JPH06228467A - Resin composition for crosslinked antifouling coating - Google Patents

Abstract

PURPOSE:To provide a non-pollutive resin composition suitable for antifouling coatings excellent in adhesivity to primer coatings and in the strength of coating films, and useful for crosslinked antifouling coatings. CONSTITUTION:A resin composition for crosslinked antifouling coatings, characterized by reacting a silicone-polyester block copolymer resin with an aminoalkoxysilane in an amount of 0.5-3 times equivalents based on the equivalents of the non-reacted epoxy groups of the resin, the silicone-polyester block copolymer resin being produced by reacting (A) an epoxy group-containing silicone resin having a mol.wt. of 700-8000 with (B) a carboxyl group-containing polyester resin having a mol.wt. of 1500-2000.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Seaweeds and shellfish adhere to and damage the pipes and intake and drainage facilities of various industrial plants such as the inner walls of the intake pipes for cooling water such as thermal power plants, nuclear power plants, and steelworks. This is causing problems such as reduced intake and drainage capacity.

The crosslinkable antifouling resin composition of the present invention comprises
Provided is a pollution-free antifouling paint which is applied to prevent the adhesion of seaweeds and shellfish as described above and has excellent coating film performance.

[0003]

2. Description of the Related Art In order to prevent the adhesion of seaweeds and shellfish of this kind as described above, conventionally, chemicals containing organotin, zinc, cadmium, mercury, etc. as a main component have been applied. It was However, these organometallic compounds are quite toxic to the human body. Particularly, the commonly used bistributyltin oxide (TBTO) also has a strong toxicity to the human body.

In order to solve this problem, silicon-based antifouling paints (JP-A-60-60167 and JP-A-64-1772) have been developed and partially put into practical use as pollution-free antifouling paints. It has problems such as poor adhesion to the base and insufficient coating film strength.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a resin composition for cross-linking antifouling paint, which provides an antifouling paint that is pollution-free and has good adhesion to a substrate and good coating strength. It is about things.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, a polyester resin having the composition shown below has excellent adhesion to a substrate and coating strength and is toxic. The present invention has been achieved by finding that the antifouling coating material does not have any stains. That is, the present invention has a molecular weight of 700-80.
00 and a silicone resin (A) having epoxy groups at both ends or one end, a carboxyl group at both ends or one end, a glass transition temperature (Tg) of 20 ° C. or higher, and a molecular weight of 1500 to 20000. With the polyester resin (B) of 1. epoxy group equivalent / carboxyl group equivalent = 1.
It is characterized by reacting in the range of 3 to 3.0 to obtain a silicone-polyester block copolymer resin, and reacting 0.5 to 3 times equivalent of aminoalkoxysilane with respect to the unreacted epoxy group equivalent of this resin. The present invention relates to a cross-linked antifouling paint resin composition.

In the present invention, the silicone / polyester block copolymer resin has a silicone / polyester weight ratio of 5
/ 95 to 60/40 is preferable. Silicon content is 5
If it is less than wt%, biofouling cannot be prevented and 60 wt%
If it exceeds the range, the adhesion with the underlying anticorrosive paint is deteriorated.

As the silicone resin (A) having a molecular weight of 700 to 8000 and having epoxy groups at both ends or one end in the present invention, a compound represented by the structural formula (1) can be mentioned.

[0009]

[Chemical 1] _{R 1, R 2, R 3} , R 4 are independently an alkyl group in the structural formula, ant - group, an alkenyl group, consisting of an aralkyl group. At least one of X and Y is a glycidyl group,
It is an organic group having an epoxy group such as a cyclohexene oxide group.

The molecular weight of the silicone resin (A) in the present invention must be 700 to 8000. If the molecular weight is less than 700, the effect of preventing biofouling will be reduced, and if the molecular weight exceeds 8,000, problems such as too low reactivity with the polyester resin (B) and poor adhesion to the base anticorrosive coating material will occur.

The molecular weight of the polyester resin (B) in the present invention is 150 when the strength of the coating film and the adhesion to the base are taken into consideration.
It is necessary to be 0 or more, preferably 2000 or more. If the molecular weight is too large, the reactivity with the epoxy group in the silicone resin becomes poor, so it is necessary to be 20,000 or less, preferably 15,000 or less.

The glass transition temperature (Tg) of the polyester resin (B) in the present invention is required to be 20 ° C. or higher in view of coating strength, and is preferably 25 ° C. or higher.

The carboxyl group concentration of the polyester resin (B) in the present invention is 100 to 3000 eq in consideration of the reactivity with the epoxy group of the silicone resin (B) and the water resistance.
/ 10 ⁶ g, preferably 120 to 1500 eq / 10 ⁶ g.

The reaction between the epoxy group of the silicone resin (A) and the carboxyl group of the polyester resin (B) in the present invention is carried out by epoxy group equivalent / carboxyl group equivalent of 1.3-
It is necessary to react in the range of 3.0. Equivalent ratio is 1.3
If the ratio is lower than the above, unreacted carboxyl groups increase and the water resistance decreases, and if the equivalent ratio is higher than 3.0, the amount of unreacted silicone resin increases and the adhesion of the coating film to the base decreases.

Examples of the dicarboxylic acid component of the polyester resin (B) in the present invention include terephthalic acid, isophthalic acid, orthophthalic acid, cyclohexyldicarboxylic acid, naphthalenedicarboxylic acid, tricyclodecanedicarboxylic acid, oxalic acid, malonic acid, succinic acid, Examples thereof include glutaric acid, adipic acid and sebacic acid.

As the glycol component of the polyester resin (B) in the present invention, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol and cyclohexanediol are used. , Cyclohexane dimethanol, bisphenol A ethylene oxide adducts, bisphenol A propylene oxide adducts, and the like.

Polymerization of the polyester resin (B) in the present invention can be obtained by any method, but it is possible to obtain a carboxylic acid-terminated polyester by carrying out usual melt reduced pressure polymerization and adding an acid anhydride thereto. it can. Of these, it is preferable to use succinic anhydride or trimellitic anhydride.

The reaction between the silicone resin (A) and the polyester resin (B) in the present invention can be carried out by melting or in a known organic solvent. As the reaction catalyst, phosphorus-based compounds such as triphenylphosphine, amine-based imidazo-
Well-known catalysts such as dimethyl ether, dimethylaminopyridine, and quaternary amines are used.

Examples of the aminoalkoxysilane in the present invention include compounds represented by the structural formula (2).

[0020]

[Chemical 2] X in the structural formula (2) is an alkyl group, an aryl group, an alkenyl group or an aralkyl group having one or more amino groups, and R ₁ and R ₂ are independently an alkyl group, an aryl group or an alkenyl group. Group, an aralkyl group, n is an integer of 0 to 30, and at least two or more of Y ₁ , Y ₂ and Y ₃ are alkoxy groups.

Examples thereof include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane and the like.

The reaction between the unreacted epoxy group in the silicone-polyester block resin and the amino group of the aminoalkoxysilane compound in the present invention is 0.5 to 0.5 in terms of equivalent ratio.
Must be 3. When it is lower than 0.5, the cross-linking property is insufficient and the physical properties of the coating film are deteriorated. When it is higher than 3, the polarity of the coating film surface is high and the antifouling property is deteriorated.

The resin composition of the present invention can be crosslinked at room temperature by reacting with water in the air. For this moisture curing, known titanic acid esters, (acetylacetonitrile) diisopropyl titanate, iron 2-ethylhexanoate, dibutyltin dilaurate, stannous acetate, stannous octoate and other organometallics, Further, an amine-based catalyst such as ethylamine or hexylamine is used.

The crosslinkable antifouling paint resin composition of the present invention may contain liquid paraffin, silicone oil,
A surface energy reducing agent such as long-chain alkylcarboxylic acids and long-chain alkylamines may be added. Further, antifouling agents such as cuprous oxide, zinc dimethylthiocarbamate and tetramethylthiuram may be blended with bactericides such as quaternary amines and phenols. Further, a crosslinking agent such as melamine, polyfunctional isocyanate, polyfunctional epoxy or polyfunctional amine may be added to improve the physical properties of the coating film.

The molecular weight in the present invention is the polystyrene-reduced number average molecular weight in gel permeation chromatography (GPC) using tetrahydrofuran (THF). The glass transition temperature of the resin in the present invention is D
It was determined by SC measurement. The carboxyl group concentration (eq / 10 ⁶ g) of the polyester resin in the present invention was determined by titrating the polyester resin dissolved in DMF. Hereinafter, details of the present invention will be described with reference to Examples, but the present invention is not limited thereto. In the examples, “parts” means “parts by weight”.

[0026]

【Example】

Example 1 Polyester polymerization: PES-1 dimethyl terephthalate 194 parts, dimethyl isophthalate 194 parts, neopentyl glycol 229 parts, ethylene glycol 136 parts, transesterification catalyst tetranornal butyl titanate (TBT) (0.1 part) was charged in a flask, and the mixture was transesterified by stirring at 180 ° C. under normal pressure. After 128 parts of methanol was distilled off, the pressure was reduced to 1 mmHg.
Polymerization was carried out at 40 ° C., then the pressure was returned to normal pressure with nitrogen gas, 20 parts of succinic anhydride was added, and the mixture was stirred at 120 ° C. for 1 hour to obtain a terminal carboxyl group-containing polyester (PES-1). The composition is shown in Table 1.

Silicon modification: SPE-1 100 parts of the above polyester, silicone resin KF-105
(Shin-Etsu Silicon Co., Ltd.) 40 parts and TPP 0.2 parts were mixed in xylene 50 parts and stirred at 130 ° C. for 5 hours to obtain a silicone-polyester block copolymer resin (SPE-1). The progress of the reaction was confirmed by measuring the resin acid value. 90 parts of cyclohexanone is added here,
A varnish having a solid content concentration of 50 wt% was obtained.

Terminal alkoxylation: SPM-1 3.2 parts of aminopropyltriethoxysilane was mixed with 100 parts of the above varnish, and the mixture was stirred at room temperature to react an unreacted terminal epoxy with an amine for alkoxysilylation to obtain a moisture-curing varnish. , 5 parts of liquid paraffin was added here (S
PM-1).

Evaluation: SPM-1 A 20 cm × 20 cm primer-treated steel sheet was coated with an anticorrosion paint.
Then varnish SPM-1 with a wire bar.
It was coated with (50 #) and dried at room temperature for 48 hours to obtain an antifouling coated steel plate.

For the evaluation of biofouling property, an immersion test was conducted for 6 months at a depth of 1.5 m in the sea off Shirahama City, Wakayama Prefecture. The degree of adhesion of shellfish and algae was evaluated as an area ratio, and a 5-level evaluation was performed. The results are shown in Table 4.
Regarding the adhesion of the coating film, the adhesion energy at the interface was evaluated by "Cycas" manufactured by Nippon Plastics Co., Ltd. The results are shown in Table 4.

Example 2 Polyester Polymerization: PES-2 Polyester having the composition shown in Table 1 was polymerized in the same manner as in Example 1. Silicon modification: SPE-2 100 parts of the above polyester, silicone resin X-22-1
40 parts of 63A (manufactured by Shin-Etsu Silicone Co., Ltd.) and 0.2 parts of TPP were mixed with 50 parts of xylene and reacted at 130 ° C. for 5 hours to obtain a silicone-polyester block copolymer resin (SPE-2). Cyclohexanone 9 here
0 part was added to obtain a varnish having a solid content concentration of 50 wt%.

Terminal alkoxysilylation: SPM-2 100 parts of the above varnish was mixed with 2.5 parts of aminopropyltriethoxysilane and stirred at room temperature for terminal alkoxysilylation. A moisture-curing varnish was added, and 5 parts of liquid paraffin was added (SPM-2). Evaluation: SPM-2 The same evaluation as in Example 1 was performed. The results are shown in Table 4.

Example 3 Polyester Polymerization: PES-3 Polyester having the composition shown in Table 1 was polymerized in the same manner as in Example 1. Silicon modification: SPE-3 100 parts of the above polyester, silicone resin X-22-1
40 parts of 63B (manufactured by Shin-Etsu Silicone Co., Ltd.) and 0.2 parts of TPP were mixed with 50 parts of xylene and reacted at 130 ° C. for 5 hours to obtain a silicone-polyester block copolymer resin (SPE-3). Cyclohexanone 90
Parts were added to obtain a varnish having a solid content concentration of 50 wt%.

Terminal alkoxysilylation: SPM-3 100 parts of the above varnish was mixed with 1.5 parts of aminopropyltriethoxysilane, and the mixture was stirred at room temperature for terminal alkoxysilylation to obtain a moisture-curing varnish. Liquid paraffin 5
Parts were added (SPM-3). Evaluation: SPM-3 The same evaluation as in Example 1 was performed. The results are shown in Table 4.

Comparative Example 1 Polyester Polymerization: PES-4 Polyester having the composition shown in Table 1 was polymerized in the same manner as in Example 1. Silicon modification: SPE-4 100 parts of the above polyester, silicone resin KF105
(Shin-Etsu Silicon Co., Ltd.) 40 parts, TPP 0.2 parts were mixed with xylene 50 parts and reacted at 130 ° C. for 5 hours to give a silicone-polyester block copolymer resin (S).
PE-4) was obtained. 90 parts of cyclohexanone was added thereto to obtain a varnish having a solid content concentration of 50 wt%.

Terminal alkoxysilylation: SPM-4 100 parts of the above varnish was mixed with 3.2 parts of aminopropyltriethoxysilane and stirred at room temperature for terminal alkoxysilylation to obtain a moisture-curing varnish, in which 5 parts of liquid paraffin were added. Was added (SPM-4). Evaluation: SPM-4 The same evaluation as in Example 1 was performed. The results are shown in Table 3.

Comparative Example 2 Polyester Polymerization: PES-5 Polyester having the composition shown in Table 1 was polymerized in the same manner as in Example 1. Silicon modification: SPE-5 100 parts of the above polyester, silicone resin KF105
(Shin-Etsu Silicon Co., Ltd.) 40 parts and TPP 0.2 parts are mixed in xylene 50 parts, and the mixture is stirred at 130 ° C. for 5 hours to obtain a silicone-polyester block copolymer resin (S).
PE-5) was obtained. 90 parts of cyclohexanone was added thereto to obtain a varnish having a solid content concentration of 50 wt%.

Terminal alkoxy silylation: SPM-5 100 parts of the above varnish was mixed with 3.2 parts of aminopropyltriethoxysilane and stirred at room temperature to react the unreacted terminal epoxy groups with amines for alkoxy silylation and moisture curing. A mold varnish was prepared, and 5 parts of liquid paraffin was added thereto (SPM-5). Evaluation: SPM-5 The same evaluation as in Example 1 was performed. The results are shown in Table 4.

Comparative Example 3 Silicon modification: SPE-6 40 parts of polyester (PES-1), silicone resin X-
22-163B (manufactured by Shin-Etsu Silicon Co., Ltd.) 100 parts, TP
0.2 parts of P in 50 parts of xylene and mixed at 130 ° C. for 5
By stirring for a time, a silicone-polyester block copolymer resin (SPE-6) was obtained. 90 parts of cyclohexanone was added thereto to obtain a varnish having a solid content concentration of 50 wt%.

Terminal alkoxysilylation: SPM-6 Terminal alkoxysilylation was carried out by mixing 100 parts of the above varnish with 1.5 parts of aminopropyltriethoxysilane and stirring at room temperature (SPM-6). Evaluation: SPM-6 The same evaluation as in Example 1 was performed. The results are shown in Table 4.

Comparative Example 4 Silicon modification: SPE-7 100 parts of polyester (PES-3), silicone resin K
F-105 (manufactured by Shin-Etsu Silicone) 3 parts, TPP 0.2
Parts in xylene 43 parts and stirred at 130 ° C. for 5 hours to give a silicone-polyester block resin (SPE-
7) was obtained. 60 parts of cyclohexanone was mixed therein to obtain a varnish having a solid content concentration of 50 wt%. Evaluation: SPE-7 5 parts of liquid paraffin was added to 100 parts of the above varnish, and the same evaluation as in Example 1 was performed. The results are shown in Table 4.

Comparative Example 5 Polyester Polymerization: PES-6 Polyester having the composition shown in Table 1 was polymerized in the same manner as in Example 1. Evaluation: PES-6 100 parts of the above polyester was dissolved in 100 parts of cyclohexanone to prepare a varnish, and the same evaluation as in Example 1 was performed. The results are shown in Table 4.

Comparative Example 6 Moisture-curing silicone resin KE44RTV (Shin-Etsu Silicon-
60 parts, liquid paraffin 5 parts, and xylene 35 parts were mixed and stirred, and the same evaluation as in Example 1 was performed. The results are shown in Table 4.

[0044]

As is clear from the results of Table 4, according to the present invention, a polyester resin composition for antifouling paint having excellent biofouling prevention properties and good coating film performance was obtained.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

Claims (1)

[Claims] 1. A silicone resin (A) having a molecular weight of 700 to 8000 and having epoxy groups at both ends or one end, and a carboxyl group at both ends or one end,
It has a glass transition temperature (Tg) of 20 ° C or higher and a molecular weight of 15
The polyester resin (B) of 0 to 20000 is reacted in the range of epoxy group equivalent / carboxyl group equivalent = 1.3 to 3.0 to give a silicone-polyester block copolymer resin, and the unreacted epoxy group equivalent of this resin is On the other hand, 0.
A resin composition for cross-linking antifouling paint, which is obtained by reacting 5 to 3 times equivalent amount of aminoalkoxysilane.