Resin composition

Abstract

The present application relates to a composition, a battery module and a battery pack. According to one example of the present application, it is possible to provide a battery module and a battery pack which have improved heat dissipation properties, adhesive force, adhesion reliability and processability as well as excellent power to volume.

Claims

1. A urethane-based composition comprising: a main composition part comprising an ester-based polyol resin; a curing agent composition part comprising a non-aromatic polyisocyanate; and a filler, wherein the ester-based polyol resin comprised in the urethane-based composition consists of an ester-based polyol resin having a viscosity of 2,000 cP or less at room temperature, wherein the ester-based polyol resin is an amorphous polyol, in which a crystallization temperature (Tc) and a melting temperature (Tm) are not observed in a DSC (differential scanning calorimetry) analysis, or has a melting temperature (Tm) of less than 15° C., wherein the filler is comprised in an amount of 50 to 2,000 parts by weight relative to 100 parts by weight of the sum of the ester-based polyol resin and the polyisocyanate contents, wherein a mixture of the ester-based polyol resin and polyisocyanate has a glass transition temperature (Tg) of less than 0° C. after curing, and wherein the urethane-based composition is a two-component room temperature curable composition formulated to be able to be cured when the main composition part and the curing agent composition are mixed at room temperature.

2. The urethane-based composition according to claim 1, wherein the polyisocyanate has a viscosity of less than 10,000 cP, measured at room temperature.

3. The urethane-based composition according to claim 1, wherein the polyisocyanate has a viscosity of 2,000 cP or less, measured at room temperature.

4. The urethane-based composition according to claim 1, wherein the ester-based polyol resin is represented by the following formula 1 or 2: ##STR00002## wherein, X is a carboxylic acid-derived unit, Y is a polyol-derived unit, n is a number within a range of 2 to 10, and m is a number within a range of 1 to 10.

5. The urethane-based composition according to claim 4, wherein the carboxylic acid-derived unit X is one or more units selected from the group consisting of a phthalic acid unit, an isophthalic acid unit, a terephthalic acid unit, a trimellitic acid unit, a tetrahydrophthalic acid unit, a hexahydrophthalic acid unit, a tetrachlorophthalic acid unit, an oxalic acid unit, an adipic acid unit, an azelaic acid unit, a sebacic acid unit, a succinic acid unit, a malic acid unit, a glutaric acid unit, a malonic acid unit, a pimelic acid unit, a suberic acid unit, a 2,2-dimethylsuccinic acid unit, a 3,3-dimethylglutaric acid unit, a 2,2-dimethylglutaric acid unit, a maleic acid unit, a fumaric acid unit, an itaconic acid unit and a fatty acid unit.

6. The urethane-based composition according to claim 4, wherein the polyol-derived unit Y is any one or two or more units selected from the group consisting of 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, a 1,3-butanediol unit, a 1,4-butanediol unit, a 1,6-hexanediol unit, a neopentyl glycol unit, a 1,2-ethylhexyldiol unit, a 1,5-pentanediol unit, a 1,9-nonanediol unit, a 1,10-decanediol unit, a 1,3-cyclohexanedimethanol unit, a 1,4-cyclohexanedimethanol unit, a glycerin unit and a trimethylolpropane unit.

7. The urethane-based composition according to claim 1, wherein the non-aromatic polyisocyanate is an alicyclic polyisocyanate, a carbodiimide-modified alicyclic polyisocyanate, or an isocyanurate-modified alicyclic polyisocyanate.

8. The urethane-based composition according to claim 1, wherein the filler comprises alumina, AlN (aluminum nitride), BN (boron nitride), silicon nitride, SiC, or BeO.

9. The urethane-based composition according to claim 8, wherein the filler is contained in an amount of 100 to 2,000 parts by weight relative to 100 parts by weight of the sum of the ester-based polyol resin and polyisocyanate contents.

10. The urethane-based composition according to claim 1, which has a first adhesive force (S.sub.1) measured with respect to an aluminum pouch when the aluminum pouch is peeling off at a peeling angle of 180° and a peeling speed of 300 mm/min at room temperature after curing of 150 gf/10 mm or more.

11. The urethane-based composition according to claim 10, which has a ratio of a second adhesive force (S.sub.2) measured with respect to an aluminum pouch when the aluminum pouch is peeling off at a peeling angle of 180° and a peeling speed of 300 mm/min after curing and storage under the conditions of 40 to 100° C. and 75% relative humidity for 10 days to the first adhesive force (S.sub.1) of 70% or more.

12. A battery module comprising a module case having a top plate, a bottom plate and sidewalls, wherein an inner space is formed by the top plate, the bottom plate, and the sidewalls; a plurality of battery cells existing in the inner space of the module case; and a resin layer formed by curing the urethane-based composition according to claim 1 and in contact with the plurality of battery cells.

13. A battery pack comprising one or more battery modules according to claim 12.

14. An automobile comprising the battery module according to claim 12.

15. A method of manufacturing a battery module, comprising injecting the urethane-based composition according to claim 1 into a module case, housing a battery cell in the module case, and curing the urethane-based composition to form the resin layer.

16. The method of manufacturing battery module according to claim 15, wherein the curing of the urethane-based composition is performed by holding the resin composition at room temperature or heating at a temperature in a range of about 30° C. to 50° C. for a predetermined time.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows an example of determining an amorphous characteristic or a sufficiently low crystallizability of an ester-based polyol according to one example of the present application.

(2) FIG. 2 shows an exemplary module case, which can be applied in the present application.

(3) FIG. 3 schematically shows a form in which battery cells are housed in a module case.

(4) FIG. 4 schematically shows an exemplary bottom plate where injection holes and observation holes are formed.

(5) FIGS. 5 and 6 schematically show an exemplary battery pouch which can be used as a battery cell.

(6) FIGS. 7 and 8 schematically show the structure of an exemplary battery module.

(7) The respective reference numerals and symbols described in connection with the drawings are as follows. 10: module case 10a: bottom plate 10b: sidewall 10c: top plate 10d: guiding portion 20: battery cell 30: resin layer 50a: injection hole 50b: observation hole 40: insulating layer 100: pouch type cell 110: electrode assembly 120: exterior material 121: upper pouch 122: lower pouch S: sealing portion

BEST MODE

(8) Hereinafter, the battery module of the present application will be described with reference to Examples and Comparative Examples. However, the scope of the present application is not limited by the scope given below.

(9) Evaluation Methods

(10) 1. Amorphous Characteristic Based on Tm (Melting Point)

(11) The Tm for the polyol resin used in Examples and Comparative Examples was measured through a DSC analysis using Q2000 (TA instruments), while changing the temperature in the order of 25° C..fwdarw.50° C..fwdarw.−70° C..fwdarw.50° C. at a temperature elevation rate of 10° C./min.

(12) 2. Adhesive Force (S1) (Unit: Gf/10 mm)

(13) The aluminum pouch used to manufacture the battery cell was cut to a width of about 10 mm. The resin composition each used in Examples and Comparative Examples was loaded on a glass plate, and the cut aluminum pouch was loaded thereon so that the resin composition was in contact with the PET (poly(ethylene terephthalate)) side of the pouch and then the resin composition was cured under the conditions of 25° C. and 50% RH for 24 hours. Subsequently, while the aluminum pouch was peeled off at a peeling angle of 180° and a peeling speed of 300 mm/min with a tensile tester (texture analyzer), the adhesive force was measured.

(14) 3. Adhesion Reliability

(15) A specimen of the cured resin composition was produced in the same manner as in the above adhesive force measurement and stored under conditions of 85° C. and 85% RH for 10 days. Thereafter, the adhesive force (S.sub.2) was measured in the same manner as in Item 2 above.

(16) 4. Tg (Glass Transition Temperature)

(17) The mixture of the same resins (without any filler) as used in Examples and Comparative Examples was cured at room temperature for 24 hours, and the Tg of the cured product was measured by a DSC analysis, while changing the temperature from −75° C. to 50° C. at a temperature elevation rate of 10° C./min.

EXAMPLES AND COMPARATIVE EXAMPLES

Example 1

(18) Preparation of Two-Component Urethane-Based Composition

(19) Polyol: A resin (having a viscosity of about 280 cP as measured with a Brookfield LV type viscometer) comprising, as the caprolactone-based polyol represented by Formula 2 above, a polyol having a number of repeating units (m in Formula 2) of about 1 to 3 or so and containing 1,4-butanediol as the polyol-derived unit (Y in Formula 2) was used in a predetermined amount in the main composition.

(20) Isocyanate: A mixture (having a viscosity of 170 cP as measured with a Brookfield LV type viscometer) of HDI (hexamethylene diisocyanate) and a HDI trimer was used in the curing agent composition. At this time, the used amount of the isocyanate compound was adjusted so that the NCO index was about 100.

(21) Filler: Alumina was used. The content thereof was adjusted in a ratio of 1,000 parts by weight relative to 100 parts by weight of the sum of the polyol and isocyanate contents, and the alumina was divided and formulated in the same amount into the main composition part and the curing agent composition part.

(22) Catalyst: Dibutyltin dilaurate (DBTDL) was used in a predetermined amount.

(23) Physical Property Measurement Results

(24) The glass transition temperature (Tg) of the prepared composition measured in the above-mentioned manner was less than 0° C. Then, the melting point (Tm) measured in the above-mentioned manner was 11° C. Also, the adhesive force (S.sub.1) was 449 gf/10 mm, and the ratio (S.sub.2/S.sub.1) between the adhesive force was 70% or more. From this, it can be seen that the composition of Example 1 can provide proper processability at the time of injection into the battery module even when containing an excessive amount of filler, and has excellent adhesion and adhesion reliability after curing.

Example 2

(25) Preparation of Two-Component Urethane-Based Composition

(26) A composition was prepared as in Example 1, except that neopentyl glycol was changed and used at the time of forming the Y unit of the polyol formula 2 (the viscosity of the prepared polyol was about 300 cP when measured with a Brookfield LV type viscometer).

(27) Physical Property Measurement Results

(28) The glass transition temperature (Tg) of the prepared composition measured in the above-mentioned manner was less than 0° C. and the used polyol had weak crystallizability, so that the crystallization temperature (Tc) and the melting temperature (Tm) were not measured on the DSC. Also, the adhesive force (S1) was 467 gf/10 mm, and the ratio (S2/S1) between the adhesive force was 70% or more. From this, it can be seen that the composition of Example 2 can provide proper processability at the time of injection into the battery module even when containing an excessive amount of filler, and has excellent adhesion and adhesion reliability after curing.

Comparative Example 1

(29) Preparation of Two-Component Urethane-Based Composition

(30) A composition was prepared in the same manner as in Example 1, except that PPG (hydroxyl group: 360 mg KOH/g) of an ether-based polyol was used as the resin used in the main composition part.

(31) Physical Property Measurement Results

(32) The glass transition temperature (Tg) of the prepared composition measured in the above-mentioned manner was less than 0° C. and the melting point was observed to be less than 15° C. Then, the adhesive force (S.sub.1) was 116 gf/10 mm, and the ratio (S2/S1) between the adhesive force was 70% or more. From this, it can be seen that the composition of Comparative Example 1, which does not have the ester-based polyol in the constitutions of the present application, cannot provide sufficient adhesive force necessary for bonding the battery cell to the case in the battery module.

Comparative Example 2

(33) Preparation of Two-Component Urethane-Based Composition

(34) A composition was prepared in the same manner as in Example 1, except that methylene diphenyl diisocyanate (MDI) of the aromatic diisocyanate was used in the curing agent composition part.

(35) Physical Property Measurement Results

(36) The glass transition temperature (Tg) of the prepared composition measured in the above-mentioned manner exceeded 0° C. and the melting point (Tm) was 15° C. or lower. Also, the adhesive force (S.sub.1) was 666 gf/10 mm, and the ratio (S.sub.2/S.sub.1) between the adhesive force was 70% or more. From this, it can be seen that the composition of Comparative Example 2 using an aromatic isocyanate as a curing component has poor injection processability and poor storage stability due to a high curing rate, and since the cured product has a high glass transition temperature, it is not suitable as a material for a battery module which requires impact resistance or vibration resistance, and the like.

Comparative Example 3

(37) Preparation of Two-Component Urethane-Based Composition

(38) A composition was prepared in the same manner as in Example 1, except that the repeating unit m of Formula 2 was 11 in the main composition part.

(39) Physical Property Measurement Results

(40) The glass transition temperature (Tg) of the prepared composition measured in the above-mentioned manner was 0° C. or lower and the melting point (Tm) exceeded 20° C. Also, the adhesive force (S.sub.1) was 467 gf/10 mm, and the ratio (S.sub.2/S.sub.1) between the adhesive force was 70% or more. From this, it can be concluded that the composition of Comparative Example 4 using a polyol having no sufficiently low crystallizability, which is required in the present application, has poor injection processability for a composition used as an adhesive in a battery module due to crystallizability at room temperature.