Adhesive, article, and method for manufacturing article

Abstract

To provide an adhesive that enables the formation of an adhesive layer that strongly adheres to a polyolefin substrate, irrespective of whether the surface of the polyolefin substrate has been modified.SOLUTION: An adhesive comprises urethane resin (A), wherein the urethane resin (A) comprises a structural unit derived from polyisobutylene polyol.SELECTED DRAWING: None

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to adhesives, articles and methods of making articles. [Background technology]

[0002] Substrates containing polyolefins such as polypropylene (hereinafter referred to as "polyolefin substrates") are widely used industrially. Polyolefin substrates have the advantages of being lighter and less expensive than metal materials, and are easier to mold and process.

[0003] It is known that the surface of a polyolefin substrate is less wettable than that of a metal substrate. The surface is less wettable, which can cause defects such as cissing when applying an adhesive or paint. In addition, substrates with a surface that is less wettable generally have poor adhesion and are prone to adhesion failure and peeling of the coating. For this reason, studies have been conducted to improve the adhesion between the substrate and an adhesive or paint by changing the composition of the substrate, modifying the surface, etc.

[0004] For example, Patent Document 1 describes a method for obtaining a modified polyolefin resin composition having improved properties such as adhesiveness by melt-kneading a polyolefin resin with a radical polymerization initiator, an unsaturated carboxylic acid monomer, and an aromatic vinyl monomer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-13230 A [Non-patent literature]

[0006] [Non-Patent Document 1] Merlino,F.;Yousif,AM;Billard,E.;Dufour-Gallant,J.;Turcotte,S.;Grieco,P.;Chatene,D.;Lubell,WDJMed.Chem.2016,59,4740-4752. [Non-Patent Document 2] Oyama,R.;Abe,MJOrg.Chem.2020,85,8627-8638. Summary of the Invention [Problem to be solved by the invention]

[0007] However, the method of changing the composition of the substrate as described in Patent Document 1 above has problems in terms of practicality and cost. In addition, the method of improving adhesion by surface modification of the substrate (e.g., corona treatment) also has the problem of requiring a large amount of capital investment because it requires a large device. Therefore, there is a need to develop a method of improving the adhesion between the polyolefin substrate and the adhesive layer without changing the composition of the substrate or modifying the surface of the substrate.

[0008] Therefore, some aspects of the present disclosure aim to provide an adhesive capable of forming an adhesive layer that is firmly adhered to a polyolefin substrate, regardless of whether the polyolefin substrate is surface-modified. Another aspect of the present disclosure aims to provide an article comprising a polyolefin substrate and an adhesive layer formed using the adhesive. Yet another aspect of the present disclosure aims to provide a method for producing the article. [Means for solving the problem]

[0009] Some aspects of the present disclosure provide the following [1] to

[16] .

[0010] [1] An adhesive containing a urethane resin (A), the urethane resin (A) contains a structural unit derived from a polyisobutylene polyol, The adhesive, wherein the urethane resin (A) has a molecular weight distribution index of 2.0 to 4.0.

[0011] [2] The adhesive according to [1], wherein the urethane resin (A) has a weight average molecular weight of 6,000 to 31,000.

[0012] [3] The adhesive according to [1] or [2], wherein the polyisobutylene polyol contains a structure represented by the following formula (b1): [ka] [In formula (b1), *3 and *4 represent bonds bonding to the polyisobutylene chain.]

[0013] [4] The adhesive according to any one of [1] to [3], wherein the polyisobutylene polyol contains a structure represented by the following formula (c1): [ka] [In formula (c1), a represents an integer of 1 or more, and *5 represents a bond bonded to a polyisobutylene chain.]

[0014] [5] The adhesive according to any one of [1] to [4], wherein the number of hydroxyl groups per molecule of the polyisobutylene polyol is more than 1.0 and 3.0 or less.

[0015] [6] The adhesive according to any one of [1] to [5], wherein one molecule of the polyisobutylene polyol contains one structure derived from the polymerization initiator.

[0016] [7] The adhesive according to any one of [1] to [6], wherein the content of the structural units derived from the polyisobutylene polyol is 75.0 to 99.9 mass % based on the total mass of the urethane resin (A).

[0017] [8] The adhesive according to any one of [1] to [7], wherein the urethane resin (A) contains a structural unit derived from at least one selected from the group consisting of diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate.

[0018] [9] The urethane resin (A) is A polyurethane (A1) containing a structural unit derived from polyisobutylene polyol and having a weight average molecular weight of 6,000 to 16,000; The adhesive according to any one of [1] to [8], further comprising: a polyurethane (A2) containing a constituent unit derived from polyisobutylene polyol and having a weight average molecular weight of 21,000 to 31,000.

[0019]

[10] The adhesive according to [9], wherein the content of the polyurethane (A1) is 50 mass % or more based on the total mass of the urethane resin (A).

[0020]

[11] The adhesive according to any one of [1] to

[10] , which is for use on a polyolefin substrate.

[0021]

[12] The adhesive layer includes a substrate and an adhesive layer that is adhered to one surface of the substrate. An article, wherein the adhesive layer is formed from the adhesive according to any one of [1] to

[11] .

[0022]

[13] The article according to

[12] , wherein the substrate is a polyolefin substrate.

[0023]

[14] A method for producing an article comprising a substrate and an adhesive layer adhered to one surface of the substrate, the method comprising the steps of: A step of disposing the adhesive according to any one of [1] to

[11] on a substrate to form an adhesive layer; and heating the adhesive layer to bond the substrate and the adhesive layer.

[0024]

[15] The method for producing an article according to

[14] , wherein the substrate is a polyolefin substrate.

[0025]

[16] An adhesive containing a urethane resin (A), The adhesive, wherein the urethane resin (A) contains a structural unit derived from a polyisobutylene polyol. Effect of the Invention

[0026] According to some aspects of the present disclosure, an adhesive can be provided that can form an adhesive layer that is firmly attached to a polyolefin substrate, regardless of whether the polyolefin substrate is surface-modified. According to another aspect of the present disclosure, an article can be provided that includes a polyolefin substrate and an adhesive layer formed using the adhesive. According to yet another aspect of the present disclosure, a method for producing the article can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Preferred embodiments of the present disclosure will be described below, however, the present disclosure is not limited to the following embodiments.

[0028] In this specification, the numerical range indicated by "~" indicates a range including the numerical values ​​described before and after "~" as the minimum and maximum values, respectively. In addition, unless specifically stated otherwise, the units of the numerical values ​​described before and after "~" are the same. In addition, in the numerical range described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the examples. In addition, the upper limit and lower limit values ​​described individually can be arbitrarily combined. In addition, the materials exemplified below may be used alone or in combination of two or more types, unless otherwise specified. When a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0029] <Adhesive> The adhesive according to an embodiment of the present disclosure contains a urethane resin. The urethane resin is made of polyurethane, which is a reaction product of a urethane resin-forming raw material containing a polyol and a polyisocyanate (for example, a reaction product obtained by reacting a polyol with a polyisocyanate in the presence of a catalyst), and contains at least a structural unit derived from a polyol and a structural unit derived from a polyisocyanate. In other words, the urethane resin is a compound containing a polyol and a polyisocyanate as structural units (monomer units).

[0030] An adhesive according to one embodiment of the present disclosure contains a urethane resin (hereinafter, sometimes referred to as "urethane resin (A)") that contains a structural unit derived from polyisobutylene polyol. More specifically, the urethane resin (A) is a resin made of a polyurethane (hereinafter, sometimes referred to as "polyurethane (A)") that contains a structural unit derived from polyisobutylene polyol. The adhesive may contain any component other than the urethane resin (A) (hereinafter, referred to as "other components") within a range that does not impair the object of the present disclosure.

[0031] According to the adhesive of the above embodiment, an adhesive layer that adheres firmly to the polyolefin substrate can be formed regardless of whether the surface of the polyolefin substrate is modified. Therefore, the adhesive of the above embodiment is suitable for use as an adhesive for polyolefin substrates. The polyolefin substrate referred to here is a substrate that contains at least polyolefin and has a coating surface made of polyolefin. Examples of polyolefin include polyethylene, polypropylene, ethylene propylene rubber, and ethylene propylene diene rubber, and the adhesive exhibits particularly strong adhesion to polyethylene and polypropylene.

[0032] Although it is not clear why the adhesive of the above embodiment can form an adhesive layer that firmly adheres to the polyolefin substrate, it is presumed that because the urethane resin (A) has a structure derived from polyisobutylene polyol, the adhesive has the property of easily penetrating into the olefin substrate (particularly the non-crystalline portion) when it flows (e.g. melts) due to heating, and that due to this property, when the adhesive is applied to a polyolefin substrate and caused to flow by heating, a bonding area is formed on the surface of the polyolefin substrate (the interface between the polyolefin substrate and the adhesive layer) where the polyolefin in the polyolefin substrate and the urethane resin (A) are mixed, resulting in strong adhesion between the polyolefin substrate and the adhesive layer.

[0033] However, polyolefin substrates generally have low heat resistance and are prone to problems such as deterioration due to heat treatment at high temperatures (e.g., 140°C or higher). On the other hand, the adhesive of the above embodiment tends to have sufficient fluidity even at low temperatures (e.g., 130°C or lower). Therefore, according to the adhesive of the above embodiment, it may be possible to form an adhesive layer that is firmly adhered to the polyolefin substrate without heat treatment at high temperatures. From this perspective, the adhesive of the above embodiment is suitable as an adhesive for polyolefin substrates or a coating material for polyolefin substrates.

[0034] (Urethane resin (A)) The urethane resin (A) contains a structural unit derived from polyisobutylene polyol. Here, the polyisobutylene polyol refers to a compound having a polyisobutylene chain and a hydroxyl group represented by the following formula (a1) or an aggregate thereof, and the number of hydroxyl groups per molecule exceeds 1.0. The compound contained in the polyisobutylene polyol may be one type or multiple types. [ka]

[0035] In the formula (a1), n ​​is an integer of 2 or more, and *1 and *2 are bonds. n is, for example, 20 to 50, and preferably 30 to 45.

[0036] A structural unit derived from polyisobutylene polyol is, for example, a structural unit formed by reaction (polymerization) of polyisobutylene polyol with polyisocyanate, and has a structure of a portion obtained by removing a hydroxyl group from polyisobutylene polyol.

[0037] The content of polyisobutylene chains in the polyisobutylene polyol may be 60 mass% or more, 70 mass% or more, or 80 mass% or more, based on the total mass of the polyisobutylene polyol. The content of polyisobutylene chains in the polyisobutylene polyol may be 99.5 mass% or less (for example, 60 to 100 mass%), 90 mass% or less, or 80 mass% or less, based on the total mass of the polyisobutylene polyol. The polyisobutylene polyol may be composed of only polyisobutylene chains and hydroxyl groups, but may also contain structures other than these.

[0038] From the viewpoint of polymerization with polyisocyanate, it is preferable that polyisobutylene polyol has a hydroxyl group at the molecular end (for example, the end of the main chain). From the viewpoint of further improving the adhesive strength of the adhesive layer to the substrate (particularly the polyolefin substrate), the number of hydroxyl groups per molecule of polyisobutylene polyol is preferably more than 1.0 and not more than 3.0, more preferably 1.5 to 2.5, and even more preferably 1.9 to 2.0. The number of hydroxyl groups per molecule of polyisobutylene polyol is: 1 It can be calculated from the signals δ 1.46-1.29 (methylene group) and δ 1.15-0.97 (methyl group) derived from the isobutylene unit, based on the signal δ 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data.

[0039] Polyisobutylene polyol can be obtained, for example, by obtaining a polymer (polyisobutylene) by living cationic polymerization of isobutene, and then introducing hydroxyl groups into the polymer. By using living cationic polymerization of isobutene, polyisobutylene having a desired molecular weight and molecular weight distribution can be obtained by changing the types of polymerization initiator and catalyst.

[0040] Living cationic polymerization of isobutene can be carried out by a conventionally known method. For example, a mixture containing isobutene and a polymerization initiator is cooled to -80 to -60°C, and then a Lewis acid such as a metal halide is added as a catalyst to the mixture and stirred to polymerize isobutene. In this reaction, a base such as 2,6-di-tert-butyl-4-methylpyridine can also be used from the viewpoint of adjusting the catalytic activity.

[0041] Examples of the polymerization initiator include 1-(tert-butyl)-3,5-bis(1-methoxy-1-methylethyl)benzene, 5-tert-butyl-1,3-bis(1-acetoxy-1-methylethyl)benzene, and 1,3-bis(1-chloro-1-methylethyl)-5-(tert-butyl)benzene. Among these, from the viewpoint of efficiently synthesizing polyisobutylene, it is preferable to use 1-(tert-butyl)-3,5-bis(1-methoxy-1-methylethyl)benzene. Note that 1-(tert-butyl)-3,5-bis(1-methoxy-1-methylethyl)benzene is a known compound and can be synthesized with reference to Non-Patent Document 1 and Non-Patent Document 2.

[0042] Since the polymer obtained by the above method has a halogen terminal, a polyisobutylene polyol can be obtained by substituting a halogen atom with a hydroxyl group using a base component such as tetrabutylammonium hydroxide. In addition, since the halogen substitution reaction using a base component simultaneously proceeds with the condensation (polymerization) of polyisobutylene polyol, an acetoxy group may be introduced using an acetate such as potassium acetate instead of a base component, and then a hydroxyl group may be introduced by eliminating an acetyl group. According to this method, the generation of a polymer of polyisobutylene polyol can be suppressed. Hereinafter, a polymer generated by condensation of polyisobutylene polyol is referred to as an oligomer of polyisobutylene polyol.

[0043] After polymerization of isobutene, if necessary, a capping agent and a catalyst (e.g., metal halide) for introducing a hydroxyl group may be added to the solution containing the polymer to introduce a structure derived from the capping agent to the end of the polyisobutylene. For example, 1,3-butadiene, allyltrimethylsilane, etc. are preferably used as the capping agent. In living cationic polymerization of isobutene, the tertiary carbon atom side becomes the growing end, so that the SN2 reaction of the halogen atom does not easily proceed, but by using the above-mentioned capping agent, the introduction of a hydroxyl group becomes easy.

[0044] The polyisobutylene polyol obtained by the above-described method contains a structure derived from the polymerization initiator, and in some cases, contains a structure derived from the capping agent. From the viewpoint of excellent adhesive performance of the urethane resin, it is preferable that one molecule of the polyisobutylene polyol contains one structure derived from the polymerization initiator.

[0045] When the polyisobutylene polyol is an oligomer, the polyisobutylene polyol has an ether bond, but from the viewpoint of excellent adhesive performance of the urethane resin, it is preferable that the polyisobutylene polyol does not have an ether bond. That is, the polyisobutylene polyol is preferably a non-oligomer.

[0046] In order to provide excellent adhesive performance for the adhesive, the polyisobutylene polyol contained in the urethane resin (A) preferably contains a structure represented by the following formula (b1) as a structure derived from the polymerization initiator, and preferably contains a structure represented by the following formula (c1) as a structure derived from the capping agent.

[0047] [ka]

[0048] [ka]

[0049] In formula (b1), *3 and *4 represent bonds bonded to a polyisobutylene chain (for example, the bond *1 in formula (a1)). In formula (c1), a represents an integer of 1 or more, and *5 represents a bond bonded to a polyisobutylene chain (for example, the bond *2 in formula (a1)). a represents an integer of 1 or more, for example, 1 to 10, and preferably 1 to 3.

[0050] The polyisobutylene polyol preferably contains a compound represented by the following formula (P1).

[0051] [ka]

[0052] In the formula (P1), n ​​and a have the same meanings as defined above. Multiple n's may be the same or different, and multiple a's may be the same or different.

[0053] The polyisobutylene polyol may contain a compound represented by the following formula (P2).

[0054] [ka]

[0055] In formula (P2), X represents a constitutional unit represented by the following formula (x1), and m represents an integer of 1 or more. m is, for example, 1 to 10, and preferably 1 to 4. Multiple Xs may be the same or different.

[0056] [ka]

[0057] In formula (x1), n ​​and a are as defined above. *6 represents a bond bonded to *7 or an OH group in formula (P2), and *7 represents a bond bonded to *6 or an H group in formula (P2).

[0058] The number average molecular weight of the polyisobutylene polyol is preferably 400 or more, and may be 1000 or more, 1500 or more, 3000 or more, or 5000 or more, from the viewpoint of further improving the adhesive strength of the urethane resin (A) to the substrate (particularly the polyolefin substrate) and from the viewpoint of enabling the heat treatment of the adhesive to be carried out at a lower temperature, and may be 20000 or less, and may be 10000 or less, 7500 or less, 5000 or less, or 3500 or less. From these viewpoints, the number average molecular weight of the polyisobutylene polyol may be, for example, 400 to 20000, 1000 to 10000, 1500 to 7500, 1500 to 5000, 3000 to 5000, or 5000 to 7500.

[0059] The molecular weight distribution index (weight average molecular weight / number average molecular weight) of the polyisobutylene polyol may be 1.00 or more, or may be 1.05 or more, or may be 1.10 or more, from the viewpoint of further improving the adhesive strength of the urethane resin (A) to a substrate (particularly a polyolefin substrate). The molecular weight distribution index of the polyisobutylene polyol is preferably 2.00 or less, and may be 1.80 or less, 1.60 or less, 1.40 or less, 1.20 or less, or 1.10 or less, from the viewpoint of further improving the adhesive strength of the urethane resin (A) to a substrate (particularly a polyolefin substrate) and from the viewpoint of enabling the heat treatment of the adhesive to be carried out at a lower temperature. From these viewpoints, the molecular weight distribution index of the polyisobutylene polyol may be, for example, 1.00 to 2.00, 1.00 to 1.80, 1.00 to 1.60, 1.00 to 1.40, 1.00 to 1.20, 1.00 to 1.10, 1.05 to 1.60, or 1.10 to 1.60.

[0060] The number average molecular weight and weight average molecular weight of the polyisobutylene polyol are polystyrene equivalent values ​​measured using gel permeation chromatography (GPC), and can be measured by the method described in the Examples.

[0061] The urethane resin (A) may contain a structural unit derived from a compound having one or more hydroxyl groups (hereinafter referred to as a "hydroxyl group-containing compound") other than the polyisobutylene polyol, or may not contain a structural unit derived from a hydroxyl group-containing compound other than the polyisobutylene polyol. The content of the structural unit derived from the polyisobutylene polyol may be 80 to 100 mass% based on the total mass of the structural units derived from all hydroxyl group-containing compounds contained in the urethane resin (A).

[0062] The urethane resin (A) may contain a structural unit derived from a polyol other than polyisobutylene polyol. For example, the urethane resin (A) may contain a structural unit derived from a polyol generally known as a chain extender.

[0063] Examples of polyols other than polyisobutylene polyols include polyether polyols such as polyethylene glycols, polypropylene glycols, and polybutylene glycols; monoglycerides such as caprylic acid monoglyceride, capric acid monoglyceride, lauric acid monoglyceride, stearic acid monoglyceride, and behenic acid monoglyceride; glycols having side chains such as 2-methyl-1,3-propanediol and 3-methyl-1,5-pentanediol; etc. These may be used alone or in combination of two or more kinds.

[0064] The content of structural units derived from polyol compounds other than polyisobutylene polyol may be 0 to 20 mass % based on the total mass of structural units derived from all hydroxyl group-containing compounds contained in the urethane resin (A).

[0065] The content of the polyisobutylene polyol-derived structural unit in the urethane resin (A) is preferably 75.0 mass% or more, more preferably 80.0 mass% or more, and even more preferably 85.0 mass% or more, based on the total mass of the urethane resin (A) (i.e., the total mass of the polyurethane (A)), from the viewpoint of further improving the adhesive strength of the urethane resin (A) to the substrate (particularly the polyolefin substrate). The content of the polyisobutylene polyol-derived structural unit in the urethane resin (A) is preferably 99.9 mass% or less, more preferably 95.0 mass% or less, and even more preferably 90.0 mass% or less, based on the total mass of the urethane resin (A) (i.e., the total mass of the polyurethane (A)), from the viewpoint of further improving the adhesive strength of the urethane resin (A) to the substrate (particularly the polyolefin substrate). From these viewpoints, the content of the structural units derived from the polyisobutylene polyol in the urethane resin (A) may be, for example, 75.0 to 99.9 mass%, 80.0 to 95.0 mass%, or 85.0 to 91.0 mass%. In this embodiment, the content of the structural units derived from the hydroxyl group-containing compound in the urethane resin (A) (based on the total mass of the urethane resin (A)) may be within the above-mentioned range.

[0066] The urethane resin (A) contains a structural unit derived from a polyisocyanate in addition to a structural unit derived from a polyisocyanate. The structural unit derived from a polyisocyanate is, for example, a structural unit formed by the reaction (polymerization) of a polyisocyanate with a polyisocyanate, and has a structure of a portion obtained by removing an isocyanate group from the polyisocyanate.

[0067] The polyisocyanate may be an aromatic polyisocyanate or a non-aromatic polyisocyanate, or may be a modified product thereof (for example, an allophanate modified product, a biuret modified product, etc.). The polyisocyanate may be one type or multiple types.

[0068] The aromatic polyisocyanate is a polyisocyanate having an aromatic skeleton. Examples of the aromatic polyisocyanate include diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate, and 1,4-tetramethylxylylene diisocyanate.

[0069] The non-aromatic polyisocyanate is a polyisocyanate that does not have an aromatic skeleton (for example, a polyisocyanate that has an aliphatic skeleton). Examples of the non-aromatic polyisocyanate include hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane-4,4'-diisocyanate, hydrogenated diphenylmethane-2,4'-diisocyanate, hydrogenated xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and norbornene diisocyanate.

[0070] From the viewpoint of facilitating the production of an adhesive layer having excellent mechanical strength, the polyisocyanate preferably contains at least one selected from the group consisting of diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate. That is, the urethane resin (A) preferably contains a structural unit derived from at least one selected from the group consisting of diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate. From the viewpoint of facilitating the production of an adhesive layer having excellent light resistance, it is preferable that the polyisocyanate contains at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane-4,4'-diisocyanate, and hydrogenated diphenylmethane-2,4'-diisocyanate.

[0071] The isocyanate group content in the polyisocyanate is preferably 1.7 mol / kg or more, more preferably 2.4 mol / kg or more, and even more preferably 4.0 mol / kg or more, from the viewpoint of further improving the adhesive strength of the urethane resin (A) to a substrate (particularly a polyolefin substrate). The isocyanate group content in the polyisocyanate is preferably 12.0 mol / kg or less, more preferably 11.0 mol / kg or less, and even more preferably 8.0 mol / kg or less, from the viewpoint of further improving the adhesive strength of the urethane resin (A) to a substrate (particularly a polyolefin substrate). From these viewpoints, the isocyanate group content in the polyisocyanate may be, for example, 1.7 to 12.0 mol / kg, 2.4 to 11.0 mol / kg, or 4.0 to 8.0 mol / kg. The isocyanate group content in the polyisocyanate can be measured in accordance with JIS K1603-1.

[0072] The content of the structural unit derived from polyisocyanate in the urethane resin (A) may be 0.01 mass% or more, 5.0 mass% or more, or 9.0 mass% or more, and 25.0 mass% or less, 20.0 mass% or less, or 15.0 mass% or less, or 0.01 to 25.0 mass%, 5.0 to 20.0 mass%, or 9.0 to 15.0 mass%, based on the total mass of the urethane resin (A) (i.e., the total mass of the polyurethane (A)). In this embodiment, the content of the structural unit derived from a compound having one or more isocyanate groups (hereinafter also referred to as an "isocyanate group-containing compound") in the urethane resin (A) (based on the total mass of the urethane resin (A)) may be in the above-mentioned range.

[0073] The urethane resin (A) may further contain structural units other than the structural units derived from the hydroxyl group-containing compound and the structural units derived from the isocyanate group-containing compound, as long as the object of the present disclosure is not impaired.

[0074] The urethane resin (A) may be composed of one type of polyurethane (A), or may contain two or more types of polyurethane (A) differing in the type of structural unit (structural unit derived from a hydroxyl group-containing compound, structural unit derived from an isocyanate group-containing compound, etc.), weight average molecular weight, etc. Among these, it is preferable that the urethane resin (A) contains two or more types of polyurethane (A) differing in weight average molecular weight, and more preferably contains a polyurethane (A1) having a weight average molecular weight of 6000 to 16000 and a polyurethane (A2) having a weight average molecular weight of 21000 to 31000. Both the polyurethanes (A1) and (A2) are polyurethanes containing structural units derived from polyisobutylene polyol.

[0075] The polyurethane (A1) contributes to improving the heat flowability of the adhesive. From the viewpoint of being able to form an adhesive layer that is firmly bonded to a polyolefin substrate at a lower heat treatment temperature, the weight average molecular weight of the polyurethane (A1) may be 14,000 or less or 12,000 or less. From the viewpoint of being able to more easily prevent layer peeling due to deformation of the adhesive layer, the weight average molecular weight of the polyurethane (A1) may be 8,000 or more or 10,000 or more.

[0076] The polyurethane (A2) contributes to improving the mechanical strength of the adhesive layer. From the viewpoint of more easily suppressing the occurrence of layer peeling due to deformation of the adhesive layer, the weight average molecular weight of the polyurethane (A2) may be 23,000 or more or 25,000 or more. From the viewpoint of obtaining a good balance of the properties of both the polyurethane (A1) and polyurethane (A2) resins, the weight average molecular weight of the polyurethane (A2) may be 29,000 or less or 27,000 or less.

[0077] From the viewpoint of obtaining well-balanced properties of both the polyurethane (A1) and polyurethane (A2), the difference between the weight average molecular weight of the polyurethane (A1) and the weight average molecular weight of the polyurethane (A2) ([weight average molecular weight of polyurethane (A2)]-[weight average molecular weight of polyurethane (A1)]) is preferably 5,000 to 25,000. The difference may be 9,000 or more or 13,000 or more, and may be 21,000 or less or 17,000 or less.

[0078] The characteristics of polyurethane (A1) and polyurethane (A2) other than the weight average molecular weight are not particularly limited as long as the above urethane resin (A) can be obtained. The characteristics of polyurethane (A1) and polyurethane (A2) other than the weight average molecular weight may be the same as the characteristics of the above urethane resin (A). From the viewpoint of being able to form an adhesive layer that is firmly adhered to a polyolefin substrate at a lower heat treatment temperature, it is preferable that the polyisobutylene polyol contained as a structural unit (monomer unit) in polyurethane (A1) and polyurethane (A2) does not have two or more structures derived from a polymerization initiator in one molecule (there is one structure derived from a polymerization initiator contained in one molecule), and from the viewpoint of being able to more easily suppress the occurrence of layer peeling due to deformation of the adhesive layer, it is preferable that the polyisobutylene polyol contained as a structural unit (monomer unit) in polyurethane (A1) and polyurethane (A2) does not have an ether bond. From these viewpoints, it is preferable that the polyisobutylene polyol contained as a structural unit (monomer unit) in polyurethane (A1) and polyurethane (A2) is a non-oligomer.

[0079] From the viewpoint of obtaining well-balanced properties of both polyurethane (A1) and polyurethane (A2), the content of polyurethane (A1) is preferably 50% by mass or more based on the total mass of the urethane resin (A) (e.g., the sum of the content of polyurethane (A1) and the content of polyurethane (A2)). From the same viewpoint, the content of polyurethane (A1) may be 60% by mass or more or 70% by mass or more, and may be 90% by mass or less or 80% by mass or less based on the total mass of the urethane resin (A) (e.g., the sum of the content of polyurethane (A1) and the content of polyurethane (A2)).

[0080] From the viewpoint of obtaining well-balanced properties of both polyurethane (A1) and polyurethane (A2), the content of polyurethane (A2) is preferably 50% by mass or less based on the total mass of the urethane resin (A) (e.g., the sum of the content of polyurethane (A1) and the content of polyurethane (A2)). From the same viewpoint, the content of polyurethane (A2) may be 40% by mass or less or 30% by mass or less, or 10% by mass or more or 20% by mass or more based on the total mass of the urethane resin (A) (e.g., the sum of the content of polyurethane (A1) and the content of polyurethane (A2)).

[0081] The weight average molecular weight of the urethane resin (A) is preferably 6000 or more, more preferably 8000 or more, and even more preferably 10000 or more. When the weight average molecular weight of the urethane resin (A) is moderately large, deformation of the adhesive layer is suppressed, and peeling of the adhesive layer from the substrate is unlikely to occur. The weight average molecular weight of the urethane resin (A) is preferably 31000 or less, more preferably 29000 or less, even more preferably 27000 or less, and particularly preferably 20000 or less. The lower the weight average molecular weight of the urethane resin (A), the lower the heat treatment temperature at which an adhesive layer that is firmly adhered to the polyolefin substrate can be formed. From these viewpoints, the weight average molecular weight of the urethane resin (A) may be, for example, 6000 to 31000.

[0082] From the viewpoint of further improving the adhesive strength of the urethane resin (A) to a substrate (particularly a polyolefin substrate), the molecular weight distribution index (weight average molecular weight / number average molecular weight) of the urethane resin (A) is preferably 2.0 or more, more preferably 2.2 or more, and even more preferably 2.4 or more. From the viewpoint of further improving the adhesive strength of the urethane resin (A) to a substrate (particularly a polyolefin substrate), the molecular weight distribution index of the urethane resin (A) is preferably 4.0 or less, more preferably 3.8 or less, and even more preferably 3.7 or less. From these viewpoints, the molecular weight distribution index of the urethane resin (A) may be, for example, 2.0 to 4.0.

[0083] The number average molecular weight and weight average molecular weight of the urethane resin (A) are polystyrene equivalent values ​​measured using gel permeation chromatography (GPC), and can be measured by the method described in the Examples. The molecular weight (number average molecular weight and weight average molecular weight) of the urethane resin (A) refers to the molecular weight (number average molecular weight and weight average molecular weight) of the entire urethane resin (A). That is, the molecular weight of the urethane resin (A) refers to the molecular weight of the polyurethane when the urethane resin (A) is composed of a single polyurethane, and refers to the molecular weight of the mixture when the urethane resin (A) is a mixture of two or more polyurethanes. The molecular weight of the mixture may be a weighted average value based on the blending ratio of the molecular weights of the polyurethanes contained in the mixture.

[0084] The urethane resin (A) can be obtained by reacting a urethane resin-forming raw material containing at least polyisobutylene polyol and polyisocyanate. Specifically, for example, a polyol containing polyisobutylene polyol and a polyisocyanate are mixed and heated in the presence of a catalyst (urethanization catalyst) and a solvent (reaction solvent), thereby obtaining a urethane resin (A) made of polyurethane (A), which is a reaction product of the polyol and the polyisocyanate. Here, the urethane resin-forming raw material is an aggregate of compounds contained in the structural units of the polyurethane (urethane resin), which is the reaction product. Therefore, the catalyst and the solvent are not included in the urethane resin-forming raw material.

[0085] The content of polyol and polyisocyanate in the urethane resin forming raw material (i.e., the blending amount of polyol and polyisocyanate) is, for example, the total number of moles of hydroxyl groups in the polyol (M OH ) and the total number of moles of isocyanate groups in the polyisocyanate (M NCO ) and the ratio (M NCO / M OH The content of the hydroxyl group-containing compound and the isocyanate group-containing compound in the urethane resin-forming raw material may be such that the total number of moles of hydroxyl groups in the hydroxyl group-containing compound (M') is 0.74 to 0.98.OH ) and the total number of moles of isocyanate groups in the isocyanate group-containing compound (M' NCO ) and the ratio (M' NCO / M' OH ) may be an amount such that the ratio is 0.74 to 0.98.

[0086] Examples of the catalyst include organometallic compounds such as dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin dilaurate; organic amines such as triethylenediamine and triethylamine, and salts thereof; etc. These may be used alone or in combination of two or more.

[0087] The amount of catalyst may be selected according to the reactivity of the polyisocyanate used. The amount of catalyst is, for example, preferably 0.00010 parts by mass or more and 25 parts by mass or less per 1 part by mass of urethane resin-forming raw material, more preferably 0.0010 parts by mass or more and 6.0 parts by mass or less, and even more preferably 0.010 parts by mass or more and 1.0 parts by mass or less. If the amount of catalyst is 0.00010 parts by mass or more per 1 part by mass of urethane resin-forming raw material, a sufficient catalytic effect is more easily obtained. If the amount of catalyst is 25 parts by mass or less per 1 part by mass of urethane resin-forming raw material, it is more preferable in terms of economic efficiency.

[0088] Examples of the solvent include aromatic hydrocarbon solvents such as toluene, ethylbenzene, trimethylbenzene, and xylene; aliphatic hydrocarbon solvents such as pentane, hexane, and cyclohexane; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohol solvents such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; glycol ether solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl diglycol, ethyl diglycol, butyl diglycol, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; amide solvents such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; ether solvents such as diethyl ether and tetrahydrofuran; and water. These may be used alone or in combination of two or more.

[0089] The blending amount of the solvent is not particularly limited, and may be, for example, from 1.0 part by mass to 10,000 parts by mass per 100 parts by mass of the urethane resin-forming raw material.

[0090] The urethane resin (A) can also be prepared by separately synthesizing polyurethanes (A1) and (A2) by the above-mentioned method of reacting urethane resin-forming raw materials containing at least polyisobutylene polyol and polyisocyanate, and then mixing the two obtained polyurethanes or compositions containing the polyurethanes.

[0091] The content of the urethane resin (A) in the adhesive varies depending on the application, but from the viewpoint of further improving the adhesion of the adhesive layer to the polyolefin substrate, it is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, and even more preferably 10.0% by mass or more, based on the total solid content of the adhesive. The content of the urethane resin (A) may be 80.0% by mass or more, 85.0% by mass or more, or 90.0% by mass or more, based on the total solid content of the adhesive. The content of the urethane resin (A) in the adhesive may be 100% by mass or less, 90.0% by mass or less, or 80.0% by mass or less, based on the total solid content of the adhesive. In this specification, the solid content means components other than the solvent (solvent).

[0092] (Other ingredients) Examples of the other components include additives such as solvents, catalysts, defoamers, leveling agents, organic thickeners, antioxidants, light stabilizers, adhesion improvers, release agents, reinforcing materials, softeners, colorants, flame retardants, antistatic agents, and wetting and dispersing agents. The other components may be urethane resin-forming raw materials such as polyols and polyisocyanates, or may be components used in the synthesis of urethane resins such as the above-mentioned urethane catalysts and reaction solvents. The other components may be urethane resins other than the urethane resin (A), that is, urethane resins made of polyurethanes that do not contain structural units derived from polyisobutylene polyols.

[0093] When the adhesive further contains a urethane resin other than the urethane resin (A), the content of the urethane resin (A) is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more based on the total mass of the urethane resin contained in the adhesive (the sum of the content of the urethane resin (A) and the content of the urethane resin other than the urethane resin (A)) from the viewpoint of making it easier to obtain the above-mentioned effects due to the urethane resin (A). The content of the urethane resin (A) may be 100% by mass or less based on the total mass of the urethane resin contained in the adhesive (the sum of the content of the urethane resin (A) and the content of the urethane resin other than the urethane resin (A)).

[0094] When the adhesive further contains a urethane resin other than the urethane resin (A), the total mass of the urethane resins contained in the adhesive may be 1.0 mass% or more, 5.0 mass% or more, 10.0 mass% or more, 80.0 mass% or more, 85.0 mass% or more, or 90.0 mass% or more, and may be 100 mass% or less, 90.0 mass% or less, or 80.0 mass% or less, or may be 1.0 to 100 mass%, based on the total solid content of the adhesive.

[0095] The adhesive may be in a liquid or solid state. A liquid adhesive is, for example, a coating liquid for forming an adhesive layer.

[0096] The adhesive may contain a solvent for the purpose of adjusting the viscosity, etc. Examples of the solvent include the compounds exemplified as reaction solvents for synthesizing the above-mentioned urethane resin (A).

[0097] The content of the solvent may be selected in consideration of the coating method of the coating liquid, the desired film thickness of the adhesive layer, etc. The content of the solvent in the adhesive is, for example, preferably 1.0 to 10,000 parts by mass, more preferably 40 to 3,200 parts by mass, and even more preferably 150 to 2,000 parts by mass, per 100 parts by mass of solids in the adhesive. When the content of the solvent is 1.0 part by mass or more per 100 parts by mass of solids in the adhesive, the viscosity of the adhesive is reduced, making coating easier. When the content of the solvent is 10,000 parts by mass or less per 100 parts by mass of solids in the adhesive, the film thickness of the coating film (adhesive layer) formed does not become too thin, and a sufficient film thickness is easily obtained.

[0098] The adhesive preferably contains a leveling agent from the viewpoint of facilitating the production of a smooth adhesive layer. Examples of the leveling agent include polyoxyethylene alkyl ethers, polyoxyethylene aryl ethers, silicon surfactants, nonionic surfactants, fluorine surfactants, and acrylic surfactants. These may be used alone or in combination of two or more. The content of the leveling agent is not particularly limited, but may be, for example, 0.0010 to 25 parts by mass relative to 100 parts by mass of the solid content in the adhesive.

[0099] The urethane resin (A) contained in the adhesive described above and the resin composition containing the urethane resin (A) can be used not only as an adhesive but also as a coating material, etc. That is, another embodiment of the present disclosure is a urethane resin composition containing the urethane resin (A), and yet another embodiment of the present disclosure is a coating material containing the urethane resin (A).

[0100] <Article and its manufacturing method> An article according to one embodiment comprises a substrate and an adhesive layer adhered to one side of the substrate.

[0101] The material constituting the substrate is not particularly limited, and may be, for example, a resin such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polycarbonate, acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS resin), nylon 6, nylon 66, aramid, acrylic, polyethylene terephthalate, polybutylene terephthalate, or a metal such as aluminum, aluminum alloy, magnesium, stainless steel, tinplate, electrogalvanized steel sheet, chrome-plated steel sheet, or glass. The substrate may contain one of these materials alone or two or more of them. The substrate may contain two or more of these materials as a composite material. For example, the substrate may be formed of a composite material consisting of the above-mentioned resin and glass fiber, or may be formed of a composite material (CFRP (Carbon Fiber Reinforced Plastics) or CFRTP (Carbon Fiber Reinforced Thermo Plastics)) of a thermosetting resin such as epoxy resin or a thermoplastic resin such as polyphenylene sulfide and carbon fiber. Among these, plastic substrates are preferred because they are easy to mold after painting and have high versatility, and polyolefin substrates (e.g., substrates having a coated surface made of polyethylene, polypropylene, ethylene propylene rubber, ethylene propylene diene rubber, etc.) are more preferred because they are lightweight and inexpensive. Among polyolefin substrates, substrates containing polyethylene and / or polypropylene are even more preferred. The substrate may be a substrate whose surface has been modified by corona treatment or the like.

[0102] The shape of the substrate is not particularly limited, and may be a flat plate (for example, a film or sheet) or may have a curved surface.

[0103] The adhesive layer is formed by the adhesive of the above embodiment. Therefore, the adhesive layer is firmly attached to the substrate even if the substrate is a polyolefin substrate that has not been surface-modified. In such an article, a bonding region in which the polyolefin in the substrate and the urethane resin (A) in the adhesive layer are mixed may be formed at the interface between the substrate (polyolefin substrate) and the adhesive layer.

[0104] The thickness of the adhesive layer is not particularly limited, but is preferably 0.05 to 300 μm, more preferably 0.1 to 200 μm, and even more preferably 5 to 100 μm. When the thickness of the adhesive layer is 0.05 μm or more, the adhesive layer tends to have even better adhesion. When the thickness of the adhesive layer is 300 μm or less, the time required for drying can be further reduced, and even better productivity can be obtained.

[0105] Another substrate (second substrate) may be adhered to the surface of the adhesive layer opposite to the substrate (first substrate). That is, the article may include a first substrate, a second substrate, and an adhesive layer between the first substrate and the second substrate to adhere the first substrate and the second substrate to each other.

[0106] Examples of materials constituting the other substrate (second substrate) include the materials exemplified as materials constituting the substrate (first substrate). The other substrate (second substrate) may be a substrate whose surface has been modified by corona treatment or the like. The other substrate (second substrate) may also be a substrate having a resin coating. The resin coating may be formed of a resin having affinity with the other substrate (second substrate). Examples of resins forming the resin coating include urethane resin, epoxy resin, and acrylic resin. Among them, in consideration of the affinity with the adhesive layer, the resin constituting the resin coating is preferably a urethane resin. The urethane resin preferably contains the urethane resin (A) of the above embodiment, and more preferably contains a mixture of polyurethane (A1) and polyurethane (A2). That is, the resin coating is preferably formed of a resin composition containing the urethane resin (A) of the above embodiment.

[0107] The above article can be produced, for example, by a method including a step (a) of placing the adhesive of the above embodiment on a first substrate to form an adhesive layer, and a step (b) of heating the adhesive layer to bond the first substrate and the adhesive layer, or a method including, in addition to the above steps (a) and (b), a step (c) of bonding a second substrate to the surface of the adhesive layer opposite to the surface bonded to the first substrate.

[0108] In step (a), for example, an adhesive layer may be formed on a substrate by applying an adhesive onto one surface of the substrate. When the adhesive is a coating liquid containing a solvent, the coating liquid may be applied onto the substrate, and the resulting coating film may be dried to form an adhesive layer. The coating liquid containing a urethane resin may be a coating liquid containing the urethane resin composition of the above embodiment.

[0109] The method for applying the coating liquid is not particularly limited, and examples thereof include an applicator method, a bar coating method, a spin coating method, a spray coating method, a dip coating method, a nozzle coating method, a gravure coating method, a reverse roll coating method, a die coating method, an air doctor coating method, a blade coating method, a rod coating method, a curtain coating method, a knife coating method, a transfer roll coating method, a squeeze coating method, an impregnation coating method, a kiss coating method, a calendar coating method, and an extrusion coating method.

[0110] The drying temperature of the coating film is not particularly limited, but is preferably 300°C or less, more preferably 150°C or less, and even more preferably 130°C or less. When the drying temperature is 300°C or less, damage to the substrate and thermal decomposition of the adhesive layer can be further suppressed. In particular, when the substrate is a polyolefin substrate, the drying temperature can be set to 130°C or less to sufficiently reduce damage to the substrate. The drying temperature of the coating film is preferably 50°C or more, and may be 70°C or more or 80°C or more. When the drying temperature is 50°C or more, the residual amount of the solvent can be further reduced. The drying time is not particularly limited, but is preferably 5 seconds to 12 hours, more preferably 20 seconds to 1 hour, and most preferably 1 minute to 30 minutes. When the drying time is 5 seconds or more, poor drying can be further suppressed. When the drying time is 12 hours or less, the time required for the process can be further reduced, so that the productivity is further excellent.

[0111] In step (a), the adhesive may be disposed (e.g., coated) in advance on a release film or the like to form an adhesive layer, and then the adhesive layer may be attached to one side of the substrate by lamination or the like to form an adhesive layer on the substrate.

[0112] The heating temperature (heat treatment temperature) in step (b) may be, for example, 70 to 300°C. When the heat treatment temperature is 70°C or higher, adhesion failure can be further suppressed. When the heat treatment temperature is 300°C or lower, damage to the substrate and thermal decomposition of the adhesive layer can be further suppressed. When the substrate is a polyolefin substrate, the heating temperature in step (b) is preferably 70 to 130°C, more preferably 80 to 100°C. In addition, the heat treatment time is not particularly limited, but is preferably 1 second to 12 hours, more preferably 10 seconds to 1 hour, and most preferably 10 seconds to 30 minutes. When the treatment time is 1 second or more, adhesion failure can be further suppressed. When the treatment time is 12 hours or less, the time required for the process can be further reduced, and even better productivity can be obtained.

[0113] The heating in step (b) may be heating for drying in step (a). That is, steps (a) and (b) may overlap. When steps (a) and (b) are performed separately, the heating temperature in step (b) may be equal to or higher than the drying temperature in step (a).

[0114] The adhesion between the second substrate and the adhesive layer in step (c) may be performed under the same heating conditions as step (b). Step (b) and step (c) may be performed simultaneously. For example, the adhesive layer and the second substrate may be arranged in this order on the first substrate (e.g., a polyolefin substrate), and then the resulting laminate may be heated to adhere the first substrate and the adhesive layer and the second substrate and the adhesive layer to each other substantially simultaneously.

[0115] In step (c), the second substrate may be bonded in an uncoated state or with the above-mentioned resin coating film. The conditions for forming the resin coating film (e.g., the conditions for application and drying) may be the same as the conditions for forming the adhesive layer in the above-mentioned step (a). EXAMPLES

[0116] The contents of the present disclosure will be described in more detail below using examples and comparative examples, but the present disclosure is not limited to the following examples.

[0117] <Synthesis of polyisobutylene polyol> (reagent) The reagents used in the preparation of the polyisobutylene polyol are shown below. 5-tert-Butyl-isophthalic acid: Tokyo Chemical Industry Co., Ltd., purity >98.0% (GC), product code: B1380 Methanol: Kanto Chemical, Grade 1, Product Code: 25183-81 Tetrahydrofuran (THF): Fujifilm Wako Pure Chemical Industries, ultra-dehydrated, stabilizer-free, for organic synthesis, product code: 207-17765 Concentrated sulfuric acid: Kanto Chemical, Grade 1, Product code: 37390-01 Sodium bicarbonate: Fujifilm Wako Pure Chemical Industries, special grade reagent, product code: 191-01305 Ethyl acetate: Fujifilm Wako Pure Chemical Industries, Wako First Grade, product code: 056-00367 Sodium sulfate anhydrous: Fujifilm Wako Pure Chemical Industries, Wako Grade 1, product code: 194-03355 3.0M Methylmagnesium bromide diethyl ether solution: Sigma-Aldrich, product code: 189898 Ammonium chloride: Fujifilm Wako Pure Chemical Industries, special grade reagent, product code: 017-02995 Sodium hydride: Kanto Chemical, purity >55% by mass, product code: 37842-35 Methyl iodide: Tokyo Chemical Industry Co., Ltd., purity >99.5% (GC), product code: I0060 2,6-Di-tert-butyl-4-methylpyridine (DTBMP): Tokyo Chemical Industry Co., Ltd., purity >98.0% (GC), product code: D2419 Isobutene n-hexane solution: Tokyo Chemical Industry Co., Ltd., 13% by mass of isobutene (1,3,5-trimethoxybenzene was used as the internal standard, and proton nuclear magnetic resonance ( 1 Quantitative analysis by H-NMR), product code: I1083 n-Hexane: Fujifilm Wako Pure Chemical Industries, ultra-dehydrated, for organic synthesis, product code: 088-09105 Methylene chloride: Fujifilm Wako Pure Chemical Industries, ultra-dehydrated, for organic synthesis, product code: 044-31235 Titanium tetrachloride methylene chloride solution: Tokyo Chemical Industry Co., Ltd., titanium tetrachloride 17% by mass (see test report), product code: T2052 1,3-Butadiene n-hexane solution: Tokyo Chemical Industry Co., Ltd., 1,3-butadiene 15% by mass (see test report), product code: B4358 Chloroform: Kanto Chemical, Grade 1, Product code: 07278-81 Tetrabutylammonium hydroxide aqueous solution: Tokyo Chemical Industry Co., Ltd., tetrabutylammonium hydroxide 40% by mass (see test report), product code: T1685 N,N-Dimethylformamide (DMF): Fujifilm Wako Pure Chemical Industries, ultra-dehydrated, for organic synthesis, product code: 041-32367 Potassium acetate: Nacalai Tesque, special grade reagent, purity >97% by mass, product code: 28405-05 Sodium methoxide: Tokyo Chemical Industry Co., Ltd., purity >96% by mass, product code: S0485 Silica gel: Kanto Chemical, Silica gel 60 (spherical, 40-50 μm), product code: 37562-84

[0118] (Measurement of number average molecular weight and weight average molecular weight) The number average molecular weight (Mn) and weight average molecular weight (Mw) of the intermediate product and the final product were measured by gel permeation chromatography (GPC) under the following conditions. The number average molecular weight (Mn) and weight average molecular weight (Mw) are polystyrene-equivalent molecular weights. Equipment: High-speed GPC equipment (Tosoh HLC-8320GPC) Column: One each of TSKgel SuperH4000 (6mm I.D. x 15cm), TSKgel SuperH3000 (6mm I.D. x 15cm), TSKgel SuperH2000 (6mm I.D. x 15cm), and TSKgel SuperH1000 (6mm I.D. x 15cm) connected in series in that order (all manufactured by Tosoh Corporation). ·Mobile phase: THF ·Mobile phase speed: 0.6mL / min Column temperature: 40℃ Detector: RI detector (polarity (+)) Sample solution: THF solution (concentration: 1mg / mL) Sample injection volume: 10μL

[0119] ( 1 H-NMR measurement) 1 H-NMR spectra were obtained from Brucker ASCEND TMMeasurement was performed using an ADVANCE III HD (400 MHz) with tetramethylsilane (TMS) as the internal standard, and the chemical shift value was set to 0 ppm.

[0120] (Analysis of polymer end structures) The terminal structure of the polymer is 1 The polymer was analyzed by H-NMR. The ratio of the functionalized polymer ends was calculated using the integral value of the signal derived from the polymer end structure and the integral value of the signal derived from the aromatic group of the initiator (the signals used for the calculation are described in each synthesis example).

[0121] (Gas Chromatography Mass Spectrometry (GC / MS)) Measurement equipment: Shimadzu GCMS-QP2010SE Column: DB-5ms (30m x 0.25mm I.D. x 0.25μm), manufactured by Agilent Technologies Measurement conditions: Mobile phase: helium, column oven: 80°C, vaporizer temperature: 280°C, pressure: 100.0 kPa, total flow rate: 50.0 mL / min, column flow rate: 1.46 mL / min Ionization method: Electron ionization (EI)

[0122] (Synthesis Example 1) [Synthesis of synthetic intermediates] [ka] With reference to Non-Patent Document 1, a compound of the above formula (2) (5-tert-butyl-dimethyl isophthalate, hereinafter referred to as "synthetic intermediate (2)") and a compound of the above formula (3) (5-tert-butyl-1,3-bis(1-hydroxy-1-methylethyl)benzene, hereinafter referred to as "synthetic intermediate (3)") were synthesized according to the above reaction scheme (A).

[0123] Specifically, 5-tert-butyl-isophthalic acid (16.7 g, 75.1 mmol), THF (100 mL), and methanol (100 mL) were placed in a 500 mL round-bottom flask equipped with a stirrer and reflux tube, and concentrated sulfuric acid (4.00 mL, 75.0 mmol) was added and stirred under reflux conditions for 4 hours. Next, the reaction solution was cooled to 0°C, and a saturated aqueous solution of sodium bicarbonate (100 mL) was added, followed by extraction with ethyl acetate (2 times with 200 mL each). The resulting organic layer was washed with saturated saline (100 mL), dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain synthetic intermediate (2) (13.0 g, 69%) as a white solid. The synthesis intermediate (2) 1 The H-NMR assignments are shown below. 1 H-NMR(CDCl3,400MHz)δ:8.51(t,J=1.6Hz,1H),8.27(d,J=1.6Hz,2H),3.45(s,6H),1.38(s,9H).

[0124] Next, under an inert gas atmosphere, synthetic intermediate (2) (13.0 g, 51.9 mmol) and THF (200 mL) were placed in a 500 mL three-neck flask equipped with a stirrer and cooled to 0°C, after which 3.0 M methylmagnesium bromide diethyl ether solution (87.3 mL, 262 mmol) was added and stirred at room temperature for 4 hours. After cooling the reaction solution to 0°C, saturated aqueous ammonium chloride solution (100 mL) was added and stirred at room temperature for 15 minutes, followed by extraction with ethyl acetate (2 times with 200 mL each). The resulting organic layer was washed with saturated saline (100 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain synthetic intermediate (3) (9.16 g, 70%) as a white solid. The amount of synthetic intermediate (3) was 100 mL. 1 The H-NMR assignments are shown below. 1 H-NMR(CDCl3,400MHz)δ:7.45-7.41(m,3H),1.73(s,2H),1.61(s,12H),1.35(s,9H).

[0125] [Synthesis of polymerization initiator] [ka] With reference to Non-Patent Document 2, the compound of the above formula (4) (1-(tert-butyl)-3,5-bis(1-methoxy-1-methylethyl)benzene, hereinafter referred to as “polymerization initiator (4)”) was synthesized according to the above reaction scheme (B).

[0126] Specifically, first, 55% by mass sodium hydride (4.12 g, 94.4 mmol) was placed in a 500 mL two-neck flask equipped with a stirrer and washed with n-hexane. Next, THF (100 mL) was added and cooled to 0°C, and synthetic intermediate (3) (5.90 g, 23.6 mmol) was added. After stirring at room temperature for 1 hour, methyl iodide (5.90 mL, 94.8 mmol) was added and stirred at the same temperature for 18 hours. After cooling the reaction solution to 0°C, a saturated aqueous ammonium chloride solution (50 mL) was added and stirred at room temperature for 30 minutes, and extracted with chloroform (2 times with 200 mL each). The obtained organic layer was washed with saturated saline (100 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain polymerization initiator (4) (6.56 g, quant.) as a white solid. The polymerization initiator (4) 1 The H-NMR assignments and the analytical results by gas chromatography-mass spectrometry are shown below. 1 H-NMR(CDCl3,400MHz)δ:7.32(d,J=1.6Hz,2H),7.23(t,J=1.6Hz,1H),3.08(s,6H),1.54(s,12H),1.34(s,9H). GC / MS, m / z (relative intensity,%):279(M+1,0.1),278(M+,1),264(19),263(M+1-CH3, 100),231(45),214(25),199(54),129(11),73(17);Purity >99.99%(GC).

[0127] (Synthesis Example 2) [Synthesis of polyisobutylene] [ka] Living cationic polymerization of isobutene was carried out according to the above reaction scheme (C) to synthesize the compound of the above formula (5) (hereinafter referred to as "polyisobutylene (5)").

[0128] Specifically, in an argon atmosphere, the polymerization initiator (4) (1.39 g, 5.00 mmol) synthesized above, DTBMP (411 mg, 10.0 mmol), 13 mass% isobutene n-hexane solution (91.6 mL, 140 mmol), n-hexane (48 mL), and methylene chloride (78 mL) were added to a 500 mL three-neck flask equipped with a stirrer. After cooling this mixture to -70°C, 17 mass% titanium tetrachloride methylene chloride solution (8.20 mL, 10.0 mmol) was added under an argon atmosphere. The reaction mixture was stirred at the same temperature for 1 hour, and then 15 mass% 1,3-butadiene n-hexane solution (22.2 mL, 40.0 mmol) and 17 mass% titanium tetrachloride methylene chloride solution (16.5 mL, 20.0 mmol) were added, followed by stirring at the same temperature for another 1 hour. After the reaction was completed, methanol / 2M aqueous ammonia solution (100 mL / 30 mL) pre-cooled to -70°C was added to the reaction mixture and stirred at room temperature for 15 minutes. The reaction solution was then concentrated under reduced pressure, and the resulting residue was extracted with chloroform (300 mL). This chloroform solution was filtered through Celite and then concentrated under reduced pressure to obtain polyisobutylene (5) (8.45 g, yield 86%) as a colorless, highly viscous liquid. 1 The H-NMR assignments are shown below. 1 H-NMR(CDCl3,400MHz)δ:7.17(brs,3H),5.80(m,1.6H),5.60(m,1.6H),4.05(d,J=7.0Hz,3.1H),2.01(d ,J=7.4Hz,3H),1.83(brs,4H),1.46-1.29(m,72H),1.18(brs,5H),1.15-0.97(m,142H),0.79(brs,12H).

[0129] The number average molecular weight (Mn) of polyisobutylene (5) was 2,540, the molecular weight distribution index (Mw / Mn) was 1.12, and the number of 4-chloro-2-butenyl groups per molecule was 1.6. 1 The calculation was based on the signal δ 5.80 (m, 1.6H) derived from the polymer terminal structure, with the signal δ 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data as the reference.

[0130] [Synthesis of polyisobutylene polyol] [ka] According to the above reaction scheme (D), the polyisobutylene (5) was terminally hydroxylated to synthesize the compound of the above formula (8) (hereinafter referred to as "synthetic intermediate (8)") and the compound of the above formula (6) (hereinafter referred to as "polyisobutylene polyol (6)").

[0131] Specifically, first, polyisobutylene (5) obtained in Synthesis Example 2 (number average molecular weight (Mn): 2,540, molecular weight distribution index (Mw / Mn): 1.12, number of 4-chloro-2-butenyl groups per molecule: 1.6, 8.45 g) and DMF (50 mL) were placed in a 300 mL round-bottom flask equipped with a stirrer and a reflux condenser, and potassium acetate (4.91 g, 50.0 mmol) was added and stirred at 120° C. for 6 hours. After the reaction was completed, the reaction solution was allowed to cool to room temperature, and then distilled water (100 mL) was added and extracted with n-hexane / ethyl acetate (4:1) (200 mL each, twice). The obtained organic layer was washed with saturated saline (100 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain synthetic intermediate (8) as a pale yellow, highly viscous liquid (8.34 g, quant.). The amount of synthetic intermediate (8) was calculated as follows: 1 The H-NMR assignments are shown below. 1H-NMR(CDCl3,400MHz)δ:7.17(brs,3H),5.79(m,1.6H),5.56(m,1.7H),5.50-5.10(m,1.2H),4.53(d,J=6.8Hz,3.2H),2.12(1.3H),2.06(s,5. 2H),2.01(d,J=7.4Hz,2.9H),1.93(d,J=7.3Hz,1H),1.83(brs,4H),1.46-1.29(m,73H),1.18(brs,5H),1.15-0.97(m,146H),0.79(brs,12H).

[0132] The number average molecular weight (Mn) of the synthetic intermediate (8) was 2,680, the molecular weight distribution index (Mw / Mn) was 1.10, and the number of acetyl groups per molecule was 1.6. 1 The calculation was performed from the signal δ 5.79 (m, 1.6H) derived from the polymer terminal structure, based on the signal δ 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data.

[0133] Next, the synthetic intermediate (8) obtained above (number average molecular weight (Mn): 2,680, molecular weight distribution index (Mw / Mn): 1.10, number of acetyl groups per molecule: 1.6, 8.34 g), methylene chloride (50 mL), and methanol (10 mL) were placed in a 300 mL round-bottom flask equipped with a stirrer, and sodium methoxide (540 mg, 9.99 mmol) was further added and stirred at room temperature for 8 hours. After the reaction was completed, the reaction mixture was neutralized with a saturated aqueous ammonium chloride solution (50 mL) and extracted with chloroform (2 times with 200 mL each). The obtained organic layer was washed with saturated saline (100 mL) and dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography (n-hexane / ethyl acetate) to obtain polyisobutylene polyol (6) (4.35 g, yield 52%) as a colorless highly viscous liquid. 1 The H-NMR assignments are shown below. 1H-NMR(CDCl3,400MHz)δ:7.17(brs,3H),5.77-5.58(m,4.0H),5.50-5.32(m,0.9H),4.11(m,4H),2.12-2.04(broad,1.9H),2.00(d, J=7.2Hz,3.2H),1.93(d,J=6.9Hz,0.9H),1.83(brs,4H),1.46-1.29(m,66H),1.18(brs,5H),1.15-0.97(m,140H),0.79(brs,12H).

[0134] The number average molecular weight (Mn) of the polyisobutylene polyol (6) was 2470, the molecular weight distribution index (Mw / Mn) was 1.04, and the number of hydroxyl groups per molecule was 2.0. 1 The signal δ of 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data was used as a reference, and the signal δ of 5.77-5.58 (m, 4.0H) derived from the polymer terminal structure was calculated. The polyisobutylene chain content in the polyisobutylene polyol (6) was 80.2 mass%, and n (average of two n's) in the formula (6) was 13. The polyisobutylene chain content in the polyisobutylene polyol (6) and n (average of two n's) in the formula (6) are 1 The calculation was based on the signal δ 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data, and on the signals δ 1.46-1.29 (methylene group) and δ 1.15-0.97 (methyl group) derived from the isobutylene unit.

[0135] (Synthesis Example 3) [Synthesis of polyisobutylene] In an argon atmosphere, the polymerization initiator (4) (1.39 g, 5.00 mmol) synthesized above, DTBMP (411 mg, 10.0 mmol), 13 mass% isobutene n-hexane solution (144 mL, 220 mmol), and methylene chloride (78 mL) were added to a 500 mL three-neck flask equipped with a stirrer. After cooling this mixture to -80°C, 14 mass% titanium tetrachloride methylene chloride solution (9.90 mL, 10.0 mmol) was added under an argon atmosphere. The reaction mixture was stirred at the same temperature for 1 hour, and then 15 mass% 1,3-butadiene n-hexane solution (25.0 mL, 45.1 mmol) and 14 mass% titanium tetrachloride methylene chloride solution (19.7 mL, 19.9 mmol) were added under an argon atmosphere, and further stirred at the same temperature for 1 hour. After the reaction was completed, methanol / 2M aqueous ammonia solution (100 mL / 30 mL) pre-cooled to -80°C was added to the reaction mixture and stirred at room temperature for 15 minutes. Next, the reaction solution was concentrated under reduced pressure, and the resulting residue was extracted with chloroform (300 mL). The extract was filtered using Celite and then concentrated under reduced pressure to obtain polyisobutylene (5) (13.0 g) as a colorless, highly viscous liquid. The number average molecular weight (Mn) of the obtained polyisobutylene (5) was 3,420, the molecular weight distribution index (Mw / Mn) was 1.05, and the number of 4-chloro-2-butenyl groups per molecule was 1.7.

[0136] [Synthesis of polyisobutylene polyol] [ka] According to the above reaction scheme (E), the polyisobutylene (5) was terminally hydroxylated to synthesize the polyisobutylene polyol (6) and the compound of the above formula (7) (hereinafter referred to as "polyisobutylene polyol (7)").

[0137] Specifically, first, the polyisobutylene (5) obtained above (number average molecular weight (Mn): 3,420, molecular weight distribution index (Mw / Mn): 1.05, number of 4-chloro-2-butenyl groups per molecule: 1.7, 12.7 g) and THF (330 mL) were placed in a 500 mL round-bottom flask equipped with a stirrer and a reflux condenser, and a 40% by mass tetrabutylammonium hydroxide aqueous solution (16.2 mL) was further added and stirred at 80 ° C for 30 hours. After the reaction was completed, the reaction solution was cooled to 0 ° C and neutralized by adding a 1N hydrochloric acid aqueous solution (60 mL), concentrated under reduced pressure, and then extracted with chloroform (2 times with 200 mL each). The obtained organic layer was washed with saturated saline (50 mL), dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (n-hexane / ethyl acetate) to obtain a colorless, highly viscous liquid polyisobutylene polyol (6) (4.98 g, yield 39%) and polyisobutylene polyol (7) (1.00 g, yield 8%). 1 The H-NMR assignments are shown below. 1 H-NMR(CDCl3,400MHz)δ:7.17(brs,3H),5.77-5.58(m,4.0H),5.50-5.32(m,0.5H),4.11(m,4.0H),2.12-2.04(broad,1H),2.00(d, J=7.1Hz,3.6H),1.93(d,J=6.9Hz,0.7H),1.83(brs,4H),1.46-1.29(m,105H),1.18(brs,5H),1.15-0.97(m,210H),0.79(brs,12H).

[0138] The number average molecular weight (Mn) of the obtained polyisobutylene polyol (6) was 3,470, the molecular weight distribution index (Mw / Mn) was 1.03, and the number of hydroxyl groups per molecule was 2.0. 1The signal δ of 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data was used as a reference, and the signal δ of 5.77-5.58 (m, 4.0H) derived from the polymer end structure was calculated. The polyisobutylene chain content in the polyisobutylene polyol (6) was 87.3 mass%, and n (average of two n's) in the formula (6) was 22. The polyisobutylene chain content in the polyisobutylene polyol (6) and n (average of two n's) in the formula (6) are 1 The calculation was based on the signal δ 7.17 (brs, 3H) derived from the polymerization initiator structure in the H-NMR data, and on the signals δ 1.46-1.29 (methylene group) and δ 1.15-0.97 (methyl group) derived from the isobutylene unit.

[0139] The obtained polyisobutylene polyol (7) had a number average molecular weight (Mn) of 5,460 and a molecular weight distribution (Mw / Mn) of 1.25. In formula (7), m is an integer of 1 to 5, and polyisobutylene polyol (7) was a mixture of a compound in which m in formula (7) is 1, a compound in which m in formula (7) is 2, a compound in which m in formula (7) is 3, a compound in which m in formula (7) is 4, and a compound in which m in formula (7) is 5.

[0140] <Synthesis of urethane resin> (Material preparation) The following materials were prepared. [Polyisobutylene polyol] Polyisobutylene polyol 1: Polyisobutylene polyol (6) obtained in Synthesis Example 2 Polyisobutylene polyol 2: Polyisobutylene polyol (6) obtained in Synthesis Example 3 Polyisobutylene polyol 3: Polyisobutylene polyol (7) obtained in Synthesis Example 3 [Hydrogenated polyisoprene polyol] Hydrogenated polyisoprene polyol 1: Product name EPOL (Idemitsu Kosan Co., Ltd.), number average molecular weight 2,500, hydroxyl group content 0.94 mol / kg, iodine value 7.9 g / 100 g [Polyisocyanate] MDI: Diphenylmethane-4,4'-diisocyanate (product name: Millionate M T, manufactured by Tosoh Corporation), isocyanate group content = 7.99 mol / kg [catalyst] Dioctyltin dilaurate: Kishida Chemical Co., Ltd. [solvent] Cyclohexanone: Fujifilm Wako Pure Chemical Industries, Ltd.

[0141] (Synthesis Example 4) In a 2L four-necked separable flask equipped with a stirrer, a thermometer, a heating device, and a reflux condenser, 9.50 g of polyisobutylene polyol 1, 1.05 g of MDI, 0.0059 g of a catalyst (dioctyltin dilaurate), and 95.0 g of a solvent (cyclohexanone) were charged at room temperature. Next, nitrogen gas was blown into the flask to replace the atmosphere in the flask. The mixture in the flask was reacted for 6 hours under a condition of 80°C while being stirred almost uniformly, to obtain a urethane resin composition (a1) containing a urethane resin (urethane resin (a1)) made of polyurethane (a1). The obtained urethane resin composition (a1) was dried under reduced pressure to remove the solvent, and the urethane resin (a1) was extracted. The number average molecular weight (Mn) and weight average molecular weight (Mw) of the urethane resin (a1) were measured by the method shown below, and the molecular weight distribution index (Mw / Mn) was calculated. Incidentally, the catalyst used in the reaction may remain in the urethane resin (a1) extracted by the above method. However, since the amount of the remaining catalyst is extremely small and below the detection limit of the measurement method, the following measurements were performed assuming that no catalyst remains.

[0142] [Measurement of number average molecular weight and weight average molecular weight] The number average molecular weight and the weight average molecular weight were measured by gel permeation chromatography (GPC) under the following conditions. The number average molecular weight and the weight average molecular weight are polystyrene-equivalent molecular weights. Equipment: High-speed GPC equipment (Tosoh HLC-8320GPC) Column: One TSKgel guardcolumn α (6.0mm I.D. x 4cm) and two +α-M (67.8mm I.D. x 30cm) connected in series in that order (all manufactured by Tosoh Corporation). Mobile phase: Cyclohexanone ·Mobile phase speed: 1.0mL / min Column temperature: 40℃ Detector: RI detector (polarity (+)) Sample solution: Cyclohexanone solution (concentration: 1mg / mL) Sample injection volume: 100μL

[0143] (Synthesis Examples 5 to 7) A urethane resin composition (a2) of Synthesis Example 5, a urethane resin composition (a3) ​​of Synthesis Example 6, and a urethane resin composition (b1) of Synthesis Example 7 were prepared in the same manner as in Synthesis Example 4, except that polyisobutylene polyol 1 was replaced with polyisobutylene polyol 2, polyisobutylene polyol 3, or hydrogenated polyisoprene polyol 1, and the amounts of each component were changed to the values ​​shown in Table 1. The urethane resin composition (a2) is a urethane resin composition containing a urethane resin made of polyurethane (a2), the urethane resin composition (a3) ​​is a urethane resin composition containing a urethane resin made of polyurethane (a3), and the urethane resin composition (b1) is a urethane resin composition containing a urethane resin made of polyurethane (b1).

[0144] Next, in the same manner as in Example 1, urethane resin (a2) was extracted from the obtained urethane resin composition (a2), and urethane resin (b1) was extracted from the urethane resin composition (b1). The number average molecular weight (Mn) and weight average molecular weight (Mw) of the urethane resin (a2) and the urethane resin (b1) were measured, and the molecular weight distribution index (Mw / Mn) was calculated. In addition, in the same manner as in Example 1, the adhesive properties of the urethane resin composition were evaluated. The results are shown in Table 1.

[0145] [Table 1]

[0146] <Example 1> The urethane resin composition (a1) obtained in the above Synthesis Example 4 was used as the adhesive of Example 1.

[0147] <Examples 2 to 5> The urethane resin composition (a1) obtained in Synthesis Example 4 and the urethane resin composition (a2) obtained in Synthesis Example 5 were mixed so that the compounding ratio of polyurethane (a1) to polyurethane (a2) was the value (unit: parts by mass) shown in Table 2, thereby obtaining a urethane resin composition containing a urethane resin including polyurethane (a1) and polyurethane (a2). The obtained urethane resin composition was used as the adhesive of Examples 2 to 5. The compounding ratio of polyurethane (a1) to polyurethane (a2) was calculated by considering the amount of solid content obtained by drying the urethane resin composition under reduced pressure and distilling off the solvent as the polyurethane content in the urethane resin composition.

[0148] <Example 6> The urethane resin composition (a3) ​​obtained in the above Synthesis Example 6 was used as the adhesive of Example 6.

[0149] <Examples 7 to 10> The urethane resin composition (a1) obtained in Synthesis Example 4 and the urethane resin composition (a3) ​​obtained in Synthesis Example 6 were mixed so that the compounding ratio of polyurethane (a1) to polyurethane (a3) ​​was the value (unit: parts by mass) shown in Table 3, thereby obtaining a urethane resin composition containing a urethane resin including polyurethane (a1) and polyurethane (a3). The obtained urethane resin composition was used as the adhesive of Examples 7 to 10. The compounding ratio of polyurethane (a1) to polyurethane (a3) ​​was calculated by considering the amount of solid content obtained by drying the urethane resin composition under reduced pressure and distilling off the solvent as the polyurethane content in the urethane resin composition.

[0150] <Comparative Example 1> The urethane resin composition (b1) obtained in Synthesis Example 7 above was used as the adhesive of Comparative Example 1.

[0151] <Evaluation> The adhesive properties of the adhesives of the Examples and Comparative Examples were evaluated by the following methods. First, the adhesive was applied to a polypropylene substrate (PP substrate: Kobe Poly Sheet PP manufactured by Hitachi Chemical Co., Ltd.) using a bar coater, left to stand for 5 minutes under room temperature conditions, and then dried at 80 ° C for 10 minutes using a hot air dryer to form an adhesive layer (film thickness 10 μm) on the PP substrate. Next, a polyethylene terephthalate film (Toyobo Ester Film E5100 manufactured by Toyobo Co., Ltd.) was attached on the adhesive layer of the obtained laminate, and then heat-treated at 80 ° C for 10 minutes to obtain a polypropylene (PP) test piece. Next, a 180-degree peel test was performed on the obtained PP test piece in accordance with JIS K6854-2 to measure the adhesive strength of the adhesive layer to the PP substrate. For the test, an Autocom type testing machine (UTPS-Acs (S) manufactured by TSE Co., Ltd.) was used. The results are shown in Tables 2 and 3.

[0152] [Table 2]

[0153] [Table 3]

Claims

1. An adhesive containing a urethane resin (A), The urethane resin (A) contains a structural unit derived from a polyisobutylene polyol, The adhesive, wherein the urethane resin (A) has a molecular weight distribution index of 2.0 to 4.

0.

2. The adhesive according to claim 1, wherein the urethane resin (A) has a weight average molecular weight of 6,000 to 31,000.

3. The adhesive according to claim 1 , wherein the polyisobutylene polyol comprises a structure represented by the following formula (b1): 【Chemistry 1】 [In formula (b1), * ３ and * ４ represents a bond that bonds to a polyisobutylene chain.

4. The adhesive of claim 1 , wherein the polyisobutylene polyol comprises a structure represented by the following formula (c1): 【Chemistry 2】 [In formula (c1), a represents an integer of 1 or more, ５ represents a bond that bonds to a polyisobutylene chain.

5. The adhesive according to claim 1 , wherein the number of hydroxyl groups per molecule of the polyisobutylene polyol is more than 1.0 and not more than 3.

0.

6. The adhesive according to claim 1 , wherein one molecule of the polyisobutylene polyol contains one structure derived from the polymerization initiator.

7. The adhesive according to claim 1, wherein the content of the structural units derived from the polyisobutylene polyol is 75.0 to 99.9 mass% based on the total mass of the urethane resin (A).

8. 2. The adhesive according to claim 1, wherein the urethane resin (A) contains a structural unit derived from at least one selected from the group consisting of diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate.

9. The urethane resin (A) is A polyurethane (A1) containing a structural unit derived from polyisobutylene polyol and having a weight average molecular weight of 6,000 to 16,000; and a polyurethane (A2) having a weight average molecular weight of 21,000 to 31,000, which contains a constituent unit derived from polyisobutylene polyol.

10. The adhesive according to claim 9 , wherein the content of the polyurethane (A1) is 50 mass % or more based on the total mass of the urethane resin (A).

11. The adhesive of claim 1 for use on a polyolefin substrate.

12. The adhesive layer includes a substrate and an adhesive layer that is adhered to one surface of the substrate. An article, wherein the adhesive layer is formed from the adhesive according to any one of claims 1 to 11.

13. The article of claim 12, wherein the substrate is a polyolefin substrate.

14. A method for producing an article comprising a substrate and an adhesive layer adhered to one surface of the substrate, the method comprising the steps of: A step of disposing the adhesive according to any one of claims 1 to 11 on a substrate to form an adhesive layer; and heating the adhesive layer to bond the substrate and the adhesive layer.

15. The method of claim 14, wherein the substrate is a polyolefin substrate.

16. An adhesive containing a urethane resin (A), The adhesive, wherein the urethane resin (A) contains a structural unit derived from a polyisobutylene polyol.

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