Curable composition for forming an encapsulating film, encapsulating film, multilayer encapsulating film, and electronic device module.

Description

/ 42 Curable composition for forming an encapsulating film, encapsulating film, multilayer encapsulating film, and electronic device module. Field

[001] This disclosure relates to polyolefin polymer compositions for photovoltaic (PV) encapsulating films. In one aspect, the disclosure relates to polyolefin polymer compositions that resist Potential Induced Degradation (PID). In another aspect, the disclosure relates to PV encapsulating films comprising a polyolefin polymer composition and electronic devices, including the same. Background

[002] The global demand for alternative energy has resulted in large increases in the production of solar panels and photovoltaic modules in the last decade. Solar cells (also called PV cells) that convert solar energy into electrical energy are extremely fragile and must be surrounded by a durable encapsulating film. Two main functions of the encapsulating film are (1) to bond the solar cell to the glass coating sheet and backsheet and (2) to protect the PV module from environmental stress (e.g., humidity, temperature, shock, vibration, electrical insulation, etc.). Current encapsulating films are mainly made of ethylene vinyl acetate (EVA), as EVA shows a good balance of properties needed for encapsulating films. EVA is a type of ethylene / unsaturated carboxylic ester copolymer in which the unsaturated carboxylic ester comonomer is a vinyl carboxylate.

[003] Certain polyolefin polymers, such as polyolefin elastomers (POEs) that are not ethylene / unsaturated carboxylic ester copolymers, have been identified as an alternative to EVA for the formation of encapsulating films and have, in comparison with EVA, Petition 870250086518, dated 09 / 24 / 2025, pages 61 / 68

Claims

1 / 6 CLAIMS 1. A curable composition for forming an encapsulating film, the composition being characterized in that it comprises: A) a polyolefin polymer; B) an organic peroxide; C) a silane adhesion promoter; and D) a crosslinking coagent, a monocyclic organosiloxane of formula (I): [R1,R2SiO2 / 2]n (I), wherein the subscript n is an integer greater than or equal to 3; each R1 is independently an alkenyl (C2-C20) and combinations thereof; and E) an anti-PID agent comprising at least one structure such as formula (II): (II) wherein R1, R2 and R3 are each independently a linear or branched, methyl, alkyl, alkenyl, alkyl or alkenyl, or cyclic, or heteroalkyl, or heteroalkenyl.

2. Curable composition according to claim 1, characterized in that the polyolefin polymer further comprises an ethylene / α-olefin copolymer with a volume resistivity (VR) greater than 1.0 x 1014 Ω-cm at 23 °C, density of 0.85 to 0.92 g / cm3, and a moisture content of 1 to 50 g / 10 min at 190 °C.

3. Curable composition according to claim 1 or 2, characterized in that the peroxide is selected from the group consisting of: isopropyl percarbonate; t-butylperoxy-2-ethylhexyl carbonate; tert-amylperoxy-2-ethylhexyl carbonate; tert-butylperoxyisopropyl carbonate; tert-butyl peroxy-3,5,5-trimethylhexanoate; 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane; 1,1-di(tert-butylperoxy)cyclohexane; 1,1-di(tert-amylperoxy)cyclohexane; dicumyl peroxide; Petition 870250086518, dated 09 / 24 / 2025, p. 62 / 68 2 / 6 tert-amyl (DTAP); bis(alpha-t-butyl-peroxy-isopropyl)benzene; and combinations thereof.

4. Curable composition according to any one of claims 1 to 3, characterized in that the crosslinking coagent is selected from the group consisting of: 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane; 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane; 2,4,6,8,10-pentavinyl-2,4,6,8,10-pentamethylcyclopentasiloxane; 1,3,5,7,9-pentamethacrylate-1,3,5,7,9-pentamethylcyclopentasiloxane; or a combination thereof.

5. Curable composition according to any one of claims 1 to 4, characterized in that the anti-PID agent is selected from the group consisting of: trimethylolethane trimethacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate; trimethylolpropane triacrylate; ethylene glycol dimethacrylate; ethylene glycol diacrylate; diethylene glycol diacrylate; triethylene glycol diacrylate; tetra(ethylene glycol) diacrylate; 1,6-hexanediol diacrylate; 1,6-hexanediol dimethacrylate; neopentanediol dimethacrylate; neopentanediol diacrylate; octadecyl acrylate; butyl acrylate; ethyl acrylate; methyl acrylate; hydroxyethyl acrylate; methyl methacrylate; butyl methacrylate; ethyl methacrylate; glycidyl methacrylate; ethyl hydroxyl methacrylate; 2-ethylhexyl acrylate; 2-ethylhexyl methacrylate; dodecyl acrylate; isodecyl acrylate; di(propylene glycol) diacrylate; tri(propylene glycol) diacrylate;lauryl acrylate; alcoholic lauryl acrylate; cyclohexane dimethanol diacrylate; tridecyl methacrylate; tridecyl acrylate; pentaerythritol triacrylate; pentaerythritol tetraacrylate; dipentaerythritol hexaacrylate; tris(2-hydroxyethyl)isocyanurate triacrylate; dipentaerythritol penta acrylate; propoxylated glyceryl triacrylate (3); zinc diacrylate; zinc dimethacrylate; sorbic acid ester such as ethyl sorbate; a monocyclic organosiloxane of formula (I): [R1,R2SiO2 / 2]n (I), and Petition 870250086518, of 09 / 24 / 2025, p. 63 / 68 3 / 6 subscript n is an integer greater than or equal to 3; each R1 is independently H2C=C(R1a)-C(=O)-O-(CH2)m-, where R1a is H or methyl and the subscript m is an integer from 1 to 4; and each R2 is independently H, alkyl (C1-C20), phenyl, or R1; and combinations thereof.

6. Composition according to any one of claims 1 to 5, the composition being characterized in that it further comprises: (A) 85% by weight to 99.5% by weight of polyolefin polymer; (B) 0.01% by weight to 2% by weight of organic peroxide; (C) 0.01% by weight to 1% by weight of silane adhesion promoter; (D) 0.01% by weight to 5% by weight of silane crosslinking coagent; and (E) 0.001% by weight to 1% by weight of anti-PID agent; 7. Composition according to any one of claims 1 to 6, characterized in that the anti-PID agent of formula II comprised in the anti-PID agent is further described by any one of the limitations (i) to (ii): (i) R1 is H, methyl, ethyl, propyl or butyl; and (ii) R3 is H, methyl, ethyl, propyl, butyl, vinyl or substituted vinyl. R2 further comprises an alkyl acrylate or multialkyl acrylate, as in formula (III) below: LJ (III) where R1 and R3 are each independently a linear or branched, or cyclic, or heteroalkyl, or heteroalkenyl, methyl, alkyl, alkenyl, alkyl or alkenyl, or heteroalkyl, or heteroalkenyl. R' is selected from a C1-C30 alkylene; Petition 870250086518, dated 24 / 09 / 2025, p.64 / 68 4 / 6 Y is selected from the group consisting of: CR4-n where n = 1 to 4, OR2-n where n = 1 to 2, NR3-n where n = 1 to 3, SR2-n where n = 1 to 2, PR3-n where n = 1 to 3, PR5-n where n = 1 to 5, SiR4-n where n = 1 to 4, a bifunctional CC core, a phenyl core, an ester-substituted phenyl core, an amide-substituted phenyl core, a tris-isocyanurate core, a melamine core or combinations thereof; 8. Composition according to any one of claims 1 to 6, characterized in that the anti-PID agent is selected from the group consisting of: methyl acrylate, ethyl acrylate, butyl acrylate, cyclopropyl acrylate, ethyl methacrylate, methyl methacrylate, bisphenol-A-glycidyl methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, trimethylethane trimethacrylate, trimethylethane triacrylate, trimethylolpropane trimethylacrylate, trimethylolpropane triacrylate, glycerol triacrylate, pentaerythrityl triacrylate and combinations thereof.

9. Encapsulating film, characterized in that it comprises a crosslinked polymeric composition comprising the reaction product of: A) a polyolefin polymer; B) an organic peroxide; C) a silane adhesion promoter; and D) a crosslinking coagent, a monocyclic organosiloxane of formula (I): [R1,R2SiO2 / 2]n (I), wherein the subscript n is an integer greater than or equal to 3; each R1 is independently an alkenyl (C2-C20) and combinations thereof; and E) an anti-PID agent comprising at least one structure such as formula (II): Petition 870250086518, dated 24 / 09 / 2025, p. 65 / 68 5 / 6 (II) where R1, R2 and R3 are each independently a linear or branched alkyl, methyl, alkenyl, alkyl or alkenyl, or cyclic, heteroalkyl, or heteroalkenyl.

10. Encapsulating film according to claim 10, characterized in that it comprises a crosslinked polymeric composition comprising the reaction product of: A) 85% by weight to 99.5% by weight of polyolefin polymer; B) 0.01% by weight to 2% by weight of organic peroxide; C) 0.01% by weight to 1% by weight of silane adhesion promoter; D) 0.01% by weight to 5% by weight of crosslinking coagent; and (E) 0.001% by weight to 1% by weight of anti-PID agent; 11. Encapsulating film according to claim 10 or 11, characterized in that the polyolefin polymer is an ethylene / alpha-olefin copolymer comprising a density of 0.850 g / cm3 to 0.890 g / cm3 (ASTM D792) and a melting index of 1.0 g / 10 min to 50.0 g / 10 min (ASTM D1238, at 190 °C / 2.16 kg).

12. Encapsulating film according to any one of claims 10 to 12, characterized in that the anti-PID agent is selected from the group consisting of: methyl acrylate, ethyl acrylate, butyl acrylate, cyclopropyl acrylate, ethyl methacrylate, methyl methacrylate, bisphenol-A-glycidyl methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, trimethylethane trimethacrylate, trimethylethane triacrylate, trimethylolpropane trimethylacrylate, trimethylolpropane triacrylate, glycerol triacrylate, pentaerythrityl triacrylate and combinations thereof.

13. Multilayer encapsulation film, characterized in that it comprises at least one layer composed of the composition as defined in any one of claims 1 to 9.

14. Encapsulating film according to any one of claims 10 to 13, characterized in that the encapsulating film has a power loss after PID on a front side and a rear side of less than 5%.

15. Electronic device module, characterized in that it comprises: A) an electronic device, B) a coating sheet, and C) the encapsulating film, as defined in any one of claims 10 to 14. Petition 870250086518, dated 09 / 24 / 2025, pp. 67 / 68

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