U.S. patent application number 10/443167 was filed with the patent office on 2003-12-11 for organosilicon compounds, process for their production and their use.
Invention is credited to Deschler, Ulrich, Hasse, Andre, Krafczyk, Roland, Luginsland, Hans-Detlef, Mayer, Melanie, Pieter, Reimund.
Application Number | 20030229166 10/443167 |
Document ID | / |
Family ID | 29414226 |
Filed Date | 2003-12-11 |
United States Patent
Application |
20030229166 |
Kind Code |
A1 |
Krafczyk, Roland ; et
al. |
December 11, 2003 |
Organosilicon compounds, process for their production and their
use
Abstract
Abstract Organosilicon compounds having the formula I and/or II
1 wherein R.sup.1 is a mixture and the proportion of one component
of the mixture is 10 to 50 mol %, are produced by reacting silanes
having the formula III 2 with mixtures of alcohols having the
general formula R.sup.1--OH, with elimination of R--OH, and R--OH
is continuously separated off from the reaction mixture by
distillation. The organosilicon compounds can be used in rubber
compounds.
Inventors: |
Krafczyk, Roland;
(Rheinfelden, DE) ; Deschler, Ulrich; (Sailauf,
DE) ; Luginsland, Hans-Detlef; (Hoboken, NJ) ;
Pieter, Reimund; (Bensheim, DE) ; Hasse, Andre;
(Linnich, DE) ; Mayer, Melanie; (Rheinfelden,
DE) |
Correspondence
Address: |
SMITH, GAMBRELL & RUSSELL, LLP
SUITE 3100, PROMENADE II
1230 PEACHTREE STREET, N.E.
ATLANTA
GA
30309-3592
US
|
Family ID: |
29414226 |
Appl. No.: |
10/443167 |
Filed: |
May 22, 2003 |
Current U.S.
Class: |
524/261 ;
556/450 |
Current CPC
Class: |
Y10S 152/905 20130101;
C08K 5/548 20130101; B60C 1/0016 20130101; C07F 7/1804 20130101;
C08K 5/548 20130101; C08L 21/00 20130101 |
Class at
Publication: |
524/261 ;
556/450 |
International
Class: |
C08K 005/24; C07F
007/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 28, 2002 |
DE |
102 23 658.5 |
Claims
We claim:
1. An organosilicon compound having the formula I or II 7wherein R
is a methyl or ethyl, R.sup.1 is the same or different and is a
C.sub.9-C.sub.30 branched or unbranched monovalent alkyl, R.sup.2
is a branched or unbranched, saturated or unsaturated, aliphatic,
aromatic or mixed aliphatic/aromatic divalent C.sub.1-C.sub.30
hydrocarbon, and R.sup.1 is a mixture and the proportion of one
component of the mixture is 10 to 50 mol %.
2. The organosilicon compound according to claim 1, wherein the
proportion of one component of the mixture is 10 to 40 mol %.
3. The organosilicon compound according to claim 1, wherein the
proportion of one component of the mixture is 15 to 30 mol %.
4. The organosilicon compound according to claim 1, wherein R.sup.2
denotes a member selected from the group consisting of CH.sub.2,
CH.sub.2CH.sub.2, CH.sub.2CH.sub.2CH.sub.2,
CH.sub.2CH.sub.2CH.sub.2CH.su- b.2, CH(CH.sub.3),
CH.sub.2CH(CH.sub.3), C(CH.sub.3).sub.2, CH(C.sub.2H.sub.5),
CH.sub.2CH.sub.2CH(CH.sub.3), CH.sub.2CH(CH.sub.3)CH.- sub.2 and
8
5. A process for the production of an organosilicon compound
according to claim 1, comprising reacting a silane having the
formula III 9wherein R is methyl or ethyl and R.sup.2 is a branched
or unbranched, saturated or unsaturated, aliphatic, aromatic or
mixed aliphatic/aromatic divalent C.sub.1C.sub.30 hydrocarbon, with
mixtures of alcohols having the general formula R.sup.1--OH, to
form a reaction mixture, wherein R.sup.1 is different and is a
C.sub.9 C.sub.30 branched or unbranched monovalent alkyl, to form
R--)H, and continuously separating off R--OH from the reaction
mixture by distillation.
6. A rubber composition comprising a natural or synthetic rubber
and an organosilicon compound according to claim 1.
7. An organic polymer composition comprising an organic polymer and
an organosilicon compound according to claim 1.
8. Rubber compounds characterised in that they contain rubber,
filler, optionally other rubber auxiliary substances and at least
one organosilicon compound according to claim 1.
9. A moulded part comprising natural or synthetic rubber or an
organic polymer and an organosilicon compound according to claim
1.
10. The moulded part according to claim 9 which is a pneumatic
tire, tire tread, cable sheath, hose, drive belt, conveyor belt,
roll covering, tire, shoe sole, sealing ring or a damping
element.
11. A tire tread comprising rubber in which the organosilicon
compound according to claim 1 is exchanged for
bis-(3-triethoxysilylpropyl) tetrasulfide in a molar ratio relative
to the silicon units of 1:1.8 to 1:2.7.
12. A rubber compound for the production of tire treads in which
the organosilicon compound according to claim 1 is exchanged for
bis-(3-triethoxysilylpropyl) tetrasulfide in a molar ratio relative
to the silicon units of 1:1.8 to 1:2.7.
Description
INTRODUCTION AND BACKGROUND
[0001] The present invention concerns organosilicon compounds, a
process for their production and their use.
[0002] The use of silanes as coupling agents is known. Thus
aminoalkyl trialkoxysilanes, methacryloxyalkyl trialkoxysilanes,
polysulfanalkyl trialkoxysilanes and mercaptoalkyl trialkoxysilanes
are used as coupling agents between inorganic materials and organic
polymers, as crosslinking agents and surface modifiers (E. P.
Plueddemann, "Silane Coupling Agents", 2.sup.nd Ed. Plenum Press
1982).
[0003] These coupling agents or bonding agents form bonds to both
the filler and the elastomer, thus creating a good interaction
between the filler surface and the elastomer.
[0004] It is also known that the use of commercial silane coupling
agents (DE 22 55 577) with three alkoxy substituents at the silicon
atom leads to the release of considerable amounts of alcohol during
and after bonding to the filler. Since trimethoxy- and
triethoxy-substituted silanes are generally used, the corresponding
alcohols, methanol and ethanol, are released in considerable
quantities.
[0005] It is also known from DE 10015309 that the use of a
mercaptosilane in combination with a long-chain alkyl silane leads
to rubber compounds with increased reinforcement and reduced
hysteresis loss. The alkyl silane is needed to ensure reliable
processability of the rubber compound.
[0006] A disadvantage of the known mercaptosilanes according to DE
10015309 is the need to add alkyl silanes to rubber compounds in
order to obtain particular properties.
[0007] It is also known that methoxy- and ethoxy-substituted
silanes are more reactive than the corresponding long-chain
alkoxy-substituted silanes and can therefore bond more quickly to
the filler, such that from a technical and economic perspective the
use of methoxy and ethoxy substituents cannot be avoided.
[0008] Organosilicon compounds having the general formula 3
[0009] are known from DE 10137809
[0010] wherein R is a methyl or ethyl group,
[0011] R' is the same or different and a C.sub.9-C.sub.30 branched
or unbranched monovalent alkyl or alkenyl group, aryl group,
aralkyl group, branched or unbranched C.sub.2-C.sub.30 alkyl ether
group, branched or unbranched C.sub.2-C.sub.30 alkyl polyether
group,
[0012] R" is a branched or unbranched, saturated or unsaturated,
aliphatic, aromatic or mixed aliphatic/aromatic divalent
C.sub.1-C.sub.30 hydrocarbon group,
[0013] X is NH.sub.(3-n) where n=1,2,3 and m=1, O(C.dbd.O)--R"'
where n=1 and m=1, SH where n=1 and m=1, S where n=2 and m=1-10 and
mixtures thereof, S(C.dbd.O)--R"' where n=1 and m=1 or H where n=1
and m=1,
[0014] where R"' equals C.sub.1-C.sub.30 branched or unbranched
alkyl or alkenyl group, aralkyl group or aryl group.
[0015] A disadvantage of the known organosilicon compounds
according to DE 10137809 is the low hardness and dynamic rigidity
in rubber compounds.
[0016] The object of the invention is to provide an organosilicon
compound with which good hardness and dynamic rigidity values can
be achieved in rubber compounds.
[0017] The object of the invention is also to provide an
organosilicon compound with which comparable properties to those in
DE 10015309 can be achieved in rubber compounds even without the
addition of alkyl silanes.
SUMMARY OF THE INVENTION
[0018] The present invention provides organosilicon compounds
having the formula I and/or II 4
[0019] wherein R is methyl or ethyl,
[0020] R.sup.1 is the same or different and a C.sub.9-C.sub.30
branched or unbranched monovalent alkyl,
[0021] R.sup.2 is a branched or unbranched, saturated or
unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic
divalent C.sub.1-C.sub.30 hydrocarbon,
[0022] which are characterised in that R.sup.1 is a mixture and the
proportion of one component of the mixture is 10 to 50 mol %,
preferably 10 to 40 mol %, particularly preferably 15 to 30 mol
%.
[0023] R.sup.1 can for example consist of 10 to 50 mol %
C.sub.14H.sub.29 and 90 to 50 mol % C.sub.12H.sub.25 or of 10 to 50
mol % C.sub.18H.sub.37 and 90 to 50 mol % C.sub.16H.sub.33. R.sup.1
can also consist of more than two different R.sup.1 compounds.
[0024] R.sup.2 can denote CH.sub.2, CH.sub.2CH.sub.2,
CH.sub.2CH.sub.2CH.sub.2, CH.sub.2CH.sub.2CH.sub.2CH.sub.2,
CH(CH.sub.3), CH.sub.2CH(CH.sub.3), C(CH.sub.3).sub.2,
CH(C.sub.2H.sub.5), CH.sub.2CH.sub.2CH(CH.sub.3),
CH.sub.2CH(CH.sub.3)CH.sub.2 or 5
[0025] The invention also provides a process for producing
organosilicon compounds having the general formula I and/or II,
which is characterised in that silanes having the general formula
III 6
[0026] wherein R and R.sup.2 have the meaning cited above, are
reacted with mixtures of alcohols having the general formula
R.sup.1--OH, wherein R.sup.1 has the meaning cited above and is
used as a mixture of at least two alcohols (R.sup.1 is different),
with elimination of R--OH, and R--OH is continuously separated off
from the reaction mixture by distillation.
[0027] Alcohol mixtures comprising 10 to 50 mol %
C.sub.14H.sub.29OH and 90 to 50 mol % C.sub.12H.sub.25OH or alcohol
mixtures comprising 10 to 50 mol % C.sub.18H.sub.37OH and 90 to 50
mol % C.sub.16H.sub.33OH can be used, for example. Alcohol mixtures
comprising several components (R.sup.1) can also be used. Lorol
Spezial or Stenol 1618 (cetyl/stearyl alcohol) produced by Cognis
or Ecorol 68/50 (cetyl stearyl alcohol) produced by Ecogreen
Oleochemicals, for example, can be used as R.sup.1--OH alcohol
mixtures.
[0028] In the process according to the invention a mixture can be
formed in which none, one, two or three of the RO groups are
replaced by R.sup.1O groups. The ratio of RO to R.sup.1O groups can
be determined by the molar ratio of the silane having the general
formula III to the alcohol having the formula R.sup.1--OH. For
example, an organosilicon compound having an average analysis
according to formula I can be obtained by reacting two molar
equivalents of the alcohol mixture having the formula R.sup.1--OH
with one molar equivalent of the silane having the general formula
III. For example, an organosilicon compound having an average
analysis according to formula II can be produced by reacting one
molar equivalent of the alcohol mixture having the general formula
R.sup.1--OH with one molar equivalent of the silane having the
general formula III.
[0029] The reaction can be accelerated by means of neutral, acid or
basic catalysts, such as e.g. hydrochloric acid, sulfuric acid,
phosphoric acid, formic acid, acetic acid, toluene-para-sulfonic
acid, sodium hydroxide solution, potassium hydroxide solution,
sodium methylate, sodium ethylate, ion-exchange resins Amberlyst
15, Deloxan ASP I/9 or metal compounds, in particular titanates,
known for example from U.S. Pat. No. 2,820,806.
[0030] The reaction can be performed at temperatures between 20 and
200.degree. C., preferably between 20 and 150.degree. C. In order
to avoid condensation reactions it can be advantageous to perform
the reaction in a moisture-free atmosphere, ideally in an inert gas
atmosphere.
[0031] The organosilicon compounds according to the invention can
be used as coupling agents between inorganic materials (for example
glass fibres, metals, oxidic fillers, silicas) and organic polymers
(for example thermosets, thennoplastics, elastomers), or as
crosslinking agents and surface modifiers. The organosilicon
compounds according to the invention can be used as coupling agents
in tires made from rubber filled with silica and/or starch.
[0032] The invention also provides rubber compounds that are
characterized in that they contain rubber, filler, such as e.g.
precipitated silica, optionally other rubber auxiliary substances,
and at least one organosilicon compound according to the
invention.
[0033] The organosilicon compound according to the invention can be
used in quantities of 0.1 to 20 wt. %, relative to the quantity of
rubber used.
[0034] Addition of the organosilicon compounds according to the
invention and addition of the fillers can preferably take place at
material temperatures of 100 to 200.degree. C. However, it can also
take place later at lower temperatures (40 to 100.degree. C.), for
example together with other rubber auxiliary substances.
[0035] The organosilicon compound can be added to the mixing
process both in pure form and attached to an inert organic or
inorganic support. Preferred supporting materials are silicas,
waxes, thermoplastics, natural or synthetic silicates, aluminum
oxide or carbon blacks. The following fillers can be used as
fillers for the rubber compounds according to the invention:
[0036] Carbon blacks: The carbon blacks to be used here are
produced by the lamp black, furnace or channel black process and
have BET surface areas of 20 to 200 m.sup.2/g, such as e.g. SAF,
ISAF, HSAF, HAF, FEF or GPF carbon blacks. The carbon blacks can
optionally also contain heteroatoms such as Si for example.
[0037] Highly disperse silicas, produced for example by
precipitation of solutions of silicates or flame hydrolysis of
silicon halides with specific surface areas of 5 to 1000,
preferably 20 to 400 m.sup.2/g (BET surface area) and with primary
particle sizes of 10 to 400 nm. The silicas can optionally also be
present as mixed oxides with other metal oxides, such as Al, Mg,
Ca, Ba, Zn and titanium oxides.
[0038] Synthetic silicates, such as aluminum silicate,
alkaline-earth silicates such as magnesium silicate or calcium
silicate, with BET surface areas of 20 to 400 m.sup.2/g and primary
particle diameters of 10 to 400 nm.
[0039] Synthetic or natural aluminum oxides and hydroxides
[0040] Natural silicates, such as kaolin and other naturally
occurring silicas.
[0041] Glass fibres and glass fibre products (mats, strands) or
glass microbeads.
[0042] Highly disperse silicas, produced by precipitation of
solutions of silicates, with BET surface areas of 20 to 400
m.sup.2/g, can preferably be used in quantities of 5 to 150 parts
by weight, relative in each case to 100 parts of rubber.
[0043] The cited fillers can be used alone or in a mixture.
[0044] In a particularly preferred embodiment, 10 to 150 parts by
weight of light-colored fillers, optionally together with 0 to 100
parts by weight of carbon black, and 1 to 10 parts by weight of the
organosilicon compound according to the invention having formula I
and/or II, relative in each case to 100 parts by weight of rubber,
can be used to produce the compounds.
[0045] In addition to natural rubber, synthetic rubbers are also
suitable to produce the rubber compounds according to the
invention. Preferred synthetic rubbers are described for example in
W. Hofmann, Kautschuktechnologie, Genter Verlag, Stuttgart 1980.
They include inter alia
[0046] Polybutadiene (BR)
[0047] Polyisoprene (IR)
[0048] Styrene/butadiene copolymers with styrene contents of 1 to
60, preferably 2 to 50 wt. % (SBR)
[0049] Isobutylene/isoprene copolymers (IIR)
[0050] Butadiene/acrylonitrile copolymers with acrylonitrile
contents of 5 to 60, preferably 10 to 50 wt. % (NBR)
[0051] Partially hydrogenated or wholly hydrogenated NBR rubber
(HNBR)
[0052] Ethylene/propylene/diene copolymers (EPDM)
[0053] and mixtures of these rubbers. For the production of motor
vehicle tires, anionically polymerized S-SBR rubbers (solution SBR)
with a glass transition temperature above -50.degree. C. and
mixtures thereof with diene rubbers are of particular interest.
[0054] The rubber vulcanizates according to the invention can
contain additional rubber auxiliary substances, such as reaction
accelerators, antioxidants, heat stabilizers, light stabilizers,
antiozonants, processing aids, plasticizers, tackifiers, blowing
agents, dyes, pigments, waxes, extenders, organic acids, retarders,
metal oxides and activators, such as triethanolamine, polyethylene
glycol, hexanetriol, which are known to the rubber industry.
[0055] The rubber auxiliary substances can be used in known
quantities, which are governed inter alia by the intended use.
Conventional quantities are for example quantities of 0.1 to 50 wt.
%, relative to rubber. Sulfur or sulfur-doning substances can be
used as crosslinking agents. The rubber compounds according to the
invention can moreover contain vulcanization accelerators. Examples
of suitable principal accelerators are mercaptobenzothiazoles,
sulfenamides, thiurams, dithiocarbamates, particularly preferably
sulfenamides, in quantities of 0.5 to 3 wt. %. Examples of
co-accelerators are guanidines, thioureas and thiocarbonates in
quantities of 0.5 to 5 wt. %. Sulfur can conventionally be used in
quantities of 0.1 to 10 wt. %, preferably 1 to 3 wt. %, relative to
rubber.
[0056] Vulcanization of the rubber compounds according to the
invention can take place at temperatures from 100 to 200.degree.
C., preferably 130 to 180.degree. C., optionally under pressure of
10 to 200 bar. The rubbers can be mixed with the filler, optionally
rubber auxiliary substances and the organosilicon compound
according to the invention in known mixing units, such as rolls,
internal mixers and compounding extruders.
[0057] The rubber compounds according to the invention are suitable
for the production of moulded parts, for example for the production
of pneumatic tires, tire treads, cable sheaths, hoses, drive belts,
conveyor belts, roll coverings, tires, shoe soles, sealing rings
and damping elements.
[0058] The organosilicon compounds according to the invention can
be used together with large-surface-area silicas with CTAB 180-220
m.sup.2/g in rubber compounds, in particular in truck tire
treads.
[0059] The rubber compound according to the invention can be used
for the production of tire treads with improved, lower rolling
resistance, improved wet skid resistance and equally good dry
performance as compared with a similar rubber compound in which the
organosilicon compound according to the invention is exchanged for
bis-(3-triethoxysilylpropyl) tetrasulfide in a molar ratio relative
to the silicon units of 1:1.8 to 1:2.7.
[0060] The rubber compound according to the invention can be used
for the production of tire treads with improved, lower rolling
resistance and improved wet skid resistance with equally good
abrasion resistance as compared with a similar rubber compound in
which the organosilicon compound according to the invention is
exchanged for bis-(3-triethoxysilylpropyl) tetrasulfide in a molar
ratio relative to the silicon units of 1:1.8 to 1:2.7.
[0061] The organosilicon compounds according to the invention have
the advantage compared with organosilicon compounds according to DE
10137809 that hardness and dynamic rigidity E* are increased while
tan .delta. 60.degree. C. (correlated with rolling resistance)
remains the same.
[0062] The organosilicon compounds according to the invention have
the advantage that less methanol or ethanol is released than is the
case with the known silanes while the reactivity remains the same.
Due to their inactivity the non-volatile alcohols are not separated
from the organosilicon compound or because of their non-volatility
they remain in the polymer matrix. In both cases they are not
released into the environment.
[0063] In addition, the organosilicon compounds according to the
invention have the advantage that there is no need to add alkyl
silane as described in DE 10015309, since in the organosilicon
compounds according to the invention having formula I and/or II no
deterioration in processability, as in the case of e.g.
3-mercaptopropyl trimethoxysilane or 3-mercaptopropyl
triethoxysilane, has been found.
[0064] The rubber compounds according to the invention have the
advantage as compared with rubber compounds containing
bis-(3-triethoxysilylpropyl) tetrasulfide that dynamic rigidity is
reduced and they are therefore especially suitable for winter tires
(soft formulation).
BRIEF DESCRIPTION OF DRAWING
[0065] FIG. 1 is a representation of a driving test track. The dots
in FIG. 1 are measuring points on x, y-coordinates of the test
track. The measuring points are linked with straight lines.
DETAILED EMBODIMENT OF THE INVENTION
EXAMPLES:
Example 1:
[0066] A mixture consisting of 286.1 g 3-mercaptopropyl
triethoxysilane (formula III where R=CH.sub.2CH.sub.3,
R.sup.2=--CH.sub.2CH.sub.2CH.sub.2- --), 313.1 g dodecanol
(R.sup.1=--C.sub.12H.sub.25) and 154.4 g 1-tetradecanol (R.sup.1
=--C.sub.14H.sub.29) is heated with 140 .mu.l tetra-n-butyl
orthotitanate to 110.degree. C. in a 1-litre flask in a rotary
evaporator and ethanol that is produced is distilled off over 4 h
in vacuo at 40 mbar. 636.86 g (99.0%) of a colorless liquid having
formula I, where R=--CH.sub.2CH.sub.3, R.sup.1
=--C.sub.12.6H.sub.26.2, R.sup.2=--CH.sub.2CH.sub.2CH.sub.2--), is
obtained.
Example 2
[0067] Production and analysis of the rubber compounds according to
the invention The formulation used for the rubber compounds is set
out in Table 1 below. The unit phr denotes contents by weight,
relative to 100 parts of the crude rubber used. The organosilicon
compound according to the invention is added in equimolar
quantities to 3-mercaptopropyl triethoxysilane relative to silicon.
The general process for the production of rubber compounds and
vulcanizates thereof is described in the book: "Rubber Technology
Handbook", W. Hofmann, Hanser Verlag 1994.
1 TABLE 1 Compound 1 Compound 2 Reference Reference Compound 3
Stage 1 Buna VSL 5025-1 96 96 96 Buna CB 24 30 30 30 Ultrasil 7000
GR 80 80 80 3-mercaptopropyl 2.4 -- -- triethoxysilane VP Si 208
2.5 -- -- Organosilicon compound -- 5.7 -- according to example 10
DE 10137809.2 Organosilicon compound -- -- 5.4 according to example
1 ZnO 2 2 2 Stearic acid 2 2 2 Naftolen 10 10 10 Vulkanox 4020 1.5
1.5 1.5 Protektor G35P 1 1 1 Stage 2 Batch from stage 1 Stage 3
Batch from stage 2 Vulkacit D 2 2 2 Vulkazit CZ 1.5 1.5 1.5 TBzTD
0.2 0.2 0.2 Sulfur 2.3 2.3 2.3
[0068] The polymer VSL 5025-1 is a solution-polymerized SBR
copolymer from Bayer AG with a styrene content of 25 wt. % and a
butadiene content of 75 wt. %. The copolymer contains 37.5 phr oil
and displays a Mooney viscosity (ML 1+4/100.degree. C.) of
50.+-.4.
[0069] The polymer Buna CB 24 is a cis-1,4-polybutadiene (neodymium
type) from Bayer AG with a cis-1,4 content of at least 97% and a
Mooney viscosity of 44.+-.5.
[0070] Naftolen ZD from Chemetall is used as aromatic oil. Vulkanox
4020 is a 6PPD from Bayer AG and Protektor G35P is an antiozonant
wax from HB-Fuller GmbH. Vulkacit D (DPG) and Vulkazit CZ (CBS) are
commercial products from Bayer AG.
[0071] Ultrasil 7000 GR is a readily dispersible precipitated
silica from Degussa AG with a BET surface area of 170 m.sup.2/g.
3-mercaptopropyl triethoxysilane is produced by ABCR GmbH CoKG and
VP Si 208, octyl triethoxysilane, is a commercial product from
Degussa AG.
[0072] The rubber compounds are produced in an internal mixer in
accordance with the mixing instructions in Table 2.
2TABLE 2 Stage 1 Settings Mixing unit Werner & Pfleiderer
E-type Speed 70 rpm Ram force 5.5 bar Void volume 1.58 I Fill ratio
0.56 Flow temp. 80.degree. C. Mixing process 0 to 1 min Buna VSL
5025-1 + Buna CB 24 1 to 3 min 1/2 filler, ZnO, stearic acid,
Naftolen ZD, organosilicon compounds 3 to 4 min 1/2 filler,
antioxidant 4 min Clean 4 to 5 min Mix, 5 min Clean 5 to 6 min Mix
and remove Batch temp. 145-150.degree. C. Storage 24 h at room
temperature Stage 2 Settings Mixing unit As for stage 1 apart from:
Speed 80 rpm Fill ratio 0.53 Mixing process 0 to 2 min Break up
batch from stage 1 2 to 5 min Maintain batch temperature at
140-150.degree. C. by varying speed 5 min Remove Batch temp.
150.degree. C. Storage 4 h at room temperature Stage 3 Settings
Mixing unit As for stage 1 except for Speed 40 rpm Fill ratio 0.51
Flow temp. 50.degree. C. Mixing process 0 to 2 min Batch from stage
2, accelerator, sulfur 2 min Remove and sheet out on laboratory
mixing rolls, (diameter 200 mm, length 450 mm, flow temperature
50.degree. C.) Homogenize: Score 3.times. on left, 3.times. on
right and fold over and pass through 8.times. with narrow nip (1
mm) and 3.times. with wide nip (3.5 mm) Remove sheet Batch temp.
85-95.degree. C.
[0073] The rubber test methods are set out in Table 3.
3 TABLE 3 Physical test Standard/conditions ML 1 + 4, 100.degree.
C., stage 3 DIN 53523/3, ISO 667 Cure-meter test, 165.degree. C.
DIN 53529/3, ISO6502 t10% and t90% (min) Tensile test on ring,
23.degree. C. DIN 53504, ISO 37 Tensile strength (MPa) Moduli (MPa)
Elongation at break (%) Shore-A hardness, 23.degree. C. (SH) DIN 53
505 Viscoelastic properties, DIN 53 513, ISO2856 0 and 60.degree.
C., 16 Hz, 50 N initial force and 25 N amplitude force Dynamic
modulus E* (MPa) Loss factor tan .delta. () Ball rebound,
60.degree. C. (%) ASTM D 5308 Goodrich flexometer DIN 53 533, 0.25
inch stroke, 25 min, 23.degree. C. ASTM D 623 A Contact temperature
(.degree. C.) Center temperature (.degree. C.) Permanent set (%)
DIN abrasion, 10 N force (mm.sup.3) DIN 53 516
[0074] Table 4 shows the results from the rubber tests. The
compounds are vulcanized for 20 min at 165.degree. C.
4TABLE 4 Features Unit 1 2 3 Results for unvulcanized mix ML(1 + 4)
at 100.degree. C/, stage 3 [MU] 69 62 72 MDR, 165.degree. C.,
0,5.degree. t 10% [min] 0.8 1.0 0.8 t 90% [min] 5.9 15.6 16.8
Results for vulcanizate Tensile test on ring Modulus 100% [MPa] 2.1
2.1 2.4 Modulus 200% [MPa] 6.7 7.1 7.5 Modulus 300% [MPa] 13.8 --
-- Modulus 300%/100% [--] 6.6 -- -- Tensile strength [MPa] 14.1
12.7 13.2 Elongation at break [%] 300 270 280 Shore-A hardness [SH]
58 55 61 Ball rebound 60.degree. C. [%] 69.0 70.2 69.7 DIN abrasion
[mm.sup.3] 62 34 50 Goodrich flexometer Contact temperature
[.degree. C.] 49 52 52 Centre temperature [.degree. C.] 87 91 90
Permanent set [%] 1.5 1.3 1.7 MTS Dynamic modulus E*, 0.degree. C.
[MPa] 12.2 10.0 12.3 Dynamic modulus E*, 60.degree. C. [MPa] 6.3
5.9 6.8 Loss factor tan .delta., 0.degree. C. [--] 0.471 0.413
0.428 Loss factor tan .delta., 60.degree. C. [--] 0.086 0.083
0.084
[0075] As can be seen from Table 4, compound 3 with the
organosilicon compound according to the invention displays good
hydrophobing and reinforcement. In particular, the moduli and
Shore-A hardness for compound 3 according to the invention are
higher than those for the reference compounds. In addition, the
dynamic rigidity (dynamic modulus E*) of compound 3 according to
the invention is higher than that of reference compound 2, with
almost the same loss factor tan .delta. 60.degree. C. Even without
the addition of alkyl silane, compound 3 displays virtually the
same dynamic rigidity and tan.delta. 60.degree. C. values as
compound 1 with alkyl silane.
Example 3
[0076] 268.08 g 3-mercaptopropyl triethoxysilane and a mixture
consisting of 313.05 g 1-dodecanol and 154.36 g 1 tetradecanol are
placed in a 1-litre three-necked flask with distillation attachment
at room temperature and 1.0 g toluene-p-sulfonic acid monohydrate
is added. The solution is heated to 120.degree. C. The ethanol that
is produced is continuously removed by distillation. Distillation
is then performed in a rotary evaporator in vacuo at 80.degree. C.
and 20 mbar. 638.7 g (99%) of a colorless liquid according to
formula I is obtained, where R=--CH.sub.2CH.sub.3, R.sup.1=mixture
of --C.sub.12H.sub.25 and --C.sub.14H.sub.29 in the ratio 2:1 and
R.sup.2=--CH.sub.2CH.sub.2CH.sub.- 2--.
Example 4
[0077] Production and Analysis of the Rubber Compounds According To
The Invention
[0078] The formulation used for the rubber compounds is set out in
Table 5 below. The silane according to the invention is added in
equimolar quantities to Si 69, relative to silicon. The sulfur
adjustment is necessary to compensate for the low sulfur content in
the organosilicon compound according to the invention.
5 TABLE 5 A B Basic compound Rubber blend .sup.1): S-SBR/BR/NR 100
100 Highly dispersible silica .sup.2) 80 80 Carbon black .sup.3)
6.6 6.6 Aromatic plasticizer 30 24 Si 69 .sup.4) 6.6 --
Organosilicon compound according to example 3 -- 5.95 Chemicals
.sup.5) Ready-to-use compound Ground sulfur 2.0 2.8 Accelerator
mixture .sup.6) .sup.1) S-SBR: solution polymerized SBR copolymer
with 25% styrene; BR: polybutadiene with at least 97% 1,4-butadiene
units; NR: natural rubber .sup.2) CTAB surface area 160 m.sup.2/g
.+-. 15 .sup.3) N300 series for tire tread .sup.4)
Bis-(3-triethoxysilypropyl) tetrasulfide, commercial product from
Degussa AG .sup.5) Zinc oxide, stearic acid, wax, antioxidant
.sup.6) Consisting of a sulfenamide accelerator and a
co-accelerator
[0079] The rubber compounds are produced in an internal mixer in a
four-stage process. All components of the basic compound are mixed
in the first mixing stage, followed by two intermediate stages and
a final stage in which the accelerators and the sulfur are added.
The mixing temperatures in the first three mixing stages range from
140 to 160.degree. C. and the temperature in the fourth stage is
<120.degree. C.
[0080] The rubber test methods are set out in Table 6.
6TABLE 6 Physical test Standard/conditions ML 1 + 4, 100.degree. C.
stage 3 DIN 53523/3, ISO 667 Cure-meter test, 165.degree. C. DIN
53529/3, ISO 6502 Dmax-Dmin (dNm) t10% and t90% (min) Tensile test
on ring, 23.degree. C. DIN 53504, ISO 37 Tensile strength (MPa)
Moduli (MPa) RF (modulus 300%/modulus 100%) Elongation at break (%)
Shore-A hardness, 23.degree. C. (SH) DIN 53 505 Viscoelastic
properties, DIN 53 513, ISO 2856 0 and 60.degree. C., 16 Hz, 50 N
initial force and 25 N amplitude force Dynamic modulus E* (MPa)
Loss factor tan .delta. () Goodrich flexometer 0.25 inch stroke, 25
min, 23.degree. C. DIN 53 533, ASTM D 623 centre temperature
(.degree. C.) DIN abrasion, 10 N force (mm.sup.3) DIN 53 516
[0081] Table 7 shows the results from the rubber tests. The
compounds are vulcanized for 10 min at 165.degree. C.
7 TABLE 7 Unit A B Data for unvulcanized mix ML (1 + 4) [--] 50 49
Dmax-Dmin [dNm] 20.5 15.2 t10% [min] 2.0 1.1 t90% [min] 5.1 3.8
Data for vulcanizate Tensile strength [MPa] 13.5 12.6 Modulus 100%
[MPa] 2.8 2.0 Modulus 300% [MPa] 10.0 9.5 RF [--] 3.6 4.8
Elongation at break [%] 390 370 Shore-A hardness [--] 74 63 E*
(60.degree. C.) [MPa] 9.2 7.8 tan .delta. (60.degree. C.) [--]
0.142 0.111 tan .delta. (0.degree. C.) [--] 0.392 0.346 Center
temperature [.degree. C.] 134 122 DIN abrasion [mm.sup.3] 59 49
[0082] As can be seen from the data in Table 7, the Mooney
viscosity of compound B according to the invention is at the same
level as reference compound A. Compound B is characterized in
particular by a low dynamic rigidity (E*), a high reinforcement
factor (RF) with reduced DIN abrasion and a reduced hysteresis loss
(tan .delta., center temperature).
[0083] The two tire tread compounds A and B are used to build test
tires A and B of size 205/65R15 94V, and these are tested by
Smithers Scientific Services Inc. Table 8 reproduces the test types
and test conditions used. The road tests are performed with a BMW
528i. The front tire pressure is 2.1 bar, the rear tire pressure
2.5 bar. The front load is 903 kg, the rear 911 kg. The relative
rating of test tire B with compound B according to the invention
relative to reference tire A is shown in Table 9. Values over 100
indicate an improvement.
8 TABLE 8 Rolling resistance ASTM J-1269; 572 kg , 2.0 bar ABS wet
braking Stopping distance from 80 km/h ABS dry braking Stopping
distance from 80 km/h Wet handling Circuit time for curve section
(FIG. 1) Dry handling Circuit time for curve section (FIG. 1)
[0084] FIG. 1 illustrates the curve section of the test track.
9 TABLE 9 Test tire B Rolling resistance 105 ABS wet braking 103
ABS dry braking 100 Wet handling 99 Dry handling 99
[0085] As can be seen, the tire rolling resistance and ABS wet
braking are significantly improved. Within the framework of
conventional fluctuations, the handling performance is similar. The
DIN abrasion value in Table 7 indicates an improved abrasion
value.
[0086] Further variations and modifications will be apparent from
the foregoing to those skilled in the art and are intended to be
encompassed by the claims appended hereto.
[0087] German priority application 102 23 658.5 filed May 28, 2002
is relied on and incorporated herein by reference.
* * * * *