JP2023094780A - industrial hose - Google Patents

Abstract

To provide an industrial hose capable of indicating high inter-layer adhesiveness without impairing physical property of a rubber layer and further without using an adhesive between a wire reinforcing layer and the rubber layer of the hose.SOLUTION: The present invention relates to an industrial hose in which at least one of an inner surface rubber layer 1 and an outer surface rubber layer 3 contains following components (A) to (C) and which consists of a vulcanizate of a diene-based rubber composition in which a ratio of the component (B) is 5 to 30 mass% with respect to 100 mass% of the component (A). A wire reinforcing layer 2 consists of a copper containing wire. The component (A) is a diene-based rubber, the component (B) is calcium carbonate of which the specific surface area is 4.8 m2/g or more and the component (C) is sulfur.SELECTED DRAWING: Figure 1

Description

The present invention relates to industrial hoses used for various high-pressure hoses with a wire reinforcing layer, such as high-pressure hydraulic hoses for construction machinery and mining machinery, and engine oil hoses for automobiles. It is a thing.

Industrial hoses such as high-pressure hydraulic hoses used in construction machinery, mining machinery and the like are usually provided with a wire reinforcing layer so as to withstand high internal pressure.
As the layer structure of the high-pressure hydraulic hose, for example, a wire reinforcing layer is provided between the inner and outer rubber layers, or an intermediate rubber layer and a wire reinforcing layer are alternately provided between the inner and outer layers. For example, a layer structure in which a plurality of wire reinforcing layers are embedded in the intermediate rubber layer is adopted.

As the metal wire that constitutes the wire reinforcing layer, a plated metal wire is usually used in order to improve rust resistance.
Further, in order to improve the durability of the hose, it is necessary to firmly bond the wire reinforcing layer formed by braiding metal wires as described above and the rubber layer in contact therewith. That is, if the adhesion between the wire reinforcing layer and the rubber layer is poor, the wire moves or loosens, which adversely affects the durability.

An adhesive is usually used to firmly bond the wire reinforcing layer and the rubber layer as described above.

In order to obtain adhesiveness (peel durability) with the wire reinforcing layer without using an adhesive (adhesive-less), for example, the wire reinforcing layer is a brass (copper-zinc alloy) plated wire etc., and a diene rubber composition is used as the rubber layer material, sulfur as a vulcanizing agent in the rubber layer material and copper ions (Cu) in the wire reinforcing layer There is a method of developing adhesiveness between the wire reinforcing layer and the rubber layer by making the rubber layer in the vicinity of the interface with the wire reinforcing layer a copper sulfide-containing layer by chemical bonding.
However, the copper ions from the wire reinforcing layer diffuse throughout the rubber layer during the vulcanization reaction of the rubber layer, and the copper ion concentration in the rubber layer near the interface with the wire reinforcing layer decreases. , there is a problem that sufficient adhesiveness (peeling durability) cannot be obtained.

Therefore, in order to obtain good interlayer adhesion, for example, a phenol resin, a maleic anhydride-modified polymer, or the like is added to the rubber layer material, an inorganic water-retaining material such as silica is added, or a vulcanization agent is added to the rubber layer material. Various techniques such as improving accelerators have been investigated (see, for example, Patent Documents 1 to 4).

JP-A-58-72436 JP 2010-254876 A JP 2014-152311 A International Publication No. 2014/175186

However, existing methods such as those disclosed in the above patent documents have problems such as excessive increase in rubber hardness leading to deterioration in fatigue resistance, and problems such as adversely affecting workability and product appearance due to increase in tackiness. , a number of problems arise.
For this reason, it is desired to obtain an effect of improving the adhesion to the wire reinforcing layer without impairing the physical properties of the rubber layer by a method different from the existing methods.

The present invention has been devised in view of such circumstances, and provides a high interlayer adhesiveness between the wire reinforcing layer and the rubber layer of the hose without impairing the physical properties of the rubber layer and without using an adhesive. The purpose is to provide an industrial hose that can demonstrate

The present inventors have made intensive studies in order to solve the above problems. In the course of the research, the present inventors found that the adhesion between the wire reinforcing layer and the rubber layer was improved by making the rubber layer in the vicinity of the interface with the wire reinforcing layer a copper sulfide-containing layer, as described above. We reexamined the method of expressing
In this method, as described above, during the vulcanization reaction of the rubber layer, copper ions (Cu) from the wire reinforcing layer diffuse throughout the rubber layer, resulting in the rubber ions near the interface with the wire reinforcing layer. There is a problem that the copper ion concentration in the layer is lowered and, as a result, it is impossible to form a copper sulfide-containing layer exhibiting sufficient adhesion.
Therefore, the inventors of the present invention suppress copper ions from diffusing throughout the rubber layer by using an additive in the rubber layer material, and by retaining the copper ions in the rubber layer near the wire reinforcing layer, sulfurization An attempt was made to improve the adhesiveness between the copper wire reinforcing layer and the rubber layer.
As a result of various experiments conducted by the present inventors in order to embody this, unexpectedly, when a specific amount of calcium carbonate having a BET specific surface area of 4.8 m ² /g or more was added to the rubber layer material, The inventors have found that the above phenomenon actually occurs and that a copper sulfide-containing layer exhibiting high adhesiveness is formed. Further, even if a specific amount of calcium carbonate having a BET specific surface area of 4.8 m ² /g or more is added to the rubber layer material as described above, the physical properties of the rubber layer are not impaired and the adhesive is not used. The inventors have found that the desired object can be achieved, since high interlaminar adhesion is exhibited between the wire reinforcing layer.

That is, the gist of the present invention is the following [1] to [7].
[1] An industrial hose having a layered structure in which a wire reinforcing layer is laminated on at least one of the inner peripheral surface and the outer peripheral surface of a tubular rubber layer,
The wire reinforcing layer is made of a wire containing copper,
The rubber layer contains the following (A) to (C), and the ratio of (B) is 5 to 30 parts by mass per 100 parts by mass of (A). , industrial hoses.
(A) a diene rubber;
(B) Calcium carbonate having a BET specific surface area of 4.8 m ² /g or more.
(C) Sulfur.
[2] The industrial hose according to [1], wherein the diene rubber (A) is a diene rubber containing acrylonitrile-butadiene rubber as a main component.
[3] The industrial hose according to [1] or [2], wherein the calcium carbonate (B) has a BET specific surface area of 5.5 m ² /g or more.
[4] The industrial hose according to any one of [1] to [3], wherein the wire reinforcing layer is made of a wire plated with a copper-zinc alloy.
[5] The industrial hose according to any one of [1] to [4], wherein the rubber layer comprises a vulcanized diene rubber composition further containing (D) below.
(D) Silica.
[6] The industrial hose according to any one of [1] to [5], wherein the sulfur (C) is sulfur containing insoluble sulfur.
[7] The industrial hose according to any one of [1] to [6], wherein the wire reinforcing layer is laminated on at least the outer peripheral surface of the rubber layer.

The industrial hose of the present invention can exhibit high interlayer adhesion between the wire reinforcing layer and the rubber layer without impairing the physical properties of the rubber layer and without using an adhesive. In addition, diffusion of copper ions from the wire reinforcing layer to the entire rubber layer can be suppressed, thereby preventing deterioration of the rubber layer (copper damage).

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the industrial hose of this invention. It is explanatory drawing which shows the peeling test in adhesive evaluation of rubber and a plating wire.

Next, an embodiment of the present invention will be described in detail. However, the present invention is not limited to this embodiment.
In the present invention, when expressing "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it means "X or more and Y or less" and "preferably larger than X" or "preferably It also includes the meaning of "smaller than Y".
In addition, when expressed as "X or more" (X is any number) or "Y or less" (Y is any number), the statement "preferably larger than X" or "preferably less than Y" It also includes intent.

An industrial hose according to one embodiment of the present invention (hereinafter referred to as "the present industrial hose") has a tubular rubber layer at least one of the inner peripheral surface and the outer peripheral surface thereof is reinforced with a wire, as described above. It has a layer structure in which layers are laminated, the wire reinforcing layer is made of a wire containing copper, the rubber layer contains the following (A) to (C), and the (B ) is a vulcanizate of a diene rubber composition in which the proportion of (A) is 5 to 30 parts by mass per 100 parts by mass.
(A) a diene rubber;
(B) Calcium carbonate having a BET specific surface area of 4.8 m ² /g or more.
(C) Sulfur.

Here, the hose shown in FIG. 1 has a wire reinforcing layer 2 formed on the outer peripheral surface of the inner rubber layer 1 and an outer rubber layer 3 formed on the outer peripheral surface of the wire reinforcing layer 2 . Therefore, it can be said that it has a layer structure in which the wire reinforcing layer 2 is laminated on the outer peripheral surface of the inner rubber layer 1 and a layer structure in which the wire reinforcing layer 2 is laminated on the inner peripheral surface of the outer rubber layer 3 .
In order to use the hose shown in FIG. 1 as the industrial hose, the wire reinforcing layer 2 must be a wire containing copper. In addition, in order to use the hose shown in FIG. 1 as the industrial hose, at least one of the inner rubber layer 1 and the outer rubber layer 3 must be a layer made of a vulcanized product of the specific diene rubber composition. be.
Then, at least the inner rubber layer 1 is a layer made of the vulcanizate of the specific diene rubber composition (that is, at least the outer circumference of the rubber layer made of the vulcanizate of the specific diene rubber composition By forming a layer structure in which the wire reinforcing layer 2 is laminated on the surface, the problem that the inner rubber layer 1 falls off due to delamination and narrows the flow path in the hose can be solved. Therefore, it is preferable. From the viewpoint of interlaminar adhesion, etc., it is more preferable that the outer rubber layer 3 is also made of a vulcanized product of the specific diene rubber composition.

Next, details of each component in the specific diene rubber composition will be described below.

<<Diene rubber (A)>>
Examples of the diene rubber (A) include natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), isoprene rubber (IR), and butadiene rubber (BR). These are used alone or in combination of two or more. Among these, when oil resistance is required, a diene-based rubber containing NBR as a main component (a diene-based rubber having an NBR content of 50% by mass or more) is preferably used, and more preferably only NBR is used. When wear resistance is required, SBR and NR are preferably used.
From the viewpoint of adhesion to the wire reinforcing layer 2, the NBR is preferably an NBR having an acrylonitrile amount (AN amount) of 10 to 33% by mass, more preferably an NBR having an AN amount of 10 to 28% by mass. is. That is, if the amount of AN is too large, the vulcanization rate will increase, and the bond between the polymers will become stronger, making it difficult for sulfur to elute to the surface, which may lead to a decrease in adhesiveness. This is because there is a possibility that the initial physical properties may deteriorate.
From the viewpoint of adhesion to the wire reinforcing layer 2, the SBR preferably has a styrene content of 10 to 25% by mass, and more preferably an SBR with a styrene content of 15 to 25% by mass. That is, if the amount of styrene is too large, the vulcanization rate will be faster, and the bond between the polymers will be stronger, making it difficult for sulfur to elute to the surface, which may cause a decrease in adhesion. This is because there is a possibility that the initial physical properties may deteriorate.

《Calcium carbonate (B)》
As the calcium carbonate (B), the effect of the present invention (suppressing copper ions from diffusing throughout the rubber layer and retaining the copper ions in the rubber layer near the wire reinforcing layer 2, copper sulfide Calcium carbonate having a BET specific surface area of 4.8 m ² /g or more is used, as described above, from the viewpoint of the function and effect of increasing the adhesiveness between the wire reinforcing layer 2 and the rubber layer. From the same point of view, the BET specific surface area of calcium carbonate (B) is preferably 5.5 m ² /g or more, more preferably 10 m ² /g or more. The upper limit of the BET specific surface area of calcium carbonate (B) is usually 55 m ² /g or less, preferably 40 m ² /g or less, more preferably 30 m ² /g or less. Examples of such calcium carbonate (B) include commercially available products such as Hakuenka CC, Silver W, and Hakuenka O (all manufactured by Shiraishi Calcium Co., Ltd.).
In addition, the BET specific surface area of the calcium carbonate (B) can be obtained, for example, by degassing the sample at 200° C. for 15 minutes and then using a mixed gas (N ₂ : 70%, He: 30%) as the adsorbed gas. It can be measured with a specific surface area measuring device (manufactured by Microdata, 4232-II).

The content of the calcium carbonate (B) with respect to 100 parts by mass of the diene rubber (A) is in the range of 5 to 30 parts by mass, preferably 5 to 20 parts by mass, more preferably in the range of 5 to 20 parts by mass, as described above. is in the range of 10 to 20 parts by mass. That is, if the content of calcium carbonate (B) is too low, the effects of the present invention described above cannot be advantageously obtained, and if the content of calcium carbonate (B) is too high, the effects of the present invention cannot be obtained. This is because the effects are inhibited, and the initial physical properties, heat resistance, and workability are deteriorated.

《Sulfur (C)》
As the sulfur (C), sulfur containing insoluble sulfur is preferable from the viewpoint of advantageously obtaining the adhesion effect with the wire reinforcing layer 2 by the function and effect of the present invention described above.
Examples of insoluble sulfur include polymeric sulfur such as μ-sulfur, π-sulfur and ω-sulfur. These are used alone or in combination of two or more. Examples of the insoluble sulfur as described above include SANFEL (manufactured by Sanshin Chemical Co., Ltd.) and SANFEL EX (manufactured by Sanshin Chemical Co., Ltd.).
The content of the insoluble sulfur with respect to 100 parts by mass of the diene rubber (A) is preferably in the range of 0.2 to 4.8 parts by mass, more preferably 0.5 to 4.5 parts by mass. is in the range of

In addition to insoluble sulfur as described above, soluble sulfur can also be used, if necessary. In this way, by using insoluble sulfur and soluble sulfur together, sulfur (insoluble sulfur) that mainly contributes to adhesion with the wire reinforcing layer 2 and sulfur (soluble sulfur) that mainly contributes to vulcanization of rubber However, it becomes possible to fully demonstrate each function.
Examples of the soluble sulfur include sulfur having a ring structure, such as α-sulfur, β-sulfur, γ-sulfur and λ-sulfur. These are used alone or in combination of two or more. In addition, the soluble sulfur as described above is specifically, Sulfax T-10 (manufactured by Tsurumi Chemical Industry Co., Ltd.), Kinkain fine powder sulfur (manufactured by Tsurumi Chemical Industry Co., Ltd.), powdered sulfur S (manufactured by Hosoi Chemical Industry Co., Ltd.) etc.
The content of the soluble sulfur with respect to 100 parts by mass of the diene rubber (A) is preferably in the range of 0.2 to 4.8 parts by mass, more preferably 0.5 to 4.5 parts by mass. is in the range of

In the present invention, insoluble sulfur refers to sulfur that exhibits 90% by mass or more of insolubility in carbon disulfide, preferably 95% by mass or more of insolubility, more preferably 98% by mass or more of insolubility. means to indicate In addition, soluble sulfur refers to sulfur that exhibits a solubility of 99.5% by mass or more in carbon disulfide, preferably a solubility of 99.9% by mass or more, more preferably a solubility of 100% by mass. means something that indicates

The total amount of sulfur (C) is preferably in the range of 1.0 to 6.0 parts by mass, more preferably 1.0 to 5 parts by mass, relative to 100 parts by mass of the diene rubber (A). .0 parts by mass. That is, within such a range, the effects of the present invention described above can be advantageously obtained, high interlayer adhesion is exhibited, and vulcanization of the rubber layer, etc., can be performed satisfactorily. .

In addition to the above (A) to (C), the specific diene rubber composition includes silica (D), carbon black, zinc oxide, stearic acid, a processing aid, a vulcanization accelerator, a plasticizer, Optional materials such as tackifiers, anti-aging agents, flame retardants, anti-scorch agents, etc. may be blended as needed.

It is preferable to incorporate silica (D) into the specific diene rubber composition, since the compatibility with the wire is improved.
The content of the silica (D) is preferably in the range of 5 to 15 parts by mass with respect to 100 parts by mass of the diene rubber (A) from the viewpoint of further improving the affinity with the wire, and more preferably. is in the range of 5 to 10 parts by mass.

The content of the carbon black is preferably in the range of 40 to 150 parts by mass, more preferably in the range of 60 to 130 parts by mass with respect to 100 parts by mass of the diene rubber (A), from the viewpoint of reinforcing properties. is.

The specific diene-based rubber composition is prepared, for example, by appropriately blending the above-described (A) to (C) components and, if necessary, various optional materials as described above, and then kneading, rolling, and Banbury mixers. It can be prepared by kneading using a kneader such as.

Here, the industrial hose shown in FIG. 1 uses the specific diene rubber composition for at least one of the rubber composition for forming the inner rubber layer 1 and the rubber composition for forming the outer rubber layer 3, For example, it can be produced as follows.
That is, first, the rubber composition for forming the inner surface rubber layer 1 is extruded onto a mandrel using an extruder. Next, a wire containing copper is braided into the outer peripheral surface of the inner rubber layer 1 in the form of a braid or a spiral to form the wire reinforcing layer 2 . After that, a rubber composition for forming the outer surface rubber layer 3 is extruded onto the outer peripheral surface of the wire reinforcing layer 2 . Finally, the laminate thus obtained is vulcanized (steam vulcanized, etc.) under predetermined conditions (for example, 140 to 170° C. for 10 to 60 minutes) to obtain the An industrial hose with a layered structure can be produced.

As the wire containing copper used for the wire reinforcing layer 2, in addition to a copper wire, a wire made of iron or steel plated with copper or brass (copper-zinc alloy) is used. . Among them, a brass-plated wire is preferable from the viewpoint of flexibility, strength, and the like.
Moreover, the diameter of the wire is usually in the range of 0.15 to 1.00 mm, preferably in the range of 0.20 to 0.80 mm.

The industrial hose is not limited to the layer structure shown in FIG. or a structure in which, in addition to these layer structures, an innermost layer and an outermost layer made of a material different from the specific diene rubber composition are laminated.

As described above, when the innermost layer made of a material different from the specific diene rubber composition is provided, the material is preferably a rubber having excellent oil resistance, etc., such as acrylonitrile butadiene rubber (NBR), Additives include acrylonitrile butadiene rubber (HNBR), acrylic rubber (ACM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), fluororubber (FKM) and the like. These are used alone or in combination of two or more. Among them, NBR is preferable from the viewpoint of oil resistance, strength and cost.
In addition to the rubber such as NBR, the rubber composition for forming the innermost layer may include a reinforcing material (such as carbon black), a white filler, a plasticizer, stearic acid, zinc white, a vulcanizing agent, and a vulcanization accelerator. , processing aids, etc. may be added as appropriate.

Further, as described above, when providing the outermost layer made of a material different from the specific diene rubber composition, the material is preferably a rubber having excellent weather resistance, such as chloroprene rubber (CR), styrene Butadiene rubber (SBR), ethylene-propylene-diene rubber (EPDM), blended rubber of SBR and EPDM, blended rubber of NBR and EPDM, blended rubber of NBR and vinyl chloride (PVC), acrylic rubber (ACM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), chlorosulfonated polyethylene (CSM), and the like. These are used alone or in combination of two or more. Among them, CR is preferable from the viewpoint of weather resistance, cost, and oil resistance.
In addition to the rubber such as CR, the rubber composition for forming the outermost layer includes a reinforcing material (carbon black, etc.), a white filler, a plasticizer, stearic acid, zinc white, an acid acceptor (highly activated magnesium , hydrotalcite, etc.), an anti-aging agent, a vulcanizing agent, a vulcanization accelerator, a processing aid, etc., may be added as necessary.

In this industrial hose, the inner diameter of the hose is usually in the range of 5-85 mm, preferably in the range of 6-80 mm.

The thickness of the inner rubber layer 1 is usually in the range of 0.7-4.0 mm, preferably in the range of 1.0-3.0 mm. The thickness of the outer rubber layer 3 is usually in the range of 0.5-2.5 mm, preferably in the range of 0.8-2.0 mm.

This industrial hose is equipped with a wire reinforcement layer for high-pressure hydraulic hoses for construction machinery (construction machinery), mining machinery, industrial vehicles (forklifts, automated guided vehicles, etc.), engine oil hoses for automobiles, etc. It can be used for various oil transportation hoses and the like.

Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

First, prior to Examples and Comparative Examples, the following materials were prepared. The BET specific surface area of calcium carbonate described below is measured by the measurement method described above.

[NBR]
Nipol DN302 (AN content: 27.5% by mass), manufactured by Nippon Zeon Co., Ltd.

[SBR]
#1500 (styrene content: 23.5% by mass), manufactured by Sumitomo Chemical Co., Ltd.

[NR]
RSS#3

[calcium carbonate (i)]
Shiraenka CC, manufactured by Shiraishi Calcium Co., Ltd., BET specific surface area: 26.0 m ² /g

[calcium carbonate (ii)]
Silver W, manufactured by Shiraishi Calcium, BET specific surface area: 5.5 m ² /g

[calcium carbonate (iii)]
Shiraenka O, manufactured by Shiraishi Calcium Co., Ltd., BET specific surface area: 55 m ² /g

[calcium carbonate (iv)]
Whiten P-30, manufactured by Shiraishi Calcium Co., Ltd., BET specific surface area: 3.4 m ² /g

[Insoluble Sulfur]
Sunfel, manufactured by Sanshin Chemical Co., Ltd.

[Soluble sulfur]
Sulfax T-10, manufactured by Tsurumi Chemical Industry Co., Ltd.

[silica]
Nip Seal VN-3, manufactured by Tosoh Silica Co., Ltd.

[Examples 1 to 10, Comparative Examples 1 to 5]
Each component shown in Tables 1 and 2 below is blended in the ratio shown in the same table, and further, 5 parts by mass of zinc oxide (zinc oxide type 2, manufactured by Sakai Chemical Co., Ltd.) and stearic acid (Lunac S-70V , manufactured by Kao Corporation), 1 part by mass of anti-aging agent (2,2,4-trimethyl-1,2-dihydroquinoline polymer), and 2 parts by mass of carbon black (Seist SO, manufactured by Tokai Carbon Co., Ltd.). 80 parts by mass, 10 parts by mass of a plasticizer, and 2 parts by mass of a sulfenamide-based accelerator (Suncellar CZ, manufactured by Sanshin Chemical Co., Ltd.) are blended and kneaded using a 3L kneader. , to prepare a rubber composition.
For rubber compositions in which NBR is the polymer, an ether ester plasticizer (ADEKA CIZER RS-107, manufactured by ADEKA) is used as the plasticizer, and for rubber compositions in which SBR is the polymer, , Using an aromatic oil (Diana Process AC-12, manufactured by Idemitsu Showa Shell Co., Ltd.) as the plasticizer, for a rubber composition in which NR is a polymer, paraffin oil (Diana Process NM-280, (manufactured by Idemitsu Kosan Co., Ltd.) was used.
Next, in order to evaluate the adhesion between the rubber layer and the wire reinforcing layer in the industrial hose, the rubber composition was used to prepare a vulcanization adhesion sample with the wire according to the following criteria, and the adhesion was evaluated. gone. The results are also shown in Tables 1 and 2 below.

≪Adhesion≫
Using the rubber composition, an unvulcanized rubber sheet (100 mm × 100 mm, thickness 2 mm) was prepared, and one plated wire (wire diameter 0.4 mm, length 300 mm) was placed on the rubber sheet. was placed. This was subjected to press vulcanization at 150° C. for 60 minutes at a surface pressure of 2 MPa to prepare a vulcanized adhesive sample (see FIG. 2).
Then, in the vulcanized adhesive sample shown in FIG. 2, the rubber 11 and the plated wire 12 are chucked, and the plated wire 12 is peeled in the direction of the arrow X according to the T-type peel test of JIS K 6256. The adhesion rate of rubber 11 on the surface of 12 was measured visually.
In addition, as the plated wire 12, a wire plated as described in "Plating type of wire" in Tables 1 and 2 below, that is, Cu/Zn (Cu/Zn=65% by mass/35% by mass % brass plating), Cu (copper plating), or Ni (nickel plating) steel wires were used.
Then, the adhesiveness was evaluated by evaluating the adhesion rate of the rubber 11 on the surface of the plated wire 12 according to the following criteria.
○: Adhesion rate is 80% or more △: Adhesion rate is 50% or more and less than 80% ×: Adhesion rate is less than 50%

From the results in Tables 1 and 2, it was confirmed that the vulcanized adhesive samples of Examples had a high adhesion rate of rubber to the surface of the plated wire, and thus had excellent adhesion between the rubber and the plated wire.
Further, in the industrial hose having the layer structure shown in FIG. When the plated wire used in the example was used as the wire used in 2, even without an adhesive, the rubber layer using the rubber composition used in the example and the wire reinforcing layer exhibited strong adhesion. It was developed and showed excellent performance as an industrial hose.

On the other hand, in Comparative Example 1, the conditions were the same as in Example 2 except that the BET specific surface area of calcium carbonate in the rubber did not satisfy the stipulations of the present invention. became. In Comparative Examples 2 to 4, the conditions were the same as in Example 2 except that the content of calcium carbonate in the rubber did not meet the requirements of the present invention, but the desired adhesion was not obtained. Comparative Example 5 has the same conditions as Examples 1 and 2 except that a nickel-plated wire is used as the plated wire (that is, no copper-containing wire is used), but the desired adhesion is achieved. This resulted in an ineffective result.
From this, it is clear that the calcium carbonate itself in the rubber did not function as a substance that imparts adhesiveness. If the combination of the rubber layer material and the wire reinforcing layer material prescribed in the present invention is not satisfied, a layer exhibiting strong adhesion (copper sulfide-containing layer) will not be formed at the interface between the two layers, and the desired adhesion will not be achieved. It turns out you can't get it.

The industrial hose of the present invention has a wire reinforcing layer such as a high-pressure hydraulic hose for construction machinery (construction machinery), mining machinery, industrial vehicles (forklifts, automatic guided vehicles, etc.), engine oil hoses for automobiles, etc. It can be used for various oil transport hoses and the like.

Claims (7)

An industrial hose having a layer structure in which a wire reinforcing layer is laminated on at least one of the inner peripheral surface and the outer peripheral surface of a tubular rubber layer,
The wire reinforcing layer is made of a wire containing copper,
The rubber layer contains the following (A) to (C), and the ratio of (B) is 5 to 30 parts by mass per 100 parts by mass of (A). , industrial hoses.
(A) a diene rubber;
(B) Calcium carbonate having a BET specific surface area of 4.8 m ² /g or more.
(C) Sulfur. The industrial hose according to claim 1, wherein the diene rubber (A) is a diene rubber containing acrylonitrile-butadiene rubber as a main component. The industrial hose according to claim 1 or 2, wherein said calcium carbonate (B) has a BET specific surface area of 5.5 m2 ^/ g or more. The industrial hose according to any one of Claims 1 to 3, wherein the wire reinforcing layer is made of a wire plated with a copper-zinc alloy. The industrial hose according to any one of claims 1 to 4, wherein the rubber layer further comprises a vulcanizate of a diene rubber composition containing (D) below.
(D) Silica. The industrial hose according to any one of claims 1 to 5, wherein said sulfur (C) is sulfur containing insoluble sulfur. The industrial hose according to any one of claims 1 to 6, wherein the wire reinforcing layer is laminated on at least the outer peripheral surface of the rubber layer.

Images