JP2020152750A - Two-fluid curable urethane composition, adhesive including the same, and adhesion method using the same - Google Patents

Abstract

To provide a two-liquid curable urethane composition exhibiting favorable adhesiveness with polypropylene and polyethylene phthalate even under high temperature, to provide an adhesive including the urethane composition, and to provide an adhesion method using the adhesive.SOLUTION: The two-liquid curable urethane composition of the present invention includes: a main agent including a polyurethane component having an isocyanate group; and a curing agent including a polyol component. In the two-liquid curable urethane composition, the main agent includes a reaction product of polybutadiene polyol with polyisocyanate, or a reaction product of polybutadiene polyol and polyether polyol with polyisocyanate, and a mixture ratio between the polybutadiene polyol and the polyether polyol is polybutadiene polyol:polyether polyol=1:0 to 1:2, by mass ratio.SELECTED DRAWING: None

Description

The present invention relates to a two-component curable urethane composition, and more particularly to a two-component curable urethane composition having excellent adhesiveness to polypropylene, an adhesive having the urethane composition, and an adhesive method using the adhesive.

Polyisocyanate compounds having two or more isocyanate (NCO) groups in their molecules, such as urethane prepolymers, form a three-dimensional crosslinked structure by reacting with a curing agent such as an amine compound or an alcohol compound, and have high strength and high elongation. , A cured polyurethane product with excellent wear resistance and grease resistance. Such a polyurethane composition containing a polyisocyanate compound as a main component has been widely used as a joint material, a sealant, an adhesive and the like.

When a curing agent such as an amine compound or an alcohol compound and a polyisocyanate compound are stored in a mixed state, there is a problem that gelation occurs during storage and the curing reaction proceeds, resulting in poor storage stability. Further, if the compatibility between the polyisocyanate compound and the curing agent is poor, there is a problem that these are separated during storage and become an inhomogeneous cured product. In order to avoid these problems, urethane-based compositions are used as so-called two-component systems (two-component type) that are mixed during work.

Further, as a packaging material for a lithium ion battery, an aluminum pouch having a multi-layer structure is widely used, and the outer layer thereof is made of polypropylene (PP) and polyethylene terephthalate (PET).
In the next generation, lithium-ion battery cells will be stacked in multiple stages, and a polypropylene (PP) plate will be sandwiched between the cells for insulation purposes, so polyethylene terephthalate and polypropylene will adhere to each other. is necessary.

In general, polypropylene base materials have a small surface polarity and are difficult to adhere to, so in order to facilitate adhesion, surface treatment is performed to introduce polar groups into the surface of the base material. Plasma treatment, corona treatment, frame treatment and the like are applied to the surface treatment, but in recent years, it has been required not to perform the surface treatment from the viewpoint of simplifying the process and improving the working environment.

International Publication No. 2018/100685 Japanese Unexamined Patent Publication No. 2007-16188

It is known that a two-component urethane-based composition having a polypropylene glycol skeleton as a main skeleton has low wettability with respect to polypropylene having low polarity and is difficult to adhere. Further, even if good adhesiveness is exhibited at room temperature, sufficient adhesiveness is often not obtained at high temperature.
Therefore, an object of the present invention is to provide a two-component curable urethane composition that exhibits good adhesiveness to polypropylene even at a high temperature, an adhesive having the urethane composition, and an adhesive method using the adhesive. To do.

As a result of studies to solve the above problems, the present invention uses a urethane prepolymer containing a polybutadiene polyol and a polyether polyol in a specific ratio as a main agent, and further uses a curing agent containing a polybutadiene polyol to obtain polypropylene and polyethylene terephthal. It was made by finding that a cured urethane resin exhibiting good adhesiveness to tarat can be obtained even at a high temperature.

The two-component curable urethane composition according to the present invention has a main agent containing a polyurethane component having an isocyanate group and a curing agent containing a polyol component, and the main agent is a reaction product of polybutadiene and polyisocyanate, or It contains a polybutadiene polyol and a reaction product of a polyether polyol and a polyisocyanate, and the mixing ratio of the polybutadiene polyol and the polyether polyol is polybutadiene polyol: polyether polyol = 1: 0 to 1: 2 in terms of mass ratio.

Further, in the two-component curable urethane composition according to the present invention, the curing agent contains a polybutadiene polyol.

Further, in the two-component curing type urethane composition according to the present invention, the curing agent further contains an amine catalyst.

The adhesive according to the present invention is an adhesive containing the two-component curable urethane composition.

In the bonding method according to the present invention, when multi-stage stacking of battery cells is performed in the production of a lithium ion battery, at least one of polypropylene and polyethylene terephthalate plastics is used using an adhesive containing the two-component curable urethane composition. It is a method of adhering a member made of.

The two-component curable urethane resin composition according to the embodiment of the present invention can obtain a cured urethane resin that has excellent curability against polypropylene and polyethylene terephthalate and exhibits good adhesiveness even at high temperatures. When multi-stage lamination of lithium ion battery cells is performed, the urethane resin composition of the present invention is used to bond a member made of at least one of polypropylene and polyethylene terephthalate plastics used as an outer layer or an insulating plate of the battery cells. The reliability of the lithium battery can be improved by using the adhesive that has.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof.

The two-component curable urethane resin composition according to the embodiment of the present invention contains a main agent (A) containing a urethane prepolymer (a) and a curing agent (B) containing a polybutadiene polyol (b) and an amine catalyst (c). Including. This urethane resin composition can be cured by mixing the main agent (A) and the curing agent (B). Hereinafter, each component will be described.

<Urethane prepolymer (a)>
The urethane prepolymer (a) is a reaction product of a polybutadiene polyol (a-1) and a polyisocyanate (a-3), or a polybutadiene polyol (a-1) and a polyether polyol (a-2) and a polyisocyanate ( It is a reaction product with a-3). In the urethane prepolymer (a), the mixing ratio of the polybutadiene polyol (a-1) and the polyether polyol (a-2) is a mass ratio of the polybutadiene polyol (a-1): the polyether polyol (a-2) = 1. : Obtained by reacting a single or mixture of polyols in the range 0 to 1: 2 with polyisocyanate (a-3). By setting the mixing ratio of the polybutadiene polyol (a-1) and the polyether polyol (a-2) in the polyol to the range of 1: 0 to 1: 2 in terms of mass ratio, the main agent (A) and the curing agent (B) ) Is mixed, and the two-component curable urethane resin composition has excellent curability and can have high adhesive strength after curing. Hereinafter, specific examples of compounds of the polybutadiene polyol (a-1), the polyether polyol (a-2), and the polyisocyanate (a-3) will be described.

<Polybutadiene polyol (a-1)>
The polybutadiene polyol (a-1) is not particularly limited as long as it is butadiene having a hydroxyl group at the terminal and a copolymer thereof. For example, the structure of the polybutadiene polyol may include a trans type, a cis type or a 1,2 vinyl type (1,2-addition type). Such microstructures can generally be identified by ¹³ C nuclear magnetic resonance (NMR) spectra in chloroform.

The number average molecular weight (Mn) of the polybutadiene polyol is not particularly limited, but is preferably 500 to 10000, and more preferably 800 to 4000. When the number average molecular weight is in this range, the polybutadiene polyol becomes liquid, and the synthesis of urethane prepolymer becomes easy.

In the present invention, the number average molecular weight is the number average molecular weight measured by gel permeation chromatography. Tetrahydrofuran (THF) is preferably used as the solvent for the measurement.

As the polybutadiene polyol, one type may be used alone, two or more types may be used in combination, or a commercially available product may be used. Specifically, for example, POLYVEST HT (Mn 2900, manufactured by Ebonic), G-1000 (Mn 1400, manufactured by Nippon Soda Co., Ltd.), G-2000 (Mn 1900, manufactured by Nippon Soda Co., Ltd.), G-3000 ( Mn 3000, manufactured by Nippon Soda Co., Ltd.), Poly-bd R-45HT (Mn 2800, manufactured by Idemitsu Kosan Co., Ltd.), Poly-bd R-45HT (Mn 1000, manufactured by Idemitsu Kosan Co., Ltd.) and the like.

<Polyether polyol (a-2)>
The above-mentioned polyether polyol (a-2) is a polyether polyol having two or more hydroxy groups. Specific examples thereof include polyethylene glycol (PEG), polypropylene glycol (PPG), ethylene oxide / propion oxide polymer, polytetramethylene glycol (PTMEG), and sorbitol-based polyol. Of these, polypropylene glycol (PPG) is desirable. Further, as the above-mentioned polyether polyol, one type (a-2) may be used alone, or two or more types may be used in combination.

<Polyisocyanate (a-3)>
The polyisocyanate (a-3) contains two or more isocyanate groups in one molecule. Specific examples of the polyisocyanate compound include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), carbodiimide-modified diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, phenylenediocyanate, naphthalin-1,5-diisocyanate, and o-toluidine diisocyanate. , Triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate, isopropylbenzene-2,4-diisocyanate and other aromatic polyisocyanates; xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI) and other aliphatic- Aromatic polyisocyanate; hexamethylene diisocyanate, dodecane diisocyanate, lysine diisocyanate, lysine ester triisocyanate, 1,6,11-undecantriisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-hexamethylene Aliphatic polyisocyanates such as triisocyanate and trimethylhexamethylene diisocyanate; transcyclohexane-1,4-diisocyanate, bicycloheptane triisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), hydrogenated tolylene diisocyanate, hydrogen Alicyclic polyisocyanates such as added xylylene diisocyanate and hydrogenated tetramethylxylylene diisocyanate; cyclized trimer (isocyanurate modified product) of the above polyisocyanate compound; burette modified product of the above polyisocyanate compound; ethylene glycol, 1,4-Butanediol, propylene glycol, dipropylene glycol, trimethylolpropane, polyether polyol, polymer polyol, polytetramethylene ether glycol, polyester polyol, acrylic polyol, polyalkaziene polyol, hydride of polyalkaziene polyol, Examples thereof include an addition reaction product of a polyol compound such as a partially saponified ethylene-vinyl acetate copolymer and a castor oil-based polyol and the above-mentioned polyisocyanate compound.

Among the above polyisocyanates (a-3), diphenylmethane diisocyanate is preferable from the viewpoint of hardness (lower elastic modulus). As this diphenylmethane diisocyanate, Millionate MT (manufactured by Tosoh Corporation) and the like are commercially available.

In addition, the polyisocyanate (a-3) may be used alone or in combination of two or more.

Further, as the polyisocyanate (a-3) used in the present invention, the isocyanate group of the polyisocyanate (a-3) may be phenols, oximes, imides, mercaptans, alcohols, ε-caprolactam, ethyleneimine, etc. A so-called blocked isocyanate compound blocked with a blocking agent such as α-pyrrolidone, diethyl malonate, sodium hydrogen sulfite, and boric acid can also be used.

<Polybutadiene polyol (b)>
The polybutadiene polyol (b) can be used in the same manner as the polybutadiene polyol (a-1).

<Amine catalyst (c)>
As the amine catalyst (c), a Kochi catalyst that promotes a urethanization reaction or a urea conversion reaction can be used. The amine catalyst (c) is preferably a tertiary amine, for example, because it can enhance the moisture reactivity.

Examples of the amine catalyst (c) include N, N, N', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylpropylenediamine, N, N, N', N'', N'. '-Pentamethyldiethylenetriamine, N, N, N', N'', N''-Pentamethyl- (3-aminopropyl) ethylenediamine, N, N, N', N'', N''-Pentamethyldipropylene triamine , N, N, N', N'-tetramethylguanidine and the like. The amine catalyst (c) may be used alone or in combination of two or more.

The content of the amine catalyst (c) in the urethane-based composition is curability and physical properties and characteristics of the cured product with respect to 100 parts by mass of the sum of the polybutadiene polyol (a-1) and the polyether polyol (a-2). From the viewpoint of the above, it is preferably 1.0 to 10.0 parts by mass, more preferably 1.0 to 8.0 parts by mass, and even more preferably 1.5 to 5.0 parts by mass.

In addition to the above components, the urethane resin composition of the present invention further contains additives such as plasticizers, softeners, stabilizers, antiaging agents, lubricants, thickeners, defoamers, and colorants. You may.

The NCO / OH group equivalent ratio, which is the abundance ratio of the isocyanate group (NCO group) and the hydroxyl group (OH group) in the main agent (A) and the curing agent (B), is preferably 1.0 to 1.5. When the NCO / OH group equivalent ratio is within the above-mentioned predetermined range, the adhesiveness of the adhesive and the workability of the bonding process are improved. The isocyanate is mainly derived from the urethane prepolymer (a), and the hydroxy group is mainly derived from the polyether polyol (b).

It is practical that the two-component curable urethane resin composition according to the embodiment of the present invention is cured at room temperature under a predetermined relative humidity. Further, the curing is not limited to room temperature, and may be performed by heating or heating in order to accelerate the curing.

The two-component curable urethane resin composition according to the embodiment of the present invention can be used, for example, as an adhesive for adhering a member made of at least one of polypropylene and polyethylene terephthalate plastics in the production of a lithium ion battery. it can. Examples of the member made of at least one of polypropylene and polyethylene terephthalate plastic include an outer layer of a packaging material for a lithium ion battery or an insulating plate sandwiched between cells of a lithium battery. Since the adhesive having the two-component curable urethane resin composition has excellent curability and high adhesiveness, a highly reliable lithium ion battery can be manufactured.

In addition, as another application, for example, for adhering poorly adhesive plastics such as polypropylene used for interior and exterior parts such as automobile bodies, front doors, rear doors, back doors, pront bumpers, rear bumpers, rocker moldings, etc. It may be used as an adhesive for.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

<Preparation of main agent (A1)>
Polybutadiene polyol (POLYVEST HT, Mn2900, hydroxyl value 44 mgKOH / g, manufactured by Ebonic) 150.00 g, Modaflow Resin (manufactured by CBC Co., Ltd.) diluted to 50% by mass with ethyl acetate, 0.02 g, diluted to 10% by mass with methyl ethyl ketone 0.04 g of phosphoric acid was stirred under vacuum at 95 ° C. for 1 hour. Then, the mixture was cooled to 45 ° C., 60.75 g of diphenylmethane diisocyanate (Millionate MT, manufactured by Tosoh Corporation) was added under a nitrogen atmosphere, and the mixture was dissolved by stirring under vacuum for 10 minutes. Further, the mixture was heated to 70 ° C. in a nitrogen atmosphere, 0.02 g of a tin catalyst (KOSMOS29, manufactured by Evonik Industries, Inc.) was added, and the mixture was stirred for 2 hours.
<Preparation of main agent (A2)>
Polybutadiene polyol (POLYVEST HT, Mn2900, hydroxyl value 44 mgKOH / g, manufactured by Ebonic) 120.00 g, trifunctional polypropylene glycol (Preminol 7012, Mn10000, hydroxyl value 16.23 mgKOH) 30.00 g, diluted to 50% by mass with ethyl acetate 0.02 g of Modaflow Resin (manufactured by CBC Co., Ltd.) and 0.04 g of phosphoric acid diluted to 10% by mass with methyl ethyl ketone were stirred under vacuum at 95 ° C. for 1 hour. Then, the mixture was cooled to 45 ° C., 31.80 g of diphenylmethane diisocyanate (Millionate MT, manufactured by Tosoh Corporation) was added under a nitrogen atmosphere, and the mixture was dissolved by stirring under vacuum for 10 minutes. Further, the mixture was heated to 70 ° C. in a nitrogen atmosphere, 0.02 g of a tin catalyst (KOSMOS29, manufactured by Evonik Industries, Inc.) was added, and the mixture was stirred for 2 hours.
<Preparation of main agent (A3)>
Polybutadiene polyol (POLYVEST HT, Mn2900, hydroxyl value 44 mgKOH / g, manufactured by Ebonic) 100.00 g, trifunctional polypropylene glycol (Preminol 7012, Mn10000, hydroxyl value 16.23 mgKOH) 50.00 g, diluted to 50% by mass with ethyl acetate 0.02 g of Modaflow Resin (manufactured by CBC Co., Ltd.) and 0.04 g of phosphoric acid diluted to 10% by mass with methyl ethyl ketone were stirred under vacuum at 95 ° C. for 1 hour. Then, the mixture was cooled to 45 ° C., 48.70 g of diphenylmethane diisocyanate (Millionate MT, manufactured by Tosoh Corporation) was added under a nitrogen atmosphere, and the mixture was dissolved by stirring under vacuum for 10 minutes. Further, the mixture was heated to 70 ° C. in a nitrogen atmosphere, 0.02 g of a tin catalyst (KOSMOS29, manufactured by Evonik Industries, Inc.) was added, and the mixture was stirred for 2 hours.
<Preparation of main agent (A4)>
Polybutadiene polyol (POLYVEST HT, Mn2900, hydroxyl value 44 mgKOH / g, manufactured by Ebonic) 50.00 g, trifunctional polypropylene glycol (Preminol 7012, Mn10000, hydroxyl value 16.23 mgKOH) 100.00 g, diluted to 50% by mass with ethyl acetate 0.02 g of Modaflow Resin (manufactured by CBC Co., Ltd.) and 0.04 g of phosphoric acid diluted to 10% by mass with methyl ethyl ketone were stirred under vacuum at 95 ° C. for 1 hour. Then, the mixture was cooled to 45 ° C., 36.60 g of diphenylmethane diisocyanate (Millionate MT, manufactured by Tosoh Corporation) was added under a nitrogen atmosphere, and the mixture was dissolved by stirring under vacuum for 10 minutes. Further, the mixture was heated to 70 ° C. in a nitrogen atmosphere, 0.02 g of a tin catalyst (KOSMOS29, manufactured by Evonik Industries) was added, and the mixture was stirred for 2 hours.
<Preparation of main agent (A5)>
Polybutadiene polyol (POLYVEST HT, Mn2900, hydroxyl value 44 mgKOH / g, manufactured by Ebonic) 30.00 g, trifunctional polypropylene glycol (Preminol 7012, Mn10000, hydroxyl value 16.23 mgKOH) 120.00 g, and ethyl acetate to 50% by mass 0.02 g of diluted Modaflow Resin (manufactured by CBC Co., Ltd.) and 0.04 g of phosphoric acid diluted to 10% by mass with methyl ethyl ketone were stirred under vacuum at 95 ° C. for 1 hour. Then, the mixture was cooled to 45 ° C., 31.80 g of diphenylmethane diisocyanate (Millionate MT, manufactured by Tosoh Corporation) was added under a nitrogen atmosphere, and the mixture was dissolved by stirring under vacuum for 10 minutes. Further, the mixture was heated to 70 ° C. in a nitrogen atmosphere, 0.02 g of a tin catalyst (KOSMOS29, manufactured by Evonik Industries, Inc.) was added, and the mixture was stirred for 2 hours.
<Preparation of main agent (A6)>
150.00 g of trifunctional polypropylene glycol (Preminol 7012, Mn10000, hydroxyl value 16.23 mgKOH), 0.02 g of Modaflow Resin (manufactured by CBC Co., Ltd.) diluted to 50% by mass with ethyl acetate, and 0.04 of phosphoric acid diluted to 10% by mass with methyl ethyl ketone. G was stirred under vacuum at 95 ° C. for 1 hour. Then, the mixture was cooled to 45 ° C., 21.90 g of diphenylmethane diisocyanate (Millionate MT, manufactured by Tosoh Corporation) was added under a nitrogen atmosphere, and the mixture was dissolved by stirring under vacuum for 10 minutes. Further, the mixture was heated to 70 ° C. in a nitrogen atmosphere, 0.02 g of a tin catalyst (KOSMOS29, manufactured by Evonik Industries, Inc.) was added, and the mixture was stirred for 2 hours.

<Preparation of hardener (B1)>
100.00 g of a polybutadiene polyol (POLYVEST HT, Mn2900, hydroxyl value 44 mgKOH / g, manufactured by Evonik Industries, Inc.) was stirred under vacuum at 95 ° C. for 1 hour. Then, 0.038 g of amine-catalyzed texnor IBM-12 (manufactured by Nippon Emulsifier Co., Ltd.) was added under a nitrogen atmosphere.
<Preparation of hardener (B2)>
100 g of trifunctional polypropylene (Preminol 7012, Mn10000, hydroxyl value 16.23 mgKOH) was stirred under vacuum at 95 ° C. for 1 hour. Then, 0.038 g of amine-catalyzed texnor IBM-12 (manufactured by Nippon Emulsifier Co., Ltd.) was added under a nitrogen atmosphere.

(Examples 1 to 4 and Comparative Examples 1 to 3)
<Preparation of urethane composition>
The obtained main agents (A1) to (A6) and the curing agents (B1) to (B2) were mixed at room temperature in the combinations shown in Table 2 below to prepare a urethane composition. The molar ratio (NCO / OH) of the isocyanate group of the urethane prepolymer in the main agent (A) to the total active hydrogen groups of the curing agent (B), and the urethane prepolymer and the curing agent (B1) in the main agent (A). )-(B2) are shown in Table 2 as "prepolymer / curing agent" showing the mixing ratio (mass ratio).

For each of the obtained urethane compositions, the adhesiveness to polyethylene terephthalate / polypropylene and the curability of each urethane composition were evaluated by the following methods. The results are shown in Table 2.

<Adhesiveness>
For the test piece, an aluminum pouch base material with polyethylene terephthalate on the front surface and polypropylene on the back surface was attached to a stainless steel plate (SUS304) with double-sided tape, and each urethane composition obtained by the above method was applied to 25 mm × 25 mm. The thickness was set to 0.5 mm by sandwiching a silicon sheet as a spacer, and the material used was cured by leaving it at 23 ° C. and 50% RH (relative humidity) for 24 hours.
Using AUTOGRAPH AGS-X (manufactured by Shimadzu Corporation), this test piece was measured for shear adhesion at a tensile speed of 500 mm / min and the number of tests n = 3, and the average value was calculated. did. It can be said that it is good if this value is 0.30 MPa or more. It should be noted that the fractured form of AF indicates interfacial peeling.

<Currability of urethane composition>
The state of each cured urethane composition when the adhesiveness was evaluated was visually evaluated. When the cured product was not sticky, it was judged to have excellent curability, and when it was sticky, it was judged that there was a problem with curability.

From Table 2, the urethane compositions of Examples 1 to 4 have a shear adhesion strength of polyethylene terephthalate / polypropylene of 0.30 N / mm ² or more as compared with the urethane compositions of Comparative Examples 1 to 3, and adhere to each other. It turned out to be excellent in sex. By using a polybutadiene polyol in the main agent and setting the mixing ratio of the polybutadiene polyol and polypropylene glycol in the range of polybutadiene polyol: polypropylene glycol = 1: 0 to 1: 2 in terms of mass ratio, the polarity of the main agent is lowered and polypropylene is used. It is considered that the factor is that the wettability to the base material is improved. In addition, Examples 1 to 4 had no stickiness after curing and were excellent in curability.

On the other hand, in Comparative Examples 1 and 2, the shear adhesive strength was less than 0.30 N / mm ² , and the adhesiveness was inferior. In addition, it was found that stickiness remained even after curing, and there was a problem in terms of curability. In Comparative Example 3, although the shear adhesive strength was as high as 0.33 N / mm ^2, it was sticky after curing, and the curability was lowered as compared with Examples 1 to 4.

As described above, the two-component curable urethane resin composition according to the embodiment of the present invention can be obtained as a cured urethane resin having excellent curability against polypropylene and polyethylene terephthalate and good adhesiveness even at high temperatures. Can be done. By using this urethane resin composition as an adhesive when adhering a member made of polypropylene and polyethylene terephthalate used as an outer layer of a packaging material or an insulating plate of the battery cell in a multi-stage lamination of lithium ion battery cells. , A highly reliable lithium-ion battery can be manufactured. Further, the adhesive according to the embodiment of the present invention can be applied to other fields as an adhesive for a poorly adhesive plastic such as polypropylene.

Claims (5)

It has a main agent containing a polyurethane component having an isocyanate group and a curing agent containing a polyol component, and the main agent is a reaction product of a polybutadiene polyol and a polyisocyanate, or a reaction of a polybutadiene polyol and a polyether polyol with a polyisocyanate. A two-component curable urethane composition containing a product, wherein the mixing ratio of the polybutadiene polyol and the polyether polyol is polybutadiene polyol: polyether polyol = 1: 0 to 1: 2 in terms of mass ratio. The two-component curable urethane composition according to claim 1, wherein the curing agent contains a polybutadiene polyol. The two-component curable urethane composition according to claim 2, wherein the curing agent further contains an amine catalyst. An adhesive containing the two-component curable urethane composition according to any one of claims 1 to 3. An adhesive method for adhering a member made of at least one of polypropylene and polyethylene terephthalate plastics using the adhesive according to claim 4, when multi-stage stacking of battery cells is performed in the manufacture of a lithium ion battery.