JPH0480653B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to materials used for fisheries, such as fishing nets, ropes, and sheets. Vinyl alcohol (PVA)
It relates to fishery materials using synthetic fibers, repellent fibers mixed with molded products, or molded products.

Items that are used in the ocean for long periods of time, such as ships, fishing nets, ropes, and construction sheets, have been observed to attract and breed organisms, causing various problems. Marine life, such as animals such as barnacles, serpulae, bryozoans, and molluscs, and plants such as brown algae and green algae, adheres to the bottom of a ship while it is sailing or at anchor. Living things cannot be separated unless a significant mechanical external force is applied.

The following problems are said to occur when marine organisms adhere to the bottom of a ship.

(1) Frictional resistance between the seawater and the ship's hull increases, reducing the ship's speed, resulting in increased fuel consumption.

(2) The cost of removing deposits and the reduction in operating income during that time.

(3) Decrease in paint life.

Antifouling paints containing cuprous oxide are generally used as ship bottom antifouling paints to prevent the adhesion of such marine organisms. On the other hand, when it comes to fishing nets, ropes, etc., the growth and reproduction of attached organisms not only change the current, but also increase their own weight, causing the fishing nets and ropes to break or break.

Therefore, as a measure to prevent adhesion, treatment with organic tin or a method of combining a copper compound with a hydrophilic binder or a hydrophobic binder has been taken. By the way, organic tin has pollution problems and processing costs are relatively high.Also, when a hydrophilic binder is used to incorporate copper compounds into fishing nets, ropes, etc., the outflow rate of the copper compounds is excessive due to swelling and washing away of the binder. Therefore, although the initial effect is tremendous, the effect is not permanent. When nets and ropes are treated using a hydrophobic binder, the copper compounds on the surface of the binder will be eluted, but those inside will not be eluted, so it can be said that there is almost no effect. Therefore, at present there is no good binder, and the use of such binders hardens the nets and ropes, worsening workability. Further, as an example of a fiber containing copper, a copper-containing acrylic fiber is known as a conductive fiber. That is, this method involves adsorbing copper ions onto acrylic fibers and then reducing and depositing metallic copper within the fibers using a reducing agent, and the copper itself is extremely small. Furthermore, since the surface of acrylic fibers is porous, if such fibers are placed in seawater, a large amount of copper ions will be eluted in the seawater at the initial stage of addition, and the effect of preventing marine organisms from adhering to the fibers cannot be expected to last long. . Furthermore, copper wire or copper-plated fibers have poor processability as textile products, and although they are effective in preventing marine organisms from attaching when they are initially put into the ocean, as the copper corrodes and the degree of corrosion progresses, copper wire, etc. In this case, it will fall off and the effect will not be permanent.

In other words, at present, no practical marine materials that are safe and have a permanent repellent effect have been proposed.

The present invention of marine materials has been made in view of these points, and is hydrophilic and swellable.
It concerns marine materials made of fibers or molded products made of PVA mixed with a copper compound.
The desired purpose is achieved by combining PVA, which is specified for long-lasting effects, and a copper compound, which is specified.

That is, the present invention provides a PVA-based synthetic fiber whose degree of swelling = (weight of swollen PVA - weight of bone-dry PVA / weight of bone-dry PVA) x 100 (%) when immersed in water at 30°C for 48 hours is 5 to 25%. Alternatively, fisheries products using PVA-based synthetic fibers or molded products with repellency made by mixing 1 to 50% by weight of PVA with a copper compound having a solubility of 1.0 g/100 g water or less at 20°C in the molded product. It is a material for use.

The subject matter of the marine products materials of the present invention is not limited to fibers, but also includes molded products such as films.
The following description will refer to fibers to avoid complexity. Since PVA-based synthetic fibers are hydrophilic fibers, materials with different degrees of swelling can be selected depending on the manufacturing conditions. In other words, if the hot drawing ratio is increased during the manufacturing process, and if necessary acetalization is performed, the degree of swelling of the resulting fiber tends to decrease, but under normal manufacturing conditions, wet PVA synthetic fibers tend to decrease. The swelling degree is about 20% for dry PVA synthetic fibers, and the swelling degree is about 20% for dry PVA synthetic fibers. The focus is on the combination of As a result of investigation by the present inventors, copper compounds are mixed.
It has been found that a degree of swelling of 5% to 25% is a necessary condition for the copper compound to be gradually eluted from the PVA synthetic fiber. As a result, the elution of the copper compound can be made permanent, and the effect of preventing the adhesion of marine organisms can be maintained for a long time. Even if copper compounds could be mixed with hydrophobic fibers (nylon, polyester, polyethylene, polypropylene, polyvinylidene, etc.), these fibers are hydrophobic and do not swell when put in water, so copper Compounds cannot be eluted. On the other hand, rayon, which is a hydrophilic fiber, uses caustic soda and
Since sulfuric acid is used, copper compounds are eluted violently and the yield of copper compounds is poor. Furthermore, since rayon has a high degree of swelling, the elution rate of the copper compound is high, and the durability of the effect is poor, and the strength of the fiber itself is low. In other words, the degree of swelling must be between 5% and 25% to maintain the effect of gradually dissolving copper compounds and preventing the adhesion and proliferation of marine organisms.
%, and even more preferably 10-15%, has been found to be optimal.

The copper compound to be mixed next has a high solubility, which causes a chelate bond when mixed with PVA for spinning, resulting in poor spinnability. Various studies were conducted regarding solubility, and the following results were obtained. That is, 1.0g/at 20℃
It is necessary that the copper compound exhibits a solubility of 100 g or less in water. Substances that satisfy this condition include cuprous oxide, cuprous chloride, copper pyrophosphate, copper thiocyanide, and copper cyanide, and it has been found that cuprous oxide and copper thiocyanide are particularly optimal.
Also, a plurality of these compounds may be used. Regarding the addition of the above-mentioned copper compound to PVA-based synthetic fibers, according to experiments by the present inventors, for example, in terms of physical properties, when considering processability (workability) during steel manufacturing, the dry knot strength is 2.0 g. If the value was lower than /d, problems such as thread breakage occurred during steel making. Therefore, considering process passability, it was found that the maximum kneading ratio of copper compound is 50% by weight based on PVA.
On the other hand, if the kneading ratio of the copper compound is too small, the desired repellency effect will be lost even if there is no problem with process passability. Therefore, it has been found that in order for the effect to last for more than half a year, it is necessary to add at least 1% by weight of PVA. The present invention will be further explained in the following examples.

Example 1 PVA with a moisture content of 45% (degree of saponification 99%, degree of polymerization
1700) Mix 10 parts of cuprous oxide powder to 100 parts.
Spun using a 2.5 inch extruder. The spun yarn was treated at a furnace temperature of 220 to 240° C. at a draw ratio of 6 times and a heat shrinkage rate of 25% to obtain the following yarn.

Single fiber strength and elongation 5.6 g/d x 16.3% Dry knot strength 3.2 g/d Hot water shrinkage rate (100℃ x 30 minutes) 7.4% Swelling degree 10.6% Copper content (based on pure copper) 7.9% This PVA-based synthetic fiber Ropes were manufactured using steel, and the ropes were placed in the sea to examine their repellency to marine life. However, even after 9 months of installation, cuprous oxide continued to be leached out, and marine life was no longer attached to the ropes. The amount was extremely low compared to PVA-based synthetic fiber ropes.

Example 2 PVA concentration 15% (saponification degree 99%, polymerization degree 1700)
Copper thiocyanide powder in an aqueous solution of 20% of PVA
% and wet spinning to obtain the following yarn.

Single fiber strength and elongation 6.7 g/d x 9.6% Dry knot strength 4.9 g/d Hot water shrinkage rate (100℃ x 30 minutes) 4.2% Swelling degree 23.5% Copper content (based on pure copper) 9.8% Obtained PVA system A rope was made using synthetic fibers and commercially available polyester fibers, set in a wooden frame, and floated on the sea surface to investigate its ability to repel marine life. In the case of this example as well, copper thiocyanide continued to be leached out even 9 months after installation, and there was very little adhesion of marine organisms.

Claims (1)

[Scope of Claims] 1. Fisheries materials made of polyvinyl alcohol fibers or molded articles, which have a swelling degree defined below of 5 to 25 when immersed in water at 30°C for 48 hours.
% of polyvinyl alcohol fibers or molded articles, by mixing 1 to 50% by weight of a copper compound with a solubility of 1.0 g/100 g of water or less at 20°C to the polyvinyl alcohol. Polyvinyl alcohol-based marine materials. However, swelling degree = swollen PVA weight - bone dry PVA weight / bone dry PVA weight x 100 (%) In the above formula, PVA is an abbreviation for polyvinyl alcohol. 2. Claim 1, characterized in that the copper compound is one or more selected from cuprous oxide, cuprous sulfide, copper pyrophosphate, copper thiocyanide, and copper cyanide. A polyvinyl alcohol-based fishery material that has the biorepellent properties described.