ADHESIVE RESIN COMPOSITION, ADHESIVE FILM, AND FLEXIBLE METAL LAMINATE

Abstract

The present invention relates to an adhesive resin composition including a styrene-ethylene-butylene-styrene copolymer with a specific chemical structure, an epoxy resin, an acid anhydride compound, and a curing catalyst, an adhesive film obtained from the resin composition, and a flexible metal laminate including the adhesive film.

Claims

1. An adhesive resin composition comprising: a styrene-ethylene-butylene-styrene copolymer to which 0.1 wt % to 15 wt % of dicarboxylic acid or an anhydride thereof is bonded; an epoxy resin; a curing catalyst comprising one or more compounds selected from the group consisting of an imidazole-based compound, an imine-based compound, and an amine-based compound; and an acid anhydride compound, and wherein the adhesive resin composition has a dielectric constant of 2.8 or less in a dried state and at 5 GHz.

2. The adhesive resin composition according to claim 1, wherein the acid anhydride compound includes one or more compounds selected from the group consisting of a styrene-maleic anhydride copolymer, methyltetrahydrophthalic anhydride, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl himic anhydride, NADIC methyl anhydride, NADIC anhydride, and dodecenyl succinic anhydride.

3. The adhesive resin composition according to claim 1, wherein the adhesive resin composition comprises, based on 100 parts by weight of the styrene-ethylene-butylene-styrene copolymer to which 0.1 wt % to 15 wt % of dicarboxylic acid or anhydride thereof is bonded: 10 to 80 parts by weight of the epoxy resin; 10 to 80 parts by weight of the acid anhydride compound; and 0.05 to 5 parts by weight of the curing catalyst comprising one or more compounds selected from the group consisting of an imidazole-based compound, an imine-based compound, and an amine-based compound.

4. The adhesive resin composition according to claim 1, wherein the adhesive resin composition has a dielectric loss factor (Df) of 0.010 or less in a dried state and at 5 GHz.

5. The adhesive resin composition according to claim 1, wherein a weight ratio of the epoxy resin to the acid anhydride compound is 2.0 to 0.05.

6. The adhesive resin composition according to claim 1, further comprising 50 to 1000 parts by weight of an organic solvent, based on 100 parts by weight of the styrene-ethylene-butylene-styrene copolymer.

7. The adhesive resin composition according to claim 6, wherein a viscosity of the adhesive resin composition changes by a ratio of 2 times or less compared to the initial viscosity within 72 hours, when exposed to the outside at room temperature.

8. The adhesive resin composition according to claim 1, wherein the styrene-ethylene-butylene-styrene copolymer to which 0.1 wt % to 15 wt % of dicarboxylic acid or an anhydride thereof is bonded has a weight average molecular weight of 30,000 to 800,000.

9. The adhesive resin composition according to claim 1, wherein the styrene-ethylene-butylene-styrene copolymer to which 01 wt % to 15 wt % of dicarboxylic acid or an anhydride thereof is bonded comprises 5 to 50 wt % of styrene-derived repeat units.

10. The adhesive resin composition according to claim 1, wherein the dicarboxylic acid includes one or more selected from the group consisting of maleic acid, phthalic acid, itaconic acid, citraconic acid, alkenyl succinic acid, cis-1,2,3,6-tetrahydrophthalic acid, and 4-methyl-1,2,3,6-tetrahydrophthalic acid.

11. The adhesive resin composition according to claim 1, wherein the epoxy resin includes one or more selected from the group consisting of biphenyl novolac epoxy resin, bisphenol A type of epoxy resin, and dicylcopentadiene phenol addition reaction type epoxy resin.

12. The adhesive resin composition according to claim 2, wherein the styrene-maleic anhydride copolymer has a weight average molecular weight of 1000 to 50,000.

13. The adhesive resin composition according to claim 2, wherein the styrene-maleic anhydride copolymer comprises 50 wt % to 95 wt % of styrene-derived repeat units.

14. An adhesive film comprising a cured product of the adhesive resin composition of claim 1, and having a dielectric constant (Dk) of 2.8 or less in a dried state and at 5 GHz.

15. The adhesive film according to claim 14, wherein the adhesive film has a dielectric loss factor (Df) of 0.010 or less in a dried state and at 5 GHz.

16. The adhesive film according to claim 14, wherein the adhesive film has a thickness of 1 μm to 100 μm.

17. A flexible metal laminate comprising: a polyimide resin film; a metal thin film comprising one or more selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver, gold, and alloys of two or more kinds thereof; and the adhesive film of claim 12 formed between the polyimide film and the metal thin film.

18. The flexible metal laminate according to claim 17, wherein the polyimide resin film has a thickness of 1 μm to 50 μm, and the polyimide resin film contains 5 to 75 wt % of a fluorine-based resin.

19. The flexible metal laminate according to claim 17, wherein the adhesive film has a dielectric constant (Dk) of 2.2 to 2.8 in a dried state and at 5 GHz.

20. The flexible metal laminate according to claim 17, wherein the adhesive film has a dielectric loss factor (Df) of 0.010 or less in a dried state and at 5 GHz.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0061] Specific embodiments of the invention will be explained in more detail in the following examples. However, the following examples are presented only as the illustration of the present invention, and the scope of the present invention is not limited by the following examples.

EXAMPLES AND COMPARATIVE EXAMPLES: PREPARATION OF ADHESIVE RESIN COMPOSITIONS AND ADHESIVE FILMS

Example 1

[0062] (1) Preparation of an Adhesive Resin Solution

[0063] 20 g of a 20 wt % solution of a styrene-ethylene-butylene-styrene copolymer grafted with 1.81 wt % of maleic anhydride (M1913, manufactured by Asahi Kasei Corporation) in xylene, 0.814 g of a 70 wt % solution of biphenyl novolac-based epoxy resin (NC-3000H, manufactured by Nippon Kayaku Co. Ltd., epoxy equivalent 288 g/eq) in xylene, 5.0 g of a 40 wt % solution of styrene-maleic anhydride copolymer (EF-40, manufactured by Sartomer company, weight ratio of styrene:maleic anhydride=4:1) in xylene, and 0.13 g of a 25% solution of 2-methylimidazole in methanol were mixed at room temperature to prepare an adhesive resin composition (solution).

[0064] (2) Preparation of an Adhesive Film

[0065] The adhesive resin solution was applied on a PET film treated to be released and dried at 100° C. for 10 minutes to prepare an adhesive film with a thickness of about 25 μm.

Example 2

[0066] (1) Preparation of an Adhesive Resin Solution

[0067] 20 g of a 20 wt % solution of styrene-ethylene-butylene-styrene copolymer grafted with 0.36 wt % of maleic anhydride (M1911, manufactured by Asahi Kasei Corporation) in xylene, 0.814 g of a 70 wt % solution of epoxy resin in xylene, 5.0 g of a 40 wt % solution of NADIC methyl anhydride in xylene, and 0.13 g of a 25% solution of 2-methylimidazole in methanol were mixed to prepare an adhesive resin composition (solution).

[0068] (2) Preparation of an Adhesive Film

[0069] The adhesive resin solution was applied on a PET film treated to be released and dried at 100° C. for 10 minutes to prepare an adhesive film with a thickness of about 25 μm.

Comparative Examples 1 to 3

[0070] (1) Preparation of Adhesive Resin Solutions

[0071] The components of the following Table 1 were mixed to prepare adhesive resin compositions (solutions) of Comparative Examples 1 to 3.

TABLE-US-00001 TABLE 1 Comparative Example1 Comparative Example2 Comparative Example3 Elastomer N34J (Zeon corporation, M1913 (Asahi Kasei M1913 (Asahi Kasei CTBN) 20 wt % solution in Corporation, SEBS-g-MA) Corporation, SEBS-g-MA) methyethylketone: 20 g 20 wt % solution in xylene: 20 wt % solution in xylene: 20 g 20 g Epoxy NC-3000H (Nippon Kayaku YDPN-631 (Kukdo Chemical YD-128 (Kukdo Chemical resin Co. Ltd., biphenyl novolac- Co. Ltd., liquid phenol Co. Ltd., BPA type epoxy based epoxy resin) 70 wt % novolac-based epoxy resin): resin): 0.2 g solution in 4.0 g methylethylketone: 2.85 g Curing 4,4′-diaminodiphenyl sulfone 4,4′-diaminodiphenyl sulfone 4,4′-diaminodiphenyl agent 25 wt % solution in methyl 2 5 wt % solution in methyl sulfone 25 wt % solution in cellosolve: 1.72 g cellosolve: 5.70 g methyl cellosolve: 0.26 g Curing 2-methylimidazol 25% 2-methylimidazol 25% 2-methylimidazol 25% catalyst solution in methanol: 0.13 g solution in methanol: 0.20 g solution in methanol: 0.01 g

[0072] (2) Preparation of Adhesive Films

[0073] The adhesive resin solutions obtained in Comparative Examples 1 to 3 were respectively applied on a PET film treated to be released and dried at 100° C. for 10 minutes to prepare adhesive films with each thickness of about 25 μm.

EXPERIMENTAL EXAMPLE: EVALUATION OF PROPERTIES OF ADHESIVE RESIN COMPOSITIONS AND ADHESIVE FILMS

[0074] Experimental Example 1: Evaluation of Storage Stability of Adhesive Resin Compositions (Solutions)

[0075] Each of the adhesive resin solutions obtained in the examples and comparative examples was maintained in a sealed state at room temperature (25° C.) for 3 days, and it was confirmed if viscosity increased or decreased. If the final viscosity after the exposure is within 100% of the initial viscosity, it was evaluated as good, and if it exceeds 100% of the initial viscosity, it was marked as faulty.

Experimental Example 2: Evaluation of Heat Resistance after Water Absorption of Adhesive Films

[0076] Each of the adhesive films obtained in the examples and comparative examples was delaminated from the PET film and inserted between a polyimide film and a copper foil, and a pressure of 30 MPa was applied at 160° C. for 1 hour to compress it. Further, the obtained polyimide film-adhesive film-copper foil composite was aged under the conditions of an 85° C. temperature and 85% relative humidity for 24 hours, and then floated in a lead bath and heat resistance was evaluated.

[0077] If a blister was generated on the surface of the adhesive film, the adhesive film was evaluated as faulty, and if a blister was not generated, it was evaluated as good.

Experimental Example 3: Measurement of Dielectric Constant and Dielectric Loss Factor

[0078] Each of the adhesive films obtained in the examples and comparative examples was put in a glove box, and dried for 24 hours under nitrogen purge, and then a dielectric constant and a dielectric loss factor under a 5 GHz condition was measured using an Agilent E5071B ENA device.

[0079] The results of Experimental Examples 1 to 3 are shown in the following Table 2.

TABLE-US-00002 TABLE 2 Com- Com- Com- Example Example parative parative parative 1 2 Example 1 Example 2 Example 3 Storage Good Good Good Faulty Faulty stability Heat Good Good Good Good Faulty resistance Dielectric 2.5 2.5 4.3 2.9 2.4 constant (Dk) Dielectric 0.007 0.007 0.15 0.015 0.004 loss factor (Df)

[0080] As shown in Table 1, it was confirmed that the adhesive films obtained in the examples have high storage stability and heat resistance, and have a dielectric constant (Dk) of 2.5 and a dielectric loss factor (Df) of 0.007 in a dried state and at 5 GHz.

[0081] To the contrary, it was confirmed that the adhesive films obtained in the comparative examples have lowered storage stability or heat resistance compared to the examples, and particularly, in the case of Comparative Example 3, heat resistance is not sufficient for use as an adhesive material of a flexible printed circuit board, and storage stability is very low, and thus it is difficult to prepare into a commercial product. It was also confirmed that the adhesive films of Comparative Examples 1 and 2 exhibit relatively high dielectric constants and dielectric loss factors.