Adhesive composition, cured product of the adhesive composition and method for producing the adhesive composition

Abstract

An adhesive composition exhibiting good film-forming properties and excellent lightfastness, tensile strength, and elongation at break, a cured product of the adhesive composition, and a method for preparing the adhesive composition are provided. The adhesive composition of the present invention comprises a urethane prepolymer with an isocyanate end group and a polyether-polycarbonate polyol, wherein the polyether-polycarbonate polyol has three or more end groups in one molecule and includes a component derived from an initiator, a component derived from a cyclic ether, and a component derived from carbon dioxide, with the proportion of the component derived from carbon dioxide in one molecule being 10 to 30 wt%.

Description

Technical area

[0001] The present invention relates to an adhesive composition, a cured product of the adhesive composition and a process for producing the adhesive composition. State of the art

[0002] In the fields of automotive, building materials, watercraft, aircraft, and the like, structural adhesives for bonding materials such as resins, glass, metals, or ceramics, and coating agents for the materials have been extensively investigated. Light resistance, good fracture strength, and elongation at break are required for these structural adhesives and coating agents.

[0003] For example, Patent Document 1 discloses a poly(propylene carbonate) polyol composition used for a coating agent, the composition having at least 95% -OH end groups, a glass transition temperature of about -20°C to about 60°C, a polydispersity index of less than 2, a number average molecular weight (Mn) of less than 15 kDa, and more than 95% carbonate linkages between adjacent monomer units in the polycarbonate chains, and it is stated that the poly(propylene carbonate) polyol composition is excellent in light resistance, breaking strength, and elongation at break.

[0004] Patent Document 2 discloses a two-component urethane-based adhesive composition comprising: a main agent comprising a urethane prepolymer having an isocyanate group; and a curing agent comprising a specific polyol compound having ethylene oxide at one end and having three active hydrogen-containing groups in one molecule, that is, being trifunctional. It is stated that the two-component urethane-based adhesive composition has excellent initial adhesion and long-term adhesion. Document listPatent documents Patent Document 1: JP 2013-543929 A Patent document 2: WO 2019 / 240046 A Summary of the inventionTechnical problem

[0005] However, the poly(propylene carbonate) polyol composition described in Patent Document 1 has problems of high viscosity and poor heat stability, and also has a problem of poor film-forming ability when used with a urethane resin. The two-component urethane-based adhesive composition described in Patent Document 2 has insufficient light resistance and needs improvement.

[0006] The present invention is intended to solve such problems, and an object of the present invention is to provide an adhesive composition having good film-forming ability and excellent in light resistance, breaking strength, and breaking elongation of a cured product, a cured product of the adhesive composition, and a process for producing the adhesive composition. Solution to the problem

[0007] The present inventors conducted diligent research to solve the problem and, as a result, found that the problems can be solved by an adhesive composition comprising an isocyanate-terminated urethane prepolymer and a polyether-polycarbonate polyol having a specific structure. Thus, the present inventors completed the present invention. Specifically, the present invention is as follows.

[0008] [1] An adhesive composition comprising: an isocyanate group-terminated urethane prepolymer; and a polyether-polycarbonate polyol, wherein the polyether-polycarbonate polyol has three or more end groups in one molecule and has a constituent unit derived from an initiator, a constituent unit derived from a cyclic ether, and a constituent unit derived from carbon dioxide, and a proportion of the constituent unit derived from carbon dioxide in one molecule is 10 to 30 mass%.

[0009] [2] Adhesive composition according to [1], wherein a hydroxyl number equivalent molecular weight of the polyether-polycarbonate polyol is 500 to 20,000.

[0010] [3] The adhesive composition according to [1] or [2], wherein a molecular weight distribution (Mw / Mn) of the polyether-polycarbonate polyol, expressed by a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is 1.05 to 3.00.

[0011] [4] The adhesive composition according to any one of [1] to [3], wherein the proportion of a constituent unit in which the constituent unit derived from carbon dioxide, the constituent unit derived from a cyclic ether, and the constituent unit derived from carbon dioxide are chain-arranged in this order in the polyether-polycarbonate polyol is 2 mass% or more.

[0012] [5] The adhesive composition according to any one of [1] to [4], wherein the constituent unit derived from a cyclic ether of the polyether-polycarbonate polyol is at least one constituent unit selected from the group consisting of a constituent unit derived from ethylene oxide and a constituent unit derived from propylene oxide.

[0013] [6] Adhesive composition according to any one of [1] to [5], wherein the end groups of the polyether-polycarbonate polyol are hydroxyl groups.

[0014] [7] The adhesive composition according to any one of [1] to [6], wherein a hundredfold molar ratio of isocyanate groups in the isocyanate group-terminated urethane prepolymer to hydroxyl groups in the polyether-polycarbonate polyol is 80 or more and 150 or less.

[0015] [8] The adhesive composition according to any one of [1] to [7], wherein a content of the polyether-polycarbonate polyol is 10 to 70 mass% based on a total amount of the adhesive composition.

[0016] [9] The adhesive composition according to any one of [1] to [8], further comprising a chain extender.

[0017]

[10] A cured product obtained by curing the adhesive composition according to any one of [1] to [9].

[0018]

[11] A process for preparing an adhesive composition comprising an isocyanate-terminated urethane prepolymer and a polyether-polycarbonate polyol, the process comprising: Polymerizing an initiator having three or more active hydrogen-containing groups in one molecule, a cyclic ether, and carbon dioxide in the presence of a catalyst to obtain a polyether-polycarbonate polyol; and mixing the polyether-polycarbonate polyol and an isocyanate-terminated urethane prepolymer, wherein a proportion of a constituent unit derived from carbon dioxide in one molecule of the polyether-polycarbonate polyol is 10 to 30 mass%.

[0019]

[12] A process for producing an adhesive composition according to

[11] , wherein the catalyst comprises at least one selected from the group consisting of a metal cyanide composite complex catalyst and a metal salen complex catalyst.

[0020]

[13] The method for producing an adhesive composition according to

[11] or

[12] , wherein the isocyanate group-terminated urethane prepolymer is a reaction product obtained by reacting a polyol and a polyisocyanate compound such that a 100-fold molar ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the polyol is 110 or more and 600 or less. Advantageous effects of the invention

[0021] According to the present invention, there can be provided an adhesive composition which has good film-forming ability and is excellent in light resistance, breaking strength and elongation at break of a cured product, and there can be provided a cured product of the adhesive composition and a process for producing the adhesive composition. Description of embodiments

[0022] The present invention will be described in detail below.

[0023] As used herein, those considered preferred may be employed where appropriate, and combinations of preferred ones may be expected to be more preferred.

[0024] As used herein, the description of “XX to YY” means “XX or more and YY or less”.

[0025] As used herein, for preferred numerical value ranges (e.g., content ranges), lower limits and upper limits described in stages can each be combined independently. For example, based on the description of "preferably 10 to 90, more preferably 30 to 60," "the preferred lower limit (10)" and "the more preferred upper limit (60)" can also be combined to "10 to 60." In the numerical value ranges described here, the upper limits or lower limits of the numerical value ranges can be replaced with values ​​shown in the examples.

[0026] As used herein, a “unit” constituting a polymer means a group of atoms formed by the polymerization of a monomer.

[0027] As used herein, an end group includes not only a functional group at the end of a main chain of a polymer, but also a functional group at the end of a branched chain equivalent to a main chain. <haftmittelzusammensetzung>

[0028] The present invention is an adhesive composition comprising: an isocyanate group-terminated urethane prepolymer; and a polyether-polycarbonate polyol, wherein the polyether-polycarbonate polyol has three or more terminal groups in one molecule and has a constituent unit derived from an initiator, a constituent unit derived from a cyclic ether, and a constituent unit derived from carbon dioxide, and a proportion of the constituent unit derived from carbon dioxide in one molecule is 10 to 30 mass%.

[0029] The adhesive composition of the present invention exhibits good film-forming ability and is excellent in light resistance, breaking strength, and elongation at break of a cured product thereof. Each component is described below. [Urethane prepolymer with isocyanate group end]

[0030] An "isocyanate group-terminated urethane prepolymer" is a compound having an isocyanate group at least at a part of the ends of the molecular chain, which is obtained by reacting a polyisocyanate compound with a compound having two or more active hydrogen-containing groups in one molecule (hereinafter referred to as "active hydrogen compound").

[0031] The isocyanate-terminated urethane prepolymer is obtained by reacting a polyisocyanate compound with a compound containing active hydrogen such that the isocyanate groups are present in excess of the active hydrogen-containing groups. Examples of the active hydrogen-containing groups include a hydroxyl group, an amino group, and an imino group.

[0032] Examples of such an active hydrogen compound include polyols having two or more hydroxyl groups in one molecule and polyamines having two or more amino groups in one molecule, and the active hydrogen compound is preferably a polyol. (Polyol)

[0033] The number-average molecular weight (Mn) of the polyol is preferably 1,000 to 50,000, more preferably 3,000 to 30,000, considering that the viscosity of the isocyanate group-terminated urethane prepolymer obtained by reaction with a polyisocyanate compound has moderate fluidity at room temperature (25°C). In the present invention, the Mn is a value obtained by the same method as the method for measuring the Mn of the polyether-polycarbonate polyol described later. When the Mn of the polyol is within the above range, the light resistance, breaking strength, and elongation at break of a cured product obtained by curing the adhesive composition of the present invention are easily made good.

[0034] When the polyol is a compound having two or more hydroxyl groups, the molecular weight, backbone, and the like thereof are not specifically limited. Examples of the polyol include polyether polyols, polyester polyols, polymer polyols, poly(meth)acrylic polyols, polycarbonate polyols, castor oil-based polyols, and polyolefin polyols, and those described in

[0016] to

[0028] of JP 2020-37689 A can be used without any specific limitation. One type of these can be used alone, or two or more of them can be used in combination.

[0035] As the polyol, a polymer polyol in which a polymer having a (meth)acrylate monomer-based unit is dispersed in a polyether polyol can also be used. The polymer polyol can be a commercially available product, and examples include the "ULTIFLOW (registered trademark)" series and the "SHARPFLOW (registered trademark)" series (the above are manufactured by Sanyo Chemical Industries, Ltd.), as well as the "EXCENOL (registered trademark)" series (manufactured by AGC).

[0036] Furthermore, a polyether-polycarbonate polyol having three or more end groups in one molecule described later may be used.

[0037] As used here, (meth)acrylic means acrylic and / or methacrylic and (meth)acrylate means acrylate and / or methacrylate. (polyisocyanate compound)

[0038] The polyisocyanate compound used to prepare the isocyanate-terminated urethane prepolymer is an organic compound containing two or more isocyanate groups in one molecule. The number of isocyanate groups in one molecule is preferably 2 to 4. One polyisocyanate compound can be used alone, or two or more polyisocyanate compounds can be used in combination.

[0039] Examples of the polyisocyanate compound include straight-chain or branched aliphatic diisocyanate compounds such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate and 3-methylpentane-1,5-diisocyanate; alicyclic diisocyanate compounds, such as norbornane diisocyanate (NBDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane and dicyclohexylmethane diisocyanate (H 12 MDI); aromatic diisocyanate compounds, such as tolylene diisocyanate (TDI), 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, polymethylenepolyphenylene polyisocyanate, xylylene diisocyanate, α,α,α',α'-tetramethylxylylene diisocyanate, 4,4'-dibenzyl diisocyanate, tolidine diisocyanate, 1,5-naphthalene diisocyanate, dialkyldiphenylmethane diisocyanate and tetraalkyldiphenylmethane diisocyanate; and Polyisocyanate compounds having three or more isocyanate groups in one molecule, such as isocyanurate-modified products of the above-described diisocyanate compounds; biuret-modified products of the above-described diisocyanate compounds; allophanate-modified products of the above-described diisocyanate compounds; carbodiimide-modified products of the above-described diisocyanate compounds; tri- and higher-functional isocyanate-terminated urethane prepolymers (adduct-modified products) obtained by reacting the above-described diisocyanate compounds with polyols having three or more hydroxyl groups in one molecule; water-dispersible polyisocyanate compounds, such as water-dispersible isocyanates and block isocyanates; and triphenylmethane triisocyanate.

[0040] Examples of commercially available isocyanurate-modified products include DURANATE TPA-100 and DURANATE TKA-100 (both manufactured by Asahi Kasei Corporation) and Coronate HX (manufactured by Tosoh Corporation).

[0041] Examples of commercially available biuret-modified products include DURANATE 24A-100 and DURANATE 22A-75P (both manufactured by Asahi Kasei Corporation).

[0042] Examples of commercially available products of the tri- and higher functional isocyanate-terminated urethane prepolymer include Coronate L, Coronate L-55E, and Coronate L-45E (all manufactured by Tosoh Corporation).

[0043] Examples of commercially available water-dispersible isocyanates include DURANATE WB40-100, DURANATE WB40-80D, DURANATE WT20-100, DURANATE WL70-100, DURANATE WE50-100, and DURANATE WR80-70P (all manufactured by Asahi Kasei Corporation), and Aquanate 105, Aquanate 130, Aquanate 140, Aquanate 200, and Aquanate 210 (all manufactured by Tosoh Corporation).

[0044] Examples of commercially available block isocyanate products include SU-268A, NBP-211, MEIKANATE CX, MEIKANATE TP-10, and DM-6400 (all manufactured by Meisei Chemical Works, Ltd.); WM44-L70G (manufactured by Asahi Kasei Corporation); Aqua BI200 and Aqua BI220 (all manufactured by Baxenden Chemicals); TAKELAC W and TAKELAC WPB (all manufactured by Mitsui Chemicals, Inc.); BURNOCK (manufactured by DIC CORPORATION); and ELASTRON (manufactured by Daiichikogyo Co., Ltd.).

[0045] The content of isocyanate groups in the polyisocyanate compound is preferably 20 mass% or more, more preferably 25 mass% or more, more preferably 30 mass% or more, and preferably 50 mass% or less, more preferably 45 mass% or less, and still more preferably 40 mass% or less, from the viewpoint of obtaining an adhesive composition excellent in the reactivity of the polyisocyanate compound with the compound having active hydrogen and excellent in the light resistance, the breaking strength, and the breaking elongation of a cured product.

[0046] Preferred specific examples of the polyisocyanate compound containing isocyanate groups in the preferred range are aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, and aromatic diisocyanate compounds, and include MDI (isocyanate group content 33.6 mass%), polymeric MDI (isocyanate group content 31.0 mass%), crude MDI (a mixture of MDI and triphenylmethane triisocyanate, isocyanate group content 30.0 to 32.6 mass%), and IPDI (isocyanate group content 37.8 mass%).

[0047] When the isocyanate group-terminated urethane prepolymer is obtained, 100 times the molar ratio of the isocyanate groups in the polyisocyanate compound to the hydroxyl groups in the polyol (isocyanate group / hydroxyl group) is preferably 110 or more and 600 or less.

[0048] Such a molar ratio is preferably 120 or more, more preferably 125 or more, more preferably 130 or more, and preferably 500 or less, more preferably 450 or less, and even more preferably 400 or less. When the molar ratio is within the preferred range, an isocyanate group-terminated urethane prepolymer with a moderate molecular chain length can be produced, and therefore, productivity improves more. The molar ratio within the preferred range is also preferred from the viewpoint of further improving the light resistance, breaking strength, and elongation at break of a cured product obtained by curing the adhesive composition of the present invention.

[0049] The isocyanate-terminated urethane prepolymer can be prepared by reacting a polyol with a polyisocyanate compound.

[0050] To prepare the isocyanate-terminated urethane prepolymer, a catalyst may optionally be used. Examples of the catalyst include tertiary amine-based compounds, tin-based compounds, and non-tin-based compounds. A catalyst may be used alone, or two or more catalysts may be used in combination.

[0051] Examples of tertiary amine-based compounds include triethylamine, triethylenediamine, and 1,8-diazabicyclo[5.4.0]-7-undecene (DBU).

[0052] Examples of the tin-based compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate and tin 2-ethylhexanoate.

[0053] Examples of the non-tin-based compounds include titanium-based compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride; lead-based compounds such as lead oleate, lead 2-ethylhexanoate, lead zoate, and lead naphthenate; iron-based compounds such as iron 2-ethylhexanoate and iron acetylacetonate; cobalt-based compounds such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc-based compounds such as zinc naphthenate and zinc 2-ethylhexanoate; and zirconium-based compounds such as zirconium naphthenate.

[0054] The amount of the catalyst used when the catalyst is used is preferably 0.001 part by mass or more, more preferably 0.002 part by mass or more, and even more preferably 0.003 part by mass or more, and preferably 1.0 part by mass or less, more preferably 0.2 part by mass or less, and even more preferably 0.05 part by mass or less, based on 100 parts by mass of the total amount of the polyol and the polyisocyanate compound.

[0055] A solvent may optionally be used to prepare the isocyanate-terminated urethane prepolymer.

[0056] Examples of solvents include ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; and aromatic hydrocarbons such as toluene and xylene. One solvent may be used alone, or two or more solvents may be used in combination.

[0057] The amount of the solvent used when the solvent is used is preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and even more preferably 50 parts by mass or more, and preferably 500 parts by mass or less, more preferably 450 parts by mass or less, and even more preferably 400 parts by mass or less based on 100 parts by mass of the total amount of the polyol and the polyisocyanate compound.

[0058] Examples of the process for producing the isocyanate group-terminated urethane prepolymer include the processes described below.

[0059] Manufacturing method 1: A method of incorporating a polyol, a polyisocyanate compound, an optional catalyst and an optional solvent

[0060] Preparation method 2: A method of introducing a polyol, an optional catalyst and an optional solvent and adding a polyisocyanate compound dropwise to these

[0061] In the case of preparation method 2, the low molecular weight components in the starting materials are preferentially converted, the molecular weight distribution can be narrowed more, and the reaction can be easily controlled.

[0062] The reaction temperature is preferably 50°C or more, more preferably 60°C or more, even more preferably 65°C or more and less than 100°C, more preferably 95°C or less, and even more preferably 85°C or less. When the reaction temperature is within this range, side reactions other than the urethane reaction are easily prevented, and therefore, the desired isocyanate group-terminated urethane prepolymer is easily obtained.

[0063] After the reaction is complete, a reaction terminator can be added to deactivate the catalyst. Examples of the reaction terminator include acetylacetone. Two or more reaction terminators can be used in combination.

[0064] The content of the isocyanate group-terminated urethane prepolymer is preferably 30 to 90 mass%, more preferably 35 to 80 mass%, and even more preferably 40 to 70 mass%, based on the total amount of the adhesive composition. When the content of the isocyanate group-terminated urethane prepolymer is greater than or equal to the lower limit, the fracture strength of the cured product obtained by curing the adhesive composition of the present invention becomes good, and when it is less than or equal to the upper limit, the elongation properties of the cured product obtained by curing the adhesive composition of the present invention become good. [Polyether Polycarbonate Polyol]

[0065] The polyether-polycarbonate polyol has three or more end groups in one molecule and has a constituent unit derived from an initiator, a constituent unit derived from a cyclic ether, and a constituent unit derived from carbon dioxide.

[0066] If the polyether-polycarbonate polyol has fewer than three terminal groups in one molecule, the light resistance, breaking strength, and elongation at break of a cured product obtained by curing the adhesive composition of the present invention may decrease. In this regard, it is preferable that the polyether-polycarbonate polyol has four or more terminal groups in one molecule. The polyether-polycarbonate polyol preferably has 10 or fewer terminal groups, and more preferably 8 or fewer terminal groups, in one molecule from the viewpoint of enabling prevention of high viscosity caused by the hydrogen bond of the hydroxyl group, ease of handling in curing the adhesive composition of the present invention, and ease of coating.

[0067] The three or more end groups in a molecule of the polyether-polycarbonate polyol are preferably active hydrogen-containing groups. Examples of the active hydrogen-containing group include a hydroxyl group, a carboxyl group, and an amino group having a hydrogen atom bonded to a nitrogen atom. The active hydrogen-containing group is preferably a hydroxyl group.

[0068] The hydroxyl value equivalent molecular weight of the polyether-polycarbonate polyol is preferably 500 to 20,000, more preferably 700 to 15,000, even more preferably 800 to 10,000, and even more preferably 900 to 8,000. When the hydroxyl value equivalent molecular weight is 500 or more, the elongation at break of the cured product obtained by the adhesive composition of the present invention becomes even better, and when the hydroxyl value equivalent molecular weight is 20,000 or less, the light resistance, the breaking strength, and the elongation at break of the cured product obtained by curing the adhesive composition of the present invention become even better.

[0069] The hydroxyl value equivalent molecular weight of the polyether-polycarbonate polyol is the molecular weight calculated using the value obtained by substituting the hydroxyl value calculated according to JIS K 1557 (2007) into the formula [56100 / (hydroxyl value)] × (number of functional groups). Specifically, it is measured by the method described in the examples described later.

[0070] The number average molecular weight (Mn) of the polyether-polycarbonate polyol is preferably 750 to 30,000, more preferably 1,000 to 22,000, even more preferably 1,200 to 15,000, and even more preferably 1,300 to 12,000. When the number average molecular weight is 750 or more, the elongation at break of the cured product obtained by curing the adhesive composition of the present invention becomes even better, and when the number average molecular weight is 30,000 or less, the light resistance, the breaking strength, and the elongation at break of the cured product obtained by curing the adhesive composition of the present invention become even better.

[0071] The molecular weight distribution (Mw / Mn) represented by the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the polyether-polycarbonate polyol is preferably 1.05 to 3.00, more preferably 1.07 to 2.50, and even more preferably 1.10 to 2.00, in view of further improving light resistance, breaking strength, and elongation at break of the cured product obtained by curing the adhesive composition of the present invention.

[0072] The Mn and molecular weight distribution of the polyether-polycarbonate polyol are values ​​obtained by measurement by the method described below.

[0073] For various types of monodisperse polystyrene with different polymerization degrees as standard samples for molecular weight measurement, a measurement is performed using a commercially available GPC instrument (HLC-8320GPC, manufactured by Tosoh Techno-System, Inc.), and a calibration curve is constructed based on the relationship between the molecular weight and retention time of the polystyrene. The polyether polycarbonate polyol, which is a measurement sample, is diluted to 0.5 mass% with tetrahydrofuran and passed through a filter with a pore diameter of 0.5 μm. Then, a measurement is performed on the measurement sample using the GPC instrument. The GPC spectrum of the measurement sample is subjected to computer analysis using the calibration curve, so that the Mn and Mw of the measurement sample are obtained.

[0074] The molecular weight distribution is the value calculated from the Mw and the Mn and is the ratio of Mw to Mn ("Mw / Mn").

[0075] The proportion of the constituent unit derived from carbon dioxide (proportion of CO2) in one molecule of the polyether-polycarbonate polyol is 10 to 30 mass%. If the proportion of the constituent unit derived from carbon dioxide is less than 10 mass%, the light resistance, breaking strength, and elongation at break of the cured product obtained by curing the adhesive composition of the present invention may decrease. If the proportion of the constituent unit derived from carbon dioxide exceeds 30 mass%, the viscosity becomes too high and the workability becomes poor, and the film-forming ability of the adhesive composition of the present invention may decrease. In view of this, the proportion of the constituent unit derived from carbon dioxide is preferably 11 to 28 mass%, more preferably 12 to 26 mass%.The proportion of the constituent unit derived from carbon dioxide is measured by the method described in Examples described later.

[0076] The proportion of a constituent unit derived from carbon dioxide, the constituent unit derived from a cyclic ether, and the constituent unit derived from carbon dioxide arranged in this order in a chain manner (hereinafter also referred to as CO2-AO-CO2 chain) in the polyether-polycarbonate polyol is preferably 2 mass% or more, more preferably 2.5 mass% or more, and even more preferably 2.6 mass% or more from the viewpoint that the light resistance, the breaking strength, and the breaking elongation of the cured product obtained by curing the adhesive composition of the present invention become further better.The proportion of the CO2-AO-CO2 chain is preferably 50 mass% or less, more preferably 40 mass% or less, even more preferably 30 mass% or less, and still more preferably 20 mass% or less, from the viewpoint of further improving the heat stability of the polyether-polycarbonate polyol and the film-forming ability of the adhesive composition of the present invention.

[0077] The proportion of a constituent unit in which the constituent unit derived from a cyclic ether, the constituent unit derived from a cyclic ether, and the constituent unit derived from a cyclic ether are chain-arranged in this order (hereinafter also referred to as AO-AO-AO chain) in the polyether-polycarbonate polyol is preferably 30 to 80 mass%, more preferably 35 to 75 mass%, still more preferably 40 to 75 mass%, and still more preferably 40 to 72 mass%, from the viewpoint of better exerting the effect of the present invention.

[0078] The proportion of a constituent unit in which the constituent unit derived from a cyclic ether, the constituent unit derived from a cyclic ether, and the constituent unit derived from carbon dioxide are chain-arranged in this order (hereinafter also referred to as AO-AO-CO2 chain) in the polyether-polycarbonate polyol is preferably 8 to 60 mass%, more preferably 15 to 55 mass%, and even more preferably 20 to 50 mass%, from the viewpoint of better exerting the effect of the present invention.

[0079] The proportion of the CO2-AO-CO2 chain, the proportion of the AO-AO-AO chain and the proportion of the AO-AO-CO2 chain in a polyether-polycarbonate polyol can be determined, for example, when the cyclic ether AO is propylene oxide PO, by dissolving the polyether-polycarbonate polyol in deuterochloroform to obtain 10 mass%, measuring the 1 H-NMR was measured using an NMR device at a resolution of 400 MHz, and the area ratio of the methyl group-derived 3H peak (δ1.34 ppm) of propylene oxide PO as a cyclic ether AO, with both ends adjacent to carbonate, the methyl group-derived 3H peak (δ1.29 ppm) of PO, with one end adjacent to carbonate and the other end adjacent to PO, and the methyl group-derived 3H peak (δ1.14 ppm) of PO, with both ends adjacent to PO, were calculated from the obtained results. Specifically, the proportions can be measured by the method described in Examples.

[0080] The proportion of the constituent unit derived from carbon dioxide can be calculated based on the area ratio described above.

[0081] The total content of the constituent unit derived from an initiator, the constituent unit derived from a cyclic ether, and the constituent unit derived from carbon dioxide in the polyether-polycarbonate polyol may preferably be 80 mass% or more, more preferably 90 mass% or more, even more preferably 95 mass% or more and 100 mass%. The polyether-polycarbonate polyol may consist only of the constituent unit derived from an initiator, the constituent unit derived from a cyclic ether, and the constituent unit derived from carbon dioxide. (Initiator)

[0082] The initiator constituting the initiator-derived constituent unit of the polyether-polycarbonate polyol preferably has three or more active hydrogen-containing groups in one molecule from the viewpoint of making the cured product obtained by curing the adhesive composition of the present invention excellent in light resistance, breaking strength, and elongation at break. Examples of the active hydrogen-containing group include a hydroxyl group, a carboxyl group, and an amino group having a hydrogen atom bonded to a nitrogen atom. The active hydrogen-containing group is preferably a hydroxyl group.

[0083] The initiator has, in view of enabling prevention of high viscosity caused by the hydrogen bonding of the hydroxyl group, easy handling of curing of the adhesive composition of the present invention, and easy coating, more preferably 4 or more active hydrogen-containing groups in one molecule, and preferably 10 or less, more preferably 8 or less active hydrogen-containing groups in one molecule.

[0084] The initiator preferably has 3.0 mol or less, more preferably 2.5 mol or less, still more preferably 2.0 mol or less of constituent units derived from a cyclic ether per molecule, or may have 0.0 mol thereof, in view of better light resistance of the cured product obtained by curing the adhesive composition of the present invention.

[0085] The initiator may be a polyol without constituent units derived from a cyclic ether.

[0086] When the initiator comprises a constituent unit derived from a cyclic ether, the constituent unit derived from a cyclic ether is preferably a constituent unit derived from ethylene oxide or a constituent unit derived from propylene oxide from the viewpoint of making the cured product obtained by curing the adhesive composition of the present invention more flexible.

[0087] The number-average molecular weight (Mn) of the initiator is preferably 40 to 3000, more preferably 40 to 2000, even more preferably 55 to 2000, and even more preferably 60 to 1500. In the present invention, the Mn is a value obtained by the same method as the above-described method for measuring the Mn of the polyether-polycarbonate polyol. When the Mn of the initiator is within the above range, the initiator can be widely selected according to the required properties of the cured product using the polyol consisting of the initiator, and a sufficient amount of CO2 can be introduced.

[0088] Specific examples of the initiator include trihydric or higher polyhydric alcohols such as glycerin, polyglycerin, trimethylolethane, trimethylolpropane, diglycerin, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, sorbitol, dextrose, fructose, sucrose, methyl glucoside, and sugars or derivatives thereof other than those described above. The above initiator also includes various optical isomers. Examples thereof also include polyether polyols having a hydroxyl value equivalent molecular weight of 50 to 8000, which are obtained by reacting them with a small amount of an alkylene oxide. (Cyclic ether)

[0089] In a cyclic ether constituting the constituent unit derived from a cyclic ether of the polyether-polycarbonate polyol, the number of carbon atoms constituting the ring of the cyclic ether is preferably 2 to 10, more preferably 2 to 6, and more preferably 2 to 4. The carbon atom constituting the ring of the cyclic ether may have a substituent, and examples of the substituent include an alkyl group having 1 to 4 carbon atoms, a halogen atom, and a hydroxyl group.

[0090] Examples of the cyclic ether include cyclic ethers in which the number of carbon atoms forming the ring is 2, such as ethylene oxide, propylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide. One type of these can be used alone, or two or more of them can be used in combination.

[0091] The constituent unit derived from the cyclic ether of the polyether-polycarbonate polyol is preferably at least one constituent unit selected from the group consisting of a constituent unit derived from ethylene oxide and a constituent unit derived from propylene oxide, and more preferably, from the viewpoint of making the cured product obtained by curing the adhesive composition of the present invention more flexible, it is a constituent unit derived from propylene oxide.

[0092] Examples of the polyether-polycarbonate polyol include a polyhydric polyether-polycarbonate polyol represented by the following general formula (X), as long as it has a constituent unit derived from an initiator, a constituent unit derived from a cyclic ether, and a constituent unit derived from carbon dioxide.

[0093] In the general formula (X), W represents a q-valent organic group, where q is 3 to 10; and R 2 represents a divalent hydrocarbon group having 2 to 10 carbon atoms, where m is 1 to 150 and n is 1 to 60. In the general formula (X), a plurality of R 2 be the same or different, a plurality of n can be the same number or different numbers and a plurality of m can be the same number or different numbers.

[0094] For example, in the general formula (X), when q is 3, W represents a trivalent organic group and the number of hydroxyl groups at the end of the general formula (X) is 3.

[0095] Examples of the q-valent organic group include a q-valent aliphatic hydrocarbon group having 2 to 12 carbon atoms and an aliphatic chain; a q-valent alicyclic hydrocarbon group having 3 to 12 carbon atoms and an alicyclic structure; a q-valent aromatic hydrocarbon group having 6 to 24 carbon atoms and an aromatic ring structure; a q-valent heterocyclic group having a heterocyclic structure containing a heteroatom such as an oxygen atom, a nitrogen atom or a sulfur atom; and trivalent or higher polyhydric alcohols such as glycerin, polyglycerin, trimethylolethane, trimethylolpropane, diglycerin, pentaerythritol, dipentaerythritol, tripentaerythritol glucose, sorbitol, dextrose, fructose, sucrose, methyl glucoside and sugars or derivatives thereof other than those described above. The above initiator also includes various optical isomers.Examples thereof also include residues excluding hydroxyl groups of one selected from the group consisting of polyether polyols having a hydroxyl value equivalent molecular weight of 50 to 8,000, which are obtained by reacting them with a small amount of an alkylene oxide. Of these, the q-valent organic group is preferably a residue excluding hydroxyl groups of one selected from the group consisting of tri- or higher-valent polyhydric alcohols, sugars, and polyether polyols having a hydroxyl value equivalent molecular weight of 50 to 8,000, and more preferably, in view of easy polymerizability of the cyclic ether, a residue excluding hydroxyl groups of one selected from the group consisting of glycerin, trimethylolpropane, diglycerin, pentaerythritol, dipentaerythritol, and sorbitol.

[0096] These organic groups may further have a substituent. Examples of the substituent that the organic group may have include a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a carbonyl group, a formyl group, an ester group, an amide group, an alkoxy group, an alkylthio group, an arylthio group, an amino group, and a silyl group.

[0097] R 2 is preferably a straight-chain or branched alkylene group having 2 to 6 carbon atoms, more preferably a tetramethylene group, a propylene group or an ethylene group, and even more preferably a propylene group or an ethylene group.

[0098] q is preferably 3 to 10, more preferably 3 to 8, and even more preferably 4 to 8, from the viewpoint of enabling prevention of high viscosity caused by hydrogen bonding of the hydroxyl group, ease of handling in curing the adhesive composition of the present invention, and ease of coating.

[0099] n is preferably 1 to 60, more preferably 2 to 55, and more preferably 3 to 45, from the viewpoint of improving the breaking strength, elongation at break, and light resistance of the cured product.

[0100] m is preferably 1 to 150, more preferably 2 to 135, and more preferably 3 to 120 in view of ease of handling due to the low viscosity of the polymer.

[0101] In the polyether-polycarbonate polyol represented by the above general formula (X), a structure represented by (-OC(=O)-OC(CH3)-CH2-) n shown, adjacent to W, and a structure formed by (-OR 2 -) m is formed at one end of the structure represented by (-OC(=O)-OC(CH3)-CH2-) n However, the polyether-polycarbonate polyol is not limited to this, and for example, a structure represented by (-OR 2 -) m shown, adjacent to W.

[0102] In addition, a structural unit of (-OR 2 -) be inserted into the structure represented by (-OC(=O)-OC(CH3)-CH2-) n and a structural unit of (-OC(=O)-OC(CH3)-CH2-) can be inserted into the structure represented by (-OR 2 -) m is shown.

[0103] If R 2 in (-OR 2 -) m different types, the structure represented by (-OR 2 -) m shown can be either a statistical structure or a block structure.

[0104] The hydroxyl value of the polyether-polycarbonate polyol is preferably 8 mg KOH / g or more, more preferably 16 mg KOH / g or more, and even more preferably 22 mg KOH / g or more, and preferably 900 mg KOH / g or less, more preferably 700 mg KOH / g or less, and even more preferably 340 mg KOH / g or less. When the hydroxyl value of the polyether-polycarbonate polyol is equal to or less than the upper limit, the light resistance, breaking strength, and elongation at break of a cured product of the resulting adhesive composition are likely to improve.

[0105] The hydroxyl value of polyether polycarbonate polyol is a value measured and calculated according to the B method of JIS K 1557-1: 2007.

[0106] The viscosity of the polyether-polycarbonate polyol at 25°C is preferably 150,000 mPa s or less, more preferably 120,000 mPa s or less, and even more preferably 100,000 mPa s or less. When the viscosity of the polyether-polycarbonate polyol at 25°C is less than or equal to the upper limit, the light resistance, fracture strength, and elongation at break of a cured product of the resulting adhesive composition are slightly improved.

[0107] The viscosity of the polyether-polycarbonate polyol at 25 °C is a value measured with an E-type viscometer. Specifically, the viscosity is measured by the method described in the examples described later.

[0108] The content of the polyether-polycarbonate polyol is preferably 10 to 70 mass%, more preferably 15 to 60 mass%, and even more preferably 20 to 50 mass%, based on the total amount of the adhesive composition. When the content of the polyether-polycarbonate polyol is greater than or equal to the lower limit, the light resistance, breaking strength, and elongation at break of a cured product of the resulting adhesive composition become better, and when it is less than or equal to the upper limit, the elongation at break of the cured product obtained by curing the adhesive composition of the present invention becomes even better. [Process for producing the polyether-polycarbonate polyol]

[0109] The polyether-polycarbonate polyol is obtained by polymerizing an initiator having three or more active hydrogen-containing groups in one molecule, a cyclic ether and carbon dioxide in the presence of a catalyst.

[0110] The initiator may be an initiator described in the section (Initiator) and the cyclic ether may be a cyclic ether described in the section (Cyclic Ether).

[0111] Ring-opening addition polymerization, when two or more cyclic ethers are reacted with an initiator and carbon dioxide, can be a random polymerization, a bulk polymerization, or a combination of a random polymerization and a bulk polymerization.

[0112] Preferred examples of the catalyst include metal cyanide composite complex catalysts (hereinafter may be referred to as "DMC catalysts") such as TBA-based metal cyanide composite complex catalysts; metal-salen complex catalysts such as cobalt-salen-based catalysts; alkali catalysts such as sodium hydroxide, potassium hydroxide, and cesium hydroxide; Ziegler-Natta catalysts composed of organic aluminum compounds and transition metal compounds; porphyrin-metal coordination catalysts as complexes obtained by reacting porphyrin; phosphazene catalysts; imino group-containing phosphazenium salts; tris(pentafluorophenyl)borane; and catalysts containing a reduced Robson-type macrocyclic ligand. One kind of these may be used alone, or two or more of them may be used in combination.

[0113] Examples of the DMC catalyst include zinc hexacyanocobaltate complexes containing ligands of t-butyl alcohol (hereinafter referred to as "TBA-DMC catalysts"), zinc hexacyanocobaltate complexes containing ligands of ethylene glycol dimethyl ether (also referred to as "glyme"), and zinc hexacyanocobaltate complexes containing ligands of diethylene glycol dimethyl ether (also referred to as "diglyme"). One type of these may be used alone, or two or more of them may be used in combination.

[0114] Of these, the TBA-DMC catalysts are preferred in view of the higher activity in polymerization and enabling restricting Mw / Mn of the polyether-polycarbonate polyol so as to make the viscosity lower.

[0115] Examples of the metal-salen complex catalysts include cobalt-salen complexes, chromium-salen complexes, and aluminum-salen complexes described in JP 2012-500867 A, JP 2015-129306 A, and JP 2015-28182 A. One type of them may be used alone, or two or more of them may be used in combination.

[0116] The catalyst preferably comprises at least one selected from the group consisting of a DMC catalyst and a metal-salen complex catalyst in view of easily adjusting the introduction rate of carbon dioxide into the polyether-polycarbonate polyol to a range specified in the present invention.

[0117] The catalyst is also preferably a DMC catalyst or a catalyst containing a reduced Robson-type macrocyclic ligand with a view to obtaining a random polyether-polycarbonate polyol polymer.

[0118] The amount of the catalyst added is preferably as small as possible, preferably 0.001 to 10 parts by mass, more preferably 0.002 to 5 parts by mass, and even more preferably 0.05 to 3 parts by mass based on 100 parts by mass of the obtained polyether-polycarbonate polyol, as long as it is the amount required for the polymerization of carbon dioxide and the ring-opening polymerization of the cyclic ether.

[0119] The smaller the amount of catalyst added, the lower the amount of catalyst contained in the resulting polyether-polycarbonate polyol. This can reduce the effect of the catalyst on the reactivity of the polyether-polycarbonate polyol with the isocyanate-terminated urethane prepolymer and can also reduce costs.

[0120] The polymerization reaction is preferably carried out at a pressure of 0.1 to 15 MPa, more preferably at a pressure of 0.2 to 10 MPa, and even more preferably at a pressure of 0.3 to 8 MPa in view of reactivity.

[0121] The polymerization temperature of the polymerization reaction is preferably 30 to 180 °C, more preferably 70 to 160 °C, and even more preferably 80 to 140 °C.

[0122] When the polymerization temperature is 30 °C or higher, the polymerization of carbon dioxide and the ring-opening polymerization of the cyclic ether can be reliably initiated, and when the polymerization temperature is 180 °C or lower, a reduction in the polymerization activity of the catalyst can be prevented.

[0123] The polymerization time of the polymerization reaction is preferably 2 to 18 hours, more preferably 2 to 14 hours, and even more preferably 2 to 10 hours.

[0124] When the polymerization time is 2 hours or more, the reactivity is excellent, and when the polymerization time is 18 hours or less, the polymerization is economically efficient.

[0125] The feed amount of the cyclic ether is preferably 40.0 to 99.0 parts by mass, more preferably 45.0 to 98.0 parts by mass, and even more preferably 50.0 to 97.0 parts by mass based on 100 parts by mass of the obtained polyether-polycarbonate polyol.

[0126] When the feed amount of the cyclic ether is within the above range, the viscosity of the obtained adhesive composition does not become too high, the workability during coating and curing becomes easily good, and the flexibility of the cured product of the adhesive composition becomes easily better.

[0127] The feed amount of carbon dioxide is preferably 0.05 to 40 mass%, more preferably 0.10 to 35 mass%, and even more preferably 1.15 to 30 mass% based on the obtained polyether-polycarbonate polyol.

[0128] When the charging amount of carbon dioxide is within the above range, the light resistance and the fracture strength of the cured product of the obtained adhesive composition become easily better.

[0129] In the adhesive composition of the present invention, the isocyanate index, which is 100 times the molar ratio of the isocyanate groups in the isocyanate group-terminated urethane prepolymer to the hydroxyl groups in the above-described polyether-polycarbonate polyol (isocyanate group / hydroxyl group), is preferably 80 or more and 150 or less.

[0130] This isocyanate index is preferably 85 or more, more preferably 90 or more, even more preferably 95 or more, and preferably 140 or less, more preferably 130 or less, and even more preferably 120 or less. When the isocyanate index is within the preferred range, the light resistance, breaking strength, and elongation at break of a cured product of the resulting adhesive composition easily become good.

[0131] The isocyanate index is the value obtained by multiplying by 100 the ratio of the number of moles of isocyanate groups of the isocyanate-terminated urethane prepolymer to the total number of moles of hydroxyl groups of the polyether-polycarbonate polyol. [Chain extender]

[0132] The adhesive composition of the present invention may further contain a chain extender to improve fracture strength by forming a hard segment. The chain extender is preferably at least one selected from the group consisting of a polyol and a polyamine and has at least two active hydrogen atoms that react with an isocyanate group.

[0133] Specific examples of the chain extender include unbranched aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and 1,12-dodecanediol; aliphatic diols with a branched chain, such as 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-heptanediol, 1,4-dimethylolhexane, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, dimerdiol and neopentyl glycol; diols with an alicyclic structure, such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxycyclohexane and 1,4-dihydroxyethylcyclohexane; diols with an aromatic group, such asXylylene glycol, 1,4-dihydroxyethylbenzene and 4,4'-methylenebis(hydroxyethylbenzene); trihydric or higher aliphatic alcohols, such as glycerin, trimethylolpropane and pentaerythritol; hydroxyamines, such as N-methylethanolamine, N-ethylethanolamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine and 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine; Polyamines without hydroxyl groups, such as ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-diphenylmethanediamine, methylenebis(o-chloroaniline), xylylenediamine, meta-xylenediamine, diphenyldiamine, tolylenediamine, hydrazine, piperazine, and N,N'-diaminopiperazine. One type of these can be used alone, or two or more of them can be used in combination.

[0134] Of these, ethylene glycol, propylene glycol, 1,4-butanediol and 1,6-hexanediol are preferred, and 1,4-butanediol is more preferred in view of the fact that the light resistance, the breaking strength and the breaking elongation of a cured product of the obtained adhesive composition become better in a simple manner and that they are commercially available in large quantities at a low cost.

[0135] The molecular weight of the chain extender is preferably 60 or more and 1000 or less, and more preferably 60 or more and less than 300. When the molecular weight of the chain extender is within the above range, the light resistance, breaking strength and elongation at break of a cured product of the obtained adhesive composition become easily better.

[0136] When the adhesive composition of the present invention contains a chain extender, the content of the chain extender is preferably 5 to 30 parts by mass, more preferably 6 to 25 parts by mass, and more preferably 8 to 20 parts by mass based on 100 parts by mass of the polyether-polycarbonate polyol, from the viewpoint of providing a suitable breaking strength of a cured product.

[0137] The adhesive composition of the present invention may further contain a solvent, an additive described later, and the like.

[0138] The solvent is preferably the solvent described above, which may optionally be used in the preparation of the isocyanate group-terminated urethane prepolymer.

[0139] When the solvent is contained, the amount of the solvent is preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and even more preferably 50 parts by mass or more, and preferably 500 parts by mass or less, more preferably 450 parts by mass or less, and even more preferably 400 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer.

[0140] The proportion (content) of the total amount of the isocyanate group-terminated urethane prepolymer and the polyether-polycarbonate polyol of the adhesive composition of the present invention is preferably 70 mass% or more, more preferably 75 mass% or more, and even more preferably 80 mass% or more. [Additives that can be mixed into the adhesive composition]

[0141] The adhesive composition of the present invention may comprise additives such as a hydrolysis inhibitor, an antioxidant, an ultraviolet absorbing agent, a light stabilizer, a filler, a plasticizer, an antistatic agent, a leveling agent and other optional components as required within a range not impairing the effect of the present invention. (hydrolysis inhibitor)

[0142] Examples of the hydrolysis inhibitor include carbodiimide-based, isocyanate-based, oxazoline-based, and epoxy-based hydrolysis inhibitors. A hydrolysis inhibitor can be used alone, or two or more hydrolysis inhibitors can be used in combination. Of these, carbodiimide-based hydrolysis inhibitors are preferred in view of the hydrolysis suppression effect.

[0143] Carbodiimide-based hydrolysis inhibitors are compounds with one or more carbodiimide groups in a molecule. Examples of monocarbodiimide compounds include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, diphenylcarbodiimide, and naphthylcarbodiimide.

[0144] Polycarbodiimide compounds can be prepared by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst.

[0145] Examples of the diisocyanate include MDI, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl 2,4-diisocyanate, IPDI, 4,4'-dicyclohexylmethane diisocyanate and tetramethylxylylene diisocyanate.

[0146] Examples of the carbodiimidization catalyst include phospholene oxides such as 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide and 3-phospholene isomers thereof.

[0147] The amount of the hydrolysis inhibitor added is preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, and more preferably 3 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (antioxidant)

[0148] By using the antioxidant, thermal degradation of the isocyanate group-terminated urethane prepolymer can be prevented.

[0149] Examples of antioxidants include radical scavengers, such as phenol-based compounds and amine-based compounds; and peroxide decomposers, such as sulfur-based compounds and phosphorus-based compounds. An antioxidant can be used alone, or two or more antioxidants can be used in combination.

[0150] As the antioxidant, one or more phenol-based compounds that act as radical scavengers are preferably used in view of stability and oxidation-preventing effects. It is also possible to use one or more phenol-based compounds that act as radical scavengers and one or more phosphorus-based compounds that act as peroxide decomposers in combination.

[0151] The amount of the antioxidant added is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (Ultraviolet absorbing agent)

[0152] Examples of the ultraviolet absorbing agent include benzophenone-based compounds, benzotriazole-based compounds, salicylic acid-based compounds, oxalic acid anilide-based compounds, cyanoacrylate-based compounds, and triazine-based compounds. One ultraviolet absorbing agent can be used alone, or two or more ultraviolet absorbing agents can be used in combination.

[0153] The amount of the ultraviolet absorbing agent added is preferably 3 parts by mass or less, more preferably 2.5 parts by mass or less, and even more preferably 2 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (Light stabilizer)

[0154] Examples of light stabilizers include hindered amine-based compounds and hindered piperidine-based compounds. A light stabilizer can be used alone, or two or more light stabilizers can be used in combination.

[0155] The amount of the light stabilizer added is preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1 part by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (Filler)

[0156] Examples of the filler include inorganic or organic fillers, for example in particular natural, heavy or precipitated calcium carbonate, which is optionally coated with a fatty acid, in particular stearic acid, barite (barite), talc, quartz powder, quartz sand, dolomite, wollastonite, kaolin, calcined kaolin, mica (potassium aluminum silicate), zeolite, molecular sieve, aluminum oxide, aluminum hydroxide, magnesium hydroxide, silicon oxide, including finely ground or fine silicon oxide from a pyrolysis process, commercially produced carbon black, graphite, metal powder, for example aluminum, copper, iron, silver or steel, and PVC powder or hollow spheres, and flame-retardant fillers, for example hydroxides or hydrates, in particular hydroxides or hydrates of aluminum, preferably aluminum hydroxide.

[0157] The amount of the filler added is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (plasticizer)

[0158] Examples of the plasticizer include di-2-ethylhexyl phthalate, dibutyl phthalate, dilauryl phthalate, dioctyl adipate, diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diisodecyl adipate, tributyl phosphate, trioctyl phosphate, propylene glycol adipate polyester, butylene glycol adipate polyester, epoxidized soybean oil, chlorinated paraffins and liquid paraffins.

[0159] The amount of the plasticizer added is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 25 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (Antistatic agent)

[0160] Examples of antistatic agents include inorganic salts, polyhydric alcohol compounds, ionic liquids, and surfactants. An antistatic agent can be used alone, or two or more antistatic agents can be used in combination.

[0161] Of these, ionic liquids are preferred. An "ionic liquid" is also referred to as a molten salt at room temperature and is a salt with fluidity at 25 °C.

[0162] The amount of the antistatic agent added is preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, and even more preferably 0.05 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (leveling agent)

[0163] Examples of the leveling agent include acrylic leveling agents, fluorine-based leveling agents, and silicone-based leveling agents. A leveling agent can be used alone, or two or more leveling agents can be used in combination. Of these, acrylic leveling agents are preferred.

[0164] The amount of the leveling agent added is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and even more preferably 0.1 part by mass or more, and preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1 part by mass or less based on 100 parts by mass of the isocyanate group-terminated urethane prepolymer. (Other optional components)

[0165] Examples of other optional ingredients include catalysts, other resins other than isocyanate-terminated urethane prepolymers, metal powders, colorants (pigments and the like), film-like materials, conductive agents, silane coupling agents, lubricants, corrosion inhibitors, heat resistance stabilizers, polymerization inhibitors, and foam inhibitors. <Verfahren zur Herstellung der Haftmittelzusammensetzung>

[0166] The process for preparing the adhesive composition of the present invention is a process for preparing an adhesive composition comprising an isocyanate group-terminated urethane prepolymer and a polyether-polycarbonate polyol, the process comprising: Polymerizing an initiator having three or more active hydrogen-containing groups in one molecule, a cyclic ether, and carbon dioxide in the presence of a catalyst to obtain a polyether-polycarbonate polyol; and mixing the polyether-polycarbonate polyol and an isocyanate-terminated urethane prepolymer.

[0167] The proportion of the constituent unit derived from carbon dioxide in one molecule of the polyether-polycarbonate polyol is 10 to 30 mass%.

[0168] The adhesive composition of the present invention is obtained by blending a polyether-polycarbonate polyol and an isocyanate-terminated urethane prepolymer. The polyether-polycarbonate polyol is obtained by the preparation process described in the section [Process for Preparing the Polyether-Polycarbonate Polyol].

[0169] When the polyether-polycarbonate polyol and the isocyanate-terminated urethane prepolymer are blended, a catalytic component, a solvent, and the above-described additives, which may be optionally included, may be further added. For blending, a known stirring and mixing machine, such as a plastomill, kneader, Banbury mixer, or roller equipped with a heating device, can be used. Blending is preferably carried out under an inert gas atmosphere such as nitrogen gas or under a dehydration atmosphere at reduced pressure.

[0170] The order of adding the components is not specifically restricted. (Two-component adhesive composition)

[0171] The adhesive composition of the present invention may be a two-component adhesive composition consisting of a main agent and a curing agent. When the adhesive composition of the present invention is a two-component adhesive composition, the main agent may be a main agent comprising the above-described isocyanate-terminated urethane prepolymer, and the curing agent may be a curing agent comprising the above-described polyether-polycarbonate polyol. The main agent can be prepared, for example, by uniformly stirring and mixing the above-described isocyanate-terminated urethane prepolymer and an optionally contained solvent, as well as one or two or more additives described above.The curing agent can be prepared, for example, by uniformly stirring and mixing the above-described polyether-polycarbonate polyol, a catalyst component and an optionally contained solvent, as well as one or two or more additives described above.

[0172] For stirring and mixing, a known stirring and mixing machine, such as a plastomill, kneader, Banbury mixer, or roller equipped with a heating device, can be used. Stirring and mixing are preferably carried out under an inert gas atmosphere, such as nitrogen gas, or under a dehydration atmosphere at reduced pressure.

[0173] The order of adding the components is not specifically restricted.

[0174] The main agent and the curing agent are each stored in separate containers. Various containers, such as tubes and bottles, can be used.

[0175] When the adhesive composition of the present invention is a two-component adhesive composition, it is preferable that the proportion (content) of the total amount of the main agent and the curing agent in the adhesive composition of the invention is 50 mass% or more and 100 mass% or less. The proportion of the total amount of the main agent and the curing agent is more preferably 55 mass% or more, more preferably 60 mass% or more, and even more preferably less than 100 mass%, more preferably 99.5 mass% or less, and even more preferably 95 mass% or less.

[0176] The content ratio of the main agent to the curing agent in the two-component adhesive composition is determined based on the isocyanate index described above.

[0177] The proportion (content) of the total amount of the main agent and the curing agent in the solids of the adhesive composition of the present invention is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 95 mass% or more, and may be 100 mass%. (Method of use)

[0178] When the adhesive composition of the present invention is a two-component adhesive composition, the main agent and the curing agent should be mixed and used.

[0179] The adhesive composition of the present invention can be cured, for example, under conditions of 5 to 90°C and a relative humidity of 5 to 95%. The mixing temperature is preferably 10°C or more, more preferably 15°C or more, and even more preferably 20°C or more, and preferably 90°C or less, more preferably 80°C or less, and even more preferably 60°C or less. When the temperature is within this range, side reactions other than the urethane reaction are easily suppressed.

[0180] The adhesive composition of the present invention can be used for bonding glass, rubber, or a metal to a resin material or the like. Examples of the resin materials include polyolefins such as polypropylene, polyethylene, ethylene-propylene copolymers, and cycloolefin polymers; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polymethyl methacrylate; polycarbonates; polystyrene; acrylonitrile-styrene copolymers; polyvinyl chloride; polyacetates; acrylonitrile-butadiene-styrene copolymers; and polyamides.

[0181] These resin materials can be subjected to a surface treatment, such as flame treatment, corona treatment, or ITRO treatment. These resin materials can contain a filler, such as talc, calcium carbonate, or aluminum oxide, and can be reinforced with carbon fibers or glass fibers.

[0182] The adhesive composition of the present invention can be used to bond parts of various structures. In addition to being used as an adhesive, the adhesive composition of the present invention can also be used, for example, as a coating agent, a paint, a waterproofing material, a flooring material, an elastomer, artificial leather, and spandex. <Ausgehärtetes Produkt>

[0183] The cured product of the present invention is a cured product obtained by curing the adhesive composition of the present invention. (Physical properties)

[0184] The breaking strength of the cured product obtained by curing the adhesive composition of the present invention is preferably 0.8 MPa or more, more preferably 1.5 MPa or more, and even more preferably 3.0 MPa or more.

[0185] The elongation at break of the cured product obtained by curing the adhesive composition of the present invention is preferably 15.0% or more, more preferably 30.0% or more, and even more preferably 50.0% or more.

[0186] The ultimate strength and ultimate elongation are measured by the methods described in examples given later. Examples

[0187] The present invention will be described in detail below based on examples. However, the present invention is not limited to the following examples. (Evaluation procedure)<Anzahl von Hydroxylgruppen (Anzahl von Endgruppen) in einem Molekül>

[0188] The number of hydroxyl groups of the initiator used in the synthesis of each polyol was adjusted to the number of hydroxyl groups in a molecule (the number of end groups) of each polyol as it existed. For example, the number of hydroxyl groups in the case of glycerol is 3, in the case of pentaerythritol 4, and in the case of sorbitol 6. <Hydroxylzahl, Hydroxylzahl-äquivalentes Molekulargewicht>

[0189] The hydroxyl value (OHV) of each polyol obtained in the synthesis examples described later was calculated by a method using an acetylating agent according to JIS K 1557 (2007).

[0190] The hydroxyl number equivalent molecular weight of the polyol was calculated by substituting the hydroxyl number into the formula [56100 / (hydroxyl number)] × (number of functional groups). <Zahlenmittel des Molekulargewichts (Mn) und Molekulargewichtsverteilung (Mw / Mn) >

[0191] The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of each polyol obtained in the synthesis examples described later are values ​​obtained by measuring by the following method.

[0192] For several types of monodisperse polystyrene with different polymerization degrees as standard samples for molecular weight measurement, measurement was performed using a commercially available GPC instrument (HLC-8320GPC, manufactured by Tosoh Techno-System, Inc.), and a calibration curve was constructed based on the relationship between the molecular weight and retention time of polystyrene. The polyol, which is a measurement sample, was diluted to 0.5 mass% with tetrahydrofuran and passed through a filter with a pore diameter of 0.5 μm, and then measurement was performed for the measurement sample using the GPC instrument. The GPC spectrum of the measurement sample was subjected to computer analysis using the calibration curve, so that Mn and Mw were obtained.

[0193] <Quantifizierung der PO-PO-PO-Kette (AO-AO-AO-Kette), der PO-PO-CO2-Kette (AO-AO-CO2-Kette) und der CO2-PO-CO2-Kette (CO2-AO-CO2-Kette) in dem Polyol und Anteil von Propylencarbonat in dem Polyol und Anteil einer Bestandteilseinheit, die von Kohlendioxid abgeleitet ist>

[0194] Each polyol obtained in the synthesis examples described later was dissolved in deuterochloroform at 10 mass% and a 1 H-NMR was measured using an NMR instrument (JNM-ECZ400S FT-NMR, product name of JEOL Ltd.) with a resolution of 400 MHz.From the results obtained, the proportion of CO2-PO-CO2 chain (the proportion of fully alternating copolymers), the proportion of PO-PO-CO2 chain (the proportion of random copolymers), the proportion of PO-PO-PO chain (the proportion of PPG), and the proportion of propylene carbonate in the polyol were calculated using the following equations based on the area S1 of the 3H peak derived from a methyl group (δ1.34 ppm) of propylene oxide PO (formula weight 58) as a cyclic ether with both ends adjacent to a carbonate, the area S2 of the 3H peak derived from a methyl group (δ1.29 ppm) of PO with one end adjacent to carbonate and the other end adjacent to PO, the area S3 of the 3H peak derived from a methyl group (δ1.14 ppm) of PO with both ends adjacent to PO, and the area S4 of the methyl-derived 3H peak (δ1.49 ppm) of propylene carbonate (formula weight 102), which is a by-product.In the following equations, the formula weight of PO with both ends adjacent to carbonate was set to 102, and the formula weight of PO with one end adjacent to carbonate and the other end adjacent to PO was set to 102.

[0195] In addition, the proportion of the constituent unit derived from carbon dioxide (proportion of CO2 (formula weight 44)) in the polyol was calculated using the following equation. (Fraction of the CO2−PO−CO2 chain [mass%]) = S1×102 / (S1×102+S2×102+S3×58+S4×102)×100 (Fraction of the PO−PO−CO2 chain [mass%]) = S2×102 / (S1×102+S2×102+S3×58+S4×102)×100 (Fraction of PO−PO−PO−chain[mass%])=S3×58 / (S1×102+S2×102+S3×58+S4×102)×100 (Proportion of propylene carbonate [mass%])=S4×102 / (S1×102+S2×102+S3×58+S4×102)×100 (Fraction of CO2[mass−%])=(S1+S2) / {(S1×102+S2×102+S3×58)}×44×100 <Viskosität bei 25 °C>

[0196] The viscosity of the polyol at 25 °C was measured using an E-type viscometer (Viscometer TV-22, manufactured by Toki Sangyo Co., Ltd). <pyrolysemessung>

[0197] 5 g of each polyol obtained in the synthesis examples described later was placed in a 15 ml vial. The internal air of the vial was replaced with nitrogen, and the vial was sealed and stored at 80 °C for 7 days at high temperature. Subsequently, analysis was performed using a high-speed GPC (HLC-8320 GPC, manufactured by Tosoh Techno-System, Inc.) using tetrahydrofuran as the partition solvent, and the area ratio of propylene carbonate after high-temperature storage was calculated. <Filmbildungsvermögen>

[0198] The urethane resin obtained in each example was applied to a commercially available PET film to a thickness of 250 µm and compression-molded using a hydraulic molding machine to obtain a urethane resin film. The obtained urethane resin film was visually inspected and evaluated according to the following criteria. [Evaluation criteria] A: The surface of the film is flat C: The surface of the film is uneven [Lightfastness]

[0199] The degree of UV degradation was evaluated by storing the urethane resin film obtained above on a QUV tester (QUV / SE, manufactured by Q-Lab Corporation) at 50°C for 120 hours, then bending the urethane resin film at 180° and examining it for damage. It was rated "A" if the film was undamaged, and "C" if the film was damaged. <Zugprüfung>

[0200] The urethane resin sheet obtained as above was punched with a dumbbell die (Dumbbell No. 3) to obtain a test specimen. The ultimate strength (unit: MPa) and ultimate elongation (unit: %) were measured using a tensile testing machine (product name: TENSILON Universal Tester RTG-1310, manufactured by A&D Company, Limited) in accordance with JIS K 7312: 1996. The measurement conditions were set to a temperature of 23 °C, a distance between the clamps of 40 mm, and a tensile speed of 50 mm / min. [Synthesis of a polyether-polycarbonate polyol][Synthesis Example 1]

[0201] A polypropylene polyol (number average molecular weight 870) in which propylene oxide was added to sorbitol was used as the initiator.

[0202] The reactor was charged with 46.0 g of the initiator and 0.04 g of a zinc hexacyanocobaltate complex with a t-butyl alcohol ligand (hereinafter referred to as "TBA-DMC catalyst") as a catalyst. A series of operations of heating the reactor to 130 °C, introducing carbon dioxide, pressurizing (about 2.0 MPa), and then depressurizing (about 0.1 MPa) was repeated three times, and then the reactor was degassed at 130 °C for 2 hours. After degassing, the carbon dioxide pressure was increased to 6.0 MPa to activate the catalyst. Then, the carbon dioxide pressure during synthesis was maintained at 6.0 MPa, 26.0 g of propylene oxide (PO) as a cyclic ether was added, and after confirming heat generation, the liquid temperature was lowered to 110 °C and 232 g of PO was added over 14 hours.After reacting at 110 °C for 3 hours, the liquid temperature was raised to 130 °C, the reactor was maintained under reduced pressure for 5 hours, and propylene carbonate, a by-product, was removed. The reactant was then discharged from the reactor, yielding a polyether-polycarbonate polyol (polyol (a1)) with a hydroxyl value of 44.9 mg KOH / g and a CO2 content of 24.1 mass%. The amount of propylene oxide introduced as the cyclic ether was 75.6 parts by mass per 100 parts by mass of the obtained polyether-polycarbonate polyol. [Synthesis Example 2]

[0203] The synthesis was carried out using the same procedure as in Synthesis Example 1, except that the carbon dioxide pressure was changed to 1.5 MPa during catalyst activation and the carbon dioxide pressure was changed to 1.5 MPa during synthesis, thereby obtaining a polyether-polycarbonate polyol (polyol (a2)) with a hydroxyl value of 44.1 mg KOH / g and a CO2 content of 12.3 mass%. The amount of propylene oxide introduced as the cyclic ether was 87.5 parts by mass based on 100 parts by mass of the obtained polyether-polycarbonate polyol. [Synthesis Example 3]

[0204] A polypropylene polyol (number average molecular weight 600) in which propylene oxide was added to pentaerythritol was used as the initiator.

[0205] The reactor was charged with 33.0 g of the initiator and 0.04 g of the TBA-DMC catalyst as the catalyst. A series of operations of heating the reactor to 130 °C, introducing carbon dioxide, pressurizing (about 2.0 MPa), and then depressurizing (about 0.1 MPa) was repeated three times, and then the reactor was degassed at 130 °C for 2 hours. After degassing, the carbon dioxide pressure was increased to 1.5 MPa to activate the catalyst. Then, the carbon dioxide pressure was maintained at 1.5 MPa during synthesis, 32.0 g of PO as the cyclic ether was added, and after confirming heat generation, the liquid temperature was lowered to 110 °C, and 285 g of PO was added over 17 hours. After reacting at 110 °C for 3 hours, the liquid temperature was increased to 130 °C, the reactor was kept under reduced pressure for 5 hours, and propylene carbonate, which is a by-product, was removed.The reactant was then removed from the reactor, yielding a polyether-polycarbonate polyol (polyol (a3)) with a hydroxyl value of 31.5 mg KOH / g and a CO2 content of 12.5 mass%. The amount of propylene oxide introduced as the cyclic ether was 87.2 parts by mass per 100 parts by mass of the resulting polyether-polycarbonate polyol. [Synthesis Example 4]

[0206] A polypropylene polyol (number average molecular weight 1000) in which propylene oxide was added to glycerol was used as the initiator.

[0207] The reactor was charged with 51.0 g of the initiator and 0.07 g of the TBA-DMC catalyst as the catalyst. A series of operations of heating the reactor to 130 °C, introducing carbon dioxide, pressurizing (about 2.0 MPa), and then depressurizing (about 0.1 MPa) was repeated three times, and then the reactor was degassed at 130 °C for 2 hours. After degassing, the carbon dioxide pressure was increased to 1.5 MPa to activate the catalyst. Then, the carbon dioxide pressure was maintained at 1.5 MPa during synthesis, 30.0 g of PO as a cyclic ether was added, and after confirming heat generation, the liquid temperature was lowered to 110 °C, and 270 g of PO was added over 16 hours. After reacting at 110 °C for 3 hours, the liquid temperature was increased to 130 °C, the reactor was kept under reduced pressure for 5 hours, and propylene carbonate, which is a by-product, was removed.The reactant was then removed from the reactor, yielding a polyether-polycarbonate polyol (polyol (a4)) with a hydroxyl value of 28.9 mg KOH / g and a CO2 content of 11.4 mass%. The amount of propylene oxide introduced as the cyclic ether was 88.4 parts by mass per 100 parts by mass of the resulting polyether-polycarbonate polyol. [Synthesis Example 5]

[0208] The reactor was charged with 25.0 g of sorbitol as the initiator and 1.8 g of cobalt-salen complex as the catalyst. A series of operations of heating the reactor to 50 °C, introducing carbon dioxide, pressurizing (about 2.0 MPa), and then depressurizing (about 0.1 MPa) was repeated three times, and then the carbon dioxide pressure was increased to 2.0 MPa to activate the catalyst. Then, 143 g of PO was added as the cyclic ether and reacted for 6 hours while replacing the internal air of the vessel with carbon dioxide. After the reaction, 66.7 ml of methanol was added, and the solvent was removed. After removal, the liquid temperature was raised to 130 °C, the reactor was maintained at reduced pressure for 5 hours, and propylene carbonate, which is a by-product, was removed.The reactant was then removed from the reactor, yielding a polyether-polycarbonate polyol (polyol (c1)) with a hydroxyl value of 47.5 mg KOH / g and a CO2 content of 43.1 mass%. The amount of propylene oxide introduced as the cyclic ether was 56.7 parts by mass per 100 parts by mass of the resulting polyether-polycarbonate polyol. [Synthesis of a polypropylene polyol][Synthesis Example 6]

[0209] A polypropylene polyol (number average molecular weight 870) in which propylene oxide was added to sorbitol was used as the initiator.

[0210] The reactor was charged with 46.0 g of the above initiator and 0.04 g of the TBA-DMC catalyst as the catalyst. A series of operations of heating the reactor to 130 °C, introducing nitrogen, pressurizing (about 0.5 MPa), and then depressurizing (about 0.1 MPa) was repeated three times, and then the reactor was degassed at 130 °C for 2 hours. After degassing, the nitrogen pressure was increased to 0.1 MPa. Then, 35.0 g of PO was added as the cyclic ether, and after confirming heat generation, an additional 319 g of PO was added over 18 hours. After reacting at 130 °C for 2 hours, the reactor was maintained at the liquid temperature of 130 °C under reduced pressure for 2 hours. The reactant was then removed from the reactor to obtain a polyether-polycarbonate polyol (polyol (c2)) with a hydroxyl number of 44.2 mg KOH / g. [Synthesis Example 7]

[0211] A polypropylene polyol (number average molecular weight 1000) in which propylene oxide was added to glycerol was used as the initiator.

[0212] The reactor was charged with 47.0 g of the initiator and 0.04 g of the TBA-DMC catalyst as the catalyst. A series of operations of heating the reactor to 130 °C, introducing nitrogen, pressurizing (about 0.5 MPa), and then depressurizing (about 0.1 MPa) was repeated three times, and then the reactor was degassed at 130 °C for 2 hours. After degassing, the nitrogen pressure was increased to 0.1 MPa. Then, 35.0 g of PO was added as the cyclic ether, and after confirming heat generation, an additional 318 g of PO was added over 18 hours. After reacting at 130 °C for 2 hours, the reactor was maintained at the liquid temperature of 130 °C under reduced pressure for 2 hours. The reactant was then removed from the reactor to obtain a polyether-polycarbonate polyol (polyol (c3)) with a hydroxyl number of 22.5 mg KOH / g. [Table 1] Polyol Number of hydroxyl groups in a molecule Hydroxyl number (mgKOH / g) Molecular weight (hydroxyl equivalent molecular weight) Mn Mf / Mn Proportion of the PO-PO-PO chain (mass%) Proportion of the PO-PO-CO2 chain (mass%) Proportion of the CO2-PO-CO2 chain (mass%) Proportion of propylene carbonate (mass%) Share of CO2 (mass%) Viscosity at 25 °C (mPa - s) Pyrolysis measurement (80 °C, 7 days) (%) (a1) 6 44,9 7500 8800 1,97 44,0 42,6 13,0 0,4 24,1 100000 1,0 (a2) 6 44,1 7633 8616 1,87 71,4 23,6 4,8 0,2 12,3 6000 0,5 (a3) 4 31,5 7124 8000 1,80 70,8 26,1 2,8 0,3 12,5 7500 0,5 (a4) 3 28,9 5824 10800 1,28 73,4 23,1 3,2 0,3 11,4 9000 0,5 (c1) 6 47,5 7086 10000 1,40 0,0 7,3 92,3 0,4 43,1 >500000 10,0 (c2) 6 44,2 7615 11000 1,10 100,0 0,0 0,0 0 0 1200 0,2 (c3) 3 22,5 7480 11200 1,08 100,0 0,0 0,0 0 0 300 0,2

[0213] In the following examples, examples 1 to 4 are examples and examples 5 to 7 are comparative examples. [Example 1](1) Synthesis of an isocyanate group-terminated urethane prepolymer (preparation of the main agent)

[0214] 280 g of a polyethylene glycol-terminated polypropylene glycol (average number of hydroxyl groups: 2, hydroxyl number equivalent molecular weight: 4000) was added to a 2000 ml reaction vessel equipped with a stirrer. Then, 126 g of 4,4'-diphenylmethane diisocyanate (isocyanate group content: 33.6 mass%) (hereinafter referred to as MDI) was added, mixed at room temperature (25 °C), then heated to 80 °C and reacted for 3 hours. Subsequently, 560 g of an oxyethylene group-terminated polyoxyethylene / propylene polyol (average number of hydroxyl groups: 3, number average molecular weight: 5100, primary alcohol content: 14.5 mass%) was added and mixed, heated to 80 °C, and reacted for 3 hours (isocyanate index: 216).Then, after cooling the reaction solution to room temperature (25 °C), 100 g of DIDP (isodecyl phthalate) as a plasticizer and 577 g of carbodiimide-modified MDI (trade name: Millionate MTL, manufactured by Tosoh Corporation, isocyanate content 28.9%) as a hydrolysis inhibitor were added and mixed and stirred at room temperature (25 °C) to obtain an isocyanate group-terminated urethane prepolymer P1 (isocyanate index: 1067). (2) Preparation of a curing agent

[0215] To the reaction vessel were added 48.0 g of polyether-polycarbonate polyol (a1) obtained in Synthesis Example 1, 8.8 g of 1,4-BD and 1.0 g of meta-xylenediamine (MXDA) as chain extenders, 10.33 g of zeolite (trade name: SP#600, manufactured by NITTO FUNKA KOGYO KK) as filler, and 0.05 g of triethylenediamine as catalyst, and the mixture was stirred in a centrifugal stirrer to obtain a curing agent. (3) Synthesis of a urethane resin

[0216] 68.2 g of the curing agent obtained above, 85.4 g of the isocyanate group-terminated urethane prepolymer P1 as the main agent, and 5.5 g of carbodiimide-denatured MDI (trade name: Millionate MTL) were mixed and reacted in a stirrer at room temperature (25 °C) to obtain a urethane resin (isocyanate index: 110).

[0217] Here, the value obtained by multiplying the number of isocyanate groups of the isocyanate group-terminated urethane prepolymer P1 by 100 times the number of hydroxyl groups of the polyether-polycarbonate polyol (a1) was the isocyanate index described above. [Examples 2 to 7]

[0218] The urethane resin was prepared by the same method as in Example 1, except that the types of the main agent and the curing agent and the amounts of the main agent and the curing agent blended were changed as shown in Table 2.

[0219] The isocyanate index and the evaluation results of film forming ability, light resistance, breaking strength and elongation at break of each adhesive composition are shown in Table 2. [Table 2] Unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 (A1) (A2) (A3) (A4) (C1) (C2) (C3) Interfere Main funds Urethane prepolymer with isocyanate group end P1 g 85,4 85,4 85,4 85,4 85,4 85,4 85,4 Millionate MTL g 5,5 5,4 4,9 4,9 5,4 5,4 5,4 Curing agent Polyol (a1) g 48,0 - - - - - - (a2) g - 48,0 - - - - - (a3) g - - 48,0 - - - - (a4) g - - - 48,0 - - - (c1) g - - - - 48,0 - - (c2) g - - - - - 48,0 - (c3) g - - - - - - 48,0 1,4-BD g 8,8 8,62 9,1 9,05 8,58 8,55 8,16 MXDA g 1,0 1,0 1,0 1,0 1,0 1,0 1,0 Triethylenediamine g 0,05 0,05 0,05 0,05 0,05 0,05 0,05 SP600 (zeolite) g 10,33 10,43 9,63 9,63 10,47 10,05 10,89 Isocyanate index - 110 110 110 110 110 110 110 Evaluation Film formation ability - A A A A C A A Lightfastness - A A A A _*1 C C Tensile test Breaking strength MPa 7,0 6,0 3,5 0,9 _*1 2,8 0,7 Elongation at break % 105,0 112,7 70,0 20,5 _*1 99,6 10,2 *1: Not assessable

[0220] The urethane resins obtained in Examples 1 to 4 all exhibit good film-forming properties. Furthermore, all cured products exhibited good results in light resistance, fracture toughness, and elongation at break, and can therefore be considered excellent in light resistance, fracture toughness, and elongation at break. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2013-543929 A

[0004] WO 2019 / 240046 A

[0004] JP 2020-37689 A

[0034] JP 2012-500867 A

[0115] JP 2015-129306 A

[0115] JP 2015-28182 A

[0115] Cited non-patent literature

[0000] JIS K 1557 (2007 [0069, 0189] JIS K 1557-1: 2007

[0105] JIS K 7312: 1996

[0200] < / pyrolysemessung> < / haftmittelzusammensetzung>

Claims

[1] An adhesive composition comprising: an isocyanate group-terminated urethane prepolymer; and a polyether-polycarbonate polyol, wherein the polyether-polycarbonate polyol has three or more terminal groups in one molecule and has a constituent unit derived from an initiator, a constituent unit derived from a cyclic ether, and a constituent unit derived from carbon dioxide, and a proportion of the constituent unit derived from carbon dioxide in one molecule is 10 to 30 mass%. [2] The adhesive composition according to claim 1, wherein a hydroxyl value equivalent molecular weight of the polyether-polycarbonate polyol is 500 to 20,000. [3] The adhesive composition according to claim 1, wherein a molecular weight distribution (Mw / Mn) of the polyether-polycarbonate polyol expressed by a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.05 to 3.

00. [4] The adhesive composition according to claim 1, wherein the proportion of a constituent unit in which the constituent unit derived from carbon dioxide, the constituent unit derived from a cyclic ether, and the constituent unit derived from carbon dioxide are chain-arranged in this order in the polyether-polycarbonate polyol is 2 mass% or more. [5] The adhesive composition according to claim 1, wherein the constituent unit derived from a cyclic ether of the polyether-polycarbonate polyol is at least one constituent unit selected from the group consisting of a constituent unit derived from ethylene oxide and a constituent unit derived from propylene oxide. [6] The adhesive composition according to claim 1, wherein the end groups of the polyether-polycarbonate polyol are hydroxyl groups. [7] The adhesive composition according to claim 6, wherein a hundredfold molar ratio of isocyanate groups in the isocyanate group-terminated urethane prepolymer to hydroxyl groups in the polyether-polycarbonate polyol is 80 or more and 150 or less. [8] The adhesive composition according to claim 1, wherein a content of the polyether-polycarbonate polyol is 10 to 70 mass% based on a total amount of the adhesive composition. [9] The adhesive composition of claim 1, further comprising a chain extender. [10] Cured product of the adhesive composition according to any one of claims 1 to 9. [11] A process for preparing an adhesive composition comprising an isocyanate-terminated urethane prepolymer and a polyether-polycarbonate polyol, the process comprising: Polymerizing an initiator having three or more active hydrogen-containing groups in one molecule, a cyclic ether, and carbon dioxide in the presence of a catalyst to obtain a polyether-polycarbonate polyol; and mixing the polyether-polycarbonate polyol and an isocyanate-terminated urethane prepolymer, wherein a proportion of a constituent unit derived from carbon dioxide in one molecule of the polyether-polycarbonate polyol is 10 to 30 mass%. [12] A process for producing an adhesive composition according to claim 11, wherein the catalyst comprises at least one selected from the group consisting of a metal cyanide composite complex catalyst and a metal salen complex catalyst. [13] A process for producing an adhesive composition according to claim 11 or 12, wherein the isocyanate group-terminated urethane prepolymer is a reaction product obtained by reacting a polyol and a polyisocyanate compound such that a 100-fold molar ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the polyol is 110 or more and 600 or less.