Polyurethane adhesive composition and uses thereof

Abstract

A polyurethane adhesive composition is provided that includes: (a) a polyol component that includes a phosphoric acid-modified polyol and a vegetable oil-modified polyol; and (b) an isocyanate component that includes an NCO-terminated polyurethane prepolymer that is the reaction product of (i) a polyester polyol based on a dimer acid and an aromatic dicarboxylic acid, and (ii) an isocyanate monomer.

Description

[Technical field]

[0001] The present disclosure relates to adhesive compositions, and more particularly to two-part polyurethane adhesive compositions. [Background technology]

[0002] Mass production of battery packs in an economical manner has undergone revolutionary developments in the last few years, advancing the adoption of electric vehicles (EVs) around the world. Due to their low cost, low volatility, high body strength, and toughness, polyurethane adhesives have become a popular solution for battery pack assembly, where battery cells are bonded onto a cooling plate by polyurethane adhesives.

[0003] The bonding substrates for battery pack assemblies mainly include aluminum alloy, PET film, polycarbonate, etc., and Al alloy-Al alloy bonding is the most important one. However, effective bonding between Al alloys is difficult due to the high surface energy and the absence of organic chemical groups on the Al alloy surface. On the other hand, moisture resistance of polyurethane components (including polyol and isocyanate parts) is another important industrial need. This is because both the polyol part and the isocyanate part can easily absorb moisture. For the isocyanate part, the absorbed moisture causes a reduction in NCO content and the formation of a solid skin starting from the top of the component. As a result, the reduction in NCO content leads to an inaccurate feeding ratio between reactive groups, and the thick skin usually blocks the storage tank and / or distribution tunnel, causing product defects and production interruptions, respectively. For the polyol part, after mixing and dispensing the polyol part with the isocyanate part, the absorbed moisture may result in a large number of air bubbles in the cured adhesive.

[0004] Thus, there remains a need for polyurethane adhesive compositions that provide good moisture resistance, adhesive strength, and cost-effectiveness. Summary of the Invention

[0005] In an aspect, the present disclosure provides a method for producing a method for treating a cancer cell comprising: (a) a polyol component including a phosphoric acid-modified polyol and a vegetable oil-modified polyol; (b) a polyurethane adhesive composition is provided, the polyurethane adhesive composition comprising: (i) an isocyanate component comprising an NCO-terminated polyurethane prepolymer that is the reaction product of a polyester polyol based on a dimer acid and an aromatic dicarboxylic acid; and (ii) an isocyanate monomer.

[0006] In a further aspect, the present disclosure provides an isocyanate agent for use in a polyurethane adhesive composition comprising an NCO-terminated polyurethane prepolymer that is the reaction product of (i) a polyester polyol based on a dimer acid and an aromatic dicarboxylic acid, and (ii) an isocyanate monomer.

[0007] In a further aspect, the present disclosure provides a method of using the polyurethane adhesive composition described herein, comprising: (a) providing a polyurethane adhesive composition as described herein, wherein a polyol component and an isocyanate component are provided separate from one another; (b) contacting the polyol component and the isocyanate component to form a curable mixture; (c) applying the curable mixture to a first substrate to which at least a second substrate is to be joined; (d) contacting the second substrate with the first substrate such that at least a portion of the curable mixture is sandwiched between the first substrate and the second substrate; (e) curing or allowing the curable mixture to cure.

[0008] In a further aspect, the present disclosure provides for the use of the polyurethane adhesive composition described herein in a battery pack.

[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and all publications, patent applications, patents, and other references mentioned herein are incorporated by reference.

[0011] As disclosed herein, "and / or" means "and, or alternatively." All ranges are inclusive of the endpoints unless otherwise indicated.

[0012] As disclosed herein, all percentages referred to herein are by weight and temperatures are in degrees Celsius unless otherwise specified.

[0013] A. Polyurethane Adhesive Composition In one aspect, the present disclosure provides a method for producing a pharmaceutical composition comprising: (a) a polyol component comprising at least one phosphoric acid-modified polyol and at least one vegetable oil-modified polyol; (b) a polyurethane adhesive composition is provided, the polyurethane adhesive composition comprising: (i) an isocyanate component comprising an NCO-terminated polyurethane prepolymer that is the reaction product of a polyester polyol based on a dimer acid and an aromatic dicarboxylic acid; and (ii) an isocyanate monomer.

[0014] The polyurethane adhesive composition described herein is a two-part composition. As used herein, the term "two-part" means that the composition is provided in parts separated from each other before reacting the composition. For example, the polyol component and the isocyanate component of the composition can be prepared, stored, transported, or fed separately and then immediately or immediately combined, for example, in a mixer, to form a reactive mixture. It is contemplated that contacting these two components initiates a curing reaction in which the polyol groups react with the isocyanate groups to form urethane bonds. The reactive polyurethane composition formed by contacting the two components can be referred to as a "reactive liquid intermediate" or a "reactive mixture."

[0015] The mixing ratio of the polyol component and the isocyanate component is not strictly limited. In some exemplary embodiments, the isocyanate component and the polyol component can have an NCO / OH molar ratio of 0.9:1 to 1.95:1, for example, 1:1 to 1.9:1 or 1.05:1 to 1.85:1. In some exemplary embodiments, the isocyanate component and the polyol component can be combined in a volume ratio of about 1:1, for example, 1:1.2 to 1:0.8, 1:1.1 to 1:0.9, or 1:1.05 to 1:0.95.

[0016] Generally, the polyurethane adhesive compositions as described are solvent-free.

[0017] (A) Polyol Component The polyol component of the polyurethane adhesive composition includes at least one phosphoric acid modified polyol and at least one vegetable oil modified polyol.

[0018] In addition to the phosphoric acid modified polyols and vegetable oil modified polyols as described, the polyol component may include one or more additional polyols.

[0019] The polyol component may optionally include one or more additives, such as a plasticizer, a flame retardant, an adhesion promoter, a rheology modifier, a filler, or any combination thereof.

[0020] Generally, the polyol component described herein is solvent-free. As used herein, the term "solvent-free" means that the adhesive composition can be applied without any organic solvent or aqueous carrier (e.g., up to 100 percent solids). In some embodiments of the present disclosure, the adhesive composition contains less than 4% by weight, less than 3% by weight, less than 2% by weight, less than 1% by weight, less than 0.5% by weight, less than 0.2% by weight, less than 0.1% by weight, less than 100 ppm by weight, less than 50 ppm by weight, less than 10 ppm by weight, less than 1 ppm by weight of any organic or inorganic solvent or water, or does not contain any organic or inorganic solvent or water.

[0021] Phosphate-modified polyols At least one phosphate-modified polyol (eg, a phosphate ester polyol) is included in the polyol component.

[0022] Generally, at least one phosphoric acid modified polyol can function as an adhesion promoter in the polyol component.

[0023] As used herein, "phosphate-modified polyol" refers to a compound having two or more hydroxyl groups and one or more structures (I).

[0024] [ka]

[0025] Included in structure I are structures in which one or more of the acidic hydrogen atoms have been abstracted. The acidic hydrogen atoms are hydrogen atoms bonded to an oxygen atom that is bonded to a phosphorus atom. When one or more acidic hydrogens have been abstracted, the phosphate group is an anion.

[0026] In some embodiments, the polyol component can include one or more phosphate-modified polyols represented by structure (II):

[0027] [ka] (In the formula, R 1 is a trivalent group, for example, C1-C 16 (For example, C1~C 10 , C1 to C8, or C1 to C6) trivalent groups (e.g., C1 to C 16 A and B are each independently a direct bond or a divalent group, for example, C1-C 16 (For example, C1~C 10 , C1 to C8, or C1 to C6) divalent groups (e.g., C1 to C 16 alkylene), with the proviso that A and B are not both direct bonds. In addition to the pendant groups shown in structure (II), R 1 , A, and B may each independently have one or more additional pendant -OH groups, and R 1 Each of A, B, and R may or may not independently have one or more additional pendant groups of structure (I). Any two or more of the -OH groups and groups of structure (I) may be selected from R 1 Each —OH group and each group of structure (I) may or may not be bonded to the same atom of R, A, or B. Preferably, each —OH group and each group of structure (I) is bonded to the same atom of R 1 , A, and B are bonded to separate atoms. In some embodiments, the phosphoric acid modified polyol is a polyether-based polyol. In some embodiments, the phosphoric acid modified polyol is a polyether-based polyurethane polyol.

[0028] Phosphate ester polyols can be made from trifunctional propylene glycol, polyphosphoric acid, and polyisocyanate. Examples of commercially available trifunctional propylene glycols suitable for use with the present disclosure include products sold under the trade names VORANOL™ CP-450, VORANOL™ CP-260, VORANOL™ CP-755, and VORANOL™ CP-1055, each of which is available from Dow Chemical Company. In some embodiments, the phosphate ester polyol has a phosphoric acid content of less than 4 weight percent based on the weight of the phosphate ester polyol, or a phosphoric acid content of 0 to 3 weight percent based on the weight of the phosphate ester polyol, or a phosphoric acid content of 1.5 to 2.5 weight percent based on the weight of the phosphate ester polyol. In some embodiments, the phosphate ester polyol has a viscosity of less than 40,000 cps at 25° C., or less than 30,000 cps at 25° C., as measured by the method of ASTM D2196. In some embodiments, the phosphate ester polyol has a hydroxyl equivalent weight of less than 330 g / mol.In some embodiments, the phosphate ester polyol has from 0 to 100 weight percent, based on the weight of the phosphate ester polyol, of a trifunctional polyether polyol having an equivalent weight of less than 2,000 g / mol.

[0029] In some embodiments, the polyol component comprises from 1% to 50% by weight of the phosphate modified polyol, e.g., from 2% to 40%, from 3% to 30%, from 3% to 15%, or from 3% to 10% by weight of the polyol component.

[0030] In some embodiments, at least one phosphate-modified polyol in the polyol component has an average hydroxyl number of 80 mg KOH / g or more. In some embodiments, at least one phosphate-modified polyol in the polyol component has an average hydroxyl number of 800 mg KOH / g or less. In some embodiments, at least one phosphate-modified polyol in the polyol component has an average hydroxyl number within a range obtained by combining any two of the following endpoints: 80, 100, 150, 200, 300, 400, 500, 600, 700, 800 mg KOH / g. In some embodiments, at least one phosphate-modified polyol in the polyol component has an average hydroxyl number of 80-800 mg KOH / g, 100-600 mg KOH / g, 150-500 mg KOH / g, or 200-400 mg KOH / g.

[0031] Vegetable oil modified polyol At least one vegetable oil modified polyol is included in the polyol component.

[0032] Generally, at least one vegetable oil-modified polyol can function as a hydrophobicity achieving agent in the polyol component.

[0033] As used herein, "vegetable oil-modified polyol" refers to a vegetable oil-based polyether polyol, vegetable oil-based polyester polyol, vegetable oil-based polyurethane polyol, or mixtures thereof, having an average hydroxyl group functionality of 2 or greater. In a preferred embodiment, the vegetable oil-modified polyol comprises a polyurethane polyol and a short-chain polyether polyol (such as Voranol CP 450). In an exemplary embodiment, the vegetable oil-modified polyol does not comprise a polyalkene polyol (such as a polybutadiene polyol). Suitable polyester polyols for use include, but are not limited to, diols, and optionally polyols (e.g., triols, tetraols), and dicarboxylic acids, and optionally polycarboxylic acids (e.g., tricarboxylic acids, tetracarboxylic acids), or polycondensates of hydroxycarboxylic acids or lactones. Polyurethane polyols can be synthesized using isocyanates as chain extenders with hydroxyl groups as terminal groups. In some embodiments, the vegetable oil-modified polyol comprises a castor oil-modified polyol. In some embodiments, the vegetable oil-modified polyol comprises a castor oil-modified polyurethane polyol.

[0034] The polyol component contains 1 wt% to 99 wt%, for example, 2 wt% to 90 wt%, 3 wt% to 80 wt%, 5 wt% to 30 wt%, 5 wt% to 20 wt%, or 5 wt% to 10 wt% of the vegetable oil-modified polyol.

[0035] Additional polyols In addition to the phosphoric acid modified polyols and vegetable oil modified polyols as described, the polyol component can include one or more additional polyols, such as one or more selected from polyester polyols, polyether polyols, polyetherester polyols, polycarbonate polyols, polyurethane polyols, and combinations thereof.

[0036] In some embodiments, the polyol component includes one or more polyether polyols. In some embodiments, the one or more polyether polyols in the polyol component have an average hydroxyl group number of 80 mgKOH / g or more. In some embodiments, the one or more polyether polyols in the polyol component have an average hydroxyl group number of 800 mgKOH / g or less. In some embodiments, the one or more polyether polyols in the polyol component have an average hydroxyl group number in the range obtained by combining any two of the following endpoints: 80, 100, 150, 200, 300, 400, 500, 600, 700, 800 mgKOH / g. In some embodiments, the one or more polyether polyols in the polyol component have an average hydroxyl group number of 80 to 800 mgKOH / g, 100 to 600 mgKOH / g, 150 to 500 mgKOH / g, or 200 to 400 mgKOH / g.

[0037] In some embodiments, the one or more additional polyols in the polyol component have an average hydroxyl group functionality of 4 or less. In some embodiments, the one or more additional polyols in the polyol component have an average hydroxyl group functionality of 2 or greater. In some embodiments, the one or more additional polyols in the polyol component have an average hydroxyl group functionality that is within the numerical range obtained by combining any two of the following endpoints: 2, 2.5, 3, 3.5, and 4. In some embodiments, the additional polyols have an average hydroxyl group functionality of 2 to 4 or 2 to 3.

[0038] In some embodiments, the additional polyol comprises one or more hydrophobic polyols, such as castor oil.

[0039] Optional Additional Ingredients The polyol component may optionally contain one or more additional agents for a particular function or purpose.

[0040] For example, one or more additional agents selected from the group consisting of chain extenders (e.g., short chain diols), moisture scavengers, catalysts, flame retardants, rheology modifiers, fillers, additional adhesion promoters, and any combination thereof may be further included in the polyol component.

[0041] In some embodiments, the polyol component may include one or more chain extenders (e.g., short chain diols) or crosslinkers. Chain extenders or crosslinkers refer to low molecular weight alcohols having hydroxyl functionality of 2 or more. Examples are 1,2-methylene glycol, 1,4-butanediol, glycerol, etc. In an exemplary embodiment, the polyol component may include 0-10% chain extender by weight of the polyol component.

[0042] In some embodiments, the polyol component may include one or more moisture scavengers. Moisture scavengers absorb moisture from the environment before reacting with NCO-containing groups in the adhesive to help solve the problem of bubble formation. A common moisture scavengers in polyurethane adhesives is molecular sieve. In an exemplary embodiment, the polyol component may include 0-10% moisture scavengers by weight of the polyol component.

[0043] In some embodiments, the polyol component may contain one or more catalysts to tailor the reaction rate to meet process requirements. Higher catalyst loadings help increase initial bond strength but reduce pot life. A balanced catalyst package is an organometallic containing Zn, Bi, and Sn containing catalyst. In an exemplary embodiment, the polyol component may contain 0-3% catalyst by weight of the polyol component.

[0044] In some embodiments, the polyol component may include one or more flame retardants. The flame retardants may help improve fire resistance during exposure of the battery cell to electrical short circuits. In an exemplary embodiment, the polyol component may include 0-20% flame retardant by weight of the polyol component.

[0045] In some embodiments, the polyol component may include one or more rheology modifiers. Rheology modifiers are often included in adhesive compositions to provide thixotropic properties to suit various application needs. Rheology modification can be provided by physical association, such as fume silica, or by chemical reaction, such as amines with NCO. In an exemplary embodiment, the polyol component may include 0-10% rheology modifier by weight of the polyol component.

[0046] In some embodiments, the polyol component may include one or more fillers. Fillers are added to the adhesive to provide lower cost, thermal conductivity, etc. Fillers may be selected from silica, calcium carbonate, kaolin, talc, aluminum hydroxide, alumina, boron nitride, etc., with or without surface modification. In an exemplary embodiment, the polyol component may include 0-95% filler by weight of the polyol component.

[0047] In some embodiments, the polyol component can include one or more additional adhesion promoters. The additional adhesion promoters are other than the phosphate-modified polyols described herein. In an exemplary embodiment, the polyol component can include 0-10% additional adhesion promoter by weight of the polyol component.

[0048] (B) Isocyanate component The isocyanate component of the polyurethane adhesive composition comprises an NCO-terminated polyurethane prepolymer that is the reaction product of (i) a polyester polyol based on dimer acid and an aromatic dicarboxylic acid ("DADPP") and (ii) an isocyanate monomer.

[0049] As used herein, "dimer acid and aromatic dicarboxylic acid based polyester polyol," "dimer acid and aromatic dicarboxylic acid based polyester polyol," or "DADPP" refers to a polyester polyol derived from, e.g., prepared from, a reactive mixture of at least one dimer acid, at least one aromatic dicarboxylic acid, and at least one polyol.

[0050] References herein to "dimer acid" also include derivatives of dimer acid, such as compounds formed by replacing a hydrogen atom in the dimer acid molecule with another atom or group of atoms (e.g., halogen or amino groups), including halides, anhydrides, esters, salts, amides, etc. of dimer acid. Similarly, references herein to "aromatic dicarboxylic acids" also include derivatives of aromatic dicarboxylic acids, such as compounds formed by replacing a hydrogen atom in the aromatic dicarboxylic acid molecule with another atom or group of atoms (e.g., halogen or amino groups), including halides, anhydrides, esters, salts, amides, etc. of aromatic dicarboxylic acids.

[0051] Generally, the isocyanate components described herein are solvent-free.

[0052] The isocyanate component may optionally include one or more additives, such as a plasticizer, a flame retardant, an adhesion promoter, a rheology modifier, a filler, or any combination thereof.

[0053] NCO-terminated polyurethane prepolymer The NCO-terminated polyurethane prepolymer included in the isocyanate component is the reaction product of at least one polyester polyol and at least one isocyanate monomer, the at least one polyester polyol comprising the DADPP described herein.

[0054] Typically, the NCO-terminated polyurethane prepolymer is prepared by using 35% to 95% by weight of an isocyanate and 5% to 65% by weight of DADPP, based on the weight of the reactive mixture.

[0055] The polyols used to prepare the NCO-terminated polyurethane prepolymers preferably do not contain phosphorus polyols, since the inventors have found that the inclusion of phosphorus polyols can compromise the hydrophobicity of the isocyanate side by increasing their moisture sensitivity.

[0056] The isocyanate component comprises 5% to 100% NCO-terminated polyurethane prepolymer by weight of the isocyanate component. For example, the content of NCO-terminated polyurethane prepolymer in the isocyanate component is in a range obtained by combining any two of the following endpoints: 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, 99%, and 100%. In some embodiments, the isocyanate component comprises from 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45% to 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, 99%, or 100% NCO-terminated polyurethane prepolymer by weight of the isocyanate component.

[0057] It is understood that the NCO-terminated polyurethane prepolymer is an intermediate between the monomer and the final polymer.

[0058] DADPP DADPP useful for preparing NCO-terminated polyurethane prepolymers is prepared from a reactive mixture of at least one dimer acid, at least one aromatic dicarboxylic acid, and at least one polyol.

[0059] The present inventors have found that dimer acid-based polyester polyols can provide low viscosity and, more importantly, hydrophobicity to the isocyanate component. In addition, incorporating aromatic dicarboxylic acids can not only reduce costs, but also promote adhesion strength to polyester polyols. In this regard, aliphatic dicarboxylic acids are not desirable to include due to the hydrophobicity and further reduction in adhesion strength that they may bring. For example, DADPP is not prepared from any adipic acid, since adipic acid is non-hydrophobic.

[0060] DADPP is typically a polycondensate of a diol and optionally a polyol (e.g., triol, tetraol), and a dimer acid and an aromatic dicarboxylic acid or its derivative. The hydroxyl groups of DADPP are further reacted with isocyanates to produce a polyurethane prepolymer.

[0061] In some embodiments, DADPP is prepared via a one-step process in which all the acids and alcohols are charged in one pot and reacted in one step.

[0062] In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <4.2. In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <3. In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <2.5. In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <2.0. In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <1.5. In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <1. In some embodiments, the weight ratio of aromatic dicarboxylic acid to dimer acid is >0 and <0.6.

[0063] Dimer Acid The "dimer acid" useful for preparing DADPP may be a dicarboxylic acid compound obtained by reacting a fatty acid having 1, 2, 3, or 4 ethylenic double bonds and 14 to 22 (e.g., 16 to 20) carbon atoms (hereinafter referred to as "unsaturated fatty acid A") with a fatty acid having 1, 2, 3, or 4 ethylenic double bonds and 14 to 22 (e.g., 16 to 20) carbon atoms (hereinafter referred to as "unsaturated fatty acid B") on the double bond in a dimerization reaction. In one embodiment, the unsaturated fatty acid A has two ethylenic double bonds and 14 to 22 (e.g., 16 to 20) carbon atoms, and the unsaturated fatty acid B has one or two ethylenic double bonds and 14 to 22 (e.g., 16 to 20) carbon atoms. Non-limiting examples of suitable unsaturated fatty acids A include tetradecadienoic acid, hexadecadienoic acid, octadecadienoic acid (such as linoleic acid), eicosadienoic acid, docosadienoic acid, octadecatrienoic acid (such as linolenic acid), eicosatetraenoic acid (such as arachidonic acid), and combinations thereof. Non-limiting examples of suitable unsaturated fatty acids B include, in addition to the above examples, tetradecenoic acid (such as tsuzuic acid, physeteric acid, myristoleic acid), hexadecenoic acid (such as palmitoleic acid), octadecenoic acid (such as oleic acid, elaidic acid, and vaccenic acid), eicosenoic acid (such as gadoleic acid), and docosenoic acid (such as erucic acid, cetoleic acid, and brassidic acid), and combinations thereof.

[0064] The resulting dimer acid may be a mixture of dimer acids differing in structure depending on the attachment site or isomerization of the double bond.

[0065] In some embodiments, dimer acids useful for preparing NCO-terminated polyurethane prepolymers may be selected from the group consisting of acyclic dimer acids, cyclic dimer acids, aromatic dimer acids, polycyclic dimer acids, and any combination thereof.

[0066] For example, the acyclic dimer acid can be represented by structure (A) or (B):

[0067] [ka]

[0068] Cyclic dimer acids can be represented by structure (C):

[0069] [ka]

[0070] Aromatic dimer acids can be represented by structure (D):

[0071] [ka]

[0072] Polycyclic dimer acids can be represented by structure (E):

[0073] [ka]

[0074] In some embodiments, the dimer acid can be a C36 dimer acid. In further embodiments, the C36 dimer acid has the structure (A).

[0075] In some embodiments, the dimer acid is unsaturated. An "unsaturated dimer acid" comprises at least one carbon-carbon double bond. For example, structure (A) is an unsaturated dimer acid. A non-limiting example of a suitable dimer acid is ATUREX-1001 (CAS61788-89-4) available from Aturex Group.

[0076] In some embodiments, the dimer acid has an acid value of from 150 mg KOH / g, or 160 mg KOH / g, or 170 mg KOH / g, or 180 mg KOH / g, or 190 mg KOH / g, or 194 mg KOH / g to 200 mg KOH / g, or 210 mg KOH / g, or 220 mg KOH / g, or 230 mg KOH / g, or 240 mg KOH / g, or 250 mg KOH / g. In other embodiments, the dimer acid has an acid value of from 150 mg KOH / g to 250 mg KOH / g, or from 180 mg KOH / g to 220 mg KOH / g, or from 190 mg KOH / g to 200 mg KOH / g.

[0077] In an embodiment, the dimer acid has structure (A) and has an acid number from 150 mg KOH / g to 250 mg KOH / g, or from 180 mg KOH / g to 220 mg KOH / g, or from 190 mg KOH / g to 200 mg KOH / g.

[0078] In some embodiments, the DADPP comprises between 5% and 80% by weight of at least one dimer acid, eg, between 10% and 75%, between 15% and 70%, or between 20% and 65% by weight of the DADPP.

[0079] In some embodiments, the NCO-terminated polyurethane prepolymer comprises from 1% to 20%, e.g., from 2% to 18%, from 3% to 17%, or from 3% to 15% by weight of the prepolymer of at least one dimer acid.

[0080] Aromatic dicarboxylic acids The aromatic dicarboxylic acids useful for preparing DADPP are not dimer acids as described above, in other words, the aromatic dicarboxylic acids are structurally and / or compositionally distinct from the dimer acids in the reaction mixture.

[0081] In some embodiments, the aromatic dicarboxylic acid comprises a carboxyl group directly attached to the aromatic ring, hi some embodiments, the aromatic dicarboxylic acid comprises no olefinic bond.

[0082] In some embodiments, the aromatic dicarboxylic acid may be selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, and any combination thereof. In some embodiments, the aromatic dicarboxylic acid comprises isophthalic acid.

[0083] In some embodiments, the DADPP comprises from 5% to 80% by weight of at least one aromatic dicarboxylic acid, e.g., from 10% to 70%, from 12% to 60%, or from 15% to 55% by weight of the DADPP.

[0084] In some embodiments, the NCO-terminated polyurethane prepolymer comprises from 0.5% to 20%, e.g., from 1% to 18%, from 2% to 15%, or from 3% to 12% by weight of the prepolymer of at least one aromatic dicarboxylic acid.

[0085] Polyol Polyols useful in preparing DADPP can be selected from the group consisting of diols, triols, tetraols, and combinations thereof.

[0086] As used herein, the term "polyol" refers to a compound having two or more hydroxyl groups. A polyol is a "diol" if it has exactly two hydroxyl groups, a "triol" if it has exactly three hydroxyl groups, a "tetraol" if it has exactly four hydroxyl groups, a "pentanol" if it has exactly five hydroxyl groups, and so on.

[0087] Non-limiting examples of suitable diols include 3-methyl-1,5-pentanediol (MPD), 2-methyl-1,3-propanediol (MPG), ethylene glycol, butylene glycol, diethylene glycol (DEG), triethylene glycol, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol (NPG). In some embodiments, the polyol comprises a diol. In further embodiments, the diol comprises MPG and / or 1,6-hexanediol.

[0088] A non-limiting example of a suitable triol is trimethylolpropane (TMP).

[0089] In some embodiments, the one or more polyols used to prepare DADPP have an average hydroxyl group functionality of 4 or less. In some embodiments, the one or more polyols used to prepare DADPP have an average hydroxyl group functionality of 2 or greater. In some embodiments, the one or more polyols used to prepare DADPP have an average hydroxyl group functionality that is within the numerical range obtained by combining any two of the following endpoints: 2, 2.5, 3, 3.5, and 4. In some embodiments, the one or more polyols used to prepare DADPP have an average hydroxyl group functionality of 2 to 4, for example, 2 to 3.

[0090] Isocyanate Monomer Isocyanate monomers useful for preparing the NCO-terminated polyurethane prepolymers can include a variety of unmodified or modified monomeric isocyanates.

[0091] As used herein, an "isocyanate monomer" or "monomer isocyanate" is any compound that contains two or more isocyanate groups.

[0092] Compounds having an isocyanate group, such as isocyanate monomers, may be characterized by the parameter "%NCO" or "-NCO content", which is the amount of isocyanate groups by weight of the compound. In some embodiments, the isocyanate monomers have a free -NCO content of 15% to 40%, for example 18% to 35%, by weight of the isocyanate monomer.

[0093] Examples of monomeric aromatic isocyanates suitable for use according to the present disclosure include isomers of methylene diphenyl diisocyanate ("MDI"), such as 4,4-MDI, 2,4-MDI, and 2,2'-MDI, or modified MDI, such as carbodiimide-modified MDI or allophanate-modified MDI; isomers of toluene-diisocyanate ("TDI"), such as 2,4-TDI, 2,6-TDI, isomers of naphthalene-diisocyanate ("NDI"), such as 1,5-ND These include, but are not limited to, I, m- and p-phenylene diisocyanate, chlorophenylene-2,4-diisocyanate, diphenylene-4,4'-diisocyanate, 3,3'-dimethyl-4,4'-diphenyl-diisocyanate, 3-methyldiphenyl-methane-4,4'-diisocyanate, diphenyl ether diisocyanate, 2,4,6-triisocyanatotoluene, 2,4,4'-triisocyanatodiphenyl ether, and combinations thereof.

[0094] In some embodiments, the isocyanate monomer may be selected from the group consisting of MDI, TDI, IPDI, HMDI, and any combination thereof. In some embodiments, MDI is included for better mechanical properties. Types of MDI include linear MDI, such as 4,4'-MDI, 2,2'-MDI, carbodiimide modified MDI, and mixtures thereof. Polymeric MDI can also be used to tailor mechanical properties, but is not preferred because it has been found to be more sensitive to moisture (e.g., compared to carbodiimide-containing isocyanates).

[0095] In some embodiments, one or more of the included isocyanate monomers is carbodiimide modified. In some embodiments, the isocyanate monomer is a carbodiimide modified MDI.

[0096] Optional Additional Ingredients The isocyanate component may optionally include one or more additional agents for a particular function or purpose.

[0097] For example, one or more additional agents selected from the group consisting of plasticizers, flame retardants, other adhesion promoters, rheology modifiers, fillers, and any combination thereof may be further included in the isocyanate component.

[0098] In some embodiments, the isocyanate component may include one or more plasticizers to reduce skin buildup during application of the isocyanate component. In an exemplary embodiment, the isocyanate component may include 0-20% plasticizer by weight of the isocyanate component.

[0099] In some embodiments, the isocyanate component may include one or more flame retardants to improve fire resistance. In an exemplary embodiment, the isocyanate component may include 0-20% flame retardant by weight of the isocyanate component.

[0100] In some embodiments where an isocyanate component is used as the isocyanate component in a polyurethane adhesive composition, the isocyanate component may include one or more adhesion promoters to increase adhesion between substrates. In an exemplary embodiment, the isocyanate component may include 0-10% by weight of the isocyanate component of another adhesion promoter. In embodiments where an isocyanate component is used as the isocyanate component in a polyurethane adhesive composition described herein, the adhesion promoter included in the isocyanate component is other than a phosphoric acid modified polyol described herein.

[0101] In some embodiments, the isocyanate component may include one or more rheology modifiers to provide thixotropic properties for various application needs. Rheology modification may be provided by physical association, such as fume silica, or by chemical reaction, such as with amines and NCO. In an exemplary embodiment, fume silica with a hydrophobic surface treatment may be used as a rheology modifier in the isocyanate component. In an exemplary embodiment, the isocyanate component may include 0-10% of the rheology modifier by weight of the isocyanate component.

[0102] In some embodiments, the isocyanate component may include one or more fillers to further reduce cost, thermal conductivity, etc. Fillers may be selected from silica, calcium carbonate, kaolin, talc, aluminum hydroxide, alumina, boron nitride, etc., with or without surface modification. In an exemplary embodiment, the isocyanate component may include 0-95% filler by weight of the isocyanate component.

[0103] B. Isocyanate agent In one aspect, the present disclosure provides an isocyanate agent comprising an NCO-terminated polyurethane prepolymer that is the reaction product of (i) a polyester polyol based on dimer acid and aromatic dicarboxylic acid (“DADPP”) and (ii) an isocyanate monomer.

[0104] The isocyanate agent may include or be one of the isocyanate components or a mixture of isocyanate components as described above in the "(B) Isocyanate Component" section, and is prepared, packaged, stored, and shipped as a separate product.

[0105] In some embodiments, the isocyanate agent is for use in a polyurethane adhesive composition. For example, the isocyanate agent can be used as an isocyanate component in a polyurethane adhesive composition according to the present disclosure, which can be mixed and reacted with a polyol component to produce a polyurethane adhesive.

[0106] C. Application of Polyurethane Adhesive Composition In a further aspect, the present disclosure provides a method of using the polyurethane adhesive composition described herein, comprising: (a) providing a polyurethane adhesive composition comprising a polyol component and an isocyanate component as described; (b) contacting the polyol component and the isocyanate component to form a curable mixture; (c) applying the curable mixture to a first substrate to which at least a second substrate is to be joined; (d) contacting the second substrate with the first substrate such that at least a portion of the curable mixture is sandwiched between the first substrate and the second substrate; (e) curing or allowing the curable mixture to cure.

[0107] In some embodiments, the curable mixture can be allowed to cure at room temperature (about 25° C.) for several days (e.g., 3-10 days). In some embodiments, the curable mixture can be subjected to pressure or heat (e.g., temperatures of 30° C. to 90° C., e.g., 30° C. to 60° C.) to accelerate curing.

[0108] The material or type of the substrate (e.g., the first substrate and the second substrate) treated with the polyurethane adhesive composition is not limited. In an exemplary embodiment, the first substrate may be one or more battery cells, and the second substrate may be a cooling plate.

[0109] In a further aspect, the present application provides the use of the described polyurethane adhesive composition in a battery pack. EXAMPLES

[0110] Certain embodiments of the present invention are now illustrated in the following examples in which all parts and percentages are by weight unless otherwise specified.

[0111] raw materials

[0112] [Table 1]

[0113] Synthesis Process Synthesis of dimer acid polyester polyol-1 (DA-1): 100g of 1,6-hexanediol, 353g of ATUREX-1001 were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled at the appropriate position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature was below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as dimer acid-based polyester polyol.

[0114] Synthesis of dimer acid polyester polyol-2 (DA-2): 100g of 2-methyl-1,3-propanediol, 467.5g of ATUREX-1001 were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled at the appropriate position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature was below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as dimer acid-based polyester polyol.

[0115] Synthesis of dimer acid / adipic acid polyester polyol (DAAP): 100g 2-methyl-1,3-propanediol, 54.3g ATUREX-1001, 129.9g adipic acid were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled in the proper position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature dropped below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid number was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid number of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH number reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as a dimer acid-based polyester polyol.

[0116] Synthesis of dimer acid / isophthalic acid polyester polyol-1 (DAIA-1): 100g 2-methyl-1,3-propanediol, 36.7g ATUREX-1001, 152.4g isophthalic acid were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled in the proper position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature dropped below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as a dimer acid-based polyester polyol.

[0117] Synthesis of dimer acid / isophthalic acid polyester polyol-2 (DAIA-2): 100g 2-methyl-1,3-propanediol, 68.2g ATUREX-1001, 141.4g isophthalic acid were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled in the proper position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature dropped below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as a dimer acid-based polyester polyol.

[0118] Synthesis of dimer acid / isophthalic acid polyester polyol-3 (DAIA-3): 100g 2-methyl-1,3-propanediol, 107.7g ATUREX-1001, 127.6g isophthalic acid were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled in the proper position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature dropped below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as a dimer acid-based polyester polyol.

[0119] Synthesis of dimer acid / isophthalic acid polyester polyol-4 (DAIA-4): 100g 2-methyl-1,3-propanediol, 175.2g ATUREX-1001, 103.8g isophthalic acid were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled in the proper position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature dropped below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as a dimer acid-based polyester polyol.

[0120] Synthesis of dimer acid / isophthalic acid polyester polyol-5 (DAIA-5): 100g 2-methyl-1,3-propanediol, 255.4g ATUREX-1001, 75.6g isophthalic acid were charged into a 500mL glass reactor and mixed thoroughly. The mixture was heated to 100°C. Agitation was started when the raw materials became liquid. The temperature was controlled in the proper position and monitored throughout the process. If the maximum temperature of the glass condenser exceeded 103°C, cooling of the reactor was started as soon as possible. The reaction temperature increased to 220°C, and when the maximum temperature dropped below 100°C, vacuum was slowly applied to 30mm Hg over 30 minutes. The acid value was checked every 30 minutes. A certain amount of catalyst Tyzor TBT was added until the acid value of the reaction system was less than 10. The catalyst was added and the reaction system was maintained under 30mmHg vacuum condition for more than 1 hour until the OH value reached the theoretical value. The temperature was cooled to 60-70°C and the final product was collected as a dimer acid-based polyester polyol.

[0121] Synthesis of castor oil modified polyol (polyurethane polyol): Polyurethane polyol was synthesized in a 1,000 mL glass reactor as a normal polyurethane prepolymer preparation process. 12 g of ISONATE OP 50 was charged into the reactor and kept at 60°C with nitrogen protection, then 44 g of castor oil and 44 g of VORANOL P 400 were charged into the reactor and mixed with ISONATE OP 50. The temperature was slowly increased to 80°C and held for 2 hours. Finally, the polyurethane polyol was charged into a well-sealed container with nitrogen protection for further use.

[0122] Synthesis of NCO-terminated prepolymer of DA-1 (Pre-DA1): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and maintained at 60°C under nitrogen protection, then 25g of DA-1 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content reached the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0123] Synthesis of NCO-terminated prepolymer of DA-2 (Pre-DA2): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and kept at 60°C under nitrogen protection, then 25g of DA-2 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0124] Synthesis of NCO-terminated prepolymer of DAAP (Pre-DAAP): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and kept at 60°C under nitrogen protection, then 25g of DAAP was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0125] Synthesis of NCO-terminated prepolymer of DAIA-1 (Pre-DAIA1): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and kept at 60°C under nitrogen protection, then 25g of DAIA-1 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0126] Synthesis of NCO-terminated prepolymer of DAIA-2 (Pre-DAIA2): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and maintained at 60°C under nitrogen protection, then 25g of DAIA-2 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0127] Synthesis of NCO-terminated prepolymer of DAIA-3 (Pre-DAIA3): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and kept at 60°C under nitrogen protection, then 25g of DAIA-3 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0128] Synthesis of NCO-terminated prepolymer of DAIA-4 (Pre-DAIA4): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and maintained at 60°C under nitrogen protection, then 25g of DAIA-4 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0129] Synthesis of NCO-terminated prepolymer of DAIA-5 (Pre-DAIA5): 75g of ISONATE 143L was charged into a 1,000mL glass reactor and maintained at 60°C under nitrogen protection, then 25g of DAIA-5 was charged into the reactor and mixed with ISONATE 143L. The temperature was slowly increased to 80°C and held for 2-3 hours until the NCO content met the theoretical value. Finally, the prepolymer was charged into a well-sealed vessel under nitrogen protection for further application.

[0130] All prepolymers were successfully synthesized.

[0131] Composition and Effects The isocyanate agents (used as Part B in the polyurethane adhesive composition) were formulated as shown in Table 2, all of which met the moisture resistance requirements.

[0132] [Table 2]

[0133] E-01 and E-02 showed good hydrophobicity, but were expensive, and as will be described later, the adhesive strength of E-02 was not satisfactory.

[0134] Comparing E02-E03 with E04-E08, the following became clear: (1) When the weight ratio of isophthalic acid / dimer acid was >0 and <0.6, the hydrophobicity of the isocyanate moiety was improved. (2) When the weight ratio of isophthalic acid / dimer acid is >0.6 and <4.2, the hydrophobicity of the isocyanate moiety is reduced but still acceptable. (3) When the weight ratio of isophthalic acid / dimer acid was ≧4.2, the hydrophobicity of the isocyanate moiety was unacceptable. (4) When isophthalic acid was changed to an aliphatic dicarboxylic acid (carbon number ≦6), the hydrophobicity of the isocyanate moiety was unacceptable, even though the dicarboxylic acid / dimer acid ratio was <4.2.

[0135] A polyurethane adhesive composition was also prepared.

[0136] The adhesive formulation is summarized in Table 3 along with the details of Part A and the corresponding examples of Part B. Adhesive applicators are mostly available with a volumetric mix ratio of 1:1. Also, to ensure complete curing of the adhesive, the stoichiometric ratio of 2K polyurethane adhesives is usually set in the range of 1.05-1.85. Therefore, the formulation was designed to meet these requirements. The volumetric mix ratio and stoichiometric ratio were calculated and listed in Table 3.

[0137] [Table 3] Note: Com. - Comparative example; Inv. - Example of the invention. Lap shear strength > 8.5 MPa and cross tensile strength > 12.5 MPa are preferred.

[0138] As comparative examples, Com.01 to Com.03 showed the following. (1) Compositions based on pure dimer acid polyesters are expensive and can compromise adhesive strength (E-02). (2) Prepolymers based on polyesters of adipic acid and dimer acid lost their adhesive strength (Com.03).

[0139] Comparing Com.04 with Inv.01-04, when the weight ratio of isophthalic acid / dimer acid is ≧4.2, the hydrophobicity of the isocyanate moiety is unacceptable. Moreover, the adhesive strength may be significantly impaired.

[0140] A comparison of Com.01-02 with Inv.01-04 revealed that the cross tensile strength increased significantly when the weight ratio of isophthalic acid / dimer acid was <4.2.

[0141] When Com.03 was compared with Inv.01, both the hydrophobicity and adhesive strength were decreased, even though the weight ratio between the dicarboxylic acid and the dimer acid was the same.

[0142] Methods and Tests The isocyanate prepolymer of Part B was prepared according to the following procedure. Step 1 The NCO-terminated prepolymer is charged to a vessel, then the other liquid ingredients (DINP, IPPP, Z-6040, etc.) are added. Step 2 Apply vacuum and mix at medium agitation speed for 30 minutes. Step 3. Charge the alumina into a container, apply vacuum after powder is loaded and mix with high speed stirring for 30 minutes. Step 4: Add the fumed silica to the container, apply vacuum after the powder is added, and mix with high speed stirring for 1 hour. Step 5 Set the temperature bath to 80°C and continue mixing at medium to low agitation speed for 30 minutes to maintain temperature. Step 6 Set the temperature bath to 20°C and cool to below 40°C.

[0143] Tack free time was tested according to the following procedure: (ASTM C679-03). Place 10 g of Part B in a 50 mL plastic beaker and place the beaker in an oven at 45% humidity and 23 °C. Begin recording the time. Periodically remove the beaker and gently touch the surface of Part B with a plastic stick. As the reaction of Part B with moisture progresses, the surface viscosity increases. Stop recording the time when the surface of Part B is no longer sticky. Record this period as the tack-free time of Part B.

[0144] Prepare Part A polyol mixture according to the following procedure. Step 1 Add castor oil, polyurethane polyol, CP450, and BDO to a container. Step 2 Heat to 80°C, apply vacuum and mix at medium speed for 1 hour to degas. Step 3 Add the ATH to the container, apply vacuum after powder is added, and mix for 15 minutes on high speed agitation. Step 4: Add molecular sieve 3A to the container, apply vacuum after powder is added, and mix at high speed for 15 minutes. Step 5 Charge the H-18 into the container, apply vacuum after powder is added and mix at high speed for 1 hour. Step 6 Cool to below 40°C.

[0145] The lap joint test coupons were prepared according to the following procedure: (GB / T7124). The substrate is made of 3003 aluminum alloy with dimensions of 1.25 mm x 12.5 mm. 2. Clean the substrate surface by wiping it with ethanol. 3. Use pressure sensitive tape to mask off the adhesive area of ​​25mmX12mm. 4. Mix parts A and B of the adhesive together and place in a speed mixer at 1000 rpm for 1 minute to ensure thorough mixing. 5. Apply 0.5g to 1.5g of adhesive to the bonding area of ​​the substrate. Insert two copper wires with a diameter of 0.25 mm to control the thickness of the adhesive. 6. Stack another masked substrate along the length so that the same adhesive areas are in contact head to head. Place two clippers side by side and press the adhesive surfaces together to secure them in place. 7. Allow the adhesive to cure for 7 days at 25°C.

[0146] The butt joint test coupons were prepared according to the following procedure: (GB / T6329). 1. Prepare a substrate from 3003 aluminum alloy with dimensions of 60 mm height and 15 mm diameter. 2. Clean the substrate surface by wiping it with ethanol. 3. Mix parts A and B of the adhesive together and place in a speed mixer at 1000 rpm for 1 minute to ensure thorough mixing. 4. Apply 0.5g to 1g of adhesive to the flat surface of the substrate. Insert two copper wires with a diameter of 1.00 mm to control the thickness of the adhesive. 5. Stack the cleaned substrates together with the flat surfaces bonded together. Keep the stacked substrates vertical so that the bonded surfaces are always held in place by gravity. 6. Allow the adhesive to cure for 7 days at 25°C.

[0147] The test coupons were assembled on an Instron fixture and tested for lap joint shear strength and butt joint tensile strength at a strain rate of 5 mm / min.

Claims

1. 1. A polyurethane adhesive composition comprising: (a) a polyol component including a phosphoric acid-modified polyol and a vegetable oil-modified polyol; (b) an isocyanate component comprising an NCO-terminated polyurethane prepolymer that is the reaction product of (i) a polyester polyol based on a dimer acid and an aromatic dicarboxylic acid, and (ii) an isocyanate monomer; 1. A polyurethane adhesive composition comprising:

2. The polyurethane adhesive composition of claim 1 , wherein the polyurethane adhesive composition is solventless.

3. 2. The polyurethane adhesive composition of claim 1, wherein the dimer acid and aromatic dicarboxylic acid based polyester polyol is prepared from a reactive mixture of at least one dimer acid, at least one aromatic dicarboxylic acid, and at least one polyol.

4. 4. The polyurethane adhesive composition of claim 3, wherein the weight ratio of said at least one aromatic dicarboxylic acid to said at least one dimer acid is greater than 0 and less than 4.

2.

5. 4. The polyurethane adhesive composition of claim 3, wherein the at least one dimer acid is selected from the group consisting of acyclic dimer acids, cyclic dimer acids, aromatic dimer acids, polycyclic dimer acids, and any combination thereof.

6. 4. The polyurethane adhesive composition of claim 3, wherein the at least one aromatic dicarboxylic acid is selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, and any combination thereof.

7. 2. The polyurethane adhesive composition of claim 1, wherein the polyol component comprises from 1% to 50% of the phosphoric acid modified polyol and from 1% to 99% of the vegetable oil modified polyol, by weight of the polyol component.

8. The polyurethane adhesive composition of claim 1, wherein said isocyanate component and said polyol component have an NCO / OH molar ratio of from 0.9:1 to 1.95:

1.

9. An isocyanate agent for use in a polyurethane adhesive composition comprising an NCO-terminated polyurethane prepolymer that is the reaction product of (i) a polyester polyol based on a dimer acid and an aromatic dicarboxylic acid, and (ii) an isocyanate monomer.

10. 13. A method of using the polyurethane adhesive composition of claim 1, comprising: (a) providing a polyurethane adhesive composition according to claim 1; (b) contacting the polyol component and the isocyanate component to form a curable mixture; (c) applying the curable mixture to a first substrate to which at least a second substrate is to be joined; (d) contacting the second substrate with the first substrate such that at least a portion of the curable mixture is sandwiched between the first substrate and the second substrate; (e) curing or allowing the curable mixture to cure.

11. 10. Use of the polyurethane adhesive composition of claim 1 in a battery pack.

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