CA1136309A

CA1136309A - Silicate-filled vulcanizable halogen rubber mixtures

Info

Publication number: CA1136309A
Application number: CA000326954A
Authority: CA
Inventors: Siegfried Wolff; Ewe H. Tan
Original assignee: Degussa GmbH
Current assignee: Evonik Operations GmbH
Priority date: 1978-05-05
Filing date: 1979-05-04
Publication date: 1982-11-23
Also published as: GB2020293A; CH640872A5; DE2819638A1; JPS57168927A; NL185670B; IT7948921A0; YU74179A; JPS54146843A; YU40552B; MY8500420A; BE876061A; JPS5749579B2; YU231482A; FR2424935A1; FR2424935B1; DE2819638B2; NL7903143A; YU44033B; BR7902679A; ES480218A1

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides a vulcanizable halogen rubber mixture of at least one halogen rubber, at least one silicate filler in an amount of 1 to 250 parts by weight, magnesium oxide in an amount of 0 to 15 parts by weight, zinc oxide in the amount of 0.1 to 15 parts by weight, sulphur in an amount of 0 to 15 parts by weight,stearic acid in an amount of 0 to 10 parts by weight, at least one vulcanization accelerator in an amount of 0 to 10 parts by weight, at least one plasticizer in an amount of 0 to 100 parts by weight, at least one stabilizer from the group of antiagers, fatigue inhibitors, antioxidants, light absorbing agents and ozone resisting agents in an amount of 0 to 10 parts by weight, carbon black in an amount of 0 to 150 parts by weight and at least one organosilane, the halogen-rubber mixture contain-ing as organosilane at least one compound having the general formula:
X-CmH2m-SiR1n(OR)3-n wherein X represents chlorine, bromine or iodine, m represents a number from 1 to 5, R1 represents a C1- to C5- alkyl group, a C5-to C8- cycloalkyl group or the phenyl group, R represents a C1-to C5-alkyl group, a C5- to C8- cycloalkyl group, the methoxy-ethyl group, the phenyl group or the benzyl group and n is 0, for 2, in an amount of 0.1 to 20 parts by weight, all the specified amounts being relative to 100 part by weight of halogen rubber.
Iudstrial fields of application for the rubber mixtures described and for their vulcanization are, for example, technical rubber articles such as cable sheathing, tubing, air tubes, driving belts, V-belts, conveyor belts, roller covers, washers, electri-cal insulations, linings, impregnating and coating of heat-resistant fabrics, damping and vibration elements and similar articles which must meet high requirements with respect to resistance to high temperatures and/or to oil.

Description

~363(~
.
The present invention relates to mouldable and vulcan-izable rubber mixtures containing, as substantial ingredients, a halogen rubber, a silicate filler, if required in admixture with carbon black, and a c~oss-linking system for the halogen rubber.
It is known that rubber mixtures which are vulcanizable with sulphur and should contain a high proportion of silicate fillers, as for example, precipitated silica, absolutely require a silane as an ingredient of the mixture in order to impart suf-ficiently good properties to the vulcanizates. Such silanes are, for example, the bis-(alkoxysilyl-alkyl)-oligosulphides, as for example, bis-(triethoxy-silyl-propyl)-tetrasulphide, which are outstandingly suitable but their production requires a relatively high expenditure. An alternative to the separate addition of silicate fillers and silanes to the rubber mixtures is the pre-liminary mixing of said substances (U.S. Patent No. 3,873,489).
A cross-linkable rubber mixture which contains sulphur-containing organosilanes, known vulcanization accelerators and a silicate filler but no elementary sulphur is also disclosed in Belgian Patent No. 832,970.
For mixtures based on SBR and EPDM rubbers mercapto-silanes such as 3-mercaptopropyl trimethoxy silane, vinyl silanes such as vinyl trimethoxy s~ane and aminosilanes such as 3-amino-propyl-triethoxy silane are known (Rubber World, October 1970, pages 54 and 55).
Surprisingly it has now been found that very valuable vulcanization products are formed from rubber mixtures which con-tain silicate fillers and are based on the selected group of the halogen-containing rubber types when the mixtures contain halogen-containing silanes which can be produced in a simple manner and are readily available.
Vulcani2able halogen rubber mixtures according to the present invention thus comprise at least one halogen rubber, at ~13~i3~J~

least one silicate filler in an amount of 1 to 250 parts by weight, magnesium oxide in an amount of 0 to 15 parts by weight, zinc oxide in an amount of 0.1 to 15 parts by weight, sulphur in an amount of 0 to 15 parts by weight, stearic acid in an amount of 0 to 10 parts by weight, at least one vulcanization accelerator in an amount of 0 to 10 ,parts by weight, at least one plasticizer in an amount of 0 to 100 parts by weight, at least one stabilizer from the group of antiagers, fatiyue inhibitors, antioxidants, light-absorbing agents and ozone resisting agents in an amount of 0 to 10 parts by weight, carbon black in an amount of 0 to 150 parts by weight and at least one organosilane. The halogen rubber mixture contains as organo-silane at least one compound having the general formula X-CmH2m~SiRn(OR)3-n wherein X represents chlorine, bromine or iodine, m represents a number from 1 to 5, R' represents a Cl- to C5- alkyl group, a C5- to C8- cycloalkyl group or the phenyl ~roup, R represents a Cl- to C5- alkyl group, a C5- to C8- cycloalkyl ~roup, the methoxy-ethyl group, the phenyl group or the benzyl group and n is0,1 or 2 in an amount of 0.1 to 20 parts by weight, all the ; specified amounts being relative to 100 parts by weight of halo-gen rubber.
The halogen silanes, which accordin~ to the invention, must be present in amounts of 0.1 to 20 parts by weight relative to 100 parts by weight of halogen rubber, include particularly the following silanes: chloromethyl-triethoxy silane, bromo-me$hyl-triethoxy silane, l-chloro-l~-methyl-methyl-trimethoxy silane, 2-chloro-ethyl-trimethoxy silane, 2-bromo-ethyl-trimethoxy silane, 2-iodo-ethyl-trimethoxy silane, 3-bromo-propyl-trimethoxy silane, 3-chloro-propyl-trimethoxy-silane, 3-iodo-propyl-tri-methoxy-silane, 3 chloro-propyl-triethoxy silane, 3-bromo-propyl-; triethoxy silane, 3-iodo-propyl-triethoxy silane, 2-bromo-P-"

- 2 -~L~3~i3~

methyl-ethyl-tripropoxy silane, 2-ioclo-ethyl-tri-n-butyroxy-silane, 2-chloro-ethyl-tri-2'-methyl--propoxy silane, 3-bromo-propyl-tri-t-butyroxy-silane,3-iodo-propyl-triisopropoxy-silane,

3-bromo-propyl-tri-n-pentoxy silane, 2-chloroethyl-tri-2'-ethyl-ethoxy silane, 2-bromo-2'-methyl-ethyl-dimethoxy-ethoxy silane, 3-iodo-propyl-methoxy-ethoxy-propoxy silane, 3-chloro-propyl-dimethoxy-methyl silane, 3-bromo-propyl-diethoxy-ethyl silane, 3-chloro-propyl-ethoxy-diethyl silane, 3-bromo-propyl-tris-(l'-methoxy-ethoxy) silane, 3-chloro-propyl-diethoxy-phenyl silane, 3-iodo-propyl-dimethoxy-cyclopentyl silane, 3-bromo-propyl-di-n-propoxy-cyclohexyl silane, 3-chloro-propyl-dicyclo-hexoxy-cyclohexyl silane, 3-bromo-propyl-diethoxy-cycloheptyl silane, 3-chloro-propyl-ethoxy-phenyloxyethyl silane, 3-iodo-propyl-benzyloxy-ethoxy-ethyl silane, 4-chloro-n-butyl-trimethoxy silane, 4-bromo-butyl-trimethoxy silane, 3-chloro-2'-methyl-propyl-trimethoxy si.lane, 3-chloro-31-methyl-propyl-cyclooctyl-dipropoxy silane, 3-chloro-2'-ethyl-propyl-diethoxy-methyl silane, 3-bromo-3'-ethyl-propyl-dimethoxy-methyl silane, 3-chloro-2'-methyl-propyl-dimethoxy-phenyl silane, 5-chloro-n-pentyl-triethoxy silane, 4-bromo-1'-methyl-butyl-cyclooctoxy-dimethoxy silane, 4-bromo-2'-methyl-butyl-triethoxy silane, 2-chloro-2'-methyl-ethyl-trioctoxy silaneand 2-iodo-2'-methyl-ethyl-trioctyl-oxy-silane.
Suitable halogen rubbers include, for example, halo-genated butyl rubbers, particularly brominated or chlorinated butyl rubbers, chlorinated rubbers, rubber hydrochlorides and preferably halogenated butyl rubbers and particularly the poly-mers of 2-chloro butadiene-1,3. Under certain conditions chloro-sulphonated polyethylene can also be used.
The silicate fillers which can be used according to the invention, even as a mixture of two or more fillers, are conven-tional fillers in the rubber technology. The term "silicate i3~

filler" is a broad term and r~lates to fillers which are compat-ible with rubber mixtures or can be incorporated therein and con-sist of or contain silicates and/or, in the widest sense, contain chemically bonded silicates. The silicat~ fillers include parti-cularly:
(1) Highly dispersed silica fillers (silicon dioxide~ having specific surface areas ranging from approximately 5 to 1000, pre-ferably from 20 to 400 sq m per gram (determined with gaseous nitrogen by means of the known method according to BET) and primary particle sizes ranging from approximately 10 to 400 nm.
These silica fillers can be produced, for example, by precipita-tion from solutions of silicates with inorganic acids, by hydro-thermal decomposition, by hydrolytic and/or oxidative high-temperature reaction (also known as flame hydrolysis) of volatile silicon halides or by an electric arc process. If required, these silicas can also be in the form of mixed oxides or oxide mixtures with the oxides o~ the metals aluminium, magnesium, calcium barium, zinc, zirconium and/or titanium.
(2) Synthetic silicates, for example, aluminium silicate or 2~ alkaline earth metal silicates, such as magnesium or calcium silicates, having specific surface areas of approximately 20 to 400 sq m per gram and primary particle sizes of approximately 10 to 400 nm.
(3) Natural silicates, for example, kaolin, clays and asbestos as well as natural silicas, as for example, quartz and kieselguhr and

(4) Glass fibres and glass fibre products such as glass fibre mats, rovings, glass cloth, clusters and the like as well as - micromarbles.
The silicate fillers are used preferably in amounts of approximately 10 (or if required in lower amounts) to approxi-mately 250 parts by weight, relative to 100 parts by weight of ' ~ - 4 -~L13~;3()~

the rubber polymer.
The following filler mixtures are mentioned here:
silica/kaolin or silica/glass fibres/asbestos as well as blends of the silicate-containing reinforcing fillers with conventional rubber blacks, for example, silica/ISAF black or silica/glass fibre cord/F~AF black.
Typical examples of the silicate fillers which are suitable according to the invention are, for example, the silicas and silicates produced and sold by DEGUSSA under the trade marks of AEROSIL , ULTR~SIL , SILTEG R, DUROSIL R, EXTRUSIL
CALSIL R, etc.
According to the invention said highly dispersed or active silicas, particularly the precipated silicas are preferred and preferably in amounts of 5 to 150 parts by weight, relative to 100 parts by weight of rubber.
Carbon black may be additionally present in the rubber mixtures according to the invention not only for dyeing tne vulcanizates gray or black but for attaining particularly vàlu-able vulcanizate properties, the conventional rubber blacks being preferred. The carbon black is applied in the rubber mixtures in amounts of 0 to 150 parts by weight, relative to 100 parts by weight of rubber.
In the mixture of the present invention a lower limit with the number zero means that the mixture ingredient can but must not necessarily be present. If carbon black is present in a mixture, then the lower limit must be set practically at 0.1 part by weight.
In case that sllicate filler and carbon black are present in the rubber mixture, the total content of filler rela-tiVe to 100 parts by weight of rubber is limited to a maximumof 250 parts by weight. In general 150 parts by weight can be regarded as the upper limit.

_ 5 _ 3~)9 For the vulcanization the rubber mixtures require at least one vulcanizin~ agent for the corresponding halogen rubber. For this purpose the agents which are conventional in the rubber technology and cause cross-linking or vulcanization are suitable. For example, for polychloro-butadiene rubbers these agents are conventional me~allic oxides such as magnesium, ~inc and/or lead oxide, particularly magn~sium oxide.
The accelerators used in the rubber-processing industry and usually applicable to several rubber types are suitable as accelerators or vulcani~ation accelerators. However, the halogen-rubber mixtures can also contain the special vulcanization accel-erators. The applicable vulcanization accelerators include the dithio-carbamate, xanthogenate and thiuram accelerators as well as the thiazole accelerators, which includes the mercapto and sulphene-amide accelerators, furthermore amine accelerators and aldehyde-amine accelerators, basic accelerators, to which belong, for example, the guanidine accelerators and other basic acceler-ators, see "Vulkanisation und Vulkanisation shilfsmittel", ` comprehensive description by Dr. W. Hoffmann, Leverkusen (Verlag Berliner Union, Stuttgart 1965, page 140 ff, particularly page 122) as well as - independent of the above classification - the general vulcanization-accelerator classes of the mercapto, disulphide, polysulphide, sulphene-amide, thiazole and thiourea accelerators. The thiuram accelerators include substantially the tetraalkyl and dialkyl-diaryl thiuram mono-, di- and tetra-sulphides such as tetramethyl-thiuram monosulphide, tetramethyl-thiuram disulphide, tetraethyl-thiuram disulphide, dipentamethyl-ene-thiuram-monosulphide, disulphide, tetrasulphide and hexa-, sulphide, dimethyl-diphenyl-thiuram disulphide, diethyl-diphenyl-thiuram disulphide, etc.
The dithiocarbamate accelerators usually are derivatives of the dialkyl, alkyl-cycloalkyl and alkyl-aryl-dithiocarbamic ~3~

acids. Two representatives o~ this accelerator class are the N-pentamethylene al~monium-N'-pentamethylene dithiocarbamate and the zinc dialkyl dithiocarbamates.
Xanthogenate accelerators are the known derivatives of the alkyl- and aryl-xanthogenic acids, as for example, zinc ethyl xanthogenate.
The mercapto accelerators include particularly the 2-mercapto benzothiazole, 2-mercapto imidazoline, mercapto thiazo-line as well as a number of monomercapto and dimercapto triazine derivatives tsee, for example, British Patent No. 1,095,219).
Mercapto triazine accelerators are, for example, 2-diethanol-amino-4,6-bis-mercapto triazine and 2-ethyl-amino-4-diethyl-amino-6-mercapto-s-triazine.
Disulphide and sulphenicamide accelerators are dis-closed, for example, in the British Patent 1,201,862, and 2-diethyl-amino-4,6-bis-(cyclohexyl-sulpheneamido)-s-triazine, 2-di-n-propyl-amino-4,6-bis-(n-tert-butyl-sulphene-amido)-s triazineas well as N-cyclohexyl-2-benzothiazole sulphene amide are among them. Examples of the disulphide accelerators are bis-(2-ethyl-amino-4-diethyl-amino-triazin-6-yl)-disulphide and bis-(2-methyl-amino-4-di-isopropyl-amino-triazin-6-yl)-disulphide as well as dibenzothiazyl disulphide.
Further sulphidic triazine accelerators are the poly-sulphidic or oligosulphidic triazine derivatives and their poly-mers which are produced according to the laid-open German Speci-~ication No. 2,027,635 and are also disclosed in the British Patent No. 1,353,532.
The aldehyde-amine accelerators include condensation products of saturated or unsaturated aliphatic aldehydes with ammonia or aromatic amines, as for example, butyraldehyde aniline and butyraldehyde-butyl amine. Other basic accelerators are for example, guanidine derivatives such as diphenyl guanidine 0~

and di-o-tolyl guanidine as well as amine accelerators such as hexamethylene tetramine, etc. The thiourea accelerators include, for example, thiourea itself and the diaryl-thioureas such as 1,3-diphenyl-2-thiourea.
The accelerators of the thiourea class, as for example, ethylene thiourea, are preferably used for the halogen-rubber mixtures according to the invention. However, the mixtures of the thiourea accelerators, the sulphene amide mentioned herein-before, the thiurams or the amines or mixtures of a thiuram accelerator and a guanidine accelerator, if required along with sulphur as the vulcanizing agent, also are particularly suitable.
For the vulcanization of the chloro sulphonated poly-ethylenes preferably magnesium oxides, particularly those having a fine or small particle size are used, if required in combina-tion with one of the thiazole accelerators and/or thiuram accelera-tors mentioned hereinbefore, such as dibenzothiazyl disulphide and/or dipentamethylene-thiuram tetrasulphide. Nickel-dibutyl-dithiocarbamate is preferably used as the antiager. For example, zinc oxides and/or magnesium oxides are used in combination with the accelerators mentioned hereinbefore, as for example, the thiazoles and/or thiurams, for the vulcanization of the halogen rubbers and particularly of the chlorobutyl rubbers.
According to the invention the accelerators are used in the usual amounts, if required in amounts of 0.2 to 10 parts by weight, relative to 100 parts by weight of halogen rubber.
Conventional stabilizers particularly those from the group of antiagers, fatigue inhibitors, anti-oxidants, light-absorbing agents and ozone-resisting agents, as well as mixtures thereof can be present with advantage in the rubber mixtures according to the invention, that is to say, in a~ounts of 0.2 to 10 parts by weight, relative to 100 parts by weight of the halogen rubber.

36i3(~

Moreover, it can be particularly favourable i~ the halogen-rubber mixtures contain plasticizers or plasticizer oils, for example, highly aromatic naphthenic or paraffinic plasticizer oils, and with advantage those having low cold setting points between approximately 0 and -60C. The amount of plasticizer oil can vary within wide limits and can thus be more than 0.5 or

5 parts by weight, particularly more than 10 up to approximately 100 parts by weight.
The halogen silanes mentioned hereinbefore and applied according to the invention are obtained by means of conventional processes from halogen silanes still containing at least one hydrogen atom by catalytically controlled addition to hydrocarbon halide containing a C-C double bond (hydrosilylation). The halogen atom or atoms on the silicon atom are then converted into alkoxy silanes in a reaction which also is known, for example, by alcoholysis.
The halogen rubber mixtures of the present invention preferably contain an organic acid which is solid at room kemper-ature and is like that used in the rubber technology, in amounts from 0.2 to 10 parts by weight, relative to 100 parts by weight of the rubber, preferably fatty acids such as stearic acid or corresponding acids of the homologous series as well as benzoic acid or salicylic acid.
Furthermore oxides of polyvalent metals like those also used in the rubber technology must be added to the rubber mixtures according to the invention in amounts of 0.1 to 15 parts by weight relative to 100 parts by weight of the rubber. One of these metallic oxides is primarily zinc oxide, particularly in a finely divided and/or active form. Moreover, magnesium oxide or possibly lead oxide are quite suitable. These oxides are preferably used in a finely divided, active or powdered form.
Mixtures of the metallic oxides can also be used.

~L~363~

The halogen-rubber mixtures are produced in the usual manner. A two-stage mixiny cycle is preferred. In the ~irst stage the following ingredients are mixed in a kneader at flow temperatures between 55 and 85C, preferably 60C.
Within the first minute the rubber and the metallic oxide, for example, the polychloro butadiene and the magnesium oxide; within the next 1 1/2 minutes one half of the silicate filler and the other fillexs; within the 1 1/2 minutes thereafter the second half of the silicate filler, the organosilane, the plasticizer, for example, the plasticizer oil, and the other ingredients with the exception of both the accelerator and the zinc oxide. After a total of four and one half minutes the mixture is removed from the kneader.
In the second mixing stage the master batch from the first mixing stage is mixed on a pair of mixing rolls with the zinc oxide and the accelerator(s) at a flow temperature of - approximately 45 to 55C, preferably 50C. This two-stage mixing process avoids the premature prevulcanization of the mixture:
Industrial fields of application for the rubber mix-tures described and for their vulcanizates are, for example,-technical rubber articles such as cable sheathing, tubing, air tubes, driving belts, V-belts, conveyer belts, roller covers, washers, electrical insulations, linings, impregnating and coat-ing of heat-resistant fabrics, damping and vibration elements and similar articles which must meet high requirements with respect to resistance to hi~h temperatures and/or to oil. The excellent effect of the halogen silanes havi~g the general formula mentioned hereinbefore particularly in halogen-rubber-containing mixtures and moulding compounds and their cross-linking products and vul-canizates was very surprising.

Examples of formulations for the halogen-rubber mixtures of the present invention are presented hereafter along with test 113~i3~)~

results, including the cross-linking products, with evaluations and comparisons of these results. Many dif~erent terms are repeated so that the following abbreviations are used.
List of Abbreviations Used abbreviation term measured in t5 Mooney scorch time (1:30C)minutes t35 Mooney cure time (130~C) minutes ML4 Mooney plasticity-viscosity at 100C
standard rotor, testing time: 4 min.

VT vulcanization temperature C
lF tensile strength kp/sq cm M100 stress value at 100% kp/sq cm M200 stress value at 200% and kp/sq cm M300 stress value at 300% kp/sq cm strain (moduli) BD elongation %
E shock elasticity SH Shore-A hardness A A abrasion (also known as DIN abrasion) cu ~T heat build-up temperature rise C
(see page 12 Goodrich flexometer) CS compression set B, 22 hours, 70C %

Testing Standards The physical tests were carried out at room temperature according to the following industrial standards:

tensile strength, elongation and stress value on DIN 53504

6 mm rings tear-propagation resistance DIN 53507 shock elasticity DIN 53512 shore hardness DIN 53505 specific gravity DIN 53550 Mooney test DIN 53524 Goodrich flexometer ~determination of the heat build-up ~T) ASTM D623-62 ~136i3~

abrasion, also known as DIN abrasion DIN 53516 determination of the compression set of rubber DIN 53517 The cross-linking products and the test samples were produced in a steam-heated gang press at the defined vulcaniza-tion temperatures and heating times (cross-linking times)~
In the examples the amounts of the mixture ingredients are expressed in parts by weight.
The corresponding comparison mixtures are characterized by the letter "V" preceding the number. The corresponding mix-tures according to the invention are characterized by the letter"E".

Three rubber mixtures were produced from the following ingredients:
. Vl El.l El.2 polychloro-butadiene rubber (chlorine content approximately 38%, viscosity rP-~D~
A 40 to 45 Mooney units: Baypren 210~ f the firm of Bayer A.G. 100 100 100 magnesium dioxide, finely divided 4 4 4 ; stearic acid 20 B /--~D~R~ ~D.~ ~
vaseline ~unctuous pure hydrocarbon mixture from residues of the petroleum distillation) phenyl-~-naphthyl amine 2 2 2 : finely divided precipitated silica (filler Ultrasil R VN3 of the Degussa) 50 50 50 highly aromatic plasticizer oil 10 10 10 3-chloro-propyl triethoxy silane - 2 2-chloro-ethyl triethoxy silane - - 2 ethylene thiourea 0.75 0.75 0.75 zinc oxide, finely divided, active ~ 5 5 5 The determination of the viscosities of the mixtures resulted in the following values:
Vl El.l El.2 3~3~i~

After the moulding of the test specimens produced from the mixtures the cross-linking was carried out at 155C in 60 minutes. The test produced the following values:
Table 1 Mixture V 1 E 1.1 E 1.2 CS 22 h/70C 30.1 10.2 16.9 CS 70 h/100C 44.0 22.6 27.4 The values for the Mooney viscosities (ML 4) show that by the addition of the chloro silanes the viscosities of the rubber mixtures according to the invention, i.e., E 1.1 and E 1.2, are distinctly reduced as compared with the viscosity of the com~
parison mixture V 1 without silane. This is equivalent to a reduction of work. Thus, at lower viscosities a lower energy consumption is required for the production of the mixtures. With-out t~e addition of chloro silane it is even possible that the mixture ingredients cannot be processed to a homogeneous mixture since the viscosity is too high.
The cross-linking products of the mixtures according to the invention show a distinctly increased tear resistance, a sub-stantial increase of the module, a marked improvement of the com-pression set and a decrease in the abrasion. All these measuredvalues for the rubber mixtures according to the invention and their cross-linking products indicate a substantial improvement 113~

of the rubber-technological properties of the cross-linking pro-ducts.
Example 2 Four of the following eight rubber mixtures are mix-tures according to the invention and four are comparison mix-tures.
In each case the comparison mixture is listed first. The co~par-ison mixtures are so-called blank mixtures, i.e., they contain no silane. However, the mixtures according to the invention contain a chloro silane. The four groups (each group comprising two mixtures) contain four different bright fillers.

1~3~3~9 ~iixture Mixture lngredients V2 E2 / V3 E3 V4 E4 ~ V5 É5 FlYchloro-butadiene rubber (BAYPREN 210* see example l) 100,0 100.0 3.0 100.0 100.0 100.0 100.0 100.0 magnesium oxide, finely divided 4.04.0 4.0 4.0 4.0 4.0 ~.0 4.0 . _ _ _ _ stearic acid 1.01.0 1.0 1.0 1.0 1.0 1.0 1.0 ~aseline~4(see example l) 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 . . ... _ _ . .. . .. _. _ _ _ __ antiager poly-2,2.4-trimethyl -1,2-dihydro quinoline 2.02.0 2.0 2.0 2.0 2.0 2.0 2.0 finely divided _ _ ~ _ _ _ __ aluminium silicate (SILTEG ~AS7 of the DEGUSSA -- -- .__ __ 50.0 50.0 __ __ -- ._ precipitated bright reinforcing filler consisting substantially of silica (average primary particle size approxima-tely 25 mm.; surface area according to BET 16 sq m/g DU~OS ~ f the DEGUSSA 50.0 50.0 ~ __ __ __ __ silica filler of average~ ¦
activity (average primary particle size approximately 85 mm; surface area according to I
BET 35 sq m/g EXTRUSIL*of the DEGUSSA) -- --kaolin (so-called hard clay, ! ¦
air-floated. SUPREX~clay of the ~ ~ ~
firm of J.M. Huber) -- -- ) - __ ~ -- -- ~oo.o 100.0 highly aromatic plasticizer oil 10.010.0 ~10.0 10.0 ~10.0 10.0 l10.0 10.0 -3-chloropropyl-triethoxy silane -- 2.0 ~ -- 2.0 ~ -- 2.0 ~ -- 2.0 t ~ .
ethylene thiourea ~0.75 0.75~0.75 0.75 ~0.750.7510.75 0.75 zinc oxide, finely divided active 5.0 5.0 ¦ 5.0 5.0 ¦ 5.0 5.0~ 5.0 5.0 * trademarks 1~3~3~9 The cros$~1inking ~ the eight mixtures ~as carried out after the moulding at 155C in 60 minutes. The testin~ of ~he cross-linking products resulted in the followlng values:

V 2 E 2 V 3 ~ 3 i V 4E 4 V 5 ~ 5 ~ ~ . . ~
ZF 63 117 64 97 j59 9~ 95 125 M loo 2~ 35 21 z5 1~4 31 33 66 M 200 46 83 34 56 ¦44 76 45 120 M 300 _ _ 47 85 ¦~ _ 56 E 42 41~ 46 47 45 50 39 12 CS 22 h/70~C 11,9 595 9-5 5,0 7,3 4,9 40,2 10,~
a T ~5 ~4 54 46 59 47 ~7 75 As is evident from the above Table 2, remarkable improve-ments in the properties of the cross-linking products from the mixtures E2 to E5 according to the invention are again obtained 20 similarly to the improvements described in the preceding example.
: Example 3 Unlike the preceding mixtures the following mixture according to the invention contains a mixture of carbon black and silica as the filler and has the following composition: ~-Mixtures Mixture Ingredients V6 E6 chlorinated butyl rubber (chlorine content 1.1 to 1.3%, viscosity 51 to 60 Mooney units.
A Chlorobutyl HT 10-66~of the firm of Esso Chemicals Co., USA) ~ O~f~ 100 100 low-structured furnace black (average particle size approximately 50 mm, surface area according to BET 30 sq- m/g. CORAX R G of the DEGUSSA)35 35 finely divided precipitated silica (filler ULTRASIL R VN 3 of the DEGUSSA) 35 35 1~3~309 3-chloropropyl-triethoxy silane - 2 stearic acid magnesium oxide 2 2 2,2'-methylene-bis-(4-methyl-6-tert-butyl phenol) highly aromatic plasticizer oil 25 25 zinc oxide, finely divided, active 5 5 tetramethyl-thiuram disulphide dibenzothiazyl disulphide 2 2 The cross-linking was carried out at 160C in 60 minutes.
The testing of the cross-linking products resulted in the follow-ing values:
Table 3 CS 22 h/70C 17.7 9.2 From the values for the mixture E 6 according to the invention it is evident that the most important rubber-techno-logical properties are distinctly improved by the addition of only 2 parts by weight of 3-chloropropyl triethoxy silaneO Thus, for example, particularly the compression set decreases from 17.7 ; to 9.2~. This is a noteworthy improvement.
; Example 4 ~ The following two mixtures contained a further halogen ; rubber and had the following composition:
mixture ingredients V 7 E 7 brominated butyl rubber 100 100 magnesium oxide, finely divided 4 4 stearic acid 1~L3~3~)~

vaseline (see example 1) antiager poly-2,2,4-trimethyl~1,2-dihydro quinoline 2 2 - finely divided precipitated silica (filler ULTRASIL R VN3 of the DEG~SSA) 50 50 highly aromatic plasticizer oil 10 10 3-chloro propyl triethoxy silane - 2 ethylene thiourea 0.75 0-75 zinc oxide, finely divided, active 5 5 The cross-linking of the two rubber mixtures was carried out after the moulding at 165C in 30 minutes. The testing of the cross-linking products resulted in the following values:
Table 4 Z~ 85 90 M 300 69 ~7 CS 22 h/70C 22.7 12.2 The cross-linking products from the mixture E 7 accord-ing to the invention once more show particularly a marked increaseof the moduli and an appreciable decrease of the compression set.
The invention also relates to the process for vulcaniz-ing and cross-linking the halogen rubber mixtures of at least one ~ halogen rubber, at least onesilicate filler.in an amount of 1 to ; 250 parts by weight, magnesium oxide in an amount of 0 to 15 parts by weight, z:inc oxide in an amount of 0.1 to 15 parts by weight, sulphur in an amount of 0 to 15 parts by weight, stearic acid in an amount of 0 to 10 parts by weight, at least one vul-canization accelerator in an amount of 0 to 10 parts by weight, at least one plasticizer in an amount of 0 to 100 parts by weight, at least one stabilizer from the group of antiagers, fatigue inhibitors, antioxidants, light-absorbing agents and ozone ~3~

resisting agents in an amount of 0 to 10 parts by weight, carbon black in an amount of 0 to 150 parts by weight and at least one organosilane by heating the mixtures to temperatures be-tween 100 and 200C after the moulding, during a period between 1 and 200 minutes depending on the heating temperature. This process is characterized in that in the halogen-rubber mixture there is incorporated as the organosilane at least one compound having the general formula X-CmH2m~SiRn(OR)3-n wherein X represents chlorine, bromine or iodine, m represents a number from 1 to 5, R' represents a Cl- to C5- alkyl group, a C5- to C8- cycloalkyl group or the phenyl group, R represents a Cl- to C5- alkyl group, a C5- to C8- cycloalkyl group, the methoxy-ethyl group, the phenyl group or the benzyl group and n is 0, 1or 2, in amounts form 0.1 to 20 parts by weight, all the specified amounts being relative to 100 parts by weight, and that this compound is uniformly distributed in said mixture.
The invention also relates to the use of halogen-containing organosilanes having the above general formula as a reinforcing additive in the cross-linkable and vulcanizable rubber mixtures described hereinbefore.

.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A vulcanizable halogen rubber mixture of at least one halogen rubber, at least one silicate filler in an amount of 1 to 250 parts by weight, magnesium oxide in an amount of 0 to 15 parts by weight, zinc oxide in the amount of 0.1 to 15 parts by weight, sulphur in an amount of 0 to 15 parts by weight, stearic acid in an amount of 0 to 10 parts by weight, at least one vul-canization accelerator in an amount of 0 to 10 parts by weight, at least one plasticizer in an amount of 0 to 100 parts by weight, at least one stabilizer from the group of antiagers, fatigue inhibitors, antioxidants, light absorbing agents and ozone resist-ing agents in an amount of 0 -to 10 parts by weight, carbon black in an amount of 0 to 150 parts by weight and at least one organo-silane, the halogen-rubber mixture containing as organosilane at least one compound having the general formula x-CmH2m-SiR1n(OR)3-n wherein X represents chlorine, bromine or iodine, m represents a number from 1 to 5, R1 represents a C1 to C5- alkyl group, a C5-to C8-cycloalkyl group or the phenyl group, R represents a C1 to C5-alkyl group, a C5- to C8-cycloalkyl group, the methoxyethyl group, the phenyl group or the benzyl group and n is 0.1 or 2, in an amount of 0.1 to 20 parts by weight, all the specified amounts being relative to 100 parts by weight of halogen rubber.

2. A mixture as claimed in Claim 1, in which the halosilane is selected from the group consisting of chloromethyl-triethoxy silane, bromomethyl-triethoxy silane, l-chloro-l-methyl-methyl-trimethoxy silane, 2-chloro-ethyl-trimethoxy silane, 2-bromo-ethyl-trimethoxy silane, 2-iodo-ethyl-trimethoxy silane, 3-bromo-propyl-trimethoxy siline, 3-chloro-propyl-triethoxy-silane, 3-iodo-propyl-trimethoxy-silane, 3-chloro-propyl-triethoxy silane, 3-bromo-propyl-triethoxy silane, 3-iodo-propyl-triethoxy silane, 2-bromo-1'-methyl-ethyl-tripropoxy silane, 2-iodo-ethyl-tri-n-butoxy-silane, 2-chloro ethyl-tri-2'-methyl-propoxy silane, 3-bromo-propyl-tri-t-butoxy-silane, 3-iodo-propyl-triisopropoxy-silane,3-bxomo-propyl-tri-n-pentoxy silane, 2-chloro-ethyl-tri-2'-ethyl-ethoxy silane, 2-bromo-2'-methyl-ethyl-dimethoxy-ethoxy silane, 3-iodo-propyl-methoxy-ethoxy-propoxy silane, 3-chloro-propyl-dimethoxy-methyl silane,3-bromo-propyl-diethoxy-ethyl silane, 3-chloro-propyl-ethoxy-diethyl silane, 3-bromo-propyl-tris-(1'-methoxy-ethoxy)silane, 3-chloro-propyl-diethoxy-phenyl silane, 3-iodo-propyl-dimethoxy-cyclopentyl silane,3-bromo-propyl-di-n-propoxy-cyclohexyl silane, 3-chloro-propyl-dicyclo-hexoxy-cyclohexyl silane,3-bromo-propyl-diethoxy-cycloheptyl silane, 3-chloro-propyl-ethoxy-phenyl-oxyethyl silane, 3-iodo-propyl-benzyl-oxy-ethoxy-ethyl silane, 4-chloro-n-butyl-trimethoxy silane, A-bromo-butyl-trimethoxy silane, 3-chloro-2'-methyl-propyl-trimethoxy silane, 3-chloro-3'-methyl-propyl-cyclooctyl-dipropoxy silane, 3-chloro-2'-ethyl-propyl-diethoxy-methyl silane, 3-bromo-3'-ethyl-propyl-dimethoxy-methyl silane, 3-chloro-2'-methyl-propyl-dimethoxy-phenyl silane, 5-chloro-n-pentyl-tri-ethoxy silane, 4-bromo-1'-methyl-butyl-cyclooctoxy-dimethoxy silane,4-bromo-2'-methyl-butyl-triethoxy silane, 2-chloro-2'-methyl-ethyl-trioctoxy silane and 2-iodo-2'-methyl-ethyl-trioctyl-oxy-silane.

3. A mixture as claimed in Claim 1, in which the halogen rubber is selected from halogenated butyl rubbers, chlorin-ated rubbers and rubber hydrochlorides.

4. A mixture as claimed in Claim 1 or 2 in which the halogen rubber is a halogenated butyl rubber.

5. A mixture as claimed in Claim 1 or 2 in which the halogen rubber is a polymer of 2 chlorobutadiene 13.

6. A mixture as claimed in Claim 1, 2 or 3, in which the silicate filler is a highly dispersed silica filler having a specific surface area in the range 5 to 1,000 square meters per gram and a primary particle size ranging from 10 to 400 nm.

7. A mixture as claimed in Claim 1, 2 or 3, in which the filler is aluminum silicate or an alkaline earth metal silicate having a specific surface area of 20 to 400 square meters per gram and the primary particle size of 10 to 400 nm.

8. A mixture as claimed in Claim 1, 2 or 3, in which the silicate filler is a natural silicate.

g. A mixture as claimed in Claim 1, 2 or 3, in which the silicate filler is present in an amount of 10 to 250 parts by weight relative to a hundred parts by weight of: rubber polymer.

10. A mixture as claimed in Claim 1, 2 or 3, in which the silicate filler is a precipitated silica present in an amount from 5 to 150 parts by weight per hundred parts by weight of rubber.

11. A mixture as claimed in Claim 1, 2 or 3, in which the vulcanization accelerator is a thiourea.

12. A mixture as claimed in Claim 1, 2 or 3, in which the vulcanization accelerator is present in an amount from 0.2 to 10 parts by weight relative to a hundred parts by weight of the halogen rubber.

13. A mixture as claimed in Claim 1, 2 or 3, in which the stabilizer is present in an amount from 0.2 to 10 parts by weight of the halogen rubber.

14. A mixture as claimed in Claim 1, 2 or 3, in which the plasticizer is an oil having a cold setting point between 0°C
and -60°C and is present in an amount from 10 to 100 parts by weight of the halogen rubber.

15. A mixture as claimed in Claim 1, 2 or 3, in which the stearic acid is present in an amount from 0.2 to 10 parts by weight of the halogen rubber.

,

16. A process for vulcanlzing and cross-linking halogen rubber mixtures of at least one halogen rubber at least one silicate filler in an amount of 1 to 250 parts by weight, magnesium oxide in an amount of 0 to 15 parts by weight, zinc oxide in an amount of 0.1 to 15 parts by weight, sulphur in an amount of to 15 parts by weight, a stearic acid in an amount of 0 to 10 parts by weight, at least one vulcanization accelerator in an amount of 0 to 100 parts by weight, at least one plasticizer in an amount of 0 to 100 parts by weight, at least one stabilizer from the group of the antiagers, fatigue inhibitors, antioxidants, light-absorbing agents and ozone resisting agents in an amount of 0 to 10 parts by weight, carbon black in an amount of 0 to 150 parts by weight and at least one organosilane by heating the mixtures after the moulding to temperatures between 100 and 200°C
during a period from 1 to 200 minutes characterized in that in the halogen-rubber mixture there is incorporated as organosilane at least one compound having the general formula X-cmH2m-SiR'n(OR)3-n wherein X represents chlorine, bromine or iodine, m represents a number from 1 to 5, R1 represents a C1- to C5- alkyl group, a C5-to C8- cycloalkyl group or the phenyl group, R represents a C1-to C5- alkyl group, a C5- to C8- cycloalkyl group, the methoxy ethyl group, the phenyl group or the benzyl group and n is 0, 1 or 2, in amounts of 0.1 to 20 parts by weight, all the specific amounts being relative to 100 parts by weight of halogen rubber, and uniformly distributed therein.