DE1171612B - Process for the production of elastomeric molded parts based on organopolysiloxanes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 08 g

German class: 39 b - 22/10

Number: 1171 612

File number: D 36341IV c / 39 b

Filing date: June 15, 1961

Opening day: June 4, 1964

In general, organopolysiloxane elastomers are made by heating mixtures of highly viscous diorganopolysiloxanes, modified (cf., for example, German Patent 936 956) or unmodified reinforcing silica fillers, hydroxyl-containing siloxanes with low molecular weight or silanols (cf., for example, US Pat. No. 2,890,188) and peroxides produced as a hardening agent. The uncured mixtures have a good shelf life, ie they do not stick together. The elastomers have good heat resistance, sufficient elasticity and tensile strengths of up to 70 kg / cm ² . What is unsatisfactory in the case of the organopolysiloxane elastomers, however, is their relatively low tear resistance. By modifying the components of the mixture in terms of type and quantity ratio in the uncured molding compositions, changes were achieved in all other properties of the elastomers produced from them, but the tear resistance has not yet been significantly improved.

A process has already become known, according to which the molding compound, which has not yet been mixed with peroxide hardener, is advantageously heated for some time with simultaneous processing in a dough mixer or kneader. After the subsequent addition of peroxide and hardening, an elastomer is obtained with physical properties which are better than those of a product which has been produced without this intermediate heating. But here the tear after heat aging 24 hours at 250 ⁰ C is inadequate.

Finally, it is known to use diorganopolysiloxanes with silica fillers that have a large surface area have, and to cure amines, it being possible for elevated temperatures to be used. Such a thing The hardening process, however, only represents a catalyzed tightening or "structure" - Formation, so that the elastomers obtained in this way cannot withstand repeated mechanical stress.

In contrast, the process according to the invention relates to the production of organopolysiloxane elastomers by peroxide hardening. In contrast to the organopolysiloxane elastomers previously produced by peroxide curing the elastomers produced according to the invention have a particularly high tear resistance, combined with high elasticity and tensile strength, which are retained even with heat aging will.

The process according to the invention for producing elastomeric molded parts by at least 5 minutes for producing elastomeric parts
Moldings based on
of organopolysiloxanes

Applicant:

Dow Corning A. G., Basel (Switzerland)

Representative:

L. F. Drissl, lawyer,

Munich 23, Clemensstr. 26th

Named as inventor:

Thomas D. Talcott, Midland, Mich. (V. St. A.)

Claimed priority:

V. St. v. America June 15, 1960 (36 139) - -

ten during heating at a temperature of 300 ⁰ C of mixtures

(A) 100 parts by weight of organopolysiloxanes with at least 150 siloxane units per molecule and an average of at least 1.99 monovalent, optionally halogenated hydrocarbon radicals each Si atom,

(B) 20 to 90 parts by weight of silica fillers with a surface area of at least 50 m ^a / g and

(C) at least 0.01 part by weight per part by weight (B) of organosilicon compounds which on average 0.1 to 2 hydroxyl and / or alkoxy groups and 1 to 3 Si-bonded perfluoroalkylethyl radicals with less as 13 carbon atoms or monovalent hydrocarbon radicals per molecule and Si atom, where in each molecule no more than about 3 Si atoms

are present in which the only organic radicals are two aliphatic, monovalent hydrocarbon radicals per Si atom are bound and in which all remaining valences of the silicon atom are saturated by siloxane residues, in the absence of peroxides, cooling, subsequent addition of peroxides and renewed heating characterized in that the heating carried out in the absence of the peroxides in the presence of

(D) at least 0.01 part by weight per 100 parts of (B) soluble or easily dispersible in (A)

(a) amino compounds having a basic dissociation constant in dilute aqueous solution of at least 10 ^-7 / 25 ^° C or

409 598/472

(b) quaternary hydrocarbon-substituted ammonium hydroxides or

(c) salts of carboxylic acids containing active hydrogen atoms only in carboxyl groups, and (1) basic amino compounds that contain active hydrogen atoms only in H - N bonds, while the remaining nitrogen valences are saturated by carbon atoms, (2) quaternary ammonium hydroxides or (3) metals of the electromotive series of metals from lead to manganese.

The surface area of the fillers given above relates to the measurement by nitrogen adsorption according to the ASTM Special Technical Bulletin No. 51, pp. 95ff. (1941), described method.

The organopolysiloxane (A) is preferably a linear diorganopolysiloxane. As examples of organic Residues in the organosiloxane (A) may be mentioned: alkyl radicals such as methyl, ethyl, isopropyl, tert-butyl, 2-ethylhexyl, dodecyl, octadecyl or myricyl radicals, alkenyl radicals such as vinyl, allyl, decenyl or hexadienyl radicals, cycloalkyl radicals such as cyclopentyl or cyclohexyl radicals, cycloalkenyl radicals such as Cyclopentenyl, cyclohexenyl or cyclo-2,4-hexadienyl radicals, aryl radicals such as phenyl, naphthyl or Xenyl radicals, aralkyl radicals such as benzyl, phenylethyl or xylyl radicals, and alkaryl radicals such as toluyl or Dimethylphenyl radicals. Examples of halogenated monovalent hydrocarbon radicals in the siloxane (A) are Chloromethyl, 3,3,3-trifluoropropyl, 3,3,4,4,5,5,5-heptafluoropentyl, Perchlorophenyl, 3,4-dibromocyclohexyl, α, α, α-trifluorotoluyl-, 2,4-dibromobenzyl-, Difluormonochlorovinyl- «, / 5, / 3-Trifluor-« - chlorocyclobutyl- or 2-iodocyclopenten-3-yl radicals.

The organopolysiloxane (A) can be some monoorganosiloxane and contain SiO _4/2 units, provided that the average number of organic radicals per Si atom in the molecule is not less than 1.99. Terminal triorganosiloxy units and other terminal groups customary in such polysiloxanes, such as hydroxyl, alkoxyl or acyloxy radicals, can also be present. Preferably there are more than 300 siloxane units per molecule. The viscosity of the siloxanes (A) is expediently at least 2000 cSt / 25 ° C. There is no decisive upper limit. If desired, polysiloxanes with 10,000 or more siloxane units per molecule can be used, as long as their viscosity of more than 10 »cSt / 25 ° C. does not make the preparation of the mixture too difficult. In general, the diorganopolysiloxanes used to produce organopolysiloxane elastomers are in a viscosity range from about 1,000,000 cSt up to 1,000,000,000 cSt / 25 ° C.

As silica filler (B), for example silica obtained pyrogenically in the gas phase, silica hydrogel (airgel) dehydrated while maintaining the structure, or a silica xerogel can be used. In general, the greater the surface area of the silica, the more suitable it is as a reinforcing filler. It is therefore expedient if the silica of at least 150m ² / g, a surface, preferably above 300 m ² / g has. There is no critical upper limit to the surface area of the silica, it can be 900 m ² / g or more.

As the organosilicon compound (C), silanes or low molecular weight siloxanes can be used will. The alkoxy radicals can, for example, methoxyl, ethoxyl, isopropoxyl-tert-butoxyl, Be 2-ethylhexoxyl, dodecoxyl or octadecoxyl radicals. However, the alkoxy radicals preferably contain less than 4 carbon atoms.

Examples of perfluoroalkylethyl radicals with fewer than 13 carbon atoms are CF ₃ CH ₂ CH ₂ , C ₂ F ₅ CH ₂ CH ₂ , C ₇ F ₁ SCH ₂ CH ₂ or C ₁₀ F ₂₁ CH ₂ CH ₂ radicals.

Examples of silicon-bound monovalent hydrocarbon radicals in organosilicon compounds

ίο (C) are alkyl radicals such as methyl, ethyl, isopropyl, tert-butyl, 2-ethylhexyl, dodecyl, octadecyl or myricyl radicals, alkenyl radicals such as vinyl, allyl, decenyl or hexadienyl radicals, Cycloalkyl radicals, such as cyclopentyl or cyclohexyl radicals, cycloalkenyl radicals, such as cyclopentenyl, cyclohexenyl or cyclo-2,4-hexadienyl radicals, aryl radicals, such as phenyl, naphthyl or xenyl radicals, and alkaryl radicals, such as toluyl or dimethylphenyl radicals, or dimethylphenyl radicals -, phenylethyl or xylyl radicals. If there are more than about three Si atoms substituted by two aliphatic monovalent hydrocarbon radicals per siloxane molecule, this leads to inferior properties in the elastomer obtained as the end product, regardless of which other organic radicals are bonded to the remaining Si atoms in (C) are. Preferably no more than one aliphatic, monovalent hydrocarbon radical is bonded to each Si atom of (C).
The organosilicon compound (C) can be built up, for example, according to the following formulas:

YSiR'R ₂ "

YSiR ₂ '"R"

YSiR ₃ "

YSiR ₃ '"

YSiR ₂ "R '"

Y ₂ SiR ₂ '

Y ₂ SiR'R "

Y ₂ SiR'R '"

Y ₂ SiR ₂ "

Y ₂ SiR "R '"

Y ₂ SiR ₂ '"

YSiR ₂ "OSiR ₂ " Y

YSiR'R "(OSiR'R") ₁₂ Y

YSiR "R '" (OSiR "R'") ₁₇ Y

YSiR ₂ '"(OSiR ₂ '") ₂ Y

R'R ₂ "Si (OSiR'R") ₅ Y

R ₃ "SiO SiR" Y ₂

Y ₂ SiR '"(OSiR"R'") ₆ OSiR '" Y ₂

Y ₂ SiR '"(OSiYR'") _e OSiR '"Y ₂

or

YSi (OSiR "R ₂ '") ₃

In the above formulas, R 'denotes one of the Si-bonded perfluoroalkylethyl radicals described above, R "denotes an Si-bonded aliphatic monovalent hydrocarbon radical, R'" denotes an Si-bonded monovalent non-aliphatic hydrocarbon radical and Y a hydroxyl and / or alkoxy radical.
The above list does not include all possible types of connections; it is only intended to indicate the multitude of possible configurations. It is advisable not to use more than 1 part (C) per part (B).

turns. It is preferable to use 0.1 to 0.8 parts (C) per part (B).

The compound (D) used in the present invention must be mixed with the siloxane (A) in an amount of at least 0.01 part by weight per 100 parts (B) compatible, i.e. H. be soluble or easily dispersible therein.

To be used according to the invention amino compounds (a) having a basic dissociation constant in dilute aqueous solution of at least 10 ^-7 / 25 ° C include ammonia and primary, secondary or tertiary amines, or any combination of these compounds. Examples of such amines are: brucine, sec-butylamine, cocaine, diethylbenzylamine, diethylamine, diisoamylamine, diisobutylamine,

Examples of quaternary, hydrocarbon-substituted ammonium hydroxides (b) are tetramethylammonium hydroxide, Benzyltrimethylammonium hydroxide or phenyltrimethylammonium hydroxide.

The cation in the salts (c) of a carboxylic acid and a (1) basic ammonium compound can be from ammonia as well as from organic primary, secondary or tertiary amines (including organosilyl amines). The amine can be one or have several amino groups and also C-bonded Si atoms and any other functional contain organic groups without active hydrogen atoms. It is only important that the in

Dimethylamine, dimethylaminomethylphenol, _ dirne- 15 these amines any active hydrogen ethylbenzylamine, Dipropylamine, ethylamine, ethylene atoms, d. H. Hydrogen atoms linked to methyldiamine, Hydrazine, isoamylamine, isobutylamine, iso- i

propylamine, menthandiamine, methylamine, methyldii li ii

pp

ethylamine, tert-octylamine, tert-nonylamine, piperidine,

Examples of which can be used to produce according to the invention Amines suitable for use with salts are: o-aminoacetanilide, iminodiacetonitrile, m-aminoacetophenone, Allylamine, N-methylallylamine, amylamine, Ν, Ν-dimethylamylamine, aniline, p-bromoaniline, 2,6-di-

magnesium iodide form methane at room temperature, are bound exclusively to nitrogen atoms. Other functional groups can be present, as can be seen from the n-propylamine, tert.-octadecylamine, quinine, tetra- 2 ° the following examples:
methylenediamine, triethylamine, triisobutylamine, the expression "basic amino compounds"

Trimethylamine, trimethylenediamine, tripropylamine, meets compounds that contain at least 1 nitrogen atom L-arginine, L-lysine, aconitine, benzylamine, cincho- contain, to which no more than 3 carbon atoms are bound nidin, codeine, coniin, emetine, ethanolamine, o-meth- are those with any double bonds present oxybenzylamine, m-methoxybenzylamine, p-methoxy 25 are only bonded to carbon atoms, such as. B. the group benzylamine, Ν, Ν-methoxybenzylamine, o-methylben- pation

zylamine, m-methylbenzylamine, p-methylbenzylamine, C = C NH ₂

Ν, Ν-methylbenzylamine, morphine, 'nicotine, p-aminobenzoic acid - diethylaminoethyl ester, ε - phenylamylamine, o-phenylbutylamine, / S-phenylethylamine, / 3-phe- 30
nylethylmethylamine, y-phenylpropylamine, Ν, Ν-isopropylbenzylamine, physostigmine, piperazine, quinidine,
Solamine, Sparteine, Tetramethylguanidine, Thebaine,
tert-butyl-2,4-dinitrophenylamine, tert-butyl-2-hydroxy-5-nitrobenzylamine, tert-butyl-4-isonitrosoamyl-35 nitroaniline, m-fluoroaniline, symm. bis-y-aminopropylamine, tert-octylamylamine, tert-octyl-2 - (/ 3-butoxy- tetramethyldisiloxane, y- (N-aminoethylamino) propylethoxy) ethylamine, 2,4,6-tris (dimethylamino) -phenol diphenylmethylsilane, o-iodoaniline, o-nitroaniline, 2,3,4, or veratrine. Also suitable are condensation 5-tetrachloroaniline, o-anisidine, 9-anthrylamine, 4,4'-diproducts of aliphatic aldehydes and aliphatic aminoazobenzene, anthranilonitrile, benzylamine, p-metic primary amines, for example those of form-thoxybenzylamine, decylamine , Diallylamine, dicycloaldehyde and methylamine, of acetaldehyde and allylhexylamine, diethylenetriamine, difurfurylamine, diamine, of crotonaldehyde and ethylamine, of isom-toluylamine, / S-ethoxyethylamine, tetrahydrofurfurylbutyraldehyde and butyraldehyde and ethylamine, of Benzylhydrazine, p-bromophenylhydraamine, of a, jS-dimethylacrolein and amylamine, of zin, 1-methyl-1-phenylhydrazine, 4,4'-diaminohydrazo-butyraldehyde and butylamine, of acrolein and allyl-45 benzene, p ₃ -leucaniline, Methylamine, morpholine, 5-amine as well as formaldehyde and heptylamine. Beetronaphthylamine, 1,2-dimethyl-4-pentenylamine, N, N-

Diethyl-p-phenylenediamine, piperazine, piperidine, 2-aminopyridine, 6-nitro-o-toluidine, 2-amino-p-tolunitrile, 9-phenanthrylamine or tribenzylamine. The degree of compatibility of a salt with the Organopolysiloxane (A) depends on the total number of C and Si atoms present and their arrangement in the salt to be used. For example, with a given polysiloxane, this is the case n-hexylamine salt of octanoic acid compatible, the di-n-hexylamine salt of succinic acid not compatible, while the dieicosylamine salt of succinic acid is again compatible. For each to be used Organopolysiloxane, suitable salts can be selected depending on their compatibility.

The most compatible and therefore preferred salts are salts of monocarboxylic acids with at least 6 carbon atoms. The following monocarboxylic acids are suitable for production, for example Ammonia can be used in the form of these salts which can be used according to the invention: Abietindaß the mixture components (A), (B) and (C) acid, acetic acid, cyanoacetic acid, phenoxyessigin an ammonia atmosphere, acrylic acid, ß-benzoylacrylic acid, Angelica rolled. acid, anisic acid, N-acetylanthranilic acid, arachidonic acid

y py

preferred organic amines are the amino hydrocarbons; H. Hydrocarbons in which the the only functional atoms are amine nitrogen atoms.

As amines, for example, aminoorganosilicon compounds, like the disiloxanes of the formula

which are described in German patent specification 869 956, or the silanes of the formula

described in U.S. Patent 2,662,909 can be used.

7 8

acid, anthropic acid, benzoic acid, o-bromobenzoic acid salts are those which contain unreacted acidic acid, p-cyanobenzoic acid, 2,6-dichlorobenzoic acid, such as 2,5-dinitrobenzoic acid, m-fluorobenzoic acid, brassidic acid, dl-campholic acid, Capric acid, cinnamic acid,
Cyclohexanecarboxylic acid, cyclopropanecarboxylic acid, 5 'formic acid, 3-furancarboxylic acid, trimethylsilyl-HOC (CHa) ₆ COH ₃ NC ₁₄ H ₂₉ acetic acid, 5-nitro-2-furonic acid, 10-hendecenoic acid, basic salts are those in which unreacted isobutyric acid, lauric acid , Laevulinic acid, ligno-amino groups, such as in cennic acid, linoleic acid, oleic acid, stearic acid, tetra

hydrobrentic acid, 3-ethylpentanoic acid or ίο Ο

2,4-xylene acid. i

Polycarboxylic acids can optionally also be used in the case of H ₂ NCH ₂ CH _{2 NHCH 2} CH ₂ Nh ₃ OCC ₁₅ H _{31 in} the preparation of those used according to the invention

Amine salts have been used. Examples of such Further examples of acids which can be used according to the invention are: adipic acid, azelaic acid, o-carboxy 15 baren amine salts are: di-2-ethylhexylamine acetate, methoxybenzoic acid, 1-camphoric acid, 1,2-cyclobu-triphenylsilpropylamine formate, trimethylsiloxydimetanedicarboxylic acid, symm. bis - /? - carboxyethyl tetramethylsilhexylamine hexoate, 4,4'-diaminobenzophenonbutyldisiloxane, 1,2,3,4,5, o-cyclohexane hexacarboxylic acid, tyrate, 4,4'-diaminodiphenyl ether decanoate, tri-n-butyl-1,2-cyclopentanedicarboxylic acid, Diphenic acid, ethylamine acrylate, 3,4-dichloroaniline caproate, aniline octanoate, malonic acid, pimelic acid, sebacic acid, succinic 20 didodecylamine - ο - chlorophenoxyacetate, ethylamic acid or l-decene-lj10-dicarboxylic acid. An amine salt 3-ethoxypropionate, diethylenetriamine monooleate, Dieiner Polycarboxylic acid must have more carbon atoms than isopropylamine palmitate, trimethylamine stearate, benzyl than an amine salt of a monocarboxylic acid to make it hydrazine hexoate, 2,5-dimethylpiperazine octoate, dimit the organopolysiloxane (A) is compatible. Bei- (octadecylamine) sebacate, ethylenediamine dihexoate or for example, hexylamine-2-ethylhexoate with an ammonium stearate and salts of any of the given mixture better tolerated and reactive to other amines and acids listed above, capable as bis-eicosylamine succinate, which more than three times As examples of carboxylic acid salts, their cations contains as many carbon atoms, but still less of quaternary ammonium hydroxides, d. H. from compatible and therefore less reactive. already derived under (b) compounds Under the same conditions, the 30 are in general, be tetramethylammonium-2-ethylhexoate, Ben-compatibility organosilyl amine salts of these sauzyltrimethylammonium acetate or phenyltrimethylren a little better. called ammonium hexoate.

The amine salts are produced by converting to the metals of the electromotive voltage ammonia, an organic amine or a range of the metals from lead to manganese, of which Aminoorganosilicon compound with a carbon 35 also usable carboxylic acid salts of acid can be derived by simply mixing, practically in waste metals, include lead, tin, Essence of water, the reactants as nickel, cobalt, iron, cadmium, chromium, or zinc such or in a common solvent in manganese. The term "carboxylic acid salt" includes obtained in a known manner. also those salts, the hydrocarbon residues to the

The amine salts can contain neutral, acidic metal bound in terms of their formula, i.e. organometallic salts,

or be basic. Among the neutral salts are, for example, dibutyltin diacetate.

to understand those who do not have unreacted examples of salts which can be used in the present invention

Contain amine or acid groups, such as the naphthenates of the above metals,

Salts of fatty acids, salts of aromatic carbon

OO 45 acids, salts of polycarboxylic acids or salts of

! Hydroxycarboxylic acids.

ic χι \ xrtrnr-r ¹ tr xrtr oAr- u Because of the better compatibility with the

(C ₂ H ₅ J ₃ JNHUCC ₇ H ₁₅ JiNrI ₄ UCC ₁₇ JrI ₃₅ ° ,., / ₄ \ j? T_-ja * * 11

Organopolysiloxane (A) are also used in the metal

Q salt those of carboxylic acids with more than

ρ 50 about 6 carbon atoms preferred.

u ^{The connection} S ( ^D ) ^{must go so far with the} organ

H ₂₆ polysiloxane (A) compatible that they are in one

_n amount of at least 0.01 part by weight (D) each

^υ Y 100 parts (B) can be evenly distributed in it.

'■ II 55 There is no critical upper limit, however

C ₁₂ H ₂₅ NH ₃ OC (CHjS) ₆ COH ₃ NC ₁₂ H ₂₅ brings one over about 20 parts by weight (D) per 100 parts

_{O (} j _er (B) excess amount no advantage.

_The range of quantities used is between 0.1 and 10

^{υ υ} parts by weight (D) per 100 parts (B).

^;: "60 The mixture of components (A), (B), (C)

C ₅ H ₁₁ COH ₃ N (CH ₂ ) ₄ NH ₃ OCC ₅ H _{11 un (} j (£>) _w j _{r (} j at least 5 minutes, preferably

but at least 1 hour, at a temperature up to

Such a formula neutral salts react according to 300 ⁰ C in the absence of Peroxydhärters heated, after the basic and acidic character of comparable wherein it is preferably processed in a known manner, often in a sour used amines and acids or 65 dough mixer or kneader. After the basic. This acidity or basicity can be compensated for by cooling in a known manner by adding an excess of the respective amine or more of the customary organic acids or acids. oxides, for example benzoyl peroxide, bis-dichloro

benzoyl, dicumyl, tert-butyl peroxide or tert-butyl perbenzoate, in an amount of 0.1 to 10 parts by weight per 100 parts of the organopolysiloxane (A). Preferably less than 5 parts of organic peroxide per 100 parts (A) are used. The usual peroxide hardening is carried out by heating to a suitable temperature until the peroxide is activated and the hardening takes place. This curing is usually carried out in a press in 1 to 15 minutes at temperatures of 100 to 300 ⁰ C. The usual hot air post-curing or tempering can then be carried out.

The mixture of components (A), (B), (C) and (D) can contain conventional additives, e.g. B. those for Increase in heat resistance, to reduce permanent deformation, as well as pigments before Heating in the absence and / or prior to heating in the presence of peroxides can be incorporated.

The elastomers obtained according to the invention can be used in all fields, for example for the production of Hoses or seals. Since the elastomers produced according to the invention are better have physical properties than comparable products available to date, they can can be used particularly advantageously if there are higher requirements in terms of tensile strength, tear resistance, Elongation and heat resistance can be provided.

In the following examples, all quantities are based on weight. When specifying the physical properties, D means the Shore hardness, T the tensile strength in kg / cm ² , E the elongation at break in% ^and d -K the tear strength in kg / cm. The surface of the silica was each determined by nitrogen adsorption in accordance with ASTM Special Technical Bulletin, No. 51, p. 95 ff. (1941).

example 1

100 parts of a copolymer containing terminal vinyl groups of 99.858 mole percent dimethyl and 0.142 mole percent methylvinylsiloxane units with a Williams plasticity of about 1.5 cm, corresponding to about 20 · 10 ⁶ cSt / 25 ° C or an average of about 3400 siloxane units per molecule, 50 parts of a reinforcing fumed in the gas phase silica obtained with a surface area of about 325 m ² / g, 30 parts of diphenyldimethoxysilane and 2 parts of n-hexylamine were miteiander verwalzt and heated in a convection oven for 8 hours 15O ⁰ C, cooled, diluted with 1 part Bis-dichlorobenzoyl peroxide rolled and. Cured for 5 minutes at 125 ° C and 105 kg / cm ^2. A sample M of the cured mass was post-cured in an oven at 150 ° C. for 1 hour and at 250 ° C. for 4 hours. Sample N was post-cured for 1 hour at 15O ⁰ C and 24 hours at 250 ⁰ C. The blank sample P corresponds to the other samples, but was produced without the use of an amine. It was also post-cured for 1 hour at 150 ° C and 4 hours at 250 ° C in an oven. The physical properties of these elastomers can be seen from Table I:

Example 2

100 parts of a copolymer containing terminal hydroxyl groups of 92.358 mole percent dimethylsiloxane, 7.5 mole percent phenylmethylsiloxane and 0.142 mole percent methylvinylsiloxane units with a Williams plasticity of about 1.5 cm, 45 parts of a reinforcing, pyrogenic silica obtained in the gas phase with a surface area of about 420 m ² / g, 18 parts Diphenylsüandiol and 0.3 parts iron octoate were verwalzt together, heated in a convection oven for 8 hours at 200 ° C, cooled, diluted with 0.60 parts of tert-butyl perbenzoate verwalzt, 10 minutes at 149 ⁰ C and 35 kg / cm ² and post-cured for 24 hours at 250 ° C in the oven.

T Table II E. R. D. 91 390 27.6 58

Example 3

100 parts of the copolymer used in Example 1, 45 parts of the reinforcing used in Example 2, pyrogenically in the gas phase silica obtained, 18 parts of diphenylmethylsilanol and 1 part of stannous octoate were miteiannder verwalzt, heated for 3 hours at 200 ⁰ C in a forced air oven, cooled, diluted with 1 part bis-dichlorobenzoyl peroxide rolled, cured for 5 minutes at 115 ° C and 35 kg / cm ² and post-cured for 24 hours at 250 ° C in an oven.

Table III

D. T E. R. Blank sample
(without tin
octoate) 47
65 77
60 540
250 32.2
14.6

Table I.

sample D. T E. R. M. 40 107 735 38.2 N 46 94 610 31.1 P. 70 70 200 12.6

60

65 Mixtures of the poisonous composition, in which only the tin octoate is replaced by lead naphthenate, cobalt octoate, Dibutyltin dibenzoate or dibutyltin dilaurate in the respective corresponding molar amounts Amounts replaced yielded elastomers with similar properties.

Example 4

100 parts of the copolymer used in Example 1, 45 parts of a reinforcing silica obtained pyrogenically in the gas phase with a surface area of about 400 m ² / g, 18 parts

HO [Si (C ₆ H ₅ ) (CH ₃ ) OkH,

where χ has an average value of 7, and

2 parts of diethylamine were rolled together,

Heated for 3 hours at 150 ° C in a forced air oven, cooled, dichlorbenzoylperoxyd bis-verwalzt with 1 part, 5 minutes at 115 ⁰ C and 35 kg / cm ² and 24 hours at 250 ⁰ C postcured.

T Table IV R. D. 86 30.3 50 E. 630

409 598/472

Equivalent results are obtained with 43 parts of HO [Si (C ₆ H ₆ ) (CH ₃ ) O] ₁₇ H instead of 18 parts of HO [Si (C ₆ H ₅ ) (CH ₃ ) O] _{7 H.}

Example 5

In each case 100 parts of the copolymer used in Example 2, 45 parts of the reinforcing pyrogenically obtained silica used in Example 2 and 2 parts of diethylamine were mixed with 20 parts of HO [Si (CH ₃ ) ₂ O] ₃ H (sample S) or . verwalzt with 30 parts of trimethylsilanol (sample T), heated for 3 hours at 150 ⁰ C in a convection oven; after cooling, with 1 part of tert-butyl peroxide verwalzt, post-cured in the oven 35 kg / cm ² cured 10 minutes at 171 ° C and for 4 hours at 25O ⁰ C.

Table V Table VII

D. T E. R. 50 65 370 22.0

sample D. T E. R. S.
T 50
41 92
113 660
640 24.0
27.2

Example 8

100 parts of the highly viscous polysiloxane used in Example 7, convertible into an elastomer, 50 parts of the reinforcing pyrogenically obtained silica used in Example 2, 25 parts of 3,3,3-trifluoropropylmethylsilanediol and 2 parts of diethylamine were rolled together for 3 hours heated at 150 ⁰ C in a convection oven, after cooling, with 1 part of bis-dichlorbenzoylperoxyd verwalzt, 5 minutes at 115 ° C and 35 kg / cm ² and cured for 24 hours at 250 ° C post-cured in the oven.

Table VIII Example 6

In each case 100 parts of the copolymer according to Example 2, 45 parts of the reinforcing, pyrogenically obtained silica according to Example 2 and 12 parts of diphenylmethylsilanol were mixed with 2.0 parts of diethylamine (sample U), 2.0 parts of tributylamine (sample V), 2 , 0 parts of di-n-hexylamine-2-ethylhexoate (sample W) rolled, ^{heated for 3 hours at 177 0} C in a convection oven, after cooling, rolled with 1 part of bis-dichlorobenzoyl peroxide, 5 minutes at 115 ° C and 35 kg / cm ^2, and post cured for 4 hours at 250 ⁰ C.

D. T E. R. 57 64 310 23.6

Table VI sample E. R. U 570 23.6 V 570 24.0 W. 510 23.6 Blank sample 370 15.8 (without amine)

In the same procedure, 13 parts of diphenylmethylsilanol were used in place of 12 parts and 2.0 parts of phenyltrimethylammomum hydroxide were used in place of 2.0 parts of diethylamine. The elastomer has an elongation at break of 540% ^for> d a tear strength of 22.8.

Example 7

100 parts of a 3,3,3-trifluoropropylmethylpolysiloxane with terminal hydroxyl groups with an average of 5000 to 7000 diloxane units per molecule, 50 parts of a reinforcing silica obtained pyrogenically in the gas phase with a surface area in the range from 180 to 250 m ² / g, 20 parts of HO [Si (CH ₃₎ (CH ₂ CH _a CF3) O] _i, H, where y has an average value of about 11 has, and 1 part of n-hexylamine were miteiander verwalzt, under a slight vacuum heated for 3 hours at 150 ⁰ C, by bis-dichlorbenzoylperoxyd verwalzt cooling, with 1 part, cured for 5 minutes at 115 ° C and 35 kg / cm ² and cured for 24 hours at 200 ⁰ C in the oven. When using 3,3,3-trifluoropropylmethyldimethoxysilane, 3,3,4,4,5,5,5-heptafluoropentyldimethylsilanol, bis-3,3,3-trifluoropropyldipropoxysilane or 3,3,3-trifluoropropylphenylsilanediol instead of those just used 25 parts of a fluoroalkylsilanol in the appropriate molar amounts will give similar results.

Example 9

In each case 100 parts of the copolymer used in Example 2, 30 parts of a reinforcing silica xerogel with a surface area of 720 m ⁸ / g, 25 parts of HO [Si (C ₆ H ₅ ) (CH ₃ ) OkH, where χ has an average value of 7 has, N-methylbutylamine, benzylamine or piperazine are mixed with 2 parts of ethylenediamine, kneaded to various mixtures which are heated in a convection oven, with further kneading for 4 hours at 15O ⁰ C. After cooling, the mixtures are each verwalzt with 1 part of bis-dichlorbenzoylperoxyd, 5 minutes at 115 ° C and 35kg / cm ^a cured and post-cured for 24 hours at 25O ⁰ C in an oven. The elastomers obtained have significantly better physical properties with regard to elongation and tear resistance than the corresponding elastomers produced without the use of an amine.

Example 10

In each case 100 parts of the copolymer used in Example 2, 75 parts of the reinforcing pyrogenically obtained silica used in Example 2, 30 parts of diphenylsilanediol are mixed with 0.5 part of the condensation product of formaldehyde and methylamine, n-hexylamine octoate, di-2- äthylhexylaminacetat, Trimethylaminstearat, Äthylendiamindihexoat, ammonium stearate or Benzyltrimethylammoniumhexoat kneaded at various mixtures and then heated for 8 hours at 200 ⁰ C under a slight vacuum while further kneading. After cooling, the mixtures are each rolled with 1 part of bis-dichlorobenzoyl peroxide and cured for 5 minutes at 115 ° C. and 35 kg / cm ²

post-cured for 24 hours at 250 ⁰ C in the oven. The elastomers obtained have significantly better physical properties with regard to elongation and tear resistance than the corresponding elastomers produced without the use of an amine compound.

Claims (1)

Claim: Process for the production of elastomeric molded parts by heating mixtures ^{at a temperature of up to 300 ° C. for at least 5 minutes} (A) 100 parts by weight of organopolysiloxanes with at least 150 siloxane units per molecule and an average of at least 1.99 monovalent, optionally halogenated hydrocarbon radicals per Si atom, (B) 20 to 90 parts by weight of silica fillers with a surface area of at least 50 m ² / g and (C) at least 0.01 part by weight per part by weight (B) of organosilicon compounds which on average 0.1 to 2 hydroxyl and / or alkoxy groups and 1 to 3 Si-bonded perfluoroalkylethyl radicals with fewer than 13 carbon atoms or monovalent hydrocarbon radicals per molecule and Contain Si atoms, with no more than approximately 3 Si atoms present in each molecule on which the only organic radicals are two aliphatic, monovalent hydrocarbon radicals bonded to each Si atom and in which all remaining valences of the silicon atom are saturated by siloxane residues are, in the absence of peroxides, cooling, subsequent addition of peroxides and more Heating, characterized in that this takes place in the absence of the peroxides Heating in the presence of (D) at least 0.01 part by weight per 100 parts of (B) of soluble or easily dispersible in (A) (a) amino compounds having a basic dissociation constant in dilute aqueous solution of at least 10 ^-7 / 25 ° C. or (b) quaternary hydrocarbon-substituted ammonium hydroxides or (c) salts of carboxylic acids containing active hydrogen atoms only in carboxyl groups, and (1) basic amino compounds that contain active hydrogen atoms only in an H — N bond, while the remaining nitrogen valencies are saturated by carbon atoms, (2) quaternary ammonium hydroxides or (3) metals of the electromotive series of metals from lead to manganese. Considered publications:
German patent specification No. 949 604. 409 598/472 5.64 © Bundesdruckerei Berlin