JP2010253782A - Rubber hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber hose which has high slidability, is suited to use requiring low friction, has high caulking workability with metal fittings without adding any complex steps, and is suitably used as a hydraulic hose etc. <P>SOLUTION: The rubber hose has an outermost layer 4 made of a cured object of a photocurable liquid resin composition. In the rubber hose, the photocurable liquid resin composition contains a hydrogenated conjugated diene-aromatic vinyl copolymer having photocurable unsaturated carbon hydrides in both tail ends of a molecule chain, synthesized from conjugated diene-aromatic vinyl copolymer having a weight average molecular weight (Mw) of 5,000-40,000 and a molecular weight distribution of 3.0 or less, and super-high molecular weight polyethylene powders or organic acid amid as a sliding component. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rubber hose that is suitably used as a hydraulic hose for construction machinery, agricultural machinery, and other industrial machines. More specifically, the outer skin layer is excellent in low friction, ozone resistance, and adhesiveness. The present invention relates to a rubber hose that is formed with excellent durability and is suitably used as the hydraulic hose or the like.

  Hydraulic hoses are used in hydraulic machines such as construction machines such as excavators and bulldozers, agricultural machines such as tillers and tractors, and other industrial equipment such as hydraulic jacks, hydraulic punchers, hydraulic presses and hydraulic benders. The driving force is transmitted by the pressure of hydraulic oil filled in the inside.

  Such a hydraulic hose is, for example, a rubber inner rubber layer 2 filled with hydraulic oil, a reinforcing layer 3 for withstanding the pressure of the hydraulic oil, and external damage, such as the hydraulic hose 1 shown in FIG. In general, a structure in which the outer rubber layer 4 is sequentially laminated from the inside is provided, and a plurality of the reinforcing layers 3 are often provided.

  Conventionally, chloroprene rubber (CR) is generally used for the outer rubber layer 4 of such a hydraulic hose, but the hydraulic hose is often used in applications where the hose frequently rubs. A hose used for various applications is strongly required to have low friction.

  In this case, for reducing friction in the rubber hose, a method of blending a lubricant such as fatty acid amide and paraffin wax (Patent Document 1: Japanese Patent Laid-Open No. 2002-39448, Patent Document 2: Japanese Patent Laid-Open No. 2006-123384), A method of winding a polyethylene film around the outermost layer (Patent Document 3: JP-A-8-296771, Patent Document 4: JP-A-2005-3171, Patent Document 5: JP-A-2005-314455) has been proposed. Yes.

  However, in the case of a method of blending a lubricant, there is a problem in terms of durability because the lubricant is removed by friction with other members. On the other hand, the method of arranging the polyethylene film in the outermost layer can obtain good adhesion due to the entanglement of the polymer chain when the polyethylene film and rubber are bonded together and vulcanized. Although a good low friction layer can be formed without requiring a special adhesive formulation, this method has the following drawbacks.

  That is, the hydraulic hose is generally used in a state of being crimped to the metal fitting, and the caulking property with the metal fitting is also an important performance, but when a polyethylene film is disposed on the outermost layer, the outermost layer is used. The rubber-like elasticity of the steel is reduced, and advanced caulking technology is required. Moreover, when designing the production process of a hose newly, the equipment which shape | molds a polyethylene film is required, and also the complicated process which winds the polyethylene film is needed, and the freedom degree of process design falls.

JP 2002-39448 A Japanese Unexamined Patent Publication No. 2006-123384 JP-A-8-296771 Japanese Patent Laid-Open No. 2005-3171 JP 2005-314455 A

  The present invention has been made in view of the above circumstances, and can be suitably used for applications requiring excellent slipperiness and low friction, and without the addition of complicated processes, An object of the present invention is to provide a rubber hose which is excellent in caulking workability and is suitably used as a hydraulic hose or the like.

  As a result of intensive studies to solve the above problems, the present inventors hydrogenated a conjugated diene-aromatic vinyl copolymer having a weight average molecular weight (Mw) of 5,000 to 40,000 and a molecular weight distribution of 3.0 or less. By photocuring a rubber compound having a polymer component by UV crosslinking or the like, it is possible to easily obtain good adhesion performance for general rubber compositions in general, and this polymer is polymerized by hydrogenation. It has excellent ozone resistance due to the disappearance of double bonds in the main chain skeleton, suitable weather resistance as the outermost layer of the rubber hose, and also has good rubber elasticity, and is also suitable for crimping work with metal fittings In addition, by blending an appropriate amount of organic acid amide such as ultra high molecular weight polyethylene powder or amide as a slipping component, it is possible to provide good low friction while maintaining good adhesion. The finding, in which the present invention has been completed.

Therefore, the present invention provides the following rubber hose (1).
(1) The outermost layer is formed of a cured product of a photocurable liquid resin composition, and the photocurable liquid resin composition has a weight average molecular weight (Mw) of 5000 to 40000 and a molecular weight distribution of 3.0 or less. A hydrogenated conjugated diene-aromatic vinyl copolymer having a photocurable unsaturated hydrocarbon group at both ends of the molecular chain, synthesized from a conjugated diene-aromatic vinyl copolymer of A rubber hose comprising a molecular weight polyethylene powder or an organic acid amide.

Furthermore, as a result of investigations, the present inventors provide the following rubber hoses (2) to (7) as preferred embodiments of the present invention.
(2) The hydrogenated conjugated diene-aromatic vinyl copolymer is a polymer of 1,3-butadiene and / or isoprene and one or more selected from styrene, α-methylstyrene and paramethylstyrene. The rubber hose according to (1).
(3) The rubber hose according to (1) or (2), wherein the photocurable unsaturated hydrocarbon group is an acryloyl group or a methacryloyl group.
(4) As the slip component, any one of (1) to (3) containing 10 to 30 parts by mass of ultrahigh molecular weight polyethylene powder with respect to 70 parts by mass of the hydrogenated conjugated diene-aromatic vinyl copolymer. A rubber hose.
(5) Any one of (1) to (4) containing 4 to 25 parts by mass of an organic acid amide with respect to 70 parts by mass of the hydrogenated conjugated diene-aromatic vinyl copolymer as the slip component. Rubber hose.
(6) The rubber hose according to (5), wherein the organic acid amide is a fatty acid amide or unsaturated fatty acid amide having 10 or more carbon atoms.
(7) The rubber hose according to any one of (1) to (6), wherein the outermost layer is a coating layer having a thickness of 0.1 to 2 mm formed by coating on the outer surface of the rubber hose.

  The rubber hose of the present invention has an outermost layer having good adhesion, low friction and ozone resistance, and can be suitably used for applications that require good friction and low friction. In addition, this outermost layer can be easily formed by applying a liquid resin composition to the hose surface and photocuring by UV irradiation or the like, and is excellent in caulking workability with metal fittings, and is suitable as a hydraulic hose. Used for.

1 is a schematic perspective view showing a cross-sectional view of a part of an example of a hydraulic hose.

  The rubber hose of the present invention has a low friction layer formed by curing a photocurable liquid resin composition described later as the outermost layer. For example, an inner rubber layer, a reinforcing layer, and an outer rubber layer are sequentially laminated from the inner side. A low-friction outermost layer formed by curing a photocurable liquid resin composition described later is formed on the surface of the outer rubber layer of the hydraulic hose.

  The photocurable liquid resin composition is synthesized from a conjugated diene-aromatic vinyl copolymer having a weight average molecular weight (Mw) of 5,000 to 40,000 and a molecular weight distribution of 3.0 or less. This includes a hydrogenated conjugated diene-aromatic vinyl copolymer having a saturated hydrocarbon group.

The hydrogenated conjugated diene-aromatic vinyl-based copolymer is described in, for example, JP-A-2007-145949, etc.
(A) A conjugated diene monomer and an aromatic vinyl monomer are polymerized with a dilithium initiator in a saturated hydrocarbon solvent, and a conjugate having a weight average molecular weight of 5000 to 40000 and a molecular weight distribution of 3.0 or less. Producing a diene-aromatic vinyl copolymer;
(B) reacting the conjugated diene-aromatic vinyl copolymer and alkylene oxide to produce a conjugated diene-aromatic vinyl copolymer polyol;
(C) hydrogenating the conjugated diene-aromatic vinyl copolymer polyol to produce a hydrogenated conjugated diene polymer polyol or a hydrogenated conjugated diene-aromatic vinyl copolymer polyol;
(D) The hydrogenated conjugated diene-aromatic vinyl copolymer polyol and the step of reacting the photocurable unsaturated hydrocarbon group-containing compound can be obtained.
Details thereof will be described below.

First, as a first step (A), a conjugated diene monomer and an aromatic vinyl monomer are polymerized with a dilithium initiator in a saturated hydrocarbon solvent to obtain a conjugated diene-aromatic vinyl copolymer. A polymer (hereinafter sometimes referred to as “copolymer”) is produced. Since this polymerization is a living anion polymerization, the polymerization can be performed while controlling the molecular weight and molecular weight distribution. The molecular weight can polymerize a polymer having a predetermined molecular weight depending on the amount of the dilithium initiator and the above monomer, and in particular, when the weight average molecular weight (Mw) is 5000 or more, a narrow polymer having a molecular weight distribution of 2 or less. It is preferable to set it as 5000-40000. If desired, anionic polymerization may be carried out in the presence of a randomizer.
Next, as the second step (B), a conjugated diene-aromatic vinyl copolymer having hydroxyl groups at both ends is obtained by performing an equivalent reaction between a polymer terminal which is a living anion and an alkylene oxide of the above copolymer. A polymer polyol (hereinafter sometimes referred to as “copolymer polyol”) can be obtained.
Further, as a third step (C), the copolymer polyol having a double bond in the main chain is subjected to a hydrogenation reaction (hereinafter referred to as a hydrogenation reaction) to have an unsaturated double bond in the main chain. No hydrogenated conjugated diene-aromatic vinyl copolymer polyol (hereinafter sometimes referred to as “hydrogenated copolymer polyol”) can be obtained.
As a fourth step (D), the hydrogenated copolymer polyol obtained as described above was reacted with a photocurable unsaturated hydrocarbon group-containing compound to introduce a photocurable unsaturated hydrocarbon group. A photocurable liquid resin (hydrogenated conjugated diene-aromatic vinyl copolymer) is obtained.

Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene, and the like. Can be mentioned. These may be used alone or in combination of two or more. Among these, 1,3-butadiene or isoprene is preferable from the viewpoint of ensuring rubber elasticity after curing.
As the aromatic vinyl monomer, styrene, α-methylstyrene or paramethylstyrene is preferable from the viewpoint of rubber physical properties after curing. These may be used alone or in combination of two or more.

  The dilithium initiator is not particularly limited, and known ones can be used. For example, Japanese Patent Publication No. 1-53681 discloses a method for producing a dilithium initiator by reacting a monolithium compound with a disubstituted vinyl or an alkenyl group-containing aromatic hydrocarbon in the presence of a tertiary amine. ing.

  Monolithium compounds used when producing a dilithium initiator include ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, tert-octyl lithium, and n-decyl. Examples of the lithium include phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, and cyclopentyl lithium. Among these, sec-butyl lithium is preferable.

Examples of the tertiary amine used when producing the dilithium initiator include lower aliphatic amines such as trimethylamine and triethylamine, N, N-diphenylmethylamine, and the like, and triethylamine is particularly preferable.
Examples of the disubstituted vinyl or alkenyl group-containing aromatic hydrocarbon include 1,3- (diisopropenyl) benzene, 1,4- (diisopropenyl) benzene, 1,3-bis (1-ethylethenyl). ) Benzene, 1,4-bis (1-ethylethenyl) benzene and the like are preferred.

  The solvent used in the preparation of the dilithium initiator and the production of the copolymer may be any organic solvent inert to the reaction, and hydrocarbon solvents such as aliphatic, alicyclic, and aromatic hydrocarbon compounds. For example, n-butane, l-butane, n-pentane, l-pentane, cis-2-butene, trans-2-butene, l-butene, n-hexane, n-heptane, n-octane, One or two kinds selected from l-octane, methylcyclopentane, cyclopentane, cyclohexane, 1-hexene, 2-hexene, 1-pentene, 2-pentene, benzene, toluene, xylene, ethylbenzene and the like are used. Of these, n-hexane and cyclohexane are usually used.

  Moreover, as an alkylene oxide used for the polyol-ized reaction which reacts with the terminal which is a living anion of said copolymer, and produces | generates a hydroxyl group at both ends, ethylene oxide, propylene oxide, or butylene oxide etc. are mentioned, for example. This polyol reaction is preferably performed immediately after the polymerization reaction.

The weight average molecular weight (Mw) of the copolymer polyol obtained by the polyol reaction is set to 5000 to 40000. When the weight average molecular weight is less than 5,000, the viscosity is too low, the appropriate viscosity required for coating cannot be obtained, and the coating operation may be difficult. On the other hand, when the molecular weight exceeds 40,000, On the other hand, the viscosity becomes excessively high, which not only impairs the coating workability but also reduces the absolute amount of terminal hydroxyl groups per unit weight, which may reduce the adhesion to rubber.
Moreover, various influences by a low molecular weight component and a high molecular weight component can be suppressed as molecular weight distribution is 3.0 or less. In particular, since the viscosity is greatly affected by the molecular weight, slight fluctuations in the molecular weight cause viscosity variations. In this method capable of synthesizing a copolymer having a narrow molecular weight distribution, a copolymer having the same molecular weight can be obtained with good reproducibility, and therefore an effect of stabilizing the viscosity can be expected.

The hydrogenation reaction in the present method is carried out by hydrogenating the copolymer polyol in an organic solvent under hydrogen pressure and in the presence of a hydrogenation catalyst. By this hydrogenation reaction, the double bond of the main chain skeleton of the polymer disappears, and the ozone resistance becomes excellent. The hydrogenation catalyst used in this method is a heterogeneous catalyst such as palladium-carbon, reduced nickel, rhodium, or the like, or an organic nickel compound such as nickel naphthenate or nickel octoate, or an organic cobalt such as cobalt naphthenate or cobalt octoate. A homogeneous catalyst in which the compound is combined with an organoaluminum compound such as triethylaluminum or triisobutylaluminum or an organolithium compound such as n-butyllithium or sec-butyllithium can be used. As a cocatalyst, an ether compound such as tetrahydrofuran, ethylene glycol dimethyl ether, or diethylene glycol dimethyl ether may be used. Further, as another hydrogenation reaction method, for example, the copolymer before hydrogenation may be dicyclopentadienyl titanium halide, organic carboxylate nickel, organic carboxylate nickel and organic compounds of Groups I to III of the periodic table. 1 to 100 atm using hydrogenation catalyst composed of metal compound, nickel, platinum, barium, ruthenium, rhenium, rhodium metal catalyst supported on carbon, silica, diatomaceous earth, etc., cobalt, nickel, rhodium, ruthenium complex, etc. Or hydrogen in the presence of lithium aluminum hydride, p-toluenesulfonyl hydrazide, Zr—Ti—Fe—V—Cr alloy, Zr—Ti—Nb—Fe—V—Cr alloy, LaNi ₅ alloy Hydrogenation in the presence of a hydrogen storage alloy such as 1 or under hydrogen pressurized to 1 to 100 atm And a hydrogenation catalyst obtained by mixing a di-p-tolyl-bis (1-cyclopentadienyl) titanium / cyclohexane solution and an n-butyllithium / n-hexane solution under hydrogen. Examples thereof include a method of adding hydrogen under hydrogen pressurized to -100 atm.

Among the various hydrogenation catalysts described above, a Ziegler hydrogenation catalyst or a palladium-carbon hydrogenation catalyst comprising a combination of a transition metal compound and an alkylaluminum compound is preferred.
Such transition metal compounds include tris (acetylacetonato) cobalt, bis (acetylacetonato) nickel, tris (acetylacetonato) iron, tris (acetylacetonato) chromium, tris (acetylacetonato) manganese, bis (acetyl). Acetonato) manganese, tris (acetylacetonato) ruthenium, bis (acetylacetonato) cobalt, bis (cyclopentadienyl) dichlorotitanium, bis (cyclopentadienyl) dichlorozirconium, bis (triphenylphosphine) cobalt dichloride, Examples thereof include bis (2-hexanoate) nickel, bis (2-hexanoate) cobalt, titanium tetraisopropoxide, and titanium tetraethoxide. Among these, bis (acetylacetonato) nickel and tris (acetylacetonato) cobalt are preferable from the viewpoint of high hydrogenation activity.
Alkyl aluminum compounds used for Ziegler hydrogenation catalysts include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, tri-n-butylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, methylaluminum. Examples include dichloride, ethylaluminum dichloride, isobutylaluminum dichloride, diethylaluminum hydride, diisobutylaluminum hydride, ethylaluminum sesquichloride and the like. Among these, triisobutylaluminum, triethylaluminum, and diisobutylaluminum hydride are preferable from the viewpoint of hydrogenation activity, and triisobutylaluminum is most preferable.

  Although there is no particular limitation on the use form of the Ziegler-based hydrogenation catalyst in this method, a method in which a catalyst solution in which a transition metal compound and an alkylaluminum compound are reacted in advance is prepared and added to the polymerization solution is preferably mentioned. I can do it. The amount of the alkylaluminum compound used in this case is preferably 0.2 to 5 mol with respect to 1 mol of the transition metal compound. The catalyst preparation reaction is carried out in the temperature range of −40 to 100 ° C., preferably 0 to 80 ° C., and the reaction time is in the range of 1 minute to 3 hours.

  The hydrogenation reaction is usually at a temperature of 50 to 180 ° C., preferably 70 to 150 ° C., and 5 to 100 atm (5066.25 to 101325 hPa), preferably 10 to 50 atm (10132.5 to 50662.5 hPa). Of hydrogen pressure. If the hydrogenation temperature is lower than 50 ° C., and if the hydrogen pressure is lower than 5 atm, the catalyst activity will be low, which is not preferable. If the hydrogenation temperature exceeds 180 ° C., catalyst deactivation, side reactions, etc. are likely to occur. It is not preferable. In general, a Ziegler-based hydrogenation catalyst is a catalyst having extremely high hydrogenation activity, and it is not preferable to set the hydrogen pressure to 100 atm (101325 hPa) or more because it is not necessary and a burden on the apparatus is increased.

In order to introduce a photocurable unsaturated hydrocarbon group into the terminal of the hydrogenated copolymer polyol by reacting the hydrogenated copolymer polyol with a photocurable unsaturated hydrocarbon group-containing compound, The photocurable unsaturated hydrocarbon group is preferably an acryloyl group or a methacryloyl group. Here, as a photocurable unsaturated hydrocarbon group containing compound, acryloyl isocyanate and methacryloyl isocyanate are preferable, and said hydrogenated copolymer polyol is (meth) acrylated by reaction with these.
Examples of acryloyl isocyanate include 2-acryloyloxyethyl isocyanate, and examples of methacryloyl isocyanate include 2-methacryloyloxyethyl isocyanate.

  The photocurable liquid resin (hydrogenated conjugated diene-aromatic vinyl copolymer) obtained by this method is usually used as a photocurable liquid resin composition, and is based on the entire photocurable liquid resin composition. The photocurable liquid resin is preferably contained in an amount of 20% by mass or more, more preferably 30% by mass or more.

  This photocurable resin composition is blended with ultrahigh molecular weight polyethylene powder or organic acid amide as a slip component. In this case, as the organic acid amide, a long-chain fatty acid amide having 12 to 22 carbon atoms, particularly an amide of an aliphatic monocarboxylic acid is preferably used. Specific examples include stearic acid amide, oleic acid amide, erucic acid amide, lauric acid amide, octadecenamide, and the like, and these can be used alone or in combination. Of these, stearic acid amide and erucic acid amide are particularly preferably used.

  The blending amount of the ultrahigh molecular weight polyethylene powder is not particularly limited, but is 10 to 30 masses with respect to 70 mass parts of the photocurable liquid resin (hydrogenated conjugated diene-aromatic vinyl copolymer). Part, especially 15 to 25 parts by mass, and if it is less than 10 parts by mass, sufficient low friction may not be obtained, while if it exceeds 30 parts by mass, the adhesion to rubber is reduced. There is. The amount of the organic acid amide is 4 to 25 parts by mass, particularly 5 to 20 parts by mass with respect to 70 parts by mass of the photocurable liquid resin (hydrogenated conjugated diene-aromatic vinyl copolymer). Preferably, if the amount is less than 4 parts by mass, a sufficiently low friction property may not be obtained. On the other hand, if it exceeds 25 parts by mass, the adhesion to rubber may be reduced.

  In addition to the photocurable liquid resin (hydrogenated conjugated diene-aromatic vinyl copolymer) and the slip component, an appropriate compounding agent may be added to the photocurable resin composition as necessary. As the compounding agent, (meth) acrylic acid ester monomer, photo radical polymerization initiator, inorganic filler and / or organic thickener are preferably used.

  The (meth) acrylic acid ester monomer reduces the viscosity of the photocurable liquid resin composition before curing and also improves various physical properties after curing. That is, it is possible to improve the adhesive strength, decrease the hardness, improve Eb (elongation), and Tb (breaking strength). As this (meth) acrylic acid ester monomer, those having a molecular weight of less than 1000 are preferred, and those having a molecular weight of 150 to 600 are more preferred. (Meth) acrylic acid ester monomers include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, diethylene glycol monoethyl ether (meth) Acrylate, dimethylaminoethyl (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, dipropylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate, ethyl (meth) acrylate, Isoamyl (meth) acrylate, isobornyl (meth) acrylate, isobutyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (Meth) acrylate, isostearyl (meth) acrylate, isomyristyl (meth) acrylate, lauroxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripylene glycol (meth) Examples include acrylate, methoxypolyethylene glycol (meth) acrylate, and methoxytriethylene glycol acrylate. In addition, (meth) acrylate means an acrylate or a methacrylate. Of these, dicyclopentanyl acrylate, dicyclopentenyl acrylate, and isobornyl acrylate are preferred in the present invention.

  The compounding amount of the (meth) acrylic acid ester monomer is 100 parts by mass when the photocurable liquid resin and the (meth) acrylic acid ester monomer are combined, with respect to 30 to 100 parts by mass of the photocurable liquid resin ( 70-0 mass parts of meth) acrylic acid ester monomers are preferable, More preferably, it is 60-10 mass parts of (meth) acrylic acid ester monomers with respect to 40-90 mass parts of photocurable liquid resins. When the amount of the (meth) acrylic acid ester monomer is less than 10 parts by mass, the elongation at break at the time of elongation is lowered although the elasticity is low, and the followability to the deformation of the rubber may be deteriorated. When it exceeds the part, the elastic modulus of the composition itself increases, and the followability to deformation of the rubber may be deteriorated.

  As radical photopolymerization initiators, benzoin derivatives, benzyl ketals [for example, Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 651], α-hydroxyacetophenones [for example, Ciba -Specialty Chemicals Co., Ltd., trade names: Darocur 1173, Irgacure 184, Irgacure 127], α-aminoacetophenones [for example, Ciba Specialty Chemicals, Inc., trade names: Irgacure 907, Irgacure 369], Combination use of α-aminoacetophenones and thioxanthones (for example, isopropylthioxanthone, diethylthioxanthone), acylphosphine oxides [for example, Ciba Specialty Chemicals, Inc., trade name: Irgacure 8 9], and the like, as a hydrogen abstraction type, combined use of benzophenones and amines, combination and the like of the thioxanthone and amine. Further, an intramolecular cleavage type and a hydrogen abstraction type may be used in combination. Of these, oligomerized α-hydroxyacetophenone and acrylated benzophenones are preferred. More specifically, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone] [for example, Lamberti S. et al. p. A product, trade name: ESACURE KIP150, etc.], acrylated benzophenone [for example, trade name: Ebecryl P136, etc., manufactured by Daicel UCB Co., Ltd.], imide acrylate, and the like.

  In addition to the above-mentioned radical photopolymerization initiators, 1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone 1-hydroxy-cyclohexyl-ketone and benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoylphenylphosphine oxide, 2,4,6- Trimethylbenzoylphenylphenylethoxyphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2- Methyl-1-[(4-methylthio) phenyl] -2-morpholinopro 1-one, benzoyl methyl ether, benzoyl ethyl ether, benzoyl butyl ether, benzoyl isopropyl ether, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-hydroxy-2-methyl- [4- (1- Methylvinyl) phenyl] propanol oligomer, mixture of 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer and 2-hydroxy-2-methyl-1-phenyl-1-propanone, isopropylthioxanthone , Methyl o-benzoylbenzoate, [4- (methylphenylthio) phenyl] phenylmethane, and the like can also be used.

  The amount of radical photopolymerization initiator blended in the photocurable liquid resin composition obtained by this method is 0.1 to 6 with respect to a total of 100 parts by mass of the photocurable liquid resin and the (meth) acrylate monomer. It is preferable that it is a mass part, More preferably, it is 0.5-4 mass part, More preferably, it is 1-3 mass part.

  When an inorganic filler and / or an organic thickener is blended with the photocurable liquid resin composition obtained by this method, the composition can have thixotropy and improve the moldability of the composition. it can.

Examples of inorganic fillers include silica (SiO ₂ ), alumina, titania, and viscosity minerals, among which silica powder, silica powder subjected to hydrophobic treatment, or a mixture thereof is preferable. More specifically, silica fine powder pulverized by a dry method [for example, product name: Aerosil 300 manufactured by Nippon Aerosil Co., Ltd.], fine powder obtained by modifying this silica fine powder with trimethyldisilazane [for example, Japan Aerosil Co., Ltd., trade name: Aerosil RX300, etc.] and fine powder obtained by modifying the above silica fine powder with polydimethylsiloxane [for example, Nippon Aerosil Co., Ltd., trade name: Aerosil RY300, etc.].

  The average particle size of the inorganic filler is preferably 5 to 50 μm, more preferably 5 to 12 μm, from the viewpoint of thickening and thixotropy.

  It is preferable that the compounding quantity of this inorganic filler is 0.1-10 mass parts with respect to a total of 100 mass parts of photocurable liquid resin and (meth) acrylic acid ester monomer, More preferably, it is 0.5- 7 parts by mass, more preferably 1 to 5 parts by mass.

  As the organic thickener, hydrogenated castor oil, amide wax or a mixture thereof is preferable. Specifically, as an organic thickener, hydrogenated castor oil which is a hydrogenated product of castor oil (non-drying oil whose main component is ricinoleic acid) [for example, product name: ADVITROL100, Enomoto Kasei Co., Ltd. Product name: Disparone 305, etc.] and high-grade amide wax which is a compound having an amide bond [for example, trade name: Disparon 6500, manufactured by Enomoto Kasei Co., Ltd.], and the like.

  It is preferable that the compounding quantity of this organic thickener is 0.1-10 mass parts with respect to a total of 100 mass parts of photocurable liquid resin and (meth) acrylic acid ester monomer, More preferably, it is 0.5. -7 parts by mass, more preferably 1-5 parts by mass.

  Moreover, a terminal (meth) acrylate oligomer can also be mix | blended with the photocurable liquid resin composition in addition to the said (meth) acrylic acid ester monomer or as an alternative. By blending this terminal (meth) acrylate oligomer, the viscosity of the photocurable liquid resin composition can be adjusted, and physically, the hardness decreases, Eb (elongation) and Tb (breaking strength). The improvement etc. can be aimed at. The terminal (meth) acrylate oligomer refers to an oligomer having an acryloyl group or a methacryloyl group at one end or both ends. The terminal (meth) acrylate oligomer is preferably a hydrocarbon oligomer, that is, a hydrogenated oligomer or a terminal (meth) acrylate hydrogenated oligomer, from the viewpoint of moisture permeability, weather resistance and heat resistance. The weight average molecular weight of the terminal (meth) acrylate oligomer is preferably 5000 to 40000. When the weight average molecular weight is within this range, there are advantages that it is easy to handle as a liquid raw material and the cured product has low hardness.

  Examples of the terminal (meth) acrylate oligomer include polyester (meth) acrylate oligomers, epoxy (meth) acrylate oligomers, urethane (meth) acrylate oligomers, polyol (meth) acrylate oligomers, and the like. As the polyester (meth) acrylate oligomer, for example, by esterifying the hydroxyl group of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, or It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid. The epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. Alternatively, it can be modified with isocyanate and the terminal hydroxyl group can be esterified with acrylic acid. The polyol (meth) acrylate oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid. The urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by a reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid.

  The amount of the terminal (meth) acrylate oligomer is preferably 30 to 100 parts by mass, more preferably 40 to 90 parts by mass with respect to 100 parts by mass in total of the photocurable liquid resin and the (meth) acrylic acid ester monomer. It is. However, the (meth) acrylic acid ester monomer and the terminal (meth) acrylate oligomer may be mutually substituted if desired.

  A stabilizer or the like may be further added to the photocurable liquid resin composition. As a stabilizer, triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] [for example, Ciba Specialty Chemicals Co., Ltd., trade name: IRGANOX245, Asahi Manufactured by Denka Kogyo Co., Ltd., trade name: ADK STAB AO-70, etc.], 3,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1, 1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane [for example, manufactured by Asahi Denka Kogyo Co., Ltd., trade name: ADK STAB AO-80, etc.] Etc.

  It is preferable that the compounding quantity of this stabilizer is 0.1-5 mass parts with respect to a total of 100 mass parts of photocurable liquid resin and (meth) acrylic acid ester monomer, More preferably, it is 0.5- 3 parts by mass, more preferably 0.5-2 parts by mass.

  Furthermore, in the photocurable liquid resin composition, terpene resin, terpene phenol resin, coumarone resin, coumarone-indene resin, petroleum hydrocarbon, rosin derivative, etc. for improving adhesion within a range that does not impair the effect. Additives such as various tackifiers and colorants such as titanium black can be added.

  The manufacturing method of the said photocurable liquid resin composition is not specifically limited, A well-known method is applicable. For example, kneading each component and optionally used additive components using a kneader capable of adjusting the temperature, such as a single screw extruder, twin screw extruder, planetary mixer, twin screw mixer, high shear mixer, etc. Can be manufactured.

  The photocurable liquid resin composition is thinly applied to the outer surface of a rubber hose such as a hydraulic hose, and is photocured by irradiating with active energy rays, thereby firmly adhering to the outer surface of the rubber hose and good slipperiness. In addition, the outermost layer having ozone resistance can be easily formed in a short time. In this case, application of the photocurable liquid resin composition to the surface of the rubber hose can be performed by any method using a coating liquid in which the temperature of the composition is adjusted as necessary and adjusted to a constant viscosity, For example, methods such as brushing and spraying can be used. Moreover, although the thickness of this coating-film layer (outermost layer) can be suitably set according to the use environment of a rubber hose, the use of rubber hose, a specification, etc., it is usually set to 0.1-2 mm.

  As active energy rays used for photocuring, for example, ionizing radiation such as ultraviolet rays and electron beams, α rays, β rays, and γ rays can be used, and ultraviolet rays can be preferably used in the present invention. Examples of the ultraviolet light source include a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and a microwave excimer lamp. The atmosphere for irradiation with ultraviolet rays is preferably an inert gas atmosphere such as nitrogen gas or carbon dioxide gas, or an atmosphere with a reduced oxygen concentration, but can be sufficiently cured even in a normal air atmosphere. In this case, the irradiation atmosphere temperature can usually be 10 to 200 ° C. The photo-curing resin can be further stabilized in properties by irradiating active energy rays again after curing or by applying heat.

  The rubber hose of the present invention has a cured product layer of the photocurable liquid resin composition formed on the outermost layer. In this case, there is no restriction | limiting in particular as a rubber hose, Although it can apply to the hose used for various uses, It is preferable to apply especially to a hydraulic hose. As the hydraulic hose, for example, as shown in FIG. 1, an internal rubber layer 2, a reinforcing layer 3 for withstanding the pressure of hydraulic oil, and an external rubber layer 4 for preventing damage from the outside are laminated in order from the inside. The hose 1 can be illustrated, and it can be set as the rubber hose (hydraulic hose) of this invention by apply | coating the said photocurable liquid resin composition on the outer surface rubber layer 4, and making it harden | cure. In this case, the photocurable liquid resin composition has good adhesiveness regardless of the type of rubber forming the outer rubber layer 4, and the type of rubber forming the outer rubber layer 4 is not limited. In particular, chloroprene rubber, ethylene propylene rubber, and acrylonitrile butadiene rubber are preferred.

  The hydraulic hose is not limited to the three-layer structure shown in FIG. 1 and may have a two-layer structure or a four-layer structure, and the rubber hose of the present invention The rubber hose can be suitably used for applications other than hydraulic hoses. The above-mentioned photo-curable liquid resin composition is coated on a rubber layer on the outer surface of various types of hoses and cured to obtain the rubber hose of the present invention. be able to.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not restrict | limited to the following Example.

[Preparation of photocurable resin]
After adding 1 mol of 1,3- (diisopropenyl) benzene to a fully dehydrated and purified cyclohexane solvent, 2 mol of triethylamine and 2 mol of sec-butyllithium are sequentially added and stirred at 50 ° C. for 2 hours. A dilithium polymerization initiator was prepared.
In a 7 liter polymerization reactor purged with argon, 1.50 kg of dehydrated purified cyclohexane, 2.00 kg of a hexane solution of 22.9% by mass of 1,3-butadiene monomer, and a cyclohexane solution of 20.0% by mass of styrene monomer were added. After adding 209.4 ml of hexane solution of 765 kg, 1.6 mol / liter OOPS (2-2'-di (tetrahydrofuryl) propane), 223.5 ml of 0.5 mol / liter dilithium polymerization initiator was added. The polymerization was started.

  Polymerization was carried out for 1.5 hours while raising the temperature of the polymerization reactor to 50 ° C., then 220.4 ml of a 1 mol / liter ethylene oxide cyclohexane solution was added, and the mixture was further stirred for 2 hours, and then 50 ml of isopropyl alcohol was added. did. A hexane solution of the polymer is precipitated in isopropyl alcohol and sufficiently dried to obtain a styrene-butadiene copolymer having hydroxyl groups at both ends of a molecular chain having a styrene content of 25% by mass, a weight average molecular weight of 7100, and a molecular weight distribution of 1.25. Obtained.

  120 g of the obtained styrene-butadiene copolymer was dissolved in 1 liter of sufficiently dehydrated and purified hexane, and then nickel naphthenate, triethylaluminum, and butadiene prepared in separate containers in advance were 1: 3: 3 (molar ratio). The catalyst solution was charged so that the amount of nickel was 1 mol with respect to 1000 mol of the butadiene portion in the copolymer solution. Hydrogen was pressurized to 27580 hPa (400 psi) in a sealed reaction vessel, and a hydrogenation reaction was performed at 110 ° C. for 4 hours. Thereafter, the catalyst residue was extracted and separated with 3N concentration hydrochloric acid, and further centrifuged to separate and separate the catalyst residue. Thereafter, the hydrogenated styrene-butadiene copolymer was precipitated in isopropyl alcohol and further sufficiently dried.

  100 g of the above sufficiently dried hydrogenated styrene-butadiene copolymer was dissolved in cyclohexane, and 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK: Karenz AOI) was slowly added dropwise with stirring at 40 ° C. Then, the mixture was further stirred for 4 hours, precipitated in isopropyl alcohol and dried. The amount of 2-acryloyloxyethyl isocyanate added was 3.75 g. As described above, a liquid photocurable resin was obtained.

[Preparation of Photocurable Resin Composition]
The components shown in Table 1 below are blended in the photocurable resin and kneaded for about 1 hour while heating to 80 to 100 ° C. using a planetary mixer, whereby the photocurable resin composition of the present invention. A product was prepared. In addition, the detail of each compounding component in Table 1 is as follows, and all compounding amounts are a mass part.
Isobonyl acrylate: Osaka Organic Chemical Industry “IBXA”
Photoradical polymerization initiator: Ciba Specialty Chemicals “Darocur 1173 (α-hydroxyacetophenone)”
Ultra high molecular weight polyethylene powder: Miteron, Mitsui Chemicals, Inc.
Organic acid amide: Octadecenamide, Nippon Kasei Co., Ltd. “Diamid M309”

  Each photocurable resin composition obtained was applied to a chloroprene rubber vulcanized rubber sheet (120 mm × 120 mm × 2 mm) to a thickness of about 1 mm, subjected to a photocuring treatment, and subjected to a peel test at a width of 10 mm. The adhesion of was evaluated. The results are shown in Table 1.

  Next, each photocurable resin composition is applied to the outer peripheral surface of the hydraulic hose having the layer structure of FIG. 1 in which the outer rubber layer 4 is formed of a rubber composition mainly composed of chloroprene rubber, and ultraviolet rays are applied under the following conditions. Was cured by irradiation to form an outermost layer having a thickness of 1 mm. The friction coefficient at normal temperature of the surface of the obtained hydraulic hose was measured and evaluated by an index with the dynamic friction coefficient of the hydraulic hose wound with the ultra-high molecular weight polyethylene sheet as 100. The results are shown in Table 1.

1 Hydraulic hose (rubber hose)
2 Inner rubber layer 3 Reinforcement layer 4 Outer rubber layer

Claims (7)

The outermost layer is formed of a cured product of a photocurable liquid resin composition, and the photocurable liquid resin composition is
Hydrogenated conjugate having a photocurable unsaturated hydrocarbon group at both ends of a molecular chain, synthesized from a conjugated diene-aromatic vinyl copolymer having a weight average molecular weight (Mw) of 5,000 to 40,000 and a molecular weight distribution of 3.0 or less. A rubber hose comprising a diene-aromatic vinyl copolymer and an ultrahigh molecular weight polyethylene powder or an organic acid amide as a sliding component.   The hydrogenated conjugated diene-aromatic vinyl copolymer is obtained by polymerizing 1,3-butadiene and / or isoprene and one or more selected from styrene, α-methylstyrene and paramethylstyrene. The rubber hose according to claim 1.   The rubber hose according to claim 1 or 2, wherein the photocurable unsaturated hydrocarbon group is an acryloyl group or a methacryloyl group.   The said sliding component contains 10-30 mass parts ultra high molecular weight polyethylene powder with respect to 70 mass parts of hydrogenated conjugated diene-aromatic vinyl-type copolymers, The any one of Claims 1-3 characterized by the above-mentioned. Rubber hose.   The rubber hose according to any one of claims 1 to 3, wherein the sliding component contains 4 to 25 parts by mass of an organic acid amide with respect to 70 parts by mass of the hydrogenated conjugated diene-aromatic vinyl copolymer.   The rubber hose according to claim 5, wherein the organic acid amide is a fatty acid amide having 10 or more carbon atoms or an unsaturated fatty acid amide.   The rubber hose according to any one of claims 1 to 6, wherein the outermost layer is a coating layer having a thickness of 0.1 to 2 mm formed on the outer surface of the rubber hose.

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