| CORP. SALE | 1,3,5-TriAzine-2,4-Di-Cl-6-(N=CH2) |
| PATENT ASSIGNEE'S COUNTRY | Japan |
| UPDATE | 05.00 |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 16.05.00 |
| PATENT TITLE |
Process to scavenge amines in polymeric compounds by treatment with triazine derivatives, and compositions therefrom |
| PATENT ABSTRACT |
A rubber tread stock comprising a vulcanizable composition of matter, and a triazine, wherein said triazine is defined by the formula ##STR1## where X is selected from the group consisting of hydrogen, halides, amines, and organic groups having from 1 to about 20 carbon atoms, Y is selected from the group consisting of halides, alkoxy derivatives, amine derivatives, aryloxy derivatives, and urea derivatives, with the proviso that the substituent Y is displacable by a reaction with a secondary amine, and Z is selected from the group consisting of alkoxy derivatives, amino derivatives, aryloxy derivatives, and urea derivatives, with the proviso that the substituent Z is displacable by a reaction with a secondary amine. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | 31.12.97 |
| PATENT REFERENCES CITED |
Nitrosamines in Rubber Vulcanizate: An Evaluation of Specific Inhibitors" by Lheureux et al., (Fed. Rep. of Germany), pp. 107-113, Feb. 1990. "Inhibierung der Bildung von N-Nitrosaminen", by Schuster et al., Beitrarage Papers (contains English language abstract), Feb. 1990. |
| PATENT CLAIMS |
What is claimed is: 1. A rubber tread stock comprising: a vulcanizable composition of matter that is devoid of metal reinforcement, and a triazine compound that is selected from the group consisting of ##STR15## where R.sub.1 is selected from the group consisting of hydrogen and organic groups having from 1 to about 20 carbon atoms, R.sub.2 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 1 to about 20, R.sub.3 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, R.sub.4 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 2 to about 12. 2. A rubber tread stock, as set forth in claim 1, where said triazine is selected from the group consisting of 2-chloro-4,6 bis(N-hexamethyleneimino)-1,3,5-triazine, 2-chloro-4,6-bis(anilion)-1,3,5-triazine, 2-chloro-4,6-bis(N-phenyl-p-phenylenediamino)-1,3,5-triazine, 2,4,6-triphenoxy-1,3,5-triazine, 1-ethoxy-4(dichloro-triazinyl)naphthalene, and (dichloro-triazinyl)-o-acetanisidide. 3. A rubber tread stock, as set forth in claim 1, where said triazine is 2-chloro-4,6 bis(N-hexamethyleneimino)-1,3,5-triazine. 4. A rubber tread stock, as set forth in claim 1, where said triazine is 2,4,6-triphenoxy-1,3,5-triazine. 5. A rubber tread stock, as set forth in claim 1, wherein said vulcanizable composition of matter includes an elastomer selected from natural and synthetic rubber. 6. A rubber tread stock, as set forth in claim 5, wherein said vulcanizable composition of matter further includes a filler selected from the group consisting of carbon black and silica. 7. A rubber composition of matter comprising: a triazine compound defined by the formula ##STR16## where X is selected from the group consisting of hydrogen, halides, and organic group having from 1 to about 20 carbon atoms, Y is selected from the group consisting of halides, alkoxy derivatives, amino derivatives, aryloxy derivatives, and urea derivatives, with the proviso that the substituent is displacable by a reaction with a secondary amine, and Z is an amine derivative that is defined by a formula selected from the group consisting of ##STR17## where R.sub.1 is selected from the group consisting of hydrogen and aliphatic organic groups having from about 1 to about 20 carbon atoms and R.sub.2 is selected from the groups consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 1 to about 20. 8. A tire component comprising: a rubber vulcanizate that is devoid of metal reinforcement and that includes the reaction product between an amine compound and a triazine, where said triazine is a compound selected from the group consisting of ##STR18## where R.sub.1 is selected from the group consisting of hydrogen and organic groups having from 1 to about 20 carbon atoms, R.sub.2 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 1 to about 20, R.sub.3 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, R.sub.4 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 2 to about 12. 9. A tire component, as set forth in claim 8, where said triazine is selected from the group consisting of 2-chloro-4,6 bis(N-hexamethyleneimino)-1,3,5-triazine, 2-chloro-4,6-bis(anilino)-1,3,5-triazine, 2-chloro-4,6-bis(N-phenyl-p-phenylenediamino)-1,3,5-triazine, 2,4,6-triphenoxy-1,3,5-triazine, 1-ethoxy-4(dichloro-triazinyl)naphthalene, and (dichloro-triazinyl)-o-acetanisidide. 10. A tire component, as set forth in claim 8, where said triazine is 2-chloro4,6 bis(N-hexamethyleneimino)-1,3,5-triazine. 11. A tire component, as set forth in claim 8, where said triazine is 2,4,6-triphenoxy-1,3,5-triazine. 12. A tire component, as set forth in claim 8, where said rubber vulcanizate is formed from an elastomer selected from natural and synthetic rubber. 13. A tire component, as set forth in claim 12, where said rubber vulcanizate further includes a filler selected from the group consisting of carbon black and silica. 14. A tire tread prepared by the steps comprising: adding a triazine compound to a rubber tread stock to thereby scavenge free amine that may exist within the tread stock, and fabricating a tire tread from said tread stock, that is devoid of metal reinforcement where said triazine is selected from the group consisting of ##STR19## where R.sub.1 is selected from the group consisting of hydrogen and organic groups having from 1 to about 20 carbon atoms, R.sub.2 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 1 to about 20, R.sub.3 is selected from the group consisting of hydrogen and organic groups having from 1 to about 1 2 carbon atoms, R.sub.4 is selected from the group consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 2 to about 12. 15. A tire tread, as set forth in claim 14, where said triazine is selected from the group consisting of 2-chloro-4,6 bis(N-hexamethyleneimino)-1,3,5-triazine, 2-chloro-4,6-bis(anilino)-1,3,5-triazine, 2-chloro-4,6-bis(N-phenyl-p-phenylenediamino)-1,3,5-triazine, 2,4,6-triphenoxy-1,3,5-triazine, 1-ethoxy-4(dichloro-triazinyl)naphthalene, and (dichloro-triazinyl)-o-acetanisidide. 16. A tire tread, as set forth in claim 14, where said triazine is 2-chloro-4,6 bis(N-hexamethyleneimino)-1,3,5-triazine. 17. A tire tread, as set forth in claim 14, where said rubber tread stock includes an elastomer selected from 2,4,6-triphenoxy-1,3,5-triazine. 18. A tire tread, as set forth in claim 14, where said rubber tread stock includes a filler selected from the group consisting of carbon black and silica. |
| PATENT DESCRIPTION |
TECHNICAL FIELD The present invention is directed toward amine scavengers that are particularly useful in polymeric compositions. More specifically, the present invention is directed toward cyanurate or triazine compounds, and their use within polymeric compositions as amine scavengers. BACKGROUND OF THE INVENTION In the art of forming and compounding polymeric compositions, impurities can be introduced into the polymeric compositions. These impurities can include secondary and tertiary amines, and can stem from contamination, the use of amine-containing initiators, the presence of amine functionalized polymers, from various compounding additives such as accelerators, or from certain short-stopping reagents used in emulsion polymerization. While it is known that amines will react with isocyanates, their use in polymeric compositions has not been found to be suitable. The literature has disclosed the use of several methods for trapping secondary amines within rubber compositions. These methods include reacting the secondary amines with isocyanates, or by acetylation with anhydrides. Such methods, however, have been unacceptable inasmuch as the use of anhydrides within rubber compositions results in poor distribution of the inhibitors, and the use of isocyanates tends to react with other rubber additives. Other known methods for removing amines from rubber compositions include the addition of aldehydes, as well as the addition of mono- functional or multi-functional isothiocyanates. Often, however, the reactants that are added to rubber compositions for scavenging amine impurities have a deleterious impact on the rubber composition and its intended purpose. There is, therefore, a need for amine reactants that do not adversely impact the rubber compositions to which they are added. SUMMARY OF INVENTION It is, therefore, an object of the present invention to provide a process for increasing the purity of polymeric compositions by scavenging amines therein. It is another object of the present invention to provide a process for increasing the purity of vulcanizable compositions by scavenging amines therein. It is still another object of the present invention to provide a process for increasing the purity of rubber compounds that contain accelerators based on secondary amines. It is yet another object of the present invention to provide a process for increasing the purity of rubber compounds that contain polymers having amino substituents. It is still a further object of the present invention to provide novel amine scavengers that are particularly useful in polymeric compositions. It is yet another object of the present invention to provide amine scavengers that are particularly useful in vulcanizable compositions of matter. It is another object of the present invention to provide tire treadstocks and sidewall stocks having increased purity. It is a further object of the present invention to provide a process for increasing the purity of polymeric and vulcanizable compositions of matter by scavenging amines therein without substantially affecting the composition or the ultimate use of the composition such as in a pneumatic tire. At least one or more of the foregoing objects, together with the advantages thereof over the known art relating to processes for purifying rubber compositions, that shall become apparent from the specification which follows, are accomplished by the invention as hereinafter described and claimed. In general the present invention provides a rubber tread stock comprising a vulcanizable composition of matter, and a triazine, wherein said triazine is defined according to the formula: ##STR2## where X is selected from the group consisting of hydrogen, halides, amines, and organic groups having from 1 to about 20 carbon atoms, Y is selected from the group consisting of halides, alkoxy derivatives, amine derivatives, aryloxy derivatives, and urea derivatives, with the proviso that the substituent Y is displacable by a reaction with a secondary amine, and Z is selected from the group consisting of alkoxy derivatives, amino derivatives, aryloxy derivatives, and urea derivatives, with the proviso that the substituent Z is displacable by a reaction with a secondary amine. The present invention also provides a rubber composition of matter comprising a triazine compound defined by the formula ##STR3## where X is selected from the group consisting of hydrogen, halides, and organic group having from 1 to about 20 carbon atoms, Y is selected from the group consisting of halides, alkoxy derivatives, amino derivatives, aryloxy derivatives, and urea derivatives, with the proviso that the substituent is displacable by a reaction with a secondary amine, and Z is an amine derivative that is defined by a formula selected from the group consisting of ##STR4## where R.sub.1 is selected from the group consisting of hydrogen and organic groups having from about 2 to about 20 carbon atoms and R.sub.2 is selected from the groups consisting of hydrogen and organic groups having from 1 to about 12 carbon atoms, and x is an integer from 1 to about 20. PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION Polymeric compositions that contain accelerators based on secondary amines, those that are short-stopped with an amine, those that contain polymers containing amino substituents, or those that have been initiated with amine containing initiators, may contain small amounts of impurities such as secondary amines. It has now been found that the addition of triazines to polymeric compositions is highly effective in reducing the quantities of amine impurities therein. Surprisingly, the addition of these triazine compounds does not lead to deleterious effects upon the polymeric composition, especially vulcanizable rubber compositions. Accordingly, the present invention is directed toward a process for reducing residual amines within polymeric compositions, as well as novel triazine scavenger compounds that have been found to be particularly useful in this process. The process of the present invention involves the addition of triazines to polymeric compositions of matter. It is here noted that the use of the term triazine may be used interchangeably throughout this specification with the term cyanurate. A variety of triazines, e.g., aryloxy triazines or alkoxy triazines, and related derivatives, are believed to be useful for practice of this invention. A general structure for the triazines of this invention can be represented by the following formula ##STR5## The substituent X is a non-specific substituent, meaning that its selection is not critical to the present invention so long as the substituent chosen will not deleteriously impact the composition to which the compounds of the present invention are added. As those skilled in the art will appreciate, X generally can include a hydrogen atom, an amine, an organic group, or a halide. To the extent that X is nonspecific, X can include any substituent that is specifically defined for the substituents Y and Z as defined hereinbelow. The organic groups may, of course, contain hetero atoms such as oxygen, sulfur, or nitrogen. Preferably, the organic groups should include those having less than about 20 carbon atoms, more preferably those having from 1 to about 12 carbon atoms, and even more preferably those having from about 2 to about 8 carbon atoms. More specifically, the groups can be aliphatic, cyclic or aromatic. The aliphatic groups may be saturated or unsaturated and include alkyls, alkenyls, and alkynyls. As a non-limiting example, those skilled in the art will recognize that the above description encompasses groups including primary and secondary amine groups, carboxyl groups, alkoxy groups, and urea groups. The substituent Y is more specifically defined because in accordance with the present invention the substituent Y must be displaced by a reaction with a secondary amine. Accordingly, as those skilled in the art will appreciate, the substituent Y can include a halide, especially chlorine or bromine, as well as, for example, groups based on O-alkyls, O-aryls, N-alkyls, N-aryls, N-carboxamides, and ureas. Those skilled in the art will also appreciate that any organic substituent having a hetero atom, such as oxygen, nitrogen, or sulfur that is tethered to the triazine ring will be displaced by a reaction with a secondary amine. The alkyl and aryl groups of the O-alkyl, O-aryl, -alkyl, N-aryl, alkyl and aryl moieties are preferably those having from about 1 to about 12 carbon atoms for the alkyls, and from about 6 to about 20 atoms for the aryls. Preferably, the groups have from about 2 to about 8 carbon atoms for the alkyls, and from about 6 to about 15 carbon atoms for the aryls. A variety of other derivatives of alkoxy-, amino-, aryloxy-, and/or halo-s-triazines and related compounds are also believed to be useful in this invention, especially those whose parent aryloxy groups have lower vapor pressures than phenol, such as long-chain alkylphenoxy-, anisyloxy-, and phenetoloxy-, and like derivatives. Alkoxy triazines (alkyl cyanurates) may also be useful in the invention, particularly if they contain higher alkyl side chains that will not volatilize appreciably on curing. Substituted cyanurates including C-alkoxy-, C-aryloxy-, C-amino- groups and the like can also be useful, provided that one or both of the C-aryloxy or C-alkoxy groups are still present for reaction with the residual amines. These cyanurates are expected to have advantages over simple halo-s-triazines, such as more solubility, handling ease, processability and compatibility with cure systems. To the extent that Z, which is defined hereinbelow, is also displacable by a reaction with a secondary amine, the substituent Y can include any group specifically defined for Z, hereinbelow. Because the substituent Z is also displaced by a secondary amine, Z may be selected from the group of substituents defined previously for the substituent Y. In a preferred embodiment, Z will not include a halogen atom. In an especially preferred embodiment, Z is an amine or a substituent based on a O-aryl group, which also may be referred to as an aryl oxide. The nitrogen of the amine and the oxygen of the aryl oxide is tethered to the triazine ring, as discussed above with respect to the Y substituent groups. The most preferred amine substituents have a hydrogen atom bonded to the amino nitrogen tethered to the ring, while the other nitrogen substituent includes an organic group. The preferred amine substituent groups can be described with reference to the following figures: ##STR6## where R.sub.1 is hydrogen or an organic group, preferably having from about 1 to about 20 carbon atoms, and R.sub.2 is hydrogen or an organic group, preferably having from 1 to about 12 carbon atoms, and x is an integer from about 1 to about 20. In an especially preferred embodiment, R.sub.1 is hydrogen or an organic group having from about 1 to about 12 carbon atoms, R.sub.2 is hydrogen or an organic groups having from 1 to about 6 carbon atoms, and x is an integer from about 2 to about 12. As noted above, it is especially preferred that at least one R.sub.1 include a hydrogen while the other R.sub.1 include an organic group. The term organic group is used in the same manner as described above, and therefore, encompasses hetero atoms, and can include alkyls, which are branched, cyclic, or straight chain, as well as aryl groups. It is here noted, and should be understood, that the cyclic structure identified above encompasses multi-cyclic compounds. Accordingly, in one embodiment of the present invention, the triazine compounds can be selected from the following compounds: ##STR7## where R.sub.1 is hydrogen or an organic group, preferably having from 1 to about 20 carbon atoms, and R.sub.2 is hydrogen or an organic group, preferably having from 1 to about 12 carbon atoms, and x is an integer from about 1 to about 20. It is especially preferred that R.sub.1 is hydrogen or an organic group having from 1 to about 12 carbon atoms, R.sub.2 is hydrogen or an organic group having from 1 to about 6 carbon atoms, and x is an integer from about 2 to about 12. These foregoing compounds include, for example, the following compounds: ##STR8## where R.sub.1 is hydrogen or an organic group, preferably having from about 1 to about 20 carbon atoms, and R.sub.3 is a hydrogen or an organic group, preferably having from 1 to about 12 carbon atoms. In an especially preferred embodiment, R.sub.1 is hydrogen or an organic group having from 1 to about 12 carbon atoms, and R.sub.3 is hydrogen or an organic group having from 1 to about 6 carbon atoms. Another preferred embodiment of the present invention includes the phenoxy derivatives, which can generally be defined by the following: ##STR9## where R.sub.3 is a hydrogen or an organic group, preferably having from 1 to about 12 carbon atoms. More preferably, R.sub.3 is hydrogen or an organic group having from 1 to about 6 carbon atoms. Still further, the following are exemplary compounds that fall within the scope of compounds that are useful for the present invention: ##STR10## where R.sub.4 is a hydrogen or an organic group, preferably having from 1 to about 12 carbon atoms. More preferably, R.sub.4 is hydrogen or an organic group having from 1 to about 6 carbon atoms. The effective level of use of the triazines of this invention can range from about 0.1 phr to 10 phr or more, depending on the amount of amine that must be removed and the equivalent weight of the triazine. The triazine additives can be added to polymeric compositions during post- polymerization finishing (e.g., before drying) of the polymer, or during compounding, e.g., in a Banbury as part of a masterbatch that generally includes the polymer, carbon black and processing aids, or at the final mixing stage, when accelerators, curatives and remaining ingredients are added. The effect on amine reduction takes place during mixing for several of the triazines, such as the chloro-substituted compounds, and continues to increase during cure, while for other triazines, such as the phenoxy derivatives, the effect is brought about during cure. In some instances, the triazine additives may retard cure. The reaction between the amines present in the polymeric composition and the triazine additives produces amino-substituted triazines. These amino-substituted triazines remain in the rubber or rubber compound and, surprisingly, do not have an adverse effect on the polymeric compositions. In some instances, cure rates may be retarded. In these cases, amino-substituted triazines may provide a benefit. For example, amino-substituted chloro triazines offset the adverse effect on cure occasioned by the presence of chloro triazines in the rubber. Any polymeric composition can benefit from the practice of the present invention, especially, anionically-polymerized polymers, e.g., polybutadiene, polyisoprene and the like, and copolymers thereof with monovinyl aromatics such as styrene, alpha methyl styrene and the like, or trienes such as myrcene. Thus, the polymers include diene homopolymers and copolymers thereof with monovinyl aromatic polymers. Suitable monomers include conjugated dienes having from about 4 to about 12 carbon atoms and monovinyl aromatic monomers having about 8 to about 18 carbon atoms and trienes. Exemplary conjugated diene monomers include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and 1,3-hexadiene, and aromatic vinyl monomers include styrene, a-methylstyrene, p-methylstyrene, vinyltoluene and vinyinaphthalene. The conjugated diene monomer and aromatic vinyl monomer are normally used at the weight ratios of 95-50:5-50, preferably 95-65:5-35 to form copolymers. Polymers of conjugated dienes and copolymers thereof with monovinyl aromatic monomers that are polymerized in the presence of amine-functional initiators include those described in U.S. Pat. Nos. 5,329,005, 5,332,810 and 5,393,721, disclosed hereinabove, the subject matter of which is incorporated herein by reference. Another class of polymers are emulsion polymers and copolymers, such as the foregoing SBR copolymers of dienes and monovinyl aromatics. As is known, these polymers are initiated with free radical initiators and subsequently terminated by the addition of a short-stopping agent. Compounds derived from amines can be used for this purpose if they will react with the polymer free radicals to quench the polymerization. When reacted with polymer free radicals, some amine impurities may be formed that are residual in the polymer. Compositions of polymers made by other catalysts, e.g., Ziegler-Natta, can also benefit from the practice of the process of this invention. The polymeric compositions treated with the triazines of the present invention find utility in the formation of rubber articles, particularly tires and tire components. Tire treads are one tire component that are advantageously manufactured from the low amine vulcanizable compounds of the present invention. Likewise, tires having such treads are also useful articles of the present invention. It is likewise particularly advantageous to use the low amine vulcanizable compounds of the present invention in the sub-tread or side-wall. Accordingly, the polymers can be compounded with carbon black in amounts ranging from about 1 to about 100 parts by weight, per 100 parts of rubber (phr), with about 5 to about 80 parts being preferred and from about 35 to about 70 phr being more preferred. The carbon blacks may include any of the commonly available, commercially-produced carbon blacks, but those having a surface area (EMSA) of at least 20 m.sup.2 /g and more preferably at least 35 m.sup.2 /g up to 200 m.sup.2 /g or higher are preferred. Surface area values used in this application are those determined by ASTM test D-1765 using the cetyltrimethyl-ammonium bromide (CTAB) technique. Among the useful carbon blacks are furnace black, channel blacks and lamp blacks. More specifically, examples of the carbon blacks include super abrasion furnace (SAF) blacks, high abrasion furnace (HAF) blacks, fast extrusion furnace (FEF) blacks, fine furnace (FF) blacks, intermediate super abrasion furnace (ISAF) blacks, semi-reinforcing furnace (SRF) blacks, medium processing channel blacks, hard processing channel blacks and conducting channel blacks. Other carbon blacks which may be utilized include acetylene blacks. Mixtures of two or more of the above blacks can be used in preparing the carbon black products of the invention. Typical values for surface areas of usable carbon blacks are summarized in the following TABLE I. TABLE I ______________________________________ CARBON BLACKS ASTM Surface Area Designation (m.sup.2 /g) (D-1765-82a) (D-3765) ______________________________________ N-110 126 N-220 111 N-339 95 N-330 83 N-550 42 N-660 35 ______________________________________ The carbon blacks utilized in the preparation of the rubber compounds of the invention may be in pelletized form or an unpelletized flocculent mass. Preferably, for more uniform mixing, unpelletized carbon black is preferred. It should also be understood that it is common in the art to employ silica as a filler as well. The reinforced rubber compounds can be cured in a conventional manner with known vulcanizing agents at about 0.5 to about 4 phr. For example, sulfur or peroxide-based curing systems may be employed. For a general disclosure of suitable vulcanizing agents one can refer to Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Wiley Interscience, N.Y. 1982, Vol. 20, pp. 365-468, particularly "Vulcanization Agents and Auxiliary Materials" pp. 390-402. Vulcanizing agents may be used alone or in combination. Cured or crosslinked polymers may be referred to as vulcanizates for purposes of this disclosure. Vulcanizable elastomeric or rubber compositions of the invention can be prepared by compounding or mixing the polymers thereof with carbon black and other conventional rubber additives such as fillers, plasticizers, antioxidants, curing agents and the like, using standard rubber mixing equipment and procedures and conventional amounts of such additives. Inasmuch as practice of the present invention is not limited by the preparation of such rubber compositions, as opposed to reduction of residual amines in the polymers, further compounding detail is not necessary. Reference to U.S. Pat. Nos. 5,329,005, 5,332,810 and 5,393,721, disclosed hereinabove, can be made. |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
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