IP Library Granted Patent US 12709668
Granted Patent B2
US 12709668 · App. 18/693,642 · Granted Aug 18, 2026

Epoxy-based resin composition for clear fiber composites and epoxy-based clear fiber composites

Inventors: Tianlei Zhou (Pasadena, TX); Raymond Wong (Pasadena, TX); Leonid Vorobyev (Pasadena, TX)
Assignee: KANEKA CORPORATION
C08J5/244B32B5/02B32B5/26C08G59/245C08G59/4238C08J5/249B32B2260/023B32B2260/046B32B2262/101B32B2307/414B32B2307/546B32B2307/718B32B2457/12C08J2363/02
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Quick Facts
Patent No.
US 12709668
App. No.
18/693,642
Granted
Aug 18, 2026
Kind
B2
Abstract

An epoxy-based resin composition for clear fiber composites includes epoxy resins and an anhydride curing agent. The epoxy resins include at least one epoxy resin having a refractive index higher than a refractive index of glass fibers, and at least one cycloaliphatic epoxy resin. The amount of non-aromatic components in the epoxy-based resin composition is 60 wt % or higher, based on the total amount of the epoxy resins and the anhydride curing agent. An epoxy-based clear fiber composite for a cover plate in a solar cell panel includes a cured matrix resin and a fiber reinforcement. The epoxy-based clear fiber composite has a refractive index ranging from 1.520 to 1.530 or 1.550 to 1.565, while the difference between the refractive index of the fiber reinforcement and the cured matrix resin is 0.001 or less. A multi-layer epoxy-based clear fiber composite includes a plurality of the epoxy-based clear fiber composite.

Claims (41)

1 . An epoxy-based resin composition for clear fiber composites, comprising:

one or more epoxy resins; and

an anhydride curing agent;

wherein:

the one or more epoxy resins comprise at least one epoxy resin having a refractive index higher than a refractive index of a glass fiber,

the one or more epoxy resins comprise at least one cycloaliphatic epoxy resin,

an amount of non-aromatic components in the epoxy-based resin composition is 60 wt % or higher, based on a total amount of the one or more epoxy resins and the anhydride curing agent,

the epoxy-based resin composition has a viscosity of lower than 1000 cPs at 25° C. and lower than 400 cPs at 35° C., and

the epoxy-based resin composition has a pot life of more than 6 hours at 25° C. and more than 3 hours at 35° C.

2 . The epoxy-based resin composition of claim 1 , further comprising one or more catalysts.

3 . The epoxy-based resin composition of claim 1 , further comprising one or more additives.

4 . The epoxy-based resin composition of claim 1 having an initial cure temperature of 120° C. or lower.

5 . The epoxy-based resin composition of claim 1 having a heat of reaction of 300 J/g or lower.

6 . An epoxy-based prepreg comprising a fiber reinforcement and the epoxy-based resin composition of claim 1 .

7 . A cured epoxy-based resin product of the epoxy-based resin composition of claim 1 .

8 . The cured epoxy-based resin product of claim 7 having a refractive index ranging from 1.520 to 1.565.

9 . The cured epoxy-based resin product of claim 7 having a glass transition temperature (Tg) higher than 120° C., according to dynamic mechanical analysis (DMA).

10 . The cured epoxy-based resin product of claim 7 having a flexural modulus higher than 3 GPa and a flexural strain higher than 3%, according to ASTM D790.

11 . The cured epoxy-based resin product of claim 7 having a density lower than 1.2 g/cm 3 .

12 . An epoxy-based clear fiber composite for a cover plate in a solar cell panel, the epoxy-based clear fiber composite comprising:

a cured matrix resin; and

a fiber reinforcement,

wherein:

a refractive index of the fiber reinforcement ranges from 1.520 to 1.530 or from 1.550 to 1.565,

a difference between the refractive index of the fiber reinforcement and a refractive index of the cured matrix resin is 0.001 or less, and

the cured matrix resin is a cured epoxy-based resin product of an epoxy-based composition comprising:

one or more epoxy resins; and

a curing agent;

wherein the epoxy-based composition has a heat of reaction of 300 J/g or lower.

13 . The epoxy-based clear fiber composite of claim 12 ,

wherein:

the one or more epoxy resins comprise at least one epoxy resin with a refractive index higher than a refractive index of a glass fiber,

the one or more epoxy resins comprise at least one cycloaliphatic epoxy resin, and

an amount of non-aromatic components in the cured matrix resin is 30 wt % or higher, based on a total amount of the one or more epoxy resins and the curing agent.

14 . The epoxy-based clear fiber composite of claim 12 , wherein the cured matrix resin further comprises one or more additives.

15 . The epoxy-based clear fiber composite of claim 12 having a flexural modulus of 15 GPa or higher according to ASTM D790.

16 . The epoxy-based clear fiber composite of claim 12 having a light transmittance of higher than 90%, when a light has a wavelength in a range of 450 nm to 650 nm and the epoxy-based clear fiber composite has a thickness of 0.6 mm or more.

17 . The epoxy-based clear fiber composite of claim 12 having a Tg of higher than 120° C., according to dynamic mechanical analysis (DMA).

18 . The epoxy-based clear fiber composite of claim 12 , having an impact resistance higher than an impact resistance of glass having a same thickness as the epoxy-based clear fiber composite.

19 . A multi-layer epoxy-based clear fiber composite comprising a plurality of the epoxy-based clear fiber composite of claim 12 .

20 . The epoxy-based clear fiber composite of claim 12 , having a glass transition temperature (Tg) in a range of from 120° C. to 148° C., according to dynamic mechanical analysis (DMA).