DE2410912A1 - Silicon-containing vulcanisable rubber - by ring-opening (co) polymn. of silicon-contg. norbornene derivs with organometal cpd. catalyst - Google Patents

Abstract

Silicon-contg. rubber polymer is prepd. by polymerising a bicyclic monoolefin of formula: (where R1, R2, R3, R6, R7 and R8 are each halogen, alkyl or haloalkyl; R4 and R5 are each H or lower alkyl; and n is 0-10) at -60 to +60, esp. -30 to +30 degrees C in an inert solvent in the presence of a catalyst consisting of (I) a Ta, Re, Mo or W cpd., (II) an organometal cpd. of a gp. Ia-IVa metal, and (III) a co-catalyst. Polymer can be vulcanised with sulphur-contg. systems, or with systems reacting with the silicon atoms. The latter can also be used for reacting with e.g. silicate fillers, or for improving the bond between the rubber and glass fibres or metals. Used for moulding highly elastic articles.

Description

Process for the production of silicon-containing polymers Subject of the invention are new polymers that have reactive silane groups in the polymer chain and a process for their production. The new polymers are made by ring-opening polymerization of norbornenes or norbornene derivatives obtained, the are substituted by silyl groups.

The copolymerization with other cycloolefins such as cyclopentene, Cyclooctene, norbornene and cyclooctadiene also lead to silicon-containing polymers.

The monomers can be obtained by reacting cyclopentadiene with unsaturated Silanes are produced.

Monomers suitable for the process are compounds of the formulas: where n = 0 to 10, R1 to R6 = C1-C20 alkyl such as F, Cl, Br or iodine or alkyl groups monosubstituted or polysubstituted by halogen.

These connections are known. Examples are: 5-trichlorosilylnorbornene-2, 5-dichloromethylsilylnorbornene-2, 5-trimethylsilylnorbornene-2, 5-trichlorosilyl-6, 6-dimethylnorbornene-2, 5-trichlorosilylmethylnorbornene-2, 5, 6-bis-trichlorosilyl-norbornene-2, 5,6-bis-trimethylsilylnorbornene-2, 5,6-bis-dichloromethylsilylnorbornene-2, 5, 6-bis-tribromosilylnorbornene-2, 5,6-bis-dibromomethylsilylnorbornene-2.

The inventive method for the preparation of polymers that contain reactive silane groups in the (side) chain, is characterized by that a bicyclic monoolefin of the formula I or II alone or as a mixture with other cycloolefins in an inert organic solvent at -60 to + 600C on a catalyst made from a) a compound of rhenium, tantalum, molybdenum or tungsten, b) an organometallic compound of a metal from groups Ia to IVa of the Periodic Table 1) and 1) Handbook of Chemistry and Physics 47th edition (1966) S. B-3 Chemical Rubber CompO Cleveland, Ohio c) if applicable converts a cocatalyst.

Other suitable cycloolefins for the copolymerization are preferred those with 5 or 7-12 carbon atoms, with one or more rings, which have a C = C double bond in at least one ring, e.g. cyclopentene, Cyclooctene, cyclooctadiene or norbornene. The proportion of silicon containing monomers According to formula I and II, 0.01 to 99% by weight, preferably 0.01 to 5% by weight, can be based on the entire monomer mixture.

Suitable catalysts for the process are made from a) compounds of the transition metals rhenium, tantalum, molybdenum and tungsten b) from organometallic Compounds of the metals of groups Ia to IVa of the periodic table c) and optionally Cocatalysts obtained.

a) is preferred: TaBr5, TaCl5, ReCl5, MoOCl3, MoCl5, WCl5, WCl6, WOCl4, the tungsten halides are particularly preferred.

b) is preferably an aluminum trialkyl, aluminum dialkyl halide, Aluminum alkyl dihalide, magnesium alkyl halide, lithium alkyl or tin tetraalkyl, preferred alkyl groups containing 1-8 carbon atoms and chlorine and bromine as halogen is preferred. Examples are: Li (C4I), Mg (C2H5) 2, Al (C2H5) 3, Al (C2H5) 2 Cl, Al (c2H5) Cl2, Sn (C2H5) 4, Sn (C4) 4.

Organoaluminum and organotin compounds are preferred.

The effectiveness of the organometallic mixed catalysts can by Addition of cocatalysts (c) can be increased.

Possible cocatalysts are: epoxides of the general formula X = H, alkyl, aryl, aralkyl Y = H, alkyl, aryl, aralkyl -CH2-Hal (Hal = F, Cl, Br, J) X and Y can be substituted by, for example, alkyl (CH3-) and / or halogen (Cl) or acetals of the general formula in which R is hydrogen, an optionally halogen-containing (F, Cl, Br, J) alkyl, aryl or alkylaryl radical and Rt is an alkylaryl radical which is optionally halogen-substituted (F, Cl, Br, J), or halogen alcohols of the general formula in which X = F-Cl, Br or I, where R1 and R2 can be identical or different and hydrogen, an alkyl, aryl or aralkyl radical, R3 and R4 can be identical or different and fluorine, chlorine, bromine, iodine , Hydrogen, alkyl, aryl or aralkyl and where R1 and R3 together with the carbon atoms on which they are attached can form a five-membered or multi-membered carbon ring or ethers of the general formula X1 (CH2) n 0 - (CH2) n - X2 where X = H, F, Cl, Br, J and n = 0-10 can be.

In the cocatalysts, alkyl groups are preferably those with 1 - 6 carbon atoms, aryl radicals those with 6-10 carbon atoms and aralkyl radicals a combination of both.

Examples of these cocatalysts are: ethylene oxide, propylene oxide, Epichlorohydrin, 2-chloroethanol, 2-bromoethanol, 2-fluoroethanol, 2-iodoethanol, 2-chlorocyclohexanol, 2-chlorocyclopentanol, o-, m-, p-chlorophenol, di-2-chloroethyl formal, diethyl formal, Diethyl ether, dibutyl ether, di (chloroethyl) ether.

The preferred molar ratio of the catalyst components a: b or a: c is 1: 0.5 to 1:15 or 1: 0.3 to 1:10.

The amount of catalyst component (a) is preferably 0.05 to 2 mmol, preferably 0.1 to 0.5 mmol per 100 g of monomers.

In a preferred embodiment of the polymerization process becomes first catalyst component (a), preferably a halide with the cocatalyst (c) in 0.05 to 0.5 molar solution in hydrocarbons, preferably in the same Solvent in which the polymerization is carried out, reacted.

Easily soluble in organic solvents are then obtained constant conversion products.

The solvents used for the process are aliphatic and cycloaliphatic and aromatic hydrocarbons such as toluene, methylene chloride, Hexane and cyclohexane. Cyclohexane is preferred.

The process according to the invention is generally carried out as follows: The monomers are usually in an inert solvent with the exclusion of Dissolved water, acidic compounds and oxygen. The concentration of the monomers can be 5 - 50%, concentrations of 5 - 20% are preferred.

The ratio of silylnorbornene used to cycloolefin can can be varied within wide limits. 1 to 99% of non-Si-containing cycloolefin can be used can be added. 90 to 99% are preferred. The reaction temperature is in the range from -60 to + 600C, preferably in the range from -30 to + 300C.

If the experiment is carried out discontinuously, preference is given to first Connection of the transition element (a) or the reaction product from (a) and (c) and then the organometallic compound (b) is added. The order is however not critical.

The process can also be carried out continuously, e.g. in a row of stirred kettles or be carried out in a reaction screw.

The reaction takes place without any major warning tone. The response time can be a few minutes to a few hours.

The silane groups introduced into the polymer by the route according to the invention can be further implemented using known methods. So the implementation of Si-Cl bonds with alcohols to the corresponding Si-OR groups.

The reaction with water, for example, leads to elimination of HCl to -Si-O-Si groups and thus to link macromolecules. You can do this Direct the reaction in such a way that uncrosslinked products with a high molecular weight are formed or in such a way that it leads to a three-dimensional network.

The polymerization is worked up and isolated according to known methods Methods, for example by precipitation with lower aliphatic alcohols the polymer solution or by adding the polymer solution to hot water (stripping) 0 The polymers according to the invention are made by adding antioxidants, e.g. protected against aging by sterically hindered phenols.

The products are rubbers that have the C = C double bonds they contain can be vulcanized in the usual way with sulfur-containing systems, but in addition or instead of it via the reactive functions on the Si atoms.

These functions are also used, for example, to chemically bond silicate fillers possible on the rubber, which gives it the properties of so-called light-colored rubber compounds can be decisively improved. Furthermore, the adhesion of the rubber to glass fibers or metals can be enlarged via these reactive silane groups.

The polymers according to the invention can be shaped into highly elastic ones Articles are processed.

Example 1: 10 g of 5-dichloromethylsilylnorbornene- (2) are in 100 ml Dissolved toluene and 0.1 m mol of the reaction product of WC16 with 2-chloroethanol in a ratio of 1: 2 (referred to as WC14 (oC2H4cl) 2) and 0.2 ni mol AlEt3 added. Polymerization is carried out at -30 ° C. for 10 minutes. Then it is done with a mixture of amine and alcohol stopped and the polymer precipitated in alcohol.

After drying in vacuo at 40 ° C., the yield is 76.

Example 2: 10 g of 5-trichlorosilylnorbornene-2 are used. Proceed as in Example 1.

The yield is 86.

Example 3: 20 g of CPE are mixed with 20 mg of 5-dichloromethylsilylnorbornene- (2) dissolved in 150 ml of toluene and treated with 0.1 mol of WC14 (OC2H4C1) 2 and 0.2 mmol of Et2AlCl. It is polymerized at -20 for one hour.

After working up as in Example 1, the yield is 72. The X value (measured at 250 in toluene) is 3558 [dl / g].

Example 4: 20 g of CPE are mixed with 20 mg of 5-trichlorosilylnorbornene- (2) dissolved in 150 ml of toluene. Proceed as in example 3. The yield is 75.

# = 3.92 [dl / g] Example 5: 25 g of cyclopentene and 5 g of 5-trichlorosilylnorbornene-2 are dissolved in 60 ml of toluene, 0.1 mol of WC14 (OC2H4C1) 2 and 0.25 m mol Et2AlCl added at -100C. It is polymerized for 3 hours at -100. After quenching with alcohol, the polymer is precipitated.

The yield is 79.

Example 6: 23 g of cyclopentene and 5 g of 5-dichloromethylsilylnorbornene-2 are mixed in 60 ml of toluene. Proceed as in example 5. The yield is 75%.

Example 7: 10 g of 5-trichlorosilylnorbornene-2 are dissolved in 100 ml of cyclohexane dissolved and mixed with 0.1 m mole WC1e, 0.2 m mole (C2H5) 20 and 0.2 m mole Sn (C2H5) 4. It is polymerized for 4 hours at 00C.

It is then stopped with alcohol and the polymer is precipitated.

After drying, the yield is 58%.

Example 8: 10 g of 5-dichloromethylsilylnorbornene- (2) are in 100 ml Dissolved cyclohexane. Proceed as in example 5.

The yield is 76%.

Example 9: 10 g of 5-dichloromethylsilylnorbornene- (2) are in 100 ml Dissolved cyclohexane. Then 0.1 mmol of a 0.05 molar WF6 solution in cyclohexane and 0.1 mmol of trichloroethanol and 0.2 mmol of Et3A12C13 were added. It will be three Polymerized at 25 ° C. for hours. After work-up (see Example 1) is the yield 82.5%.

Claims (1)

Claim: Process for the preparation of polymers, characterized in that a bicyclic monoolefin of the formula I or II where n = 0 to 10, R1 to R6 = C1 - C20 alkyl such as F, C1, Br or iodine or alkyl groups monosubstituted or polysubstituted by halogen, alone or in a mixture with other cycloolefins in an inert organic solvent at -60 to + 600C to a catalyst composed of a) a compound of rhenium, tantalum, molybdenum or tungsten, b) an organometallic compound of a metal from groups Ia to IVa of the periodic table and c) optionally a cocatalyst.