RESIN COMPOSITION, LAYERED BODY INCLUDING RESIN COMPOSITION LAYER, LAYERED BODY, AND ELECTROMAGNETIC WAVE SHIELDING FILM

Abstract

Provided are: a resin composition, containing a polyester polyurethane resin (A), an epoxy resin (B), and a polyolefin resin (C); as well as a layered body including a resin composition layer, a layered body, and an electromagnetic wave shielding film, each using the resin composition.

Claims

1. A resin composition, comprising: a polyester polyurethane resin (A); an epoxy resin (B); and a polyolefin resin (C).

2. The resin composition according to claim 1, wherein a content of the polyester polyurethane resin (A) is from 10% by mass to 70% by mass, and a content of the polyolefin resin (C) is from 10% by mass to 70% by mass, each with respect to a total amount of a resin solid content except for a filler component.

3. The resin composition according to claim 1, further comprising an organic filler (D).

4. The resin composition according to claim 3, comprising the organic filler (D) in an amount of from 5 parts by mass to 40 parts by mass with respect to a total amount, of 100 parts by mass, of a resin solid content except for a filler component.

5. The resin composition according to claim 1, wherein the epoxy resin (B) comprises at least one of a bisphenol type epoxy resin or a bisphenol novolak type epoxy resin.

6. The resin composition according to claim 1, wherein a number average molecular weight of the polyester polyurethane resin (A) is from 10,000 to 80,000, and a molecular weight per urethane bond in the polyester polyurethane resin (A) is from 200 to 8,000.

7. The resin composition according to claim 1, wherein the polyester polyurethane resin (A) comprises a polyester polyurethane resin having a polyester structure that has a number average molecular weight of from 8,000 to 30,000.

8. The resin composition according to claim 1, wherein an acid value of the polyester polyurethane resin (A) is from 0.1 mgKOH/g to 20 mgKOH/g.

9. The resin composition according to claim 1, wherein a diol component configuring the polyester polyurethane resin (A) comprises a diol having a side chain.

10. The resin composition according to claim 1, wherein the polyolefin resin (C) is a polypropylene-based resin that is graft-modified with a modifier comprising an α,β-unsaturated carboxylic acid or a derivative thereof, and a content of a graft portion is from 0.1% by mass to 20% by mass with respect to a total mass of the polyolefin resin (C).

11. The resin composition according to claim 1, further comprising a metal filler (E).

12. The resin composition according to claim 11, comprising the metal filler (E) in an amount of from 10 parts by mass to 350 parts by mass with respect to a total amount, of 100 parts by mass, of a resin solid content except for a filler component.

13. The resin composition according to claim 11, wherein the metal filler (E) is a conductive filler.

14. A layered body including a resin composition layer, the layered body comprising: a resin composition layer that consists of the resin composition according to claim 1; and a base film that is in contact with at least one surface of the resin composition layer, wherein the resin composition layer is in a B-stage state.

15. A layered body, comprising a cured layer obtained by curing the resin composition according to claim 1.

16. An electromagnetic wave shielding film, comprising a resin composition layer that consists of the resin composition according to claim 1.

Description

EXAMPLES

[0246] Hereinafter, the present invention will be more specifically described based on Examples. The present invention is not limited to these Examples. Further, “parts” and “%” indicated below mean “parts by mass” and “% by mass”, respectively, unless otherwise specified.

[0247] 1. Raw Materials

[0248] 1-1. Polyester

[0249] Commercial products and synthetic products were used as polyesters to be used in the production of polyester polyurethane resins and to be evaluated.

[0250] <Commercial Product>

[0251] As a commercial product, Aronmelt PES-360HVXM30, manufactured by Toagosei Co. Ltd., was used. Aronmelt PES-360HVXM30 has a number average molecular weight of 20,000.

[0252] <Synthesis of Polyester (PES-1)>

[0253] In a flask equipped with a stirrer, a nitrogen introduction tube, a distillation tube, and a thermometer, 201 parts by mass of dimethyl terephthalate, 86 parts by mass of ethylene glycol, 140 parts by mass of neopentyl glycol, 0.9 parts by mass of trimethylolpropane, and 0.22 parts by mass of zinc acetate as a catalyst were charged, the temperature was raised while introducing nitrogen to distill off methanol at from 150° C. to 180° C. Then, 183 parts by mass of isophthalic acid, 0.6 parts by mass of trimethylolpropane, and 0.12 parts by mass of antimony trioxide were added, and water was distilled off at from 180° C. to 210° C. Thereafter, while gradually reducing the pressure, the reaction was continued for 6 hours at 230° C. under the reduced pressure of 200 Pa. The obtained polyester resin has a number average molecular weight of 7,000. Then, 180 parts by mass of the synthesized polyester resin was taken, and 378 parts by mass of toluene and 42 parts by mass of methyl isobutyl ketone were added thereto, to prepare a polyester solution (PES-1).

[0254] 1-2. Polyester Polyurethane Resin

[0255] Polyester polyurethane resins a1 to a7 that were obtained by the following methods were used.

[0256] (1) Polyester Polyurethane Resin a1

[0257] In a flask equipped with a stirrer, a reflux dehydrator, and a distillation tube, 600 parts by mass of PES-360HVXM30, 100 parts by mass of toluene, and 20 parts by mass of neopentyl glycol were charged. After raising the temperature to 120° C. to distill off 100 parts by mass of the solvent containing water, the temperature was lowered to 105° C., and 0.4 parts by mass of 2,2-bis(hydroxymethyl)propionic acid was charged and dissolved therein. Thereafter, 34 parts by mass of hexamethylene diisocyanate was added and, after 30 minutes, 0.2 parts by mass of dimethyl tin dilaurate was added. After continuing the reaction for 6 hours, a solution of polyester polyurethane resin a1 was obtained by diluting with toluene/2-propanol to adjust the solid content concentration to 30%. The number average molecular weight of polyester polyurethane resin a1 was 36,000 and the acid value was 2 mgKOH/g.

[0258] (2) Synthesis of Polyester Polyurethane Resins a2 to a7

[0259] The synthesis was carried out in the same manner as the synthesis method of polyester polyurethane resin a1, except that the parts by mass of the polyester, the diol, and the diisocyanate were changed to those as shown in Table 1.

TABLE-US-00001 TABLE 1 Polyester polyurethane resin Parts by mass a1 a2 a3 a4 a5 a6 a7 Polyester resin PES-360HVXM30 600 600 600 600 600 — — PES-1 — — — — — 600 600 Diol Neopentyl glycol 20 — — 133 — 65 — component 2-Butyl-2-ethyl-1,3-propanediol — 30 — — — — — 1,4-Butandiol — — — — 17 — — 3,3-Dimethylolpropionic acid 0.4 0.4 0.5 0.5 0.4 1.4 0.4 Isocyanate component Hexamethylene diisocyanate 34 34 3 216 34 106 1.5 Glass transition temperature of polyester (° C.) 65 65 65 65 65 62 62 Number average molecular weight 36,000 35,000 32,000 40,000 40,000 15,000 9,000 Molecular weight per urethane bond 920 920 10,700 160 1,030 380 3,000 Acid value (mgKOH/g) 2 2 2 2 2 3 11

[0260] The unit of the numerical value in each component column shown in Table 1 is parts by mass.

[0261] 1-3. Epoxy Resin (B)

[0262] The following commercial products were used.

[0263] (1) Epoxy Resin b1

[0264] Bisphenol A novolak type epoxy resin “EPICLON N-865” (trade name), manufactured by DIC Corporation

[0265] (2) Epoxy Resin b2

[0266] Bisphenol A type epoxy resin “jER 1055” (trade name), manufactured by Mitsubishi Chemical Corporation

[0267] 1-4. Polyolefin Resin (C)

[0268] (1) Polyolefin Resin c1

[0269] 100 parts by mass of a propylene-butene random copolymer that was made of 80% by mass of propylene unit and 20% by mass of butene unit, and was produced using a metallocene catalyst as a polymerization catalyst, 1 parts by mass of maleic anhydride, 0.3 parts by mass of lauryl methacrylate, and 0.4 parts by mass of di-t-butyl peroxide were kneaded and reacted using a twin-screw extruder in which the maximum temperature of the cylinder part was set to 170° C. Then, degassing under reduced pressure was performed within the extruder to remove the residual unreacted material, to produce polyolefin resin c1. Polyolefin resin c1 had a weight average molecular weight of 80,000 and an acid value of 10 mgKOH/g. The content ratio of the graft portion in polyolefin resin c1 was 1.5% by mass.

[0270] (2) Olefin Resin c2

[0271] Using a metallocene catalyst as a polymerization catalyst, 80% by mass of propylene unit and 20% by mass of butene unit were reacted to obtain polyolefin resin c2. Polyolefin resin c2 had a weight average molecular weight of 100,000.

[0272] 1-5. Organic Filler (D)

[0273] (1) Filler d1 Urethane beads “TK-800T” (trade name, average particle diameter 8 μm), manufactured by Negami Kogyo Co., Ltd.

[0274] (2) Filler d2

[0275] Acrylic beads “J-4P” (trade name, average particle diameter 2.2 μm), manufactured by Negami Kogyo Co., Ltd.

[0276] 1-6. Metal Filler (E)

[0277] Copper powder “FCC-115A” (trade name; in particle size distribution, the amount of particles of 45 μm or less is more than 90% by mass, the amount of particles of from 45 μm to 63 μm is less than 10% by mass, and the amount of particles of from 63 μm to 75 μm is less than 3% by mass), manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.

[0278] 1-7. Flame Retardant

[0279] Aluminum dimethylphosphinate “Exolit OP935” (trade name), manufactured by Clariant

[0280] 1-8. Curing Promoter

[0281] Imidazole-based curing promoter “Curesol C11-Z” (trade name), manufactured by Shikoku Kasei Kogyo Co., Ltd.

[0282] 1-9. Solvent

[0283] A mixed solvent consisting of toluene, methyl isobutyl ketone, 2-propanol, and methylcyclohexane (mass ratio=100:20:20:20)

Examples 1 to 19 and Comparative Examples 1 to 3

[0284] To a flask equipped with a stirrer, the raw materials described above were added at the ratio shown in Table 2, and stirred under heating at 60° C. for 6 hours to dissolve the component (A), the component (B), the component (C), and the curing promoter in the solvent and then disperse the component (D), carbon black, and the flame retardant, thereby producing the liquid adhesive compositions. Thereafter, these all liquid adhesive compositions were used to prepare coverlay films, bonding sheets, and adhesion test pieces A and B, and the evaluations in accordance with (i) to (vi) below were performed.

[0285] (1) Preparation of Coverlay Film

[0286] The liquid adhesive composition is roll-coated onto the surface of a polyimide film having a thickness of 25 μm so that the thickness after drying was 15 μm, and dried at 120° C. for 2 minutes to obtain a coverlay film that includes an adhesive layer.

[0287] (2) Preparation of Adhesion Test Piece A

[0288] A gold-plated copper foil with a thickness of 35 μm was prepared. Then, the gold-plated surface was layered so as to be brought into contact with the surface of the adhesive layer of the coverlay film described above, and laminating was performed under the conditions of 150° C., 0.3 MPa. and 1 m/min. The obtained layered body (polyimide film/adhesive layer/gold-plated copper foil) was subject to thermal compression bonding for 5 minutes under the conditions of 150° C. and 3 MPa, and then further underwent after-cure at 160° C. for 2 hours in an oven, by which an adhesion test piece A was obtained.

[0289] (3) Preparation of Bonding Sheet

[0290] A releasable PET film with a thickness of 35 μm was prepared. Then, the liquid adhesive composition was roll-coated onto the surface thereof so that the thickness after drying was 25 μm, and dried at 140° C. for 2 minutes to obtain a bonding sheet that includes an adhesive layer.

[0291] (4) Preparation of Adhesion Test Piece B

[0292] A nickel-plated SUS 304 plate with a thickness of 300 μm, and a flexible printed wiring board in which a copper wiring pattern was formed on the surface of a polyimide film with a thickness of 25 μm and a coverlay film with a thickness of 37.5 μm having a through hole with a diameter of 1 mm was layered on the wiring pattern, were prepared. First, the nickel-plated surface of the SUS 304 plate was layered so as to be brought into contact with the surface of the adhesive layer of the bonding sheet described above, and laminating was performed under the conditions of 150° C., 0.3 MPa, and 1 m/min to obtain a layered body (SUS plate/adhesive layer/releasable PET film). Then, the releasable PET film was peeled off, and the flexible printed wiring board (wiring board in which a copper foil wiring was formed on the polyimide film with a thickness of 25 μm and a coverlay film with a thickness of 37.5 μm having a through hole with a diameter of 1 mm was layered on the copper foil wiring) was bonded to the surface of the exposed adhesive layer by thermal compression bonding for 5 minutes under the conditions of 150° C. and 3 MPa, and then further underwent after-cure at 160° C. for 2 hours in an oven, by which an adhesion test piece B (SUS plate/adhesive layer/flexible printed wiring board) was prepared.

[0293] (i) Peel Adhesion Strength (Initial)

[0294] In order to evaluate the adhesiveness, the 1800 peel adhesion strength (N/mm) when the gold-plated copper foil of each adhesion test piece A was peeled off from the polyimide film under the conditions of the temperature of 23° C. and the tensile speed of 50 mm/min in accordance with JIS C 6481 “Test methods of copper-clad laminates for printed wiring boards” was measured. The width of the adhesion test piece during the measurement was 10 mm.

[0295] (ii) Solder Heat Resistance (Peel Adhesion Strength after Soldering Process and Appearance at the Time of Soldering)

[0296] The test was conducted under the following conditions in accordance with JIS C 6481.

[0297] The adhesion test piece A described above was floated in a solder bath at 260° C. for 60 seconds with the surface of the polyimide film up, and the presence or absence of appearance abnormalities such as swelling or peeling of the adhesive layer was visually evaluated. As a result, those in which appearance abnormalities such as microvoids, swelling, or peeling were not confirmed were indicated as “A”, those in which slight microvoids were observed were indicated as “B”, and those in which appearance abnormalities such as swelling and peeling were confirmed were indicated as “C”. Further, the test piece taken out from the solder bath was measured in terms of 1800 peel adhesion strength (N/cm) when the polyimide film was peeled off from the gold-plated copper foil at 23° C. in accordance with JIS C 6481. The width of the adhesion test piece during the measurement was 10 mm, and the tensile speed was 50 mm/min.

[0298] (iii) Flame Retardancy

[0299] The coverlay film described above was heat-cured at 160° C. for 2 hours, and the flame retardancy was evaluated in accordance with UL-94. Those that passed the test (VTM-0 class) were indicated as “A”, and those that failed were indicated as “F”.

[0300] (iv) Conductivity (Connection Resistance) Initial

[0301] The connection resistance value between the SUS plate and the copper foil wiring of the flexible printed wiring board of the adhesion test piece B described above (SUS plate/adhesive layer/flexible printed wiring board) was measured with a resistance value measuring instrument. As a result, those in which the connection resistance value was less than 0.5Ω were indicated as “A”, those in which the connection resistance value was 0.5Ω or more but less than 1Ω were indicated as “B”, those in which the connection resistance value was 1Ω or more but 3Ω or less were indicated as “C”, and those in which the connection resistance value was more than 3Ω were indicated as “D”.

[0302] (v) Conductivity (Connection Resistance) after Soldering

[0303] The adhesion test piece B described above was floated in a solder bath at 260° C. for 60 seconds. Thereafter, the connection resistance value between the SUS plate and the copper foil wiring of the flexible printed wiring board of the adhesion test piece B taken out from the solder bath was measured with a resistance value measuring instrument. As a result, those in which the connection resistance value was less than 0.5Ω were indicated as “A”, those in which the connection resistance value was 0.5Ω or more but less than 1Ω were indicated as “B”, those in which the connection resistance value was 1Ω or more but 3Ω or less were indicated as “C”, and those in which the connection resistance value was more than 3Ω were indicated as “D”.

[0304] (vi) Conductivity (Connection Resistance) after Long-Term Reliability Test

[0305] The adhesion test piece B described above was left in a constant temperature and humidity chamber at 85° C. and 85% RH for 1,000 hours. Thereafter, the connection resistance value between the SUS plate and the copper foil wiring of the flexible printed wiring board of the adhesion test piece B was measured with a resistance value measuring instrument. As a result, those in which the connection resistance value was less than 0.5Ω were indicated as “A”, those in which the connection resistance value was 0.5Ω or more but less than 1Ω were indicated as “B”, those in which the connection resistance value was 1Ω or more but 3Ω or less were indicated as “C”, and those in which the connection resistance value was more than 3Ω were indicated as “D”.

[0306] (vii) Storage Stability of Adhesive Composition

[0307] Each of the adhesive compositions of Examples 1 to 19 and Comparative Examples 1 to 3 having the compositions shown in Table 2 was put in a glass bottle, sealed, stored at 5° C. for a predetermined period, and observed in terms of crystallinity of the composition. Those in which gelation of the adhesive composition or liquid separation was confirmed after storage for the predetermined period were regarded as poor in storage stability and evaluated.

[0308] <Evaluation Criteria>

[0309] A: 1 week or longer.

[0310] F: shorter than 1 week.

TABLE-US-00002 TABLE 2 Examples 1 2 3 4 5 6 7 Composition Polyester a1 50 82 8 50 50 50 50 of resin polyurethane a2 — — — — — — — composition resin (A) a3 — — — — — — — a4 — — — — — — — a5 — — — — — — — a6 — — — — — — — a7 — — — — — — — Epoxy b1 5 5 5 5 5 5 5 resin (B) b2 5 5 5 5 5 5 5 Olefin c1 40 8 82 40 40 40 40 resin (C) c2 — — — — — — — Organic d1 — — — 15 — 45 5 filler (D) d2 — — — — 15 — — Metal filler (E) 20 20 20 20 20 20 20 Curing promoter 1 1 1 1 1 1 1 Flame retardant 5 5 5 5 5 5 5 Solvent (mixed solvent) 200 200 200 200 200 200 200 Evaluation Peel adhesion Initial 5 4 9 5 5 4 5 result strength (N/mm) After 7 6 11 7 7 5 7 soldering Appearance at the line of A B A A A A A soldering Flame retardancy A A A A A A A Conductivity Initial B B B A A A B After B C B A A B B soldering After storage B C C A B B B 85° C./85%/ 1,000 hrs Storage stability A A A A A A A Examples 8 9 10 11 12 13 14 Composition Polyester a1 50 — — — — — — of resin polyurethane a2 — 50 — — — — — composition resin (A) a3 — — 50 — — — — a4 — — — 50 — — — a5 — — — — 50 — — a6 — — — — — 50 — a7 — — — — — — 50 Epoxy b1 — 5 5 5 5 5 5 resin (B) b2 10 5 5 5 5 5 5 Olefin c1 40 40 40 40 40 40 40 resin (C) c2 — — — — — — — Organic d1 15 15 15 15 15 15 15 filler (D) d2 — — — — — — — Metal filler (E) 20 20 20 20 20 20 20 Curing promoter 1 1 1 1 1 1 1 Flame retardant 5 5 5 5 5 5 5 Solvent (mixed solvent) 200 200 200 200 200 200 200 Evaluation Peel adhesion Initial 5 5 4 7 4 5 5 result strength (N/mm) After 7 7 6 9 6 7 7 soldering Appearance at the time of A A B A A B B soldering Flame retardancy A A A A A A A Conductivity Initial B A C A B C C After B A C A B C C soldering After storage B A C C B C C 85° C./85%/ 1,000 hrs Storage stability A A A F F A A Comparative Examples Examples 15 16 17 18 19 1 2 3 Composition Polyester a1 50 50 50 8 70 90 — 50 of resin polyurethane a2 — — — — — — — — composition resin (A) a3 — — — — — — — — a4 — — — — — — — — a5 — — — — — — — — a6 — — — — — — — — a7 — — — — — — — — Epoxy b1 5 5 5 15 15 5 5 — resin (B) b2 5 5 5 15 15 5 5 — Olefin c1 40 40 — 70 8 — 90 40 resin (C) c2 — — 40 — — — — — Organic d1 — — 15 — — 10 10 10 filler (D) d2 — — — — — — — — Metal filler (E) 9 360 20 20 20 20 20 20 Curing promoter 1 1 1 1 1 1 1 1 Flame retardant 5 5 5 5 5 5 5 5 Solvent (mixed solvent) 200 200 200 200 200 200 200 200 Evaluation Peel adhesion Initial 5 3 3 8 4 2 11 5 result strength After 7 5 5 9 6 3 13 7 (N/mm) soldering Appearance at the time of A B B A B C A C soldering Flame retardancy A A A A A A A A Conductivity Initial C B C B B D B D After C B C B C D B D soldering After C B C C C D D D storage 85° C./85%/ 1,000 hrs Storage stability A F A A A A A A

[0311] As is clear from the results shown in Table 2, the resin compositions of Examples 1 to 19 were resin compositions superior in conductivity compared to the resin compositions of Comparative Examples 1 to 3, even after the long-term storage under environment of high temperature and high humidity.

[0312] Further, as is clear from the results shown in Table 2, the resin compositions of Examples 1 to 19 were superior in initial adhesiveness and adhesiveness after soldering, and also superior in appearance after soldering formation, and also superior in flame retardancy after curing.

[0313] The disclosure of Japanese Patent Application No. 2019-120891, filed Jun. 28, 2019, is incorporated herein by reference in its entirety.

[0314] All publications, patent applications, and technical standards described in present specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.