JP4457849B2 - Wear resistant hose - Google Patents

Description

  The present invention provides a driving tip hose that is used by being connected to the tip of the transport pipe, when the ready-mixed concrete, particularly high-performance ready-mixed concrete is pumped in a transport pipe and placed in a predetermined place, The present invention relates to a wear-resistant hose used for a hose for discharging muddy water or the like.

Conventionally, when the ready-mixed concrete transported to a construction site by a concrete mixer truck is placed at a predetermined location by a pump truck via a transport pipe, it is connected to the tip of the transport pipe for pressure feeding. An installation tip hose is used. As such a hose, for example, one having a configuration in which a pressure-resistant reinforcing layer and a rubber outer layer are sequentially laminated on the outer periphery of a rubber inner layer having an annular cross section for circulating ready-mixed concrete is known (for example, Patent Document 1). reference). In recent years, there has been an increase in the use of high-viscosity ready-mixed concrete called high-performance ready-mixed concrete, which has a higher viscosity than ordinary ready-mixed concrete. In this case, the viscosity is higher than ordinary ready-made concrete and difficult to pump. For this reason, a large load is applied to the hose itself. In other words, the pressure of the pumping source is increased and the pressure applied per unit area is increased because the pumping pressure of the pumping source is increased and the pressure applied per unit area is increased, compared to the case of pumping normal ready-mixed concrete. Is extremely short.
JP-A-8-291886

  For the purpose of solving such problems, for example, by increasing the thickness of the rubber inner layer of the hose, or by forming a resin layer with good wear resistance on the inner peripheral surface of the rubber inner layer, the durability of the hose is increased. The lifetime is improved. However, if the thickness of the rubber inner layer is increased as described above, the weight of the entire hose increases, which increases the burden on the worker who handles the hose and reduces the workability of placing the ready-mixed concrete. In addition, there is a problem that an increase in the amount of rubber used leads to an increase in the cost of the hose. Further, when the resin layer is formed, there arises a problem that the bending characteristic of the hose itself is remarkably lowered and becomes difficult to handle.

  The present invention has been made in view of such circumstances, and can provide a wear-resistant hose that can achieve a long life and cost reduction by improving wear resistance, and that does not cause deterioration in workability. Objective.

In order to achieve the above object, the wear-resistant hose of the present invention has a rubber inner layer, a reinforcing layer formed on the outer periphery thereof via an intermediate rubber layer, and a rubber outer layer formed on the outer periphery thereof. The rubber inner layer is formed using a rubber composition containing the following components (A) and (B), and the intermediate rubber layer and the rubber outer layer are the following ( B '), and the component (A) is contained only in the rubber inner layer, and the content of the component (A) is 100 parts by weight of the component (B). The ratio is set to 5 to 30 parts by weight.
(A) Fatty acid amide.
(B) It is a mixture of natural rubber and butadiene rubber, and the weight mixing ratio of natural rubber and butadiene rubber is in the range of natural rubber / butadiene rubber = 30/70 to 70/30.
(B ') Natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), acrylonitrile-butadiene rubber (NBR), water Attachment NBR, hydrogenated SBR, isoprene rubber, the a Kurirugomu alone or two or more kinds.

  That is, the present inventors have formed a rubber layer that is the inner layer of the hose in order to improve the wear resistance of the hose without increasing the thickness of the rubber layer of the hose or forming a new resin layer. We have earnestly researched mainly on materials. As a result, when the inner layer is formed using a rubber composition containing a fatty acid amide, the friction coefficient of the inner peripheral surface of the rubber layer is reduced, the friction with the fluid flowing inside the hose is reduced, and the wear resistance is improved. In addition, since the pressure loss of the fluid is reduced, it is not necessary to increase the pump pressure extremely when pumping a highly viscous fluid, and it has been found that the life can be extended and the present invention has been achieved.

  As described above, in the wear resistant hose of the present invention, the rubber inner layer is formed using the rubber composition containing the fatty acid amide [(A) component]. For this reason, the friction coefficient of the inner peripheral surface of the rubber inner layer is reduced, and the wear resistance is improved. Since the pressure loss is reduced by realizing low friction, it is possible to suppress an increase in pressure when pumping, and a long life can be realized. Further, by reducing the friction, for example, the hose can be prevented from being blocked due to blockage of the hose or delamination caused by the aggregate sticking into the hose surface when the ready-mixed concrete is pumped. Further, since the pumping pressure can be reduced, the pressure applied per unit area of the hose is also reduced, and a hose rupture accident such as during high-pressure pumping can be prevented. Therefore, it is possible to avoid cost reduction and increase in workability due to increase in hose weight by increasing the thickness of the rubber layer, thereby realizing a long life of the hose. For this reason, the wear-resistant hose of the present invention is, for example, a driving tip hose used for pumping high-performance ready-mixed concrete having a higher viscosity than ordinary ready-mixed concrete, and tunnel earth and sand. This is useful for draining hoses such as water and muddy water.

  When the intermediate rubber layer containing no fatty acid amide is interposed between the inner rubber layer and the reinforcing layer, the intermediate layer acts as an affinity layer, so that the adhesion between the inner rubber layer and the reinforcing layer is improved. And the reliability and durability of the hose are further improved.

  Further, when the content of the fatty acid amide [component (A)] is set within a specific range, it is possible to realize further improved wear resistance.

  For example, as shown in FIG. 1, the wear resistant hose of the present invention has an intermediate rubber layer 2 formed on the outer peripheral surface of the rubber inner layer 1, and the first reinforcing layer 3 is formed on the outer peripheral surface of the intermediate rubber layer 2. The spiral reinforcing wire 4 is wound around the outer periphery of the first reinforcing layer 3, and the second reinforcing layer 5 is formed around the outer periphery of the first reinforcing layer 3. The outer peripheral surface of the second reinforcing layer 5 is made of rubber. An outer layer 6 is formed and configured. And in this invention, it is the biggest characteristics that the said rubber inner layer 1 is formed using the rubber composition which mix | blended fatty acid amide.

  As the rubber inner layer 1 forming material, a rubber composition containing a fatty acid amide (component A) is used.

As the rubber component is a matrix component constituting the rubber composition, durability, low cost, from the viewpoint of wettability with fatty acid amide, a mixture of natural rubber (NR) and butadiene rubber (BR) is, NR / BR used within the scope of (weight ratio) = 30 / 70-70 / 30.

  Examples of the fatty acid amide (component A) include unsaturated fatty acid amides, N-substituted unsaturated fatty acid amides, and the like.

The unsaturated fatty acid amide is represented by the general formula: RCONH ₂ (R is an unsaturated fatty acid alkyl group). More specifically, the R (unsaturated fatty acid alkyl group) is an unsaturated group having 17 to 21 carbon atoms. Fatty acid alkyl groups are preferred. For example, those having a molecular weight of 250 to 350 and a melting point of 90 ° C. or less are preferably used. Specific examples include oleic acid amide and erucic acid amide, and these are used alone or in combination of two or more.

The N-substituted unsaturated fatty acid amide is represented by the general formula: R ₁ CONHR ₂ NHCOR ₁ (where R ₁ is an unsaturated fatty acid alkyl group and R ₂ is an alkylene group). ₁ is preferably an unsaturated fatty acid alkyl group having 10 to 22 carbon atoms, and R ₂ is preferably an alkylene group having 2 to 6 carbon atoms. For example, those having a molecular weight of 550 to 650 and a melting point of 100 to 130 ° C. are preferably used. Specific examples include N, N′-ethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, and the like. These may be used alone or in combination of two or more.

  Among these fatty acid amides (component A), oleic acid amides and erucic acid amides are preferably used from the viewpoints of melting point, bleeding property and lubricity.

The content of the fatty acid amide (A component) is set to a ratio of 5 to 30 parts by weight of the rubber component 100 parts by weight of matrix component, good Mashiku is 10 to 25 parts by weight. At below 5 parts by weight, hardly improving effect of sufficient abrasion resistance is obtained in the rubber layer 1, when it exceeds 30 parts by weight, to decrease adhesion between the intermediate rubber layer 2 or the reinforcing layer Luca et al It is.

  In addition to the rubber component and the fatty acid amide (component A), the rubber composition as the material for forming the rubber inner layer 1 includes a reinforcing agent, a process oil, a vulcanizing agent such as sulfur, and a vulcanization accelerating aid as necessary. Antiaging agents, plasticizers, processing aids, and the like can be appropriately blended.

  Examples of the reinforcing material include various conventionally known reinforcing materials such as carbon black and white carbon.

  Examples of the vulcanization acceleration aid include zinc oxide, activated zinc white, and magnesium oxide.

  Examples of the antiaging agent include carbamate type antiaging agents, phenylenediamine type antiaging agents, phenol type antiaging agents, diphenylamine type antiaging agents, quinoline type antiaging agents, and waxes. These may be used alone or in combination of two or more.

  Examples of the plasticizer include phthalic acid plasticizers such as dioctyl phthalate (DOP) and di-n-butyl phthalate (DBP), and adipic acids such as dibutyl carbitol adipate and dioctyl adipate (DOA). Examples of the plasticizer include sebacic acid plasticizers such as dioctyl sebacate (DOS) and dibutyl sebacate (DBS).

  Examples of the processing aid include stearic acid, fatty acid ester, fatty acid amide, and hydrocarbon resin.

Next, as the material for forming the intermediate rubber layer 2 containing no fatty acid amide formed on the outer peripheral surface of the rubber inner layer 1, natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene - propylene rubber (EPM), ethylene - propylene - diene rubber (EPDM), acrylonitrile - butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR, isoprene rubber, A Kurirugo arm used. These may be used alone or in combination of two or more. The term “free of fatty acid amide” as used herein does not literally contain fatty acid amide, but may mean that it may be contained in a small amount (several weight percent). From the viewpoint of adhesion to the rubber inner layer 1 and the first reinforcing layer 3, it is preferable to use natural rubber or a mixture of natural rubber and butadiene rubber.

  As the intermediate rubber layer 2 forming material, in addition to the rubber component, as in the case of the rubber inner layer 1 forming material, other additives such as reinforcing agents, vulcanizing agents such as sulfur, Sulfur acceleration aids, anti-aging agents, plasticizers, processing aids, and the like can be appropriately blended as necessary.

Examples of the first reinforcing layer 3 forming material formed on the outer peripheral surface of the intermediate rubber layer 2 include reinforcing yarns such as polyester yarn, vinylon yarn, nylon yarn, and aramid yarn. Examples of the method for braiding the reinforcing yarn include spiral knitting and blade knitting. Alternatively, a sheet-like reinforcing yarn forming material is prepared in which a large number of the reinforcing yarns are aligned in the longitudinal direction and constrained by entangled yarns, and the sheet-like reinforcing yarn-forming material is used to form a multilayer structure. A first reinforcing layer 3 formed by a multilayer structure composed of a sheet-like reinforcing yarn forming material and an adhesive rubber layer, which is bonded between the layers using an adhesive rubber layer (thickness of about 0.2 to 0.3 mm), can give.

  Examples of the adhesive rubber layer forming material include natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), isoprene rubber (IR) and the like.

  As the spiral reinforcing wire 4 wound around the outer periphery of the first reinforcing layer 3, for example, a wire such as a copper wire is used.

Further, as the second reinforcing layer 5 forming material formed on the outer periphery of the helical reinforcing wire 4, for example, polyester yarn, vinylon yarn, nylon yarn, aramid yarn, as in the first reinforcing layer 3 forming material. And the like. Examples of the method for braiding the reinforcing yarn include spiral knitting and blade knitting. Alternatively, a sheet-like reinforcing yarn forming material is prepared in which a large number of the reinforcing yarns are aligned in the longitudinal direction and constrained by entangled yarns, and the sheet-like reinforcing yarn-forming material is used to form a multilayer structure. A second reinforcing layer 5 formed by a multi-layer structure composed of a sheet-like reinforcing yarn forming material and an adhesive rubber layer bonded between the layers using an adhesive rubber layer (thickness of about 0.2 to 0.3 mm) is provided. can give.

The rubber outer layer 6 forming material formed on the outer peripheral surface of the second reinforcing layer 5 includes natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), and ethylene-propylene rubber (EPM). , ethylene - propylene - diene rubber (EPDM), acrylonitrile - butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR, isoprene rubber, A Kurirugo arm used. These may be used alone or in combination of two or more. Among these, it is preferable to use a mixture of natural rubber (NR) and butadiene rubber (BR) from the viewpoints of durability, flexibility, wearability, and the like.

  As the rubber outer layer 6 forming material, in addition to the rubber component, as in the case of the rubber inner layer 1 forming material and the intermediate rubber layer 2 forming material, as other additives, reinforcing agents, sulfur A vulcanizing agent such as vulcanization accelerator, a vulcanization accelerating aid, an anti-aging agent, a plasticizer, a processing aid and the like can be appropriately blended as necessary.

  The wear resistant hose of the present invention can be manufactured as follows, for example. That is, first, a rubber inner layer forming material is extruded into a sheet shape using an extruder and wound around a mandrel in a spiral shape. Next, the intermediate rubber layer forming material is extruded into a sheet shape using an extruder on the outer peripheral surface around which the sheet rubber inner layer forming material is wound, and the sheet is wound. Next, the first reinforcing layer 3 is formed by spirally knitting a reinforcing yarn on the outer peripheral surface of the intermediate layer formed by the winding or by spirally winding the sheet-shaped reinforcing layer forming material. Form. Next, a reinforcing wire is wound around the outer peripheral surface of the first reinforcing layer 3 in a spiral shape, and the second reinforcing layer 5 is formed on the spiral reinforcing wire formed by the winding in the same manner as described above. Next, a rubber outer layer forming material is extruded into a sheet shape on the outer peripheral surface of the second reinforcing layer 5 using an extruder, and the sheet is wound. And the target abrasion-resistant hose (refer FIG. 1) can be produced by heat-vulcanizing the whole on predetermined conditions (for example, 150-180 degreeC temperature conditions).

  In the above manufacturing method, after the sheet-like rubber inner layer forming material is wound to form the rubber inner layer 1, the intermediate rubber layer 2 is formed on the surface by winding, and then the first reinforcing layer is formed on the surface. 3 is formed, the helical reinforcing wire 4 is formed, the second reinforcing layer 5 is further formed, and then the rubber outer layer 6 is formed. However, the present invention is not limited to this. For example, Following the winding of the rubber inner layer 1 forming material, the intermediate rubber layer 2 forming material is wound, and the first reinforcing layer 3 is formed, the helical reinforcing wire 4 is formed, and then the second reinforcing layer 5 is formed. Further, the rubber outer layer 6 may be continuously formed.

  Thus, the thickness of each layer of the abrasion-resistant hose of this invention obtained is 1-20 mm normally in the thickness of the rubber inner layer 1, Preferably it is 1.5-10 mm. The thickness of the intermediate rubber layer 2 is usually 0.5 to 5 mm, preferably 0.5 to 3 mm. Moreover, each thickness of the said 1st reinforcement layer 3 and the 2nd reinforcement layer 5 is 0.5-5 mm normally, respectively, Preferably it is 0.5-3 mm. The thickness of the rubber outer layer 6 is usually 1 to 10 mm, preferably 1 to 5 mm. And although the internal diameter of the abrasion-resistant hose of this invention is suitably set according to a use, it is 12-1000 mm normally, Preferably it is 20-600 mm.

  Next, examples will be described together with comparative examples.

  First, prior to the examples and comparative examples, the following materials were prepared.

(1) Rubber inner layer forming material [Rubber component]
60 parts by weight of natural rubber (manufactured by Toyota Tsusho Corporation, RSS No. 3) and 40 parts by weight of butadiene rubber (manufactured by Ube Industries, Ubepol BR-150) were blended and kneaded using a biaxial kneader. Mixed rubber material.

[Fatty acid amide a]
Oleic acid amide

[Fatty acid amide b]
Erucamide

[Other inner layer forming materials]
Stearic acid 3 parts by weight Zinc oxide 4 parts by weight Carbon black 70 parts by weight Process oil 5 parts by weight Vulcanization accelerator (N-cyclohexyl-2-benzothiazylsulfenamide: CBS)
1 part by weight Sulfur 2 parts by weight

(2) Intermediate rubber layer forming material

[Rubber component]
100 parts by weight of natural rubber (manufactured by Toyota Tsusho, RSS No. 3)

[Other intermediate rubber layer forming materials]
Stearic acid 3 parts by weight Zinc oxide 4 parts by weight Carbon black 70 parts by weight Process oil 10 parts by weight Vulcanization accelerator (CBS) 1 part by weight Sulfur 2 parts by weight

(3) First and second reinforcing layer forming material [sheet-like reinforcing layer forming material a]
A first reinforcing yarn layer formed by constraining a plurality of polyester reinforcing yarns (manufactured by Teijin Ltd., P900M) in the longitudinal direction and constraining them with tangled yarns is topped with an adhesive rubber comprising the following compounding components. A sheet-shaped reinforcing layer forming material (total thickness: 1 mm) was prepared.
[Adhesive rubber compounding ingredients]
Styrene-butadiene rubber (manufactured by JSR, SBR1500) 100 parts by weight Stearic acid 3 parts by weight Zinc oxide 4 parts by weight Carbon black 45 parts by weight Calcium carbonate 100 parts by weight Process oil 45 parts by weight Vulcanization accelerator (dibenzothiazyl disulfide: MBTS 1 part by weight Sulfur 3 parts by weight

[Sheet-like reinforcing layer forming material b]
The above-mentioned sheet-like reinforcing layer forming material a is used for a second reinforcing yarn layer that is constrained with a stringed yarn in a state in which a plurality of nylon reinforcing yarns (manufactured by Teijin Limited, T-5) are aligned in the longitudinal direction. A sheet-like reinforcing layer forming material (total thickness 0.6 mm) formed by topping the same adhesive rubber as the blended ingredients was prepared.

(4) Rubber outer layer forming material

[Rubber component]
50 parts by weight of natural rubber (manufactured by Toyota Tsusho Co., Ltd., RSS No. 3) and 50 parts by weight of butadiene rubber (manufactured by Ube Industries, Ubepol BR-150) were blended, and these were kneaded using a biaxial kneader. Mixed rubber material.

[Other rubber outer layer forming materials]
Stearic acid 3 parts by weight Zinc oxide 4 parts by weight Carbon black 70 parts by weight Process oil 10 parts by weight Ozone anti-aging agent 2 parts by weight Vulcanization accelerator (CBS) 1 part by weight Sulfur 3 parts by weight

  Next, an abrasion-resistant hose was produced using the above materials as follows.

[Example 1]
First, materials shown in Table 1 below were prepared as rubber inner layer forming materials. Next, this rubber inner layer forming material is extruded into a sheet using an extruder, and wound in a spiral shape at an angle of 60 ° with respect to the axis of an iron mandrel having a diameter of 90 mm. did. Subsequently, the intermediate rubber layer forming material shown in Table 1 described later is extruded into a sheet shape using an extruder, and this is formed on the outer peripheral surface around which the sheet rubber inner layer forming material is wound. It was wound in a spiral shape at an angle of 60 ° and a fixed interval with respect to the axis of the iron mandrel in the opposite direction.

  Next, the sheet-like reinforcing layer forming material a is used, and this is wound on the outer peripheral surface around which the sheet-like intermediate rubber layer forming material is wound, with respect to the axis of the iron mandrel in the direction opposite to that at the time of forming the intermediate rubber layer. A first reinforcing layer was formed by winding in a spiral shape at an angle of 60 ° and at a constant interval. Then, a wire (copper wire) having a diameter of 2.6 mm was wound in a spiral shape on the outer peripheral surface around which the sheet-shaped reinforcing layer forming material a was wound. Next, a sheet-shaped reinforcing layer forming material b is used on the outer peripheral surface, and the outer peripheral surface around which the wire is wound is provided with a spiral at an angle of 85 ° with respect to the axis of the iron mandrel. And a second reinforcing layer was formed. In this way, two reinforcing layers were formed via the wires.

  Next, the rubber outer layer forming material shown in Table 1 described later is extruded into a sheet shape using an extruder, and this is formed on the outer peripheral surface of the second reinforcing layer, which is opposite to that at the time of forming the second reinforcing layer. It was wound in a spiral at an angle of 60 ° with respect to the axis of the iron mandrel in the direction.

  Then, the whole was subjected to heat vulcanization (conditions: 150 ° C. × 60 minutes) to produce a target wear-resistant hose (inner diameter: 90 mm, outer diameter: 105 mm) shown in FIG. The thickness of each layer of the produced hose is also shown in Table 1 below.

[Examples 2-6, Comparative Examples 1-2]
Rubber inner layer forming material, intermediate rubber layer forming material, two layers of reinforcing layer forming material (first and second reinforcing layer forming material) and rubber outer layer forming material shown in Tables 1 and 2 below are used. It was. Otherwise, a wear resistant hose (inner diameter 90 mm, outer diameter 105 mm) was prepared in the same manner as in Example 1. The thickness of each layer is shown in Tables 1 and 2 below.

[Comparative Example 3]
A resin layer having a thickness of 0.1 mm was formed by lining the inner circumference of the rubber inner layer of Example 1 using a polyethylene resin (manufactured by Sakushin Kogyo Co., Ltd., Newlite). Otherwise, an abrasion resistant hose was produced in the same manner as in Example 1.

  Using the wear-resistant hoses of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are also shown in Tables 3 to 4 below.

(Abrasion resistance)
(1) Measurement of static friction coefficient Using a static / dynamic friction coefficient meter DEPM (manufactured by Kyowa Interface Science Co., Ltd.), the friction element was measured with a steel ball having a diameter of 3 mm under a load of 500 g.

(2) Measurement of dynamic friction coefficient It measured similarly using the static and dynamic friction coefficient meter DEPM (made by Kyowa Interface Science Co., Ltd.) used by the measurement of the said static friction coefficient.

(Bending properties)
A 2 m long hose was bent 180 ° along a pipe having a radius of 500 mm, and the repulsive force at one end of the hose was measured with a spring balance.

  From the above results, it can be seen that the products of all Examples are excellent in wear resistance because both the static friction coefficient and the dynamic friction coefficient are low. Further, regarding the bending characteristics, it can be seen from the measurement evaluation results that good values are obtained and the workability is excellent.

On the other hand, it can be seen that Comparative Examples 1 and 2 had a high friction coefficient and poor wear resistance because a rubber composition containing no fatty acid amide was used as the rubber inner layer forming material. In Comparative Example 3, the polyethylene resin was lined on the inner periphery of the rubber inner layer , so that good results were obtained in terms of wear resistance, but the bending properties were inferior.

  The wear-resistant hose of the present invention is a driving tip hose that is used by being connected to the tip of the transport pipe when the concrete, particularly high-performance ready-mixed concrete, is pumped through the transport pipe and placed in a predetermined place. It is preferably used for a hose for discharging tunnel earth and sand or muddy water.

It is a block diagram which shows an example of the abrasion-resistant hose of this invention.

DESCRIPTION OF SYMBOLS 1 Rubber inner layer 2 Intermediate rubber layer 3 1st reinforcement layer 4 Spiral reinforcement wire 5 2nd reinforcement layer 6 Rubber outer layer

Claims (6)

A rubber inner layer and a wear-resistant hose in which a reinforcing layer is formed on the outer periphery via an intermediate rubber layer and a rubber outer layer is formed on the outer periphery. The rubber inner layer has the following ( A) and (B) are formed using a rubber composition containing the component, and the intermediate rubber layer and the rubber outer layer are formed using a rubber composition containing the following (B ′) , The component (A) is contained only in the rubber inner layer, and the content of the component (A) is set to a ratio of 5 to 30 parts by weight with respect to 100 parts by weight of the component (B). Wear resistant hose.
(A) Fatty acid amide.
(B) It is a mixture of natural rubber and butadiene rubber, and the weight mixing ratio of natural rubber and butadiene rubber is in the range of natural rubber / butadiene rubber = 30/70 to 70/30.
(B ') Natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), acrylonitrile-butadiene rubber (NBR), water Attachment NBR, hydrogenated SBR, isoprene rubber, the a Kurirugomu alone or two or more kinds.   The wear resistant hose according to claim 1, wherein the fatty acid amide as the component (A) is at least one of a saturated fatty acid amide and an unsaturated fatty acid amide. The wear resistant hose according to claim 1 or 2 , wherein (B ') of the intermediate rubber layer forming material is natural rubber or a mixture of natural rubber and butadiene rubber. The wear resistant hose according to any one of claims 1 to 3 , wherein (B ') of the rubber outer layer forming material is a mixture of natural rubber and butadiene rubber. When pouring is pumped transport pipe raw concrete, according to claim 1-4 for use in droplet設用tip hose or discharge hose tunnel sand and mud, are used to connect to the tip of the transport tube The wear-resistant hose according to any one of the above. A bending characteristic obtained by bending a hose having a length of 2 m by 180 ° along a pipe having a radius of 500 mm and measuring a repulsive force at one end of the hose with a spring balance is within a range of 67.69 to 72.59 N. The wear-resistant hose according to any one of 1 to 5 .

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