Adhesive removal agent and adhesive removal method using said adhesive removal agent

Abstract

The present invention addresses the problem of providing an adhesive removal agent capable of sufficiently removing an adhesive from a material, and an adhesive removal method using the adhesive removal agent. The aforementioned problem can be solved by an adhesive remover comprising an oil and a surfactant, the oil comprising at least one selected from the group consisting of a specific vegetable oil, a specific ester oil, an aliphatic carboxylic acid, and a mineral oil, and the surfactant comprising at least one compound selected from the group consisting of at least one compound selected from the group consisting of at least one compound selected from the group consisting of at least one compound selected from the group consisting of at least one compound selected from the group consisting of at least one compound. The surfactant contains an anionic surfactant and / or a nonionic surfactant that has a hydrophilic-lipophilic balance (HLB) of more than 5 and is liquid at room temperature.

Description

Technical Field

[0001] The present invention relates to an adhesive remover and an adhesive removing method using the adhesive remover. Background Art

[0002] Conventionally, adhesives have been widely used in fields such as furniture, construction, electrical and electronic components, automobiles, packaging materials, clothing, and household goods. Moreover, various articles such as food packaging materials, corrugated cardboard, books, sanitary products such as diapers, and automotive mats are formed by bonding materials using adhesives.

[0003] In recent years, from the viewpoint of reducing the environmental load, technologies for reusing used articles have received attention.

[0004] For example, Patent Document 1 discloses a method for recovering pulp fibers from a used absorbent article containing pulp fibers and a superabsorbent polymer. This method is characterized by including the following steps: treating the used absorbent article with an aqueous solution containing at least one terpene selected from the group consisting of terpene olefins, terpene aldehydes, and terpene ketones and containing a deactivator capable of deactivating the superabsorbent polymer to deactivate the superabsorbent polymer. In addition, this document discloses putting the used absorbent article into a washing machine filled with the aforementioned aqueous solution and using centrifugal force to decompose the article.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Publication "Japanese Patent Application Laid-Open No. 2018-24964". Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] As described above, the prior art decomposes absorbent articles into constituent components (materials) and reuses the recovered pulp fibers as resources. However, in the prior art as described above, adhesives remain in the constituent components obtained by decomposing the absorbent articles, and the constituent components may adhere to each other again. In addition, when adhesives remain in the recovered pulp fibers, quality problems may sometimes occur when the recovered pulp fibers are reused as resources. From these viewpoints, there is room for improvement in the above prior art.

[0010] One embodiment of the present invention has been proposed in view of the above problems, and an object thereof is to provide an adhesive remover capable of sufficiently removing adhesives from materials and an adhesive removing method using the adhesive remover.

[0011] Means for Solving the Problem

[0012] In order to solve the above problems, the adhesive remover according to an embodiment of the present invention includes the following constitution.

[0013] An adhesive remover, wherein the adhesive remover contains oil and a surfactant, the oil contains one or more selected from the group consisting of vegetable oil, ester oil, aliphatic carboxylic acid, and mineral oil, the iodine value of the vegetable oil is 70 to 160, the ester oil has 3 or less ester groups in one molecule, and the surfactant contains an anionic surfactant and / or a nonionic surfactant having a hydrophilic-lipophilic balance value (HLB) greater than 5 and being liquid under normal temperature conditions.

[0014] Effects of the Invention

[0015] According to one aspect of the present invention, it is possible to provide an adhesive remover capable of sufficiently removing an adhesive from a material, and a method for removing an adhesive using the adhesive remover. Detailed Embodiments

[0016] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and various modifications can be made within the described scope, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. It should be noted that, unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more and B or less". In addition, in this specification, normal temperature means 18°C to 26°C.

[0017] 〔1. Adhesive Remover〕

[0018] The adhesive remover according to an embodiment of the present invention (hereinafter, sometimes referred to as "this adhesive remover") contains oil and a surfactant, the oil contains one or more selected from the group consisting of vegetable oil, ester oil, aliphatic carboxylic acid, and mineral oil, the iodine value of the vegetable oil is 70 to 160, the ester oil has 3 or less ester groups in one molecule, and the surfactant contains an anionic surfactant and / or a nonionic surfactant having a hydrophilic-lipophilic balance value (HLB) greater than 5 and being liquid under normal temperature conditions. Such an adhesive remover has the advantage of being able to sufficiently remove the adhesive from the material. According to the above constitution, it is possible to separate the articles adhered by the adhesive by material without leaving the adhesive remaining. Therefore, it has the advantage of being able to appropriately reuse the articles adhered by the adhesive. Such an effect also contributes to, for example, achieving Goal 12, "Responsible consumption and production", of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0019] In addition, according to the above configuration, since the adhesive can be sufficiently removed from the material, there is also an advantage that the article can be separated into the constituent materials without using centrifugal force or the like. Further, since the adhesive does not remain on the material, there is also an advantage that the materials do not adhere to each other again after the adhesive is removed. That is, according to the above configuration, there is an advantage that the article adhered by the adhesive can be efficiently reused.

[0020] Furthermore, when the article obtained by adhering materials with an adhesive is a disposable diaper, by using this adhesive remover, even in the state where the disposable diaper is rolled up, the adhesive remover can penetrate into the interior and remove the adhesive. That is, there is an advantage that the adhesive can be removed without opening the used and rolled-up disposable diaper, enabling the decomposition of the article. In addition, there are advantages that not only pulp and SAP (superabsorbent polymer) can be separated and recovered from the disposable diaper, but also non-woven fabric, film, rubber filaments, etc. can be separately separated and recovered.

[0021] Preferably, this adhesive remover is a liquid under normal temperature conditions. The viscosity of this adhesive remover is not particularly limited, and is preferably 15 mPa·s to 2600 mPa·s, more preferably 30 mPa·s to 1700 mPa·s. According to this configuration, there are advantages that it is easy to penetrate into the adhesive and the adhesive can be sufficiently removed from the material. In addition, the value of the viscosity of the adhesive remover varies with the contained components and the mixing ratio of the components. Further, this adhesive remover is preferably an oil-based type. In this specification, "this adhesive remover is an oil-based type" means "an adhesive remover in which the total blending amount of oil and surfactant is more than the blending amount of other components".

[0022] (1-1. Oil)

[0023] This adhesive remover contains oil. According to this configuration, there are advantages that the adhesive can be dissolved and the adhesive can be removed from the article.

[0024] In addition, it is preferable that the oil is a liquid under normal temperature conditions. According to this configuration, there is an advantage that it can be easily mixed with the surfactant under normal temperature conditions.

[0025] In addition, in one embodiment of the present invention, the oil contains one or more selected from the group consisting of vegetable oil, ester oil, aliphatic carboxylic acid, and mineral oil. More preferably, the oil contains vegetable oil or ester oil, and further preferably consists of vegetable oil or ester oil. According to this configuration, there are advantages that the affinity with the surfactant is high and the adhesive can be more sufficiently removed from the material. It should be noted that for the oil, at least two or more selected from the group consisting of vegetable oil, ester oil, aliphatic carboxylic acid, and mineral oil can also be mixed.

[0026] In this adhesive remover, with respect to the total amount of oil and surfactant being 100% by weight, the content ratio of oil is preferably greater than 10% by weight and less than 70% by weight, more preferably 15% by weight or more and 65% by weight or less, more preferably 18% by weight or more and 60% by weight or less, more preferably 20% by weight or more and 55% by weight or less, further preferably 20% by weight or more and 50% by weight or less, and particularly preferably 20% by weight or more and 45% by weight or less. According to this configuration, it has the advantages of strong affinity with the surfactant and being able to more fully remove the adhesive from the material.

[0027] (1-1-1. Vegetable oil)

[0028] Preferably, this adhesive remover contains vegetable oil. According to this configuration, it has the advantage of being able to more fully remove the adhesive from the material.

[0029] Preferably, this adhesive remover does not contain animal oil. Most animal oils are solid and tend to be difficult to mix with surfactants under normal temperature conditions.

[0030] When this adhesive remover contains vegetable oil, the iodine value of the vegetable oil is 70 to 160, more preferably 80 to 150, further preferably 90 to 140, and particularly preferably 100 to 130. According to this configuration, since the affinity between the oil and the surfactant is good, the adhesive remover has the advantage of being able to more fully remove the adhesive from the material. Vegetable oils with a low iodine value (for example, 140 or less) have high safety, so they can be processed with simple equipment.

[0031] In addition, this adhesive remover may also contain multiple types of vegetable oils. Here, when this adhesive remover contains one type of vegetable oil, the "iodine value of the vegetable oil" refers to the iodine value of that vegetable oil. When this adhesive remover contains multiple types of vegetable oils, the "iodine value of the vegetable oil" refers to the iodine value of the mixed vegetable oil composed of multiple types of vegetable oils contained in this adhesive remover. That is, when this adhesive remover contains multiple types of vegetable oils, the iodine value of the mixed vegetable oil composed of these multiple types of vegetable oils is 70 to 160.

[0032] In this specification, the iodine value refers to the number of grams of iodine (I) that can be added to 100 g of oil or fat. That is, the larger the iodine value, the higher the degree of unsaturation of the fatty acids in the sample (the more double bonds). When this adhesive remover contains multiple types of vegetable oils, the "iodine value of the vegetable oil" is determined by the measurement method according to JIS K0070-1992. The vegetable oil can also be a vegetable oil mixed by selecting at least two or more from the group consisting of semi-drying oils, non-drying oils, and drying oils.

[0033] In this specification, oils having an iodine value of 140 or more are referred to as drying oils, oils having an iodine value of more than 100 and less than 140 are referred to as semi-drying oils, and oils having an iodine value of 100 or less are referred to as non-drying oils.

[0034] In one embodiment of the present invention, the vegetable oil is preferably selected from the group consisting of soybean oil, rice oil, olive oil, avocado oil, rice bran oil, orange seed oil, carrot seed oil, canola oil, apricot kernel oil, peach kernel oil, sweet almond oil, deep sea two-jointed camellia oil, sesame oil, rice germ oil, watermelon seed oil, grapefruit seed oil, tomato seed oil, passion fruit seed oil, wheat germ oil, corn oil, linseed oil, rapeseed oil, coconut oil, palm kernel oil and castor oil, more preferably selected from the group consisting of soybean oil, rice oil, olive oil and rapeseed oil, more preferably soybean oil and / or rice oil. According to this configuration, there is an advantage that the adhesive can be more fully removed from the material.

[0035] In one embodiment of the present invention, the flash point of the vegetable oil is not particularly limited, but is preferably 150° C. or higher, more preferably 200° C. or higher, from the viewpoint of safety and ease of handling.

[0036] (1-1-2. Ester oil)

[0037] Preferably, the present adhesive remover comprises an ester oil.

[0038] In one embodiment of the present invention, the ester oil has 3 or less ester groups in one molecule, preferably 2 or less, and more preferably 2. This configuration has the advantage that the adhesive can be more fully removed from the material.

[0039] The solubility parameter value (SP value) of the ester oil is preferably 8.0 to 9.5, more preferably 8.3 to 9.4, further preferably 8.5 to 9.3, and particularly preferably 8.7 to 9.2. This configuration has the advantage that the adhesive can be more fully removed from the material.

[0040] In this specification, the SP value (Solubility Parameter) refers to the Hansen solubility parameter (HSP value) defined by the Hansen method. d , set the polar term to δ p , and set the hydrogen bond term to δ h When the SP value δ is given by δ=(δ d 2 +δ p 2 +δ h 2 ) 1 / 2The defined quantity δ is an inherent value of the substance.

[0041] In one embodiment of the present invention, the ester oil is not particularly limited. For example, DOS (bis(2-ethylhexyl) sebacate), DIDA (diisodecyl adipate), DINA (diisononyl adipate), DOA (bis(2-ethylhexyl) adipate), diisobutyl adipate, 2-hexyldecyl adipate, di-2-heptylundecyl adipate, isostearyl isostearate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, neopentyl glycol di-2-ethylhexanoate, trimethylolpropane tri-2-ethylhexanoate, cetyl octanoate, oleyl oleate, octyldodecyl oleate, decyl oleate, neopentyl glycol didecanoate, 2-ethylhexyl succinate, isocetyl stearate, butyl stearate, diisopropyl sebacate, cetyl lactate, myristyl lactate, isopropyl myristate, octyldodecyl myristate, cetyl myristate, myristyl myristate, octyl palmitate, 2-ethylhexyl palmitate, 2-hexyldecyl palmitate, 2-heptylundecyl palmitate, cholesteryl 12-hydroxystearate, phytosteryl oleate, diisostearyl malate, methoxycinnamate, pentaerythritol tetrahydroabietate, etc. can be cited. The ester oil is more preferably DOS. According to this configuration, it has the advantage of being able to more fully remove the adhesive from the material.

[0042] (1-1-3. Aliphatic carboxylic acid)

[0043] Preferably, this adhesive remover contains an aliphatic carboxylic acid. As the aliphatic carboxylic acid, for example, monocarboxylic acid, dicarboxylic acid, acid anhydride, polycarboxylic acid, etc. can be cited. In one embodiment of the present invention, the aliphatic carboxylic acid is more preferably an aliphatic carboxylic acid or carboxylic anhydride having 2 carboxyl groups, more preferably succinic acid or its acid anhydride, and also more preferably alkenyl succinic acid or its acid anhydride. In addition, the aliphatic carboxylic acid is more preferably an unsaturated aliphatic carboxylic acid. According to this configuration, it has the advantage of being able to more fully remove the adhesive from the material. In one embodiment of the present invention, the aliphatic carboxylic acid is further preferably at least one selected from the group consisting of dodecenyl succinic acid, hexadecenyl succinic acid, octadecenyl succinic acid, and their acid anhydrides.

[0044] In one embodiment of the present invention, the molecular weight of the aliphatic carboxylic acid is not particularly limited. For example, the weight average molecular weight is preferably 200 to 1200, and more preferably 250 to 1000.

[0045] (1-1-4. Mineral oil)

[0046] Preferably, this adhesive remover contains mineral oil.

[0047] The SP value of the mineral oil is preferably 8.0 to 9.5, more preferably 8.0 to 9.3, still more preferably 8.0 to 9.0, even more preferably 8.0 to 8.5, and particularly preferably 8.0 to 8.3. According to this configuration, there is an advantage that the adhesive can be more sufficiently removed from the material.

[0048] In one embodiment of the present invention, the mineral oil having an SP value of 8.0 to 9.5 is not particularly limited. For example, aromatic hydrocarbons, paraffinic hydrocarbons, naphthenic hydrocarbons, light mineral oil, white mineral oil, etc. can be cited. More specifically, for example, spindle oil, liquid paraffin, etc. can be preferably used. According to this configuration, there is an advantage that the adhesive can be more sufficiently removed from the material.

[0049] In one embodiment of the present invention, the normal temperature viscosity of the ester oil and the mineral oil is not particularly limited, and is preferably 1 mPa·s to 200 mPa·s, more preferably 5 mPa·s to 100 mPa·s. According to this configuration, there is an advantage that the adhesive can be more sufficiently removed from the material.

[0050] In one embodiment of the present invention, the flash points of the ester oil, the aliphatic carboxylic acid, and the mineral oil are not particularly limited. From the viewpoints of safety and ease of handling, they are preferably 150°C or higher, more preferably 200°C or higher.

[0051] (1-2. Surfactant)

[0052] This adhesive remover contains a surfactant. According to this configuration, the adhesive remover can be easily removed from the separated material. In other words, for the purpose of dissolving the adhesive, only oil can be used. On the other hand, since this adhesive remover contains a surfactant, the adhesive remover can be sufficiently removed from the material in the article. Thereby, it is easy to process the separated material.

[0053] In one embodiment of the present invention, the surfactant contains an anionic surfactant and / or a nonionic surfactant having an HLB greater than 5 and being liquid under normal temperature conditions. In one embodiment of the present invention, it is preferred that the surfactant contains an anionic surfactant or a nonionic surfactant having an HLB greater than 5 and being liquid under normal temperature conditions, and it is further preferred that it is composed of a nonionic surfactant having an HLB greater than 5 and being liquid under normal temperature conditions.

[0054] In one embodiment of the present invention, in 100% by weight of the surfactant, the total content of the anionic surfactant and the nonionic surfactant having an HLB greater than 5 is preferably 70% by weight or more, more preferably 90% by weight or more, and further preferably 100% by weight. According to this configuration, there is an advantage that the adhesive can be more sufficiently removed from the material.

[0055] In addition, in one embodiment of the present invention, it preferably contains a nonionic surfactant having an HLB greater than 5 in a larger amount than an anionic surfactant. In 100% by weight of the total amount of the anionic surfactant and the nonionic surfactant having an HLB greater than 5, the content of the nonionic surfactant having an HLB greater than 5 is preferably 60% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and particularly preferably 100% by weight. According to this configuration, it has the advantage of being able to more sufficiently remove the adhesive from the material.

[0056] In the present specification, HLB (Hydrophile-Lipophile Balance) is a value representing the balance between the lipophilicity and hydrophilicity in a surfactant. It is a value obtained by equally dividing the HLB of a substance having no hydrophilic group as HLB = 0 and the HLB of a substance having only a hydrophilic group and no lipophilic group as HLB = 20.

[0057] The HLB of the nonionic surfactant having an HLB greater than 5 is preferably greater than 5 and 15 or less, more preferably 7 or more and 13 or less, still more preferably 9 or more and 11 or less. According to this configuration, it has the advantages of good affinity for oil and being able to sufficiently remove the adhesive from the material.

[0058] In addition, in one embodiment of the present invention, the nonionic surfactant is a liquid under normal temperature conditions. According to this configuration, it has good affinity for oil, and the oil and the surfactant can be mixed without the need for energy such as heating.

[0059] The nonionic surfactant is not particularly limited. For example, polyoxyalkylene alkyl ethers; polyoxyalkylene alkenyl ethers; polyoxyalkylene alkyl phenyl ethers; polyoxyethylene castor oil; sorbitan fatty acid esters and their alkylene oxide adducts; polyoxyalkylene fatty acid esters; polyoxyethylene hydrogenated castor oil, etc. are preferred.

[0060] Examples of the polyoxyalkylene alkyl ether include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene polyoxypropylene lauryl ether, polyoxypropylene cetyl ether, polyoxypropylene isocetyl ether, polyoxypropylene stearyl ether, polyoxyethylene docosyl ether, etc.

[0061] Examples of the polyoxyalkylene alkenyl ether include polyoxyethylene oleyl ether, polyoxypropylene oleyl ether, etc.

[0062] Examples of the polyoxyalkylene alkyl phenyl ether include polyoxyethylene octyl phenyl ether, etc.

[0063] Polyoxyethylene castor oil is a compound formed by the addition polymerization of ethylene oxide and castor oil. The average number of moles of ethylene oxide added is not particularly limited, preferably 2 to 100, more preferably 10 to 50. As the polyoxyethylene castor oil, for example, NIKKOL CO-3, NIKKOL CO-10, NIKKOL CO-35 (Nikko Chemicals Co., Ltd.); EMALEX C-20, EMALEX C-30, EMALEX C-40, EMALEX C-50 (NIHON EMULSION Co., Ltd.); and Kolliphor EL (BASF) can be cited.

[0064] As sorbitan fatty acid esters, for example, sorbitan monooleate, sorbitan monostearate, sorbitan monoisostearate, sorbitan monopalmitate, sorbitan monolaurate, sorbitan trioleate, sorbitan tristearate, sorbitan sesquistearate, sorbitan sesquioleate, sorbitan sesquisoisostearate, sorbitan coconut oil fatty acid ester, etc. can be cited. In addition, as the alkylene oxide adduct of sorbitan fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monoisostearate, polyoxyethylene sorbitan monococonut oil fatty acid ester, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan trioleate, etc. can be cited.

[0065] As polyoxyalkylene fatty acid esters, for example, it includes any one of polyoxyalkylene monofatty acid esters and polyoxyalkylene difatty acid esters. As polyoxyalkylene monofatty acid esters, for example, polyoxyethylene monofatty acid esters such as polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene monolaurate; propylene glycol monostearate, propylene glycol monolaurate, propylene glycol monooleate and other propylene glycol monofatty acid esters, etc.

[0066] As the nonionic surfactant with an HLB greater than 5, there is no particular limitation. For example, as polyoxyalkylene alkyl ethers, DKS NL30 and DKS NL 50 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) can be preferably used. As sorbitan fatty acid esters, Tween (registered trademark) 80, EMASOL O-120V (both are polyoxyethylene (20) sorbitan monooleate), etc. can be preferably used. According to this configuration, it has the advantages of good affinity for oil and being able to sufficiently remove the adhesive from the material.

[0067] In one embodiment of the present invention, it is preferred that the anionic surfactant contains sulfonate. According to this configuration, there is an advantage that the adhesive can be sufficiently removed from the material.

[0068] The anionic surfactant is not particularly limited, and sulfonate type and phosphate type are preferred, and alkyl sulfonate, polyoxyalkylene alkyl ether sulfonate, polyoxyalkylene alkyl ether phosphate, etc. are more preferred. The anionic surfactant is more preferably alkyl sulfonate. According to this configuration, there is an advantage that the adhesive can be sufficiently removed from the material.

[0069] (1-3. Other components)

[0070] This adhesive remover may also contain other components. The other components are not particularly limited, and examples thereof include water, petroleum resin, hydrogenated petroleum resin, plant-derived resin, hydrogenated plant-derived resin, antibacterial agent, fungicide, deodorant, mildew-proof agent, preservative, fragrance, pigment, dye, dispersant, pH indicator, dehydrating agent, and rust inhibitor.

[0071] When this adhesive remover contains water, it is easy to rinse the adhesive remover that has penetrated into the material in the washing process (described later) after the removal process. The addition amount of water is preferably 10% by weight or less relative to the total amount of the adhesive remover. When removing the adhesive from the constituent material of an article containing a superabsorbent polymer as a constituent material and separating the superabsorbent polymer for reuse as a superabsorbent polymer for sanitary materials such as diapers, it is preferred that the adhesive remover may or may not contain water.

[0072] In addition, within the range of the allowable removal performance of the adhesive, an organic solvent may also be contained in the adhesive remover. Examples of the organic solvent include toluene, limonene, chloroform, hexane, ethyl acetate, benzene, alcohol, acetic acid, and acetone.

[0073] When this adhesive remover contains an organic solvent, the content of the organic solvent is preferably 0% by weight to 20% by weight, more preferably 0% by weight to 15% by weight, further preferably 0% by weight to 10% by weight, and particularly preferably 0% by weight to 5% by weight relative to the total amount of the adhesive remover. According to this configuration, there is an advantage that the adhesive can be removed. Preferably, the total blending amount of the oil and the surfactant is more than the blending amount of the other components, and this adhesive remover is an oil-based type. In addition, a non-emulsified type that does not contain components with low compatibility with the oil is preferred.

[0074] (1-4. Adhesive)

[0075] The adhesive that can be removed by this adhesive remover is not particularly limited. For example, hot-melt adhesives, solvent-based adhesives, and water-based adhesives are preferred, and adhesives other than curable adhesives are preferably used. When using this adhesive remover, it has the advantage of being able to also remove the base polymer and tackifier that are difficult to remove in the adhesive. In addition, since the tackifier can also be removed, there is also the advantage that no residual glue remains on the material.

[0076] This adhesive remover is more preferably a hot-melt adhesive remover. This adhesive remover more suitably exerts the effect of removing the adhesive on the hot-melt adhesive.

[0077] The hot-melt adhesive is not particularly limited. For example, synthetic rubber (elastomer)-based hot-melt adhesives, polyamide-based hot-melt adhesives, polyester-based hot-melt adhesives, acrylic-based hot-melt adhesives, EVA (ethylene vinyl acetate copolymer)-based hot-melt adhesives, and olefin-based hot-melt adhesives can be cited. Among them, synthetic rubber-based hot-melt adhesives using elastomers and acrylic-based hot-melt adhesives using elastomers are more preferably used. According to this configuration, it has the advantage of being able to sufficiently remove the adhesive from the material.

[0078] As the solvent-based adhesive, for example, (meth)acrylate-based, silicone-based, polyvinyl acetate-based, polyvinyl acetate-based, polyisoprene rubber-based, styrene-methyl acrylate copolymer-based, styrene-butadiene rubber-based, styrene-isoprene rubber-based, methacrylate-butadiene-styrene copolymer-based, and combinations thereof can be cited. Among them, (meth)acrylate-based, polyisoprene rubber-based, styrene-methyl acrylate copolymer-based, styrene-butadiene rubber-based, styrene-isoprene rubber-based, methacrylate-butadiene-styrene copolymer-based, and combinations thereof are preferred. According to this configuration, it has the advantage of being able to sufficiently remove the adhesive from the material.

[0079] (1-5. Uses)

[0080] This adhesive remover is applicable to removing adhesives from various articles such as food packaging materials, corrugated cardboard, books, sanitary products (diapers, sanitary products, pet pads, urine pads, breast pads, etc.), and automotive mats.

[0081] 〔2. Adhesive removal method〕

[0082] (2-1. Adhesive removal process)

[0083] The adhesive removal method according to an embodiment of the present invention (hereinafter, sometimes referred to as "this removal method") includes an adhesive removal process of removing the adhesive from the material to which the adhesive is attached using the adhesive remover described in 〔1. Adhesive remover〕.

[0084] The material to which the adhesive is attached is not particularly limited. For example, it can be used for plastics, plastic films, pulp, superabsorbent polymers, paper, non-woven fabrics, rubber threads, corrugated cardboard, felt, or foamed urethane, etc.

[0085] The method for removing the adhesive from the material to which the adhesive is attached using this adhesive remover is not particularly limited, and examples thereof include a method of immersing the material in this adhesive remover. Here, the material immersed in this adhesive remover only needs to be attached with an adhesive, and it can be a single material, or a plurality and / or a plurality of types of materials. Each material can be in a state where it is bonded with an adhesive, or at least a part thereof may not be bonded. The material immersed in this adhesive remover can be an article formed by bonding constituent components (materials) with an adhesive. Heating can also be performed in the process of removing the adhesive from the material. From the viewpoints of reducing energy consumption and miniaturization of equipment, the method of immersing the material in this adhesive remover is more preferable. From the viewpoint of the removal efficiency of the adhesive, a method of immersing and stirring is preferred.

[0086] (2-2. Washing process)

[0087] Preferably, this removal method further includes a process of washing the material from which the adhesive has been removed with water, in other words, a process of washing with an aqueous washing liquid. It should be noted that here, the aqueous washing liquid refers to a washing liquid composed of water or a washing liquid containing water. Thereby, it is possible to rinse the adhesive remover that has penetrated into the material, and it is easy to process the material.

[0088] The temperature of the aqueous washing liquid is not limited. From the viewpoint of shortening the washing time, it is preferably 40°C to 80°C. The temperature of the aqueous washing liquid is more preferably 45°C to 80°C, still more preferably 50°C to 80°C, further preferably 55°C to 80°C, and particularly preferably 60°C to 80°C. According to this configuration, there is an advantage that the adhesive can be sufficiently removed from the material. In particular, if the temperature of the aqueous washing liquid is set to 40°C to 80°C, it is easy to rinse the oil component.

[0089] The aqueous washing liquid is not particularly limited as long as it can remove the adhesive remover from the material to the extent that the material can be reused, and it may also contain substances other than water. For the aqueous washing liquid, water is preferably the main component. Therefore, the weight of water is preferably at least 60% by weight or more, more preferably 90% by weight or more, relative to the total weight of water and substances other than water (the total weight of the aqueous washing liquid). Examples of water include tap water, soft water, hard water, carbonated water, alkaline ion water, pure water, and mixtures thereof. Examples of substances other than water include alcohols, acetone, etc. When the article contains a superabsorbent polymer and the superabsorbent polymer will not be reused as a superabsorbent polymer, in the aqueous washing liquid, as substances other than water, dehydrating agents, etc. may also be included. The concentration of the dehydrating agent in the aqueous washing liquid only needs to be determined according to the amount of the superabsorbent polymer contained in the article whose constituent material is washed by being immersed in the aqueous washing liquid, and is preferably 0.1% by weight to 10% by weight. Examples of the dehydrating agent include calcium chloride, magnesium sulfate, citric acid, acetic acid, etc. By including a dehydrating agent in the aqueous washing liquid, after removing the adhesive from the material, when washing with the aqueous washing liquid and removing the remover from the material, the water absorption of the superabsorbent polymer can be prevented, and thus, the treatment is facilitated. When the superabsorbent polymer is used for applications other than water absorption applications (such as fuels, etc.), there is no problem in including a dehydrating agent in the superabsorbent polymer, and the treatment also becomes easy. Therefore, it is preferred to include a dehydrating agent in the aqueous washing liquid.

[0090] (2-3. Separation step)

[0091] When the material in the article adhered by an adhesive contains a superabsorbent polymer, preferably, this removal method further includes a separation step of separating the material from which the adhesive has been removed into a superabsorbent polymer and a material other than the superabsorbent polymer after the adhesive removal step of removing the adhesive from the material with the adhesive remover. After the adhesive removal step, without performing a step of washing with water, by providing this separation step, the operability of the superabsorbent polymer will not deteriorate due to water absorption in the washing step using water, or the superabsorbent polymer will not deteriorate due to the dehydrating agent, and the separated superabsorbent polymer can be regenerated. Therefore, it is easy to reuse the superabsorbent polymer.

[0092] The method for separating the material from which the adhesive has been removed in the adhesive removal step into a superabsorbent polymer and a material other than the superabsorbent polymer is not particularly limited. For example, filtration separation, centrifugal separation, etc. can be cited. In the case of filtration separation, the mesh size of the filter can be appropriately determined according to the size of the materials contained in the article taken out from the adhesive remover. For example, a filter with a mesh size of 0.01 mm to 5 mm is used. The superabsorbent polymer passes through the filter together with the adhesive remover, and the materials other than the superabsorbent polymer do not pass through the filter. Therefore, the superabsorbent polymer and the materials other than the superabsorbent polymer can be separated.

[0093] More preferably, this removal method further includes a step of washing the separated superabsorbent polymer with an organic solvent and / or a step of washing the material other than the superabsorbent polymer with an aqueous washing liquid. The superabsorbent polymer usually uses crosslinked polyacrylic acid and its salts and has the property of absorbing water and swelling. If the superabsorbent polymer absorbs water, it is difficult to handle. Therefore, when washing with an aqueous washing liquid, a dehydrating agent such as calcium chloride is used. However, if a dehydrating agent is used for the superabsorbent polymer, the structure changes and it cannot absorb water (deteriorates), so it is difficult to be reused as a superabsorbent polymer. To prevent this problem, it is preferable to wash the superabsorbent polymer with an organic solvent. To reduce the environmental load, it is preferable that the material other than the superabsorbent polymer (for example, non-woven fabric, pulp, film) is washed with an aqueous washing liquid in the same manner as described above. The aqueous washing liquid used for washing the material other than the superabsorbent polymer can be the same washing liquid as the aqueous washing liquid described in the step of washing the material from which the adhesive has been removed. It should be noted that when the superabsorbent polymer is not reused or when it is no problem for the superabsorbent polymer to contain water, the step of washing with the aforementioned aqueous washing liquid can also be carried out without separating the material from which the adhesive has been removed into a superabsorbent polymer and a material other than the superabsorbent polymer. In one embodiment, this removal method includes: an adhesive removal step of removing the adhesive from the material having the adhesive attached to the article adhered by the adhesive; a separation step of separating the material from which the adhesive has been removed into the superabsorbent polymer and a material other than the superabsorbent polymer; and a washing step of washing the superabsorbent polymer separated in the separation step with an organic solvent. When the article is immersed in an organic solvent to remove the adhesive, the amount of the organic solvent used is larger compared with this removal method. In addition, in this case, when reusing non-woven fabric, pulp, film, etc. as the material other than the superabsorbent polymer, the organic solvent cannot be easily removed and labor is required.

[0094] The organic solvent used for washing the separated superabsorbent polymer in the washing and separation process only needs to be able to rinse the adhesive remover infiltrated into the material and wash it to the extent that the superabsorbent polymer can be reused again, and there are no particular limitations on the type, purity, etc. As the organic solvent, for example, polar solvents, non-polar solvents, and mixtures thereof can be cited. As polar solvents, alcohols such as methanol, ethanol, and glycerol can be cited; ketones such as acetone and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; and dimethyl sulfoxide, etc. As non-polar solvents, aliphatic compounds such as hexane, cyclohexane, and limonene can be cited; and aromatic hydrocarbons such as toluene and xylene. From the viewpoint of the solubility of the adhesive remover, the molecular weight of the organic solvent is preferably 200 or less. The polar solvent is more preferably methanol or ethanol. The non-polar solvent is more preferably pentane, hexane, or cyclohexane.

[0095] As a method for washing the superabsorbent polymer with an organic solvent, one organic solvent can be used, or a plurality of organic solvents can be used, and the number of washing times is not limited. For example, a single organic solvent can be used, a mixed solvent of a plurality of organic solvents can be used, or it can be washed with a non-polar solvent after washing with a polar solvent or washed with a polar solvent after washing with a non-polar solvent. When using a mixed solvent of a polar solvent and a non-polar solvent, the ratio of the polar solvent to the non-polar solvent can be 1:9 to 9:1 based on volume. As a method for washing the superabsorbent polymer with an organic solvent, it is preferable to mix the polar solvent and the non-polar solvent or use them stepwise for washing. The process of washing with an organic solvent is usually carried out under normal temperature conditions, but the temperature can also be appropriately raised.

[0096] As a method for washing the material from which the adhesive has been removed in the adhesive removal process and the separated superabsorbent polymer or the material other than the superabsorbent polymer in the separation process, there are no particular limitations, and examples include methods of stirring the object to be washed using a washing machine, stirring blades, or a stirrer in an aqueous washing solution or an organic solvent. In addition, the number of washing times is not particularly limited and can be once or a plurality of times.

[0097] <Summary>

[0098] One embodiment of the present invention includes the following configurations.

[0099] 〔1〕An adhesive remover, wherein the adhesive remover contains oil and a surfactant, the oil contains one or more selected from the group consisting of vegetable oil, ester oil, aliphatic carboxylic acid, and mineral oil, the iodine value of the vegetable oil is 70 to 160, the ester oil has 3 or less ester groups in one molecule, and the surfactant contains an anionic surfactant and / or a non-ionic surfactant with an HLB greater than 5 and being a liquid under normal temperature conditions.

[0100] 〔2〕The adhesive remover according to 〔1〕, wherein the content ratio of the oil is more than 10% by weight and less than 70% by weight with respect to the total amount of 100% by weight of the oil and the surfactant.

[0101] 〔3〕The adhesive remover according to any one of 〔1〕 or 〔2〕, wherein the HLB of the nonionic surfactant is 15 or less.

[0102] 〔4〕The adhesive remover according to any one of 〔1〕 to 〔3〕, wherein the SP values of both the ester oil and the mineral oil are 8.0 or more and 9.5 or less.

[0103] 〔5〕The adhesive remover according to any one of 〔1〕 to 〔4〕, wherein the adhesive remover is a hot melt adhesive remover.

[0104] 〔6〕An adhesive removing method, wherein the adhesive removing method includes an adhesive removing step of removing an adhesive from a material to which the adhesive is attached by using the adhesive remover according to any one of 〔1〕 to 〔5〕.

[0105] 〔7〕The adhesive removing method according to 〔6〕, wherein the adhesive removing method further includes a washing step of washing the material from which the adhesive has been removed in the adhesive removing with water.

[0106] 〔8〕The adhesive removing method according to 〔6〕, wherein the material contains a superabsorbent polymer, and the adhesive removing method includes a separating step of separating the material from which the adhesive has been removed into the superabsorbent polymer and a material other than the superabsorbent polymer.

[0107] 〔9〕The adhesive removing method according to 〔8〕, wherein the adhesive removing method includes a washing step of washing the superabsorbent polymer separated in the separating step with an organic solvent.

[0108] 〔10〕The adhesive removing method according to 〔8〕 or 〔9〕, wherein the adhesive removing method includes a washing step of washing the material other than the superabsorbent polymer separated in the separating step with water.

[0109] Examples

[0110] Hereinafter, examples will be described. It should be noted that the present invention is not limited to the following examples.

[0111] 〔Materials〕

[0112] In the following Examples and Comparative Examples, the following materials were used.

[0113] "Oil"

[0114] (Vegetable oil)

[0115] Soybean oil (iodine value 131): manufactured by KANEDA Co., Ltd.

[0116] Rice bran oil (iodine value 104): manufactured by Boso oil and fat Co., Ltd.

[0117] Rapeseed oil (iodine value 110): manufactured by Yonezawa Oil Mill Co., Ltd.

[0118] Olive oil (iodine value 85): manufactured by J-oil mills, inc.

[0119] Linseed oil (iodine value 187): manufactured by Nisshin Flour Milling Co., Ltd.

[0120] (Ester oil)

[0121] DOS (bis(2-ethylhexyl) sebacate: the number of ester groups in one molecule is 2, SP value 9.1): manufactured by Shin Nippon Rika Co., Ltd.

[0122] ATBC (tributyl acetylcitrate: the number of ester groups in one molecule is 4, SP value 9.8): manufactured by Taoka Chemical Co., Ltd.

[0123] (Aliphatic carboxylic acid)

[0124] Alkenyl succinic anhydride (maleic acid-modified α-olefin) (SP value 10.1): manufactured by Starlight PMC Co., Ltd., AS-1532.

[0125] (Mineral oil)

[0126] MORESCO WHITE "P-200" (liquid paraffin: SP value 8.1): manufactured by MORESCO.

[0127] Cosmo Neutral 150 (aromatic mineral oil: SP value 8.7): manufactured by COSMO OIL LUBRICANTS CO., LTD.

[0128] "Others"

[0129] d-Limonene.

[0130] "Surfactant"

[0131] (Nonionic surfactant)

[0132] DKS NL 15 (HLB = 5, liquid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0133] DKS NL 30 (HLB = 8, liquid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0134] DKS NL 50 (HLB = 10, liquid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0135] DKS NL Dash 410 (HLB = 12, liquid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0136] DKS NL 110 (HLB = 14, semi - solid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0137] EMASOL O - 120V (HLB = 15, liquid): manufactured by Kao Corporation.

[0138] DKS NL 180 (HLB = 16, semi - solid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0139] DKS NL 450F (HLB = 18, solid): manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

[0140] (Anionic surfactant)

[0141] SULFOL 430A (65% surfactant (sodium sulfonate), 30% spindle oil, 5% water, liquid): manufactured by MORESCO Corporation.

[0142] 《Solvent》

[0143] Water.

[0144] 《Dehydrating agent》

[0145] Citric acid.

[0146] 〔Preparation method of samples for evaluation〕

[0147] Apply a hot - melt adhesive (rubber - based, manufactured by MORESCO Corporation) to the first substrate (spunbond non - woven fabric) at a coating temperature of 150 °C using a ZIP coater (manufactured by SUNTOOL CORPORATION). The coating amount is 5 g / m 2, the coating width is 15 mm. Then, the second substrate (polyethylene film) is laminated on the surface of the first substrate coated with the hot-melt adhesive and pressed at 23°C to prepare a laminate. The time from when the hot-melt adhesive is coated on the first substrate until the second substrate is pressed and the laminate is prepared is 0.5 seconds. A sample of the obtained laminate is cut into 50×50 mm with the 15-mm-wide adhesive-coated portion arranged parallel to one side and placed in the center as a sample for evaluation.

[0148] 〔Preparation of Adhesive Remover (Examples 1 to 19, Comparative Examples 1 to 8)〕

[0149] Measure a specified amount of oil and surfactant in the proportions (parts by weight) shown in Tables 1 to 3 and place them in a glass container. Stir at room temperature for 1 minute until there is no phase separation to obtain an adhesive remover. In addition, for Examples 5 and 11 where SULFOL 430A is used as the surfactant, the surfactant (sodium sulfonate), oil, and water are included in the SULFOL 430A used. Therefore, in Examples 5 and 11, the content of the surfactant (sodium sulfonate) is formulated to be 50% by weight based on 100% by weight of the adhesive remover.

[0150] 〔Removal of Adhesive Using Adhesive Remover (Examples 1 to 19, Comparative Examples 1 to 8)〕

[0151] Put the evaluation sample into 10 g of the adhesive remover and immerse it for 1 hour. The evaluation sample separates in the adhesive remover. Take out the immersed evaluation sample from the remover and put it into another glass bottle. Put 100 g of warm water at 60°C into this glass bottle and stir well for 10 seconds. Repeat the above operation two more times for washing. Take out the washed evaluation sample and dry it, and confirm the state. Regarding whether the adhesive and the adhesive remover can be sufficiently removed from the material, the evaluation was carried out according to the following evaluation criteria.

[0152] (Mixing State of Adhesive Remover)

[0153] ◎ (Excellent): The liquid is transparent in the mixing state.

[0154] 〇 (Good): The liquid is uniform in the mixing state.

[0155] △ (Poor): The mixture separates after standing for 3 hours.

[0156] × (Not Acceptable): The mixture separates or is solid.

[0157] (Peeling State of Evaluation Sample after Immersion in Adhesive Remover)

[0158] 〇 (Good): The evaluation sample peels off.

[0159] × (Not acceptable): The sample for evaluation is not peeled off.

[0160] (Surface state of the sample for evaluation after washing)

[0161] ◎ (Excellent): Not sticky or slippery.

[0162] 〇 (Good): Slightly sticky or slippery.

[0163] × (Not acceptable): Sticky or slippery, or residual hot melt adhesive remains.

[0164] In this specification, "sticky or slippery" refers to the stickiness or slipperiness caused by the oil in the adhesive remover.

[0165] 〔Viscosity〕

[0166] The viscosity is measured according to JIS K 6862. The viscosity of the oil and the adhesive remover at 23 °C is measured using a Brookfield viscometer model RVDV2T (spindle 21) manufactured by Brookfield Co., Ltd., USA.

[0167] Table 1

[0168]

[0169] * SULFOL 430A contains surfactant, oil, and water. Therefore, the surfactant is formulated so that its content is 50% by mass relative to 100% by mass of the adhesive remover.

[0170] Table 2

[0171]

[0172] * SULFOL 430A contains surfactant, oil, and water. Therefore, the surfactant is formulated so that its content is 50% by mass relative to 100% by mass of the adhesive remover.

[0173] Table 3

[0174]

[0175] (Discussion)

[0176] Table 1 shows the results of evaluating an adhesive remover prepared by mixing various surfactants into soybean oil (iodine value 131). For Examples 1 to 5 using an anionic surfactant or a nonionic surfactant with an HLB greater than 5 and being liquid at room temperature, the adhesive could be sufficiently removed from the sample, and the adhesive remover could be removed from the substrate by washing. On the other hand, in Comparative Example 1 using a nonionic surfactant with an HLB of 5 or less, part of the oil and adhesive of the adhesive remover remained on the washed substrate. In addition, in Comparative Example 2 using a semi-solid nonionic surfactant, the adhesive also remained on the washed substrate. For Comparative Examples 3 and 4 in which a semi-solid or solid nonionic surfactant was mixed, the surfactant was separated without dissolving in the oil, so it was not suitable.

[0177] Table 2 shows the results of evaluating an adhesive remover prepared by mixing various surfactants into various oils other than soybean oil. For Examples 6 to 9 using vegetable oils with an iodine value of 70 to 160, the adhesive could be sufficiently removed from the sample, and the adhesive remover could be removed from the washed substrate. In addition, the same results were obtained for Examples 10 to 15 using an ester oil, an aliphatic carboxylic acid, and a mineral oil having 2 or less ester groups in one molecule. However, for Comparative Example 5 using ATBC having 3 or more ester groups in one molecule, the adhesive could not be sufficiently removed, and the adhesive remained on the washed substrate. Comparative Example 6 using only linseed oil with an iodine value greater than 160 had a natural ignition property and was difficult to handle, so it was not suitable for the present invention.

[0178] According to the results of Examples 16 to 19 and Comparative Example 7 in Table 3, by including a surfactant in the adhesive remover, the adhesive could be sufficiently removed from the sample, and the adhesive remover could be rinsed from the washed substrate. Thus, the recycled articles could be easily reused as resources. On the other hand, Comparative Example 8 shows the result of attempting the removal method of the present invention using an aqueous solution of a prior art terpene (d-limonene). The prior art uses the centrifugal force of a washing machine to decompose an article attached with an adhesive. When attempting the removal method of the present invention using an aqueous solution of a prior art terpene, limonene is separated from water. Therefore, when the sample is only immersed in the aqueous solution of terpene, the sample does not peel off. In addition, it is known that since the adhesive also remains on the substrate after washing the sample, the adhesive cannot be removed from the substrate using an aqueous solution of a prior art terpene.

[0179] 〔Removal of Adhesive Using Adhesive Remover (Diaper)〕

[0180] (Removal of Adhesive)

[0181] Into an adhesive remover prepared by mixing 50 parts by weight of soybean oil and 50 parts by weight of EMASOL O-120V, a commercially available disposable diaper for children fixed with hook-and-loop fasteners and rolled up was placed and immersed for 1 hour. In the adhesive remover, the fixing came off and the surface layer was separated.

[0182] (Washing with water)

[0183] After gently wringing out the diaper taken out from the adhesive remover, the diaper was put into a washing net and put into a washing machine. 20 g of calcium chloride (dehydrating agent) was added to the washing tub and 10 L of warm water at 60 °C was put in, and stirred in the washing machine for 15 minutes. After the stirring, water was added for two rinses and dehydrated for 5 minutes. The diaper was taken out from the washing net and evaluated. The diaper was separated into each base material (material), and there was no residue of the adhesive and the remover in each base material (material), nor was there any stickiness. Compared with the result (Comparative Example 8) obtained by the method described in Patent Document 1, this result was a good result. It should be noted that even if the diaper is not stirred during the immersion in the adhesive remover, the adhesive can be removed, but if it is stirred during the immersion, the adhesive can be removed in a short time. Since the dehydrating agent causes the superabsorbent polymer to deteriorate, it is difficult to reuse the superabsorbent polymer as a water-absorbing substance, but since there is no residue of the adhesive or the like on the base material, it is a treatment method suitable for reusing the base material.

[0184] (Separation into superabsorbent polymer and materials other than superabsorbent polymer, and washing)

[0185] After immersing the disposable diaper for children in the adhesive remover for 1 hour by the method described in (Removal of adhesive), the adhesive remover in the state of the immersed diaper was passed through a filter, thereby separating into a superabsorbent polymer (filtrate side) and materials other than the superabsorbent polymer (residue side). The materials other than the superabsorbent polymer separated were washed with water according to the above-mentioned procedure, and as a result, there was no residue of the adhesive and the adhesive remover in each material, nor was there any stickiness.

[0186] The separated superabsorbent polymer was immersed in methanol at room temperature for 1 minute and stirred. The superabsorbent polymer was taken out from the methanol and immersed in n-hexane at room temperature for 1 minute and stirred. The superabsorbent polymer taken out from the n-hexane had no stickiness and tackiness, and no residue of the adhesive and the adhesive remover was observed.

[0187] Water was poured into the superabsorbent polymer after washing with an organic solvent, and as a result, it was found that since the superabsorbent polymer absorbed water and swelled, the superabsorbent polymer from which the adhesive was removed by this washing method did not deteriorate and could be reused as a water-absorbing substance.

[0188] In addition, the disposable diaper was immersed in the adhesive remover used in Examples 1 to 19. After removing the adhesive, it was separated into a superabsorbent polymer and materials other than the superabsorbent polymer. It was confirmed that washing the separated superabsorbent polymer with an organic solvent also gave good results.

[0189] Similarly, the materials other than the superabsorbent polymer that had been separated were stirred in a washing machine in warm water (10 L) at 60°C for 15 minutes. After stirring, water was added for two rinses and dehydration for 5 minutes. As a result, it was found that no adhesive or adhesive remover remained on each material, and there was no stickiness or tackiness.

[0190] Industrial Applicability

[0191] The present invention can be used for removing adhesives.

Claims

1. An adhesive remover, wherein, the adhesive remover contains an oil and a surfactant, the oil contains one or more selected from the group consisting of vegetable oils, ester oils, aliphatic carboxylic acids, and mineral oils, the iodine value of the vegetable oil is 70 to 160, the ester oil has 3 or less ester groups in one molecule, the surfactant contains an anionic surfactant and / or a nonionic surfactant having a hydrophilic-lipophilic balance value greater than 5 and being liquid under normal temperature conditions.

2. The adhesive remover according to claim 1, wherein, relative to 100% by weight of the total amount of the oil and the surfactant, the content ratio of the oil is greater than 10% by weight and less than 70% by weight.

3. The adhesive remover according to claim 1, wherein, the hydrophilic-lipophilic balance value of the nonionic surfactant is 15 or less.

4. The adhesive remover according to claim 1, wherein, the solubility parameter values of both the ester oil and the mineral oil are 8.0 or more and 9.5 or less.

5. The adhesive remover according to claim 1, wherein, the adhesive remover is a hot-melt adhesive remover.

6. An adhesive removing method, wherein, the adhesive removing method includes an adhesive removing step of removing an adhesive from a material with an adhesive attached thereto using the adhesive remover according to any one of claims 1 to 5.

7. The adhesive removing method according to claim 6, wherein, the adhesive removing method further includes a washing step of washing the material from which the adhesive has been removed in the adhesive removing step with water.

8. The adhesive removing method according to claim 6, wherein, the material contains a superabsorbent polymer, and the adhesive removing method includes a separating step of separating the material from which the adhesive has been removed into the superabsorbent polymer and a material other than the superabsorbent polymer.

9. The adhesive removing method according to claim 8, wherein, the adhesive removing method includes a washing step of washing the superabsorbent polymer separated in the separating step with an organic solvent.

10. The adhesive removing method according to claim 8, wherein, the adhesive removing method includes a washing step of washing the material other than the superabsorbent polymer separated in the separating step with water.

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