Coating compositions for solar selective absorption comprising a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon polymer

• US 4,426,465 A
• Filed: 02/18/1982
• Issued: 01/17/1984
• Est. Priority Date: 02/19/1981
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Maki, Masao, Fukuda, Hiroshi, Sano, Seiichi
• Primary Examiner(s): Marquis, Melvyn I.
• Assistant Examiner(s): Lilling, Herbert J.
• Application Number:
  US06/350,040
• Time in Patent Office: 698 Days
• Field of Search: 523/135, 524/407, 524/413, 524/431
• US Class Current: 523/135
• CPC Class Codes: C08L 2205/18 Spheres
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/54 Inorganic substances
• CPC Class Codes: C08L 27/12 containing fluorine atoms
• CPC Class Codes: C09D 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09D 5/32 Radiation-absorbing paints protection against X-, gamma- or corpuscular radiation G21F
• CPC Class Codes: F24S 70/20 characterised by absorbing coatings; characterised by surface treatment for increasing absorption
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers

Abstract

A coating composition for solar selective absorption comprising, in solvent, particles of an inorganic black pigment dispersed in a dissolved binder of a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon resin contained in an amount of 5-15 parts by weight per 100 parts by weight of the acrylic resin. The inorganic black particles have a size of 0.01-0.5 microns and are contained in an amount of 45-65 parts by weight per 100 parts by weight of the acrylic resin. An article having a metal substrate and a paint film formed thereon from the composition in a dry thickness of 1.5 microns or more is also described.

Claims

1. A coating composition for selective solar absorption which comprises a disperson, in a binder of a thermosetting acrylic resin, of particles of:

an inorganic black pigment having a size ranging from 0.01 to 0.5 microns and selected from the group consisting of oxides and double oxides of Fe, Mn, Cu, Cr, Co and Ni and mixtures thereof; and

particles of a low molecular weight fluorocarbon resin containing in an amount of from 5 to 15 parts by weight per 100 parts by weight of the acrylic resin, the particles of the pigment being present in an amount of from 45 to 65 parts by weight per 100 parts by weight of the acrylic resin.

2. A coating composition according to claim 1, wherein the particles of the pigments are present in an amount of from 50 to 55 parts by weight per 100 parts by weight of the acrylic resin.

3. A coating composition according to claim 1, wherein the acrylic resin is made of monomer units which have a main chain of acrylic acid, methacrylic acid or an ester thereof and functional side chains capable of crosslinkage.

4. A coating composition according to claim 1, wherein the particles of the fluorocarbon resin have a size ranging from 0.1 to 1 micrometer.

5. A coating composition according to claim 1 or 4, wherein the fluorocarbon resin is tetrafluoroethylene resin, vinyl fluoride resin or vinylidene fluoride resin.

6. A coating composition according to claim 5, wherein the fluorocarbon resin is tetrafluoroethylene resin.

7. A coating composition according to claim 1, wherein the dispersion has a solid content of 5 to 20 wt% of the composition.

8. A coating composition according to claim 7, wherein the solid content is in the range of 10 to 17 wt%.