JP4851863B2 - Rubber composition and rubber product using the same - Google Patents

Description

  The present invention relates to a rubber composition and a rubber product using the same, and more specifically, for fuels such as automobiles (gasoline, alcohol-mixed gasoline (gasohol), alcohol, hydrogen, light oil, dimethyl ether, LPG, CNG, etc.). The present invention relates to a rubber composition and a rubber product using the same, which are used for a fuel pipe hose, a fuel transport hose, and an air conditioner hose for sending an air conditioner refrigerant.

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, a rubber material in which a flaky filler such as clay is blended with butyl rubber such as chlorinated butyl rubber has been used (see, for example, Patent Document 1). However, such a rubber material has a problem that scaly fillers such as clay are not sufficiently dispersed. In order to solve this problem, a rubber material in which the dispersibility of the clay is improved by blending a diene rubber and clay with a low molecular weight liquid rubber such as liquid polybutadiene has been proposed (for example, patents). Reference 2).
Japanese Patent Laid-Open No. 10-47552 Japanese Patent Publication No. 6-84456

  However, in the above-mentioned Patent Document 2, although clay is nano-dispersed, a low molecular weight liquid rubber is not crosslinked with a matrix rubber (diene rubber), so that sufficient characteristics [modulus 100 (M100), fracture Elongation (EB) etc.] cannot be obtained.

  The present invention has been made in view of such circumstances, and has excellent clay dispersibility, low permeability and sufficient properties [modulus 100 (M100), elongation at break (EB), etc.]. The object is to provide a composition and a rubber product using the composition.

（Ｃ）ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビスフェノールＡＤ型エポキシ樹脂および臭素化ビスフェノールＡ型エポキシ樹脂からなる群から選ばれた少なくとも一つの、両末端にエポキシ基を有するエポキシ樹脂。
（Ｄ）下記の一般式（４）で表される、メチロール基を有するフェノール系樹脂。

In order to achieve the above object, the present invention has the following components (A) to (D) as essential components, and the blending amount of the component (B) is 5 to 30 parts per 100 parts by weight of the component (A). The range of parts by weight, the blending amount of the component (C) is in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the component (A), and the blending amount of the component (D) is 100 parts by weight of the component (A). the scope der Ru rubber composition 2 to 20 parts by weight of the first aspect with respect, also, the rubber products made from the rubber composition and the second aspect.
(A) Natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), chlorinated butyl (Cl-IIR) , At least one diene rubber selected from the group consisting of brominated butyl (Br-IIR) and ethylene-propylene-diene rubber (EPDM) .
(B) A clay formed by surface treatment with an organic treatment agent, wherein the organic treatment agent comprises an organic treatment agent comprising a compound represented by the following structural formula (1) as a main component, and the following structural formula: (1) at least one selected from the group consisting of an organic treatment agent containing as a main component a compound represented by (2) and an organic treatment agent containing as a main component a compound represented by the following structural formula (3) It is .

(C) At least one epoxy resin selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin and brominated bisphenol A type epoxy resin , having an epoxy group at both ends.
(D) A phenolic resin having a methylol group represented by the following general formula (4) .

  That is, the present inventors are eager to obtain a rubber composition that is excellent in dispersibility of clay, has low permeability and sufficient properties [modulus 100 (M100), elongation at break (EB), etc.]. Repeated examination. In the course of the research, instead of ordinary clay, clay (organically treated clay) obtained by surface treatment with an organic treating agent is used, which has an epoxy resin having an epoxy group at both ends and a methylol group. It has been found that the intended purpose can be achieved by using a phenolic resin in combination, and the present invention has been achieved. This is thought to be based on the following reasons. That is, as shown in FIG. 1, the epoxy groups in the epoxy resin 3 having epoxy groups at both ends have an affinity for the clay 2 of each layer surface-treated with the organic treatment agent 1. When the epoxy resin 3 enters the interlayer of each clay 2, the dispersibility of the clay 2 is improved. Furthermore, by continuing the kneading, the epoxy group of the specific epoxy resin 3 reacts with the methylol group of the phenolic resin 4 having a methylol group (not limited to the structure shown in the figure), The hydroxyl group of the specific phenolic resin 4 also reacts with the diene rubber (not shown). In this way, the methylol group of the specific phenolic resin 4 reacts with the epoxy group in the specific epoxy resin 3 that has entered the interlayer of each clay 2, and the hydroxyl group of the specific phenolic resin 4 is converted to a diene rubber ( By reacting with a specific phenol resin 4 and a specific epoxy resin 3 (so-called bridging bond), the dispersed clay 2 is dispersed in a diene rubber (not shown). As a result of being able to be fixed, the dispersibility of the clay 2 is improved, the added specific epoxy resin 3 is cured, the physical properties are greatly improved, and the dispersed clay 2 is considered to act effectively. It is done.

  Thus, the rubber composition of the present invention comprises a diene rubber, a clay formed by surface treatment with an organic treatment agent, an epoxy resin having an epoxy group at both ends, and a phenolic resin having a methylol group. Used together. Therefore, as described above, the methylol group of the specific phenolic resin reacts with the epoxy group in the specific epoxy resin that has entered the interlayer of each clay, and the hydroxyl group of the specific phenolic resin is diene rubber (see FIG. By reacting with (not shown), the dispersed clay can be fixed in the diene rubber via a bond between a specific phenol resin and a specific epoxy resin (so-called bridging bond). As a result, the dispersibility of the clay is improved, the added specific epoxy resin is cured, the physical properties are greatly improved, and the dispersed clay effectively acts.

  And rubber products, such as a hose using the rubber composition of the present invention, have improved strength and permeation resistance to gases and liquids (excellent in low permeability).

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

  The rubber composition of the present invention comprises a diene rubber (component A), a clay (B component) obtained by surface treatment with an organic treatment agent, an epoxy resin having epoxy groups at both ends (component C), and methylol. It can be obtained using a phenolic resin having a group (D component).

As the diene rubber (A component), natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene - butadiene rubber (SBR), acrylonitrile - butadiene rubber (NBR), butyl rubber (IIR) At least one selected from the group consisting of chlorinated butyl (Cl-IIR), brominated butyl (Br-IIR), and ethylene-propylene-diene rubber (EPDM) is used. Among these, NBR is preferably used in terms of rubber properties.

  Next, as a clay [organization treated clay] (component B) used with the diene rubber (component A) and surface-treated with an organic treatment agent, for example, montmorillonite, saponite, hectorite, beidellite, Examples include smectite-based layered clay minerals such as nontronite, soconite, and stevensite, and layered clay minerals such as vermiculite, halloysite, and mica that have a cation exchange ability, and the like, treated with an organic treatment agent. These may be used alone or in combination of two or more.

Is the above organic treatment agents, organic mainly organic treatment agent containing as a main component a compound represented by the following structural formula (1), a compound represented by the following structural formula (2) treatment agent, and at least one is used the following structural formula the compound represented by formula (3) selected from the group consisting of organic treatment agents composed mainly.

The amount of the organically treated clay (component B) is in the range of 5 to 30 parts , preferably 5 to 100 parts by weight (hereinafter abbreviated as “part”) of the diene rubber (component A). The range is 15 parts. That is, when the amount of the organically treated clay (component B) is less than 5 parts, it is difficult to sufficiently achieve the intended effect of the present invention. This is because the reinforcement becomes high and the rubber tends to become hard.

Next, the Component A and the specific epoxy resin used in conjunction with B component (C component), bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, and brominated bisphenol A type epoxy At least one epoxy resin having epoxy groups at both ends selected from the group consisting of resins is used. Among these, bisphenol A type epoxy resins are preferably used. The specific epoxy resin (C component) is preferably in a liquid form from the viewpoint of easy entry into the respective layers of the organically treated clay (B component) during kneading.

  Specific examples of the specific epoxy resin (component C) include bisphenol A type epoxy resin (Japan Epoxy Resin, Epicoat 828), Japan Epoxy Resin Epicoat 827, Epicoat 828EL, Epicoat 828XA and the like. It is done.

The compounding amount of the specific epoxy resin (component C) is in the range of 2 to 20 parts , preferably in the range of 5 to 15 parts , with respect to 100 parts of the diene rubber (component A). That is, when the blending amount of the specific epoxy resin (component C) is less than 2 parts, the effect of expanding the clay layer tends to be lowered, and conversely, when it exceeds 20 parts, the physical properties of the rubber are lowered. This is because there is a tendency.

  The specific epoxy resin (component C) is preferably an oligomer, and its weight average molecular weight (Mw) is preferably in the range of 100 to 500, particularly preferably in the range of 200 to 400.

Next, as the specific phenolic resin (D component) used together with the components A to C, a phenolic resin having at least one methylol group represented by the following general formula (4) is used . As described above, when a phenolic resin having a methylol group (component D) is used, it reacts with the epoxy group in a specific epoxy resin (component C) to increase the molecular weight, thereby suppressing re-aggregation of clay and dispersing clay. Can be improved. The specific phenolic resin (D component) is preferably melted during kneading with a diene rubber (A component) or the like, and usually the rubber temperature during rubber kneading is 100 ° C. or higher. The phenolic resin (component D) preferably has a melting point of 100 ° C. or higher.

  In the general formula (4), examples of the organic group represented by R include an alkyl group. Moreover, in the said General formula (4), n shows the integer from which the number average molecular weight (Mn) of a phenol-type resin becomes the range of 1300-1400.

  Specific examples of the specific phenol-based resin (component D) include Takkol 201G manufactured by Taoka Chemical Industry Co., Ltd.

  The specific phenolic resin (D component) is preferably one in which the methylol group site is halogenated (brominated or the like) from the viewpoint of reactivity with the diene rubber (A component).

The amount of the specific phenolic resin (component D) is in the range of 2 to 20 parts , preferably in the range of 5 to 15 parts , with respect to 100 parts of the diene rubber (component A). That is, if the blending amount of the specific phenolic resin (D component) is less than 2 parts, since the D component involved in the reaction with the specific epoxy resin (C component) is small, the dispersion of clay is not sufficient. On the other hand, if it exceeds 20 parts, the physical properties of the rubber tend to decrease.

  In addition, when using the specific phenol-based resin (D component) where the methylol group site is not halogenated (brominated, etc.), from the point of reactivity with the diene rubber (component A), It is preferable to add a known Lewis acid catalyst.

  In addition, the rubber composition of the present invention contains a reinforcing agent, a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, an anti-aging agent, a process oil, and the like as needed along with the components A to D. It is also possible to do.

  Examples of the reinforcing agent include carbon black, silica, clay, talc and the like.

  The carbon black is not particularly limited, and examples thereof include various grades of carbon black such as SAF class, ISAF class, HAF class, MAF class, FEF class, GPF class, SRF class, FT class, and MT class. . These may be used alone or in combination of two or more. Among these, FEF grade carbon black is preferably used from the viewpoints of cost, durability, and the like.

  The amount of the reinforcing agent such as carbon black is preferably 100 parts or less, particularly preferably 30 to 80 parts, per 100 parts of the diene rubber (component A). That is, when the compounding amount of the reinforcing agent such as carbon black exceeds 100 parts, the Mooney viscosity increases and the workability tends to deteriorate.

  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 diene rubber (component A).

  The vulcanization accelerator is not particularly limited, and examples thereof include thiazole type, sulfenamide type, aldehyde ammonia type, aldehyde amine type, guanidine type, thiourea type vulcanization accelerators. These may be used alone or in combination of two or more. Among these, a sulfenamide-based vulcanization accelerator is preferable from the viewpoint of excellent crosslinking reactivity.

  Further, the blending amount of the vulcanization accelerator is preferably 0.5 to 7 parts, particularly preferably 0.5 to 5 parts, relative to 100 parts of the diene rubber (component A).

  Examples of the thiazole vulcanization accelerator include dibenzothiazyl disulfide (MBTS), 2-mercaptobenzothiazole (MBT), 2-mercaptobenzothiazole sodium salt (NaMBT), and 2-mercaptobenzothiazole zinc salt (ZnMBT). Etc. These may be used alone or in combination of two or more. Among these, dibenzothiazyl disulfide (MBTS) and 2-mercaptobenzothiazole (MBT) are preferably used because they are particularly excellent in crosslinking reactivity.

  Examples of the sulfenamide-based vulcanization accelerator include N-oxydiethylene-2-benzothiazolylsulfenamide (NOBS), N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), and Nt. -Butyl-2-benzothiazoylsulfenamide (BBS), N, N'-dicyclohexyl-2-benzothiazoylsulfenamide and the like.

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

  The amount of the vulcanization aid is preferably 1 to 25 parts, particularly preferably 3 to 10 parts, per 100 parts of the diene rubber (component A).

  Examples of the anti-aging agent include carbamate-based anti-aging agents, phenylenediamine-based anti-aging agents, phenol-based anti-aging agents, diphenylamine-based anti-aging agents, quinoline-based anti-aging agents, imidazole-based anti-aging agents, and waxes. can give. These may be used alone or in combination of two or more.

  Further, the blending amount of the anti-aging agent is preferably 1 to 10 parts, particularly preferably 2 to 5 parts with respect to 100 parts of the diene rubber (component A).

  Examples of the process oil include naphthenic oil, paraffinic oil, and aroma oil. These may be used alone or in combination of two or more.

  The amount of the process oil is preferably 1 to 50 parts, particularly preferably 3 to 30 parts, per 100 parts of the diene rubber (component A).

  The rubber composition of the present invention is prepared using, for example, a closed kneader, a diene rubber (component A), an organically treated clay (component B), and an epoxy resin (component C) having epoxy groups at both ends. And kneaded for 3 to 10 minutes in a state where the rubber temperature is 130 ° C. or lower to disperse the organically treated clay (component B). Next, a phenolic resin having a methylol group (D component) is added thereto, and the rubber temperature is increased to 160 to 180 ° C. (temperature at which the C component and D component react), and further The components C and D are reacted by kneading for 5 to 15 minutes. Next, the rubber composition can be prepared by kneading the vulcanizing agent and the vulcanization accelerator using a roll.

  A rubber product (hose) using the rubber composition of the present invention can be produced, for example, as follows. That is, a hose having a single layer structure including only the innermost layer 11 can be produced by extruding a rubber composition prepared in the same manner as described above using an extruder (see FIG. 2).

  The thickness of the innermost layer 11 is usually set in the range of 0.1 to 3.0 mm, preferably 0.3 to 2.0 mm.

  The rubber product (hose) of the present invention is not limited to the single-layer structure shown in FIG. 2. For example, as shown in FIG. 3, the outer layer 12 is formed on the outer peripheral surface of the innermost layer 11. Even a two-layer structure can be used. In addition, a three-layer structure in which an intermediate layer made of, for example, a reinforcing yarn is formed between the innermost layer 11 and the outer layer 12 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 12 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 11 is not particularly limited. 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 11 using a special rubber composition similar to the innermost layer 11.

  The shape of the hose is not particularly limited, and may be either a long hose or a short hose, and may be formed into a bellows shape.

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

[Example 1]
Using a closed kneader (Toyo Seiki Co., Ltd., Labo Plast Mill Capacity 600 cc), 100 parts of diene rubber (component A), 30 parts of carbon black, and 14.3 parts of organically treated clay a (component B) Then, 5 parts of an epoxy resin (C component) having an epoxy group at both ends was added and kneaded for 5 minutes at a rubber temperature of 130 ° C. or lower to disperse the B component. Next, in this, 5 parts of phenolic resin having a methylol group (component D) is added, the temperature of the rubber is raised to 160 to 170 ° C., and the mixture is further kneaded for 10 minutes. The D component was reacted. Next, 2.5 parts of a vulcanizing agent (sulfur) and 1 part of a vulcanization accelerator (CBS) were kneaded using a roll to prepare a rubber composition.

[Examples 2 to 7]
A rubber composition was prepared in accordance with Example 1 except that the type and amount of each component were changed as shown in Table 1 below.

[Comparative Example 1]
50 parts of diene rubber (component A), 14.3 parts of organically treated clay a (component B), 30 parts of carbon black, 2.5 parts of vulcanizing agent (sulfur), and vulcanization accelerator (CBS) ) 1 part was kneaded using a roll, and the kneaded product was kneaded with 50 parts of a diene rubber (component A) to prepare a rubber composition (master batch method).

  The materials shown in Table 1 are as follows.

[Diene rubber (component A)]
NBR (Nippon Zeon, Nipol DN003, acrylonitrile content: 50%)
[Organization treated clay a (component B)]
Clay organized by an organic treating agent containing the compound represented by the structural formula (1) as a main component (Closite 30B, manufactured by Southern Clay Products Co., Ltd.)
[Organization treated clay b (component B)]
Clay organized by an organic treatment agent containing as a main component a compound represented by the structural formula (2) (Closite 10A, manufactured by Southern Clay Products)
[Organization treated clay c (component B)]
Clay (Organization 15A, manufactured by Southern Clay Product Co., Ltd.) organized with an organic treatment agent comprising the compound represented by the structural formula (3) as a main component.
[Epoxy resin having epoxy groups at both ends (C component)]
Bisphenol A epoxy resin (Japan Epoxy Resin, Epicoat 828)
[Phenolic resin having methylol group (component D)]
Made by Taoka Chemical Co., Ltd.
〔Carbon black〕
SEAST SO manufactured by Tokai Carbon
[Vulcanizing agent]
Sulfur (Tsurumi Chemical Co., Ltd., Sulfax200S)
[Vulcanization accelerator (CBS)]
N-cyclohexyl-2-benzothiazolylsulfenamide (manufactured by Sanshin Chemical Co., Ltd.)

  Using the rubber compositions of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are also shown in Table 1 above.

[Normal properties]
Each rubber composition was press vulcanized at 160 ° C. for 30 minutes to form a rubber sheet (120 mm × 120 mm, thickness 2 mm). Then, using this rubber sheet, the modulus 100 (M100), breaking strength (TB), breaking elongation (EB), and hardness (Hs: JIS A) were measured in accordance with JIS K 6251.

(Transparency)
Each rubber composition was press vulcanized at 160 ° C. for 30 minutes to form a rubber sheet (120 mm × 120 mm, thickness 2 mm). And it replaced with the measurement and evaluation of the nitrogen gas permeability of hose itself, and measured and evaluated using this rubber sheet. That is, with a gas permeability measuring device MT-C3 (manufactured by Toyo Seiki Seisakusho Co., Ltd.), a nitrogen gas permeability coefficient (cm ³ · cm / cm ² · sec · cmHg) at a test temperature of 80 ° C. according to the pressure method of JIS K7126. , At 80 ° C.). And the coefficient ratio when the nitrogen gas permeation coefficient of Comparative Example 1 is 1 is shown in the table.

  From the results of Table 1 above, the product of the example had a high value of M100 and excellent strength and low transmission as compared with the product of the comparative example. This is because the example product uses both an epoxy resin having an epoxy group at both ends and a phenolic resin having a methylol group, so that the dispersed clay is fixed in the diene rubber, and the dispersibility of the clay This is considered to be because the re-aggregation of clay is suppressed.

  On the other hand, since the product of Comparative Example 1 uses neither an epoxy resin having an epoxy group at both ends nor a phenolic resin having a methylol group, the value of M100 is small and the strength is inferior. The value was large and the flexibility was poor, and the low permeability was also poor.

  The rubber composition of the present invention and a rubber product using the rubber composition are used for connecting a hose for a fuel pipe such as a feed hose, a return hose, a breather hose, an evaporative hose, a filler hose, and an engine and a radiator in a vehicle such as an automobile. Water hoses for automobiles such as radiator hoses used, engine cooling system hoses such as heater hoses used to connect the engine and heater core, refrigerant transport hoses for coolers, fuel cell system hoses for fuel cell electric vehicles (FCEV), etc. As well as general high-pressure hoses (for hydraulic and hydraulic equipment), as well as anti-vibration materials such as engine mounts, stabilizer bushes and suspension bushes used in automobile vehicles, etc. Can do.

It is a schematic diagram which shows the reaction estimation mechanism in the rubber composition of this invention. It is a block diagram which shows an example of the rubber product (hose) using the rubber composition of this invention. It is a block diagram which shows the other example of the rubber product (hose) using the rubber composition of this invention.

DESCRIPTION OF SYMBOLS 1 Organizing agent 2 Clay 3 Epoxy resin which has an epoxy group at both ends 4 Phenolic resin which has a methylol group

Claims (2)

The following (A) to (D) are essential components, and the blending amount of the component (B) is in the range of 5 to 30 parts by weight with respect to 100 parts by weight of the component (A). The amount is in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the component (A), and the blending amount of the component (D) is in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the component (A). The rubber composition characterized by the above-mentioned.
(A) Natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), chlorinated butyl (Cl-IIR) , At least one diene rubber selected from the group consisting of brominated butyl (Br-IIR) and ethylene-propylene-diene rubber (EPDM) .
(B) A clay formed by surface treatment with an organic treatment agent, wherein the organic treatment agent comprises an organic treatment agent comprising a compound represented by the following structural formula (1) as a main component, and the following structural formula: (1) at least one selected from the group consisting of an organic treatment agent containing as a main component a compound represented by (2) and an organic treatment agent containing as a main component a compound represented by the following structural formula (3) It is .

(C) At least one epoxy resin selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin and brominated bisphenol A type epoxy resin , having an epoxy group at both ends.
(D) A phenolic resin having a methylol group represented by the following general formula (4) .

Rubber products made with claim 1 Symbol placement of the rubber composition.

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