JPH0345113B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anti-corrosion rubber paint, and more particularly to an anti-corrosion rubber paint made by dissolving a rubber component consisting of three components: butyl rubber, chlorosulfonated polyethylene, and chlorinated rubber. Rust prevention measures have been taken on iron surfaces for a long time, and there are a wide variety of methods, but one method that is superior in terms of performance and workability is to coat the iron surface with paint and isolate it from an environment where rust is likely to occur. There are known ways to do this. However, in bad environments, such as sewage-related facilities and the inside of drainage pipes, factory facilities, marine structures, ships,
For areas that require heavy corrosion protection such as bridges,
It is common to apply several types of paint several times, but despite this, the anticorrosive performance and durability are insufficient, and a paint that has long-term anticorrosion performance is desired. That is, the drawback of conventional paints is that they do not have sufficient chemical stability, including chemical resistance, because the molecular weight of the polymer components constituting the paints is low. Since the paint has poor rubber elasticity and lacks flexibility, the stress experienced between the coated object and the paint and between different types of paint due to seasonal temperature changes increases, resulting in a lack of long-term adhesion. Poor ability to block oxidation-promoting substances including gases. It is complicated because several types of paint need to be applied over and over again, and many types require mixing for two nights before use, making it easy for errors to occur and for variations in paint film performance to occur. etc. can be mentioned. Therefore, the inventors of the present invention have completed the present invention as a result of intensive research aimed at solving these drawbacks, exhibiting anticorrosion performance for a long period of time, and allowing thick coating with only one type of one-component paint. I've reached it. The features of the present invention are the environmental barrier performance of butyl rubber, the three characteristics of chlorosulfonated polyethylene, and chlorinated rubber.
The advantage is that the vehicle is a rubber component that combines the weather resistance, high hardness, and beautiful finish of a paint film. To explain in more detail, until the present inventors recently proposed a butyl rubber paint, rubber paints were limited to chlorinated rubber, cyclized rubber, and chlorosulfonated polyethylene. Chemical rubber paints have a low molecular weight and have shortcomings in impact resistance and adhesion between coats, while chlorosulfonated polyethylene paints have excellent weather resistance but cannot achieve the goal of corrosion resistance. Further, the reason why rubber paints have not developed in the past is that rubber generally has a high molecular weight, so it is difficult to dissolve, and the dissolved product has a high viscosity and lacks painting workability and storage stability. The coating film of rubber is too soft, and there is no suitable room-temperature crosslinking method to solve this problem. can be mentioned. The inventors of the present invention also tried to solve the above two problems through repeated trial and error, and were able to solve them using the following method. In other words, the problem is that by mixing the rubber components with a general-purpose rubber mixing machine such as an open roll or kneader and adjusting the Mooney viscosity of the rubber components, it becomes easier to dissolve, and the viscosity after melting is lower. Stability and paintability were also improved. It was also confirmed that the viscosity stability and paintability after dissolution were significantly improved depending on the solvent composition. The next problem is that by using chlorosulfonated polyethylene and/or chlorinated rubber, sufficient coating hardness can be obtained without crosslinking. Therefore, the present inventors focused on butyl rubber, which has excellent environmental barrier performance, and proposed a butyl rubber paint.
Although this butyl rubber paint certainly far exceeds conventional anticorrosive paints in terms of anticorrosion performance, it has the disadvantage that the paint film is easily scratched due to its low coating hardness. Therefore, we proposed a type that can be used in combination with epoxy resin and a type that can be used in combination with cement.
The above-mentioned type also has drawbacks such as the troublesome mixing of the two components and the risk of errors in measuring and mixing during work, and the type that uses cement is not suitable for coating. The drawback was the fragility of the membrane. Therefore, in order to maintain the excellent anticorrosion effect of butyl rubber paint and further eliminate the drawbacks of the above-mentioned anti-corrosion products, the inventors of the present invention have conducted trial and error using various polymers. A rubber paint consisting of a rubber component that uses a combination of
We have completed the present invention by confirming that liquid-based paints alone can provide long-term anticorrosion performance and overcome the lack of hardness of butyl rubber paints. That is, the anticorrosive rubber paint of the present invention is mainly composed of a desired solvent and a rubber component dissolved and dispersed in the solvent, wherein the rubber component is butyl rubber, chlorosulfonated polyethylene, and chlorinated rubber. and the butyl rubber accounts for 10 to 70% by weight of the total rubber component.
It is characterized by occupying . Further, in the present invention, the above-mentioned butyl rubber can be made into recycled butyl rubber. Furthermore, the present invention provides an anticorrosion rubber coating mainly consisting of a desired solvent and a rubber component dissolved and dispersed in the solvent, wherein the rubber component is a combination of butyl rubber, chlorosulfonated polyethylene, and chlorinated rubber. The butyl rubber accounts for 10 to 70% by weight of the total rubber components, and the Mooney viscosity can be adjusted by using at least one of the rubber components alone or in combination. Next, the constituent components of the present invention will be described. In the present invention, the rubber component refers to butyl rubber, chlorosulfonated polyethylene, and chlorinated rubber. Furthermore, butyl rubber refers to virgin butyl rubber, recycled butyl rubber, chlorinated butyl rubber, brominated butyl rubber, partially crosslinked bityl rubber, and polyisobutylene. As is well known, butyl rubber has one of the best gas barrier properties among polymers including rubber, and can be said to be an indispensable rubber for tire tubes and other parts that require gas barrier properties. This is because paint containing butyl rubber is exposed to oxygen.
This indicates that it has a great effect in preventing corrosive substances such as corrosive gases such as chlorine and sulfur dioxide from permeating into the anticorrosion member. In addition, recycled butyl rubber, especially recycled butyl rubber, is made by crushing mono-vulcanized butyl rubber, so recycled rubber naturally has fewer double bonds than virgin butyl rubber, making it chemically stable. It has characteristics such as improved heat resistance due to the presence of vulcanized gel content, and completely eliminates the flow phenomenon that occurs when left at low temperatures for long periods of time, which is often a problem with virgin butyl rubber. It provides unparalleled performance. As mentioned above, other butyl rubbers include virgin butyl rubber, chlorinated butyl rubber, brominated butyl rubber, partially crosslinked butyl rubber, and polyisobutylene, but these butyl rubbers, including recycled butyl rubber, have poor dissolution efficiency, coating performance, It is preferable to use them alone or in combination in consideration of painting workability, storage stability, etc. The proportion of butyl rubber in the rubber component is preferably 10 to 70% by weight, more preferably 15 to 50% by weight. When the proportion of butyl rubber in the rubber component is less than 10% by weight, the environmental barrier performance is poor, and the organic acid resistance and adhesion are also poor. On the other hand, if it exceeds 70% by weight, the coating film will have low hardness and will be easily scratched. Next, regarding chlorsulfonated polyethylene, chlorsulfonated polyethylene is a polymer with no double bonds and excellent chemical stability, and is known to have particularly excellent weather resistance. The drawback is that it has poor anti-choke properties. However, this drawback can be improved by combining the above-mentioned butyl rubber and chlorinated rubber. Chlorsulfonated polyethylene is a polymer with excellent weather resistance, and it is desirable to increase its proportion in the rubber component for applications that particularly require weather resistance, but if used in large quantities, it will have poor corrosion resistance and stiffening resistance. It is not preferable because it is inferior. On the other hand, if the amount is small, the impact resistance, bending resistance, and appearance of the coating film will be poor. Next, talking about chlorinated rubber, chlorinated rubber has the chemical structure expressed as (C ₅ H ₇ Cl ₃ ) _x (C ₅ H ₆ Cl ₄ ) _y (C ₁₀ H ₁₁ Cl ₄ ) _z . Although it is used as an anti-corrosion rubber paint, the rubber paint made of chlorinated rubber alone has a low molecular weight and has disadvantages as a rubber paint in terms of flexibility, impact resistance, and adhesion after heat cycles, so it cannot be used as a heavy-duty anti-corrosion paint. Although the anticorrosion performance for edible use is not satisfactory, it greatly improves the low hardness and scratch resistance, which are the shortcomings of butyl rubber paints. If the proportion of chlorinated rubber in the rubber component is small, the hardness will be low, it will be easily scratched, and the adhesion will be poor, whereas if the proportion is large, the impact resistance, bending resistance, and adhesion after heat cycles will be poor. The structure of the present invention uses the above-mentioned rubber component as a vehicle, and is composed of a solvent, a filler, an additive, etc., which will be described in order below. Solvents include aromatic hydrocarbons such as toluene, xylene, and aromatic petroleum naphtha, aliphatic hydrocarbons such as hexane, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as methyl acetate and butyl acetate, methanol, These include alcohols such as ethanol and isopropyl alcohol, and ethylene glycol derivatives such as ethylene glycol and monomethyl ether ethylene glycol monoethyl ether acetate, and may be used alone or in an appropriate combination of two or more. As is known, the viscosity of the solvent is
It also has a large effect on coating film drying properties, painting workability, viscosity stability, etc., and it is desirable to use a combination of a good solvent and a poor solvent depending on the composition of the rubber component. Fillers include coloring pigments such as iron oxide, zinc oxide, titanium oxide, and carbon, anticorrosion pigments such as red lead, yellow lead, and zinc powder, calcium carbonate, talc, clay, finely divided silica, barium sulfate, mica, ferrite, and glass. Flakes etc. can be mentioned, and one type or a combination of two or more types can be used. These affect the physical properties of the coating film, corrosion resistance, economic efficiency, etc. Additives include thickeners, leveling agents, antifoaming agents, antifouling agents, antifungal agents, antibacterial agents, insect repellents, antioxidants, ultraviolet absorbers, coupling agents, surfactants, etc. You may use two or more types in combination. In addition, resins such as phenol resins, epoxy resins, terpene resins, and petroleum resins, softeners, and plasticizers may be added to improve various workability and to modify coating films. Next, an example of the method for manufacturing the anticorrosive rubber paint of the present invention will be described, but the present invention is not limited in any way by the example of the manufacturing method described below. First, the rubber components are mixed in a pressure kneader, the Mooney viscosity is adjusted, the mixture is cut into small pieces, stirred and dissolved in some solvent, and the filler is added.Then, the necessary additives are added as appropriate, and the mixture is stirred and dispersed. After that, the mixture is passed through an ink roll, the remaining solvent is added and stirred, and the mixture is made into a sufficiently uniform state to form a paint. Next, a method of using the anticorrosive rubber paint of the present invention will be explained. The anticorrosive rubber paint of the present invention can be applied in exactly the same manner as ordinary paints, ie, airless spraying, air spraying, brushing, roller brushing, etc., and may be applied by any method. Next, the present invention will be further explained with reference to Examples and Comparative Examples.

[Table] Test method and judgment method 1 Preparation of sample All samples except moisture permeability and storage stability were SS.
-41 steel plate (approximately 200 x 100 x 4 mm) with a dry coating thickness of 350μ. For moisture permeability, a film-like coating was prepared with a dry coating thickness of 100μ and used as a sample. 2 Chemical resistance test A 10% aqueous solution of each of acetic acid, butyric acid, lactic acid, sulfuric acid, and sodium hydroxide was soaked at room temperature for 6 months, and the coating film did not rust, blister, peel, crack, or
Those in which no abnormalities such as swelling or coloring of the chemical solution were observed were rated as ○, and those in which abnormalities were observed were rated as ×. 3 Salt spray resistance After conducting an impact resistance test according to JIS-K-5400 Section 6.13 Method A, it was tested according to JIS-K-5400 Section 7.8.
After 1,000 hours of salt water spraying, there was no abnormality such as rust, blistering, peeling, cracking, etc. on the paint film with a diameter of 20 mm or more centered around the point where the weight fell, and other parts of the body were exposed to the impact. The case where no abnormality such as rust, blistering, peeling, cracking, etc. was observed in the coating film was marked as ○, and the other cases were marked as ×. 4. Weather resistance After 6 months of outdoor exposure, the appearance of the coating film was checked for abnormalities, and those with no abnormalities were marked as ○, and those with abnormalities were marked as ×. 5 Coastal exposure resistance Scratch marks that reach the substrate with a single-edged razor are cut into the sample, and 1
Drying and immersion in seawater were repeated twice a day, and the presence or absence of any abnormalities in the coating film was checked after 6 months. Items with abnormalities such as rust, blistering, peeling, etc. within a width of 3 mm on one side along the scratch mark and a total of 6 mm are ○, and those with a width of 3 mm on one side along the scratch mark and a total of 6 mm or more, and a total of 5 mm on one side. Items with abnormalities such as rust, blistering, peeling, etc. contained within a width of 10 mm were evaluated as △, and items with abnormalities extending over a width of 5 mm on one side and a total of 10 mm were evaluated as ×. 6 Moisture Permeability Measured on a film-like coating film of approximately 100 μm according to JIS-Z-0208, and rated as ○ if the moisture permeability was 0.5 g/m ² ·24 h or less, and × if it was 0.05 g. 7 Adhesion after heat cycle After preparing the sample, it was incubated at room temperature for 7 days, and then a cut was made to reach the substrate so that the adhesive area was 1 inch square, and the coating film was tested vertically using a tensile tester.
After measuring the normal adhesive force by pulling at a speed of 200 mm/min, one cycle was a heat cycle of 8 hours at 80°C and 16 hours at -10°C, and after repeating 30 cycles, the adhesion was the same as normal. A test was conducted, and those with a retention rate of normal adhesive strength of 70% or more were rated ○, and those with a retention rate of 70% or less were rated ×. 8 Recoat adhesion A sample was prepared using the method in 1, and after it became tack-free, it was exposed outdoors for 2 weeks, and the paint was recoated in the same manner as in 1, JIS-K-5400 6.15.
JIS-K-
5400 An evaluation score of 8 or more in Section 6.15 was marked as ○, and a score of 8 or less was marked as ×. 9 Impact resistance According to JIS-5400 Section 6.13 Method A, scrape off the area around the point where the weight falls, and mark as ○ if the diameter of the part that is easily peeled off from the substrate is within 20 mm around the point of fall.
20 mm or more was marked as ×. 10 Storage stability Measure the viscosity on the first day and 6 months after making the paint. If the rate of change is within ±10% and there is no phase separation or sedimentation, it is marked as ○. Otherwise, it is marked as ○. was marked as ×. 11 Appearance of the paint film Visually inspect the film to check for repellents, cracks, holes, blisters, smoothness, uneven coating, etc. If any abnormality is observed, it is marked as ○, and if any abnormality is observed, it is marked as ×. Examples 1 and 2 are anticorrosive rubber paints of the present invention, which have excellent environmental barrier performance represented by chemical resistance, salt spray resistance, weather resistance, resistance to coastal exposure, and moisture permeability.
It has excellent adhesion after heat cycling and rubber elasticity as represented by impact resistance, as well as storage stability and adhesion after repeated coatings. In Comparative Example 1, butyl rubber was 10% by weight in the rubber component.
The following cases are shown, and it can be seen that the environmental isolation properties are inferior. In Comparative Example 2, butyl rubber was 70% by weight in the rubber component.
The above cases are shown, and it can be seen that the storage stability and coating appearance are poor. In Comparative Example 3, butyl rubber was 10% by weight in the rubber component.
The following case is shown, in which chlorosulfonated polyethylene accounts for most of the rubber component. It can be seen that this material has excellent rubber elasticity, but is inferior in environmental barrier properties. In Comparative Example 4, butyl rubber was 10% by weight in the rubber component.
The following case is shown, in which chlorinated rubber accounts for most of the rubber component. It can be seen that this is inferior in rubber elasticity, recoating adhesion, and organic acid resistance. Comparative Example 5 shows a case in which a commercially available zinc-rich primer and a commercially available tar epoxy are combined, and it is found that the adhesion after heat cycling, impact resistance, and recoat adhesion are inferior. Comparative Example 6 shows a combination of a commercially available zinc-rich primer, a commercially available epoxy paint, and a commercially available urethane paint, and it can be seen that the salt water sprayability after impact resistance and the adhesion of multiple coats are inferior. Comparative example 7
The figure shows the case where a commercially available chlorinated rubber paint is used.In particular, it has poor coastal exposure resistance, adhesion after heat cycles, and impact resistance, and a paint made only of chlorinated rubber cannot be applied to areas that require heavy corrosion protection. It turns out there isn't. Comparative Example 8 shows a case where a commercially available chlorsulfonated polyethylene coating acid was used, and it was particularly poor in organic resistance, salt spray resistance, and coastal exposure resistance, and in terms of weather resistance, it suffered from significant tyokeing and weather resistance. Her health was also not necessarily good. Therefore, it is clear that paints made of chlorosulfonated polyethylene alone cannot be applied to areas that require heavy corrosion protection. As mentioned above, the anticorrosive rubber paint of the present invention has excellent environmental barrier performance against organic and inorganic acids, salt water, alkalis, etc., and in particular, its resistance to organic acids is far superior to paints currently used for heavy corrosion protection applications. It is effective for applications that are easily affected by organic acids, such as the inner surface of sewage drainage pipes and sewage treatment-related facilities. In addition, it exhibits excellent impact resistance and bending resistance, and its corrosion resistance after impact is significantly different from that of paints currently used for heavy-duty corrosion protection applications. Even if the surface of the coating is damaged to the extent that it is exposed, the propagation speed to the surrounding area is very slow. This shows that it can follow the distortion of objects and maintain adhesion and environmental barrier properties. Furthermore, the anticorrosive rubber paint of the present invention has excellent recoatability, and even if the surface of the object to be coated is exposed, it can be easily repaired, and problems such as delamination between the layers in the repaired area do not occur. From this point on, vehicles, ships,
This shows that it can provide long-term corrosion protection for applications that are susceptible to shocks, such as offshore structures. Secondly, it has excellent adhesion after heat cycles, and resists distortion caused by differences in linear expansion coefficient between the coating material and the coating material due to seasonal temperature changes. Applications that are susceptible to temperature changes and applications that are subject to constant vibration and distortion between the coated object and the paint and between the paints.
For example, this indicates that it is effective for bridges, large structures, ships, vehicles, etc. In addition, the anticorrosive rubber paint of the present invention does not require the use of other materials such as a primer, is one-component, allows for a very long recoating time, and has good recoat adhesion, so it can be used in several types. There is no need to consider the allowable time for recoating the paint, and to organize the process, eliminating work errors associated with mixing two components, and making it possible to efficiently form a stable paint film on the surface of the object to be coated. , there is also the advantage of shortening the process. Furthermore, if the anticorrosive rubber coating of the present invention contains recycled butyl rubber, it will not be possible to improve chemical stability and heat resistance in terms of performance, and since recycled butyl rubber is recycled from tire tubes,
There is also the added benefit of effective use of resources. As mentioned above, the anti-corrosion rubber paint of the present invention forms a rubber elastic coating film that can exhibit long-term anti-corrosion performance using only one type of one-component paint, which cannot be found in conventional anti-corrosion paints. It is an anticorrosion paint that will help extend the life cycle of various facilities and structures that require heavy corrosion protection.

Claims (1)

[Scope of Claims] 1. An anticorrosion rubber coating mainly consisting of a desired solvent and a rubber component dissolved and dispersed therein, wherein the rubber component is composed of three of butyl rubber, chlorosulfonated polyethylene, and chlorinated rubber. 1. An anticorrosive rubber paint comprising the following components, and the butyl rubber accounts for 10 to 70% by weight of the total rubber component. 2. The anticorrosive rubber paint according to claim 1, wherein the butyl rubber is recycled butyl rubber.