JP3643197B2 - Floating hose and method for manufacturing the same - Google Patents

Description

【００３３】
次に、易剥離性シートの効果につき検討した。
【００３４】
［実施例６］
１ 試料調製
（１）ゴム粗原料１００重量部当りのゴム配合組成を表１の如くとし、ゴム素原料にアクリロニトリル−ブタジエンゴム（アクリロニトリル含有量３５％、商品名 Ｎ２３０Ｓ 日本合成ゴム（株）製）として、バンバリーにより混練し、未加硫ゴム組成物を得る。次に、浮揚式ホースと同一構造のモデルホースを上記ゴム組成物を用いて第１カバー層を形成した後、下記の易剥離性シートを第１カバー層の外周に巻回して、１４０℃、１８０分間で加硫した。
［易剥離性シート］
ＰＥＴ製帆布［２５０Ｄ／１（２０３本／５ｃｍ）×２５０Ｄ／２（１２２本／５ｃｍ）］（商品名 タフタ・オックス 帝人商事（株）製）
更に、液状ウレタンゴム原料として、ＰＴＭＧ−ＴＤＩ系プレポリマー（商品名 コロネート４０９０ 日本ポリウレタン工業（株）製）を選択し、上記易剥離性シートを第１カバー層から巻き戻しながら剥離させ、剥離直後に上記ホースを回転しながら第１カバー層の剥離面に上記液状ウレタンゴム原料を塗布、被覆して第２カバー層を形成した。
（２）次に、上記のように形成された第１カバー層及び第２カバー層部分を裁断して評価サンプルを採取した。
２ 接着力試験
（１）オリジナル（初期）接着力の評価は、ＪＩＳ Ｋ６３０１−７項に準拠して測定した。
（２）耐水接着力の評価は、７０℃のウォーターバス中に１ケ月浸漬した後、ＪＩＳ Ｋ６３０１−７項に準拠して測定した。
３ 測定結果
（１）溶解度パラメーター
表１に示す通りである。
（２）接着力
表１に示す通りである。
［実施例７］
ゴム素原料にアクリロニトリル−ブタジエンゴム（アクリロニトリル含有量４１％、商品名 Ｎ２２０Ｓ 日本合成ゴム（株）製）とした以外は、その他の条件は実施例６に準ずる。
【００３５】
上記実施例及び比較例の配合処方、溶解度パラメーターＳＰ値、接着性についてそれらの結果を表１に示す。これらの結果から明らかなように、いずれの実施例６、７も実施例２、３に比し、優れた接着力を得た。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る浮揚性ホースの要部拡大断面図である。
【符号の説明】
１ 浮揚性ホース
２ ホース本体
３ 接続用フランジ
４ スポンジ
５ 第１カバー層
６ 第２カバー層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a buoyant hose and a manufacturing method thereof, and more particularly to a buoyant hose such as a cargo handling hose used when a cargo handling material such as crude oil is transported from a ship and a manufacturing method thereof.
[0002]
[Prior art]
Floating hoses such as hoses used for transporting conventional cargo handling goods such as crude oil are filled with polyurethane foam inside the hose body embedded with rubber, wire and fiber, and the outer shell is made of hard material The hose was suspended on the sea by inserting the float covered with.
However, these floats must be assembled at the site of use, and in order to save time, there is a buoyancy material integrated hose in which a rubber or synthetic resin sponge is wound around the outer periphery of the hose body and a rubber cover is applied to the outer periphery. Has been developed.
[0003]
However, conventional buoyancy material-integrated hoses use natural rubber, styrene-butadiene, chloroprene, or other general rubber as a cover. For this reason, the tanker is liable to be damaged when the tanker comes into contact with the hose during use as a buoyant hose at sea, or when the hoses come in contact with each other. I could only expect a life of about half a year to a year.
[0004]
In order to solve such a conventional problem, in order to protect the first cover layer (vulcanized rubber layer) on the outer periphery of the buoyant body (sponge) from damages, a second cover layer is made of urethane rubber having high wear resistance and weather resistance. It is possible to extend the life of the hose by coating as
In this case, the oil, wax, anti-aging agent, and the like, which are the rubber composition, bleed on the surface of the cover vulcanized rubber, which hinders stable coating of the second cover layer.
Therefore, in order to provide a strong adhesion state between the first cover layer and the second cover layer, for example, a pseudohalogen compound, N, N-dichloro-p-toluenesulfonamide, or trichloroisocyanuric acid is added to acetone, methylene chloride, or the like. These first solutions are dissolved in an organic solvent, applied to the surface of the vulcanized rubber of the first cover layer, chemically altered, and the rubber surface itself is activated for adhesion. A second cover layer of ether liquid urethane rubber was adhered to the cover layer by chemical bonding.
[0005]
[Problems to be solved by the invention]
However, it is industrially considered that the primer treatment (or acid treatment) with a solution composed of such an organic solvent is applied to the entire surface of the first cover layer coated on the huge hose body, and the operation of the used solvent Adverse effects on the environment (hydrocarbon pollution, health and safety impacts on human health, etc.), high cost for solvent recovery, and also the dispersion of coating work during primer treatment and deterioration of adhesive quality due to aging, It was a bonding method that caused a large variation in product quality and lacked reliability.
[0006]
The present invention has been made paying attention to such conventional problems, and the object of the present invention is to use an adhesive without performing primer treatment or acid treatment on the surface of the first cover layer. The material composition of the 1st cover layer and the 2nd cover layer is chosen suitably, and also adhesion of the 1st cover layer and the 2nd cover layer is carried out by modifying the surface state of the 1st cover layer. To provide a buoyant hose that can maintain sufficient force, can be efficiently manufactured while avoiding the effects on health and safety, and can improve quality, and a method for manufacturing the same. It is in.
[0007]
[Means for Solving the Problems]
The present invention has the following configuration in order to achieve the above object.
That is, the buoyant hose according to claim 1 is provided with a sponge layer having closed cells on the outer peripheral surface of a main body in which a reinforcing layer is embedded in rubber, and further on the outer peripheral surface of the sponge layer. A first cover layer made of vulcanized rubber in which a fibrous body is embedded, and a second cover layer formed by applying and curing liquid urethane rubber on the outer peripheral surface of the first cover layer are integrated. In the buoyant hose formed in the above, no adhesive is used between the first cover layer and the second cover layer, and the polarity value of the vulcanized rubber of the first cover layer is a solubility parameter. δ is 9.5 to 10. It is 6 (cal / cm ³ ) ^1/2 .
[0008]
The buoyant hose according to claim 2 is characterized in that the vulcanized rubber of the first cover layer is a rubber component made of a diene polymer having an acrylonitrile content of 25 to 45% by weight. It is.
[0009]
Further, in the buoyant hose according to claim 3, the rubber component made of the diene polymer is acrylonitrile-butadiene rubber, or natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber is added to acrylonitrile-butadiene rubber. , Isobutylene-isoprene and chloroprene, which are blended with a rubber component consisting of at least one diene polymer.
[0010]
The buoyant hose according to claim 4 is characterized in that the liquid urethane rubber of the second cover layer is an ether-based liquid urethane rubber.
[0011]
The buoyant hose according to claim 5 is configured such that, when the vulcanized rubber of the first cover layer is vulcanized and formed, the outer surface of the vulcanized rubber of the first cover layer is formed with irregularities on at least one side and A sheet that can be easily peeled off from the vulcanized rubber of the first cover layer is wound and vulcanized, and then the sheet is peeled and removed immediately before the second cover layer is provided, and the liquid urethane rubber is applied to the peeled surface. It is characterized by being cured.
[0012]
The method of manufacturing a buoyant hose according to claim 6 is a polar value in which a sponge having closed cells is wound around an outer peripheral surface of a hose body formed integrally with a nipple and a connecting flange, and a fibrous body is embedded in the outer periphery thereof. Is 9.5-10. As the solubility parameter δ. 6 (cal / cm ³ ) ^1/2 of a vulcanized rubber first cover layer is coated, and the outer surface of the first cover layer is formed with at least one surface without using an adhesive. In addition, after winding and vulcanizing a sheet that can be easily peeled off from the vulcanized rubber of the first cover layer, the sheet is peeled and removed immediately before, and then an ether-based liquid urethane rubber is applied to the peeled surface and cured. The second cover layer is formed.
[0013]
The buoyant hose manufacturing method according to claim 7, wherein the vulcanized rubber of the first cover layer is a rubber component made of a diene polymer having an acrylonitrile content of 25 to 45% by weight. Is.
[0014]
The method for producing a buoyant hose according to claim 8, wherein the rubber component made of the diene polymer is acrylonitrile-butadiene rubber, or natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene is added to acrylonitrile-butadiene rubber. It is characterized by blending a rubber component composed of at least one diene polymer selected from the group consisting of rubber, isobutylene-isoprene, and chloroprene.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a partially enlarged cross-sectional view of a buoyant hose embodying the present invention. A buoyant hose 1 has a nipple at the end of a main body 2 in which a reinforcing layer such as a fiber or a spiral wire is embedded in rubber. The connecting flange 3 is integrally formed.
A sponge having closed cells is wound around the outer peripheral surface of the main body 2, and the sponge 4 functions as a buoyancy material when used at sea. The outer periphery of the sponge 4 is covered with a first cover layer 5 made of rubber in which a fibrous body is embedded, and the first cover layer 5 is made of vulcanized acrylonitrile-butadiene rubber and / or chlorine-containing rubber. In addition, the inner peripheral rubber is composed of a plurality of layers by being composed of styrene-butadiene copolymer rubber or the like.
[0016]
In general, according to the theory of solubility parameter (SP value SP = δ: unit [(cal / cm ³ ) ^1/2 ]) in dissolution and adhesion phenomena, etc., in order to obtain a dissolution and adhesion effect that provides good compatibility The SP value (Solubility Parameter) indicating the polarities of the mutually interacting substances such as solvent / solute, adhesive / adhesive, etc. can be achieved as much as possible. In order to optimally cover and cover the first cover layer 5 made of acrylonitrile-butadiene rubber with the second cover layer 6 made of urethane rubber, the SP value of acrylonitrile-butadiene rubber is changed to the SP value of urethane rubber ( (δ = 10.0) is necessary.
On the other hand, it is known that the SP value of acrylonitrile-butadiene rubber is proportional to the content of AN (acrylonitrile), and the AN content of the diene rubber is 20 to 50% by weight, preferably 26 to 41% by weight. A certain acrylonitrile-butadiene rubber is suitable, and in this case, the SP value of the acrylonitrile-butadiene rubber can be δ = 9.5 to 10.6. As a matter of course, if the SP value is δ = 9.5 to 10.6, it is not limited to acrylonitrile-butadiene rubber.
[0017]
The first cover layer 5 may be coated by applying a rubber adhesive, for example, a solution in which a rubber having the same quality as the cover is dissolved in toluene, to the outer periphery of the sponge 4, followed by a rubber sheet, a fiber sheet, and a rubber sheet in this order. It is preferable to laminate while pressing.
When the lamination is completed, the surface of the first cover layer 5 is cleaned, and in order to form irregularities, a sheet that is easy to peel off from the vulcanized rubber provided with irregularities on the first cover layer side, for example, canvas-like A canvas (hereinafter referred to as an easily peelable sheet) is wound around the entire outer periphery of the first cover layer, and then vulcanized in a steam layer.
As such an easily peelable sheet, a dense plain woven fabric having a density in which various twisted yarns are used for warps and a single twisted yarn is used for wefts, such as taffeta and ox (Oxford) weave, is preferable. When the vulcanized rubber of the first cover layer vulcanized by covering the surface with a plain woven fabric is vulcanized, the detachable sheet (not shown) is unwound from the first cover layer 5 while being rewound. The first cover is clean and suitable for adhesion without the surface unevenness of the fabric being stamped and transferred, and without the oil, wax, anti-aging agent and the like being a rubber composition bleeding on the surface of the vulcanized rubber. The outer surface of layer 5 is obtained.
[0018]
Next, liquid urethane rubber is applied and cast on the outer peripheral surface of the first cover layer 5 thus molded, and the second cover is formed by rotating and hardening the main body until the liquid urethane rubber loses its fluidity. Layer 6 is formed.
[0019]
Representative examples of the liquid urethane rubber that can be used in the embodiments of the present invention will be described below.
First, urethane refers to a urethane elastomer and may be an ether-based urethane resin having elasticity. In more detail, the composition of urethane consists of urethane prepolymer, curing agent and catalyst, and if necessary, color, additives (anti-sagging agent, extender, plasticizer, light stabilizer) etc. Also good.
[0020]
The main component of the urethane prepolymer consists of a polyol and a polyisocyanate. Polyether-based polyols such as polytetramethylene glycol, polyethylene glycol, and polypropylene glycol can be used as the polyol used in the present invention. For marine products, polyethers are preferred in consideration of water resistance and weather resistance. If necessary, several kinds of olefin-based polyols such as polybutadiene polyol and polyisoprene polyol, polyester-based polyols such as adipate-based polyol, lactone-based polyol and castor oil can be combined.
[0021]
As the polyisocyanate, tolylene diisocyanate, diphenylmethane 4,4′-diisocyanate, and modified products thereof, 1,5-naphthylene diisocyanate, vitrylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and the like can be used.
Usually, the urethane prepolymer is reacted at an equivalent ratio of (polyisocyanate (NCO) / polyol (OH)) = 1.4 / 1 to 2.5 / 1, preferably 1.8 / 1 to 2.2 / 1. Can be obtained.
[0022]
Examples of the curing agent include 3,3′-dicyclo-4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, amine-based curing agents such as tolylenediamine, 1,4-butanediol, and 1,6-hexane. Polyol curing agents such as diol, 1,5-pentanediol, diethylene glycol, and ethylene glycol, glycerin, trimethylolpropane, ethylene oxide derivative polyol, polytetramethylene glycol, β-hydroxylethoxybenzene, and the like can be used. You may use it combining several types of these hardening | curing agents as needed.
[0023]
Catalysts are usually known as catalysts for urethane (tin, lead, potassium, titanium, bismuth, nickel, cobalt, iron, calcium, magnesium, cadmium, mercury, etc.) salts, amine catalysts (generally tertiary amines) ), Acidic catalysts such as carboxylic acids can be used.
[0024]
As a matter of course, the urethane material shows a part of the whole, and does not limit the urethane material used in the present invention. The urethane is substantially a two-component urethane, but a one-component urethane can also be applied to the present invention. One-part urethane is roughly classified into moisture-curing urethane and ultraviolet-curing urethane.
For example, some moisture curable urethanes use the above urethane polymer and use moisture in the atmosphere as a curing agent.
[0025]
As the polyisocyanate for urethane prepolymer, diphenylmethane 4,4′-diisocyanate is preferable from the viewpoints of reactivity and price. Furthermore, since carbon dioxide gas is generated due to the reaction between the isocyanate group and water and becomes a source of bubbles, the NCO% of the urethane prepolymer is preferably 3% or less, preferably 1% or less. The addition of a carbon dioxide absorbent is also effective.
[0026]
The method of forming the second cover layer, which is urethane rubber, is to supply liquid urethane rubber while rotating the hose core and smooth it with a scraper, doctor knife, etc., as well as spray coating, iron coating, etc. is there. Then, the thickness of the urethane cover is finished to at least 3 mm. Although the number of rotations depends on the product diameter, it is preferably 8 to 15 rotations per minute at 800 φ to 1200 φ.
The scraper can be a rubber plate with a JIS hardness of 70 to 110, a resin plate such as hard vinyl chloride, polyethylene, fluororesin, polystyrene, ABS resin, and a thin metal plate such as stainless steel, copper, aluminum, iron or the like. .
[0027]
In the case of rotational molding, the reaction proceeds after the application of the liquid urethane rubber, and the viscosity of the liquid urethane rubber increases. Generally, when the viscosity is 10,000 sp, preferably 100,000 sp or more, the fluidity is lost, and even if the rotation is stopped, the dripping phenomenon of the liquid urethane rubber disappears. The rotation is stopped when the dripping phenomenon of the liquid urethane rubber disappears, whereby a uniform layer is obtained without the liquid urethane rubber flowing down and the finished surface irregularities.
If the thickness of the first cover layer is 4 to 15 mm and the thickness of the second cover layer is 2 to 6 mm, an appropriate life can be expected.
[0028]
【The invention's effect】
Since the present invention is configured as described above, the first cover layer and the second cover layer can be formed without performing primer treatment or acid treatment on the surface of the first cover layer and without using an adhesive. By appropriately selecting the material configuration and further modifying the surface state of the first cover layer, the adhesive force between the first cover layer and the second cover layer can be sufficiently maintained, and in terms of safety and health. It is possible to provide a buoyant hose that can be efficiently manufactured while avoiding the influence, and can improve quality, and a method for manufacturing the same.
[0029]
【Example】
The following examples illustrate the invention in more detail.
[0030]
[Example 1]
1 Sample Preparation (1) The rubber compounding composition per 100 parts by weight of rubber raw material is as shown in Table 1, and acrylonitrile-butadiene rubber (26% acrylonitrile content, trade name N240S manufactured by Nippon Synthetic Rubber Co., Ltd.) is used as the rubber raw material. As above, kneading is carried out by Banbury to obtain an unvulcanized rubber composition. Next, after forming a first cover layer using the rubber composition, a model hose having the same structure as the floating hose was vulcanized at 140 ° C. for 180 minutes.
Furthermore, as a liquid urethane rubber material for the first cover layer, a PTMG-TDI prepolymer (trade name Coronate 4090, manufactured by Nippon Polyurethane Industry Co., Ltd.) is selected, and the first cover layer is rotated while the hose is rotated. The liquid urethane rubber material was applied and coated to form a second cover layer.
(2) Next, the first cover layer and the second cover layer formed as described above were cut to obtain an evaluation sample.
2 Adhesive strength test (1) Original (initial) adhesive strength was evaluated according to JIS K6301-7.
(2) Evaluation of water-resistant adhesive strength was measured according to JIS K6301-7 term after being immersed in a 70 ° C. water bath for 1 month.
3 Measurement results (1) Solubility parameters As shown in Table 1.
(2) Adhesive strength As shown in Table 1.
[Example 2]
Except for the rubber raw material being acrylonitrile-butadiene rubber (acrylonitrile content 35%, trade name N230S manufactured by Nippon Synthetic Rubber Co., Ltd.), other conditions are the same as in Example 1.
[Example 3]
The other conditions are the same as in Example 1 except that the rubber raw material is acrylonitrile-butadiene rubber (acrylonitrile content 41%, trade name N220S manufactured by Nippon Synthetic Rubber Co., Ltd.).
[Example 4]
Except for blending styrene-butadiene rubber with acrylonitrile-butadiene rubber (41% acrylonitrile content, trade name N220S manufactured by Nippon Synthetic Rubber Co., Ltd.) as the rubber raw material, the other conditions are the same as in Example 1.
[Example 5]
Except for blending natural rubber with acrylonitrile-butadiene rubber (41% acrylonitrile content, trade name: N220S manufactured by Nippon Synthetic Rubber Co., Ltd.) as the rubber raw material, the other conditions are the same as in Example 1.
[Comparative Example 1]
Except for the rubber raw material being acrylonitrile-butadiene rubber (acrylonitrile content 20%, trade name N250S manufactured by Nippon Synthetic Rubber Co., Ltd.), other conditions are the same as in Example 1.
[Comparative Example 2]
Except for the rubber raw material being acrylonitrile-butadiene rubber (acrylonitrile content 48%, trade name N215SL manufactured by Nippon Synthetic Rubber Co., Ltd.), other conditions are the same as in Example 1.
[Comparative Example 3]
Other conditions are the same as those in Example 1 except that the rubber raw material is natural rubber.
[Comparative Example 4]
Other conditions are the same as in Example 1 except that the rubber raw material is styrene-butadiene rubber.
[Comparative Example 5]
Other conditions are the same as in Example 1 except that the raw rubber material is chloroprene rubber.
[0031]
Table 1 shows the results of the formulation, the solubility parameter SP value, and the adhesiveness of the above Examples and Comparative Examples. As is clear from these results, all the examples obtained superior adhesive strength as compared with the comparative examples.
[0032]
[Table 1]

[0033]
Next, the effect of the easily peelable sheet was examined.
[0034]
[Example 6]
1 Sample preparation (1) The rubber compounding composition per 100 parts by weight of the raw rubber raw material is as shown in Table 1, and acrylonitrile-butadiene rubber (35% acrylonitrile content, trade name: N230S manufactured by Nippon Synthetic Rubber Co., Ltd.) is used as the rubber raw material. As above, kneading is carried out by Banbury to obtain an unvulcanized rubber composition. Next, after forming the first cover layer of the model hose having the same structure as the floating hose using the rubber composition, the following easily peelable sheet is wound around the outer periphery of the first cover layer, 140 ° C., Vulcanized in 180 minutes.
[Easily peelable sheet]
PET canvas [250D / 1 (203 / 5cm) x 250D / 2 (122 / 5cm)] (trade name: Taffeta Ox made by Teijin Shoji Co., Ltd.)
Furthermore, as a liquid urethane rubber material, PTMG-TDI prepolymer (trade name: Coronate 4090, manufactured by Nippon Polyurethane Industry Co., Ltd.) is selected, and the above easy-release sheet is peeled off from the first cover layer and immediately after peeling. While the hose was rotated, the liquid urethane rubber raw material was applied and coated on the release surface of the first cover layer to form a second cover layer.
(2) Next, the first cover layer and the second cover layer formed as described above were cut to obtain an evaluation sample.
2 Adhesive strength test (1) Original (initial) adhesive strength was evaluated according to JIS K6301-7.
(2) The water-resistant adhesive strength was measured according to JIS K6301-7, after being immersed in a 70 ° C. water bath for 1 month.
3 Measurement results (1) Solubility parameters As shown in Table 1.
(2) Adhesive strength As shown in Table 1.
[Example 7]
Except for using acrylonitrile-butadiene rubber (41% acrylonitrile content, trade name: N220S manufactured by Nippon Synthetic Rubber Co., Ltd.) as the rubber raw material, other conditions are the same as in Example 6.
[0035]
Table 1 shows the results of the formulation, the solubility parameter SP value, and the adhesiveness of the above Examples and Comparative Examples. As is clear from these results, each of Examples 6 and 7 obtained superior adhesive strength as compared with Examples 2 and 3.
[Brief description of the drawings]
FIG. 1 is an enlarged cross-sectional view of a main part of a buoyant hose according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Floating hose 2 Hose main body 3 Flange for connection 4 Sponge 5 1st cover layer 6 2nd cover layer

Claims (8)

Nipples, connecting flanges,
A sponge layer having closed cells is provided on the outer peripheral surface of a main body in which a reinforcing layer is embedded in rubber, and a first cover layer made of vulcanized rubber in which a fibrous body is embedded is provided on the outer peripheral surface of the sponge layer. In the buoyant hose formed integrally with the outer peripheral surface of the cover layer, which is provided with a second cover layer formed by applying and curing liquid urethane rubber,
No adhesive is used between the first cover layer and the second cover layer, and the polarity value of the vulcanized rubber of the first cover layer is 9.5-10. 6 (cal / cm ³ ) ^1/2 buoyant hose characterized by   2. The buoyant hose according to claim 1, wherein the vulcanized rubber of the first cover layer is a rubber component made of a diene polymer having an acrylonitrile content of 25 to 45 wt%.   The rubber component comprising the diene polymer is acrylonitrile-butadiene rubber, or selected from the group consisting of acrylonitrile-butadiene rubber, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, isobutylene-isoprene, and chloroprene. The buoyant hose according to claim 2, wherein a rubber component made of at least one diene polymer is blended.   The buoyant hose according to any one of claims 1 to 3, wherein the liquid urethane rubber of the second cover layer is an ether-based liquid urethane rubber.   When the vulcanized rubber of the first cover layer is vulcanized and molded, at least one surface is uneven on the outer surface of the vulcanized rubber of the first cover layer, and the first cover layer is peeled from the vulcanized rubber. An easy sheet is wound and vulcanized, and then the sheet is peeled and removed immediately before the second cover layer is provided, and the liquid urethane rubber is applied to the peeled surface and cured. Item 5. The buoyant hose according to any one of items 1 to 4. A sponge having closed cells is wound around the outer peripheral surface of the hose body formed integrally with the nipple and the connecting flange, and the polarity value in which the fibrous body is embedded on the outer periphery is 9.5-10. 6 (cal / cm ³ ) ^1/2 of a vulcanized rubber first cover layer is coated, and the outer surface of the first cover layer is formed with at least one surface irregularity without using an adhesive. In addition, after winding and vulcanizing a sheet that can be easily peeled off from the vulcanized rubber of the first cover layer, the sheet is peeled and removed immediately before, and then an ether-based liquid urethane rubber is applied to the peeled surface and cured. A method for producing a buoyant hose, comprising forming a second cover layer.   The method for producing a buoyant hose according to claim 6, wherein the vulcanized rubber of the first cover layer is a rubber component made of a diene polymer having an acrylonitrile content of 25 to 45% by weight.   The rubber component comprising the diene polymer is acrylonitrile-butadiene rubber, or selected from the group consisting of acrylonitrile-butadiene rubber, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, isobutylene-isoprene, and chloroprene. The method for producing a buoyant hose according to claim 6 or 7, wherein a rubber component comprising at least one diene polymer is blended.

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