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, there is provided a urethane-based heat dissipation material capable of providing excellent thermal conductivity and storage stability.

Claims

1. A urethane-based composition comprising a main composition part comprising an ester-based polyol resin; a curing agent composition part comprising a polyisocyanate; a filler; and a moisture scavenger, 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.

2. The urethane-based composition according to claim 1, wherein the filler and the moisture scavenger are included in the main composition part or the curing agent composition part.

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

4. The urethane-based composition according to claim 1, wherein the filler is contained 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 polyisocyanate.

5. The urethane-based composition according to claim 1, wherein the moisture scavenger is selected from methyldiphenylethoxysilane, molecular sieves, p-toluenesulfonyl isocyanate (PTSI), an acid anhydride ester, a silane compound represented by the following formula, and a mixture thereof:
R.sup.1SiR.sup.2.sub.(n)R.sup.3.sub.(3-n)[Formula] wherein, R.sup.1 is a functional group having an inter-carbon double bond bonded to the silicon atom, R.sup.2 and R.sup.3 each independently represent a hydroxyl group, halogen, an amine group or R.sup.4R.sup.5, which is bonded to the silicon atom, where R.sup.4 is an oxygen or sulfur atom, and R.sup.5 is an alkyl group, an aryl group, an aralkyl group, an acyl group or R.sup.6R.sup.7, where R.sup.6 is an alkylene group or an alkylidene group, and R.sup.7 is an alkoxy group.

6. The urethane-based composition according to claim 5, wherein the silane compound comprises vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentoxysilane, vinyltriphenoxysilane, vinyltriacethoxysilane, or vinyltris(2-methoxyethoxy)silane.

7. The urethane-based composition according to claim 1, wherein a mixture of the ester-based polyol resin and polyisocyanate has a glass transition temperature (Tg) of less than 0 C. after curing.

8. The urethane-based composition according to claim 1, wherein each of the ester-based polyol resin and the polyisocyanate has a viscosity of less than 900 cP.

9. 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.

10. The urethane-based composition according to claim 9, 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.

11. The urethane-based composition according to claim 9, 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.

12. The urethane-based composition according to claim 1, wherein the polyisocyanate is a non-aromatic polyisocyanate.

13. 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.

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

15. An automobile comprising the battery module according to claim 13.

16. The urethane-based composition according to claim 1, wherein the moisture scavenger is included in the curing agent composition part.

17. The urethane-based composition according to claim 16, wherein the moisture scavenger is included in an amount of about 5 wt % or less based on 100 parts by weight of the curing agent composition part.

18. 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.

19. The method of manufacturing battery module according to claim 18, 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

[0126] 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.

[0127] FIG. 2 shows an exemplary module case, which can be applied in the present application.

[0128] FIG. 3 schematically shows a form in which battery cells are housed in a module case.

[0129] FIG. 4 schematically shows an exemplary bottom plate where injection holes and observation holes are formed.

[0130] FIGS. 5 and 6 schematically show an exemplary battery pouch which can be used as a battery cell.

[0131] FIGS. 7 and 8 schematically show the structure of an exemplary battery module.

[0132] The reference numerals and symbols related to the drawings are as follows. [0133] 10: module case [0134] 10a: bottom plate [0135] 10b: sidewall [0136] 10c: top plate [0137] 10d: guiding portion [0138] 20: battery cell [0139] 30: resin layer [0140] 50a: injection hole [0141] 50b: observation hole [0142] 40: insulating layer [0143] 100: pouch type cell [0144] 110: electrode assembly [0145] 120: exterior material [0146] 121: upper pouch [0147] 122: lower pouch [0148] S: sealing portion

BEST MODE

[0149] Hereinafter, the battery module of the present application will be described with reference to examples and comparative examples, but the scope of the present application is not limited by the following range.

[0150] Evaluation Methods

[0151] 1. Storage Stability

[0152] Viscosities of isocyanate-containing curing agent composition parts prepared in Examples and Comparative Examples were measured. Specifically, the viscosity was confirmed at two months after mixing the constituents contained in the curing agent composition part. It was evaluated as fail in the case where the viscosity after 2 months was too high, that is, in the case of exceeding 400,000 cP, as compared with the initial viscosity of the prepared composition. It was evaluated as pass in the case of showing an appropriate level of viscosity increase, that is, in the case of about 100,000 to 400,000 cP. The fact that the viscosity after 2 months relative to the initial viscosity has been excessively increased under the condition controlled such that the influence of external factors such as heat is not so great on the composition can be seen as storage stability degradation due to moisture penetration. That is, in the case of being evaluated as fail, it is considered that the moisture penetrates during the storage for 2 months and simultaneously the moisture reacts with the isocyanate component, whereby the viscosity increases. The viscosity was measured at room temperature and a shear rate condition of 0.01 to 10.0/s using a rheological property measuring device (ARES). The viscosity described in Table 1 below is the viscosity at a shear rate of 2.5/s.

[0153] 2. Thermal Conductivity

[0154] The thermal conductivity was measured according to ISO 22007-2 standard for the cured product of the following constituent composition.

EXAMPLES AND COMPARATIVE EXAMPLES

Example 1

[0155] 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.

[0156] 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.

[0157] Filler: Alumina was used. The content thereof was adjusted in a ratio of 500 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. In the case of the formulated filler, the filler was used after drying (moisture treating) it in an oven at 200 C. for 12 hours or more before formulating.

[0158] Moisture scavenger: VTMO (vinyltrimethoxysilane) was used. The content was in a ratio of 20 parts by weight relative to 100 parts by weight of the sum of the polyol and isocyanate contents, and the VTMO was divided and formulated in the same amount into the main composition part and the curing agent composition part.

[0159] Catalyst: Dibutyltin dilaurate (DBTDL) was used in a predetermined amount.

Examples 2 to 4 and Comparative Examples 1 to 2

[0160] The same method as in Example 1 was used except that the compositions were changed as shown in Table 1 below.

TABLE-US-00001 TABLE 1 Thermal Moisture Filler content Moisture Storage conductivity Filler treatment (part by weight) scavenger stability (W/mK) Example 1 Alumina Proceeding 500 Use Pass 1.7 2 Alumina Proceeding 1,000 Use Pass 3.0 3 BN Proceeding 150 Use Pass 1.2 4 Alumina Not-proceeding 1,000 Use Pass 2.9 Comparative 1 Alumina Proceeding 1,300 Non-use Fail 3.5 Example 2 Alumina Proceeding 1,000 Non-use Fail 3.0

[0161] In Table 1, upon a comparison of the Examples and Comparative Examples, when the moisture scavenger is included in the curing agent composition part, the viscosity after two months compared to the initial viscosity is 100,000 to 400,000 cP, which shows excellent storage stability. However, when the moisture scavenger is not included in the curing agent composition part, the viscosity after two months compared to the initial viscosity is more than 400,000 cP, which shows that the storage stability is poor.

[0162] On the other hand, in Table 1, when comparing Example 2 and Example 4, it can be confirmed that thermal conductivity is more excellent when the filler is water-treated before blending.