JPS6212923B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a chlorinated ethylene terpolymer. It is well known that when an ethylene-α-olefin-nonconjugated diolefin copolymer is vulcanized, it becomes a rubber material with excellent ozone resistance and heat resistance. However, the copolymer
Its use is limited because it lacks oil resistance, adhesiveness, and co-vulcanization. It is also already known that the above drawbacks can be overcome by chlorinating this polymer (Japanese Patent Publication No. 41-911
No., Special Publication No. 46-4829, Japanese Patent Publication No. 126728-1972).
However, all of these were produced by chlorinating the copolymer in an organic solvent solution or using a chlorinating reagent.
As a chlorination method using an aqueous suspension method that can be produced industrially at low cost, a method that provides a chlorine content of 3 to 6% by weight (USP 3896095) has been proposed, but the chlorine obtained by this method Chemical polymers do not provide rubber materials with sufficient oil resistance. The present invention involves chlorinating an ethylene-α-olefin-5-ethylidene-2-norbornene copolymer (hereinafter referred to as an ethylene terpolymer) to a chlorine content of 20 to 35% by weight in an aqueous suspension. Therefore, it provides a method for producing a chlorinated ethylene-based terpolymer having excellent properties such as thermal stability, oil resistance, workability, and vulcanization speed (using a sulfur-based vulcanizing agent). It is something to do. The ethylene-based terpolymer used as a raw material in the present invention has a molar ratio of ethylene and α-olefin of 85 to 95:15.
5, the copolymer preferably has an iodine value of 5 to 20 and a melt index of 1 to 30 in powder form.
The α-olefin is preferably an olefin having 3 or 4 carbon atoms, such as propylene and 1-butene. Ethylene-based ternary copolymers with a molar ratio of ethylene and α-olefin in the above range are crystalline polymers, but copolymers with a molar ratio of ethylene and α-olefin outside the above range and less than 85/15 are Even if an attempt is made to obtain a chlorinated ethylene terpolymer with a chlorine content of 20 to 35% by weight under chlorination temperature conditions, the polymer particles will aggregate and form lumps during the chlorination reaction or in the post-treatment process, making the process difficult. It doesn't progress. In order to prevent this, it is necessary to lower the slurry concentration and increase the amount of surfactant and suspension stabilizer, which reduces the industrial value of the production method. Furthermore, the chlorinated terpolymer obtained by taking such considerations has drawbacks such as a high gel content, poor thermal stability, and failure to form a soft rubber-like material. Furthermore, when the non-conjugated diene component of the ethylene-based ternary copolymer of the present invention is another diene, for example, dicyclopentadiene, the resulting chlorinated polymer has a significantly high gel content and is rubbery. The material becomes unsuitable. The content of 5-ethylidene-2-norbornene, which is the diene component of the ethylene terpolymer of the present invention, is suitably 5 to 20 in terms of iodine value. If it is less than 5, the resulting chlorinated ethylene terpolymer will have a low vulcanization density and will not have practical performance. On the other hand, if it exceeds 20, the gel content of the obtained chlorinated ethylene terpolymer increases significantly and the thermal stability deteriorates, which is not preferable. A melt index of 1 to 30 is suitable for the raw material copolymer of the present invention. Chlorinated ethylene-based terpolymers obtained from those smaller than 1 have high viscosity, which impedes processing workability. In addition, if it is larger than 30, the powder will aggregate during the chlorination reaction,
Chlorination reaction does not proceed smoothly. The raw material copolymer is suitably in the form of a powder that can pass through a 10-mesh sieve. Chlorination larger than this is difficult to penetrate into the interior, and random chlorination is difficult to occur. In carrying out the present invention, when suspending the raw ethylene terpolymer in water, a suspension stabilizer such as a surfactant, polyvinyl alcohol, carboxymethyl cellulose, starch, or gelatin is dissolved or dispersed in the water. It's a good idea to leave it there. If necessary, sodium chloride, silica, barium sulfate, calcium chloride,
It is preferable to disperse or dissolve an inorganic compound such as graphite. Next, chlorination is performed by supplying chlorine gas while heating and stirring the suspension system. In order to promote the chlorination reaction, a radical generator such as tert-butyl hydroperoxide may be added as a catalyst. Chlorination is carried out at a chlorination temperature of 50-70°C, preferably 55-65°C, up to a chlorine content of 10-15% by weight, and thereafter at a temperature of 70-100°C, preferably
A multi-stage chlorination method is used in which chlorination is carried out at 75-95°C. If all steps of the chlorination reaction are carried out at temperatures below 70°C, it is difficult to obtain a sufficiently soft rubber-like chlorinated ethylene terpolymer. In addition, the entire process is carried out at 70 to 100℃ or 100℃.
Although it is possible to conduct the reaction at temperatures above ℃, the reactants tend to aggregate with each other, and to prevent this, the slurry concentration must be lowered and large amounts of surfactants, suspension stabilizers, etc. must be added, making it difficult to carry out industrially. The value decreases significantly. In order to obtain the chlorinated ethylene terpolymer which is the object of the present invention, the degree of chlorination is adjusted so that the chlorine content in the polymer is 20 to 35% by weight. If the chlorine content is less than 20% by weight, the vulcanizate will not be of practical use. Moreover, if it exceeds 35% by weight, it is not preferable because it tends to aggregate during the chlorination reaction and in the post-treatment process, and the thermal stability of the polymer sharply decreases. In the present invention, a step may be provided during the chlorination reaction to interrupt the introduction of chlorine and heat-treat the reactant. Heat treatment is usually carried out after the second chlorination step in the chlorination process, and the conditions are:
Most preferably, the time is between 180 minutes and 180 minutes. This heat treatment step is advantageous in order to obtain very soft chlorinated polymers without risk of agglomeration. After completion of the reaction, the chlorinated ethylene terpolymer is washed with normal washing, if necessary alkaline washing.
After drying, it becomes a product. The chlorinated ethylene terpolymer obtained by the present invention has excellent thermal stability and processability, and exhibits an excellent vulcanization rate even with ordinary vulcanizing agents. The product has particularly good oil resistance. When vulcanizing the chlorinated ethylene terpolymer of the present invention, the vulcanizing agent used is a sulfur vulcanizing agent normally used for diene rubber, such as sulfur, morpholine polysulfides, thiuram polysulfides, etc. etc. can be used as is. Other vulcanization accelerators include thiuram sulfides, mercaptobenzothiazole and its derivatives, dithiocarbamates, xanthates, dithiophosphates, amines, and other diene rubber accelerators, as well as zinc oxide and stearic acid. Zinc compounds such as zinc can also be used as excellent vulcanization accelerators. Furthermore, it is effective to use fillers, reinforcing agents, plasticizers, stabilizers, anti-aging agents, lubricants, tackifiers, pigments, flame retardants, etc. that are usually added during vulcanization, and these can be selected and used at will. can. Further, the addition of a certain kind of metal compound or epoxy compound that can act as an acid acceptor is very preferable from the viewpoint of thermal stability of the vulcanized composition.
Such metal compounds include oxides, hydroxides, carbonates, carboxylates, silicates, phosphites of metals from group a of the periodic table, oxides of metals from group a of the periodic table, basic Carbonates, basic carboxylates,
Examples include basic phosphites, and epoxy compounds include reaction products of bisphenol A and epichlorohydrin, epoxidized soybean oil, and the like. The chlorinated ethylene terpolymer of the present invention can also be blended with other elastomers to form a covulcanizate. In particular, blended covulcanizates with diene rubbers provide preferable performance. Elastomers for blending include natural rubber, styrene-butadiene copolymer, polybutadiene, butadiene-acrylonitrile copolymer, isoprene-isobutylene copolymer, and ethylene-propylene copolymer.
Non-conjugated diophthalmic interpolymer, halogenated isoprene-isobutylene copolymer, chlorosulfonated polyethylene, chlorinated polyethylene, polychloroprene, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin
Examples include ethylene oxide-allyl glycidyl ether terpolymer. Vulcanization is usually carried out by heating the formulation at 100-200°C for 1-120 minutes. Conventional methods such as open rolls, blenders, and kneaders are used to mix the compounds, and vulcanization methods include press molding with a mold, injection molding, steam vulcanization cans, air baths, and vulcanization using electromagnetic waves. Various methods can be used, such as heating using a sulfur pot. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Molar ratio of ethylene and propylene as raw materials
87:13, iodine value 7, melt index 5, particle size 15 mesh pass ethylene-propylene-5-
Ethylidene-2-norbornene terpolymer 10
Kg, deionized water 70, ethylene oxide-propylene oxide copolymer 40 g as suspension stabilizer
into a glass-lined autoclave with a capacity of 100 and heated at 65°C until the chlorine content is 14% by weight.
Chlorination was carried out at 80°C. One-stage and two-stage co-chlorine gas were introduced at a rate of 1 to 2 kg/hour, and chlorination was completed when the chlorine content of the produced polymer reached 22% by weight. After the reaction is completed, the product is washed with water and dried to give a diameter of 2
A white powder of less than mm in size was obtained. Example 2 Using the same raw materials and method as in Example 1, chlorination was carried out at 65°C up to a chlorine content of 14% by weight and at 80°C up to 22% by weight, then the introduction of chlorine was interrupted and the mixture was heated to 95°C. After holding at the same temperature for 1 hour, the temperature was lowered again to 80℃ and chlorine gas was introduced at a rate of 1 to 2 kg/hour to continue chlorination, until the chlorine content of the polymer was 30°C.
The chlorination reaction was carried out until the weight percent was reached. After the reaction was completed, the product was washed with water and dried to obtain a white powder with a diameter of 2 mm or less. Comparative Example 1 A suspension system was formed using the same raw materials and charging conditions as in Example 1, heated to 80°C, and 1 chlorine gas was added at the same temperature.
Chlorination was carried out by introducing at a rate of ~2 Kg/hour.
When the chlorine content of the polymer was around 15% by weight, the slurry began to aggregate and become coarse, and when the chlorine content was around 18% by weight, the chlorination reaction rate decreased significantly, so subsequent reactions were discontinued. The obtained chlorinated polymer had a coarse particle size and was difficult to clean, so no further physical property tests were conducted. Comparative Example 2 A suspension system was formed using the same raw materials and charging conditions as in Example 1, and chlorination was carried out at 65°C by introducing chlorine gas at a rate of 1 to 2 kg/hour to reduce the chlorine content of the final polymer to 12 It was expressed as weight%. After the reaction was completed, the product was washed and dried to obtain a white powder with a diameter of 2 mm or less. Comparative Example 3 5 kg of the same raw materials as in Example 1 and 70 kg of deionized water
, 40 g of the same suspension stabilizer as in Example 1 was added to a volume of 100
The chlorine content was introduced into a glass-lined autoclave at 65°C until the chlorine content was 14% by weight, and at 80°C thereafter, at a chlorine gas introduction rate of 1 to 2 kg/hour.
The chlorination reaction was carried out until the concentration was 42% by weight. After the reaction was completed, the product was washed with water and dried to obtain a yellow powder with a diameter of 3 mm or less. Example 3 As raw materials, the molar ratio of ethylene and 1-butene is
Ethylene-1-butene-5-93:7, iodine value 15, melt index 20, particle size 15 mesh pass
Ethylidene-2-norbornene terpolymer 10
Kg, deionized water 70, suspension stabilizer as in Example 1
40g was placed in a glass-lined autoclave with a capacity of 100, heated to 58℃ until the chlorine content was 12% by weight, and 90℃ thereafter, and chlorine gas was introduced at a rate of 1 to 2kg/hour to remove chlorine from the polymer produced. Content is 25% by weight
The chlorination reaction was carried out until After the reaction, the product was washed with water and dried to obtain a white powder with a diameter of 2 mm or less. Example 4 Using the same raw materials and charging conditions as in Example 3, heating was performed at 58°C until the chlorine content was 12% by weight, and at 90°C thereafter, and chlorine gas was introduced at a rate of 1 to 2 kg/hour to reduce the amount of produced polymer. The chlorination reaction was carried out until the chlorine content was 32% by weight. After the reaction is completed, the product is washed with water and dried.
A white powder with a diameter of less than 2 mm was obtained. Comparative Example 4 Using the same raw materials, preparation conditions, and chlorine gas introduction rate as in Example 3, the chlorine content was reduced at a reaction temperature of 60°C.
The chlorination reaction was carried out until the concentration was 30% by weight. After the reaction, the product was washed with water and dried to obtain a relatively hard white powder with a diameter of 2 mm or less. Comparative Example 5 Raw materials having the same molar ratio, iodine value, melt index, and particle size as in Example 3 were used except that the non-conjugated diene component was dicyclopentadiene, and the chlorination method was also the same as in Example 3. A yellow powder with a diameter of less than 2 mm and a chlorine content of 25% by weight was obtained. Comparative Example 6 As raw materials, the molar ratio of ethylene and 1-butene is
Ethylene-1-butene-5-93:7, iodine value 30, melt index 20, particle size 15 mesh pass
Ethylidene-2-norbornene terpolymer 10
Kg, deionized water 70, suspension stabilizer as in Example 1
Charge 40g into a glass-lined autoclave with a capacity of 100, introduce chlorine gas at a rate of 1 to 2kg/hour, and increase the chlorine content to 58℃ until the chlorine content is 12% by weight, and then increase the chlorine content to 32% by weight at 90℃. The chlorination reaction was carried out up to After the reaction, the product was washed with water and dried to a diameter of 3.
A yellow powder of less than mm was obtained. Comparative Example 7 As raw materials, the molar ratio of ethylene and 1-butene is
80:20, iodine value 7, melt index 2, particle size 15 mesh pass ethylene-1-butene-5-
1 of ethylidene-2-norbornene terpolymer
Kg, deionized water 70, suspension stabilizer as in Example 1
80g was placed in a glass-lined autoclave with a capacity of 100, and chlorine gas was introduced at a rate of 200 to 400g hours.
Chlorination was carried out at 80°C until the chlorine content was 30% by weight.
After the reaction, the product was washed with water and dried to obtain yellow coarse particles with a diameter of 4 mm or less. The thus obtained chlorinated products of Examples 1 to 4 and Comparative Examples 2 to 7 and the ethylene terpolymer as a raw material were formed into a sheet with a 6-inch roll at 110°C, and this was A molded sheet was obtained by pressure molding in a mold at 80 kg/cm ² at 80°C for 5 minutes. Physical property tests were conducted on each of these molded sheets, and the results are shown in Table 1.

【table】

【table】

[Table] Examples 5 to 9, Comparative Examples, 8 to 11 Using Examples 1, 2, Comparative Examples 2 and 3 and their raw materials, and Examples 3 and 4 and their raw materials, the formulations shown in Table 2 were prepared using 80% The mixture was kneaded at ~110°C to form a sheet, which was then placed in a mold and pressure-molded at 155°C and 80 kg/cm ² for 15 minutes. Physical property tests were conducted on the obtained vulcanizate, and the results are shown in Table 2. The vulcanization curves of the formulations of Examples 5 to 9 and Comparative Examples 8 to 11 were measured at an amplitude angle of 3° and 155°C using a JSR type culastometer, and the results are shown in Figures 1 and 2. It was shown to.

【table】

【table】 [Brief explanation of the drawing]

Figure 1 shows the vulcanization curves of 1: Example 5, 2: Example 6, 3: Comparative Example 8, 4: Comparative Example 9, and 5: Comparative Example 10, and Figure 2 shows the vulcanization curves of 6: Example 7. , 7: Example 8, 8: Example 9, 9: Comparative example 11, respectively.

Claims (1)

[Claims] 1. An ethylene-α-olefin-5-ethylidene-2-norbornene copolymer, in which the molar ratio of ethylene and α-olefin is 85 to 95:15 to 5, and the iodine value of the copolymer is 5. ~20 and a melt index of 1 to 30 is chlorinated in aqueous suspension at a temperature of 50 to 70°C up to a chlorine content of 10 to 15% by weight, and 70 to 100°C thereafter. Content 20
A method for producing a chlorinated ethylene terpolymer, characterized in that the amount is 35% by weight.