JPH0195178A - Powdery composition for drawing line - Google Patents

Abstract

PURPOSE:To realize the formation of a safe and economical powdery composition for drawing a line on, e.g., a playground and having both of the fluidity and apparent specific gravity comparable to those of slaked lime, by mixing calcium carbonate and/or calcium sulfate with silica. CONSTITUTION:The title composition comprises calcium carbonate and/or calcium sulfate and silica. The calcium carbonate is a powder such as ground calcium carbonate or precipitated calcium carbonate, and the calcium sulfate is a powder of calcium sulfate dihydrate, calcium sulfate hemihydrate, anhydrous calcium sulfate, etc., among which ground calcium carbonate or calcium sulfate dihydrate is preferably used. As the silica, powdered silica is used in an amount of 1-40% based on the powdery composition.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a powder composition for line use. More specifically, the present invention relates to a powder composition that can be used for signs or identification lines provided on grounds or the like.

White slaked lime is usually used for the lines provided on the grounds of conventional technical school sports fields, stadiums, etc. In some cases, white powders such as calcium carbonate and calcium sulfate are also used.

Problems to be Solved by the Invention When slaked lime is used on lines such as glands, slaked lime has strong alkalinity, and the dust (generated by wind, etc. when drawing the line or even after the line is drawn) can be harmful to the eyes and nose. It has been pointed out that falling on the line can cause skin injuries such as burns, and these problems have become a major hygiene problem, especially for school children. Carbonate, lucium, or calcium sulfate are used as neutral to slightly alkaline chemicals to replace slaked lime, but those that have the same fluidity as slaked lime generally have a large apparent specific gravity and a line per weight. The distance it can be drawn is short. Therefore, if a line is drawn using the same amount of calcium carbonate or calcium sulfate as slaked lime, the line will only be about half that of slaked lime, which is not economical.

In addition, calcium carbonate and calcium sulfate that have been crushed to have an apparent specific gravity similar to that of slaked lime generally have poor fluidity, making it difficult for the powder in the line drawing device to fall onto the ground, making it difficult to draw lines with a constant width and uniform thickness. It becomes difficult to pull.

For the reasons mentioned above, there is a demand for a line powder that is inexpensive, highly safe, and has the same apparent specific gravity and fluidity as slaked lime.

Means for Solving the Problems The present inventor has conducted extensive research to solve the above-mentioned problems, and as a result has arrived at the present invention. That is, the present invention provides a powder composition for lines comprising calcium carbonate and/or calcium sulfate and silica.

The powder composition for lines of the present invention is safer than slaked lime, and has the same apparent specific gravity and fluidity as slaked lime, making it possible to draw and provide lines safely and economically. It is something to do.

The powder composition for lines of the present invention will be explained in detail.

The calcium carbonate used in the present invention includes powdered products such as heavy calcium carbonate and light calcium carbonate, and the calcium sulfate used includes calcium sulfate dihydrate, calcium sulfate 0.5 hydrate, and calcium sulfate anhydrous salt. Powder products such as the following are used, but preferred are powder products of heavy calcium carbonate or calcium sulfate dihydrate.

The properties of these calcium carbonate and calcium sulfate include a particle size of 2 to 1000 μm and an apparent specific gravity of 0.25 to 1.4 g/m.
1 is preferred for preparing the compositions of the present invention. (Particle size means the maximum length of the particle. The same applies hereinafter.) Next, as the silica used in the present invention, powdered silica is used, and for the powdery composition of the present invention, the particle size is 5 mμ to 2 μm.
0μ and apparent specific gravity of 0.03 to 03 g/ml are preferred. In addition to ordinary silicon dioxide, the silica used in the present invention includes calcium silicate (2Ca0.3SI02).
It may contain components other than silicon dioxide υ such as 8102, but the silicon content needs to be 50% or more as 8102.

Silica is present in the powder composition in an amount of 1 to 40%, preferably 2 to 40%.
The line powder composition of the present invention can be modified by mixing calcium carbonate and/or calcium sulfate to a content of 20%.

In this case, calcium carbonate and calcium sulfate may have a specific particle size range alone or may be a mixture of two or more types with different average particle sizes, but two or more types with different average particle sizes may be mixed. It is more preferable to use it in terms of apparent specific gravity, fluidity, etc. Mixing of calcium carbonate and/or calcium sulfate and silica can be carried out by a method of mixing for 20 to 120 minutes using a conventional blender such as a Nauta mixer 1V type mixer.

The line powder composition of the present invention has the advantage that it can be safely and economically used as a line powder for marking or indicating grounds etc. by a conventional method.

Example The present invention will be explained in more detail with reference to Examples.

Example 1 Aerosil 300 (fine particulate silica, apparent specific gravity 0.06 g/m) was added to 95 g of heavy calcium carbonate (average particle size 20 μm).
l, average particle size 6-8 mμ, 5in2 content 99% or more,
(manufactured by Nippon Aerosil ■) 5g in 12 plastic containers with a diameter of 2
The mixture was placed together with 3 cm balls and stirred (using a blender) while rotating at a rotational speed of 50 rpm for 30 minutes to obtain a long powder composition for lines of the present invention. This powder composition 1
When 0g was suspended in water lp and pIl was measured, pl
-18.5. On the other hand, pl-1 measured in the same manner for 10 g of slaked lime was 13.0.

Example 2 95 g of calcium sulfate dihydrate (average particle size 12μ) and 3005 g of Aerosil used in Example 1 were stirred and mixed in the same manner as in Example 1 to prepare the powder composition for lines of the present invention too.
I got g. The pH of 10 g of this powdered composition was measured in the same manner as in Example 1 and found to be 75.

Example 3 Tokusil P (fine particulate silica, apparent specific gravity 0, 16 g/m) was added to 95 g of heavy calcium carbonate (average particle size 20 μm).
1, average particle size 5 to 7 μ, SiO2 content 93% or more, manufactured by Tokuyama Soda ■) were mixed in the same manner as in Example 1.
A powder composition for a line according to the present invention was obtained.

Example 4 5 g of Tokunur P used in Example 3 was added to 95 g of calcium sulfate dihydrate (average particle size 12μ) and mixed with stirring in the same manner as in Example 1 to obtain 100 g of the powder composition for lines of the present invention.
I got it.

Example 5 5 g of Tokusil P used in Example 3 was added to 95 g of heavy calcium carbonate (average particle size 20 μm) and mixed with stirring in the same manner as in Example 1 to obtain 100 g of a powder composition for lines of the present invention.

Example 6 5 g of Tokusil P used in Example 3 was added to 95 g of heavy calcium carbonate (average particle size 6 μm) and stirred and mixed in the same manner as in Example 1 to obtain a long powder composition for lines of the present invention.

Example 7 7 kg of heavy calcium carbonate (average particle size 2oμ), 2.5kg of heavy calcium carbonate (average particle size 9oμ).

Tokusil P 0.5 kg was added using a 30A capacity V-type compounding machine (
(manufactured by Nichiwa Kikai Co., Ltd.) at a rotation speed of 30 revolutions/min.
The mixture was rotated and mixed for a minute to obtain 10 kg of the powder composition for line use of the present invention having an apparent specific gravity of 0.62 g/ml. The fluidity (described below) of this product was 4o0. Also, this powder composition 1k
When I put g into a line drawer and drew a 5 cm wide line, I was able to draw a 26 m long line. This value was almost the same as that for slaked lime.

Example 8　8 kg of heavy calcium carbonate (average particle size 2oμ), 1.2 kg of heavy calcium carbonate (average particle size 9oμ), 0.3kg of heavy calcium carbonate (average particle size 800μ), and Tokusil P 0.5 kg were stirred and mixed in the same manner as in Example 7 to obtain 10 kg of the linear powder composition of the present invention having an apparent specific gravity of 0.62 g/ml. This powder composition 1k
When a line was drawn in the same manner as in Example 7 using g, it was possible to draw a 26 m line. This value was almost the same as that for slaked lime.

Performance Test The apparent specific gravity and fluidity of the line powder compositions of the present invention obtained in Examples 1 to 6, which are important factors for powders for drawing lines, were measured. Comparative take was also measured for slaked lime, calcium carbonate, and calcium sulfate.

Apparent specific gravity (g/ml): Compliant with JISK5 ] 01.

Fluidity (0): Take 5 ml of the sample (powder) at the bottom of a test tube with an inner diameter of 2.5 cm and keep the test tube horizontal. When the bottom of the test tube was lifted little by little from this state, the angle of the test tube when all the specimen in the test tube collapsed was measured and used as a proxy for fluidity. The closer the value is to 90°, the poorer the fluidity.

Measurement result example 1 0.55 4022
0.4843 '3 0.6142 24 0.5445 '5 0.61. 13F
6 0.65 38 slaked lime (1
5)) 0.62 40 heavy coal (fl calcium (20, u”) 0.95 60 (6
0F 1.02 51 Calcium sulfate・
Dihydrate salt (12, a”) o, so 76
X indicates average particle size.

As is clear from the above measurement results, the powder composition for line use of the present invention had much better apparent specific gravity and fluidity than heavy calcium carbonate alone or calcium sulfate alone, and exhibited values almost similar to those of slaked lime.

Effects of the Invention An economical powder composition for lines that is safe as a powder for lines provided in glands and the like and has both the apparent specific gravity and fluidity of a slaked lime tray was obtained.

Claims (1)

[Claims] 1. Powder composition for line consisting of calcium carbonate and/or calcium sulfate and silica