FR2523586A1 - PROCESS FOR MODIFYING UNSATURATED ELASTOMERS - Google Patents

Abstract

PROCEDURE FOR MODIFYING AN UNSATURE POLYMERIC RUBBER WHICH CONSISTS OF REACTING AN UNSATURE POLYMERIC RUBBER CONTAINING AN ALKALINE METAL IN SOLUTION WITH AN AROMATIC KETONE REPRESENTED BY THE FOLLOWING FORMULA: (CF DRAWING IN BOPI) IN WHICH A DRAWING IN BOPI) RE AND RACHENE RACHENE RACHENE R AND RACHENE R , A GROUP OR A RADICAL ALKYL, A CYCLOALKYL GROUP, AN ALCENYL GROUP, AN ALCOXY GROUP, AN AMINO GROUP, AN ALKYLAMINO GROUP, A DIALKYLAMINO GROUP OR A HYDROGEN ATOM AND OR M AND N COMPRESENT UNTIL 5.

Description

The present invention relates to a method for modifying the

  unsaturated polymeric elastomers and more particularly relates to a process for modifying an unsaturated polymeric elastomer containing an alkali metal by reacting it with a given aromatic ketone.

  In recent years,

  tires with low rolling resistance and high resistance to slipping or skidding when wet

  have been heavily sought after for use in

  pneumatic tire enclosure for motor vehicles

  for fuel economy and to increase the safety of

  However, these two properties

  are intrinsically incompatible and various methods of

  polymers have been proposed for the purpose of

  In this way, for example, with regard to the styrene-butadiene copolymers, it has been proposed that

  a process in which the ratio of the number of

  vinyl and styrene groups is set in a specific range (Japanese Patent Publication No. 62248/1979), as well as a process in which the sequences

  styrene occur in a specified distribution (possibly

  Japanese Patent Application Publication No. 14,3209 / 1981), as well as a method in which the vinyl sequences are provided in a given distribution (Japanese Patent Publication No. 149413/1981). However, the improvements made by

  these processes are weak and need to be strengthened.

  It has been proposed, on the other hand, to improve the bouncing properties of an active polymer having an alkali metal or alkaline earth metal at its ends in the

  reacting with a given aromatic thioketone, introduced

  thus forming the SH group in the ends of the polymer (US Patent No. 3,755,269). It is known that the bouncing properties and the rolling resistance are within

  mutual inverse relationships and that the higher the bouncing factor

  is higher, the lower the rolling resistance.

  Accordingly, it can also be said that the process described in the US patent is intended to reduce the resistance to a high temperature. As a result, it is possible to reduce the resistance to a high temperature. onotio -Inovo un a Tfiv 9 a ques Tej ue nueqqo eaqw Alod el enb eluvue 2 d -ans elaa Anoogp el I Tvj v quiteepuuuea el Sc taiew A Tod a p 99-4 T "x-4 xa salt sulep Hs adnox B al Tnpoz-4 uF V juvis Tuoo enusep-To nuuoo gpgoozd np slua Tug Auoou T sie A tp sep uos Tva ue 'NS ednoib unp uo Tlonpoziu Tp eanpgooad el 1 sinoooi a To Av on the gl I Trem IV 49,1 V queuggs TI 6 op gotml -s Tsga vs Aulne anod jejaejjv sues u T Ivolv julgtu a juvenile OC -uoo ganivou T enb Tapm J lod onoqo 4 nouz unp 4 uemess Tpuoqqi op soig Tadoid Bal 2920 TIVUM p jamaed Tnb ppgooad a to Tuan O j op Ise uo T: Iue au T aquesgid Pl op s s Inq sep un Hs ednoafi np ag Aelq 91 TAT, 4 ovil Z q TT Ise Tooo enb emnsgid uo Is Tojejnol g Aelq SZ -4 uatuess Tpuoqea op in e 4 ov; a ssqad HS sadnoifi sep -4 Tnpoi-4 u Tvuo lenbnp aulvqo vi op 99 I Turgalxa salt suvp azeud Tod an Ol Tenbu T anod UOSTVI VI svd Ilvuuoo to uo ela Tilonpu T ueld el ans aenb Tivid V el TD Tjj Tp Ise gi Togad UTVOT 29 tuu I Have 2 q np gpgooad el OUOUTUI ellea inod oz -gqoaeqoez Tn Ieo V an * Tjgju T zoë aiem Alod np: uemess Tpuoqej op jnajov; np uo Tlelueu 5 nvp gabap el enb elnopus Tonb? eluv 4 -Tai T inapo eunp elnoogp ue Tnb luameb Qbgp el laiieq Dgs op la uo Tieln 6 voo op sadvig sep sanoo ne HS adnoab np uo TI Tsod -moogp el 291 TA 9 svd 4 ned to uo lea Qw Alod np egi Tmgxqxe xnv Ns SI adnoab a ea Tnpoi 4 ui V juvis Touoo tsep-To gpgooad el quep laouenbgsuoa ua -Doç op ainivagdwal eun V enjoejjes obei -jnvqo el lebuqags op sgpgoozd BUTU Ileo suep no selem Alod op sad Al Su Tullea Da Ae la IUOTIUIU Zpxqsgp op 40 UOTIV Inbuoa op sadvig sep sanoo ne D, 001 questedgp seanquagdurel sep V sdmel 01 op sopo Tagd senbuo T op juppued qsodxe s Tojied -4 se-aaem A-rod el lalla Talsnpu T al Taqog aun ans eaem Alod Toi unp UOT- 4 n-tos aunp enb Tigmoiselq aa Qw Alod unp uo Tleaudgs Pl op sanoo ne iio 094 TA 9 ail ITOP Dosi juussedgp seanquagdurai sep V TD-Tn Tea op uo TI Tsodxe aun Uo a Tel aa Ar ei Qm, Iod np jouquoo a jna Tvqa S el op no to Qb Lxo T op uo T-4 o-el snos i; uame-lTzej esoduroogp es I Tnb la ina Teqo PT V on Qb Xxo TV e Tq Tsues seil Ise -X Iod np HS juvumdnoa 5 el anb quuop which s Togainoi -91 I Tnour lvq 9-1 V quaass TT 5 OP a Due to the fact that it has a large rebound factor, which is equivalent to that obtained by introducing an SH group into the ends of the polymer chain, despite the fact that it has an atomic group ( probably the OH group) having a lower activity than that of the SH group and inde-

  from the position of the atomic group thus introduced

duit in the polymer chain.

  Accordingly, according to the invention, a method for modifying an unsaturated polymeric rubber is to react an unsaturated polymeric rubber containing

  an alkali metal in solution with an aromatic ketone

presented by the following formula:

O

  in which R 1 and R 2 each represent a hydrogen atom

  gene, a group or an alkyl radical, a cycloalkyl group, an alkenyl group, an alkoxy group, an amino group, a

  alkylamino group, a dialkylamino group or a hydrogen atom

  gene and o m and N each represent an integer between

1 and 5.

  In the implementation of the method of the invention,

  it is possible to produce, in a stable way, a rubber

  unsaturated polymeric rubber with low resistance

  turnover and an increased rebound factor without

  its slip resistance or wet slip resistance, without taking special measures to prevent the decomposition of the atomic group introduced.

  during the separation and drying stages.

  The alkali metal-containing polymer used in the invention comprises polymeric rubbers having

  an alkaline metal bonded to the ends of the chain of poly-

  diene mothers obtained by polymerisation or copolymerisation

  conjugated diene monomers using a catalytic

  alkali metal-based lyseur, as well as rubbers

  resulting from the addition of alkali metals to rubber

  unsaturated polymeric bucks having a double bond by any polymerization process (polymerization in

solution, in emulsion, etc.).

  Examples of polymeric diene-type rubbers include polymers and copolymers of conjugated diene monomers such as 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3 butadiene and 1,3-hexadiene and copolymers of conjugated diene monomers and monomers copolymerizable therewith (such as, for example, vinyl aromatic compounds such as styrene, e-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene and the like). divinylnaphthalene, unsaturated nitriles such as acrylonitrile, esters of acrylic acid and esters of methacrylic acid, and

  vinylpyridine) These examples have no limiting character

  As specific examples of diene polymers, mention may be made of polybutadiene rubber, of polyisoptene,

  copolymers of butadiene / isoprene and butadiene / styrene.

  A diene type polymeric rubber in which an alkali metal is bonded to the ends of the chain

  is that obtained by polymerization by means of a catalytic

  alkali metal-based lysine In this polymer, the metal

  alkaline is bound to at least one end of the chain.

  Polymerization can be performed without any restrictions

  and the alkali metal catalyst, the poly-

  merization, the dispersing agent, the microstructure control agent of the conjugated diene groups, etc., used

  in this polymerization may be those commonly used in

  The amount of alkali metal catalyst used is

  is usually in the range of 0.1 to 10 millimoles

100 parts by weight of monomer.

  The polymeric rubber which results from the addition of an alkali metal to an unsaturated polymer

  meaning the polymeric rubber obtained by the polymer

  of said conjugated diene monomer or its copolymer

  with a copolymerizable monomer by a process of

  ordinary polymerization, such as a polymeric

  solution in solution using an alkali metal catalyst or a Ziegler catalyst or by emulsion polymerization using a redox catalyst to form a diene rubber, a polymeric rubber obtained by polymerization of olefins or cycloolefins, (more specifically, polybutadiene rubber, polyisoprene rubber,

  butadiene / styrene / butadiene / isoprene copolymer,

  pentadiene, a butadiene / piperylene copolymer, an alternating butadiene-propylene copolymer, a polypentenamer, a polyoctenamer, an ethylene / propylene terpolymer

  diene, etc.), followed by the addition of an alkali metal.

  The addition of an alkali metal to an unsaturated polymeric rubber can be carried out by any of the methods commonly practiced.

  be made by reacting the polymeric rubber

  saturated in a hydrocarbon solvent at a temperature of 30 to 100 ° C for a period of a few tens of minutes to several tens of hours in the presence of an ordinary alkali metal catalyst and a polar compound such

  a compound of ether, amines or a phosphine

  The alkali metal catalyst used is usually

  between 0.1 and 10 millimoles per 100 g of

  polymeric rubber insatur 6 When the quantity is

  less than 0.1 millimole, we can not obtain an increase

  On the other hand, when it exceeds 10 millimoles, secondary reactions are observed, such as

  that a crosslinking or cleavage of the polymer reduces the

rebounding.

  The amount of polar compound is usually between 0.1 and 10 millimoles, preferably between 0.5

  and 2 moles per mole of the alkali metal catalyst.

  The alkali metal catalyst used in the polymerization and addition reactions is lithium, sodium, potassium, rubidium or cesium or a complex of such a metal with a hydrocarbon compound or a polar compound Preferably use is made of a lithium compound having 2 to 20 carbon atoms. Specific examples include ethyllithium, n-propyllithium,

  i-propyllithium, n-butyllithium, sec-butyllit, lum, t-octylli-

  thium, n-decyllithium, phenyllithilum, 2-naphthyllithium, 2butylphenyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4cyclopentyllithium, 1,4-dilithio-2-butene, sodium naphthalene, sodium biphenyl, potassium-tetrahydrofuran complexes, diethoxy potassium complexes Ethane and sodium salt

  of a t 6 tram of c-methylstyrene.

  The polymerization reaction and the alkali metal inlet reaction are carried out in a solvent which does not destroy the alkali metal catalyst, such as

  hydrocarbon solvent, tetrahydrofuran, tetrahydro-

  pyran or dioxane Suitable hydrocarbon solvents

  are chosen from aliphatic hydrocarbons, hydro-

  aromatic hydrocarbons and alicyclic hydrocarbons. Hydrocarbons having from 2 to 12 are particularly preferred.

  carbon atoms such as propane, n-butane, t-butane, n-penane,

  tane, i-pentane, n-hexane, cyclchexane, propane, 1-butene, i-butene, trans-2-butene, cis-2-butene,

  1-pentene, 2-pentene, 1-hexene, 2-hexene, ben-

  zene, toluene, xylene and ethylbenzene These solvents

  can be used in mixtures of two or more.

  The aromatic ketone used in the invention is a compound represented by the following general formula: (R 1) m (R 2) n in which R 1 and R 2 represent a hydrogen atom, or an alkyl, cycloalkyl or alkenyl group Alkoxy, amino, alkylamino, dialkylamino or a halogen atom. Preferred examples of preferred aromatic ketones include 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino)

  benzophenone, 4,4'-bis (dibutylamino) benzophenone, 4,4 '-

  diaminobenzophenone, 4,4'-dimethoxybenzophenone, 2,2 ',

  3,3'-tetramethylbenzophenone, and 4-dimethylaminobenzophenol

  Particularly preferred are aromatic ketone compounds having the general formula above in

  which R 1 and R 2 are amino, alkylamino or dialkyl

  mino. The amount of the aromatic ketone compound used is between 0.05 and 10 moles, preferably between 0.2 and 2 moles, per mole of the alkali metal catalyst used to produce a diene polymer having an alkali metal bonded to its ends or the alkali metal catalyst for introducing an alkali metal into the unsaturated polymeric rubber Since the reaction of the aromatic ketone with the active polymeric rubber having a terminal alkali metal or with the unsaturated polymeric rubber to which an alkali metal is added takes place quickly, the temperature and the duration of the reaction can be chosen

  between wide limits In general, the tempera-

  reaction temperature ranges from room temperature to 1000 C and the reaction time is between a few

seconds and several hours.

  The reaction is carried out by contacting the unsaturated polymeric rubber containing an alkali metal with an aromatic ketone compound.

  can recommend as a preferred embodiment a

  wherein the diene-type polymeric rubber is produced by polymerization with an alkali metal catalyst and after the polymerization reaction is complete, a predetermined amount of the aromatic ketone compound is added to the resulting polymeric solution, and a process in which after the addition reaction of the alkali metal is completed in the solution containing the

  unsaturated polymeric rubber, a quantity of

  predetermined temperature of the aromatic ketone compound.

  the mode of reaction is not limited to these modes of

specificity.

  After the reaction, the polybrominated rubber is isolated

  To this end, the same coagulation methods as those used in the production of rubber by conventional solution polymerization, for example, by the addition of coagulation agent or by using steam entrainment or "stripping",

  no particular restriction being imposed on the temperature

  coagulation The separated lumps of the reaction mixture

  can be dried using standard equipment.

  used in the production of synthetic rubbers, for example, a belt dryer or an extrusion dryer.

  Drying temperature is also not restricted.

  The modified unsaturated polymeric rubber results

  both has a greatly improved rebound factor and, therefore, is very useful as a rubber for manufacturing

  O pneumatic envelopes to reduce the consumption of

fuel.

  Examples, which of course have no

  limiting the scope of the invention:

Example 1

  Washed, dried, purged with dry nitrogen, then introduced into a polymerization reactor a steel

  2-liter stainless steel, 150 g of 1,3-butadiene, 820 g of benzene

  zeen, 0.5 millimole of diethylene glycol dimethyl ether (diglyme) and 1.3 millimoles of n-butyllithium (in the form of a solution in hexane) while stirring the contents,

  the polymerization of 1,3-butadiene is carried out at 40 ° C.

  1 hour when the polymerization reaction was completed

  have been added, each of the components indicated in the table

  2, and the mixture was stirred for 5 minutes.

  the polymeric solution was extracted from the polymer reactor.

  in a 1.5% by weight solution of 2,6-methanol

  di-t-butyl-p-cresol (BHT) to coagulate the resultant polymer.

  This polymer was then dried at 60 ° C. for 24 hours.

  under reduced pressure and its Mooney viscosity was measured.

  A solution in BHT benzene was then added to the polymeric solution which had reacted with each of the compounds shown in Table 2 in the same manner as above so that the amount of BHT was a part

  in weight per 100 parts by weight of the solids of the poly-

  mother -While shaking, the mixture was coagulated with

  After draining the water, the coagulated product was dried with hot air at 800 ° C. for 1 hour. The polymer content was measured by a method.

  classical infra-red spectral analysis.

  The polymeric rubber of test N 14 (comparison) was obtained by addition of methanol when the polymerization reaction was complete, stirring the

  mixture for 5 minutes, adding 4,4'-bis (dimethyl)

  mino) benzophenone, stirring the mixture again for 5 minutes, then proceeding to the same coagulation and the same

drying as above.

  Each of the polymers thus obtained was kneaded in a cylinder kneader with the compounds shown in Table 1. The rubber was then baked.

  under pressure at 160 ° C for 25 minutes.

  After that, we measured the rebound factor

  530 C Vulcanized Rubber Using a Dunlop Tripodometer The wet slip or wiper resistance of the vulcanized rubber was also measured at 25 C using a portable test apparatus manufactured by the company. Stanley using the surface of a roadway (type B outdoor device, black, manufactured by the 3M company of the type

ASTM E 303-74).

  The results are shown in Table 2.

  Table 1: Formula of the compound Polymer 100 parts by weight Carbon black HAF 50 Aromatic treatment oil 5 "Zinc oxide 3 Stearic acid 2 Sulfur 1 N-oxydiethylene-2-benzothiazole 2 sulfenamide

Table 2

  (see next page) j i a p i j d n L M i

Table 2

  Visco-1 Bite 4 ooney mantite n mmo 1,

u com

  Dose of enone Coagulation and drying processes inyl ene mole%

-Ebon-

weaverbirds

ient (Z)

ésistan-

  Example 4 - 4,4'-bis (dimethylamino) benzoylone 4,4'-bis (diethylamino) benzophenone ido 4,41-diaminobenzophenone, aromatic compound Empty air / hot air ditto ït'thanol / vacuum Steam / hot air 4 ethanol / vacuum V Lpeur / hot air 0, 8 0,8 3,0 3,0 3,0 3,0 69 t O 72 5 73,0 69.0 73.0 73.0 cw 4 ja r b-4

  4,4'-bis (dimethylamino) bentothio-

  phenone 9 ido Io ido il ido 12 Wthanol i 13 id '14 i Methanol 4.4 g (diethylamino) benzophenyl 13 none 16 1 no ethanol / v ide Steam / hot air ethanol / vacuum i Steam / hot air ethanol / v ide Steam / hot air thanol / vacuum ethanol / hot vacuum goose 69.0, 69.0 W 77.0 77.0 78.5 77, W 79.0 3.0 O r MH lu (a U PO It is apparent from the results shown in Table 2 that the modified polymers in accordance with the invention have a significantly better rebound factor without either reducing the slip resistance or slippage in the wet state when changing

  coagulation and drying processes.

  With the modified comparison polymers and using aromatic thioketone, the same effect as that of the present invention was achieved provided that the coagulation and drying were performed at a relatively mild temperature, but the improvement of the rebound was observed.

  decreased when the polymers have undergone

  goureus E during the steps of steam coagulation

and drying with hot air.

Example 2

  The same polymerization reaction is carried out as in Example 1 except that the amount of diethylene glycol dimethyl ether (diglyme) is varied as indicated

Table 3.

  When the polymerization was complete, 3 millimoles of 4,4'bis (dimethylamino) benzophenone or 50 millimoles of methanol were added, and the mixture was stirred for 5 minutes. Then, in the same manner as in Example 1, the polymer was coagulated with methanol and dried under

reduced pressure.

  The properties of the polymer obtained are shown in Table 3

Table 3

(see next page)

Table 3

  Diglym test E Compound quantity isco content ebon-l esis

  N (mmoles added in mmo La-ity in isse ance ai

com 4 ooney vinyl are smooth-

  Mole% (%) wet ketone 17 0.29.4 '-bis (di 3 70 63 65 74 Ethylamino O benzophenone 18 0.36 ID 71 68 65 76

"6

  > 19 0.53 id "68 75 64 78 p I o 20 o, 29 ethanol 50 69 63 57 74 O o 21 0, 36 id" 69 68 57 76 04 __le_ _ O 22 0.53 id "67 75 56 78 DO We see in Table 3 that with a polybutadiene

  variable vinyl contents, the same degree of improvement

  bounce in Example 1 was noted.

Example 3

  A 2-liter stainless steel polymerization reactor was washed and dried and 65 g of polybutadiene having a Mooney viscosity of 40 and

  vinyl 70 mole%, and 650 g dehydrated n-heptane.

  The mixture is stirred to form a solution. Then 2.3 millimoles of n-butyllithium (in the form of a

  solution in n-hexane) and 2.3 millimoles of tetramethyl

  Nediamine, then run the reaction at 70 for 1 hour.

  Then, 4,4'-bis (dimethylamino) benzophenone is added and the mixture is stirred for 5 minutes. The polymer is coagulated with methanol and dried under reduced pressure.

  the same way as in Example 1.

  The properties of the polymers and the

  The results are shown in Table 4 below.

Table 4

  Test No Viscosity Rebound-Resistance Mooney (%) at wet level

close to

  Invention 23 lification 58 60 78 before mo- Zomparaison 24 lificaticn 40 56 78

1 1

Example 4

  The 2 liter stainless steel polymerization reactor was washed, dried and purged with dry nitrogen, and 112.5 g of 1,3-butadiene, 37.5 g of styrene, 820 g of benzene were introduced. 0.75 g of tetrahydrofuran and 2 mmol of n-butyllithium (in the form of a solution in n-hexane). While stirring the contents, 1,3-butadiene and styrene are polymerized at 450 ° C. for 2 hours. hours when

  the polymerization reaction is complete, 3 milliliters

  moles of 4,4'-bis (dimethylamino) benzophenone The mixture is stirred for 5 minutes, then the polymer is coagulated with steam and dried with hot air in the same way

only in the example 1.

  A comparison sample was prepared in the same manner as in the above example, except that 50 millimoles of methanol was added instead of 4,4'-bis (dimethylamino).

  benzophenone when the polymerization reaction is complete.

  The properties are treated, vulcanized and evaluated

  of these two polymers in the same manner as in Example 1.

  The results are shown in Table 5 below.

Table 5 thereA

  N test compound Visco reneur Teneurebon Resist

N in isse tance

  Mooney inyle Styrene ent (% with glue.

  (mole%) (p%) sily wettable V 4,4 '-bismouill Invention 25 dimethyla 60 3515 24.9 65 75

ino) benzo

  henone Comparai 26 Methanol 58 36.0 24.8 59 75 I-mon D_ 11

Example 5

  The same reaction is carried out as in Example 3 except that a polybutadiene having a Mooney viscosity of 42 and a cis-1,4 content of 98 mol% is used. The polymer is coagulated with methanol and dried under reduced pressure in the same manner as in Example 1 The results

  of the evaluation are shown in Table 6 below.

o 10 Tablaul 6

  Test N Viscosity Mooney Rebound

_ "'vmentte)

after

Invention 25 fication 45 66

Comparai before

its fication 42 60 _

Claims (4)

  A process for modifying an unsaturated polymeric rubber which comprises reacting an alkali metal-containing unsaturated polymeric rubber in solution with an aromatic ketone represented by the following formula: (R 1) m (R 2) n wherein R 1 and R 2 each represents a hydrogen atom, a trp or alkyl radical, a cycloalkyl group, an alkenyl group, an alkoxy group, an amino group, an alkylamino group, a dialkylamino group or a hydrogen atom and   o m and N each represent an integer from 1 to 5.   Process according to claim 1, characterized in that the alkali metal-containing unsaturated polymeric rubber is an alkali metal-terminated diene-type polymer rubber obtained by polymerization of a conjugated diene monomer using an alkali-metal catalyst. . Process according to claim 1, characterized in that the alkali metal-containing unsaturated polymer is an unsaturated polymeric rubber to which an alkali metal has been added and which has been obtained by reacting a rubber   polymeric unsaturated with an alkali metal containing compound.   Process according to claim 3, characterized in that the unsaturated polymeric rubber to which a metal   alkali has been added is an adduct of an alkali metal   301 in to a diene polymer rubber.   Process according to claim 3, characterized in that the unsaturated polymeric rubber to which an alkali metal has been added is an adduct of a polymer rubber based on an open ring cycloolefin and a alkali metal.