Coating material, cover glass, solar cell module and outer wall material for building
To provide a coating material capable of forming a solar cell module excellent in the weather resistance, the power generation efficiency and the design, a cover glass, a solar cell module comprising the cover glass, and an outer wall material for building. The cover glass of the present invention is a cover glass comprising a glass plate and a layer containing a fluorinated polymer having units based on a fluoroolefin, on at least one surface of the glass plate, which has an average visible reflectance of from 10 to 100%, and an average near infrared transmittance of from 20 to 100%.
1. A cover glass comprising a glass plate and a layer covering at least one surface of the glass plate, the layer containing a fluorinated polymer having units based on a fluoroolefin and particles consisting of one or more inorganic metal oxide pigments,
wherein a Fe 2 O 3 content determined as a content of total iron contained in the glass plate as calculated as Fe 2 O 3 is from 0 to 0.3 mass % relative to the total mass of the glass plate,
the particles of the one or more inorganic metal oxide pigments have a maximum near infrared reflectance in a near infrared region at a wavelength of from 780 to 1,500 nm of at least 50%,
the cover glass has an average visible reflectance of from 10 to 100%, which is an arithmetic mean of reflectances at 5 nm intervals in a visible region at a wavelength of from 380 to 780 nm, and
the cover glass has an average near infrared transmittance of from 20 to 100%, which is an arithmetic mean of transmittances at 5 nm intervals in a near infrared region at a wavelength of from 780 to 1,500 nm.
2. The cover glass according to claim 1 , which has an average visible transmittance of less than 70%, which is an arithmetic mean of transmittances at 5 nm intervals in a visible region at a wavelength of from 380 to 780 nm.
3. The cover glass according to claim 1 , which has a maximum reflectance of from 20 to 100% among reflectances at 5 nm intervals in a visible region at a wavelength of from 380 to 780 nm.
4. The cover glass according to claim 1 , wherein the glass plate contains no Fe 2 O 3 .
5. The cover glass according to claim 1 , wherein a content of the particles consisting of one or more inorganic metal oxide pigments is from 10 to 1,000 parts by mass per 100 parts by mass of the fluorinated polymer.
6. The cover glass according to claim 1 , wherein an average particle size of the particles consisting of one or more inorganic metal oxide pigments is from 5.0 to 280.0 nm and a specific surface area of from 5.0 to 1,000 m 2 /g.
7. The cover glass according to claim 1 , wherein the one or more inorganic metal oxide pigment has in the L*a*b* color space an L* value of from 5 to 100, an a* value of from −60 to 60, and a b* value of from −60 to 60.
8. The cover glass according to claim 1 , wherein the fluorinated polymer has a fluorine atom content of from 15 to 30 mass %.
9. The cover glass according to claim 1 , wherein the fluorinated polymer is a fluorinated polymer having a crosslinked structure formed by reaction of a copolymer having units based on a fluoroolefin and units having a crosslinkable group, and a curing agent capable of crosslinking crosslinkable groups, and
the curing agent is a compound having in one molecule at least two groups of at least one type selected from the group consisting of an isocyanate group, a blocked isocyanate group, an epoxy group, a carbodiimide group, an oxazoline group, a β-hydroxyalkylamide group, a hydrolysable silyl group and a silanol group.
10. A solar cell module, comprising solar cells and a cover glass on a light-receiving surface side of the solar cells; wherein
the cover glass comprises:
a glass plate; and
a layer of a fluorinated polymer having units based on a fluoroolefin and particles consisting of one or more inorganic metal oxide pigments covering at least one surface of the glass plate;
wherein
the cover glass has an average visible reflectance of from 10 to 100%, which is an arithmetic mean of reflectances at 5 nm intervals in a visible region at a wavelength of from 380 to 780 nm,
the cover glass has an average near infrared transmittance of from 20 to 100%, which is an arithmetic mean of transmittances at 5 nm intervals in a near infrared region at a wavelength of from 780 to 1,500 nm,
a Fe 2 O 3 content determined as a content of total iron contained in the glass plate as calculated as Fe 2 O 3 is from 0 to 0.3 mass % relative to the total mass of the glass plate, and
the particles consisting of one or more inorganic metal oxide pigments have a maximum near infrared reflectance in a near infrared region at a wavelength of from 780 to 1,500 nm of at least 50%.
11. An outer wall material for building, comprising the solar cell module defined in claim 10 .
12. The solar cell module according to claim 10 , wherein an average visible transmittance of the cover glass is less than 70%, determined as an arithmetic mean of transmittances at 5 nm intervals in a visible region at a wavelength of from 380 to 780 nm.
13. The solar cell module according to claim 10 , wherein a maximum reflectance of the cover glass is from 20 to 100% among reflectances at 5 nm intervals in a visible region at a wavelength of from 380 to 780 nm.
14. The solar cell module according to claim 10 , wherein the glass plate contains no Fe 2 O 3 .
15. The solar cell module according to claim 10 , wherein a content of the particles consisting of one or more inorganic metal oxide pigments in the layer of a fluorinated polymer is from 10 to 1,000 parts by mass per 100 parts by mass of the fluorinated polymer.
16. The solar cell module according to claim 10 , wherein an average particle size of the particles consisting of one or more inorganic metal oxide pigments is from 5.0 to 280.0 am and a specific surface area of the inorganic particles is from 5.0 to 1,000 m′/g.
17. The solar cell module according to claim 10 , wherein the one or more inorganic metal oxide pigment has in the L*a*b* color space an L* value of from 5 to 100, an a* value of from −60 to 60, and a b* value of from −60 to 60.
18. The solar cell module according to claim 10 , wherein a fluorine atom content of the fluorinated polymer is from 15 to 30 mass %.
19. The solar cell module according to claim 10 , wherein the fluorinated polymer is a fluorinated polymer having a crosslinked structure formed by, reaction of a copolymer having units based on a fluoroolefin and units having a crosslinkable group, and a curing agent capable of crosslinking the crosslinkable groups, and
the curing agent is a compound having in one molecule at least two groups of at least one type selected from the group consisting of an isocyanate group, a blocked isocyanate group, an epoxy group, a carbodiimide group, an oxazoline group, a β-hydroxyalkylamide group, a hydrolysable silyl group and a silanol group.