JPH0285380A - Volatile powdery corrosion inhibitor having improved flowability and blocking resistance - Google Patents

Abstract

PURPOSE:To obtain the title corrosion inhibitor preventing blocking during storage, having improved flowability and easily undergoing sprinkling with a spray gun, etc., by adding a specified amt. of superfine aluminum oxide powder to a volatile powdery corrosion inhibitor and uniformly mixing them. CONSTITUTION:Superfine aluminum oxide powder is added to a volatile powdery corrosion inhibitor such as dicyclohexylammonium nitrite by 0.01-1.5wt.% and they are uniformly mixed. The flowability of the corrosion inhibitor can be improved without adversely affecting the corrosion inhibiting effect and a corrosion inhibitor easily undergoing sprinkling with a spray gun, etc., ensuring increased work efficiency of filling into small bags and having improved blocking resistance can be obtd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention blends an appropriate amount of ultrafine aluminum oxide powder into a volatile powder rust preventive agent to prevent blocking during storage and improve fluidity. The present invention relates to a vaporizable powder rust preventive agent that can be easily sprayed using a sprayer such as the above, and has improved workability such as filling into sachets.

[Prior Art] The present inventors have been conducting research on volatile powder rust preventive agents for some time, such as cyclohexylamine carbonate, dicyclohexylammonium nitrite,
We have provided volatile powder rust preventive agents containing diisopropylammonium nitrite, benzotriazole, etc. as active ingredients. In other words, these volatile powder rust inhibitors are used for rust prevention when storing large tanks, boiler reaction towers, reaction vessels, heat exchangers, metal pipes, etc., for example, temporarily or long-term. The rust preventive agent is sprayed inside the object to be rust-prevented using a spray gun, etc., or it is packed in a small bag and left inside, and the action of the vaporized rust preventive gas prevents metal from rusting. Because it is extremely easy to treat and handle to prevent rust, it is widely used not only for the purposes mentioned above, but also for anti-rust packaging and export packaging for automobile parts and various mechanical parts.

[Problems to be Solved by the Invention] Incidentally, the above-mentioned volatile powder rust preventive agent has poor fluidity and high vapor pressure to exert its rust preventive effect. Therefore, it is difficult to adopt excessive drying conditions, and it is difficult to obtain a sufficient dry state, so the fluidity is poor, and moreover, it is easy to cause blocking, and it becomes lumpy when stored for a short period of time. Therefore, if used alone, it is difficult to spray with a spray gun or the like, and it is also difficult to automate the filling operation into small bags, etc., and problems arise in measurement accuracy. Moreover, after long-term storage, it cannot be put to practical use unless it is once re-pulverized.

To deal with these problems, at present, fine powders such as magnesium carbonate and calcium carbonate are added to prevent blocking and improve fluidity. In order to increase the fluidity and fluidity to a certain level, it is necessary to mix the fine powder with the volatile powder rust preventive agent in an amount of about 10% by weight or more, which dilutes the rust preventive effect of the product as a whole. Not only that, but especially when the scattering method is adopted, a large amount of powder remains inside the tank etc. after rust-preventing storage, making post-treatment very troublesome.

The present invention was made in view of these circumstances, and
The purpose is to establish a technique that can improve the fluidity and blocking resistance of a volatile powder rust inhibitor by adding a small amount of a fluidity and blocking resistance improving agent.

[Means for Solving the Problems] The structure of the present invention that achieves the above object is that the ultrafine powder of aluminum oxide is
．． The gist is that 2.5% by weight of O2N is added and mixed uniformly.

[Effect] In order to solve the problems seen in the prior art as described above, the present inventors investigated the effects of various substances, including lubricants, on improving the fluidity and blocking resistance of the volatile powder rust preventive agent. . As a result, ultrafine aluminum oxide powder has the effect of significantly increasing fluidity and preventing blocking by adding a small amount to a volatile powder rust preventive agent.
The volatile powder rust preventive agent containing an appropriate amount of ultra-fine aluminum oxide powder does not cause intermittent accidents when sprayed with a spray gun, etc., and also facilitates tasks such as bagging and improves weighing accuracy. It was clear that the anti-blocking property was also significantly improved.

In order to effectively exhibit the effect of improving the fluidity and blocking resistance of ultrafine aluminum oxide powder, it must be added at least 0.01% by weight to the volatile powder rust preventive agent. If the spray gun nozzle is insufficient, the nozzle of the spray gun becomes clogged, or the flow during measurement becomes poor, which tends to cause measurement errors.Furthermore, blocking occurs easily during storage. On the other hand, from the viewpoint of fluidity and blocking resistance, there is no upper limit to the amount of ultrafine aluminum oxide powder added, but the above fluidity and blocking resistance improvement effect reaches a saturation level at 1.51% by weight. Furthermore, even if the amount added is increased, the fluidity and blocking resistance will not be improved any further; rather, the rust prevention effect will decrease due to an increase in the amount of components that are inert to the rust prevention effect, and the amount of residual substances after rust prevention treatment will increase. Therefore, cleaning work afterwards becomes troublesome. For this reason, in the present invention, the blending amount of the ultrafine aluminum oxide powder is defined as 0.01 to 1.5 1% by weight, but it is more preferably in the range of 0.1 to 1.0% by weight. Although the particle size structure of the ultrafine aluminum oxide powder is not particularly limited, it is the ultrafine powder of about 0.05 μm to submicron class that exhibits the most effective effect of improving fluidity and blocking resistance. For example, the fluidity of submicron class aluminum oxide ultrafine powder itself cannot necessarily be said to be good, but when an appropriate amount of this is added to a volatile powder rust preventive agent, its fluidity improves as will be shown in the examples below. is significantly improved. The reason for this has not been theoretically investigated, but when considered in light of the fact that volatile powder rust preventive agents tend to generate static electricity, which is a major cause of decreased fluidity, aluminum oxide ultra-fine It is thought that the powder adsorbs to the surface of the volatile powder rust preventive agent, prevents the generation of static electricity, and contributes to improving fluidity and blocking resistance.

The volatile powder rust preventive agent whose fluidity and blocking resistance are to be improved in the present invention is not limited in any way as long as it is volatile and has a rust preventive effect, but the most common ones are cyclohexylamine carbonate, These include dicyclohexylammonium nitrite, diisopropylammonium nitrite, benzotriazole, tolyltriazole, etc., and these may be used by appropriately selecting one type or 2 ft1 or more depending on the type of metal to be rust-prevented. There is no reason to limit the procedure or method of mixing ultrafine aluminum oxide powder to the volatile powder rust preventive agent, and any procedure or method can be adopted.

EXAMPLES The configuration and effects of the present invention will be specifically explained below with reference to Examples, but the present invention is not limited by the Examples below.

[Example] Dicyclohexyl ammonium nitrite (DICHAN), cyclohexylamine carbonate (CHC) (all white crystalline powder), or a mixture thereof was used as a vaporizable powder rust preventive agent in Group A, and 0.01 ~3.0
Weight% aluminum oxide ultrafine powder (average particle size: 0.
02μm, apparent density; 75g/12. , specific surface area: 10
0m''7g) was added and mixed uniformly, and the fluidity was examined using the method described below.

That is, the fluidity was determined by using a funnel 1 made of 5US304 with the dimensions shown in Fig. 1, closing the sliding shutter 2, charging each sample powder inside, and opening the shutter 2 to complete the outflow of the sample powder. It was calculated based on the time required to complete the process.

The results are summarized in Table 1, and the preferred amount of ultrafine aluminum oxide powder to be added varies depending on the type of volatile powder rust preventive agent, but by adding 0.01 to 1.5%, It can be seen that the fluidity can be improved. In addition, when a blocking test was conducted on a product containing 0.1 to 1.5% by weight of ultrafine aluminum oxide powder, it was found that
No blocking occurred even after storage at 65% RH for one month.

For reference, calcium carbonate fine powder (average particle size: 1.1
μm, apparent density: 330g/j2, specific surface area: 2.1
m2/g) and magnesium carbonate fine powder (average particle size: 0.1 μm, apparent density: 1B5g/λ, specific surface area:
When trying to improve fluidity using 2Bm"7g),
The results shown in Table 2 were obtained, and even though a large amount was added compared to ultrafine aluminum oxide powder, fluidity at the level of the examples of the present invention could not be obtained.

5 ■ Rainbow dichlorohexylamine carbonate (CHC) 30Kg
into a conical concrete mixer type kneading device, add o, oos ~ 3.01i% ultrafine aluminum oxide powder (properties are the same as those used in Example 1), and stir for 1 hour. It was mixed evenly.

10 kg of each of the obtained mixtures and those containing no ultrafine aluminum oxide powder were weighed and placed in a polyethylene bag, placed in a rectangular cardboard box, and left indoors. When the package was opened one month later and the state of each powder was observed, the powder containing no ultrafine aluminum oxide powder was completely solidified, and the one containing ultrafine aluminum oxide powder was completely solidified. ．． In the case where 0.05% by weight was added, the caking state was relaxed, but the whole was solidified. On the other hand, in the case where aluminum oxide ultrafine powder was added in an amount of 0.0% by weight, blocking occurred partially, but it could be easily loosened by hand. Those containing 1% or more did not cause any blocking and maintained almost the same fluidity during mixing.

[Effects of the Invention] The present invention is constructed as described above, and simply adding a small amount of ultrafine aluminum oxide powder to a volatile powdered rust preventive agent with poor fluidity does not adversely affect the rust preventive effect. It is possible to significantly improve fluidity without causing any problems, and to make it easier to spray with a spray gun, etc., to improve the flow during bagging and to increase weighing accuracy, and also to significantly improve blocking resistance. was completed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of the instrument used for the fluidity test.

Claims (1)

[Claims] A vaporizer with improved fluidity and anti-blocking properties, characterized by adding 0.01 to 1.5% by weight of ultrafine powder of aluminum oxide to a vaporizable powder rust preventive agent and uniformly mixing it. Powder rust preventive agent.