Acrylic elastomer copolymer

Abstract

To provide an acrylic elastomer copolymer stabilized against thermal oxidative degradation.SOLUTION: An acrylic elastomer copolymer contains 0.01-3 wt.% of a phenothiazine derivative compound represented by the general formula in the figure (where R1 is a monovalent aliphatic hydrocarbon group having 1-10 carbon atoms, and R2 is a hydrogen atom or a methyl group), 0.5-10 wt.% of an ethylene monomer, 82-98.99 wt.% of an alkyl (meth)acrylate monomer and / or an alkoxyalkyl (meth)acrylate monomer, and 0.5-5 wt.% of a crosslinking site monomer.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to elastomeric acrylic copolymers, and more particularly to elastomeric acrylic copolymers stabilized against thermo-oxidative degradation. [Background technology]

[0002] Acrylic elastomer copolymers have an excellent balance of heat resistance, oil resistance, and cold resistance, and are reasonably priced, and therefore are used in rubber components and the like around internal combustion engines, such as automobile engines, including gasoline engines and diesel engines.

[0003] In the acrylic elastomer copolymer manufacturing process, after the polymerization of the raw material monomers, phenolic antioxidants are added to the polymerization emulsion or polymerization solution to prevent oxidative deterioration of the copolymer caused by the heat history during coagulation, drying, and storage. When adding antioxidants to the polymerization emulsion or polymerization solution, they can also be added as a dispersion or emulsion using a solvent or surfactant.

[0004] In addition, since the environment around the automobile engine, such as the temperature, is severe, antioxidants are added to the rubber components used to prevent oxidation deterioration caused by oxygen and ozone and to extend their life. Specifically, amine-based antioxidants and the like are added to the crosslinkable composition of the acrylic elastomer copolymer in the manufacturing process of the crosslinked product. When adding the amine-based antioxidant, depending on the type, it may be necessary to take occupational safety and health measures, such as avoiding contact with the human body. In addition, there may be concerns about poor dispersion during the mixing process.

[0005] Furthermore, when the crosslinked product is used, the antioxidant in the crosslinked product is lost over time due to surface migration of the antioxidant, volatilization due to high temperatures, extraction with water, oils and fats, organic solvents, etc., and the original antioxidant function is reduced. As a result, problems such as deterioration of various physical properties such as mechanical properties due to thermal oxidative deterioration may occur. Furthermore, volatilization of the antioxidant into the external environment by water, etc. is undesirable from the viewpoint of environmental conservation.

[0006] For example, in the case of acrylic elastomer copolymers, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine is used as an amine-based antioxidant, but this does not fully address the above-mentioned problems and issues such as extending the product's life in a variety of environments.

[0007] As a countermeasure, studies have been conducted for many years on increasing the molecular weight and melting point of amine-based antioxidants, but this has problems such as reduced dispersibility in rubber and reduced migration within the rubber.

[0008] In addition, several methods have been disclosed for introducing a diphenylamino structure into a polymer by a modification reaction of an elastomeric polymer (Patent Documents 1-2, Non-Patent Document 1). However, these methods require an additional modification step for introducing a diphenylamino group after the production of the base copolymer, and are therefore not practical in terms of production costs.

[0009] In addition, several methods have been disclosed for introducing diphenylamino groups into polymer chains by copolymerizing a diphenylamine derivative compound having a polymerizable unsaturated group with a polymerizable unsaturated monomer. For example, Non-Patent Document 2 proposes a method for copolymerizing N-(4-anilinophenyl)methacrylamide with butadiene and acrylonitrile, and Patent Document 3 proposes a method for copolymerizing N-(4-anilinophenyl)methacrylamide with an alkyl acrylate monomer. However, the diphenylamino group of N-(4-anilinophenyl)methacrylamide has the effect of suppressing radical polymerization reactions, so it is difficult to say that this method is effective.

[0010] Furthermore, a new method has been proposed in which a phenothiazine derivative compound is used instead of an amine-based antioxidant such as 4,4'-bis(α,α-dimethylbenzyl)diphenylamine (Patent Documents 4 to 5).

[0011] Here, the synthesis and polymerization of phenothiazine derivative compounds having a vinyl group as a polymerizable unsaturated group, and application of the polymer to an antioxidant are publicly known, for example, from Non-Patent Documents 3 and 4.

[0012] In addition, the synthesis, polymerization and redox properties of phenothiazine derivative compounds having a vinyl group as a polymerizable unsaturated group and in which the hydrogen atom on the nitrogen at the 10-position is substituted with a methyl group are known in Non-Patent Documents 5 and 6.

[0013] However, none of Non-Patent Documents 3 to 6 describes the efficacy of stabilizing an acrylic elastomer copolymer against thermo-oxidative degradation by copolymerizing a phenothiazine derivative compound having a vinyl group and in which the hydrogen atom on the 10-position nitrogen is substituted with an alkyl group with an ethylene monomer and an acrylate monomer. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Japanese Patent Application Publication No. 4-264106 [Patent Document 2] Japanese Patent Application Publication No. 5-230132 [Patent Document 3] JP 2009-209268 A [Patent Document 4] JP 2015-227402 A [Patent Document 5] WO2011 / 093443 A1 [Non-patent literature]

[0015] [Non-Patent Document 1] Rubber Chem.Technol., Vol. 45, p. 204 (1972) [Non-Patent Document 2] Rubber Chem.Technol., Vol. 52, p. 883 (1979) [Non-Patent Document 3] J. Poly. Sci., Vol. 2, p. 3603 (1964) [Non-Patent Document 4] Russian Journal of Applied Chemistry, Vol. 76, p. 1327 (2003) [Non-Patent Document 5] Macromolecules, vol. 20, p. 978 (1987) [Non-Patent Document 6] Energy Environ.Sci, Vol. 10, p. 2384 (2017) [Non-Patent Document 7] Organic Letters, Vol. 23, p. 4564 (2021) Summary of the Invention [Problem to be solved by the invention]

[0016] The present invention has been made in view of the above problems, and an object of the present invention is to provide an acrylic elastomer copolymer which is stabilized against thermo-oxidative degradation. [Means for solving the problem]

[0017] The object of the present invention is to provide a compound of the general formula TIFF2024171026000001.tif25129 (where R 1 is a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and R 2 This is achieved by an acrylic elastomer copolymer comprising 0.01 to 3 weight % of a phenothiazine derivative compound represented by the formula (I) (wherein R is a hydrogen atom or a methyl group), 0.5 to 10 weight % of an ethylene monomer, 82 to 98.99 weight % of an alkyl (meth)acrylate monomer and / or an alkoxyalkyl (meth)acrylate monomer, and 0.5 to 5 weight % of a crosslinking site monomer. Effect of the Invention

[0018] The acrylic elastomer copolymer of the present invention makes it possible to prevent thermal degradation or thermo-oxidative degradation due to thermal history in the copolymer production process.

[0019] Specifically, for example, when the acrylic elastomer copolymer of the present invention is produced by emulsion polymerization, the copolymer can be prevented from deteriorating during storage of the polymerized emulsion due to its own anti-oxidative deterioration effect.

[0020] Furthermore, in the hot air drying process or extrusion drying process after the copolymer coagulation process, the acrylic elastomer copolymer itself has the anti-oxidative deterioration effect, which prevents its deterioration, and allows the dried copolymer to be stored in air for a long period of time.As described above, the acrylic elastomer copolymer of the present invention is stabilized against thermal deterioration or thermal oxidation deterioration caused by the thermal history during the production process and storage stage, so that it is effective in improving its productivity and storage stability, such as omitting the antioxidant addition process.

[0021] In addition, in the manufacturing process of the crosslinkable composition using the acrylic elastomer copolymer, the process of measuring, adding and mixing the amine-based antioxidant can be omitted, and the manufacturing process can be simplified. At the same time, the possibility of defects caused by poor dispersion of the amine-based antioxidant can be eliminated.

[0022] Furthermore, the rubber member obtained by crosslinking the acrylic elastomer copolymer of the present invention solves the problem of poor appearance caused by surface migration of the antioxidant, and inhibits the volatilization of the antioxidant component due to heat, or the extraction of the antioxidant component by liquid media such as water, oils and fats, or organic solvents, thereby providing the excellent effect of enabling the acrylic rubber member to have a longer life even in a variety of deterioration environments.

[0023] Furthermore, since the antioxidant component is directly chemically bonded to the polymer chain, it has the advantage that the amount of antioxidant component used can be significantly reduced compared to conventional antioxidants. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention relates to an acrylic elastomer copolymer, TIFF2024171026000002.tif25129 (where R 1 is a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and R 2 is a hydrogen atom or a methyl group), an ethylene monomer, an alkyl (meth)acrylate monomer and / or an alkoxyalkyl (meth)acrylate monomer, and a crosslinking site monomer.

[0025] In the phenothiazine derivative compound represented by the general formula [I], R 1 Specific examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, isopropyl, 2-butyl, 2-pentyl, 3-pentyl, 2-hexyl, 3-hexyl, 2-heptyl, 3-heptyl, 4-heptyl, 2-octyl, 3-octyl, 4-octyl, tert-butyl, 1,1-dimethyl- Examples of such alkyl groups include a 1-propyl group, a 1,1-dimethyl-1-butyl group, a 1,1-dimethyl-1-pentyl group, a 1,1-dimethyl-1-hexyl group, a 3-methyl-3-pentyl group, a 3-ethyl-3-pentyl group, a 3-methyl-3-hexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a 1-methyl-1-cyclopentyl group, a 1-methyl-1-cyclohexyl group, and a 1-adamantyl group.

[0026] Specific examples of the phenothiazine derivative compound [I] include 2-ethenyl-10-methyl-10H-phenothiazine, 2-(1-methylethenyl)-10-methyl-10H-phenothiazine, 3-ethenyl-10-methyl-10H-phenothiazine, 3-(1-methylethenyl)-10-methyl-10H-phenothiazine, and the like.

[0027] The method for producing the phenothiazine derivative compound [I] is not particularly limited, and it can be produced using diphenylamine or 10H-phenothiazine as a starting material. For example, Non-Patent Documents 6 and 7 describe methods for producing 3-ethenyl-10-methyl-10H-phenothiazine and 2-(1-methylethenyl)-10-methyl-10H-phenothiazine, respectively.

[0028] In the phenothiazine derivative compound [I], the hydrogen atom at the 10-position is replaced with an aliphatic hydrocarbon group, whereby the radical polymerization inhibitory effect peculiar to phenothiazine is suppressed, and as a result, radical copolymerization with various polymerizable unsaturated monomers becomes possible, and high molecular weight copolymers can be produced.

[0029] At the same time, the hydrogen atom at the 10-position, which is active against basic compounds such as alkyllithium compounds, is replaced with an aliphatic hydrocarbon group, thereby substantially avoiding hydrogen abstraction reactions, and thus enabling anionic copolymerization with various polymerizable unsaturated monomers.

[0030] In copolymerizing the phenothiazine derivative compound represented by the general formula [I] with an ethylene monomer, an alkyl (meth)acrylic and / or alkoxyalkyl (meth)acrylate monomer, and a crosslinking site monomer, [I] is used in an amount of about 0.01 to 3 parts by weight, preferably about 0.05 to 1 part by weight, per 100 parts by weight of the monomer mixture. If it is used in a proportion less than this, a sufficient antioxidant effect cannot be expected, whereas if it is used in a proportion greater than this, no improvement in the antioxidant effect can be expected, which is uneconomical.

[0031] The amount of the ethylene monomer constituting the acrylic elastomer copolymer of the present invention is about 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the monomer mixture. If it is less than 0.5 parts by weight, the molecular weight of the copolymer decreases in a heat aging test, causing softening and deterioration. If it is more than 10 parts by weight, the crosslinking reaction of the polymer chain derived from the ethylene monomer becomes dominant in the heat aging test, which tends to cause a decrease in the elongation of the crosslinked product.

[0032] As the alkyl(meth)acrylate monomer and / or alkoxyalkyl(meth)acrylate monomer constituting the acrylic elastomer copolymer of the present invention, at least one type of (meth)acrylate selected from alkyl(meth)acrylates having an alkyl group with 1 to 20 carbon atoms, aralkyl(meth)acrylates having an aralkyl group with 7 to 20 carbon atoms, and alkoxyalkyl(meth)acrylates having an alkoxyalkyl group with 2 to 20 carbon atoms is used.

[0033] Examples of the alkyl (meth)acrylate that can be used include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, cyclohexyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, and n-octadecyl (meth)acrylate.

[0034] As the aralkyl(meth)acrylate, for example, benzyl(meth)acrylate and the like are used.

[0035] Examples of the alkoxyalkyl (meth)acrylate that can be used include methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, n-butoxyethyl (meth)acrylate, ethoxypropyl (meth)acrylate, methoxyethoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, polyethylene glycol monomethyl ether (meth)acrylate, and polypropylene glycol monoethyl ether (meth)acrylate.

[0036] The alkyl (meth)acrylate monomer and / or alkoxyalkyl (meth)acrylate monomer constituting the acrylic elastomer copolymer of the present invention is about 82 to 98.99 parts by weight, preferably 91 to 98 parts by weight, in 100 parts by weight of the monomer mixture.

[0037] As the crosslinking site monomer constituting the acrylic elastomer copolymer of the present invention, an α,β-unsaturated carboxylic acid monomer, an active chlorine-containing unsaturated monomer or an epoxy group-containing unsaturated monomer is used.

[0038] The α,β-unsaturated carboxylic acid monomer includes a monobasic α,β-unsaturated carboxylic acid, a dibasic α,β-unsaturated carboxylic acid, or a dibasic α,β-unsaturated carboxylic acid monoalkyl ester.

[0039] Examples of the monobasic α,β-unsaturated carboxylic acid include acrylic acid and methacrylic acid.

[0040] Examples of the dibasic α,β-unsaturated carboxylic acid include maleic acid, fumaric acid, itaconic acid, and citraconic acid.

[0041] Examples of dibasic α,β-unsaturated carboxylic acid monoalkyl esters include monoalkyl esters of maleic acid, fumaric acid, itaconic acid, and citraconic acid. Specific examples include monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, monoisopropyl maleate, mono-n-butyl maleate, monoisobutyl maleate, mono-n-hexyl maleate, monocyclohexyl maleate, monomethyl fumarate, monoethyl fumarate, mono-n-propyl fumarate, monoisopropyl fumarate, mono-n-butyl fumarate, monoisobutyl fumarate, mono-n-hexyl fumarate, and monocyclohexyl fumarate.

[0042] Examples of the active chlorine-containing unsaturated monomer include 4-chloromethylstyrene and vinyl chloroacetate.

[0043] Examples of the epoxy group-containing unsaturated monomer include glycidyl acrylate and glycidyl methacrylate.

[0044] The crosslinking site monomer in the acrylic elastomer copolymer of the present invention is copolymerized in a ratio of 0.5 to 5% by weight, preferably 1 to 3% by weight.

[0045] In addition to these main components of the acrylic elastomer copolymer of the present invention, other polymerizable unsaturated monomers can be used as necessary.

[0046] Examples of other polymerizable unsaturated monomers include styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, acrylonitrile, methacrylonitrile, acrylic acid amide, vinyl acetate, methyl vinyl ether, ethyl vinyl ether, propylene, piperylene, butadiene, isoprene, chloroprene, cyclopentadiene, vinyl chloride, and vinylidene chloride.

[0047] The acrylic elastomer copolymer is produced by a general copolymerization method for acrylic rubber. The copolymerization reaction can be carried out by any method such as emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization.

[0048] For example, when an emulsion polymerization method is used, the reaction is carried out at a reaction temperature of about -10 to 100°C, preferably about 5 to 80°C.

[0049] There is no restriction on the emulsifier used in the polymerization, but among them, those using PVA as an emulsifier are particularly preferred. The type of PVA may be any of partially saponified PVA, fully saponified PVA, and modified PVA.

[0050] As the polymerization initiator for the reaction, organic peroxides or organic hydroperoxides such as benzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, cumyl hydroperoxide, and p-methylene hydroperoxide, diazo compounds such as azobisisobutyronitrile and azobisisobutylamidine, and peroxide salts such as ammonium salts represented by ammonium persulfate, sodium salts, and potassium salts are used alone or as redox systems.

[0051] The polymerization reaction is continued until the conversion of the monomer mixture reaches 90% or more.

[0052] Examples of methods for coagulating an acrylic elastomer copolymer from an aqueous emulsion include a salt-acid coagulation method, a method using a water-soluble inorganic electrolyte compound such as calcium chloride, magnesium sulfate, sodium sulfate, ammonium sulfate, potassium alum, etc., a method using a boron compound such as boric acid, potassium tetraborate, ammonium hydrogen tetraborate, sodium tetraborate (borax), etc., a heat coagulation method, a freeze coagulation method, etc. In particular, when PVA is used as an emulsion system, borax is the most effective coagulant and is preferred.

[0053] The copolymer solidified from the aqueous emulsion obtained is thoroughly washed with water and dried. This acrylic elastomer copolymer has a Mooney viscosity ML of about 5 to 100, preferably about 20 to 80. 1+4 (100°C).

[0054] The acrylic elastomer copolymer of the present invention can form a crosslinkable acrylic elastomer copolymer composition together with a crosslinking agent according to the type of crosslinking site monomer used.

[0055] Here, for example, when the crosslinking site monomer is an α,β-unsaturated carboxylic acid monomer, a polyamine compound is used as the crosslinking agent.

[0056] Polyamine crosslinking agents include hexamethylenediamine, hexamethylenediamine carbamate, N,N'-dicinnamylidene-1,6-hexanediamine, 4,4'-bis(aminocyclohexyl)methane, ethylenediamine, ethylenediamine carbamate, cyclohexanediamine, hexamethylenediamine benzoate, diamino-modified siloxane, 4,4'-methylenebiscyclohexylamine, bis(4-amino-3-methyldicyclohexyl)methane, 4,4'-methylenebiscyclohexylamine-cinnamaldehyde adduct, N,N'-dicinnamylidene-1,6-hexanediamine, 4,4'-(α,α-dimethylbenzyl)diphenylamine, 4,4'-methylenedianiline, m-phenylenediamine, 4,4'-diaminodiphenyl ether, p-phenylenediamine, p,p '-ethylenedianiline, 4,4'-(p-phenylenediisopropylidene)dianiline, 4,4'-(m-phenylenediisopropylidene)dianiline, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, m-xylylenediamine, p-xylylenediamine, and the like.

[0057] In the case of crosslinking with a polyamine compound, a guanidine compound, a diazabicycloalkene compound or an organic acid salt thereof is used as a crosslinking accelerator.

[0058] The guanidine compound includes tetramethylguanidine, tetraethylguanidine, 1,3-diphenylguanidine, 1,3-di-o-tolylguanidine, etc. Preferred are 1,3-diphenylguanidine, 1,3-di-o-tolylguanidine, or a combination thereof.

[0059] The diazabicycloalkene compound is preferably 1,8-diazabicyclo[5.4.0]-7-undecene.

[0060] As the organic acid salt of the diazabicycloalkene compound, an organic acid salt of 1,8-diazabicyclo[5.4.0]-7-undecene is preferred.

[0061] The organic acid used for the organic acid salt of 1,8-diazabicyclo[5.4.0]-7-undecene can be an organic monobasic acid or an organic dibasic acid.

[0062] Examples of the organic monobasic acid include n-hexanoic acid, n-heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, n-capric acid, n-lauric acid, p-toluenesulfonic acid, phenol, etc. Examples of the organic dibasic acid include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, orthophthalic acid, phthalic acid, etc., and monocarboxylic or dicarboxylic acids having 6 to 18 carbon atoms are preferred.

[0063] When the crosslinking site monomer is an active chlorine-containing unsaturated monomer, a triazine thiol compound or an alkali metal salt of a fatty acid is used as the crosslinking agent.

[0064] The triazine thiol compound includes triazine thiol (2,4,6-trimercapto-s-triazine) and its derivatives. The derivatives include compounds in which a part of the thiol group of triazine thiol is substituted with an amino group or an aliphatic hydrocarbon group. 2,4,6-trimercapto-s-triazine is preferable.

[0065] When the crosslinking agent is a triazine thiol compound, the crosslinking accelerator can preferably be a metal dithiocarbamate or thiuram sulfide, etc. Examples of the metal dithiocarbamate include zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc di-n-hexyldithiocarbamate, zinc di-n-octyldithiocarbamate, zinc di-n-decyldithiocarbamate, zinc di-n-dodecyldithiocarbamate, zinc methylbenzyldithiocarbamate, zinc dibenzyldithiocarbamate, zinc methylcyclohexyldithiocarbamate, zinc dicyclohexyldithiocarbamate, etc. Specific examples of thiuram sulfides include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide, and the like.

[0066] Examples of the fatty acid alkali metal salt include alkali metal salts of fatty acids having a carbon number of 10 to 22. Sodium stearate and potassium stearate are particularly preferred.

[0067] Furthermore, when a fatty acid alkali metal salt is used as a crosslinking agent, the crosslinking reaction can be effectively promoted by using sulfur in combination, and therefore the crosslinking method using a fatty acid alkali metal salt in combination with sulfur is more common.

[0068] When the crosslinking site unsaturated monomer is an epoxy group-containing unsaturated monomer, an aromatic carboxylic acid ammonium salt is used as a crosslinking agent, or a polyamine compound used when the crosslinking site monomer is an α,β-unsaturated carboxylic acid monomer is used as a crosslinking agent. Examples of the aromatic carboxylic acid ammonium salt include ammonium benzoate.

[0069] Examples of the crosslinking accelerator used when the crosslinking site monomer is an epoxy group-containing unsaturated monomer include the crosslinking accelerators used when the crosslinking site monomer is an α,β-unsaturated carboxylic acid monomer, imidazole compounds, quaternary ammonium salts, tertiary amine compounds, and alkali metal salts of aliphatic carboxylic acids.

[0070] Examples of the imidazole compound include 2-methylimidazole and 2-phenylimidazole. Examples of the quaternary ammonium salt include tetra-n-butylammonium bromide and octadecyltri-n-butylammonium bromide. Examples of the tertiary amine compound include dimethylstearylamine. Examples of the alkali metal salt of an aliphatic carboxylic acid include sodium stearate and potassium stearate.

[0071] The crosslinking is carried out by primary crosslinking at about 120 to 250° C. for about 1 to 60 minutes, and, if necessary, oven crosslinking (secondary crosslinking) at about 120 to 200° C. for about 1 to 20 hours. EXAMPLES

[0072] The present invention will now be described in detail with reference to examples. However, the present invention, including its effects, is not limited to these examples.

[0073] Reference example Preparation of compound (I') TIFF2024171026000003.tif25129 Compound (I') was prepared by the following method. TIFF2024171026000004.tif24166

[0074] [1st process] [PTZ] → (b-1): 2.0 L of thoroughly dehydrated N,N-dimethylformamide was placed in a 5-L five-neck flask equipped with a stirrer, a thermometer, a dropping funnel, a nitrogen gas inlet tube, and an outlet tube, and the temperature in the system was cooled to below 10°C under a nitrogen atmosphere. 103.4 g (2.59 mol) of sodium hydride (purity 60%) was added and stirred for 10 minutes, and then 401.0 g (2.01 mol) of phenothiazine [PTZ] was added in several portions and reacted for 30 minutes while maintaining the temperature in the system below 10°C. 312.3 g (2.20 mol) of iodomethane was added dropwise while maintaining the temperature in the system below 10°C, and the reaction was continued for another hour. After the reaction was completed, the reaction mixture was added to 4 L of a 10% aqueous sodium chloride solution. The precipitated colorless solid was filtered off and then washed with 4 L of distilled water. The obtained solid was dissolved in 2.5 L of warm ethyl acetate at about 50°C, and the lower layer (aqueous layer) was separated. The upper layer (organic layer) was dried over anhydrous magnesium sulfate, and then insoluble matter was filtered off. Volatile components were removed from the filtrate under reduced pressure to obtain 451.4 g of a crude product (crude yield 105%). This was washed (defatted) with 0.7 L of isooctane to obtain 421.2 g of 10-methyl-10H-phenothiazine (b-1) as a slightly greenish crystalline solid (yield 98.2%). TIFF2024171026000005.tif25129 1 H NMR (400MHz, Acetone-d6, δ ppm): 3.39 (s, 3H, NC H 3) 6.91-6.98 (m, 4H, Ar) 7.14 (dd, J=7.6Hz, J=1.6Hz, 2H, Ar) 7.21 (td, J=7.6Hz, J=1.6Hz, 2H, Ar)

[0075] [Second process] (b-1)→(b-2): 0.7 L of thoroughly dehydrated N,N-dimethylformamide was placed in a 3 L five-neck flask equipped with a stirrer, a dropping funnel, a thermometer, a gas inlet / gas outlet, and a reflux condenser. Under a nitrogen atmosphere, 509 g (3.32 mol) of phosphoryl chloride was added dropwise while maintaining the internal temperature of the system at 10°C or less, and the reaction was continued for another 30 minutes. Next, 291.2 g (1.37 mol) of 10-methyl-10H-phenothiazine (b-1) obtained in the first step above was added, and the reaction was continued at 60°C for 17 hours. After the reaction was completed, the contents were poured into 2.3 kg of 50% aqueous sodium acetate solution cooled in an ice-water bath, and 194 g of sodium hydroxide was added to adjust the pH to 6 or higher. The resulting solution was left to stand for 2 hours while being cooled in an ice-water bath. The precipitated solid was filtered off, washed with 3 L of distilled water, and the inorganic electrolytes were dissolved. The remaining brown solid was dissolved in 1.5 L of warm ethyl acetate at about 50°C, and the lower layer (water layer) was separated, and the organic layer was dried over anhydrous magnesium sulfate. After filtering out the insoluble matter, the volatile components were distilled off from the filtrate under reduced pressure to obtain 329.0 g of crude product (crude yield 99.9%) as a reddish-brown oily substance. The crude product was dissolved in about 1 L of ethyl acetate, and low Rf components were removed through a silica gel (stationary phase: Wako Gel C300, length about 10 cm, φ10 cm) column. The volatile components were distilled off from the eluate under reduced pressure to obtain 321.6 g of the desired crude product (yield 97.6%) as a yellow solid. Further, by recrystallization using 320 ml of ethyl acetate, 308.2 g of 10-methyl-10H-phenothiazine-3-carbaldehyde (b-2) was obtained as yellow crystals (yield 93.6%). TIFF2024171026000006.tif29129 1 H NMR (400MHz, Acetone d6, δ ppm): 3.49 (s, 3H, NC H 3) 7.00-7.06 (m, 2H, Ar) 7.10 (d, J=8.4Hz, 1H, Ar) 7.15-7.19(m, 1H, Ar) 7.22-7.28(m, 1H, Ar) 7.61(d, J=1.6Hz, 1H, Ar) 7.75(dd, J=8.4Hz, J=1.6Hz, 1H, Ar) 9.85(s, 1H, -C H O)

[0076] [3rd step] (b-2)→(I′): 2.3 L of thoroughly dehydrated tetrahydrofuran was put into a 5 L five-neck flask equipped with a stirrer, a thermometer, a gas inlet tube, and a gas outlet tube, and the inside temperature was cooled to 10 ° C or less while replacing the inside of the reaction vessel with nitrogen. 175.0 g (1.56 mol) of potassium tert-butoxide and then 557.3 g (1.56 mol) of methyltriphenylphosphonium bromide were added and reacted for 30 minutes. 313.7 g (1.30 mol) of compound (b-2) was added to this and reacted at -10 to 40 ° C for 1 hour to obtain a reaction mixture. The reaction mixture obtained was added to 1.7 L of a 10% aqueous sodium chloride solution to stop the reaction. The organic layer was collected, while the aqueous layer was extracted with ethyl acetate, which was mixed with the previous organic layer. 0.35 g of p-methoxyphenol was added to this mixture, dried with anhydrous magnesium sulfate, and insoluble matter was filtered off. Volatile components were distilled off from the filtrate under reduced pressure, and 718.4 g of a pale yellow solid was obtained.

[0077] This was pulverized in a mortar to obtain a powder. The powdered pale yellow solid was dissolved in 2.1 L of ethanol, after which a small amount of insoluble matter was filtered off, and the filtrate was left overnight at 5°C or lower to crystallize [I']. The amount of crystallized yellow crystals was 286.3 g (yield 92.0%). The same procedure was repeated using 3.3 L of ethanol on the 286.3 g of the crystallized yellow crystals, yielding 259.2 g of [I'] as pale yellow crystals (yield 83.3%). TIFF2024171026000007.tif25129 Melting point: 102℃ 1 H NMR (400MHz, CDCl3, δ ppm): 3.37 (s, 3H, NC H 3) 5.14 (d, J=10.8Hz, 1H, C H 2=CH-PTZ (trans to the phenothiazine group) 5.61 (d, J=17.6Hz, 1H, C H 2=CH-PTZ (cis to the phenothiazine group) 6.59 (dd, J=10.8Hz, 17.6Hz, 1H, CH2=C H -PTZ) 6.75 (d, J=8.4Hz, 1H, Ar) 6.81 (d, J=9.2Hz, 1H, Ar) 6.92 (td, J=7.6Hz, 1.2Hz, 1H, Ar) 7.11-7.23 (m, 4H, Ar)

[0078] Example 1 Production of acrylic elastomer copolymer A In a pressure-resistant reactor with a capacity of 40 liters, 17 kg of a 4% by weight aqueous solution of partially saponified polyvinyl and 22 g of sodium acetate were charged, and the air in the upper part of the vessel was replaced with nitrogen while mixing thoroughly with a stirrer, and then ethylene [E] was forced into the upper part of the vessel to adjust the pressure to 3.5 MPa. Stirring was continued, and the vessel was kept at 55°C, and then a monomer mixture of 7.8 kg of ethyl acrylate [EA], 3.4 kg of n-butyl acrylate [BA], 300 g of mono-n-butyl maleate [MBF], 1.8 g of tertiary-dodecyl mercaptan, and 22 g of the compound [I'] obtained in the reference example was forced into the vessel. A separate aqueous solution of tertiary-butyl hydroperoxide (0.25% by weight, 2 liters) was forced into the vessel from an inlet over 6 hours, and polymerization was carried out until the final polymerization rate reached 95%. To the resulting polymerization solution, an aqueous solution of sodium borate (3.5% by weight, 7 L) was added as a coagulant to coagulate the copolymer, which was then dehydrated and dried to obtain an acrylic elastomer copolymer A (weight fraction composition of E:EA:BA:MBF:compound [I'] was 2.0:70.0:25.8:2.0:0.2).

[0079] Comparative Example 1 Copolymer B (weight fraction composition of E:EA:BA:MBF was 2.0:70.0:26.0:2.0) was prepared in the same manner as acrylic elastomer copolymer A, except that compound [I'] was not used.

[0080] Example 2 Acrylic elastomer copolymer A 100 parts by weight FEF Carbon Black (Tokai Carbon Products Seast GSO) 50 〃 Stearic acid (Miyoshi Oil Products TST) 1.0 Same Hexamethylenediamine carbamate 0.6 〃 Stearylamine (Kao product Farmin 80) 1.0 Same Vulcofac ACT55 (Safic-Alcan product) 1.0 Same Among the above components, acrylic elastomer copolymer A, carbon black and stearic acid were mixed in a Banbury mixer, and the remaining components were added to the mixture and mixed in an open roll to obtain an acrylic elastomer copolymer composition. This was subjected to primary crosslinking at 180°C for 8 minutes in a 100-ton press molding machine, and further subjected to secondary crosslinking at 175°C for 4 hours to obtain a sheet-like crosslinked product with a thickness of about 2 mm.

[0081] The crosslinked physical properties of the acrylic elastomer copolymer composition were measured as follows. Normal state physical properties: Compliant with JIS K6251 and JIS K6253 Air heating aging test: JIS K6257 compliant (175℃, 500 hours)

[0082] Comparative Example 2 In Example 2, acrylic elastomer copolymer B was used instead of acrylic elastomer copolymer A, and 2.0 parts by weight of the antioxidant 4,4'-bis(α,α)dimethylbenzyldiphenylamine (Nocrac CD, Ouchi Shinko Chemical Products) was used.

[0083] Comparative Example 3 In Example 2, acrylic elastomer copolymer B was used instead of acrylic elastomer copolymer A.

[0084] The results obtained in Example 2 and Comparative Examples 2 and 3 are shown in the following table. table Measurement results Example 2 Comparative Example 2 Comparative Example 3 Normal physical properties Hardness (Duro A) 60 59 60 Strength at break (MPa) 12.0 11.5 12.0 Elongation at break (%) 200 210 200 Heat aging test (175℃, 500 hours) Hardness Change (Duro A) +10 +7 +13 Strength change rate at break (%) -30 -50 -40 Elongation change at break (%) -10 +20 -50

Claims

1. general formula (where R 1 is a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and R 2 is a hydrogen atom or a methyl group), 0.5 to 10 weight % of an ethylene monomer, 82 to 98.99 weight % of an alkyl (meth)acrylate monomer and / or an alkoxyalkyl (meth)acrylate monomer, and 0.5 to 5 weight % of a crosslinking site monomer.

2. 2. The acrylic elastomer copolymer according to claim 1, wherein the crosslinking site monomer is an α,β-unsaturated carboxylic acid monomer.

3. 2. The acrylic elastomer copolymer according to claim 1, wherein the crosslinking site monomer is an active chlorine-containing unsaturated monomer.

4. 2. The acrylic elastomer copolymer according to claim 1, wherein the crosslinking site monomer is an epoxy group-containing unsaturated monomer.

5. A crosslinkable acrylic elastomer copolymer composition comprising the acrylic elastomer copolymer according to claim 1 and a crosslinking agent.

6. A crosslinked molded product of the crosslinkable acrylic elastomer copolymer composition according to claim 5.

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