JP5374689B2 - Water-based emulsion-type heat-sensitive adhesive, heat-sensitive label and labeled container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous emulsion-type heat-sensitive adhesive which is excellent in workability, sticking stability, and storage stability and forms an adhesive layer having excellent paste residue-suppressing properties in which no paste remains on a container when the adhesive layer is released even after the elapse of a long period of time after it is pasted, and to provide a heat-sensitive label using the heat-sensitive adhesive and a container with the label. <P>SOLUTION: The aqueous emulsion-type heat-sensitive adhesive includes a base polymer, a solid plasticizer, and a specific compound for improving storage stability and paste residue-suppressing properties of a pressure sensitive adhesive. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a water-based emulsion type heat-sensitive adhesive. More specifically, the present invention relates to a water-based emulsion-type heat-sensitive adhesive that can form an adhesive layer that is a delayed-type heat-sensitive adhesive and has excellent storage stability of the adhesive and maintains excellent adhesive residue control. The present invention also relates to a heat-sensitive label and a labeled container using the heat-sensitive adhesive.

  In recent years, when selling water, soft drinks, etc., plastic containers such as polyethylene terephthalate (PET) bottles are widely used, and these containers include product names, designs, explanations about contents, etc. A printed label is often attached. As such a label, for example, a heat-sensitive label of a type in which a label coated with a heat-sensitive adhesive (heat-sensitive adhesive) is wound around and attached to the entire surface or both ends is also used.

  Such a heat-sensitive label can develop adhesiveness by heating the adhesive layer (glue) part at the time of sticking, so it does not have adhesiveness until use, without using release paper There is an advantage that it can be stored. Among the above-mentioned heat-sensitive adhesives, the delayed heat-sensitive adhesive has an advantage that it is particularly excellent in sticking stability because once it develops tackiness by heating, the tackiness persists for a certain time after the heating is stopped. Such a delayed heat-sensitive adhesive generally comprises a thermoplastic resin (base polymer) and a solid plasticizer as constituent components (for example, see Patent Document 1).

  The heat-sensitive adhesive used for the above heat-sensitive labels is strongly responsive to containers and label base materials because it does not cause troubles such as thermal responsiveness that quickly exhibits tackiness by heating or peeling of the label when the container is used. Adhesive properties are required. However, on the other hand, from the viewpoint of recycling, it is required that the label can be easily peeled after use of the container, and that the adhesive does not remain on the container side at the time of peeling (no so-called “glue residue”). That is, the heat-sensitive adhesive is required to have various characteristics such as thermal responsiveness, adhesiveness, and suppression of adhesive residue.

  However, in a label using a heat-sensitive adhesive containing a solid plasticizer as described above, the solid plasticizer crystallizes over time in the adhesive layer even when it exhibits good adhesive residue deterrence at the beginning of label attachment. As a result, there is a problem that adhesive residue is likely to occur after a long period of time. Further, when the heat-sensitive adhesive is stored for a long time, the solid plasticizer dispersed in the adhesive is agglomerated or recrystallized, resulting in a problem that storage stability is lowered. Furthermore, in order to improve the thermal responsiveness and adhesiveness of the heat-sensitive adhesive, it is effective to reduce the particle size (dispersion diameter) of the solid plasticizer, but such a solid plasticizer was finely dispersed. With heat-sensitive adhesives, the problems of reduced adhesive residue deterrence and storage stability over time are more prominent, and heat response, adhesiveness and adhesive residue deterrence persistence and storage stability are higher. It was difficult to achieve both levels.

JP 2002-20705 A

  The object of the present invention is a heat-sensitive adhesive that exhibits excellent workability and sticking stability due to the delay property, is excellent in storage stability, and peels off even when a long time has passed after sticking as a label. It is an object of the present invention to provide a water-based emulsion-type heat-sensitive adhesive that forms an adhesive layer having excellent adhesive residue deterrence that does not cause adhesive residue in a container. Another object of the present invention is to provide a heat-sensitive label using the heat-sensitive adhesive and a labeled container equipped with the label.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have determined that the solid plasticizer in the adhesive and the adhesive layer is aged by using a thermoplastic resin, a solid plasticizer and a specific compound as essential components. It is found that a water-based emulsion-type heat-sensitive adhesive can be obtained, which can form a heat-sensitive adhesive layer that can suppress recrystallization at a low temperature, has excellent storage stability, and has a long-lasting adhesiveness-inhibiting property. Was completed. Moreover, it discovered that the thermosensitive label and labeled container using this thermosensitive adhesive were obtained.

（式中、ｎは１、ＸはＮａ、Ｋ、又はＣａ、Ｒ₁〜Ｒ₈はそれぞれ水素原子又は炭素数が１〜６のアルキル基を表す）で表される化合物を含有する水系エマルジョン型感熱接着剤で形成されていることを特徴とする感熱ラベルを提供する。 That is, the present invention is a thermosensitive label in which an adhesive layer is laminated on a label base material, and the adhesive layer includes a thermoplastic resin, a solid plasticizer, and the following formula (1)

(In the formula, n 1, X is Na, K, or Ca, R ₁ ~R ₈ are each a hydrogen atom or a carbon atoms represent 1-6 alkyl group) aqueous emulsion type, containing a compound represented by A heat-sensitive label is provided which is formed of a heat-sensitive adhesive .

Furthermore, the present invention relates to the above-mentioned heat-sensitive adhesive formed of an aqueous emulsion-type heat-sensitive adhesive containing 0.3 to 20 parts by weight of the compound represented by the formula (1) with respect to 100 parts by weight of the solid plasticizer. Provide a label .

Furthermore, the present invention is formed of a water-based emulsion type thermosensitive adhesive having a content of [the thermoplastic resin (solid content) / a content of the solid plasticizer (solid content)] of 70/30 to 30/70. A thermal label as described above is provided.

Furthermore, the present invention is formed of an aqueous emulsion-type heat-sensitive adhesive in which the total content (solid content) of the thermoplastic resin and the solid plasticizer is 65% by weight or more based on the total solid content of the heat-sensitive adhesive. A thermal label as described above is provided.

  Furthermore, the present invention provides a labeled container in which the thermosensitive label is attached to the container.

  Since the water-based emulsion type heat-sensitive adhesive of the present invention is delayed, it is excellent in workability and label sticking stability. In addition, even when stored for a long time, the solid plasticizer in the adhesive hardly recrystallizes and re-aggregates over time, and is excellent in storage stability. Furthermore, the adhesive layer formed from the adhesive is excellent in recyclability because the solid plasticizer in the adhesive layer is less likely to recrystallize over time, and no adhesive residue is produced even after a long time has elapsed after sticking. Moreover, since the solid plasticizer can be maintained in a finely dispersed state, the thermal responsiveness and adhesiveness of the adhesive layer can be improved. Therefore, it is particularly useful as a heat-sensitive adhesive for heat-sensitive labels used for PET bottles and the like.

  The water-based emulsion-type heat-sensitive adhesive of the present invention (hereinafter, “water-based emulsion-type heat-sensitive adhesive” may be simply referred to as “heat-sensitive adhesive” or “adhesive”) includes a thermoplastic resin, a solid plasticizer, and It contains at least one compound selected from the above formulas (1) to (4) (hereinafter sometimes referred to as “compound (A)”) as an essential component. The adhesive layer formed by the heat-sensitive adhesive of the present invention (hereinafter sometimes simply referred to as “heat-sensitive adhesive layer” or “adhesive layer”) is activated by heat and exhibits tack, and is constant. It has a delay property that maintains the stickiness for a period. The adhesive layer having the above characteristics has almost no tack at normal temperature until it is activated by heating, and therefore does not require a release paper, and is excellent in environmental suitability and handleability. In addition, since the adhesiveness is maintained for a long time even after heat release after heating, it is easy to handle in the label mounting process and the like, which is advantageous in terms of improving workability and productivity. In the case of an adhesive layer that does not have a delay property, such as an adhesive layer with a hot-melt adhesive, the adhesiveness is lost when heat is dissipated, so it is necessary to attach the label immediately after heating, so workability and production May decrease.

  The thermoplastic resin (base polymer) used in the heat-sensitive adhesive of the present invention is a main component of the adhesive and is a component that greatly affects basic properties such as adhesive properties, adhesive layer flexibility, and cohesive strength. It is. The thermoplastic resin is not particularly limited, and a thermoplastic resin generally used as a base polymer of a heat-sensitive adhesive can be used. For example, acrylic resin, olefin resin, vinyl acetate resin, urethane And rubber resins such as thermoplastic resins, styrene resins, polyester resins, and thermoplastic elastomers.

  Examples of the olefin resin include α-olefins such as polyethylene and polypropylene, for example, ethylene-vinyl acetate copolymer (EVA); ethylene-acrylic acid copolymer (EAA); ethylene-methacrylic acid copolymer. Polymer (EMAA); Ethylene-acrylate copolymer such as ethylene-ethyl acrylate copolymer (EEA); Ethylene-methacrylate copolymer such as ethylene-methyl methacrylate copolymer (EMMA) And ethylene-carboxylic acid copolymers and ethylene-carboxylic acid ester copolymers. Among these, ethylene-carboxylic acid copolymers and ethylene-carboxylic acid ester copolymers are preferable, and ethylene-vinyl acetate copolymers are particularly preferably used. These can be used alone or in combination of two or more.

  The ethylene-vinyl acetate copolymer is a copolymer having ethylene and vinyl acetate as essential monomer components, and within the range not impeding the effects of the present invention, other than the above ethylene and vinyl acetate, A copolymer component may be used. Examples of the copolymer component include vinyl monomers such as vinyl chloride, (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, and 5-norbornene-2,3-dicarboxylic acid. Unsaturated carboxylic acid; unsaturated carboxylic anhydride such as maleic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride; methyl (meth) acrylate, (meth) acrylic acid Ethyl, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid Unsaturated carboxylic acid esters such as glycidyl, monoethyl maleate, diethyl maleate Acrylamide, methacrylamide, unsaturated amides or imides, such as maleimide; (meth) sodium acrylate, and the like unsaturated carboxylic acid salt such as zinc (meth) acrylate. These copolymerization components can be used alone or in combination of two or more.

  Examples of the rubber resin include butadiene rubbers such as butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), acrylate-butadiene rubber (ABR), and ethylene propylene (diene) rubber. Examples thereof include olefinic rubbers such as (EPM, EPDM), urethane rubber, and silicone rubber. Of these, butadiene rubbers such as styrene-butadiene rubber and methyl methacrylate-butadiene copolymer are preferable, and styrene-butadiene rubber (styrene-butadiene copolymer elastomer) is most preferable. Further, the butadiene rubber such as styrene-butadiene rubber may be a modified product having a reactive functional group introduced therein. Examples of the reactive functional group include a functional group that reacts or interacts with an ester bond portion of a polyester (such as a hydrogen bond), and includes a carboxyl group (including a carboxylic acid anhydride), a hydroxyl group, an isocyanate group, and an epoxy group. Etc. Among these, from the viewpoint of improving adhesiveness, a dicarboxylic anhydride group (dicarboxylic anhydride modified) is preferable, and a maleic anhydride group (maleic anhydride modified) is particularly preferable. The term “modified” includes both “reactive functional groups introduced into the polymer main chain by grafting” and “introduced by copolymerization”.

The acrylic resin is a resin composed of (meth) acrylic acid ester (acrylic acid ester and / or methacrylic acid ester) as a monomer component. Examples of the monomer component constituting the acrylic resin include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth ) (Meth) acrylic acid alkyl esters such as isononyl acrylate, (meth) acrylic acid decyl, and (meth) acrylic acid dodecyl [preferably (meth) acrylic acid C _1-12 alkyl ester and the like]; (meth) acrylic acid, Carboxyl group-containing polymerizable unsaturated compounds such as crotonic acid, itaconic acid, fumaric acid, maleic acid, etc. Anhydrous; 2-hydroxymethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono Examples include hydroxyl group-containing (meth) acrylic acid esters such as (meth) acrylate [preferably (meth) acrylic acid hydroxy C _1-8 alkyl ester and the like].

  In addition to the above, as required, (meth) acrylic acid cycloalkyl esters such as cyclohexyl (meth) acrylate; N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (Meth) acrylic acid amide derivatives such as (meth) acrylamide, N, N-diethyl (meth) acrylamide; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, dimethylamino (Meth) acrylic acid dialkylaminoalkyl esters such as propyl (meth) acrylate and dipropylaminopropyl (meth) acrylate; styrene compounds such as styrene, vinyltoluene and α-methylstyrene; vinyl acetate, Vinyl esters such as vinyl pionate; vinyl halides such as vinyl chloride; vinyl ethers such as methyl vinyl ether; cyano group-containing vinyl compounds such as (meth) acrylonitrile; polymerizable unsaturated compounds such as ethylene as monomer components It can also be used. These monomer components can be used alone or in combination of two or more.

  Specific examples of the acrylic resin include, for example, poly (meth) acrylic acid ester, poly (meth) acrylic acid; acrylic resin such as (meth) acrylic acid ester- (meth) acrylic acid; styrene- (meth) Styrene-acrylic resin such as acrylic acid; Vinyl acetate- (meth) acrylic acid ester, vinyl acetate-acrylic resin such as vinyl acetate- (meth) acrylic acid; Ethylene-styrene- (meth) acrylic acid ester, vinyl acetate -Styrene- (meth) acrylic acid etc. are mentioned.

  It does not specifically limit as said polyester-type resin, For example, the various polyester comprised by a polybasic acid component and a polyhydric alcohol component is mentioned.

  Examples of the polybasic acid component include terephthalic acid, isophthalic acid, phthalic acid, 5-t-butylisophthalic acid, 4,4′-biphenyldicarboxylic acid, trans-3,3′-stilbene dicarboxylic acid, and trans-4. , 4′-stilbene dicarboxylic acid, 4,4′-dibenzyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,2,6,6-tetramethylbiphenyl-4,4′-dicarboxylic acid, 1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid, Aromatic dicar such as 2-diphenoxyethane-4,4′-dicarboxylic acid, diphenyl ether dicarboxylic acid, and substituted products thereof Acid; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, Aliphatic dicarboxylic acids such as heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, icosanedioic acid, docosanedioic acid, 1,12-dodecanedioic acid, and their substitutions; 1,4-decahydronaphthalenedicarboxylic acid, 1,5-decahydronaphthalenedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, trans-1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and these Dicarboxylic acid components such as alicyclic dicarboxylic acids such as substituted products of . Further, if necessary, it may contain oxycarboxylic acids such as p-oxybenzoic acid and p-oxyethoxybenzoic acid; monocarboxylic acids such as benzoic acid and benzoylbenzoic acid; and polyvalent carboxylic acids such as trimellitic acid. Good. These can be used alone or in combination of two or more.

  Examples of the polyhydric alcohol component include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2 , 2-dimethyl-1,3-propanediol (neopentyl glycol), 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propane Diol, 1,8-octanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2,4-dimethyl-1,3-hexanediol, 1,10-decanediol, polyethylene glycol Aliphatic diols such as polypropylene glycol; 1,2-cyclohexanedimethanol, 1,3-silane Cyclohexane dimethanol, 1,4-cyclohexanedimethanol, alicyclic diols such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol; 2,2-bis (4′-β-hydroxyethoxy) Examples thereof include ethylene oxide adducts of bisphenol compounds such as diphenyl) propane and bis (4′-β-hydroxyethoxyphenyl) sulfone, and aromatic diols such as xylylene glycol. Moreover, you may contain monohydric alcohols, such as polyalkylene glycol monomethyl ether; Polyhydric alcohols, such as glycerol, pentaerythritol, a trimethylol propane, etc. as needed. These can be used alone or in combination of two or more.

  When making the said polyester-type resin water-dispersible, you may copolymerize the compound containing sulfonate groups, such as sulfoterephthalic acid, and the compound containing carboxylate group.

  A commercial item can also be used for the said thermoplastic resin. Examples of such commercially available products include Sumitomo Chemical Co., Ltd. “Sumikaflex” (EVA), Denki Kagaku Kogyo Co., Ltd. “Denka EVA Tex” (EVA), Nippon A & L Co., Ltd. “Nalstar SR Series” (styrene) -Butadiene rubber), "Siatex NA series" (acrylonitrile-butadiene rubber), and the like.

  The thermoplastic resin may be used by mixing different resins. Especially when acrylic resin and olefin resin, or ethylene-vinyl acetate copolymer and rubber resin are used in combination, polyolefin resin (particularly polypropylene resin) used as a label substrate or container material And polyester resin (especially polyethylene terephthalate resin). Among these, from the viewpoint of adhesiveness, the mixing ratio of the acrylic resin and the olefin resin is preferably the former / the latter = 10/90 to 90/10, more preferably 20/80 to the weight ratio in terms of solid content. 80/20. Further, the mixing ratio of the ethylene-vinyl acetate copolymer and the rubber resin is preferably the former / the latter = 20/80 to 80/20, more preferably 25/75 to 75 / in terms of solid content. 25. When it has particularly excellent adhesion to polyester resins and polyolefin resins, for example, it can be used as an adhesive for label substrates made of polyolefin resins or as an adhesive for containers made of polyester resins. Therefore, it is not necessary to use two different types of adhesives in the label manufacturing process, which is preferable from the viewpoint of cost and productivity.

  The solid plasticizer used in the heat-sensitive adhesive of the present invention is non-tacky at room temperature, but melts by heating, adjusts the solidification rate of the adhesive, imparts delay properties, that is, plasticizes the thermoplastic resin. It has a role of developing and maintaining adhesiveness. As such a solid plasticizer, known solid plasticizers can be used, such as diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate (DCHP: melting point 66 ° C.), dihydroabiethyl phthalate, dimethyl isophthalate. Phthalate compounds such as trimethylolethane tribenzoate, trimethylolpropane tribenzoate (melting point 88 ° C.), glyceride tribenzoate (melting point 73 ° C.), pentabenzoate tribenzoate, etc. Sucrose octaacetate, tricyclohexyl ketenoate, triethylene glycol bis [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate)] (melting point 77 ° C.), 1,6-hexanediol bis [ 3- (2,5-di-tert-butyl-4-hydroxyphenyl) Fatty acid ester compounds such as (Lopionate) (melting point 103 ° C.); sulfonic acid ester compounds such as N-cyclohexyl-p-toluenesulfonic acid amide; phosphate ester compounds, hindered phenol compounds, triazole compounds, hydroquinone It can be selected from system compounds. Among them, DCHP and tribenzoic acid glyceride are preferable, and DCHP is particularly preferably used.

  Although melting | fusing point of the said solid plasticizer is not specifically limited, 50-120 degreeC is preferable, More preferably, it is 55-110 degreeC, More preferably, it is 60-105 degreeC. If the melting point is less than 50 ° C., blocking may easily occur. If the melting point exceeds 120 ° C., adhesiveness and delay properties will not be exhibited unless heated to a high temperature. It may be necessary.

  As the solid plasticizer, for example, a commercially available product such as “DCHP” manufactured by Osaka Organic Chemical Industry Co., Ltd. can be used.

  The average particle size of the solid plasticizer is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.2 to 5 μm, and still more preferably 0.3 from the viewpoint of improving thermal response and adhesiveness. ~ 2 μm. If the average particle size exceeds 10 μm, the heat-sensitive response and adhesiveness may be inferior. The “average particle diameter” is an average particle diameter (average dispersion diameter) in the heat-sensitive adhesive.

  The particle size of the solid plasticizer can be determined by, for example, using a kneader, a colloid mill, a bead mill, a ball mill, an attritor, a paint shaker, a sand mill, a roll mill or the like to grind the solid content and disperse it in a dispersion medium such as water. Can be adjusted.

  In the heat-sensitive adhesive of the present invention, the content ratio (weight ratio in terms of solid content) of the thermoplastic resin and the solid plasticizer is the former / the latter [the content of the thermoplastic resin (solid content) / the content of the solid plasticizer. The amount (solid content)] is preferably in the range of 70/30 to 30/70, more preferably 65/35 to 35/65. When the ratio of the solid plasticizer is less than the above range, the heat-sensitive adhesive property and the delay property may be lowered. On the other hand, when the ratio of the thermoplastic resin is less than the above range, adhesiveness to an adherend such as polyester or polyolefin may decrease, or the adhesive cohesive force may decrease and adhesive residue may easily occur. .

  The total content (solid content) of the thermoplastic resin and the solid plasticizer is preferably 65% by weight or more, more preferably 80% by weight or more, based on the total solid content of the heat-sensitive adhesive. It is. When the total amount of the thermoplastic resin and the solid plasticizer is less than 65% by weight, the adhesive strength may be lowered.

The at least one compound (A) selected from the following formulas (1) to (4) used in the heat-sensitive adhesive of the present invention is reconstituted with time in the heat-sensitive adhesive or heat-sensitive adhesive layer. It plays a role of suppressing aggregation and recrystallization. This prevents problems such as the thermal responsiveness of the thermal adhesive being lowered during long-term storage, and the solid plasticizer being recrystallized in the thermal adhesive layer of the thermal label and causing adhesive residue. The storage stability of the heat-sensitive adhesive and the adhesive residue deterrence are improved.

で表される化合物が挙げられる。上記式（５）の化合物は、（株）ＡＤＥＫＡ製、商品名「アデカスタブＮＡ−１１」として入手可能である。 In said formula (1), n is an integer of 0-2, Preferably it is 1. X is a group 1 element (excluding hydrogen) or a group 2 element, preferably Na, K, or Ca. R _{1 to} R ₈ are each a hydrogen atom, an alkyl group or an aryl group, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Among the R ₁ to R _8, it is preferred that at least two or more of them are an alkyl group or an aryl group. Examples of the compound of the formula (1) include the following formula (5)

The compound represented by these is mentioned. The compound of the above formula (5) is available from ADEKA Corporation under the trade name “ADK STAB NA-11”.

In said formula (2), n is an integer of 0-2, Preferably it is 1. X is a group 1 element (excluding hydrogen) or a group 2 element, preferably Na, K, or Ca. R _{1 to} R ₈ are each a hydrogen atom, an alkyl group or an aryl group, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Among the R ₁ to R _8, it is preferred that at least two or more of them are an alkyl group or an aryl group.

で表される化合物が挙げられる。上記式（６）の化合物は、花王（株）製、商品名「エマルゲンＡ−６０」、「エマルゲンＡ−９０」、「エマルゲンＡ−５００」、上記式（７）の化合物は、花王（株）製、商品名「エマルゲンＢ−６６」として入手可能である。なお、上記式（６）中、ｓは１〜２０の整数であり、上記式（７）中、ｔは１〜２０の整数である。 In said formula (3), p is an integer of 1-3, Preferably it is 2 or 3. q is an integer of 1-20, preferably 5-15. R _{9 to} R ₁₄ are each a hydrogen atom, an alkyl group or an aryl group, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the compound of the formula (3) include the following formulas (6) and (7)

The compound represented by these is mentioned. The compound of the above formula (6) is manufactured by Kao Corporation, trade names “Emulgen A-60”, “Emulgen A-90”, “Emulgen A-500”, and the compound of the above formula (7) is Kao Corporation. ) And trade name “Emulgen B-66”. In addition, in said formula (6), s is an integer of 1-20, and in said formula (7), t is an integer of 1-20.

で表されるα−シクロデキストリンや、下記式（９）

で表されるβ−シクロデキストリンが挙げられる。 In said formula (4), r is an integer of 6-8. Examples of the compound of the formula (4) include the following formula (8)

Α-cyclodextrin represented by the following formula (9)

Β-cyclodextrin represented by

  As the compound (A), a compound of the formula (1) or the formula (2) is particularly preferable. Moreover, the said compound (A) may use only 1 type, but may be used in combination of 2 or more type. Among these, when the compound of the formula (1) and the compound of the formula (3), or the compound of the formula (2) and the compound of the formula (3) are used in combination, the adhesive residue deterring property is particularly good, which is preferable.

  As for content (solid content) of said compound (A), 0.3-20 weight part is preferable with respect to 100 weight part of solid plasticizers (solid content). When the content of the compound (A) is less than 0.3 parts by weight, the effect of suppressing recrystallization of the solid plasticizer is small, and storage stability and adhesive residue suppression may be reduced. The viscosity may increase or the adhesiveness may decrease. In addition, when using 2 or more types of compounds (A), it is preferable that the total amount of all the compounds (A) satisfy | fills the said relationship. In addition, as for content of the said compound (A), 0.5 weight part or more is more preferable, More preferably, it is 1 weight part or more. Moreover, 15 weight part or less is more preferable, More preferably, it is 10 weight part or less.

  If necessary, a tackifier may be added to the heat-sensitive adhesive in the present invention. The tackifier exhibits an effect of improving adhesiveness, and includes, for example, rosin resins (rosins such as rosin, polymerized rosin, and hydrogenated rosin, and rosin derivatives (rosin derivatives such as polyhydric alcohols such as glycerin and pentaerythritol). Rosin ester compounds esterified with rosins, rosin phenol compounds in which modified phenols such as phenol and resol type phenol resins are added to rosins), resin acid dimers), terpene resins (terpene resins, aromatic modified terpenes) Resin, hydrogenated terpene resin, terpene-phenol resin, etc.), petroleum resin (aliphatic, aromatic, alicyclic), coumarone-indene resin, styrene resin, phenol resin and the like. A tackifier can be used individually or in combination of 2 or more types. Of these, terpene resins, rosin derivatives (particularly rosin phenol compounds) and the like are preferably used.

  The above-mentioned tackifier is also available on the market. For example, “YS Polyster” manufactured by Yashara Chemical Co., Ltd., “Pine Crystal” manufactured by Arakawa Chemical Co., Ltd., “Tamanol E-200NT (softening point 150 ° C.)”, Yashara Chemical “Narret R-1050 (softening point: 105 ° C.)” manufactured by Co., Ltd.

  The content of the tackifier (solid content) is preferably 0 to 40 parts by weight, more preferably 3 to 35 parts by weight with respect to 100 parts by weight of the total amount (solid content) of the thermoplastic resin and the solid plasticizer. More preferably, it is 5-30 weight part. If the content of the tackifier is too large, adhesive residue may be generated or the adhesive strength may be reduced. If the content is too small, the effect of addition may not be obtained.

  In the present invention, an antiblocking agent or the like may be added to the heat sensitive adhesive. Examples of such an antiblocking agent include inorganic particles such as silicone oil, water-soluble organic compounds, calcium carbonate, clay, talc, silica, alumina, mica, alumina sol, colloidal silica; paraffin, polypropylene (PP) wax, polyethylene Particles made of organic compounds such as (PE) wax, acrylic beads, fatty acid amide, and fluorine wax can be used.

  In addition to the above, the heat-sensitive adhesive of the present invention may contain known additives such as emulsifiers, dispersants, viscosity modifiers, antifoaming agents, leveling agents, and antifungal agents as necessary.

  In the heat-sensitive adhesive of the present invention, the total solid content is not particularly limited, but is 30% by weight or more based on the total weight of the adhesive (weight including dispersion medium (water, etc.)). Is more preferable, 35 to 80% by weight, more preferably 40 to 70% by weight. If the total solid content is less than 30% by weight, the drying property is poor, and good adhesion and heat sensitivity may not be obtained.

  The temperature at which the heat-sensitive adhesive in the present invention exhibits adhesiveness (tackiness), that is, the activation temperature of the heat-sensitive adhesive is preferably about 50 to 120 ° C, more preferably about 60 to 110 ° C. When a heat-sensitive adhesive with an activation temperature of less than 50 ° C is used, the labels are likely to block each other when storing the labels in roll form. If the activation temperature is too high, the label base material shrinks or deforms during processing. Or a high temperature heat source may be required. If a heat-sensitive adhesive having an activation temperature in the above range is used, blocking does not occur at room temperature, and handling is easy, and attachment of the heat-sensitive label to the adherend can be facilitated. The activation temperature can be adjusted by appropriately selecting the type and amount of each component such as a thermoplastic resin, a solid plasticizer, and a tackifier, and other additives. In the present invention, the activation temperature of the adhesive layer is a temperature that produces an adhesive strength of 0.5 N / 15 mm or more when measured according to JIS K 6854-3. The heat-sensitive adhesive generally develops tackiness when heated at a temperature higher than the activation temperature.

  The heat-sensitive adhesive in the present invention can be produced by a known method using the above components (thermoplastic resin, solid plasticizer, compound (A) and other additives). The heat-sensitive adhesive is used in the form of an aqueous emulsion in which a thermoplastic resin and a solid plasticizer, which are constituent components, are dispersed in a dispersion medium in the form of fine particles having an average particle diameter (dispersion diameter) of about 10 μm or less. As described above, the solid plasticizer is pulverized to a particle size in the above preferred range using a kneader, colloid mill, bead mill, ball mill, attritor, paint shaker, sand mill, roll mill, etc. Used in a dispersed state. As the tackifier, an aqueous dispersion or an aqueous emulsion is used. The heat-sensitive adhesive can be prepared by mixing and stirring these. The dispersion medium is not particularly limited as long as it is aqueous. For example, water; a water-soluble organic compound such as a lower alcohol having 1 to 4 carbon atoms; and a mixture thereof can be used. If necessary, an emulsifier, a dispersant, an antifoaming agent, an anti-settling agent, a stabilizer, and the like may be added to the emulsion.

  The heat-sensitive adhesive is, for example, a thermoplastic resin emulsion, a solid plasticizer emulsion, a compound (A), a tackifier (emulsion), and other components are simultaneously added to a container such as a stirring and mixing tank or sequentially. Or it can obtain by stirring continuously and stirring and mixing uniformly. These components may be emulsified at the same time.

  In the heat-sensitive adhesive of the present invention, the effect of the compound (A) suppresses the solid plasticizer dispersed in the adhesive from re-aggregating or recrystallizing over time to increase the particle size. For this reason, there is no decrease in thermal responsiveness and adhesiveness accompanying the increase in the particle size of the solid plasticizer, and the storage stability of the adhesive is improved. In general, the smaller the particle size of the solid plasticizer, that is, the finer the dispersion, the better the thermal responsiveness and adhesiveness of the adhesive layer, but it tends to agglomerate during storage and the storage stability tends to decrease. is there. According to the present invention, even when the solid plasticizer has a small particle size (fine dispersion), re-aggregation and recrystallization hardly occur, and good storage stability can be maintained. And storage stability can be achieved at a high level.

  The heat-sensitive label of the present invention has a layer structure in which at least one adhesive layer formed of the heat-sensitive adhesive is laminated on a label base material. The adhesive layer is coated with the above-mentioned heat-sensitive adhesive on at least one side of the label base material by a known coating method such as a bar coater, gravure coater, flexo coater, roll coater, curtain coater, spray coater, brush coating, or die coating. -It can be formed by drying. In particular, when a gravure coater (gravure printing) or a flexo coater (flexo printing) is used, an adhesive layer can be partially provided at a desired location, which is preferable.

  The thickness of the adhesive layer is not particularly limited as long as it is appropriately selected in consideration of adhesiveness, appearance, cost, etc., but the thickness after drying is preferably 1 to 30 μm, more preferably 5 to 15 μm. When the thickness of the adhesive layer is greater than 30 μm, cohesive failure may occur and adhesive residue may be easily generated, or drying may be reduced and productivity when the adhesive layer is applied may be reduced. In some cases, the adhesiveness may decrease. The thickness of the adhesive layer can be measured with a micro gauge or a three-dimensional microscope.

  Since the adhesive layer of the heat-sensitive label of the present invention is formed of the heat-sensitive adhesive having the above-described configuration, it can quickly develop tackiness by heating. Also, the solid plasticizer in the adhesive layer is difficult to recrystallize over time. For this reason, adhesive residue due to a decrease in the cohesive force of the pressure-sensitive adhesive layer at the crystal portion is unlikely to occur, and the effect lasts for a long time. Moreover, since the plasticizing effect by heating of the pressure-sensitive adhesive layer also lasts for a long time, excellent heat-sensitive adhesiveness can be exhibited even after long-term storage after the formation of the pressure-sensitive adhesive layer. Furthermore, when the solid plasticizer is finely dispersed as described above, the thermal sensitivity and adhesiveness are particularly improved.

  The label substrate in the heat-sensitive label of the present invention can be appropriately selected in consideration of heat resistance, handleability, printability, etc., such as plastic film, plastic sheet; coated paper and other water-resistant paper, Japanese paper, synthetic paper, etc. Paper; metal foil such as aluminum foil; non-woven fabric and composites thereof can be used. Of these, a plastic film is preferable from the viewpoint of physical properties such as strength and handleability, and a transparent plastic film is particularly preferable. The plastic film can be appropriately selected according to the required physical properties, application, cost, and the like, and is not particularly limited. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and poly (ethylene- Polyester resins such as 2,6-naphthalenedicarboxylate (PEN); polyolefin resins such as polyethylene and polypropylene; polystyrene resins such as styrene-butadiene copolymer; polyvinyl chloride, polyamide, aramid, polyimide, polyphenylene sulfide And a film made of a resin such as acrylic. Among these, from the viewpoints of adhesiveness with the heat-sensitive adhesive layer of the present invention, cost, handleability, strength and flexibility as a support, a polyester resin or a polyolefin resin is preferable, and a polyolefin resin is more preferable. These may be used alone or in combination of two or more, copolymerized or laminated.

  Among the above, in particular, the label base material of a label to be mounted on a container having a specific gravity of 1 or more such as a PET bottle is preferably made of a material having a specific gravity of less than 1, for example, a polyolefin resin, preferably a polypropylene resin. . In such a case, after using the container equipped with the label, it can be easily separated from the container main body (or a pulverized product thereof) by utilizing the specific gravity difference, and the label and the container main body can be easily recycled. At this time, it is preferable to use hot alkaline water because the label can be peeled and separated at the same time.

  The plastic film used as the label substrate may be a single layer film or a laminated film in which a plurality of film layers are laminated according to required physical properties, applications, and the like. In the case of a laminated film, film layers made of different resins may be laminated. For example, it may be a three-layer or five-layer laminated film having a center layer and a surface layer, the center layer being made of a polyolefin resin or a polystyrene resin, and the surface layer being a polyester resin.

  Moreover, the plastic film used as a label base material may use any of an unstretched film, a uniaxially stretched film, and a biaxially stretched film according to a required physical property, a use, etc. For example, a non-heat-shrinkable film, such as an unstretched film or a biaxially stretched film, is used as a label base material for a label that is attached or pressed by winding, and particularly a biaxially stretched polypropylene film (OPP) And PET film etc. are used. In addition, a film that has been stretched in at least one direction is used as a label base material (heat-shrinkable film) of a label having heat-shrinkability such as a shrink label.

  Although the thickness of a label base material can be suitably selected in the range which does not impair mechanical strength, the handleability of a label, etc., it is about 5-100 micrometers, for example, Preferably it is about 8-60 micrometers. When the label base material of the label stuck by winding attachment or pressurization is an unstretched film or a biaxially stretched film, it is generally about 5-60 micrometers, Preferably it is about 8-50 micrometers. In the case of a label substrate (heat-shrinkable film) for shrink labels, the thickness is generally about 20 to 100 μm, preferably about 25 to 60 μm.

  The thermal contraction rate of the label base material varies depending on the type of label and is not particularly limited. However, when the label base material is a non-shrinkable film, the MD direction and the TD direction are immersed in hot water at 90 ° C. for 5 seconds. Both are preferably less than 5%, more preferably less than 1%. If the heat shrinkage rate is 5% or more, the label may shrink due to heat at the time of sticking, and wrinkles or misalignment may occur. On the other hand, when the label base material is a heat-shrinkable film, it is preferable to use a heat-shrinkable film mainly stretched in the MD direction (a film that shrinks more in the MD direction than in the TD direction). As the thermal shrinkage rate, for example, 10 to 60% in the MD direction and about −3 to 20% in the TD direction are immersed in hot water at 90 ° C. for 10 seconds. When the heat-shrinkable film is used as a winding label, the MD direction is wound as the circumferential direction of the container during use. Moreover, you may use the film which shrink | contracts greatly in TD direction, In that case, TD direction is used as the circumferential direction of a container.

  A commercial item can also be used for the label substrate. As a commercially available plastic film, for example, as a biaxially stretched polyethylene terephthalate (PET) film, “Lumirror” manufactured by Toray Industries, Inc., as a biaxially stretched polypropylene (OPP) film, “Trephan” manufactured by Toray Industries, Inc. “A1” manufactured by Gunze Co., Ltd., “U-1” manufactured by Tosero Co., Ltd., and the like can be used.

  The heat-sensitive label of the present invention is preferably provided with a printing layer in addition to the adhesive layer. The printing layer is a layer displaying a product name, an illustration, handling precautions, and the like, and can be formed by a conventional printing method such as letterpress printing, silk screen printing, gravure printing, flexographic printing, and the like. In the present invention, gravure printing and flexographic printing are preferably used in that the printing layer and the adhesive layer can be formed in one step, the printing speed is high, and the production efficiency can be improved. The printing layer is made of, for example, a pigment or a binder resin. As the binder resin, general resins such as acrylic, urethane, polyamide, vinyl chloride-vinyl acetate copolymer, cellulose, and nitrocellulose are used. it can. The thickness of the printing layer is not particularly limited and is, for example, about 0.1 to 10 μm.

  In the heat-sensitive label of the present invention, the adhesive layer and the print layer do not need to be provided on the entire surface of the label substrate, and may be provided on a part of the label substrate. Among them, the adhesive layer is strip-shaped when it is provided on the entire surface, or in the direction of the height direction of the container after being wound around the portion of the label that is the ends of the container in the circumferential direction after being wound. Is preferable. When the adhesive layer is provided in a strip shape at both ends in the label width direction as in the latter, one end of the label is attached to the container, the label is wound, and the other end is the label surface on the one end. It is preferably used as a type of label (wrapping label) that is attached to the sheet by being overlapped with each other.

  The laminated structure of the adhesive layer and the printing layer is not particularly limited, and an adhesive layer may be provided on the printing layer (label base material / printing layer / adhesive layer) or on the label base material. A portion where only the adhesive layer is provided (label base material / adhesive layer) and a portion where only the printing layer is provided (label base material / printing layer) may exist separately, and their lamination The configurations may be combined. In particular, a label having a layer structure of printing layer / label base material / adhesive layer in which a printing layer is laminated on one surface side of a label base material and an adhesive layer is laminated on the opposite surface side is preferably used. In addition, from the viewpoint of exhibiting the effect of the present invention, the heat-sensitive label has a layer configuration in which the adhesive layer is at least partially included in the outermost layer. If there is no portion where the adhesive layer is the outermost layer, the effect of the present invention cannot be exhibited. In particular, the heat-sensitive label of the present invention preferably has at least two separated portions where the adhesive layer becomes the outermost layer.

  In addition, in the thermosensitive label of this invention, you may provide a primer coat layer between a printing layer and a label base material from a viewpoint of the adhesive improvement of a printing layer and a label base material. The primer coat layer can be formed of a known primer such as an acrylic primer, a polyester primer, an isocyanate primer (two-component mixed primer, etc.), and the like. The thickness of a primer coat layer can be suitably selected in the range which does not impair transparency and the handleability of a label, For example, 0.1-3.0 micrometers is preferable.

  In addition, the thermal label of the present invention may be provided with an overcoat layer from the viewpoint of protecting the printed layer and imparting slipperiness and gloss. The overcoat layer is usually provided on the outside (on the side not in contact with the container) when mounted on a container, and is a transparent UV curable varnish, polyester resin, acrylic resin, epoxy resin, and silicone with a lubricant added as necessary. It can be formed by coating or printing a resin or the like. Note that the overcoat layer is preferably formed so as to avoid a region in contact with the adhesive layer. Although the thickness of an overcoat layer is not specifically limited, 0.1-3.0 micrometers is preferable.

  The thermosensitive label of the present invention is provided with a coating layer, a resin layer, an anchor coat layer, an overlaminate layer, etc. in addition to the label base material, the print layer, the adhesive layer, the primer coat layer, and the overcoat layer. A layer of non-woven fabric, paper, plastic, etc. may be provided as necessary.

  The heat-sensitive label of the present invention has particularly good adhesiveness when the average particle size of the solid plasticizer is small. Adhesiveness is the same as the surface of the container or label substrate, or the surface of the container or label substrate, and the label activated by heating above the activation temperature (for example, activation temperature +5 to + 20 ° C.) About the sample adhere | attached on the plastic sheet which has a physical property, it can evaluate as an adhesive strength with respect to the container surface and an adhesive strength with respect to a label base material by the test according to JISK6854-3 (T-type peeling) (peeling speed 300mm / min) ( The sample preparation conditions and the like are the same as the test method for “adhesive residue deterrence” described later). The adhesive strength of the adhesive layer based on the above method to the plastic sheet is preferably 0.5 to 3 N / 15 mm, more preferably 0.7 to 3 N / 15 mm. When the adhesive strength is less than 0.5 N / 15 mm, the adhesiveness is insufficient, and mounting defects such as inability to adhere the thermosensitive label to the container are likely to occur. On the other hand, if it exceeds 3 N / 15 mm, it is difficult to peel off the thermosensitive label from the container after use, or adhesive residue may be generated, which is not preferable. Among the above, it is preferable that the adhesive strength to the material used for the container (particularly preferably polyethylene terephthalate (PET)) and the adhesive strength to the material used for the label substrate (particularly preferably polypropylene (PP)) are in the above ranges. . In addition, the initial adhesive strength (adhesive strength immediately after adhering the label) and the adhesive strength after aging (for example, adhesive strength after storage for 3 weeks in an environment of 23 ° C. and 55% RH after adhering the label) Both are preferably in the above range.

  The heat-sensitive label of the present invention has a good adhesive residue deterring property even after a long time has elapsed after being attached to an adherend. Adhesive residue deterrence is determined by visually checking the presence or absence of adhesive residue on the plastic sheet after affixing and peeling the label according to the T-type peel test using the same material and physical properties as the container surface. It can be evaluated by observation (details are based on the test method described later). Normally, a heat-sensitive adhesive layer to which a solid plasticizer is added to give delayed tackiness recrystallizes the solid plasticizer in the adhesive layer over time, resulting in a decrease in cohesive strength at the crystal part, resulting in adhesive residue. In the present invention, however, the addition of the compound (A) suppresses crystallization of the solid plasticizer in the adhesive layer, so that no increase in adhesive residue over time occurs, and delayed tackiness and adhesive residue are prevented. Both deterrence and sustainability can be achieved.

  The heat-sensitive label of the present invention can be used by attaching an adhesive layer to an adherend. The adherend is not particularly limited and may be any of plastic, glass, metal, etc., but is made of a polyester resin such as polyethylene terephthalate (PET), or a plastic made of an olefin resin such as high density polyethylene or polypropylene. Those made of are preferred. Among these, an adherend made of a polyester resin such as PET is preferable.

  Examples of the adherend include bottles for soft drinks such as PET bottles, milk bottles for home delivery, food containers such as seasonings, bottles for alcoholic beverages, pharmaceutical containers, containers for chemical products such as detergents and sprays, cups, etc. Containers such as noodle containers are included. The shape of the container is not particularly limited, and includes various shapes such as a cylindrical shape, a square bottle, and a cup type. In particular, a plastic container made of a polyester resin such as polyethylene terephthalate (PET) or an olefin resin such as high density polyethylene or polypropylene is preferable, and a polyester resin container is particularly preferable.

  Since the heat-sensitive adhesive used in the heat-sensitive label of the present invention has both adhesiveness and adhesive residue inhibiting properties, one end of the label is directly bonded to the adherend, and then wrapped around the adherend, and the other end is placed on one end of the label. It can be preferably used as a wrapping label that adheres to (label surface). When used in this application, it can be used as an adhesive (excellent adhesiveness and adhesive residue deterrence required) used on the side that adheres to the bottle. It can be used as any of the adhesives used on the side that adheres to the surface (excellent adhesiveness and easy peelability are required). For this reason, it is not necessary to use two different types of adhesives in the label manufacturing process, which is preferable from the viewpoint of cost and productivity. The heat-sensitive adhesive of the present invention can be preferably used particularly when it is used as a heat-sensitive label having a label substrate made of a polyolefin resin and is attached to a container made of a polyester resin.

  The labeled container of the present invention is formed by mounting the thermosensitive label of the present invention on the container. The thermosensitive label may be attached to the entire surface of the container or may be attached to a part thereof. The heat-sensitive label can be attached to the container by a known or conventional method. For label mounting, for example, the adhesive layer side of the thermal label is placed on the container surface, a hot plate is pressed from the label substrate side, or the thermal label is sucked from the label substrate side to the heating drum. Usually, a labeler (automatic labeling machine: label sticker) is applied by activating the adhesive layer by applying heat to the adhesive layer with a heat source such as heat or infrared rays, and then applying it to the container by pressing. For example, those described in JP-A-8-58755, JP-A-11-321831, and JP-A-2000-25725 can be used. The heating temperature is appropriately selected according to the activation temperature of the adhesive layer, and is preferably 70 to 150 ° C, and more preferably 80 to 120 ° C, for example.

[Methods for measuring physical properties and methods for evaluating effects]
(1) Inhibition of crystallization (solid plasticizer emulsion)
The solid plasticizer emulsions obtained in Examples and Comparative Examples were stored at 40 ° C. for 4 days, and the average particle size (average particle size) of the solid plasticizer in the emulsion after storage was observed by laser diffraction method. did. Nikkiso Co., Ltd. MT3300EXII was used for the measurement.
When the average particle size of the measurement sample is less than the average particle size in the solid plasticizer emulsion of Comparative Example 1, it is judged that the crystallization inhibition property (storage stability) is good (◯), and the solid plasticizer of Comparative Example 1 When the average particle diameter in the emulsion was larger than the average particle size, it was judged that the crystallization inhibitory property (storage stability) was poor (x).
The crystallization inhibitory property (storage stability) of the solid plasticizer emulsion is a model representing the crystallization inhibitory property (storage stability) of an aqueous emulsion-type heat-sensitive adhesive using the solid plasticizer emulsion. The crystallization inhibition property of the water-based emulsion type heat-sensitive adhesive itself can also be measured by the same method as described above.

(2) Residue of adhesive residue (after long-term storage)
From the heat-sensitive labels obtained in the examples and comparative examples, strip-shaped test pieces having a width of 15 mm and a length of 40 mm were produced. The surface of the test piece on the adhesive layer side is attached to a polyethylene terephthalate (PET) container (manufactured by Toyo Seikan Co., Ltd.). It was pressure-bonded with a hot plate under the conditions of 10 MPa and 0.5 second. After storage for 3 weeks in an environment of 23 ± 2 ° C and 55 ± 15% RH, the container is cut open, and a sample with a shape used for the T-type peel test (a strip-shaped thermal label and a strip-shaped container member are attached) And used for the measurement.
Using a tensile tester (manufactured by Shimadzu Corporation, trade name “Autograph”), the thermal label and the sample attached to the container member were peeled off by a method in accordance with JIS K 6854-3 (peeling speed 300 mm / min). Went.
The presence or absence of adhesive residue on the surface of the peeled container member (PET) was visually observed and evaluated according to the following criteria.
No adhesive residue was seen: Good adhesive residue deterrence (○)
Slight adhesive residue was observed (less than 10% of the applied area): Usable level (△)
A large amount of adhesive residue was observed (more than 10% of the pasting area): Poor adhesive residue deterrence (×)

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. Table 1 shows the blending amounts (contents) and evaluation results of the components of Examples and Comparative Examples. In addition, in the table | surface, all the compounding quantities of each component are represented by the weight part of solid content (nonvolatile content) of each component. In addition, Example 2 and Example 3 are described as reference examples.

Example 1
(Solid plasticizer emulsion)
According to the blending amount in Table 1, 25 parts by weight (converted to solid content) of dicyclohexyl phthalate (DCHP) (produced by Osaka Organic Chemical Industry Co., Ltd.) was dispersed in water using a bead mill while reducing the particles of the solid plasticizer. Thus, an aqueous dispersion of DCHP (solid concentration: 50% by weight) was obtained. Next, a compound represented by the above formula (1) (manufactured by ADEKA, trade name “Adeka Stub NA-11”, 1.5 parts by weight (in terms of solid content) is added and dispersed, and a solid plasticizer emulsion (water The average particle diameter (dispersion diameter) of the solid plasticizer immediately after the production of the solid plasticizer emulsion was 0.8 μm.
This solid plasticizer emulsion was evaluated for crystallization inhibition. As shown in Table 1, the obtained solid plasticizer emulsion had good crystallization inhibitory properties and excellent storage stability. The average particle size of the solid plasticizer after storage for 4 days under the condition of 40 ° C. was 1.0 μm.
(Water-based emulsion-type heat-sensitive adhesive)
According to the blending amount of Table 1, 12.5 parts by weight (in terms of solid content) of an ethylene-vinyl acetate-acrylic copolymer resin emulsion (manufactured by Sumitomo Chemical Co., Ltd., trade name “Sumikaflex 900HL”) and carboxyl are used as thermoplastic resins. A modified styrene-butadiene latex (manufactured by Nippon A & L Co., Ltd., trade name “Nalstar SR-100”) 12.5 parts by weight (in terms of solid content) is mixed with the solid plasticizer emulsion to obtain an aqueous emulsion type of the present invention. A heat-sensitive adhesive (solid content concentration: 53% by weight) was obtained. In addition, the adhesive agent was produced using the solid plasticizer emulsion immediately after manufacture.

(Thermal label)
A biaxially stretched polypropylene (OPP) film (trade name “Trephan”, thickness 50 μm) manufactured by Toray Industries, Inc. is used as a label base material, and urethane-based solvent type white ink (Daiichi Seika Kogyo Co., Ltd. )) To produce a thermal label.
On one surface of the label base material, the printing ink was printed by gravure printing to form a printing layer (thickness 2 μm). Subsequently, the heat-sensitive adhesive obtained above is applied by gravure printing to both ends of one surface (surface on the printing layer side) of the label base material to form an adhesive layer (thickness 10 μm). Obtained.
As shown in Table 1, the obtained thermosensitive label had excellent adhesive residue deterrence.

Examples 2-6
As shown in Table 1, the type and blending amount of compound (A) were changed as shown in Table 1, and in the same manner as in Example 1, a solid plasticizer emulsion, a water-based emulsion type thermal adhesive and a thermal label were produced. In Examples 3 and 4, two kinds of compounds (A) were mixed and used. The average particle size of the solid plasticizer immediately after the production of the solid plasticizer emulsion was the same as in Example 1.
As shown in Table 1, the obtained solid plasticizer emulsion, water-based emulsion type heat-sensitive adhesive and heat-sensitive label had excellent characteristics.

Comparative Example 1
As shown in Table 1, a solid plasticizer emulsion, a water-based emulsion type thermosensitive adhesive, and a thermosensitive label were produced in the same manner as in Example 1 except that the compound (A) was not used. The average particle size of the solid plasticizer immediately after the production of the solid plasticizer emulsion was the same as in Example 1.
However, the solid plasticizer emulsion obtained in Comparative Example 1 was coarser than that of Example 1 in that the average particle size of the solid plasticizer after storage for 4 days in an environment of 40 ° C. was 2.2 μm. The anti-oxidation property (storage stability) was inferior.
Moreover, as shown in Table 1, the obtained thermosensitive label was inferior in adhesive residue deterrence.

Comparative Examples 2-10
As shown in Table 1, a solid plasticizer emulsion, a water-based emulsion type heat-sensitive adhesive and a heat-sensitive label were produced in the same manner as in Example 2 except that a compound other than the compound (A) of the present invention was used. The average particle size of the solid plasticizer immediately after the production of the solid plasticizer emulsion was the same as in Example 1.
As shown in Table 1, the obtained solid plasticizer emulsion, water-based emulsion-type heat-sensitive adhesive and heat-sensitive label were inferior in crystallization inhibition (storage stability) and adhesive residue inhibition.

  In addition to the above evaluation, for Example 1 and Comparative Example 1, the obtained water-based emulsion-type heat-sensitive adhesive was also compared for crystallization inhibition. Each heat-sensitive adhesive was stored in an environment of 40 ° C. for 4 days, and the average particle size of the solid plasticizer in the adhesive after storage was compared. As a result, in Example 1 in which the crystallization inhibitory property of the solid plasticizer emulsion was good, the average particle size of the solid plasticizer was smaller than that in Comparative Example 1 even in the state of the water-based emulsion type heat-sensitive adhesive. It was found that the deterrence is excellent.

  In addition, the heat-sensitive label obtained in Examples 1 to 6 was overlapped with one end portion on the surface of a PET bottle (manufactured by Toyo Sei) and pressed with a hot plate (temperature 100 ° C.) from the label substrate side. After activating and crimping the layer, the thermosensitive label is wound around the bottle, the other end is overlaid on one end, and the adhesive layer is activated by pressing the hot plate from the label substrate side to label An attached container was obtained.

レオドール ＳＰ−Ｏ１０Ｖ ： 花王（株）製、以下の構造式を有する界面活性剤（下記の左右の化合物の混合物）

Ａｌ−ＰＴＢＢＡ ： 日東化成工業（株）製、以下の構造式を有する造核剤

アデカスタブ ＨＰ−１０ ： （株）ＡＤＥＫＡ製、以下の構造式を有する酸化防止剤

ＩＲＧＡＮＯＸ １４２５ＷＬ ： チバ・スペシャルティ・ケミカルズ（株）製、以下の構造式を有する酸化防止剤

ＩＲＧＡＮＯＸ １３３０ ： チバ・スペシャルティ・ケミカルズ（株）製、以下の構造式を有する酸化防止剤

ＩＲＧＡＦＯＳ １２ ： チバ・スペシャルティ・ケミカルズ（株）製、以下の構造式を有する安定剤

ペレックスＳＳ−Ｌ ： 花王（株）製、以下の構造式を有する界面活性剤
（上記式中、Ｒはドデシル基である。）

安息香酸ナトリウム ： 和光純薬工業（株）製、以下の構造式を有する保存料

Details of the compounds other than the thermoplastic resin, solid plasticizer, compound (A) and compound (A) used in Table 1 are as follows.
[Thermoplastic resin]
Sumikaflex 900HL: manufactured by Sumitomo Chemical Co., Ltd., ethylene-vinyl acetate-acrylic copolymer resin emulsion (solid content concentration: 60%)
Nalstar SR-100: Nippon A & L Co., Ltd., carboxyl-modified styrene-butadiene latex (solid content concentration: 51%)
[Solid plasticizer]
DCHP: manufactured by Osaka Organic Chemical Industry Co., Ltd., dicyclohexyl phthalate [compound (A)]
ADK STAB NA-11: manufactured by ADEKA Corporation, compound of the above formula (1) Emulgen A-60: manufactured by Kao Corporation, compound of the above formula (3) α-cyclodextrin: manufactured by Wako Pure Chemical Industries, Ltd. Compound of formula (4) above [compound other than compound (A)]
Gerol MD: Shin Nippon Rika Co., Ltd., nucleating agent having the following structural formula

Rheodor SP-O10V: manufactured by Kao Corporation, surfactant having the following structural formula (mixture of the following left and right compounds)

Al-PTBBA: manufactured by Nitto Kasei Kogyo Co., Ltd., nucleating agent having the following structural formula

ADK STAB HP-10: manufactured by ADEKA Corporation, an antioxidant having the following structural formula

IRGANOX 1425WL: manufactured by Ciba Specialty Chemicals Co., Ltd., antioxidant having the following structural formula

IRGANOX 1330: manufactured by Ciba Specialty Chemicals Co., Ltd., antioxidant having the following structural formula

IRGAFOS 12: manufactured by Ciba Specialty Chemicals Co., Ltd., stabilizer having the following structural formula

Perex SS-L: manufactured by Kao Corporation, a surfactant having the following structural formula (in the above formula, R is a dodecyl group)

Sodium benzoate: Wako Pure Chemical Industries, Ltd., preservative having the following structural formula

Claims (5)

A heat-sensitive label in which an adhesive layer is laminated on a label substrate,
The adhesive layer comprises a thermoplastic resin, a solid plasticizer, and the following formula (1)

(In the formula, n 1, X is Na, K, or Ca, R ₁ ~R ₈ are each a hydrogen atom or a carbon atoms represent 1-6 alkyl group) aqueous emulsion type, containing a compound represented by A heat-sensitive label, which is formed of a heat-sensitive adhesive. The thermosensitive label according to claim 1, wherein the thermosensitive label is formed of an aqueous emulsion type thermosensitive adhesive containing 0.3 to 20 parts by weight of the compound represented by the formula (1) with respect to 100 parts by weight of the solid plasticizer . 2. The water-based emulsion type heat-sensitive adhesive having a content of [thermoplastic resin (solid content) / content of solid plasticizer (solid content)] of 70/30 to 30/70. 2. The thermal label according to 2. The total content (solid content) of the said thermoplastic resin and the said solid plasticizer is formed with the water-system emulsion type heat sensitive adhesive which is 65 weight% or more with respect to the total solid of the said heat sensitive adhesive. 3. The heat-sensitive label according to any one of items 3. A labeled container in which the thermosensitive label according to any one of claims 1 to 4 is mounted on the container.