JPH0459337B2 - - Google Patents

Description

[Detailed description of the invention]

DETAILED DESCRIPTION OF THE INVENTION This application is a continuation-in-part of U.S. Application No. 456,874, filed January 10, 1983. The present invention relates to peroxide vulcanizable polymeric compositions containing a combination of zinc dimethacrylate and various fillers or mixtures of fillers. In particular, the present invention provides copolymers of natural rubber or conjugated dienes with monoolefins, zinc dimethacrylate with a small amount of a specific surface area, various fillers or mixtures of fillers, and peroxides. The present invention relates to vulcanizable polymeric compositions containing vulcanizing agents. The invention further relates to certain vulcanizable polymeric compositions containing a combination of zinc dimethacrylate and clay to synergistically enhance the strength of the vulcanized compositions. It is something. U.S. Pat. No. 3,823,122 relates to vulcanizable SBR or neoprene elastomer compositions containing 1 to 15 parts by weight of substituted acrylic acid or acid salt per 100 parts by weight of elastomer; The preferred acid salt shown is zinc methacrylate. The disclosed elastomeric compositions include reinforcing fillers such as carbon black, but do not include peroxide vulcanizing agents. U.S. Pat. Free radical crosslinkable elastomeric compositions are disclosed containing reinforcing fillers such as litharge or zinc oxide in an amount of 2 to 10 parts by weight. U.S. Pat. No. 4,191,671 discloses (A) a diene elastomer, (B) an alpha, beta ethylenically unsaturated carboxylic acid, wherein the weight ratio of component (A) to component (B) is 87/13.
~55/45, 50 per 100 parts by weight of component (B) (C)
(D) an organic compound present in an amount of 0.3 to 5.0 parts by weight per 100 parts by weight of components (A) and (B); vulcanizable rubbery compositions consisting of peroxides. The compositions further include a non-polymerizable carboxylic acid,
Amounts of up to 50 parts by weight of carbon black and amine and/or phenolic compounds can also be included per 100 parts by weight of elastomer. US Pat. No. 4,192,790 relates to elastomeric compositions having reduced Mooney viscosity in the blended state. The Mooney viscosity of elastomer compositions is reduced by adding therein from 0.1 to 7.0 parts by weight of basic zinc methacrylate per 100 parts by weight of elastomer. In addition to the basic zinc methacrylate, the elastomer compositions may contain various elastomers or elastomer blends, inorganic particulate fillers such as silica, calcium carbonate, silicates such as clays, hydrated aluminum silicates, and optionally carbon black (20 to 150 parts per 100 parts by weight of elastomer) and vulcanizing agents, such as peroxide vulcanizing agents. U.S. Pat. No. 4,266,772 discloses free radical crosslinkable elastomers, particularly peroxide crosslinkable elastomers, basic zinc methacrylate (from about 10 to about 60 parts by weight per 100 parts of elastomer), and a vulcanizing agent. such as peroxide vulcanizing agents,
The present invention relates to a hard golf ball made from a vulcanizable elastomeric composition comprising: The compositions may also optionally contain reinforcing fillers such as litharge or zinc oxide, for example in amounts of 2 to 10 parts per 100 parts by weight of elastomer. British Patent Specification 1091818 describes alpha-olefin polymers and 1 to 10 parts per 100 parts of polymer.
Vulcanizable compositions are disclosed that are comprised of a vulcanization system consisting of a metal salt of acrylic acid or methacrylic acid in an amount of 50% and an organic peroxide. The compositions can also contain reinforcing agents and fillers such as carbon black, metal oxides, clays and silica pigments. British Patent Specification 2042553 describes natural and/or synthetic rubbers, cross-linking agents such as peroxides, monomeric metal salts such as zinc dimethacrylate, zinc diacrylate, preferably basic zinc methacrylate,
Crosslinked cellular elastomer compositions made from elastomer compositions comprising a blowing agent and a blowing agent are disclosed. The compositions may also contain fillers such as carbon black or titanium dioxide, and other known miscible additives. Although the above patents describe compositions that are similar in some respects to the compositions of the present invention, they do not disclose or suggest two key elements of the compositions of the present invention. That is, these patents are approximately
The importance of using zinc dimethacrylate with a surface area of 3.7 to about 5.4 m ² /g or greater was not recognized. Furthermore, the patents did not disclose or suggest compositions containing synergistic combinations of zinc dimethacrylate and clay. According to the present invention, a continuous vulcanization process containing certain rubbery polymers, zinc dimethacrylate with a specific surface area, various fillers or mixtures of fillers, and a peroxide vulcanizing agent is used. Possible polymer compositions are provided. The compositions include (a) a rubbery polymer selected from the group consisting of natural rubber and copolymers of conjugated godiene and at least one monoolefin; (b) 100 parts by weight of the rubbery polymer. Approximately 2.5 to approx.
20 parts by weight of zinc dimethacrylate having a surface area of from about 3.7 to about 5.4 m ² /g or more; (c) from about 30 to about 20 parts per 100 parts by weight of the rubbery polymer;
70 parts by weight of carbon black, clay, silica, a mixture of carbon black and clay,
and (d) a vulcanizing effective amount of a peroxide vulcanizing agent. In a preferred embodiment of the invention, a vulcanizable polymeric composition containing a copolymer of natural rubber or a co-condensed diene and a vinyl aromatic hydrocarbon, and a synergistic combination of zinc dimethacrylate and clay. types are provided. It has been discovered that the combination of zinc dimethacrylate and clay in these compositions synergistically enhances the strength of the vulcanized compositions. Rubbery polymers that can be used in the compositions of the invention include natural rubber and a conjugated diene and at least one
Copolymers with various monoolefins are included. Copolymers of conjugated dienes include, for example, 1,3-
Conjugated dienes such as butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the aforementioned dienes. can be derived from mixtures of A preferred conjugated diene is 1,3-butadiene. Copolymers include vinyl aromatic monomers such as styrene, alpha-methylstyrene, vinylnaphthalene, vinylpyridine, etc.; alkyl acrylates or methacrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, Methyl methacrylate, butyl methacrylate, etc.; unsaturated nitrites, such as acrylonitrile, methacrylonitriles, etc., and vinyl halides, such as vinyl chloride, vinylidene chloride, etc., and mixtures of the above monoolefins. It can be derived from a variety of monoolefin monomers. The copolymer is 50% based on the total weight of the copolymer.
It can contain up to % by weight of monoolefins. Suitable copolymers are copolymers of conjugated dienes, especially butadiene, and vinyl aromatic hydrocarbons, especially styrene. Typical styrene-butadiene rubbery copolymers that can be used are those named after The Firestone Tire and Rubber Company.
It is a styrene-butadiene copolymer with a combined styrene content of 23.5%, a viscosity of 50 (ML4 at 212〓) and a specific gravity of 0.94, available as S1502. Copolymers of conjugated dienes and methods for their preparation are well known in the rubber and polymer arts. A large number of polymers and copolymers are commercially available. The zinc dimethacrylate used in the compositions is a zinc dimethacrylate powder having a surface area of about 3.7 to about 5.4 m ² /g or more. Zinc dimethacrylate powder with the required surface area is prepared by reacting zinc oxide and methacrylic acid in a liquid aliphatic hydrocarbon dispersion medium with stirring in an amount of about 0.5 to 0.6 moles of zinc oxide per mole of methacrylic acid. The particles of zinc dimethacrylate can be produced by producing particles of zinc dimethacrylate in a liquid medium, recovering the particles of zinc dimethacrylate from the liquid medium, and drying the particles of zinc dimethacrylate. Details of the method for manufacturing the above zinc dimethacrylate powder are described in U.S. No. 4,500,466, U.S. Pat. has been done. A suitable zinc dimethacrylate powder is one having a surface area of 4.5 m ² /g, which was produced, for example, according to the process shown in Example 3 of Japanese Patent Application No. 188998/1998. The amount of zinc dimethacrylate that can be used in the compositions depends on the type of rubbery polymer, the type and amount of filler or mixture of fillers, and the properties desired in the vulcanized composition. are doing. Generally, zinc dimethacrylate can be used in an amount of about 2.5 to about 20 parts by weight per 100 parts by weight of rubbery polymer. Fillers or mixtures of fillers that can be used in the compositions include carbon black, clay,
Included are mixtures of silica, carbon black and clay, and mixtures of clay and silica. The amount of such fillers or mixtures of fillers that can be used in the compositions depends on the type of rubbery polymer, the amount of zinc dimethacrylate, and what is desired in the vulcanized composition. Depends on nature. Generally, fillers or mixtures of fillers can be used in amounts of about 30 to about 70 parts by weight per 100 parts by weight of rubbery polymer. Peroxide vulcanizing agents that can be used in the compositions include organic peroxides such as dicumyl peroxide, bis-(t-butylperoxy)diisopropylbenzene, t-butyl perbenzoate, di- t-
butyl, 2,5-dimethyl-2,5-di-5-butylperoxy-hexane, and the like. Suitable peroxide vulcanizing agents are bis-(t-butylperoxy)diisopropylbenzene and dicumyl peroxide. The amount of peroxide vulcanizing agents that can be used in the compositions is dependent on the type of rubbery polymer used and can be broadly referred to as the vulcanizing effective amount. Generally, such amounts can be from about 0.2 to about 2.0 parts by weight per 100 parts by weight of rubbery polymer. The compositions may optionally also contain other additives commonly used in rubbery compositions, such as processing and extender oils, antioxidants, waxes, and the like. As mentioned above, preferred embodiments of the compositions of the present invention contain a rubbery polymer selected from natural rubber or copolymers of conjugated dienes and vinyl aromatic hydrocarbons in combination with zinc dimethacrylate and clay. Vulcanizable polymer compositions are provided. A surprising and unexpected aspect of such compositions is the discovery that the combination of clay and zinc dimethacrylate synergistically enhances the strength of vulcanized compositions. That is, the effect of the combination of zinc dimethacrylate and clay on the strength of these vulcanized compositions as shown in Examples 7-17 below was greater than that of zinc dimethacrylate alone and clay alone. It's not just the addition of separate effects, it's actually much more than that. This is particularly surprising since clay itself has little, if any, reinforcing effect on rubbery compounds. The vulcanizable polymer compositions of the present invention are used in the production of molded rubber products such as automobile tires. The following examples are provided for the purpose of further illustrating the nature of the invention and are not intended to limit its scope. Parts and percentages given in the examples and throughout the specification are by weight unless otherwise indicated. First, the production of zinc dimethacrylate powder used in the present invention will be described. Example of manufacturing zinc dimethacrylate powder: 5 gallon top with polypropylene liner, baffle placed between liner and bucket, high speed air motor attached to stirrer, and thermometer. Hexane 12000 c.c., Triton X-15 in an open bucket
3.44cc, Triton X-45 3.4cc, Triton X-100
3.4cc, zinc oxide 1008g and methacrylic acid 2062g
(Triton X-15, X-45 and X-
100 is a nonionic octylphenoxy polyethoxyethanol surfactant manufactured by Rohm & Haas Company. ) Following the addition of methacrylic acid,
The bucket was covered with a polyethylene cover to prevent loss of hexane by evaporation. These ingredients were added with vigorous stirring. Before adding methacrylic acid, the temperature inside the bucket was 27°C (i.e. room temperature).
It was hot. An exotherm occurred within 2 minutes following the addition and the temperature rose to 44°C. Once the temperature had fallen to 40°C, the contents of the bucket were stirred vigorously for 8 hours. Reduce the degree of stirring slightly, and bring the temperature to 36
Once the temperature had cooled to 0.degree. C., the reaction was continued for an additional 15 hours (total reaction time 23 hours). When the reaction approaches yield,
The contents of the bucket were in a liquid suspension.
The suspension was then removed from the bucket, filtered, and the collected particles were washed. The filter cake was then placed in a large dish, broken up by hand, and dried in a hood for 3 hours with frequent stirring.
The dish was then placed in a vacuum oven set at a temperature of 65° C. and 0.08 mm Hg for 40 hours. The resulting slightly cakey powdered zinc dimethacrylate was then ground in a Waring blender and passed through a 50 mesh sieve. A sample of the product was analyzed and the ash content was 33.6
I got %. This preparation was repeated several times and the products from each experiment were combined. Evaluation of samples of this combined product revealed that the nitrogen adsorption surface area was
It was found to have a calculated particle size of 4.5 m ² /g and 0.78 μm. Nitrogen adsorption surface area is essentially "Surface Area By Monosorb Analyser"
The measurement was carried out by the method described in ASTM D3037, Method D, entitled 100° C. instead of the 200° C. degassing temperature shown here. In the following examples, the zinc dimethacrylate powder having a surface area of 4.5 m ² /g obtained in the production example of zinc dimethacrylate powder was used. Examples 1-3 In these examples, vulcanizable polymer compositions of the present invention containing styrene-butadiene rubber, zinc dimethacrylate, HAF carbon black, and a peroxide vulcanizing agent were prepared. Manufactured. Compositions containing the same ingredients other than the zinc dimethacrylate component were also prepared for control purposes. The compositions were mixed on an electric mill without external heat. The mixed compositions were vulcanized and then tested for stress-strain properties. the composition of the composition;
The vulcanization conditions and stress-strain properties are shown in the table.

[Table] Examples 4-6 In these examples, vulcanizable polymers of the present invention containing styrene-butadiene rubber, zinc dimethacrylate, silica, an antioxidant, and a peroxide vulcanizing agent were used. Combined compositions were produced. Compositions containing the same ingredients other than the zinc dimethacrylate component were also prepared for control purposes. The above compositions were mixed on an electric mill without external heat. The mixed compositions were vulcanized and then tested for stress-strain properties. The composition, vulcanization conditions and stress-strain properties of the composition are shown in the table.

Table: Examples 7-17 below illustrate vulcanizable polymer compositions of the present invention containing synergistic combinations of natural rubber and styrene-butadiene rubber and zinc dimethacrylate and clay. It is something. Examples 7-10 In these examples, vulcanizable polymer compositions of the present invention containing styrene-butadiene rubber, zinc dimethacrylate, clay, peroxide vulcanizing agent, and antioxidant were prepared as in Examples 1-6, mixed, vulcanized, and tested for stress-strain. For comparative purposes, zinc dimethacrylate alone (A) was prepared using a virtually identical process.
and preparing and mixing control compositions designated A and B containing only clay (B);
Vulcanized and tested for stress-strain properties. The composition, vulcanization conditions and stress-strain properties of the composition are shown in the table.

【table】

Table: As can be seen from the above data, the combination of zinc dimethacrylate and clay enhances the strength of the vulcanized compositions of the present invention beyond the effects of the separate components alone and by simply adding them together. It has been shown that the combination produced a synergistic effect on such properties. Thus, for example, a composition containing 10 parts zinc dimethacrylate and 60 parts clay would have approximately
Vulcanized tensile strength of 6.8MPa (i.e.
It would have been expected that the combined tensile strength of Examples A and B). However, as can be seen from Example 10, this combination actually produced a vulcanized tensile strength of 16.2 MPa, thereby indicating that the combination synergistically enhanced the strength of the vulcanized composition. It shows. Not more than 10 parts of zinc dimethacrylate and
A composition containing 60 parts of clay would be expected to exhibit a vulcanized tensile strength of less than 6.8 MPa. However, as can be seen from Examples 7-9, compositions containing 2.5, 5.0, and 7.5 parts of zinc dimethacrylate in combination with 60 parts of clay produced 10.7, 12.9, and 16.7 MPa, respectively.
of vulcanized tensile strength, thereby indicating that these combinations are also synergistic. Examples 11-13 In these examples, styrene-butadiene rubber, various standards of zinc dimethacrylate and clay, peroxide vulcanizing agents, and antioxidants were prepared. Polymer compositions were prepared as in Examples 1-6, mixed, and vulcanized;
It was then tested for stress-strain properties. For comparison purposes, controls, designated Examples C, D and E, containing only zinc dimethacrylate (C and D) and only clay (E) using substantially the same process. Compositions were prepared, mixed, vulcanized, and tested for stress-strain properties. The composition, vulcanization conditions and stress-strain properties of the composition are shown in the table.

Table: As can be seen from the data above, combining zinc dimethacrylate and clay on a basis of 10 parts or more zinc dimethacrylate and 60 parts clay or less increases the strength of vulcanized compositions of the present invention. It has been shown that the combined effect of the separate components alone was stronger than the merely added criteria, whereby the combination produced a synergistic effect on such properties. Examples 14-17 In these examples, natural rubber (NR),
Vulcanizable polymer compositions containing zinc dimethacrylate, clay, and peroxide vulcanizing agents were prepared as in Examples 1-6, mixed, vulcanized, and stress-strain. tested for gender. For comparison purposes, symmetry compositions, designated Examples F and G, containing only zinc dimethacrylate (F) and only clay (G) were prepared using substantially the same process. They were prepared, mixed, cured, and tested for stress-strain properties. The composition, vulcanization conditions and stress-strain properties of the composition are shown in Table V.

Table: As can be seen from the comparison of Examples F and G with Example 16, the combination of 10 parts zinc dimethacrylate and 60 parts clay significantly improved the strength of the vulcanized compositions of the invention. It has been shown that the combined effect of the classification alone was stronger than just the added criteria, whereby the combination produced a synergistic effect on such properties. That is, if the results were merely additive, one would have expected to obtain a tensile strength of about 8 MPa, but the actual tensile result for Example 16 was 12.8 MPa. Examples 18-19 In these examples, a rubbery nitrile polymer (i.e., a copolymer of butadiene and acrylonitrile as defined below), zinc dimethacrylate, clay, a peroxide vulcanizing agent, and an oxidized Vulcanizable polymer compositions containing inhibitors were prepared as in Examples 1-6, mixed, and vulcanized;
It was then tested for stress-strain properties. For comparative purposes, control compositions, designated H, J and K, containing only clay (H) and only zinc dimethacrylate (J and K) using substantially the same process. were prepared, mixed, vulcanized and tested for stress-strain properties. The composition, vulcanization conditions and stress-strain properties of the composition are shown in the table.

【table】

[Table] Ronitrile copolymer.
In the above evaluation, it appears that the combination of zinc dimethacrylate and clay in a composition containing a butadiene-acrylonitrile copolymer did not synergistically enhance the strength of the vulcanized composition. Examples 20-25 In these examples, vulcanizable polymeric compositions containing natural rubber, zinc dimethacrylate, clay, carbon black, peroxide vulcanizing agents, and antioxidants were prepared. They were prepared, mixed, vulcanized, and tested for stress-strain properties as in Examples 1-6. The composition, vulcanization conditions and stress-strain properties of the composition are shown in the table.

Table Examples 26-28 In these examples, vulcanizable polymers containing styrene-butadiene rubber, zinc dimethacrylate, clay, silica, peroxide vulcanizing agent, and antioxidant Compositions were prepared as in Examples 1-6, mixed, vulcanized, and tested for stress-strain properties. The composition, vulcanization conditions and stress-strain properties of the composition are shown in the table.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (a) a rubbery polymer selected from the group consisting of natural rubber and a copolymer of a conjugated diene and at least one monoolefin; (b) 100 parts by weight of the rubbery polymer; 2.5 to 20 parts by weight per combination of zinc dimethacrylate having a surface area of 3.7 to 5.4 m ² /g; (c) 30 to 70 parts by weight per 100 parts by weight of the rubbery polymer of carbon black, clay; silica,
A vulcanizable polymer composition comprising a filler selected from the group consisting of a mixture of carbon black and clay, and a mixture of clay and silica, and (d) a vulcanizing effective amount of a peroxide vulcanizing agent. . 2 The copolymer is 50% based on the total weight of the copolymer.
containing up to % by weight of said monoolefin,
A composition according to claim 1. 3. The composition according to claim 1, wherein the copolymer is a copolymer of a conjugated diene and a vinyl aromatic hydrocarbon. 4. The composition according to claim 3, wherein the copolymer is a copolymer of butadiene and styrene. 5. The composition according to claim 1, wherein the copolymer is a copolymer of butadiene and acrylonitrile. 6. The composition of claim 1, wherein the zinc dimethacrylate has a surface area of 4.5 m ² /g. 7 0.2-2.0 per 100 parts by weight of the rubbery polymer
A composition according to claim 1, containing parts by weight of a peroxide vulcanizing agent. 8. The composition of claim 7, wherein the peroxide vulcanizing agent is dicumyl peroxide or bis-(t-butylperoxy)diisopropylbenzene. 9. The rubbery polymer of claim 1, wherein the rubbery polymer is natural rubber and the copolymer is a copolymer of styrene and butadiene containing 23.5% bound styrene. Composition. 10. The composition of claim 1, wherein the copolymer is a copolymer of butadiene and acrylonitrile containing 32% by weight acrylonitrile. 11 the rubbery polymer is natural rubber or a styrene-butadiene copolymer containing 23.5% bound styrene, the filler is clay, and wherein the filler is a clay and a A composition according to claim 1, wherein the combination synergistically increases the strength of the composition upon vulcanization. 12. The composition of claim 11, wherein the peroxide vulcanizing agent is bis-(t-butylperoxy)diisopropylbenzene.