JPS6210526B2 - - Google Patents

Description

[Detailed description of the invention]

a. Field of Industrial Application The present invention relates to a method for producing a multicomponent copolymer rubber consisting of an α/β-unsaturated nitrile, a conjugated diene, and a fluorine-containing α-olefin. - It relates to a method for producing a multicomponent copolymer of β-unsaturated nitrile, conjugated diene, and fluorine-containing α-olefin. b. Conventional technology In recent years, automobile exhaust gas regulations have become stricter, and each automobile manufacturer has taken the necessary measures. For details, see A.Nersasian:
Described in Rubber and Plastics News June 26 (1978). ) is occurring, which is a new problem. Furthermore, due to the tight global supply and demand for crude oil, attempts have been made to mix alcohol with gasoline. Therefore, the butadiene-acrylonitrile rubber material that has been used as a conventional fuel rubber material cannot withstand the above-mentioned sour gasoline and alcohol-containing gasoline. Therefore, to improve this, butadiene-
A rubber material with improved sour gasoline resistance by using a blend of acrylonitrile rubber and polyvinyl chloride is disclosed in JP-A-55-89338. c Problems to be Solved by the Invention However, the rubber material with improved sour gasoline resistance has the disadvantage that other physical properties required for fuel rubber materials such as cold resistance and compression set are poor. It is desired to develop a rubber material that improves these drawbacks. On the other hand, it was announced that fluorocarbon rubber has excellent resistance to sour gasoline and alcohol-containing gasoline. Due to the development of Showa Neoprene Co., Ltd. (Tsuyoshi Sugiki), fluorocarbon rubber suddenly came into the limelight as a rubber material for fuel.However, fluorocarbon rubber cannot be vulcanized with sulfur, and its physical properties are poor, making it difficult to handle. It is difficult to use and is also very expensive, so it is not versatile enough to be used as a fuel rubber material. d. Means to Solve the Problems Therefore, the present inventors developed a rubber material with sour gasoline resistance and alcohol resistance. As a result of various studies on materials that have excellent gasoline properties, can be vulcanized with sulfur, and can be easily used as fuel rubber materials using conventional molding equipment and technology, we have found that fluorine-containing α-olefin is used as a monomer component. By using (A) an α/β-unsaturated nitrile, (B) a conjugated diene, and (C) a fluorine-containing α-olefin, a novel method for producing a multicomponent copolymer rubber has been achieved. By polymerizing using a radical polymerization initiator,
(A)α・with a glass transition temperature (Tg) of −50 to −20℃
β-unsaturated nitrile unit component is 15 to 60 mol%, (B)
This is a method for producing a multicomponent copolymer rubber having a polymer composition of 20 to 75 mol % of a conjugated diene unit component and 1 to 45 mol % of (C) a fluorine-containing α-olefin unit component. e Specific description of the invention Monomer component (A) used in the method for producing a multi-component copolymer of the present invention
Specific examples of the component α/β-unsaturated nitrile monomer include acrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, ethacrylonitrile, and among these, acrylonitrile is particularly preferred. (B) used in the method for producing a multicomponent copolymer of the present invention
As a conjugated diene monomer, butadiene-1.
3,2-chlorobutadiene-1,3,2-fluorobutadiene-1,3,2-methylbutadiene-
Among these monomers, butadiene-1.3 is particularly preferred. Further, examples of the fluorine-containing α-olefin monomer used in the method for producing a multicomponent copolymer of the present invention include vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, dichlorodifluoroethylene, hexafluoropropylene, 1.1.1
-trifluoropropylene, 1-hydropentafluoropropylene, etc. Among these monomers, chlorotrifluoroethylene and/or dichlorodifluoroethylene are particularly preferred. Copolymerization Conditions In the method for producing a multi-component copolymer of the present invention, the monomer components are mixed and a radical polymerization initiator is added at a predetermined temperature to easily react and polymerize.
Polymerization methods include batch polymerization, continuous polymerization, and polymerization of monomers and other components by known general polymerization methods including bulk polymerization, liquid polymerization, emulsion or suspension polymerization methods.
Alternatively, it can be carried out by intermittent addition. As the radical polymerization initiator used in the polymerization process of the present invention, conventional free radical catalysts such as peroxides, redox persulfates and azos can be used. Specific examples include paramenthane hydroperoxide, benzoyl peroxide, potassium persulfate, and azobisisobutyronitrile. Further, as the polymerization regulator, long-chain alkyl mercaptans such as tertiary dodecyl mercaptan can be used. Further, reducing agents include sodium formaldehyde sulfoxylate and polyamines, electrolytes include trisodium salt of ethylenediaminetetraacetic acid, potassium chloride, sodium phosphate, and sodium sulfate, and polymerization terminators include hydroquinones and dimethyldithiocarbamate. Salt etc. can be used. In addition, the polymerization temperature is 5°C to 80°C, preferably 5°C to 80°C.
It is carried out within the temperature range from ℃ to 60℃. The polymer obtained by the above polymerization reaction can be recovered by a normal coagulation method using a metal salt such as calcium chloride or a normal coagulation method using a non-solvent such as ethanol or methanol to recover the produced elastomer. . Copolymer produced The polymer produced by the method for producing a multicomponent copolymer of the present invention has a composition ratio of each unit component (A), (B) and (C). Based on the total number of moles of (C), the unit component (A) is 15 to 60 mol%, preferably 20 to 55 mol%,
More preferably 20 to 45 mol%, (B) unit component is 20
-75 mol%, preferably 30-70 mol%, more preferably 40-70 mol%, unit component (C) is 1-45 mol%, preferably 2-35 mol%, more preferably 2-25 mol% It is essential that it be configured within the range of . If the ratio of unit component (A) in the polymer is less than 15 mol%, solvent resistance will be poor, and if it exceeds 60 mol%, it will become resinous and have poor processability. If the ratio of the unit component (B) is less than 20 mol%, the rubber elasticity will be poor and the normal physical properties of the polymer will be poor. Also (B)
When the ratio of unit components exceeds 75 mol%, solvent resistance
Resistance to alcohol-containing gasoline deteriorates. If the ratio of the unit component (C) is less than 1 mol%, there will be no effect on sour gasoline resistance and alcohol-containing gasoline resistance, and if it exceeds 45 mol%, cold resistance will deteriorate. In addition, the glass transition temperature (Tg) of the copolymer
It is essential that the temperature is -50 to -20℃, and the Tg is -50
If the copolymer composition is lower than ℃, the oil resistance will be poor, and if the temperature is -20℃ or higher, the cold resistance will be poor. The shape of the terpolymer produced according to the method of the present invention is not particularly limited, and it can be used in either solid or liquid form depending on the purpose. Further, the molecular weight is not particularly limited, but when used in solid form, it is preferable that the Mooney viscosity (ML ₁₊₄ , ₁₀₀ ° C.) is within the range of 30 to 150. Applications The multi-component copolymer produced by the method of the present invention can be used as a vulcanizing agent, vulcanization accelerator, reinforcing agent, filler, plasticizer, softener, anti-aging agent, stabilizer and blowing agent. A vulcanizate can be easily obtained by a conventional vulcanization method. The vulcanizing agent can be arbitrarily selected from common vulcanizing systems such as sulfur-based, thiuram-based, and organic peroxides. Further, the multi-component copolymer produced by the method of the present invention can be used by blending it with polyvinyl chloride or the like in the same manner as ordinary butadiene-acrylonitrile rubber, if necessary. By vulcanization, the multi-component copolymer produced by the method of the present invention has excellent tensile strength, elongation, cold resistance, resistance to alcohol-containing gasoline, resistance to sour gasoline, and oil resistance, and is compression permanent. Since it can be made into a vulcanized product with low distortion, it can be suitably used as a rubber material for various fuels. f. Examples The present invention will be explained in more detail with reference to Examples, but the method of the present invention is not limited to these Examples as long as the gist thereof is not exceeded. "Parts" below are based on weight unless otherwise specified. Examples 1 to 6 and Comparative Examples 1 to 7 A polymerization reaction was carried out at 50° C. in an autoclave having an internal volume of 6 using the monomers and polymerization additives shown below.

[Table] When the polymerization rate shown in the Termination Polymerization Rate section of Table 1 was reached, 0.2 parts of hydroquinone per 100 parts of monomer was added to terminate the polymerization. Then, after removing residual monomers under reduced pressure with heating, 1.5 parts of the antiaging agent alkylated allyl phosphite are added per 100 parts of rubber solids.
The latex was coagulated with an aqueous calcium chloride solution. After washing the obtained crumb with water, it was dried under reduced pressure at 50°C to prepare a sample for evaluation. Table 1 shows the results of measuring the Mooney viscosity, copolymer composition, and glass transition temperature of each sample. The infrared absorption spectrum of this copolymer is 2200cm
^-1 shows characteristic absorption of C≡N bond, 1250 to 1150 cm
^-1 shows the characteristic absorption of C-F bond. Also 970cm ^-1
showed the characteristic absorption of cis HC=CH bond. Furthermore, when the glass transition temperature (Tg) was measured by differential thermal analysis, each showed a single Tg listed in Table 1, indicating that this copolymer was not a mixture of multiple polymers but a single copolymer. It shows that it is composed of. <Testing properties of vulcanizate> The copolymers shown in Table 1 were prepared into a blend according to the following formulation, and vulcanized at 160°C for 15 minutes. The properties of the obtained vulcanizate were measured by the method specified in JIS K6301. In addition, sour gasoline resistance and alcohol-containing gasoline resistance were evaluated using the following methods. Compound content Polymer 100 (parts) Zinc white 5 Stearic acid 1 Carbon black MTCB ^* 70 Sulfur 0.5 Accelerator TT ^** 1.8 〃 CZ ^** 2.0 * Medium thermal furnace black ** TT: Tetramethylthiuram disulfide * ** CZ: N-cyclohexyl-2-benzothiazole sulfenamide <Evaluation method of sour gasoline resistance> The sample was mixed with 1 g of lauroyl peroxide as fuel.
C (isooctane:toluene = 1:1 (volume%)
One cycle is immersion in a solution of 99g of a mixed solvent) at 80℃ for 24 hours, and after 3 cycles of immersion, and after drying under reduced pressure at 100℃ for 15 hours, the elongation at crack initiation and elongation at break are specified in JIS K6301. It was measured and evaluated using the method described above. <Evaluation method for alcohol-containing gasoline resistance> After immersing the sample in a mixed solution with a composition of MeOH/Fuel C = 20/80 (volume ratio) at 40°C for 48 hours, JIS
Alcohol resistance to gasoline was evaluated by measuring ΔV using the method specified in the K6301 method. The evaluation results are shown in Table-2.

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[Table] g Effects of the Invention As is clear from the description of the above examples, the multi-component copolymer produced by the method for producing a multi-component polymer of the present invention has excellent resistance to sour gasoline and alcohol-containing gasoline; It is a multicomponent copolymer that can be vulcanized by sulfur, and has excellent properties as a fuel rubber material, so it can be used as a fuel rubber material for automobiles subject to exhaust gas regulations.

Claims (1)

[Claims] 1. Glass transition temperature obtained by polymerizing (A) α/β-unsaturated nitrile, (B) conjugated diene, and (C) fluorine-containing α-olefin using a radical polymerization initiator. (A) 15 to 60 mol% of α/β-unsaturated nitrile unit component with (Tg) of -50 to -20°C, (B) 20 to 75 mol% of conjugated diene unit component, and (C) Fluorine-containing unit component A method for producing a multicomponent copolymer rubber having a polymer component containing 1 to 45 mol% of α-olefin unit components. 2. The method for producing a multi-component copolymer rubber according to claim 1, wherein (A) the α/β-unsaturated nitrile is acrylonitrile. 3. The method for producing a multicomponent copolymer rubber according to claim 1, wherein the conjugated diene (B) is butadiene 1.3. 4. The method for producing a multi-component copolymer rubber according to claim 1, wherein the fluorine-containing α-olefin (C) is chlorotrifluoroethylene and/or dichlorodifluoroethylene.