Reaction product of 4,4-bis-(hydroxymethyl)-cyclohexene compounds with sulfur

There are prepared reaction products of (a) 4,4-bis(hydroxymethyl)-cyclohexene compounds of the formula ##STR1## where R.sup.1, R.sup.2 and R.sup.4 are the same or different and are hydrogen, methyl or phenyl and there is also present either (1) X as the bridging member methylene or ethylene or (2) X is absent and there are present both R.sup.3 and R.sup.5 wherein R.sup.3 and R.sup.5 are the same or different and are hydrogen, methyl or phenyl with (b) sulfur. The compounds are useful in cross-linking vulcanizable elastomers.

The invention is directed to reaction products. 
There are prepared reaction products of (a) 
4,4-bis-(hydroxymethyl)-cyclohexene compounds of the formula 
##STR2## 
in which R.sup.1, R.sup.2 and R.sup.4 are the same or different and 
represent hydrogen, methyl or phenyl and there is also present either (1) 
X as the bridging member representing methylene or ethylene of (2) X is 
absent and there are present both R.sup.3 and R.sup.5 whereby R.sup.3 and 
R.sup.5 are the same or different and represent hydrogen, methyl or phenyl 
with (b) sulfur. The exact structure of the compounds of the invention is 
not known. 
The starting compounds employed in the invention for reaction with sulfur 
can also be expressed by the following two formulae: 
##STR3## 
The starting compounds of formula I which also can be designated geminal 
dimethylol compounds or as alcohols for the greatest part are known. They 
can be produced from the corresponding .DELTA.3 unsaturated aldehydes and 
formaldehyde according to the Cannizzaro reaction employing alkalis. The 
unsaturated aldehydes are obtained according to the Diels-Alder reaction 
from a diene and an unsaturated aldehyde. Examples of dienes (always 
conjugated) are butadiene-1,3, pentadiene-1,3, 2-methylbutadiene, 
2,3-dimethyl butadiene, 2-methyl pentadiene-1,3, trimethyl butadiene 
(1,2,3-trimethyl butadiene-1,3), tetramethyl butadiene (3,4-dimethyl 
hexadiene-2,4), 1-phenyl butadiene, hexadiene-2,4, cyclopentadiene, 
cyclohexadiene, 1-methyl cyclohexadiene, etc. As aldehydes there can be 
used for example acrolein, crotonaldehyde and cinnamaldehyde. 
Examples of compounds within formula I are 
4,4-bis-(hydroxymethyl)-cyclohexene, 
3,6-methano-4,4-bis-(hydroxymethyl)-cyclohexene 
(4,4-bis-(hydroxymethyl)-bicyclo [2,1,2]-heptene-1), 
3,6-ethano-4,4-bis(hydroxymethyl) cyclohexene, 
1-methyl-3,6-methano-4,4-bis-(hydroxymethyl)-cyclohexene, 
1-methyl-4,4-bis-(hydroxymethyl) cyclohexene, 
4,4-bis-(hydroxymethyl)-5-methylcyclohexene, 
2-methyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
3-methyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
6-methyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
4,4-bis-(hydroxymethyl)-5-phenyl cyclohexene, 
1,2,5-trimethyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
1,2,3,4-tetramethyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
1,2,3,4,5-pentamethyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
3,5-diphenyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
3-phenyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
3-phenyl-5-methyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
1-methyl-5-phenyl-4,4-bis-(hydroxymethyl)-cyclohexene. 
The reaction of the above named dimethylol compounds within formula I with 
sulfur can take place in the presence or absence of inert organic 
solvents. Preferably, however, the reaction is carried out in the absence 
of a solvent. 
The reaction temperature is adjusted according to whether the operation is 
carried out in a solvent or without a solvent. In the direct reaction 
without a solvent it is necessary to use temperatures above 100.degree. C. 
Preferably the reaction temperature is between 120.degree. and 160.degree. 
C. The upper temperature can be about 200.degree. C. or in a given case 
somewhat higher. 
When a solvent is employed the same temperatures can be employed or even 
somewhat lower temperatures, e.g. 80.degree. C. A convenient temperature 
is the reflux temperature for the solvent. Typical inert solvents include 
aromatic hydrocarbons such as benzene, toluene and xylene. Other suitable 
solvents include chlorobenzene, naphthalene, alkyl(C.sub.1 -C.sub.5) 
substituted naphthalenes, cumene, anisole and other phenolic ethers. 
In the reaction the sulfur attacks the double bond of the cyclohexene ring. 
Thereby there are formed mono and polysulfides of a highly complex 
structure. According to the amount of sulfur added there are formed 
compounds with different sulfur contents. Accordingly, the ratio of diol 
to sulfur can be varied within quite wide ranges, for example, molar 
ratios between about 1:0.1 and 1:20. Preferably the molar ratio of diol to 
sulfur is in the range from 1:1 and 1:8. Depending upon the amount of 
sulfur taken up the reaction products formed are highly viscous oils, some 
of which solidifying when cold up to oligomers with properties similar to 
rosin. 
The course of the reaction of the dimethylol compounds with the sulfur 
according to the invention can be followed by IR-measurements. Thus, for 
example, it is possible in the case of sulfurization of 
4,4-bis-(hydroxymethyl)-cyclohexene to evaluate the ratio of the maximum 
absorbance values of the olefinic and cycloaliphatic CH-stretching 
vibrational bands at 3015 and 2920 cm.sup.-1 and also the ratio of the 
maximum absorbance values of the --C=C-- band at 1650 cm.sup.-1 and of the 
--CH.sub.2 -- deformation vibrational band at 1440 cm.sup.-1. In the NMR 
spectrum (NMR is magnetic nuclear resonance) in analogous manner the ratio 
of the area of the =CH-- signal to the area of the --CH-- plus --CH.sub.2 
-- signals is a corresponding measure. 
In can be assumed that in the reaction there are formed primarily 
polysulfides of the alkyl alkenyl polysulfides type which then can be 
split up in secondary reactions into a number of sulfurization products. 
Indications in support of this explanation of the reaction may be found, 
for example, in the book, "Chemistry and Physics of Rubber-like 
Substances" by L. Bateman, published in 1973 by Maclaren and Sons Ltd., 
pages 449 et seq. Attention is also directed to "Mechanism of Sulfur 
Reactions" by William A. Pryor, McGraw-Hill Book Company, Inc. (1962) 
Chapter 5, "The reactions of Sulfur with Olefins to Produce Organic 
Sulfides and Polysulfides." Further references include "The Chemistry of 
Organic Sulphur Compounds" by Normal Kharasch and Cal Y. Meyers, Volume 1, 
chapter 20, "Reactions of Sulphur With Olefins" by L. Bateman and C. G. 
Moore pages 210 to 228; R. T. Armstrong, J. R. Little and K. W. Doak, 
Industrial and Engineering Chemistry, Volume 36, pages 628-633 (1944); M. 
L. Selker and A. R. Kemp, Industrial and Engineering Chemistry Volume 39, 
pages 895 et seq. (1947); E. H. Farmer and F. W. Shipley, J. Chem. Soc. 
(London) pages 1519-1532 (1947); A. S. Brown, M. G. Voronkov and K. P. 
Kashkova, Zh. Obshcher Khim (Russian), Volume 20, pages 726 et seq. 
(1950). 
Unless otherwise indicated all parts and percentages are by weight. 
Examples of the reaction according to the invention include 
1. Sulfurization of 4,4-bis-(hydroxymethyl)-cyclohexene in the molar ratio 
of alcohol to sulfur of 1:2. 
There is melted in a 10 liter flask equipped with a stirrer and placed in 
an oil bath 6 kg of 4,4-bis-(hydroxymethyl)-cyclohexene and the material 
heated to 130.degree. to 135.degree. C. At this temperature there is 
introduced into the melt within about 3 hours 2.7 kg of sulfur powder. The 
reaction is initially slightly exothermic. The course of the reaction is 
followed by IR analysis. After a further 60 minutes the temperature is 
increased to 145.degree. to 150.degree. C. After a total of 8 hours of 
reaction the sulfurization was complete. 
The at first viscous, dark brown oil formed is poured on a plate and 
allowed to solidify in the air. The solidified mass can be broken, 
comminuted or ground for further use. There were obtained 8.61 kg of 
reaction product with a sulfur content of 31 weight percent. The brown 
powder upon heating to about 50.degree. C. becomes plastic and melts at 
about 95.degree. C. 
The same cyclohexene starting product can be reacted in an analogous way 
with sulfur for example in the molar ratios of 1:1, 1:1.5, 1:3, 1:6, 1:8, 
1:10; 1:20, etc. Thereby the reaction time can be varied, for example it 
can be increased. 
2. Reaction of 4,4-bis-(hydroxymethyl)-cyclohexene with sulfur in the molar 
ratio of 1:8. 
There were heated to 135.degree. C. as described in example 1 above 142 
grams of 4,4-bis-(hydroxymethyl)-cyclohexene and then there were 
introduced with stirring a total of 256 grams of sulfur in powder form 
within 8 hours. Then the melt was heated for 16 more hours at 145.degree. 
to 150.degree. C. 
The at first highly viscous reaction product was poured in a dish and 
allowed to solidify to a stone hard mass. There was obtained the reaction 
product in an amount of 381.5 grams and it had a sulfur content of 65.2%. 
The dark brown powder melted at about 110.degree. C. 
3. Reaction of 4,4-bis-(hydroxymethyl)-cyclohexene with sulfur in the mole 
ratio of 1:4 in xylene. 
There were provided in a 2-liter round-bottomed flask equipped with a 
reflux condenser 1 liter of xylene and 142 grams of 
4,4-bis-(hydroxymethyl)-cyclohexene, 128 grams of sulfur in powder form 
and 2 ml of tributylamine. The mixture was boiled under reflux for 12 
hours and subsequently evaporated in a vacuum, terminal conditions being 
100.degree. C. and a pressure of 12 mm Hg. There were obtained 269.5 grams 
of a dark brown oil, which solidified in the cold, and according to the 
analysis contained 47.1 weight percent sulfur. 
4. Reaction of 3,6-Methano-4,4-bis-(hydroxymethyl)-cyclohexene 
[4,4-bis-(hydroxymethyl)-bicyclo [2,1,2]-heptene-1] having a melting point 
of 111.degree. to 114.degree. C. with sulfur in the mole ratio of 1:4. 
154 grams of the geminal diol were melted in a 500 ml round-bottomed flask 
and heated to 130.degree. C. With stirring there were added 128 grams of 
sulfur within 6 hours and the mixture subsequently heated a further 20 
hours to 145.degree. to 150.degree. C., the reaction product was 
subsequently poured into a mortar and pulverized. There was obtained a 
brown powder in an amount of 271 grams with a melting point of about 
95.degree. to 100.degree. C. and a sulfur content of 45.5 weight %. In an 
analogous reaction there was also recovered the reaction product of 1 mole 
of cyclohexene with 8 moles of sulfur. Differences between the starting 
material and reaction product were observed in the IR-spectrum. 
In place of the 3,6-methano compound there can also be employed 
3,6-ethano-4,4-bis-(hydroxymethyl)-cyclohexene and reacted with sulfur in 
an analogous way in the desired mole ratio. 
5. Reaction of 1-methyl-4,4-bis-(hydroxymethyl)-cyclohexene with sulfur in 
the mole ratio of 1:1. 
There were melted 78 grams of 1-methyl-4,4-bis-(hydroxymethyl)-cyclohexene 
in a round bottomed flask and there were introduced into the melt with 
stirring at about 130.degree. C. within 3 hours, 16 grams of sulfur. After 
heating for five hours at 140.degree. to 145.degree. C. the double bond in 
the cyclohexene ring had disappeared as shown by IR measurement. There was 
obtained a viscous resin having an amber-like appearance in an amount of 
82 grams. The analysis showed a sulfur content of 17 weight percent. 
6. Reaction of 4,4-bis-(hydroxymethyl)-cyclohexene with sulfur in the mole 
ratio of 1:6. 
There were mixed 156 grams of 4,4-bis-(hydroxymethyl)-5-methyl-cyclohexene 
with 192 grams of sulfur and 1 gram of tributylamine and the mixture was 
then heated with stirring for 18 hours at 140.degree. to 150.degree. C. 
There was obtained a dark brown melt which solidified below 100.degree. C. 
in an amount of 341 grams. The sulfur analysis was 54.1 weight percent. 
In the same manner there can also be reacted with sulfur 
2-methyl-4,4-bis-(hydroxymethyl)-cyclohexene, 
3-methyl-4,4-bis-(hydroxymethyl)-cyclohexene and 
4,4-bis-hydroxymethyl)-6-methyl-cyclohexene. 
7. Reaction of 4,4-bis-(hydroxymethyl)-5-phenyl-cyclohexene with sulfur in 
the mole ratio of 1:3. 
218 grams of 4,4-bis-(hydroxymethyl)-5-phenylcyclohexene and 96 grams of 
sulfur were stirred and heated for 16 hours at 140.degree.-145.degree. C. 
The dark brown melt solidified at about 75.degree. C. The amount of product 
was 306.5 grams and contained 30.1 weight percent of sulfur. 
8. Reaction of 1,2,5-trimethyl-4,4-bis-(hydroxymethyl)-cyclohexene with 
sulfur in the mole ratio of 1:5. 
184 grams of 1,2,5-trimethyl-4,4-bis-(hydroxymethyl)-cyclohexene were 
heated with stirring to about 135.degree. C. With further stirring there 
were added within 4 hours at the same temperature 120 grams of sulfur and 
stirring continued for another 12 hours at this temperature. 
The working up of the reaction product produced 298.5 grams of a brown 
product which solidified at about 70.degree. C. The analysis showed a 
sulfur content of 39.5 weight percent. 
The reaction products of the invention have a different sulfur content 
depending on the amount of sulfur added in relation to the amount of 
alcohol. However, the individual products are produced reproducibly, 
especially in checking the course of the reaction by IR analysis, which 
also can be gathered from the combustion analysis. 
The new reaction products can, as has been unexpectedly proven, be used 
with outstanding success as reinforcing additives in the rubber processing 
industry with both natural and synthetic rubbers containing light fillers 
such as, for example, silica. 
With these types of rubber mixtures there is the industrial problem that 
under the influence of light reinforcing fillers the viscosity of the raw 
mixtures can be very high and therewith there is increased difficulty in 
working the mixtures during the processes of production. This increase in 
viscosity is related to the amount and activity of the filler. The more 
active the fillers the higher is the viscosity of the mixtures and 
therewith the more difficult the workability. 
There is already known an entire series of additives in the industry which 
have as the object the reduction of the viscosity of the raw mixtures. For 
this purpose these have been added for example glycol, hexanetriol, 
polywaxes and other compounds. A serious disadvantage of these compounds 
is that in order to cause a noticeable reduction in viscosity they must be 
added in large amounts. However, this has the consequence that the 
industrial properties of the mixtures produced with the addition of these 
components of the mixture and the vulcanizates produced become impaired. 
This is especially noticeable in the reduction of the stress values at 
300% elongation (300 Modulus), an important property for the industrial 
characterization of vulcanizates. 
The reaction products of the invention have proved themselves as 
reinforcing additives and especially possess the properties of strongly 
reducing the viscosity of the unvulcanized mixtures. With help of the new 
reinforcing additives there are even workable those mixtures which contain 
for example a highly active silica with an average primary particle size 
of 18 nm (nanometers) and a surface area of 210 m.sup.2 /g measured 
according to the known BET-method (Ultrasil .RTM. VN 3 of Degussa), even 
in large amounts, for example more than 50 parts by weight per 100 parts 
by weight of elastomer. 
In comparison to the previously employed additives for reduction of the 
viscosity the new reinforcing additives have no negative influence on the 
level of properties of the vulcanizate. Unexpectedly the addition of the 
new reinforcing additives improves tensile strength modulus, Shore 
hardness, elasticity and abrasion resistance of the vulcanizates. 
It is further surprising that the hydrophilic properties of the vulcanizate 
which are already present through addition of the light reinforcing filler 
are considerably increased by the addition of the new reinforcing 
additive, which for example makes itself known in wet skid resistance and 
the favorable behavior on ice of treads as well as of vehicle tires. 
There are included in the light or white fillers usable in elastomer 
mixtures with the reaction products of the invention the following: 
Silicas of every activity and fillers containing predominant amounts of 
silica, in amounts of 1 to 500 parts by weight, preferably 40 to 250 parts 
by weight, based on 100 parts by weight of the elastomer, silicates of 
every activity (e.g. aluminum silicate or alkaline earth silicates such as 
magnesium silicate and calcium silicate) in amounts of 1 to 1000 parts by 
weight, preferably 10 to 500 parts by weight based on 100 parts by weight 
of the elastomer, silicatic products such as for example glass fibers and 
glass fiber products, for example, webs, mats, strands, fabrics, non-woven 
fabrics and the like as well as glass microspheres (microballoons). 
In the named silicas there are especially considered finely divided, very 
pure silica with specific surface areas in the range of about 5 to 1000, 
preferably 20 to 400 m.sup.2 /g, determined with gaseous nitrogen 
according to the known BET method and with average primary particle sizes 
of about 10 to 400 nm, which can be produced for example by precipitation 
from solutions of silicates, by hydrolytic and/or oxidative high 
temperature reaction (also called flame hydrolysis), from volatile 
silicon-halides, e.g., silicon tetrachloride, or by an electric arc 
process. These silicas in a given case can also be present as mixed oxides 
or oxide mixtures with oxides of the metals aluminum, magnesium, calcium 
or zinc. 
In the named silicates there are included both natural and synthetic 
silicates, especially silicates of magnesium, calcium and/or aluminum as 
fillers which contain these components in predominant amount. Among the 
natural silicates are included for example Kaolin and natural silicas. The 
synthetic silicates such as aluminum, magnesium or calcium silicate have 
specific surface areas of about 20 to 400 m.sup.2 /g and primary particle 
sizes of about 10 to 400 nm. 
Light reinforcing fillers also include finely divided oxides of aluminum 
and titanium as well as their mixed oxides as well as their mixed products 
with silicates and/or silicas, which fillers are added in amounts of 1 to 
1000, preferably 10 to 500 parts by weight based on 100 parts by weight of 
the elastomers. 
Among the light or white fillers which are known and used in the rubber 
processing industry are also included chalks, modified calcium carbonates, 
siliceous chalks, barite, lithopone and the like, which likewise are used 
in amounts of 1 to 1000 parts by weight preferably 10 to 800 parts by 
weight based on 100 parts by weight of the elastomers. 
The above named light fillers can be used individually or several can be 
used together in the elastomer mixtures. Additionally carbon black can be 
added, especially the known rubber carbon blacks, namely in amounts of 
0.05 to 50 parts by weight based on 100 parts by weight of the elastomer. 
Typical examples of light reinforcing fillers usable in the invention are 
for example silicas or silicates with the trademarks Aerosil, Ultrasil, 
Silteg, Durosil, Extrusil and Calsil made and sold by Degussa. 
Furthermore there can be added to the rubber mixtures various additives 
that are used in the rubber industry and further described below. 
There are several advantages in not adding the reinforcing additive as such 
to the rubber mixture but instead first preparing a mixture of at least 
one filler and at least one of the reaction products of the invention and 
then, or still later, mixing this mixture with the remaining constituents 
of the rubber mixture in the usual way and with the help of known mixing 
apparatus until homogeneous distribution occurs. 
The new reaction products (reinforcing additives) of the invention can be 
added individually or as mixtures of several of them into the elastomer 
mixtures in amounts of 0.05 to 100 parts by weight, preferably in the 
range between 0.5 and 25 parts by weight based on 100 parts by weight of 
the elastomer. 
As the elastomer there can be used especially those which can be 
cross-linked with sulfur or peroxides. Thus there can be used one or more 
natural or synthetic rubbers in admixture, in a given case oil extended 
rubber, especially diene elastomers such as natural rubber polybutadiene, 
polyisoprene, e.g., cis-polyisoprene, butadiene styrene copolymer, 
butadiene-acrylonitrile copolymer, butadiene vinyl pyridine copolymer, 
polymerized 2-chlorobutadiene, carboxyl rubber, transpolypenteneamer, 
butyl rubber, halogenated butyl rubber such as chlorinated butyl rubber 
and brominated butyl rubber as well as other known diene rubbers as for 
example terpolymers of ethylene, propylene and for example non-congugated 
polyenes, e.g. ethylene-propylenecyclooctadiene, 
ethylene-propylene-norbornadiene, ethylene-propylene-dicyclopentadiene and 
ethylene-propylene-cyclododecatriene. 
The mixtures of elastomers, rubber, the cross-linking system, the light 
fillers and the sulfur-containing reaction products of the invention can 
also include in a given case known vulcanization accelerators as well as 
in a given case one or more compounds of the group of anti-agers, heat 
stabilizers, light stabilizers, ozone stabilizers, processing aids, 
plasticizers, adhesive agents, foaming agents, dyes, pigments, waxes, 
extenders, as for example, sawdust, organic acids as for example stearic 
acid, benzoic acid or salicylic acid, additionally lead oxide or zinc 
oxide, activators as for example triethanolamine, polyethylene glycol or 
hexanetriol which collectively are known in the rubber industry and rubber 
art. For the cross-linking or vulcanization there are generally mixed into 
the mixtures cross-linking agents as especially peroxides, sulfur or in 
special cases magnesium oxide. 
According to the height of the sulfur content of the reaction products of 
the invention the customary amount of sulfur required for the 
vulcanization can be reduced. It is suitable and in most cases associated 
with advantages to carry out the vulcanization with addition of very small 
amounts of sulfur because the addition of lower amounts of sulfur 
favorably influences the vulcanization characteristics. Low amounts of 
sulfur means in this case about 0.2 to 0.5 parts by weight of sulfur per 
100 parts by weight ot the elastomers. Higher or lower amounts of sulfur 
are not excluded. 
It can be of especial advantage for the vulcanization and the properties of 
the vulcanizate if there are used as the vulcanization accelerator one or 
more triazine compounds containing sulfur in their molecule as set forth 
in German Pat. No. 1,669,954 and Westlinning U.S. Pat. No. 3,801,537. The 
entire disclosure of the Westlinning U.S. Patent is hereby incorporated by 
reference and relied upon. Thus there can be used, for example, 
2-ethylamino-4-diethylamino-6-mercaptotriazine, 
2-ethylamino-4-isopropylamino-6-mercapto-triazine and/or 
bis-(2-ethylamino-4-diethylamino-triazin-6-yl)-disulfide or any of the 
other triazines shown in Westlinning, for example those set forth in the 
table on columns 5-6, lines 3-33 and also column 5, lines 34 to column 8, 
line 50. Thus the triazines can have the formula 
##STR4## 
wherein R.sup.1 and R.sup.3 are each selected from the group consisting of 
hydrogen, alkyl, alkenyl, cycloalkyl, phenyl, aralkyl and substituted 
alkyl, alkenyl, cycloalkyl, phenyl and, aralkyl wherein the substituents 
are selected from the group consisting of --OH, --OR and --CN, R being 
alkyl with up to 18 carbon atoms, R.sup.2 and R.sup.4 are each selected 
from the group consisting of hydrogen, alkyl, alkenyl, cycloalkyl, phenyl, 
aralkyl and substituted alkyl, alkenyl, cycloalkyl, phenyl and aralkyl 
wherein the substituents are selected from the group consisting of --OH, 
--OR and --CN, R being alkyl with up to 18 carbon atoms, X is selected 
from the group consisting of (a) hydrogen, 
##STR5## 
R.sup.6 being selected from the group consisting of hydrogen, alkyl, 
aralkyl and cycloalkyl and R.sup.7 being selected from the group 
consisting of alkyl, aralkyl and cycloalkyl and wherein R.sup.6 and 
R.sup.7 together may also form a cycloaliphatic ring having from 5 to 7 
carbon atoms in the ring and from 5 to 10 carbon atoms, including lower 
alkyl, attached to the ring or wherein R.sup.6 and R.sup.7 may be linked 
by a member of the group consisting of --O--, --S-- and 
##STR6## 
and wherein the number of carbon atoms in R.sup.1, R.sup.2, R.sup.3, 
R.sup.4, R.sup.6 and R.sup.7 is as follows: 
alkyl: up to 18 carbon atoms 
alkenyl: up to 6 carbon atoms 
cycloalkyl: from 5 to 7 carbon atoms 
aralkyl: from 7 to 9 carbon atoms. 
Also in a given case one or more known vulcanization accelerators can be 
used in addition in the elastomer mixture. 
As has furthermore been found the use of the reaction products of the 
invention can be advantageously combined with the addition of specific 
sulfur containing silanes which are described in Belgian Pat. No. 787,691 
and Meyer-Simon U.S. Pat. No. 3,842,111. The entire disclosure of 
Meyer-Simon is incorporated by reference and relied upon. This combined 
use of two very different reinforcing additives is of especial advantage 
for example in the production of tread strips for vehicle tires. Such 
silanes include for example bis-(3-triethoxysilylpropyl)-trisulfide, 
bis-(3-triethoxysilylpropyl)-tetrasulfide, 
bis-(3-trimethoxysilylpropyl)-trisulfide, 
bis-(3-trimethoxysilylpropyl)-tetrasulfide, bis-(3-diethoxy 
ethylsilylpropyl)-trisulfide, bis-(3-diethoxy 
ethylsilylpropyl)-tetrasulfide or any of the other silanes shown in 
Meyer-Simon, for example those set forth on column 2, line 56 to column 3, 
line 39. Thus the silanes can have the formula Z-alk-S.sub.n -alk-Z in 
which Z is: 
##STR7## 
and in which R.sub.1 is an alkyl group of 1 to 4 carbon atoms or phenyl 
and R.sub.2 is an alkoxy group with 1 to 8, preferably 1 to 4, carbon 
atoms, a cycloalkoxy group with 5 to 8 carbon atoms or a straight or 
branched chain alkyl-mercapto group with 1 to 8 carbon atoms. All the 
R.sub.1 and R.sub.2 groups can be the same or different. Alk is a divalent 
hydrocarbon group with 1 to 18 carbon atoms. It can be straight or 
branched chain and can be a saturated aliphatic hydrocarbon group, an 
unsaturated aliphatic hydrocarbon group or a cyclic hydrocarbon group. 
Preferably alk has 1 to 6, most preferably 2 to 3 carbon atoms and n is a 
number of 2 to 6, especially 2 to 4, most preferably 3 to 4. Mixtures of 
the silanes can be used. 
In industrial rubber processing it is more and more preferred to order from 
manufacturers already premixed constituents of the later rubber mixtures. 
The objects of the invention therefore also include the preparation of the 
following mixtures or premixtures and their use in the production of 
cross-linkable elastomer mixtures. 
A mixture consisting of at least one of the reaction products of the 
invention and at least one light filler used in the rubber processing 
industry wherein the weight ratio of the both constituents of the mixture 
is in the range of for example 3:1 to 1:3 can be used for example. 
Mixtures consist of at least one of the reaction products of the invention, 
at least one light filler used in the rubber processing industry and at 
least one elastomer of the group of natural and synthetic rubbers 
vulcanizable with sulfur. 
Industrial areas of use for the described elastomer mixtures are for 
example, vehicle tires, especially automobile tires, including special 
cross-country tires, and airplane tires, namely both for the foundation 
(carcass), the belt and the tread surface (tread strip) of the tires; 
additionally industrial rubber articles as for example cable jackets, 
hoses, transmission belts, V-belts, conveyor belts, roll covers, sealing 
rings, cushioning elements and many more; additionally sole materials for 
shoes. The new elastomer mixtures have also been found suitable for glass 
fiber adhesive mixtures and the like. 
Unless otherwise indicated all parts and percentages are by weight. 
The quality improving effect of the reaction products of the invention are 
illustrated in the following examples.

EXAMPLE I 
To a base mixture of the following composition 
______________________________________ 
Amount in parts 
Constituent by weight 
______________________________________ 
styrene-butadiene rubber (SBR 1500) 
100 
finely divided precipitated silica 
(Ultrasil VN 3 of Degussa) 
50 
zinc oxide (red seal quality) 
3 
stearic acid 1 
N-cyclohexyl-2-benzothiazole- 
sulfenamide 1 
diphenyl guanidine 1.5 
sulfur 2 
______________________________________ 
there were added the following reaction products of the invention by mixing 
with the filler. Each time there was used 10 parts by weight of the 
compound of the invention, 
a 1. Reaction product prepared by Example 1, 
a 2. Reaction product prepared by Example 3, 
a 3. Reaction product prepared by Example 2, 
b 1. Reaction product of 3,6-methano-4,4-bis(hydroxymethyl)-cyclohexene 
with sulfur in the mole ratio of 1:1.78 having 25 weight percent sulfur, 
b 2. Reaction product of 3,6-methano-4,4-bis(hydroxymethyl)-cyclohexene 
with sulfur in the mole ratio of 1:1 with 17.2 weight percent sulfur, 
b 3. Reaction product of the same starting materials as in b(1) but in the 
mole ratio of 1:2 with a sulfur content of 29.4%, 
b 4. Reaction product prepared by example 4, 
c 1. Reaction product prepared by Example 5, 
c. 2. Starting materials as in c(1) but in the mole ratio of 1:2 with a 
sulfur content of 28.8 weight percent, 
c 3. Starting materials as in c(1) but in the mole ratio of 1:4 with a 
sulfur content of 45.0 weight percent, 
d 1. Reaction product of 2-methyl-4,4-bis-(hydroxymethyl) cyclohexene with 
sulfur in the mole ratio of 1:2 with a sulfur content of 26.0 weight 
percent. 
The viscosity lowering effect of the reinforcing additive is plainly 
evident from the following Table 1. By the addition of 10 parts of the 
reinforcing additive the Mooney viscosity falls about 100 units and 
therewith into the viscosity range which is customary for furnace black 
filled vulcanizates. 
Simultaneously, as is evident from following Table 2, the physical 
properties of the vulcanizate are changed favorably. Thus the tensile 
strength increase, the modulus level becomes increased depending on the 
structure of the gem dimethylol compound which is treated with sulfur and 
the sulfur content of the reaction product, likewise the Shore hardness is 
increased. The elongation at break behavior is inverse to the moduli and 
the rebound values (impact resilience) decrease, according to the 
increased filler activity. It is also clearly evident from Table 2 that 
the DIN (German Industrial Standard) abrasion is improved. 
TABLE 1 
______________________________________ 
Mixture Containing Reaction 
Mooney Viscosity, 
Product According to 
ML 4 
______________________________________ 
a (1) 91 
a (2) 92 
a (3) 92 
b (1) 91 
b (2) 95 
b (3) 90 
b (4) 89 
c (1) 84 
c (2) 88 
c (3) 92 
d (1) 82 
No additive 182 
______________________________________ 
TABLE 2 
__________________________________________________________________________ 
In kp/cm 
Heating 
Tensile 
Modulus 
Elongation Shore- 
Tear 
Reaction Product 
Time Strength 
300 in 
At Break 
Rebound 
A- Propagation 
Abrasion 
Containing Mixture 
in Minutes 
in kp/cm.sup.2 
kp/cm.sup.2 
in % in % Hardness 
Resistance 
in mm.sup.3 
__________________________________________________________________________ 
No mixing 60 197 39 665 34 76 18 170 
a (1) 60 238 65 625 28 77 17 150 
a (2) 55 198 111 443 26 79 11 131 
a (3) 60 234 129 480 26 82 9 142 
b (1) 45 224 52 643 27 86 20 150 
b (2) 40 196 41 655 28 75 20 148 
b (3) 50 208 66 573 29 76 14 135 
b (4) 60 239 96 503 29 77 10 139 
c (1) 45 237 47 673 28 70 19 135 
c (2) 45 258 67 640 29 72 17 130 
c (3) 60 256 99 535 28 76 13 122 
d (1) 60 233 58 610 27 72 14 134 
__________________________________________________________________________ 
EXAMPLE II 
In a base mixture of the following composition 
______________________________________ 
Amount in Parts 
Constituent by Weight 
______________________________________ 
natural rubber (ribbed smoked 
sheets No. 1 of a Defo 
hardness of 800) 100 
finely divided, precipitated 
pure silica (Ultrasil 
VN 3 of Degussa) 50 
zinc oxide (red seal quality) 
3 
stearic acid 2 
N-cyclohexyl-2-benzothiazole- 
sulfenamide 0.8 
diphenyl guanidine 1.5 
sulfur 2.5 
______________________________________ 
there were again added each time 10 parts by weight of the named reaction 
products of the invention, namely by admixture with the filler (silica). 
From Table 3 belonging to Example II it can be seen how the properties of 
natural rubber vulcanizates can be influenced with the help of the 
reinforcing additives of the invention. As in styrene-butadiene rubber 
(SBR 1500) also in natural rubber the tensile strength increases around 30 
to 50 kp/cm.sup.2, the modulus at 300% increases above all depending on 
the sulfur content of the reaction product, the elongation at break is 
influenced to a relatively minor extent, on the contrary the elasticity of 
the vulcanizate is significantly lowered according to the increased filler 
activity. The Shore hardness and tear propagation resistance are generally 
increased, and the DIN abrasion is strongly reduced. 
TABLE 3 
__________________________________________________________________________ 
In kp/cm 
Heating 
Tensile 
Modulus 
Elongation Shore 
Tear 
Reaction Product 
Time Strength 
300 in 
At Break 
Rebound 
A- Propagation 
Abrasion 
Containing Mixture 
in Minutes 
in kp/cm.sup.2 
kp/cm.sup.2 
in % in % Hardness 
Resistance 
in mm.sup.3 
__________________________________________________________________________ 
No mixing 80 213 41 670 44 70 47 241 
a (1) 40 244 55 665 32 79 58 195 
a (2) 45 243 72 630 34 81 42 142 
a (3) 40 244 95 550 37 75 59 153 
b (1) 40 260 57 680 32 77 54 196 
b (2) 40 254 58 670 34 76 45 218 
b (3) 45 259 68 630 34 76 52 206 
b (4) 45 254 80 600 34 79 33 174 
c (1) 26 267 54 675 29 67 57 184 
c (2) 30 257 62 645 31 72 59 204 
c (3) 30 248 72 615 32 78 58 180 
d (1) 30 247 58 645 30 69 52 155 
__________________________________________________________________________ 
EXAMPLE III 
Three mixtures are used in this example. Mixture 1 is a conventional rubber 
mixture for the production of treads (tread strips) for automobile tires. 
It contained the reinforcing black N339. 
Mixture 2 contains the reinforcing additive of the invention made in 
Example 2. With the help of this reinforcing additive Mixture 2 was so 
made up that the vulcanizate from Mixture 2 reached the same modulus level 
as the vulcanizate from Mixture 1. Mixture 2 according to the invention 
contained no carbon black but as a light filler an active, precipitated 
silica. 
The Mixture 3 contained as a comparison mixture to Mixture 2 no additive of 
the invention (omission of the reinforcing additive). The three mixtures 
had the following compositions: 
______________________________________ 
Mixture 
Constituent (in parts by weight) 
1 2 3 
______________________________________ 
styrene-butadiene rubber 
(SBR 1712) 137.5 137.5 137.5 
carbon black N339 80 -- -- 
finely divided, precipitated 
silica (Ultrasil VN 3 of Degussa) 
-- 80 80 
reaction product of Example 2 
-- 6 -- 
zinc oxide 4 4 4 
stearic acid 1.2 1.2 1.2 
phenyl-B-naphthylamine 
1.5 1.5 1.5 
N-isopropyl-N'-phenyl-p- 
phenylenediamine 1.5 1.5 1.5 
N-tert.,butyl-2-benzothiazyl 
sulfenamide 1.2 -- -- 
2-ethylamino-4-diethylamino- 
6-mercapto-s-triazine 
-- 2.0 2.0 
sulfur 1.4 0.5 0.5 
______________________________________ 
First the corresponding premixtures 1 to 3 which did not contain sulfur or 
an accelerator were produced at a flow temperature of 80.degree. C. in an 
internal mixer (Type GK2 of Werner and Pfleiderer, Stuttgart-Feuerbach) 
according to the "Upsidedown Process." 
The final mixtures were also produced after a 24-hour intermediate storage 
in a kneader (internal mixer) at a flow temperature of 80.degree. C. 
The vulcanization took place at 160.degree. C. for a period of 40 minutes. 
The measured properties of the vulcanizate are given in the following Table 
4. 
TABLE 4 
______________________________________ 
Mixture 
1 2 3 
______________________________________ 
Tensile strength (measured 
according to DIN 53504) 
204 198 11 
Modulus 300 (according to DIN 
53504) 104 98 7 
Elongation at break (according 
to DIN 53504) 470 490 1100 
Tear Propagation resistance 
(according to DIN 53507) 
9 17 16 
Rebound 
(according to DIN 
53512) 23 29 31 
Shore A-Hardness (according 
to DIN 53504) 64 73 68 
______________________________________ 
From Table 4 it is clear that at the same modulus level of mixtures 1 and 
2, the Mixture 2 has the higher tear strength, the higher Shore A hardness 
and the higher elasticity. 
It is worthy of note that the comparison Mixture 3 whose Mooney viscosity 
is clearly higher than that of Mixtures 1 and 2 results in a vulcanizate 
which in no way satisfies the requirements for tensile strength and 
modulus. 
EXAMPLES IV and V 
These examples show the utility of the new reinforcing additive in polymer 
blends wherein in Example IV there is used a blend of natural rubber with 
polybutadiene and in Example V there is used a blend of styrenebutadiene 
rubber with polybutadiene. 
In both mixtures 1 and 2 there were used tire tread compositions for winter 
tires with strong grip on snow and ice. 
______________________________________ 
Mixture 
Constituents (in parts by weight) 
1 2 
______________________________________ 
natural rubber (RSS I, Defo hardness 
800) 30 -- 
styrene-butadiene rubber 
(SBR 1507) -- 30 
polybutadiene with high cis-1,4 
content (Buna CB 10) 70 70 
silica (Ultrasil VN 3 of Degussa) 
100 100 
Reaction product of Example 1 
10 14 
Reaction product of Example 2 
10 6 
zinc oxide 4 4 
stearic acid 1 1 
phenyl-.alpha.-naphthylamine 
1.5 1.5 
N-isopropyl-N'-phenyl-p-phenylenediamine 
1.5 1.5 
plasticizer (napthenic hydrocarbons) 
70 70 
sulfur 1 0.8 
4-dimethylamino-2,6-bis-(dimethyl- 
aminothio)-s-triazine 3 3 
2-ethylamino-4-diethylamino-6-mercapto-s- 
triazine 1.5 1.5 
tetramethyl thiurammonosulfide 
0.2 0.2 
______________________________________ 
Mixing procedure: Upsidedown process (as in Example III). 
The vulcanization was carried out at 160.degree. C. The vulcanization time 
was fixed according to the Vulcameter optimum. 
______________________________________ 
Mixture 
1 2 
______________________________________ 
Prevulcanization time t.sub.5 measured 
in minutes (according to DIN 
53524) at 130.degree. C. (Mooney Scorch) 
14.1 12.9 
Prevulcanization time t.sub.35 in 
minutes (130.degree. C. 
Mooney Cure) 17.9 17.3 
Mooney plasticity at 100.degree. C., Standard 
rotor, time of test: 4 minutes (ML4) 
88 87 
Tensile strength (see Example I) 
91 97 
300% Modulus (see Example I) 
62 63 
Elongation at break in % 463 477 
Tear Propagation Resistance 
(See Example I) 23 27 
Rebound 
(See Example I) 27 26 
Shore A hardness 78 77 
Abrasion in mm.sup.3 (DIN Abrasion) 
108 108 
______________________________________ 
Treads (tread strips) for winter tires were produced from both mixtures and 
the tires tested on a smooth winter-like ice surface in comparison with 
tires which had a carbon black filled standard automobile tread surface 
wherein for the standard tires there was fixed a friction value of 100 
(%). With the automobiles which were always equipped with four of the same 
tires there were determined the acceleration value, the circular 
acceleration value and the deceleration value and from these the friction 
value (as an average) calculated. The friction values (.mu. value) on 
smooth ice at -5.degree. C. for the tires of examples IV and V were 118% 
and 120% respectively. 
EXAMPLES VI and VII 
Examples VI and VII relate to the following mixtures 1 and 2 for the 
production of ice slip resistant winter tread surfaces of automobile 
tires. In these mixtures there are blends of two different reaction 
products of the invention which also contain a reinforcing additive based 
on a silane. 
In regard to the properties of the vulcanizates, the mixtures correspond to 
those of Examples IV and V and, hence, are typical of skid resistant 
winter tire tread mixtures, and differ therefrom on account of the 
addition of the second reinforcing additive based on a silane in that they 
result in lower Shore hardnesses and higher elasticities. 
______________________________________ 
Mixture 
Constituent (in parts by weight) 
1 2 
______________________________________ 
natural rubber (RSS I, Defo 
hardness 800) 30 -- 
styrene-butadiene rubber (SBR 1507) 
-- 30 
polybutadiene with high cis-1,4- 
content (Buna CB 10) 70 70 
silica (Ultrasil VN3 of Degussa) 
100 100 
mixture of equal parts of a precipitated 
silica (Ultrasil VN 3 of Degussa) 
and bis-(3-triethoxysilylpropyl)- 
tetrasulfide 10 10 
reaction product of Example 1 
5 5 
reaction product of Example 2 
5 4 
zinc oxide 4 4 
stearic acid 1 1 
phenyl-.alpha.-naphthylamine 
1.5 1.5 
N-isopropyl-N'-phenyl-p- 
phenylenediamine 1.5 1.5 
plasticizer (naphthenic hydro- 
carbons) 70 70 
sulfur 0.5 0.3 
2,4-bis-(N-dimethylsulfenamido)-6- 
dimethylamino-s-triazine 
1.2 1.2 
2-ethylamino-4-diethylamino-6- 
mercapto-s-triazine 1.3 1.4 
______________________________________ 
The vulcanization was carried out at 160.degree. C. The vulcanization times 
which varied between 20 and 60 minutes were chosen as optimum from the 
vulcameter curve. 
The properties of both mixtures and their vulcanizates are shown in the 
following Table: 
______________________________________ 
Mixtures 
1 2 
______________________________________ 
Prevulcanization time t.sub.5 
measured in minutes 
(according to DIN 53524) at 
130.degree. C. (Mooney Scorch) 
17.8 17.5 
Prevulcanization time t.sub.35 in 
minutes (130.degree. C. Mooney 
cure) 27.7 27.0 
Mooney plasticity at 100.degree. C., 
standard rotor, time of test: 4 
minutes (ML 4) 85 87 
Tensile strength (see Example I) 
101 97 
300% Modulus (see Example I) 
61 58 
Elongation at break in % 
510 525 
Tear Propagation Resistance 
(See Example I) 25 22 
Rebound 
(see Example I) 29 29 
Shore A-hardness 71 69 
Abrasion in mm.sup.3 (DIN abrasion) 
76 82 
______________________________________ 
The figures above show that mixtures of the reaction products of the 
invention with selected silanes may also be successfully used in the 
vulcanizable rubber mixtures. 
In the attached drawings FIGS. 1 through 4 there are given the IR spectra 
of two reaction products according to the invention or reinforcing 
additives (FIGS. 2 and 4) and their starting compounds (FIGS. 1 and 3). 
FIG. 1 contains the infrared spectrum of 
4,4-bis-(hydroxymethyl)-cyclohexene itself (M.P. 94.degree. to 96.degree. 
C.). The sulfurization product produced therefrom containing 31 weight 
percent sulfur (see Example 1) has the IR spectrum of FIG. 2. 
FIG. 3 is the IR spectrum of 
3,3-methano-4,4-bis-(hydroxymethyl)-cyclohexene with the formula 
##STR8## 
The IR spectrum in FIG. 4 is that of the sulfurization product produced 
from this diol and sulfur in a molar reaction ratio of 1:8 (see Example 
4). 
All IR spectra were taken with the ultrared spectrophotometer 21 of the 
firm Perkin-Elmer using a NaCl prism (slit program 927; time constant 1; 
intensification 5; speed 4 minutes per micron; damping 1; scale 1 micron = 
5 cm). 
From the curves it is clear that through the sulfurization process the 
characteristic double bond band at 3.3.lambda. = 3030 cm.sup.-1 has 
practically completely disappeared.