EP1315764A2

EP1315764A2 - Metallized unsaturated polymer anions, stabilized by a coordinate bond and having a large portion of cis double bonds

Info

Publication number: EP1315764A2
Application number: EP01974160A
Authority: EP
Inventors: Michael GRÜN; Thomas Knauf; Wilfried Braubach
Original assignee: Bayer AG
Current assignee: Lanxess Deutschland GmbH
Priority date: 2000-08-23
Filing date: 2001-08-10
Publication date: 2003-06-04
Also published as: US20030176573A1; MXPA03001608A; TW572920B; BR0113403A; JP2004506786A; CA2420265A1; WO2002016448A2; KR20030025299A; AU2001293755A1; WO2002016448A3

Abstract

The invention relates to metallized unsaturated polymer anions, stabilized by a coordinate bond and having a large portion of cis double bonds. The invention further relates to a method for producing the same and to the use of said novel polymer anions in the production of graft polymers that are obtained by reacting the unsaturated polymer anions with anionically polymerizable nonpolar monomers. The graft polymers so obtained can be used for producing all sorts of shaped rubber bodies by corresponding vulcanization methods.

Description

Metallized, coordinated bond stabilized, unsaturated polymer anions with a high proportion of cis double bonds

The invention relates to metallized, coordinated binding, unsaturated polymer anions with a high proportion of cis-permanent double bonds, a process for their preparation and the use of the new polymer anions for the production of graft polymers by reacting the unsaturated polymer anions with anionically polymerizable, non-polar monomers are available. A wide variety can be obtained from the graft polymers prepared in this way

Rubber moldings are produced by appropriate vulcanization processes.

It is known in principle to metallize polymers containing activated hydrogen atoms by e.g. with alkali metals or organic

Alkali metal compounds, in particular organolithium compounds, such as butyllithium, in the presence of complexing compounds, such as alkali metal alkoxides, alkali metal phenoxides, tertiary polyamines or crown polyethers. Such metallization reactions for activated hydrogen-containing polymers based on, for example, conjugated dienes or copolymers based on such conjugated dienes and vinylaromatic compounds, such as styrenes, or based on ethylene, propylene and non-conjugated dienes, such as hexadienes, dicyclopentadienes or ethylene norbornenes (EPDM) are described, for example, in US Pat. No. 3,781,262, TJS-A 3 925 511, US-A 3 978 161, US-A 4 761 456, US-A 5 652 310 and EP-A 0 942 004 and Houben-Weyl ; Methods of organic chemistry; 4th edition, volume E20, macromolecular substances, p. 129 ff. And 1994 ff .; Georg-Thieme Verlag Stuttgart-New York 1987.

It is also known from the publications mentioned that the metallized polymers or polymer anions, for example, for the production of graft polymers serve, which are obtained by reaction with suitable polymerizable monomers.

From GB 11 73 508 A it is known to produce high molecular weight reactive group-carrying polymers by using a homopolymer of a conjugated C 1 -C 6 -diolene (1,3-butadiene, isoprene), a copolymer of such a diolefin with a monovinyl aromatic compound (Styrene) or a mixture thereof with an alkali metal or an alkali organic compound (or a mixture thereof, in particular a Li or an organo-Li compound) in the presence of a defined tertiary amine. Active alkali radicals can be omitted in the presence of the amines mentioned

Introduce preservation of the double bond into the polymer. The polymers containing active alkali radicals can, according to the cited patent publication, for the production of graft copolymers, for the production of high molecular weight crosslinked polymers using polyfunctional compounds or for the production of polymers with functional groups by reaction with functional groups

Connections, e.g. Carbon dioxide is used, from which fibers, resins and elastomers can in turn be produced (see also High Molecular Report 1970, Unit H 7686/79).

The homopolymers or copolymers are prepared in accordance with GB

11 73 508 A by ionic (anionic or cationic) polymerization or radical polymerization. The polymerization can - as described above - e.g. in the presence of alkali metals or alkali metal compounds or in the presence of Ziegler-Natta catalysts, the alkali compounds or hydrides of the elements of L, II. and III. Group of the Periodic Table of the Elements and

Halides, alcoholates and acetonates of the transition metals of IV., V. and VI. Group include, be performed.

The disadvantage of the metallized polymers or polymer anions produced by anionic polymerization is that only the properties of anionically polymerized polymers are linked to one another and the setting of the Microstructure is only possible in the context of anionic polymerization. With this production method it is not possible, for example, to obtain a high cis-containing polymer in which the cis-1,4 content is above 50%.

The polymer anions obtained according to British patent application GB 11 73 508 A have a cis-1,4 content of approx. 92%. This cis-1,4 content is still too low for certain physical properties of the vulcanizates produced from it.

The object of the present invention was now metallized, by coordinative

To provide bond stabilized, unsaturated polymer anions with a high proportion of cis- double bonds, which are obtained by polymerizing corresponding unsaturated monomers in the presence of rare earth metal catalysts and subsequent metallization reaction, and which result in improved impact resistance in thermoplastics (e.g. at HLPS and

ABS products), which can be mixed better than the known products in tire compounds and which result in improved physical properties for rubber vulcanizates.

The present invention therefore relates to metallized, coordinative

Binding stabilized, unsaturated polymer anions with a high proportion (greater than 92%, preferably greater than 95%, in particular greater than 97%, based on 100 g of polymer) of cis-permanent double bonds, producible by polymerizing unsaturated monomers in the presence of rare earth metal Catalysts, with the proviso that the polymers thus obtained contain 1.0 to 1000, preferably 1.5 to 100, particularly preferably 2 to 30 mmol, per 100 g of polymer, active hydrogen atoms, and subsequent reaction of the polymers obtained with to coordinate native binding capable reagents in the presence of organometallic compounds, the organometallic compounds being used in amounts of 1.0 to 1,000, preferably 1.5 to 100, particularly preferably 2 to 30 mmol per 100 g of polymer. An active hydrogen atom is a hydrogen atom that can be easily substituted by the corresponding metals. Examples of active hydrogen atoms are allylic hydrogen atoms or hydrogen atoms which are in the vicinity of electron-attracting groups.

In particular, conjugated dienes, such as 1,3-butadiene, isoprene, piperylene, 1,3-hexadiene, 1,3-octadiene, 2-phenyl-1,3-butadiene, are suitable as unsaturated monomers for the preparation of the metallized polymer anions according to the invention , preferably 1,3-butadiene.

The conjugated dienes mentioned can of course be copolymerized with vinyl aromatic monomers such as styrenes.

In addition, alkenes, such as ethylene and propylene, can also be used to build up the polymers to be metallized, which in a known manner optionally with non-conjugated polyenes, such as ethylidene norbornene, vinylidene norbornene, dicyclopentadiene, 2-methyl-l, 5-hexadienes, 3.3 Dimethyl-l, 5-hexadiene, 1,6-hepadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene and / or 1,19-eicosadiene to the corresponding terpolymers, such as EPDM Rubber properties can be implemented. The proportion of non-conjugated polyenes is usually up to 15% by weight, the proportion of alkenes is correspondingly 100% by weight.

The proportion of the vinyl aromatic monomers copolymerizable with the conjugated dienes can be up to 40% by weight. A higher percentage is possible. This depends on the later intended use of the metallized polymer anions.

In principle, all known monomer building blocks which are in the presence of .mu Polymerize or copolymerize rare earth metal catalysts, with the above stipulation regarding the number of active hydrogen atoms.

In the copolymerization, the amount of the monomers to be used - as mentioned - depends in particular on the later intended use of the polymers and the desired properties of the polymers.

Particular mention should be made of polymer anions which are constructed as follows: homopolybutadiene with greater than 92% double bonds, preferably greater than 95%, in particular greater than 97% double bonds; Copolymers composed of 2 to 98% 1,3-butadiene and a correspondingly 100% complementary proportion of a comonomer such as 1,3-isoprene, piperylene, 1,3-hexadiene, 1,3-octadiene or 2-phenyl-1 , 3-butadiene. Also to be mentioned are copolymer anions composed of styrenes (20 to 40%) and 1,3-butadiene (80 to 60%).

As mentioned, the polymerization of the monomers used to build up the polymers is carried out according to the invention in the presence of rare earth metal catalysts.

The use of rare earth metal catalysts in the polymerization is important for the metallized polymer anions according to the invention, since only with these catalysts can certain physical properties be achieved which contribute to the solution of the object according to the invention.

Compounds of rare earth metals, such as cerium, lanthanum, praseodymium, gadolinium or neodymium compounds which are soluble in hydrocarbons, are used as rare earth metal catalysts. The corresponding salts of the rare earth metals are particularly preferably used as catalysts, such as neodymium carboxylates, in particular neodymium neodecanoate, neodymium octanoate, neodymium naphthenai, neodymium 2,2-diethyl hexanoate and neodymium 2,2-diethyl heptanoate , as well as the corresponding salts of lanthanum or praseodymium. Neodymium neodecanoate is very particularly preferred.

The above-mentioned rare earth metal catalysts are known and are described, for example, in the German patent application with the application number

19 951 841.6 and in DE-A 28 48 964 and DE-A 26 25 390.

In a preferred embodiment, the polymerization of the unsaturated monomers is carried out in the presence of a rare earth metal catalyst system, as described in German Patent Application No. 19 951 841.6.

According to the German patent application mentioned, a catalyst system based on compounds of rare earth metals, consisting of

a) a compound of rare earth metals, b) an organic aluminum compound c) a trihalosilane of the formula

R- Si- al ^X al where

hal stands for fluorine, chlorine and bromine and

R represents hydrogen or a vinyl group,

wherein components a): b): c) in anhydrous form (water content: <1,000 ppm, preferably <500 ppm, based on a 20% by weight solution of component a) in an inert, aliphatic solvent) in one Ratio of 1: 0.5 to 5: 0.05 to 0.5. Component a) of the catalyst system just mentioned, based on rare earth metal compounds, uses the rare earth metal compounds already mentioned; Suitable organic aluminum compounds (component b)) are in particular aluminum alkyls and aluminum alkyl hydrides in which the alkyl group has 1 to 10, preferably 1 to 6, carbon atoms. The aluminum alkyl hydrides can have one or two alkyl groups. The following should preferably be mentioned: aluminum triethyl, diisobutyl aluminum hydride, aluminum triisobutyl, very particularly preferably diisobutyl aluminum hydride. Trichlorosilane is preferably used as the trihalosilane (component c)).

Catalyst systems based on compounds of the rare earth metals in which components a): b): c) are present in a weight ratio of 1: 1 to 2: 0.1 to 0.4 and component a) is neodymium versatate are preferred, component b) is diisobutyl aluminum hydride and component c) is trichlorosilane.

The metallization of the polymers or elastomers thus obtained with active hydrogen atoms is then carried out by reacting these polymers or elastomers with suitable organometallic compounds in the presence of reagents capable of coordinative binding.

All organometallic compounds known from the prior art, including the metals themselves, can be used as organometallic compounds for the metallization. Organometallic compounds or their underlying metals are preferably used as the organometallic compound. Organolithium compounds which are represented by the formula R-Li, where R symbolizes a hydrocarbyl radical with 1 to 20 C atoms, are very particularly preferred. Such monofunctional organolithium compounds preferably contain 1 to 10 carbon atoms. Examples include: methyl lithium, ethyl lithium, isopropyllithium, n-butyllithium, sec-butyllithium, n-

Octyllithium, tert-octyithithium, n-decyllithium, phenyllithium, 1-naphthyllithium, 4- Butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-butylcyclohexyllithium and or 4-cyclohexylbutyllithium. Ethyl lithium, isopropyllithium, n-butyllithium, sec-butyllithium, n-hexyllithium, tert-octyllithium, phenyllithium, 2-naphthyllithium, 4-butylphenyllithium, and / or cyclohexyllithium are preferred. n-Butyllithium and / or sec-Butyllithium are very particularly preferred.

To stabilize the metallized polymers or polymer anions, the metallization is carried out in the known manner in the presence of reagents capable of coordinative binding. Such reagents capable of coordinative binding are also known from the prior art discussed above.

Examples of suitable reagents capable of coordinating binding are: tert-diamines with three saturated aliphatic hydrocarbon esters, cyclic diamines or bridged diamines. Worth mentioning in particular are tetramethylethylenediamine, tetraethylethylenediamine, tetradecylethylenediamine, tetralkyl-1,2-diaminocyclohexane, tetralkyl-l, 4-diaminocyclohexane, piperazines, N, N'-dimethylpiperazine and sparteine or triethylenediamine. Of course, the amines mentioned can be used individually or in a mixture with one another.

Furthermore, the known alkali metal alkoxides and the alkali metal phenoxides or crown polyethers can be used as reagents capable of coordinative binding. Potassium tert-amyl oxide, sodium tert-amyl oxide and / or potassium tert-butyl oxide should be mentioned in particular.

The amount of reagents capable of coordinative binding to be used is usually 0.1 to 8% by weight, preferably 0.1 to 4% by weight, based on 100 g of polymer.

Another object of the present invention is the production of the metallized, unsaturated polymer anions stabilized by coordinative binding with a previously described high proportion of cis double bonds, by polymerizing unsaturated monomers in the presence of rare earth metal catalysts, with the proviso that the polymers thus obtained 1.0 to 1000, preferably 1.5 to 100, in particular preferably 2 to 30 mmol per 100 g of polymer containing active hydrogen atoms, and then reacting the polymer obtained with reagents capable of coordinative binding in the presence of organometallic compounds, the organometallic compounds in amounts of 1.0 to 1000, preferably 1.5 up to 100, particularly preferably 2 to 30 mmol per 100 g of polymer are used.

The polymerization of the aforementioned unsaturated monomers in the presence of the catalysts mentioned is usually carried out at temperatures in the range from -30 to 130 ° C., preferably 20 to 100 ° C., if appropriate under elevated pressure (2 to 10 bar).

It is customary to carry out the polymerization in the presence of inert, aliphatic solvents such as pentanes, hexanes, heptanes or cyclohexane. With these aliphatic solvents, both the straight-chain and their branched isomers can be considered. Aromatic solvents such as benzene, toluene or ethylbenzene can also be used. The solvents can be used either individually or in a mixture with one another; the favorable mixture ratio can be easily determined by means of appropriate preliminary tests.

The amount of solvent in the process according to the invention is usually 1000 to 100 g, preferably 500 to 150 g, based on 100 g of the total amount of monomer used. Of course, it is also possible to polymerize the monomers used in the absence of solvents. Polymerization is preferably carried out in the presence of a solvent. The polymerization of the unsaturated monomers according to the invention in the presence of the catalysts mentioned can be carried out until the monomers used are completely converted. Of course, it is also possible to interrupt the polymerization prematurely depending on the desired polymer properties, for example when about 80% of the monomers are converted.

The polymerization of the unsaturated monomers is preferably carried out until their quantitative conversion. The quantitative conversion is the conversion at which a maximum amount of about 5,000 ppm, preferably 500 ppm, of residual monomers is still present in the reaction mixture. Is the content of

Residual monomers in the reaction mixture higher than the specified values, it is advisable to separate the residual monomers by, for example, distillation.

In the preparation of the unsaturated polymer anions according to the invention, it is possible to isolate, purify and work up the polymers obtained from the polymerization of the unsaturated monomers in the presence of the catalysts mentioned in a known manner and then to subject the isolated polymers to a metallization reaction in dissolved form.

The polymers obtained by the process (polymerization) according to the invention are preferably directly, i.e. subjected to a metallization reaction in situ in the reaction mixture without isolation of the polymers obtained.

It is also of particular advantage if both the polymerization with the catalysts mentioned and the subsequent metallization reaction are carried out practically without water, the maximum water content having already been mentioned above.

The metallization reaction is usually carried out at temperatures in the range from 20 to 200 ° C., preferably at 40 to 120 ° C., in the presence of the above-mentioned inert solvents. According to the invention, the rare earth metal catalysts are used in amounts of about 0.001 to 0.5% by weight, preferably 0.01 to 0.3% by weight, based on the amount of unsaturated monomers present. The most favorable amount of catalysts to be used can easily be determined by appropriate preliminary tests.

According to the invention, the unsaturated monomers are very preferably composed of in the presence of the catalyst system described above

_/ hal R— Si- al ^N hal where

hal stands for fluorine, chlorine and bromine and

R represents hydrogen or a vinyl group,

wherein components a): b): c) in anhydrous form (water content: <1,000 ppm, preferably <500 ppm, based on a 20% by weight solution of component a) in an inert, aliphatic solvent) in one Ratio of 1: 0.5 to 5: 0.05 to 0.5 are present, polymerized. In particular, the polymerization of the unsaturated monomers is carried out using a catalyst system based on neodymium versatate, diisobutyl aluminum hydride and trichlorosilane, as also mentioned above. For example, the metallized polymer anions according to the invention can be produced as follows:

The monomers to be polymerized and the corresponding solvent are placed in an autoclave equipped with a stirrer and then the catalyst is metered into the solution. The autoclave is previously rendered inert by flushing with an inert gas such as nitrogen. After the desired conversion has been reached, the polymer obtained is preferably metallized in situ by reaction with reagents capable of coordinative binding in the presence of the organometallic compounds mentioned. When working in situ and with incomplete monomer conversion, it is advantageous if the unreacted monomers - as mentioned above - are previously, i.e. before the metallization reaction, removed from the polymer mixture.

The metallized unsaturated polymer anions produced according to the invention have a higher cis-position double bond content than the polymer anions obtained according to the prior art discussed. In addition, they have a comparatively high content of active hydrogen atoms, as a result of which reactive centers are obtained in the polymer which are capable of further reactions, as described, for example, in GB 1, 173, 508-A. Starting from the metallized unsaturated polymer anions according to the invention with the described high proportion of cis-permanent double bonds and active centers, polymers can be produced with improved physical properties.

Another object of the present invention is therefore the use of the metallized polymer anions prepared according to the invention for the production of graft polymers.

The metallized polymer anions are in a known manner with corresponding anionically polymerizable, non-polar monomers, such as diolefins, e.g.

1,3-butadiene, 1,3-isoprene, piperylene, and vinyl aromatic compounds, such as Styrene, α-methylstyrene, preferably 1,3-butadiene, 1,3-isoprene, styrene or α-methylstyrene, implemented in a known manner. Of course, it is also possible to use the nonpolar monomers mentioned in mixtures with one another.

The preparation of such graft polymers is generally known and is described, for example, in the patent publications cited above.

The graft polymers produced by reacting the metallized polymer anions with anionically polymerizable nonpolar monomers can in turn be used for the production of all kinds of rubber moldings, for example for the production of tires. In addition, they can be used advantageously for impact modification of thermoplastics, for example HTPS and ABS.

Examples

1. Production of lithium metallized polybutadiene

8,200 g of n-hexane were placed in an autoclave flushed with nitrogen and provided with a stirrer. Thereafter, 2 mmol of neodymium versatate, 16.7 mmol of diisobutylaluminum hydride and 1.9 mmol of trichlorosilane were added to the initially introduced hexane, and 1,800 g of dried, destabilized 1,3-butadiene were added to this mixture. The polymerization of 1,3-butadiene was carried out at a temperature from 60 ° C. until the quantitative conversion of the monomers. The polybutadiene anion obtained had a cis-1,4 content of 98.5%.

7.5 ml of dried N, N, N ', N'-tetramethylethylenediamine and 50 mmol of n-butyllithium were added directly to the polymer obtained in situ, and the mixture was stirred at a temperature of 100 ° C. for about 1 hour ,

2. Reaction of the metallized polybutadiene anion with anionically polymerizable monomers (grafting reaction):

The metallized polybutadiene anion obtained in 1) was mixed with 180 g of dried isoprene, butadiene or styrene and stirred at 100 ° C. for one hour. The grafting reaction was then stopped with ethanol. The graft product obtained was stabilized, washed with water and dried at 60.degree.

Analysis of the propolymers obtained gave the following data: a) Isoprene grafted: Mooney: 38

(Sample a) 1.4 ice content: 90.5%

1,2-content: 6.8%

1,4-trans content: 2.6%

Tg: -103 ° C

b) Grafted butadiene: Mooney: 73

(Sample b) 1.4 ice content: 85.9%

1,2-content: 9.9%

1,4-trans content: 4.2%

Tg: -102 ° C

c) Styrene grafted: Mooney: 78

(Sample c) 1.4 ice content: 75.2%

1,2-content: 6.6%

1,4-trans content: 4.7%

Styrene content: 13.6%

Tg: -103 ° C

In a further experiment, the metallized polymer or polymer mixture obtained according to 1) was cooled to 50.degree. A mixture of 1 125 g of 1,3-butadiene, 375 g of styrene and 3.46 mmol of dried divinylbenzene was added in portions to 4.46 kg of the polymer mixture in such a way that the internal temperature of the mixture did not exceed 70.degree. After complete conversion of the monomers used, the grafting reaction was stopped as described above and the graft polymer obtained was worked up accordingly.

The analysis of the graft copolymer obtained which had been grafted with styrene and butadiene gave the following data (sample d): Mooney: 67

1.4 ice content: 43.8%

1,2-content: 23.1%

1,4-trans content: 16.0%

Styrene content: 17.1%

Tg: -63 ° C

3. Production of vulcanizates and determination of their physical properties

The vulcanizates are those used for tire treads, each with soot and silica as filler (Tables 2 and 3).

Table 1

(Graft polymers used from the previous samples and non-grafted polybutadiene)

Table 2 Carbon black mixtures

* Mineral oil softener, Mobil lubricant GmbH ** light protection wax, Rhein Chemie Rheinau *** anti-aging agent (6PPD), Bayer AG **** anti-aging agent (TMQ), Bayer AG ***** sulfenamide accelerator (TBBS), Bayer AG

****** Sulfenamide Accelerator (CBS), Bayer AG ******* Guanidine Accelerator (DPG), Bayer AG ******** Silica, Bayer AG ********* Silane, Degussa

Table 3 silica mixtures

Attenuation (Röhlig 10 Hz) DIN 53513

Based on the reference material used (comparison), which describes the current state of the art, the graft polymers according to the invention are distinguished by excellent processing behavior. The mechanical properties, such as strength, stress values and hardness, are at the level of the reference material. The tear strength of the polymers according to the invention are improved. Particularly positive is the increase in the dynamic loss angle tan delta at low temperatures (-20 ° C), which is generally accepted in industry as an indication of improved wetness properties of tires and the decrease in the dynamic loss angle at high temperatures (60 ° C). This reduction correlates with the rolling resistance of tires and the better the lower the loss angle, the better. The polymers according to the invention are easily processable products with which tire treads can be compounded, the properties of which, in particular wet handling and / or rolling resistance, are significantly improved compared to the prior art.

Claims

claims

1. Metallized, coordinated binding, unsaturated polymer anions with a high proportion of cis-permanent double bonds, producible by polymerizing unsaturated monomers in the presence of

Rare earth metal catalysts, with the proviso that the polymers thus obtained contain 1.0 to 1000 mmol per 100 g of polymer active hydrogen atoms, and subsequent reaction of the polymers obtained with reagents capable of coordinative binding in the presence of organometallic compounds, where the organometallic compounds in

Amounts of 1.0 to 1,000 mmol per 100 g of polymer are used.

2. Process for the production of metallized, coordinated binding, unsaturated polymer anions with a high proportion of cis-positioned double bonds, characterized in that unsaturated

Monomers polymerized in the presence of rare earth metal catalysts, with the proviso that the polymers thus obtained contain 1.0 to 1000 mmol per 100 g of monomer active hydrogen atoms, and then the polymer obtained with reagents capable of coordinative binding in the presence of organometallic Reacts compounds, the organometallic compounds being used in amounts of 1.0 to 1000 mmol per 100 g of monomer.

3. Use of the metallized polymer anions according to claim 1 for the preparation of graft polymers which are obtained by reacting the metallized polymer anions with anionically polymerizable, non-polar monomers.

4. Use of the graft polymers according to claim 3 for the production of rubber moldings of all kinds, and for the impact modification of

Thermoplastics.