JPH08109283A - Copolyester resin composition - Google Patents

Abstract

PURPOSE: To obtain a copolyester resin composition highly effective in preventing the attachment of algae and shellfish. CONSTITUTION: The composition comprises as the essential components a copolyester containing at least 95mol% structural units represented by the formula and a natural antifouling agent. In the formula, R is H or a 1-3C alkyl and n is an integer of 0-4. The composition is a highly safe antifouling composition and undergoes polyester hydrolysis in seawater to release biodegradable resin components and the antifouling agent simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is directed to the fouling of various structures such as ships, marine structures, seawater introduction pipes and fishing nets by marine attached organisms such as microorganisms, algae and animals attached to the surface of submerged parts in the sea or underwater. The present invention relates to a copolymerized polyester resin composition used for preventing the above.

[0002]

2. Description of the Related Art At present, ship bottoms, undersea communication cables, transportation pipelines, observation buoys, buoys, oil fences, silt protectors, piers, cooling channels for thermal power or nuclear power plants, industrial cooling channels, Wave power buoy,
Various equipment related to marine development and marine civil engineering, fishing nets, fishing gear, equipment and structures that are submerged in water for a long time include equipment such as barnacles, mussels, hydrozoa, serps, bryozoans, squirts, and sponges. Adhering animals and sea lettuce, blue seaweed, Shio Midoro, Himidoro, Shiogusa
Algae such as a mill and adherent microorganisms that form slime such as cyanobacteria, diatoms and bacteria adhere to the algae, which causes various losses.

For example, when these fouling organisms adhere to a ship, they increase the frictional resistance between the hull and seawater, lower the ship speed, increase the fuel consumption, and cause not only a great economic loss in the process. In addition, it causes a loss due to suspension of operation due to stains on the bottom of the ship and economic loss such as cleaning cost. Also, in marine structures such as piers, the anticorrosion coating is reduced, resulting in a shorter useful life of the structure. Buoys and other floating structures have reduced buoyancy and submerged. In cooling channels such as condensers of power plants and heat exchangers of various industries, heat exchange efficiency decreases due to a decrease in the amount of water intake, and the performance of condensers and heat exchangers due to the biological mass that has fallen from the channels decreases. It causes various damages such as causing. Furthermore, when attached to aquaculture fishing nets of seafood, the durability of the net itself is impaired, or the nets are covered and seawater inflow and outflow is obstructed,
This causes oxygen deficiency, causes the cultured fish and shellfish to die due to difficulty in breathing, and promotes the growth of bacteria to cause fish diseases such as norcadia disease and verdenia disease, which damages the fish.

As described above, the adhesion of marine organisms causes a great deal of industrial damage. Therefore, in order to prevent the adhesion, heavy metal compounds such as cuprous oxide, rhodan copper, and organic tin have been used as antifouling agents, and chlorine as a resin. Resin compositions containing functionalized polypropylene, hydrolyzable acrylic resin, and the like have been used.

[0005]

However, the heavy metal compounds have considerably high toxicity, and are non-natural compounds, therefore, they are accumulative and hardly decomposable compounds, and it is hard to say that they are preferable antifouling agents for the marine environment. Acrylic resin dissolved in seawater also gives a load on the environment.

[0006]

The present invention is a polyester in which the structural unit represented by the following structural formula (I) is copolymerized, and the proportion of the structural unit (I) in the polymer is 95 mol% or more. The present invention relates to a copolyester resin composition comprising the copolyester (A) and the natural product antifouling agent (B) as essential components.

[0007]

Embedded image (However, R represents H or an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 0 to 4.)

As a method of using the above composition, not only is it used as a coating agent by dissolving it in an organic solvent or emulsifying and dispersing it in water to use it for antifouling purposes, but also using the above resin composition as a sheath, PET, nylon, etc. There are various usages such as obtaining an antifouling fish net by compound spinning with a core.

Copolyester (A) in the present invention
Is an oxyacid such as glycolic acid, lactic acid, or caprolactone, which releases a natural antifouling agent (B) contained therein by causing a hydrolysis reaction. Since the constituent monomer of the copolyester (A) in the present invention is biodegradable and the natural product antifouling agent (B) is also biodegradable, there is no problem of accumulating in the environment.

Copolyester (A) in the present invention
In the above, as a copolymerization component other than the structural formula (I), succinic acid, adipic acid, azelaic acid, myristyl alcohol, propylene glycol, glycerin, polyethylene glycol, calcium lactate and the like can be copolymerized.

Copolyester (A) in the present invention
In order to obtain the above, a method of polymerizing a cyclic monomer such as glycolide, lactide, caprolactone, etc. using a known ring-opening polymerization catalyst, a method of polymerizing by direct dehydration polycondensation, etc. are not particularly limited.

Examples of the natural product antifouling agent (B) in the present invention include natural product phenols such as gallic acid, tannic acid and catechin, terpenes such as geraniol and farnesol, and mustard oil such as benzyl isothiocyanate. Examples thereof are not particularly limited. The details of the present invention are described in the following examples.

The reduced viscosity measurement (ηSP /
C) is a sample concentration of 125 mg, solvent chloroform,
The measurement was carried out at a temperature of 25 ° C. using an Ubbelohde viscosity tube. The glass transition point (Tg) in the present invention was measured by DSC measurement.

[0014]

【Example】

Example 1 Polymerization: Copolyester (1) L-lactide 100 g, DL-lactide 100 g, polyethylene glycol (molecular weight 4000) 22 g, ring-opening polymerization catalyst aluminum acetylacetonate 0.1 g 4
Copolymerized polyester (1) was prepared by charging in a one-necked flask and heating at 190 ° C. under nitrogen atmosphere for ring-opening polymerization.
I got Table 1 shows measured values of physical properties of the obtained copolyester.

A resin composition (1) was obtained by blending 100 g of the copolyester (1) with 25 g of benzyl mustard oil, which is a natural antifouling agent. The composition is shown in Table 2.

Preparation of paint: 100 g of the resin composition (1) was dissolved in 100 g of toluene to obtain an antifouling paint (1).

Evaluation of paint: Antifouling paint (1) of 10 × 20c
m FRP plate was coated with a wet thickness of 300 μm, and air-dried at room temperature for 48 hours, and the antifouling property and the coating film reduction rate were evaluated. The antifouling property was evaluated by floating a raft off the coast of Iwakuni and fixing the sample 1 m below the water surface. The evaluation was visually conducted in three levels. The rate of coating reduction was determined by fixing the rotor in seawater under a raft, rotating it at 15 knots, and measuring the surface roughness one month later. The results are shown in Table 3.

Example 2 Polymerization: Copolyester (2) 100 g of L-lactide, 100 g of DL-lactide, 0.5 g of glycolic acid and 0.1 g of ring-opening polymerization catalyst aluminum acetylacetonate were charged in a four-necked flask, Copolymerized polyester (2) was obtained by ring-opening polymerization at 190 ° C. in a nitrogen atmosphere. Table 1 shows measured values of physical properties of the obtained copolyester.

50 g of tannic acid was added to 100 g of the copolyester (2) to obtain a resin composition (2). The composition is shown in Table 2.

Preparation of paint: 100 g of the resin composition (2) was dissolved in 100 g of ethyl acetate to obtain an antifouling paint (2).

Evaluation of paint: The same evaluation as in Example 1 was carried out. The results are shown in Table 3.

Comparative Example 1 Preparation of Paint: Aromatic Copolyester RV200
Antifouling paint (3) was obtained by mixing 50 g of tannic acid with 100 g (manufactured by Toyobo Co., Ltd.) and dissolving it in 150 g of ethyl acetate.

Evaluation of paint: The same evaluation as in Example 1 was performed. The results are shown in Table 3.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

EFFECT OF THE INVENTION In the copolymerized polyester resin composition of the present invention, as is clear from Table 3, the hydrolysis of the polyester in seawater causes the biodegradable resin component to elute, and at the same time, the natural product antifouling agent is added. It is a highly safe antifouling resin composition that elutes, and by using the resin composition of the present invention, highly safe antifouling fishing nets, antifouling paints, fishing net treating agents and the like can be obtained.

Claims (1)

[Claims] 1. A copolyester in which a structural unit represented by the following structural formula (I) is copolymerized, and the proportion of the structural unit (I) in the polymer is 95 mol% or more. A copolymerized polyester resin composition comprising (A) and a natural product antifouling agent (B) as essential components. Embedded image (However, R represents H or an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 0 to 4.)