Method for rustproofing metal component, and rubber composition
A rubber composition with aliphatic amines and nonionic surfactants prevents rust on metal parts by inhibiting the crystallization of brown substances, achieving effective rust prevention and maintaining appearance in humid conditions.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KAO CORP
- Filing Date
- 2025-11-26
- Publication Date
- 2026-06-04
AI Technical Summary
Metal parts, particularly iron and steel, are prone to oxidation and rusting due to environmental oxygen and water, and existing rust prevention methods for metal parts and rubber compositions used in contact with metals are inadequate in preventing rust and appearance deterioration.
A rubber composition containing aliphatic amines and nonionic surfactants is used to create a rubber molded body that, when contacted with metal parts, inhibits rusting by preventing the crystallization of brown substances and oils that typically cause rust and appearance issues.
The rubber composition effectively prevents rust on metal surfaces by inhibiting the crystallization of brown substances and oils, resulting in undetectable metal component leaching and no visible discoloration, suitable for components exposed to humid environments.
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Abstract
Description
Method for rust prevention treatment of metal parts, and rubber composition
[0001] This invention relates to a method for rust prevention treatment of metal parts and a rubber composition used therein.
[0002] Metal materials are fundamental to industry, and metal parts have traditionally been used in various fields, such as automobile parts and molds. However, because metal materials are prone to rusting, rust prevention treatment is necessary for long-term use as metal parts.
[0003] Typically, metal parts are treated to prevent rust by methods such as coating the surface with an oil-based or water-soluble rust inhibitor, or by performing metal processing with a processing oil that provides rust prevention. For example, Japanese Patent Publication No. 5-222390 (Patent Document 1) describes formula (1): -(CH2CR 1 R 2 ) - and formula (2): - [R 3 O(O=C)CH-CH(C=O)OR 4 The following is a rust-preventive oil containing a copolymer having repeating units indicated by ] and / or a salt thereof in a total amount of 1 to 50% by weight.
[0004] Japanese Patent Publication No. 8-213727 (Patent Document 2) describes a laminated substrate in which dissimilar metals coexist and are partially rust-preventively treated. The laminated substrate is composed of a metal-core copper-clad laminate having a base material made of an iron-based metal including metallic iron or an alloy thereof, an electrical insulating layer formed on the base material, a copper-containing foil pressed onto the electrical insulating layer, a rust-preventively treated film formed on the copper-containing foil as needed, a circuit formed on one side of the copper-containing foil as needed, and a surface rust-preventively treated surface formed on the other side by surface rust-preventive treatment. Partial rust-preventive treatment is applied to the end face of the iron-based metal base material of the metal-core copper-clad laminate and, if necessary, the exposed iron-based metal portion using a chemical agent containing an organic surfactant mixture mainly composed of an amine-based nonionic surfactant.
[0005] Japanese Patent Publication No. 9-255940 (Patent Document 3) states that general formula (1): R 1 R 2 R 3 N, general formula (2): R 4R 5 R 6 R 7 N + B - , General formula (3): R 8 R 9 N(AO) m H and general formula (4): H(OA) m NR 10 (AO) n A surface treatment agent composed of a nitrogen-containing compound selected from the group consisting of H is described. In Japanese Patent Application Laid-Open No. 2022-112615 (Patent Document 4), a rust inhibitor for an aqueous hypochlorous acid solution that imparts a rust prevention effect for suppressing the generation of rust on the contacted metal surface is described.
[0006] By the way, the molded body of the rubber composition used for tires and the like is often used by adhering to the surface of metal parts. Various fillers are added to these rubber compositions for imparting abrasion resistance, preventing ozone deterioration and discoloration, etc. For example, a rubber composition (Japanese Patent No. 4157608 (Patent Document 5)) in which silica and a specific tertiary amine compound are blended with natural rubber and / or diene-based synthetic rubber, a rubber composition (Japanese Patent No. 6608602 (Patent Document 6)) containing silica and glycerin fatty acid ester in a diene-based rubber, and a rubber composition in which a specific nonionic surfactant or the like is blended with at least one rubber component selected from diene-based synthetic rubber and natural rubber are known (Japanese Patent No. 5731768 (Patent Document 7), Japanese Patent No. 5926902 (Patent Document 8)).
[0007] The present invention relates to the following [1] to [3]. [1] A method for rust prevention of metal parts, comprising contacting a metal with a rubber molded body obtained from a rubber composition containing one or more rubber composition additives selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds. [2] A rubber composition used in the rust prevention method for metal parts described in [1], containing one or more rubber composition additives selected from the group consisting of aliphatic amines and nonionic surfactants. [3] A rubber composition comprising rubber and an additive, wherein the additive comprises one or more selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds, and the content of the additive per 100 parts by mass is more than 3 parts by mass and less than 5 parts by mass.
[0008] Among the metals used in metal parts, iron and steel in particular are prone to oxidation and rusting due to oxygen and water in the environment. Therefore, there is a need for the development of rust prevention technologies, such as imparting rust-preventive properties to rubber molded bodies used for bonding to metal parts.
[0009] The present invention relates to a method for applying rust prevention treatment to metal parts using a rubber molded article obtained from a rust-preventive rubber composition, and to a rubber composition used in the same.
[0010] The inventors have found that a rubber composition containing additives for rubber compositions, such as aliphatic amines and nonionic surfactants, acts as a rust inhibitor, and that when a rubber molded body obtained from this rubber composition is brought into contact with metal, the problems of the prior art described above can be solved, and the surface of metal parts can be effectively rust-prevented.
[0011] According to the present invention, it is possible to provide a method for rust prevention treatment of metal parts using a rubber molded article obtained from a rubber composition having rust-preventive properties, and a rubber composition used therein.
[0012] The present invention relates to a method for rust prevention of metal parts, which involves contacting a metal with a rubber molded body obtained from a rubber composition containing one or more rubber composition additives selected from the group consisting of aliphatic amines and nonionic surfactants.
[0013] In other words, the present invention provides a method for rust prevention treatment of metal parts by bringing a rubber molded body obtained from a rubber composition containing an additive for rubber compositions into contact with metal.
[0014] Although the reason is not entirely clear, it is thought that when a rubber composition comes into contact with a metal, brown substances and waxes caused by the antioxidants in the rubber composition seep out of the rubber composition and adhere to the metal surface, crystallize, and this causes rusting and deterioration of the appearance of the metal. In the present invention, in addition to additives such as antioxidants and waxes, aliphatic amines and nonionic surfactants are also added to the rubber composition. It is presumed that these aliphatic amines and nonionic surfactants inhibit the crystallization described above, and as a result, the rubber molded body obtained from the rubber composition prevents rusting on the metal surface it comes into contact with.
[0015] [Rubber Composition] In one or more embodiments, the rubber composition of the present invention comprises rubber and an additive for rubber compositions. In one or more embodiments, the rubber composition of the present invention comprises rubber and an additive for rubber compositions, and may further contain other components (for example, reinforcing fillers). The components of the rubber composition (rubber, additive for rubber compositions, and other components) are described below.
[0016] <Rubber> Examples of rubber used in the rubber composition according to the present invention include diene rubber, specifically conjugated diene rubber. While the main application of the rubber composition according to the present invention is tires, the rubber that can be used in the rubber composition according to the present invention is not limited to diene rubber. Examples of diene rubber include at least one selected from the group consisting of natural rubber (NR) and synthetic diene rubber.
[0017] Examples of synthetic diene rubbers include polybutadiene rubber (BR), synthetic polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), and styrene-isoprene copolymer rubber (SIR).
[0018] Of these, the diene rubber is preferably made of styrene-butadiene copolymer rubber (SBR) because it has a small tanδ and reduces the rolling resistance of the tire. The SBR content in the diene rubber is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and 100% by mass or less.
[0019] Diene rubber may be used alone or in combination of two or more types. Furthermore, the diene rubber used may be modified or unmodified.
[0020] The rubber content in the rubber composition is preferably 30% by mass or more, more preferably 38% by mass or more, even more preferably 45% by mass or more, and preferably 75% by mass or less, more preferably 65% by mass or less, and even more preferably 57% by mass or less, from the viewpoint of exhibiting rubber-derived physical properties.
[0021] <Additives for Rubber Compositions> The additive for rubber compositions according to the present invention is an additive comprising one or more selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds. The additive for rubber compositions is a component that acts as a rust inhibitor. The content of the additive for rubber compositions in the rubber composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, even more preferably more than 3 parts by mass, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, even more preferably 7 parts by mass or less, and even more preferably less than 5 parts by mass, from the viewpoint of rust prevention effect on the surface of metal parts that come into contact with the rubber molded body obtained from the rubber composition.
[0022] (Aliphatic amines) Primary to tertiary aliphatic amines are used as aliphatic amines. In addition, primary to tertiary aliphatic amines may be alkanolamines. Specific examples of primary aliphatic amines include methylamine, ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, 2-aminobutane, 2-amino-2-methylpropane, pentylamine, isopentylamine, 2-amino-2-methylbutane, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, monoethanolamine, monoisopropanolamine, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, ethylenediamine, coconutamine, laurylamine, stearylamine, and oleylamine. Specific examples of secondary aliphatic amines include dimethylamine, diethylamine, dipropylamine, and diisopropylamine. Examples of tertiary aliphatic amines include N-methylethylamine, N-ethylhexylamine, diethanolamine, ethylmonoethanolamine, dipropanolamine, and diisopropanolamine. Specific examples of tertiary aliphatic amines include triethylamine, tributylamine, tripropylamine, trioctylamine, trilaurylamine, methyldiethanolamine, ethyldiethanolamine, diethylethanolamine, dimethylhexylamine, dimethyldodecylamine, dimethylcoconutamine, dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, dimethylpalmitylamine, dimethylstearylamine, dimethylmyristylamine, dimethylbehenylamine, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2,2'-(n-butylimino)diethanol, and triethanolamine.
[0023] Of these, primary or tertiary aliphatic amines are preferred, and primary or tertiary higher alkylamines are more preferred. A higher alkyl group refers to an alkyl group having 12 to 24 carbon atoms. Primary higher alkylamines include coconutamine, octylamine, laurylamine, stearylamine, and oleylamine, while tertiary higher alkylamines include dimethylcoconutamine, dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, dimethylpalmitylamine, dimethylstearylamine, dimethylmyristylamine, and dimethylbehenylamine. Of these, tertiary higher alkylamines such as dimethylstearylamine are even more preferred.
[0024] (Nonionic surfactant) As the nonionic surfactant, polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene alkylamines, and fatty acid ester compounds can be used, but one or more selected from the group consisting of polyoxyethylene alkylamines and fatty acid ester compounds are preferred.
[0025] Examples of polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene myristyl ether, and polyoxyethylene octyldodecyl ether.
[0026] Polyoxyethylene alkenyl ethers include polyoxyethylene alkenyl ethers having a 2-methyl-1-butenyl group (H(OA2) n (OA1) m Examples include -O-CH2CH2C(CH3)=CH2) (OA1 and OA2 represent oxyalkylene groups).
[0027] Examples of polyoxyethylene alkylamines used include higher alkylamine ethylene oxide (EO) adducts such as polyoxyethylene octadecylamine and N,N-bis(polyoxyethylene)stearylamine. The average number of moles of EO added is preferably, for example, 2 to 20.
[0028] Examples of fatty acid ester compounds include sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan monolaurate, and sorbitan sesquioleate; polyoxyethylene fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate; and polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan Examples include polyoxyethylene sorbitan fatty acid esters such as monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan triisostearate, and polyoxyethylene sorbitan monolaurate; polyoxyethylene sorbitol fatty acid esters such as tetraoleate polyoxyethylene sorbitate; and glycerol fatty acid esters such as glycerol monostearate, glycerol monooleate, and self-emulsifying glycerol monostearate.
[0029] Of these, the fatty acid ester compound described above is preferred, the glycerol fatty acid ester described above is more preferred, and glycerol monostearate or glycerol monooleate is even more preferred.
[0030] (Maleic acid ester compounds) Examples of the maleic acid ester compounds include polyoxyalkylene alkyl maleic acid esters. Polyoxypropylene alkyl maleic acid esters and polyoxyethylene alkyl maleic acid esters are preferred. Of these, polyoxypropylene alkyl maleic acid esters are preferred, and the number of moles of oxypropylene added is preferably 2 or more and 8 or less.
[0031] As maleic acid ester compounds, polyoxyethylene alkyl maleic acid esters and polyoxypropylene alkyl maleic acid esters are more preferable from the viewpoint of visibility. As polyoxyethylene alkyl maleic acid esters, polyoxyethylene(6) alkyl maleic acid esters are even more preferable. As polyoxypropylene alkyl maleic acid esters, polyoxypropylene alkyl maleic acid esters with the added number of oxypropylene being 2 or more and 7 or less are more preferable, and polyoxypropylene(3) alkyl maleic acid esters and polyoxypropylene(6) alkyl maleic acid esters are even more preferable. The numerical value in ( ) indicates the added molar number of oxypropylene (PO).
[0032] As described later, the content of aliphatic amine, nonionic surfactant or maleic acid ester compound in the rubber composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, even more preferably more than 3 parts by mass, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, even more preferably 7 parts by mass or less, even more preferably less than 5 parts by mass, from the viewpoint of the rust prevention effect on the surface of metal parts contacted with the rubber molded body obtained from the rubber composition, per 100 parts by mass of rubber.
[0033] <Other components> In addition to the rubber, aliphatic amine, nonionic surfactant or maleic acid ester compound described above, a reinforcing filler, and rubber additives such as a coupling agent, a vulcanizing agent such as sulfur, zinc oxide, a vulcanization accelerator, a softening agent such as oil, stearic acid, and an antioxidant may be appropriately added within a range not impairing the object of the present invention to the rubber composition according to the present invention. Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazole sulfenamide, 1,3-diphenylguanidine, etc. Examples of the antioxidant include N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, etc.
[0034] Examples of reinforcing fillers include organic fillers such as carbon black of GPF, FEF, HAF, ISAF, and SAF grades, and functionalized polyvinyl aromatic fillers, as well as inorganic fillers such as silica, aluminum hydroxide, clay, talc, calcium carbonate, and zeolite. The silica can be wet silica (hydrated silica), dry silica (anhydrous silica), calcium silicate, aluminum silicate, etc. These components may be used individually or in combination of two or more.
[0035] From the viewpoint of improving the strength of the rubber molded article, the content of the reinforcing filler in the rubber composition is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less, per 100 parts by mass of rubber. From a similar viewpoint, the content of the reinforcing filler in the rubber composition is preferably 2 parts by mass or more, more preferably 10 parts by mass or more, and preferably 120 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably less than 30 parts by mass, per 1 part by mass of rubber composition additive containing one or more selected from the group consisting of aliphatic amines, nonionic surfactants and maleic acid ester compounds.
[0036] The coupling agent is usually a silane coupling agent, preferably a silane coupling agent having a sulfur atom. Specific examples of the silane coupling agent having a sulfur atom include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, and dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide, etc.
[0037] The content of the silane coupling agent in the rubber composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 15 parts by mass or less, more preferably 12 parts by mass or less, and still more preferably 10 parts by mass or less with respect to 100 parts by mass of silica.
[0038] Of the rubber additives, the content of oil in the rubber composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, from the viewpoint of softening the rubber composition and improving its processability.
[0039] The content of rubber additives other than coupling agents and oils in the rubber composition is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and preferably 150 parts by mass or less, and more preferably 100 parts by mass or less, per 100 parts by mass of rubber, from the viewpoint of the reinforcing properties of the rubber molded article obtained from the rubber composition.
[0040] <Method for Producing Rubber Composition> The rubber composition according to the present invention contains one or more rust inhibitors selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds, i.e., additives for rubber compositions. The rubber composition can be produced, for example, by blending and mixing each component contained in the rubber composition using a kneader such as a Banbury mixer, roll mixer, or intensive mixer.
[0041] In this case, from the viewpoint of suppressing vulcanization during the manufacture of the rubber composition and improving handling during manufacture, it is preferable to manufacture the rubber composition by first blending and mixing the components of the rubber composition, excluding the vulcanizing agent and vulcanization accelerator (first kneading step), and then blending and mixing the vulcanizing agent and vulcanization accelerator (second kneading step). With this method, vulcanization does not occur even if the first kneading step is carried out under high temperature conditions, and the rubber composition of the present invention can be manufactured with high productivity.
[0042] In the first kneading step, the mixing temperature is preferably 250°C or lower, more preferably 200°C or lower, and even more preferably 170°C or lower, from the viewpoint of suppressing thermal decomposition of each component, and preferably 90°C or higher, more preferably 110°C or higher, and even more preferably 130°C or higher, from the viewpoint of productivity.
[0043] In the second kneading step, the mixing temperature is preferably 130°C or lower, more preferably 120°C or lower, from the viewpoint of suppressing vulcanization during mixing, and preferably 80°C or higher, more preferably 100°C or higher, from the viewpoint of productivity.
[0044] [Method for applying rust inhibitor] The method for applying the rust inhibitor of the present invention involves bringing a rubber molded body obtained from a rubber composition containing the rust inhibitor into contact with a metal. It is preferable to degrease and clean the metal beforehand. Therefore, the effects of the present invention are suitably exhibited in components that are exposed to a humid environment and in which the rubber molded body and the metal come into contact. The rust-preventive effect is exhibited on the surface of the metal covered with the rubber molded body. The rust-preventive effect is evident from the fact that discoloration of the surface of the metal part is not visible, and that the amount of metal components leached from the surface of the metal part by inductively coupled plasma mass spectrometry (ICP-MS) is almost undetectable.
[0045] The material of the metal is not limited as long as the rubber molded body can be brought into contact with its surface. For example, one or more metals selected from the group consisting of aluminum, copper, iron, and aluminum alloys can be used. The shape of the metal is not limited, and can be flat, columnar, spherical, etc.
[0046] [Method for preventing rust on metal parts] The present invention provides a method for preventing rust on metal parts, which involves bringing a rubber molded body obtained from a rubber composition containing the aforementioned additive for rubber compositions into contact with a metal.
[0047] In this invention, by including the aforementioned rubber composition additive in addition to reinforcing fillers and rubber additives in the rubber composition, a rust-preventive effect is achieved on the surface of metal parts in contact with the molded body obtained from the rubber composition. This effect is achieved because the aliphatic amine or nonionic surfactant suppresses rusting caused by antioxidants and oils contained in the rubber composition. Brown substances from antioxidants and oil films that seep from the rubber molded body to the surface of metal parts in contact with the rubber molded body crystallize, causing damage to the appearance of the metal parts, rusting, and discoloration. In this invention, it is believed that the nonionic surfactant, along with the reinforcing fillers and rubber additives, seeps to the surface of metal parts in contact with the rubber molded body and adheres to the surface of the metal parts, thereby inhibiting crystallization caused by the brown substances and films, and consequently exhibiting a rust-preventive effect.
[0048] [Rubber Molded Article] The rubber molded article of the present invention is obtained from the rubber composition of the present invention described above. In one or more embodiments, the rubber molded article of the present invention is obtained by vulcanizing an unvulcanized rubber composition (the rubber molded article of the present invention). The unvulcanized rubber composition can be molded by a known method, heated or heated and pressurized to obtain a vulcanized rubber molded article.
[0049] <Applications of the rubber molded articles> In one or more embodiments, the rubber molded articles of the present invention are used in methods for applying rust inhibitors or methods for rust prevention treatment of metal parts.
[0050] The aforementioned rubber molded body is suitably used in one or more embodiments as a component that can provide rust prevention, i.e., a component that comes into contact with metal parts. Specifically, it is suitably exhibited in components that are exposed to environments with high moisture content, such as rain and humidity, and that come into contact with metal parts, specifically in automobile wheels and tires, bicycle rims and tires, machine bearing seals, door seals, pipe joints, shaft seals, hydraulic systems, air conditioning duct seals, window frame seals, gaskets, engine seals, pedal rubber pads, tool grips, waterproof seals, car wipers, industrial machinery seals, and pump systems. The rust prevention effect is exhibited on the metal surface covered with the rubber molded body. The rust prevention effect is evident from the fact that discoloration of the metal part surface is not visible, and that metal components leached from the metal surface by inductively coupled plasma mass spectrometry (ICP-MS) are almost undetectable.
[0051] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. In the table, the numerical values for the composition are the solid content values, and "%" refers to "mass%" unless otherwise specified.
[0052] [Example 1] [Preparation of Rubber Composition] Using the formulation shown in Table 1, a rubber composition was prepared by kneading in the following order: first kneading step, then second kneading step, using a standard Banbury mixer. In the first mixing step, 100 parts by mass of styrene-butadiene copolymer rubber (SBR) (manufactured by Nippon Zeon Co., Ltd., trade name "NS210"), 5 parts by mass of carbon black (manufactured by Tokai Carbon Co., Ltd., trade name "Seasto 3 (HAF)"), 60 parts by mass of silica (manufactured by Tosoh Silica Co., Ltd., trade name "Nipsil AQ"), 4.8 parts by mass of bis(triethoxysilylpropyl) tetrasulfide (manufactured by Evonik, trade name "Si69") as a silane coupling agent, 2 parts by mass of stearic acid (manufactured by Kao Corporation, trade name "Lunaq® S70-V"), 1 part by mass of N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) as an antioxidant, and oil (manufactured by Nippon Sun Oil Co., Ltd., trade name "Sunsen 15 parts by mass of 410) and 4 parts by mass of polyoxyethylene alkylamine (manufactured by Kao Corporation, trade name "Amite® 302"), which is an additive for rubber compositions, were mixed and kneaded in a Banbury mixer for 4 minutes at a maximum temperature of 150°C.
[0053] Next, in the second kneading step, 3 parts by mass of zinc oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 1.5 parts by mass of sulfur (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 1.8 parts by mass of N-cyclohexyl-2-benzothiazole sulfenamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as vulcanization accelerator 1, and 1.5 parts by mass of 1,3-diphenylguanidine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as vulcanization accelerator 2 were added to the kneaded product obtained in the first kneading step, and the mixture was kneaded in the Banbury mixer for 2 minutes and 30 seconds at a maximum temperature of 110°C to obtain an unvulcanized rubber composition.
[0054] <Rust Prevention Test and Metal Component Leaching Measurement Test> The unvulcanized rubber composition obtained in Example 1 was heated at 160°C for 15 minutes to obtain a 2 mm thick sheet-like vulcanized rubber molded body. An aluminum alloy plate (ADC12 50 mm × 20 mm × 1.6 mm) that had been degreased and cleaned with acetone was sandwiched between two vulcanized rubber sheets (70 mm × 40 mm × 2 mm) and left to stand for two weeks. Next, the aluminum alloy plate from which the vulcanized rubber sheets had been removed was immersed in 50 g of water heated to 50°C for one hour. After that, the amount of aluminum ions leached into the water was measured using an ICP emission spectrometer (Agilent 5110 ICP-OES), and the amount of aluminum leached per unit area (g / m²) was calculated from the measurement results and the surface area of the aluminum alloy plate. 2 The following was calculated: The surface of the aluminum alloy plate after the test was visually inspected and evaluated according to the following criteria: 1: No rust observed 2: Some rust observed 3: Extensive deterioration due to rust observed
[0055] [Examples 2] to [Examples 6] Unvulcanized rubber compositions were obtained in the same manner as in Example 1, except that rubber composition additive 1 was changed to rubber composition additives 2 to 6. Specifically, using the formulation shown in Table 1 and a standard Banbury mixer, in the same manner as in Example 1, in the first kneading step, components other than zinc oxide, sulfur, and vulcanization accelerators 1 and 2 were kneaded at a maximum temperature of 150°C, and in the second kneading step, zinc oxide, sulfur, and vulcanization accelerators 1 and 2 were kneaded at a maximum temperature of 110°C to obtain an unvulcanized rubber composition. After obtaining a sheet-like vulcanized rubber molded article in the same manner as in Example 1, a rust prevention test and a metal component elution amount measurement test were performed. The test results are shown in Table 1.
[0056] Table 1 lists the following components: • Rubber: Styrene-butadiene copolymer rubber, manufactured by Zeon Corporation, SBR, trade name "NS210" • Carbon black: manufactured by Tokai Carbon Co., Ltd., trade name "Seasto 3 (HAF)" • Silica: manufactured by Tosoh Silica Co., Ltd., trade name "Nipsil AQ" • Silane coupling agent: Bis(3-triethoxysilylpropyl) tetrasulfide, manufactured by Evonik, trade name "Si69" • Stearic acid: manufactured by Kao Corporation, trade name "Lunaq (registered trademark) S70-V" • Anti-aging agent: manufactured by Tokyo Chemical Industry Co., Ltd., N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine oil: manufactured by Sun Oil Co., Ltd., trade name "Sansen 410" • Zinc oxide: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. • Sulfur: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. • Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazole sulfenamide, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. • Vulcanization accelerator 2: 1,3-diphenylguanidine, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. • Additive for rubber composition 1: Polyoxyethylene (2) octadecylamine, manufactured by Kao Corporation, product name "Amite® 302" • Additive for rubber composition 2: Polyoxyethylene (20) octadecylamine, manufactured by Kao Corporation, product name "Amite® 320" • Additive for rubber composition 3: Dimethylstearylamine, manufactured by Kao Corporation, product name "Farmin® DM8098" • Additive for rubber composition 4: Glycerin monooleate, manufactured by Kao Corporation, product name "Leodor® MO-60" - Rubber composition additive 5: Glycerol monostearate, manufactured by Kao Corporation, product name "Excel® VS-95" - Rubber composition additive 6: Polyoxypropylene alkyl maleate, "C12-PO6-maleic acid"
[0057] [Comparative Example 1] A sheet-like vulcanized rubber molded article was obtained in the same manner as in Example 1, except that rubber composition additive 1 was not added. A rust prevention test and a metal component elution measurement test were performed in the same manner as in Example 1. The test results are shown in Table 1.
[0058] [Comparative Example 2] A sheet-like vulcanized rubber molded article was obtained in the same manner as in Example 1, except that calcium stearate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), which is rubber composition additive C1, was added instead of rubber composition additive 1. A rust prevention test and a metal component elution measurement test were performed in the same manner as in Example 1. The test results are shown in Table 1.
[0059] Table 1 shows that by using aliphatic amines and nonionic surfactants such as polyoxyethylene alkylamine, dimethylstearylamine, glycerin fatty acid ester, and polyoxypropylene alkyl maleate ester as additives, rust prevention effects were obtained on metal plates. On the other hand, in Comparative Example 1, which did not use the specific additive according to the present invention, and in Comparative Example 2, which used calcium stearate (additive C1), the entire surface of the aluminum alloy plate was corroded in the rust prevention test.
[0060]
Claims
1. A method for preventing rust on metal parts, comprising contacting a molded rubber body obtained from a rubber composition containing one or more additives for rubber compositions selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds, with a metal.
2. The method for rust prevention treatment of metal parts according to claim 1, wherein the nonionic surfactant is one or more selected from the group consisting of polyoxyethylene alkylamines and fatty acid ester compounds.
3. The rust prevention treatment method for metal parts according to claim 1 or 2, wherein the metal is one or more selected from the group consisting of aluminum, copper, iron, and aluminum alloys.
4. The method for rust prevention treatment of metal parts according to any one of claims 1 to 3, wherein the rubber composition comprises rubber, and the rubber is a synthetic diene rubber.
5. The method for rust prevention treatment of metal parts according to claim 4, wherein the rubber content in the rubber composition is 30% by mass or more and 57% by mass or less.
6. The method for rust prevention of metal parts according to claim 4 or 5, wherein the content of the rubber composition additive in the rubber composition is 0.5 parts by mass or more and 15 parts by mass or less per 100 parts by mass of rubber.
7. A rubber composition containing one or more rubber composition additives selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds, for use in a rust prevention treatment method for metal parts according to any one of claims 1 to 6.
8. A rubber composition comprising rubber and an additive for rubber compositions, wherein the additive for rubber compositions comprises one or more selected from the group consisting of aliphatic amines, nonionic surfactants, and maleic acid ester compounds, and the content of the additive for rubber compositions is more than 3 parts by mass and less than 5 parts by mass per 100 parts by mass of rubber.
9. The rubber composition according to claim 8, further comprising a reinforcing filler, wherein the content of the reinforcing filler per 1 part by mass of the rubber composition additive is 10 parts by mass or more and less than 120 parts by mass.