Method for producing improved polymer composition and its vulcanizate

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an improved polymer composition and a method for producing a vulcanized product thereof. More specifically, in one aspect thereof, the present invention relates to a rubber composition having improved hot air aging properties. In another aspect, the invention relates to methods for improving scorch safety of polymeric vulcanizers.

【0002】

[Conventional technology]

The effect of oxidizing conditions on the vulcanized product obtained from the polymer has long been a challenge, especially in applications where the vulcanized product is exposed to high temperatures for extended periods of time. Various methods for solving this problem are being studied in this field.

【0003】

In a composition comprising a monomer-based polymer that provides a polymer backbone having a repeating unit containing at least one carbon-hydrogen bond (ie, a repeating unit having a secondary or tertiary carbon), it is initiated by a radical mechanism. The thermal oxidative attacks that are carried out are known to be highly associated with the reduction of useful properties of such compositions during oxidative aging. See, for example: 1. S. Bhattacharjee, AK Bhowmick and BN Avasthi: "Degradation of Hydrogenated Nitrile Rubber"; Polymer Degradation and Stability, 31, 71-87 (1991), and 2. KC Smith and BS Tripathy: "HNBR and Long Term Durability in Modern Automotive Lubricants"; Rubber World, 217 (5), 28-45 (1998).

【0004】

During the oxidative degradation process at such carbon-hydrogen bond sites, especially hydroperoxides, alcohols, ketos, aldehydes, and carboxylic acid functional groups are introduced into the main polymer chain (also referred to as the "polymer skeleton"). This results in a breaking or cross-linking reaction of the polymer chains, which can lead to changes and reductions in useful properties of the composition such as tensile strength, hardness, static and dynamic stiffness, break point elongation, compressive permanent strain. There are many.

【0005】

The thermal oxidation reaction as described above is an autocatalytic chain reaction in which reactive radicals are regenerated in the reaction cascade. Additives (often referred to as antioxidants) are added to the polymer composition to facilitate the decomposition of radicals or reactive intermediates produced during the polymer oxidation process, thereby the composition's resistance to oxidative heat aging. Is known in the art to improve.

【0006】

Non-limiting examples of effective antioxidants are sterically hindered phenols, p-phenylenediamine derivatives, quinoline derivatives, and mixtures thereof. Phosphite, dithiophosphate, dithiocarbamate, and mercaptoimidazole derivatives are also commonly used as antioxidants. These substances often donate hydrogen atoms to other radicals during the polymer oxidation process, which (i) are converted to non-reactive radicals themselves; (ii) lead to the production of free radicals. It blocks certain reactions (eg, heavy metal trapping); and / or (iii) assists in the reaction of reactive intermediates leading to the formation of non-radical reaction products (eg, hydroperoxide degradants).

【0007】

Often, the rubber composition is cured by a cross-linking system generally selected from the group consisting of sulfur, sulfur donor compounds, and / or peroxides to obtain the desired properties. It is known in the art that inhibition of antioxidants by the curing system often causes major problems.

【0008】

The reaction of the antioxidant with the curing system can significantly reduce the desired curing state of the composition. When the curing system generates radicals during vulcanization, it appears that total or partial depletion of the antioxidant in the composition occurs during curing.

【0009】

Canadian Patent Application No. 2231300 (filed March 6, 1998) teaches nitrile polymer vulcanizers with improved hot air aging properties. This nitrile polymer vulcanized product consists of a group consisting of (i) nitrile polymer; (ii) filler; (iii) strong base, strong base salt, weak acid, weak acid salt, carbodiimide, polycarbodiimide, and a mixture thereof. It is produced by mixing a composition comprising a selected additive; as well as (iv) a vulcanization system; under vulcanization conditions.

【0010】

Canadian Patent Application No. 2281274 (filed August 31, 1999) also teaches vulcanizers with improved hot air aging properties. This polymer composition contains two components. The first component is (i) at least about 30% by weight of the first monomer, which introduces at least one secondary and tertiary carbon into the backbone, and (ii) 0 to about 70% by weight. A polymer having a main polymer chain derived from at least one other monomer of. The second component is a salt of a strong base and a weak acid, which comprises a metal selected from Group I of the Periodic Table of the Elements. The polymer composition may further comprise one or more vulcanization systems, polycarbodiimides and optional ingredients such as fillers.

【0011】

These two Canadian patent applications represent significant advances in the art of improving the hot air aging properties of various polymer vulcanizers. Nevertheless, there is still room for improvement. In particular, both Canadian patent applications do not disclose or suggest the limitations set forth with the use of a particular vulcanization system. In fact, Canadian Patent Application No. 2281274 states that the vulcanization system is optional. Moreover, in some cases, the benefits of using these two Canadian patent applications are at the expense of other properties [eg, compound Mooney, compression set, heat generation. Gender, and permanent distortion].

【0012】

Therefore, there is still a need in the art to further improve the properties of polymeric vulcanizers, particularly while substantially maintaining the advantages disclosed in Canadian Patent Applications Nos. 2231300 and 2281274. It would be particularly advantageous if the objects described in the Canadian patent application could be used while reducing and / or preventing the deterioration of other properties of the polymeric vulcanizer.

【0013】

[Problems to be Solved by the Invention]

An object of the present invention is to eliminate or mitigate at least one of the above drawbacks of the prior art. Another object of the present invention is to provide a novel polymer composition. Another object of the present invention is to provide a novel method for producing a polymer vulcanized product. Another object of the present invention is to provide a novel method for improving the hot air aging properties of polymer vulcanized products.

【0014】

[Means for solving problems]

That is, in one embodiment, the present invention (i) Polymers selected from the group consisting of nitrile polymers and ethylene polymers; (ii) Salts of strong bases and weak acids, containing metals selected from Group I of the Periodic Table of the Elements; (iii) A polymer composition comprising a vulcanization system comprising an inorganic peroxide compound and a sulfur-containing compound;

【0015】

In another aspect, the present invention (i) Polymers selected from the group consisting of nitrile polymers and ethylene polymers; (ii) Salts of strong bases and weak acids, containing metals selected from Group I of the Periodic Table of the Elements; (iii) A step of mixing a vulcanization system containing an inorganic peroxide compound and a sulfur-containing compound; and a step of vulcanizing the polymer composition; for improving the hot air aging properties of the polymer. It provides a method.

【0016】

That is, surprisingly, a vulcanized product using a combination of a particular polymer, a particular salt additive, and a particular vulcanization system, for example, having one or more of the desired combinations of properties listed below. Unexpectedly found to be obtained: Decrease in Mooney viscosity; Increased time to compound scorch (also known as scorch safety); -Increased ODR delta torque and compound modulus; Reduced ODR return; Decrease in elastic modulus increase rate during aging; Decrease in growth rate; Reduction of compression set; Decrease in Goodrich HBU; Reduction of permanent strain; · Increased dynamic stiffness; and -Reduction of rigidity change due to temperature.

【0017】

The above improvements are observed compared to similar vulcanizers produced using inorganic peroxide as the sole vulcanizer or sulfur-containing compounds as the sole vulcanizer. Many improvements are synergistic, as explained below.

【0018】

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described with reference to the accompanying drawings. FIGS. 1 to 8 are graphs comparing various properties of various vulcanized products produced in the examples described later.

【0019】

The first component of the polymer composition of the present invention is a polymer selected from the group consisting of nitrile polymers and ethylene polymers. The term "nitrile polymer" as used herein is intended to have broader meaning and includes copolymers of conjugated diene and unsaturated nitriles.

【0020】

Conjugated diene is C₄~ C₆It may be a conjugated diene. Suitable non-limiting examples of such conjugated diene can be selected from the group consisting of butadiene, isoprene, piperylene, 2,3-dimethylbutadiene, and mixtures thereof. Most preferred C₄~ C₆The conjugated diene is butadiene.

【0021】

Unsaturated nitrile is C₃~ C₅It may be α, β-unsaturated nitrile. Suitable such C₃~ C₅Non-limiting examples of α, β-unsaturated nitriles can be selected from the group consisting of acrylonitrile, methacrylonitrile, etacrylonitrile, and mixtures thereof. Most preferred C₃~ C₅The α, β-unsaturated nitriles of are acrylonitrile.

【0022】

Preferably, the copolymer comprises from about 40 to about 85% by weight of a conjugated diene copolymer and from about 15 to about 60% by weight of a copolymer of unsaturated nitriles. More preferably, the copolymer comprises from about 60 to about 75% by weight of a conjugated conjugated diene copolymer and from about 25 to about 40% by weight of a conjugated unsaturated nitrile copolymer. Most preferably, the copolymer comprises from about 60 to about 70% by weight of a conjugated diene copolymer and from about 30 to about 40% by weight of a copolymer of unsaturated nitriles.

【0023】

Optionally, the copolymer can further comprise a bound unsaturated carboxylic acid. Non-limiting examples of suitable such bound unsaturated carboxylic acids can be selected from the group consisting of fumaric acid, maleic acid, acrylic acid, methacrylic acid, and mixtures thereof. The bound unsaturated carboxylic acid can be present in an amount of about 1 to about 10% by weight relative to the copolymer, which is an amount that replaces the corresponding amount of conjugated diolefin.

【0024】

In addition, a third monomer can be used in the production of nitrile polymers. Preferably, the third monomer is an unsaturated mono or dicarboxylic acid or a derivative thereof (eg, ester, amide, etc.).

【0025】

Although fully or partially unsaturated nitrile polymers can be used in the present invention, a particularly preferred group of nitrile polymers useful in the production of the vulcanized products of the present invention are hydrogenated or partially hydrogenated nitrile polymers. (Also known as HNBR in this field). Preferably, the copolymer is hydrogenated and has a residual carbon-carbon double bond unsaturated of less than about 30 mol%, more preferably about 30 to about 0.05 mol%, even more preferably about 15 to about 0.05 mol. %, More preferably from about 10.0 to about 0.05 mol%, even more preferably from about 7.0 to about 0.05 mol%, most preferably from about 5.5 to about 0.05 mol%.

【0026】

The term "ethylene polymer" as used herein is intended to have broad meaning and includes copolymers of ethylene and at least one other monomer, preferably elastomers. More preferably, the ethylene polymer is an elastomer selected from the group consisting of: -Ethylene-propylene copolymer; Ethylene-propylene-non-conjugated dienterpolymer; and -Ethylene vinyl acetate copolymer. Such copolymers are commonplace in the art.

【0027】

The second component is a salt of a strong base and a weak acid, which salt comprises a metal selected from Group I of the Periodic Table of the Elements.

【0028】

Non-limiting examples of weak acids useful in the production of the above salts are carbonic acid, C.₁~ C₅₀It can be selected from the group consisting of fatty acids, ethylenediamine tetra (acetic acid), phosphoric acid, and mixtures thereof. Preferred salts for use in the polymer compositions of the present invention can be selected from the group consisting of sodium carbonate, potassium carbonate, sodium stearate, potassium stearate, and mixtures thereof. The most preferred salt for use in the polymeric compositions of the present invention is sodium carbonate.

【0029】

The salt is present in the polymer composition in an amount of preferably from about 0.5 to about 50 parts by weight, more preferably from about 1 to about 20 parts by weight, and most preferably from about 2.5 to about 7.5 parts by weight.

【0030】

The third component of the polymer composition of the present invention is a vulcanization system. The vulcanization system comprises a sulfur-containing compound and an inorganic compound.

【0031】

The sulfur-containing compound is preferably selected from the group consisting of sulfur, sulfur donation hardening systems, and mixtures thereof.

【0032】

Non-limiting examples of useful sulfur donation hardening systems consist of a group consisting of thiuram compounds (eg, tetramethylthiuram disulfides, tetraethylthiuram disulfides, tetramethylthiuram monosulfides, etc.), and morpholin compounds (eg, morpholini disulfides). You can choose. In addition, dithiobis (caprolactam) can be used in sulfur donation hardening systems. The effective amount of sulfur or sulfur donor compound is preferably about 0.1 to about 5 parts by weight.

【0033】

As is known in the art, when the vulcanizing agent is sulfur or a sulfur donating curing system, it generally contains a vulcanization accelerator. Non-limiting examples of effective vulcanization accelerators include thiazole compounds [eg, 2-mercaptobenzothiazole (MBT), dithiobismercaptobenzothiazole (MBTS), etc.], sulfenamide compounds (eg, N-cyclohexyl-). It can be selected from the group consisting of 2-benzothiazolyl sulfenamide, etc.), dithiocarbamate (eg, zinc-dibutyldithiocarbamate), and mixtures thereof. Such a vulcanization accelerator is preferably used in an amount of 0.5 to 5 parts by weight. Furthermore, it is also known that metal oxides such as zinc oxide and magnesium oxide, and acids such as stearic acid are used as curing accelerators in these vulcanization systems.

【0034】

Other components of the vulcanization system used in the polymer composition of the present invention are inorganic peroxides, preferably zinc peroxide. Suitable zinc peroxide-containing compositions that can be used in the polymer compositions of the present invention are Struktol from the Struktol Company of the United States.^TM It is commercially available under the trade name of ZP 1014. Such a composition is preferably in an amount of about 2 to about 10 parts by weight, more preferably about 4 to about 6 parts by weight, most preferably about 5 parts by weight, based on 100 parts by weight of the polymer in the composition. used. Pure zinc peroxide can also be used, in which case it is preferably from about 0.5 to about 2.5 parts by weight, more preferably from about 1.0 to about 1.0 parts by weight, based on 100 parts by weight of the polymer in the composition. It is used in an amount of 1.5 parts by weight, most preferably about 1.25 parts by weight.

【0035】

Optionally, the polymeric compositions of the present invention further contain carbodiimides, polycarbodiimides, or mixtures thereof. The preferred carbodiimide is Rhenogram^TM P50 and Stabaxol^TM It is commercially available under the trade name of P. This component can be used in the polymer composition of the present invention in an amount of 0 to about 15 parts by weight, more preferably 0 to about 10 parts by weight, still more preferably about 0 to about 2 parts by weight.

【0036】

The polymer composition of the present invention preferably further contains a filler. The properties of the filler are not particularly limited, and the selection of a suitable filler is within the knowledge of those skilled in the art. Non-limiting examples of suitable fillers include carbon black (eg, N330, N550, N990, N660 and N770), clay, titanium dioxide, silica fillers (with or without unsaturated silanes), calcium carbonate, For example, talc (magnesium silicate). The amount of filler is a normal amount. Preferably, the filler is present in an amount of about 20 to about 200 parts by weight per 100 parts by weight of the polymer. More preferably, the filler is present in an amount of about 20 to about 100 parts by weight with respect to 100 parts by weight of the polymer. Most preferably, the filler is present in an amount of about 40 to about 80 parts by weight per 100 parts by weight of the polymer.

【0037】

In the methods of the invention, polymers, salt additives, vulcanization systems, and optional components (if any) may be mixed by conventional methods known in the art. The polymer composition can be mixed, for example, by a double roll machine for rubber or a closed mixer.

【0038】

That is, the polymer compositions are mixed by conventional methods and their temperature during mixing is maintained as known in the art.

【0039】

In the method of the present invention, it is preferable to heat the polymer composition to form a vulcanized product using a general method well known in the art. The polymer composition is heated to preferably from about 130 ° C to about 200 ° C, more preferably from about 140 ° C to about 190 ° C, and even more preferably from about 150 ° C to about 180 ° C.

【0040】

Heating is preferably carried out for about 1 minute to about 15 hours, more preferably for about 5 minutes to about 30 minutes. As is well known in the art, various post-curing methods can be used to terminate the vulcanization process.

【0041】

In many cases, the polymeric compositions of the present invention further contain an antioxidant. Non-limiting examples of useful antioxidant compounds are alkylated diphenylamines (eg, styrenated diphenylamines), quinoline stabilizers (eg, 2,2,4-trimethyl-1,2-dihydroquinoline polymers). , Mercaptobenzimidazole (eg, zinc salt of methyl mercaptobenzimidazole, etc.) and the like. A phenylenediamine derivative (eg, N-phenyl-N'-isopropyl-p-phenylenediamine, etc.) and a sterically hindered phenol (eg, butylated hydroxytoluene, etc.) can also be used with the sulfur-containing vulcanization system. The amount of antioxidant used is within the knowledge of those skilled in the art.

【0042】

Other common ingredients can also be included by mixing with the copolymer by conventional methods. Such other ingredients are used for their usual purposes and are known in the art in amounts of activators (such as zinc oxide and magnesium oxide); stearic acid; plasticizers; processing aids; enhancers; promotes. Includes agents; and retarders.

【0043】

While producing the vulture from the polymer composition, for example, polyester fiber, nylon fiber, aramid fiber, glass fiber, carbon fiber, steel fiber cord or woven fabric is used to form the sulfide into a composite. This allows the desired rubber composite product to be obtained.

【0044】

[Example]

Embodiments of the present invention will be illustrated in the following examples, but these examples are given for illustration purposes only and do not limit the scope of the present invention. Unless otherwise stated, all copies in the Examples are parts by weight.

【0045】

The raw materials used in the examples include: Therban^TM C3446: Hydrogenated Nitrile Butadiene Polymer (commercially available from Bayer Inc.); Therban^TM HT VP KA8805: Hydrogenated nitrile butadiene polymer containing the above salt additives (commercially available from Bayer Inc.); Maglite^TM D: Magnesium Oxide, Activator (commercially available from CP Hall); Stearic Acid, Emersol^TM 132NF: Activator; Zinc oxide: Activator; Carbon Black, N550: Filler; Vulkanox^TM ZMB-2 / C5: Degradation inhibitor (commercially available from Bayer Inc.); Naugard^TM 445: Antioxidant (commercially available from Uniroyal Chemicals); Struktol^TM ZP 1014: Zinc peroxide (commercially available from Struktol Company, USA); Sulfur: Vulcanizer; Vulkacit^TM CZ / EG-C: N-cyclohexyl-2-benzothiazyl sulfenamide, vulcanizer (commercially available from Bayer Inc.); and Vulkacit^TM Thiuram / C: Tetramethylthiuram disulfide, vulcanizer (commercially available from Bayer Inc.).

【0046】

Examples 1 to 4 The following operations were used for each of Examples 1 to 4. The polymer compositions used in Examples 1 to 4 are shown in Table 1.

[table 1]

<img file="JP2001192524A_D0001.tif" />【0047】

As will be apparent to those skilled in the art, the polymer composition of Example 1 uses the sulfur-containing compound as the only vulcanizing agent, no salt additives, and Example 2 uses the sulfur-containing compound and peroxide. Zinc was used as the vulcanizing agent and no salt additive was used. In Example 3, the sulfur-containing compound was used as the only vulcanizing agent and the salt additive was used. Therefore, Examples 1 to 3 are comparative examples and are not included in the scope of the present invention. Example 4 in which a sulfur-containing compound and zinc peroxide are used as vulcanizing agents in the presence of a salt additive is included within the scope of the present invention.

【0048】

All components of the polymer composition, excluding the sulfur-containing vulcanizer, were mixed in a Banbury mixer by conventional methods. For each of Examples 1-4, the composition was removed from the mixer at temperatures of 151 ° C, 151 ° C, 142 ° C and 140 ° C, respectively. A vulcanizing agent was added to the composition in a heat-adding roll machine by a conventional method.

【0049】

The break point elongation of the vulcanized product was measured by ASTM D412-80. Hardness properties were measured by ASTM D2240-81 with a Shore-A hardness tester.

【0050】

FIGS. 1 to 8 show a comparison of various characteristics of the vulcanized products produced in Examples 1 to 4. In these drawings, "HRT" is the term "Therban".^TM The presence of HT VP KA8805 means the presence of the salt additives mentioned above.

【0051】

In FIG. 1, the compound Mooney of each embodiment is shown. As shown in the figure, in the sulfur curing system, the use of the salt additive (Example 3) is a compound compared to the use of the sulfur / zinc peroxide curing system without the salt additive (Example 2). Increase Mooney. In Example 4, the compound Mooney is conveniently reduced to levels comparable to Example 2 (ie, using a sulfur and zinc peroxide curing system without the use of salt additives). This is advantageous in connection with all the results shown here. The reason is that, as can be seen below, the benefits of using salt additives are achieved while preventing this drawback.

【0052】

FIG. 2 shows the important advantages of the present invention. In particular, the single use of zinc peroxide or salt additives in sulfur curing systems (Examples 2 and 3 respectively) provides a small increase in compound scorch safety. However, the combination of sulfur / zinc peroxide curing system and salt additive (Example 4) is synergistic in compound scorch safety compared to the additional effect on compound scorch safety in Examples 2 and 3. Give an increase.

【0053】

In FIG. 3, ODR delta torques in various examples are shown. Return resistance can be predicted from the ODR test by subtracting the maximum torque from the final torque of the test. FIG. 3 shows that the vulcanized product of Example 4 returns the delta torque profile of Example 3 to the same delta torque profile as in Example 2.

【0054】

In FIG. 4, 100% modulus of non-aging and hot air aging is shown for each example. From FIG. 4, when zinc peroxide is used in the sulfur curing system without using the salt additive (Example 2), it is compared with the vulcanized product containing the salt additive (that is, Examples 3 and 4). It is easy to see that it gives only a slight improvement in resistance to increased elastic modulus. In other words, the vulcanized product of Example 4 can obtain favorable modulus properties equivalent to those using salt additives in a sulfur curing system, and can provide additional advantages that the latter cannot provide. it can.

【0055】

FIG. 5 shows the elongation at break points of the non-aged and aged vulcanized products of Examples 1 to 4. The trends and advantages here are similar to those described above for Figure 4.

【0056】

FIG. 6 shows the compression set of various vulcanized products of Examples 1 to 4. As can be seen from the figure, the use of salt additives in the sulfur curing system (Example 3) tends to increase the compression set of the vulcanized product to a level equivalent to that of the sulfur curing system alone (Example 1). There is. In other words, the benefits of using a sulfur-zinc peroxide curing system (Example 2) are reduced when salt additives are used (Example 3). In Example 4, the profile of compression set reverts to the same profile as in Example 2, while gaining the above and other advantages not available with the vulcanized product of Example 2.

【0057】

FIG. 7 shows the non-aging heat generation and permanent strain characteristics of the Goodrich bending tester with respect to the vulcanized products of Examples 1 to 4. As shown in the figure, the use of the salt additive in the sulfur curing system (Example 3) is compared with the case where the sulfur / zinc peroxide curing system is used without using the salt additive (Example 2). Gives a significant increase in heat generation and permanent strain. In contrast, the vulcanized product of Example 4 has significantly reduced heat generation and permanent strain properties as compared to the vulcanized product of Example 3. As shown in the figure, the profile of the heat generation and permanent strain properties of Example 4 is similar to that of Example 2, while achieving other advantages not achievable with the sulphate of Example 2. it can.

【0058】

FIG. 8 shows the dynamic rigidity of the vulcanized products produced in Examples 1 to 4. As shown in the figure, the basic feature of hydrogenated nitrile butadiene rubber when compared with other polymers is that the decrease in elastic modulus with increasing operating temperature is relatively small. This can be an important feature in certain applications. For example, in timing belt applications, it is important to maintain the stiffness of the belt teeth as constant as possible within the belt operating temperature range. MER 1100B (Mechanical Energy) to measure the compound stiffness of each vulcanized product The Resolver) test was performed and the results are shown in Fig. 8. This figure shows that the use of zinc peroxide in the sulfur hardening system (Example 2) slightly increases the dynamic stiffness compared to the sulfur hardening system (Example 1). More importantly, there is relatively little reduction in stiffness when the temperature rises to 150 ° C. As shown in the figure, the addition of the salt additive to the sulfur curing system (Example 3) increases the dynamic stiffness but does not reduce the change in stiffness with increasing temperature. In contrast, the combination of a sulfur / zinc peroxide curing system and a salt additive (Example 4) has increased stiffness and temperature compared to a sulfur curing system control (Example 1). Gives both a reduction in the associated stiffness changes.

【0059】

In summary, the above results show that the combination of sulfur / zinc peroxide curing system and the above salt additives has the advantage of sulfur / zinc peroxide curing system without the use of specific additives, and the salt additive is sulfur (it). Only) Shows that it has the advantage of being used with a curing system. In other words, the vulcanized products produced using the combination of sulfur / zinc peroxide curing system and salt additive are sulfur-only curing system (no salt additive used) and sulfur / zinc peroxide curing system (salt). It has a combination of properties that cannot be obtained when using an additive-free) or sulfur-curing system (using a salt additive). These advantages are amazing and unexpected.

[Simple explanation of drawings]

[Figure 1]

It is a graph which compares the compound Mooney of the vulcanized product of Examples 1 to 4.

[Figure 2]

It is a graph which compares the compound scorch of the vulcanized product of Examples 1 to 4.

[Fig. 3]

It is a graph which compares the ODR delta torque of the vulcanized product of Examples 1 to 4.

[Fig. 4]

It is a graph which compares 100% modulus of the vulcanized product of Examples 1 to 4.

[Fig. 5]

It is a graph which compares the break point elongation of the vulcanized product of Examples 1 to 4.

[Fig. 6]

It is a graph which compares the compression set with respect to the vulcanized product of Examples 1 to 4.

[Fig. 7]

It is a graph which compares the heat generation and the permanent strain in the Goodrich bending tester of the vulcanized matter of Examples 1 to 4.

[Fig. 8]

It is a graph which compares the dynamic stiffness of the vulcanized products of Examples 1 to 4.