foaming heat insulating layer of the present invention, the above-mentioned fine hollow particles and porous pigment are dispersed in water together with a binder, and this is applied onto a substrate and dried. In this case, the coating amount of the fine hollow particles is at least 1 g per 1 m ² of the support, more preferably about 2 to 15 g. The amount of the binder resin applied may be an amount sufficient to strongly bond the heat insulating layer to the substrate, and is usually 2 to 50% by weight based on the total amount of the fine hollow particles and the binder resin.

The binder used when forming the non-foaming heat insulating layer is appropriately selected from conventionally known water-soluble polymers and / or aqueous polymer emulsions.
Specific examples thereof include water-soluble polymers such as polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylic acid. Ester copolymer, acrylamide / acrylic ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. Is mentioned.

  Examples of the aqueous polymer emulsion include latex such as styrene / butadiene copolymer, styrene / butadiene / acrylic copolymer, vinyl acetate resin, vinyl acetate / acrylic acid copolymer, and styrene / acrylic acid ester copolymer. And emulsions such as acrylic ester resins and polyurethane resins.

  The foamable filler used in the present invention is a hollow plastic filler containing a foaming agent of a low-boiling-point solvent inside with a thermoplastic resin as a base, and various types are applied. Is 2 to 50 μm in the unfoamed state, and 10 to 100 μm, preferably 10 to 50 μm in the foamed state. Examples of the thermoplastic resin used as the plastic filler include polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, and copolymers thereof. Further, as the foaming agent contained in the bag, propane, butane or a mixture thereof is generally used.

In order to form a foamable heat insulating layer on a substrate, the foamable plastic filler described above is applied onto a support together with a binder and dried, and then a hot plate is adhered to the coated surface, and the plastic filler is heated and foamed. You can do it. The coating amount of the plastic filler is at least 1 g as an unfoamed filler with respect to 1 m ² of the support, preferably about ² to 5 g. The amount of the binder used may be an amount that strongly binds the foamable heat insulating layer to the support, and is usually 5 to 50 based on the total amount of the unfoamed filler and the binder. % By weight. The heating foaming temperature is a temperature at which the thermoplastic resin constituting the filler ridge is softened. The expansion ratio is usually 2 to 4 times, preferably about 2 to 3 times, and is appropriately selected so as to achieve the above foaming.

  As described above, the surface of the foamable heat insulating layer formed on the base material is considerably uneven, so that the flat surface is smoothed by calendering after the foamable heat insulating layer is formed (after heating and foaming). In addition, if necessary, one or more undercoat layers can be provided on the surface or the lower surface of the foamable heat insulating layer.

In the heat insulating layer of the present invention, a filler, a heat-fusible substance (sensitizer), a surfactant, etc. are used in combination with the fine hollow particles, the porous pigment or the foamable filler and the binder as necessary. can do.
In this case, examples of the filler include inorganic fine powders such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, and the like. Organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and the like. Examples of the heat fusible substance (sensitizer) include higher fatty acids or their In addition to esters, amides or metal salts, various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, p -Benzylbiphenyl and other thermofusible organic compounds such as those having a melting point of about 50 to 200 ° C.

  In addition, the base material used in the present invention is not particularly limited, such as high-quality paper, art paper, coated paper, other than paper, polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate, Polyolefin films such as polypropylene and polyethylene, polystyrene films, films obtained by bonding these, and the like can be used.

  Coating methods for providing the coating layer include blade coating method, gravure coating method, gravure offset coating method, bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U comma coating method, and AKKU. Known coating methods such as coating method, smoothing coating method, microgravure coating method, reverse roll coating method, four or five roll coating method, dip coating method, falling curtain coating method, slide coating method, die coating method, etc. Is available.

  The heat-sensitive adhesive material of the present invention can be suitably used by being cut before or after thermal activation (heating) of the heat-sensitive adhesive layer. In this case, A cut may be formed in advance. In these cases, the heat-sensitive adhesive material is advantageous in that it can be suitably used for various uses such as labels and tags.

  There is no restriction | limiting in particular as a shape of the heat sensitive adhesive material of this invention, A label form, a sheet form, a roll form etc. are mentioned suitably.

  The adherend to which the heat-sensitive adhesive material of the present invention is affixed is not particularly limited, and its size, shape, structure, material, and the like can be appropriately selected according to the purpose. For example, polyolefins such as polyethylene and polypropylene, resin plates such as acrylic, polyethylene terephthalate (PET), polystyrene and nylon, metal plates such as SUS and aluminum, paper products such as envelopes and cardboard, polyolefin wraps, polyvinyl chloride Preferable examples include wraps made of polyethylene and non-woven fabric made of polyethylene (envelopes and the like).

  Among these, the cardboard is generally difficult to affix a heat-sensitive adhesive material. However, in the case of the heat-sensitive adhesive material of the present invention, a strong adhesive force can be expressed over time. This is advantageous in that it can be firmly attached.

  The method for thermally activating the heat-sensitive adhesive layer in the heat-sensitive adhesive material of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an activation method using hot air, an activity using a hot roll, etc. And an activation method using a thermal head.

  Among these, the activation method using a thermal head is preferable, and the following thermal activation method for the heat-sensitive adhesive material of the present invention is particularly preferable. In this case, it is possible to perform recording on the heat-sensitive recording layer and heat activation of the heat-sensitive adhesive layer by heating both surfaces of the heat-sensitive adhesive material using an existing heat-sensitive recording printer device. Is advantageous.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, all the parts and% shown below are based on weight.

[Example 1]
(Manufacture of heat-meltable substance P-1)
In a 300 ml separable flask equipped with a Dimroth, dropping funnel, thermometer, nitrogen inlet tube, and stirring device, 45 g of 2-hydroxy-4-methacryloyloxybenzophenone, 50 g of methyl methacrylate, 1.5 g of n-dodecyl mercaptan, ethyl acetate 80 g was added, and the mixture was heated to 50 ° C. and stirred while nitrogen was blown from the nitrogen introduction tube.
Thereafter, 0.3 g of azobisisobutyronitrile (AIBN) dissolved in 20 g of ethyl acetate was added and stirred for 1 hour. After completion of the stirring, the temperature was raised to 70 ° C. and the reaction was carried out for 8 hours.
After completion of the polymerization, the polymer was put into 1 kg of methanol and stirred for 30 minutes with a homomixer. After stirring, no. Suction filtration was carried out with the filter paper of No. 2, and the filtrate was dried for 24 hours with a 60 ° C. hot-air circulating drier to prepare a copolymer. The weight average molecular weight (Mw) of this copolymer was 20,000.

[Liquid A] Hot-melting substance dispersion liquid Hot-melting substance P-1 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64. 85 parts of the mixture having the above composition was dispersed using a sand mill so that the average particle size was 1.0 μm to obtain a dispersion [solution A].

[Liquid B] Thermosensitive adhesive liquid 20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C., non-volatile content 50%)
Heat-meltable substance dispersion [liquid A] 33.3 parts Heat-sensitive adhesive dispersion [liquid B] having the above composition is applied to the back of 80 g / m ² single-sided coated paper so that the dry weight is 16 g / m ^2. The coating was dried to obtain a heat-sensitive adhesive sheet.

[Examples 2 to 4]
(Manufacture of heat-meltable substance P-2)
In a 300 ml separable flask equipped with a Dimroth, dropping funnel, thermometer, nitrogen inlet tube, and stirrer, 45 g of 2-hydroxy-4-acryloyloxybenzophenone, 50 g of methyl methacrylate, 1.5 g of n-dodecyl mercaptan, ethyl acetate 80 g was added, and the mixture was heated to 50 ° C. and stirred while nitrogen was blown from the nitrogen introduction tube.
Thereafter, 0.3 g of azobisisobutyronitrile (AIBN) dissolved in 20 g of ethyl acetate was added and stirred for 1 hour. After completion of the stirring, the temperature was raised to 70 ° C. and the reaction was carried out for 8 hours.
After completion of the polymerization, the polymer was put into 1 kg of methanol and stirred for 30 minutes with a homomixer. After stirring, no. Suction filtration was carried out with the filter paper of No. 2, and the filtrate was dried for 24 hours with a 60 ° C. hot-air circulating drier to prepare a copolymer. The weight average molecular weight (Mw) of this copolymer was 15,000.

(Production of heat-meltable substance P-3)
In a 300 ml separable flask equipped with a Dimroth, dropping funnel, thermometer, nitrogen inlet tube, and stirrer, 45 g of 2-hydroxy-4-methacryloyloxybenzophenone, 50 g of methyl acrylate, 1.5 g of n-dodecyl mercaptan, ethyl acetate 80 g was added, and the mixture was heated to 50 ° C. and stirred while nitrogen was blown from the nitrogen introduction tube.
Thereafter, 0.3 g of azobisisobutyronitrile (AIBN) dissolved in 20 g of ethyl acetate was added and stirred for 1 hour. After completion of the stirring, the temperature was raised to 70 ° C. and the reaction was carried out for 8 hours.
After completion of the polymerization, the polymer was put into 1 kg of methanol and stirred for 30 minutes with a homomixer. After stirring, no. Suction filtration was carried out with the filter paper of No. 2, and the filtrate was dried for 24 hours with a 60 ° C. hot-air circulating drier to prepare a copolymer. The weight average molecular weight (Mw) of this copolymer was 35,000.

(Production of heat-meltable substance P-4)
In a 300 ml separable flask equipped with a Dimroth, dropping funnel, thermometer, nitrogen inlet tube, and stirrer, 45 g of 2-hydroxy-4-acryloyloxybenzophenone, 50 g of methyl acrylate, 1.5 g of n-dodecyl mercaptan, ethyl acetate 80 g was added, and the mixture was heated to 50 ° C. and stirred while nitrogen was blown from the nitrogen introduction tube.
Thereafter, 0.3 g of azobisisobutyronitrile (AIBN) dissolved in 20 g of ethyl acetate was added and stirred for 1 hour. After completion of the stirring, the temperature was raised to 70 ° C. and the reaction was carried out for 8 hours.
After completion of the polymerization, the polymer was put into 1 kg of methanol and stirred for 30 minutes with a homomixer. After stirring, no. Suction filtration was carried out with the filter paper of No. 2, and the filtrate was dried for 24 hours with a 60 ° C. hot-air circulating drier to prepare a copolymer. The weight average molecular weight (Mw) of this copolymer was 12,000.

  A heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that P-1 was changed to P-2 to P-4 as the hot-melt material of Example 1.

[Example 5]
A heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid B] was changed to the following composition in Example 1.
[Liquid B] Thermosensitive adhesive liquid 20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C., non-volatile content 50%)
17 parts of heat-meltable substance dispersion (liquid A)

[Example 6]
A heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid B] was changed to the following composition in Example 1.
[Liquid B] Thermosensitive adhesive liquid 20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C., non-volatile content 50%)
166 parts of hot-melt material dispersion (liquid A)

[Example 7]
A heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid B] was changed to the following composition in Example 1.
[Liquid B] Thermosensitive adhesive liquid 20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C., non-volatile content 50%)
Hot melt material dispersion [liquid A] 10 parts

[Example 8]
A heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid B] was changed to the following composition in Example 1.
[Liquid B] Thermosensitive adhesive liquid 20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C., non-volatile content 50%)
170 parts of heat-meltable substance dispersion (liquid A)

[Example 9]
A heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the following [C solution] was used instead of [B solution] in Example 1.
[Liquid C] Heat-sensitive adhesive dispersion 20 parts of methyl methacrylate-butyl acrylate copolymer emulsion (Tg-62 ° C., non-volatile content 50%)
Heat-meltable substance dispersion (liquid A) 33.3 parts Polymerized rosin emulsion (softening point 145 ° C., nonvolatile content 50%) 6.5 parts

[Example 10]
[Liquid E] Coating fine hollow particle dispersion for heat insulation layer Copolymer resin mainly composed of vinylidene chloride / acrylonitrile (solid content concentration 32%, average particle diameter 3.0 μm, hollowness 92%) 30 parts Styrene / butadiene Polymer latex (Tg + 4 ° C.) 10 parts Water 60 parts A mixture comprising the above composition was stirred and dispersed to prepare a coating solution [E liquid] for heat insulation layer.

<Adjustment of thermosensitive coloring layer solution>
[F liquid] Color former dispersion liquid 3-Di-n-butylamino-6-methyl-7-anilinofluorane 20 parts Polyvinyl alcohol (10% aqueous solution) 10 parts Water 70 parts

[G liquid] Developer dispersion 4-isopropoxy-4′-hydroxydiphenylsulfone 10 parts Polyvinyl alcohol (10% aqueous solution) 25 parts Calcium carbonate 15 parts Water 50 parts Disperse using a sand mill so that the diameter is about 1.5 μm to prepare [F liquid] and [G liquid], and then mix [F liquid]: [G liquid] = 1: 8 The mixture was stirred to obtain a thermosensitive coloring layer solution [solution H].

The above [E solution] was applied and dried on the surface of the base material so that the weight after drying was 4 g / m ² to provide a heat insulating layer.
On top of this, the above-mentioned [Liquid H] was applied and dried so as to have a weight of 5 g / m ² after drying to provide a thermosensitive coloring layer.

<Adjustment of protective layer solution>
[Primary dispersion for protective layer]
Aluminum hydroxide 20 parts 10% PVA aqueous solution 20 parts Water 40 parts Next, a protective layer solution having the following composition was prepared using the primary dispersion of the protective layer.

[Adjustment of protective liquid]
Primary dispersion of protective layer 10 parts 10% PVA aqueous solution 20 parts 12.5% epichlorohydrin aqueous solution 5 parts 30% zinc stearate dispersion 2 parts A mixture of the above composition is pulverized to a mean particle size of 1 μm or less with a vertical sand mill The protective layer primary dispersion was prepared by dispersing.

On the thermosensitive coloring layer, the protective layer solution is applied and dried so that the weight when dried is about 3 g / m ^2, and further super calendered so that the Oken smoothness becomes 2000 seconds. A thermal recording paper was obtained.

  Instead of the single-sided coated paper of Example 1, a thermosensitive adhesive layer was provided on the back surface of the thermosensitive coloring layer in the same manner as in Example 2 to obtain a thermosensitive adhesive sheet.

[Example 11]
[Liquid H] Intermediate layer coating liquid Fine hollow particles (acrylonitrile /
14.6 parts of vinylidene chloride / methyl methacrylate copolymer)
(Solid content 41%, average particle size 3.6 μm, hollowness 90%)
2-ethylhexyl acrylate /
Methyl methacrylate / styrene copolymer (Tg-65 ° C.) 21.7 parts
(Solid content 55.4%, Showa Polymer)
Surfactant Dapro W-77 (manufactured by Elementis Japan) 0.1 part Water 63.6 parts A mixture of the above composition was stirred and dispersed to prepare an intermediate layer coating solution [solution H].

The above [Liquid H] was dried on the back of 80 g / m ² single-sided coated paper and dried so as to have a weight of 5 g / m ² to provide an intermediate layer. On this intermediate layer, the heat-sensitive adhesive dispersion liquid [I liquid] described in Example 1 was applied and dried to a dry weight of 16 g / m ² to obtain a heat-sensitive adhesive label.

[Comparative Example 1]
In Example 1, a heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [A liquid] was replaced with the following [J liquid].
[Liquid J] Hot melt material dispersion 2- (2-hydroxy-5-t-
Octylphenyl) -2H-benzotriazole 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts

[Comparative Example 2]
In Example 1, a heat-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that [A liquid] was replaced with the following [K liquid].
[Liquid K] Hot melt material dispersion 2- (3,5-di-t-pentyl-2-
Hydroxyphenyl) -2H-benzotriazole 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts

[Comparative Example 3]
In Example 1, a heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid A] was replaced with [Liquid L] below.
[Liquid L] Hot meltable material dispersion 5-chloro-2- (3,5-di-t-butyl
-2-hydroxyphenyl) -2H-benzotriazole 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts

[Comparative Example 4]
In Example 1, a heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid A] was replaced with [Liquid L] below.
[Liquid L] Hot melt material dispersion 2-hydroxy-4-benzyloxybenzophenone 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 parts

[Comparative Example 5]
In Example 1, a heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid A] was replaced with [Liquid L] below.
[Liquid L] Hot melt material dispersion 2,4-dihydroxybenzophenone 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0.15 parts Water 64.85 Part

[Comparative Example 6]
In Example 1, a heat-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that [Liquid A] was replaced with [Liquid L] below.
[Liquid L] Hot melt material dispersion 2,2′-dihydroxy-4,4-dimethoxybenzophenone 30.0 parts Polyvinyl alcohol (30% aqueous solution) 5.0 parts Surfactant (alkyl-allyl sulfonate) 0 .15 parts water 64.85 parts

<Adhesive properties>
1) Adhesive strength measurement The heat-sensitive adhesive sheet of the present invention is cut into a 40 mm × 150 mm rectangle to form a heat-sensitive adhesive label, using a thermal printing device TH-PMD manufactured by Okura Electric Co., Ltd., head conditions: each energy 0.5 mJ / dot Thermal activation was performed under the conditions of a printing speed of 4 ms / line and a platen pressure of 6 kgf / line. Subsequently, it was affixed to the corrugated cardboard with a 2 kg pressure rubber roller in the longitudinal direction, and after 2 minutes, it was peeled off under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 mm / min. The adhesive strength at that time was measured with a force gauge, and the values obtained by reading and averaging the data at 0.1 second intervals are shown in Table 1. The unit is gf / 40 mm. This test was conducted in a normal temperature environment (22 ° C., 65% RH).

2) Measurement of adhesive strength over time The heat-sensitive adhesive sheet of the present invention was cut into a 40 mm × 150 mm rectangle to form a heat-sensitive adhesive label, using a thermal printer TH-PMD manufactured by Okura Electric Co., Ltd., head conditions: each energy 0.5 mJ / Thermal activation was performed under the conditions of dot, printing speed of 4 ms / line, and platen pressure of 6 kgf / line. Subsequently, the cardboard was affixed in the longitudinal direction with a rubber roller with a pressure of 2 kg, and after being stored at 40 ° C. for 30 days, it was peeled off under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 mm / min. The adhesive strength at that time was measured with a force gauge, and the values obtained by reading and averaging the data at 0.1 second intervals are shown in Table 1. The unit is gf / 40 mm. This test was conducted in a normal temperature environment (24 ° C., 65% RH).

<Blocking property>
The surface of the same sample and the surface of the heat-sensitive adhesive layer were brought into contact with each other and tested at 200 g / cm ² at 60 ° C. under dry conditions for 24 hours. After leaving at room temperature, the sample was peeled off and the blocking property at that time was shown. It was evaluated with a rank like 1.

About Examples 1-11 and Comparative Examples 1-6, it shows in Table 2 about the measurement result of the adhesion characteristic and blocking property.
The adhesion rank is
○: 500 gf / 40 mm or more
Δ: 100 gf / 40 mm to 500 gf / 40 mm
X: 100 gf / 40 mm or less

Claims (7)

At least a thermoplastic resin, and a heat-sensitive adhesive mainly composed of a heat-meltable substance that melts when heated, wherein the heat-meltable substance is at least one benzophenone monomer (a) selected from the following formula (1): And a heat-sensitive adhesive comprising a polymer hot-melt material obtained by polymerizing the copolymerizable vinyl monomer (b) as an essential component.

(In Formula (1), R ¹¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyl group. R ¹² represents an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group, and m ¹ is 0 or .X ¹ .R ¹³ is showing a hydrogen atom or a lower alkyl group represented by 1 illustrates an ester bond, an amide bond, an ether bond, or urethane bond.)   2. The heat-sensitive adhesive according to claim 1, wherein the polymer hot-melt material is contained in an amount of 50 to 500 parts with respect to 100 parts of a thermoplastic resin (pressure-sensitive adhesive).   The heat-sensitive adhesive according to claim 1 or 2, further comprising a tackifier in the heat-sensitive adhesive.   A heat-sensitive adhesive material, comprising a layer made of the heat-sensitive adhesive according to any one of claims 1 to 3 on one side of a substrate.   The heat-sensitive adhesive material according to claim 4, wherein a heat-sensitive recording layer mainly comprising a leuco dye and a developer is provided on the opposite surface of the substrate to the heat-sensitive adhesive layer.   The heat-sensitive adhesive material according to claim 4 or 5, wherein an intermediate layer mainly comprising fine hollow particles and a binder is provided between the heat-sensitive adhesive layer and the substrate. The heat-sensitive adhesive material according to any one of claims 4 to 6, which is any one of a label shape, a sheet shape, and a roll shape.