JP2020139127A - Refractory coating agent for steel material - Google Patents

Abstract

To provide a refractory coating agent for a steel material, which can be applied to a steel material for a building structure in a factory for manufacturing and processing a steel material for a building structure, in which the refractory coating agent for structural use of the present invention is a two-component type including a main agent and a curing accelerator, and is used by mixing and stirring the two components immediately before.SOLUTION: The main raw material is sodium silicate. Water is added to sodium silicate in a ratio of 1:1 by weight and the mixture is stirred to form a sodium silicate solution. To 100 pts of this sodium silicate solution, 30 to 50 pts of montmorillonite and 30 to 50 pts of alumina are added, and the mixture is stirred for 2 to 3 hours by a stirring device. To the intermediate agent after stirring, diatomaceous earth is added in an amount of 5 to 10 pts by weight relative to 100 pts of the intermediate agent, and the mixture is stirred for 1 to 2 hours. Further, sidal fiber powder is added as a modifier, the mixture is stirred for 1 to 2 hours, and after stirring, a curing period of 24 hours is set to complete the main agent. The curing accelerator is either fumigated charcoal or graphite, and the mixing ratio of the main agent and the curing accelerator is such that 5 to 20 pts of the curing accelerator is added per 100 pts of the main agent.SELECTED DRAWING: None

Description

The present invention relates to a refractory coating for steel materials.

Conventionally, steel manufacturers have developed and marketed FR steel (fire-resistant steel material for building structures), but when FR steel exceeds 600 ° C, the yield strength of the room temperature standard decreases to two-thirds and exceeds 800 ° C at the fire site. The normal temperature standard proof stress was reduced to one-third, and there was a possibility that major damage such as collapse of the building would occur.

Conventionally, paint manufacturers have developed and marketed fire-resistant paints, but the painting work requires four processes: undercoating, main agent coating, intermediate coating, and topcoating, and the guidelines of the Japan Federation of Construction Contractors Fireproof Structure Study Group A minimum of 15 days and a maximum of about 1 month of on-site construction period are required. In addition, since it is a human action at the construction site, it is unavoidable that the quality varies depending on the worker.

Conventionally, some buildings use rock wool, but it requires a worker to manually attach it to the steel material for building structure at the construction site, which takes a long construction period and is human at the construction site. Since it is a work, it is unavoidable that the quality varies depending on the worker.

The present invention provides a fireproof coating agent for steel materials that can be applied to steel materials for building structures in a factory that manufactures and processes steel materials for building structures. However, it does not interfere with the coating work at the construction site.

In the present invention, the main agent and the curing accelerator are two-component, and immediately before use, 100 parts of the main agent is mixed and stirred with the curing accelerator at a ratio of 5 to 20.

The main raw material of the present invention is sodium silicate. Water is added to sodium silicate at a weight ratio of 1: 1 and stirred to make a sodium silicate solution.

In the present invention, 30 to 50 parts of montmorillonite and 30 to 50 parts of alumina are added to 100 parts of the sodium silicate solution prepared in (0007) above, and the mixture is stirred with a stirrer for 2 to 3 hours.

In the present invention, 5 to 10 parts of diatomaceous earth is added to the mixture of the above (0008) in order to increase the water retention capacity, and the mixture is stirred with a stirrer for 2 to 3 hours.

In the present invention, the main agent is completed by adding 1 to 5 parts of sidal fiber powder as a modifier to the mixture of the above (0009), stirring with a stirrer for 3 to 5 hours, and providing a curing period of 24 hours. ..

The curing accelerator of the present invention is smoked charcoal or graphite. The mixing ratio is 100 parts of the main agent, 5 to 20 parts of the curing accelerator is added and stirred.

The present invention is a refractory coating agent for steel materials, which can be provided with fire resistance by applying a hardening accelerator to a main agent at a predetermined ratio and stirring the mixture, and then applying and curing the steel material for building structure.

The viscosity of the fireproof coating agent for steel materials of the present invention is preferably 90 to 150 seconds as measured by Anest Iwata's cup-type viscometer NK-2, and the coating work can be performed by any coating method such as a spray gun, a brush or a roller. is there. Therefore, in the steel processing factory, which is the object of the present invention, the coating work can be applied to the steel material for building structure, the quality can be stabilized, the painting process of the fireproof paint at the construction site is eliminated, and the process can be shortened and the work can be performed. There is no variation in quality depending on the individual, and the fire resistance is stable.

Since the refractory coating agent for steel materials of the present invention is a two-component type, the curing time can be adjusted by increasing or decreasing the amount of the curing accelerator added, so that it can respond to temperature changes in the workplace.

Since the fire-resistant coating agent for steel materials of the present invention exhibits fire resistance at a coating thickness of 1.0 to 1.5 mm during coating work, the coating work time can be shortened and the coating amount is small due to the thin coating thickness. Therefore, the raw material cost is low, and the work cost and the raw material cost can be reduced.

It is a figure which shows the continuous heating test result of the test piece which applied 1mm of the refractory coating agent for steel of this invention to the iron plate □ 100x100x3mm. It is a photograph taken after the continuous heating test for 3 hours of the test body of FIG. It is a proof stress comparison table of FR steel and general steel.

The refractory coating agent for steel materials of the present invention was applied to one side of an iron plate SS400 length x width x thickness = 100 x 100 x 3 mm so that the coating thickness after curing was 1 mm and cured.
This iron plate is erected vertically on the workbench, and the burner position is adjusted so that the tip of the flame of RZ-730 manufactured by Shin-Fuji Burner Co., Ltd. comes to the center of the iron plate at the center of the surface to be painted, and the tip temperature of the flame is set to 800 ° C. Was set to, and heated continuously for 3 hours.
The non-contact surface temperature was positioned so that the temperature at point A on the unpainted surface could be measured, and the temperature at point A was measured every 30 minutes after heating.
As a result of point A measurement, the maximum temperature was 357.3 ° C. Therefore, it is within the temperature that satisfies the proof stress at the time of heating of the refractory steel material for gold district structure (commonly known as FR steel) issued by the Corporation Law Material Steel Club. Below is a list of the backside temperature (point A) every 30 minutes in the 3-hour continuous heating test.

A photograph was taken of the state of the refractory coating agent for steel materials after the completion of the continuous heating test for 3 hours. As can be seen from this photograph, there is no peeling of the iron plate and the refractory coating agent for steel materials.
In addition, there are no cracks or cracks in the refractory coating for steel materials.

Although it is described in the high temperature proof stress standard data of refractory steel for building structures (commonly known as FR steel) and general steel issued by the Steel Club, even if it is refractory steel, if the ambient temperature reaches 700 ° C, it will be at room temperature. It is reduced to one-third of the yield strength of.

As a result of differential thermal analysis (DTA) analysis of the refractory coating agent for steel produced in the present embodiment, the hardening transition point was 120 ° C. Therefore, in the case of factory production, the refractory coating agent for steel materials of the present implementation can be cured in 30 to 60 minutes by setting the temperature setting of the curing furnace to the temperature of this transition point.

The coating thickness of the refractory coating agent for steel produced in the present embodiment in the coating operation is preferably 1 to 2 mm in consideration of shrinkage of 10% due to curing shrinkage. If it is thin, the heat insulating effect when heated is small, and if it is thick, cracks and foaming may occur in the refractory coating material for steel materials during heating, which causes peeling from the iron plate.

Claims (4)

It is a two-component refractory coating agent for steel materials that uses a main agent of montmorillonite and alumina inorganic substances added to a sodium silicate solution and smoked charcoal as a curing accelerator. Montmorillonite is the refractory coating agent for steel materials according to claim 1, wherein kaolinite is preferable. The refractory coating agent for steel materials according to claims 1 and 2, to which diatomaceous earth is added to increase water retention and a powder of sidal fiber is added as a modifier. The hardening accelerator is a refractory coating agent for steel materials according to claims 1, 2 and 3, which is at least one of smoked charcoal and graphite.