Label and container with label attached

Abstract

To provide a label with excellent alkaline dispersibility, which has sufficient adhesive force, is high in resistance force and followability of hot melt with respect to deviation of the label due to expansion of a bottle during heating, is less likely to deviate when stored at a high temperature, is less likely to deviate even when stored at a low temperature, and can easily peel an adhesion object from a container by a hot alkaline aqueous solution without leaving any adhesive residue.SOLUTION: A label is mounted so as to be wound around an outer periphery of a container, which has a specific pressure-sensitive adhesive layer (a) and a specific pressure-sensitive adhesive layer (b) at one end part (I) and the other end part (II) of a base material film, respectively.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to labels and containers with such labels that are suitable for use on glass bottles and PET (polyethylene terephthalate) containers used for soft drinks, seasonings, detergents, shampoos, edible oils, cosmetics, pharmaceuticals, etc. [Background technology]

[0002] In recent years, the amount of polyethylene terephthalate (hereinafter referred to as PET) bottles used for beverages has been increasing along with the production volume of PET bottles. PET bottles usually have a plastic label attached to the outside of the body to display the product name, etc. There are several methods for attaching a plastic label to the outside of the body of a PET bottle, including the "roll label method" and the "shrink label method."

[0003] In either method, it is required that used PET bottles are collected and can be recycled as raw materials. For example, the "voluntary control guidelines for designated PET bottles" issued by the PET Bottle Recycling Promotion Council lists the following indicators. That is, when pellets made by cutting a bottle with a label are immersed in a 1.5% aqueous sodium hydroxide solution at 85°C at a pellet concentration of 10% (weight ratio) and stirred for 15 minutes, the label is peeled off from the PET pellets and printing ink, adhesive, etc. do not remain on the PET pellets. In order to peel off the label in the recycling process (alkali dispersion type), an alkali dispersion type hot melt adhesive composition has been developed and is used as an adhesive for labels on containers such as PET bottles (Patent Documents 1 to 4).

[0004] The "roll label method" allows labels to be made thinner than those used in the "shrink label method," and has become increasingly popular in recent years because it produces less carbon dioxide than the "shrink label method," which uses large amounts of steam during labeling.

[0005] However, the hot melt adhesive used in the "roll label method" has a softening point of 90°C or less to make it easier to disperse in a 1.5% sodium hydroxide solution at 90°C. Therefore, when the beverage is heated in its container using a hot vending machine in winter, part of the label peels off, and so the "roll label method" has not been used.

[0006] Patent Document 1 discloses a water-dispersible hot melt adhesive composition containing a copolyester. However, the copolyester described in Patent Document 1 has poor heat resistance and is partially thermally decomposed, which causes a problem that the adhesive strength of the adhesive composition is not stable.

[0007] Patent Document 2 discloses a hot melt adhesive comprising a thermoplastic elastomer (A), a rosin-based tackifier (B) having an acid value of 100 to 300 mgKOH / g, a terpene phenol resin (C), a process oil (D), and a polypropylene wax (E) graft-polymerized with maleic anhydride.

[0008] Patent Document 3 discloses a hot melt adhesive containing a thermoplastic elastomer (A), a rosin-based tackifier (B) having an acid value of 100 to 300 mgKOH / g, a process oil (C), a wax (D) having a needle penetration at 25°C of 10 dmm or less, and a polyethylene glycol (E) having a number average molecular weight of 1,000 or more.

[0009] Patent Document 4 discloses a hot melt adhesive comprising a thermoplastic elastomer (A), a solid tackifier (B) having an acid value of 100 to 300 mgKOH / g, a liquid tackifier (C), a wax (D), and a specific nonionic surfactant (E).

[0010] Labels using hot melt adhesives disclosed in the cited documents 1 to 4 have sufficient adhesive strength between alkali dispersion type plastic films and retention, but when the container is heated, the adhesive strength is significantly reduced, and furthermore, the resistance and conformability of the hot melt adhesive composition to the label displacement caused by bottle expansion is lost, causing the label to peel off, and there is a problem with heat resistance. In addition, if the heat resistance is improved, there is also a problem that the label peels off even when a PET bottle stored at low temperature is dropped.

[0011] In other words, there was a demand for a label that had sufficient adhesive strength, high hot melt resistance and conformability to the label's displacement due to the expansion of the bottle when heated, and that was unlikely to shift when stored at high temperatures and also unlikely to shift when stored at low temperatures, and that had excellent alkali dispersibility and could be easily peeled off from the container with a hot alkaline aqueous solution without leaving any glue behind. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Special Publication No. 11-512134 [Patent Document 2] JP 2010-90185 A [Patent Document 3] JP 2010-280878 A [Patent Document 4] JP 2012-1624 A Summary of the Invention [Problem to be solved by the invention]

[0013] To provide a label having sufficient adhesive strength, high resistance and conformity of hot melt to label displacement caused by expansion of a bottle when heated, which is unlikely to be displaced when stored at high temperature and also when stored at low temperature, which does not peel off even when dropped, and which allows the adhered matter to be easily peeled off from a container with a hot alkaline aqueous solution without leaving any adhesive residue, and a container to which the label is attached, which has excellent alkali dispersibility. [Means for solving the problem]

[0014] The present disclosure provides the following labels and containers having the labels attached thereto. [1]: A label to be attached by wrapping around the outer periphery of a container, the label having pressure-sensitive adhesive layers (A) and (B) on one end (I) and the other end (II) of a base film, The end portion (I) is a joint portion between the base film and the container, and the end portion (II) is a fixing portion where the base films are joined to each other after winding, A label characterized in that the adhesive layer (i) contains an alkali dispersible hot melt adhesive (a) having a softening point of 90°C or lower, and the adhesive layer (ii) contains a hot melt adhesive (b) having a softening point of higher than 90°C. [2] The label according to [1], characterized in that it contains 5 to 35 mass% of a thermoplastic elastomer (A1) having a styrene content of 25 to 50 mass% in 100 mass% of a hot melt adhesive (b) having a softening point higher than 90°C. [3]: The label according to [2], further comprising a thermoplastic elastomer (A2) having a styrene content of more than 5% by mass and less than 25% by mass in 100% by mass of a hot melt adhesive (b) having a softening point of more than 90°C and not more than 20% by mass. [4]: The label according to [2] or [3], further comprising 5 to 40 mass% in total of polybutene (D) and / or process oil (E) in 100 mass% of hot melt adhesive (b) having a softening point higher than 90°C. [5]: A label according to any one of [2] to [4], further comprising 20 to 70 mass% of a solid tackifier (B) and 1 to 20 mass% of a wax (C) in 100 mass% of a hot melt adhesive (b) having a softening point higher than 90°C. [6]: The label according to any one of [1] to [5], wherein a 25% by mass solution of the thermoplastic elastomer (A1) in toluene at 25° C. has a viscosity of 100 to 50,000 mPa·s. [7]: The label according to [5] or [6], characterized in that the melting point of the wax (C) is 90 to 160°C. [8]: A container with a label bearing any of the following: [1] to [7]. [9]: A container according to [8], characterized in that the material of the container is polyethylene terephthalate.

[10] : A container according to [8] or [9], which is for hot beverages. Effect of the Invention

[0015] The present invention can provide a label and a container to which the label is attached that have sufficient adhesive strength, high resistance and conformity of the hot melt to label shifting due to bottle expansion, and are particularly resistant to peeling or shifting when the bottle is warmed and stored, and are also resistant to shifting when stored at low temperatures, and are easily peeled off from containers, etc. without leaving any glue residue when immersed in a hot alkaline aqueous solution and do not reattach. The label and the container to which the label is attached have excellent alkali dispersibility. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present disclosure will be described in detail below. It should be noted that other embodiments are of course included in the scope of the present invention as long as they conform to the spirit of the present invention.

[0017] In this specification, a numerical range specified by using "~" includes the numerical values ​​before and after "~" as the lower and upper limit ranges. In addition, unless otherwise noted, each of the various components appearing in this specification may be used independently, either alone or in combination of two or more types. In addition, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0018] In this specification, the "softening point" was measured according to JIS K6863 (test method for softening point of hot melt adhesives). In this specification, the "viscosity of a 25% by mass toluene solution of a thermoplastic elastomer at 25°C" refers to the viscosity of a toluene solution of a thermoplastic elastomer with a solid content of 25% by mass measured at 25°C using a Brookfield viscometer under appropriate spindle and rotation speed conditions. In this specification, the "weight average molecular weight of the thermoplastic elastomer (A1)" refers to the molecular weight distribution measured in terms of polystyrene by analysis using gel permeation chromatography (GPC). Tetrahydrofuran (THF) was used as the eluent. In this specification, the "melting point of the wax" is a value measured by a differential scanning calorimeter (Shimadzu automatic differential calorimeter DSC-60A Plus).

[0019] In this specification, an alkali-dispersible hot-melt pressure-sensitive adhesive (a) having a softening point of 90° C. or lower may be abbreviated as "alkali-dispersible hot-melt pressure-sensitive adhesive (a)." A hot-melt pressure-sensitive adhesive (b) having a softening point of higher than 90° C. may be abbreviated as "hot-melt pressure-sensitive adhesive (b)." "Hot melt" refers to a property that is solid or viscous at room temperature and melts and softens when heated, becoming fluid or liquid. The term "alkali dispersion type" means that the label can be peeled off with an alkaline processing solution in the recycling process.

[0020] <Label> The label of the present invention is a label to be attached by wrapping it around the outer periphery of a container, and has adhesive layers (a) and (b) at one end (I) and the other end (II) of a base film, respectively. End (I) is the joint between the base film and the container, and end (II) is a fixing part where the base films are joined to each other after wrapping. The adhesive layer (a) contains an alkali dispersible hot melt adhesive (a) having a softening point of 90°C or lower, and the adhesive layer (b) contains a hot melt adhesive (b) having a softening point higher than 90°C.

[0021] By simultaneously using an alkali dispersible hot melt adhesive (a) with a softening point of 90°C or less and a hot melt adhesive (b) with a softening point of more than 90°C in the label, it is possible to provide a labeled container that is both heat resistant and recyclable (compliant with the "Voluntary Control Guidelines for Designated PET Bottles").

[0022] <Base film> As the base film, biaxially oriented polypropylene (OPP), polyethylene (PE), PET, and even paper are usually used. In addition, as the label, a suitable printing is applied to the side opposite to the side to which the hot melt adhesive is applied, i.e., the front side of the label, or to the side to which the alkali dispersible hot melt adhesive is applied, i.e., the back side of the label. In the present invention, the alkali dispersible hot melt adhesive material can be applied to the printed side of the label that has been printed, or of course, it can be applied to the side that has not been printed. In either case, it exhibits a predetermined adhesiveness, peelability, and hot alkaline water solubility. In addition, the printing may be performed on the entire back side of the label, or may be performed on only a part of the surface. The printing may be performed by any of the conventionally known printing methods, such as gravure printing and UV printing.

[0023] Materials used for the alkali dispersible hot melt adhesive (a) and the hot melt adhesive (b) for forming the adhesive layer will be described below.

[0024] [Thermoplastic elastomer (A)] Thermoplastic elastomers are elastic materials that have the same properties as vulcanized rubber at room temperature, and at high temperatures they are polymeric materials that can be used with existing molding machines just like ordinary thermoplastic resins. Thermoplastic elastomers have both elastic rubber components in the molecules (soft segments: soft phase) and molecular restraint components (hard segments: hard phase) to prevent plastic deformation, so they have properties between rubber and plastic. Thermoplastic elastomers generally have a polystyrene block and a rubber middle block, with the polystyrene portion forming a physical crosslink (domain) and becoming the crosslinking point, and the middle rubber block giving the product rubber elasticity. The middle soft segment includes polybutadiene (B), polyisoprene (I) and polyolefin elastomers (ethylene-propylene (EP), ethylene-butylene (EB), butylene-butadiene (BB)), and depending on the arrangement with the hard segment polystyrene (S), they are divided into linear type and branched type (radial type).

[0025] Examples of the thermoplastic elastomer include styrene-based elastomers such as styrene-butadiene-styrene block copolymer (hereinafter sometimes abbreviated as SBS), styrene-ethylene-butylene-styrene block copolymer (hereinafter sometimes abbreviated as SEBS), styrene-ethylene-propylene-styrene block copolymer (hereinafter sometimes abbreviated as SEPS), styrene-isoprene-styrene block copolymer (hereinafter sometimes abbreviated as SIS), and styrene-butylene-butadiene-styrene block copolymer (hereinafter sometimes abbreviated as SBBS), as well as triblock block polymers such as methyl methacrylate-butyl acrylate-methyl methacrylate, and methyl methacrylate-butyl acrylate-methyl acrylate-methyl methacrylate, and diblock polymers thereof. As the thermoplastic elastomer (A) of the present invention, styrene-based elastomers such as styrene-ethylene-butylene-styrene block copolymer (SEBS) are preferred.

[0026] Thermoplastic elastomers are roughly classified into thermoplastic elastomers (A1) having a styrene content of 25% by mass or more and less than 50% by mass, thermoplastic elastomers (A2) having a styrene content of 5% by mass or more and less than 25% by mass, and other thermoplastic elastomers (A3). The styrene content refers to the styrene content in the total mass of the thermoplastic elastomer.

[0027] [Solid tackifier (B)] The solid tackifier (B) used in the present invention is not particularly limited as long as it is solid at room temperature (23° C.). The solid tackifier (B) is divided into solid tackifiers (B1) having an acid value of 100 to 300 mgKOH / g and solid tackifiers (B2) other than (B1).

[0028] The solid tackifier (B1) having an acid value of 100 to 300 mgKOH / g is not particularly limited, and an example thereof is a rosin-based tackifier. Examples of the rosin-based tackifier include unmodified unhydrogenated rosin, unmodified hydrogenated rosin, (meth)acrylic acid modified rosin, hydrogenated (meth)acrylic acid modified rosin, maleic acid modified rosin, hydrogenated maleic acid modified rosin, fumaric acid modified rosin, and hydrogenated fumaric acid modified rosin.

[0029] (B2) is not particularly limited as long as it is a solid adhesive having an acid value of less than 100 mgKOH / g or more than 300 mgKOH / g, and examples thereof include phenolic resin, modified phenolic resin, terpene phenolic resin, xylene phenolic resin, cyclopentadiene-phenolic resin, xylene resin, aliphatic, alicyclic, aromatic petroleum resins, hydrogenated aliphatic, alicyclic, aromatic petroleum resins, phenol-modified petroleum resin, rosin ester resin, hydrogenated rosin, acid-modified rosin, hydrogenated rosin ester resin, low molecular weight polystyrene resin, terpene resin, hydrogenated terpene resin, etc. The acid value is the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of a sample, and is a value measured in accordance with JIS K5601-2-1 Acid Value (Titration Method). The method for measuring the acid value is described in detail in the Examples section.

[0030] Wax Waxes (C) are broadly classified into natural waxes (animal waxes (beeswax, etc.), plant waxes (japanese wax, rice bran wax, etc.), mineral waxes (ozokerite, etc.), petroleum waxes (paraffin wax, microcrystalline wax, etc.)) and synthetic waxes (Fischer-Tropsch wax, polyethylene wax, polypropylene and acid-modified waxes, etc.). Waxes (C) are used alone or in combination of two or more kinds. From the viewpoints of adhesive strength and impact resistance, synthetic waxes are preferred as wax (C). More preferred are polypropylene wax and its acid-modified waxes from the viewpoint of adhesive strength (adhesion).

[0031] [Polybutene (D)] Polybutene (D) is a long-chain copolymer in which isobutene is the main monomer and normal butene is partially reacted as a secondary monomer. Unlike low-molecular-weight polyisobutylene in which purified isobutylene is the main monomer, the remaining fraction obtained by extracting butadiene from the C4 fraction produced by naphtha cracking can be used as it is as the monomer (raw material) for such polybutene. Note that polybutene may be a liquid polymer in which a small amount of butene-1 is copolymerized.

[0032] [Process oil (E)] The process oil (E) is an oil generally used as a plasticizer for rubber, thermoplastic elastomers, etc., that is, a process oil produced in a petroleum refinery, etc., and is roughly classified into a paraffin-based process oil, a naphthenic process oil, and an aromatic process oil. From the viewpoint of alkali dispersibility, a naphthenic oil is preferred. Process oil is a mixture of aromatic rings, naphthenic rings, and paraffin chains, and naphthenic process oil in this application refers to process oil in which naphthenic ring carbons account for 35-46% by mass of the total carbon of the process oil. In addition, process oils in which aromatic carbons account for 30% by mass or more of the total carbon are classified as aromatic process oils, and process oils in which paraffin chain carbons account for 50% by mass or more of the total carbon are classified as paraffinic process oils.

[0033] <Alkaline dispersible hot melt adhesive (a) having a softening point of 90°C or less> The alkaline dispersion type hot melt adhesive (a) is, for example, an adhesive that complies with the "voluntary control guidelines for designated PET bottles" issued by the PET Bottle Recycling Promotion Council. That is, when pellets made by cutting a bottle with a label are immersed in a 1.5% sodium hydroxide solution at 90°C at a pellet concentration of 10% (by weight) and stirred for 15 minutes, the label peels off from the PET pellets and no printing ink, adhesive, etc. remain on the PET pellets. The adhesive strength (adhesion) of the alkaline dispersible hot melt pressure sensitive adhesive (a) is sufficient if it is capable of temporarily attaching the container and the label.

[0034] The alkali-dispersible hot-melt pressure-sensitive adhesive (a) having a softening point of 90°C or lower preferably contains a thermoplastic elastomer (A), a solid tackifier (B1) having an acid value of 100 to 300 mgKOH / g, and polybutene (D) and / or process oil (E), and more preferably further contains a wax (C). By including a solid tackifier (B1) having an acid value of 100 to 300 mgKOH / g, an alkali-dispersible hot melt pressure-sensitive adhesive can be obtained which exhibits sufficient alkali dispersibility, has excellent compatibility, suppresses melt viscosity, improves coatability, and further has excellent adhesive strength (adhesion).

[0035] The content of the thermoplastic elastomer (A) in 100% by mass of the alkali dispersible hot melt pressure sensitive adhesive (a) is preferably from 5 to 40% by mass, more preferably from 10 to 30% by mass, from the viewpoints of alkali dispersibility and cohesive strength. The thermoplastic elastomer (A) in 100 mass % of the alkali dispersion-type hot melt pressure sensitive adhesive (a) may be any one of the thermoplastic elastomers (A1), (A2) and (A3), and two or more types may be used.

[0036] The content of the solid tackifier (B1) having an acid value of 100 to 300 mgKOH / g in 100 mass% of the alkali dispersible hot melt pressure sensitive adhesive (a) is preferably 20 to 70 mass%, more preferably 30 to 60 mass%, and even more preferably 40 to 55 mass%. By containing the solid tackifier (B1) having an acid value of 100 to 300 mgKOH / g in the above range, both alkali dispersibility and adhesiveness (adhesiveness) can be achieved, which is preferable.

[0037] From the viewpoint of adhesiveness (holding power), the content of the wax (C) in 100% by mass of the alkali dispersion-type hot melt pressure sensitive adhesive (a) is preferably 0 to 20% by mass, more preferably 3 to 15% by mass, and even more preferably 5 to 10% by mass.

[0038] The total content of the polybutene (D) and the process oil (E) in 100% by mass of the alkali dispersible hot melt pressure sensitive adhesive (a) is preferably from 25 to 75% by mass, more preferably from 30 to 70% by mass, from the viewpoints of alkali dispersibility and adhesion.

[0039] (Method for producing alkali dispersible hot melt pressure sensitive adhesive (a)) The alkali-dispersible hot-melt pressure-sensitive adhesive (a) of the present invention having a softening point of 90°C or lower can be produced, for example, by melting wax (C), polybutene (D) and process oil (E) in a melting pot equipped with a stirrer, mixing and dispersing thermoplastic elastomer (A) into the melt, and further adding and mixing a solid tackifier (B1) having an acid value of 100 to 300 mgKOH / g.

[0040] The alkali dispersible hot melt pressure sensitive adhesive (a) may be used by mixing the compounding components and forming them into a desired shape. The desired shape may be granular, pellet, planar, or block. These methods may be any known method without any restrictions.

[0041] <Hot melt adhesive (b) with a softening point higher than 90°C> The hot melt pressure sensitive adhesive (b) having a softening point higher than 90°C preferably contains 5-35% by mass of a thermoplastic elastomer (A1) having a styrene content of 25% by mass or more and less than 50% by mass per 100% by mass of the hot melt pressure sensitive adhesive (b). By setting the content of the thermoplastic elastomer (A1) to 5-35% by mass, the adhesiveness (cohesive strength) can be kept good. The content is more preferably 10-30% by mass, and even more preferably 15-25% by mass.

[0042] The viscosity of a 25% by mass toluene solution of the thermoplastic elastomer (A1) at 25° C. is preferably 100 to 50,000 mPa s, more preferably 150 to 10,000 mPa s, and even more preferably 250 to 5,000 mPa s. When the viscosity is within the above range, both heat resistance and stringiness during coating can be achieved.

[0043] The hot melt pressure sensitive adhesive (b) having a softening point higher than 90° C. preferably further contains a thermoplastic elastomer (A2) having a styrene content of 5% by mass or more and less than 25% by mass. The combined use of thermoplastic elastomers (A1) and (A2) makes it possible to provide excellent adhesion (adhesion) when the label is attached to a container and the container is heated, and to reduce stringiness when the hot melt adhesive (b) is applied to the label. However, the stringiness when applying the hot melt adhesive to the label can also be reduced by changing the type of labeler that applies the hot melt adhesive to the label.

[0044] The hot melt pressure sensitive adhesive (b) having a softening point higher than 90°C preferably contains, in addition to the thermoplastic elastomer (A1), a thermoplastic elastomer (A2) having a styrene content of 5% or more and less than 25% by mass, in an amount of more than 0% by mass and not more than 20% by mass, based on 100% by mass of the hot melt pressure sensitive adhesive (b). By setting the content of the thermoplastic elastomer (A2) to more than 0% by mass and not more than 20% by mass, the adhesiveness (adhesion) can be kept good. The content is more preferably 5 to 15% by mass.

[0045] In addition, the hot melt adhesive (b) having a softening point higher than 90°C preferably contains, in addition to the thermoplastic elastomer (A1), 20 to 70 mass% of a solid tackifier (B) per 100 mass% of the hot melt adhesive (b). By setting the content of the solid tackifier (B) at 20 to 70 mass%, good adhesiveness (adhesion) can be maintained. 30 to 60 mass% is more preferable, and 40 to 55 mass% is even more preferable.

[0046] The solid tackifier (B) is preferably the above-mentioned (B1). Although there is no problem if the hot melt adhesive (b) having a softening point higher than 90° C. does not have alkali dispersibility, the use of the solid tackifier (B1) can impart alkali dispersibility to prevent re-adhesion when the label and container are separated with a hot alkaline aqueous solution.

[0047] Furthermore, the hot melt pressure sensitive adhesive (b) having a softening point higher than 90°C preferably contains 1 to 20 mass% of wax (C) in addition to the thermoplastic elastomer (A1). By setting the content of wax (C) at 1 to 20 mass%, the cohesive strength can be maintained at a good level, more preferably 3 to 15 mass%, and even more preferably 5 to 10 mass%.

[0048] The wax (C) contained in the hot melt pressure-sensitive adhesive (b) is preferably a wax (C1) having a melting point in the range of 90 to 160°C as measured by a differential scanning calorimeter (DSC). A melting point of 90°C or higher provides good heat resistance and adhesiveness (cohesion), while a melting point of 160°C or lower provides good coatability and alkali dispersibility of the hot melt pressure-sensitive adhesive. The melting point of the wax (C1) is more preferably 120 to 150°C or lower, even more preferably 130 to 150°C, and particularly preferably 140 to 150°C.

[0049] In addition, the hot melt pressure sensitive adhesive (b) having a softening point higher than 90°C preferably contains, in addition to the thermoplastic elastomer (A1), a total of 5 to 40 mass% of polybutene (D) and / or process oil (E) per 100 mass% of the hot melt pressure sensitive adhesive (b). By setting the total content of polybutene (D) and / or process oil (E) to 5 to 40 mass%, it is possible to improve heat resistance and cold resistance. The content of polybutene (D) is more preferably 10 to 25 mass%, and even more preferably 15 to 20 mass%.

[0050] The polybutene (D) contained in the hot melt adhesive (b) has a kinetic viscosity (JIS K2283) of 70 to 1000 mm at 100°C. 2 Polybutene (D) having a kinematic viscosity in the range of 70 mm / s at 100°C is preferred. 2 / s or more, the adhesive strength (holding power) of the label is strong, and the 2 By setting the kinematic viscosity at 100° C. to be not more than 100 mm / s, the label can be easily peeled off in a hot alkaline aqueous solution. 2 / s, and more preferably 150 to 300 mm 2 The method for measuring the kinetic viscosity is described in the Examples section.

[0051] The process oil (E) contained in the hot melt adhesive (b) has a kinetic viscosity (JIS K2283) of 20 to 350 mm at 40°C. 2 The range of kinematic viscosity at 40°C is preferably 20mm / s. 2 / s or more, the adhesive strength (holding strength) of the label is strong, and the 2 / s or less, the label can be easily peeled off in a hot alkaline aqueous solution (reattachment of the label is reduced).

[0052] Although not limited to the following embodiment, the hot melt pressure sensitive adhesive (b) having a softening point higher than 90°C preferably contains a thermoplastic elastomer (A1), a solid tackifier (B), a wax (C), polybutene (D) and / or process oil (E), and preferably further contains a thermoplastic elastomer (A2).

[0053] (Production of hot melt adhesive (b) having a softening point of 90°C or higher) The hot melt pressure-sensitive adhesive (b) of the present invention can be produced, for example, by mixing and dispersing the thermoplastic elastomer (A) into melted wax (C) and polybutene (D) in a melting kettle equipped with a stirrer, and then adding and mixing the solid tackifier (B).

[0054] The hot melt pressure sensitive adhesive (b) may be used by mixing the ingredients and molding them into a desired shape. Examples of the desired shape include granules, pellets, sheets, and blocks. These methods can be used without any restrictions using known methods.

[0055] The hot melt pressure sensitive adhesives (a) and (b) of the present invention may further contain other components within the range that does not impair the effects of the present invention. Examples of other components include colorants, antiblocking agents, inorganic fillers, antioxidants, flame retardants, plasticizers, antistatic agents, light stabilizers, ultraviolet absorbers, heavy metal deactivators, and fluorescent whitening agents. These components may be used alone or in combination of two or more.

[0056] The colorant may be a commonly used colorant such as red, blue, green, yellow, etc. The colorant may be any of pigments, dyes, and colorants, and examples of the colorant include monoazo, dizazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, quinacridone, phthalocyanine, and anthraquinone, and examples of the pigment include pigment, perylene, monoazo, condensed azo, isoindolinone, titanium oxide, and carbon.

[0057] The antiblocking agent includes silicone, unsaturated fatty acid amides such as stearic acid amide, oleic acid amide, erucic acid amide, oleic acid amide and behenic acid amide.

[0058] Examples of the inorganic filler include particles and fibers of metals, metal oxides, metal hydroxides, etc. Specific examples include glass fibers, carbon fibers, calcium silicate, calcium titanate, aluminum borate fibers, flake glass, talc, kaolin, mica, hydrotalcite, calcium carbonate, zinc carbonate, zinc oxide, calcium hydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, alumina sodium silicate, magnesium silicate, carbon nanotube, graphite, copper, silver, aluminum, nickel, iron, calcium fluoride, mica, montmorillonite, apatite, etc.

[0059] Examples of the antioxidant include pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene)bis[3-(5-t-butyl-4-hydroxy-m-tolyl]propionate, tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, etc. These antioxidants may be used alone or in combination of two or more.

[0060] Examples of the flame retardant include phosphorus-containing compound-based flame retardants, halogen-containing compound-based flame retardants, sulfonic acid metal salt-based flame retardants, and silicon-containing compound-based flame retardants.

[0061] Examples of the plasticizer include phthalate ester plasticizers, polyester plasticizers, aliphatic dibasic acid ester plasticizers, aliphatic monobasic acid ester plasticizers, phosphate ester plasticizers, citrate ester plasticizers, epoxy plasticizers, trimellitate ester plasticizers, tetrahydrophthalate ester plasticizers, glycol plasticizers, and bisphenol A alkylene oxide derivatives.

[0062] The antistatic agent may be any agent commonly used as an antistatic agent for plastics, and specific examples thereof include nonionic surfactants (e.g., fatty acid esters of polyhydric alcohols, ethylene oxide adducts of alkylamines, and fatty acid esters of ethylene oxide adducts of alkylamines), anionic surfactants (e.g., alkylbenzenesulfonates, higher alcohol sulfate salts), cationic surfactants (e.g., aliphatic amine salts, quaternary ammonium salts), and amphoteric surfactants (e.g., imidazoline type, betaine type, etc.).

[0063] Examples of the light stabilizer include hindered amine compounds and benzoate compounds.

[0064] Examples of the ultraviolet absorbing agent include a benzophenone-based ultraviolet absorbing agent, a triazine-based ultraviolet absorbing agent, and a benzotriazole-based ultraviolet absorbing agent.

[0065] The heavy metal deactivator includes a salicylic acid derivative, a hydrazide derivative, an oxalic acid amide derivative, and the like.

[0066] Examples of the fluorescent whitening agent include stilbene-based, coumarin-based, oxazole-based, and naphthalimide-based agents.

[0067] The content of the other components in the hot-melt pressure-sensitive adhesive (a) having a softening point of 90° C. or lower and the hot-melt pressure-sensitive adhesive (b) having a softening point higher than 90° C. is preferably 0 to 40 mass% per 100 mass% of the hot-melt pressure-sensitive adhesive (a) having a softening point of 90° C. or lower and the hot-melt pressure-sensitive adhesive (b) having a softening point higher than 90° C., respectively. The content is more preferably 0 to 30 mass%, and even more preferably 0 to 20 mass%.

[0068] (container) The container in the present invention refers to a container to which the label of the present invention using the alkali-dispersible hot melt adhesive (a) and the hot melt adhesive (b) is attached. The material of the container includes glass, plastic, paper, etc., but is not particularly limited. In addition, the shape of the container may be round or non-round, such as square.

[0069] In the case of PET bottles, in addition to the label attached to a part of the body of the PET bottle, the label is used as a roll label wound around the body of the bottle to cover it. OPP film is often used as such a roll label. The label of the present invention can be well adhered whether the back side is printed or not. In the present invention, the alkali dispersion type hot melt adhesive (a) and the hot melt adhesive (b) are applied to a part of the back side of the label. The application method includes the open wheel method, the closed gun method, the direct coat method, etc. As a method that does not leave glue on the PET bottle when peeled off, the open wheel method and the direct coat method are preferable.

[0070] The coating amount of the alkali dispersible hot melt adhesive (a) and the hot melt adhesive (b) of the label to be attached to the container of the present invention is 10 to 300 g / m 2 The coating amount is preferably 10 to 300 g / m 2 As a result, it exhibits excellent effects in terms of adhesiveness (adhesion) and the like. EXAMPLES

[0071] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to the following examples. In the examples, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0072] [Method for measuring the acid value of solid adhesives] The acid value was measured in accordance with JIS K5601-2-1 Acid Value (Titration Method). Specifically, 1 g of sample was precisely weighed and placed in a 250 ml flask, 50 ml of a 2:1 mixed solvent of toluene and ethanol was added, and the mixture was heated to dissolve it, and titrated with 0.1N potassium hydroxide solution while occasionally shaking (indicator: phenolphthalein). The end point of the titration was the point at which the light pink color of the solution remained for 30 seconds. Next, a blank test was performed in the same manner to make corrections, and the acid value was calculated from the following formula. Acid value = [amount of 0.1N potassium hydroxide solution consumed (ml) x 5.611] / [amount of sample (g)]

[0073] [Method of measuring the melting point of wax (C)] The melting point of the wax (C) was measured using a differential scanning calorimeter (Shimadzu Automatic Differential Calorimeter DSC-60A Plus). Approximately 5 mg of a sample was taken, cooled to 0°C, heated to 170°C at a heating rate of 10°C / min, and then cooled to 0°C at a cooling rate of -20°C / min. After being held at 0°C for 1 minute, it was heated again at a heating rate of 10°C / min, and the amount of heat released and absorbed when heated to 170°C was measured. The melting peak when the wax melted was taken as the melting point.

[0074] [Method for measuring kinematic viscosity of polybutene (D)] The kinetic viscosity of polybutene was measured in accordance with JIS K2283. The kinetic viscosity of polybutene (D) was measured at 100°C.

[0075] The raw materials used for the alkali dispersible hot melt adhesive (a) and the hot melt adhesive (b) are shown below.

[0076] [Thermoplastic elastomer (A)] (Thermoplastic elastomer A1) Kraton G1650 (Kraton Polymers), styrene content: 30% by mass, viscosity of 25% solids in toluene solution at 25°C: 8,000 mPa s, SEBS Kraton G1651 (Kraton Polymers), styrene content: 33% by mass, viscosity of 25% solids in toluene solution at 25°C: 50,000 mPa·s or more, SEBS Kraton G1652 (Kraton Polymers), styrene content: 30% by mass, viscosity of 25% solids in toluene solution at 25°C: 1,800 mPa s, SEBS Kraton G1726 (Kraton Polymers), styrene content: 30% by mass, viscosity of 25% solids in toluene solution at 25°C: 200 mPa s, SEBS Kraton D1102 (Kraton Polymers), styrene content: 28% by mass, viscosity of 25% solids in toluene solution at 25°C: 1,100 mPa s, SBS Kraton D1162 (Kraton Polymers), styrene content: 43% by mass, viscosity of 25% solids in toluene solution at 25°C: 120 mPa s, SIS (Thermoplastic elastomer A2) Kraton G1645 (Kraton Polymers), styrene content: 13% by mass, viscosity of 25% solids in toluene solution at 25°C: 120 mPa·s or less, SEBS Kraton D1161 (Kraton Polymers), styrene content: 15% by mass, viscosity of 25% solids in toluene solution at 25°C: 1,200 mPa s, SIS Kraton G1643 (Kraton Polymers), styrene content: 19% by mass, viscosity of 25% solids in toluene solution at 25°C: 200 mPa s, SEBS Kraton D1111 (Kraton Polymers), styrene content: 22% by mass, viscosity of 25% solids in toluene solution at 25°C: 1,100 mPa s, SIS (Thermoplastic elastomer A3) Kraton A1535 (Kraton Polymers), styrene content: 58% by mass, viscosity of 25% solids in toluene solution at 25°C: not soluble in toluene, not measurable, SEBS

[0077] [Solid tackifier (B)] (Solid tackifier (B1) with an acid value of 100 to 300 mg KOH / g) RHR-301 (manufactured by Wuzhou Sun Shine Forestry & Chemicals Co.,LTD of Guangxi, China), hydrogenated rosin, acid value: 165mgKOH / g KE-604B: Pine Cristal KE-604B (Arakawa Chemical Co., Ltd.), acrylic modified rosin, acid value: 246 mg KOH / g Haritac AQ-90A (Harima Chemicals), modified rosin, acid value: 105 mg KOH / g

[0078] [Other solid tackifiers (B2)] Alcon P-70 (Arakawa Chemical Co., Ltd.), alicyclic saturated hydrocarbon resin, acid value 0 mgKOH / g, softening point: 70°C Alcon P-90 (Arakawa Chemical Co., Ltd.), alicyclic saturated hydrocarbon resin, acid value 0 mgKOH / g, softening point: 90°C Alcon P-100 (Arakawa Chemical Co., Ltd.), alicyclic saturated hydrocarbon resin, acid value 0 mgKOH / g, softening point: 100°C Alcon P-125 (Arakawa Chemical Co., Ltd.), alicyclic saturated hydrocarbon resin, acid value 0 mgKOH / g, softening point: 125°C

[0079] Wax NP805: Hiwax NP805 (Mitsui Chemicals), polypropylene wax, melting point 145℃ NP056: Hiwax NP056 (Mitsui Chemicals), polypropylene wax, melting point 124℃ PPMA6252: Ricosene PPMA6252 (Client Chemicals), acid-modified polypropylene wax, melting point: 140℃ Viscol 660P (Sanyo Chemical Industries, Ltd.), polyethylene wax, melting point: 136°C

[0080] [Polybutene (D)] HV-35 (ENEOS) 100℃ kinematic viscosity: 85mm 2 / s HV-50 (ENEOS) 100℃ kinematic viscosity: 110mm 2 / s HV-100 (ENEOS) 100℃ kinematic viscosity: 220mm 2 / s HV-300 (ENEOS) 100℃ kinematic viscosity: 590mm 2 / s

[0081] [Process oil (E)] PW-32: Diana Process Oil PW-32 (Idemitsu Kosan Co., Ltd.), 40°C kinematic viscosity: 31mm 2 / s PW-90: Diana Process Oil PW-90 (Idemitsu Kosan Co., Ltd.), 40°C kinematic viscosity: 95mm 2 / s PW-150: Diana Process Oil PW-150 (Idemitsu Kosan Co., Ltd.), 40°C kinematic viscosity: 145mm 2 / s PW-380: Diana Process Oil PW-380 (Idemitsu Kosan Co., Ltd.), 40°C kinematic viscosity: 381mm 2 / s PS-430: Diana Process Oil PS-430 (Idemitsu Kosan Co., Ltd.), 40°C kinematic viscosity: 438mm 2 / s

[0082] [Antioxidants] IRG1010: Irganox 1010 (BASF), pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]

[0083] <Production of alkali dispersible hot melt pressure sensitive adhesive (a) having a softening point of 90° C. or lower> (Manufacturing example a-1) In a stainless steel beaker equipped with a stirrer, 30 parts of process oil (E): PW-90 and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 5 parts of thermoplastic elastomer (A1): Kraton G1651 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A1). Then, 65 parts of solid tackifier (B): RHR-301 were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive having a softening point of 90°C or less.

[0084] (Manufacturing example a-2) In a stainless steel beaker equipped with a stirrer, 25 parts of process oil (E): PW-150 and 0.5 parts of other components: IRG1010 were added and heated to melt. Heating was performed carefully so that the contents would reach 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 35 parts of thermoplastic elastomer (A1): Kraton D1162 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A1). Then, 40 parts of solid tackifier (B): RHR-301 were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive having a softening point of 90°C or less.

[0085] (Manufacturing example a-3) In a stainless steel beaker equipped with a stirrer, 18 parts of wax (C): HNP-11, 32 parts of process oil (E): PW-32, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 15 parts of thermoplastic elastomer (A1): Kraton D1102 and 15 parts of thermoplastic elastomer (A2): Kraton G1161 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Then, 20 parts of solid tackifier (B): RHR-301 were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive having a softening point of 90°C or less.

[0086] (Manufacturing example a-4) In a stainless steel beaker equipped with a stirrer, 5 parts of wax (C): POLYWAX655, 20 parts of polybutene (D): HV-100, 10 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were added and heated to melt. Heating was performed carefully so that the contents would reach 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 10 parts of thermoplastic elastomer (A1): Kraton D1652 and 10 parts of thermoplastic elastomer (A2): Kraton G1643 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, 45 parts of solid tackifier (B): RHR-301 was added to obtain a molten homogeneous mixture, which was then cooled to produce an alkali dispersible hot melt adhesive having a softening point of 90° C. or less.

[0087] (Manufacturing example a-5) In a stainless steel beaker equipped with a stirrer, 25 parts of polybutene (D): HV-300, 30 parts of solid tackifier (B): RHR-301, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 20 parts of thermoplastic elastomer (A1): Kraton G1726 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A1). Then, 20 parts of solid tackifier (B): RHR-301 and 5 parts of KE-604B were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive with a softening point of 90°C or less.

[0088] (Manufacturing example a-6)> In a stainless steel beaker equipped with a stirrer, 30 parts of polybutene (D): HV-100, 35 parts of process oil (E): PW-32, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 15 parts of thermoplastic elastomer (A1): Kraton G1650 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A1). Then, 20 parts of solid tackifier (B): RHR-301 were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive having a softening point of 90°C or less.

[0089] (Manufacturing example a-7) In a stainless steel beaker equipped with a stirrer, 5 parts of polybutene (D): HV-50, 10 parts of wax (C): PPMA6252, 25 parts of process oil (E): PW-90, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 20 parts of thermoplastic elastomer (A2): Kraton D1111 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A2). Then, 40 parts of solid tackifier (B): Haritac AQ-90A were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive having a softening point of 90°C or less.

[0090] (Manufacturing example a-8) In a stainless steel beaker equipped with a stirrer, 5 parts of polybutene (D): HV-35, 35 parts of process oil (E): PW-90, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 20 parts of thermoplastic elastomer (A1): Kraton G1652 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A1). Then, 40 parts of solid tackifier (B): RHR-301 were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive having a softening point of 90°C or less.

[0091] [Table 1]

[0092] <Production of hot melt adhesive with softening point of 90°C or higher> (Manufacturing example b-1) In a stainless steel beaker equipped with a stirrer, 1 part of wax (C): PPMA6252, 8 parts of Viscol 660P, 5 parts of polybutene (D): HV-100, 30 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were added and heated to melt. Heating was performed carefully so that the contents would be at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 7 parts of thermoplastic elastomer (A1): Kraton G1651 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing to stir. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Then, 49 parts of solid tackifier (B): RHR-301 were added to obtain a molten uniform mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive with a softening point of 90°C or less.

[0093] (Manufacturing examples b-2 to b-6, 34) Except for changing the materials and blending amounts to those shown in Table 2, an alkali dispersible-type hot melt pressure sensitive adhesive was produced in the same manner as in Production Example b-1.

[0094] (Manufacturing example b-7) In a stainless steel beaker equipped with a stirrer, 5 parts of wax (C): PPMA6252, 10 parts of polybutene (D): HV-100, 25 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents were kept at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 5 parts of thermoplastic elastomer (A1): Kraton G1726 and 35 parts of thermoplastic elastomer (A2): Kraton G1645 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, 20 parts of solid tackifier (B1): RHR-30 was added to form a molten homogeneous mixture, which was then cooled to produce an alkali dispersible hot melt adhesive having a softening point of 90° C. or less.

[0095] (Manufacturing examples b-8, 9, 29, 32) Except for changing the materials and blending amounts to those shown in Table 2, an alkali dispersible-type hot melt pressure sensitive adhesive was produced in the same manner as in Production Example b-7.

[0096] (Manufacturing example b-10) In a stainless steel beaker equipped with a stirrer, 5 parts of wax (C): PPMA6252, 10 parts of polybutene (D): HV-100, 20 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents were kept at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 10 parts of thermoplastic elastomer (A1): Kraton G1652 and 10 parts of thermoplastic elastomer (A2): Kraton D1161 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Then, 30 parts of solid tackifier (B1): RHR-301 and 15 parts by weight of solid tackifier (B2): Alcon P-125 were added to form a molten homogeneous mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive with a softening point of 90°C or less.

[0097] (Production examples b-11, 13, 15, 17~24, 33) Except for changing the materials and blending amounts to those shown in Table 2, an alkali dispersible-type hot melt pressure sensitive adhesive was produced in the same manner as in Production Example b-10.

[0098] (Manufacturing example b-12) In a stainless steel beaker equipped with a stirrer, 5 parts of wax (C): Viscol 660P, 10 parts of polybutene (D): HV-100, 25 parts of solid tackifier (B2): Alcon P-125, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents were kept at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 10 parts of thermoplastic elastomer (A1): Kraton G1650 and 10 parts of thermoplastic elastomer (A2): Kraton D1161 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, 40 parts of solid tackifier (B): RHR-301 was added to obtain a molten homogeneous mixture, which was then cooled to produce an alkali dispersible hot melt adhesive having a softening point of 90° C. or less.

[0099] (Manufacturing example b-14) In a stainless steel beaker equipped with a stirrer, 5 parts of polybutene (D): HV-100, 15 parts of process oil (E): PW-150, 25 parts of solid tackifier (B2): Alcon P-100, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents were kept at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 10 parts of thermoplastic elastomer (A1): Kraton G1652 and 10 parts of thermoplastic elastomer (A2): Kraton G1643 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, a solid tackifier (B1): 30 parts of RHR-301 and 5 parts of KE-604B was added to form a molten homogeneous mixture, which was then cooled to produce an alkali dispersible hot melt adhesive having a softening point of 90°C or less.

[0100] (Manufacturing example b-31) Except for changing the materials and blending amounts to those shown in Table 3, an alkali dispersible-type hot melt pressure sensitive adhesive was produced in the same manner as in Production Example b-14.

[0101] (Manufacturing example b-16) In a stainless steel beaker equipped with a stirrer, 5 parts of wax (C): NP056, 25 parts of polybutene (D): HV-100, 20 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents were kept at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 10 parts of thermoplastic elastomer (A1): Kraton G1652 and 10 parts of thermoplastic elastomer (A2): Kraton D1161 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, 30 parts of solid tackifier (B1): RHR-301 was added to form a molten homogeneous mixture, which was then cooled to prepare an alkali dispersible hot melt pressure sensitive adhesive having a softening point of 90° C. or lower.

[0102] (Manufacturing example b-25) In a stainless steel beaker equipped with a stirrer, 5 parts of wax (C): PPMA6252, 20 parts of process oil (E): PW-380, 25 parts of solid tackifier (B2): Alcon P-125, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents were kept at 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 10 parts of thermoplastic elastomer (A1): Kraton G1652 and 10 parts of thermoplastic elastomer (A2): Kraton D1161 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, 30 parts of solid tackifier (B1): RHR-301 was added to form a molten homogeneous mixture, which was then cooled to produce an alkali dispersible hot melt adhesive having a softening point of 90° C. or lower.

[0103] (Manufacturing examples b-26, 27) Except for changing the materials and compounding amounts to those shown in Table 3, an alkali dispersible-type hot melt pressure sensitive adhesive was produced in the same manner as in Production Example b-26.

[0104] (Manufacturing example b-28) In a stainless steel beaker equipped with a stirrer, 10 parts of wax (C): NP056, 3 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were placed and melted by heating. Heating was performed carefully so that the contents would reach 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 20 parts of thermoplastic elastomer (A1): Kraton G1726 and 10 parts of thermoplastic elastomer (A2): Kraton D1161 were gradually added to the melt while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Then, 42 parts of solid tackifier (B1): RHR-301 and 15 parts by weight of solid tackifier (B2): Alcon P-125 were added to form a molten homogeneous mixture, which was then cooled to produce an alkali-dispersible hot melt adhesive with a softening point of 90°C or less.

[0105] (Manufacturing example b-30) In a stainless steel beaker equipped with a stirrer, 22 parts by weight of solid tackifier (B-2): Alcon P-125, 5 parts of wax (C): NP056, 10 parts of polybutene (D): HV-100, 8 parts of process oil (E): PW-380, and 0.5 parts of other components: IRG1010 were added and melted by heating. Heating was performed carefully so that the contents would reach 130 to 150°C. After melting, stirring was performed to obtain a uniform molten solution, and then 5 parts of thermoplastic elastomer (A1): Kraton G1650 and 10 parts of thermoplastic elastomer (A2): Kraton D1161 were gradually added to the molten solution while maintaining the temperature at 130 to 150°C and continuing stirring. After the addition was completed, the mixture was heated and stirred at a temperature of 130 to 150°C to completely melt the thermoplastic elastomer (A). Thereafter, 50 parts of solid tackifier (B1): RHR-301 was added to form a molten homogeneous mixture, which was then cooled to prepare an alkali dispersible hot melt pressure sensitive adhesive having a softening point of 90° C. or lower.

[0106] [Table 2]

[0107] [Table 3]

[0108] Example 1 One end of a 50 mm wide, 30 μm thick OPP sheet printed on one side (I) is coated with approximately 20 g / m of hot melt adhesive (a-1) on the printed surface. 2 Then, apply hot melt adhesive (b-10) to the printed surface at the other end (II) in an amount of approximately 20 g / m using a hand applicator (adhesive temperature: 150°C). 2 The adhesive was applied using a hand applicator (adhesive temperature: 150°C) so as to form a label.

[0109] (Examples 2 to 41, Comparative Examples 1 to 3) Labels were produced in the same manner as in Example 1, except that the hot melt adhesives (a) and (b) were changed to those shown in Tables 4-8.

[0110] [Evaluation of labels wrapped around bottles] <Cold resistance evaluation> (Sample preparation) The label was attached to a PET bottle (Kirin's Gogo no Kocha Straight Tea 500ml square PET bottle) by adhering the hot melt adhesive (a) to the PET bottle, wrapping the label around the PET bottle, and adhering the hot melt adhesive (b) to the unprinted side of the label. The hot melt adhesives (a) and (b) were firmly pressed onto the PET bottle and label with a finger to firmly attach them to the label, creating a PET bottle with a label. (Test Method) The cold resistance test method involved storing the prepared samples in a freezer at 5°C for more than 24 hours to thoroughly cool them, and then dropping them from a height of approximately 1m so that the bottom of the PET bottle hit PVC flooring and measuring the number of times the label could be peeled off. The more times the label was not peeled off, the better. Evaluation results of 2 to 5 were rated as passing, and evaluation result 1 was rated as failing. (Evaluation Criteria) 5: No peeling even after 10 drops. Very good. 4: Peeling occurred after 6 to 10 tries. Good. 3: Peeled off after 4 to 5 tries. Fairly good. 2: Peeled off after 2 or 3 tries. Usable. 1: Peeled off on the first try. Not practical.

[0111] <Heat resistance evaluation> (Sample preparation) It was prepared in the same manner as in the cold resistance evaluation. (Test Method) Heat resistance was tested by evaluating the holding strength of an adhesive surface area of ​​15 mm x 15 mm. Measurement temperature: 50℃ Load: 200g Measurement time: 24 hours Evaluation results 2 to 5, where the label did not peel off, were rated as pass, and evaluation result 1, where the label peeled off, was rated as fail. (Evaluation Criteria) 5: No falls. Very good. 4: Falls within 12 to 24 hours. Good. 3: Falls between 6 and 12 hours. Fairly good. 2: Falls within 2 to 6 hours. Practical use possible. 1: It fell in less than 2 hours. Not practical.

[0112] <Alkaline dispersibility> (Preparation of evaluation samples) In the same manner as in the cold resistance evaluation, a sample was prepared by attaching a label to a PET bottle, and the portion where the hot melt adhesives (a) and (b) were adhered was cut out with scissors together with the PET bottle, and further cut into approximately 8 mm x 8 mm squares to prepare an evaluation sample (pellet). (Test Method) In a 1000 ml round flask, 180 g of 2.0 mass % sodium hydroxide aqueous solution at 85-90°C and 20 g of the pellets were placed and stirred at 120 rpm (stirring blade: propeller). After 10 minutes, the mixture was filtered and the residual rate (area %) of the adhesive remaining on the PET pellets was visually observed and evaluated. The better the label was peeled off from the PET pellets and the less hot melt adhesive there was, a rating of 2 or higher was considered to be a pass, and a rating of 1, where the label remained on the PET pellets, was considered to be a fail. (Evaluation Criteria) 5: The hot melt adhesive label is completely peeled off from the PET, and no hot melt adhesive remains on the PET pellets. Very good. 4: The hot melt adhesive label is completely removed from the PET, but less than 30% of the hot melt adhesive remains on the PET pellet. Good. 3: The entire label with hot melt adhesive peels off from the PET, but 30% to less than 50% of the hot melt adhesive remains on the PET pellet. Fairly good. 2: The entire label with hot melt adhesive peels off from the PET, but more than 50% of the hot melt adhesive remains on the PET pellets, making it usable. 1: Label with hot melt adhesive cannot be peeled off from PET. Not practical.

[0113] [Table 4]

[0114] [Table 5]

[0115] [Table 6]

[0116] [Table 7]

[0117] [Table 8]

[0118] As can be seen from Tables 4 to 7, the labels using the two types of hot melt adhesives have heat resistance, cold resistance and alkali peelability. On the other hand, Comparative Examples 1 to 3 (Table 8) did not achieve satisfactory results in terms of heat resistance, cold resistance and alkali peelability. [Industrial Applicability]

[0119] As explained above, the label of the present invention allows used containers to be easily separated by immersing them in a hot alkaline aqueous solution when recycling. When used on containers such as PET bottles, the label will not peel off even when heated by vendors or in stores. It has also been found that the same performance is exhibited not only on PET bottles but also on glass containers, making the label suitable for recycling glass containers.

Claims

1. A label to be attached by wrapping around the outer periphery of a container, the label having an adhesive layer (A) and an adhesive layer (B) on one end (I) and the other end (II) of a base film, respectively, The end portion (I) is a joint portion between the base film and the container, and the end portion (II) is a fixing portion where the base films are joined to each other after winding, The pressure-sensitive adhesive layer (a) is formed from an alkali dispersible hot-melt pressure-sensitive adhesive (a) having a softening point of 90° C. or less, The label is characterized in that the adhesive layer (b) is formed from a hot melt adhesive (b) having a softening point higher than 90°C.

2. The label according to claim 1, characterized in that it contains 5 to 35 mass% of a thermoplastic elastomer (A1) having a styrene content of 25 to 50 mass% in 100 mass% of a hot melt adhesive (b) having a softening point of higher than 90°C.

3. The label described in claim 2, further characterized in that it contains a thermoplastic elastomer (A2) having a styrene content of more than 5% by mass and less than 25% by mass in 100% by mass of a hot melt adhesive (b) having a softening point higher than 90°C, in an amount of more than 0% by mass and not more than 20% by mass.

4. The label according to claim 2, further comprising 5 to 40 mass% in total of polybutene (D) and / or process oil (E) per 100 mass% of the hot melt adhesive (b) having a softening point higher than 90°C.

5. The label according to claim 2, further comprising 20 to 70 mass% of a solid tackifier (B) and 1 to 20 mass% of a wax (C) in 100 mass% of a hot melt adhesive (b) having a softening point higher than 90°C.

6. The label according to claim 2, characterized in that a 25% by mass solution of the thermoplastic elastomer (A1) in toluene at 25°C has a viscosity of 100 to 50,000 mPa·s.

7. The label according to claim 5, characterized in that the melting point of the wax (C) is 90 to 160°C.

8. A container having the label according to any one of claims 1 to 7 attached thereto.

9. A container, wherein the label according to any one of claims 1 to 7 is a body-wrapped label.

10. 9. The container according to claim 8, wherein the material of the container is polyethylene terephthalate.

11. 11. The container according to claim 10, for hot beverages.

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