Butane diisocyanate derivative, polyisocyanate composition, polyurethane resin formative composition, adhesive composition and laminated structure

Abstract

To provide a butane diisocyanate derivative which contributes to production of an urethane resin that is excellent in handling property and adhesive characteristics.SOLUTION: A butane diisocyanate derivative has at least one functional group selected from an isocyanurate group, an urethodione group, an iminooxadiazon group, an urethane group, an allophanate group, a urea group, and a biuret group. A ratio RD of a molar ratio of the urethane group in the butane diisocyanate derivative is 70 to 100 mol%, the urethane group includes an urethanization reaction structure composed of a structure derived from one or more kinds of diols and a structure derived from butane diisocyanate, when a molar ratio of a structure derived from linear diol which has hydroxyl groups at both terminals and has 2 to 30 carbon atoms is represented by Y, and a molar ratio of a structure derived from the diol other than the linear diol is represented by X, a composition ratio (X / X+Y) of the diol is 60 to 100 mol%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a butane diisocyanate derivative, a polyisocyanate composition, a polyurethane resin-forming composition, an adhesive composition, and a laminate structure. [Background technology]

[0002] Polyurethane coatings based on general-purpose hexamethylene diisocyanate, pentamethylene diisocyanate, etc., and using aliphatic polyisocyanates as curing agents have the advantages of lower baking temperatures and high weather resistance, and as demand for them increases, the required performance is also becoming higher.

[0003] Patent Document 1 discloses a laminating adhesive containing a polyisocyanate component and a polyol component, characterized in that the polyol component contains a polyol having a polycarbonate skeleton and a monool obtained by reacting the polyol having a carbonate skeleton with a monoisocyanate. According to Patent Document 1, this laminating adhesive has both excellent initial adhesive strength and excellent durability, and can be suitably used for laminating outdoor composite sheets.

[0004] Patent Document 2 discloses a polyisocyanate composition containing an allophanate derivative of xylylene diisocyanate, characterized in that the content of allophanate dimolecules of xylylene diisocyanate is 50% by mass or more and 72% by mass or less, and the content of uretdione dimolecules of xylylene diisocyanate is 12% by mass or less, relative to the total amount of the polyisocyanate composition. According to Patent Document 2, a polyurethane resin with excellent smoothness, chemical resistance, and adhesiveness can be obtained. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-77099 [Patent Document 2] Patent Publication No. 2021-38304 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in recent years in particular, the market has been demanding increasingly higher performance from polyurethane coating films, and there has been a strong demand for the development of polyisocyanate compositions that contribute to the production of urethane resins that are excellent in handleability and adhesive properties.

[0007] Therefore, one aspect of the present disclosure is directed to providing a polyisocyanate composition that contributes to the preparation of a urethane resin having excellent handleability and adhesive properties. Other aspects of the present disclosure are directed to providing a butane diisocyanate derivative that contributes to the preparation of the polyisocyanate composition. Still other aspects of the present disclosure are directed to providing a polyurethane resin-forming composition, an adhesive composition, and a laminate structure that use the polyisocyanate composition. [Means for solving the problem]

[0008] In some aspects, the present disclosure provides the following [1] to [8].

[0009] [1] A butane diisocyanate derivative having at least one functional group selected from an isocyanurate group, a uretdione group, an iminooxadiadione group, a urethane group, an allophanate group, a urea group, and a biuret group, Formula (D): D / (A+B+C+D+E+F+G)×100...Formula (D) [In the formula, A, B, C, D, E, F, and G represent the molar ratios of the isocyanurate group, the uretdione group, the iminooxadiadione group, the urethane group, the allophanate group, the urea group, and the biuret group, respectively.] The molar ratio (R D ) is 70 to 100 mol %, the urethane group contains a urethane reaction structure consisting of one or more diol-derived structures and a butane diisocyanate-derived structure, Formula (X): X / (X+Y)×100...Formula (X) [In the formula, X represents the molar ratio of the structure derived from a diol having 3 to 30 carbon atoms other than a linear diol having hydroxyl groups at both ends, and Y represents the molar ratio of the structure derived from a linear diol having 2 to 30 carbon atoms and having hydroxyl groups at both ends.] The butane diisocyanate derivative is represented by the following formula, in which the composition ratio of the diol is 60 to 100 mol %. [2] The molar ratio of the urethane group (R D ) is 90 to 100 mol %. [3] The butane diisocyanate derivative according to [1] or [2], wherein the composition ratio of the diol represented by the formula (X) is 95 to 100 mol %. [4] The butane diisocyanate derivative according to any one of [1] to [3], wherein the one or more diols have an average carbon number of 3 to 10. [5] A polyisocyanate composition comprising the butane diisocyanate derivative according to any one of [1] to [4]. [6] A polyurethane resin-forming composition comprising the polyisocyanate composition according to [5] and a polyol. [7] An adhesive composition comprising the polyisocyanate composition according to [5] and a compound having two or more isocyanate-reactive groups. [8] A laminated structure comprising a cured product of the adhesive composition according to [7]. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to provide a polyisocyanate composition that contributes to the production of a urethane resin having excellent handleability and adhesive properties. According to other aspects of the present disclosure, it is possible to provide a butane diisocyanate derivative that contributes to the production of the polyisocyanate composition. According to still other aspects of the present disclosure, it is possible to provide a polyurethane resin-forming composition, an adhesive composition, and a laminate structure that use the polyisocyanate composition. DETAILED DESCRIPTION OF THE INVENTION

[0011] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a numerical range in a certain stage may be replaced with the upper limit or lower limit of a numerical range in another stage. Furthermore, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with a value shown in the examples. Furthermore, the upper limit and lower limit values ​​described individually can be combined in any way.

[0012] Preferred embodiments of each aspect of the present disclosure will be described below, although the aspects of the present disclosure are not limited to the following embodiments.

[0013] <Butane diisocyanate derivative and polyisocyanate composition> A butane diisocyanate derivative according to one embodiment of the present disclosure is a butane diisocyanate derivative having at least one functional group selected from an isocyanurate group, a uretdione group, an iminooxadiadione group, a urethane group, an allophanate group, a urea group, and a biuret group, Formula (D): D / (A+B+C+D+E+F+G)×100...Formula (D) [In the formula, A, B, C, D, E, F, and G represent the molar ratios of the isocyanurate group, the uretdione group, the iminooxadiadione group, the urethane group, the allophanate group, the urea group, and the biuret group, respectively.] The molar ratio (R D ) is 70 to 100 mol %, the urethane group contains a urethane reaction structure consisting of one or more diol-derived structures and a butane diisocyanate-derived structure, Formula (X): X / (X+Y)×100...Formula (X) [In the formula, X represents the molar ratio of the structure derived from a diol having 3 to 30 carbon atoms other than a linear diol having hydroxyl groups at both ends, and Y represents the molar ratio of the structure derived from a linear diol having 2 to 30 carbon atoms and having hydroxyl groups at both ends.] The composition ratio of the diol represented by the formula (I) is 60 to 100 mol %. In the following description, butane diisocyanate may be abbreviated as "BDI."

[0014] The BDI derivatives described above can be used to prepare polyisocyanate compositions that are useful for producing urethane resins with excellent handling and adhesive properties. The excellent handling properties of the polyisocyanate composition can be confirmed, for example, by a solubility test at 25°C. The excellent adhesive properties of the urethane resins obtained using the polyisocyanate composition can be confirmed, for example, by a T-peel test at 23°C.

[0015] A polyisocyanate composition according to another embodiment of the present disclosure includes a BDI derivative, The BDI derivative is a butane diisocyanate derivative having at least one functional group selected from an isocyanurate group, a uretdione group, an iminooxadiadione group, a urethane group, an allophanate group, a urea group, and a biuret group, Formula (D): D / (A+B+C+D+E+F+G)×100...Formula (D) [In the formula, A, B, C, D, E, F, and G represent the molar ratios of the isocyanurate group, the uretdione group, the iminooxadiadione group, the urethane group, the allophanate group, the urea group, and the biuret group, respectively.] The molar ratio (R D ) is 70 to 100 mol %, the urethane group contains a urethane reaction structure consisting of one or more diol-derived structures and a butane diisocyanate-derived structure, Formula (X): X / (X+Y)×100...Formula (X) [In the formula, X represents the molar ratio of the structure derived from a diol having 3 to 30 carbon atoms other than a linear diol having hydroxyl groups at both ends, and Y represents the molar ratio of the structure derived from a linear diol having 2 to 30 carbon atoms and having hydroxyl groups at both ends.] The composition ratio of the diol represented by the following formula is 60 to 100 mol %. That is, the BDI derivative is preferably the BDI derivative described above.

[0016] The polyisocyanate composition tends to have excellent handleability. Furthermore, the polyisocyanate composition makes it easy to obtain a urethane resin having good adhesive properties.

[0017] The BDI derivative is a mixture of multiple compounds derived from a BDI monomer. The BDI derivative includes, for example, one or more compounds selected from the group consisting of an isocyanurate of BDI, a uretdione of BDI, an iminooxadiazinedione of BDI, a urethane of BDI, an allophanate of BDI, a urea of ​​BDI, and a biuret of BDI. Preferably, the BDI derivative includes a urethane of BDI. The urethane of BDI is a compound derived from a BDI monomer that has a urethane group and has a group represented by formula (1).

[0018] [ka]

[0019] Examples of BDI monomers used as raw materials for the urethane form of BDI include 1,2-butane diisocyanate, 1,3-butane diisocyanate, 1,4-butane diisocyanate, 2,3-butane diisocyanate, and mixtures thereof. The raw material for the urethane form of BDI preferably contains 1,4-butane diisocyanate due to the high reactivity of the isocyanate group bonded to the primary carbon. The proportion of 1,4-butane diisocyanate in the raw material for the urethane form of BDI may be 90% by mass or more, 95% by mass or more, or even 100% by mass. The following description may use an example of using 1,4-butane diisocyanate as the BDI monomer, but unless otherwise specified, this is not intended to be limiting.

[0020] The molar ratio of urethane groups (R D ) is 70 to 100 mol %, and may be 75 mol % or more, 80 mol % or more, 85 mol % or more, or 90 mol % or more. When the molar ratio of urethane groups is 90 mol % or more, a urethane resin with higher adhesive strength tends to be obtained. The molar ratio of urethane groups can be determined, for example, by using a nuclear magnetic resonance (NMR) device. 13 It can be measured by C-NMR, more specifically, in accordance with the examples described below.

[0021] In addition to a urethane compound, the BDI derivative may contain one or more compounds selected from the group consisting of an isocyanurate compound, a uretdione compound, an iminooxadiazinedione compound, an allophanate compound, a urea compound, and a biuret compound. The isocyanurate compound of BDI is a compound derived from a BDI monomer that has an isocyanurate group and has a group represented by formula (2). The uretdione compound of BDI is a compound derived from a BDI monomer that has a uretdione group and has a group represented by formula (3). The iminooxadiazinedione compound of BDI is a compound derived from a BDI monomer that has an iminooxadiazinedione group and has a group represented by formula (4). The allophanate compound of BDI is a compound derived from a BDI monomer that has an allophanate group and has a group represented by formula (5). The urea compound of BDI is a compound derived from a BDI monomer that has a urea group and has a group represented by formula (6). The biuret form of BDI is a compound derived from a BDI monomer and has a biuret group, and has a group represented by formula (7).

[0022] [ka]

[0023] BDI derivatives are compounds derived from BDI monomers that have one functional group selected from the group consisting of an isocyanurate group, a uretdione group, an iminooxadiadione group, a urethane group, an allophanate group, a urea group, and a biuret group. They may also include compounds that have two or more different types of groups in one molecule. For example, they may include compounds that have both a urethane group and an isocyanurate group (a compound that is both a urethane and an isocyanurate). Such compounds are considered to be both urethane and isocyanurate forms of BDI.

[0024] The BDI derivative contains a urethane-reacted structure consisting of one or more diol-derived structures and butane diisocyanate-derived structures, Formula (X): X / (X+Y)×100...Formula (X) [In the formula, X represents the molar ratio of the structure derived from a diol having 3 to 30 carbon atoms other than a linear diol having hydroxyl groups at both ends, and Y represents the molar ratio of the structure derived from a linear diol having 2 to 30 carbon atoms and having hydroxyl groups at both ends.] The composition ratio of the diol represented by the formula (I) is 60 to 100 mol %, and may be 65 mol % or more, 70 mol % or more, 75 mol % or more, 80 mol % or more, 85 mol % or more, 90 mol % or more, or 95 mol % or more. When the composition ratio of the diol is 90 mol % or more, a polyisocyanate composition having excellent handleability tends to be obtained.

[0025] The carbon number of the diol other than the linear diol having hydroxyl groups at both ends, which is added to form the urethane group (hereinafter also referred to as "first diol"), is 3 to 30, and may be 3 to 25, 3 to 15, or 3 to 10. When the carbon number of the first diol used is 3 to 10, a urethane resin having higher adhesive strength tends to be obtained. More specifically, the first diols described below can be preferably used.

[0026] The carbon number of the linear diol having hydroxyl groups at both ends, which is added to form the urethane group (hereinafter also referred to as "second diol"), is 2 to 30, and may be 2 to 25, 2 to 15, or 2 to 10. When the carbon number of the linear diol used is 2 to 10, a urethane resin having higher adhesive strength tends to be obtained. More specifically, the second diol described below can be preferably used.

[0027] In other words, the urethane group contains a urethane reaction structure consisting of a structure derived from one or more diols and a structure derived from butane diisocyanate. The one or more diol-derived structures are a structure derived from a diol other than a linear diol having hydroxyl groups at both ends; and a structure derived from a linear diol having hydroxyl groups at both ends. The structure derived from the first diol has 3 to 30 carbon atoms, and may have 3 to 25 carbon atoms, 3 to 15 carbon atoms, or 3 to 10 carbon atoms. The second diol-derived structure has 2 to 30 carbon atoms, and may have 2 to 25 carbon atoms, 2 to 15 carbon atoms, or 2 to 10 carbon atoms.

[0028] The average carbon number of the one or more diols added to form urethane groups is preferably 3 to 30, more preferably 3 to 25, even more preferably 3 to 15, still more preferably 3 to 10, and particularly preferably 3 to 8. When the average carbon number is 3 to 8, a urethane resin with higher adhesive strength tends to be obtained. Specifically, the average carbon number of the one or more diols added to form urethane groups can be calculated in accordance with the examples described later.

[0029] The BDI derivative may be blocked with a known blocking agent to extend the pot life and create a one-component coating composition. That is, some or all of the NCO groups of the compound derived from the BDI monomer may be blocked with a blocking agent. Blocked polyisocyanates are inactive at room temperature, but upon heating, the blocking agent dissociates, reactivating the isocyanate groups and allowing them to react with active hydrogen groups. The blocking agent is a compound containing one active hydrogen atom in the molecule, and known blocking agents such as alcohols, alkylphenols, phenols, active methylenes, mercaptans, acid amides, acid imides, imidazoles, ureas, oximes, amines, imides, and pyrazoles can be used.

[0030] The polyisocyanate composition may contain components other than the BDI derivative, or may consist solely of the BDI derivative. Examples of other components include 1,6-hexane diisocyanate (hereinafter sometimes abbreviated as "HDI") and its derivatives. The BDI derivative is preferred over the HDI derivative in that it is easier to obtain a urethane resin with better adhesive properties.

[0031] The polyisocyanate composition may contain other isocyanate compounds (e.g., polyisocyanates such as BDI monomer, HDI monomer, and HDI derivatives) as other components, but the content of BDI monomer in the polyisocyanate composition is preferably 5% by mass or less, and more preferably 1% by mass or less (substantially free of BDI monomer). The content of isocyanate compounds other than BDI derivatives in the polyisocyanate composition is preferably 50% by mass or less, and more preferably 1% by mass or less (substantially free of isocyanate compounds other than BDI derivatives). The above content is based on the total mass of the solids in the polyisocyanate composition.

[0032] The polyisocyanate composition may contain an organic solvent as another component, as described below, but the content of the organic solvent in the polyisocyanate composition is preferably 50% by mass or less, and more preferably 20% by mass or less (substantially no organic solvent is contained). The above content is based on the total mass of the solid content in the polyisocyanate composition.

[0033] The BDI derivatives and polyisocyanate compositions described above are suitable for use as curing agent components in adhesive compositions. That is, another embodiment of the present disclosure is an adhesive curing agent containing the BDI derivative, and yet another embodiment of the present disclosure is an adhesive curing agent comprising the polyisocyanate composition. The main component of these adhesive curing agents can be an isocyanate-reactive compound (such as a polyol), as described below.

[0034] <Method for producing BDI derivative> The method for producing a BDI derivative according to this embodiment includes a polymerization step of obtaining a urethane body of BDI by performing a urethanization reaction for forming a urethane group.

[0035] The urethanization reaction is carried out by reacting a reactant (for example, a BDI monomer) with a diol. The first diol may contain a functional group such as a halogen atom such as chlorine or fluorine, a methoxy group, an azide group, or a vinyl group, and may contain a cyclic structure. Examples of the first diol include 1,2-propanediol, 3-methoxy-1,2-propanediol, 2-methyl-2-nitro-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 2,4-dihydroxy-2-methylpentane, 3-methyl-1,5-pentanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol, and 1,2-hexane. Examples of suitable diols include 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 4,4'-bicyclohexanol, pinacol, 1,2-heptanediol, 1,3-heptanediol, 1,2-octanediol, 1,3-octanediol, 1,2-nonanediol, 2,2-bis(4-hydroxycyclohexyl)propane, and batyl alcohol. Among these, diols without functional groups, such as 2,2-dimethyl-1,3-propanediol and 1,3-butanediol, are more preferred because they can increase the NCO content. The first diol may be a diol having 3 to 30 carbon atoms and one or more tertiary or quaternary carbon atoms. The first diols used in the reaction may be used alone or in combination of two or more.

[0036] Examples of the second diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, etc. The second diol used in the reaction can be used alone or in combination of two or more.

[0037] The amount of diol used in the reaction varies depending on the molecular weight of the diol used, but is preferably 0.5 to 40 parts by mass, and more preferably 1 to 30 parts by mass, per 100 parts by mass of BDI charged.

[0038] The reaction temperature of the urethanization reaction is preferably 50 to 140° C., more preferably 60 to 120° C. When the reaction temperature of the urethanization reaction is 50° C. or higher, the reaction time can be shortened, and coloration of the polyisocyanate composition can be further suppressed.

[0039] The urethanization reaction may be terminated when the target isocyanate group content and urethane group content are reached. When the reaction temperature of the urethanization reaction is 50 to 140°C, the reaction time of the urethanization reaction is, for example, 0.5 to 8 hours.

[0040] The urethanization reaction may be carried out in the presence of a commonly known urethanization catalyst. Examples of the urethanization catalyst include organometallic compounds such as dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin dilaurate, and organic amines such as triethylenediamine and triethylamine, or salts thereof. The urethanization catalyst may be used alone or in combination of two or more.

[0041] The amount of the urethanization catalyst used is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 3 parts by mass, per 100 parts by mass of the charged amount of BDI.

[0042] The reaction temperature of the urethanization reaction when a urethanization catalyst is used is preferably 30 to 120°C, and more preferably 50 to 100°C. When the reaction temperature of the urethanization reaction when a urethanization catalyst is used is 30°C or higher, the reaction time can be shortened, and coloration of the polyisocyanate composition can be further suppressed. Furthermore, when the reaction temperature of the urethanization reaction when a urethanization catalyst is used is 120°C or lower, side reactions such as urethodionation can be further suppressed, and a polyisocyanate composition with higher storage stability can be easily obtained.

[0043] The urethanization reaction using a urethanization catalyst may be terminated when the target isocyanate group content and urethane group content are reached. When the reaction temperature of the urethanization reaction using a urethanization catalyst is 30 to 120°C, the reaction time of the urethanization reaction using a urethanization catalyst is, for example, 0.1 to 3 hours.

[0044] The urethanization reaction may be carried out under an inert gas atmosphere such as nitrogen, argon, etc. Specifically, BDI may be introduced into a reaction vessel, and an inert gas such as nitrogen, argon, etc. may be introduced into the vessel to make the reaction atmosphere an inert gas atmosphere, and then the urethanization reaction may be carried out by the method described above.

[0045] The urethanization reaction may be carried out in the absence or presence of an organic solvent. When the reaction is carried out in the presence of an organic solvent, it is preferable to use an organic solvent that does not affect the reaction and has a boiling point equal to or higher than the reaction temperature. Examples of organic solvents include aliphatic hydrocarbons such as octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, ketones such as methyl isobutyl ketone and cyclohexanone, esters such as butyl acetate and isobutyl acetate, glycol ether esters such as ethylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methyl-3-methoxybutyl acetate, and ethyl-3-ethoxypropionate, ethers such as dioxane, halogenated hydrocarbons such as methylene iodide and monochlorobenzene, and polar aprotic solvents such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphonylamide. From the viewpoint of suppressing the formation of high-molecular-weight compounds, it is particularly preferable to use a polar solvent that has a high affinity with the diols to be added. The organic solvents can be used alone or in combination of two or more.

[0046] After the reaction is complete, unreacted BDI monomer (free BDI) may be removed from the reaction solution containing the reaction product. That is, the method for producing a BDI derivative may further include a BDI removal step for removing free BDI after the urethanization step. Free BDI can be removed, for example, by thin-film distillation at 90 to 130°C under a high vacuum of 10 to 100 Pa, or by extraction with an organic solvent. The removal is preferably carried out so that the residual content of free BDI in the reaction solution is 5% by mass or less. A residual free BDI content of 5% by mass or less can further suppress odor generation and deterioration of storage stability. When an organic solvent is used in the reaction, the organic solvent can be removed simultaneously with the removal of free BDI.

[0047] The BDI derivative (or a reaction solution containing the BDI derivative) obtained by the above method can be used as a polyisocyanate composition either directly or after being mixed with the other components described above. The polyurethane resin-forming composition according to one embodiment of the present disclosure can be obtained by blending the polyisocyanate composition thus obtained with a polyol.

[0048] <Polyurethane Resin-Forming Composition> A polyurethane resin-forming composition according to one aspect of the present disclosure includes the polyisocyanate composition of the above embodiment and a polyol. The composition has polyurethane resin-forming properties, and the polyurethane resin is formed as a reaction product of the polyisocyanate and the polyol by reaction of the polyisocyanate (e.g., a BDI derivative) and the polyol in the composition.

[0049] The polyol is a compound having two or more hydroxy groups, which are active hydrogen groups, as reactive groups with isocyanate groups. The polyol is not particularly limited, but polyester polyol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, silicone polyol, castor oil-based polyol, fluorine-based polyol, transesterification products of two or more polyols, and hydroxyl-terminated prepolymers obtained by urethane reaction with polyisocyanate are preferably used. The polyol can be used alone or in combination of two or more.

[0050] (polyester polyol) Examples of polyester polyols include those obtained by a condensation polymerization reaction between one or more dicarboxylic acids or anhydrides thereof and one or more low-molecular-weight polyols having a molecular weight of not more than 500. Examples of dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, glutaconic acid, azelaic acid, sebacic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α,β-diethylsuccinic acid, maleic acid, and fumaric acid. Examples of low molecular weight polyols having a molecular weight of 500 or less include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer diol, bisphenol A, ethylene oxide or propylene oxide adducts of bisphenol A, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, and pentaerythritol. Also usable are lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (so-called lactone) monomers such as ε-caprolactone, alkyl-substituted ε-caprolactone, δ-valerolactone, alkyl-substituted δ-valerolactone, etc. Furthermore, it is also possible to use polyester-amide polyols obtained by replacing a portion of the low-molecular-weight polyol with a low-molecular-weight polyamine or low-molecular-weight amino alcohol such as hexamethylenediamine, isophoronediamine, or monoethanolamine.

[0051] (Polyether polyol) Examples of polyether polyols include polyether polyols obtained by addition polymerization of alkylene oxides using a compound having two or more, preferably two to three, active hydrogen groups as an initiator, such as low-molecular-weight polyols or low-molecular-weight polyamines. Examples of low-molecular-weight polyols include the same compounds exemplified above as low-molecular-weight polyols having a molecular weight of 500 or less. Examples of low-molecular-weight polyamines include ethylene diamine, propylene diamine, toluene diamine, metaphenylenediamine, diphenylmethane diamine, and xylylene diamine. Examples of alkylene oxides include ethylene oxide, propylene oxide, and butylene oxide. In addition, polyether polyols obtained by ring-opening polymerization of alkyl glycidyl ethers such as methyl glycidyl ether, aryl glycidyl ethers such as phenyl glycidyl ether, and cyclic ether monomers such as tetrahydrofuran can also be used.

[0052] (Polycarbonate polyol) Examples of polycarbonate polyols include those obtained by dealcoholization or dephenolation of one or more low-molecular-weight polyols with diaryl carbonates. Examples of low-molecular-weight polyols include the same compounds exemplified as the low-molecular-weight polyols having a molecular weight of 500 or less. Examples of diaryl carbonates include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, alkylene carbonates such as ethylene carbonate and propylene carbonate, diphenyl carbonate, dinaphthyl carbonate, dianthryl carbonate, diphenanthryl carbonate, diindanyl carbonate, and tetrahydronaphthyl carbonate. Furthermore, examples of polycarbonate polyols that can be used include polyols obtained by transesterification of polycarbonate polyol, polyester polyol, and low-molecular-weight polyol.

[0053] (Polyolefin polyol) Examples of polyolefin polyols include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene.

[0054] (acrylic polyol) Examples of acrylic polyols include those obtained by polymerizing or copolymerizing an acrylic acid ester and / or a methacrylic acid ester (hereinafter referred to as a (meth)acrylic acid ester), an acrylic acid hydroxy compound and / or a methacrylic acid hydroxy compound (hereinafter referred to as a (meth)acrylic acid hydroxy compound), and a polymerization initiator using light energy such as ultraviolet light or an electron beam, or heat energy.

[0055] [(Meth)acrylic acid ester] Examples of (meth)acrylic acid esters include alkyl esters having 1 to 20 carbon atoms. Examples of such (meth)acrylic acid esters include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, and dodecyl (meth)acrylate; esters of (meth)acrylic acid with alicyclic alcohols such as cyclohexyl (meth)acrylate; and (meth)acrylic acid aryl esters such as phenyl (meth)acrylate and benzyl (meth)acrylate. The (meth)acrylic acid esters can be used alone or in combination of two or more.

[0056] [(Meth)acrylic acid hydroxy compound] The (meth)acrylic acid hydroxy compound has at least one hydroxyl group in the molecule that can serve as a reaction site with polyisocyanate. Examples of the (meth)acrylic acid hydroxy compound include acrylic acid hydroxy compounds such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 3-hydroxy-2,2-dimethylpropyl acrylate, and pentaerythritol triacrylate. Methacrylic acid hydroxy compounds such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 3-hydroxy-2,2-dimethylpropyl methacrylate, and pentaerythritol trimethacrylate can also be used. The (meth)acrylic acid hydroxy compound can be used alone or in combination of two or more.

[0057] (Silicone polyol) Examples of silicone polyols include vinyl group-containing silicone compounds obtained by polymerizing γ-methacryloxypropyltrimethoxysilane, and polysiloxanes having at least one terminal hydroxyl group in the molecule, such as α,ω-dihydroxypolydimethylsiloxane and α,ω-dihydroxypolydiphenylsiloxane.

[0058] (Castor oil polyol) Examples of castor oil-based polyols include linear or branched polyester polyols obtained by reacting castor oil fatty acids with polyols. Dehydrated castor oil, partially dehydrated castor oil, and hydrogenated castor oil can also be used.

[0059] (Fluorine-based polyol) Examples of fluorine-containing polyols include linear or branched polyols obtained by copolymerization of a fluorine-containing monomer and a monomer having a hydroxy group as essential components. Here, the fluorine-containing monomer is preferably a fluoroolefin. Examples of fluorine-containing monomers include tetrafluoroethylene, chlorotrifluoroethylene, trichlorofluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, and trifluoromethyltrifluoroethylene. Examples of monomers having a hydroxyl group include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and cyclohexanediol monovinyl ether; hydroxyalkyl allyl ethers such as 2-hydroxyethyl allyl ether; hydroxyl group-containing vinyl carboxylates such as hydroxyalkyl vinyl crotonates; and hydroxyl group-containing allyl esters.

[0060] The number of active hydrogen groups (average number of functional groups) in one molecule of the polyol is preferably 1.9 to 6.0. If the number of active hydrogen groups is within the above range, the resulting urethane resin tends to exhibit better adhesive strength.

[0061] The number average molecular weight of the polyol is preferably in the range of 750 to 50,000. When the number average molecular weight of the polyol is equal to or greater than the lower limit, the adhesiveness tends to be further improved. When the number average molecular weight of the polyol is equal to or less than the upper limit, the solubility in low-polarity organic solvents tends to be further improved, and the adhesiveness tends to be further improved.

[0062] The content ratio of the polyisocyanate composition to the polyol in the polyurethane resin-forming composition is not particularly limited, but the molar ratio R (isocyanate groups / hydroxyl groups) of the isocyanate groups in the polyisocyanate composition to the hydroxyl groups in the polyol is preferably 0.01 to 2.5. When the molar ratio R is equal to or greater than the above-mentioned lower limit, the hydroxyl groups do not become excessive, which tends to further improve adhesion, and also suppresses a decrease in crosslink density, making it easier to improve durability and the mechanical strength of the urethane resin. When the molar ratio R is equal to or less than the above-mentioned upper limit, the isocyanate groups do not become excessive, which suppresses reaction with moisture in the air, which further reduces swelling of the urethane resin and tends to further suppress a decrease in adhesion.

[0063] The polyurethane resin-forming composition may be a one-component composition in which all of the constituent components are contained in one component, or a multi-component composition in which the constituent components are present in multiple components. The multi-component composition may, for example, comprise a first component (base) containing a polyol and a second component (curing agent) consisting of a polyisocyanate composition.

[0064] The polyurethane resin-forming composition may contain a dilution solvent. When the polyurethane resin-forming composition is a multi-component type, the dilution solvent may be contained in either the first or second component, or both. The dilution solvent is, for example, an organic solvent. Examples of the dilution solvent include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, and cellosolve acetate; alcohols such as butanol and isopropyl alcohol; and hydrocarbons such as toluene, xylene, cyclohexane, mineral spirits, and naphtha. The dilution solvent can be appropriately selected and used depending on the purpose and application. The dilution solvent can be used alone or in combination of two or more.

[0065] The polyurethane resin-forming composition may contain a urethanization catalyst. As the urethanization catalyst, a known urethanization catalyst can be used as appropriate, taking into consideration pot life, curing conditions, working conditions, and the like. Specific examples of the urethanization catalyst include organometallic compounds such as dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin dilaurate, and organic amines such as triethylenediamine and triethylamine, or salts thereof. The urethanization catalyst can be used alone or in combination of two or more.

[0066] The polyurethane resin-forming composition may contain additives, as needed, such as antioxidants such as 2,6-di-tert-butyl-4-methylphenol, ultraviolet absorbers, pigments, dyes, solvents, flame retardants, hydrolysis inhibitors, lubricants, plasticizers, fillers, antistatic agents, dispersants, catalysts, storage stabilizers, surfactants, leveling agents, etc. When the polyurethane resin-forming composition is a multi-component type, these additives may be contained in either the first or second component, or in both components.

[0067] The polyurethane resin-forming composition can be suitably used as an adhesive composition.

[0068] <Adhesive composition and laminate structure> An adhesive composition according to one aspect of the present disclosure includes the polyisocyanate composition of the above embodiment and a compound having two or more isocyanate-reactive groups (hereinafter referred to as an isocyanate-reactive compound). Also, a laminate structure according to one aspect of the present disclosure includes a cured product of the above adhesive composition.

[0069] The isocyanate-reactive compound may be a polyol. That is, the adhesive composition may contain the polyurethane resin-forming composition of the above embodiment. The isocyanate-reactive compound may be any compound having two or more isocyanate-reactive groups (e.g., active hydrogen groups), and may be a polyamine, an amino alcohol, or the like.

[0070] The laminate structure has high adhesive strength because the adhesive composition contains the polyisocyanate composition of the above embodiment. The adhesive strength measured in a T-peel test at 23°C is preferably 10 N / 20 mm or more, more preferably 13 N / 20 mm or more, and even more preferably 20 N / 20 mm or more. The adhesive strength measured in a T-peel test can be measured in accordance with JIS K 6854-3.

[0071] The laminated structure includes an adhesive layer and a substrate. The adhesive composition on the substrate is cured to form an adhesive layer containing a cured product. As a result, in the laminated structure, a layer in contact with one side of the adhesive layer (an adherend; which may be a substrate) and a layer in contact with the other side are bonded by the adhesive layer.

[0072] The material of the substrate is not particularly limited, and examples thereof include plastic substrates such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polycarbonate, acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS resin), nylon 6, nylon 66, aramid, acrylic, polyethylene terephthalate, and polybutylene terephthalate; composite materials composed of the above plastic substrates and glass fibers; composite materials of thermosetting resins such as epoxy resins or thermoplastic resins such as polyphenylene sulfide and carbon fibers; metals such as aluminum, aluminum alloys, magnesium, stainless steel, tinplate, electrogalvanized steel sheets, and chrome-plated steel sheets; and glass. These substrates may be used alone, or two or more may be used in combination or as a composite material made by mixing them.

[0073] The method for applying the adhesive composition 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.

[0074] The curing conditions for the adhesive composition are not particularly limited, but preferably the curing temperature is −5 to 300° C., the humidity is 10 to 95% RH, and the curing time is 0.5 to 336 hours.

[0075] The thickness of the adhesive layer formed on the surface of the adherend is not particularly limited, but is preferably 0.05 to 300 μm, more preferably 0.1 to 200 μm, and most preferably 5 to 100 μm. A thickness of 0.05 μm or more provides even better adhesion of the adhesive layer. A thickness of 300 μm or less provides even better productivity, as the time required for drying can be further reduced.

[0076] <Paint composition and coating> The polyurethane resin-forming composition according to one aspect of the present disclosure exhibits good resin properties and can therefore be suitably used as a coating composition. The coating composition includes the polyisocyanate composition of the above embodiment and an isocyanate-reactive compound. The coating film includes a cured product of the coating composition.

[0077] The coating film can be formed by applying the coating composition onto the surface of the substrate by a known method such as spraying, brushing, dipping, or using a coater, and then curing the composition.

[0078] The adherend is not particularly limited, and examples thereof include adherends molded from materials such as stainless steel, phosphate-treated steel, galvanized steel, iron, copper, aluminum, brass, glass, slate, acrylic resin, polycarbonate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene phthalate resin, polystyrene resin, AS resin, ABS resin, polycarbonate-ABS resin, 6-nylon resin, 6,6-nylon resin, MXD6 nylon resin, polyvinyl chloride resin, polyvinyl alcohol resin, polyurethane resin, phenolic resin, melamine resin, polyacetal resin, chlorinated polyolefin resin, polyolefin resin, polyamide resin, polyether ether ketone resin, polyphenylene sulfide resin, NBR resin, chloroprene resin, SBR resin, and SEBS resin; olefin resins such as polyethylene and polypropylene that have been subjected to corona discharge treatment or other surface treatment; and those having an intermediate layer formed on the surface of these.

[0079] The curing conditions for the coating composition are not particularly limited, but preferably the curing temperature is −5 to 150° C., the humidity is 10 to 95% RH, and the curing time is 0.5 to 336 hours.

[0080] The coating film formed on the surface of the adherend has excellent recoatability and durability, so it is sufficient to form a coating film of at least 10 μm on the adherend. A coating film of 10 μm or more improves durability and further prevents the coating film from breaking due to impact. [Example]

[0081] 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.

[0082] Example 1 (Preparation of Polyisocyanate Composition) A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 921 g of 1,4-BDI (1,4-butane diisocyanate, NCO content: 60.0% by mass), and 79 g of 1,3-butanediol (manufactured by Wako Pure Chemical Industries, Ltd.) was added, followed by stirring at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa), yielding 344 g of polyisocyanate composition P-1. The properties of the resulting polyisocyanate composition P-1 are shown in Table 1. In this example, the properties of the polyisocyanate composition were measured by the following methods.

[0083] (Calculation of the average carbon number of the diol) The average carbon number of the diol species used can be calculated by identifying the diol components contained in the polyisocyanate composition and then determining the molar ratio of each diol. Specifically, the chemical structure of the diol is first identified by analyzing the MS spectrum pattern of the decomposition product obtained by pyrolysis GC-MS measurement of the obtained polyisocyanate composition. 1 By measuring H-NMR, the molar ratio of various diols can be calculated. If all of the diol used has reacted, or if it can be assumed that all of the diol has reacted, and the type and amount of the diol used are known, pyrolysis GC-MS measurement, 1 The molar ratios of various diols can be calculated without using H-NMR measurement. In this example, the molar ratios were calculated based on the types and amounts of diols used.

[0084] The average carbon number of the diol was calculated by the following formula. Average number of carbon atoms in n types of diols (units) = (a1 × b1 + a2 × b2 + a3 × b3 + + a n ×b n ) / (b1+b2+b3+···+b n ) [In the formula, a n represents the number of carbon atoms in the nth diol, and b nrepresents the molar ratio of the nth diol.

[0085] (Calculation of Diol Composition Ratio) The composition ratio of the diol species used was determined by identifying the diol components contained in the polyisocyanate composition by pyrolysis GC-MS, in the same way as in the method for calculating the average carbon number of the diol species. 1 By measuring H-NMR, the molar ratio of various diols can be calculated. If all of the diol used has reacted, or if it can be assumed that all of the diol has reacted, and the type and amount of the diol used are known, pyrolysis GC-MS measurement, 1 The molar ratios of various diols can be calculated without using H-NMR measurement. In this example, the molar ratios were calculated based on the types and amounts of diols used.

[0086] (Measurement of the molar ratio of each functional group) The molar ratios of the isocyanurate group, uretdione group, iminooxadiadione group, urethane group, allophanate group, urea group, and biuret group contained in the polyisocyanate composition were determined by the following formula: 13 The carbon content was determined by C-NMR.

[0087] Specifically, first, the polyisocyanate composition was dissolved in deuterated chloroform containing 0.2 mass% of tetramethylsilane to prepare a measurement sample. The sample concentration was 0.2 g / 1 mL mass%. The chemical shift reference was the carbon signal of chloroform at 77.16 ppm. 13 Measurement was performed by C-NMR, and the signal areas of carbon atoms corresponding to isocyanurate groups, uretdione groups, iminooxadiadione groups, urethane groups, allophanate groups, urea groups, and biuret groups were determined, and the molar ratio of each functional group was calculated using the following calculation method. The resonance frequency was 125 MHz, and the number of integrations was 1024. Next, the molar ratio of urethane groups in the butane diisocyanate derivative represented by formula (D) (R D ) was calculated. D / (A+B+C+D+E+F+G)×100...Formula (D) [In the formula, A, B, C, D, E, F, and G represent the molar ratios of the isocyanurate group, the uretdione group, the iminooxadiadione group, the urethane group, the allophanate group, the urea group, and the biuret group, respectively.]

[0088] [Calculation method for the molar ratio of each functional group] Molar ratio of isocyanurate group: A = signal area around 148.7 ppm / 3 Molar ratio of uretdione group: B = signal area around 157.4 ppm / 2 Molar ratio of iminooxadiazinedione group: Signal area around C = 139.3 ppm / 1 Molar ratio of urethane group: D = signal area around 156.6 ppm / 1 Molar ratio of allophanate group: E = signal area around 153.5 ppm / 1 Molar ratio of urea group: F = signal area around 157.5 ppm / 1 Molar ratio of biuret groups: G = signal area around 156.1 ppm / 2

[0089] <Example 2> A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 800 g of 1,4-BDI and heated to 100°C. 4.4 g of hexamethyldisilazane (Tokyo Chemical Industry Co., Ltd.), an isocyanurate catalyst, was added, and the mixture was heated to 160°C and stirred for 3 hours. The mixture was then cooled to 50°C in a water bath, and 2.6 g of ethanol (Wako Pure Chemical Industries, Ltd.), a reaction terminator, was added. The reaction mixture was then stopped at 50°C for 0.5 hours. After cooling, excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa) to obtain 196 g of polyisocyanate composition B-1. A 300 mL three-neck flask equipped with a stirrer and a nitrogen gas inlet tube was charged with 20 g of B-1 and 180 g of P-1, and the mixture was stirred for 0.5 hours to obtain polyisocyanate composition P-2. The properties of the obtained polyisocyanate composition P-2 are shown in Table 1.

[0090] Example 3 A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 800 g of 1,4-BDI and heated to 100°C. 1.1 g of hexamethyldisilazane, an isocyanuration catalyst, was added, and the mixture was heated to 160°C and stirred for 1 hour. The mixture was then cooled to 50°C in a water bath, and 0.7 g of ethanol, a reaction terminator, was added. The reaction was stopped at 50°C for 0.5 hours. 60 g of 1,3-butanediol was then added, and the mixture was stirred at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa) to yield 363 g of polyisocyanate composition P-3. The properties of the resulting polyisocyanate composition P-3 are shown in Table 1.

[0091] Example 4 A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 823 g of 1,4-BDI, and 173 g of batyl alcohol (Tokyo Chemical Industry Co., Ltd.) was added, followed by stirring at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa) to obtain 457 g of polyisocyanate composition P-4. The properties of the resulting polyisocyanate composition P-4 are shown in Table 1.

[0092] <Example 5> A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 921 g of 1,4-BDI, and then 63 g of 1,3-butanediol and 16 g of 1,4-butanediol (Wako Pure Chemical Industries, Ltd.) were added and stirred at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa) to obtain 341 g of polyisocyanate composition P-5. The properties of the resulting polyisocyanate composition P-5 are shown in Table 1.

[0093] Example 6 A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 894 g of 1,4-BDI, and then 27 g of 1,3-butanediol, 24 g of neopentyl glycol (Tokyo Chemical Industry Co., Ltd.), and 55 g of 2,2-bis(4-hydroxycyclohexyl)propane (Tokyo Chemical Industry Co., Ltd.) were added and stirred at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa) to yield 346 g of polyisocyanate composition P-6. The properties of the resulting polyisocyanate composition P-6 are shown in Table 1.

[0094] Example 7 A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 905 g of 1,4-BDI, and then 37 g of 1,3-butanediol and 58 g of 1,4-cyclohexanedimethanol (Tokyo Chemical Industry Co., Ltd.) were added and stirred at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by thin-film distillation (conditions: 110°C, 0.04 kPa) to yield 347 g of Polyisocyanate Composition P-7. The properties of the resulting Polyisocyanate Composition P-7 are shown in Table 1.

[0095] <Comparative Example 1> A 300 mL three-neck flask equipped with a stirrer and a nitrogen gas inlet tube was charged with 110 g of B-1 and 90 g of P-1, and the mixture was stirred for 0.5 hours to obtain polyisocyanate composition P-8. The properties of the obtained polyisocyanate composition P-8 are shown in Table 1.

[0096] <Comparative Example 2> A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 921 g of 1,4-BDI, and 79 g of 1,4-butanediol was added, followed by stirring at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by distillation under reduced pressure (conditions: 110°C, 0.04 kPa), yielding 344 g of Polyisocyanate Composition P-9. The resulting Polyisocyanate Composition P-9 was a white solid, and its properties are shown in Table 1.

[0097] <Comparative Example 3> A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 877 g of 1,4-BDI, and 123 g of 1,10-decanediol (Wako Pure Chemical Industries, Ltd.) was added, followed by stirring at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by distillation under reduced pressure (conditions: 110°C, 0.04 kPa), yielding 390 g of Polyisocyanate Composition P-10. The resulting Polyisocyanate Composition P-10 was a white solid, and its properties are shown in Table 1.

[0098] <Comparative Example 4> A 1-liter four-neck flask equipped with a stirrer, thermometer, condenser, and nitrogen gas inlet tube was charged with 920 g of 1,4-BDI, and 40 g of 1,3-butanediol and 40 g of 1,4-butanediol were added. The mixture was stirred at 80°C for 5 hours. The reaction solution was then cooled, and excess 1,4-BDI was removed by distillation under reduced pressure (conditions: 110°C, 0.04 kPa), yielding 341 g of Polyisocyanate Composition P-11. The resulting Polyisocyanate Composition P-11 was a white solid, and its properties are shown in Table 1.

[0099] <Evaluation> (Handling evaluation) The handleability of the obtained polyisocyanate compositions P-1 to P-11 was confirmed by a solubility test at 25°C. Specifically, first, each of the polyisocyanate compositions P-1 to P-11 was placed in a cylindrical glass container having an inner diameter of 20 mm, and methyl ethyl ketone (manufactured by Maruzen Petrochemical Co., Ltd.) was gradually added as a solvent. The solids concentration at which the polyisocyanate composition was completely dissolved was calculated using the following formula: Solid content concentration [unit: mass %] = total mass of weighed polyisocyanate composition / (total mass of weighed polyisocyanate composition + total mass of methyl ethyl ketone added until the polyisocyanate composition is completely dissolved) × 100 The handleability of the polyisocyanate composition was evaluated according to the following criteria. A higher solids concentration means better handleability. A: Solid content concentration = 50% by mass or more and 100% by mass or less B: Solid content concentration = 20% by mass or more and less than 50% by mass C: Solid content concentration = 0% by mass or more and less than 20% by mass D: Not soluble

[0100] (Adhesion evaluation) Adhesive compositions (two-component adhesive compositions) were prepared from the obtained polyisocyanate compositions P-1 to P-11 and polycarbonate diol, and the obtained adhesive compositions were used to prepare laminate structures with PET films, and the adhesive strength of the obtained test pieces was measured by a T-peel test. Specifically, polycarbonate diol (trade name: Nipporan 965, hydroxyl value: 224 KOH mg / g, functionality: 2, manufactured by Tosoh Corporation) and each of the polyisocyanate compositions P-1 to P-11 were first blended to an equivalent ratio of hydroxyl groups to isocyanate groups of 1.05:1, followed by the addition of 100 ppm of dioctyltin dilaurate (manufactured by Kishida Chemical Industry Co., Ltd.) and thorough mixing. The mixture was then degassed at 25°C and 0.04 kPa for 1 minute to prepare an adhesive composition. The adhesive composition was then applied to a 125 mm thick PET film (trade name: Lumirror Film T60-A4, manufactured by Toray Industries, Inc.) to a thickness of 90 μm and heated at 100°C for 2 minutes. The PET film was then placed on top of the adhesive composition, sandwiching it between the PET films to produce a laminate structure, which was then heat-treated at 80°C for 3 hours. The heat-treated laminate structure was then cured for two days at 23°C and 50% relative humidity to obtain a laminate structure containing a cured adhesive composition. The resulting laminate structure was cut to a width of 20 mm, and the adhesive strength of the test specimens was measured using a tensile tester (product name: Autocom Universal Tester AC-10kN-C, manufactured by TSE Corporation) in accordance with JIS K 6854-3. P-9 and P-10 were difficult to prepare test specimens for because of their poor compatibility with the base resin and poor solubility in organic solvents.

[0101]

Table 1

Claims

1. A butane diisocyanate derivative having at least one functional group selected from an isocyanurate group, a uretdione group, an iminooxadiadione group, a urethane group, an allophanate group, a urea group, and a biuret group, Formula (D): D / (A+B+C+D+E+F+G)×100...Formula (D) [In the formula, A, B, C, D, E, F, and G represent the molar ratios of the isocyanurate group, the uretdione group, the iminooxadiadione group, the urethane group, the allophanate group, the urea group, and the biuret group, respectively.] The molar ratio of the urethane group in the butane diisocyanate derivative (R Ｄ ) is 70 to 100 mol %, the urethane group contains a urethane reaction structure consisting of one or more diol-derived structures and a butane diisocyanate-derived structure, Formula (X): X / (X+Y)×100...Formula (X) [In the formula, X represents the molar ratio of the structure derived from a diol having 3 to 30 carbon atoms other than a linear diol having hydroxyl groups at both ends, and Y represents the molar ratio of the structure derived from a linear diol having 2 to 30 carbon atoms and having hydroxyl groups at both ends.] The butane diisocyanate derivative represented by the formula (I) is a butane diisocyanate derivative having a diol content of 60 to 100 mol %.

2. The molar ratio of the urethane group (R Ｄ 2. The butane diisocyanate derivative according to claim 1, wherein the proportion of methyl isocyanate in the butane diisocyanate derivative is 90 to 100 mol %.

3. The butane diisocyanate derivative according to claim 1, wherein the composition ratio of the diol represented by formula (X) is 95 to 100 mol %.

4. The butane diisocyanate derivative according to claim 1, wherein the one or more diols have an average carbon number of 3 to 10.

5. A polyisocyanate composition comprising the butane diisocyanate derivative according to any one of claims 1 to 4.

6. A polyurethane resin-forming composition comprising the polyisocyanate composition according to claim 5 and a polyol.

7. An adhesive composition comprising the polyisocyanate composition according to claim 5 and a compound having two or more isocyanate-reactive groups.

8. A laminated structure comprising a cured product of the adhesive composition according to claim 7.

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