RU2073694C1 - Rubber composition being resistant to decomposition - Google Patents

Abstract

FIELD: production of caoutchouc thermal reactive compositions. SUBSTANCE: proposed rubber composition comprises vulcanized unsaturated polymer (e. g. natural rubber, styrene, polyisoprene, butadiene rubber, polybutene), vulcanizing system which comprises sulfur and/or promoter of sulfur vulcanization (e.g., thiourea, xanthanes, mercaptobenzothiazoles) and antiozonate. EFFECT: improved quality. 8 tbl

Description

 The present invention relates to new compounds, a method for the production and use of new triazine compounds as antiozonates for thermoset rubber compositions. They are mainly used in the manufacture of tires and other rubber products. These compounds can be used in mixtures of highly unsaturated elastomers and less unsaturated elastomers, such as rubber based on a copolymer of ethylene, propylene and diene monomer (EPDM).

 It is well known that ozone causes surface cracking of the standard highly unsaturated vulcanized rubber used in tire manufacturing if it is placed in a deformed state in the ozone environment. The most serious damage occurs when a small number of formed cracks rapidly growing in depth form fractures that destroy the material. These cracks significantly shorten tire life, especially in the sidewalls.

 Conventional chemical antiozonants, currently developed, delay the formation of cracks under the influence of ozone under static and dynamic conditions. Examples of currently used antiozonants are: N-phenyl-N '- (1,3-dimethylbutyl) -p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N-phenyl-N '- (1,4-dimethylpentyl) -p-phenylenediamine, N-phenyl-N' - (1-methylheptyl) -p-phenylenediamine, N-phenyl-N'-cyclohexyl-p-phenylenediamine, mixed diaryl-p-phenylenediamines , N, N'-diphenyl-p-phenylenediamine, N, N'-di-beta-naphthyl-p-phenylenediamine, N, N'-bis- (1,4-dimethylpentyl) -p-phenylenediamine, N, N ' bis- (N-ethyl-3-methylpentyl) -p-phenylenediamine, N, N'-bis- (1-methylheptyl) -p-phenylenediamine, N-phenyl-N-p-toluenesulfonyl-p-phenyl endiamine, and a mixture of these substances.

 The use of these well-known paraphenylenediamine compounds increases anti-ozone protection under static and dynamic conditions, however, even the best of the class of compounds just listed have a significant tendency to wear and discoloration. The term "paint" or "dyeing" is used here to describe the characteristics of a substance that diffuses through the polymer base and discolours the adjacent surface. This diffuse staining is very unpleasant for most rubber products. In widely used tires where ozone protection is required, diffuse staining of the above-mentioned paraphenylenediamine substances is especially unpleasant if the tires have a white sidewall. Even for tires with a non-white sidewall, this surface diffusion phenomenon can be unpleasant in that a dull brown surface forms on the side of the tire. At the same time, exhaust soot further worsens the appearance of the new tire. In addition, it is quite obvious that for tires with a white sidewall, the penetration of a brown bleaching substance on this white surface is a very unpleasant phenomenon and its result is difficult to eliminate when cleaning this surface.

 Less unsaturated rubbers can be blended with diene-based highly unsaturated rubbers for anti-ozone protection, as described in US Pat. Nos. 3,630,974, 3,706,819, 3,830,274, 3,915,907, 3,937,862, 4,224,196. The results described in these patents improved the anti-ozone protection, however other positive qualities of rubber decreased, namely adhesion, fatigue during repeated deformations, etc.

 In particular, tris- (N-alkyl-p-phenylenediamino) -1,3,5-triazine compounds were used to protect highly unsaturated elastomeric polymers in industrial rubber products. The outer surface of the products is the area subject to the destructive effect of ozone, so it is best to use these compounds not on the external elastomeric layers of the products, which are most exposed to the environment. The present invention is most applicable to those types of elastomeric products that are subject to severe dynamic deformations during exposure to ozone. Products of this type: conveyor belts, belts for power transmissions, hoses, elastic springs, roofing films, insulators, expansion joints, jackets for wires and cables.

 The aim of the invention is to obtain highly effective antiozonates to protect materials from the destructive effects of ozone. The next objective of the invention is the protection of rubber compositions such as EPDM / diene and increase the fatigue threshold during repeated deformations of tires, which are made from these compounds. In addition, the aim of the invention is to obtain antiozonates that diffuse weakly and do not leave a brown color on a black or white surface.

 The novel arylenediamine substituted triazine compounds of the present invention provide an exceptionally long anti-ozone protection period under static conditions without the use of waxing. An advantage of substituted triazine compounds is that they are mainly non-staining, high molecular weight antiozonates. Another advantage of these compounds is that they gradually form a coating on the surface of the rubber product. A further advantage of the compounds of the present invention is that they provide exceptional dynamic protection without the use of waxing, which is achieved by mixing the above triazine compounds with other known antiozonants and antioxidants. A further advantage of these compounds is that they do not show a tendency to increase the susceptibility to vulcanization of the rubber composition of which they are incorporated. This increases the safety of processing other paraphenylenediamine antizonants.

где R¹, R² и R³ являются радикалами, независимо выбранными из C₃ C₁₂-алкила с разветвленной цепью и с нормальной цепью, или C₃ C₁₂-циклоалкила или C₃-C₁₂-циклоалкила, замещенного одной или более C₁ - C₁₂ алкильной группой. Соединение со структурой (I) входит в термоотверждающую композицию или каучук, содержащий, по меньшей мере, один высоконенасыщенный эластомерный полимер и, по меньшей мере, один другой эластомер с меньшей ненасыщенностью, такиe как ЭПДМ, эластомерный сополимер этилена и пропилена (ЭПР) или бутилкаучук. Композиция может быть вулканизирована серой или, что предпочтительнее, смесью органического пероксида с серой или донорным серным ускорителем.The purpose and advantages of the present invention can be achieved by using, as the main ingredient, a compound whose basic formula is:

where R ¹ , R ² and R ³ are radicals independently selected from branched and straight chain C ₃ C ₁₂ alkyl, or C ₃ C ₁₂ cycloalkyl or C ₃ -C ₁₂ cycloalkyl substituted with one or more C ₁ - C ₁₂ alkyl group. A compound with structure (I) is included in a thermosetting composition or rubber containing at least one highly unsaturated elastomeric polymer and at least one other less unsaturated elastomer, such as EPDM, an elastomeric ethylene-propylene copolymer (EPR) or butyl rubber . The composition may be vulcanized with sulfur or, preferably, a mixture of organic peroxide with sulfur or a donor sulfur accelerator.

The novel compounds contemplated by the present invention can be prepared by Method A, comprising:
the interaction of N-alkyl-p-phenylenediamine with tri-halotriazine in solution to obtain a reaction mixture comprising: 2,4,6-tris- (N-alkyl-p-phenylenediamino) -1,3,5-triazine trihydrohalide, and
neutralization of this 2,4,6-tris- (N-alkyl-p-phenylenediamino) -1,3,5-triazine trihydrohalide with a base to obtain 2,4,6-tris- (N-alkyl-p-phenylenediamino) -1, 3,5-triazine.

When considering structure (I), it should be noted that preferred compositions are those in which R ¹ , R ² and R ³ are C ₃ C ₁₈ branched and straight chain alkyl groups. More preferred alkyl groups are those with a secondary carbon in the α-position to nitrogen. With this configuration, the activity of the antiozonant will obviously increase. Therefore, the most preferred alkyl group is a branched chain group which gives an alkyl substituent in accordance with the above configuration. Cycloalkyl or C ₁ C ₁₂ alkyl substituted cycloalkyls also provide such an a-carbon configuration. Currently, the most preferred compounds are compounds of structural formula (I) in which R ¹ , R ² and R ³ are C ₆ C ₈ branched chain alkyl groups. Examples of such preferred chemical compounds are:
2,4,6-tris- (N-1,4-dimethylpentyl-p-phenylenediamino) -1,3,5-triazine, 2,4,6-tris- (N-isopropyl-p-phenylenediamino) -1, 3,5-triazine, 2,4,6-tris- (N-cyclohexyl-p-phenylenediamino) -1,3,5-triazine, 2,4,6-tris- (N-sec-butyl-p-phenylenediamino ) -1,3,5-triazine, 2,4,6-tris- (N-1,3-dimethylbutyl-p-phenylenediamino) -1,3,5-triazine, 2,4,6-tris- (N -1-methylheptyl-p-phenylenediamino) -1,3,5-triazine, 2,4,6-tris- (N-2,4-di-tri-butylcyclohexyl-n-phenylenediamino) -1,3,5- triazine, 2,4,6-tris- (2-sec-butylcyclohexyl) -p-phenylenediamino) - 1,3,5-triazine, 2,4,6-tris- (1-methydecyl-p-phenylenediamino) -1 3,5-triazine. Most preferred is a 2,4,6-tris- (N-1,4-dimethylpentyl-p-phenylenediamino) -1,3,5-triazine compound.

The compounds described in the present invention can be synthesized mainly by the following main method. Although the reagents can be added in a different order, as shown in some examples, the preferred method is as follows:
The N-alkyl-p-phenylenediamine obtained by a method known to those skilled in the art reacts with 2,4,6-tri-halo-1,3,5-triazine. The molar equivalent of a preferred tri-halotriazine, commonly called cyanuric chloride, is added in powder form to a solution of 3 mol of N-alkyl-p-phenyldiamine in an appropriate solvent, such as isopropanol, at room temperature with appropriate cooling. The first two halogen atoms are rapidly replaced. The reaction mixture is then heated to 60 80 ^o C until the tertiary halogen atom is completely replaced. After heating for 4-5 hours at a temperature of 60 ^° -80 ^° C., the formation of 2,4,6-tris- (N-alkyl-p-phenylenediamino) -1,3,5-triazine trihydrochloride can be considered complete.

 This method is specific in the sense that the basicity of the alkyl-p-phenylenediamine allows the substituted halogen atom in the cyanogen halide to form a hydrohalide, thereby allowing the trihalide to be directly isolated and performing the purification step.

 Tris hydrochloride can be removed by filtration, then redissolved in an appropriate aqueous mixed solution, neutralized with an aqueous base such as sodium hydroxide, and crystallized from a mixture of aqueous solvents.

 If the starting material N-alkyl-p-phenylenediamine is sufficiently pure or, being less pure, is quite acceptable, the isolation of Tris hydrochloride is not necessary and the reaction mixture can be neutralized and the product crystallized and isolated by filtration.

Temperature control of the reaction is very important. It is better if the first stage of the reaction proceeds at a temperature below 30 ^o C, and the second stage at a temperature of at least above 30 ^o C. The choice of optimal temperatures, of course, depends on the identity of the selected compounds of p-phenylenediamine and solvent.

 The best solvents are alcohols, although any suitable solution can be used. The term "solution" means to include an excess of N-alkyl-p-phenylenediamine, which can serve to solvate the reaction product with further separation.

 It should be noted that any use of the term “alkyl” in the context of the expression “starting material (i.e., N-alkyl-p-phenylenediamine) or the substituted substituted triazine compounds” in the present invention also includes the inclusion of cycloalkyl alkyl-substituted cycloalkyl.

 The compounds of this invention are preferably used as antiozonants to protect compositions of highly unsaturated polymers, such as natural and synthetic elastomers, and less unsaturated polymers, such as EPDM or butyl rubber. A characteristic representative of highly unsaturated polymers that can practically be used in the invention are diene elastomers. Such elastomers typically have an iodine number in the range of 100,400, although highly unsaturated rubbers having a higher iodine number or lower (i.e. 50,100) can also be used. Examples of diene elastomers that can be used are conjugated diene polymers such as 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3-pentadiene, 2-chloro-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and the like, as well as copolymers of conjugated dienes with monomers such as styrene, alpha-methylstyrene, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinyl acetate, etc. .P.

 Solution-polymerized butadiene-styrene copolymers and derivative-type polypentamers obtained from cyclopentene compounds by ring-opening polymerization can also be used. Preferred unsaturated rubbers include natural rubber, cis-polyisoprene and poly (acrylonitrile butadiene). In addition, a mixture of two or more highly unsaturated rubbers may also be used. Most preferred in the present invention is a mixture of highly unsaturated rubbers with less unsaturated elastomers, such as EPDM (rubbers based on a copolymer of ethylene, propylene and diene monomer), EPR (elastomeric copolymer of ethylene and propylene), butyl or halogenated butyl rubbers. These less unsaturated elastomers or rubbers have an iodine number below 100 and preferably between 10 and 100, and preferably between 10 and 50. Typical EPDM polymers have an iodine number between 20 and 40.

 US Pat. No. 3,706,819 describes in detail the use of EPDM triple polymers with other highly unsaturated rubbers, where EPDM has an ethylene / propylene ratio of between 80/20 and 20/80 and diene with non-conjugated double bonds with a concentration of 2 to 20% by weight.

 US Pat. No. 4,645,793 (Von Hellemset al) describes preferred high molecular weight EPDM polymers that belong to the class of compounds with high molecular weights, such as ethylene and propylene, and their weight ratios are in the range of (50:50) (75:25) , preferably (60:40) - (75: 25) and the concentration of the bound diene with non-conjugated double bonds with respect to the full EPDM is at least about 6% wt. better than about 7.5, and even better from 9 to 15% wt. The most suitable non-conjugated dienes are straight-chain dienes and cyclic dienes such as 1,4-hexadiene, ethylidene norbornene, norbornadiene, methylnorbornene, dicyclopentadiene, 2-methylnorbornadiene, 5-vinyl-2-norbornene and the like. Among these dienes, ethylidene norbornene is most preferred. Preferably, the EPDM has a non-conjugated diene containing 7.5 to 15% by weight.

 The method for producing such EPDM polymers is well known in the art. The preferred concentration of EPDM polymer in the elastomeric composition is from 15 to 50% wt. For easy and efficient polymer blending, a high molecular weight ERDM polymer is prepared as an oil-filled polymer in advance, and then mixed with other polymers. The oil filling of the EPDM polymer can be performed by a well-known method by adding oil to the polymer solution from the polymerization reactors and obtaining an oil-filled polymer, the oil is extracted from aromatic, non-phenic and paraffinic oils in a concentration of from 50 to 150% wt. by weight of the EPDM polymer. Alternatively, a fully separated oil may be added to the high molecular weight EPDM polymer during polymer blending.

где молярное отношение указанного N-хлоротиосульфонамида к ненасыщенным центрам в данном тройном полимере составляет от 0,06: 1 до 1:1, где R¹ и R² отобраны из группы, содержащей алкильные радикалы, имеющие 7 20 атомов углерода, аларкильные радикалы, имеющие 7 20 атомов углерода и галоарильные радикалы, имеющие 6 10 атомов углерода и где R" также выбрано из радикалов, имеющих формулу:

R³ и R⁴ являются взятыми отдельно из вышеупомянутых алкильных, аралкильных и галоарильных радикалов, где R³ и R⁴ могут быть объединены вместе для изображения радикалов, взятых из -CH₂-, n целое число 4 7 и -(CH₂)₂ -O-(CH₂)-.Another EPDM polymer that can be used in the present invention is described in US Pat. No. 3,915,907 (Hopper), in which an admixture of an elastomeric ternary polymer is introduced into a modified rubber polymer: ethylene, alpha-olifin containing 3 6 carbon atoms and a non-conjugated diene containing 6 12 carbon atoms with N-chlorothiosulfonamide of the formula:

where the molar ratio of the specified N-chlorothiosulfonamide to unsaturated centers in this ternary polymer is from 0.06: 1 to 1: 1, where R ¹ and R ^{2 are} selected from the group consisting of alkyl radicals having 7 to 20 carbon atoms, alaryl radicals having 7 to 20 carbon atoms and haloaryl radicals having 6 to 10 carbon atoms and where R "is also selected from radicals having the formula:

R ³ and R ⁴ are taken separately from the aforementioned alkyl, aralkyl and haloaryl radicals, where R ³ and R ⁴ can be combined together to represent radicals taken from —CH ₂ -, n is an integer of 4 7 and - (CH ₂ ) ₂ -O- (CH ₂ ) -.

 Compositions of highly unsubstituted rubbers, namely EPDM and halobutyl rubbers, can also be used in the present invention. These compositions are known, but their effectiveness can be, oddly enough, improved by the addition of the triazine (I) compound described in the present invention.

In US patent N 3630974 (Ladocsi et al) describes compositions that give vulcanizates with good dynamic resistance to ozone and to deformations from heat, which are obtained by mixing halobutyl rubber in an amount of 25 to 30% wt. with highly unsaturated rubber and a ternary polymer consisting of ethylene, lower 1-alkene and a non-conjugated diene, i.e. EPDM. The EPDM polymer used in the compositions of Ladosci et al consists of 20 to 80% by weight. ethylene, 75 15% wt. C ₂ C ₁₀ alkene (propylene) and not more than 20% wt. diene, preferably 0.1 to 6 mol. In the compositions used for the production of tire sidewalls, the EPDM polymer is 15-30% by weight.

 In US patent N 3830274 (Waser) describes the composition of the elastomer, which is used for the manufacture of sidewalls for pneumatic tires and which consists of 20 to 60% wt. natural or synthetic cis-1,4-polyisoprene mixed with 20 to 35% wt. polymer EPDM, and from 20 to 45% wt. bromobutyl rubber having specific properties. The EPDM component has the following structure: the ratio of ethylene and propylene is in the range (50:50) (75:25) (ratios were calculated by weight) and the content of the non-conjugated diene is in the range of 2 to 20 wt%.

US Pat. No. 4,224,196 (Gursky) discloses a composition used in the manufacture of sidewalls for pneumatic tires, consisting of halobutyl rubber, highly unsaturated rubber and an oil-filled EPDM polymer. The EPDM component of the above composition contains: ultra high molecular weight polymers having a Mooney viscosity above 100 at 260 ^° F prior to filling with oil, ethylene with a concentration in the range of 50 75% and diene with a content of 3 to 12%. Naphthenic is used to fill the EPDM polymer and paraffin oil in amounts from 25 to 150 wt. hours per 100 wt. including polymer.

 In accordance with the present invention, tires which are made from one or more compositions of a diene type and an ethylene propylene type elastomer are characterized in that the compositions of which the parts are made of the sidewalls are cured by means of an organic peroxide and a sulfur and / or sulfur donor accelerator.

 The most preferred ethylene propylene elastomer for use is an ethylene propylene diene triple polymer containing a small amount of a diene selected mainly from ethylidene norbronene, hexadiene-1,4- or, preferably, methylene norborene, dicyclopentadiene and cyclo-octadiene-1,5 . It is particularly surprising that there is an additional co-vulcanization with peroxide of a triple ethylene-propylene-diene polymer into which diene has been introduced to facilitate sulfuric vulcanization.

The amount of ethylene propylene type elastomer used is from 15 to 60% wt. from the total mass of elastomers. A smaller amount (about 20 to 40% by weight) can be advantageously used with a ternary polymer having a high macromolecule content at high molecular weight, in other words, with a ternary polymer having a Mooney M (1 + 8) plasticity of more than 100 at 100 ^o C for unfilled polymer. The best proportion is about 30% wt. and about 45% wt. for a standard ternary polymer containing a relatively large number of macromolecules at a relatively low molecular weight, in other words, having a Mooney plasticity in the range of 50 to 100 at 100 ^° C. It is obvious that the use of the ethylene-propylene copolymer requires a larger amount of the elastomer in which it is incorporated when same efficiency. However, this copolymer can be successfully used by mixing it for overall efficiency with a ternary polymer.

 A vulcanization system is used if the physical properties of highly unsaturated and less unsaturated rubbers are critical. A well-known sulfur vulcanization system can be used here. Preferably, the system consists of sulfur containing a vulcanizing component selected from a sulfur compound or a donor sulfur compound, at least one sulfur accelerator and at least one organic peroxide vulcanizer.

 Sulfur donor compounds, used in combination or alternatively with sulfur, are well known to those skilled in the art of rubber mixtures. Examples of such sulfur donor compounds are: 2- (4-morpholinylldithio) benzothiazole, tetramethylthiuram disulfide, tetraethylthiuram disulfide, dipentamethylethiuram hexasulfide, N, N'-caprolactam disulfide, and the like.

 Sulfur vulcanization accelerators that can be used include: thioureas, such as N, N'-dibutylthiourea, 2-mercaptoimidazoline, tetramethylthiourea, and the like. guanidine derivatives such as N, N'-diphenylguanidine and the like. xanthates, such as zinc dibutyl xanthogenate and the like. dithiocarbamates; such as zinc dimethyldithiocarbamate, zinc diethyl dithiocarbamate, zinc dibutyldiothiocarbamate, sodium diethyl dithiocarbamate and the like. thiuram sulfides such as dipentamethylentiuram disulfide, dipentamethylethiuram hexasulfide, tetrabutylthiuram monosulfide, tetramethylthiuram monosulfide, tetraethylthiuram monosulfide, tetraethyl diuram disulfide and the like. heterocyclic compounds such as mercaptobenzimidazole, mercaptobenzthiazole, 2,2'-dibenzothiazyl disulfide, zinc 2-mercaptobenzothiazole and the like. and sulfenamides, such as N-hydroxyethylene-2-benzothiazolsulfenamide, N-tert-butylbenzothiazylsulfenamide, N-cyclohexyl-2-benzothiazylsulfenamide, N, N-diisopropyl-2-bezothiazylsulfenamide, etc. Moreover, two volcanic agents can be used. or more sulfur accelerators. Thiazoles are preferred accelerators, especially if they are used together with sulfenamides.

 The peroxides used in the present invention have an activation temperature below the temperature at which the degradation of the rubber used occurs. Examples of such peroxides are: benzoyl peroxide, dibenzoyl peroxide, 1,3-bis- (tert-butyl peroxyisopropyl) benzene, diacetyl peroxide, butyl 4,4-bis (tert-butyl peroxy) valerate, p-chlorobenzoyl peroxide, cumene hydroperoxide, butyl cumyl peroxide, tert -butylperbenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, 2,5-di-tert-butylperoxyhexane, 2,5-dimethyl-2,5-di-tert-butylperoxyhex-3- in, 4-methyl-2,2-di-tert-butyl peroxypentane and the like. Mixtures of one or more peroxides are also used. Most preferred are decumyl peroxide and 2,5-dimethyl-2,5-di tert-butyl peroxyhexane.

 The following are the most acceptable products and their trademarks.

 Dicup 40 manufactured by Hercules Chemical Co. containing 40% dicumyl peroxide.

 Perkadox V12 manufactured by Noury van der Lande containing 40% bis- (tert-butyl-peroxy-isopropyl) benzene.

 Feroximon F40 manufactured by Montecatini Edison, S.p.A. containing 40% bis- (tert-butyl-peroxy) diisopropylbenzene. Frigonox manufactured by Noury van der Lande containing 40% 1,1-di-tert-butyl-peroxy-3,3,5-trimethylcyclohexane; Varox manufactured by R.T. Vanderbilt Co. containing 50% 2,5-dimethyl-2,4-bis- (tert-butyl-peroxy) hexane, and Luperko manufactured by Wallace Tiernan, Inc. containing 45% 2,5-dimethyl-2,5-bis- (tert-butyl-peroxy) hexane-3.

 The above vulcanizing agents usually have a composition: in the range from 0.5 to 200, preferably in the range from 5 to 150, and even better in the range from 6 to 14 grams of sulfur atoms per 1 mol of peroxide.

 The sulfur vulcanization accelerator is usually presented in an amount: between about 0.1 parts and about 5 parts per 100 parts of rubber, and preferably between about 0.3 parts and about 3 parts of the accelerator per 100 parts of rubber. Most preferred is a composition: between about 0.3 parts and about 1.0 parts of accelerator per 100 parts of rubber used.

 The sulfur content usually ranges from 0.2 to 5, preferably from 0.5 to 3, and even better from 0.5 to 1.5 parts by weight sulfur per 100 parts by weight of rubber.

 Using the above ratio of sulfur and peroxide, a specialist can easily calculate the required amount of specific peroxide used. However, in general, the amount of organic peroxide varies between 0.3 to 10 parts by weight per 100 parts by weight of the elastomer, and preferably within 0.3 to 5 parts. These limits are set for vulcanizing agents with 100% activity and should be adjusted for products with less active ingredients.

 It is recommended to use sulfur in small amounts, namely from 0.5 to 3.0 parts by weight for every 100 parts by weight of elastomers. For the manufacture of tires, it is preferable to use from 1.0 to 3.0 shares of sulfur, but this amount may not be sufficient for vulcanization in the absence of peroxide and accelerator.

 In addition to elastomers and vulcanizing systems, the composition also includes the usual ingredients, such as an antioxidant, filler or plasticizing oil, fillers (black coal, silica, titanium and zinc oxides), activators, retarders in proportions that are commonly used in the manufacture of rubber tires, and depending from the desired properties. For example, the compositions contain from about 30 to 65 weight. fractions of black coal per 100 fractions of the entire elastomer.

Peroxide vulcanization of compositions intended for the manufacture of tire sidewalls and based on ethylene propylene type elastomers bonded to diene elastomers along with triazine compounds with structure (I) has several advantages over sulfur vulcanized compositions, namely:
1. Increased ozone resistance with equal amounts of ethylene propylene elastomers. This advantage is all the more the greater the amount of the ethylene propylene triple polymer used and the higher the average molecular weight of its components.

 2. Improving adhesion to rubber compositions after vulcanization. Rubber sidewalls adhere better to the frame, which eliminates the risk of internal sticking and allows the use of ethylene propylene elastomer in large quantities, and therefore, is more effective for anti-zone protection.

 3. Increase in fatigue strength, in particular resistance to bending deformations.

 The above-described vulcanized peroxide / sulfur composition based on diene and EPDM is the most preferred form of polymer composition and vulcanization. However, it should be noted that triazine, with structure (I), is used with a standard sulfur vulcanization system, as it is usually used with a diene elastomer for the production of carcass tires. The term “carcass” as used herein means all parts of the body of a diagonal tire or tire with a radially spaced cord layer in the carcass. Used as such, the framework consists of many different layers of elastomer. Some of these layers contain fabrics, cords, or other types of reinforcement introduced into these layers. Some of these parts of the tire carcass are mentioned by way of example only. The corona or tread zone of the upper layers of the tire is a tread reinforcement zone in which primary breakers are embedded, which give stability to the structure. Underneath these brackets are the fabric-reinforced inner layers, which can be radially oriented to form the tire carcass. Inside the reinforced carcass are the inner rubber layers. Many layers can be located in the direction of the sidewall plane, but usually four layers are located from the tread through the shoulder zones of the tire to the bead zone. Radially inward, the first layer is usually traced with varying thickness all the way down to the plane of the rim reinforcement.

 Layers are located radially outward from the innermost layer, which may include a portion of the white sidewall with the outermost black layer lying on the other side of the white sidewall. In this regard, it should be noted that it is in this very outer layer that it is useful to use an elastomer composition with a triazine compound of structure (I). The outermost layers of the sidewall are particularly strongly affected by adverse external conditions, as well as repeated deformations during their service life. Layers of sidewalls should have good physical properties, as well as a pleasant appearance. When designing tires with a black sidewall, all outer layers must be black, i.e. reinforced with black coal, which is necessary to preserve the glossy surface of the tire. For sidewalls of white color, it is necessary to use appropriate compositions of white color so that white surfaces do not turn yellow and do not darken during use. It is well known that when using a normal amount, i.e. 2 8 parts of ordinary paraphenyldiamine as an antiozonant per 100 parts of rubber hydrocarbon, the white surfaces of the sidewalls darken over time under the influence of external conditions. The use of the triazine compound described in the present invention minimizes the undesirable discoloration of both white and black sidewalls made from elastomeric compositions. Most preferred is a composition consisting of diene-based unsaturated EPDM elastomers. Such compositions are resistant to atmospheric ozone and can extend the life of the tire. It is especially important to use these elastomers in the manufacture of tires for trucks in off-road conditions, this allows you to extend their service life four, five or six times and safely travel distances of up to 1,000,000 miles.

The new compounds described in the present invention can be used in conjunction with other antiozonants and less preferably with microcrystalline lubricants, which are usually used as anti-ozone protection. Other antiozonants that can be used include well-known paraphenyldiamine class materials:
N-phenyl-N '- (1,3-dimethylbutyl) -p-phenylenediamine,
N-phenyl-N'-isopropyl-p-phenylenediamine,
N-phenyl-N '- (1-methylheptyl) -p-phenylenediamine,
N-phenyl-N'-cyclohexyl-p-phenylenediamine, mixed diaryl-p-phenylenediamines,
N, N'-di-betanaphthyl-p-phenylenediamine,
N, N'-bis- (1,4-dimethylpentyl) -p-phenylenediamine
N, N'-bis- (1-ethyl-3-methyllpentyl) -p-phenylenediamine,
N, N'-bis- (1-methylheptyl) -p-phenylenediamine,
N-phenyl-N'-p-toluenesulfonyl-p-phenylenediamine,
N-phenyl-N'-alkyl-p-phenylenediamine,
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and nickel dibutyl dicarboamate.

 The most preferred antiozonant used in combination with the novel triazine compound of the present invention is N-phenyl-N '- (1,3-dimethylbutyl-p-phenylenediamine.

 The new compound can also be added to an unsaturated polymer with a concentration of from about 0.1 to 10 weight. shares per 100 weight. fraction of rubber hydrocarbon (below PHR). For these purposes, natural or synthetic rubber is allowed. A more preferred additive is about 2-8 fractions of PHR. Most preferably, the content is from about 2 to 6 fractions of PHR. If triazine compounds are used in combination with other antiozonants, for example substances of the class of paraphenylenediamines, they can be added entirely within the limits suggested above, although a higher level of their contents than the one indicated above, as preferred, may be ideal when used this mixture.

 The compounds of the invention can be mixed with other antiozonants in ratios ranging from 1: 3 to 3: 1. A more preferred ratio range is from 2: 3 to 3: 2. These ratios should indicate percentages from 40:60 to 60:40, where in all cases the triazine compounds of the present invention represent the first number of each ratio. Most preferably a ratio of about 50:50. It should be noted that in some applications and with some other antiozonants ratios per 100 weight. including rubber antiozonant, above, can be changed in order to obtain maximum protection. Acceptable experimentation should be carried out in order to optimize the ratios and total levels of the mixture when the triazine compounds of the invention are mixed with other conventional antioxidants and antiozonants.

 The novel triazine compounds of the invention can be synthesized by a suitable synthesis route. The following synthesis examples are provided to illustrate a preferred method for preparing some of the class of triazine compounds (I) of the present invention.

 Synthesis of triazine compounds.

 Example 1. 2,4,6-tris- / N-1,4-dimethylpentyl-p-phenylenediamino / -1,3,5-triazine.

1500 ml of isopropanol are placed in a 3-liter four-necked round-bottom flask equipped with a thermometer, a drive stirrer, a condenser and a dropping funnel. Isopopanol is cooled to a temperature of -10 ^° C. and 184.4 g (1 mol) of cyanuric chloride are added. To this stirred suspension was added 680 g (3.3 mol) of 4-amino-N- / 1,4-dimethylpentyl / aniline (dropwise) over 1 hour, keeping the temperature between -10 and -5 ^° C. Over 1 h, the reaction mixture is heated to a temperature of 30 ^o C, and then maintained for 16 h 30 ^o C. The reaction mixture is heated under reflux for 1 h at a temperature of about 80 ^o C. The reaction is then followed by high-pressure liquid chromatography, observing the disappearance of the original amine and conversion of intermediate mono- and bisubstituted compounds into the final product of tro substitution. After cooling to a temperature of 60 ^° C., 240 g (3 mol) of a 50% sodium hydroxide solution are added dropwise over 1 hour. Sodium chloride is removed by filtration at a temperature of 40 ^° C. The filtrate is cooled to a temperature of 10 ^° C. and the solvent is decanted. The oily bottom layer was extracted with water at a temperature of 60 ^° C., then crystallized from fresh isopropanol. Specified in the preform, the compound is recrystallized from hexane, and it melts at a temperature of 128 - 132 ^o C. The yield is 78.1%
The IR spectrum is consistent with the structure. High-performance liquid chromatography indicates that the product is 95.8% pure.

 Example 2

 2,4,6-tris- / N-isopropyl-p-phenylenediamino / -1,3,5-triazine.

650 ml of isopropanol are placed in a 2-liter four-necked round-bottom flask equipped with a thermometer, a drive stirrer, a condenser and a dropping funnel. Isopropanol is cooled to a temperature of -5 ^° C, after which 36.8 g (0.2 mol) of cyanuric chloride are added. To this stirred suspension was added a solution of 90 g (0.6 mol) of 4-amino-N-isopropylaniline in 100 ml of isopropanol (dropwise) over 1 h, maintaining the temperature between -5 and 0 ^o C. For 0.5 h the reaction mixture is heated to a temperature of 30 ^° C, then heated under reflux for 2 hours. The reaction is followed by high pressure liquid chromatography to observe the disappearance of the starting amine and the conversion of the intermediate mono- and bisubstituted compounds to the final product of triple substitution. The reaction mixture was cooled and allowed to stand overnight. The amine hydrochloride salt is neutralized by adding 96 g (0.6 mol) of a 25% sodium hydroxide solution for 0.5 h, after which the mixture is refluxed for 0.5 h. The title compound precipitates upon cooling, and it is isolated by filtration, washed with isopropanol and hot water (60 ^o C), melting point 196 198 ^o C. The yield is 75.2%. The IR spectrum corresponds to the structure. High-performance liquid chromatography shows that the product has a purity of 95.3%
Example 3. 2,4,6-Tris- / N-cyclohexyl-p-phenylenediamino / -1,3,5-triazine.

The procedure of Example 2 is repeated, except for using a 0.1 molar scale with 4-amino-N-cyclohexylaniline used to obtain the compound indicated in the workpiece, melting point 215,217 ^° C. The yield is 89.9%.
The IR spectrum is consistent with the structure. High-performance liquid chromatography shows that the product has a purity of 90.1%
Example 4. 2,4,6-tris- / N-sec-butyl-p-phenylenediamino / -1,3,5-triazine.

The procedure of Example 2 is repeated, except that 4-amino-N-fluorobutylaniline is used to give the title compound, melting point 167 169 ^° C. The yield is 90.8%. The IR spectrum corresponds to the structure. High-performance liquid chromatography shows that the product has a purity of 94.6%
Example 5. 2,4,6-tris- / N-1,3-dimethylbutyl-p-phenylenediamino / -1,3,5-triazine.

A solution of 316.8 g (1.65 mol) of 4-amino-N- (1,3-dimethylbutyl) aniline in 1500 ml of isopropanol is placed in a 3-liter, four-necked round-bottom flask equipped with a thermometer, a drive stirrer, a condenser and a bulk funnel. The temperature of the solution was adjusted to 30 ^° C., after which 92.2 g (0.5 mol) of cyanuric chloride were added over a period of 0.5 hours, maintaining the temperature between 30 ^° and 40 ^° C. The reaction mixture was heated under reflux for 1-1 / 2 hours. The reaction was followed by liquid chromatography under high pressure, observing the disappearance of the starting amine and the conversion of the intermediate mono- and bisubstituted compounds to the final product of triple substitution. After the reaction mixture was cooled to a temperature of 60 ^° C., 120 g (1.5 mol) of a 50% sodium hydroxide solution was added dropwise over 1 hour. Sodium chloride was removed by filtration at a temperature of 40 ^° C. The filtrate was charged back to the reaction flask, where 250 ml of water are added dropwise. The compound indicated in the workpiece precipitates and is removed by filtration, melting point 124 127 ^° C. The yield is 82.6%. The IR spectrum corresponds to the structure. High-performance liquid chromatography shows that the product has a purity of 95.3%
Example 6. 2,4,6-tris- / N-1-methylheptyl-p-phenylenediamino / -1,3,5-triazine.

The procedure of Example 5 is repeated, except for using a 0.225 molar scale with 4-amino-N- / 1-methylheptyl / aniline, resulting in the title compound. After recrystallization from a 28% toluene-hexane mixture, the melting point of the product is 87 90 ^° C. The IR spectrum is consistent with the structure, and high-performance liquid chromatography shows that the product has a purity of 90.7%
Example 7. 2,4,6-tris- (N-2,4-di-tert-butylcyclohexyl-p-phenylenediamino) -1,3,5-triazine.

The procedure of Example 5 is repeated, except for using a 0.25 molar scale with 4-amino-N- / 2,4-di-tert-butylcyclohexyl / aniline, resulting in the title compound, melting point 147 - 152 ^° C. Yield 85.7%. The IR spectrum corresponds to the structure.

 Example 8. 2,4,6-tris- (N-2-sec-butylcyclohexyl-p-phenylenediamino) -1,3,5-triazine.

The procedure of Example 5 was repeated, except for using a 0.25 molar scale with 4-amino-N- / 2-sec-butylcyclohexyl / - aniline, resulting in the title compound. The product does not crystallize and is isolated as a distillation residue, melting point 122 130 ^° C. The yield is 95.8%. The IR spectrum is consistent with the structure, and high-performance liquid chromatography shows that the product has a purity of 86.6%.
Examples 9 to 24 on the suitability of an antiozonant.

 The N-alkylarylenediaminotriazine compounds of the present invention function as excellent antiozonants in rubber polymers without the tendency to migratory staining evident at that time. The following examples demonstrate the suitability of the compounds in a variety of ozone and light resistance test conditions. All trials use triazines in vulcanizate compounds typical of industry. The following test formulation is a typical rubber compound.

 Recipe for testing, wt. h

Natural Rubber (SMR5CV) 50.0
Polybutadiene (cis -1.4 BR) 50.0
Carbon black (N-326) 50.0
Zinc Oxide 3.0
Microcrystalline Wax 1.5
Stearic acid 1.0
Aromatic Petroleum Oil 5.0
Benzothiazolsulfenamide 1.0
Sulfur 2.0
Antiozonant variable Variable
Table of antiozonants.

 Comparative A N-phenyl-N '- / 1,3-dimethylbutyl / -p-phenylenediamine (commercially available as Flexzone TM 7F from Uniroyal Chemical Company).

 Comparative B mixed diaryl-p-phenylenediamine (commercially available as Novazone TM AS from Uniroyal Chemical Company).

 Example 1. 2,4,6-tris- / N-1,4-dimethylpentyl-p-phenylenediamino / -1,3,5-triazine.

 The above test formulation is used for all test samples unless otherwise indicated. The formulation is an approximation of a typical tire sidewall connection. The identity and level of antiozonant are variables, evaluated in the following examples.

The test composition is used in order to obtain unvulcanized test sheets by pre-mixing natural rubber and polybutadiene. After mixing, all other components, except sulfur and benzothiazole sulfenamide, are added to form a non-producing compound, and already in the next mixing step, these components will be added. Test sheets for subsequent testing are vulcanized in a frame press between heated plates for a time sufficient to achieve full vulcanization. For the purpose of the test, a vulcanization mode of 15 minutes is used at a temperature of 160 ^° C. The exact configuration of the test sample for ozone aging tests varies depending on the description of the ASTM test method used (American Standard Test Method). Reference is made to the testing methods of the American Society for Testing Materials, and such methods are incorporated by reference in order to reduce the necessary descriptive information regarding sample preparation, test methods and test results (see table 1-8).

 Ozone aging test results.

The aging test in ozone is carried out using the standard test method ASTMD 1149-81, which is called rubber wear - surface cracking in the chamber (flat sample). This method involves evaluating the resistance of vulcanized rubber to cracking when exposed to an atmosphere containing ozone. Rubber samples are maintained at a surface relative tensile strain, and the ozone content in the test chamber is maintained at 50 ppm at a temperature of 100 ^o F (38 ^o C). The common designation for this test is the curved loop test method, since the test sample is placed during deformation so that it forms a loop configuration in which varying degrees of deformation and elongation are evaluated. This curved loop configuration is an extremely rigorous test configuration in which destruction can be expected within a few hours at high temperature and high ozone atmosphere where the test samples are placed.

 Additional Examples IIa and IIc on the suitability of an antiozonant.

 The N-alkylarylenediaminotriazine compounds of the invention function as remarkable antiozonants in rubber polymers without the tendency to migratory staining evident at that time. The following examples demonstrate the suitability of the compounds in a variety of ozone and light resistance test conditions. All trials use triazines in vulcanizate compounds typical of industry. The following test formulation is a typical rubber compound.

 Recipe for testing, wt. h

Natural rubber / SMP5CV / 50.0
Polybutadiene / CIS -1.4 BR / 50.0
Carbon black / N-326 / 50.0
Zinc Oxide 3.0
Microcrystalline Wax 1.5
Stearic acid 1.0
Aromatic Petroleum Oil 5.0
Benzothiazolsulfenamide 1.0
Sulfur 2.0
Antiozonant Variable
Table of antiozonants.

Comparative A N-phenyl-N '- / 1,3-dimethylbutyl / -p-phenylenediamine / is commercially available as Flexson ^TM 71 from Uniroyal Chemical Company /.

Comparative B mixed diaryl-p-phenylenediamine (commercially available as Novazone ^TM AS from Uniromed Chemical Company).

 2,4,6-tris / N-1,4-dimethylpentyl-p-phenylenediamino / -1,3,5-triazine.

 The above test formulation is used for all test samples unless otherwise indicated. The formulation is an approximation of a typical tire sidewall connection. The identity and level of antiozonant are variables carried out in the following examples.

The test composition is used in order to obtain unvulcanized test sheets by pre-mixing natural rubber and polybutadiene. After mixing, all other components, except sulfur and benzothiazole sulfenamide, are added to form a non-derivative compound, and in the next mixing step, these components will be added. Test sheets for subsequent testing are vulcanized in a frame press between heated plates for a time sufficient to achieve full vulcanization. For testing purposes, the vulcanization mode is used: 15 min at a temperature of 160 ^o C. The exact configuration of the sample test samples for aging test in ozone varies depending on the description of the used ASTM test method / American standard test method /. Reference is made to the American Society for Testing Materials test methods, and such methods are incorporated by reference in order to reduce the necessary descriptive information regarding sample preparation, test methods, and test results.

 Ozone aging test results.

The aging test in ozone is carried out using the standard test method ASTMD 1149-81, which is called rubber wear - surface cracking in the chamber / flat sample /. This method involves evaluating the resistance of vulcanized rubber to cracking when exposed to an atmosphere containing ozone. Rubber samples are maintained at a surface relative tensile strain, and the ozone content in the test chamber is maintained at 50 ppm at a temperature of 100 ^o F / 38 ^o C /. The common designation for this test is the curved loop test method, since the test sample is placed during deformation so that it forms a loop configuration in which varying degrees of deformation and elongation are evaluated. This curved loop configuration is an extremely rigorous test configuration in which destruction can be expected within a few hours at high temperature and high ozone atmosphere where the test samples are placed.

 The obtained samples age without tension at room temperature for the sixth month and twelfth month and are investigated. Therefore, three groups of test data are presented: before aging, aging of 6 months and aging of 12 months. The column entitled "control" indicates a composition that does not contain antiozonant protection. This unprotected sample disintegrates after 6-17 hours of exposure, depending on the degree of aging that the sample received before exposure to ozone. Example "comparative A" is the result of the addition of traditional paraphenylenediamine (Flexson 71) at 6 parts of PHR and 8 parts of PHR and it cracks in the range from 600 to 24 hours of exposure. In Example IIa and IIc, the rubber composition protected by the substituted triazine of the present invention shown in Example 1 is maintained in the range of 1040 to 1128 hours for various non-aged and aged samples. It is clear that the ozone protection provided by the compounds of the present invention is remarkable compared to traditional antiozonants, which are well known in the rubber field.

 The obtained samples age without tension at room temperature for the sixth month and twelfth month and are investigated. Therefore, three groups of test data are presented: before aging, aging of 6 months and aging of 12 months. The column of example 9, entitled the term "control" refers to a composition that does not contain antiozonant protection. This unprotected sample disintegrates after 6-17 hours of exposure, depending on the degree of aging that the sample received before exposure to ozone. Example 10 with Comparative A is the result of adding traditional paraphenylenediamine (Flexson 71) at 4 parts of PHR, and it cracks in the range of 600 and 24 hours of exposure. In Example II, the rubber composition protected by the substituted triazine of the present invention shown in Example 1 is maintained in the range of 1040 and 1128 hours for various non-aged and aged samples. It is clear that the ozone protection provided by the compounds of the present invention is remarkable compared to traditional antiozonants, which are well known in the rubber field.

Table 2 shows the aging test data in ozone under static conditions, carried out in the same way as in table 1. Test samples in the form of a dumbbell, 3 mm x 50 mm, are stretched by 20% on a specially designed stretcher, and the degree of cracking is periodically recorded. In this method, the test sample is exposed to an ozone atmosphere of 50 ppm at a temperature of 100 ^o F (38 ^o C) with 20% elongation or stretching. This additional degree of deformation is an additional characteristic of the preparation of the sample, which differs from the test carried out as shown in table 1. All other details regarding the test method are similar to those previously described for the results of table 1.

 Unprotected control test samples of example 12 are stored in the range from 8 to 552 hours, depending on how long the sample has been aging. Comparative Composition A, in a non-aging state at 600 hours, exhibits very little cracking. Example 13 of a sample with an aging of 6 and 12 months shows cracking in the range of 56 and 24 hours. The compounds of the present invention shown as Example 14 again show a very significant improvement in quality compared to the known antiozonants with respect to ozone protection that exceeds 1000 h under such test conditions. This again demonstrates the superiority of the N-alkyl-arylenediamine-triazines of the present invention over the conventionally used antiperspirants of the paraphenylenediamine class.

Rubber products can be protected against exposure to ozone when they are exposed to this effect in atmospheric conditions. One of the most difficult applications is on the tire when the vehicle remains in the air and in an ozone-containing atmosphere for an unlimited period of time. The true operating conditions under which the tire operates, it is difficult to reproduce as an aging test in ozone in static conditions, which are described in tables 1 and 2, and test methods in dynamic conditions. De Mattia Multiple Bending Fatigue Test. When trying to reproduce a typical surface condition of a tire, the following test method is used. During testing, the samples are installed in airborne test fixtures facing south, exposing them to full environmental conditions, as can be achieved in Naugatuck, Connecticut. Samples are continuously bent for 8 hours at approximately an angle of 78 ^o . After this bending period, the sample is weakened and left in this weakened static state for 16 hours. The procedure is repeated day after day until the quality of the sample deteriorates, as indicated by the appearance and growth of cracks on the surface of the sample, which is immediately recorded. This intermittent bending / relaxation test method is in good agreement with the actual conditions under which the tire is functioning. That is, the tire moves for many hours and during this time it completes a cycle with similar elongations that accompany its work during bending during the test. Then the bus is in static conditions for a long time, which are reproduced during the 16-hour static period of the cycle. Test results are expressed in thousands of periods. During the bending period, the samples bend at an angle of 78 ^o at 8.5 thousand periods per hour.

 This test for fatigue under repeated bending under dynamic conditions involves the use of rectangular specimens, 12 x 76 mm with 3 mm in radius, an annular groove through the center of the specimen.

 From the results it can be seen that Example 15, which does not contain an antiozonant, persists for less than 3,000 thousand periods in this test. Examples 16 and 17, which are protected by the paraphenylenediamine known in the art and the triazine of the present invention, exhibit a very significant improvement in their ability to withstand aging outdoors under natural conditions. The triazine compound of the present invention protects the sample of Example 17 with almost the same result as the paraphenylenediamine of Comparative Example A, which is generally considered to be the best antiozonant acceptable for dynamic applications.

 Mixing antiozonants examples 18 21.

 The triazine compounds of the present invention, in comparison with N-phenyl-N '- / 1,3-dimethylbutyl / -p-phenylenediamine (comparative A flexson 7F), usually show much better protection under static conditions and slightly worse protection under severe dynamic conditions, as estimated various laboratory test methods. However, it was unexpectedly and surprisingly discovered that the dynamic protection properties can be greatly improved by mixing triazine compounds with traditional p-phenylenediamines. This is carried out without prejudice to ozone protection in static conditions. Examples 18 to 21 demonstrate this synergistic effect.

 In examples 18 and 19, the antiozonant of example 1 is mixed with two traditional antiozonants in order to evaluate the cumulative effect in both static and dynamic conditions of the aging test in ozone. The results are compared with the results of the unmixed control samples 20 and 21. The rubber composition used is the same as the previously used test composition in all tests, except that the microcrystalline wax is canceled so as to ensure that the antiozonant action of the wax is absent and not has an effect on the results.

 The aging test in ozone under dynamic outdoor conditions is carried out as described for testing 8 hours of bending / 16 hours of static conditions for examples 12 to 24 of table 3, except that bending at 8.5 thousand periods per hour is performed continuously. There is no relaxation period. The test continues and therefore not a single sample has yet reached the point of final cracking (fracture).

 The aging test in the ozone in the chamber, carried out under static conditions, is carried out as described for examples 9 to 11.

 The results shown in table 4 for the aging test in ozone in a chamber under dynamic conditions show that comparative A (Flexson 7F) cracks after 216 hours (Example 20), while the compound of Example 1 used in Examples 18, 19, 21 individually or in combination with comparative A or B, provides excellent protection, as evidenced by the fact that not a single crack is visible after 1016 hours of testing.

 A dynamic outdoor test (Examples 18–20) shows that the mixtures of Example 1 with Comparative A and B provide excellent protection under dynamic conditions. The mixtures of examples 18 and 19 unexpectedly increase dynamic ozone resistance compared to example 21, which uses the compound of example 1.

 Characterization of non-staining examples 22 24.

 Sample instances are prepared using the test formulation given above, but without wax. The test composition is compounded, mixed and vulcanized in flat test sheets for subsequent analysis of the characteristics of bleaching and staining. A specific test is carried out in accordance with the method of CASTM-D 925-83. Method C assesses the degree of tendency to stain the material by determining the amount of bleaching that occurs from the carrier material through a white varnish coating that is applied to the test sample. Use the test composition shown for all test samples of the invention. After the test sample is mixed and vulcanized, it is coated with white varnish veneer in accordance with ASTM-D 925 method. Then it is exposed to the mountain sun lamp source in a suitable test chamber for a set period of time. A Hunter Lab TM colorimeter is used to objectively determine the color change of the white lacquer during a four-hour exposure to the mountain sun lamp. ASTM D 2244-79, entitled "Color Differences of Opaque Materials", provides a number of characteristics through the standard letters a, b and L. Since the staining characteristics of normal antiozonants are very extreme, the color scale L is given below. The color scale L is a scale from 0 to 100, with 0 representing completely black and 100 representing completely white. Therefore, the higher the L value, the more white the sample. The composition for testing example 22 was obtained as a control, which does not contain antiozonant. Example 24 contains the antiozonant of the present invention described in example 1, i.e., 2,4,6-tris- / N-1,4-dimethylpentyl-p-phenylenediamino / -1,3,5-triazine.

 Example 23 uses comparative substance A, which is N-phenyl-N '- / 1,3-dimethylbutyl / -p-phenylenediamine (Flexzon 7F, obtained from Uniroal Chemical Company, Inc.). The test results of the three samples are presented in table 5, showing the value of L Hunter after four hours of exposure.

 The results given above clearly show that the traditional substance paraphenylenediamine of Example 23 exhibits significant staining (32.6) after 4 hours exposure. In contrast, the test formula containing the compound of the invention of Example 1 has a color saturation of 81.5, which is very close to the value of 87.9 set forth for the control sample of Example 22. Thus, the compound of the present invention has minimal diffusion staining, which is extremely unusual result for an amine class stabilizer. Thus, the compounds of the present invention can be advantageously used as antiozonants without the accompanying effects of diffusion staining and discoloration, such as those shown, for example, in the results of comparative composition A. This class of materials can be described as non-staining antiozonants.

 The compounds of the present invention can be used to advantage in mixtures with antioxidants and antiozonants known in the art to enhance specific properties. Although the substituted triazine compounds of the present invention are described here only as antiozonants, it is clear that the substances can also function as antioxidants for rubber, thereby providing protection against oxidative degradation as well as protection against ozone. It should be noted that when used as an antioxidant, the levels are usually much lower per 100 wt. including rubber hydrocarbon than when used as an antiozonant.

 Unsaturated polymers can optionally be protected against oxidative and ozone degradation by mixing the triazine compounds of the invention with conventional antioxidants. Many classes of phenoplasts, amines, etc. function as antioxidants. Index of Industrial Antioxidants and Antiozonants, 3rd Edition, published by the Gudear Taye and Rabber Company, lists materials commonly regarded as substances having antioxidant properties and is incorporated herein by reference. Characteristic classes of such antioxidant materials are spatially hindered phenols, alkyl substituted diphenylamines, aryl substituted diphenylamines, naphthylamines, reaction products of diarylamine and ketone, mono-phenols, bis-phenols, polyphenols, hydroquinone derivatives and polymerized quinolines. The antioxidant system may contain one or more of these substances. Optimal levels of addition (PHR) for antioxidants can be easily determined through a simple experiment, and they can vary widely depending on the end use.

 2,4,6-tris- (N-alkyl-p-phenylenediamino) -1,3,5-triazines can most advantageously be used in the tire as a component of any or all of the thermoset rubber-containing parts of the tire. They include the tread, side and carcass parts of a tire of a freight, passenger or off-road vehicle, the tire also containing many different reinforcing layers. These components typically contain more than one thermosetting polymer in a mixture that can be protected from degradation by ozone and oxidative degradation.

 Methods for introducing these compounds into a tire are conventional and well known. These compounds increase the safety of the vulcanization of the rubber composition into which they are added, compared to traditional paraphenylenediamines.

 Tire sidewall compositions examples 25 33.

 The following examples illustrate the preferred suitability of triazines in the outer sidewall of a pneumatic tire containing mixtures of highly unsaturated rubber, such as EPDM (rubber based on a copolymer of ethylene, propylene and diene monomer), which has less unsaturation.

Examples 25, 26 and 27 are comparative examples and are not included in the scope of the present invention. Example 25 contains neither the essential component of the triazine (I) of the present invention, nor EPDM. Examples 26 and 27 do not contain triazine. These control examples show cracking in a 72-hour test for aging in ozone (ASTMD 3395B-82), which is an extremely stringent test method for aging in ozone under dynamic conditions, and this test method involves vulcanizing samples of compounds on a tissue belt. The belt rests on a number of rollers in order to cause surface deformation in the ozone chamber at 50 ppm ozone at a temperature of 100 ^o F (38 ^o C).

 Examples 25 and 26 crack during exposure to the ozone belt, while example 27 shows an improved result (very slight cracking) due to the presence of EPDM.

 Example 28 illustrates the improvement in the art in formulating a rubber compound. This compound, which has a substantial triazine and EPDM, is retained when tested for the ozone belt in a dynamic state without any formation of cracks.

 Note to table 6.

1. Triple ethylene-propylene-5-ethylidene-2-norbornene copolymer; weight ratio E / P = 66/34; mass diene 82; IV = 26 deciliters / gram / decalin at 135 ^o C /; Mooney viscosity / ML I +4 at a temperature of 100 ^° C / = 65 at 75 PHR of an oil-filled polymer. All oil is shown in the line below regarding naphthenic oil.

 2. 2,4,6-tris / N-1,4-dimethylpentyl-n-phenylenediamino / -1,3,5-triazine (see Synthesis Example I).

 3. Mixed diaryl-r-phenylenediamine / technically available as Novazone TM AS from Uniroal Chemical Company, Inc.

 4. NR- not carried out.

 5. OK - no cracks; VS- very slight cracks; VVS - very, very minor cracks; S- weak cracks and C- cracking.

 Examples 29 to 33 illustrate the importance of levels of addition of essential components, EPDM or triazine. Without adhering to the scientific basis of the explanation, it is believed that optional protection can be achieved by using adequately high levels of either EPDM or a triazine compound. It is believed that it is not necessary to have high levels of both compounds in order to obtain exceptional ozone resistance and fatigue resistance properties. However, it should be noted that excellent ozone resistance can be achieved at lower levels of any significant component, compared with other methods of protection against ozone.

 The effect of progressively higher levels of the triazine compound (Example 1) is shown as the results of exposure to ozone (curved loop test) of Examples 29 and 30 (two parts of the triazine compound), which show the development of cracks during the test. Whereas the higher levels of addition of Examples 31 and 32 did not show cracking during the 1080 hours of the test.

 The beneficial effect of progressively higher EPDM levels is shown by comparing Examples 29, 30 and 33, which has progressively more EPDM. Ozone protection levels increase with increasing levels of EPDM. Significant triazine addition is present at a constant level in all three of these examples. Thus, it can be concluded that the desired properties can be obtained by changing the level of the elastomer with less unsaturation (i.e. EPDM) and the triazine compound.

 Examples 34 to 41.

 Examples 34, 35, 36 and 40 are comparative examples and are not included in the scope of the present invention. Examples 34, 35 and 40 do not contain a triazine antiozonant, and examples 34 and 36 do not contain EPDM (polymer with less unsaturation). The results of the Monsanto Multiple Bend Fatigue Test are very decisive results that have a good correlation to the carcass performance rock properties. Example 37 shows a multiple bend fatigue value of 106 against the much lower values of comparative examples 34, 35, 36, which all do not contain at least one key component of the present invention.

 The advantages of using the preferred peroxide / sulfur combination as a vulcanizing group are shown by comparing the results of multiple bending fatigue tests of comparative examples 35 (13.3), 39 and 41 (75 and 162.6, respectively). The choice of vulcanizing group is another important factor. Vulcanization using a combination of peroxide / sulfur increases the results of fatigue during repeated deformations.

 The importance of the triazine antiozonant is shown when comparing the multiple bending fatigue values of comparative example 35 (13.3) versus example 37 (106). Example 41 shows optimal fatigue test results for repeated deformations using high molecular weight EPDM, a triazine antiozonant and a peroxide / sulfur vulcanizing group.

In a tire, a new joint is only useful when it has good adhesion to adjacent layers of tire rubber. The results of the adhesion test under static conditions are always good for all mixtures of the present invention, with a value of 10, as a rule, is considered as a fully adequate result of this adhesion test. The adhesion of the characteristics of each compound of the examples is evaluated by their adhesion to the standard tread composition shown in Table 7. The test compound is duplicated in comparison with the standard tread composition with a latex layer containing resorcinol formaldehyde resin, which treated the fabric on both sides, which forms the test pillow. The pad was cured under pressure for 15 minutes at a temperature of 177 ^° C. The vulcanized pad was stretched in a Scott tensile testing machine (or Instron tensile testing machine) to generate the force necessary to cause the test compound to separate from the standard tread test composition. Repeat samples are also tested and are set out in table 8 in kilonewtons / meter.

 Fitness in rubber products in dynamics.

 2,4,6-tris- / N-alkyl-p-phenylenediamino / -1,3,5-triazines can most advantageously be used as a component of the outermost layers of a rubber product having an elastomeric body. The outer layers are those that are directly exposed to the ozone-containing environment. There is a long-standing need in industry for a non-stainable antiozonant material that can effectively protect a rubber product in both static and dynamic conditions of the ozone environment. The following sections describe specific rubber products that are most favorably protected by the materials of the present invention. In the wide range of industrial rubber products to be discussed, many different types of rubbers are disclosed previously as being useful in the present invention. It should be noted that the triazine compounds of the invention can be used to increase the wear resistance of any polymer system used in any traditional construction of a particular rubber product. Major progress can be achieved by using triazine antiozonants to increase the protection of oil-resistant polymers, especially copolymers of butadiene and acrylonitrile (butadiene-acrylonitrile rubbers or nitrile rubbers). These types of ozone resistance of the invention can be used to replace neoprene (polychloroprene) in many applications when neoprene is used because of its moderate resistance to ozone and moderate oil resistance. It should also be noted that the various highly unsaturated polymers used in these industrial rubber products can be further improved with respect to their ozone resistance and multiple bending fatigue by mixing less unsaturated rubbers, such as EPDM, with the traditional highly unsaturated rubbers currently used .

 Belts.

 Among the various types of belts manufactured in the rubber industry, drive belts are the types that are most advanced using the materials and compounds described in the present invention. The drive belt is commonly described as a V-belt, as well as a drive belt and a timing belt. All of these types of belts can be greatly improved using the compounds of the invention. The rubber compounds described above and which contain compounds of structure (I) can be most advantageously used on the outer surfaces of the belt structure. In wedge-shaped, forced and toothed drive belts, these joints can replace neoprene in the lower engagement areas of the belt pulleys, alternatively described as belt mass, sealing mass, or buckle pulleys, depending on the structure of the belt. In order to better understand the suitability of drive belts, it will be useful to give a general description of the structure of the belt. The drive belt has an elastomeric body that forms the bulk of the belt. There is a geometrically defined neutral axis of most belts that runs over a variety of pulleys. The neutral axis simply indicates that the region above the neutral axis is in tension when it passes through the pulley, and the region below the neutral axis is described in a compression state. Therefore, a typical drive belt will have a tension section and a compression section that are separated by a plane of the neutral axis. Basic longitudinal reinforcements are completely traditional in the art and are cord layers or fabric or steel tows that are located approximately on the plane of the neutral axis. The drive belt consists of one or more rubber compounds having the same or different rubber-based rubbers. As indicated, the outer wrapping layers of the drive belt can be most favorably improved using the rubber compounds of the present invention. In addition, a compression section that experiences significant repeated bending over the life of the belt can benefit from the increased durability resulting from the use of triazine, and especially when EPDM rubber is introduced with a rubber compound such as an unsaturated diene. These areas traditionally use rubber based on neoprene (polychloroprene), which can now be replaced using cheap, high oil and solvent resistant polymers such as butadiene acrylonitrile rubber (NBR) and NBR in mixtures with other polymers such as styrene butadiene rubber (SBR ), natural rubber, EPDM, etc. Since the rubber compound used in the elastomeric body of the drive belt must be capable of being embedded within a plurality of layers of various types of reinforcing materials, the adhesion of rubber compounds to adjacent layers is absolutely critical to the success of the belt manufacturing operation. It has been found that excellent adhesion levels can be achieved using the materials of the present invention.

 Conveyor belts.

 Conveyor belts are used widely in industry and carry an endless variety of payload. The conveyor belt is usually made of an elastomeric body formed by one or more rubber compounds with a plurality of reinforcements embedded in the elastomeric body in a position between the upper casing and the lower casing. It is the coating materials that can most advantageously use rubber compounds with a triazine compound in a mixture with a variety of synthetic and natural rubbers. The characterization of the triazine substance of the present invention carries with it the hallmark of non-staining. This limits the use of many antiozonants in conveyor belts, as they can come into contact with materials that can be painted as a result of prolonged contact with the surface of the belt. The use of non-staining compounds of structure (I) can allow for increased protection against ozone and fatigue resistance during repeated bending, which will be possessed by the products of the manufacture of conveyor belts. Details of specific types of conveyor belt designs can be gleaned from the descriptions of the Rubber Product Manufacturers Association (RMA), which relate to many types and designs of conveyor belts. Such traditional structures and materials do not need to be described in detail here and it is believed that one skilled in the art can, through trial and error, introduce polymers protected with triazine compounds into the manufacturing process of conveyor belts.

 Pneumatic springs.

 One of the most difficult applications in the rubber product industry is the use of a fluid spring, commonly referred to as a pneumatic spring, which is used both to excite and vibrational calm a particular mechanical device. The two main types of air springs are the corrugated type and the swing cam type. A type of rocking cam, called a clutch type, is used in pneumatic shock absorbers for vehicles. Designs differ, however, only in physical characteristics, but not in purpose. The required materials are very similar for both types of air springs. During the life of the air spring, it can cycle millions of times, and during this time the internal air pressure will vary, causing deformation of the elastomeric sleeve or diaphragm of the air spring. A typical pneumatic spring is manufactured using an upper and lower holder having a rigid structure through which air can be pumped or discharged from a pneumatic working chamber formed by a flexible element that spans the gap between the upper and lower holders. This fabric-reinforced airtight membrane is formed into a straight sleeve or folding shape and seals tightly to the upper and lower holders to form a pneumatic working chamber between them. The exact structural similarities and differences between the swing cam springs and the corrugated type are well known in the art and only a minor structural detail is believed to be a prerequisite for the skilled person to make optimum use of the present invention. The fabric-reinforced airtight membrane is an elastomeric body that can be greatly improved using polymers stabilized by the substances of structure (I) of the present invention. Neoprene has so far been used commonly due to its ability to resist ozone. By using the triazines of the invention, the membrane can be improved by the use of a substance such as natural rubber, which has excellent resistance to repeated bending, but is rapidly destroyed by ozone. The incorporation of this non-stainable antiozonant material into polymers such as natural rubber can increase the resistance to repeated bending of flexible membranes of air springs. This represents a decisive step forward in the production of pneumatic shock absorbers.

 Sleeves.

 A wide variety of sleeves will not be described in detail, except for the indication that the outer casing of most sleeves can be used with greater efficiency if the triazine compounds of the present invention are used, at least in this part of the elastomeric body of the sleeve. The sleeve, of course, contains an outer casing that is resistant to the environment in which the sleeve operates, and an inner tube or lining that can withstand a specific fluid or material supplied along the sleeve. Between these two layers are many reinforcing materials, which may be a fabric with a diagonal line, woven or knitted fiber, or a composite material filled with rubber. Such structural details of the sleeves will not be considered in detail, however, a link is given to the description of the sleeves of the Rubber Manufacturers Association (RMA), where structural details of various designs of the sleeves are described in detail and detail. The invention relates to the choice of materials and, therefore, it suffices to describe the fact that the traditionally used unsaturated rubbers or rubbers with less unsaturation can be improved in many ways, including ozone resistance and resistance to repeated bending, which was previously described in detail.

 Many other rubber products can benefit from the characteristics of the compound of structure (I), and they can include gaskets, liners, engine mounts, window seals, window overlay trimmings, pillows for bridge supports, rubber roofing membranes, geophysical membranes such as lining of ponds, soles and heels for shoes, expansion joints, vibratory seams, parts for oil fields and other rubber products.

 In light of the many changes and modifications that may be made within the scope of the present invention, reference should be made to the appended claims to understand the scope of protection of the invention.

Claims (5)

1. Resistant to decomposition of a rubber composition containing a curable unsaturated polymer, a vulcanizing system comprising sulfur and / or an accelerator of sulfuric vulcanization and an antiozonant, characterized in that a triazine of the general formula is used as an antiozonant

where R ¹ , R ² and R ³ C C ₇ - branched alkyl or C ₃ C ₆ cycloalkyl unsubstituted or substituted by one or two C ₁ C ₄ alkyl groups, with the following amount of ingredients, parts by weight Unsaturated polymer 100
Sulfur 0.2 5.0
Vulcanization accelerator 0.1 5.0
Antiozonant 2 8
2. The composition according to p. 1, characterized in that it further comprises 1.0
1.5 parts by weight paraphenylenediamine antiozonant.  3. The composition according to p. 1, characterized in that the unsaturated polymer is selected from the group consisting of natural rubber, polyisoprene, polybutadiene, styrene, butadiene rubber, ethylene propylene diene terpolymer, butyl rubber, polychloroprene, acrylonitrile butadiene rubber.  4. The composition according to claim 1, characterized in that the sulfur vulcanization accelerator is selected from the group consisting of thiourea, derivatives of guanidine, xanthan, dithiocarbamates, thiuramsulfides, mercaptobenzimidazole, mercaptobenzthiazole, 2,2'-dibenzothiazyl disulfide, 2-merbenzothiazene disulfide, 2-mer their mixtures.  5. The composition according to claim 1, characterized in that it further comprises fillers, plasticizers, activators, flame retardants and peroxides. Priority on points:
08/28/87 according to claims 1, 3 5.  03.03.88 according to claim 2.

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