JPS5916827B2 - Long-term antifouling and anticorrosion coating method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a long-term antifouling and anticorrosion coating method.

More specifically, the present invention relates to a method for coating ship bottoms, marine structures, etc. with an antifouling and anticorrosion paint composition that forms a film with excellent antifouling properties over a long period of time. Many types of substances are already known as antifouling agents for use in pillar materials.

However, with emphasis on safety for the human body, cuprous oxide, tributyltin compounds, triphenyltin compounds, zinc dialkyldithiocarbamates, tetraalkyldithiocarbamates, tetraalkylthiuram dithiosulfides, etc. are mainly used. These compounds have 0 chloride
It is used as a mixture in a color vehicle such as a combination of rubber, vinyl chloride resin, or drying oil-modified phenol resin and rosin. Generally, the antifouling property of a coating film is exerted by the gradual elution and diffusion of the antifouling agent contained in the paint or its decomposition products from the coating film into the sea or water.

The elution mechanism can be roughly divided into the following two modes.

One embodiment is to mix cuprous oxide as an antifouling agent in a high concentration in a paint that uses a water-resistant resin (such as vinyl chloride resin) as a color vehicle and is capable of forming a film without rosin. It is a so-called isosol pull type that utilizes cuprous oxide's solubility in water to continuously elute cuprous oxide from the paint film over a long period of time.

In this type, when the content of cuprous oxide in the paint is low, the amount of cuprous oxide eluted during immersion in seawater decreases in a short period of time, and the sustainability of the antifouling effect is extremely reduced.

In other words, this type of paint generally requires a large amount of antifouling agent to be blended into the coating material, and as a result, for example, cuprous oxide tends to precipitate during storage and cause hard cake fern. , as well as impairing painting workability,
It has defects such as brittle coating, poor adhesion, easy cracking, and easy peeling, and due to the price of 35 paint, it is hardly used these days. Another embodiment is a paint having a so-called sol-pull matrix type elution mechanism, which is made by using rosin as the main film-forming component and adding an antifouling agent such as cuprous oxide to the rosin.

In this type of paint, rosin gradually dissolves from the surface of the paint film in seawater as a matrix component, and as a result, the antifouling agent is constantly exposed on the surface of the paint film, dissolves into the seawater, and exhibits antifouling properties. do.

However, this method can also be expected to improve the durability of the antifouling effect to some extent compared to the former, but this will only last for about a year at most.

As mentioned above, using rosin as a color vehicle in antifouling paints is effective in improving the sustainability of the antifouling effect, but the film obtained from rosin is extremely fragile and has poor water resistance, so it is difficult to use as a paint film. Performance (particularly strength) was low, and wear and tear in water was also high.

Therefore, in order to improve the strength of the coating film, small amounts of resins, oils, or plasticizers that can form a coating are added.
The reality is that nothing has been obtained that satisfies both the sustainability of the antifouling effect and the durability of the coating film. The reason for this is that if a sufficient amount of oil or resin is added to give the strength and durability of the paint film, the antifouling properties of the paint film will be extremely low from the beginning. This is because they do not demonstrate their true potential.

The object of the present invention is to provide an antifouling and anticorrosion coating method that improves or eliminates the defects of conventional antifouling paints as described above, has a long duration of antifouling effect, and has high coating film strength. It is. That is, the present invention consists of (C) 100 parts by weight of an epoxy resin that is liquid at room temperature, a main agent consisting of 10 to 900 parts by weight of glass flakes and/or silica sand, and 10 to 50 parts by weight of furfuryl alcohol;
) A hardening agent is applied to a base material, and after drying, an antifouling paint made of a silicone resin is applied on the primer layer.

By the way, regarding the use of silicone resin as an antifouling material, for example, Japanese Patent Publication No. 53-35974 and Japanese Unexamined Patent Application Publication No. 1983-1989 disclose
It is known from No. 96830.

However, even with these methods, sufficient effects were not achieved as described above. In addition, silicone resin has poor adhesion to the base material, so the conventional base treatment,
Also, the use of primers did not give satisfactory results.

In particular, it had the disadvantage of not being able to withstand medium to long term use. Therefore, another aspect of the present invention is to achieve the object of long-term stain and corrosion protection by using a preferable primer.

The primer used in the present invention includes: A) 100 parts by weight of an epoxy resin that is liquid at room temperature, 10 to 900 parts by weight of glass flakes and/or silica sand, and 1 part by weight of furfuryl alcohol.
It consists of a main ingredient consisting of 0 to 50 parts by weight, and B) a curing agent.

The epoxy resin used in the present invention has an epoxy equivalent of 150 to 300 and is liquid at room temperature.

For example, ether type epoxy resins such as bisphenol type epoxy resin, novolak type epoxy resin, polyphenol type epoxy resin, aliphatic type epoxy resin; aromatic type epoxy resin, cycloaliphatic type epoxy resin, aliphatic type epoxy resin, etc. Ester type epoxy resin; ether ester type epoxy resin and the like. Among these, bisphenol type epoxy resins and novolak type epoxy resins are preferably used. These may be used alone or as a mixture of two or more. The glass flakes used in the present invention have a thickness of 0.1 to 10 microns and a size (maximum length) of 0.03
It is a glassy, extremely thin flat particle with a diameter of ~3 mm.

When a mixture of glass flakes and the resin mentioned above is applied to a material, the glass flakes are layered in parallel to the material in the coating film that is formed, preventing external vapors, moisture, salt, etc. Shows the effect of preventing the penetration and penetration of corrosive materials.

Generally, such an effect is greater as the thickness of the flat pigment is thinner and the diameter thereof is larger. Therefore, if the corrosive environment is severe, glass flakes with a maximum length of 0.3mm or more are suitable. Moreover, the silica sand used in the present invention has a size of 0.03 to Im
Commercially available products can be used.

As a filler, the silica sand serves to prevent the permeation of corrosive substances as described above. The glass flakes and/or silica sand are
It is used in an amount of 10 to 900 parts by weight, preferably 20 to 800 parts by weight, based on 100 parts by weight of the epoxy resin.

Especially when using glass flakes, epoxy resin 1
10 to 100 parts by weight, preferably 2 parts by weight
When monolithic silica sand is used, it is used in a proportion of 50 to 900 parts by weight, preferably 200 to 800 parts by weight. Furthermore, the mixture of glass flakes and silica sand has a weight ratio of glass flakes and silica sand of 1:1.
It is preferable to use them in a ratio of 1 to 1:100.

If the amount of the glass flakes and/or silica sand mixed is less than 10 parts by weight, the effect of preventing the permeation of corrosive substances such as moisture will be reduced, and if it exceeds 900 parts by weight, the film will become brittle. do not have.

The use of furfuryl alcohol is essential in the composition of the present invention. The component is used to adjust the viscosity of the composition. In addition, since it has a high boiling point, it does not become a volatile component from the film after painting. Furfuryl alcohol has good solubility in the epoxy resin and curing agent, and has the same viscosity-lowering effect as xylene, toluol, methyl isobutyl ketone, butanol, etc., which are generally used as solvents for epoxy resins. Because it has extremely low volatility, it has the advantage that there are almost no problems with industrial hygiene or air pollution caused by solvents during painting operations. Further, the furfuryl alcohol remaining in the coating film acts as a plasticizer and has the effect of alleviating the deterioration of physical properties due to curing distortion of thick coating films.

By adding this component, one of the characteristics of the composition of the present invention, which is excellent coating workability and contains no volatile components, can be achieved. In the present invention, the furfuryl alcohol is used in an amount of 10 to 50 parts by weight, preferably 15 to 45 parts by weight, based on 100 parts by weight of the epoxy resin.

In the above ratio, if furfuryl alcohol is less than 10 parts by weight, the viscosity of the composition will be high and the coating workability will be reduced, and if it is added in excess of 50 parts by weight, the performance such as water resistance of the film will be deteriorated. Both are unfavorable as they result in a decrease in The primer composition of the present invention includes the above-mentioned epoxy resin. , glass flakes and/or silica sand, furfuryl alcohol, and, if necessary, a silane coupling agent, are mixed in a conventional manner to form a main ingredient.

If necessary, commonly used coloring pigments, extender pigments, anticorrosive pigments, dispersion aids, suspending agents, diluents, hardening accelerators, etc. can be added to the main ingredient. The primer composition of the present invention can be obtained by adding a curing agent to the base resin thus obtained at the time of use. As the curing agent for curing the epoxy resin of the present invention, any curing agent generally used as a curing agent for epoxy resins such as amine adduct resin, polyamide resin, polyamine resin, etc. may be used alone or in combination.

In order to carry out a cross-linking reaction with the above-mentioned epoxy resin, these need to have at least two or more nitrogen atoms and an active hydrogen bonded to them in one molecule.

The thus obtained primer composition of the present invention is applied onto steel materials by a conventional method such as brushing, rolling, or air spraying.
After being applied to a film thickness of 5ml to 6n, it is dried at room temperature or by heating.

In the present invention, an antifouling paint composition made of silicone resin is then applied and dried on the thus formed primer layer to form a film. The silicone resin used in the present invention is a polymer formed on a repeating central axis of -Si-0- having the following repeating chain.

(R represents an alkyl group, an aryl group, or a vinyl group, and the two groups R bonded to the same silicon atom are the same or different.) In this field, three types of Polymers are distinguished: 1. Also known as silicone oils, or silicone fluids. 2 Silicone rubber - sometimes called silicone elastomer or silicone rubber.

．． 3 Silicone Resins Silicone oils generally have molecular weights in the range of 2,000 to 30,000 and viscosities in the range of 20 to 1,000 centistokes.

Silicone rubber generally costs 40,000 to 100,000
and a viscosity ranging from 10 to 1000 Stokes. Preference is given to using silicone rubber.
Mixtures of these with rosin may also be used. When mixing rosin and silicone resin, the mixing ratio is 20/8.
It is preferable to set it to about 0 to 80/20 (weight 01). In the present invention, it is preferable to further use an antifouling agent.

As the antifouling agent, those used in general antifouling paints are used. Examples include suboxide steel, triphenyltin compounds (e.g., triphenyltin hydroxide, triphenyltin acetate, triphenyltin chloride, etc.), tetramethylthiuram sulfide, zinc methyldithiocarbamate, tributyltin compounds (e.g., tributyltin fluorade, tributyltin chloride, etc.), or in some cases, mercury or arsenic compounds such as mercury oxide or arsenite may also be used. Further, as the antifouling agent, organic tin polymers such as poly(tributyltin acrylate), poly(tripropyltin acrylate), poly(tributyltin methacrylate), and poly(triprobyltin methacrylate) may also be used. The above antifouling agents may be used alone or as a mixture of two or more.

The blending ratio of the antifouling agent and the color vehicle is 1:1 of the color vehicle (solid content)
If the amount of antifouling agent mixed is less than 10 parts by weight at a ratio of 10 to 350 parts by weight of antifouling agent to 00 parts by weight,
If it is added in an amount exceeding 350 parts by weight, the strength and durability of the coating film will decrease, which is not preferable.

Furthermore, in the antifouling paint of the present invention, it is more preferable to use glass flakes in addition to the above.

．． The glass flakes are extremely thin flat glasses with a thickness of 0.1 to 10 microns and a size (maximum length) of about 0.03 to 3 nm. When glass flakes are mixed into an antifouling coating, glass flakes form within the coating when the coating is applied onto a substrate. Because the flakes are laminated in many layers parallel to the base material, it is possible to control the elution of a large amount of the antifouling agent, and therefore the duration of the antifouling property can be greatly extended. .

Furthermore, coating films containing glass flakes can improve the strength of the film, as the layering of glass flakes increases the film's hardness and improves its flexibility. It has excellent effects such as improved water resistance.

Therefore, it is possible to prevent film fragility, deterioration, and short-term disappearance of the antifouling agent, which were major problems with conventional antifouling paints, and maintain a strong film for a long period of time.

This effect is particularly remarkable in sol-pul type antifouling paints that use rosin as a color vehicle. According to experiments conducted by the present inventors, mica, scale-like iron oxide, talc, etc., which are generally known as flat pigments, have an effect on suppressing the amount of elution of the antifouling agent of the present invention and reinforcing the film. The effect was far from that of flakes.

In the present invention, the glass flakes contain a color vehicle (solid content) of 10
If the amount is 10 to 70 parts by weight relative to 0 parts by weight, and 1 glass flake is less than 10 parts by weight, the effect of suppressing and controlling the amount of elution of the antifouling agent and the effect of reinforcing the film will be poor.
If more than 70 parts by weight is added, the fluidity of the antifouling coating composition will decrease, making painting operations difficult, and the antifouling properties of the film will also decrease, which is not preferable.

The antifouling paint composition of the present invention may optionally contain colored pigments,
Extender pigments, other dispersants, suspending agents, etc. can be added as appropriate.

The antifouling coating composition of the present invention can be applied to the primer layer in the same manner as the application of the primer.

The coating film is dried at room temperature and has a thickness of about 50 to 300 microns. The film thus obtained has excellent antifouling properties over a long period of time.

The details of the present invention will be explained below with reference to Examples.

"Part" or "section" is expressed in "part by weight" or "% by weight." Example 1 Primer Coating Composition A After kneading the base composition excluding glass flakes with a roller, glass flakes were added and mixed with stirring using a dispersion machine to prepare a base composition.

The rust-preventive coating composition of the present invention was obtained by stirring and mixing the curing agent with the main ingredient using a dispenser. 1
! A mild steel plate (JlS-G-3141) was used to completely remove black scale, rust, and oil using shotplast, and then the coating composition was applied with air spray to a dry film thickness of 1 μ. It was dried at 75(f) R1I for 7 days to obtain a primer-coated board.

After that, the following antifouling paint composition A was applied with air spray to a thickness of 250μ, and the coating was heated at 20°C with a 75% volume of 7.
It was dried for several days and used for testing.

In the above formulation, the rosin is first dissolved in xylol and each raw material except the glass flakes is added thereto and mixed, then dispersed using a ball mill, and then the glass flakes are mixed with a high speed stirrer to form the antifouling paint composition of the present invention. I got item A.

Example 2 (Curing agent) Amine adduct resin (same as Example 1) 30 Example 1
The paint was kneaded in the same manner as in Example 1, coated and dried in the same manner as in Example 1, and a primer coated plate was prepared.

Antifouling Paint Composition B Thereafter, antifouling paint composition B was applied in the same manner as in Example 1 and subjected to a first test.

Example 3 After coating and drying the primer paint composition A in the same manner as in Example 1, the following antifouling paint composition C was applied and tested.

Antifouling Paint Composition C A paint was kneaded in the same manner as in Example 1, coated and dried in the same manner as in Example 1, and a primer coated plate was prepared.

Thereafter, the following antifouling paint composition D was applied in the same manner as in Example 1, and subjected to a test. Antifouling Paint Composition D The primer paint composition D and the antifouling paint composition E were applied and dried in the same manner as in Example 1, and then subjected to a test.

After kneading the main ingredients with a roller, silica sand and a hardening agent were added, stirred with a dispenser, and then coated in the same manner as in Example 1 to prepare a test piece with a coating thickness of 3.

Then, the following antifouling paint composition F was applied in the same manner as in Example 1 and subjected to a test.

Antifouling Paint Composition F A test was prepared in the same manner as in Example 6, and then the following antifouling paint composition G was subjected to a post-coating test in the same manner as in Example 1.

After kneading the base ingredient composition excluding the glass flakes and silica sand with a roller, the glass flakes and silica sand were added and mixed with stirring in a dispersion machine to prepare a base ingredient.

The anticorrosive coating composition of the present invention was obtained by stirring and mixing the curing agent with the main ingredient using a dispenser, and then applied in the same manner as in Example 6. Then, the antifouling paint composition F was applied in the same manner as in Example 1 and subjected to a test.

The paint was mixed in the same manner as in Example 8, and painted and dried in the same manner as in Example 6 to produce a primer-coated plate.

Then, the following antifouling coating composition H was applied in the same manner as in Example 1 and subjected to a test.

A paint was kneaded in the same manner as in Example 8, applied in the same manner as in Example 6, and after drying, the antifouling paint composition E was applied in the same manner as in Example 1 and tested.

Example 11 The primer paint composition C and the antifouling paint composition A were coated in the same manner as in Example 1, and after drying, they were subjected to a test.

Example 12 The primer paint composition F and the antifouling paint composition A were coated in the same manner as in Example 7, and after drying, they were subjected to a test.

A paint was prepared in the same manner as in Example 1.

The antifouling paint composition 1 was applied to a mild steel plate of approximately 300 x 300 x 1.61 nm, which had been previously coated with an oil-based anti-corrosion primer coating, to a film thickness of approximately 100 μm, and dried at room temperature for 10 days. and was subjected to a comparative test.

Comparative Example 2 The antifouling paint composition J was It was clothed and used for testing.

Comparative Example 3 Primer Paint Composition J After kneading the paint in the same manner as in Comparative Example 1 and in the same manner as in Coating Example 1, the composition was coated in the same manner as in Example 1.
After drying, the antifouling paint composition D was applied in the same manner as in Example 1 and tested.

Comparative Example 4 A paint was prepared in the same manner as in Example 7, applied and dried in the same manner, and then the antifouling paint composition D was applied in the same manner as in Example 1 and subjected to a test.

Comparative Example 5 After kneading a paint in the same manner as in Example 1, painting and drying in the same manner, the antifouling paint composition A was applied in the same manner as in Example 1 and subjected to a test.

Comparative Example 6 The primer coating composition A and the antifouling coating composition I were coated and dried in the same manner as in Example 1, and then subjected to a test.

Comparative Example 7 An attempt was made to form the paint into a paint in the same manner as in Example 6, but a normal primer paint composition could not be obtained.

Comparative Example 8 The coating was applied in the same manner as in Example 1.
After drying, the antifouling paint composition A was applied in the same manner as in Example 1 and tested.

As can be clearly seen from the comparative test results table, the coating film obtained by the coating method of the present invention exhibited excellent antifouling properties, coating strength, and durability.

On the other hand, the coating films obtained by a method using a conventionally known coating composition (Comparative Examples 1 and 2) had extremely poor antifouling properties and coating strength. A system in which furfuryl alcohol was removed from the composition (Comparative Example 3)
- 4) require the use of organic solvents when forming and painting paints, and the strength and water resistance of the paint film are inferior, so glass flakes and silica sand are excluded from the primer paint composition of the method of the present invention. The coating film strength of the system (Comparative Example 5) was significantly reduced, and even when the primer paint composition of the present invention was used, the system (Comparative Example 6) using a known antifouling paint composition had extremely poor antifouling properties. In the primer coating composition of the ZZ method of the present invention in which a large amount of furfuryl alcohol was used (Comparative Example 8), the strength of the coating film was poor.

Furthermore, in the primer coating composition of the method of the present invention, a normal coating composition could not be obtained in the system in which a large amount of silica sand was mixed (Comparative Example 7).

As mentioned above, in none of the comparative examples, a coating film satisfying both antifouling properties and coating strength was not obtained.

Claims (1)

[Scope of Claims] 1 A) A main agent consisting of 100 parts by weight of an epoxy resin that is liquid at room temperature, 10 to 900 parts by weight of glass flakes and/or silica sand, and 10 to 50 parts by weight of furfuryl alcohol, and B) Curing. A long-term antifouling and anticorrosion coating method, which comprises applying a primer consisting of an agent and the like to a base material, and after drying, coating an antifouling paint consisting of a silicone resin on the primer layer. 2. The long-term antifouling and anticorrosion coating method according to claim 1, wherein the antifouling paint comprises 100 parts by weight of silicone resin and 10 to 350 parts by weight of an antifouling agent. 3 The antifouling paint contains 100 parts by weight of silicone resin and 1 part of antifouling agent.
The long-term antifouling and anticorrosion coating method according to claim 1, comprising 0 to 350 parts by weight of glass flakes and 10 to 70 parts by weight of glass flakes.