JPS59138237A - Prevention of contamination of pipe lined with polyolefin - Google Patents

Abstract

PURPOSE:To prevent contamination of lined pipes of cooling water system of power stations and chemical plants with improved adhesivity of coated film for a long period, by using a chlorinated polyolefin resin as a primer, applying an antifouling coating compound of an organotin polymer. CONSTITUTION:Seawater contact faces of pipes lined with polyolefin of cooling water system using seawater are coated with a primer containing 5-40wt% chlorinated polyolefin resin, and then coated with an antifouling coating compound consisting of a (co)polymer of an unsaturated organotin monomer shown by the formula (R3 is 3-5C alkyl, or phenyl; R' and R'' are H, or CH3) or a copolymer of the organotin monomer shown by the formula and another copolymerizable unsaturated compound (e.g., methyl acrylate, styrene, etc.) as a main component, to prevent contamination of lined pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a polyolefin lining for power plant and scientific plant cooling water systems. This invention relates to an effective antifouling method for pipes.

Most of these plants are built on coastal areas and use seawater as cooling water. As a result, marine flora and fauna, especially animals such as purple mussels and fujibo, attach to the seawater contact surfaces of power plants and chemical plant cooling water systems, grow, and cause narrowing and blockage of water flow paths, reducing cooling efficiency. In addition to reducing power generation efficiency and production efficiency, it also causes damage to equipment and structures such as damage and corrosion. Antifouling methods and antifouling methods by applying suboxide saw-shaped antifouling paint have been studied and implemented, but these methods are difficult to implement, have insufficient effects, and have problems with environmental pollution.
No. 8612 and Japanese Patent Application No. 56-18.9898, an antifouling coating agent (hereinafter referred to as
It is called an organic tin polymer antifouling coating agent. ) has become an effective antifouling agent.

On the other hand, in recent years, polyolefin has been used to line the cooling water systems of power plants and chemical plants, as well as pipes, for the purpose of reinforcing and preventing corrosion.

When a polyolefin lining is installed, it is quite effective in terms of corrosion prevention, but it is completely defenseless from an antifouling perspective, so marine fouling organisms can arrive and affect the corrosion protection. The current situation is that

For this reason, it has become desirable to apply an organic tin polymer antifouling coating agent to polyolefin lined pipes as well. However, even if the organic tin polymer antifouling coating agent is applied directly to the polyolefin lining, the lining The adhesion to the organic tin polymer is very weak, and even if a coating agent used as a base coat is applied, the adhesion is weak and peels off in a short period of time. The coating agent was unable to exhibit its excellent antifouling properties.

As a result of intensive research on this point, the inventors of the present invention found that when chlorinated polyolefin Tochisashi is used as an undercoating agent, it has strong adhesion to the polyolefin lining material, and
The present invention was completed by discovering that the organic tin polymer also has excellent adhesion to antifouling coating agents.

That is, the present invention provides polyolefins (polyethylene, polypropylene, etc.) for cooling water systems of power plants and chemical plants.
On the seawater contact surface of the lining pipe, a general formula (% formula %) (in the formula, R is alkyl with 3 to 5 carbon atoms, !!11: or a phenyl group, R1 and R" represent a hydrogen atom or a methyl group) is applied. This is an antifouling method for polyolefin lined pipes, the gist of which is to apply an organotin polymer antifouling coating agent containing a polymer containing the unsaturated organotin monomer shown below as a main component.

Since the polyolefin used in the present invention has a non-polar structure, it inherently has poor adhesion to the coating agent, and although most coating agents do not adhere to it, similar 41
Focusing on the fact that four types of compounds are relatively compatible and that halogenated hydrocarbons have a similar effect on polyolefins, we investigated various formulations, mainly using chlorinated polyolefins, as primer coating agents. As a result of moistening, it was found that the coating agent containing 5 to 10 parts by weight of chlorinated polyolefin (olefins include ethylene and propylene) resin with a chlorine content of 66% or more had good adhesion to the polyolefin lining material, and It was given an A rating based on the knowledge that it has the highest plausibility with organic tin polymer antifouling coating agents.

The chlorinated polyolenoin resin used in the primer coating agent is limited to chlorinated polyethylene resin and chlorinated polypropylene resin, and the reason is that other examples include chlorinated polyolenoin resin, polyamide resin, polyhexylene resin, etc. In the obtained chlorinated Boriole≠Fin resin, chlorination is not uniformly performed, and the solution viscosity of the obtained chlorinated resin is high. Since the aT used in the present invention is determined by its molecular weight, when applied as a coating agent, the coating film lacks toughness, generates cracks, and inhibits adhesion to the lining material.
Although the solution viscosity of fat is low, it has a high molecular weight,
This is because the coating film is strong and has excellent adhesion to the lining. In addition, the chlorine content of the resin was set to 66
This is because if the amount is less than 1% by weight even though it is placed on a weight rack, it lacks stability and has an adverse effect on the final coating system consisting of the undercoat and antifouling coating.

Examples of these chlorinated polyolefin resins include chlorinated polyethylene resins such as those manufactured by Deyu Kokusaku Pulp Co., Ltd., 2 Sparklon 907MA and 907LL Katsutaba, and chlorinated polypropylene resins such as those manufactured by Deyu Kokusaku Pulp Co., Ltd. Super Chron 1.06H, 306, 40
6 size or these; tl] This item is available.

If the resin content in the primer coating agent is less than 5 overlapping parts, the viscosity of the coating agent will be low, and if applied to an extent that does not cause sagging,
If the amount exceeds 40 parts by weight, some of the resin may become suspended in the form of particles, and the coating film may not form continuously.
#i l+f: When kneaded, the dispersibility of the pigment in the resin may be inhibited and the pigment may separate from the fat. The total content of 3ji is limited to 5-40% by weight.

As the base coating agent, chlorinated polyethylene resin and chlorinated polypropylene resin are dissolved in a suitable bath agent, and if necessary 1. Then, pigments, plasticizers, coal cour, additives, etc. are added, and the mixture is kneaded by a conventional method to form an undercoat.

The general formula OR' 11 R1Sn-0-C-C=CHR:'-(A) (in the formula, R is 3 carbon atoms) is applied as a final coat. ~5 alkyl groups or feu/l/ groups, i ('zR'' represents a hydrogen atom or a methyl group) such as tripropyltin, triinopropyltin, tributyltin, tributyltin , tributyltin da r
Acrylate polymerizable unsaturated compounds of three organotin compounds, such as acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and octyl acrylate, butyl tsuccrylate, ethyl tuccrylate, butyl tuccrylate, A coating agent mainly composed of a polymer obtained by copolymerizing a methacrylic acid ester such as octyl methacrylate, and an unsaturated compound 5'-d such as matagestyrene and vinyltoluene, and optionally contains an antifouling agent: Pigments and other additives are added and kneaded by a conventional method to prepare a coating agent.

When applying primer coating to polyolefin-lined pipes, use air spray, airless spray, or manual ν(
For spraying of electrostatic materials, etc., a method selected from among painting, brush painting using a cylinder brush, flat brush, roller brush, etc., or flow painting is used, but after applying the primer coating agent, the organic tin polymer is When applying the antifouling coating agent, it is desirable to leave an interval of 30 minutes as the drying time for the undercoat film in 1) above. Furthermore, as long as the coating film has no repellency or uncoated areas, and a series of 112LA is formed, it is not necessary to specify it strictly, but it is considered to be the practical limit for forming a continuous film. Coating film j! C. It is desirable to apply a coating of 0μ or less.

The coating strength a of the organic tin polymer antifouling coating agent used for the second coating is also applied in the same manner as the one coating, but the coating thickness is different from that of the seawater taken as cooling water. It is determined by the flow rate, pH and temperature of at least 30
μ or more is required.

In the antifouling method by combining the base coat containing the chlorinated polyolefin resin of the present invention obtained in this way and the organic tin polymer antifouling coating, the resulting coating film is essentially made of polyolefin. It has an adhesive force with the lining moon,
When applied as a top coat, the antifouling coating film on the machine and tin car can be prevented from damaging the lining material, achieving long-term antifouling that is advantageous in terms of pollution control.

Next, the present invention will be explained in detail with reference to Examples and Comparative Examples.

Unless otherwise specified, parts are parts by weight.

Preparation of base coat coating agent (A) An undercoat coating agent (A) was prepared using the following formulation.

Chlorinated polypropylene 125 parts (Super Chron 306° above) Talc 385 parts Toluene 285 parts Ky/Lene
175 parts inopropyl alcohol/l/
3. Preparation of O undercoating agent (3) An undercoating agent CB) was prepared using the following formulation.

Chlorinated polyethylene 345 parts (Super Chron 9'07MA: mentioned above)
255 parts toluene
22.0 part upper level 15.0
Part inpropyl alcohol 30 parts Preparation of organotin polymer antifouling coating agent (A)
1 Butyl acrylate 10. A mixture of P, octyl acrylate 23y1, benzoyl peroxide 1.2P and Kinren 200j/ is charged and heated to 85°C to 90'C.
Copolymerization was carried out at 211j'lj'iJ, 100'C to 1 O5'C for 3 hours, and further heated and stirred at 120'C for 1 hour. The obtained kiln solution of the tributyltin-containing copolymer was colorless and transparent, and the viscosity at 25°C was 6.
By kneading, a) machine part polymer antifouling coating agent (A) was prepared.

Copolymer liquid resistance 40.0 parts titanium dioxide
10.0 parts Phthalonoamine blue
2.0 parts Talc 34.5 parts Xylene 13.5 parts [Example 51] 1.
) Apply primer coating agent (A) to a polyethylene molded plate to a film thickness of 3
Apply organic tin polymer antifouling coating agent (A) once at 0μ (60 μm)
Three test plates were prepared using L twice with a brush, and 1
One sheet was immersed in artificial seawater at 40°C to examine the adhesion of the coating film to the substrate over time, and the other two sheets were d. The antifouling effect and adhesion of the coating film to the substrate were examined over time. The results are shown in Tables 1 to 3.

[Example 2] Coating the undercoating agent (B) on a polypropylene molded plate to a film thickness of 3
Three test plates were prepared by applying the organic tin polymer antifouling coating agent (A) once at 0μ and twice at a coating thickness of 6071 using a brush, and the same test as in Example 1 was conducted. The results are shown in Tables 1 to 3.

[Comparative Example 1] Organic tin polymer antifouling coating agent (A) k on polyethylene molded plate
The test plate was coated twice with a brush at a coating thickness of 60μ.
A sheet was prepared and the same test as in Example 1 was conducted. Display the results -
Shown in Tables 1 to 3.

Preparation and Preparation of Comparative Undercoat Application Agent (C) The comparative undercoat application agent (C) was prepared by using the following formula: φ2.
did.

ratio 4I! Preparation of base coating agent (C) for 2 Epoxy resin solution 38.0iX1°, 1□-, a b'fu b
6. .

Titanium dioxide +o, 07il (Begara
12, 51jlX xylene
7.5 parts methyl ethyl ketone
7.5Q11 Comparative undercoat coating agent (C) Preparation of curing agent
85, 5 parts (DSX-204: manufactured by Daiichi Z-Ral Co., Ltd.) Methyl Ethyl Keto 7 145 parts Base coating agent for comparison (C) Base agent and base coating agent for comparison (C)
The curing agent was mixed and stirred in a weight ratio of 80/20 immediately before use to prepare an undercoat coating agent (C) for comparison.

Preparation of comparative primer coating agent (D) A comparative undercoat coating agent (D) was prepared using the following formulation.

Aluminum paste 25.0 parts Notylisophyl alcohol ketone 10.081s [Comparison 82 2
] A comparative undercoat coating agent (C) was coated on a polyethylene molded plate. Three samples of Test 1/Test plate' (!1) coated using the same method were prepared and tested in the same manner as in Example 1. The results are shown in Tables 1 to 3.

[Comparative Example 3] Comparative undercoat coating agent (D) was coated once with a film thickness of 4071 on a polyethylene molded plate, and organic tin polymer antifouling coating agent (A) k
Three test plates coated twice with a brush at a film thickness of 60 JL were prepared, and the same test as in Example 1 was conducted. The results are shown in Tables 1 to 3.

Table - 140°C Artificial Seawater Immersion Test I/Note 1 The numbers in the table are the number of times remaining after cutting 25 gobans with a spacing of 1'17j 2 mm and peeling. (Hereinafter referred to as "Govan i" test.) As shown in Table 1, an undercoating agent (A) 21d40°C artificial seawater &! There were no abnormalities in the burr/eye test after 6 months, showing good adhesion, but compared to when organic tin polymer antifouling coating agent (A) was directly applied! i
Example 1 Epoxy resin base coat coating agent (C) f: Comparative example 2 and vinyl resin base coat coat agent (D'
) f: Comparative Example 3, which was applied in advance, was heated to 40°C.
Even before being immersed in artificial seawater, the adhesion strength Z was significantly inferior to Example 1 and Example 2 as evaluated by the burlap test, and after 2 months of immersion, the number of pupil marks remaining in the burlap test was significantly lower. 0, indicating that chlorinated polyethylene resin and chlorinated polypropylene resin have strong adhesion to polyolefin lining materials.

Table-2 Antifouling effect (immersion in Yura Bay) Example-2' OI O,'
O1, Ol comparative example-il 501 70
・ 100 1 100 1 Note 2 The numbers in the table indicate the area occupied by the attached fouling organisms as a percentage of the total area of the immersion test plate, and 0 means no attachment, ioo
indicates full-scale adhesion.

All the fouling organisms are attached to the areas where the organic tin polymer antifouling coating has peeled off, and the organic tin polymer antifouling coating [J
There was no 1st place in the area where the membrane was healthy.

The results in Table 2 are expressed as the bite rate of fouling organisms in the total area of the test plate, but the essential point is (in case of 11 bite cases - 1, no primer was applied). ) and the difference in the sticking force with the polyolefin molded plate due to the difference in the type of primer coating agent, and the tendency is the same as the results of the cross-cut test in Table 1.

Table 3: Seawater immersion test for mucus adhesion (Yura Bay immersion) Note 3 The numbers in the table are the same as the numbers in Table 1 (Note 1). Note that the - mark indicates that the coating film was completely peeled off and disappeared during immersion in seawater, so the cross-cut test could not be performed.

[Example 3] The inner surface of a polyethylene-lined seawater pipe in a power plant was coated with primer coating agent CB) once at a film thickness of -10JL, and an organic tin polymer antifouling coating agent (A) was coated once. Thickness 607
It was applied twice using a roller brush. The condition was observed after 1 and 2 years of water flow, and there was no adhesion of fouling organisms or peeling of the coating, and no problems were found.

[Example 4] Polyethylene-lined infiltration at power plant B
The inner surface of the cleaning ball transfer tube was coated with primer coating agent (A) once at a coating thickness of 40 μm and organic tin polymer antifouling coating agent (A) twice at a coating thickness of 6011 μm using a roller brush. . 2
When the condition was observed after a year, there was no adhesion of fouling organisms or peeling of the coating, and there were no problems.

[Comparative Example 4] Comparative primer coating agent (D) was coated on the inner surface of the polyethylene-lined tube cleaning ball transfer tube in power plant B. Organotin polymer antifouling coating agent (D) was coated once with a film of 30μ. A) was applied twice using a roller brush to a coating thickness of 60 μm.

When the condition was observed one year after water flow, the coating film had completely peeled off and disappeared, and fouling organisms had adhered to the entire surface.

As explained above in the Examples and Comparative Examples, the antifouling method of the present invention applies chlorinated polyolefin (if any) to the surface of kidney stones lined with polyolefin for cooling water systems of power plants and chemical plants. , ethylene, fluoropylene) resin base coating agent and organic tin polymer antifouling coating agent 1J can be expected to have an effect of 1υ1 in both antifouling power and +1 adhesion of coating aX. It is very useful.

Patent applicant: NOF Corporation

Claims (1)

[Claims] After applying an undercoating agent containing 5 to 40 overlapping parts of chlorinated polyolefin resin to the seawater contact surface of a polyolefin-lined pipe for a cooling water system that uses seawater, the general formula % formula %) (formula R is an alkyl group having 3 to 5 carbon atoms or a phenyl group, and R' and R'' are a hydrogen atom or a methyl group. An antifouling method for polyolefin-lined pipes, which comprises applying an antifouling coating agent whose main component is coalescence.