Hot melt adhesive and container

Abstract

To provide a hot melt adhesive that, even when applied as a thin film, exhibits high adhesive strength, resistance to label displacement due to bottle expansion, and conformability (actual adhesion), making the label less likely to peel off, and which can be separated from PET bottles in a short time using a hot alkaline aqueous solution. [Solution] A hot melt adhesive comprising a styrene elastomer (A), a rosin-based tackifier (B) with an acid value of 100-350 mgKOH / g, and a polyoxyethylene alkyl ether (C) with an HLB value of 12.1 or higher.

Description

Technical Field

[0001] The present invention relates to a hot melt adhesive, and more particularly to an alkali-peelable hot melt suitable for a label adhesive used for PET bottles and glass bottles. The present invention also relates to a container to which a label is adhered by the hot melt adhesive.

Background Art

[0002] In recent years, with the increasing demand for PET bottles, the usage amount of PET bottles for beverages has also increased, and the technology for recycling PET bottles has become important. Labels are attached to the surface of this PET bottle container by an adhesive, and biaxially stretched polypropylene films (OPP) and body wrap labels (roll labels) made of PET films are often used for the labels.

[0003] In the recycling of PET bottles, there is a step of separating the PET bottle and the label by washing the PET bottle with a label attached with a heated aqueous alkali solution. Therefore, the hot melt adhesive used for attaching the label to the PET bottle is required to have alkali peelability. Regarding alkali peelability, the following indicators are listed in the "Voluntary Regulation Guidelines for Specified PET Bottles" issued by the PET Bottle Recycling Promotion Council. That is, when pellets made by cutting a labeled bottle are immersed in a 1.5% aqueous sodium hydroxide solution at 85°C and stirred for 15 minutes, the label peels off from the PET pellets, and printing ink, adhesive, etc. do not remain on the PET pellets. Recently, the demand for recycling PET bottles and remanufacturing them as PET bottles is very high, and it is required that the label separation be easier in the recycling process than before and that the alkali peeling be performed in a shorter time than the above indicators.

[0004] On the other hand, when a consumer peels off the label of a PET bottle beverage, it is common to peel it off by hand. Considering the reuse of PET bottles, it is desirable that no adhesive remains on the PET bottle (difficult to leave glue residue: glue residue property) when the label is peeled off by hand.

[0005] Furthermore, when the contents contain carbon dioxide, the PET bottle expands over time, putting stress on the label, which can cause the label to shift, lift, and eventually peel off. Therefore, the label needs to be resistant to shifting, and even if it does shift, it needs to not peel off (effective adhesion). For this reason, hot melt adhesives need to have high adhesive strength to the label, as well as resistance to and adaptability to label shifting due to bottle expansion.

[0006] Furthermore, in recent years, due to environmental concerns, labels and adhesives have become thinner (normal: 30-50 μm, thin film: 5-15 μm), and hot melt adhesives are required to have high adhesive strength to labels, resistance to shifting, and conformability so that labels do not peel off even when thin films are applied.

[0007] Patent Document 1 discloses a hot melt adhesive comprising a styrene elastomer (A), a rosin-based tackifier (B) having an acid value of 100 mg KOH / g or more and 300 mg KOH / g or less, a process oil (C), a specific wax (D) consisting of acrylic acid wax and maleic anhydride wax, and a hydrogenated petroleum-based tackifier (E).

[0008] Patent Document 2 discloses a hot-melt adhesive comprising a thermoplastic elastomer (A), a solid tackifier (B) having an acid value of 100 mg KOH / g or more and 300 mg KOH / g or less, a liquid tackifier (C), a wax (D), and a specific nonionic surfactant (E).

[0009] While the hot-melt adhesives described in Patent Documents 1 and 2 have sufficiently high adhesive strength between labels and resistance to label displacement, the inventors of this invention have found that the adhesive strength and resistance decrease significantly when applied as a thin film, posing challenges to the practical application of the adhesive in such cases. Furthermore, since alkali delamination takes a relatively long time, it cannot be said that the requirement for complete removal in a short time is met.

[0010] Therefore, there is a need for the development of a hot-melt adhesive that exhibits excellent performance in all aspects, including alkali release properties, adhesive strength, and actual bonding properties, even when applied as a thin film coating. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2019-119811 [Patent Document 2] Japanese Patent Publication No. 2012-1624 [Overview of the project] [Problems that the invention aims to solve]

[0012] The object of the present invention is to provide a hot melt adhesive that, even when applied as a thin film, exhibits high adhesive strength, resistance to label displacement due to bottle expansion, and conformability (actual adhesion), making the label difficult to peel off, and which can be separated from the PET bottle in a short time using a hot alkaline aqueous solution. [Means for solving the problem]

[0013] The present invention relates to the following hot-melt adhesive and container. [1] A hot melt adhesive comprising a styrene elastomer (A), a rosin-based tackifier (B) with an acid value of 100-350 mgKOH / g, and a polyoxyethylene alkyl ether (C) with an HLB value of 12.1 or higher.

[0014] [2] The hot melt adhesive having a polyoxyethylene alkyl ether (C) content of 1 to 5% by mass in 100% by mass of the hot melt adhesive.

[0015] [3] The hot melt adhesive further comprising a hydrogenated petroleum-based tackifier (D).

[0016] [4] The hot-melt adhesive wherein the content of the hydrogenated petroleum tackifier (D) in 100% by mass of the hot-melt adhesive exceeds 25% by mass and is 45% by mass or less.

[0017] [5] A container to which a label is adhered by the above hot-melt adhesive.

[0018] [6] The above container wherein the label is a body wrap label.

[0019] [7] The above container wherein the label is made of polypropylene. [Advantages of the Invention]

[0020] The hot-melt adhesive of the present invention has high alkali peelability, and when immersed in a hot alkaline aqueous solution, the label can be peeled off from the container without glue residue in a shorter time than the index of the current guidelines and will not reattach.

[0021] The hot-melt adhesive of the present invention is excellent in adhesive strength and actual sticking property even in thin film coating. Therefore, when a label is attached to a PET bottle of a carbonated beverage with the hot-melt adhesive of the present invention, it is less likely that the label will shift, float, and peel off when the PET bottle expands. [Embodiments for Carrying Out the Invention]

[0022] Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents as long as it does not exceed the gist thereof.

[0023] In this specification, a numerical range specified using "~" shall include the numerical values described before and after "~" as the range of the lower limit value and the upper limit value.

[0024] ≪Hot-Melt Adhesive≫ The hot-melt adhesive of the present invention contains a styrene-based elastomer (A), a rosin tackifier (B) with an acid value of 100 to 350 mgKOH / g, and a polyoxyethylene alkyl ether (C) with an HLB value of 12.1 or more. The hot-melt adhesive of the present invention is suitable as an adhesive for labels used for PET bottles or glass bottles, and is particularly suitable as an adhesive used for bonding a PET bottle of a carbonated beverage and a label.

[0025] (Styrene-based elastomer (A)) As the styrene-based elastomer (A), known styrene-based copolymers can be preferably used, and there is no particular limitation. Specifically, styrene-butadiene-styrene copolymer (hereinafter, also simply referred to as SBS), styrene-butadiene-styrene-butadiene copolymer (hereinafter, also simply referred to as SBSB), styrene-butadiene / butylene-styrene copolymer (hereinafter, also simply referred to as SBBS), styrene-ethylene / butylene-styrene copolymer (hereinafter, also simply referred to as SEBS), styrene-ethylene / propylene-styrene copolymer (hereinafter, also simply referred to as SEPS), styrene-ethylene-ethylene / propylene-styrene copolymer (hereinafter, also simply referred to as SEEPS), styrene-isoprene-styrene block copolymer (hereinafter, also simply referred to as SIS), etc. can be mentioned.

[0026] Furthermore, it is preferable that the styrene-based elastomer (A) contains a hydrogenated styrene-based elastomer in part or all of it. By including a hydrogenated styrene-based elastomer, viscosity changes are reduced even when the hot melt adhesive is heated in the applicator tank for a long period of time, and fluctuations in adhesive properties can be minimized. Specific examples of hydrogenated styrene-based elastomers include styrene-butadiene / butylene-styrene block copolymer (SBBS), styrene-ethylene / propylene-styrene (SEPS), and styrene-ethylene / butylene-styrene (SEBS). Among these, it is particularly preferable to include styrene-ethylene / butylene-styrene (SEBS) because it allows for easier balancing of various physical properties.

[0027] The content of styrene-based elastomer (A) in 100% by mass of the hot melt adhesive is preferably 10 to 30% by mass, and more preferably 12 to 25% by mass. Including styrene-based elastomer (A) within the above range is preferable because it allows for both alkali release properties and adhesive strength.

[0028] (Rosin-based tackifier (B)) The rosin-based tackifier (B) is not particularly limited as long as its acid value is between 100 and 350 mgKOH / g. If the acid value is less than 100 mgKOH / g, sufficient alkaline release properties cannot be achieved, while if the acid value is greater than 350 mgKOH / g, the viscosity of the hot melt adhesive becomes too high. The acid value is the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of the sample. The method for measuring the acid value is described in detail in the Examples section.

[0029] Examples of rosin-based tackifiers (B) include unhydrogenated rosin that has not been modified, unhydrogenated rosin that has not been modified, (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. The above-mentioned rosin-based tackifiers (B) may be used individually or in combination of two or more types.

[0030] The content of rosin-based tackifier (B) in 100% by mass of the hot melt adhesive is preferably 10 to 35% by mass, and more preferably 15 to 30% by mass. Including rosin-based tackifier (B) within the above range is preferable because it allows for both alkali release and actual bonding properties.

[0031] (Polyoxyethylene alkyl ether (C)) Polyoxyethylene alkyl ether (C) is an ether obtained by ethoxylation of an alcohol with ethylene oxide, having an HLB value of 12.1 or higher. The inclusion of polyoxyethylene alkyl ether makes alkali peeling easier and reduces adhesive residue when the label is removed. If the HLB value of polyoxyethylene alkyl ether (C) is less than 12.1, sufficient alkaline stripping properties cannot be achieved. HLB is an index that indicates the hydrophilic-lipophilic balance, and is calculated using the Griffin method as follows: "HLB = 20 × (weight %) of hydrophilic groups".

[0032] The polyoxyethylene alkyl ether (C) is preferably one with a melting point of 86°C or lower, or one that is liquid at room temperature (no melting point). The inclusion of such a polyoxyethylene alkyl ether (C) is preferable because it allows for rapid alkali removal.

[0033] The content of polyoxyethylene alkyl ether (C) in 100% by mass of the hot melt adhesive is preferably 1 to 5% by mass, and more preferably 2 to 4% by mass. Including polyoxyethylene alkyl ether (C) within this range is preferable because it allows for both alkali release and actual bonding properties.

[0034] (Hydrogenated petroleum-based tackifier (D)) The hot melt adhesive of the present invention is preferably further comprising a hydrogenated petroleum-based tackifier (D) in terms of practical adhesion. The hydrogenated petroleum-based tackifier (D) can be any known hydrogenated petroleum-based tackifier, and is not particularly limited. Specifically, examples include partially hydrogenated petroleum resins and / or fully hydrogenated petroleum resins obtained by adding hydrogen to one or more petroleum resins selected from the group consisting of petroleum resins such as C5 petroleum resins, C9 petroleum resins, C5C9 petroleum resins, and dicyclopentadiene petroleum resins. The above-mentioned hydrogenated petroleum-based tackifier (D) may be used alone or in combination of two or more types.

[0035] The content of hydrogenated petroleum-based tackifier (D) in 100% by mass of the hot melt adhesive is preferably more than 25% by mass and 45% by mass or less, and more preferably 28 to 40% by mass. Including hydrogenated petroleum-based tackifier (D) within the above range is preferable because it allows for a higher level of balance between alkali release properties and actual bonding properties.

[0036] (Process oil (E)) The hot-melt adhesive of the present invention may contain a process oil (E). Examples of process oil (E) include paraffinic process oils, naphthenic process oils, and aromatic process oils. It is particularly preferable to include a paraffinic process oil or a naphthenic process oil. This is preferable because it allows for both alkali release properties and high adhesive strength. Furthermore, the above-mentioned process oil (E) may be used alone or in combination of two or more types.

[0037] The content of process oil (E) in 100% by mass of the hot melt adhesive is preferably 15 to 40% by mass, and more preferably 20 to 35% by mass. Including process oil (E) within the above range is preferable because it allows for a higher level of balance between alkali release properties and actual bonding properties, and reduces adhesive residue when peeled off.

[0038] (Wax (F)) The hot-melt adhesive of the present invention may contain wax (F). Wax (F) can be any known wax, and is not particularly limited. Specifically, examples include paraffin wax, Fischer-Tropsch wax, carnauba wax, candelilla wax, montan wax, polyethylene wax, polypropylene wax, acid-modified products of these waxes, special monomer-modified products, ethylene-acrylic acid copolymer wax, ethylene-methacrylic acid copolymer wax, and the like. The above-mentioned wax (F) may be used individually or in combination of two or more types.

[0039] The wax (F) content in 100% by mass of the hot melt adhesive is preferably 1 to 10% by mass, and more preferably 2 to 7% by mass. Including wax (F) within the above range is preferable because it allows for a higher level of balance between alkali release properties and actual bonding properties, and reduces adhesive residue when peeled off.

[0040] (Additives) In addition to the components (A) to (F) described above, the hot melt adhesive of the present invention may contain additives as appropriate to impart desired properties. Examples of such additives include antioxidants, ultraviolet absorbers, and fluorescent whitening agents. The content of the additives should be adjusted as appropriate within a range that satisfies the content of the components (A) to (F) described above in the hot melt adhesive.

[0041] ≪Container≫ In this invention, the term "container" refers to a container to which a label has been attached using the hot-melt adhesive. The hot-melt adhesive of this invention is preferably used to attach labels to PET bottles, in which case the PET bottle to which the label has been attached is the container in this invention.

[0042] In PET bottles, labels are attached to a portion of the bottle's body, and wrap-around labels are also used, covering the entire circumference of the bottle. The hot-melt adhesive of the present invention is also suitable for bonding these wrap-around labels. OPP film is frequently used for such wrap-around labels. The hot-melt adhesive of the present invention can bond wrap-around labels made of OPP film, etc., to both those with printing on the back and those without. The hot-melt adhesive of the present invention may be applied to the entire back surface of the label, or it may be applied to only a portion of the back surface. Application methods include open-wheel method, closed-gun method, and direct-coat method. The open-wheel method and direct-coat method are preferred as they do not leave any adhesive residue on the PET bottle when peeled off.

[0043] Typically, biaxially oriented polypropylene (OPP), polyethylene (PE), PET, and even paper are used as label substrates for PET bottles. Furthermore, labels may have printing applied to the surface opposite to the side to which the hot-melt adhesive is applied (i.e., the front surface of the label), or to the surface to which the hot-melt adhesive is applied (i.e., the back surface of the label). The hot-melt adhesive of the present invention can be applied to the printed surface of a label, or to an unprinted surface; in either case, it exhibits predetermined adhesion, release properties, and hot alkaline water solubility. The printing may cover the entire back surface of the label, or only a portion of the surface. The printing may be performed using any of the conventionally known printing methods, such as gravure printing or UV printing. [Examples]

[0044] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention This is not limited to the following examples. In the examples, unless otherwise specified, "part" refers to "quality". "Parts" indicates volume, and "%" indicates mass %.

[0045] [Measurement of acid value] The measurement was performed in accordance with JIS K2501 (indicator titration method). Specifically, the sample was accurately weighed, placed in a 250 ml flask, 50 ml of ethanol or an equal volume mixture of ethanol and ether was added, and the sample was dissolved by heating. The sample was then titrated with 0.1 N potassium hydroxide solution while frequently shaking (indicator: phenolphthalein). The endpoint of the titration was defined as the point at which the pale pink color of the solution remained for 30 seconds. Subsequently, a blank test was performed in the same manner to correct for the result, and the acid value was determined from the following formula (1). (Formula 1) Acid value (mgKOH / g) = [Amount of 0.1N potassium hydroxide solution consumed (ml) × 5.611] / [Amount of sample (g)]

[0046] [Measuring the melting point] The PerkinElmer Pysis 1 measuring device was used. The measurement was performed by first holding the sample at 0°C for 5 minutes, then increasing the temperature to 170°C at a rate of 10°C / min, holding it at 170°C for 1 minute, then decreasing the temperature to 0°C at a rate of 40°C / min, holding it at 1°C for 1 minute, and finally increasing the temperature again to 170°C at a rate of 10°C / min. The measured melting point was defined as the melting point at this point.

[0047] The abbreviations listed in Tables 1-4 are as follows: [Styrene-based elastomer (A)] A1: G-1650 (Styrene-ethylene / butylene-styrene block copolymer, hydrogenated elastomer, manufactured by Kraton Corporation) A2: G-1652 (Styrene-ethylene / butylene-styrene block copolymer, hydrogenated elastomer, manufactured by Kraton Corporation) A3: G-1726 (Styrene-ethylene / butylene-styrene block copolymer, hydrogenated elastomer, manufactured by Kraton Corporation) [Rosin-based tackifier (B)] B1: Haritack F (Hydrogenated rosin manufactured by Harima Chemicals, acid value 170-175 mg KOH / g) B2: KR-120 (Acid-modified rosin manufactured by Arakawa Chemical Co., Ltd., acid value 305-345 mg KOH / g) [Polyoxyethylene alkyl ether (C)] C1: Unitox 480 (Polyoxyethylene alkyl ether manufactured by NuCera Solutions, HLB 16.0, melting point 86°C) C2: Unitox 490 (Polyoxyethylene alkyl ether, manufactured by NuCera Solutions, HLB 18.0, melting point 71°C) C3: Emulgen 320P (Kao Corporation polyoxyethylene alkyl ether, HLB 13.9, melting point 28°C) C4: Emulgen 707 (Kao Corporation polyoxyethylene alkyl ether, HLB 12.1, liquid at room temperature) [Other polyoxyethylene alkyl ethers (C')] C'1: Unitox 450 (Polyoxyethylene alkyl ether, manufactured by NuCera Solutions, HLB 10, melting point 91°C) [Hydrogenated petroleum-based tackifier (D)] D1: Alcon P-90 (Hydrogenated aliphatic hydrocarbon resin manufactured by Arakawa Chemical Co., Ltd.) D2: Alcon P-100 (Hydrogenated aliphatic hydrocarbon resin manufactured by Arakawa Chemical Co., Ltd.) [Process oil (E)] E1: PS-32 (Paraffin-based process oil manufactured by Idemitsu Kosan Co., Ltd.) E2: PW-90 (Paraffin-based process oil manufactured by Idemitsu Kosan Co., Ltd.) E3:N-90 (Naphthenic process oil manufactured by Idemitsu Kosan Co., Ltd.) [Wax (F)] F1: Sazole Wax C80 (Fischer-Tropsch Wax manufactured by Sazole Chemical Industries Limited) F2: Viscol 660-P (Polypropylene wax manufactured by Sanyo Chemical Industries, Ltd.) F3: Polylets 200EL (Polyethylene wax manufactured by SCG Performance Chemicals)

[0048] (Example 1) <Manufacturing of hot melt adhesives> In a stainless steel beaker equipped with a stirrer, 22 parts of process oil (E) E1 (PS-32), 24 parts of rosin-based tackifier (B) B1 (Haritack F), and 34 parts of hydrogenated petroleum-based tackifier (D) D1 (Alcon P-90) were added and heated to melt. Heating was carried out carefully to ensure the contents reached 130-150°C. After melting, the mixture was stirred to obtain a homogeneous molten solution. While maintaining a temperature of 130-150°C and continuing to stir, 13 parts of styrene-based elastomer (A) A1 (G-1650) were added to the molten material. After the addition was complete, the mixture was heated and stirred at 130-150°C to completely melt the styrene-based elastomer (A). Subsequently, 5 parts of F1 (Sazole wax C80) as wax (F) and 2 parts of C1 (Unitox 480) as polyoxyethylene alkyl ether (C) were added to form a homogeneous molten mixture, which was then cooled to produce a hot-melt adhesive.

[0049] (Examples 2-33, Comparative Examples 1-3) Hot melt adhesives were prepared by melting and mixing the compositions shown in Tables 1-4 in the same manner as in Example 1.

[0050] The alkali release properties, adhesive strength (against OPP), and actual bonding properties of the obtained hot melt adhesive were evaluated using the following methods.

[0051] <Alkaline peeling properties> (Sample preparation method) A label printed on a 30 μm thick OPP film was coated with hot-melt adhesive to the printed surface by hand to a thickness of 5 to 15 μm (temperature condition: 150°C) to obtain a label with hot-melt adhesive. The label with hot-melt adhesive was attached to a PET bottle at 23°C, pressed down with a hand roller for one pass, and then crushed into approximately 8 mm x 8 mm squares to obtain PET pellets with the labels still attached. (Test method) 180 g of a 1.5% by mass sodium hydroxide aqueous solution at 80-85°C and 20 g of the aforementioned pellets were placed in a 1000 ml round-bottom flask and stirred at 120 rpm (using a propeller-type stirring blade). After 5 minutes, the mixture was filtered, and the remaining percentage (area %) of adhesive on the PET pellets was visually observed. (Evaluation Criteria) ◎: No residue of hot-melt adhesive remains on the label or PET pellets: Very good ○: No hot melt adhesive residue remains on the label, but less than 10% (area %) of the hot melt adhesive remains on the PET pellet: Good △: Hot melt adhesive remains on PET pellets at a rate of 10% to less than 30% (area percentage): Usable. ×: More than 30% (area %) of hot melt adhesive remains on the PET pellets: Not practical for use.

[0052] <Adhesive strength> (Sample preparation method) Labels with hot-melt adhesive were obtained in the same manner as described above. The labels with hot-melt adhesive were attached to the non-printed surface of a 30 μm thick OPP film at 23°C, pressed down with a hand roller (one pass back and forth), and cut to a width of 15 mm to obtain test samples. (Test method) The peeling was performed in a constant temperature room at 23°C at a 180°C angle (peeling speed: 300 mm / min). (Evaluation Criteria) ◎: 3.0N / 15mm or more: Very good ○: 2.0N / 15mm or more and less than 3.0N / 15mm: Good △: 1.0N / 15mm or more and less than 2.0N / 15mm: Usable ×: Less than 1.0N / 15mm: Not practical for use

[0053] <Practicality of application> (Sample preparation method) Labels with hot-melt adhesive were obtained in the same manner as described above. The labels with hot-melt adhesive were attached to 1.5L round PET bottles. The resulting labeled bottles were filled with carbonated water (commercially available) to create test samples. (Test method) The bottles were placed in a constant-temperature oven at 40°C, and their appearance was observed after one week. (Evaluation Criteria) ◎: Label misalignment less than 1mm: Excellent ○: Label misalignment of 1mm to less than 10mm: Good △: Label misalignment of 10mm or more: Usable ×: Label peels off: Unusable

[0054] Examples 1 to 33 in Tables 1 to 4 show that the hot melt adhesive of the present invention exhibits high adhesive strength and excellent hot melt adhesion resistance against label displacement due to bottle expansion, even when the hot melt adhesive is applied as a thin film, making the label less likely to peel off, and also exhibiting excellent alkali peelability in a short time. On the other hand, the hot-melt adhesives in Comparative Examples 1-3 did not satisfy all of the requirements regarding alkali release properties, adhesive strength, and actual bonding performance.

[0055] [Table 1]

[0056] [Table 2]

[0057] [Table 3]

[0058] [Table 4] [Industrial applicability]

[0059] As explained above, the hot-melt adhesive of the present invention allows for easy removal of labels from containers and other items when recycling them after use, and enables easy separation by immersion in a hot alkaline aqueous solution. Furthermore, it has been found that it exhibits similar performance not only on PET bottles but also on glass containers, making it a hot-melt adhesive suitable for recycling glass containers as well.

Claims

1. A hot melt adhesive comprising a styrene elastomer (A), a rosin-based tackifier (B) with an acid value of 100 to 350 mg KOH / g, and a polyoxyethylene alkyl ether (C) with an HLB value of 12.1 or higher.

2. The hot melt adhesive according to claim 1, wherein the content of polyoxyethylene alkyl ether (C) in 100% by mass of the hot melt adhesive is 1 to 5% by mass.

3. Furthermore, the hot melt adhesive according to claim 1, further comprising a hydrogenated petroleum-based tackifier (D).

4. The hot melt adhesive according to claim 3, wherein the content of hydrogenated petroleum-based tackifier (D) in 100% by mass of the hot melt adhesive is greater than 25% by mass and less than or equal to 45% by mass.

5. A container on which a label is attached with a hot melt adhesive according to any one of claims 1 to 4.

6. The container according to claim 5, wherein the label is a wrap-around label.

7. The container according to claim 5, wherein the label material is made of polypropylene.

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