JP4346405B2 - Fiber for culture material and seaweed culture net using the same - Google Patents

Description

  The present invention relates to a fiber for aquaculture materials to be used in water and a seaweed aquaculture net using the same, and in particular, has good adhesion and viability of seaweeds, is excellent in durability, and is suitable even in places with severe wave conditions. The present invention relates to a culture material fiber suitable for obtaining a culture material such as a seaweed culture net that can be used and a seaweed culture net using the same.

  Conventionally, vinylon fibers have been widely used for a network of aquaculture nets for culturing seaweed such as laver because of its excellent ability to establish seaweeds. Seaweed aquaculture nets made only of vinylon fibers are mainly used in places where the strength of the netting is not so necessary, for example, in the bay where the wave conditions are mild as represented by the Ariake Sea. When the strength of the netting is required, the netting is formed with fibers obtained by twisting vinylon fibers and other fibers having excellent strength, for example, fibers obtained by twisting vinylon fibers and polyamide fibers. Yes.

  However, when the above conventional seaweed aquaculture nets are used in places with severe wave conditions such as outside the bay, the vinylon fibers are liable to break due to bending fatigue, and they are twisted with the vinylon fibers. Because the fiber of the seaweed has low viability of seaweeds, the growing seaweeds attached to the surface of the net are easy to drop off, and the yield of the seaweeds cannot be maintained until harvesting, resulting in a decrease in yield. was there.

Japanese Patent Publication No. 7-8188 proposes a technique for improving the viability of laver spores by treating polyamide fibers and the like with a compound such as tannic acid having 3 or more hydroxyl groups in one molecule. However, this method has problems such as complicated processing steps and high costs.
Japanese Patent Publication No. 7-8188

  The present invention solves the above-mentioned problems, and is suitable for obtaining an aquaculture material suitable for use in a place where the seaweed has excellent adhesion and viability, excellent durability, and severe wave conditions. And a seaweed aquaculture net using the same.

The gist of the present invention is a fiber for an aquaculture material, which is a fiber constituting an aquaculture material used in water and is formed of a polyamide containing an oxyalkylene group-containing polyvinyl alcohol. . Moreover, the present invention is the above-mentioned fiber for aquaculture materials, wherein the fiber is a fiber having a core-sheath structure, and only the sheath part is formed of a polyamide containing oxyalkylene group-containing polyvinyl alcohol. This is the gist of the fiber for aquaculture materials. Moreover, this invention makes the summary the seaweed aquaculture net | network characterized by using the above-mentioned fiber for culture materials.

  Since the fiber for aquaculture materials of the present invention is formed of polyamide containing a modified polyvinyl alcohol resin, it has excellent durability and adhesion and viability of seaweeds. Even if used in severe conditions, seaweeds have good viability and can maintain a high yield by maintaining adhesion of seaweeds until harvest time. As aquaculture materials such as seaweed aquaculture nets, ropes and twisted yarns, etc. Is preferred. Moreover, since the seaweed aquaculture net | network using this fiber for aquaculture materials has the outstanding characteristic as mentioned above, it is especially suitable as a culture net for a laver.

  Hereinafter, the present invention will be described in detail.

  The fiber for aquaculture materials in the present invention is a fiber constituting a culture material used in water and needs to be formed of polyamide containing a modified polyvinyl alcohol resin. The culture material referred to in the present invention is specifically a material for attaching seaweed or the like to grow in water, and refers to a culture net, rope, twisted yarn or the like.

  The modified polyvinyl alcohol resin has hydrophilicity derived from a hydroxyl group in the same manner as the polyvinyl alcohol resin constituting the vinylon fiber shown in the above-mentioned conventional example, and adheres to adhere spore of seaweed, and attached seaweed. Has excellent ability to grow spore. Moreover, the polyamide which is the main component of the fiber is excellent in mechanical strength. The polyvinyl alcohol resin constituting the vinylon fiber cannot be melt-spun, but the modified polyvinyl alcohol resin in the present invention can be melt-spun together with polyamide. Therefore, in a simple process of melt spinning the modified polyvinyl alcohol resin and polyamide, durability that combines the adhesion and viability of seaweed, which is unique to the modified polyvinyl alcohol resin, and the excellent mechanical strength unique to polyamide. High quality fiber for aquaculture materials can be realized. The aquaculture materials that use fibers for aquaculture materials with such characteristics are not susceptible to cutting of the constituent fibers even when used in places with severe wave conditions, and are growing seaweed that are attached to the surface of the fibers. Since it is possible to retain the species until the time of harvest, the yield of seaweeds can be improved.

  The blending ratio of the modified polyvinyl alcohol resin and the polyamide is not particularly limited, but the modified polyvinyl alcohol resin is preferably contained in the polyamide in an amount of 10 to 40% by mass, and 15 to 35% by mass. Is more preferable. When the content of the modified polyvinyl alcohol resin is less than 10% by mass, sufficient activities of seaweeds cannot be obtained, and when the content of the modified polyvinyl alcohol resin exceeds 40% by mass, the modified polyvinyl alcohol resin is peeled off or It tends to decrease the viability of seaweeds by elution and to decrease spinning and operability.

  It is preferable that the fiber for aquaculture materials of the present invention is a fiber obtained by spinning a blend body in which a modified polyvinyl alcohol resin is contained in a polyamide in the above ratio. That is, it is preferable that the modified polyvinyl alcohol resin does not exist as an independent layer in the polyamide, but the modified polyvinyl alcohol resin is mixed almost uniformly. Thereby, it can prevent that a modified polyvinyl alcohol resin peels or elutes from a fiber, and the sustainability of the effect which a modified polyvinyl alcohol resin shows is improved.

  The fiber for aquaculture materials of the present invention is not only a fiber formed of only the above-mentioned modified polyvinyl alcohol resin-containing polyamide, but at least a part thereof is a fiber formed of the above-described modified polyvinyl alcohol resin-containing polyamide. There may be. As such a thing, the fiber which formed only the sheath part of the core-sheath composite fiber with the polyamide containing modified polyvinyl alcohol resin is mentioned, for example. In this way, when a part of the fiber structure is formed of polyamide containing a modified polyvinyl alcohol resin, the polyamide containing the modified polyvinyl alcohol resin is exposed on the surface of the fiber in consideration of the viability of seaweeds. It is preferable. Thus, also when using the polyamide which contains a modified polyvinyl alcohol only for a part of structure of a fiber, it is preferable that the mixture ratio of a polyamide and modified polyvinyl alcohol is made the same as the above.

  The shape of the fiber for aquaculture material of the present invention is not particularly limited, and may be a conventionally known multifilament or monofilament. In the case of a multifilament, the fineness of the single yarn constituting the multifilament is preferably 3.3 to 22 dtex, and the total fineness of the multifilament is preferably 55 to 2200 dtex. In the case of a monofilament, the single yarn fineness is preferably 55 to 1100 dtex, and 220 to 670 dtex from the viewpoint of convergence, durability and weaving properties when twisted when constructing an aquaculture material, particularly a seaweed aquaculture net. Further preferred. Moreover, in the multifilament and the monofilament, the cross-sectional shape of the single fiber forming the fiber may be any shape, for example, a circle, an ellipse, a triangle, T, Y, H, + type, 5 leaves, 6 leaves, 7 leaves, A multi-leaf shape such as eight leaves, a square, a rectangle, a rhombus, a saddle shape, a horseshoe shape, and the like can be given, and these shapes may be partially changed. Moreover, you may use combining suitably the fiber of these various cross-sectional shapes.

  Polyamides that are the main components constituting the fiber for aquaculture materials of the present invention include polycapramide (nylon 6), polyundecanamide (nylon 11), polylaurolactamide (nylon 12), polytetramethylene adipamide (nylon) 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebamide (nylon 610), and the like. These may be used alone, or may be copolymerized or blended. . Of these, nylon 6 is preferable because it is inexpensive and has excellent strength and durability.

  In addition to particles such as various types of inorganic particles such as titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, crosslinked polymer particles, various metal particles, etc., depending on the application, polyamides are also used to prevent aging. Conventionally known additives such as additives, antioxidants, anti-coloring agents, light-resistant agents, clathrate compounds, antistatic agents, various colorants, various surfactants, various reinforcing fibers and the like do not impair the effects of the present invention May be added.

As the modified polyvinyl alcohol resin in the present invention, oxyalkylene group-containing polyvinyl alcohol is used . Specifically, oxyalkylene group-containing polyvinyl alcohol is a copolymer of vinyl acetate and polyoxyalkylene (meth) allyl ether such as polyoxyethylene (meth) allyl ether, polyoxypropylene (meth) allyl ether, It is then obtained by saponification. In this case, the copolymerization ratio (content) of the polyoxyalkylene (meth) allyl ether is preferably 0.1 to 20 mol%, particularly preferably 0.1 to 5 mol%. The degree of condensation of polyoxyalkylene in is preferably 1 to 300, particularly 3 to 50. Moreover, it is preferable that the ratio of the oxyalkylene unit to the whole oxyalkylene group containing polyvinyl alcohol is 3-40 mass%. This indicates that there is an optimum range for the degree of localization-delocalization of oxyalkylene units and the length of oxyalkylene units in the copolymer.

  The saponification degree of the vinyl acetate unit in the oxyalkylene group-containing polyvinyl alcohol is 50 to 100 mol%, preferably 70 to 99 mol%. Moreover, 150-1500 are preferable and, as for the average degree of polymerization of polyvinyl alcohol, it is suitable that it is 200-1000. In addition, as a copolymerization component, components other than polyoxyalkylene (meth) allyl ether, for example, α-olefin such as ethylene, propylene, and long chain α-olefin, ethylenically unsaturated carboxylic acid monomer, acrylate, methacrylate, acrylonitrile, methacrylate Components such as ronitrile, vinyl chloride, and vinyl ether may be contained as long as they are about 30 mol% or less.

  As the polymerization method for obtaining the oxyalkylene group-containing polyvinyl alcohol, a solution polymerization method is usually employed, and in some cases, a suspension polymerization method, an emulsion polymerization method, or the like can also be employed. As the saponification reaction, an alkali saponification method, an acid saponification method or the like is employed.

  In addition to the above, polyvinyl alcohol containing oxyalkylene group includes vinyl acetate, polyoxyethylene (meth) acrylate, polyoxypropylene (meth) acrylate, polyoxyethylene (meth) acrylamide, polyoxypropylene (meth) acrylamide, polyoxyethylene (1- (meth) acrylamide-1,1-dimethylpropyl) ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, polyoxyethylene allylamide, polyoxypropylene allylamide, polyoxyethylene vinylamide, polyoxypropylene vinylamide Etc. can be obtained by copolymerization and then saponification.

  The oxyalkylene group-containing polyvinyl alcohol can also be obtained by reaction of alkylene oxide with polyvinyl alcohol, or polymerization of vinyl acetate with polyoxyalkylene glycol and subsequent saponification.

  The oxyalkylene group-containing polyvinyl alcohol obtained as described above further comprises at least one of (I) a phenol compound having a melting point of 50 to 250 ° C., (II) a thioether compound, and (III) a phosphite compound. It is preferable to add 0.01 to 5 mass%, preferably 0.1 to 0.5 mass% of the seed. Thereby, the thermal stability of a fiber can be improved. If the amount added is less than 0.01% by mass, improvement in thermal stability cannot be expected, and if it exceeds 5% by mass, the viability of seaweeds is reduced.

  (I) Examples of phenolic compounds having a melting point of 50 to 250 ° C. include 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4′-thiobis- (6 -T-butylphenol), 2,2'-methylene-bis (4-methyl-6-t-butylphenol), tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxy Phenylpropionate] methane, octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 4,4′-thiobis- (6-tert-butylphenol), N, N ′ Hexamethylene-bis (3,5-di-t-butyl-4'-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t -Butyl-4-hydride Loxybenzyl) benzene, pentaerythryl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,1,3-tris (2-methyl-4-hydroxy-5- t-butylphenyl) butane and the like.

  (II) As the thioether compound, pentaerythritol-tetrakis- (β-laurylthiopropionate), tetrakis [methylene-3- (dodecylthio) propionate] methane, bis [2-methyl-4- {3-n- Alkylthiopropionyloxy} -5-t-butylphenyl] sulfide and the like.

  (III) Examples of phosphite compounds include triaryl phosphites such as triphenyl phosphite, tris (p-nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, and diphenylisooctyl. Monoalkyl diphenyl phosphites such as phosphites, diphenylisodecyl phosphites, alkylaryl phosphites such as dialkyl monophenyl phosphites such as phenyl diisooctyl phosphites, phenyl diisodecyl phosphites, triisooctyl phosphites, tristearyl phosphites Trialkyl phosphites such as tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenephosphonite, di (2,4-di-t-butylphenyl) pentaerythritol Over diphosphite, and the like.

  In the oxyalkylene group-containing polyvinyl alcohol resin composition in the present invention, (IV) at least one of a fatty acid having 10 or more carbon atoms or a salt thereof, a fatty acid amide compound, or a fatty acid ester compound is added in an amount of 0.01 to 3. It is preferable to add 0.1 mass%, Preferably 0.1-0.5 mass%, and heat stability improves further by this.

  Fatty acids having 10 or more carbon atoms or salts thereof include higher fatty acids such as lauric acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid, arachidinic acid, behenic acid, erucic acid, hydroxystearic acid, hydroxyricinoleic acid, etc. Examples thereof include hydroxy fatty acids or metal salts of these magnesium, calcium, strontium, barium, zinc, etc. Among them, stearic acid, magnesium stearate, calcium stearate, 12-hydroxy magnesium stearate, magnesium behenate are practical. . The fatty acid amide compounds are fatty acid amides such as stearic acid amide, palmitic acid amide, oleic acid amide, behenic acid amide, erucic acid amide, or alkylene bis fatty acid amides such as methylene bis stearic acid amide and ethylene bis stearic acid amide. Is mentioned. Examples of fatty acid ester compounds include fatty acid esters of monohydric alcohols such as butyl stearate and butyl palmitate, and fatty acid esters of polyhydric alcohols such as ethylene glycol monostearate.

  As a method of blending oxyalkylene group-containing polyvinyl alcohol and (I) (II) (III) and (IV), a generally well-known method, that is, a melting can with an agitator, an extruder, a roll kneader The method of melt-mixing using the method etc. and pelletizing is mentioned. There are no special restrictions on the blending order. The melt mixing temperature is suitably 160 to 250 ° C, preferably 180 to 230 ° C.

  As described above, when the modified polyvinyl alcohol resin is added to and mixed with the polyamide, a pellet is prepared by melt-blending the components (I) to (IV) with the modified polyvinyl alcohol resin. May be added to the polyamide and melt blended, but the modified polyvinyl alcohol resin and (I) to (I) ( Each component of IV) and polyamide may be directly melt blended.

  In addition, other polymers can be blended in the modified polyvinyl alcohol resin as long as the effects of the invention are not impaired, and various additives such as plasticizers, fillers, colorants, and stabilizers are blended. You can also

  The fiber for aquaculture materials of the present invention configured as described above is suitable for aquaculture materials used underwater such as seaweed aquaculture nets, twisted yarns, ropes, etc. Especially, it is suitable as an aquaculture net for nori culture. These aquaculture materials may be composed of only the aquaculture material fibers of the present invention, but together with the fibers of the present invention, one or more other materials selected from polyamide fibers, polyester fibers, polypropylene fibers, polyethylene fibers and the like. These fibers may be used in combination.

  The seaweed aquaculture net of the present invention is made by using at least a part of the above-mentioned fiber for aquaculture materials. The shape of the net is not particularly limited, and can be applied to conventionally known ones such as a knot net, a knotless net, a cocoon net, and a woven net.

  In addition, the seaweed aquaculture net of the present invention has the above-described aspect of the present invention according to the purposes such as net strength, flexibility, dryness, dimensional stability, adhesion of seaweed spores, thinning properties of seaweed spores, and adjustment of specific gravity. You may use the fiber which twisted the fiber for culture materials, and the above-mentioned other fiber. The intertwisting ratio between the fiber for aquaculture material of the present invention and these various fibers varies depending on the place where the fiber is used and the respective required characteristics, but the total fineness of the net yarn constituting the net of the fiber for the aquaculture material of the present invention is 30. % Or more is preferable.

  The seaweed aquaculture net in which the fiber for aquaculture material of the present invention configured as described above is used can break the constituent fiber even when used in places with severe wave conditions (fast flow places) such as outside the bay. It is hard to occur and has excellent durability, and because it is excellent in the viability of seaweeds such as seaweed and mozuku, it is difficult for seaweeds growing on the surface of fibers to fall off, The adhesion is maintained and the yield is good, and in particular, it can be suitably used as a nori culture net.

EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by these Examples. In the following examples and comparative examples, various physical property values were measured by the following methods.
(1) Strength (cN / dtex) and elongation (%) of monofilament: In accordance with the method described in JIS L-1013, using an autograph DSS-500 type manufactured by Shimadzu Corporation, a grip interval of 25 cn and a tensile speed of 30 cm Measured at / min.
(2) Number of Nori shoots grown (number / field of view) and rate of Nori shoots grown after 30 days (-): 36 yarns were used to create twisted yarn and seeded in the same way as onshore seedlings of Nori net 4 hours later, the number of nori buds was examined. The number of seedlings of the seaweed buds was measured with a biological microscope X2F manufactured by Nikon Corporation at 125 times 10 fields per specimen, and the average value was obtained.

  Next, the seeded twisted yarn was immersed in seawater to which nutrient salts were added, and aeration culture was performed for 30 days. After this cultivation, the twisted yarn was pulled up, and the amount of laver sprout per twisted yarn was examined in the same manner as described above. The growth rate of the seaweed buds was expressed as a relative value to this value, assuming that the amount of growth on the vinylon fiber of Comparative Example 2 was 1.0.

In addition, the number of seedlings of seaweed buds is an index of adhesion of the seaweed species, and the rate of growth after 30 days is an index of survival. In the present invention, the rate of establishment after 30 days is preferably 0.5 or more, more preferably 0.8 or more.
(3) Relative viscosity of polyamide: Measured under the conditions of 96% concentrated sulfuric acid as a solvent, concentration of 1 g / dl and temperature of 25 ° C.

<Method for producing modified polyvinyl alcohol resin>
Polyoxyethylene monoallyl ether having an average degree of condensation of oxyalkylene and vinyl acetate are copolymerized in methanol in the presence of azobisisobutyronitrile to drive out residual monomers, and then methanol solution of sodium hydroxide To saponify. The copolymer was separated from the slurry produced by the saponification reaction, and washed with methanol 5 times the volume of the polyvinyl alcohol resin. Next, after adding 1.5 equivalents of acetic acid to sodium acetate, it was washed twice with methanol that was 5 times the volume of the polyvinyl alcohol resin again. The amount was adjusted to 0.026% by mass (0.5 mol with respect to 1 mol of sodium acetate). Then, it dried and obtained the oxyalkylene group containing polyvinyl alcohol-type resin (henceforth "EO-PVA").

  The average degree of polymerization of this polymer is 270, the copolymerization ratio of the polyoxyethylene monoallyl ether unit is 1.0 mol%, the ratio of the oxyalkylene unit in the whole polymer is 16.1% by mass, the vinyl acetate component The degree of conversion was 96 mol%, the sodium acetate content was 0.07 mass%, and the acetic acid content was 0.026 mass%.

100 parts by mass of the obtained EO-PVA and 0.3 parts by mass of pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] are twin-screw extruded with a round die It was supplied to a machine and extruded at a temperature of 210 ° C. to obtain a pellet-like modified polypolyvinyl alcohol resin.
Example 1
A nylon 6 chip having a relative viscosity of 3.1 is blended with the pellet-like modified polyvinyl alcohol resin prepared as described above so that the content is 20% by mass of the whole, and a 40 mm uniaxial extruder is obtained. The yarn was continuously fed and was spun from a spinneret for circular cross-section yarn through a spinning pack at a spinning temperature of 255 ° C. by a conventional method. After cooling the spun monofilament in a water bath at 20 ° C., it is stretched and heat-set to a total of 5.0 times according to a conventional method, and wound on a bobbin to obtain a monofilament having a single yarn fineness of 600 dtex and a circular cross section. It was.

Then, 36 monofilaments were twisted to determine the number of laver buds grown (pieces / field of view) and the rate of settlement.
Table 1 shows the properties of the obtained monofilament and twisted yarn.

実施例２
変性ポリビニルアルコール樹脂の含有量が全体の４０質量％となるようにした。そしてそれ以外は実施例１と同様にして単糸繊度が６００ｄｔｅｘで、断面形状が円形のモノフィラメントおよびこれを用いた撚糸を得た。

Example 2
The content of the modified polyvinyl alcohol resin was adjusted to 40% by mass. Otherwise, in the same manner as in Example 1, a monofilament having a single yarn fineness of 600 dtex and a circular sectional shape and a twisted yarn using the monofilament were obtained.

Table 1 shows the properties of the obtained monofilament and twisted yarn.
Example 3
The content of the modified polyvinyl alcohol resin was adjusted to 15% by mass. Otherwise, in the same manner as in Example 1, a monofilament having a single yarn fineness of 600 dtex and a circular sectional shape and a twisted yarn using the monofilament were obtained.

Table 1 shows the properties of the obtained monofilament and twisted yarn.
Example 4
Nylon 6 chips with a relative viscosity of 3.1 as the core component and nylon 6 chips with a relative viscosity of 3.1 as the sheath component blended so that the content of the modified polyvinyl alcohol resin is 20% by mass Was used. Then, the core-sheath composite ratio is continuously supplied to a 40 mm uniaxial extruder so that the core / sheath ratio is 70/30, and spinning for circular cross-sectional yarns is performed through a spinning pack at a spinning temperature of 255 ° C. by a conventional method. Spinned from the base. Next, after the spun monofilament is cooled in a 20 ° C. water bath, it is stretched and heat-set so as to be a total of 5.0 times in accordance with a conventional method, is wound on a bobbin, and the cross-sectional shape with a single yarn fineness of 600 dtex is circular Monofilament was obtained. Then, 36 monofilaments were twisted to obtain the number of nori buds and the rate of establishment.

Table 1 shows the properties of the obtained monofilament and twisted yarn.
The comparative example for comparing with the Example of this invention is shown below.
Comparative Example 1
Only nylon 6 tips with a relative viscosity of 3.1 were used. Other than that, a nylon 6 monofilament and a twisted yarn using the same were obtained in the same manner as in Example 1.

Table 1 shows the properties of the obtained monofilament and twisted yarn.
Comparative Example 2
A polyvinyl alcohol monofilament (Unitika Vinilon No. 5 [MF5], 560 dtex) manufactured by Unitika, produced by wet spinning was used. And the twisted yarn which consists only of this monofilament was created like Example 1. FIG.

Table 1 shows the properties of the obtained monofilament and twisted yarn.
Since the monofilaments obtained in Examples 1 to 4 were all polyamide fibers containing a modified polyvinyl alcohol resin, they had excellent tensile strength and elongation equivalent to the polyamide fibers consisting only of nylon 6 shown in Comparative Example 1. Obtained.

  In addition, the twisted yarns obtained in Examples 1 to 4 had the same number of nori buds as the vinylon fibers shown in Comparative Example 2, and had good adhesion. Furthermore, the nori bud formation rate after 30 days was also sufficient, and it had good survival.

  Thus, the monofilaments and twisted yarns shown in Examples 1 to 4 have both the mechanical strength possessed by the polyamide fibers and the adhesion and viability of the seaweeds possessed by the vinylon fibers, and are therefore suitably used as a seaweed aquaculture net. It was possible.

  In addition, a laver net is made using the twisted yarns used in Example 1 and Comparative Examples 1 and 2, and seedlings are collected on land, and the laver net is floated and cultured in the Seto Inland Sea where the wave conditions are severe. As a result of the comparison, the laver net using the twisted yarn of Example 1 yielded almost the same amount of harvest as the laver net using the twisted yarn of Comparative Example 2. In addition, despite the use in places with severe wave conditions, there was almost no decrease in strength due to bending fatigue.

On the other hand, in the laver net using the twisted yarn of Comparative Example 1, most of the laver was lost and the yield was remarkably low, although almost no decrease in strength due to bending fatigue was observed.
Moreover, although the laver net using the twisted yarn of Comparative Example 2 was excellent in the yield of laver, the net strength was greatly reduced due to bending fatigue, and it could not be reused repeatedly.

  The fiber for aquaculture material of the present invention can be suitably used as a net for aquaculture of seaweed such as laver, and is particularly suitable as a floating laver aquaculture net used in places with severe wave conditions.

Claims (3)

A fiber for an aquaculture material, which is a fiber constituting an aquaculture material used in water, and is formed of a polyamide containing an oxyalkylene group-containing polyvinyl alcohol . The fiber for cultured material according to claim 1, wherein the fiber is a fiber having a core-sheath structure, and only the sheath part is formed of polyamide containing oxyalkylene group-containing polyvinyl alcohol. A seaweed aquaculture net, wherein the fiber for aquaculture materials according to claim 1 or 2 is used.