JP2005187584A - Hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a hose having excellent gas permeation resistance without impairing physical properties such as flexibility, etc., as a hose. <P>SOLUTION: The hose comprises at least one constituent layer in which its innermost layer 1 is composed of a rubber composition comprising (A) polar group-containing rubber and (B) an organically modified layered clay mineral organically modified with an organically modifying treatment agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hose, and more specifically, it is very useful in the use of piping and transportation of fuel for automobiles and the like (gasoline, alcohol-mixed gasoline (gasohol), alcohol, hydrogen, light oil, dimethyl ether, LPG, CNG, etc.). It relates to a useful hose.

In recent years, the transpiration regulation of fuel gas surrounding automobiles and the like has become stricter, and a low-permeability automobile hose corresponding to this has been required. Under such circumstances, conventionally, reinforcing materials such as carbon black and scaly talc have been added to materials for hoses (especially, materials for forming the innermost layer of hoses) containing diene rubber as a polymer component. A hose is produced to improve the gas permeation resistance (gas barrier property) of the hose (see Patent Document 1).
Japanese Patent Laid-Open No. 10-47552

  However, in order to obtain sufficient gas permeation resistance, it is necessary to contain a large amount of reinforcing material such as carbon black, which may adversely affect the physical properties of the hose such as flexibility. Is done.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a hose excellent in gas permeability resistance without impairing physical properties as a hose such as flexibility.

In order to achieve the above object, the hose of the present invention is a hose provided with at least one constituent layer, the innermost layer of which is a rubber composition containing the following (A) and (B) as essential components: It takes the composition that it is formed by.
(A) Polar group-containing rubber.
(B) An organized layered clay mineral organized by an organotreating agent having a polar group.

  That is, in order to solve the above problems, the present inventor firstly improved gas permeability resistance when a polar group-containing rubber such as a diene rubber is used as a polymer component as a material for forming the innermost layer of the hose. We have earnestly researched about. In the course of the research, instead of containing a large amount of carbon black or other reinforcing material as in the past, organically treated layered clay minerals are uniformly dispersed in the above polymer components to improve gas permeation resistance. Inspired to plan. And, in combination with the polar group-containing rubber as the polymer component, as a result of further research to improve the dispersibility of the layered clay mineral, the organic treatment agent having a polar group such as a hydroxyl group described above. It has been found that when the layered clay mineral is organically treated, rubber is effectively introduced between the layers of the layered clay mineral, and the nano-dispersion of the layered clay mineral is favorably achieved.

As a result, even if the content ratio of carbon black or the like is reduced (or not included), the above-mentioned layered clay mineral is nano-dispersed in a uniform manner in parallel to the longitudinal direction of the hose, so that good gas permeation resistance is achieved. Sex can be obtained. In addition, since the content ratio of carbon black or the like is small, the physical properties of the hose such as flexibility are not impaired. Here, the nano-dispersion is usually dispersed in a rubber polymer in a state where the size of the organically modified layered clay mineral is on the order of nanometers (1 × 10 ⁻⁷ to 1 × 10 ⁻⁹ m). For example, in the case of a plate-like crystal of an organized layered clay mineral having a thickness of about 1 nm and a length of about 50 to 1000 nm, it means that the interlayer distance (inter-crystal distance) is generally 30 to 85 mm or more. The interlayer distance is measured by, for example, an X-ray diffraction method. The innermost layer in the hose of the present invention means the layer in the case of a single layer structure, and the innermost layer in the case of a multilayer structure of two or more layers.

  As described above, the hose of the present invention is formed using a polar group-containing rubber and a specific organic layered clay mineral as the innermost layer forming material. Therefore, in the innermost layer, the organically modified layered clay mineral is present in an effectively dispersed state, gas permeation is blocked by the dispersed organicized layered clay mineral, and the dispersion is nanodispersed or the like. Therefore, the hose properties such as flexibility are not impaired and good hose characteristics are exhibited. Therefore, it is particularly suitable as a fuel hose used for transportation of fuel such as automobiles.

  Further, when the content of the organically modified layered clay mineral is in the range of 5 to 50 parts by weight with respect to 100 parts by weight of the polar group-containing rubber as the main component, gas permeability resistance can be effectively obtained. At the same time, the physical properties of the hose such as flexibility become more excellent.

  Furthermore, the dispersibility of the layered clay mineral in the rubber is more improved when the above-mentioned organically modified layered clay mineral is organically treated with an organic treatment agent containing a compound represented by the following formula (1) as a main component. To improve.

  Next, embodiments of the present invention will be described in detail.

  The hose of the present invention is not particularly limited even if it has a single layer structure or a multilayer structure of two or more layers, but at least the innermost layer has a polar group-containing rubber as a main component and has a polar group. It is formed of a rubber composition containing an organically modified layered clay mineral that has been organicized with an organic treatment agent, and this is the greatest feature. Here, FIG. 1 shows a hose having a single layer structure composed of only the innermost layer 1 formed of the special rubber composition.

  As the material for the innermost layer 1, polar group-containing rubber [component (A)] and the above-mentioned specific organically modified layered clay mineral [component (B)] are used as essential components.

  Examples of the polar group-containing rubber of the component (A) include acrylonitrile-butadiene rubber (NBR), hydrogenated acrylonitrile-butadiene rubber (H-NBR), butyl chloride rubber (Cl-IIR), chloroprene rubber (CR), chloro Examples thereof include sulfonated polyethylene (CSM), fluorine rubber (FKM), epichlorohydrin rubber (CO, ECO), urethane rubber (U), and acrylic rubber (ACM). These may be used alone or in combination of two or more.

  Examples of the specific organic layered clay mineral [component (B)] used together with the component (A) include smectite layered clay minerals such as montmorillonite, saponite, hectorite, beidellite, nontronite, soconite, and stevensite. In addition, a layered clay mineral having a conventionally known cation exchange ability such as vermiculite, halloysite, mica, and the like is organically treated with an organic treating agent having a polar group. By performing the organic treatment in this manner, the interlayer distance of the clay mineral is increased, and further, the clay mineral is organicized by the organic treatment agent having a polar group, so that the polar group-containing rubber [component (A)] The organically modified layered clay mineral is easily nano-dispersed. Such organically modified layered clay minerals may be used alone or in combination of two or more.

  As described above, the organic treatment agent for treating the clay mineral is a treatment agent having a polar group, and specifically, a compound represented by the following formula (1) is preferably used. In addition, as an organically modified layered clay mineral treated with such an organic treatment agent, for example, Cloisite 30B manufactured by Southern Clay Products can be mentioned as a suitable product.

  The blending ratio of the component (B) is preferably set in the range of 3 to 50 parts with respect to 100 parts by weight (hereinafter abbreviated as “part”) of the polar group-containing rubber of the component (A). Preferably it is the range of 5-20 parts. That is, if the organically modified layered clay mineral is less than 3 parts, the desired gas permeation resistance effect cannot be sufficiently obtained. Conversely, if it exceeds 50 parts, the physical properties of the hose such as flexibility can be improved. This is because there is an adverse effect.

  By the way, in the innermost layer 1 of the hose of the present invention, when a carboxyl-modified diene rubber is contained in addition to the components (A) and (B) that are essential components, the interlayer of the clay mineral of the above (B). As a result of the more effective introduction of rubber into the material and the improved dispersibility of the clay mineral, properties such as gas permeation resistance become more excellent.

  Examples of the carboxyl-modified diene rubber include carboxyl-modified diene rubbers such as acrylonitrile-butadiene rubber (NBR), hydrogenated acrylonitrile-butadiene rubber (H-NBR), styrene-butadiene rubber (SBR), and butadiene rubber (BR). I can give you. These may be used alone or in combination of two or more.

  The compounding amount of the carboxyl-modified diene rubber is preferably in the range of 3 to 20 parts, particularly preferably in the range of 5 to 15 parts, with respect to 100 parts of the polar group-containing rubber of the component (A).

  The innermost layer 1 material may be appropriately mixed with carbon black as necessary. The compounding amount of the carbon black is preferably in the range of 3 to 50 parts, particularly preferably in the range of 5 to 20 parts, with respect to 100 parts of the polar group-containing rubber of the component (A). That is, in the present invention, even when the blending ratio of carbon black is thus reduced, good gas permeation resistance can be obtained.

  As the material for the innermost layer 1, in addition to the above-mentioned components, a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, an anti-aging agent, a processing aid, a softening agent, and a filler are added within a range not impairing physical properties. Etc. may be blended as necessary.

  Sulfur is preferably used as the vulcanizing agent. The amount of sulfur is preferably in the range of 0.3 to 10 parts, particularly preferably in the range of 0.5 to 5 parts, with respect to 100 parts of the polar group-containing rubber of the component (A).

  The vulcanization accelerator is not particularly limited. For example, thiazole accelerator, thiuram accelerator, N-cyclohexyl-2-benzothiazylsulfenamide (CBS), dibenzothiazyl disulfide (MBTS), 2 -Sulfenamide accelerators such as mercaptobenzothiazole (MBT) and tetramethylthiuram monosulfide (TMTM).

  The blending amount of the vulcanization accelerator is preferably in the range of 0.1 to 3 parts, particularly preferably in the range of 0.5 to 2 parts, with respect to 100 parts of the polar group-containing rubber of the component (A). It is.

  The vulcanization aid is not particularly limited, and examples thereof include zinc oxide (ZnO) and magnesium oxide. These may be used alone or in combination of two or more.

  The blending amount of the ZnO is preferably 10 parts or less with respect to 100 parts of the polar group-containing rubber of the component (A). If it is in such a range, it will be in a normal range, and there will also be no problem of the weight increase of the product accompanying the increase in ZnO.

  Examples of the antiaging agent include carbamate type antiaging agent, phenylenediamine type antiaging agent, phenol type antiaging agent, diphenylamine type antiaging agent, quinoline type antiaging agent, and waxes.

  The blending amount of this anti-aging agent is preferably in the range of 1 to 7 parts, particularly preferably in the range of 2 to 5 parts, with respect to 100 parts of the polar group-containing rubber of the component (A).

  Examples of processing aids include stearic acid, fatty acid esters, fatty acid amides, hydrocarbon resins, and the like.

  The blending amount of this processing aid is preferably in the range of 1 to 5 parts, particularly preferably in the range of 1 to 3 parts, relative to 100 parts of the polar group-containing rubber of the component (A).

  The hose of the present invention can be manufactured, for example, as follows. That is, first, each component material of the above (A) and (B) is prepared, and other component materials are also prepared as required, and these are kneaded by a roll, a kneader, a Banbury mixer, a twin-screw kneading extruder or the like. The above-mentioned specific material composition for the innermost layer 1 is prepared by kneading using the above. When preparing the material for the innermost layer 1, a part (about 50% by weight) of the polar group-containing rubber (A), which is the main component, and the organically modified layered clay mineral (B) When the kneaded product is kneaded with the remainder (about 50% by weight) of the polar group-containing rubber (master batch method), the organically modified layered clay is more effectively incorporated into the rubber. This is preferable because minerals can be nano-dispersed. And this material composition for innermost layer 1 is extrusion-molded using an extruder, The hose of the single layer structure which consists only of innermost layer 1 can be produced (refer FIG. 1).

  The thickness of the innermost layer 1 is usually set in the range of 0.1 to 3.0 mm, preferably 0.3 to 2.0 mm.

  The hose of the present invention is not limited to the single layer structure as shown in FIG. 1, and for example, the outer layer 2 is formed on the outer peripheral surface of the innermost layer 1 as shown in FIG. A two-layer structure may be used. Further, a three-layer structure in which an intermediate layer made of reinforcing yarn or the like is formed between the innermost layer 1 and the outer layer 2 may be used, or a multilayer structure having four or more layers may be used. It should be noted that an adhesive may be used as necessary for bonding the layers.

  Although the thickness of the said outer layer 2 is based also on the use of a hose, it is 0.1-3.0 mm normally, Preferably it is 0.3-2.0 mm.

  The material for forming each layer formed on the outer peripheral surface of the innermost layer 1 is not particularly limited, and for example, a rubber material, a resin material, or the like is used. Further, a layer may be formed on the outer peripheral surface of the innermost layer 1 using a special rubber composition similar to the innermost layer 1.

  Moreover, the shape of the hose of the present invention is not particularly limited, and either a long hose or a short hose may be used, or it may be formed into a bellows shape.

  The hose of the present invention is suitably used as an automotive fuel piping hose such as a feed hose, return hose, breather hose, evaporation hose, filler hose, and the like.

  Next, examples will be described together with comparative examples.

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

[NBR (component A)]
Nipol DN202 (bound acrylonitrile content: 31% by weight), manufactured by Nippon Zeon

[Zinc oxide]
2 types of zinc oxide, made by Mitsui Mining & Mining

〔stearic acid〕
LUNAC S30, manufactured by Kao

〔Carbon black〕
Seast SO, manufactured by Tokai Carbon

[Organized layered clay mineral (a) (component B)]
Cloisite 30B, manufactured by Southern Clay Products

[Organized layered clay mineral (b)]
Esven NX (di-cured beef tallow alkyldimethylammonium is used as an organic treatment agent), manufactured by Hojun Co.

[Carboxyl-modified NBR]
Nipol 1072J, manufactured by Nippon Zeon

[Vulcanization accelerator]
Sunseller CZ-G, manufactured by Sanshin Chemical Co., Ltd.

〔sulfur〕
Sulfur-PTC, manufactured by Daito Sangyo

[Examples 1-4, Comparative Examples 1-3]
After blending the materials shown above in the proportions shown in Tables 1 and 2 below, these are kneaded (kneading by a master batch method) using a hermetic kneader (Banbury type) and rolls, thereby producing a hose. A rubber composition was prepared. In addition, when measured by the X-ray diffraction method, the interlayer distance (inter-crystal distance) of the plate-like crystals of the organically modified layered clay mineral in Examples 1 to 4 and Comparative Example 3 was about 30 to 85 mm.

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

[Normal properties]
Using the rubber composition for each hose, this was press vulcanized at 160 ° C. for 30 minutes to form a vulcanized sheet (120 mm × 120 mm × thickness 2 mm). Then, instead of the normal physical properties of the hose itself, this vulcanized sheet was used to measure the normal physical properties (TB, EB, Hs) according to JIS K6251.
TB: Strength at break (MPa)
EB: Elongation at break (%)
Hs: Hardness (JIS A)

[Nitrogen gas permeability coefficient, resistance to nitrogen gas permeability]
Using the rubber composition for each hose, this was press vulcanized at 160 ° C. for 30 minutes to form a vulcanized sheet (120 mm × 120 mm × thickness 2 mm). Then, instead of measuring and evaluating the nitrogen gas permeability of the hose itself, this vulcanized sheet was used for measurement and evaluation. That is, the nitrogen gas permeability coefficient was measured by a gas permeability measuring device MT-C3 (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a test temperature of 80 ° C. according to the pressure method of JIS K7126. In the evaluation of nitrogen gas resistance, if the nitrogen gas permeability coefficient is less than 1.0 × 10 ⁻⁹ (cm ³ cm / cm ² sec cmHg at 80 ° C.), it is evaluated as “good”, and 1.0 If it was more than x10 < ^-9 > (cm < ³ > cm / cm < ² > sec cmHg at 80 degreeC), it evaluated as x.

  From the above results, the hose obtained by extruding the rubber composition for hoses of all Examples (the hose of all Examples) has excellent normal properties and low nitrogen gas permeability, and is excellent as an automotive hose. I understand that.

  On the other hand, it can be seen that the hoses of Comparative Examples 1 and 2 have insufficient reinforcement and high nitrogen gas permeability. In addition, the hose of Comparative Example 3 contains an organically modified layered clay mineral in the material, but is organicized with a nonpolar organic treatment agent, resulting in poor dispersibility with respect to NBR. It can be seen that the effect of improving the nitrogen gas resistance is hardly obtained.

It is a block diagram which shows an example of the hose of this invention. It is a block diagram which shows the other example of the hose of this invention.

Explanation of symbols

  1 innermost layer

Claims (3)

A hose comprising at least one constituent layer, wherein the innermost layer is formed of a rubber composition having the following (A) and (B) as essential components.
(A) Polar group-containing rubber.
(B) An organized layered clay mineral organized by an organotreating agent having a polar group.   The hose according to claim 1, wherein the content of the organically layered clay mineral of the component (B) is in the range of 3 to 50 parts by weight with respect to 100 parts by weight of the component (A). The hose according to claim 1 or 2, wherein the organically modified layered clay mineral of component (B) is organically treated with an organic treatment agent comprising a compound represented by the following formula (1) as a main component.