JP3044112B2 - Marine structural materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine structural material,
For example, Ikes frame, surf boat, floating pier structure,
It is suitably used as a fender, a water surface division fence, a wave-proof net, and other components for wave resistance, tidal current resistance, corrosion resistance to seawater, and light weight and strength required for floating structures on the sea surface that require strength. Things.

[0002]

2. Description of the Related Art In this type of marine structural material, in order to withstand long-term use, wave resistance and tidal current resistance are particularly important. In addition, it is required that the structural material has a high bending rigidity, a sufficient shape retention force, and a high elongation at break. Furthermore, this type of marine structural material is required to have corrosion resistance to seawater and weather resistance, to be lightweight and strong in terms of buoyancy, to be inexpensive and to have good workability.

[0003] Structural materials having the above functions are urgently demanded, especially in a culture ikesu frame, which is a means of producing fisheries. The Ikes frame surrounds a certain section of the sea surface with a floating body,
A bottomed net is attached to the lower part, and fish and shellfish are cultivated within the volume. The above-mentioned function is required for the ikes frame, but in particular, when the frame is deformed, the cultivated portion becomes narrow, and the fish is damaged or dies due to lack of oxygen. Needs to be high. Also, from the point that the aquaculture industry has recently shifted to offshore aquaculture where wave countermeasures are more important than coastal aquaculture, the frame that constitutes the floating body has, in particular, wave resistance and tide resistance, That is, a structural material excellent in both bending rigidity and breaking elongation is required. Furthermore, since algae and the like adhere to the net hanging from the ikes frame and increase the weight, the net needs to be lightweight in order to float on the water surface.

[0004] Conventionally, the ikes frame is made of bamboo, wood or an iron material with a float attached near the water surface.
The Ikesu frame made of bamboo and wood is mainly 15
Small size up to m-square and has a certain degree of flexibility, so it can follow waves and tidal currents well, but its dimensions are not constant and its strength is weak. There was a problem of corrosion, and it was difficult to increase the size and use for a long time. Therefore, this kind of ikes frame can be used for coastal aquaculture, but it has been difficult to use it for offshore aquaculture.

[0005] In addition, as an Ikes frame made of an iron material to which a float is attached, a large one having a square shape with a side of 20 m, a circular shape having a diameter of 40 m or a polygonal shape is provided. The iron ikes frame has a problem of corrosion (rust) due to seawater and is heavy, so it is necessary to attach a large float. In addition, when the iron material itself is rigid and has a small elastic deformation area and a large IKES frame, the entire IKES frame cannot follow the waves and tides, and the stress due to the repetition acts on the iron material, resulting in long-term strength. There is a problem that it cannot be used. Therefore, to prevent deformation,
It is necessary to use a large member with sufficient strength, but in this case, it is necessary to make the float larger, so that this type of iron ikes frame can also be used for coastal culture with gentle waves However, its use for offshore aquaculture was problematic.

In the offshore aquaculture frame described above, a frame body composed of a plurality of elastic cylindrical hoses connected by a joint (Japanese Patent Application Laid-Open No. 60-34121) has been proposed to improve the wave following property particularly required. (Japanese Patent Application Laid-Open No. Sho 62-1716)
No. 27) has been proposed.

[0007]

With the IKES frame having the above-described structure, it is possible to secure so-called wave followability, which is not against waves or the like. However, these IKES frames are made of a reinforced elastic body such as an elastic cylindrical hose. Since it is used for the body, the shape of the frame is not a rigid structure, and there is a disadvantage that the shape of the frame is easily deformed due to the strength of the reinforcing elastic body, particularly, the bending rigidity. Usually, the elastic modulus E of the elastic body reinforced with synthetic fibers is 2-3 kg / m.
m ^2, it is only about 5 kg / mm ² even if the elastic modulus is large. In contrast, the elastic modulus of iron is 20,000 kg / mm ²
It is.

As described above, since the elastic body frame has a small elastic coefficient, the planar shape is likely to be deformed. Therefore, in order to reduce the shape deformation and enhance the shape holding ability even as a frame, the sectional shape is increased, the value of the shape factor (second moment of area) I is increased, and the value of the bending rigidity E × I is increased. Need to be increased. However, the moment of inertia I is a value that depends on the cross-sectional shape, i.e., a solid round bar in the diameter d, an I = πd ^4/64, the inner diameter d _1, a hollow pipe having an outer diameter d ₂ is ^{_{I = π (d 2 4 -d}} 1 4) is / 64. Therefore, when an attempt is made to increase the value of the second moment of area, there are disadvantages such as an increase in the sectional shape, an increase in size and an increase in cost.

The present invention has been made in view of the above-mentioned problems, and has a large shape holding ability for maintaining a planar shape required as an IKES frame, that is, a large value of bending rigidity E × I, and
By having the ability to follow waves and the strength against waves (elongation at break), it has excellent performance in terms of wave resistance and tidal current.In addition, it is lightweight for floating on seawater and has seawater corrosion resistance. However, the aim is to provide a cheap frame material that is inexpensive. The performance required for the above-mentioned IKES frame is the performance naturally required for other marine structural materials floating on the sea surface. It will not be provided.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a structural material constituting an IKES frame or the like is made of an elastic rubber composition in order to improve the ability to follow waves, and the rubber composition itself is The elastic modulus is dramatically increased compared to ordinary rubber products, and by giving a particularly large strength in the direction in which waves mainly act to give anisotropy in strength, An object of the present invention is to provide a marine structural material having a planar shape retaining ability against waves without increasing the value of the moment I, increasing the bending stiffness E × I, and increasing the sectional shape.

That is, according to the present invention, a rubber composition containing a metal salt of an α, β-unsaturated fatty acid is kneaded by applying a shearing force in a certain direction and vulcanized in a state where the strength is oriented in one direction. An object of the present invention is to provide a marine structural material characterized in that it is formed into a required shape by molding and has a configuration in which strength in a required direction is higher than in other directions.

The rubber composition comprises (a) 100 parts by weight of a base rubber, (b) 10 to 70 parts by weight of an α, β-unsaturated fatty acid,
(c) Metal oxides, hydroxides or carbonates 10 to 70
Parts by weight, (d) 0.5 to 5.0 parts by weight of an organic peroxide.

As the base rubber (a), rubber components conventionally used in rubber compositions can be used.
For example, isoprene rubber, natural rubber, butadiene rubber,
Styrene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubber, ethylene propylene rubber, chloroprene rubber, butyl rubber, urethane rubber, acrylic rubber, silicone rubber, and the like are included. One or more of these may be used. A particularly preferred rubber substrate is cis-1,4-polybutadiene, especially one having a cis structure of 90% or more, or a blend thereof. The reason is that the cis structure is 9
If the content is 0% or more, graft polymerization is likely to occur, crosslinking proceeds, the number of bonding points of the rubber component increases, and both the elastic modulus and the strength of the rubber are improved.

As the α, β-unsaturated fatty acid of the above (b), an α, β-monoethylenically unsaturated carboxylic acid having 3 to 8 carbon atoms is preferable. Examples thereof include methacrylic acid, acrylic acid, itaconic acid, crotonic acid and the like, and one or more of these are used. The amount of the α, β-unsaturated fatty acid is 10 to 10 parts by weight of the base rubber.
70 parts by weight, preferably 20 to 50 parts by weight. The reason for the limitation is that if the amount is less than 10 parts by weight, sufficient strength cannot be obtained, and if the amount exceeds 70 parts by weight, the composition becomes hard,
This is because workability is deteriorated and moldability is also deteriorated.

The metal oxides, hydroxides or carbonates of the above (c) (hereinafter abbreviated as metal oxides) include the α, β-diamines of the above (b) when kneading the rubber composition. It forms a metal salt of a saturated fatty acid, which is a co-crosslinking agent for rubber. The metal species is a divalent metal, preferably zinc or magnesium. When zinc and magnesium are used, graft polymerization is promoted, and the elastic modulus and strength of rubber are improved. Note that other metals, for example, sodium, lithium, aluminum, and the like may be used. The amount of the metal oxide is 10 to 70 parts by weight based on 100 parts by weight of the base rubber.
Parts by weight, preferably 20 to 50 parts by weight, for the same reasons as in (b) above.

The fatty acid of (b) and the metal oxide of (c) may be used instead of or in combination with the rubber composition to form a metal salt composed of the fatty acid and the metal oxide in advance. This may be blended with the rubber composition. α, β
The amount of the metal salt of unsaturated fatty acid is (a) the base rubber 10
20 to 100 parts by weight, preferably 4 parts by weight, per 0 parts by weight
0 to 80 parts by weight.

The organic peroxide of the above (d) includes perbenzoic acid, benzoyl peroxide, cumene peroxide, dicumyl peroxide, 1-1-bis-t-butylperoxy 3,3,5-trioxy. -Methylcyclohexane, di-t-butyl peroxide, di-t-butylperoxy-m-diisopropylbenzene, 2,5-dimethyl-2,5-di-
T-butyl peroxyhexane or the like is used. Preferably, it is dicumyl peroxide. The amount of the organic peroxide is 0.5 to 5.0 per 100 parts by weight of the base rubber.
Parts by weight, preferably 0.5 to 3.0 parts by weight. The reason for the limitation is that if the amount is less than 0.5 part by weight, crosslinking of the α, β-unsaturated fatty acid hardly occurs, and if it exceeds 5.0 parts by weight, the molded product becomes brittle and impractical.

The rubber composition is kneaded by applying a shearing force in a certain direction to orient the strength in one direction, and vulcanizing the rubber composition as it is in a mold in this state. Has anisotropic strength. In the rubber composition containing the metal salt of the α, β-unsaturated fatty acid, α, β
-When the crystal of the metal salt of the unsaturated fatty acid is kneaded by applying a shear force to the rubber composition in a certain direction, the crystal is largely oriented in the direction of the grain of the rubber, and the shear force is applied in the certain direction. When the kneaded rubber composition is vulcanized in a mold as it is, the rubber composition has an extremely strong strength in the direction of the grain of the rubber, and a strength different from that of the rubber composition, particularly, the strength in the vertical direction is not so high. The body is obtained as described in Japanese Patent Application No. 2-106713 filed earlier by the present applicant.

By using the rubber molded body having the above-described strength anisotropy, if the direction of the strong strength is set to the direction in which the tensile force acts, the bending rigidity is high and the shape holding force can be sufficiently provided. I can do it. Therefore, for example, a long frame to be floated on the sea surface of the Ikes frame is formed from the rubber molded body, the orientation direction of the strength is set in the axial direction, and the elastic modulus in the axial direction is the elastic modulus in the direction perpendicular to the axis. By giving anisotropy to the strength so as to be higher, it is possible to reduce deformation of the frame by waves, mainly acting horizontally on the frame and applying tensile force in the axial direction, The IKES frame has excellent wave and tide resistance.

[0020]

The marine structural material obtained by vulcanizing and molding the rubber composition used in the present invention is excellent in wave followability due to elasticity, and has shape retaining power due to high bending rigidity. In addition, since the strength in the direction in which deformation due to waves is likely to occur is increased, the shape holding force can be further increased. Therefore, when the cross-sectional shape is designed to obtain the same bending rigidity, the cross-sectional shape of the rubber molded product of the present invention can be extremely reduced as compared with a normal rubber molded product.

Furthermore, it has a high elongation at break, is hard to break even when strain occurs, and is a rubber molded article, so it is lightweight and has no problem of corrosion by seawater.
Easy molding and high degree of freedom in shape design.

[0022]

The present invention will be described below in detail with reference to examples. This embodiment relates to an Ikes frame, which is a kind of marine structural material. As shown in FIGS. 1 and 2, the shape of the IKES frame 1 itself is the same as the conventional one and is the most basic shape. That is, a long (10 m in this embodiment) frame 2 made of a solid rod having a circular cross section is provided, two of these frames 2 are horizontally arranged as respective sides of a square frame, and four corners are formed. It is fastened with a connecting tool 3 made of wire or the like to form a square frame having a square planar shape. In addition, while suspending the float 4 at a required interval on each side of the square frame formed by these two frames 2,
A bottomed net 5 is provided vertically. Further, mooring lines 6 are connected to required places.

The structure of the frame of the IKES frame is not limited to the above-described structure. For example, L-shaped joints are provided at four corners, and flanges are provided at the joint ends of the joint and the round bar-shaped frame 2, respectively. It may be formed and fastened by fasteners. At this time, as a material of the joint, it may be formed of a rubber molded body of the same material as the frame 2 having the following configuration, or may be formed of another elastic body having more flexibility. . Further, the frame body may have a hollow pipe shape.

The frame 2 is made of a base rubber as described above.
(a) is mixed with α, β-unsaturated fatty acid (b), metal oxide (c), and organic peroxide (d) at the required weight ratio described above, and the mixture is kneaded by applying a shear force in a certain direction. In a state where the crystals of the metal salt of α, β-unsaturated fatty acid are oriented in one direction of the grain direction of the rubber, the crystals are placed in a mold so that the orientation direction is the axial direction of the frame. It is formed by vulcanization molding.

In this embodiment, the base rubber (a) is cis-
Natural rubber (NR) and ethylene propylene rubber (EPD) having excellent weather resistance are added to 1,4-polybutadiene rubber (BR).
M) is used. Α, β-
As the unsaturated fatty acid (b), basic zinc methacrylate (MA
A), zinc white (ZnO) is used as the metal oxide (c), and dicumyl peroxide (DCP) is used as the organic peroxide (d).

In this embodiment, as shown in Table 1 below,
Two types of examples, A type and B type, were provided, and the normal physical properties of these A type and B type were measured.

[0027]

[Table 1]

In Table 1, the physical property test was conducted according to JIS K63.
01 and K7055. Retsuri: Properties vertical roll direction (the axial direction of the frame): the roll direction perpendicular physical properties M _10: 10% Modulus (MPa) TR: tear strength (KN / m) T _B: tensile strength (MPa) E: Flexural modulus (kg / mm ² ) E _B : Elongation at break (%)

The shape holding ability of the ikes frame depends on the size of the ikes frame.
The flexural rigidity value E × I is preferably 0.003 Ton-m ² or more, and the higher the EI value, the better. In the 10 m frame made of the rubber molded body according to the present invention, the elastic modulus E is as high as about 40 to 50 kg / mm ^{2 in the} grain direction, so that the value of the second moment of area I is not increased, that is, The required bending stiffness value can be obtained without increasing the cross-sectional area. In the case of normal rubber, E = 0.01
０0.5 kg / mm ² = (0.01 to 0.5) × 10 ⁶ kg / m ² .

Therefore, E = 0.01 kg / mm ² with ordinary rubber
In order to secure the above-mentioned EI = 3 kg / m ² using a solid round bar, the secondary moment of area I is I = E · I / I = 3 / (0.01 × 10 ⁶ ) = 0.0003m
^{From 2} πd ⁴ /64=0.0003, d = 0.280 m,
A solid round bar with a diameter of 28 cm is required. In contrast, the rubber molded article of the present invention is E = 40~50kg / mm ^2, if the use of solid round bar in the E = 40kg / mm ^2, in the same manner as described above calculations, d = 0 0.0352 m, which satisfies the condition with a solid round bar of 3.5 cm in diameter.

When a solid round bar having a diameter of 5 cm is used in the rubber molded article of the present invention in consideration of workability and rubber workability in actual specifications, E · I = 40 × 10 ⁶ × π × ( 0.05) ⁴ ÷ 64 = 0.01
It is ² Ton-m ² , and sufficient bending rigidity can be obtained as an Ikes frame having a side of 10 m. Similarly, 10cm in diameter
In the case of a solid round bar, E · I = 0.196 Ton-m ² , and it is possible to cope with a larger ikes frame.

In the IKES frame according to the above-described embodiment of the present invention, as shown in FIG. 3, the IKES frame 2 floating on the sea is deformed by the waves in the vertical direction so that the waves X in the horizontal direction are deformed.
Therefore, there is a problem that a long ikesu frame is deformed. When receiving this transverse wave, the long frame body receives a tensile force in the axial direction, and tends to be distorted in the axial direction. When this distortion occurs, it becomes impossible to maintain the planar shape consisting of the square frame shape, and when deformed in a direction approaching each other and the area within the square frame is reduced, the volume accommodating the cultured fish decreases, Fish can be damaged or killed by lack of oxygen.

In order to solve the above-mentioned problem, since the Ikes frame made of the rubber molded article of the present invention has a particularly high strength in the axial direction and a high elastic modulus, the shape retention ability is high, and deformation due to transverse waves is prevented or reduced. And is excellent in wave resistance and tide resistance.

Further, the deformation due to the waves is reduced as described above. However, since the deformation of the frame of the IKES frame is several percent, the breaking elongation of the frame is 1 in consideration of durability.
0% or more is necessary. Also in this respect, the frame made of the rubber molded article of the present invention has a breaking elongation of 10 to 100%.

Table 2 below shows a comparison between the rubber molded article according to the present invention and other materials for important properties as an IKES frame together with the elastic modulus and elongation at break described above.

[0036]

[Table 2]

In Table 2, the elastic modulus E is JIS.
It measured according to K-7055. In Table 2, ◎ indicates good, Δ indicates normal, and × indicates bad. This Table 2
As is clear, among the materials having a breaking elongation of 10% or more and having good wave followability, the product of the present invention has the most elastic modulus E.
And it is favorable in terms of other rust, shape selection (ease of processing, etc.) and price. Therefore, it is proved that it is the best material for IKES frame.

In the above embodiment, the rubber molded body of the present invention is formed as a frame of an IKES frame. However, deformation due to waves is a problem, and the above seawater corrosion resistance and the like are required. A marine structure, for example, a floating pier structure, a breakwater net, a structure to be installed floating on the sea surface such as a sea surface division fence, and a sea surface floating body such as a surf boat are formed of the rubber molded body. Is preferred.

[0039]

As is apparent from the above description, the rubber molded article according to the present invention has a high bending rigidity, has a sufficient shape holding force, has a high elongation at break, and can sufficiently deform to follow waves. In addition, since it is lightweight, and excellent in seawater corrosion resistance, weather resistance, and durability, it can satisfy all the characteristics required for a marine structure such as an Ikes frame.

In particular, since the rubber molded article of the present invention has anisotropy in strength, the strength in the direction in which the repeated stress due to waves acts, particularly the elastic modulus, is increased from the other directions, so that the shape retaining force is increased. Can be further improved. Further, the rubber molded body is inexpensive compared to other materials and is easy to process, so that the rubber molded body can be inexpensively and easily used as a marine structure.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an IKES frame according to the present invention.

FIG. 2 is a schematic perspective view of the IKES frame.

FIG. 3 is a view showing a direction in which waves act on a frame of the ikes frame.

[Explanation of symbols]

 1 Ikes frame 2 Frame

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akihiro Nakahara 1-15-22 Ota, Ibaraki City, Osaka Prefecture (72) Inventor Makoto Sakuraoka 4-9-5 Minami Tamondai, Tarumi-ku, Kobe City, Hyogo Prefecture (56) Reference Document JP-A-3-259026 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A01K 63/00

Claims (2)

(57) [Claims] 1. A rubber composition containing a metal salt of an α, β-unsaturated fatty acid is kneaded by applying shearing force in a certain direction.
Vulcanization molding with the strength oriented in the desired direction and the required shape
Formed and has stronger strength in the required direction than other directions
A marine structural material characterized in that it has a configuration in which it is arranged . 2. A long frame formed by the vulcanization molding.
Forming an Ikes frame, the orientation direction of the elastic coefficient in one direction
Of the Ikes frame floating on the sea surface with
The elastic modulus in the axial direction is calculated from the elastic modulus in the direction perpendicular to the axis (vertical direction).
Wave resistance with anisotropic elastic modulus
2. The structural material for marine use according to claim 1, wherein the structural material comprises a sex ikes frame .