DE2164810B2 - Vulcanizable mixture - Google Patents

Description

one of R ^{3 is} a monovalent group R ² , a hydrogen atom or a group R ² S, in which R ^{2 is} a monovalent group R ² ,

mean; and
R is an organic radical of valence π

represents and

- when η stands for the value 1, independently a monovalent group R ² or a group of the formula

R ⁵ —N -

1.

in the

R ^{5 represents} a hydrogen atom or a monovalent group R ² and
R ^{3 has} the meanings given above,

or

- if η has the value 2, a divalent group R ² or

- if η has the value 3, a C6H3 = group

means.

2. Mixture according to claim 1, characterized in that it is a vulcanization inhibitor general formula

R-SO ₂ -N (Ri) -SR ²
contains, in the

R is a tolyl group, a phenyl group or a

low molecular weight alkyl group, R ^{2 is} a monovalent hydrocarbon group and R ^{1 is} a hydrogen atom or a group R ² .

3. Mixture according to claim 1, characterized in that it is a vulcanization inhibitor general formula

R-SO ₂ -N (R ^{1 contains} JSC ₆ H _n , wherein

R is an aryl hydrocarbon group and R ^{1 is} a hydrogen atom or a monovalent one

Group R ^{2 of} the type defined in claim 1, mean.

4. Mixture according to claim 1, characterized in that it is a vulcanization inhibitor general formula

R-SO ₂ -N (Ri) -SC ₆ H ₅
contains where

R is an aryl hydrocarbon group and R ^{1 is} a hydrogen atom or a monovalent group R ^{2 of} the type defined in claim 1.

mean.

This invention relates to the subject matter characterized by the claims.

In the manufacture of vulcanized rubber products, raw rubber is mixed with various others Ingredients such as fillers, accelerators and anti-degradation agents combined to facilitate the processing of the To improve rubber and the properties of the end product. The raw rubber goes through various

Stages of the plant before it prepares for the final stage of vulcanization: st Usually, the rubber is first mixed with carbon black and other components, and only then are the vulcanizing and accelerating agents added to this principle in a Banbury mixer or in a grinding device. At this processing stage, during storage before vulcanization and during the actual vulcanization, premature vulcanization, namely so-called "scorching", can occur. After adding the vulcanizing and accelerating agents, the raw rubber mixture is ready for calendering or extrusion and vulcanization. If premature vulcanization occurs during storage of the raw mixture or during processing before vulcanization, further processing can no longer be carried out because the prematurely vulcanized rubber is rough and lumpy and consequently unusable. Premature vulcanization is a major problem in the rubber industry and must be avoided otherwise it is not possible to manufacture and shape the rubber mixture before curing or vulcanization.

Due to the development of flame black with a high pH value which has the inherent inhibiting effect the acid carbon black is absent and through the use of certain phenylenediamine anti-degradation agents, which promote premature vulcanization are increasingly sharper Requirements placed on the curing system. The premature vulcanization has so far been partly due Delaying accelerators, of which the thiazole sulfenamides are a typical example, controlled either alone or in combination with retarders and activators. One because of its processing security Selected accelerators can be used to achieve satisfactory curing properties require the use of a secondary accelerator. In US-PS 25 90 737 it is shown that Certain sulfonamides are powerful vulcanization activators when used as secondary accelerators can be used, although used alone they have little accelerating effect. to such retarders include N-nitrosodiphenylamine. Salicylic acid and a terpene resin acid mixture. See also Rubber World, Compounding Ingredients for Rubber ", 91-94 (3rd edition, 1961). Acids are used together with thiazole sulfenamide accelerator Retarders are generally ineffective or have an adverse effect on the vulcanization process. Nitrosoamine retardants, along with thiazole sulfenamides derived from primary amines, are only beneficial limited effect.

The vulcanization inhibitors used in the vulcanizable mixture according to the invention belong to the class of sulfonamides and are effective inhibitors of premature vulcanization. They are characterized by the presence of an organic thio substituent on the salphonamide nitrogen. The characteristic core in these compounds is -SN-SO ₂ -

there may be more than one such core. The term "sulfonamide" is used here in a binding manner for all cases and includes sulfonediamides or sulfamides, in which case the free valence on the -SO ₂ group is linked to another nitrogen which can also be linked to a thio substituent . The property of inhibiting prevulcanization appears to be a general property of organic thio-substituted sulfonamides. Examples of thiosulfonamides which are suitable for inhibiting prevulcanization correspond to the following general formula

in which the radicals R, R ¹ and R ² and the indices η and n 'have the meaning given in claim 1.

When n '= 1, R ^{2 is} monovalent and the compounds are derivatives of monomericaptans. R ² is then an aryl, alkyl, alicyclic radical, rings fused to aryl and acyclic radicals or any. Combinations thereof, for example, alkaryl, aralkyl, alkylalicyclic rings or fused bicyclic rings having an aromatic ring fused with a non-aromatic ring, such as tetrahydronaphthyl and indanyl. for reasons of simplicity, aryl is used in the usual general sense, including any monovalent organic radical whose free valence belongs to an aromatic carbocyclic nucleus and which includes alkaryl, bicyclic radicals which contain an aromatic ring, the valence of which belongs to this ring and include radicals which are contained in the carbocyclic nucleus as alkoxy, chlorine, bromine, fluorine or iodine substituents, but which preferably contain no more than 12 carbon atoms and no more than one electronegative substituent. For example, the aryl radical can be phenyl, naphthy] or biphenyl, preferably unsubstituted, with the exception of lower alkyl. Alkyl is to be understood as meaning a monovalent aliphatic hydrocarbon radical of the series C "H2n + i, in which / 7 = 1 to 20, preferably 1 to 12, the radical being primary, secondary or tertiary and the chain or chains associated with the primary, secondary or tertiary carbon atom are connected, straight or branched. Cycloalkyl is to be understood as meaning cyclic aliphatic radicals preferably having 5 to 12 carbon atoms in the carbocyclic ring, the ring being unsubstituted except by lower alkyl. Aralkyl is to be understood as meaning aryl-substituted alkyl. Lower alkyl groups of 1 to 5 carbon atoms substituted by phenyl are the preferred aralkyl substituents.

Explanatory examples for R ² now follow when n ' in the above formula has the value 1, that is to say the above formula has the form

(R- [SO ₂ N (R ¹ ) -S — R ² ] ,,

accepts: phenyl, ο-, m- or p-tolyl, o-, m- or p-ethylphenyl, o-, m- or p-isopropylphenyl, p-tert-butylphenyl, o-, m- or p-chlorophenyl, o-, m- or p-bromophenyl, o-, m- or p-fluorophenyl, 2,5-dichlorophenyl, 2,4,5-trichlorophenyl, 2,4,6-trichlorophenyl, 2,5-dimethylphenyl, o-, m- or p-methoxyphenyl, Pentachlorophenyl, methyl, ethyl, propyl, isopropyl, η-butyl, isobutyl, sec-butyl, tert-butyl, amyl, hexyl, Octyl, decyl, dodecyl, tetradecyl, benzyl, decahydronaphthyl, Cyclohexyl, Cyclopeniyl, Cjelooctyl, Cyclododecyl, 4-methylcyclohexyl, 5-indanyl, 2-mesityl, biphenylyl, and - with the proviso that R is lower alkyl - nitrophenyl.

When / J = I, R is of course monovalent and is independently selected from the same group of monovalent radicals as R ^2. Irrespective of the value of π and n ' , R ^{1 can} also be hydrogen or is independently selected from the same group of monovalent radicals selected organic radicals such as R ² , or completes a thiobis sulfonamide, in which two sulfonamides are linked by nitrogen to form a divalent radical. Such thiobis sulfonamides, the starting materials of which are diamines, form a valuable class of compounds such as can be contained as vulcanization inhibitors in the vulcanizable mixtures according to the invention. Examples of these compounds are obtained when R ^{1 is} a group of the formula

-ANSO ₂ R ⁴

i.

represents wherein R ³ , R ⁴ and A have the same meaning as in claim 1.

When n = 1, the formula is a typical subgroup of these diamides

/ RSO ₂ NAN-SO ₂ R ⁴¹ JR ² I S- R 'j,

wherein A, R, R ² , R ³ , R ⁴ and the index n 'have the same meaning as in claim 1.

Examples of divalent radicals A are those obtained by removing two hydrogen atoms from methane, propane, cyclohexane, isopropane, butane, isobutane, pentane, hexane, heptane, octane, benzene, toluene, diphenyl or any methyl from p-xyloI (phenylenedimethylene) , which is here regarded as alkylene. The meaning of R ² outside the brackets depends on the value of n ' . For example, when n '= 2, R ^{2 is selected} from the same group as A, and when n' - 'is i or 4, R ^{2 is} a trivalent or tetravalent radical, as explained below.

Sulfondiamides or sulfamides, which are characterized in that they have two nitrogen atoms bonded to the same - SO2 group, are a valuable class of vulcanization inhibitors which can be used in the vulcanizable mixtures according to the invention. When n = \ , these compounds have the general formula

R ⁵ - N - SO ₂ - N (R ') S
R ³

R ²

wherein R ^{1 has} the same meaning as in claim 1, but is preferably hydrogen, or is independently selected from the same group of monovalent radicals as R ² , and R has the general formula

R ⁵ —N -

R ³

of R ² outside the brackets in turn depends on the value of n ', where R ^{2 is} monovalent if 11' = 1, is selected from the same group as A if n '= 2, or trivalent and tetravalent means organic residues when η '= 3 or 4

Disulfonamides, in which two sulfonamide nuclei _{are linked by -SO 2} groups to form a divalent radical, are similarly useful. Disulfonamides where n '= \ can be given by the following

ίο general formula

R [SO ₂ N (Ri) -SR ² J ₂

are represented, wherein R is a divalent, selected from the same group as A, preferably hydrocarbon radical with 1 to 12 carbon atoms ■ st. As defined above, R ² is a monovalent, organic radical and R ¹ has the same meaning as above, but is preferably hydrogen or is independently selected from the same group as R ² .

Disulfonamides, in which two sulfonamide nuclei are linked by a divalent sulfur atom to form a divalent radical R ² (where n '= 2 ), are valuable prevulcanization inhibitors which can be used according to the invention and which are represented by the following general formula

(R-SO ₂ N (R ') - S-) ₂ R ²

wherein R ^{5 is} hydrogen or has the same meaning as the monovalent Rtst R ² . and R ^{1 is} in turn hydrogen, R ² or H ² S-, where R ^{2 has} the same meaning as above. The meaning can be represented where R ^{2 is} an organic divalent radical selected from the same group as A, and preferably a hydrocarbon radical having 1 to 12 carbon atoms, R is a monovalent, organic radical having the same meaning as above (if monovalent) , and R 'has the same meaning as above, but is preferably hydrogen or is independently selected from the same group as R.

When / 7 = 3 and n '= \ , the prevulcanization inhibitors have the general formula

R [-SO ₂ N (R ') ^{-SR 2} J ₃

4 (i where R is trivalent, for example = Cf, H _3. R ^{1 has} the same meaning as above, but is preferably hydrogen, or is independently selected from the same group of monovalent radicals as R ² , and R ^{2 is} a monovalent radical as defined above,

<» ^R > represents.

The compounds corresponding to the preceding formulas are prepared by a N-halosulfonamide condensed with mono- or dimercaptans or the mercaptan to a sulfenyl halide converts and the halide with a sulfonamide, which is a reactive hydrogen the nitrogen, condenses.

For the preparation of inhibitors, where η = 3 or 4, tri- and tetramercaptans are necessary, of which some suitable, available compounds are listed below:

Pentaerythritol tetra (3-mercaptopropionate)

QCH ₂ OOCCH ₂ Ch ₂ SH) ₄ ,
^b0 pentaerythritol tetra (thioglycoiate)

QCH ₂ OOCCH ₂ SH) ₄ ,
Trimethy! Olethane-tri (3-mercaptopropionate)

CH ₃ C (CH ₂ OOCCh ₂ CH ₂ SH) ₃ ,
I limethylolethane trihioglycolate

CH ₃ C (Ch ₂ OOCCH ₂ SH) ₃ , and
Trimethylol propane trithioglycolate

CHiCH ₂ QCH ₂ OOCCH ₂ SH) ₃ .

Similarly, suitable dimercaptans include esters of mercaptocarboxylic acids, for example glycol dimercaptoacetate C ₂ H ₄ (OOCCH ₂ SH) ₂ , glycol dimercaptopropionate and other compounds of the formula ■>

Lower alkylenebis [OOC (CH ₂ ) "· -]

where n "= 1 or 2.

The preferred vulcanization inhibitors used in the vulcanizable mixtures according to the invention are those in which R ^{2 is} cyclohexyl or phenyl. It should be pointed out that the corresponding phenyl compounds are similarly effective and that if one ^{replaces cyclohexyl or phenyl by other radicals designated here as typical for R 2} , one obtains compounds with valuable inhibiting properties, which, however, are not necessarily equivalent.

Examples of vulcanization inhibitors that are used in the inventive Vulcanizable mixtures can be used with advantage, and those of the general formula

R-SO ₂ N (Ri) -SR ²

(n and n '= \), where R ^{1 is} hydrogen or 2 ^r > one of the above-mentioned monovalent organic radicals to which R ² belongs are listed below:

N- (Cyclohexylthio) -benzenesulfonaniIid, j «

N- (Cyclohexylthio) -o-, ρ- or m-tolylsulfone-

anilide or mixtures thereof, N-iCyclopentylthioJ-benzenesulfonanilide. N ^ CyclooctylihioJ-benzenesulfonanilide, N ^ CyclododecylthioJ-benzenesulfonanilide, y,

N-Cyclohexylthio-N-cyclohexylbenzenesulfonamide, N-Cyclohexylthio-N-cyclohexyl-o-, p- or

m-tolylsulfonamide or mixtures thereof, N-Cyclohexylthio-N-methylbenzenesulfonamide, N-Cyclohexylthio-N-methyl-o-, p- or

m-tolylsulfonamide or mixtures thereof, N- (CycIohexylthio) -benzenesulfonamide, N- (Cyclohexylthio) -methanesulphonanilide, N- (Cyclohexylthio) -ethanesulphonanilide, N- (Cyclohexylthio) -butanesulphonanilide,

N-iCyclohexylthioj-N-butylbenzenesulfonamide, N-Cyclohexylthio-N-butyl-p-chlorobenzenesulfonamide.

N-Cyclohexylthio-N-isopropylbenzenesulfonamide, N-Cyclohexylthio-N-2,5-dichlorophenyI-

2,5-dichlorobenzenesulfonamide,
N-Cyclohexylthio-No-chlorphenyl ^ AS-tri-

chlorobenzenesulfonamide,
N-Cyclohexylthio-Np-chlorophenyl-Z. ^ E-trichlorobenzenesulfonamide,

N-Cyclohexylthio-N-2,4,6-trichlorophenyl-

2,4,5-trichlorobenzenesulfonamide, N-Cyclohexylthio-N-ethylbenzenesulfonamide, N-Cyclohexylthio-N-ethyl-p-chlorobenzenesulfonamide,

N-Cyclohexylthio-N-selo-butylbenzene-

sulfonamide,
N-Cyclohexylthio-N-isopropyl-p-toluenesulfonamide,

N-Cyclohexylthio-N-butyl-p-toluenesulfonamide, N-Cyclohexylthio-N-butyl-o-toluenesultonamide, N-Cyclohexylthio-N-ethyl-o-isopropylbenzolstilfonamide.

N-iCyclohexylthioJ-butanesulfonamide, N-iCyclohexylthioj-octanesulfonamide, N-iCyclohexylthioJ-decahydronaphthylenesulfonamide,

N-CyclohexylthioJ-n-methyldodecanesulfonamide, N-CyclohexyIthio-N-benzyl-4-methylcyclohexanesulfonamide.

Examples of sulfonediamide inhibitors of the general formula

R ⁵ -N-SO ₂ -N-SR ²

N- (Cyclohexylthio) -N, N'-dicyclohexylsulfamide, N-iCyclohexylthioj-sulfanilide, N-J-cyclohexylthio-sulfamide, N.N'-iDicyclohexylthioJ-N.N'-dimethylsulfamide.

Examples of vulcanization inhibitors of the general formula of claim 1, in which n = 2 , are:

N- (cyclohexylthio) -4,4'-biphenyldisulfonamide, N, N '- (dicyclohexylthio) -4,4'-biphenyldisulfonamide,

N- (Cyclohexylthio) -1,3-benzenedisulfonamide, N, N '- (dicyclohexylthio) -1,3-benzenedisulfonamide,

and where η = 3: N-iCyclohexylthioJ-I.S.S-benzenetrisulfonamide.

Vulcanization inhibitors of the general formula R-SO ₂ -NAN-SO ₂ -R ² SR ² R ³

that come from diamines are for example:

N-iCyclohexylthioJ-N.N'-ethylene bismethane

sulfonamide, N.N'-dicyclohexylthio-N.N'-ethylenebismethane

sulfonamide, N-cyclohexylthio-N.N'-ethylene bisbenzene

sulfonamide, N.N'-dicyclohexylthio-N.N'-ethylene bisbenzene

sulfonamide, N.N'-dicyclohexylthio-N.N'-p-phenylenebismethanesulfonamide.

Vulcanization inhibitors of the general formula / RSO ₂ N-SJ R ²

I Rl

derived from dimercaptans are for example:

1,2-bis (N-thiomethanesulfonamide) -ethane, l ^ -bis (N-thiobenzenesulfonamide) -ethane, l ^ -Bis (N-thiotoluenesulfonamide) -ethane, l ^ -Bis (N-methyl-N-thiomethanesulfonamide) - : ethane,

l ^ -Bis (N-methyl-N-thiotoluenesulfonamide) -ethane.

1,6-bis (N-methyl-N-thiomethanesulfonamide) -

hexane,
1,4-bis (N-methyl-N-thiomethanesulfonamide) -

butane.

In addition to the vulcanization inhibitor, the vulcanizable mixtures according to the invention contain sulfur vulcanizing agents and organic vulcanization accelerators, and can be even cheaper, the premature Vulcanization stronger initiating accelerators in addition to anti-degradation agents, as well as flame black and other types of carbon black and fillers such as those used in rubber compounding. Among sulfur vulcanizing agents for purposes of this invention are elemental sulfur or a Sulfur-containing vulcanizing agent, for example Amine disulfide or polymeric polysulfide can be understood as a vulcanization accelerator aromatic thiazole accelerators, such as N-cyclohexyI-2-benzothiazolesulfenamide, 2-mercaptobenzothiazole, 2,2'-dithiobisbenzothiazole, N-tert-butyl-2-benzothiazolesulfenamide, 2-benzothiazolyl diethyldithiocarbamate and 2- (Morpholinothio) -benzothiazole may be included. Also amine salts of the mercaptobenzothiazole accelerators, for example the tert-butylamine salt of mercaptobenzothiazole, and salts of morpholine and 2,6-dimethylmorpholine can be present. But it can also other accelerators, such as tetramethylthiuram disulfide, tetramethylthiuram monosulfide, Aldehyde amine condensation products, thiocarbamyl sulfenamides. Thioureas, metal dithiocarbamates, alkyl dithiocarbamates, hexamethylenetetramine, xanthates and guanidine derivatives can be used. Examples of thiocarbamyl sulfenamide accelerators are found in U.S. Patents 23 81 392, 23 88 236, 24 24 927 and GB-PS 8 80 912 refer to. Furthermore, the vulcanizable mixtures according to the invention can also use accelerator mixtures as well as amine degraders such as

N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine,
N, N'-bis (1,4-dimethylpentyl) -p-phenylenediamine and other phenylenediamines, ketones, ethers and hydroxy degradants, as well as mixtures thereof. Mixtures of anti-degradation agents, for example a mixture of Nl, 3-dimethylbutyl-N'-phenyl-p-phenylenediamine and N, N'-bis (1,4-dimethy] pentyl) -p-phenylenediamine, provide a significantly improved end product of the vulcanizable mixtures, if they are used together with the vulcanization inhibitors used according to the invention.

The vulcanizable compositions of this invention can include natural and synthetic rubbers, as also contain mixtures thereof. Synthetic rubbers include cis-4 polybutadiene, butyl rubber, Ethylene / propylene terpolymers, polymers of 1,3-butadiene, for example 1,3-butadiene itself and isoprene, copolymers of 1,3-butadiene with other monomers, for example with styrene, acrylonitrile, Isobutylene and methyl methacrylate. The invention also relates to vulcanizable mixtures, the diene rubbers contain. The terms rubber and diene rubber are for the purposes of this invention Synonyma.

Those contained in the vulcanizable mixtures according to the invention as vulcanization inhibitors Connections are preferably established

jo provides that the corresponding sulfenyl halide is condensed with a sulfonamide containing reactive hydrogen on the amide nitrogen in the presence of a hydrogen halide acceptor. The general reaction when using a sulfenyl chloride and a sulphonamide, where n '= \ , proceeds as follows:

R ¹
I. "+ Η CISR ² > R R ¹ R. I.
SO ₂ NH If you use
RSO ₂ N (H) AN (H) SO ₂ R ¹
or
R ⁴ N (H) SO ₂ N (H) R ' SO ₂ N-SR ² 45
Vl
ti

as starting materials, one or both of the nitrogen atoms is easily substituted with -SR ² groups depending on the molecular ^{ratio of CISR 2} . 2 moles of CISR ² per mole of sulfamide lead to a substitution on both nitrogen atoms. Any hydrogen chloride acceptor such as tertiary amines or alkali metal hydroxides can be used. The reaction is expediently carried out in organic solvents, for example in benzene, toluene, xylene, chlorobenzene, chloroform, carbon tetrachloride or hexane. Dilute alkali metal hydroxide can be present as an aqueous phase, which serves as a suitable hydrogen halide acceptor.The reactions are usually slightly exothermic and take place after the reactants have been mixed smooth at ordinary temperatures. After the gradual addition of a solution of sulfenyl halide to a solution of sulfonamide, the reaction is soon complete.

The production of the vulcanization inhibitors used in the vulcanizable mixtures according to the invention is explained in more detail below.

Manufacturing process A

A glass flask is filled with 23.3 g (0.1 mol) of benzenesulfonanilide, 11 g of triethylamine and 200 ml of benzene are charged 11.6 g of cyclohexyl mercaptan in hexane are then gradually added at room temperature Cyclohexylsulfenyl chloride produced by chlorine is added, and when the addition is complete and the mixture is briefly stirred, it is poured in the reaction mixture in water and extracted twice with 2% sodium hydroxide solution and then twice with water. The benzene layer is dried over sodium sulfate and the benzene is removed by evaporation The oily residue is treated with a small amount of hexane to initiate crystallization and the solid product recrystallized from hexane. N- (CycIohexylthio) -benzenesulfonanilide is obtained as a cream-colored Solid; Melting point 57 ° to 60 "C.

If 24.7 g of N-benzylbenzenesulfonamide are used instead of benzenesulfonanilide, N-cyclohexylthio-N-benzylbenzenesulfonamide is obtained as a brown solid; Melting point 46 ° to 48 ° C

Manufacturing process B

A glass flask is charged with 10.9 g (0.1 mol) of N-methyl methanesulfonamide, 11 g of triethylamine and 100 ml of benzene. A solution of 0.1 mol, prepared by adding 8 g of chlorine to 30.5 g of p-nitrophenyl disulfide in benzene, of p-nitrobenzenesulfenyl chloride in benzene is then gradually added. A weak exothermic reaction takes place during the dropwise addition of p-nitrophenylsulfenyl chloride. After the addition is complete and the stirring is continued for a short time, the reaction mixture is filtered to remove the triethylamine hydrochloride, washed with dilute sodium hydroxide and dried, and the benzene is removed by evaporation, whereby Np-nitrophcnylthio-N-methylmethanesulfonamide is obtained as a cream-colored solid; Melting point 112 ^C to 114 ° C. Another amount is obtained from the triethylamine hydrochloride as a remainder by dissolving the salt in water.

In the above process, 17.1 g are used instead of N-methyl methanesulfonamide (0.1 mol) p-toluenesulfonamide, N-p-nitrophenylthio-p-toluenesulfonamide is obtained as an off-white solid; Melting point 102 ° to 105 ° C.

Is used in the above manufacturing process instead of p-nitrobenzenesulfenyl chloride 0.1 Moles of benzenesulfenyl chloride. this gives N-phenylthio-N-methylmelhansulfonamide. The benzene is removed from the filtered reaction mixture by evaporation. The remaining dark brown liquid is extracted with cold hexane, dissolved in benzene and extracted three times with 100 ml of cold water. the Benzene layer is dried, treated with charcoal, filtered and the benzene is removed by evaporation, whereby the product described above is obtained as a yellow oil. The NMR analysis confirms this Connection identity.

If 0.1 mol of cyclohexanesulfenyl chloride is used in the above process instead of p-nitrobenzenesulfenyl chloride, so one obtains N-cyclohexylthio-N-methylmeihansulfonamid; Melting point 30 ° to 32 ° C. The filtered reaction mixture is diluted three times with 100 ml of water instead of washing Sodium hydroxide extracted. After evaporation of the benzene, an oily residue remains, which is after Treat with cold hexane gradually crystallizes. The crystalline mass becomes good with cold hexane rinsed to give the aforesaid product as a pale yellow solid. The NMR analysis confirmed the identity of this connection.

Manufacturing process C

In a suitable reaction vessel, 46 g (0.2 mol) of benzenesulfonanilide are dissolved in a mixture of 100 ml of benzene, 100 ml of water and 8 g of sodium hydroxide benzenesulfenyl chloride prepared in benzene g of chlorine in benzene was added dropwise. After the addition has ended, the mixture is stirred for a short time, then the water layer is removed and the benzene layer is extracted with 100 ml of 4% sodium hydroxide and twice with 100 ml of water. The benzene is dried over sodium sulfate and removed by distillation to give N- (phenylthio) benzenesulfonanilide as a residue; Scmelzpunkt 80 ° to 83 ⁰ Q After recrystallization from methyl alcohol to obtain a white solid; Melting point 86 ° C.

Manufacturing process D

ϊ A suitable reaction vessel is used to manufacture a solution with 17.1 g (0.1 mol) of N-methylbenzenesulfonamide, Charged 4 g (0.1 mole) sodium hydroxide, 100 ml water and 50 ml benzene. Do this slowly 0.1 mol of cyclohexylsulfenyl chloride in 100 ml of benzene was added. After the addition and finished Reaction is the product by extracting the reaction mixture with water, drying over sodium sulfate and evaporating the benzene isolated. N-Cyclohexylthio-N-methylbenzenesulfonamide is obtained as crystalline solid; melting point 59 ° to 61 ° C.

If 0.1 mol of p-toluenesulfonamide is used in the above process instead of N-methylbenzenesulfonamide, this gives N-cyclohexylthio-p-toluenesulfonamide as a crystalline solid; Melting point 95.5 ° to 97 ° C.

Manufacturing process E

A glass flask is filled with 18.5 g (0.1 mol) of N-methyl-ptoluenesulfonamide, dissolved in 100 ml of dichloromethane and 11 g of triethylamine, charged. Then you give gradually 0.1 mol of benzenesulfenyl chloride is added at room temperature and, when the addition is complete, the reaction mixture is extracted first with 100 ml of 2% sodium hydroxide and then with water. The product has no further Cleaning a melting point of 69 ° to 71 ° C and the NMR analysis confirmed that the compound is the desired N- (PhenyIthio) -N-methy! -P-toluenesulfonamide.

Manufacturing process F

6.5 g (0.025 mol) of Ν, Ν'-diphenylsulfondiamide (C ₆ H ₅ NH) ₂ SO ₂ , 6 g of triethylamine and 100 ml of benzene are introduced into a suitable reaction vessel, and 0.075 mol of cyclohexylsulfenyl chloride is gradually added. When the addition is complete, the reaction mixture is filtered, the benzene is removed by distillation and the residue is treated with hexane to give a dark solid which is recrystallized from methanol. The product is Ν, Ν'-Diphenyl-Ν, Ν'-dicycIohexylthiosulfondiamid, a white solid; Melting point 105 ° to 107 ° C. The NMR analysis confirmed the identity of the compound.

If Ν, Ν'-Diphenylsulfondiamid is replaced by an equal molar amount of Ν, Ν'-Äthylenbisbenzenesulfonamid, thus one obtains N ^ '- dicyclohexylthio-N.N'-ethylene bisbenzenesulfonamide.

Manufacturing process G

A glass flask is filled with 36 g (0.2 mol) of N-methyl-ptoluenesulfonamide, 150 ml of benzene and 23 g of triethylamine are charged. They are then gradually added at room temperature by adding 7.5 g of chlorine to 17.8 g (0.2MoI) sec-butyl disulfide sec-butylsulfenyl chloride prepared in 100 ml benzene to. After the addition is complete, the product is extracted twice with the benzene 100 ml of 2% sodium hydroxide solution each, followed by two washes of water. The benzene is extracted dried over sodium sulfate and removed by evaporation. The oily residue is repeatedly with Washed cold hexane and a lot of unreacted N-methyl-p-toluoIsulfonamid by careful Precipitation of a hexane solution of the residue was removed from the cold hexane wash liquors

The hexane filtrate is cooled in dry ice with N-sec-butylthio-N-methyl-p-toluenesulfonamide as a solid obtained, which melts with increasing temperature. The identity of the product is determined by means of NMR analysis confirmed.

Manufacturing process H

A glass flask is filled with 37 g (0.2 mol) of N-methyl-ptoluenesulfonamide, 24.5 g of Colliden and 350 ml of dimethylformamide are charged. Then you gradually give in Room temperature essentially 0.1 mol by adding 14 g of chlorine to 9.4 g of 1,2-ethanedithiol in benzene produced 1,2-Äthandisulfenylchlorid to. After finished Addition, stirring is continued for a few minutes, the reaction mixture is filtered and the Removed solvent from the filtrate by distillation. The remaining product is 1,2-bis (N-methyl-N-thio-p-toluenesulfonamide) -ethane, a solid which, after recrystallization from hexane, has a melting point of 172 ° to 174 ° C. The NMR analysis confirmed the identity of the connection.

Manufacturing process I

A glass flask is filled with 43.6 g (0.4 mol) of N-methyl methanesulfonamide, 44 gtriethylamine and 300 ml of benzene charged. Then gradually add 0.1 mole of one Benzene solution of sulfenyl chloride produced by adding chlorine to pentaerythritol tetra (thioglycolate) to. Triethylamine hydrochloride is removed from the reaction mixture and the desired product the formula

(CH3S0 ₂ N (CH 3) SCH ₂ COOCH ₂₎ 4C

is isolated from the reaction mixture as described in preparation process B.

The following example illustrates the improved vulcanizable compositions of this invention and demonstrates the beneficial effect of the vulcanization inhibitors described. For all the vulcanizable mixtures investigated and described, the time in minutes required for the viscosity of the batch to rise by 5 units above the minimum viscosity ^{was determined by means of a r> Mooney plastometer.} These values are commonly known as the "Mooney Scorch Time" (is) . Longer Mooney Scorch lines leave on

κι a better inhibitory effect, and are desirable in the Mooney Scorch test because they are a indicate greater procedural security. The hardening properties are measured using the »Monsanto Oscillating Disk Rheometers ”(described by Decker, Wise

π and Guerry in Rubber World, 1962, page 68). The Rheometerangaben /?,".· "is the maximum torque in Rheometereinheiten, f _2, the time in minutes to the rise of two Rheometereinheiten above the minimum reading and fi" - / _2, the time difference

2 (i is required to get a torque of 90% of the maximum and f ₂ .

example

Table I illustrates the results using N- (cyclohexylthio) benzenesulfonanilide and N- (phenylthio) -N-methyl-p-toluenesulfonamide as inhibitors for premature vulcanization in approaches of natural rubber, which is a p-phenylenediamine antioxidant and contains antiozonants and sulfena-3 »mid accelerators with a retarding effect, from the results of Table I it can be seen that the inhibitors investigated here in the presence of the The accelerator and the antioxidant are fully effective as inhibitors of premature vulcanization r, are.

Table I.

Natural rubber smoked sheets Parts by weight B. ο O Lampblack (ISAF) Λ 100 ι oo 100 zinc oxide 100 45 45 45 Stearic acid 45 3 3 -ι Hydrocarbon plasticizers 3 2 2 2 sulfur 2 5 5 5 N-1,3-dimethylbutyl-N'-phenyl- 5 2 2 2 p-phenylenediamine 2 2 2 2 N-tert-butyl-2-benzothiazole sulfenamide 2 N-Cyclohexylthiobenzenesulfonanilide 0.5 0.5 0.5 ! ■ Viii N-phenylthio-N-methyl-p-toluene- 0.5 0.2 0.4 - ft " sulfonamide - - - 0.4 I. Mooney scorch time at 121 C. - 1 i

/ 5

Rheometer at 144 C
'2

'90 ~ h

38.8

9.6
12.4
66

46.4

11.5
12.6
66

15 16

Results comparable to those in this table with the composition of batch A durc

are also achieved with numerous others in the invention incorporation of 0.4% vulcanization inhibitor

According to vulcanisieuaren mixtures used improvement was the percentage increase de

Get vulcanization inhibitors. Attempts to look - Scorcn delay is calculated, for which purpose the Moonej

borrowed the concentration show that the Vulkanisationsin- 5 scorch time of the approach, the Vulkanisationsinhibi

Contains hibitoren in rubber in concentrations from 0.05 to tor, by the Mooney scorch time of the control

5.0 parts by weight per 100 parts by weight of rubber, batch divides, multiplied by 100 and subtract 100

preferably in the range from 0.1 to 3.0 parts by weight per this percentage increase (summarized in de

Parts by weight of rubber can be used. Table II) shows the percentage of improvement de

nen. to scorch delay versus control approachJ

To explain the comparison to a control mixture which does not contain an inhibitor.

Table Il

Viilkanis.tlionsinhihitor Percentage increase

tier Scorch-Yerzögerunc

N-phenylthio-N-methyl-p-toluene isulfonamide 69

N-Cyclohexylthio-p-toluenesulfonamide 75

N-Cyelohexylthio-N-methylbenzenesulfonamide 57

N-Cyclohexylthiü-N-benzylbenzenesulfonamide 40

N- (Phenylthio) -benzoIsuifonanilid 24

NK CyclohexylthioJ-benzenesulfonanilide 67

N-p-nitrophenylthio-N-methyl methanesulfonamide 28

N-p-nitrophenylthio-p-toluenesulfonamide 3

N-phenylthio-N-methyl methanesulfonamide 90

N-Cyclohexyllhio-N-methylmethanesulfonamide 46

N.N'-Diphenyl-1 ^ N'-dicyclohexylthiosulfondiamide 59

N-sec-butylthio-N-methyl-p-toliolsulfonamide 40

The adverse effect of the highly electronegative nitro substituent is in the previous figures information can be found.

Table III illustrates the premature vulcanization inhibitor properties for a styrene · Butadiene rubber preparation. The basic preparation is compounded from the following ingredients

Parts by weight

Oil-extended styrene / butadiene rubber with a 137.5% 37.5% highly aromatic oil content

Soot (ISAF) 65

Zinc oxide 3

Stearic acid 1

Hydrocarbon plasticizer 1.5

N-tert-butyl-2-benzothiazole sulfenamide 1.0

N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine 2.0

Sulfur 2.0

0.4% by weight vulcanization inhibitor is added to the basic preparation and the Mooney-Scnrch-Zci! hei 13 S ('best in ml

18th

Table IH

Mooney Scorch Time at 135X (J ₅ )

(min)

No addition (comparison) 20.1

N-Cyclohexylthio-p-toluenesulfonamide 23.6

N-Cyclohexylthio-N-methylbenzoisulphamide 24.6

N-Cyclohexylthio-N-benzylbenzenesulfonamide 22.1

N-phenylthiobenzenesulfonanilide 22.1

N-Cyclohexylthiobenzenesulfonanilide 27.7

N-p -nitrophenylthio-N-methylmethanesulfonamide 22.7

Claims (1)

Patent claims: 1. Vulcanizable mixture with improved resistance to premature vulcanization, from a vulcanizable diene rubber, a sulfur vulcanizing agent, an organic one Vulcanization accelerator and an effective amount of a vulcanization inhibitor, thereby characterized in that it is a compound of the general formula as a vulcanization inhibitor (R- ^ SO ₂ N (R ¹ ) - contains where π I, 2 or 3 and n ' 1, 2, 3 or 4 with the proviso that η and n 'are not simultaneously greater than 1; and R ² - if π 'has the value 1, is monovalent and is a phenyl, naphthyl or biphenylyl group, an aryl group substituted by low molecular weight alkyl groups, halogen atoms, low molecular weight alkoxy groups or combinations thereof, or - if η has the value 1 and R stands for a low molecular weight alkyl group, nitro group, an alkyl group with 1 to 20 carbon atoms, a phenyl-substituted low molecular weight alkyl group, an unsubstituted mono- or bicycloalkyl group with 5 to 12 ring members or a mono- or bicycloalkyl group substituted with low molecular weight alkyl groups with 5 up to 12 ring members and fused bicyclic phenyl rings and a non-aromatic hydrocarbon ring, or - if n 'has the value 2, is bivalent, 1 to 12 carbon atoms and an alkylene group, arylene group, cycloalkylene group or a group of the formula Lower alkylene = [00qCH ₂ -) "] ₂ in which /? "stands for 1 or 2, or - if n 'has the value 3, a group of the formula Lower alkyl C [CH ₂ OOC (CH ₂ -) _n .] ₃ in which π "stands for 1 or 2, or - if n 'has the value 4, a group of the formula C [CH ₂ OOC (CH ₂ Vh indern "stands for 1 or 2,
means; R ¹ independently represents a monovalent group R ² , hydrogen atom or a group formula -ANSO ₂ R ⁴ R ¹ represents in the R ^{4 is} a monovalent group R ² , A is a divalent group R ² and 55