JPS6154360B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-resistant rust-preventing composition containing petrolatum as a main component and useful as a rust-preventing material for metal structures in high-temperature corrosive environments. Conventionally, in this type of rust-preventing composition, due to the temperature characteristics of petrolatum, the composition is not likely to flow down metal structures used in high-temperature corrosive environments, such as piping that transports high-temperature fluids such as steam piping. I couldn't use it because it was stored away. In addition, even in pipelines and other piping used outdoors, the temperature of the surface of the steel pipe becomes quite high when exposed to direct sunlight such as in the summer, causing the composition to soften or, in extreme cases, to drip. This caused problems in terms of rust prevention performance and appearance. The present invention has been made in view of the above circumstances, and at the same time effectively prevents metal structures used in high-temperature corrosive environments from becoming soft or eventually sagging even in such environments. It is an object of the present invention to provide a rust preventive composition that has heat resistance and does not fall off. The present invention consists of petrolatum as a main component, polyisobutylene having an average molecular weight of 2000 or more to improve heat resistance and adhesion to metal surfaces, and an additive to prevent the composition from flowing or flowing down in a high-temperature atmosphere. It contains a sticky agent and at least one of petrolatum oxide metal salt or sulfonic acid metal salt as a rust preventive agent to further improve the rust preventive effect, in an appropriate range.In particular, the thixotropy effect provided by the above combination, i.e. It exhibits fluidity when an external force is applied to it, but does not flow when it is at rest.
The feature is that the composition does not flow or flow down even at high temperatures. The specific blending range of the present invention is 3 to 120 parts by weight of polyisobutylene with an average molecular weight of 2000 or more, and 1 to 1 to 120 parts by weight of a thickener to 100 parts by weight of petrolatum.
4 parts by weight, to which was further added an appropriate amount of at least one of petrolatum oxide metal salt and sulfonic acid metal salt. Petrolatum used in the present invention is not particularly limited, but includes dark green, green, red,
Amber, light amber, etc. (JISK2237) are suitable. In addition, as a thickener, ultrafine powder silica,
Inorganic thickeners such as ultrafine precipitated calcium carbonate and bentonite are suitable, but other organic thickeners such as metal soaps such as zinc stearate and aluminum stearate, organic bentonite, and polyethylene oxide may also be used. be able to. In addition, inorganic fillings such as inert silica, clay, calcium carbonate, talc, silicic acid, silicates, asbestos, diatomaceous earth, graphite, and glass fiber are used to give properties depending on the purpose of use and as fillers. Appropriate amounts of materials can also be added. The amount of petrolatum oxide metal salt and sulfonic acid metal salt, which are rust preventive materials, depends on the application, the required rust preventive performance, etc., but is usually about 10 parts by weight. In the present invention, the blending ratio of polyisobutylene having an average molecular weight of 2000 or more is 3 to 120 parts by weight to 100 parts by weight of petrolatum, because if it is less than 3 parts by weight, the composition will not have sufficient heat resistance. On the other hand, if it exceeds 120 parts by weight, the tackiness increases and the workability of compounding the composition deteriorates. Similarly, the reason for setting the blending ratio of the thickener to 1 to 40 parts by weight is that if it is less than 1 part by weight, sufficient thickening agent and thixotropic properties cannot be imparted to the composition. This is because things flow and flow down, and vice versa.
This is because if the amount exceeds 40 parts by weight, the adhesiveness of the composition to the metal surface will decrease and the antirust performance will not be sufficiently exhibited. The reason why the average molecular weight of polyisobutylene is set to 2,000 or more is that if the average molecular weight is less than 2,000, the viscosity decreases significantly in a high temperature range, making it impossible to impart sufficient heat resistance to the composition. Next, the rust preventive performance and heat resistance of Examples of the present invention were investigated by dripping the composition, and the results will be explained in comparison with conventional rust preventive compositions containing petrolatum as a main component. First, for 100 parts by weight of the main ingredient petrolatum,
Polyisobutylene, ultrafine silica, talc, petrolatum oxide Ca salt, sulfonic acid Ba salt, etc. were blended in various proportions, and the resulting compositions of this example and comparative example were impregnated into a polyester nonwoven fabric, and the thickness
I made a 1.1mm tape. Next, put this tape 1
Wrap inch steam piping (carbon steel pipe for piping) twice over a length of 50 cm, place the tape-wrapped part in a box containing a container of water, and isolate it from the outside air. Steam inside (3.87Kg/cm ² , 151
°C) for 12 hours, then the steam was stopped for 12 hours. After repeating this cycle about 30 times, the occurrence of rust on the surface of the steel pipe and the dripping of the composition were investigated. At this time, the maximum temperature between the steel pipe surface and the composition during steam inflow is 130℃, and the maximum temperature inside the box is 80℃.
℃, and the temperature on the surface of the steel pipe and inside the box while the steam is stopped is
At 20°C, water precipitated on the surface of the stopped steel pipe. The results were as shown in the following table. In addition, in this table, the reference example shows the case where the steam piping was not treated with the antirust composition.

【table】

[Table] According to this table, as a matter of course, rust generation was observed in the reference examples which were not treated with the antirust composition. Furthermore, in Comparative Examples 1 to 5, which did not meet the conditions of the present invention, dripping of the composition and generation of rust were observed. In contrast, embodiments 1 to 1 of the present invention
It was found that in all cases No. 3, not only did rust occur, but the composition also did not run down. As described above, according to the present invention, in addition to petrolatum as a main component, polyisobutylene having an average molecular weight of 2000 or more that improves heat resistance and adhesion to metal surfaces, and fluidity of the composition in a high temperature atmosphere,
Contains a thickener that prevents run-off and at least one of petrolatum oxide metal salt or sulfonic acid metal salt that improves rust prevention effect in an appropriate range, so it has good adhesion to metal structures and rust prevention performance. It is possible to provide an excellent heat-resistant rust-preventing composition that has a high resistance to corrosion, good heat resistance, and does not soften or drip even when used in a high-temperature corrosive environment.

Claims (1)

[Claims] 1 Average molecular weight based on 100 parts by weight of petrolatum
3 to 120 parts by weight of polyisobutylene of 2000 or more,
1. A heat-resistant rust-preventing composition, characterized in that 1 to 40 parts by weight of a thickener is added and at least one of a petrolatum oxide metal salt or a sulfonic acid metal salt is added.