JPH0337977B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] This invention relates to a surface material for a top plate for a laboratory bench. [Prior art] Conventionally, the surface material of the top plate for a laboratory table is an organic material such as a melamine decorative board, or an alkali metal silicate such as phosphate, sodium silicate, or potassium silicate as a main component. An inorganic material is used, which is made by applying paint to an asbestos cement board or a hard calcium silicate board and hardening it by baking. However, each of these materials has advantages and disadvantages. That is, although organic materials have the advantage of having excellent surface smoothness, colorability, etc. and being inexpensive, they do not have sufficient heat resistance as a top plate for a laboratory bench. For example, radiant heat from the burner may cause swelling during use, or if the red-hot crucible is accidentally dropped or the burner is tipped over, a fire may occur.
Furthermore, it has the disadvantage of being easily scratched due to its low surface hardness, and furthermore being severely eroded by concentrated sulfuric acid and concentrated nitric acid, which are general-purpose reagents. On the other hand, although inorganic materials are superior to the organic materials mentioned above in terms of heat resistance, chemical resistance, etc., their chemical resistance is still not sufficient for special uses such as laboratory benches.
It has drawbacks such as low surface gloss, easy surface roughening, and poor stain resistance. Therefore, there is still a strong demand for surface materials for laboratory tabletops that have excellent properties. [Problem to be solved by the invention] As described above, in the conventional technology, heat resistance,
There is a problem in that a surface material for a top plate for a laboratory bench that is satisfactory in all respects such as chemical resistance, stain resistance, surface smoothness, and gloss has not been obtained, and it has been a challenge to solve this problem. [Means for Solving the Problems] In order to solve the above problems, the present invention contains 25 to 70 parts by weight of potassium silicate in 100 parts by weight of an inorganic paint, and A water-soluble inorganic paint in which 20 to 200 parts by weight of lithium silicate was added and mixed before painting was treated with a base treatment agent containing sodium silicate, potassium silicate, or a mixture thereof as a main component. This method uses an asbestos cement board or a hard calcium silicate board that has undergone the same surface treatment as the surface material for a top plate for a laboratory bench, which is painted and fired.
The details will be described below. Paints used as surface materials for laboratory bench tops include:
Since the above-mentioned special properties are required, an inorganic paint containing 25 to 70 parts by weight of potassium silicate in 100 parts by weight of the inorganic paint, and 20 to 200 parts by weight of lithium silicate per 100 parts by weight of potassium silicate. The system is configured to use a mixed system in which a portion is added after the coating. In other words, if the potassium silicate content is less than 25 parts by weight, the film forming ability will be poor, if it exceeds 70 parts by weight, the chemical resistance and water resistance will be poor, and if the lithium silicate content is less than 20 parts by weight, the chemical resistance and water resistance will be poor. If it exceeds 200 parts by weight, the film-forming ability will be poor and there is a possibility that many cracks will form on the surface, which is not preferable. Here, potassium silicate is K ₂ O・nSiO ₂ [n=2-3.8], and lithium silicate is Li ₂ O・nSiO ₂ [n=3.5-7], but a mixture of these Since the pot life is short, an inorganic paint containing potassium silicate as a main component is first prepared, and a predetermined amount of lithium silicate is subsequently added to form a water-soluble inorganic paint. Since this inorganic paint does not have sufficient adhesion to asbestos cement boards or hard calcium silicate boards, for example, an inorganic base treatment agent containing sodium silicate or potassium silicate as a main component is used. By pre-coating the surface, an inorganic coating is formed to provide sufficient adhesive strength. The method for coating the asbestos cement board or hard calcium silicate board with the mixture thus prepared is not particularly limited, but air spraying, electrostatic coating, etc. are convenient. The coated board is fired at 150 to 400°C because the material to be coated is asbestos cement or hard calcium silicate board. because,
This is because firing at a temperature lower than 150°C makes it difficult to fully exhibit the characteristics of the inorganic coating film, and firing at a temperature higher than 400°C is undesirable because the strength of the coated object rapidly decreases. The surface material of the present invention is obtained through the above steps, and the surface material obtained has extremely good heat resistance, chemical resistance, stain resistance, and surface condition that are not found in conventional products. Ta. [Example] Examples and comparative examples are shown below. Examples 1 to 11 100 parts by weight of No. 1 sodium silicate, potassium silicate
A surface treatment agent consisting of 40 parts by weight, 50 parts by weight of aluminum phosphate, and 60 parts by weight of silica powder was applied to an autoclaved hard calcium silicate plate at a rate of 200 g/m ² by air spray. 200g of the inorganic paint shown in
After applying ^m2 and drying with far infrared rays, it was heated to 250℃ for 30 minutes.
A surface material for a top plate for a laboratory table was obtained by baking for a minute. Various tests were conducted on this surface material, including chemical resistance, surface smoothness, boiling water resistance (3 hours), motor hardness, and resistance to red-hot crucibles, and the results are shown in Table 2. . In addition, chemical resistance is determined by dropping 0.2ml of the specified reagent.
Cover the area with a 30mm diameter watch glass, leave it for 24 hours, wash it with water, dry it, examine the surface condition, and mark it with ◎.

【table】

[Table] (Almost no abnormalities), ○ mark (discoloration observed),
Evaluation was given in four stages: △ mark (significant discoloration or slight erosion observed) and × mark (significant erosion observed). In addition, abnormalities in surface smoothness and boiling water resistance (3 hours) were indicated by roughness (roughening) and turbidity (clouding). As is clear from Table 2, the experimental bench of this invention

【table】

[Table] It has been recognized that the surface material of the top plate is extremely excellent, and it can be said that the influence of this invention on this industry is extremely large.

[Table] Comparative Examples 1 to 5 As shown in Table 3, samples were treated in exactly the same way as in the examples using an inorganic paint containing sodium silicate as the main component and an inorganic paint containing potassium silicate and sodium silicate as the main components. In addition to the three types (Comparative Examples 1 to 3), the conventionally used melamine decorative board (Comparative Example 4), and the surface material made of the same type of decorative board with an inorganic coating (Comparative Example 5), there are also A total of 6 of the paints of Examples 2 and 5 (Comparative Example 6) described in the publication No.
The same tests as in the examples were performed on the different types of samples. The results are summarized in Table 4, and it became clear that the surface material was considerably inferior to the surface material according to the present invention.

【table】

〔effect〕

As mentioned above, the surface material of the top plate for a laboratory bench according to the present invention has various issues that have been addressed, such as heat resistance, chemical resistance, surface smoothness, gloss, boiling water resistance, Mohs hardness, and resistance to red-hot crucibles. This invention is of great significance because it is excellent in all aspects.

Claims (1)

[Claims] 1 Potassium silicate 25% in 100 parts by weight of inorganic paint
A water-soluble inorganic paint containing ~70 parts by weight and mixed with 20 to 200 parts by weight of lithium silicate to 100 parts by weight of potassium silicate is mixed with sodium silicate and potassium silicate. Or a top plate for a laboratory bench, characterized in that it is painted and fired on an asbestos cement board treated with a base treatment agent containing a mixture of these or a hard calcium silicate board treated with the same base treatment. Surface material.