JPS60156772A - Corrosion-proof coating composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition of high rustproofness, capable of suppressing debonding, cracking or rust development at the welded joint in copper plate etc., for application to tanks, etc. by incorporating a combination of vinyl ester resin and a monomer with specific particle size of a mixture comprising mica, finely powdery silica, and glass beads in specific proportion. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100pts.wt. of a combination of (i) vinyl ester resin (e.g. methacrylic ester) and (ii) a reactive monomer (e.g. styrene) with (B) pref. 5-200pts.wt. of such a mixture as to be fully passable through 325 mesh-sized sieve made up of (i) 5-20wt% of mica (ii) 10-50wt% of finely powdery silica, (iii) 5-25wt% of glass beads and (iv) 15-80wt% of a combination of rustproof pigment and dispersing agent totalling 100wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anticorrosive coating composition, and more particularly,
This invention relates to an anti-corrosion paint composition that covers the surface of steel plates, etc. in environments that are susceptible to rusting, such as those affected by chemicals, acids, alkalis, etc.

Conventional rust prevention, for example, takes tank rust prevention by applying a flake lining layer made of vinyl ester resin containing flat particles such as glass directly to the bottom steel plate with surface treatment such as Shot Plus 1-. Or, after applying one layer of primer, two or three layers of painting were performed. In addition, in areas with irregularities such as the weld bead and side edges, especially areas that are prone to rust, zinc-rich paint and calcium carbonate are added to improve anti-corrosion performance and round edges. It has been proposed and practiced to apply vinyl ester resin coating and then flake lining.

However, such conventional methods have the following drawbacks. First, depending on the quality of the painting work, uneven coating may occur, resulting in a large difference in rust prevention ability, resulting in a slight lack of reliability. In addition, areas on the bottom of the tank that are susceptible to distortion and stress (for example, near the welded parts of the side edges and bottom where the load of tank J5 and contents are applied, shrinkage due to temperature differences, etc.)
(near the welded part of the bottom plate, etc. where stress due to compression is easily applied)
Cracks, peeling, or rust may occur in areas where impurities in the steel material have precipitated, such as the weld bead area, and the expected rust prevention effect may not be achieved.

This is due to the use of a highly anisotropic lining layer in which flat particles are oriented parallel to the painted surface.
The resistance to mass transfer (diffusion of water, 02, etc.) increases, which is advantageous for rust prevention, but on the other hand, the mechanical strength of the lining layer, especially the peeling resistance and cranking resistance, which depend on the flexibility, decreases. It is assumed that this is due to this.

Therefore, although the above-mentioned conventional methods have some degree of rust prevention ability, they are not perfect when used in welded areas that are particularly susceptible to rust, and cracks and peeling occur, resulting in The problem arises that rust occurs.

As described above, flake lining using glass flakes can provide the desired anti-rust and anti-corrosion effect when the working conditions are perfect, but if the conditions deviate even slightly, the lining will peel off, swell, or crack.

In this case, the reason that the desired anticorrosion effect could not be obtained was mainly due to the skill of the painting process. Anticorrosion paints were recommended to prevent this from occurring.

The present invention not only has high rust prevention properties, but also eliminates peeling and cracking of steel plates, etc., which are the drawbacks of rust prevention construction by flake lining, which has been widely used in the past. The purpose is to provide an anticorrosive paint composition that suppresses rusting, and is used for anticorrosive linings.

This object of the present invention is achieved by the following anticorrosive coating composition.

That is, the present invention includes (A>vinyl ester resin and 7-mer-1 having reactivity with the resin) (B) 5 to 20% by weight of mica, 10 to 50% by weight of fine powder silica, 5 to 25% by weight of glass peas, An anticorrosion paint composition characterized by being mixed with a mixture of a total of 100% by weight of a pigment having anticorrosion properties and a dispersion aid of 15 to 80% by weight passing through a 325 mesh sieve. It's in things.

In the present invention, as component (A), a vinyl ester resin and a hexamer having reactivity with the vinyl ester resin are used. Vinyl ester resins are generally called epoxy acrylates, and include methacrylic esters of bisphenol-type diglycidyl ethers and methacrylic esters of novolac-type polyfunctional glycidyl ethers. Examples of monomers that are reactive with the ester resin include styrene, vinyl chloride, and vinyl acetate. In the present invention, a diluted mixture of this vinyl ester resin and a copolymerizable monomer is used as component (A), and a typical example is Delacane (
(trade name, manufactured by Dow Chemical Company). Since the coating composition of the present invention contains fine ceramic powder described below, the monomer such as styrene that is reactive with the vinyl ester resin preferably has a low viscosity, and (A
) It is more preferable that it be contained relatively between the rows in the component.

In the present invention, as component (B), a) 5 to 20% by weight of mica 4-, b) 10 to 50% by weight of fine powder silica,
(However, at least 5% by weight of this should be ultrafine powder made by gas phase synthesis such as Aerosil.) C) 5 to 25% by weight of glass peas, d) Pigment with rust prevention properties, and e) Dispersion. A fine ceramic powder having anticorrosive properties is used, which is a mixture of 15 to 80% by weight of auxiliaries and passing through a 325-mesh sieve with a total of 100% by weight. Anything that deviates from the blending ratio of each component in component (B) will only have an effect as an inorganic filler, and even in the conventional method of flake lining, the shape of the glass to be filled is specifically defined. It's the same as if you don't do it, you won't get the effect.

The mica of component a) may be biotite or muscovite, and for the present invention it is necessary that it be flat and easily cleaved. The particle size is also very small, and it is necessary to completely pass through the 325 mesh. It is clear from the fact that fine powder is used in the present invention that mica is not used to create a labyrinthine effect on the mass transfer path of flakes in flake lining. a) If a large number of ingredients are used,
Since the lining film is easily peeled off, the content of mica in component (B) is 5 to 20% by weight.

The chemical formula for component b) silica is 5i02, and all of them are grouped together. However, there are a wide variety of silicas used in the industry, and their properties, prices, and uses vary greatly. In the present invention, component (B) contains 10 to 50
It is necessary to use ultrafine powder silica, such as Aerosil (trade name), which is obtained by a synthetic method rather than by pulverization, for at least 5% by weight. Others are S! Powder such as silica stone shown by the chemical formula of Oz may be used. Of course these are 32
5. It is used after being finely divided until it passes through the entire mesh, but if we focus on the particle size, it is made up of a combination of different materials: submicron ultrafine powder and micron-order crushed particles. There is one characteristic. b)
The more ingredients there are, the better the properties of the lining film will be, such as rust prevention, no pinholes, and no dripping during construction.
Other components must also be blended in the necessary minimum amount, and the above-mentioned <50% by weight is the possible upper limit.

The glass steel used as component C) has a diameter of 10 μm or less. It is thought that a glass made of C glass, which has high acid resistance, would be better, but in experiments conducted by the present inventors, sufficiently satisfactory results were obtained using a glass made of ordinary glass. The amount to be blended is preferably about the same as that of mica, and the possible range is 5 to 25% by weight.

A relatively large amount of components a) to C) in component (B) will give better results, but from a cost standpoint, rust prevention effect, or as an acceptor for penetrating sulfate ions, d) pigments with rust prevention properties, e) Using a dispersion aid. d) and e)
Examples of the components include compounds such as chromium, lead, and zinc, which have a filling effect and antirust effect, and calcium carbonate, and the content thereof is 15 to 80% by weight in the component (B).

This component (B) needs to be made into a fine powder so that the entire 325 mesh is passed through, and the blending amount is (A).
The proportion of component (B) 7-5 to 200 parts by weight is approximately 5 to 200 parts by weight per 100 parts by weight of component.

The present invention will be specifically described below based on Examples and Comparative Examples.

Example 1 and Comparative Examples 1 to 2 Component (B): a) Mica 15 parts by weight b) Ultrafine powder silica 10 parts by weight (Aerosil: trade name) Finely ground silica 30 parts by weight C) Glass peas 15 parts by weight ( d) Chromium oxide 100 parts by weight Molywhite 15 parts by weight e) Titanium oxide A total of 100 parts by weight of 5 parts was placed in a Pormill, and pulverization was repeated until it became 325 mesh. -1 Pale green ceramic fine powder was obtained without rinsing.

On the other hand, as component (A), 50% by weight of vinyl ester,
Derake 9-8-1 No. 411 (trade name, manufactured by Dow Chemical Company) consisting of 50% by weight of styrene monomer was used.

To 100 parts by weight of Delacane No. 411, which is component (A), 3 parts by weight of the above-mentioned ceramic fine powder, which is component (B), is added.
When 5 parts by weight was added, a green viscous liquid was obtained.

Furthermore, 1 part by weight of methyl ethyl ketone peroxide (purity 60% by weight), cobalt naphthenate (cobalt 6
% by weight) was added as a curing agent according to a conventional method, and 1 tsubo of the anticorrosive coating composition of the present invention was prepared (Example 1). This composition exhibits a viscosity of about 100 voids at 20° C. and can be applied by brush, spray, or roller.

In order to evaluate the anti-corrosion ability and peeling force of this composition, tests were conducted including salt water spray with cross cut (2000 hr), T-shaped peeling, and coffee spray after bending fatigue (2000 hr). In addition, 5 cl of salt water spray with cross cut 1~
Clean the steel plate of 1X10caX 1.61RIIl by shot blasting, apply the paint to a thickness of approximately 300μ with a brush, let it harden, and cross-cut (make diagonal cuts on the painted surface of the sample). (1 convex) was placed in the container, and salt water was sprayed. After 2000 hours, it was examined whether rust had progressed at the cross-cut portion.

Lower mold peeling is 2.5cm x 15cm x O, 7I
After applying Shot Plus 1 to one side of a 1m iron plate,
A coating with a thickness of about 150 μm was applied, sandwiched between similarly treated iron plates, and one week after curing, a test was conducted at a tensile speed of 50 nm/min. Salt spray after flex fatigue
A specimen made in the same manner as the cross-cut salt spray was placed with the cross-cut side facing down, and the center of the 8 cm span was bent In+m using a Ron dynamic fatigue testing machine. Repeated 10 times, then salt spray test (after 20001+r) in the same way as cross-cut salt spray
I did this.

The test results are shown in Table 1.

In addition, as a comparison, a commercial product in which glass flakes were dispersed in vinyl ester resin (Comparative Example 1), Gera No. 1-2411 used in Example 1 (vinyl ester 50% by weight, styrene monomer 50% by weight) 100% 35 parts by weight of silane-treated glass flakes several microns thick and several hundred seventy centimeters in diameter were added to the glass flakes and cured with a curing agent in the same manner as in Example 1 (Comparative Example 2), and the same tests as in Example 1 were carried out. I did this. The results are shown in Table 1.

Table 1 As is clear from Table 1, no rust was observed in Example 1 even when subjected to cross-cut salt water spray and salt water spray after bending fatigue. Also, the peeling of the lower mold is at a high level.

On the other hand, Comparative Example 1 and Comparative Example 2 are cross-cut]
Although no rust was observed in =11- in salt water spray, rust occurred in salt water spray after bending fatigue. Also, peeling off from the bottom mold is low.

From this, it is clear that the composition of J: Sea urchin of the present invention improves the rust formation in areas where repetitive stress is easily applied, which is a problem in the conventional antirust treatment by flake lining. In addition, since the lower mold peeling is excellent, peeling 1i! It is expected that rusting caused by III will be improved. The reason why the flake-containing linings of Comparative Examples 1 and 2 are significantly inferior in peeling from the lower mold is that the flakes are oriented in layers against the iron plate, forming a film with extremely large anisotropy. It seems that there is.

Furthermore, the fact that the composition of the present invention is relatively resistant to dynamic fatigue is extremely easy to understand as a difference between isotropic materials and anisotropic materials, along with experimental facts. The superior properties are due to a mechanism different from flake lining due to the shape, particle size, and combination of materials of the fine ceramic powder that is blended. Improved barrier properties against rust-causing substances, and the use of fine powder. 12- It is expected that the activity of anti-rust pigments will be improved, but it is not clear.

As explained above, the anticorrosive paint composition of the present invention is made by mixing a vinyl ester resin, a component consisting of the resin and a reactive polymer, and a ceramic fine powder component such as mica, fine powder silica, etc. It improves abnormal rust caused by peeling or cracking on the bottom of the flake lining, which is conventionally widely used as the bottom lining of petroleum storage tanks, etc., so it becomes a more reliable rust-preventing paint material, and is suitable for use in oil storage tanks, ships, ground, etc. Suitable for use in locations that require corrosion protection, such as painting equipment buried inside.

Patent Applicant Yokohama Rubber Co., Ltd. Patent Applicant Iwasaki Heat Resistant Chemical Laboratory Co., Ltd. Agent Patent Attorney Tatsuo Ito Patent Attorney Tetsuya Ito

Claims (1)

[Scope of Claims] (A) Vinyl ester resin J and a monomer reactive with the resin; (B) 5-20% by weight of mica, 10-50% by weight of finely powdered silica, 5-25% by weight of glass beads. %, a total of 15 to 80% by weight of pigments and dispersion aids having antirust properties, and a mixture of 100% by weight and a particle size of 325 mesh sieve. Anticorrosive paint composition.