JPH02135265A - Far-infrared ray radiating coating - Google Patents

Abstract

PURPOSE:To obtain the title coating having good coating workability and excellent adhesion strength of coating film without clogging spray gun by adding specific crystalline zirconia based ceramic particles to coating. CONSTITUTION:The aimed coating obtained by adding crystalline zirconia based ceramic particles having <=15nm crystalline diameter obtained from half value width of powdery X ray diffraction (111) face peak using formula of Scherrer to a coating (preferably emulsion type synthetic resin based coating). Furthermore, crystallinity of the above-mentioned ceramic particle is preferably >=80%.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a paint with an excellent far-infrared radiation effect, and more specifically, a far-infrared radiation-emitting paint with excellent painting workability and coating adhesive strength. It is related to.

<Prior art> Zirconia ceramics have the property of emitting far-infrared rays with a wavelength of 8 to 14 μm, which are said to have a positive effect on living organisms, with high efficiency. Attempts have been made to impart far-infrared radiation by mixing zirconia-based ceramics with ordinary paint and applying this paint to various materials.

<Problems to be Solved by the Invention> However, in the conventional far-infrared emissive paint described above, the particle size of the zirconia ceramic particles contained is large and the particle size distribution is wide, so that, for example, the paint cannot be used. When spray coating, the nozzle is easily clogged, resulting in poor coating workability, and especially when large particles are present, the adhesive strength of the coating film is impaired.

Therefore, in order to avoid the above-mentioned problems, it is necessary to set the mixing ratio of zirconia ceramic particles to the paint at a low level, which causes the problem that sufficient far-infrared radiation cannot be exhibited.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a far-infrared emitting paint that has excellent coating workability and adhesive strength of a coating film.

Means for Solving the Problems> That is, the present invention provides crystalline zirconia ceramic particles having a crystallite diameter of 15r+n+ or less, which is determined from the half-width of the (111) plane peak in powder X-ray diffraction using the 5cherrer formula. The gist thereof is a far-infrared emissive paint characterized by containing the following.

The present invention will be explained in detail below.

In addition to zirconia alone, the crystalline zirconia-based ceramic particles used in the present invention include elements that can be solid-dissolved in zirconia, such as alkaline earth metals such as calcium and magnesium, clay group elements such as yttrium, and rare earth elements such as cerium. Also included are those containing oxides of.

It is important that the crystalline zirconia ceramic particles used in the present invention have a crystallite diameter of 15 nm or less, particularly 10 nm or less.

The crystallite diameter here is a value determined from the half-value width of the (111) plane peak in powder X-ray diffraction using the 5cherrer formula, and the crystallite diameter of the crystalline zirconia ceramic particles used exceeds 15 nm. In such cases, fine particles may be formed in the coating material, and the particle size distribution of the particles becomes large, making it impossible to sufficiently improve the coating workability of the coating material and the adhesive strength of the coating film, which is undesirable.

The crystal form of the crystalline zirconia ceramic particles may be monoclinic, tetragonal, or cubic, but the degree of crystallinity is 50% or more, particularly 80% or more, and exhibits so-called crystallinity. It is necessary.

In addition, the degree of crystallinity here is 0.3 mol/U
An aqueous suspension containing zirconium hydroxide of It refers to a comparison of the areas of the (111) plane peaks of zirconia in charts obtained by one diffraction measurement, and is expressed as a relative value.

If the degree of crystallinity of the crystalline zirconia ceramic particles is lower than 50%, the stability of the particles will be poor, and problems such as abnormally high viscosity of paints mixed with the particles and progress of gelation may occur. This is undesirable because it causes

Although the method for producing the crystallized zirconia ceramic particles used in the present invention is not particularly limited, they can preferably be produced by, for example, a hydrothermal crystallization method.

In other words, typical examples of hydrothermal crystallization methods include neutralizing a zirconium salt with a base, or neutralizing a mixed aqueous solution of a salt of zirconium and an element that can form a solid solution with an alkaline aqueous solution. Then, the hydroxide is co-precipitated and treated in a pressure vessel at a temperature of about 100 to 300°C to crystallize it.

When the particles produced in this manner are washed with water to remove salt impurities, the particles can be dispersed in a uniform size and have a small particle size.

If you want to further improve the dispersibility of particles, it is desirable to add an alkali such as an acid or an amine. For example, by peptizing with acetic acid, 0.03μ
The average particle diameter can be set to about m.

The zirconia ceramic particles obtained by the hydrothermal crystallization method in this manner can be prepared as a sol having a desired pH.

The far-infrared emissive paint of the present invention can be obtained by mixing the above-mentioned crystalline zirconia ceramic particles with a paint, but compounds generally known as dispersants for ceramic particles, such as sodium polyacrylate and polyacrylic acid Ammonium etc. can be mixed at the same time if necessary.

In addition, in order to improve the dispersibility of crystalline zirconia-based ceramic particles, they can be mixed into paints after being subjected to generally known surface coating treatments using oil and fat raw materials, surfactant treatments, and metal soap treatments. .

The paint used in the present invention is preferably an emulsion type synthetic resin paint. Specific examples of these emulsion type synthetic resin paints include emulsion type acrylic resins and emulsion type urethane resins.

The mixing ratio of the crystalline zirconia ceramic particles to the paint is 50 parts by weight of the crystalline zirconia ceramic particles to 13 parts by weight of the resin content in the paint in terms of solid content.
00 parts by weight, especially 100 to 200 parts by weight, is preferred.The crystalline zirconia ceramic particles used in the present invention have a small crystallite size, but have a narrow particle size distribution, so the mixing ratio in the paint is lower than in the past. By setting a high value, it is possible to exhibit an excellent far-infrared radiation effect.

The crystalline zirconia ceramic particles and the paint can be mixed by various methods, but among them, an aqueous slurry or sol containing the zirconia ceramic particles and an aqueous suspension containing the paint are mixed. A method of mixing in liquid-liquid form is preferred.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 4000 cc of 1.2M zirconyl chloride aqueous solution, 4.
The mixture was mixed with 4000 cc of 8M ammonia water with stirring, then placed in a pressure container and heat-treated at 150° C. for 24 hours.

The produced slurry was thoroughly washed with distilled water so that the chlorine ion content was 0.1% by weight or less based on the solid content of the zirconia particles.

Here, as a result of drying a part of the crystalline zirconia ceramic particles produced and measuring the degree of crystallinity,
It showed a degree of crystallinity of 85% or more.

In addition, the crystallite diameter of the crystalline zirconia ceramic particles is 10n11, and the average particle diameter of the Stokes diameter is 0.5.
It was μm.

To the thus obtained cake of crystalline zirconia ceramic particles (water content: 60%) lkr, 20 cc of ammonia water, 1000 cc of water and ammonium polyacrylate (Aron A-30...Toagosei 1) were added as a dispersant. Co., Ltd.) was added thereto, and +r was further added to 1°8 of an emulsion type acrylic resin paint with a solid content of 45% and mixed.

Regarding the far-infrared emissive paint obtained in this way,
As a result of a spray application test, there was no clogging of the spray gun, the coating workability was very good, and no sediment was observed.

The adhesive strength of the coating film was also good, and it exhibited excellent far-infrared radiation effects.

Comparative Example 1 The degree of crystallinity of zirconia powder obtained by calcining and pulverizing zirconium hydroxide produced by a neutralization method at 1000°C for 2 hours was measured, and the crystallinity was 100% or more. showed that.

In addition, the crystallite diameter of the crystalline zirconia ceramic particles is 27 nn, and the average particle diameter of the Stokes diameter is 0.5 μm.
It was m.

This zirconia powder was mixed with an emulsion-type acrylic resin paint to have the same composition as in Example 1, and a spray coating test was conducted. As a result, the spray gun was significantly clogged and there were many sediments. Ta.

<Effects of the Invention> As explained above, crystalline zirconia ceramic particles having a crystallite diameter of 15r+1 or less determined from the half-width of the powder X-ray diffraction (11,1) plane peak using the 5cherrer formula, Compared to conventional zirconia-containing paints, the far-infrared emissive paint of the present invention, which is incorporated into paints, has extremely good coating workability without clogging spray guns, and has excellent adhesive strength of the paint film. It has many advantages and features a high far-infrared blocking effect.

Claims (2)

[Claims] (1) From the half-value width of the powder X-ray diffraction (111) plane peak,
The crystallite diameter determined using Scherrer's formula is 15n.
A far-infrared emissive paint characterized by containing crystalline zirconia-based ceramic particles with a size of less than m. (2) The far-infrared emissive paint according to claim (1), wherein the paint is an emulsion type synthetic resin paint.