Lump body and container

Abstract

The present invention provides: a lump body which is more excellent in terms of bag breaking properties than ever before even if a low-viscosity hot melt adhesive is contained in a meltable bag, and which is excellent in terms of solubility (compatibility) between the meltable bag and the hot melt adhesive, and stringiness at the time of coating; and a container to which a label is adhered with use of the lump body. A lump body according to the present disclosure contains a hot melt adhesive in a meltable bag. The meltable bag is formed of a mixed resin film that contains a low density polyethylene resin (A) which has a density of 923-930 kg / m3 and an ethylene-vinyl acetate copolymer resin (B). The hot melt adhesive contains a wax (C), and has a viscosity of 500-2,500 mPa∙s at 140°C.

Description

Masses and containers

[0001] The present disclosure relates to a mass containing a hot melt adhesive in a melting bag, and to a container to which a label is attached using the mass.

[0002] Hot melt adhesives, after melting and bonding objects together, quickly demonstrate their adhesive properties by cooling and allowing them to cool. This advantage of not requiring a curing period has led to a renewed appreciation for the benefits of hot melt adhesives, and their use is expanding in packaging and industrial applications. Furthermore, in light of the recent social shift to emphasizing the need to reduce environmental impact, the advantage of not requiring solvents or drying processes during use has also been recognized, and their use is expanding.

[0003] As the range of applications for hot melt adhesives expands, improvements in workability are required. For example, in the summer, a problem called blocking occurs, in which blocks of hot melt adhesive stick together, resulting in huge blocks when removed from the cardboard packaging, significantly reducing workability. Therefore, hot melt adhesives that remain adhesive at room temperature have traditionally been packaged, transported, and stored in a release material such as release paper or film, and the release material is peeled off and discarded before use. However, disposal of the release material is also becoming a problem as an environmental burden.

[0004] To solve these problems, a so-called melting bag (bulk) has been developed, in which the hot-melt adhesive is packaged in a hard material and melted while still in the bag when used (Patent Document 1). The practical application of this bulk avoids the environmental impact of disposing of a release material, while also eliminating the need to peel off the release material, significantly improving workability. Because the hot-melt adhesive is melted while still packaged in the melting bag, the bulk requires basic performance, such as the solubility (compatibility) of the melting bag and the hot-melt adhesive, and the ability to break the bag during storage in a high-temperature environment (such as summer). In recent years, measures to prevent blocking have been taken, such as increasing the strength of the melting bag (Patent Document 2) or embossing the shape of the melting bag (Patent Document 3).

[0005] Hot melt adhesives are often used to attach labels wrapped around polyethylene terephthalate bottles (hereinafter referred to as PET bottles) used for beverages, etc. Hot melt adhesives used for PET bottle labels are preferably low-viscosity hot melt adhesives with a viscosity of 2,500 mPa·s or less at 140°C to prevent the hot melt adhesive from scattering and contaminating the labeler in stringy threads (stringiness) when the hot melt adhesive is applied to the label (Patent Document 4).

[0006] JP 2004-002581 A International Publication No. 2014 / 194087 JP 2019-065164 A Japanese Patent No. 4278704 A

[0007] With the increasing use of PET beverage bottles, there is a growing demand for such low-viscosity hot melts packaged in melting bags, but the stringiness of the molten masses is problematic. Furthermore, the inventors have conducted research and found that in the inventions described in Patent Documents 1 to 3, when a low-viscosity hot melt is packaged in a melting bag, cold flow (a phenomenon in which the hot melt gradually deforms and spreads) occurs during storage, causing the hot melt to leach out of the melting bag, which then breaks during packaging, exposing the hot melt adhesive to the surface, resulting in blocking between the masses. Therefore, there is a strong need for the development of a mass containing a low-viscosity hot melt packaged in a melting bag that satisfies the solubility of the melting bag and the hot melt adhesive during use, the bag tearability to prevent blocking during storage, and the stringiness during application.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a mass that exhibits superior bag-breaking properties compared to conventional masses, superior solubility (compatibility) between the melting bag and the hot-melt adhesive, and superior stringiness during application, even when the melting bag contains a low-viscosity hot-melt adhesive with a viscosity of 500 to 2500 mPa·s at 140°C, and a container to which a label is attached using the mass. In this specification, "excellent bag-breaking properties" refers to excellent resistance to tearing of the melting bag during storage. Furthermore, "excellent stringiness properties" refers to excellent properties that prevent the hot-melt adhesive from scattering in the form of strings during application.

[0009] The present disclosure provides the following mass and a container to which a label is attached using the mass: [1]: A mass containing a hot melt adhesive in a melting bag, wherein the melting bag has a density of 923 to 930 kg / m ３ The mass is made of a mixed resin film containing a low-density polyethylene resin (A) and an ethylene-vinyl acetate copolymer resin (B), and the hot melt adhesive contains a wax (C) and has a viscosity of 500 to 2500 mPa·s at 140°C.

[0010] [2]: The aggregate according to [1], wherein the content of the ethylene-vinyl acetate copolymer resin (B) in 100% by mass of the mixed resin film is 10 to 50% by mass.

[0011] [3]: The lump according to [1] or [2], wherein the vinyl acetate content of the ethylene-vinyl acetate copolymer resin (B) is 5 to 30% by mass.

[0012] [4]: Low density polyethylene resin (A) 190 ° C, 2.16 kgf / cm ２ The aggregate according to any one of [1] to [3], characterized in that the melt mass flow rate in the above ranges from 1 to 25 g / 10 min.

[0013] [5]: The lump according to any one of [1] to [4], characterized in that the melting point of the wax (C) is 70 to 150°C.

[0014] [6]: The lump according to any one of [1] to [5], characterized in that the wax (C) contains at least one of a polyethylene-based wax (C-1) having a melting point of 90 to 150°C and a polypropylene-based wax (C-2) having a melting point of 90 to 150°C.

[0015] [7]: The lump according to any one of [1] to [6], characterized in that the thickness of the melting bag is 10 to 500 μm.

[0016] [8]: The aggregate according to any one of [1] to [7], characterized in that it contains a polypropylene wax (C-2) having a melting point of 90 to 150°C, and the wax (C-2) contains a polypropylene wax graft-polymerized with maleic anhydride.

[0017] [9]: The lump according to any one of [1] to [8], wherein the hot-melt adhesive is an alkali-dispersible hot-melt adhesive.

[0018]

[10] : A container to which a label is attached using the mass according to any one of [1] to [9].

[0019]

[11] : The container according to

[10] , characterized in that the material of the container is polyethylene terephthalate or glass.

[0020] According to the invention of the present disclosure, even when a low-viscosity hot-melt adhesive having a viscosity of 500 to 2500 mPa·s at 140°C is contained in a melting bag, the invention has the excellent effect of providing a mass that is superior to conventional masses in terms of bag-breaking resistance, solubility (compatibility) between the melting bag and the hot-melt adhesive, and stringiness during application, as well as a container to which a label is adhered using the mass.

[0021] The present disclosure will be described in detail below. It goes without saying that other embodiments are also included within the scope of the present disclosure as long as they are consistent with the spirit of the present disclosure. In this specification, a numerical range specified using "to" includes the numerical values ​​before and after "to" as the lower and upper limit ranges. Unless otherwise noted, the various components appearing in this specification may each be used independently, either alone or in combination of two or more. Furthermore, "parts" and "%" represent "parts by mass" and "% by mass," respectively, unless otherwise specified.

[0022] In this specification, "viscosity" was measured in accordance with JIS K6862 (Melt viscosity test method for hot melt adhesives). In this specification, "melt mass flow rate (hereinafter abbreviated as MFR)" was measured in accordance with JIS K7210 (Flow test method for thermoplastic plastics). In this specification, "melting point of wax" is a value measured with a differential scanning calorimeter (Shimadzu automatic differential calorimeter DSC-60A Plus). In this specification, "film thickness" was measured with a PEACOCK DIGITAL THICKNESS GAUGE G2-205 manufactured by Ozaki Manufacturing Co., Ltd.

[0023] In this specification, the term "hot melt" refers to a material that is solid or viscous at room temperature and melts and softens to become fluid or liquid when heated.

[0024] <Melt Bag> The melt bag is used to package hot melt adhesives. However, this is not limited to this as long as it can contribute technically to products other than hot melt adhesives. The melt bag used in this disclosure has a density of 923 to 930 kg / m ３ The melt bag is made of a mixed resin film containing a low-density polyethylene resin (A) and an ethylene-vinyl acetate copolymer resin (B). The melt bag can be formed (manufactured) by heating and melting the mixed resin film using a known method. It is desirable that the thickness of the melt bag is as uniform as possible.

[0025] From the viewpoints of meltability and tearability, the mixed resin film preferably contains 50 to 90 mass% of low-density polyethylene resin (A), more preferably 70 to 90 mass%. From the viewpoints of tearability and solubility, the mixed resin film preferably contains 10 to 50 mass% of ethylene-vinyl acetate copolymer resin (B), more preferably 10 to 30 mass%.

[0026] The thickness of the melting bag is preferably 10 to 500 μm, more preferably 20 to 200 μm, and even more preferably 30 to 100 μm. A thickness of 10 to 500 μm makes it easy to achieve both solubility and bag tearability.

[0027] [Low-density polyethylene resin (A)] The density of the low-density polyethylene (A) is 923 to 930 kg / m ３ The density is 923 to 930 kg / m ３ From the viewpoint of melting property and bag-breaking property, the MFR of the low-density polyethylene resin (A) is preferably 1 to 25 g / 10 min, and more preferably 7 to 25 g / 10 min.

[0028] [Ethylene-vinyl acetate copolymer resin (B)] The ethylene-vinyl acetate copolymer resin (B) is not particularly limited as long as it is a copolymer of ethylene and vinyl acetate. From the viewpoints of bag-breaking property and solubility, the vinyl acetate content of the ethylene-vinyl acetate copolymer resin (B) is preferably 5 to 30% by mass, more preferably 10 to 25% by mass. The vinyl acetate content refers to the content (% by mass) of structural units derived from vinyl acetate contained in the ethylene-vinyl acetate copolymer resin.

[0029] (Method for manufacturing mixed resin film) The method for manufacturing the film used in the melt bag is not particularly limited as long as it can obtain the hot-melt pressure-sensitive adhesive mass intended by the present disclosure, and examples include known melt extrusion methods such as melt casting, T-die method, and inflation method. The thermoplastic film of the embodiment of the present disclosure may be a single-layer film or a multi-layer film consisting of two or more layers. The surface of the thermoplastic film may be roughened to form irregularities. There are no particular limitations as long as it can obtain the hot-melt pressure-sensitive adhesive mass intended by the present disclosure.

[0030] <Hot-melt adhesive> The hot-melt adhesive contains a wax (C) from the viewpoint of bag-breaking properties and stringiness, and has a viscosity at 140°C of 500 to 2000 mPa·s, more preferably 700 to 1300 mPa·s.

[0031] [Wax (C)] Wax (C) is 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, acid-modified wax, etc.). Wax (C) is used alone or in combination of two or more types.

[0032] The wax (C) preferably has a melting point of 70 to 150°C, from the viewpoint of improving the tearability of the mass containing the hot-melt adhesive in the melt bag.

[0033] The wax (C) preferably contains a polyethylene wax (C-1) having a melting point of 90 to 150°C and / or a polypropylene wax (C-2) having a melting point of 90 to 150°C. By containing (C-1) and / or (C-2), the bag-breaking properties of the agglomerates can be improved. It is more preferable that the wax contains a polypropylene wax (C-2) having a melting point of 90 to 150°C.

[0034] Polyethylene waxes (C-1) are produced from ethylene and include modified products such as those modified with maleic acid. Examples include Polywax (manufactured by NuCera) and waxes modified with maleic acid. Examples include Sanwax (manufactured by Sanyo Chemical Industries, Ltd.) and Hiwax (manufactured by Mitsui Chemicals, Inc.). Polypropylene waxes (C-2) are produced primarily from propylene and include modified products such as those modified with maleic acid. Examples include block polypropylenes obtained by copolymerizing another monomer in a block form, such as Viscol (manufactured by Sanyo Chemical Industries, Ltd.), Hiwax NP series (manufactured by Mitsui Chemicals, Inc.), and Ricosene PP series (manufactured by Client Chemicals). The polypropylene wax (C-2) is preferably a polypropylene wax graft-polymerized with maleic anhydride, from the viewpoint of alkali dispersibility of the block.

[0035] In addition to the wax (C), the hot melt pressure-sensitive adhesive may contain components such as a thermoplastic elastomer, a tackifier, an oil, a colorant, an antiblocking agent, an inorganic filler, an antioxidant, a bulking agent, a flame retardant, a plasticizer, an antistatic agent, a light stabilizer, an ultraviolet absorber, a heavy metal deactivator, and a fluorescent brightener.

[0036] Thermoplastic elastomers are elastic polymeric materials that have properties similar to vulcanized rubber at room temperature, but can be molded using existing molding machines at high temperatures, just like ordinary thermoplastic resins. Thermoplastic elastomers possess properties intermediate between rubber and plastic, due to their combination of elastic rubber components (soft segments, or soft phases) and molecular constraints (hard segments, or hard phases) that prevent plastic deformation. Thermoplastic elastomers generally have polystyrene blocks and rubber midblocks. The polystyrene segments form physical crosslinks (domains) and act as crosslinking points, while the middle rubber blocks provide rubbery elasticity to the product. The middle soft segments include polybutadiene (B), polyisoprene (I), and polyolefin elastomers (ethylene-propylene (EP), ethylene-butylene (EB), and butylene-butadiene (BB)). Depending on the arrangement of the hard segments with polystyrene (S), they are classified as linear or branched.

[0037] (Tackifier) ​​Examples of the tackifier include phenolic resins, modified phenolic resins, terpene phenolic resins, xylene phenolic resins, cyclopentadiene-phenolic resins, xylene resins, aliphatic, alicyclic, and aromatic petroleum resins, hydrogenated aliphatic, alicyclic, and aromatic petroleum resins, phenol-modified petroleum resins, rosin ester resins, hydrogenated rosin, acid-modified rosin, hydrogenated rosin ester resins, low-molecular-weight polystyrene resins, terpene resins, and hydrogenated terpene resins. In particular, tackifiers having an acid value of 100 to 300 mgKOH / g are suitable for alkali-dispersible hot-melt adhesives. Examples include hydrogenated rosin and acid-modified rosin.

[0038] (Oil) Oil is an oil commonly used as a plasticizer for rubber, thermoplastic elastomers, etc., i.e., a process oil produced in petroleum refineries, etc., and is broadly classified into paraffinic process oil, naphthenic process oil, and aromatic process oil. Process oil is a mixture of aromatic rings, naphthenic rings, and paraffin chains, and naphthenic process oil in this specification refers to process oil in which naphthenic ring carbons account for 35 to 46 mass% of the total carbon of the process oil. In addition, oils in which aromatic carbons account for 30 mass% or more of the total carbon are classified as aromatic process oils, and oils in which paraffin chain carbons account for 50 mass% or more of the total carbon are classified as paraffinic process oils.

[0039] (Colorant) As the colorant, conventionally known colorants such as red, blue, green, yellow, etc. may be used. The colorant may be any of pigments, dyes, and coloring matters, and examples thereof include monoazo-based, dizazo-based, azo-lake-based, benzimidazolone-based, perylene-based, diketopyrrolopyrrole-based, condensed azo-based, anthraquinone-based, quinacridone-based, phthalocyanine-based, and anthraquinone-based colorants. Examples of pigment-based colorants include pigments, perylene-based, monoazo-based, condensed azo-based, isoindolinone-based, titanium oxide, and carbon.

[0040] (Anti-blocking Agent) Examples of the anti-blocking agent include silicone, unsaturated fatty acid amides such as stearic acid amide, oleic acid amide, erucic acid amide, oleic acid amide, and behenic acid amide.

[0041] (Inorganic Filler) Examples of inorganic fillers 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, flaked 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, sodium aluminosilicate, magnesium silicate, carbon nanotube, graphite, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, and apatite.

[0042] (Antioxidant) 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.

[0043] (Filler) Examples of the filler include wet silica, aluminum hydroxide, aluminum oxide, magnesium oxide, montmorillonite, mica, smectite, organically modified montmorillonite, organically modified mica, and organically modified smectite.

[0044] (Flame Retardant) 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.

[0045] (Plasticizer) Examples of the plasticizer include phthalate ester-based plasticizers, polyester-based plasticizers, aliphatic dibasic acid ester-based plasticizers, aliphatic monobasic acid ester-based plasticizers, phosphate ester-based plasticizers, citrate ester-based plasticizers, epoxy-based plasticizers, trimellitate ester-based plasticizers, tetrahydrophthalate ester-based plasticizers, glycol-based plasticizers, and bisphenol A alkylene oxide derivatives.

[0046] (Light Stabilizer) Examples of the light stabilizer include hindered amine compounds and benzoate compounds.

[0047] (Ultraviolet Absorber) Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzotriazole-based ultraviolet absorbers.

[0048] (Heavy Metal Deactivator) Examples of the heavy metal deactivator include salicylic acid derivatives, hydrazide derivatives, and oxalic acid amide derivatives.

[0049] (Fluorescent Brightening Agent) Fluorescent brightening agents include stilbene-based, coumarin-based, oxazole-based, and naphthalimide-based agents.

[0050] <Method for producing hot-melt pressure-sensitive adhesive> There are no particular limitations on the method for producing the hot-melt pressure-sensitive adhesive, as long as the hot-melt pressure-sensitive adhesive can be obtained. One example of the production method includes heating a melting pot equipped with a stirrer to about 150°C, mixing and dispersing a thermoplastic elastomer into the heated and melted wax (C), oil, etc., adding a tackifier, and further mixing.

[0051] <Lump> The lump of the present disclosure is the melting bag containing the hot-melt pressure-sensitive adhesive. The mass of the lump is preferably 10 g to 5,000 g. A mass within the above range is preferable because it is easy to handle and has excellent workability in terms of the number of times it can be filled. The film thickness of the melting bag can be appropriately adjusted depending on the mass.

[0052] The hot-melt adhesive contained in the melting bag may be an alkali-dispersible hot-melt adhesive. PET bottles filled with soft drinks, seasonings, etc., and bottles filled with beer, sake, etc., are recycled or reused. Typically, the recycling or reuse process involves a step of removing labels affixed to PET bottles or bottles, which is typically performed with a 1.5 to 4% by mass aqueous sodium hydroxide solution at approximately 85 to 95°C. Therefore, alkali-dispersible hot-melt adhesives are used for label applications. The aggregates of the present disclosure are suitable as aggregates containing such alkali-dispersible hot-melt adhesives. The tackifier used in alkali-dispersible hot-melt adhesives preferably contains a tackifier with an acid value of 100 to 300 mgKOH / g, from the viewpoint of the alkali dispersibility of the hot-melt adhesive. One example is a rosin-based tackifier. The acid value is the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of sample, and is a value measured in accordance with JIS K5601-2-1 Acid Value (Titration Method).

[0053] (Method for Producing Agglomerates) In the present disclosure, the method for producing agglomerates containing a hot-melt pressure-sensitive adhesive is not particularly limited as long as it can produce agglomerates containing a hot-melt pressure-sensitive adhesive as intended by the present disclosure, and examples thereof include the following methods. A hot-melt pressure-sensitive adhesive in a thermally molten state is left at room temperature to solidify, producing a block of the hot-melt pressure-sensitive adhesive. The block of the hot-melt pressure-sensitive adhesive is packaged in a mixed resin film (melt bag) to produce agglomerates. Alternatively, the hot-melt pressure-sensitive adhesive may be poured onto a mixed resin film and solidified to produce a block of the hot-melt pressure-sensitive adhesive, and the block of the hot-melt pressure-sensitive adhesive may be packaged in the mixed resin film (melt bag) at the same time.

[0054] <<Container>> In the present disclosure, a container refers to a mass to which a label is attached. The container may be made of glass, plastic, paper, or the like, but is not particularly limited to such materials. The container may also be round or non-round, such as rectangular. The container is preferably made of PET or glass, more preferably PET.

[0055] In the case of PET bottles, labels are applied to a portion of the body of the PET bottle, and also roll labels are used that are wound around the body of the bottle. OPP film is often used for such roll labels. The labels of the present disclosure can be applied well to both labels with and without printing on the back side. In the present disclosure, the mass is coated on a portion of the back side of the label. Coating methods include the open wheel method, the closed gun method, and the direct coating method. The open wheel method and the direct coating method are preferred as methods that do not leave adhesive on the PET bottle or the like when peeled off.

[0056] The present disclosure will be described in more detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the following examples. In the examples, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0057] [Method for measuring the acid value of adhesive] 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, and 50 mL of a neutral solvent such as ethanol or ethanol and ether was added. The sample was dissolved by heating, and titrated with 0.1 N potassium hydroxide solution (indicator: phenolphthalein) while occasionally shaking. The titration endpoint was determined as the point at which the pale pink color of the solution remained for 30 seconds. Next, a blank test was performed in the same manner to correct for the acid value, and the acid value was calculated using the following formula: Acid value = [amount of 0.1 N potassium hydroxide solution consumed (mL) × 5.611] / [amount of sample (g)]

[0058] [Method for measuring melting point of wax (C)] The melting point of wax (C) was measured using a differential scanning calorimeter (Shimadzu automatic differential calorimeter DSC-60A Plus). Approximately 5 mg of sample was weighed out and cooled to 0°C, then 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 holding at 0°C for 1 minute, the sample was heated again at a heating rate of 10°C / min, and the exothermic and endothermic heat amounts when heated to 170°C were measured. The melting peak when wax (C) melted was taken as the melting point.

[0059] [Low-density polyethylene resin (A)] Petrothene 205: manufactured by Tosoh Corporation, density: 924 kg / m ３ Petrothene 230: manufactured by Tosoh Corporation, MFR: 3 g / 10 min, density: 925 kg / m ３ Petrothene 208: manufactured by Tosoh Corporation, MFR: 8 g / 10 min, density: 924 kg / m ３ Petrothene 1384R: manufactured by Tosoh Corporation, MFR: 23 g / 10 min, density: 928 kg / m ３ Petrothene 173: manufactured by Tosoh Corporation, density: 924 kg / m ３ Petrothene 209: manufactured by Tosoh Corporation, density: 924 kg / m ３ , MFR: 45g / 10min

[0060] [Other low-density polyethylene resins] Novatec LD LC720: manufactured by Japan Polyethylene Corporation, density: 922 kg / m ３ MFR: 9.4 g / 10 min

[0061] [Ethylene-vinyl acetate copolymer resin (B)] Ultrathene 526: manufactured by Tosoh Corporation, vinyl acetate content: 25% by mass Ultrathene 633: manufactured by Tosoh Corporation, vinyl acetate content: 20% by mass Ultrathene 710: manufactured by Tosoh Corporation, vinyl acetate content: 28% by mass Ultrathene 750: manufactured by Tosoh Corporation, vinyl acetate content: 32% by mass Ultrathene 625: manufactured by Tosoh Corporation, vinyl acetate content: 15% by mass

[0062] [Waxes (C)] Wax (C-1) PW655: Polyethylene wax manufactured by NuCera, melting point: 99°C PW2000: Polyethylene wax manufactured by NuCera, melting point: 126°C Wax (C-2) PPMA6252: Ricothene PPMA6252, acid-modified polypropylene wax manufactured by Client Chemicals, melting point: 127°C Viscol 660P: Polypropylene wax manufactured by Sanyo Chemical Industries, Ltd., melting point: 136°C Others HNP-9: Paraffin wax manufactured by Nippon Seiro Co., Ltd., melting point: 75°C HNP-11: Paraffin wax manufactured by Nippon Seiro Co., Ltd., melting point: 68°C

[0063] [Antioxidant] IRG1010: Irganox 1010, manufactured by BASF, pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]

[0064] [Thermoplastic elastomers] G1650: Kraton G1650, manufactured by Kraton Polymers, SEBS G1643: Kraton G1643, manufactured by Kraton Polymers, SEBS G1652: Kraton G1652, manufactured by Kraton Polymers, SEBS G1726: Kraton G1726, manufactured by Kraton Polymers, SEBS D1118: Kraton D1118, manufactured by Kraton Polymers, SBS

[0065] [Tackifiers] RHR-301 (manufactured by Wuzhou Sun Shine Forestry & Chemicals Co., LTD of Guangxi, China) hydrogenated rosin, acid value: 170 mg KOH / g KE-604B: Pine Crystal KE-604B (manufactured by Arakawa Chemical Industries, Ltd.) acrylic modified rosin, acid value: 230 mg KOH / g Alcon M-90 (manufactured by Arakawa Chemical Industries, Ltd.) hydrogenated petroleum resin, acid value: none

[0066] [Oil] N90: N-90 (Idemitsu Kosan Co., Ltd.), naphthenic process oil PW-90: Diana process oil PW-90 (Idemitsu Kosan Co., Ltd.), paraffinic process oil PW-380: Diana process oil PW-380 (Idemitsu Kosan Co., Ltd.), paraffinic process oil

[0067] <Production of Mixed Resin for Melt Bag> (Production Example F-1) LDPE: 80 parts of Petrothene 205 and 20 parts of Ultrathene 710 were pre-blended and charged into the hopper of an IKG co-rotating twin-screw extruder (PMT32-40.5) and fed to the extruder using a screw feeder. An extrusion process was carried out under conditions of a screw rotation speed of 50 rpm and a feed rate of 5 kg / hr, to obtain a mixed resin of low-density polyethylene resin and ethylene-vinyl acetate copolymer resin.

[0068] (Production Examples F-2 to F-14) Mixed resins of Production Examples F-2 to F-14 were produced in the same manner as Production Example F-1 using the compounding ratios shown in Table 1.

[0069]

[0070] <Production of Hot Melt Pressure Sensitive Adhesive> (Production Example: HM-1) 8 parts of wax (PPMA6252), 17 parts by mass of oil (PW-90), 17 parts by mass of oil (PW-380), and 0.5 parts of antioxidant (IRG1010) were placed in a stainless steel beaker equipped with a stirrer, and the contents were carefully heated to 130 to 150°C. After melting, the mixture was stirred to form a homogeneous molten solution. While maintaining the temperature at 130 to 150°C and continuing to stir, 10 parts of thermoplastic elastomer (G1643) and 10 parts of thermoplastic elastomer (G1652) were gradually added to the molten mixture. After the addition was completed, the mixture was heated and stirred at 130 to 150°C until 38 parts of tackifier (RHR-301) was completely melted, forming a homogeneous mixture, which was then cooled to produce a hot melt pressure sensitive adhesive.

[0071] (Production Examples: HM-2 to HM-10) Production Examples HM-2 to HM-10 were produced in the same manner as Production Example HM-1 using the blending ratios shown in Table 2.

[0072] (Production Example: HM'-1) 20 parts of oil PW-90, 20 parts of oil PW-380, and 0.5 parts of antioxidant IRG1010 were placed in a stainless steel beaker equipped with a stirrer, and the contents were carefully heated to 130 to 150°C. After melting, the mixture was stirred to form a homogeneous molten solution, and then, while maintaining the temperature at 130 to 150°C and continuing to stir, 10 parts of thermoplastic elastomer G1643 and 10 parts of thermoplastic elastomer G1652 were gradually added to the molten mixture. After the addition was completed, the mixture was heated and stirred at 130 to 150°C until 40 parts of tackifier RHR-301 was completely melted, forming a homogeneous mixture, which was then cooled to produce a hot-melt pressure-sensitive adhesive.

[0073]

[0074] [Example 1] The mixed resin (F-1) was formed into a film on a release-treated layer of PET / release-treated layer (silicone treatment) using a T-die to obtain a mixed resin film with a thickness of 50 μm. The obtained mixed resin film was cut into a size of 15 cm × 30 cm, folded so as to enclose 500 g of hot-melt pressure-sensitive adhesive (HM-1), and the three open sides were heat-sealed to obtain a mass (X) of Example 1.

[0075] [Examples 2 to 19 and Comparative Examples 1 to 5] The aggregates (X) of Examples 2 to 19 and Comparative Examples 1 to 5 were obtained in the same manner as in Example 1, except that the type of mixed resin, the thickness of the mixed resin film, and the type of hot-melt pressure-sensitive adhesive were changed to those shown in Table 3.

[0076] (Bag Breakability) 40 pieces of the lumps (X) were placed in a cardboard box measuring 50 cm long x 38 cm wide x 30 cm high, and left in a 40°C oven for 24 hours, after which the state of the molten bags was visually inspected and evaluated. +++, ++, and + were rated as pass, and NG was rated as fail. [Evaluation Criteria] +++: No breakage of the molten bag. Excellent. ++: The molten bag was broken, but the lumps were not adhered to each other. Good. +: The molten bag was broken, and the lumps were adhered to each other, but could be easily peeled off. No problem in practical use. NG: The molten bag was broken, and the lumps were adhered to each other and could not be easily peeled off. Not practical.

[0077] (Solubility) For each of HM-1 to HM-10 and HM'-1, a white hot-melt adhesive was prepared by blending 1% by mass of titanium oxide relative to the total mass of the hot-melt adhesive. The resulting mixed resin film was cut into a 15 cm x 30 cm piece, folded to encase 500 g of the white hot-melt adhesive, and the three open edges were heat-sealed to obtain a mass (Y) containing the white hot-melt adhesive. The mass (Y) was placed in a beaker and heated to 150°C. After stirring at 500 rpm for 1 minute using a stirring blade (IKA Japan, R1381), the molten material was dripped onto black paper and visually evaluated for color unevenness. +++, ++, and + were considered acceptable, while NG was considered unacceptable. [Evaluation Criteria] +++: No color unevenness. Excellent. ++: Partial color unevenness. Good. +: Color unevenness is observed overall, but there is no remaining melted part of the melting bag. No problem for practical use. NG: Color unevenness is observed overall, and the melting bag remains. Not suitable for practical use.

[0078] (Stringiness) The lumps were placed in the melting tank of a hot melt gun, heated to 150°C, and intermittently applied 600 times horizontally to an adherend 30 cm away from the tip of the hot melt gun. The weight of the material that fell between the hot melt gun and the adherend was measured to evaluate stringiness. The test conditions were as follows: Discharge temperature: 140°C, Discharge amount: 0.2 g / time, Discharge time: 0.2 seconds, Discharge interval: 0.2 seconds. [Evaluation criteria] +++, ++, and + were considered pass, and NG was considered fail. +++: 200 mg or less. Excellent. ++: More than 200 mg but less than 500 mg. Good. +: More than 500 mg but less than 1 g. No practical problems. NG: More than 1 g or the melted lumps clogged the nozzle, making application impossible. Not practical.

[0079]

[0080]

[0081]

[0082] The lumps of this example, which contain a hot-melt adhesive in a melting bag made of a mixed resin film, have excellent solubility and bag-breaking properties and good stringiness during labeling, as shown in Tables 3 and 4. On the other hand, the lumps that do not satisfy the requirements of this example have problems with either solubility, bag-breaking properties, or stringiness during labeling, as shown in Table 5, and no lumps that satisfy these requirements were obtained.

[0083] The mass of the present disclosure has superior bag-breaking properties, solubility (compatibility) between melting bags and hot-melt adhesives, and stringiness during application, making it suitable for joining a variety of objects. For example, it is suitable for the manufacture of hygiene products, disposable medical drapes, paper, tape, labels, furniture, textiles, and footwear. It is also suitable for use in wood processing or the construction industry, for example, in roofing membranes or other architectural laminates.

[0084] This application claims priority based on Japanese Patent Application No. 2024-019157, filed February 13, 2024, the disclosure of which is incorporated herein in its entirety by reference.

Claims

1. A mass containing a hot melt adhesive in a melting bag, the melting bag having a density of 923 to 930 kg / m ３ a mixed resin film containing a low-density polyethylene resin (A) and an ethylene-vinyl acetate copolymer resin (B); and a hot melt adhesive containing a wax (C) and having a viscosity of 500 to 2500 mPa·s at 140°C.

2. The mass according to claim 1, wherein the content of the ethylene-vinyl acetate copolymer resin (B) in 100% by mass of the mixed resin film is 10 to 50% by mass.

3. The mass according to claim 1, wherein the vinyl acetate content of the ethylene-vinyl acetate copolymer resin (B) is 5 to 30% by mass.

4. Low-density polyethylene resin (A) at 190°C and 2.16 kgf / cm ２ 2. The agglomerate according to claim 1, wherein the melt mass flow rate is 1 to 25 g / 10 min.

5. The mass according to claim 1, wherein the melting point of the wax (C) is 70 to 150°C.

6. The lump according to claim 1, wherein the wax (C) contains at least one of a polyethylene wax (C-1) having a melting point of 90 to 150°C and a polypropylene wax (C-2) having a melting point of 90 to 150°C.

7. The mass according to claim 1, wherein the thickness of the melting bag is 10 to 500 μm.

8. The mass according to claim 6, characterized in that it contains a polypropylene wax (C-2) having a melting point of 90 to 150°C, and the wax (C-2) includes a polypropylene wax graft-polymerized with maleic anhydride.

9. The mass according to claim 1, wherein the hot melt adhesive is an alkali dispersible hot melt adhesive.

10. A container to which a label is attached using the mass according to any one of claims 1 to 9.

11. The container according to claim 10, characterized in that the container is made of polyethylene terephthalate or glass.

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