JPH0219142B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to aminomercaptans useful in making aging-resistant polymers. The polymers disclosed in U.S. Pat. No. 3,658,769 (Kline) have a relatively low content of certain N,
Contains N'-disubstituted-p-phenylenediamine units, and this diamine unit is chemically bonded to the polymer as a substituent for the acrylic monomer unit present in the polymer, making it resistant to aging at high temperatures. . Similar polymers that do not contain such substituents do not have this resistance. The introduction of aging-resistant groups into the polymer is accomplished by copolymerizing acrylic monomers containing such groups with vinyl monomers or diene monomers. Meyer, Tewksbury and Pierson, High Plymers, Volume 19, edited by EMFetles, Intersciens, New York;
A review published in Chapter 2 in 1964 discloses the incorporation of varying degrees of aliphatic mercaptans into polydienes by a number of researchers. The reaction is said to be the addition of mercaptans to the double bonds of the polymer. The difference in physical properties between the resulting addition polymer and the polymer reactant depends on the degree of interaction. The present invention discloses aminomercaptans useful in making self-aging resistant polymers. The aminomercaptan of the present invention has the formula [In the formula, R is (a) phenyl, or an alkyl group or alkoxy group having from 4 carbon atoms, or a formula

[Formula] (In the formula, both R ₇ and R ₈ have 1 to 1 carbon atoms.
phenyl groups substituted at any one or more positions with a substituent (representing an alkyl group or hydrogen of 4); (b) a cycloalkyl group having 5 to 12 carbon atoms; (c) a cycloalkyl group having 5 to 12 carbon atoms; a branched acyclic group in which each straight chain carbon atom of 1 to 12 is substituted with 1 to 2 alkyl groups of 1 to 3 carbon atoms, and (d)
Represents a substituent selected from the group consisting of alicyclic aralkyl groups or aryl groups having 7 to 14 carbon atoms; m represents 0 or 1; n represents 0 to 12; R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ each represent the same or different substituents selected from the group consisting of hydrogen and an alkyl group having 1 to 5 carbon atoms. ]. In the following, this compound will be abbreviated as ZSH if necessary. Representative examples of the aminomercaptans of the present invention are listed below. Note that the numbers given below correspond to the numbers in Table 1.

[Table]

[Table] These aminomercaptans can be used as antioxidants according to conventional methods.
Among the group of amino sulfide groups, designated as ZS-groups in the formula, there is a group of amino groups that have structural characteristics essential to certain diamines used industrially as antiozonants. That is, at least one nitrogen atom of the p-phenylenediamine group is secondary or tertiary.
N-substituted with an alkyl group through a carbon atom in which m is 0 and R ₃ and
when at least one of R ₄ is an alkyl group rather than hydrogen), the other nitrogen atom of this diamine group is a secondary carbon atom or a tertiary carbon atom (i.e., a carbon that does not have two or more hydrogen atoms). an amino group bonded to an alkyl group, phenyl group or substituted phenyl group via an atom). When aminosulfide groups belonging to this group are attached to polymers as described below, they not only increase resistance to forms of oxygen other than ozone, but also provide considerable resistance to ozone cracking. There are various methods for preparing aminomercaptans. For example, N with the desired aryl or alkyl substituent
-Substituted p-phenylenediamine RNH・
Direct amidation of C ₆ H ₄ .NH ₂ with a mercapto acid, e.g. thioglycolic acid or β-mercaptopropionic acid to give the N-mercaptoalkylacyl derivative RNH .C ₆ H ₄ .NHC=O(CH ₂ ) _o SH Transform. This type of preparation is illustrated in Example 1.
In addition, in order to prepare the N-mercaptoalkyl derivative [when m in the formula is 0] from the same substituted p-phenylenediamine as above, the substituted p-
The dithiodiimine is formed by treating the phenylene diamine with ethylene sulfide or propylene sulfide, or by treating the diamine with 0.5 molar equivalent of a dithiodialdehyde, such as α,α'-dithioisobutyraldehyde.・
JJD'Amico and WEDahl, The Journal of Organic Chemistry (J.Org.
Chem) Vol. 40, p. 1224 (1975)] and then reduce the diamine to aminomercaptan using lithium aluminum hydride under refluxing tetrahydrofuran [JLCorbin and D.L. DEWork, The Journal of Organic Chemistry, Volume 41, Page 489 (1976)
] or by a two-step treatment method in which a reduction system is used to form a ring. This type of preparation is illustrated in Example 2. Examples of suitable diamine substrates for the preparation of aminomercaptans of the invention are as follows. However, the numbers assigned correspond to the numbers in Table 2.

[Table] The use of N,N'-disubstituted-p-phenylene-diamine derivatives as additives in certain oxidizable oils, fats or polymers in relatively small amounts can improve the aging resistance or antioxidant properties of these substances. It is known that the sexiness is significantly increased. Therefore, if a compound having such a diamine substituent is introduced into a polymer by chemical bonding, a polymer with internal aging resistance will be obtained. Such aging resistance cannot be lost from the polymer by extraction, sublimation, decantation, filtration or other conventional physical means of removing antioxidant additives from the polymer. The amino-substituted mercaptans of the present invention can be used in relatively small amounts to introduce amino antioxidant functional groups into polymers. This uses relatively small amounts of amino-substituted mercaptans (a) as chain transfer agents that react with both the monomer and the propagating polymer radical in free radical polymerization and (b) in the addition step with preformed mercaptans having at least one double bond. (c) as a reactant that reacts with the polymer
This can be achieved by interaction as a reactant that reacts with the polydiene homopolymer or copolymer during the rolling and curing steps. All such interactions occur in emulsions, solutions,
It can be carried out in a dispersion or in a bulk medium. The polymers produced by the above method are superior to similar polymer compositions containing conventional anti-aging agents without containing chemically bound anti-aging agents. Polymers with such chemically bonded anti-aging groups therefore have distinct advantages over polymers of similar structure but which are protected against oxidation by the addition of conventional anti-aging compounds. . The polymer having an aging-resistant group is usually a segment of a conjugated diene monomer having 4 to 10 carbon atoms, a segment of a non-conjugated cyclic or acyclic olefin monomer having 2 to 20 carbon atoms, or a segment of a non-conjugated cyclic or acyclic olefin monomer having 2 to 20 carbon atoms. Consists of ~10 vinyl monomer segments. Examples of products that can be made from the new polymers incorporating aging-resistant groups include rubber products that are exposed to high temperatures and/or come into contact with oils or solvents, such as liners, gaskets, hoses and belts, and dry cleaning products. There are foam rubber backing materials for carpets. Products incorporating aging-resistant groups may be liquids or elastomeric solids. These products are elastomers or resins depending on the properties of the monomers used and the molecular weight of the polymer, and there are no restrictions on the molecular weight. Elastomer products can be vulcanized if a vulcanizing component is added, and can be used in all applications that use rubber. Some of these are used as gums without being vulcanized. Depending on the nature of the polymer, it can also be used as coating materials, caulking materials and molded articles such as wood, fabrics and metals. In general, the amount of aging-resistant groups attached to the polymer is similar to the amount of conventional antioxidants or antiozonants used, and is from 0.10 to 10 parts by weight, preferably from 0.5 to 10 parts by weight, based on 100 parts by weight of the polymer. 5 parts by weight. The amount used will vary depending on the particular aminomercaptan, the nature of the polymer and the application of the product. For example, equipment located in the tropics requires greater usage than similar equipment located in colder regions. One method for chemically introducing aging-resistant groups into polymers using the aminomercaptans of the present invention is to
It is a chain transfer reaction. In this reaction, N,
Certain mercaptoalkyl derivatives with antioxidant properties of N'-disubstituted-p-phenylenediamines interact with the polymerized monomer system to form polymers with these diamino substituents attached to the polymer through monosulfide bonds. generate. This reaction will be described later as a chain transfer reaction. The resulting polymer is self-aging resistant. To produce such polymers, homopolymerization by a free radical mechanism in the presence of diamine derivatives as described above,
Any monomer or monomer mixture that can be copolymerized and interpolymerized is polymerized. Such monomers include conjugated dienes with 4 to 6 or more carbon atoms, such as 10, and their halogen derivatives, such as butadiene-1,3, 2-ethylbutadiene-1,3, 2,3-dimethyl-butadiene-1, 3, isoprene, piperylene, 1,3
-Hexadienes, 1,3-decadienes and 2-chlorobutadiene, and vinyl monomers such as styrene, α-methylstyrene, divinylbenzene, vinyl chloride, vinyl acetate, vinylpyridines, vinylidene chloride, acrylonitrile, methacrylate Nitrile, ethyl acrylate,
These include methyl methacrylate, acrylic acid, methacrylic acid, maleic acid, itaconic acid and maleic anhydride. Another method is another free radical reaction of the same aminomercaptans as described above with a polymer matrix having at least one reactive double bond per polymer molecule. This reaction is an addition reaction, in which aminomercaptans react with the double bonds mentioned above. This reaction will be described later as a free radical addition reaction. Thus, any isotactic, syndiotactic or atactic homopolymer or copolymer having double bonds capable of reacting with the aminomercaptans used can be used as substrate polymer in this addition reaction process. Yet another method involves rolling and curing in the presence of rubber additives such as reinforcing agents and pigments to interact any of the polydiene homopolymers and copolymers described above with the aminomercaptans described above. Since this reaction occurs during the rolling and curing steps, the nature of the reaction is not necessarily clear, but a self-aging resistant vulcanized product is obtained. This reaction will be described later as a roll kneading and curing method. In this method, a small amount of aminomercaptan is used, for example about 0.10 to 5 parts by weight. Temperatures can vary over a wide range. If roll kneading is carried out at a sufficiently high temperature, part or all of the reaction will be completed before curing. Thus, the curing operation can be carried out at any conventional temperature and the time required depends on the polymer system, temperature and curing agent. 1 Chain Transfer Reaction In this reaction, a mercaptoalkyl derivative of an N,N'-disubstituted diamine is chemically introduced into a polymer via a monosulfide bond by a chain transfer reaction. Each step of the reaction can be represented by the formula below. I・+M←→IM・ Equation 1 IM・+nM←→IM _o+1・=P _x・ Equation 2 P _x・+ZSH←→P _x H+ZS・ Equation 3 ZS・+M←→ZSM・ Equation 4 ZSM・+qM← →ZSM _q+1・=Py・Formula 5 Py・+ZSH←→PyH+ZS・Formula 6 In the above formula, I is an activated initiator radical, and M is a reacting monomer (shown earlier as a chain transfer reaction). ), n and p are the number of monomer molecules that react with the initial monomer radical, _P Most of the chemically generated polymer radicals are represented by ZSH, and ZSH represents one of the aminomercaptans used [however, the structure ZS is the amino sulfide group shown in the formula]. Examples of such chain transfer reactions as a method of introducing aralkyl sulfide groups into polymers can be found in studies of the interaction of 2-mercaptomethylnaphthalene with polystyrene radicals, e.g. Pierson, Costanza.
and Journal of Polymer Science by Weinstein [J.
Polymer Science] Vol. 17, p. 221 (1955). When using this chain transfer method to chemically introduce amino-based antioxidant groups into polymers, one or more monomers known to polymerize in the presence of free radicals are added to the polymer. Polymerization is carried out in the presence of low concentrations of one of the aminomercaptans of the invention. Polymerization can be carried out in an emulsion, suspension, bulk or solution system. Some adjustments to the polymerization recipe and/or conditions may be necessary to obtain a satisfactory polymerization rate and desired polymer molecular weight. The essential parameter in achieving this chain transfer method is the amount of aminomercaptan charged, which not only affects the degree of polymerization inhibition but also the amount of aging-resistant groups introduced into the polymer and the amount of aminomercaptan charged. There is a strong influence on the average molecular weight of the polymer. Other adjustments to achieve this goal include selecting a free radical initiator system that does not pre-oxidize the aminomercaptan to produce substances that significantly retard or interfere with polymerization; Use solvents or diluent additives whenever possible, such as using comonomers selected to ensure solubility of the aminomercaptan in the polymerization reaction system. In emulsion polymerization systems, certain solvents, such as pyridine or toluene, or small amounts of comonomers, such as styrene, acrylonitrile or acrylic esters, may be used to achieve the above objectives. Examples of free radical initiator systems that can be used to carry out chain transfer reactions are so-called redox systems. One example of such an initiator uses a combination of, for example, a chelated ferrous salt, sodium formaldehyde sulfoxylate, and an organic hydroperoxide, such as a hydroperoxide of cumene or p-menthane. Heat dissociable compounds may also be used as initiators in this polymerization process. Such thermally dissociable compounds that do not oxidize aminomercaptans, such as azo compounds such as α,α′-azobis-isobutyronitrile and α,α′-azobis(α,γ-dimethyl-valeronitrile), are thermally dissociable. It is preferred over peroxy initiators such as ammonium persulfate or tert-butyl-peroxyisobutyrate, the latter being slightly more effective. This reaction can be carried out in solution. When using an emulsifier, choose an appropriate emulsifier. other ingredients,
For example, a buffer (for pH adjustment) may also be used. Suspending agents are used if desired. The amounts of these components and other components, such as colorants, may be optional. The temperature depends on the initiator used, etc. In redox systems, the temperature is usually between 0 and 50°C. If a thermally dissociable initiator is used, the temperature will vary from about 30 to about 100 to 120°C depending on the half-life of the initiator and the particular monomer system. 2 Free Radical Addition Reaction In this method, aging-resistant groups are introduced into the polymer by an addition reaction. This reaction combines an arylaminoalkyl mercaptan with at least 1 mercaptan per molecule.
This is an interaction with a polymer having vinyl-type double bonds or internal double bonds. This interaction is similar to known addition reactions in which methyl mercaptan molecules are added to the olefin units of polydienes to form adducts that are fully or partially saturated and have methyl sulfide substituents.
[Mayer, Tewkesbury and Pearson, High Polymers Volume 19, edited by E. M. Huetrus, Interscience, New York, 1964
Please refer to the article in Chapter 2, page 133 onwards.
There are also many patents outside the United States relating to this reaction]. The stereochemical properties of the polymers that can be used in this addition reaction vary widely, and these polymers are those obtained from monomers containing 2 to 20 carbon atoms. These polymers include isotactic, syndiotactic and atactic polydiene homopolymers and copolymers with other conjugated or non-conjugated dienes or vinyl monomers, respectively. As long as there is at least one reactive olefin unit per polymer molecule,
The method of preparing such polymers itself is not critical. Polymers that can be used include natural polydienes such as natural rubber, gutta percha, balata and polydienes synthesized from monomers.
The preparation of such polymers can be thermally initiated, radiation initiated or using various catalysts such as free radical initiator-based, cationic, anionic or coordination complex-based catalysts such as Ziegler-Natsuta type catalysts. Start. Polymeric substrates that can be used in this method include free radical polymers prepared from the same monomers or monomer mixtures as for the chain transfer process described above. However, the free radical polymer must have at least one reactive olefin unit per polymer molecule. Polymers that can be used include furthermore conjugated or non-conjugated cyclic or acyclic dienes or polyolefins such as isoprene, butadiene-1,3,1
- polymers of ethylene, propylene or isobutylene with small amounts of segments such as norbornene and 1,5-cyclooctadiene. Useful polymeric substrates prepared by non-free radical methods include cis and trans 1,2-polybutadiene or 1,4-polybutadiene;
Syndiotactic or atactic homopolymers or copolymers prepared from butadiene-1,3, cis and trans 3,
4-polyisoprene or 1,4-polyisoprene, syndiotactic or atactic homopolymers or copolymers prepared from isoprene, 2-ethyl-butadiene-1,3, piperylene, 2,3-, similarly prepared. dimethyl-butadiene, 2-chloro-butadiene-
There are homopolymers or copolymers of 1,3 or 1,3-hexadienes. Other polymers that can be used as substrates include bicyclo-monoolefins, cyclo-diolefins, bicyclo-monoolefins and cyclodiolefins and mixtures thereof, α-olefins, the olefins mentioned above and α-olefins. There are polymers produced by copolymers with or metathesis reactions with norbornene. What is meant by the term "metathesis reaction" is the exchange reaction of a substituent on an olefin carbon atom of one monomer molecule with a similar substituent on the other monomer molecule. Polymers prepared in this way include polypentenylene, polyoctenylene or polyoctadienylene. Polymers prepared by ring-opening reactions of certain cyclic olefins, such as norbornene, with non-metathesis catalysts, such as cationic or Ziegler-Natsuta type catalysts, may also be used as polymer substrates in this process. Regarding the interaction of the aminomercaptan with existing double bonds in the polymer, this interaction can be effected in various ways. The polymer matrix is dispersed in an emulsion, suspension or solution. Catalysts for this addition reaction are free radical initiators of the thermally dissociation type or of the redox type, preferably of the former type, examples include azo compounds such as bis-azoisobutyronitrile, and hydroperoxides such as cumene hydroperoxide and p −
There is menthane hydroperoxide. The temperature required to effectively add the aminomercaptans of the present invention to the polymeric matrix is that required for continuous dissociation of the particular catalyst employed and will vary from about 0 to about 100°C. The time required for the reaction depends on many factors, such as the catalyst used and its concentration, the desired amount of mercaptan added, and the allowable amount of conformational isomerization of the polymer, especially when added to stereoregular polydienes. In this addition reaction, the amount of aminomercaptan charged is the amount (php) based on 100 parts of polymer.
The amount of catalyst is 0.1 to 10.0 parts, preferably 0.5 to 5 parts, and the amount of catalyst is 0.05 to 5 p.hp, preferably 0.05 to 5 p.hp in the thermally dissociated type.
It is 1.0php. When a thermally dissociable catalyst is used, the reaction temperature is 20 to 120°C, preferably 30 to 80°C. In order to obtain the desired mercaptan loading within a reasonable time, the polymer system must be free of appreciable amounts of reactive olefin monomers and free radical inhibitors. Such reactions may be carried out in a medium such as an emulsion, suspension or solution. 3. Roll kneading and curing method In this method, reinforcement is carried out during processing in a rubber mill, e.g. a Banbury mixer, in the presence of chemical additives commonly used for curing or vulcanizing rubber, in the presence of air, at normal rubber kneading temperatures. The aminomercaptan is added to the rollable elastomeric diene homopolymer or copolymer in the presence or absence of pigment. This rubber dough is then heated to a temperature commonly used for the production of vulcanized rubber, for example 250.
Cure in oven or press at ~350°C. Representative examples of polymers and copolymers useful in this method include polybutadiene, polyisoprene,
Isoprene-styrene copolymer, butadiene-
There are styrene copolymers, isoprene-acrylonitrile copolymers and butadiene-acrylonitrile copolymers (here meant elastomers), the major part of which is butadiene or isoprene. The resulting vulcanized rubber, from which non-rubber additives have been removed by extraction with a solvent such as acetone or methyl ethyl ketone, is free from the presence of conventional antioxidants such as 2,6-di-tert-butyl-p-cresol. It has much greater oxidation and aging resistance than the vulcanized rubber produced below, in which the antioxidant is extracted and removed. Reference Example 8 shows the introduction of aging-resistant groups by this method. Apparently, the aminomercaptan used is introduced into such polymer vulcanizates by a combined roll milling/curing process. Next, the aging-resistant polymer will be described. The aging-resistant polymers obtained by the several methods described above are represented by the formula ZSP. During the ceremony,
ZS is an aminosulfide group of formula i.e. as defined above , and the omitted p indicates the polymer matrix portion of the above-mentioned aging-resistant polymer. Therefore, this aging-resistant polymer has the formula It is represented by. Next, the present invention will be explained in more detail with reference to Examples and Reference Examples. Examples 1 and 2 demonstrate the preparation of certain aminomercaptans of the present invention. Reference Example 1 relates to the production of an intermediate used in the production of aminomercaptan. Reference Examples 2, 3, 4 and 5 illustrate methods for producing aging-resistant polymers by chain transfer reactions. Reference Examples 6 and 7 are examples of methods for producing aging-resistant polymers by addition reactions. Reference Example 8 illustrates the introduction of aging-resistant aminosulfide groups into the polymer by roll kneading and hardening methods. Reference Example 9 shows the use of the aminomercaptan of the invention as a conventional antiaging agent. Example 1 This example shows N-(4-anilino-phenyl)-β
- Concerning the production of mercapto-propionamide. 18.4 g N-phenyl-p-phenylenediamine, 10.6 g β-mercaptopropionic acid and
A mixture of 120 ml of xylene (technical grade) was heated to reflux temperature (approximately 140° C.) with stirring under nitrogen atmosphere. From this mixture 1.6ml water (90% of the theoretical amount)
was removed by azeotropic distillation using a Vigreux column with a Dien-Stark trap over a period of 13 hours. The reaction mixture was cooled and poured into hexane, the resulting crystalline product was filtered off, the ground crystalline product was washed with more hexane and evaporated to dryness to give 18.7 g of solid product. isolated. This product was recrystallized from hot toluene to give 17.6 g (64.5% of theory) with a melting point of 98.3~
White plate-like crystals at 99.5°C were obtained. The novel compound N-(4-anilino-phenyl)-β-mercaptopropionamide obtained is sometimes referred to as MPDA below. This thing, R.
A potential difference was created using a solution of silver nitrate in isopropyl alcohol according to the method described by M. Pearson, A.G. Costanza and A.H.Vinstein, Journal of Polymer Science, Vol. 17, p. 234 (1955). Titration yielded a mercaptan analysis value of 93.8% of the theoretical amount. A series of aminomercaptans were prepared using the appropriate diamine and mercapto acid substrate by a method similar to that described above. These are shown in Table 1. For products that do not easily crystallize, prior to isolation, the benzene solution was extracted with an aqueous sodium carbonate solution and then with water to remove mercaptoic acid.

[Table] Reference example 1 This reference example shows alkyl- or aryl-substituted -
Relating to p-phenylenediamine substrates. The diamine substrates used to prepare the aminomercaptans shown in Table 1 and aminomercaptan XI whose preparation method is shown in Example 2 are shown in Table 2. Regarding the examples in Table 2, some were used as free amines () or as hydrochloride salts (XI). Compounds and compounds are described in RHKline, Rubber Chem. Technol., Vol. 46, p. 96 (1973).
It was prepared from p-nitrochlorobenzene and the appropriate toluidine according to the method described in 2010). Compound
XII is Morris Freifelder
Freifelder] is a practical catalyst.
Hydrogenation [Practical Catalytic]
Hydrogenation], Wiley-Interscience, New York, 1971,
p-Aminoacetanilide was prepared by reductive alkylation with methyl isobutyl ketone by the general procedure discussed in Chapter 17, page 346.

[Table] Example 2 In this example, N-(β-mercapto-β,β-
The present invention relates to the production of (dimethyl-ethyl)-N'-phenyl-p-phenylenediamine. First, the intermediate compound bis-[β-(4-anilino-
phenyl-imino)-α,α-dimethylethyl]
Disulfide was prepared as follows. α, α produced from isobutyraldehyde and sulfur monochloride according to the method described by J.A. D'Amico and D. E. Dahl in The Journal of Organic Chemistry, Vol. 40, p. 1224 (1975). '-Diotibis-isobutyraldehyde was allowed to interact with 2 molar equivalents of N-phenyl-p-phenylenediamine () in methanol solvent at room temperature. The product obtained with a yield of 89% from the water-washed benzene extract of the reaction mixture was
Bis-[β-(4
-anilino-phenyl-amino)-α,α-dimethylethyl] disulfide. This diaminodisulfide was reduced to a mercaptan as described below. Compound 39.2 obtained above
A solution of 5.0 g of lithium aluminum hydride in 150 ml of anhydrous tetrahydrofuran in 150 ml of anhydrous tetrahydrofuran was added dropwise with stirring under an inert atmosphere over a period of 40 minutes to a refluxing solution of 5.0 g of lithium aluminum hydride dissolved in over 200 ml of the same solvent. The reaction mixture was refluxed for several more hours. The conditions for this reaction and the work-up of its products followed the conditions for the preparation of homologous compounds described by Corbin and Wark, The Journal of Organic Chemistry, Vol. 41, p. 489 (1976). excessive
LiAlH ₄ was decomposed with aqueous sodium potassium tartrate solution and the desired product was isolated from the water-washed diethyl ether extract by vacuum evaporation. In this way,
47% of mercaptan, i.e. N-(β-mercapto-β,β-dimethyl-ethyl)-N′-phenyl-p-phenylenediamine (compounds in Table 2).
A viscous dark brown syrupy substance containing
37.2g was obtained. This mercaptan has a theoretical molecular weight of 272. Reference Example 2 This reference example relates to the introduction of aminomercaptans into polystyrene by chain transfer reaction. Two separate experiments were conducted. The active mercaptan content was adjusted by taking 1.00 parts by weight of each of the compounds in Table 1, 100 parts of styrene,
0.10 parts of bis-azoisobutyronitrile and
Two reagent bottles were charged with 5.0 parts of pyridine. The third reagent bottle lacked the aminomercaptan but contained the other components in the same proportions. Seal the three reagent bottles under nitrogen atmosphere and
Tumbled in a water bath at 16 h. Low conversion polystyrene samples were isolated from each of the three solutions by coagulation in isopropyl alcohol. When measuring the internal viscosity of a benzene solution of a dried polystyrene sample, F.R.
F.R.Mayo, Journal of the American Chemical Society, Vol. 65, No.
The number average molecular weight was obtained for each sample using the formula described on page 2324 (1943). Thus, the polymer produced in the presence of the compound [MPDA] had a molecular weight of 17,100, while the control polymer had a molecular weight of 266,000. By substituting these molecular weight values into the formula derived by the above author, the chain transfer constant (TC), that is, a numerical value indicating the ratio of the reactivity of the compound to the polystyrene radical with respect to the reactivity of the styrene monomer and the polystyrene radical, was calculated. The significant TC value of the compound thus obtained at 50° C., namely 1.40, indicates that a significant amount of the compound has reacted with the polymer by the mercaptan introduction mechanism.
Similarly, a compound with a TC value of 0.27 [MADA]
showed a considerable tendency to bind to polystyrene, although to a lesser extent. Reference Example 3 This reference example shows isoprene/
Concerning the introduction of MPDA into styrene copolymers. 4oz bottle with screw-on cap
A series of emulsion copolymerizations A through E were carried out with identical charges of the components listed below (parts by weight per 100 parts of monomer) containing 20.0 g of monomer. Isoprene 75.0 Styrene 25.0 Pyridine 5.00 Potassium stearate 5.00 Distilled water 200 In addition to the above, variable amounts of ingredients shown in Table 3 (parts by weight per 100 parts of monomer) were also charged into the bottle.
The same table also shows the polymerization rate obtained after purging the inside of the bottle with nitrogen, sealing the bottle, and tumbling it in an aqueous solution at a predetermined temperature for 17 hours.

【table】

[Table] Next, inject into isoprene/styrene copolymer
Consider the efficiency of MPDA implementation. A copolymer consisting essentially of 75% isoprene and 25% styrene was prepared as in Formulation Example D above using MPDA and other variables as shown in Table 4. The polymer was coagulated in isopropyl alcohol, extracted repeatedly with hot isopropyl alcohol to remove non-polymer components, and then dried under vacuum. The amount of 4-anilino-phenyl-carbamyl unit introduced per 100 parts of polymer (phr) is measured by colorimetric analysis using the blue color of the quinone-imine chromophore, which is produced by oxidizing a chloroform solution of the polymer with benzoyl peroxide. I did it. Dry the polymer benzene cement and
A thin polymer film of known weight, 1.5 g, with a surface area of 1500
Formed on a number of aluminum sheets of known weight in cm ² . These sheets were inserted into the chamber of a typical oxygen absorber. The measured value of the oxidation resistance (OR) of these polymers is the time (hours) required for a polymer sample to absorb 1% by weight of oxygen from an oxygen atmosphere at a given temperature (here 90°C).
I went to sleep. Data regarding the efficiency of amino group introduction and the oxidation resistance of these polymers are also shown in Table 4. According to the data in Table 4, it was introduced into the polymer.
MPDA has the effect of significantly increasing the oxidation resistance of polymers.

[Table] Reference example 4 This reference example shows isoprene/
Concerning the introduction of other aminomercaptans into styrene copolymers. Generally, follow the procedure in Reference Example 3, but
The mercaptan activity was adjusted by replacing MPDA with 2.00 parts of other aminomercaptans shown in Table 1.
A series of mixtures of 75.0 parts isoprene/25.0 parts styrene was polymerized at 70°C for 17 hours. Next, reference example 3
The polymer was separated, post-treated, and tested using the method described in . Parameters related to polymerization and polymer properties are shown in Table 5.

Reference Example 5 This reference example concerns the introduction of aminomercaptan and into a butadiene copolymer by chain transfer reaction. Acrylonitrile or a mixture of 20.0 g of methyl methacrylate and butadiene was polymerized in parallel with the control polymer in the presence of 1.60 parts of the aminomercaptan shown in Table 6 in 4 oz. screw cap bottles. In the formulation used, the 6th
The reduced oxidation type (redox type) initiator system shown in the table was added. The same table also shows the polymerization rate of the obtained polymer and its oxidation resistance value after extraction and removal of non-polymer components.

[Table] The two ingredients, cumene hydroperoxide and butadiene, were charged into the bottle last.
The bottles were pre-cooled to 0°C before the butadiene was added, the excess butadiene monomer being passed through to drive out any air, and each bottle was sealed with a self-sealing rubber gasket and a threaded cap with a Teflon gasket. Hydroperoxide was then added through the cap using a hypodermic needle. The bottles were then tumbled in a 10°C water bath for 16 hours. The polymer latex was coagulated in isopropyl alcohol and the resulting coagulum was extracted repeatedly with hot isopropyl alcohol to remove non-polymer components. The copolymer was evaporated to dryness under vacuum and subjected to an oxidation resistance test in the same manner as in Reference Example 4. However, the nitrile copolymer film was molded from methyl ethyl ketone, and the acrylic ester copolymer film was molded from benzene. In this reference example, the oxidation resistance value was measured at 100°C. According to the results shown in Table 6, the butadiene/acrylonitrile copolymers with oxidation-resistant groups introduced using aminomercaptans (MADA) or (MPDA) have significantly higher oxidation resistance than the control polymers; Similarly, a butadiene/methyl methacrylate copolymer incorporating MPDA also exhibited significantly higher oxidation resistance than its control polymer. Reference Example 6 This reference example relates to the introduction of aminomercaptans into polybutadiene by emulsion addition reaction. A polybutadiene latex was prepared by polymerizing butadiene according to the formulation in Table 7 for 16 hours at 50°C in an 8 oz. screw cap bottle.

[Table] The latex obtained was gently distilled under a nitrogen atmosphere to drive off the butadiene monomer and continued until a few drops of water had condensed without the formation of bubbles. This latex contains 20.0 grams of rubber in two 8-ounce bottles with screw-on caps.
g (solid content 23.9%) were charged respectively. To each was added 0.25 parts per 100 parts of rubber (phr) azobisisobutyronitrile. on one side of the bottle
One was charged with 2.00 parts of MADA and the other with 2.00 parts of MPDA, both adjusted to 100% mercaptan activity. Both bottles were purged with nitrogen, sealed, and tumbled in a 50°C water bath for 16 hours. These latexes and untreated polybutadiene latexes were coagulated in isopropyl alcohol, non-polymeric additives were extracted, and dried.
An oxidation resistance test was conducted at 90°C as described in Reference Example 4. According to the results shown in Table 8, it can be seen that by using MADA or MPDA in this method, a considerable amount of internal oxidation-resistant groups were introduced into the polybutadiene.

[Table] Reference Example 7 This reference example relates to a solution addition reaction of aminomercaptans into an unsaturated hydrocarbon polymer. Samples of cis-1,4-polybutadiene, cis-1,4-polyisoprene, and 1,5-polypentenylene without antioxidants and radical inhibitors were dissolved in benzene and treated with azobis-isobutylo-nitrile (AIBN) catalyst. was treated with 2.00 parts of aminomercaptan under the conditions shown in Table 9 at 70° C. in the presence of nitrogen atmosphere. The polymer was coagulated in isopropyl alcohol to remove non-polymer components and subjected to an oxidation resistance test at 90°C as described in Reference Example 5 along with a control polymer. The mercaptans used are as specified in Tables 1 and 2.

【table】

[Table] According to the results shown in Table 9, it can be seen that the internal oxidation resistance of the polymer matrix is significantly increased by interacting with aminomercaptan. Reference Example 8 MPDA was introduced into the butadiene/styrene copolymer during roll kneading and curing. 1.25 parts of the non-fouling phenolic antioxidant Wingstay T. Goodyerar Tire and Rubber Company
Commercially available butadiene/styrene copolymers protected against oxidation with Tire and Rubber Cnmpany products.
SBR1502 (containing 23.5% combined styrene) was milled with the ingredients in Table 10 in a mill.

[Table] Press the polymer into a 0.020 inch sheet,
300° for 45 minutes to cure to 90% of the optimum cure according to Monsanto rheometer data.
A control polymer similarly formulated but lacking MPDA was pressed into a similar sheet and cured at 300°C for 30 minutes to achieve the same cure. A number of 1 inch wide strips were cut from each white vulcanizate. Some of the strips are 80/20
It was extracted repeatedly using a benzene/ethanol mixture for two weeks at room temperature and then dried. The time required for extracted strips to absorb 1% oxygen at 100°C was compared to the time required for unextracted strips. As is clear from the data presented in Table 11, the control
While the SBR vulcanizate loses most of its oxidation resistance due to the extraction of the antioxidant Wingstay T, the SBR vulcanizate rolled and cured in the presence of MPDA retains its oxidation resistance even after extraction. It maintains high oxidation resistance. This is because a significant portion of MPDA is chemically bound in the vulcanizate.

[Table] Reference Example 9 In this reference example, aminomercaptan is used as a conventional antioxidant in a butadiene/styrene copolymer. A butadiene/styrene copolymer was prepared according to the preparation method of SBR-1006. The polymerization rate of the latex was kept at 70%, and no commercially available antioxidants were used. This latex was coagulated in isopropyl alcohol, non-polymer components were extracted and removed with hot isopropyl alcohol, and dried under vacuum. A 3% benzene solution of the copolymer was prepared. 2.00% of various aminomercaptans were added to each batch of this cement. The oxidation resistance of films formed from these cement batches was measured at 100°C. These values are shown in Table 12 along with comparative examples. In Table 12, the structures of aminomercaptans are shown using the Roman numerals specified in Table 1 or Table 2. As is clear from Table 12, when a small amount is uniformly dispersed in SBR that does not contain any other antioxidants,
Both aminomercaptan and XI significantly increase the oxidation resistance of this polymer. This is similar to the commercially available antioxidant Wingstay L, which was dispersed in the same way.

[Table] Ru-based antioxidants.
When the aminomercaptans described above are distributed in the polymer by conventional methods such as addition to a polymer cement or latex, blending with a solid polymer in a mill or Banbury mixer, or mixing with a liquid polymer or solid polymer powder, , acts as an antioxidant that stabilizes the polymer against aging. These aminomercaptans include N-(4-anilino-phenyl-)-α-mercapto-acetamide, N-(4-anilino-phenyl-)-β-mercapto-propionamide, N-[4-(α' , γ′-dimethyl-butylamino)
-phenyl]-β-mercapto-propionamide and N-(β-mercapto-β,β-dimethyl-ethyl),N'-phenyl-p-phenylenediamine. All of the above compounds are considered new compounds.
These have antioxidant properties. The latter of the above also has anti-ozone cracking properties.

Claims (1)

[Claims] 1 formula [In the formula, R is (a) a phenyl group; or _an alkyl group or alkoxy group having 1 to 4 carbon atoms; or [ _Formula ]
a phenyl group substituted at any one or more positions with a substituent (indicating an alkyl group or hydrogen of 4), (b) a cycloalkyl group having 5 to 12 carbon atoms, (c) a cycloalkyl group having 1 carbon atom ~12 straight chain acyclic groups in which each carbon atom is substituted with 1 to 2 alkyl groups having 1 to 3 carbon atoms; and (d) alicyclic groups having 7 to 14 carbon atoms. represents a substituent selected from the group consisting of the formula aralkyl group or aryl group;
m represents 0 or 1; n represents 0 to 12;
R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ each represent the same or different substituents selected from the group consisting of hydrogen and an alkyl group having 1 to 5 carbon atoms. ]
A compound with 2. The compound according to claim 1, which is N-(4-anilino-phenyl)-α-mercaptoacetamide. 3 N-(4-anilino-phenyl)-β-mercaptopropionamide Claim 1
Compounds described in Section.