JPS60155267A - Infrared radiating coating composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which can be shaped into a thin film and has high emissivity in the far-infrared region, by dispersing a resin having a specified particle size and zirconia or zirconium having a specified particle size or a mixture thereof with a rare earth element oxide in an acrylic resin binder. CONSTITUTION:An infrared radiating coating compsn. is obtd. by dispersing at least one resin having a particle size of 0.5-5mu selected from among PE, PP, chlorinated PE, chlorinated PP, a fluororesin and vinyl fluoride resin and zirconia or zirconium having a particle size of 0.1-0.5mu or a compound oxide thereof with a rare earth element oxide in an acrylic resin binder. The compsn. can be shaped into a thin film of 5-50mu and can form a high radiator having an emissivity of 0.8 or above in the far-infrared region of 4-15mu. A radiation surface can be inexpensively formed by a spray method with excellent productivity. A coat which is highly radiative and has a very high strength and high adhesion reliability can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in the field of infrared heating, which performs radiant heating for purposes such as space heating, to form a highly efficient infrared radiator at 160°C.
The present invention relates to an infrared radiation coating composition applied to the surface of a heating element such as the following metal.

Conventional configurations and their problems Conventionally, methods of heating objects using infrared radiation have been known, but in recent years, far-infrared rays with long wavelengths have been found to match well with the absorption characteristics of the heated object. It has been found to have good heating efficiency and has attracted attention.

As a conventional far-infrared radiation coating, zircon (ZrO5
The main component is iron oxide (Fe 20
s ), cobalt oxide (Coo), disokel oxide (N
Products made by adding oxides and clay such as iO), rim oxide (C'r203), and manganese oxide (MnO2) and molding and sintering are known. The process is complicated and expensive, and since it is a type of porcelain, it has poor mechanical strength (especially impact resistance).
Since the film thickness is usually as thick as 200 μm, there is a drawback that the heating rate is poor. Regarding its radiation characteristics, it is 4 to 1
The emissivity in the far infrared region of 6 μm was also low.

OBJECTS OF THE INVENTION The present invention solves these conventional drawbacks, and provides five to five points.
By forming a thin film of 60 μm, a high emissivity body having an emissivity of 0.8 or more in the infrared wavelength region of 4 μm to 16 μm is formed.

It also provides an inexpensive radiant surface using a highly productive method such as a spraying method using a conventional coating method.

It is also an object of the present invention that the corrugator not only has high radiation but also forms a coating with very high strength and high adhesion reliability.

Structure of the Invention To achieve this objective, the present invention uses acrylic resin as a binder. In the insect acrylic resin binder, polyethylene resin, polypropylene resin, chlorinated polyethylene resin, chlorinated propylene resin, fluororesin,
One or more resins selected from the group of vinyl fluoride resins, resins with a particle size in the range of 0.5 to 6 μm, zirconia or zircon alone or crushed, or rare earth element oxides. A composite oxide with a particle size of 0.1~
An infrared radiation coating is obtained as a cured product after being coated on a substrate using a coating material in which 0.6 μm oxide is dispersed.

Polyethylene resin, polypropylene resin, chlorinated polyethylene resin, chlorinated polypropylene resin, fluororesin,
Vinyl fluoride resin usually does not dissolve in a solvent, but is used after being dispersed as a powder. Acrylic resin, whether thermoplastic or thermosetting, has a refractive index of 1.05 to 1.
It is applicable as long as it is in the range of 30. Further, polyethylene resin, . . . , vinyl fluoride resin can be applied as long as the refractive index is within the range of 1.3 to 1.5. Polyethylene resin or the like dispersed in acrylic resin acts as a far-infrared scattering absorber due to the difference in refractive index between the two. A composite oxide of zirconia or zircon and oxides of rare earth elements, especially those with a particle size of 0.
．． Oxides with a diameter of 1 to 0.5 μm also act as far-infrared absorbing and scattering bodies. While the former contributes in the short wavelength region even in the far infrared region, the latter contributes in the long wavelength region of 7 μm or more.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows a conceptual diagram of the present invention. In FIG. 1, numeral 1 indicates a base material, which can be made of metal, glass, or the like. 2 is an acrylic resin. Thermoplastic or thermosetting, etc.
Any material having a refractive index in the range of 1.05 to 1.30 is applicable. 3 is zirconia (i.e. Zr02)
Or Zir: +7 (Zr5iO4) alone, or
It is a composite oxide of these and rare elements, and has a refractive index of 1.
8 to 2.5, in particular, the particle size is 0.1 to 0.
The 5 μm oxide ・4 is one or more resins selected from the group of polyethylene resin, polypropylene resin, chlorinated polyethylene resin, chlorinated polypropylene resin, fluororesin, and vinyl fluoride resin, especially with a refractive index of 1. .3～
1.5 and the particle size is in the range of 0.5 to 5 μm.

Regarding the infrared light absorption behavior of this coating, the resin No. 4 is relatively transparent in the infrared region, but when combined with an acrylic resin binder, it scatters and absorbs far infrared rays of 4 to 6 μm well. . Further, metal oxide No. 3 similarly scatters and absorbs far infrared rays of 6 to 15 μm well. According to Kirchkiff's law, emissivity is equal to absorption, so the above effect radiates.

The refractive index of zirconia or zircon is 2°0~2
．． Although it is in second place, this and rare earth element oxide, that is, L'
a, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb
.

When oxides of elements such as Dy, Ho, Er, Tm, Yb, and Lu are made into a solid solution or made into a composite oxide, the refractive index is about 0.2 higher, which is advantageous for scattering and absorption on the long wavelength side. The blending ratio of the oxide No. 3 to the acrylic resin is preferably in the range of 5/100 to 100/100. This is from the point of scattering and absorption, and above 6Q/1oO,
Absorption characteristics remain almost unchanged. In addition, the blending ratio of the resin in No. 4 is s/100 to 15/
A range of 100 is desirable. Since these vinyl resins are all hydrophobic, they have a particularly favorable effect on corrosion resistance.

However, if it exceeds 15/100, the influence of the infrared absorption characteristics of these vinyl resins themselves becomes noticeable, as well as the scattering effect, and since vinyl resins themselves are very transparent to infrared rays, Outside, ili! The radiation becomes worse with tP.

Examples will be described below.

Each paint was prepared according to the formulation shown in Table 1. The mixture of paint is
Each raw material was dispersed and mixed for about 10 hours using "Attritor" (trade name).

Each paint is applied onto an aluminum plate as a base material so that the film thickness after drying is 10 μm, and in the case of thermoplastic acrylic resin, it is left at room temperature for 24 hours, and in the case of thermosetting acrylic resin, it is left at room temperature. , baked at 180°C for 20 minutes. Regarding this test piece, the surface hot water temperature was set at 100° C., and the spectral radiation characteristics of each coating were evaluated using a spectral radiation device manufactured by JASCO Corporation.

The emissivity shown in Table 1 below indicates the average emissivity at wavelengths of 4 μm to 16 μm.

FIG. 2 shows data on typical spectral radiation characteristics. Second
In the figure, A is the case where only the aluminum base material is used, and B is the case where the thermosetting acrylic resin is used, and 10 parts by weight of calcium carbonate and 50 parts by weight of metal oxide (Fe20
3.MnO2.Cu0) pigment is included. P-1
3 is the system of the present invention, especially in the case of high radiation, but P-
2 to P-13 also showed radiation patterns similar to Habo. As is clear from the difference between P-14 and P-13,
By adding vinyl resin, the rising wavelength of radiation is increased to 7.
It can be seen that the wavelength shifts from μm to 4 μm.

As is clear from P-1, in systems using carbon as a pigment, the emissivity at longer wavelengths, that is, on the far infrared rays side, tends to be lower.

In Table 1, the particle size of the fluororesin used is 2μ.
m, the polyethylene resin has a median particle size of 4 μm, and the chlorinated polyethylene has a median particle size of 3 μm. However, both zirconia and zircon-based metal oxides have a central particle size of 0.3 μm.
I'm using one.

As described above, although the coating of the present invention is extremely thin at approximately 10 μm, it is effective in the far infrared region (4 μm to 16 μm).
It can be seen that it has extremely high radiation.

The coating of the present invention exhibited extremely excellent adhesion, corrosion resistance, stain resistance, etc. The reason why such excellent corrosion resistance and #1 stain resistance were obtained is thought to be due to the hydrophobicity and non-adhesive physical properties of the vinyl resin such as fluororesin.

Effects of the Invention As described above, the coating of the present invention achieves high far-infrared radiation performance of 4 μm or more with a normal coating film thickness of 130 μm or less.

2. It can be applied by regular spray and has excellent mass productivity.

3. Compared to conventional porous ceramic coatings, the coating film is denser and has particularly excellent corrosion resistance and stain resistance.

4. Since the coating system of the present invention is white, it can be colored in various colors as required, and a colorful high radiation surface can be formed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a high-infrared radiation coating according to an embodiment of the present invention, and FIG. 2 is a spectral radiation characteristic diagram thereof. 1...Base material, 2...Acrylic resin, 3
...Zirconia, etc., 4...Resin.

Claims (1)

[Claims] (1) Acrylic resin, and one or more resins selected from the group of polyethylene resins, polypropylene resins, purchased polyethylene resins, chlorinated polypropylene resins, fluororesins, and vinyl fluoride resins, especially those with a particle size of 0.5 to 5μm
An infrared radiation coating composition consisting mainly of a resin in the range of and zirconia or zircon alone or a composite oxide with a rare earth element oxide, especially an oxide with a particle size of 0.1 to 0.5 μm.