JP7232688B2 - Prop for seaweed culture and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a prop for laver culture and a method for producing the same.

In seaweed farming, bamboo is used as a pillar in the sea and placed at equal intervals. In recent years, due to the difficulty in obtaining bamboo, uneven thickness and length, and durability issues, fiber-reinforced synthetic resin (hereinafter referred to as "FRP") that can be made uniform in thickness. steel stanchions are now used.

As a method for manufacturing FRP props for seaweed cultivation, reinforcing fibers are impregnated with an uncured thermosetting resin composition, and continuously cured while being drawn into a pipe shape with a heated annular mold. , a so-called pultrusion method (1), or a long mandrel with an outer diameter corresponding to the inner diameter of a pipe, and a reinforcing fiber impregnated with an uncured thermosetting resin composition while traversing a predetermined A method (2) is known in which a pipe layer is formed by winding at a winding angle of 100 mm and hardened to form a pipe-shaped support.
Furthermore, there has been proposed an FRP column having a fiber reinforced resin layer formed by winding and laminating a sheet-like fiber reinforced resin material using an epoxy resin as a synthetic resin for the reinforcing fiber on a mandrel for forming the column. (See Patent Document 1, for example).

However, in the aforementioned pultrusion molding method (1) using a mold, a high pull-out force is required to pull the hardened or semi-hardened FRP post out of the mold due to the presence of frictional resistance with the mold. The size of the equipment is increased, which inevitably leads to increases in energy consumption and equipment costs.
On the other hand, in the method for manufacturing an FRP column described in Patent Document 1, a sheet-like fiber reinforced resin material is wound and laminated on a mandrel for forming the column. The maximum length is about 6m. However, the seaweed farming grounds have a depth of about 12 m, and this cannot be used as a manufacturing method for continuously obtaining long pillars.

In addition, the FRP support for seaweed farming prevents part of the FRP layer from peeling off during handling and piercing fingers and injuring the user. It is preferable that the outer surface of the FRP layer is coated with a thermoplastic resin or the like for the purpose of preventing decomposition and weathering deterioration of the FRP layer. In addition, it is desirable that the inner surface of the FRP layer is also coated from the viewpoint of preventing hydrolysis of the FRP layer when standing in seawater for use.
The applicant of the present invention has a core layer made of a thermoplastic resin, an FRP layer in which long fiber-like glass fibers are bound with a matrix resin on the outer periphery, and a thermoplastic resin coating layer on the outer periphery of the FRP layer. Equipped with a three-layer structure of thermoplastic resin core layer / FRP layer / thermoplastic resin coating layer, FRP posts with an outer diameter of 35 to 57 mm are used as a product name: "Compose, registered trademark" for seaweed farming Marketed as a prop, it is highly valued by seaweed farmers for practical use due to its ease of handling, durability, and advantages over bamboo.

JP-A-2007-259838

However, the following problems are raised even with the three-layer structure FRP prop for seaweed cultivation.
(i) Since the installation of the props for cultivating seaweed is carried out manually, heavy weight makes the work difficult.
(ii) When grasping a pole for seaweed cultivation by hand, if it is thick, it is difficult to grasp and work. easier.
(iii) Equipment such as aquaculture poles is usually transported to the farm by boat, but if the poles are bulky, the frequency of transportation will increase and the work will take more time.
(iv) Carbon fiber may be used as the FRP material to solve the above problems, but if the FRP column is made only of carbon fiber, the cost will be very high and the practicality will be poor.

Therefore, the present inventors have made intensive studies on FRP seaweed aquaculture posts that are easy to handle manually, can achieve both light weight and high rigidity, are relatively inexpensive and highly practical, and have found the present invention. Completed.

That is, the present invention provides the following inventions [1] to [4].
[1] Seaweed farming with a composite structure that includes a core layer made of a thermoplastic resin, an FRP layer formed on the outer periphery of the core layer, and a coating layer formed on the outer periphery of the FRP layer. at least the outer peripheral surface of the core layer is made of a thermoplastic resin having a chemical affinity with a thermosetting resin that is a matrix component constituting the FRP layer, and the FRP layer is Reinforcing fibers of long fibers containing at least glass fibers and carbon fibers are vertically attached to the outer circumference of the core layer in the longitudinal direction, and the carbon fibers are arranged on the outer circumference side of the FRP layer. The cross-sectional area ratio of the glass fiber to the carbon fiber in the cross section is 60:40 to 95:5, and the coating layer has at least the inner peripheral surface of a thermosetting resin that is a matrix component constituting the FRP layer. A prop for seaweed cultivation, characterized by being composed of a thermoplastic resin having chemical affinity.
[2] The prop for seaweed cultivation according to [1], wherein the cross-sectional area ratio of the glass fiber to the carbon fiber in the FRP layer is 80:20 to 95:5.
[3] The cross-sectional area ratio of the glass fiber and the carbon fiber in the FRP layer is 90:10 to 95:5, and in the cross section orthogonal to the longitudinal direction of the FRP layer, the carbon fiber bundle is the outer periphery of the FRP layer. The props for laver cultivation according to the above [1], which are arranged on the surface side at substantially the same center angle.
[4] The method for producing a prop for laver cultivation according to any one of [1] to [3], which comprises the following steps (i) to (vii).
(i) Prepare a required number of glass fiber bundles and carbon fiber bundles as long-fiber-like reinforcing fibers, insert each of the glass fiber bundles and carbon fiber bundles into predetermined guide holes of a gathering guide, and further insert them into A step of preparing the reinforcing fiber bundle so that it can be taken through the impregnation operation guide of the impregnation tank arranged in parallel, the drawing die for longitudinally attaching to the outer periphery of the core layer in a predetermined arrangement, the extruder for the coating layer and the production line,
(ii) injecting a liquid curable resin composition containing a thermosetting resin and a thermosetting agent into the impregnation layer;
(iii) a core layer manufacturing step of continuously extruding a thermoplastic resin forming the core layer from a melt extruder into a circular tube shape of a predetermined size and continuously taking it through a production line;
(iv) While taking out the reinforcing fiber bundle prepared in (i) above, the impregnation operation guide is lowered into the impregnation tank to impregnate the reinforcing fiber bundle with the curable resin composition, and the curable resin composition is impregnated into the hole of the drawing die. A step of vertically attaching to the outer periphery of the core layer running in the center of the, and gradually squeezing the excess resin with a drawing die to form an uncured tubular product in which the reinforcing fiber bundle is vertically attached to the core layer;
(v) a melt-coating step of passing the uncured tubular article through the crosshead of a melt extruder to circularly extrusion-coat it with a thermoplastic resin for a coating layer, and cooling the coating layer;
(vi) a step of introducing the coated uncured tubular article into a curing bath to thermally cure the uncured thermosetting resin composition inside, and taking out the tubular article having a composite structure that is adhered and integrated;
(vii) A step of cutting the collected tubular object into a predetermined length as a prop for laver cultivation.

The post for seaweed cultivation of the present invention can be made more rigid and lighter than the conventional FRP layer composed only of glass fiber with the same outer diameter. Further, if it is desired to achieve the same level of rigidity as the conventional one, the outer diameter can be made smaller, and the reduction in weight and the improvement in handleability due to the smaller diameter can be achieved.
In addition, the method for manufacturing the laver aquaculture prop of the present invention provides the laver aquaculture prop of the present invention, which is excellent in manual handling, can achieve both light weight and high rigidity, is relatively inexpensive, and is highly practical. It can be produced stably and economically with good reproducibility.

FIG. 4 is a schematic cross-sectional view of a prop for laver cultivation according to Example 4 of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory diagram of an example of a production line used in the method for producing a prop for laver culture according to the present invention;

Preferred embodiments of the present invention are described below. It should be noted that each embodiment shown in the accompanying drawings is a drawing for explaining an example of a representative embodiment related to the present invention, and the dimensions and the like are not adapted to the actuality, and the present invention is not based on these drawings. should not be interpreted narrowly.

The post for laver cultivation of the present invention has a core layer made of a thermoplastic resin, an FRP layer formed on the outer periphery of the core layer, and a coating layer formed on the outer periphery of the FRP layer. The core layer is composed of a thermoplastic resin having a chemical affinity with a thermosetting resin, which is a matrix component constituting the FRP layer, at least on the outer peripheral surface of the core layer. In the FRP layer, long fiber reinforcing fibers containing at least glass fiber and carbon fiber are vertically attached to the outer circumference of the core layer in the longitudinal direction, and the carbon fiber is arranged on the outer circumference side of the FRP layer. and the cross-sectional area ratio of the glass fiber to the carbon fiber in the cross section of the FRP layer is 60:40 to 95:5, and the coating layer is a matrix component that constitutes the FRP layer at least on the inner peripheral surface. It is characterized by being composed of a thermoplastic resin having chemical affinity with a thermosetting resin.

As shown in FIG. 1, an example of a layer structure of a laver culture prop 10 of the present invention in a cross section perpendicular to the longitudinal direction is composed of a core layer 1 made of a thermoplastic resin and glass fibers 2a having a predetermined cross-sectional area ratio as reinforcing fibers. and carbon fibers 2b bound together with a cured thermosetting resin 2c as a matrix component, and a coating layer 3 made of a thermoplastic resin formed on the outer periphery of the FRP layer 2.
The prop 10 for laver cultivation of the present invention supports a laver net and has an outer diameter of approximately 35 mm to 60 mm from the rigidity required to withstand waves when used standing in the sea. The main part to be erected on the seabed is the one with a diameter. There is a conical tip at the tip of the seabed side, and on the sea surface side, through a joint, an antenna with an outer diameter of 10 to 20 mm and a length of 1 to 2.0 m is used to hold the net rope at high tide. to ensure that the tip is connected. The present invention is an invention relating to the main body of the above-mentioned nori aquaculture support, and the length thereof is approximately 4 to 15 m in consideration of the sea depth of the fishing ground.

(Thermoplastic resin of core layer)
In connection with the manufacturing method of the prop for laver cultivation of the present invention, the core layer is manufactured by melt extruding a thermoplastic resin. At least the outer peripheral surface of the core layer is required to adhere (adhere) to the interface of the innermost layer of the FRP layer due to chemical affinity. Therefore, the thermoplastic resin used for the core layer is selected from thermoplastic resins having chemical affinity with the thermosetting resin, which is the matrix component constituting the FRP layer, such as ABS (acrylonitrile-butadiene-styrene resin). , AES (acrylonitrile/ethylene propylene rubber/styrene resin), AS (acrylonitrile-styrene resin), AAS (acrylonitrile-acrylic-styrene resin), PS (polystyrene resin), PC (polycarbonate resin), PPE (modified polyphenylene ether resin; graft copolymers of polyphenylene and polystyrene), polyvinyl chloride resins, and the like.
The core layer has an inner diameter of approximately 30.5 to 50.5 mm and a layer thickness of approximately 1.5 to 3.0 mm. At least the outer peripheral surface of the core layer needs to have chemical affinity with the thermosetting resin, which is the matrix component of the FRP layer. It may be formed by extruding multiple layers of a resin, a thermoplastic resin copolymer modified to improve adhesiveness, or the like.

[FRP layer]
In the FRP layer of the prop for seaweed cultivation of the present invention, long fiber reinforcing fibers containing at least glass fiber and carbon fiber are longitudinally attached to the outer circumference of the core layer in the longitudinal direction by a matrix component, and the carbon fiber is They are arranged on the outer peripheral side of the FRP layer, and the cross-sectional area ratio of the glass fiber and the carbon fiber in the cross section of the FRP layer is 60:40 to 95:5.
In connection with the manufacturing method of the prop for laver cultivation of the present invention, the FRP layer is first assembled in a predetermined cross-sectional area ratio as (iv) reinforcing fibers on the outer periphery of the core layer that is continuously extruded. Long glass fiber bundles and carbon fiber bundles are impregnated with a curable resin composition and vertically attached, excess resin is gradually squeezed with a squeezing die, and the reinforcing fiber is vertically attached to the core layer. After the step of forming a cured tubular product, the next step is performed.
(v) passing the uncured tubular material through the crosshead of a melt extruder to circularly extrusion-coat it with a thermoplastic resin for a coating layer; (vi) introducing the coated uncured tubular article into a curing bath to heat-cure the uncured thermosetting resin composition inside, and taking out the tubular article having a composite structure that is adhered and integrated; be.

(Cross-sectional area ratio in reinforcing fiber and FRP layer)
The reinforcing fibers that can be used in the present invention can be used in the form of fiber bundles in which 1,000 to 50,000 single reinforcing fibers having an average diameter of 5 to 10 μm are bundled. The reinforcing fibers preferably have a specific strength of 1,000 kN·m/kg or more and a specific elastic modulus of 20,000 kN·m/kg or more.
At least glass fiber and carbon fiber are used in combination for the long-fiber reinforcing fiber used in the FRP layer of the prop for laver cultivation of the present invention. The cross-sectional area ratio of the glass fiber to the carbon fiber in the cross section of the FRP layer in the longitudinal direction of the prop for laver culture is 60:40 to 95:5, more preferably 80:20 to 95:5, and even more preferably. , 90:10 to 95:5. If the cross-sectional area ratio of glass fiber and carbon fiber in the cross section of the FRP layer is 60:40, that is, if the area ratio of carbon fiber is 40% or less, the cost of raw materials due to carbon fiber can be increased. , It is possible to provide a prop for laver cultivation that can express the effect of improving workability, and if 95: 5, that is, if the carbon fiber is 5% or more in terms of area ratio, the carbon fiber has high rigidity, lightness, and workability. An improvement effect can be expressed.
If the cross-sectional area ratio of glass fiber to carbon fiber in the cross section of the FRP layer is 80:20 to 95:5, it is possible to provide a less expensive prop for seaweed cultivation.
The cross-sectional area ratio of the reinforcing fibers in the cross section of the FRP layer can be obtained by calculating the cross-sectional areas of the glass fibers and carbon fibers used in the FRP layer from the number of fibers used, fineness, and density.

Furthermore, in order to maximize the effect of the added carbon fiber and reduce the amount of carbon fiber used, the cross-sectional area ratio of the glass fiber and the carbon fiber in the FRP layer is 90: 10 to 95: 5. In some cases, satisfying the following two requirements can provide a more suitable one.
(A) The carbon fibers (bundles) are arranged on the outer peripheral side of the glass fibers in the FRP layer.
(B) The carbon fibers (bundles) are arranged symmetrically with substantially the same center angle θ on the outer peripheral side of the FRP layer with respect to the center of the support.
When the carbon fibers (bundles) are arranged on the outer peripheral side of the FRP layer, and the carbon fibers are arranged symmetrically with substantially the same central angle θ with respect to the center of the support, the carbon fibers with a high elastic modulus are arranged on the outer peripheral side. Therefore, when the column is bent in the longitudinal direction, the carbon fibers (bundles) farther from the neutral axis resist bending, so a column with high rigidity can be obtained.
In addition, when the carbon fibers (bundles) are arranged symmetrically with substantially the same central angle θ on the outer peripheral side of the FRP layer with respect to the center of the support, the carbon fibers (bundles) are evenly arranged in the cross section in the longitudinal direction. Therefore, the practically necessary degree of straightness and straightness recovery can be maintained without causing the adverse effects of the struts becoming eccentric in the longitudinal direction and causing anisotropy during use.
From the viewpoints of reducing the carbon fiber amount and maintaining strength, the carbon fiber bundle preferably has an oblateness of 0.33 to 0.83 and an aspect ratio of 3:2 to 6:1.

Examples of the glass fiber that can be used as the reinforcing fiber of the FRP layer of the laver culture prop of the present invention include E glass fiber (for electricity), C glass fiber (for corrosion resistance), S glass fiber, and T glass fiber. . As for the form of fibers, glass rovings in which glass fibers (filaments) are bundled are suitable for use in the FRP layer. Glass fibers that can be used include, for example, Nitto Boseki Co., Ltd. product names: RS110QL-533AH, RS220RL-510AH, RS440RR-531AH, and Central Glass Co., Ltd. product names: ERS2200-820/LX, ERS4400-820/LX, Chongqing. International Composite Materials Co., Ltd. (CPIC) product names: ER469-4400, ER469-2200; .

Examples of the carbon fiber that can be used as the reinforcing fiber of the FRP layer of the laver culture prop of the present invention include PAN-based carbon fiber made from polyacrylonitrile (PAN) fiber, and pitch-based carbon made from petroleum tar or petroleum pitch. Examples include fibers, cellulose-based carbon fibers made from viscose rayon, cellulose acetate, etc., vapor-grown carbon fibers made from hydrocarbons, graphitized fibers thereof, and the like. Among these carbon fibers, PAN-based carbon fibers are preferably used because they have an excellent balance between strength and elastic modulus. Examples of commercially available carbon fibers that can be used include TRW40 50L 3750tex manufactured by Mitsubishi Chemical Corporation and PX35 (50K) manufactured by Zoltek Companies, Inc.

(matrix component)
The matrix component of the FRP layer of the prop for seaweed cultivation of the present invention is formed by curing a thermosetting resin composition. Examples of thermosetting resins include unsaturated polyester resins, unsaturated carboxylic acid-modified vinyl ester resins, and epoxy resins.
Among these resins, unsaturated polyester resins are preferably used from the viewpoints of thermosetting, versatility, economy, and the like.
In addition, the unsaturated polyester resin contains styrene as a monomer component and can be selected from those having chemical affinity for the thermoplastic resin of the core layer and the coating layer, and after thermosetting, these three layers are tightly integrated. You can also use things.
Thermosetting resin is a thermosetting resin that is added and mixed with a thermosetting catalyst (curing agent), calcium carbonate for adjusting viscosity, and, if necessary, a thixotropic agent such as Aerosil (trade name), which is ultrafine silica particles. It is prepared as a composition, impregnated into reinforcing fibers, and finally heat-cured to form a matrix component.

(coating layer)
In the coating layer of the prop for laver cultivation of the present invention, the thermoplastic resin constituting at least the inner peripheral surface of the coating layer is selected from thermoplastic resins containing styrene as a component, and the thermosetting resin constituting the matrix component of the FRP layer. By contacting the uncured resin with the unsaturated polyester resin containing styrene monomer as a monomer component, the FRP layer/coating layer are bonded and integrated with each other after curing of the thermosetting resin due to chemical affinity. It can also be configured as follows.

[Manufacturing method of prop for seaweed cultivation]
The method for producing a prop for laver culture according to the present invention is characterized by including the following steps (i) to (vii). Each step will be described below in order.

(i) Reinforcing fiber preparation process As shown in FIG. 2, prepare a required number of glass fiber bundles 2a and carbon fiber bundles 2b as fibrous reinforcing fibers, and consider the arrangement in the FRP layer. When arranging carbon fibers, two impregnation tanks 14 and 16 are prepared, and glass fiber bundles and carbon fiber bundles are respectively inserted into predetermined guide holes (not shown) of the respective assembly guides (batches) (not shown). are arranged in parallel to guide the impregnation operation of the impregnation tank (not shown), and are vertically attached to the outer periphery of the core layer 1 in a predetermined arrangement during steady running to squeeze out excess thermosetting resin. It is a step of preparing for take-up through a drawing die, a coating layer extruder, and a subsequent (downstream) production line. In addition, at the stage of this reinforcing fiber preparation process, extrusion of the core layer, resin impregnation of the reinforcing fiber bundle in the thermosetting resin impregnation tank, draw molding, and coating with the coating extruder are not performed. This is a process that prepares the production line for the placement of reinforcing fibers during operation.

(ii) Step of preparing curable resin composition This is a step of injecting a liquid curable resin composition containing a thermosetting resin and a thermosetting agent into the impregnation tanks 14 and 16 . The thermosetting resin is selected from the above and used, and the thermosetting resin includes a predetermined amount of thermosetting catalyst (curing agent), calcium carbonate for viscosity adjustment, and if necessary, ultrafine silica particles. A thixotropic agent such as Aerosil (trade name) is added and stirred to form a thermosetting resin composition, which is then poured into impregnation tanks 14 and 16 . Stirring and mixing may be performed in advance, or after shifting to a steady production state, a predetermined amount of each substance constituting the thermosetting resin composition is weighed, and the thermosetting resin is mixed with a mixing device. You may pour into an impregnation tank continuously corresponding to the consumption of a composition.

(iii) Core layer manufacturing process Continuously extruding the thermoplastic resin forming the core layer 1 from the melt extruder 11 into a circular tube shape of a predetermined size while controlling the inner diameter with a mandrel or the outer diameter with a mold, The uncured resin composition impregnated into the reinforcing fibers of the long fibers is drawn to a predetermined outer diameter after the fact by the core layer manufacturing process that is continuously taken out through the manufacturing line, and can be coated by the coating extruder 18. It is a process to

(iv) Manufacturing process of uncured tubular part While taking out the reinforcing fibers prepared in the above (i), the impregnating operation guide (not shown) is lowered toward the impregnation tanks 14 and 16 to form a reinforcing fiber bundle. is impregnated with a curable resin composition, and this is vertically attached to the outer periphery of the core layer 1 running in the center of the hole of the drawing die 17, and excess resin is gradually drawn by the drawing die, and the core layer It is a step of forming an uncured tubular material 4 in which reinforcing fibers are longitudinally attached to.

(v) Melt coating of uncured tubular material and cooling step The uncured tubular material 4 is passed through the crosshead of a melt extruder 18 to be circularly extrusion-coated with a thermoplastic resin for a coating layer, and immediately The coating layer is cooled and solidified in the cooling tank 19 to obtain the uncured tubular article 5 with the coating layer, which is a melt-coating and cooling process.

(vi) Thermal curing of uncured thermosetting resin composition and take-up step The uncured tubular article 5 with the coating layer is introduced into a curing tank 20 to thermally cure the uncured thermosetting resin composition inside. Then, a tubular article (composite tubular article) 6 having a composite structure in which the three layers of the core layer 1, the FRP layer 2, and the covering layer 3 are tightly integrated is picked up by a rubber belt type or caterpillar type take-up machine (not shown) or the like. It is a process.

(vii) A step of cutting the composite tubular material to a predetermined length. disconnected.

(Other processes)
Since it is not the main part of the present invention, detailed description will be omitted. A cone-shaped tip member (not shown) for piercing, and a composite tubular object with a small diameter and a predetermined length is connected to the other end via a connecting member as a tip member (so-called "antenna") for laver cultivation. Serves as a prop. It is efficient to connect these members in a line that is continuous with the cutting process.

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The following description will also refer to the drawings.

Example 1
A composite pipe for the main body of a prop for laver culture was produced using the materials shown below.
[Material composition]
(Thermoplastic resin for core layer)
· ABS resin: manufactured by Toray Industries, Inc., Toyolac (registered trademark) 600-309N
(Thermosetting resin composition)
・Unsaturated polyester resin 100 parts by mass: U-Pica (registered trademark) 3464 manufactured by Japan U-Pica Co., Ltd.
・ 10 parts by mass of calcium carbonate: NS#200 manufactured by Nitto Funka Kogyo Co., Ltd.
・ Organic peroxide-1 4 parts by mass: Kayaku Akzo Co., Ltd., Kayaester (registered trademark) O-50E
・ Organic peroxide-2 1 part by mass: Trigonox (registered trademark) 117 manufactured by Kayaku Akzo Co., Ltd.
(reinforced fiber)
・ 168 glass fiber rovings: RS220RL-510AH (2200tex) manufactured by Nitto Boseki Co., Ltd.
・ 12 carbon fiber tows: PYROFIL (registered trademark), TRW40 50 manufactured by Mitsubishi Chemical Corporation
(Thermoplastic resin for coating)
· ABS resin: manufactured by Toray Industries, Inc., Toyolac (registered trademark) 600-309N, FB-1682 (black colored masterbatch)
(Preparation and preparation of uncured thermosetting resin)
As an uncured thermosetting resin composition to be impregnated into the reinforcing fibers constituting the FRP layer, predetermined amounts of the unsaturated polyester resin, the organic peroxide, and calcium carbonate as a filler are weighed, and a stirring device is added. was stirred and mixed in a mixing tank equipped with, and injected into the impregnation tanks 14 and 16.

As shown in FIG. 2, the ABS resin was continuously extruded as a core layer 1 from a core melt extruder 11 into a pipe having an outer diameter of 35.6 mm and an inner diameter of 31.8 mm.
A glass fiber roving 2a arranged on a creel 13 (detailed illustration is omitted) is bundled around the periphery thereof and impregnated with a thermosetting resin composition in an impregnation bath 14, so that the inner diameter is gradually increased to the outside of the FRP layer. It was led to a drawing die device 17 having a plurality of drawing dies converging to a diameter of 41.5 mm.
On the other hand, the carbon fibers are arranged on the outer peripheral side of the FRP layer by bundling the carbon fibers arranged on the creel 15 (detailed illustration is omitted) and impregnating them with the thermosetting resin composition in the impregnation tank 16. , from the drawing die on the downstream side of the drawing die device 17 (on the coating layer extruder side). In addition, in order to arrange 12 carbon fibers symmetrically with respect to the central axis in the longitudinal direction on the outer peripheral side in the cross section of the FRP layer, a grid plate (not shown) having a guide hole every 360/12 = 30 ° is introduced. Placed in front of the drawing die.
A layer formed of glass fibers 2a and a curable resin composition impregnated in the glass fiber 2a on the outer periphery of the core layer, carbon fibers arranged at a central angle of 30° on the outer periphery, and a curable resin composition impregnated in the carbon fiber. It is vertically joined and molded by a final drawing die to form an uncured tubular body 4 having an outer diameter of 41.5 mm. It was coated with the above ABS resin and immediately led to a cooling water tank 19 to obtain an uncured tubular article 5 with a coating layer.
Next, the uncured tubular article 5 with the coating layer is introduced into a thermosetting bath 20 using hot water as a heating medium to thermally cure the inner uncured FRP layer, and then cooled in a cooling water bath (not shown). A composite tubular article 6 having a layered structure was obtained and cut to a length of 10 m with a cutting device (not shown). The obtained strut (composite tubular article) had an outer diameter of 42.8 mm. Table 1 summarizes the glass fiber/carbon fiber cross-sectional area ratio, unit weight, flexural modulus, performance evaluation results, etc. of the obtained support.

Example 2
In Example 1, a core layer having an outer diameter of 37.6 mm and an inner diameter of 33.8 mm was extruded, and 96 glass fiber rovings and 26 carbon fiber tows were used. A 10 m long sample was obtained. The outer diameter was 42.8 mm.

Example 3
In Example 1, the same method as in Example 1 except that a core having an outer diameter of 41.0 mm and an inner diameter of 37.0 mm was extruded into a pipe shape, and 171 glass fiber rovings and 4 carbon fiber tows were used. obtained a sample with a length of 10 m. The outer diameter of the obtained strut was 46.2 mm.

Example 4
A sample having a length of 10 m was obtained in the same manner as in Example 3, except that 162 glass fiber rovings and 8 carbon fiber tows were used. The outer diameter was 46.2 mm.

Example 5
A sample having a length of 10 m was obtained in the same manner as in Example 3, except that 144 glass fiber rovings and 15 carbon fiber tows were used. The outer diameter was 46.2 mm.

Example 6
A sample having a length of 10 m was obtained in the same manner as in Example 3, except that 126 glass fiber rovings and 23 carbon fiber tows were used. The outer diameter was 46.2 mm.

Example 7
A sample with a length of 10 m was obtained in the same manner as in Example 3 except that the glass fiber roving was changed to 60 RS440RR-531AH (4400 tex) manufactured by Nitto Boseki Co., Ltd. and 46 carbon fiber tows. . The outer diameter was 46.2 mm.

Example 8
Example 1 except that the core layer of Example 1 having an outer diameter of 44.3 mm and an inner diameter of 41.0 mm was extruded into a pipe shape and replaced with glass fiber rovings, 82 RS440RR-531AH, and 18 carbon fiber tows. A sample with a length of 10 m was obtained by the same method as. The outer diameter of the obtained strut was 50.0 mm.

Comparative example 1
A sample with a length of 10 m was obtained in the same manner as in Example 2, except that the number of glass fiber rovings was changed to 150 and the carbon fiber tow was not used. The outer diameter was 42.8 mm.

Comparative example 2
In Example 1, 12 carbon fiber tows were prepared for the creel 13 and 166 glass fiber rovings were prepared for the creel 15, and the curable resin composition was impregnated into the rovings and the core layer was vertically attached in the longitudinal direction. A sample with a length of 10 m was obtained in the same manner as in Example 1, except that the procedure was reversed. The outer diameter was 42.8 mm.

Comparative example 3
A sample with a length of 10 m was obtained in the same manner as in Example 3 except that the number of glass fiber rovings was changed from 171 to 180 and the carbon fiber tow was not used. The outer diameter was 46.2 mm.

Comparative example 4
In Example 4, the same method as in Example 4 except that the carbon fibers were arranged at 60° on the semicircular side with respect to the central axis in the longitudinal direction, and the other semicircular side was asymmetric at 36°. obtained a sample with a length of 10 m. The outer diameter was 46.2 mm.

Comparative example 5
A sample with a length of 10 m was obtained in the same manner as in Example 3, except that the order of placing 171 glass fiber rovings and 4 carbon fiber tows in the core layer in the longitudinal direction was reversed. . The outer diameter was 46.2 mm.

Comparative example 6
Using the same ABS resin as in Example 1, a core layer was extruded into a pipe shape having an outer diameter of 44.3 mm and an inner diameter of 41.0 mm from a core extruder. 132 glass fiber rovings RS440RR-531AH impregnated with the same thermosetting resin composition as in Example 1 were attached to the outer periphery of the core layer in the longitudinal direction, excess resin was removed in the drawing process, and the outer diameter was 50.5 mm. It was used as an uncured product.
This was further melt-coated with the same ABS resin as in Example 1 using a coating extruder, and a sample with a length of 10 m was obtained in the same manner as in Example 1. The outer diameter of the obtained strut was 52.0 mm.

Evaluation of prop samples for laver culture obtained in Examples and Comparative Examples
(weight)
The weight of 0.5 m taken as a sample for physical property measurement was weighed with a digital scale and converted to unit weight (g/m).
(warp)
Place a 4 m long seaweed prop sample on a horizontal floor surface with a straight line displayed, let it stand with both ends attached to the straight line, and use a metal rule as the point at which the distance from the straight line is the maximum. Measurement was performed, and 2 cm or less was given as “◯” and more than 2 cm as “x”.
(Dimensions of cross section of strut sample)
Cut perpendicular to the longitudinal direction with a circular saw tip saw cutter, and measure the inner diameter and outer diameter of the core layer, the outer diameter of the FRP layer, and the outer diameter of the coating layer in the cross section with a vernier caliper (CD-20CPX, manufactured by Mitutoyo Co., Ltd.). Measured by The number of measurements n was set to 5 points, and the average was shown.
(Volume content of reinforcing fibers in FRP layer and cross-sectional area ratio of glass fibers and carbon fibers in cross section of FRP layer)
A cross-sectional area Sf of the FRP layer is calculated from the above cross-sectional dimensions. For the glass fiber rovings and carbon fiber tows in each example and comparative example, the cross-sectional area Sg of the glass fiber and the cross-sectional area Sc of the carbon fiber were calculated from the number of used glass fiber rovings and the carbon fiber tow, and their fineness and density, and [(Sg + Sc) / Sf ]×100.
The cross-sectional area ratio of the glass fiber to the carbon fiber in the cross section of the FRP layer was expressed using the cross-sectional area Sg of the glass fiber and the cross-sectional area Sc of the carbon fiber.
The density of the glass fiber roving (RS220RL-510AH and RS440RR-531AH: E glass manufactured by Nitto Boseki Co., Ltd.) is 2.54 g/cm ³ , and the carbon fiber carbon fiber tow (Mitsubishi Chemical Corporation, PYROFIL (registered trademark) ), the density of TRW40 50) was calculated as 1.81 g/cm ³ .

(bending rigidity)
With reference to JIS K 7074:1988, measurement was performed under the following conditions in a three-point bending test (n=5).
Bending direction: Bending was performed in a direction perpendicular to the longitudinal direction of the fiber-reinforced resin tubular body and in a direction in which the diameter of the fiber-reinforced resin tubular body was the shortest (a direction perpendicular to the parallel portion).
・Test piece diameter D: The width of the fiber-reinforced resin tubular body in the load direction directly below the indenter was measured with a vernier caliper (n = 1) ・Radius of fulcrum: 2.0 mm ・Radius of indenter: 5.0 mm ・Distance between fulcrums L _m : (40±8)×D mm (In JIS, the thickness H of the solid is used for calculation, but the diameter D of the test piece is used for calculation.)
・Test piece length l _m : L _m + 20 mm
・Test speed: 20 mm/min (0.01 L _m ² /6H in JIS)
・Bending strength: It was obtained by the following formula from the load at break, the distance between fulcrums, the geometrical moment of inertia of the test piece, and the distance from the center of gravity.
Bending strength σ _max , load at break P _m , distance between fulcrums L _m , geometric moment of inertia I of the test piece, center-of-gravity distance d,
It was calculated by σ _max =FL _m d/8I.
Bending elastic modulus (E): Obtained from the slope of the straight line of the load-deflection curve, the distance between fulcrums, and the geometrical moment of inertia of the test piece.
That is, _{E = (L m 3} ^/ _{48I) × P m /} δ
・Bending rigidity (EI): Obtained by the following formula from the gradient P _m /δ of the straight portion of the load-deflection curve and the distance L _m between fulcrums.
EI ⁼ ( _Lm3 /48)× _Pm /δ

(ease of grip)
Considering the workability of erecting the posts for seaweed cultivation, it is preferable to set the outer diameter of the posts to Φ50 mm or less. This can be read from the survey results of "easy-to-grip thickness" in the database of infrastructure maintenance for elderly people of the Research Center for Human Life Science, but it is indicated as "thickness that makes it difficult to grip if it is thicker." Although there are differences depending on gender, age, grip method, etc., it is roughly between Φ45 and 50mm. For this reason, it is considered that a column having an outer diameter close to Φ45 mm is easy to grip and work, but a column having an outer diameter close to Φ50 mm or more is difficult to grip and workability deteriorates. Therefore, the evaluation of the seaweed aquaculture prop with an outer diameter exceeding 50 mm was given as "x".

Cross-sectional size and shape of the seaweed culture prop samples of each example and comparative example, carbon fiber bundle arrangement site, glass fiber / carbon fiber cross-sectional volume ratio, and bending rigidity, unit weight, longitudinal warpage as performance evaluation, Table 1 summarizes the easiness of gripping.

As shown in Table 1, in Comparative Example 1 in which the reinforcing fiber made of conventional glass fibers alone was used and the outer diameter of the support was 42.8 mm, the bending rigidity was 2,060 (N m ² ) and the weight was 754 (g/m). However, in Example 2, where the FRP layer thickness is 2.0, the cross-sectional area ratio of glass fiber/carbon fiber in the FRP layer is 60.7:39.3, which is the maximum ratio of carbon fiber, so the weight is 723 g/m, and the rigidity is 3,354 (N·m ² ), achieving a weight reduction of about 4% and an increase in rigidity of 1.61 times. This is because Comparative Example 1 has low rigidity, so there are restrictions on where it can be used, such as use in environments with shallow water depths or weak tidal currents. 0.8mm can be deployed in a wide range of locations as a support for seaweed cultivation. Furthermore, as described above, because of its high rigidity, it can be used as a versatile laver aquaculture prop that can be used in a wide range, and is about 14% compared to the commonly used conventional prop of Comparative Example 3 with an outer diameter of 46.2 mm. The weight can be reduced, and a reduction in the workload can be expected.

In Examples 3 to 7, the inner diameter/outer diameter of the core layer is 37.0 mm/41.0 mm, the FRP layer outer diameter is 45.1 mm, the FRP layer thickness is 2.1 mm, and the column outer diameter is 46.2 mm. , changing the cross-sectional area ratio of glass fiber and carbon fiber in the FRP layer.
As the carbon fiber cross-sectional area increases, the bending stiffness increases to 3,124-5,192 (N·m ² ) and the weight decreases to 833-756 (g/m). On the other hand, in the case of FRP composed only of glass fibers with the same dimensions as shown in Comparative Example 3, the weight was 838 (g/m) and the rigidity was 2,890 (N m ² ), which is desirable. By adjusting the cross-sectional area ratio of the carbon fiber according to the rigidity or weight, the prop for laver cultivation can be manufactured.

In addition, when used in a deep field of about 15 m in the sea, from the viewpoint of rigidity, conventionally, the outer diameter of 52 mm shown in Comparative Example 6 has a rigidity of 5,169 (N·m ² ) and a weight of 1,187 (N·m 2 ). g/m) is required, but in order to satisfy the rigidity, the support of Example 7 with a weight of 756 (g/m) and an outer diameter of 46.2 mm, and the weight of 911 (g/m) with an outer diameter of 46.2 mm A strut with a diameter of 50 mm can be selected.
In addition, it was confirmed from the comparison between Example 1 and Comparative Example 2 that the carbon fibers in the FRP layer should be arranged outside the FRP layer in order to obtain higher rigidity.
In addition, regarding the central axis symmetry of the carbon fiber, from the comparison between Example 4 and Comparative Example 4, warpage occurs in the asymmetric Comparative Example 4, and the rigidity is also inferior. It was confirmed that it is preferable to arrange them on the surface side at substantially the same central angle.

The post for laver cultivation of the present invention can be used as a post for laver cultivation that is more rigid and lighter than the FRP layer that has conventionally been composed only of glass fibers with the same outer diameter. In addition, if you want to have the same rigidity as before, you can make the outer diameter smaller, and it can be used as a prop for seaweed cultivation that can reduce the weight and improve the handleability by reducing the diameter. .
In addition, the method for manufacturing the laver aquaculture prop of the present invention provides the laver aquaculture prop of the present invention, which is excellent in manual handling, can achieve both light weight and high rigidity, is relatively inexpensive, and is highly practical. It can be used as a method for stable and economical production with good reproducibility.

REFERENCE SIGNS LIST 1 core layer 2 FRP layer 2a glass fiber 2b carbon fiber 2c matrix component 3 thermoplastic resin coating layer 4 uncured tubular article 5 uncured tubular article with coating layer 6 composite tubular article 10 column for seaweed cultivation 11 core layer melt extruder 12 cooling tank 13 glass fiber roving creel 14 thermosetting resin impregnating tank 15 carbon fiber tow creel 16 thermosetting resin impregnating tank 2a′, 2b′ uncured thermosetting resin composition impregnated fiber 17 Drawing die device 18 Melting extruder for coating layer 19 Cooling water bath 20 Thermal curing bath

Claims (4)

Nori seaweed aquaculture posts with a composite structure that are tightly integrated, each having a core layer made of a thermoplastic resin, an FRP layer formed on the outer periphery of the core layer, and a coating layer formed on the outer periphery of the FRP layer. There is
At least the outer peripheral surface of the core layer is made of a thermoplastic resin having a chemical affinity with a thermosetting resin, which is a matrix component of the FRP layer,
In the FRP layer, long-fiber reinforcing fibers containing at least glass fiber and carbon fiber are vertically attached to the outer circumference of the core layer in the longitudinal direction, and the carbon fiber is arranged on the outer circumference side of the FRP layer. , the cross-sectional area ratio of the glass fiber and the carbon fiber in the cross section of the FRP layer is 60:40 to 95:5,
A prop for seaweed cultivation, wherein at least the inner peripheral surface of the coating layer is made of a thermoplastic resin having a chemical affinity with a thermosetting resin that is a matrix component of the FRP layer. The prop for seaweed cultivation according to claim 1, wherein the cross-sectional area ratio of the glass fiber to the carbon fiber in the FRP layer is 80:20 to 95:5. The cross-sectional area ratio of the glass fiber to the carbon fiber in the FRP layer is 90:10 to 95:5, and in the cross section orthogonal to the longitudinal direction of the FRP layer, the carbon fiber bundle is on the outer peripheral surface side of the FRP layer. The columns for nori culture according to claim 1, which are arranged at substantially the same central angle. 4. The method for producing a prop for laver culture according to any one of claims 1 to 3, comprising the following steps (i) to (vii).
(i) Prepare a required number of glass fiber bundles and carbon fiber bundles as long-fiber-like reinforcing fibers, insert each of the glass fiber bundles and carbon fiber bundles into predetermined guide holes of a gathering guide, and further insert them into A step of preparing the reinforcing fiber bundle so that it can be taken through the impregnation operation guide of the impregnation tank arranged in parallel, the drawing die for longitudinally attaching to the outer periphery of the core layer in a predetermined arrangement, the extruder for the coating layer and the production line,
(ii) injecting a liquid curable resin composition containing a thermosetting resin and a thermosetting agent into the impregnation layer;
(iii) a core layer manufacturing step of continuously extruding a thermoplastic resin forming the core layer from a melt extruder into a circular tube shape of a predetermined size and continuously taking it through a production line;
(iv) While taking out the reinforcing fiber bundle prepared in (i) above, the impregnation operation guide is lowered into the impregnation tank to impregnate the reinforcing fiber bundle with the curable resin composition, and the curable resin composition is impregnated into the hole of the drawing die. A step of vertically attaching to the outer periphery of the core layer running in the center of the, and gradually squeezing the excess resin with a drawing die to form an uncured tubular product in which the reinforcing fiber bundle is vertically attached to the core layer;
(v) a melt-coating step of passing the uncured tubular article through the crosshead of a melt extruder to circularly extrusion-coat it with a thermoplastic resin for a coating layer, and cooling the coating layer;
(vi) a step of introducing the coated uncured tubular article into a curing bath to thermally cure the uncured thermosetting resin composition inside, and taking out the tubular article having a composite structure that is adhered and integrated;
(vii) A step of cutting the collected tubular object into a predetermined length as a prop for laver cultivation.

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