JPS6023458A - Aquatic antifouling paint having high adhesivity and crack resistance - Google Patents

Abstract

PURPOSE:To provide the titled paint suitable for the coating of ships, etc. and giving a coating film having excellent adhesivity and crack resistance, etc., and obtained by adding an antifouling agent to a vehicle comprising a specific copolymer resin containing tributyltin (meth)acrylate as a constituent unit. CONSTITUTION:The objective paint is produced by using (A) a vehicle comprising a copolymer resin containing tributyltin (meth)acrylate, devoid of free carboxyl group, and having a glass transition temperature of -5-+25 deg.C, and adding (B) one or more antifouling agents (e.g. cuprous oxide) to the vehicle. The copolymer resin in the component A is preferably a polymer obtained by copolymerizing the monomer using an azo-type polymerization initiator free from carboxyl group, e.g. alpha,alpha'-azobisisobutyronitrile. The amount of tributyltin (meth) acrylate unit in the copolymer of the component A is preferably 30-70wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater antifouling paint with good adhesion and crank resistance.

Ships, underwater structures, fishing nets for aquaculture, etc. are covered with marine organisms such as fujibo and sea lettuce, causing damage such as corrosion of structures, increased seawater frictional resistance of ships, and mass death of fish due to clogging of nets. arise. In order to prevent the attachment of these harmful aquatic organisms, an underwater antifouling paint containing an anti-leta agent such as cuprous oxide is applied.

Recently, antifouling paints using trialkyltin polymer compounds as vehicles have appeared and are attracting attention. The characteristics of this anti-leta paint are that the trialkyltin polymer compound hydrolyzes in a slightly alkaline atmosphere in seawater, releasing the tin compound, and the vehicle becomes water-soluble, causing the paint film to self-polish and smooth the paint film. The purpose is to reduce the seawater frictional resistance of ships and help cut down on fuel costs. However, this l.
One of the drawbacks of antifouling paints using realyl tin polymer compounds as a vehicle is that the paint film peels off easily. Peeling may be caused by poor treatment of the base before painting, such as poor washing of the old paint film during repainting, but it may also be due to insufficient adhesion and crack resistance of the paint itself.

It is an object of the present invention to provide an underwater antifouling paint using a trialkyltin polymer compound as a vehicle, which has excellent adhesive properties and crank resistance. Here, "excellent recoatability" means that when the paint film of the present invention becomes a top coat or a base coat, no peeling phenomenon occurs in tubes with the same or different types of coatings.

According to the invention, said object is achieved by using as a vehicle a copolymer resin containing tributyltin (meth)acrylate as a constitutional unit and free of free carboxyl groups and having a glass transition temperature of 15°C to 25°C. Ru.

By setting the glass transition temperature (Tg) of the copolymer resin in the range of 5°C to 25°C, the resin becomes flexible, and when the paint of the present invention is used as Tosopko-1.
Adhesion to the old paint film and crank resistance are improved, and peeling can be prevented.

In addition to lowering the Tg of the resin, there is also a method of adding a plasticizer (DOP, etc.) to soften the coating film (external plasticization), but selective elution of the plasticizer into water or plasticization It is impossible to maintain the same coating performance over a long period of time due to the migration of However, such disadvantages are not observed in the antifouling paint of the present invention.

The tributyltin (meth)acrylate copolymer is hydrolyzed in seawater according to the following formula.

This hydrolysis occurs from the coating film surface, and therefore the resin near the coating film surface becomes a high acid value resin. This high acid value resin layer can be removed to some extent by washing with water during repainting, but there is a limit; for example, it may remain on the bottom of a ship due to poor washing. Therefore, when the paint of the present invention is used as a base coat, it is necessary to prevent it from peeling off from the top coat.

In order to prevent this, the Tg of the high acid value resin obtained by hydrolyzing the tributyltin (meth)acrylate structural units in the copolymer into the corresponding free carboxylic acid structural units must be set to 100.
This can be achieved by keeping the temperature below ℃. Tg to 100℃
By setting it as follows, the solvent resistance of the high acid value resin can be reduced, the affinity with the top coat paint solvent can be increased, and the adhesion can be improved.

Of course, the tributyltin (meth)acrylate structural unit in the copolymer is not 100% hydrolyzed to the corresponding carboxylic acid, but the adhesive coating property of the high acid value resin layer actually produced is 100%. % of the hydrolyzed corresponding copolymer and the Tg of the corresponding copolymer.

The copolymer can be produced by copolymerizing 30 to 570% by weight of tributyltin (meth)acrylate and the remaining comonomer having no free carboxyl group that can be copolymerized with the tributyltin (meth)acrylate by a conventional method. In this case, it is preferable to use an azo initiator having no free carboxyl group as the polymerization initiator. This is because if the resin contains free carboxyl groups, it may react with the antifouling agent and reduce the storage stability of the paint.

If the proportion of the tributyltin (meth)acrylate structural unit in the copolymer exceeds 70% by weight, the storage stability of the paint will be poor, and if it does not reach 30% by weight, the coating film will hardly be leached in seawater. Therefore, long-term antifouling properties and fuel savings during ship operation cannot be expected.

If the Tg of the copolymer does not reach 15°C, the drying properties of the paint will be poor, and if it exceeds 25°C, when the paint of the present invention is used as a top coat, the adhesion to the old paint film will not be sufficient and cracks will occur. Easy to cause peeling.

Furthermore, if the Tg of the copolymer after hydrolysis exceeds 100° C., when the paint of the present invention is used as a base coat, it will not have sufficient adhesion to a repainted film.

Here, the Tg of the copolymer can be determined by calculation using the formula Tgi = 'rg of the homopolymer Xi = weight %, or it can be measured using a thermomechanical analyzer, such as Konsei Seisakusho TMA-30. I can do it.

The antifouling paint of the present invention can contain at least one antifouling agent.

These antifouling agents include copper-based antifouling agents such as cuprous oxide and copper rhodanide, and slime-resistant nitrogen-containing organic sulfur compounds such as 'ethylene-bis(dithiocarbamate) zinc (abbreviated as ZINEB) and ethylene-bis(dithiocarbamate) zinc (ZINEB). Manganese (dithiocarbamic acid) (abbreviated as MANIEB),
Tetramethylthiuram monosulfide (abbreviated as TS),
Copper bis(dimethyldithiocarbamate) (abbreviation TTC)
u) etc.

When a copper compound and a nitrogen-containing sulfur compound are used together, the ratio can be varied over a wide range depending on the purpose;
It is appropriate to use 5 to 200 parts by weight, preferably 10 to 1.50 parts by weight, of the nitrogen-containing sulfur compound.

Also, the total amount of antifouling agent is 5% based on the weight of the entire paint.
From 6 to 70% by weight, preferably from 6 to 55% by weight is suitable.

The antifouling paint of the present invention exhibits sufficient slime resistance and/or antifouling properties by containing at least one of the above-mentioned antifouling agents, so there is no need to further blend other antifouling agents. However, this does not preclude the admixture of other known antifouling agents and fungicides, if desired, such as bis(tributyltin) oxide, tributyltin chloride, tributyltin fluoride, tributyltin acetate, tributyltin nicotinate, tributyltin persatate, bis( tributyltin) α, α”-dibrom succinate, triphenyltin hydroxide, triphenyltin nicotinate, triphenyltin persate, bis(triphenyltin) α, α”-dibrom succinate, bis(triphenyltin) It is also possible to use it in combination with organic tin compounds such as tin) oxide.

In addition, commonly used coloring pigments, extender pigments, organic solvents, etc. can be freely selected and used.

The antifouling paint of the present invention can be prepared by a method known per se in the field of paint manufacturing technology. For compounding, known ta machines such as ball mills, pebble mills, roll mills, speed run mills, etc. can be used.

According to the present invention, by selecting as a vehicle a copolymer having Tg within a certain range before and after hydrolysis among the copolymers containing tributyltin (meth)acrylate as a constituent unit, as a top coat, And, as a base coat, an underwater antifouling paint with excellent recoatability, good adhesion and crank resistance is provided.

In addition, a paint that has a self-polishing effect on the paint film by hydrolyzing a tributyltin polymer compound is provided, making it possible to effectively prevent the adhesion of aquatic organisms to ships, underwater structures, fishing nets, etc., and reduce fuel consumption during ship operation. do.

The present invention will be explained in detail below with reference to Examples. Note that "1 part" in "Production Examples", "Examples", and "Comparative Examples" is based on weight.

Further, "Tsurhenoso 100" used in the present invention is a trade name manufactured by Esso Standard.

Example 1 of producing Dandan Kusuienjii 40 parts of Kijirole was added to a four-bottle flask equipped with a reflux condenser, a dropping funnel, and a stirrer, and the temperature was maintained at 80°C to 85°C. In this solution, 60 parts of tributyltin methacrylate,
35 parts of methyl methacrylate, 5 parts of ethyl acrylate, α
A mixed solution of 1 part of α''-azobisisobutyronitrile was added dropwise over 4 hours, and the mixture was kept warm for 3 hours.

After that, 26 parts of Kijiroru was added, and the solid content was 60.1%, the viscosity was 6.0 poise, and the number average molecular weight of the resin was 18,000°T.
g Varnish A at 15.4°C was obtained.

The Tg of this resin after hydrolysis was calculated to be 93.6°C.

Production Example 2 Using the same reaction apparatus as Production Example 1, 40 parts of pheasant roll was added to a four-bottle flask and maintained at 80 to 85°C.

In this solution, 1 to 55 parts of butyltin methacrylate, 40 parts of methyl methacrylate, 5 parts of ethyl acrylate, α,
A mixed solution of 1 part of α゛-azobisisobutyronitrile was added dropwise over 4 hours, and the temperature was kept for 3 hours after the addition. After that, 26 parts of pheasant roll was added, and the solid content was 60.3% and the viscosity was 6.
2 voids, number average molecular weight of resin 1.8,000. T
Varnish B of g 21 "C was obtained.

The calculated Tg of this resin after hydrolysis was 93°C.

Production Example 3 Using the same reaction apparatus as Production Example 1, 40 parts of pheasant roll was added to a four-bottle flask and maintained at 80 to 85°C.

In this solution, 40 parts of tributyltin methacrylate, 30 parts of methyl methacrylate, 30 parts of ethyl acrylate, α,
A mixed solution of 1 part of α' to azobisisobutyronitrile was added dropwise over 4 hours, and the mixture was kept warm for 3 hours after the addition. After that, 26 parts of pheasant roll was added, and the solid content was 59.7% and the viscosity was 5.
8 voids, number average molecular weight of resin 19,000. T g
Varnish C at s°C was obtained.

The calculated Tg of this resin after hydrolysis was 39°C.

Production Example 4 Using the same reaction apparatus as Production Example 1, 40 parts of pheasant roll was added to a four-bottle flask and maintained at 80 to 85°C.

In this solution, 40 parts of tributyltin methacrylate, 20 parts of methyl methacrylate, 40 parts of ethyl acrylate, α,
A mixed solution of 1 part of α゛-azobisisobutyronitrile was added dropwise over 4 hours, and the temperature was kept for 3 hours after the addition. After that, 26 parts of pheasant roll was added, and the solid content was 60.0% and the viscosity was 5.0%.
6 voids, resin number average molecular weight 19,000. Tg4
．． Varnish D at 9°C was obtained.

The calculated Tg of this resin after hydrolysis was 21°C.

Production Example 5 Using the same reaction apparatus as Production Example 1, 40 parts of Tsurpetz-100 was added to a fourth flask and maintained at 80-85'C.

A mixed solution of 60 parts of tributyltin methacrylate, 33 parts of methyl methacrylate, 7 parts of 2-ethylhexyl methacrylate, and 1 part of α,α'-abbisisobutyronitrile was added dropwise to this solution over 4 hours. Keep warm for hours. After that, 26 parts of pheasant roll was added, and the solid content was 59.6.
%, viscosity 6.1 voids, number average molecular weight of resin 18.00
0. Varnish E with Tgl 6°C was obtained.

The calculated Tg of this resin after hydrolysis was 95°C.

Production Example 6 Using the same reaction apparatus as in Production Example 1, 30 parts of white spirit was added to four flasks and kept at 80-85°C.

In this solution, 55 parts of tributyltin methacrylate, 35 parts of methyl methacrylate, 5 parts of isobutyl methacrylate,
A mixture/8 solution of 5 parts of ethyl acrylate and 1 part of α,α゛-azobisisobutyronitrile was added dropwise over 4 hours, and kept warm for 3 hours after the addition.

Then add 26 parts to 1 part of White Spirino, solid content 60
．． 1%, viscosity 6.0 voids, number average molecular weight of resin 18.
000. Varnish F with a Tgl of 9°C was obtained.

The calculated Tg of this resin after hydrolysis was 88°C.

Production Example 7 Using the same reaction apparatus as in Production Example 1, 30 parts of pheasant roll was added to a flask for 4 days and kept at 80 to 85°C.

In this solution, 40 parts of tributyltin methacrylate, 20 parts of methyl methacrylate, 10 parts of acriconilyl, 20 parts of ethyl acrylate, 10 parts of isobutyl acrylate,
A mixed solution of 1 part of α, α”-abbis isoptilonitrile is added dropwise over 4 hours, and kept warm for 3 hours after dropping. Then, 37 parts of Kijirole are added, solids content is 58.8%, viscosity is 6.4 voids, resin Number average molecular weight of 19,000.T
Varnish G at 6°C was obtained.

]g of this resin after hydrolysis was calculated to be 57°C.

Production Example 8 Using the same reaction apparatus as Production Example 1, 30 parts of pheasant and 3 parts of di(2-ethylhexyl itaconate) were added to a four-bottle flask and maintained at 80 to 85°C.

A mixed solution of 60 parts of tributyltin methacrylate, 30 parts of methyl methacrylate, 5 parts of isobutyl acrylate, 2 parts of acrylonitrile, and 1 part of α, α”-azobisisobutyronitrile was added dropwise to this solution over 4 hours. Keep warm for the next 3 hours. Then add 36 parts of pheasant roll to give a solid content of 59.7%.

Viscosity 6.1 voids, resin number average molecular weight 18,000.
1 g of Varnish H at 10° C. was obtained.

The calculated Tg of this resin after hydrolysis was 79°C.

Comparative Production Example 1 Using the same reaction apparatus as in Production Example 1, 30 parts of pheasant roll was added to a four-bottle flask and maintained at 8.0 to 85°C.

A mixed solution of 50 parts of tributyltin methacrylate, 50 parts of methyl methacrylate, and 1 part of α,α°-azobisisobutyroni-dyl was added dropwise to this solution over 4 hours.
Keep warm for 3 hours after dropping. After that, 36 parts of Kijiroru was added, and the solid content was 60.3%, the viscosity was 6.6 voids, and the number average molecular weight of the resin was 19,000. T g Comparison varnish A at 32°C
I got it.

The calculated Tg of this resin after hydrolysis was 110°C.

Comparative Production Example 2 Using the same reaction apparatus as in Production Example 1, 1-30 parts of Boyte's Spiris was added to a fourth flask and maintained at 80-85°C.

A mixed solution of 70 parts of tributyltin methacrylate, 30 parts of methyl methacrylate, and 1 part of α,α”-azobisisobutyronitrile is dropped into this solution over 4 hours, and kept warm for 3 hours after the dropwise addition.Then, White Spirit 36 Comparative varnish B with a solid content of 60.4%, a viscosity of 6.1 voids, and a resin number average molecule i of 19.000°TglO°C.
I got it.

The Tg after hydrolysis of this resin is calculated as 11.3
It was ℃.

Comparative Production Example 3 Using the same reaction apparatus as in Production Example 1, 30 parts of white spirit was added to a fourth flask and maintained at 80 to 85°C.

In this solution, 60 parts of tributyltin methacrylate, 35 parts of methyl methacrylate, 5 parts of isobutyl methacrylate,
A mixed solution of 1 part of α,α゛-azobisisobutyronitrile was added dropwise over 4 hours, and the temperature was kept for 3 hours after the addition. After that, 1 to 36 parts of spirit were added, and the solid content was 59.
8%, viscosity 6.4 voids, number average molecular weight of resin 18.0
00. A comparative varnish C with a T g of 18°C was obtained.

The calculated Tg of this resin after hydrolysis was 117°C.

Comparative Production Example 4 Using the same reaction apparatus as in Production Example 1, 30 parts of pheasant roll was added to a four-bottle flask and maintained at 80 to 85°C.

A mixed solution of 48 parts of tributyltin methacrylate, 45 parts of methyl methacrylate, 7 parts of 2-ethylhexyl methacrylate, and 1 part of α,α゛-azobisisobutyronitrile was added dropwise to this solution over a period of 4 hours. Keep warm for hours. Then add 36 parts of pheasant roll, solid content 60.2
%, viscosity 6.4 voids, number average molecular weight of resin 19,00
0. A comparative varnish D with a T g of 27°C was obtained.

The calculated Tg of this resin after hydrolysis was 91°C.

Comparative Production Example 5 Using the same reaction apparatus as Production Example 1, 30 parts of pheasant roll was added to a fourth flask and maintained at 80 to 85°C.

In this solution, 1 to 45 parts of butyltin methacrylate, 50 parts of methyl methacrylate, 5 parts of n-butyl acrylate,
A mixed solution of 1 part of α,α°-azobisisobutyronitrile was added dropwise over 4 hours, and the mixture was kept warm for 3 hours after the addition. Then add 36 parts of pheasant roll, solid content 60.3%, viscosity 6.
．． 5 poise, number average molecule of resin (219,000, T
g Comparative varnish E at 29°C was obtained.

The calculated Tg of this resin after hydrolysis was 87°C.

EXAMPLES Example and Comparative Example Using the varnishes A to H obtained in Production Examples 1 to 8, antifouling paints according to the present invention having the formulations shown in Table 1 were prepared by a conventional method.

As a comparative example, comparative varnish A- obtained in Comparative Production Examples 1 to 5 was used.
D was used to prepare anti-lη paints having the formulations shown in Table 2.

(Left below) Top coat the paint obtained in Shoji's Mitsugu example and Hisaki example.
The adhesion was evaluated.

In Experiment 1, the base coat (undercoat) was a commercially available hydrolyzable paint, and in Experiment 2, the base coat was also the antifouling paint of the present invention.

Table 3 shows the results.

(Left below) Experiment 1: The undercoat was a commercially available hydrolyzable paint that had been immersed in seawater for 3 months after painting, and was then washed with water to remove any attached organisms. After drying outdoors day and night, the present invention was prepared. After applying the paint with a brush to a thickness of 100μ, dry it indoors for a day.
The appearance of the coating film was examined in an adhesion test after 3 months of immersion in seawater again.

Experiment 2: Same as Experiment 1 except that the undercoat was also the paint of the present invention.

Evaluation Criteria Adhesion 2. Creation % ◎ Very good without peeling 0~5% ○ Slightly poor adhesion but no problem To 5~25% Peeling is large and there is a practical problem 25~75%X Full peeling 75~100% Adhesion test method (11th board test) After washing and drying the test board, make 4 squares of 5 dragons on each side (1 cm)
(4 squares with 5 dragons on each side) Cut with a knife and check the adhesion using cellophane tape.The number of squares that peeled off was expressed as a percentage.

Note that the results in Table 3 show the average values obtained by performing the experiment five times (repeatedly) using the method described above.

From the above results, it is clear that the glass transition point of the resin in the paint greatly contributes to the adhesion (recoatability) and quality of the coating film appearance.

41

Claims (4)

[Claims] (1) The vehicle is a copolymer resin that contains tributyltin (meth)acrylate as a structural unit, does not contain free carboxyl groups, and has a glass transition temperature of 15°C to 25°C, and contains at least one antifouling agent. An underwater antifouling paint with good adhesion and crank resistance. (2) The underwater antifouling paint according to claim 1, wherein the vehicle is a copolymer resin obtained by copolymerization using an Ab type polymerization initiator that does not contain free carboxyl groups. (3) The underwater antifouling paint according to claim 1 or 2, wherein the proportion of the I-butyltin (meth)acrylate structural unit in the copolymer is 30 to 70% by weight. (4) The copolymer has a glass transition temperature of 100°C or less when its tributyltin (meth)acrylate constituent units are hydrolyzed to the corresponding free carboxylic acid constituent units. Underwater antifouling paints listed in any of the above.