JPH07305002A - Aqueous antifouling coating - Google Patents

Abstract

PURPOSE:To obtain an aqueous antifouling coating containing a specified polyester-based particle, a natural material-based antifouling agent and a water- soluble natural material-based polymer as the essential components, free from toxicity, excellent in removal and prevention of adhesion of living bodies and useful for application to, e.g. the bottom of a boat or a port facility. CONSTITUTION:This aqueous antifouling coating contains (A) a natural material- based antifouling agent such as guaiacol, (B) a particle composed of a polyester- based homopolymer and/or a polyesterbased copolymer (preferably 0.2 to 1.5 intrinsic viscosity) having a structural unit of the formula [R is H or a 1 to 3C alkyl; (n) is 0 to 4] and having 0.1 to 20mum average particle size and (C) a water-soluble natural material-based polymer such as xanthan gum as the essential components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a ship bottom, various port facilities,
The present invention relates to a coating applied to prevent adhesion of aquatic organisms such as barnacles, mussels, and algae to aquaculture fishing nets and cooling water pipes of power plants.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the adhesion of seaweeds and shellfish of this kind as described above, an organic solvent-based antifouling paint containing organic tin, cuprous oxide or the like as a main component has been applied. Was done. However, these organometallic compounds have considerably strong toxicity to the human body and have the ability to accumulate in shellfish. In addition, most of these antifouling paints are applied outdoors and air pollution by organic solvents is also a problem.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, the present invention has a problem that the constituent components of a coating film are a natural product and a biodegradable polymer, and the accumulation and marine pollution of conventional antifouling paints occur. The present invention provides a water-based antifouling paint that is free of organic solvents.

[0004]

The present invention provides an average particle diameter of a homopolymer and / or a copolymer of a natural product type antifouling agent (A) and a structural unit of the general formula (I). A water-based antifouling paint comprising particles (B) of 0.1 to 20 µm and a water-soluble natural polymer (C) as essential components in the paint.

The above polyester particles (B) are hydrolyzed from the portion in contact with seawater to release the natural product type antifouling agent (A) from the surface of the coating film. The released natural product type antifouling agent prevents the attachment of organisms. Further, the polyester constituting the particles (B) and the water-soluble natural polymer (C) gradually elute into seawater, so that the surface of the coating film is renewed and the detachment of attached organisms is promoted.

The natural product type antifouling agent (A) in the present invention includes guaiacol, eugenol, olivetol, orcin, tannic acid, catechin, anethole, thymol, citronellol, allyl isothiocyanate, benzyl isothiocyanate, hinokitiol, diallyl disulfide, vanillin. Acid etc. are mentioned.

Examples of the water-soluble natural polymer (C) in the present invention include xanthan gum, pullulan, sodium hyaluronate, corn starch, chitosan, carboxymethyl cellulose and the like.

Polymerization of the polyester represented by the structural unit (I) in the present invention can be obtained by direct dehydration polycondensation and ring-opening polymerization of a cyclic dimer using a known catalyst.

The molecular weight of the polyester represented by the structural unit (I) according to the present invention has an intrinsic viscosity (dl / g) of 0.
It is 1 to 3.0, preferably 0.2 to 1.5. Chloroform solvent, sample concentration 1w /
v%, Ubbelohde viscometer, measurement temperature 25 ° C.

If the molecular weight of the polyester is too high, the hydrolysis rate will be too slow and the effect of slowly releasing the antifouling agent will be low, and stable particle formation will occur. If the molecular weight is too low, the hydrolysis rate will be too fast to maintain the antifouling property for a long time.

If desired, oil may be added to the particles (B) in the present invention. The oil is preferably vegetable oil such as soybean oil and cottonseed oil, but may be silicone oil, liquid paraffin, polar group-containing silicone oil such as amino group, carbosyl group and epoxy group.

In the preparation of the particles (B) in the present invention, when the natural product type antifouling agent is soluble in an organic solvent such as chloroform, it is mixed and dissolved in the same manner as polyester and the solution is stirred and dispersed in a large amount of water. It is obtained by evaporating the organic solvent. A normal emulsifier may be used if necessary. Also, when oil is included in the particles (B), it is prepared in the same manner.

In the preparation of the particles (B) in the present invention, when the natural product type antifouling agent (A) is water-soluble, the antifouling agent is made into an aqueous solution together with a retaining agent such as a polysaccharide, and the polyester is added thereto. Particles can be obtained by adding the organic solvent solution of 1 above and stirring to prepare a W / O / W type emulsion and volatilizing the organic solvent. Hereinafter, details of the present invention will be described with reference to examples.

[0014]

【Example】

Example 1 Preparation of particles: Particle (I) 10 g of polylactic acid, 1 g of olivetol and 30 parts of chloroform
Particles (I) were prepared by dissolving them in 100 g, mixing them in 100 g of distilled water while stirring, forcibly emulsifying, and distilling off chloroform. The average particle size was 5 μm.

Preparation and Evaluation of Coating Material 1 g of xanthan gum was dissolved in 20 g of an aqueous solution to prepare a viscous aqueous solution, and 20 g of particles (I) were mixed therein to prepare a coating material, and a dry thickness of 100 μm was set on an acrylic plate of 7 × 15 cm.
Coated with. The coated plate was fixed to a stainless plate, immersed in 1.5 m in the sea off Yaizu Bay, and subjected to a biofouling test for 6 months. The evaluation of the adherence of organisms was carried out on a scale of 5 according to the adhered area. The results are shown in Table 1.

Example 2 Preparation of particles: Particle (II) 10 g of polylactic acid and 1 g of eugenol were added to 30 parts of chloroform.
Particles (II) were prepared by dissolving them in 100 g, mixing them in 100 g of distilled water with stirring to emulsify, and distilling off chloroform. The average particle size was 4 μm.

Preparation and Evaluation of Coating Material 1 g of chitosan was dissolved in 20 g of an acetic acid aqueous solution, and 20 g of particles (II) were mixed therein to prepare a coating material (II).
m acrylic plate was coated to a dry thickness of 100 μm, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Example 3 Preparation of Particles: Particles (III) 10 g of lactic acid-caprolactone block copolymer and 1 g of diallyl disulfide were dissolved in 30 g of chloroform and mixed in 100 g of distilled water with stirring to force emulsification to remove chloroform. Particles (III) were prepared by leaving. The average particle size was 6 μm.

Preparation and Evaluation of Coating Material 1 g of carboxymethyl cellulose was dissolved in 20 g of distilled water, 20 g of particles (III) and 20 g of coating material (III) were mixed to prepare coating material (III), and dried on a 7 × 15 cm acrylic plate. After coating with a thickness of 100 μm, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Comparative Example 1 Polyester RV200 (manufactured by Toyobo Co., Ltd.) 10
g, 1 g of olivetol are dissolved in 20 g of chloroform, and a dry thickness of 100 μm is applied to an acrylic plate of 7 × 15 cm.
Was coated, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

[0021]

[Table 1]

[0022]

As is clear from the results of Table 1, according to the present invention, a water-based antifouling paint having excellent anti-biofouling property was obtained.

Claims (1)

[Claims] 1. An average particle diameter of 0.1 comprising a polyester homopolymer and / or a polyester copolymer containing a natural product antifouling agent (A) and comprising a structural unit represented by the following general formula (I). A water-based antifouling paint comprising particles (B) and a water-soluble natural polymer (C) having a particle size of up to 20 μm as essential components in the paint. [Chemical 1]