JPS6035065A - Antifouling method for material in contact with sea water - Google Patents

Abstract

PURPOSE:To prevent effectively the deposition of marine organisms on a structure in contact with sea water, by applying a coating compsn. contg. an alkali metal silicate, activated magnesium oxide, calcium sulfite, and zinc (compd.) to said structure. CONSTITUTION:An alkali metal silicate (A) as a binder, 15-400wt% (based on the quantity of SiO2 in component A) activated magnesium oxide (B) having an iodine absorption of 30-300mg.I/g of MgO, 0-15wt% (based on the combined quantity of components B and C) calcium sulfite (C) and 0-900wt% (based on the combined quantity of components B and C) at least one member (D) selected from among metallic zinc and inorg. zinc compds. (e.g. zinc oxide) are mixed together to prepare a coating compsn. The coating compsn. is applied to the surface of a structure in contact with sea water to prevent the deposition of marine organisms thereon.

Description

[Detailed description of the invention]

The present invention applies to structures that come into contact with seawater, such as light buoys, buoys, floating piers, and floating breakwaters. Contamination (falling, fo.
The present invention relates to a method for preventing fouling of structures by sessile marine organisms such as tentacles, annelids, arthropods, molluscs, protozoa, etc., which cause uling. More specifically, the present invention includes a) an alkali silicate as a binder, b) an activated magnesium oxide having an iodine absorption amount of 30 to 300 mg·I/(+·11+0) on at least the contact surface of a structure that comes into contact with seawater. a) Based on SL 02M in 15-400ii1% C) Add calcium sulfite to the above b
) 0-15% by weight based on the total amount b) + c)
d) At least one type of metal 1T11j (l and jll (from the group consisting of mechanical metal compounds)) is added to the above combination of 0 to 900% by weight per 1 metal, or more a) b) ) C) A method for preventing fouling of objects in contact with seawater, characterized by applying a coating composition containing d) and preventing adherent marine organisms from adhering to the coated surface. With the progress of marine development in the LJ area, various types of [1, large marine structures, Part 1] +
Construction of Mm objects and other similar structures in contact with seawater;
Installations are increasing. Structures that come into contact with seawater like this are exposed to seawater.
In addition to the problem of corrosion, there is also the problem of contamination caused by the growth of adherent marine organisms that cause contamination at or near the contact area. It is desired to develop an effective method for controlling iJ. Bays, harbor facilities structures such as channel buoys, light buoys, mooring buoys, floating piers, floating breakwaters, floating docks, etc., such as moored ships restaurants and hotels, moored floating fishing structures and other leisure structures, e.g. Structures that come into contact with seawater, such as ike structures for fish and shellfish farming, fixed nets for the fish industry, and similar structures for fisheries facilities, are exposed to the structure base material due to the growth of adherent marine organisms that cause contamination on these structures. Acceleration of corrosion, undesirable subsidence due to increased weight, and unstable balance occur. In addition, when seawater is used for cooling and other purposes in various facilities, factories, power plants, etc. on the coast, contamination occurs in coastal structures such as seawater collection pipes, discharge pipes, waterways, eddies, etc. The resulting adherent marine organisms grow adherently, and in extreme cases, adherently grow on the order of several senna, reducing the effective area of the waterway, increasing flow resistance, and clogging screens for removing suspended solids.
suffer other damage. In order to prevent contamination of such structures that come into contact with seawater by 3-L/ft, it has been common practice to inject sodium hypochlorite or chlorinated water, etc. However, since it is unavoidable that problems with environmental pollution are involved, at present, a coating composition containing an antifouling agent is used to prevent the elution of an effective concentration of the antifouling agent from the composition. A common method is to kill or avoid adhering to marine organisms that cause contamination. For example, ship bottom paints used as antifouling coating compositions contain antifouling agents such as cuprous oxide, tetramethylthiuram sulfide, zinc methyldithiocarbame-1, and triphenyltin hydroxide. , 1 to rifhenyltin acetate, triphenyltin lorite, etc. are used. however,
Such antifouling agents have a problem with their toxicity, and the organotin compounds and other antifouling agents exemplified above have a t-1-so of 1,000 after 24 hours of oral administration to mice.
m (less than 1/ko), which exhibits relatively high toxicity, and its negative effects on living organisms cannot be ignored, leaving questions about safety, and there is a risk of secondary marine pollution. Based on the prevention mechanism that prevents contamination by elution of an effective concentration of antifouling agent sufficient to kill or repel adherent marine organisms that cause
Of course, - In addition to the drawback that it is difficult to avoid the trouble of secondary contamination mentioned in E, there is the technical problem that it is practically difficult to control the elution rate of the inhibitor, and the inclusion of the antifouling agent as it elutes. Since the amount decreases, there is also an essential defect in the sustainability of the antifouling effect. Furthermore, since this is a contaminated coating composition used for a structure in contact with seawater, it is required to have sufficient adhesion strength to the surface of the structure and seawater resistance to withstand waves and seawater. The inventors of the present invention have satisfied these requirements and solved the above-mentioned secondary contamination I~syllable and persistence ↑1 which is inherent in conventional compositions due to the prevention mechanism of preventing contamination by elution of the antifouling agent. We have been conducting research in order to develop a new type of preventive agent that can overcome the problems of lack of protection. As a result, it exhibited satisfactory adhesion strength and seawater resistance without containing any removal agents that would cause secondary marine pollution. We have also succeeded in developing an inorganic antifouling coating composition that can exhibit an antifouling effect of 61 flH. According to the research of the present inventor, a) using an alkali silicate as a binder, h) based on 5L()iffi in a), 15
In amounts of ~500% by weight, iodine adsorption between 30-300
Even though an inorganic composition containing activated magnesium oxide with mO-1/Q flil 0 as an essential component does not particularly contain a component called a so-called anti-fouler+gagent, it has an adhesive property that causes staining. It exhibits a remarkable antifouling effect on marine organisms, and also has satisfactory adhesion strength to structures that come into contact with seawater or may come into contact with it, and excellent seawater resistance f1.
It has been discovered that the composition of the present invention results in a neutral antifouling coating composition. Although the mechanism of action that produces this unexpected effect is unknown, as will be shown experimentally later with many examples and comparative examples, the antifouling coating composition used in the present invention has excellent water resistance. A new type of non-environmentally polluting, antifouling coating composition that has excellent antifouling effects against adherent marine organisms that cause contamination, as well as seawater resistance, adhesion to substrates, and workability. It was discovered that. The present inventor has developed the above a) alkali silicate as a binder, and b) based on &02 m in a).
The amount of iodine adsorbed in an amount of 500% by weight is 30-300J)-
I/(1-1190 active magnesium oxide and C)
A self-curing inorganic composition containing a hardening agent made of calcium sulfite has a composition that exhibits excellent workability, water resistance, weather resistance, surface hardness, especially boiling water resistance, heat resistance, etc. Discovered and published Japanese Patent Publication No. 57-563
No. 64 was proposed. However, in this proposal, there is no mention of the antifouling effect on organisms that cause pollution, and the inventor himself did not notice the unexpected effect at all. . Therefore, as a matter of course, the present inventor's proposal in JP-A-1G (b756364) does not include any disclosure that could suggest such new uses. (b) The composition containing the optional components <C,) and/or (d> above causes contamination of seawater contact structures and has an antifouling effect against φ-adhesive marine organisms. Furthermore, despite not containing any antifouling agents that can cause secondary pollution light G4, it exhibits an outstandingly excellent antifouling effect for a long time and has a satisfactory adhesion strength that can withstand waves. Furthermore, it has been discovered that sessile marine organisms belonging to the mussels, which are widely distributed in coastal areas of the world except in particularly cold sea waters and cause pollution, can maintain seawater resistance. - It has been found that it exhibits particularly excellent antifouling effects against Bamura 1J mussels, etc. Therefore, the object of the present invention is to treat structures that come into contact with seawater or have the possibility of coming into contact with seawater by using the above-mentioned antifouling composition. An object of the present invention is to provide an antifouling method for coating with a substance.The antifouling coating composition used in the present invention contains the following a) and b) as essential components. a) alkali silicate as a binder, b) active magnesium oxide with an iodine adsorption amount of 30 to 300 m9.17 g.I'190, 1% to 1% based on SL02M in a) above, a) silicic acid Examples of the alkali include silium silicate, potassium silicate, lithium silicate, quaternary ammonium silicate, and mixtures of any two or more of these. The solid content of these alkali silicates can be selected as appropriate, and may be, for example, about 15 to 50% by weight. 1) above
) Active V[magnesium oxide is commercially available and can be used in the present invention. The manufacturing method is also known, for example, by pulverizing basic magnesium carbonate, magnesium carbonate, magnesium hydroxide, etc. into particles with a particle size of several hundred microns or less, and firing them in, for example, a tarry kiln or other suitable firing equipment. The composition can be ground, for example, in a pebble mill or other suitable grinder, and if desired, the particle size can be adjusted by means such as sieving to obtain the desired active magnesium oxide. In the present invention, the active magnesium oxide obtained as described above has an iodine absorption IB of 30-3.
0011 (+・I/g・−0) active magnesium oxide is selected and used. If the iodine adsorption amount is too small outside the above range, the curing effect on component a) tends to be insufficient, and the resistance also increases. It also gets worse when it comes to seawater. On the other hand, if the iodine adsorption ratio is too large outside the above range, the curing effect on component a), especially the curing speed, will be excessive, causing gelation in a very short time during mixing, resulting in extremely poor workability in coating processing. Become. Therefore, it is appropriately selected and utilized within the above-mentioned iodine adsorption amount range. b) The amount of active magnesium oxide is 1 based on the amount of 5L02 in the alkali silicate as binder in a).
The amount is 5 to 400% by weight, preferably 30 to 300% by weight. If the amount of magnesium oxide (b) is too large outside this amount range, the workability during coating treatment will be poor and it will also cause deterioration of seawater resistance, so the amount is selected within the above range. The antifouling coating composition used in the present invention can further contain C) calcium sulfite. Its used part is the same as b) above! It can be used in amounts such that less than 15% by weight based on Fflb) + C), ie based on the total amount b) active magnesium oxide accounts for more than 85% by weight of the main component. C) If the amount of calcium sulfite used exceeds the range of less than 0 to 1511% by weight based on the above total amount b) + O), for example, when in contact with seawater for a long period of time, gnats may form on the paint film. There is a problem of the occurrence of kings, and the sustainability of the antifouling effect against marine organisms that cause contamination is lost, so when using C) ingredients, the total amount b) 15f based on 10 c)
It is used with less than flti%. C) The combined use of calcium sulfite helps to further improve the adhesion to the base material. Preferably it is available in an amount of 5 to less than 15 weight based on the total amount b) + C). The antifouling composition used in the present invention can contain at least one selected from the group consisting of d) metallic zinc and inorganic zinc compounds. Its usage is ”-to 0 based on the total amount b) ten c)-
90 (1% by weight, preferably 0 to 300% by weight). Component d) is useful for improving adhesion to wet substrates such as wet concrete. However, the total amount b
)+c) If the amount exceeds about 900% by weight based on c), it tends to reduce the seawater resistance of the strength composition, so the total amount should exceed 1b)+900ffi% based on c). used in large quantities. Examples of inorganic zinc compounds in component d) include zinc oxide, zinc carbonate, and zinc sulfate. The antifouling composition used in the present invention for coating structures that come into contact with seawater or may come into contact with seawater includes the above-mentioned essential components a) and b), as well as optional components C) and/or
or d) can contain other auxiliary additives. Such additives include fillers, dispersants, colorants,
Examples include thickening agents, antifoaming agents, and antisettling agents. Specific examples thereof include inorganic or organic powdery or fibrous fillers such as talc, kaolin, calcium carbonate, asbestos, pulp, etc., titanium oxide, chromium oxide, cobalt oxide, white lead, litharge, red iron, Inorganic materials such as ultramarine and molybdenum red

[Coloring agents such as 1 size and water-dispersible organic pigments, sodium hexametaphosphate, polyA-xyJ tyrene alkylphenyl ether, naphthalene sulfonic acid condensate, sodium polyacrylate, ammonium polyacrylate hydroxyethyl cellulose, etc. For example, thickeners such as polymethylsiloxane, antifoaming agents such as polymethyl siloxane and derivatives of polymethylsiloxane, and antisedimentation agents such as pentophyte, mica, silica gel, etc. can be used. The amount of these additives to be used can be selected as appropriate, but an example is an amount of about 85% by weight or less based on the weight of the antifouling coating composition. The composition used in the present invention has the above-described essential component a.
) and b), optional components C) and/or d), and/or additives. There are no particular restrictions on the mixing means, but for example, it is easiest to use a high-speed rotating stirrer for liquid substances, and for powder substances, it is easiest to use a suitable mixer such as a static mixer, ribbon blender, etc. Can be mixed. Using such an antifouling composition, it is possible to provide a method for antifouling a structure that comes into contact with seawater or has the possibility of coming into contact with seawater. Examples of the above-mentioned structures include bays, port facility structures, leisure structures, fishery facility structures, and coastal structures as already exemplified. Examples of base materials constituting the contact portion of structures that come into contact with seawater include concrete, stone,
Examples include various slates, inorganic materials such as plates such as calcium silicate plates, columns and pipes, and metal inorganic substrates such as metal plates, columns and tubes made of aluminum, iron, stainless steel and the like. The above-mentioned coating treatment can be performed using any method capable of coating the above-mentioned structure with the composition used in the present invention. For example, spray coating, roller coating, brush coating or any other known coating process.
5-]! r! method can be used. The antifouling composition used in the present invention is self-curing at room temperature (11).
After being formed into a composition, it cannot be stored for a long time. Therefore, at least b essential components a) and b),
Furthermore, it is recommended that C) and/or d) be mixed and used prior to application at or near the site to be coated. It is good to have a self-hardening material after coating, but
If desired, the material can be heated in the late stage of curing or after curing with hot air, infrared rays, or other suitable heating means to further improve the physical properties and shorten the curing period. The coating thickness can be appropriately selected as desired, and for example, a coating thickness of about 20 μm to about 1 cage can be exemplified. The method of the present invention exhibits an excellent prevention effect in preventing the adhesion of adherent marine organisms that cause pollution. In particular, it can exhibit a remarkable effect in controlling sessile marine organisms belonging to the family Mussel, such as the mussel. 161 The antifouling coating composition used in the present invention exhibits an excellent antifouling effect against adherent marine organisms that cause contamination, although it does not contain any components that correspond to so-called antifouling agents.
Furthermore, unlike organic antifouling paint compositions containing leachable antifouling agents consisting of organic film-forming components, the present invention is a substantially inorganic coating composition and has many excellent advantages. For example, 1) it exhibits an excellent antifouling effect without the trouble of secondary contamination caused by antifouling agents, and exhibits excellent sustainability of the effect; 11) It is a substantially inorganic composition that is water-soluble and odorless before application and hardening, and has the advantage that, for example, dilution, cleaning of painting tools, etc. can be carried out using water. For example, even when painting under sealed conditions, there is no risk of unpleasant odors, flammable or combustible gas generation, etc., and it has excellent work safety and sanitary safety during handling and construction. (Thank you) It has extremely strong adhesion to cement-based substrates such as concrete walls, and maintains sufficient adhesion and strong electricity without any problems when painting on wet surfaces. With general high quality paints, it is necessary to dry the surface to be coated sufficiently, and considerable effort is required to prepare the base before painting, but Coating F1 used in the present invention does not require such base treatment. . With this J, sea urchin, the drying operation of the surface to be painted is omitted.
Further, since primer application is not required, the number of painting operations and number of times can be reduced, and construction is extremely easy and the construction period can be shortened. iV) The composition of item 1 is self-curing and can be easily coated at the construction site to form a cured coating film without the need for particular heat treatment. [Heat treatment for curing] [j] can be omitted. Comparative examples are shown below, and the embodiments of the present invention will be explained in more detail with reference to Examples. In addition, in the following examples, test methods and evaluations are as follows. (1) The water-resistant knee test coating composition was coated on a glass-reinforced cement board (5x 75x
1501m), painted to a thickness of approximately 200 μm.
Samples aged for 24 hours at 60% R1-1 (relative humidity) are tested. After immersing the same sample in water for 720 hours, it was taken out and the surface condition of the paint film was observed with the naked eye, and it was determined according to the paint film evaluation standards (1970) of the Japan Paint Inspection Association.
Evaluate chalking, blistering, and peeling according to the evaluation below. 1. Chalking Using a chalking tester specified in 5.17.4 of JIS K5516, the degree of detached powder adhering to the coated surface of photographic paper is expressed as a score by comparing it with a standard judgment photograph. When there is no chalking 1
Score 0 points. 4 The larger the numerical value, the better the stiffening resistance. 2. No bulges are given 10 points, and bulges = 19 The combination of the total area of the part and the size of the bulges (average diameter) 1!
J: Grade according to the table below. 3. 10 points are given for peeling and no peeling, and the grade is determined based on the total area of the peeled parts. (2) Seawater resistant! 1. : - 1 [Description (1) Test the sample prepared in the same manner as described in m4 aqueous. After immersing the sample in artificial seawater specified in JISK 2510 for 720 hours, the surface condition of the coating film was observed with the naked eye for 20 hours, and the 'f1' value of the coating film was determined by the same Japanese Paint Inspection Association as in (1) above. Therefore evaluate. (3) The adhesion knee test coating composition was applied to a thickness of about 200 μm on concrete plates 25×75×751× with a moisture content of 5% and 80%, respectively, at 20°C and 60%R]-1. Samples cured for 24 hours under these conditions are tested. After immersing the sample in the same artificial seawater as in (2) above for 240 hours,
Take it out and J I SA 6. ．． The adhesion strength (IM/alt) was measured according to the plane tensile test method defined in 909, and is expressed as a numerical value. The larger the value, the greater the adhesion. (4) Pot life (coating workability) After the components for forming the knee coating composition are mixed in a constant temperature room at 20°C, the run-off time is measured every 30 minutes using a J4 SK 54.02 paint Ford cup. Perform measurements. In the cup, cL
The time it takes for the product to stop flowing out is defined as the pot life (hrs). (11.1 interval of T, coating work is unsatisfactory at about 1 or J).Pot life is about 1 hour or more. (5)) Prevention νi 14. (61rt llJ Ability to prevent adhesion of probiotic organisms) The knee test coating composition was applied to glass-reinforced cement 1 to plate (5x 1
,000x 1. ooolm), thickness approximately 20071
Test 1'+1 was performed by painting 1 ft and supplying it for 2'It+M under the condition of 60% Rl-1. Attachment 1↑IroN Living things (sessile marine things that mainly belong to the mussels, such as mussels)
The above test sample 1 was immersed for 2 years in natural seawater below sea level 1111, and the weight of adherent marine organisms belonging to mussels per medium area was measured. Tests of Examples and Comparative Examples with an arithmetic mean value (expressed as (1/TI') of 1° or less were conducted at three locations: Osaka Bay, off Matsu 111, and off Jashiki. Examples 1 to 6 and Comparative Examples and Control Examples Each coating composition shown in Table 1 was prepared.The various tests described above were conducted on these coating compositions, and the results are shown in Table 1.In Table 1, the coating compositions used were 10 in parentheses r
2[]110% by weight solid content 40% by weight, potassium silicate 3LQ227% by weight, K2O 13% by weight, solid content 40% by weight. Further, in Table 1, the numerical value indicating safety is the LD50 value of the oral acute toxicity test in mice. In Table 1, (b)"' and (b)"' are other hardening agents Ha2Str known as hardening agents for alkali silicate.
6 and A2B PS 011 T al.

Claims (1)

[Scope of Claims] At least the contact surface of the structure that comes into contact with seawater contains a) an alkali silicate as a binder b) an active compound having an adsorption amount of 30 to 300 m (l I/(1--0) 15 to 400% by weight of magnesium oxide based on 5LO2 in a) above C) Amount of calcium sulfite mixed with b) above b) +c
d) at least one selected from the group consisting of metallic zinc and inorganic zinc compounds based on the above total amount b) + c)
A seawater-contact article characterized in that a coating composition containing at least 900% by weight of a), b), C), and d) is applied to prevent adherent marine organisms from adhering to the coated surface. Antifouling method.