Heat-insulation film, and heat-insulation-film structure

• US 10,385,801 B2
• Filed: 05/18/2016
• Issued: 08/20/2019
• Est. Priority Date: 06/20/2012
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Kobayashi, Hiroharu, Tomita, Takahiro, Oribe, Akinobu
• Primary Examiner(s): Yang, Z. Jim
• Application Number:
  US15/157,534
• Publication Number:
  US 20160258383A1
• Time in Patent Office: 1,189 Days
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2307/304 Insulating
• CPC Class Codes: B32B 2307/3065 Flame resistant or retardant, fire resistant or retardant
• CPC Class Codes: B32B 2307/554 Wear resistance
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 5/16 characterised by features of a layer formed of particles, e.g. chips, powder or granules layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02
• CPC Class Codes: B32B 5/30 one layer being formed of particles, e.g. chips, granules, powder
• CPC Class Codes: B32B 9/005 comprising one layer of ceramic material, e.g. porcelain, ceramic tile layered products with at least two ceramic layers composed mainly of ceramic B32B18/00
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2004/22 with a polygonal circumferential shape
• CPC Class Codes: C04B 2201/30 for heat transfer properties such as thermal insulation values, e.g. R-values
• CPC Class Codes: C04B 2201/32 for the thermal conductivity, e.g. K-factors
• CPC Class Codes: C04B 2235/3246 Stabilised zirconias, e.g. YSZ or cerium stabilised zirconia
• CPC Class Codes: C04B 2235/6025 Tape casting, e.g. with a doctor blade
• CPC Class Codes: C04B 35/48 based on zirconium or hafnium oxides, zirconates, zircon or hafnates
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 38/0054 the pores being microsized or nanosized
• CPC Class Codes: C04B 38/0074 expressed as porosity percentage
• CPC Class Codes: C04B 38/0655 Porous materials C04B38/0625 takes precedence
• CPC Class Codes: C08K 7/24 inorganic
• CPC Class Codes: F02F 1/00 : Cylinders; Cylinder heads
• CPC Class Codes: F02F 1/24 : Cylinder heads
• CPC Class Codes: F02F 1/42 : Shape or arrangement of intake or exhaust channels in cylinder heads
• CPC Class Codes: F02F 2001/249 : with flame plate, e.g. insert in the cylinder head used as a thermal insulation between cylinder head and combustion chamber
• CPC Class Codes: F02F 3/12 : on piston heads

Abstract

In a heat-insulation film, porous plate fillers are dispersed in a matrix to bond the porous plate fillers. The porous plate filler includes plates having an aspect ratio of 3 or more, a minimum length of 0.1 to 50 μm and a porosity of 20 to 90%. In the heat-insulation film, a volume ratio between the porous plate fillers and the matrix is from 50:50 to 95:5. In the heat-insulation film in which the porous plate fillers are used, a length of a heat transfer path increases and a thermal conductivity can be decreased, as compared with a case where spherical or cubic fillers are used.

Claims

1. A heat-insulation film in which porous plate fillers comprising plates having an aspect ratio of 3 or more, a thickness of 0.1 to 50 μ

m and a porosity of 20 to 90% are dispersed in a matrix to bond the porous plate fillers, and a volume ratio between the porous plate fillers and the matrix is from 60;

40 to 90;

10,

wherein when a line is drawn from a first surface to a second surface on an opposite side to the first surface in a thickness direction in a cross section parallel to the thickness direct, a ratio between a sum of lengths of line segments present on the porous plate fillers and sum of lengths of line segments present on the matrix is from 50;

50 to 95;

5.

2. The heat-insulation film according to claim 1, wherein a thermal conductivity of the porous plate filler is 1 W/(m·

K) or less.

3. The heat-insulation film according to claim 1, wherein a heat capacity of the porous plate filler is from 10 to 3000 kJ/(m³·

K).

4. The heat-insulation film according to claim 1, wherein the porous plate filler comprises pores of a nanoorder.

5. The heat-insulation film according to claim 1, wherein the porous plate filler includes a metal oxide.

6. The heat-insulation film according to claim 1, wherein the porous plate filler comprises particles having particle diameters of 1 nm to 10 μ

m.

7. The heat-insulation film according to claim 1, wherein a heat capacity of the film is 1500 kJ/(m³·

K) or less.

8. The heat-insulation film according to claim 1, wherein a thermal conductivity of the film is 1.5 W/(m·

K) or less.

9. A heat-insulation-film structure in which the heat-insulation film according to claim 1 is formed on a substrate.

10. The heat-insulation-film structure according to claim 9, which has, on the surface of the heat-insulation film, a surface dense layer including ceramics and/or glass and having a porosity of 5% or less.

11. The heat-insulation-film structure according to claim 10, which comprises a buffer bonding layer having a thickness smaller than the heat-insulation film, between the substrate and the heat-insulation film and/or between the heat-insulation film and the surface dense layer.