JP2008094947A - Rubber composition and hose for refrigerant transportation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hose excellent in gas leakage prevention, heat resistance, pressure resistance, and durability and a rubber composition to be used in this hose. <P>SOLUTION: The hose 10 for refrigerant transportation has a four-layered structure and is obtained by laminating a fluororesin layer 1, a first rubber layer 2, a brass plated wire layer 3, and a second rubber layer 4 in the order named from the inner side. The first rubber layer 2 and the second rubber layer 4 comprise 100 pts.mass rubber component containing an acrylic rubber having a carboxyl group and/or an acid anhydride group as a crosslinking site, 1-30 pts.mass phenolic resin, 1-30 pts.mass silica, 0.1-5 pts.mass triazine based compound, and 0.5-10 pts.mass polyamine. The fluororesin layer 1 is composed of a fluororesin having a carboxyl group and/or an acid anhydride group. The carboxyl groups and/or the acid anhydride groups of the first rubber layer 2 and the fluororesin layer 1 mutually form a crosslinked structure with the use of the triazine based compound as a crosslinking agent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hose excellent in gas leakage prevention, heat resistance and pressure resistance, and a rubber composition used for the hose.

  Conventionally, CFCs such as HFC-134a have been used as refrigerants in automobile air conditioners. The piping of this air conditioner for automobiles is strongly required to have a vibration absorbing performance from the viewpoint of improving riding comfort, and therefore, a rubber hose is widely used as this piping.

  For example, JP-A-6-294484 describes a refrigerant transport hose having a four-layer structure. In the refrigerant transport hose of the example of the publication, a nylon resin layer, a butyl rubber (IIR) layer, a vinylon, and an EPDM rubber layer are laminated in this order from the inside. This nylon resin layer functions as a gas barrier and prevents leakage of chlorofluorocarbon gas. In addition, vinylon functions as a reinforcing material.

  Incidentally, in recent years, carbon dioxide has attracted attention as a candidate for a next-generation refrigerant. Carbon dioxide has a small global warming potential of 1/1300 that of HFC-134a, and has an ozone depletion coefficient of zero.

  In order for this carbon dioxide to function as a refrigerant, it is necessary to bring the carbon dioxide into a supercritical state, that is, a high temperature and high pressure state at a temperature of 150 ° C. or higher and a pressure of 15 MPa or higher. For this reason, it is necessary for the refrigerant piping to be able to withstand this high-temperature and high-pressure state, and to suppress leakage due to the permeation of carbon dioxide even in this situation.

  However, a conventional refrigerant transport hose such as the refrigerant transport hose disclosed in JP-A-6-294484 cannot satisfy such required performance. That is, nylon resin has a large amount of carbon dioxide permeation under such high temperature and high pressure conditions. Also, butyl rubber (IIR) layers and EPDM rubber layers cannot withstand such high temperatures for a long period of time. Furthermore, vinylon has insufficient pressure resistance under such high pressure conditions, and performance stability of the crimped portion is also insufficient.

In addition, when a hose consists of a composite body of multiple layers, it is requested | required that adhesion | attachment of each layer is sufficiently strong and it is excellent in durability.
JP-A-6-294484

  An object of this invention is to provide the hose excellent in the gas leakage prevention property, heat resistance, pressure | voltage resistance, and durability, and the rubber composition used for this hose.

  The rubber composition according to claim 1 is 100 parts by mass of a rubber component containing an acrylic rubber having a carboxyl group and / or an acid anhydride group as a crosslinking site, 1-30 parts by mass of a phenol resin, 1-30 parts by mass of silica, It contains 0.1 to 5 parts by mass of a triazine compound and 0.5 to 10 parts by mass of a polyamine.

  The rubber composition of claim 2 is characterized in that, in claim 1, the triazine compound is represented by the following general formula (I).

（式中、Ｒはメルカプト基、アルコキシ基、モノアルキルアミノ基、ジアルキルアミノ基、モノシクロアルキルアミノ基、ジシクロアルキルアミノ基又はＮ−アルキル−Ｎ−アリールアミノ基である。）
請求項３の冷媒輸送用ホースは、冷媒を輸送するための冷媒輸送用ホースであって、ゴム層と、該ゴム層の内周面又は外周面のいずれか一方を覆い冷媒の透過を防止する樹脂層と、該ゴム層の内周面又は外周面のいずれか他方を覆いホースを補強する補強層とを含む冷媒輸送用ホースにおいて、該ゴム層が請求項１又は２に記載のゴム組成物よりなるものであり、該樹脂層が、カルボキシル基及び／又は酸無水物基を有するフッ素樹脂よりなるものであり、該補強層がブラスメッキワイヤよりなるものであることを特徴とするものである。

(In the formula, R is a mercapto group, an alkoxy group, a monoalkylamino group, a dialkylamino group, a monocycloalkylamino group, a dicycloalkylamino group, or an N-alkyl-N-arylamino group.)
The refrigerant transport hose according to claim 3 is a refrigerant transport hose for transporting the refrigerant, and covers the rubber layer and either the inner peripheral surface or the outer peripheral surface of the rubber layer to prevent permeation of the refrigerant. The rubber composition according to claim 1 or 2, wherein the rubber layer comprises a resin layer and a reinforcing layer that covers either the inner peripheral surface or the outer peripheral surface of the rubber layer and reinforces the hose. The resin layer is made of a fluororesin having a carboxyl group and / or an acid anhydride group, and the reinforcing layer is made of a brass plated wire. .

  According to a fourth aspect of the present invention, there is provided a refrigerant transport hose according to the third aspect, wherein a ceramic vapor-deposited layer is provided on the peripheral surface of the resin layer opposite to the side covered with the rubber layer. is there.

  The refrigerant transport hose according to claim 5 is characterized in that, in claim 4, the vapor deposition layer is made of alumina, and the thickness of the vapor deposition layer is 0.05 to 10 μm.

  A refrigerant transport hose according to claim 6 is the hose for transporting refrigerant according to claim 3, wherein the peripheral surface of the resin layer opposite to the side covered with the rubber layer is also made of the rubber composition according to claim 1 or 2. It is characterized by being covered with a rubber layer.

  The rubber composition of the present invention is excellent in heat resistance. Moreover, it can adhere | attach with sufficient adhesiveness with respect to the fluororesin which has a carboxyl group and / or an acid anhydride group as a bridge | crosslinking site | part, and can adhere | attach also with respect to brass plating wire with sufficient adhesiveness.

  Since the refrigerant transportation hose of the present invention uses acrylic rubber as a rubber component, it is excellent in heat resistance. Moreover, since it has a resin layer which consists of a fluororesin as a resin layer for preventing permeation | transmission of a refrigerant | coolant, it is excellent in the gas leakage prevention property. Furthermore, since it has a brass plating wire as a reinforcing layer, it is excellent in pressure resistance. In addition, the refrigerant transport hose of the present invention is excellent in durability because the resin layer, the reinforcing layer, and the rubber layer are bonded with good adhesion.

  In the refrigerant transport hose of the present invention, it is preferable that a ceramic vapor deposition layer is provided on the peripheral surface of the resin layer opposite to the side covered with the rubber layer. If there is this ceramic vapor deposition layer, the permeation of the refrigerant is more reliably prevented. Moreover, since this vapor deposition layer prevents permeation | transmission of a refrigerant | coolant, the thickness of a fluororesin can be made small and, thereby, the softness | flexibility of a hose improves.

  The vapor deposition layer is preferably made of alumina, and the thickness of the vapor deposition layer is preferably 0.05 to 10 μm.

  The peripheral surface of the fluororesin layer opposite to the side covered with the rubber layer may also be covered with a rubber layer made of the rubber composition of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a refrigerant transport hose 10 according to an embodiment.

  The refrigerant transport hose 10 shown in FIG. 1 has a four-layer structure, in which a fluororesin layer 1, a first rubber layer 2, a brass-plated wire layer 3, and a second rubber layer 4 are laminated in this order from the inside. .

  The first rubber layer 2 and the second rubber layer 4 are composed of 100 parts by mass of a rubber component containing acrylic rubber having a carboxyl group and / or an acid anhydride group as a crosslinking site, 1 to 30 parts by mass of a phenol resin, It contains 1-30 parts by mass of silica, 0.1-5 parts by mass of triazine compound and 0.5-10 parts by mass of polyamine. The fluororesin layer 1 is made of a fluororesin having a carboxyl group and / or an acid anhydride group.

  The refrigerant transport hose 10 is excellent in heat resistance because the first rubber layer 2 and the second rubber layer 4 have acrylic rubber as a rubber component. Moreover, since the fluororesin layer 1 is included and the fluororesin layer 1 is difficult to permeate refrigerants such as chlorofluorocarbon and carbon dioxide, leakage of the refrigerant from the refrigerant transport hose 10 is suppressed. Further, since the brass plating wire is provided, the pressure resistance of the refrigerant transport hose 10 is improved.

  The first rubber layer 2 has a carboxyl group and / or an acid anhydride group as a crosslinking site, and also has a polyamine as a crosslinking agent. The fluororesin layer 1 is made of a fluororesin having a carboxyl group and / or an acid anhydride group. Therefore, the carboxyl group and / or acid anhydride group in the first rubber layer 2 and the carboxyl group and / or acid anhydride group in the fluororesin layer 4 form the polyamine in the first rubber layer 2. A crosslinked structure is formed as a crosslinking agent, and as a result, the first rubber layer 2 and the fluororesin layer 4 are favorably bonded.

  Further, since the first and second rubber layers 2 and 4 contain a phenol resin, silica, and a triazine compound, the first and second rubber layers 2 and 4 and the brass plating wire 3 are favorably bonded. It will be.

  Next, the first and second rubber compositions, the fluororesin layer, and the brass plating wire will be described in detail.

<First and second rubber compositions>
Examples of the acrylic rubber having a carboxyl group and / or an acid anhydride group as a crosslinking site include a carboxylic acid such as maleic anhydride, or an acrylic rubber chemically modified with the acid anhydride. There is no restriction | limiting in particular as acrylic rubber (AR), What is necessary is just a polymer which has acrylic acid alkylester as a component. Also preferred are ethylene-methyl acrylate copolymers.

  In addition to the rubber component described above, other rubber components may be added to the rubber composition of the present invention as long as the effects of the present invention are not impaired.

  Examples of the phenol resin include oligomers and polymers obtained by condensing phenols and aldehydes. Examples of phenols include phenol, lower alkylphenols such as cresol, xylenol, and tert-butylphenol, higher phenols such as nonylphenol, cashew oil, and lignin, and divalent phenols such as resorcin and catechol. As aldehydes, formaldehyde is mainly used.

  The main phenolic resins include phenol-formaldehyde resin, resorcinol-formaldehyde resin, cresol resin, etc., but phenol-formaldehyde resin is easy to mix into rubber and improves the elastic modulus and tension of rubber composition. This is particularly preferable in terms of improving strength.

  In addition to 100% phenol resin, natural resin-modified phenol resin, oil-modified phenol resin, and the like can be used as the phenol resin.

  Further, as the phenol resin, a novolak type resin that is a two-step resin that is cured using a curing agent can be used. Examples of the curing agent include hexamethylenetetramine and hexamethoxymethylmelamine. These combinations can be freely selected, and a plurality of resins and their curing agents may be selected. Further, a resin in which a curing agent is internally added may be used.

  A phenol resin is mix | blended in 1-30 mass parts with respect to 100 mass parts of said rubber components. When the blending amount of the phenol resin is less than 1 part by mass, sufficient adhesion with the brass plating wire cannot be obtained, and when it exceeds 30 parts by mass, the rubber composition becomes too hard and lacks flexibility. Arise. From the above points, the blending amount of the phenol resin is more preferably in the range of 2 to 20 parts by mass.

Silica (SiO ₂ ) is not particularly limited as long as it is generally used in rubber compositions, and may be crystalline or amorphous. As a commercial item, Nippon Silica Industry Co., Ltd. nip seal AQ etc. can be mentioned.

  Silica is blended in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the rubber component. If it is less than 1 part by mass, sufficient adhesion to the brass-plated wire cannot be obtained, and if it exceeds 30 parts by mass, the viscosity of the rubber composition when unvulcanized becomes too high, and the processability such as extrusion is poor. Become. From the above points, the amount of silica is more preferably in the range of 2 to 20 parts by mass.

  As the triazine compound, those represented by the following general formula (I) are preferably used.

式中、Ｒはメルカプト基、アルコキシ基、モノアルキルアミノ基、ジアルキルアミノ基、モノシクロアルキルアミノ基、ジシクロアルキルアミノ基又はＮ−アルキル−Ｎ−アリールアミノ基である。これらのうち特にメルカプト基であることが好ましい。

In the formula, R is a mercapto group, an alkoxy group, a monoalkylamino group, a dialkylamino group, a monocycloalkylamino group, a dicycloalkylamino group or an N-alkyl-N-arylamino group. Of these, a mercapto group is particularly preferable.

  Examples of commercially available products include “ZISNET-F” manufactured by Sankyo Kasei Co., Ltd. and “TDCA” manufactured by Ouchi Shinsei Chemical Co., Ltd.

  A triazine type compound is mix | blended in 0.1-5 mass parts with respect to 100 mass parts of said rubber components. If the amount is less than 0.1 parts by mass, sufficient adhesion to the brass-plated wire cannot be obtained. If the amount exceeds 5 parts by mass, the vulcanization reaction is hindered. From the above points, the blending amount of the triazine compound is more preferably in the range of 0.5 to 2 parts by mass.

  Examples of the polyamine include diamines such as 2,2-bis (4- (4-aminophenoxy) phenyl) propane, diaminodiphenylmethane, hexamethylenediamine carbamate, and triethylenetetramine. These polyamines may be used alone or in combination of two or more.

  Contacting a fluororesin material having a carboxyl group and / or an acid anhydride group with a rubber component having a carboxyl group and / or an acid anhydride group as a crosslinking site and an unvulcanized rubber containing a polyamine as a crosslinking agent; By heating to the vulcanization temperature of the rubber, the unvulcanized rubber is vulcanized and cured, and the carboxyl group and / or acid anhydride group, preferably the acid anhydride group of the fluororesin, and the crosslinking of the rubber component Fluorine resin / rubber in which carboxyl group and / or acid anhydride group, preferably acid anhydride group of site is cross-linked by polyamine of cross-linking agent and vulcanized rubber is firmly bonded to fluororesin material A composite material can be obtained.

  The polyamine content is not particularly limited as long as it is a sufficient amount for vulcanization of rubber and the formation of the above-mentioned crosslinked structure, but is usually 0.5% relative to 100 parts by weight of the rubber component in the unvulcanized rubber. It is preferably about 10 to 10 parts by mass.

  In addition, you may mix | blend an organic peroxide with a polyamine as a crosslinking agent. As the organic peroxide, any organic peroxide that is a vulcanizing agent and that does not allow the crosslinking reaction to proceed extremely at the processing temperature may be used, such as ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide. Examples thereof include oxides, diacyl peroxides, peroxydicarbonates, and peroxyesters. More specifically, dicumyl peroxide, 1,3-bis- (t-butyl-peroxy-isopropyl) benzene, 4,4-di-tert-butyl peroxyvaleric acid n-butyl and the like can be mentioned. Moreover, as a commercial item, "Perkadox 14/40" by Kayaku Nouri Co., Ltd., "Peroximon F40" by Nippon Oil & Fats, etc. are mentioned.

  The organic peroxide is preferably blended in the range of 1 to 15 parts by mass with respect to 100 parts by mass of the rubber component. If it is less than 1 part by mass, there are few crosslinking points, so that sufficient crosslinking is not achieved. On the other hand, if it exceeds 15 parts by mass, the residue of the organic peroxide may adversely affect heat aging. From the above points, the blending amount of the organic peroxide is more preferably in the range of 2 to 10 parts by mass.

  Moreover, you may mix | blend polyether ester, phthalic acid ester, adipic acid ester, etc. with the rubber composition of this invention as a plasticizer. These plasticizers may be used alone or in combination of two or more. Moreover, as the compounding quantity, the range of 5-20 mass parts is suitable with respect to 100 mass parts of said rubber components. Cold resistance improves by mix | blending 5 mass parts or more. On the other hand, when it is less than 20 parts by mass, there is an advantage that the elastic modulus and tensile strength of the rubber are not lowered and the adhesion is not lowered. From the above points, the blending amount of the plasticizer is preferably in the range of 7.5 to 15 parts by mass.

  Moreover, it is preferable to mix | blend a co-crosslinking agent with the rubber composition of this invention. The co-crosslinking agent increases the crosslinking efficiency of the organic peroxide. Specifically, triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), triacryl formal (TAF), diallyl phthalate (DAP) Etc. Of these, TAIC and TAF are particularly preferable in terms of crosslinking efficiency.

  These co-crosslinking agents can be used singly or in combination of two or more, and the blending amount thereof is preferably in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the rubber component. . When the amount is 1 part by mass or more, sufficient crosslinking is obtained, and when the amount is 10 parts by mass or less, the co-crosslinking agent residue does not adversely affect thermal aging. From the above points, the amount of the co-crosslinking agent is more preferably in the range of 1.5 to 5 parts by mass.

  The rubber composition of the present invention may be blended with an appropriate amount of an anti-aging agent, a filler, a reinforcing agent, a softening agent and other compounding agents that are usually used as necessary.

  The anti-aging agent is not particularly limited as long as it is a heat-resistant or weather-resistant anti-aging agent. For example, naphthylamine type such as phenyl-α-naphthylamine; diphenylamine type such as octyldiphenylamine; N-isopropyl-N′-phenyl P-phenylenediamine systems such as -p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine; Quinoline series such as polymer of 2,2,4-trimethyl-1,2-dihydroquinoline; 2,6-di-t-butyl-4-methylphenol, styrenated phenol, tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] and phenolic anti-aging agents such as methane. It is.

  These anti-aging agents may be used alone or in combination of two or more. Moreover, as the compounding quantity, the range of 0.5-5 mass parts is preferable with respect to 100 mass parts of said rubber components. By blending 0.5 parts by mass or more, aging can be sufficiently prevented, and when it is 5 parts by mass or less, crosslinking is not inhibited, which is preferable. From the above points, the blending amount of the antioxidant is preferably in the range of 1 to 3 parts by mass.

  Examples of the filler include carbon black, calcium carbonate, talc, clay, barium sulfate, and titanium oxide.

  As the carbon black used in the present invention, those usually used in the rubber industry can be used. For example, there are channel black, furnace black, acetylene black and thermal black depending on the manufacturing method, but any of them can be used, and various grades of carbon black such as SAF, HAF, ISAF, FEF, GPF can be used. They can be used alone or in combination.

  As a compounding quantity of carbon black, the range of 50-100 mass parts is preferable with respect to 100 mass parts of said rubber components.

<Fluorine resin layer>
The fluororesin is made of a fluororesin having a carboxyl group and / or an acid anhydride group. The fluorine resin having a carboxyl group and / or an acid anhydride group is a fluorine resin chemically modified with a carboxylic acid such as maleic anhydride or an acid anhydride thereof. There is no limitation, for example, polyvinyl fluoride, polyvinylidene fluoride, polyfluorinated ethylene, polychloroethylene trifluoride, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene- Crystalline fluororesin such as ethylene chloride trifluoride copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, or fluororesin rubber And a soft fluororesin obtained by graft polymerization.

  Preferably, it is an ethylene-tetrafluoroethylene copolymer (ETFE) in terms of flexibility and melting point. In particular, the fluororesin preferably has an acid anhydride group in order to have a crosslinked structure composed of an amide bond.

  As the fluorine-based resin, two or more kinds of those chemically modified with different carboxylic acids or acid anhydrides or those having different degrees of chemical modification may be used.

<Brass plated wire>
The brass plating wire used in the present invention is a steel material plated with brass, and the diameter of the wire is appropriately selected according to the pressure applied to the pressure hose. The net structure is not particularly limited, and examples thereof include a braided one.

  Next, an example of a method for manufacturing the refrigerant transport hose 10 of FIG. 1 will be described.

  The refrigerant transport hose 10 is obtained by arranging the fluororesin layer 1, the first rubber layer 2, the brass plating wire 3 and the second rubber layer 4 in this order from the inside and vulcanizing them to form a composite. . Here, as vulcanization conditions, a range of 140 to 170 ° C. is usually used, and as a vulcanization method, steam vulcanization or the like that is usually used can be used.

  Specifically, first, the fluororesin is extruded onto a mandrel coated with a release agent by an extruder to form a tubular fluororesin layer. Next, the rubber composition is extruded onto the outer peripheral surface of the fluororesin layer by an extruder to form a first rubber layer. Further, a brass plated wire netted on the first rubber layer is disposed, and the rubber composition is further extruded on the outer peripheral surface of the first rubber layer by an extruder to form a second rubber layer. Thereafter, a vulcanization treatment can be performed to obtain the refrigerant transport hose shown in FIG.

  In the refrigerant transport hose of the present invention, the thickness of the fluororesin layer is, for example, 20 to 400 μm, preferably 50 to 100 μm.

  The thickness of the first rubber layer is, for example, 0.5 to 2.0 mm, particularly 0.8 to 1.6 mm. The thickness of the brass plating wire is, for example, 0.3 to 0.9 mm, particularly 0.4 to 0.8 mm. The thickness of the second rubber layer is, for example, 0.5 to 2.0 mm, particularly 0.8 to 1.6 mm.

  FIG. 2 is a perspective view showing a refrigerant transport hose 10A according to a different embodiment of the present invention. In the refrigerant transport hose 10A, a vapor deposition layer 5 is further formed on the inner peripheral surface of the fluororesin layer 1 in the refrigerant transport hose 10 of FIG.

  In the refrigerant transport hose 10A of FIG. 2, the vapor deposition layer 5 is extremely excellent in the refrigerant permeation preventing performance (gas barrier property), so that the refrigerant is prevented from leaking out of the hose. When the vapor deposition layer is directly deposited on the rubber, the vapor deposition layer may be cracked by elastic deformation of the rubber, and the gas barrier property may be destroyed. However, when the vapor deposition layer is deposited on the fluororesin layer in this manner, the fluororesin layer is less likely to be deformed than rubber, so that the vapor deposition layer is not easily cracked and the gas barrier property is not easily destroyed.

  Examples of the vapor deposition layer 5 include alumina (aluminum oxide), silicon oxide, aluminum, and the like. The deposited layer 5 is deposited on the fluororesin layer by a PVD (Physical Vapor Deposition) method, a CVD (Chemical Vapor Deposition) method, a sputtering method, or the like.

  The vapor deposition layer 5 is preferably 0.05 to 10 μm. If it is 0.05 μm or more, the permeation of the refrigerant is more reliably prevented. When the thickness is 10 μm or less, there is a problem that the deposited film hardly follows the deformation of the hose and causes cracks.

  The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment. For example, a third rubber layer 6 may be further formed on the inner peripheral surface of the fluororesin layer 1 in the refrigerant transport hose 10 of FIG. 1 as in the refrigerant transport hose 10B of FIG.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

  In addition, the specification of the resin material used by the following example and the comparative example, the component mix | blended with a rubber composition, and a brass plating wire is as follows.

<Specifications of resin material>
Fluororesin F1; maleic anhydride-modified ETFE (acid anhydride group formed by Asahi Glass Co., Ltd.)
Have. ) "LM-ETFE-AH-2000"
Fluorine-based resin F2; ETFE (unmodified product) manufactured by Asahi Glass Co., Ltd.
Fluorine-based resin F3: Sumitomo 3M, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer "THV600".

<Specifications of ingredients blended in rubber composition>
Acrylic rubber: Dupont ethylene-methyl acrylate copolymer
"Vamac-G"
Phenol resin: “Sumilite Resin PR12687” manufactured by Sumitomo Bakelite Co., Ltd.)
Silica; “Nipseal AQ” manufactured by Tosoh Silica Corporation
Triazine compound; “Disnet F” manufactured by Sankyo Kasei Co., Ltd. (where R is a mercapto group in chemical formula (I))
Polyamine: Diaminodiphenylmethane "DAM" manufactured by Hodogaya Chemical Co., Ltd.
Organic peroxide: “Peroximon F40” manufactured by NOF Corporation
Co-crosslinking agent TAIC; Nihon Kasei Co., Ltd. Co-crosslinking agent TAF; Kawaguchi Chemical Industry Co., Ltd. FEF carbon black; Tokai Carbon Co., Ltd. “Seast F”
Plasticizer: “Adeka Sizer RS735” manufactured by Asahi Denka Kogyo Co., Ltd.
Anti-aging agent: “NOCRACK CD” manufactured by Ouchi Shinsei Chemical Co., Ltd.
Stearic acid: “Lunac RA” manufactured by Kao Corporation
Zinc flower: Zinc oxide (manufactured by Kyushu Hakusui Co., Ltd.).

<Specifications of brass plated wire>
Brass plated wire; Bridgestone brass plated wire
Diameter 0.33mm, driving 100, blade structure.

Example 1
The resin is extruded by an extruder onto a mandrel coated with a release agent to form a tubular fluororesin layer. Next, the rubber composition is extruded onto the outer peripheral surface of the fluororesin layer by an extruder to form a first rubber layer. Further, a brass plated wire netted on the first rubber layer is disposed, and the rubber composition is further extruded on the outer peripheral surface of the first rubber layer by an extruder to form a second rubber layer. Thereafter, vulcanization is performed under the following vulcanization conditions to obtain the refrigerant transport hose shown in FIG.

Vulcanization conditions Primary vulcanization: 160 ° C x 45 minutes Secondary vulcanization: 160 ° C x 4 hours

  The rubber composition of the first rubber layer and the second rubber layer is the same, and the composition is as shown in Table 1.

  The dimensions of the refrigerant transport hose obtained are as follows.

Resin layer thickness: 200 μm
Thickness of the first rubber layer; 1.5 mm
Brass plated wire thickness; 0.45mm
The thickness of the second rubber layer: 1.5 mm.

Example 2
The resin is extruded by an extruder onto a mandrel coated with a release agent to form a tubular fluororesin layer. Next, the rubber composition is extruded onto the outer peripheral surface and inner peripheral surface of the fluororesin layer by an extruder to form a first rubber layer and a third rubber layer. Further, a brass plated wire netted on the first rubber layer is disposed, and the rubber composition is further extruded on the outer peripheral surface of the first rubber layer by an extruder to form a second rubber layer. Thereafter, vulcanization is performed under the following vulcanization conditions to obtain the refrigerant transport hose shown in FIG.

Vulcanization conditions Primary vulcanization: 160 ° C. × 45 minutes Secondary vulcanization: 160 ° C. × 4 hours.

  The rubber compositions of the first rubber layer, the second rubber layer, and the third rubber layer are the same, and the compositions are as shown in Table 1.

  The dimensions of the refrigerant transport hose obtained are as follows.

The thickness of the third rubber layer; 1.0 mm
Resin layer thickness: 200 μm
The thickness of the first rubber layer; 1.0 mm
Brass plated wire thickness; 0.45mm
The thickness of the second rubber layer; 1.0 mm.

Comparative Example 1
A refrigerant transport hose having the same dimensions as in Example 1 was prepared in the same manner as in Example 1 except that the rubber compositions of the first rubber layer and the second rubber layer were as shown in Comparative Example 1 of Table 1. obtain.

Comparative Example 2
The same dimensions as in Example 2 except that the rubber compositions of the first rubber layer, the second rubber layer, and the third rubber layer were as shown in Comparative Example 2 in Table 1. A refrigerant transport hose is obtained.

<Gas barrier resistance evaluation>
CO ₂ is sealed inside the hose at a pressure of 5 MPa, both ends of the end are sealed and left in an oven at 150 ° C. The gas permeation amount (g / m · day) is measured by accurately measuring the weight loss every other day.

  The case where the gas permeation amount is 2.2 (g / m · day) or less is indicated by “◯”, and the case where the gas permeation amount exceeds 2.2 (g / m · day) is indicated by “X”. The results are shown in Table 2.

<Evaluation of heat resistance / pressure resistance>
Under an atmosphere of 150 ° C., a cycle in which the pressure in the hose is increased from 1 MPa to 10 MPa and then reduced to 1 MPa is repeated at 35 cycles / minute, and the number of times until the hose bursts is measured. As the repeated pressurizing medium, polyalkylene glycol (Daphney NF) manufactured by Idemitsu Kosan is used.

  The results are shown in Table 2. In Table 2, the symbols 、, ○, and X mean the following.

◎; More than 500,000 times
○: 300,000 times or more
×: Less than 300,000 times

<Rubber / wire adhesion>
First, cut the hose to a length of about 20 cm and halve the hose in the longitudinal direction with a fine cutter or the like. After cutting with a cutter or the like at the interface between the wire layer braided into a blade and the rubber layer, the interface is peeled off using a tool such as pliers to visually check the state of the rubber layer attached to the wire surface. Check.

  The results are shown in Table 2. In Table 2, the symbols 、, ○, and X mean the following.

A: Surface area with rubber 100%
○: Surface area with rubber 70% or more
×: Surface area with rubber rate 69% or less

<Rubber / resin adhesion>
In the hose of Example 1 and Comparative Example 1, first, the hose is cut to a length of about 20 cm, and the hose is halved by a fine cutter or the like in the longitudinal direction. With respect to the fluororesin on the inner peripheral surface of the hose, several cuts with a depth of about 0.5 mm are made at intervals of about 3 mm in the longitudinal direction with a cutter or the like. Only the resin layer is peeled off with a tool such as pliers, and the state of the resin layer with rubber is visually confirmed.

  Moreover, in the hose of Example 2 and Comparative Example 2, a strip-shaped sample that is vertically divided into a width of 10 mm and a length of 200 mm in the longitudinal direction of the hose is prepared. Using a cutter or the like, a cut having a length of about 40 mm is made at the interface between the fluororesin layer and the third rubber layer so as not to damage the fluororesin layer. Using a strograph manufactured by Toyo Seiki Co., Ltd. as a tensile tester, the strip test piece is pulled into a T shape at a tensile speed of 50 mm / min, and a peel test is performed. The state of the fluororesin layer with rubber is visually confirmed.

  The results are shown in Table 2. In Table 2, the symbols 、, ○, and X mean the following.

A: Surface area with rubber 100%
○: Surface area with rubber 70% or more
×: Surface area with rubber rate 69% or less

  As is apparent from Table 2, the refrigerant transport hose of the present invention is excellent in flexibility, gas barrier resistance, heat resistance and durability.

It is a perspective view which shows an example of the hose for refrigerant | coolant transport which concerns on embodiment. It is a perspective view which shows an example of the hose for refrigerant | coolant transport which concerns on different embodiment. It is a perspective view which shows an example of the hose for refrigerant | coolant transport which concerns on different embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluororesin layer 2 1st rubber layer 3 Brass plating wire 4 2nd rubber layer 5 Deposition layer 6 3rd rubber layer

Claims (6)

100 parts by mass of a rubber component containing an acrylic rubber having a carboxyl group and / or an acid anhydride group as a crosslinking site,
1-30 parts by mass of phenolic resin,
1-30 parts by mass of silica,
A rubber composition comprising 0.1 to 5 parts by mass of a triazine compound and 0.5 to 10 parts by mass of a polyamine. The rubber composition according to claim 1, wherein the triazine compound is represented by the following general formula (I).

(In the formula, R is a mercapto group, an alkoxy group, a monoalkylamino group, a dialkylamino group, a monocycloalkylamino group, a dicycloalkylamino group, or an N-alkyl-N-arylamino group.) A refrigerant transport hose for transporting a refrigerant,
A rubber layer, a resin layer that covers either the inner or outer peripheral surface of the rubber layer and prevents the permeation of the refrigerant, and a hose that covers either the inner or outer peripheral surface of the rubber layer In a refrigerant transport hose including a reinforcing layer,
The rubber layer is made of the rubber composition according to claim 1 or 2,
The resin layer is made of a fluororesin having a carboxyl group and / or an acid anhydride group,
A refrigerant transport hose characterized in that the reinforcing layer is made of brass-plated wire.   4. The refrigerant transport hose according to claim 3, wherein a ceramic vapor deposition layer is provided on a peripheral surface of the resin layer opposite to the side covered with the rubber layer.   5. The refrigerant transport hose according to claim 4, wherein the vapor deposition layer is made of alumina, and the thickness of the vapor deposition layer is 0.05 to 10 [mu] m.   In Claim 3, the peripheral surface on the opposite side to the side covered with this rubber layer among this resin layer is also covered with the 2nd rubber layer which consists of a rubber composition of Claim 1 or 2. A refrigerant transport hose.

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