KR20200003442A - A composition and method for preparing the same - Google Patents

Abstract

The present invention relates to a method for producing a two-part urethane-based adhesive composition. The urethane-based adhesive composition having the constant curing rate can be provided, thereby improving the processability associated with the production of a battery module. The two-part urethane-based adhesive composition comprises: a main agent unit including a polyol resin, an additive, and a catalyst; and a curing agent unit including a polyisocyanate compound.

Description

A composition and method for preparing the same

The present application relates to a composition and a method of manufacturing the same.

The secondary battery includes a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery or a lithium secondary battery, and a lithium secondary battery is typical.

Lithium secondary batteries mainly use lithium oxide and carbon materials as positive and negative electrode active materials, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode active material and a negative electrode active material are respectively coated, and an electrode assembly in which a negative electrode plate is disposed with a separator interposed therebetween, and an exterior material for sealingly accommodating the electrode assembly together with an electrolyte solution. And pouch type secondary batteries. Such a single secondary battery may be referred to as a battery cell.

In the case of medium and large devices such as automobiles and power storage devices, a battery module in which a large number of battery cells are electrically connected to each other or a battery pack in which a plurality of such battery modules are connected may be used to increase capacity and output power.

One of the methods of configuring the battery module or the battery pack as described above is to use an adhesive material to fix the plurality of battery cells inside the battery module. In this case, the adhesive material may be injected into the battery module through an injection hole formed in the surface of the battery module.

One object of the present application is to provide an adhesive composition which has a constant curing rate after being injected into a battery module and can improve process efficiency.

Another object of the present application is to provide a battery module having excellent heat dissipation performance, a battery pack including the battery module, and a vehicle including the same.

The above and other objects of the present application can all be solved by the present application described in detail below.

In one example of the present application, the present application relates to an adhesive composition for use in a battery module or battery pack.

The composition prepared according to the present application is a two-component urethane-based composition. Two-component urethane means a polyurethane formed by mixing an isocyanate compound and a polyol compound, and is distinguished from a one-component polyurethane having a urethane group in a single composition.

In the case of the two-component polyurethane, a main agent including a polyol and a curing agent including an isocyanate may be reacted at room temperature to cure. That is, the composition prepared according to the present application may be a room temperature curing type. In the present application, "room temperature" is a state in which it is not particularly warmed or reduced, and any temperature within a range of about 10 ° C or more and less than 30 ° C, for example, about 15 ° C or more, about 18 ° C or more, about 20 ° C or more or about 23 ° C. or higher and about 27 ° C. or lower. The room temperature curing type two-component urethane-based composition in which curing is performed while mixing a main component and a curing agent component may include a physical mixture of the main component (polyol) and the curing agent component (isocyanate), and / or a reactant of the main component and the curing agent component. (Cured product).

Specifically, the composition may include a main portion including at least a polyol resin, and a curing agent portion including at least a polyisocyanate compound. Accordingly, the cured product of the resin composition may include both the polyol-derived unit and the polyisocyanate-derived unit. In this case, the polyol-derived unit may be a unit formed by a polyol reacting with a polyisocyanate and a urethane, and the polyisocyanate-derived unit may be a unit formed by reacting a polyol with a urethane.

The composition may include a predetermined catalyst for the progress of the urethane curing reaction. In addition, the compositions of the present application having the uses described below may further comprise additives for implementing certain functions. For example, additives may be used to secure thixotropy as needed in the process, or to secure physical properties such as thermal conductivity, insulation, heat resistance (TGA analysis), and heat dissipation (thermal conductivity).

Specifically, the composition is injected into the case of the battery module and can be used to contact the one or more battery cells present in the battery module to secure the battery cell within the module case. Regarding the above use, it will be described with reference to FIGS.

1 shows an example module case 10 comprising one bottom plate 10a and four sidewalls 10b. 2 is a schematic view of the module case 10 of FIG. 2 in which the battery cells 20 are housed. As shown in Figure 1, the module case may further include a top plate (10c) for sealing the interior space. As shown in FIG. 3, a hole may be formed in the lower plate, the side wall, and / or the upper plate of the module case. The hole may be an injection hole 50a used to inject the resin composition, and the observation hole 50b formed to observe whether the composition injected through the injection hole is well injected to the end of the side wall, the lower plate or the upper plate. Can be. The injection hole 50a may be located at an approximately middle portion of the lower plate 10a, and the observation hole 50b may be formed at the ends of the upper plate and the lower plate on which the injection hole is formed. The method of injecting the resin composition into the module case is not particularly limited, and a known method may be applied. For example, the resin composition is poured into the opening of the module case to inject the resin composition, or the resin composition is injected through the above-described injection holes formed in the module case, the resin composition in both the battery cell and the battery module. The method of applying this may be applied. The implantation process may be performed while constantly vibrating the battery module or battery cell for proper fixation. The manner of curing the resin composition to fix the battery cell is also not particularly limited. For example, a method of maintaining the injected composition at room temperature for a predetermined time may be used, or curing may be performed by applying heat in a range of about 30 ° C. to 50 ° C. for a predetermined time at a level that does not impair the thermal stability of the cell.

Regarding the curing of the composition injected into the battery module, there is a problem in that uniform injection into the module is not easy when the curing rate of the composition in which each component is blended is so high that the viscosity is sharply increased. On the other hand, if the adhesive injected into the battery module does not cure sufficiently after a predetermined time due to a slow curing rate, the adhesive has a low viscosity. Leaks or parts may be contaminated, and the interface between the parts to be bonded through the adhesive may be raised. As such, when the curing speed is not constant, the characteristics (eg, impact durability, insulation, heat dissipation, adhesiveness, etc.) to be imparted to the battery module through the cured product may not be sufficiently realized. In particular, the adhesive component used in the battery module may include an excess of additives (eg, a heat dissipating filler, an insulating filler, etc.) in order to ensure heat dissipation performance or insulation, in which case the viscosity of the composition is greatly increased, Injection processability of the battery module may be deteriorated. In view of this point, it can be said that securing an appropriate curing rate is very important.

On the other hand, when the resin composition is back discharged to the outside of the battery module due to excessive injection into the battery module, etc., the back discharged resin composition should be removed. Before injecting the resin composition into the battery module through the injection hole formed in the battery module, the adhesive tape is attached to the injection hole of the battery module, and the resin is discharged back while peeling off the adhesive tape after a certain time after the resin composition is injected. The compositions can be removed together. In this case, the back discharged resin composition may be removed from the battery module without a residue depending on the degree of curing of the resin composition. The removal of the back discharged resin composition without residue from the battery module means that when the back discharged resin composition is removed from the resin composition injected into the battery module, the removed portion does not leave a tail as if it is drooping. It may mean to be separated from the resin composition injected into the battery module. 4 is an exemplary photograph showing a removal state of the resin composition. 4 is an exemplary photograph showing a state in which the resin composition is removed without a residue, and a photograph on the right is an example photograph showing a state in which the resin composition is removed with a residue. In consideration of additional processability after composition injection, it is preferable to shorten the time point at which the discharged resin composition can be removed from the battery module without residue.

Adhesive composition of the present application is a composition that can provide a constant curing rate in the manufacturing process, may be a composition prepared in consideration of compatibility with the polyol. The criterion for determining compatibility in the present application is mixing energy as described below.

Specifically, the composition may be prepared by mixing the polyol-containing main portion and the polyisocyanate compound-containing curing agent portion. In this case, the main part may include a polyol resin, an additive, and a catalyst. That is, as described below, in consideration of the compounding energy of each component and the rate determining step of the urethane reaction, etc., the composition of the present application includes a polyisocyanate compound containing a polyisocyanate compound. It may be a composition formed by mixing with a curing agent portion.

In one example, the composition may include the polyisocyanate compound and / or additives that satisfy each of Equation 1 below.

[Equation 1]

δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <0

In Equation 1, the unit of energy is Kcal / mol, the solvent is a polyol resin, and the solute is a polyisocyanate mixture or additive.

The main part may have a viscosity measured at room temperature and a shear rate of 2.5 / s at a range of 100,000 to 400,000 cP. If less than the above range, since the viscosity is too low, contamination or interfacial peeling of components may occur during the movement of the battery module in which the adhesive composition is injected. In addition, when it exceeds the said range, since a viscosity is too high, it is not suitable for the injection process into a battery module. The viscosity of the subject portion can be measured by a rheometer (ARES).

The mixing energy may be calculated using COSMOlogic's COSMO-RS theoretical calculation package COSMOtherm (version C30_1301) and DFT calculation package Turbomole (version 6.5). Specifically, the BP_TZVP_C30_1301 parameter set is used as the COSMOtherm, and the BP functional / def-TZVP basis may be used in the case of Turbomole. In general, _{ΔG fus} when calculating the blended energy The value of can also be considered. In this application, since each constituent material related to the compounding energy calculation is assumed to be in the liquid state, the value is treated as zero.

In addition, in Equation 1, the mixing energy of the solvent and the self mixing energy of the solute may be a value calculated at a specific temperature in the range of −40 to 120 ° C. For example, the 'mixed energy of the solvent' and the 'self-mixed energy of the solute' may both be a value measured at 40 ℃, in this case, the blending energy of Equation 1 is a blending energy at 40 ℃ less than 0 To have.

Since the compounding energy of Equation 1 is determined in a relative relationship with a polyol which is a solvent, the lower limit may be determined according to the material selected for forming the composition, and the value thereof is not specified. When using a polyisocyanate compound and additives having the properties or configurations described below, the lower blending energy value of Equation 1 may be about -2.5, -2, -1.5-1.0 or -0.5.

When the polyisocyanate compound or additive satisfies Equation 1 above, it means that the polyisocyanate compound or additive is excellent in blendability with the polyol, compared to other materials that do not satisfy the above formula. Uniform formulation allows each component in the composition to have a good dispersion, thus contributing to achieving a uniform cure rate.

Specific components for satisfying the compounding energy, and at the same time to provide the physical properties required for the adhesive for the battery module after curing is as follows.

In one example, an ester-based polyol resin may be used as the polyol resin included in the main part. In the case of using an ester-based polyol, it is advantageous to ensure excellent adhesion in the battery module after curing the resin composition.

In one example, as the ester polyol, for example, a carboxylic acid polyol or a caprolactone polyol may be used.

The carboxylic acid-based polyol may be formed by reacting a component including a carboxylic acid and a polyol (ex. Diol or triol, etc.), and the caprolactone-based polyol may include caprolactone and a polyol (ex. Diol or triol). It can form by making a component react. In this case, the carboxylic acid may be a dicarboxylic acid.

In one example, the polyol may be a polyol represented by the following Chemical Formula 1 or 2.

[Formula 1]

[Formula 2]

In formulas (1) and (2), X is a unit derived from carboxylic acid, and Y is a unit derived from polyol. The unit derived from a polyol may be a triol unit or a diol unit, for example. Also, n and m can be any number.

In the above formula, the carboxylic acid-derived unit is a unit formed by reacting a carboxylic acid with a polyol, and the polyol-derived unit is a unit formed by reacting a polyol with a carboxylic acid or caprolactone.

That is, when the hydroxyl group of the polyol and the carboxyl group of the carboxylic acid react, the water (HO ₂ ) molecules are detached by the condensation reaction, and an ester bond is formed. After that means a portion except the ester bond portion. In addition, Y is a part except the ester bond after a polyol forms an ester bond by the said condensation reaction. The ester bond is shown in the formula (1).

In addition, Y of the formula (2) also represents a portion excluding the ester bond after the polyol forms an ester bond with the caprolactone. The ester bond is shown in the formula (2).

Meanwhile, when the polyol-derived unit of Y in the formula is a unit derived from a polyol including three or more hydroxy groups, such as a triol unit, a structure in which a branch is formed in the Y part in the formula structure may be implemented.

In Chemical Formula 1, the type of the carboxylic acid-derived unit of X is not particularly limited, but in order to secure desired physical properties, phthalic acid units, isophthalic acid units, terephthalic acid units, trimellitic acid units, tetrahydrophthalic acid units, hexahydrophthalic acid units, Tetrachlorophthalic acid unit, oxalic acid unit, adipic acid unit, azelaic acid unit, sebacic acid unit, succinic acid unit, malic acid unit, glataric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2,2-dimethyl It may be any one unit selected from the group consisting of succinic acid unit, 3,3-dimethylglutaric acid unit, 2,2-dimethylglutaric acid unit, maleic acid unit, fumaric acid unit, itaconic acid unit and fatty acid unit. . In view of the low glass transition temperatures in the above-described ranges, aliphatic carboxylic acid derived units may be preferred over aromatic carboxylic acid derived units.

On the other hand, the type of the polyol-derived unit of Y in the general formula (1) and (2) is not particularly limited, in order to ensure the desired physical properties, ethylene glycol units, diethylene glycol units, propylene glycol units, 1,2-butylene glycol units, 2,3-butylene glycol unit, 1,3-propanediol unit, 1,3-butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentyl glycol unit, 1,2-ethylhexyl Diol units, 1,5-pentanediol units, 1,9-nonanediol units, 1,10-decanediol units, 1,3-cyclohexanedimethanol units, 1,4-cyclohexanedimethanol units, glycerin units and It may be any one or more selected from the group consisting of trimethylolpropane units.

Meanwhile, n in Formula 1 may be any number, and the range may be selected in consideration of the desired physical properties of the resin composition or the cured resin layer thereof. For example, n may be about 2-10 or 2-5.

In addition, m in the formula (2) is an arbitrary number, the range may be selected in consideration of the desired physical properties of the resin composition or the cured resin layer thereof, m is about 1 to 10 or 1 to 5 days Can be.

When n and m in the formulas (1) and (2) are out of the above ranges, the crystalline expression of the polyol may become stronger and may adversely affect the injection processability of the composition.

The molecular weight of the polyol may be adjusted in consideration of the low viscosity characteristics, durability, or adhesiveness described below, for example, may be in the range of about 300 to 2,000. Unless otherwise specified, in the present specification, "molecular weight" may be a weight average molecular weight (Mw) measured using GPC (Gel Permeation Chromatograph). If it is out of the above range, the resin layer may not be reliable after curing, or problems related to volatile components may occur.

In the present application, the polyisocyanate may mean a compound including two or more isocyanate groups.

In the present application, the kind of polyisocyanate included in the curing agent portion is not particularly limited, but a non-aromatic isocyanate compound containing no aromatic group may be used to secure desired physical properties. That is, it may be advantageous to use aliphatic or cycloaliphatic series. When using an aromatic polyisocyanate, since the reaction rate is too fast and the glass transition temperature of the cured product may be high, it may be difficult to secure processability and physical properties suitable for use of the present application composition.

For example, aliphatic or alicyclic cyclic polyisocyanates or modified substances thereof can be used. Specifically, aliphatic polyisocyanate, such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate or tetramethylene diisocyanate; Aliphatic cyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isophorone diisocyanate, bis (isocyanatemethyl) cyclohexane diisocyanate or dicyclohexylmethane diisocyanate; Or at least one of the above carbodiimide-modified polyisocyanates and isocyanurate-modified polyisocyanates; And the like can be used. In addition, mixtures of two or more of the compounds listed above may be used.

The ratio of the polyol (derived) component and the polyisocyanate (derived) component in the resin composition is not particularly limited and may be appropriately adjusted to enable urethane reaction therebetween.

The polyol resin and the isocyanate component included in the urethane composition may have a glass transition temperature (Tg) of less than 0 ° C. after curing. In the present application, the "glass transition temperature after hardening" refers to the NCO peak reference conversion rate near 2250 cm ^{-1 as} confirmed by FT-IR analysis, based on a 24-hour curing state at room temperature and 30 to 70% relative humidity conditions. glass transition temperature measured for a cured product having a conversion of 80% or more.

When the glass transition temperature range is satisfied, the brittle characteristic can be secured within a relatively short time even at a low temperature at which the battery module or the battery pack can be used, and thus shock resistance and vibration resistance can be ensured. Can be. On the other hand, when the said range is not satisfied, there exists a possibility that the adhesiveness (tacky) of hardened | cured material may be too high or thermal stability may fall. In one example, the lower limit of the glass transition temperature of the urethane-based composition after curing may be-70 ℃ or more,-60 ℃ or more,-50 ℃ or more,-40 ℃ or more or-30 ℃ or more, the upper limit is-5 C or less, -10 degrees C or less, -15 degrees C or less, or -20 degrees C or less.

In one example, the composition may be formulated with a thermally conductive (heat resistant) filler as an additive. As used herein, the term thermally conductive filler may refer to a material having a thermal conductivity of about 1 W / mK or more, about 5 W / mK or more, about 10 W / mK or more, or about 15 W / mK or more. Specifically, the thermal conductivity of the thermally conductive filler may be about 400 W / mK or less, about 350 W / mK or less or about 300 W / mK or less. The type of thermally conductive filler that can be used is not particularly limited, but may be a ceramic filler in consideration of insulation and the like. For example, ceramic particles such as alumina, aluminum nitride (AlN), boron nitride (BN), silicon nitride, SiC, or BeO may be used. The form or ratio of the filler is not particularly limited, and is appropriately adjusted in consideration of the viscosity of the urethane-based composition, the possibility of sedimentation in the cured resin layer, the desired thermal resistance or thermal conductivity, insulation, filling effect or dispersibility, and the like. Can be. In general, the larger the size of the filler, the higher the viscosity of the composition including the same, and the higher the possibility that the filler precipitates in the resin layer. In addition, the smaller the size, the higher the heat resistance tends to be. Therefore, in consideration of the above point, a filler of an appropriate type and size may be selected, and two or more fillers may be used together if necessary. In addition, it is advantageous to use a spherical filler in consideration of the filling amount, but fillers in the form of a needle or plate may be used in consideration of the formation of a network or conductivity.

In one example, the composition may include a thermally conductive filler having an average particle diameter in the range of 0.001 μm to 80 μm. In another example, the average particle diameter of the filler may be at least 0.01 μm, at least 0.1 μm, at least 0.5 μm, at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, or at least about 6 μm. The average particle diameter of the filler is, in another example, about 75 μm or less, about 70 μm or less, about 65 μm or less, about 60 μm or less, about 55 μm or less, about 50 μm or less, about 45 μm or less, about 40 μm or less, about 35 μm or less, about 30 μm or less, about 25 μm or less, about 20 μm or less, about 15 μm or less, about 10 μm or less, or about 5 μm or less.

In order to obtain excellent heat dissipation performance, it may be considered that a high content of thermally conductive filler is blended. For example, the filler may be used in the range of about 50 to 2,000 parts by weight, based on 100 parts by weight of the total resin component, that is, the total content of the ester-based polyol resin and the polyisocyanate. In another example, the filler content may be used in excess of the total resin component. Specifically, based on 100 parts by weight of the total content of the ester-based polyol resin and polyisocyanate, about 100 parts by weight or more, about 150 parts by weight or more, about 200 parts by weight or more, about 250 parts by weight or more, about 300 parts by weight, At least about 350 parts by weight, at least about 400 parts by weight, at least about 500 parts by weight, at least about 550 parts by weight, at least about 600 parts by weight or at least about 650 parts by weight of fillers may be used. In one example, when the filler is used in the above range, it may be dispensed in the same amount in the main portion and the hardener portion.

As described above, in order to secure heat dissipation (thermal conductivity) or in order to obtain thixotropy according to a process necessity, an excess filler may be included in the composition. The processability when injecting the composition into the case may be worse. Therefore, there is a need for a low viscosity characteristic sufficient to include an excess of filler but not to interfere with fairness.

In one example, each of the ester-based polyol resin and the polyisocyanate compound component may have a viscosity of 10,000 cP or less. Specifically, the resin component may have a viscosity of 8,000 cP or less, 6,000 cP or less, 4,000 cP or less, 2,000 cP or 1,000 CP or less. Preferably, the upper limit of the viscosity may be 900 cP or less, 800 cP or less, 700 cP or less, 600 cP or less, 500 cP or less, or 400 cP or less. Although not particularly limited, the lower limit of the viscosity of each resin component may be 50 cP or more or 100 cP or more. If the viscosity is too low, the fairness may be good, but as the molecular weight of the raw material is lowered, the likelihood of volatilization may increase, and heat resistance / cold resistance, flame retardancy, and adhesive strength may deteriorate. Such disadvantages may be prevented by satisfying the lower limit. The viscosity can be measured at room temperature, for example using a Brookfield LV type viscometer.

On the other hand, ester-based polyols are advantageous for securing adhesiveness after curing, but because of their strong crystallinity, they are likely to be in a wax state at room temperature, and have disadvantages in securing proper injection processability due to an increase in viscosity. Even if the viscosity is lowered through melting, the crystallinity naturally occurring during the storage process causes a viscosity increase due to crystallization in the injection or application process of the composition which may follow after mixing with the filler. As a result, fairness may be reduced. In consideration of this point, the ester polyol used in the present application may satisfy the following characteristics.

In the present application, the ester-based polyol may be amorphous or polyol having a low enough crystallinity. "Amorphous" means the case where no crystallization temperature (Tc) and melting temperature (Tm) are observed in DSC (Differential Scanning calorimetry) analysis. At this time, the DSC analysis can be carried out in the range of -80 to 60 ℃ at a rate of 10 ℃ / min, for example, after the temperature is raised from 25 ℃ to 50 ℃ at the rate-to 70 ℃, and again It may be made by heating up to 50 ℃. In addition, the above-mentioned "low enough crystallinity" means that the melting point or melting temperature (Tm) observed in the DSC analysis is less than 15 ° C, about 10 ° C or less, 5 ° C or less, 0 ° C or less, -5 ° C or less, It means the case of -10 degrees C or less, or -20 degrees C or less. In this case, the lower limit of the melting point is not particularly limited, but for example, the melting point may be about −80 ° C. or more, about −75 ° C. or more, or about −70 ° C. or more. In the case where the polyol is crystalline or has a strong (at room temperature) crystallinity such as not satisfying the melting point range, the viscosity difference with temperature tends to be large, so that the filler dispersion and the viscosity of the final mixture in the process of mixing the filler and the resin It may adversely affect, lower the processability, and as a result it may be difficult to meet the cold resistance, heat resistance and water resistance required in the adhesive composition for the battery module.

In addition to the above-mentioned thermally conductive fillers, various kinds of additives may be used. For example, in order to secure the insulating properties of the resin layer on which the resin composition is cured, the use of a carbon (based) filler such as graphite may be considered. Alternatively, for example, fillers such as fumed silica, clay or calcium carbonate may be used. The form or content ratio of the filler is not particularly limited and may be selected in consideration of the viscosity of the resin composition, the possibility of sedimentation in the resin layer, thixotropy, insulation, filling effect or dispersibility.

In addition, the composition may be a viscosity modifier such as a thixotropy agent, a surface treatment agent, a coupling agent, a diluent, a dispersant to adjust the required viscosity, for example to increase or decrease the viscosity or to adjust the viscosity according to shear force. And additives such as the like.

The thixotropic agent may adjust the viscosity according to the shear force of the resin composition so that the manufacturing process of the battery module is effectively performed. Examples of the thixotropic agent that can be used include fumed silica and the like.

The surface treating agent is for surface treatment of the filler introduced into the resin layer, and various kinds known in the art can be used without limitation as long as it can exhibit the above-described action.

In the case of the coupling agent, for example, it can be used to improve the dispersibility of a thermally conductive filler such as alumina, and various kinds known in the art can be used without limitation as long as it can exhibit the above action.

Diluents or dispersants are usually used to lower the viscosity of the resin composition, so long as they can exhibit the same action can be used without limitation various kinds known in the art.

In one example, an anionic phosphate ester-based dispersant may be used as the dispersant. Phosphoric acid ester-based dispersant is not particularly limited as long as it includes a unit of the formula (1).

[Formula 3]

 In Formula 3, R1 and R2 may each independently be hydrogen, an alkyl group having 1 to 20 carbon atoms, or a polyalkylene oxide having n alkylene oxide repeat units having 1 to 4 carbon atoms. The repeating unit n may be 1 to 5.

The type or polarity of other functional groups or chemical structures bonded to one terminal of Chemical Formula 3 is not particularly limited. For example, the dispersant may be adsorbed onto the filler surface through the functional group of Formula 3, and steric hindrance, steric repulsion required for dispersion by another functional group or chemical structure that binds to one end of the Formula 3 functional group. It is sufficient to be able to obtain a steric repulsion or ionic repulsion effect.

In addition, the resin composition may further include a flame retardant or a flame retardant aid. In this case, a known flame retardant may be used without particular limitation, and for example, a solid filler-type flame retardant or a liquid flame retardant may be applied. Flame retardants include, for example, organic flame retardants such as melamine cyanurate and inorganic flame retardants such as magnesium hydroxide. When the amount of filler filled in the resin layer is large, a liquid type flame retardant material (TEP, Triethyl phosphate or TCPP, tris (1,3-chloro-2-propyl) phosphate, etc.) may be used. In addition, a silane coupling agent may be added that can act as a flame retardant synergist.

The kind of catalyst included in the composition is not particularly limited, and a known catalyst may be used. For example, an iron-based (center) catalyst or a tin (center) catalyst and the like can be used.

In one example, the catalyst may satisfy the following equation (2).

[Equation 2]

δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <2.5

In Equation 2, the unit of energy is Kcal / mol, the solvent is a polyol resin, and the solute is a catalyst.

In the case of the catalyst used in the composition, the blending energy may be greater than that of the isocyanate compound or additive described above. That is, the blendability of the catalyst with the polyol may be lower than the rest of the components. In theory, as in Equation 1, it is preferable that the blending energy value of the catalyst and the polyol is less than 0, but considering the catalyst component used in practice, the blending energy represented by the formula 2 may have a value greater than about 0. For example, the lower limit can be about 2.0, 1.5, 1.0, or 0.5. When the catalyst component having the blending energy represented by the above formula (2) is included in the composition, as described below, it is preferable that the catalyst component having the larger blending energy is blended with the polyol before the other components when preparing the composition. .

The composition may include a composition as described above, and may also be a solvent-type composition, an aqueous composition, or a solvent-free composition, but considering the convenience of the manufacturing process described below, a solvent-free type may be appropriate.

In another example relating to the present application, the present application relates to a method of blending or preparing the compositions described above. The preparation method may be performed while adjusting the blending order of the polyol and the individual components according to the blending energy of the isocyanate compound, the additive, and the catalyst with respect to the polyol. Specifically, the preparation method may be performed while calculating the blending energy of each of the polyisocyanate compound, the additive, and the catalyst, and first blending the component having the high calculated blending energy with the polyol resin.

As described above, each component used to prepare the composition of the present application is selected so as to satisfy a predetermined compounding energy and at the same time provide the necessary properties for the adhesive for the battery module after curing.

The manufacturing method may include a step of blending a polyisocyanate or an additive that satisfies the following Equation 1 with the polyol resin.

[Equation 1]

δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <0

In Equation 1, the unit of energy is Kcal / mol, the solvent is a polyol resin, and the solute is a polyisocyanate mixture or additive.

In addition, the manufacturing method may further comprise the step of combining the catalyst satisfying the following equation (2) with a polyol resin.

[Equation 2]

δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <2.5

In Equation 2, the unit of energy is Kcal / mol, the solvent is a polyol resin, and the solute is a catalyst.

Specific contents related to Equations 1 and 2 are the same as those described in the above composition.

In the present application, the formulation may mean that two or more components are physically mixed. For example, referring to a polyol, it may mean that one or more of the polyol and components other than the polyol are physically mixed. Therefore, the above formulation may be used to encompass not only the case where a mixture containing a polyol and a catalyst is prepared, but also a case where an isocyanate and / or additive component is additionally added to the mixture of the polyol and the catalyst.

Regarding the calculated compounding energy, the manufacturing method may be performed in the following manner.

For example, if the blending energy of the polyol and the catalyst is the largest, followed by the blending energy of the polyol and the additive, and the blending energy of the polyol and the polyisocyanate is large, then the polyol and the catalyst can be blended first. . The greatest mixing energy of the catalyst and polyol means that the compatibility between the catalyst and the polyol is poor. That is, when other components (eg, isocyanates and / or additives) are combined with the polyol before the catalyst or before all the components constituting the two-component urethane-based composition are mixed at the same time before the polyol and the catalyst are blended, This means that the reaction between and the catalyst can be interrupted by other components. Therefore, it is advantageous to ensure a constant curing rate by admixing a catalyst having a high blending energy, that is, a low compatibility with the polyol, with the polyol first and then mixing other components to proceed the urethane reaction. In one example, the method may be performed by first blending the polyol resin and the catalyst, followed by further compounding the additive and the polyisocyanate compound sequentially. That is, in one example, the manufacturing method may be a method for preparing a two-component urethane-based adhesive composition formed by mixing a main part prepared to include a polyol resin, an additive, and a catalyst with a curing agent part including a polyisocyanate compound.

It is known that the binding (binding) of the catalyst and the polyol in the urethane reaction is a rate determining step. When the compounding sequence is as described above, the catalyst and the polyol may form a condition in which a uniform complex is formed. It is thought to be able to have a uniform curing rate when meeting with the polyol. Thus, the composition prepared according to the present application can provide improved processability.

It is preferable that compounding is made at the temperature above normal temperature. For example, it may be made at 30 to 70 ℃ or less, or 40 to 60 ℃ or less. When the compound is satisfied to satisfy the above temperature, the viscosity measured at the normal temperature and the shear rate of 2.5 / s may satisfy the range of 100,000 to 400,000 cP. In the case of the compounding, thixotropy occurs as the additive, for example, the heat dissipating filler or the flame retardant component is broken, but because the temperature is low at the temperature below the temperature, the additive component is more broken and thus the viscosity becomes excessively high. .

The blending time is not particularly limited but may be blended for at least 20 minutes or at least 30 minutes for components having the lowest compatibility with polyols, for example, catalysts, and for the remaining components having good compatibility. Formulation may take place for at least 1 minute or at least 5 minutes. The upper limit of the blending time may be appropriately selected in consideration of the curing rate or degree of curing, and may be, for example, 10 hours or less or 5 hours or less. For this formulation, for example, equipment such as a planatary mixer, a trimixer, a paste mixer, a reactor, and a milling mill can be used.

In one example, the blending may be at a temperature that is approximately equal to or the same as the temperature at which the blending energy is measured. The difference between the temperature at which the blending energy is measured and the temperature at which the actual blending is made may be about ± 10 ° C or ± 5 ° C. For example, if the blending energy is calculated at 40 ° C, the blending may also be done at 40 ° C or near 30 to 50 ° C. Alternatively, the blending may be performed at a temperature above the temperature at which the blending energy is measured.

According to an example of the present application, a urethane-based adhesive composition having a constant curing rate may be provided. Accordingly, the fairness associated with battery module manufacturing can be improved.

1 illustrates an example module case that may be applied in the present application.
2 schematically illustrates a form in which a battery cell is accommodated in a module case.
3 schematically illustrates an example bottom plate in which injection and observation holes are formed.
4 is an exemplary photograph showing a removal state of the resin composition.
Figure 5 shows the results of the blending energy measurement of the polyol of the components prepared in Example 1.

Hereinafter, the battery module of the present application will be described through Examples and Comparative Examples. However, the scope of the present application is not limited by the scope given below.

Related evaluation method

* Mixing energy of each component : COSMOlogic's COSMO-RS theoretical calculation package COSMOtherm (version C30_1301) and DFT calculation package Turbomole (version 6.5) were used to calculate the blended energy. COSMOtherm used the BP _TZVP_C30_1301 parameter set and Turbomole used the BP functional / def-TZVP basis. The compounding energy was calculated in the range of -40 to 120, and the result is shown in FIG. Table 1 only records the results for some temperature intervals.

* Viscosity: The viscosity of the main part was measured under shear rate conditions from 0.01 to 10.0 / s using a rheometer (ARES). The viscosity reported in Tables 2 and 3 below is at the 2.5 / s point.

* Remove tape: The tape having an opening for accommodating the resin composition was attached to the aluminum battery module case used for manufacturing the battery module, the resin composition was applied to the opening of the attached tape, and the tape was removed after 80 minutes. When the cured resin composition can be removed from the battery module without residue was measured.

Thermal conductivity: The thermal conductivity of the adhesive sample formed from the composition was measured using a hot disk device. In the case of hot disk equipment, it follows the ISO 22007-2 standard, and a nickel spiral double spiral sensor measures the temperature change (electric resistance change) while heating. Specifically, the main part and the hardener component were put in a two-component cartridge, respectively, mixed at a ratio of 1: 1, and applied to a mold having a thickness of 5 mm or more, and the samples were cured. The hardened sample was measured for thermal conductivity in the through plane direction using a hot disk device.

Example  And Comparative example

Example  One

Components of the Composition

A component for preparing a two-component urethane composition was prepared as follows.

Polyol: A sock end polyol (normal temperature viscosity of 260 cps) formed by esterifying butanediol and caprolactone at a level of about 1.2: 7.8 was used.

Isocyanate: An isocyanate (normal temperature viscosity of 170 cps) formed by urea-linked amine linked to isocyanurate with hexamethylene diisocyanate (HDI) was used.

Additives: A liquid flame retardant (phosphorus (P) component content of 10-12%) was used 15 parts by weight based on 100 parts by weight of the main body. In addition, 0.27 parts by weight of the phosphoric acid dispersant (BYK 111) was used based on 100 parts by weight of the main ingredient.

Catalyst Ingredient: Dibutyltin Dilaurate (DBTDL)

Preparation of the composition

The polyol was combined with the catalyst at 40 ° C. for 50 minutes. Thereafter, a flame retardant and a dispersant were added to the blend of the polyol and the catalyst and blended at 40 ° C. for 10 minutes. Thereafter, the thermally conductive filler (alumina) was divided into three sizes (2, 20, and 40 µm), divided into three portions, and a main portion was prepared. The ratio of the injected thermally conductive filler is 1,000 parts by weight relative to 100 parts by weight of the total polyol. The viscosity of the prepared main parts is shown in Table 2.

Thereafter, a polyisocyanate (curing agent part) and the main part were combined to prepare a urethane composition. The results of measuring tape fairness and thermal conductivity are shown in Table 2.

Example  2

It mix | blended in the same procedure as Example 1 except having changed mix | blending conditions as shown in following Table 2. The measurement results regarding the viscosity, processability, and thermal conductivity are shown in Table 2.

Example  3

It mix | blended in the same procedure as Example 1 except having changed mix | blending conditions as shown in following Table 2. The measurement results regarding the viscosity, processability, and thermal conductivity are shown in Table 3.

Comparative example  One

Unlike Example 1, all the components were mixed at the same time, and blended for 10 minutes at 40 ℃ condition to prepare a urethane composition. The measurement results regarding the viscosity, processability, and thermal conductivity are shown in Table 3.

Comparative example  2

A urethane composition was prepared in the same manner as in Comparative Example 1 except that the mixing temperature conditions were changed to 20 ° C. The measurement results regarding the viscosity, processability, and thermal conductivity are shown in Table 3.

Comparative example  3

The urethane composition was manufactured like Example 1 except having changed the compounding temperature at the time of manufacture of a main part to 20 degreeC. The measurement results regarding the viscosity, processability, and thermal conductivity are shown in Table 2.

TABLE 1

TABLE 2

TABLE 3

10: module case
10a: bottom plate
10b: sidewall
10c: top plate
20: battery cell
50a: injection hole
50b: observation hall

Claims (18)

A main part comprising a polyol resin, an additive, and a catalyst, and having a viscosity measured at a point of normal temperature and shear rate of 2.5 / s satisfying 100,000 to 400,000 cP; And
It is a two-component urethane type adhesive composition containing the hardening | curing agent part containing a polyisocyanate compound,
The polyisocyanate compound and the additives each satisfy the following Equation 1:
[Equation 1]
δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <0
In Equation 1, the unit of energy is Kcal / mol, the solvent is a polyol resin, the solute is a polyisocyanate compound or an additive, and the mixed energy of the solvent and the self-mixing energy of the solute are any specific temperature within a range of -40 to 120 ° C. Calculated from The two-component urethane-based adhesive composition of claim 1, wherein the catalyst satisfies Equation 2.
[Equation 2]
δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <2.5
In Equation 2, the unit of energy is Kcal / mol, the solvent is a polyol resin, and the solute is a catalyst. The two-component urethane-based adhesive composition according to claim 2, which is formed by mixing a main portion prepared to include a polyol resin, an additive, and a catalyst with a curing agent portion containing a polyisocyanate compound. The two-component urethane-based adhesive composition according to claim 3, wherein the main part is prepared by sequentially mixing a polyol resin with a catalyst and an additive. The adhesive composition according to claim 1, wherein the polyol resin is an ester polyol and is an amorphous polyol or a polyol having a melting point (Tm) of less than 15 ° C. The two-component urethane-based composition of claim 1, wherein the ester polyol is represented by the following Chemical Formula 1 or 2:
[Formula 1]

[Formula 2]

In formulas (1) and (2), X is a carboxylic acid derived unit, Y is a polyol derived unit, n is a number in the range of 2 to 10, and m is a number in the range of 1 to 10. The carboxylic acid-derived unit X is a phthalic acid unit, isophthalic acid unit, terephthalic acid unit, trimellitic acid unit, tetrahydrophthalic acid unit, hexahydrophthalic acid unit, tetrachlorophthalic acid unit, oxalic acid unit, adipic acid Unit, azelaic acid unit, sebacic acid unit, succinic acid unit, malic acid unit, glataric acid unit, malonic acid unit, pimelic acid unit, suberic acid unit, 2, 2-dimethylsuccinic acid unit, 3,3-dimethylglutaric acid A two-component urethane-based composition which is at least one unit selected from the group consisting of units, 2,2-dimethylglutaric acid units, maleic acid units, fumaric acid units, itaconic acid units, and fatty acid units. The polyol-derived unit Y according to claim 6, wherein the polyol-derived unit Y is an ethylene glycol unit, a propylene glycol unit, a 1,2-butylene glycol unit, a 2,3-butylene glycol unit, a 1,3-propanediol unit, 1,3 -Butanediol unit, 1,4-butanediol unit, 1,6-hexanediol unit, neopentylglycol unit, 1,2-ethylhexyldiol unit, 1,5-pentanediol unit, 1,9-nonanediol unit, 1 Two-part form which is one or two or more units selected from the group consisting of 10-decanediol units, 1,3-cyclohexanedimethanol units, 1,4-cyclohexanedimethanol units, glycerin units and trimethylolpropane units Urethane-based composition. The two-component urethane composition according to claim 1, wherein the polyisocyanate compound is a non-aromatic polyisocyanate compound. The two-component urethane composition according to claim 9, wherein the polyisocyanate compound is an alicyclic polyisocyanate compound, a carbodiimide modified polyisocyanate compound of an alicyclic polyisocyanate, or an isocyanurate modified polyisocyanate compound of an alicyclic polyisocyanate. The method of claim 1, wherein the additive is a thermally conductive filler or an insulating filler, and the filler is fumed silica, clay, calcium carbonate, alumina, aluminum nitride (AlN), boron nitride, silicon nitride, and SiC. At least one two-component urethane-based composition selected from the group consisting of BeO and carbon filler. 12. The two-component urethane-based composition according to claim 11, comprising 50 to 2,000 parts by weight of a filler based on 100 parts by weight of the sum of the ester-based polyol resin and the polyisocyanate resin. The two-component urethane composition according to claim 11, further comprising at least one additive selected from the group consisting of thixotropic agents, surface treatment agents, coupling agents, diluents, dispersants, and flame retardants. The two-component urethane-based composition according to claim 2, wherein the catalyst is an iron catalyst or a tin catalyst. A method for producing a two-component urethane-based adhesive composition, which is performed by calculating a compounding energy for a polyol resin of each of a polyisocyanate compound, an additive, and a catalyst, and first blending a component having a high calculated compounding energy with a polyol resin. The method for producing a two-component urethane-based adhesive composition according to claim 15, which is formed by mixing a main part prepared to include a polyol resin, an additive, and a catalyst with a curing agent part containing a polyisocyanate compound,
Method for producing a two-component urethane-based adhesive composition comprising the step of blending a polyisocyanate compound or additive each satisfying the following formula 1 with a polyol resin at a temperature of 30 ℃ or more:
[Equation 1]
δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <0
In Equation 1, the unit of energy is Kcal / mol, the solvent is a polyol resin, the solute is a polyisocyanate mixture or additive, and the mixed energy of the solvent and the self mixing energy of the solute are any specific temperature in the range of -40 to 120 ° C. Calculated from The method of claim 16, further comprising combining the catalyst satisfying Equation 2 with a polyol resin:
[Equation 2]
δ (mixed energy) = (mixed energy of solvent)-(self-mixed energy of solute) <2.5
In Equation 2, the unit of energy is Kcal / mol, the solvent is a polyol resin, and the solute is a catalyst. The method for producing a two-component urethane-based adhesive composition according to claim 15, wherein the polyol resin and the catalyst are first blended, and the additive and the polyisocyanate compound are sequentially further blended.

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