JPS603433B2 - Paint for preventing marine organisms from adhering - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paint that is applied for the purpose of preventing the adhesion of marine organisms to water-contact parts of ships, marine structures, seawater utilization equipment, etc.

It is said that there are more than 200 types of adherent organisms that live in the ocean, and when these organisms adhere to the hull of a ship, they increase the frictional resistance of the ship and reduce its speed, making it difficult for ships to maintain a constant speed while navigating. Attempting to do so would increase fuel consumption and worsen operational economics.

In offshore structures, such as offshore oil drilling rigs, corrosion caused by the destruction of the anticorrosion coating by attached organisms can lead to premature decline in the life of the structure, and accidents such as blockage due to attached organisms on the inside of heat exchangers that use seawater, etc. The damage caused by this is enormous. As described above, adhesion of marine organisms causes serious industrial damage, and as a conventional countermeasure, paints containing various antifouling agents are applied to the submerged surfaces of structures, and the paint film is removed underwater. A method was used to prevent fouling due to adhesion of marine organisms by using the toxic effects of antifoulant components that are eluted in small amounts.

However, although the ingredients of this antifouling agent are commonly used, such as inorganic steel compounds and organic tin compounds, they are not completely harmless in terms of environmental protection.
It is necessary to develop antifouling paints (hereinafter referred to as antifouling paints). A method of utilizing a low critical surface tension substance such as an oligomeric room-temperature curing silicone rubber alone or a mixture of this silicone rubber and silicone oil as a non-plexing antifouling paint is disclosed, for example, in U.S. Pat. No. 3,702,778; Kosho 53-
This method is disclosed in Japanese Patent Application Laid-Open No. 35974 and Japanese Patent Application Laid-open No. 51-96830. However, as a result of follow-up studies, these inventors have now determined that the effect of preventing the adhesion of marine organisms (hereinafter referred to as antifouling performance) is insufficient.

This means that the critical surface tension of the coating film obtained by curing the oligomeric room temperature curing silicone rubber alone or a mixture of this silicone rubber and silicone oil increases in a short period of time, resulting in a decrease in the antifouling effect. This is due to The cause of this is the siloxane bonded Si-
This is considered to be because the dipole efficiency of Si110 in 0-Si becomes weaker, and the intermolecular attraction becomes stronger, resulting in the collapse of the amorphous structure. Furthermore, the high cost of oligomeric room temperature curing silicone rubbers and silicone oils has also been an obstacle in practical use.

The present invention has been made with the aim of solving the above-mentioned problems, improving the antifouling performance, and reducing costs in antifouling paints that utilize these oligomeric room-temperature-curing silicone rubbers.

The most characteristic feature of the embodiments of the present invention is that liquid paraffin and vetrolatam, which are petroleum direct distillation products, have a low critical surface tension equivalent to that of silicone rubber or silicone oil, and have a lower critical surface tension than silicone rubber. The reason for this is that it has a specific range of compatible ridges and is inexpensive. That is, the present invention involves mixing an oligomeric room-temperature-curing silicone rubber with petroleum-based liquid paraffin or vetrolatum having a low critical surface tension in a ratio within a range that provides good compatibility, and further mixing an organic solvent. This relates to an antifouling paint that has a suitable fluidity. The present invention will be explained in detail below. The oligomeric room-temperature-curing silicone rubber used in the present invention has a chemical mechanism that cures and forms a film under the action of moisture in the air, such as KE45TS and KE44RTV (both products of Shin-Etsu Chemical Co., Ltd.). name) is available.

Liquid paraffin is a mixture of highly pure liquid saturated hydrocarbons obtained by distilling crude oil to remove gasoline, kerosene, light oil, etc., and searching and refining fractions from spindle oil to engine oil. As for the product, one that is equivalent to JIS K2231 and has a kinematic viscosity at 40:00 in the range of 9 to 110 centistokes can be used.

Betrolatam is a jelly-like semi-solid wax made by decolorizing and refining raw lubricating oil raw material obtained by vacuum distilling crude oil or residual oil from the pot, and is a jelly-like semi-solid wax made from JIS K2235 1 to 4.
It is possible to use a product equivalent to the above No. 2003, with a melting point of 45 to 80°C, a rarity of 80 to 210 at 25 qo, and a kinematic viscosity of 10 to 30 centistokes at 100 q0.

The critical surface tension of liquid paraffin and vetrolatum can be in the range of 19 to 2 red skin e/arc, but preferably those close to the lower limit exhibit good antifouling I performance. If the upper limit is exceeded, the antifouling performance will be poor. Further, as the organic solvent, one or at least a mixed solvent of two selected from toluene, xylene, methyl isobutyl ketone, hard ethyl acid, mineral spirit, etc. can be used, but preferably toluene and xylene are used. Appropriate.

If it is necessary to apply a relatively thick film, use Erosil NO. as an anti-sagging agent. 200 (silica-based, West German Degussa product name) or Disparon 4200-20 (
It is also possible to add a small amount of polyethylene oxide (trade name, Kusumoto Kasei Co., Ltd.).

All of the above materials are exemplified, and other equivalent materials can be used without departing from the technical idea of the present invention.

Next, formulation examples and test examples (hereinafter collectively referred to as Examples) of the present invention will be explained.

Table 1 shows formulation examples. All compounding ratios of components in this table are expressed in weight %. As shown in the formulation examples in Table 1, liquid paraffin and betrolatum can be used alone or in combination.

As described above, the organic solvents may be used alone or in combination of at least two kinds. Additionally, anti-sagging agents may be added depending on the desired thickness of the film to be formed on the surface of the object to be coated, but when adding them, it is necessary to select an agent that does not inhibit the low critical surface tension of the coating film. Must be. Coloring pigments, extender pigments, etc. are not added because they inhibit the low critical surface tension of the coating film and reduce the stain resistance. Table 1 Next, the paint with the above formulation example is coated with tar-epoxy paint as an anti-corrosion coating with a dry film thickness of approximately 2.
A steel plate (100 x 300 x 3 ribs) was painted to a thickness of 50 microns, and then coated with a paint mixture of 10% by weight of KE45TS as an intermediate coating to a thickness of about 100 microns as an intermediate coating. It was painted on both sides and immersed in Nagasaki Bay for 24 months to conduct an antifouling test.

As comparative examples, the following paints were also tested in the same manner. Comparative example 1 Comparative example of long-term antifouling paint using organic tin and cuprous oxide “AF Seaflow” (trade name of the applicant company)
2KE45TS 45% by weight KF
54 5 Toluene
50 Comparative Example 3 KE45TS 4 weight% KF5
4 10 Toluene
50 Comparative Example 4 KE45TS 5 weight% toluene 50 (Note) KF5
4: Silicone oil (trade name, Shin-Etsu Chemical Co., Ltd.) The bond test results are listed in Table 2.

As is clear from the test results, the antifouling paint according to the present invention maintained its antifouling performance for a long period of 24 months, compared to the conventional long-term high-performance antifouling paint that combines organic tin and cuprous oxide with synthetic resin. (It was comparable in quality.) In addition, in the method of mixing silicone oil with room-temperature curing silicone rubber, which belongs to the known technology, if the amount of silicone oil mixed is less than 5% by weight, long-term stain resistance and properties cannot be expected. It is necessary to add more than % by weight. However, the liquid paraffin, vetrolatum, etc. blended into the paint of the present invention can exhibit long-term antifouling properties that are equivalent to or even better than when silicone oil is added in an amount within the range of 5 to 2% by weight in the paint. was confirmed. Regarding the amount of liquid paraffin and vetrolatum added, if it is less than 5% by weight, the antifouling property will not be sufficient.
If the amount is more than 2% by weight, the compatibility with silicone rubber will be poor, and the drying properties of the paint, adhesion to the base, etc. will be poor, so it is not suitable. Table 2 Based on the above-mentioned own soaking test results, the paints of Formulation Example 1 and Formulation Example 5 were applied to the bottom of a 400-ton steel fishing boat with a film thickness of 80 microns and 150 microns, respectively, about 3 coats. Other parts were coated with the paint of Comparative Example 1 to a film thickness of 150 microns, and as a result of a 24-month actual ship test, Comparative Example 1
No difference was observed in the antifouling performance compared to the other paints, and good results were obtained.

The present invention having the above configuration can significantly improve the antifouling performance due to the low critical surface tension of the silicone rubber by mixing the oligomeric cold-setting silicone rubber with liquid paraffin or vetrolatum.

The reason for this is that the critical surface tension of liquid paraffin or betrolatum or a mixture of both is equivalent to that of silicone rubber or silicone oil, and as mentioned above, silicone rubber undergoes structural failure during long-term exposure to water. This is because liquid paraffin and vetrolatum complement the phenomenon that occurs and increases the critical surface tension, maintaining a low-energy surface condition, which is effective in preventing marine organisms from adhering to the coated surface over a long period of time. . In addition, since liquid paraffin and vetrolatam are relatively inexpensive, the amount of silicone rubber used can be reduced by the amount equivalent to the amount of these mixed, resulting in lower material costs compared to known silicone oil addition methods. Since the difference in price can be saved, it is extremely effective as a cost reduction measure for paint.

Claims (1)

[Claims] 1. Consists of a mixture of an oligomeric room-temperature curing silicone rubber and a low critical surface tension substance derived from direct petroleum distillation, and the low critical surface tension substance derived from direct petroleum distillation is liquid paraffin or petrolatum. , a marine biofouling prevention paint diluted with an organic solution. 2. The oligomeric room-temperature-curing silicone rubber of claim 1 is a moisture-curing type. 3. The mixing ratio of the direct petroleum distilled low critical surface tension substance of Claim 1 to the oligomeric room temperature curing silicone rubber is 10 to 50% by weight. 4. The critical surface tension of the direct petroleum distillation-based low critical surface tension material of claim 1 is 19 to 23 dynes/glue. 5 The liquid paraffin according to claim 1 is heated at 40°C.
The kinematic viscosity is 9 to 110 centistokes. 6 Petrolatum in claim 1 has a melting point of 45
Consistency at ~80℃, 25℃ is 80-210, 100
The kinematic viscosity at °C is 10 to 30 centistokes.