LU87057A1 - RADIAL AND BRANCHED SEQUENCE COPOLYMERS, COMPOSITIONS CONTAINING THEM, THEIR PREPARATION AND THEIR USE IN BITUMINOUS COMPOSITIONS - Google Patents

Description

4 Q "7 Π K If GRAND-DUCHY OF LUXEMBOURG BL-4073 / ML

*: Patent N W / U 3 f,. ,.

ΨΤ.'ϊΓ '*} · Minister of November 30, 1987 of the Economy and the Middle Classes,. , Intellectual Property Service

LUXEMBOURG book title

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Patent Application ..... _ ....... ............................... (1) I. Application

The company known as: ENICHEM ELASTOMERI-Sp ”A ........................................ ............. <2) 55., Via Ruggero Settimo ............................ ................. PALERMO / Italy .............................. ................................................

represented by: E.T. EREYLINGER & E.MEYERS, Ing. cens. in own. indi 3) 46, rue ..... du. cemetery, LUXEMBOURG, representatives files! nt) this thirty November one thousand nine hundred and eighty seven (4) at 3 .. ”0.0 ..-. hours, at the Ministry of the Economy and the Middle Classes, in Luxembourg: 1. this request for obtaining a patent for invention concerning:. ........................... _ .... .................. (5)

Radial and branched block copolymers, compositions containing them, their preparation and their use in bituminous compositions 2. the description in French of the invention in triplicate: 3.! drawing plates, in triplicate: November 20, 1987 4. receipt of the fees paid to the Luxembourg Registration Office, .. ^ priVPTn> irp 1937 '5. the delegation of power, dated PALERMO on November 13, 1987 : 6. the successor document (authorization); declares (s) assuming responsibility for this declaration, that the inventor (s) is (are): (61

Sergio CUSTRO, ...... Via Lago di Garda, 11 J RAVENNA - Italy

Elio DIANI, ........... Via ..... Trento, 1 / CAS S INA DE PECCHI - Italy

Alessandro ZAZETTA, Via Grams ci, 35 / CESANA _ Italy claims (s) for the above patent application the priority of one (or more) application (s) for (7i invention patent (s) filed in (8) Italy on (9) ............... December 1, 1986 ..................

under N ° (10) 22 519 A / 86 ...................... .....

on behalf of (11) ENICHEM ELASTOMERI S.p.A.

elect (elect) domicile for him / her and, if designated, for his / her representative, in Luxembourg 46, <.xue du cemetery, LUXEMBOURG ........ (12) requests (s) the issue of a invention patent for the subject described and represented in the abovementioned appendices.

with postponement of this issue to .......... s D-X .... months. (13) T.c deVÎWsaïiv / agent: (14) II. Deposit Minutes

The aforementioned patent application has been filed with the Ministry of the Economy and the Middle Classes. Intellectual Property Service ÀL ^ ’ensbo ^ g, dated: November 30, 1987

A V

4 · -. U '/ -? "' ·. \ \ Pr. The Minister of Ecdhomy and the Middle Classes, t: at 15.00 hours / zjlPri ^ ··) d.

\ v '4 n‘j; The head of the intellectual property department,

Coüf —_ ^ * __ EXPLANATIONS RELATING TO THE DEPOSIT FORM "7 / (if applicable" Request for certificate of addition to the main patent, to 12 requests for main breeder N. ... // ... iu ....... (2 · deserves the, black .. taking pr, I / ~ ÏÛ I address of the claimant. When the latter is unparueuher or ies corporate name lundique form. Address of the registered office. When the if you are a legal person, - (..i

_J ‘BL-4073 / ML

Claim to the priority of the patent application filed in ITALY, on December 1, 1986 under No. 22,519 A / 86 Descriptive memorandum filed in support of an invention patent application for: COPOLYMERS RADIAL AND BRANCHED SEQUENCES, COMPOSITIONS CONTAINING THEM, THEIR PREPARATION AND THEIR USE IN BITUMINOUS COMPOSITIONS.

ENICHEM ELASTOMERI S.p.A.

Via Ruggero Settimo 55 PALERMO / ITALY

* /

1 BL-4073 / M

Radial and branched block copolymers »compositions containing them, their preparation and their use in bituminous compositions.

The present invention relates to radial and branched block copolymers, the compositions containing them, their preparation and their use in bituminous compositions.

Anionic polymerization of suitable monomers is known, in the presence of alkylmetallic or arylmetallic catalysts, to produce "living" polymers which are capable of undergoing other transformations, as described for example by M. Shvarc in "Carbanions, Living Polymers and El. Transfer Processes", Interscience Publishers, J, Wiley 6c Sons, Nev York, 1968.

By the "living" polymer technique, it is possible to prepare linear or radial (i.e., radiant) block copolymers. Among the linear block copolymers, it is possible to obtain, for example, polymers of the A-B-A type, in which "A" is a polystyrene block exhibiting non-elastomeric thermoplastic properties. and B" . is an elastomeric polybutadiene block.

The radial block copolymers can be obtained by a reaction of the living polymer with a suitable coupling agent.

In the case where, for example, carbon tetrachloride is used, polymers are obtained which can be represented by the following formula:

If (B-A) 4 20 in which A and B meet the definition given above.

The use of block copolymers, both linear and radial, in bituminous compositions is also known to improve the general characteristics of bitumens, in particular their adhesion, elasticity and anti-creep behavior.

Patent BE 738 281 describes, for example, bituminous compositions, which contain approximately 15% by weight of a linear block copolymer ABA in which "A" is a thermoplastic block (generally a polystyrene block), and "B" is a block elastomer (usually a polybutadiene block).

2 The use of radial block copolymers of the polystyrene-polybutadiene type is described for example in patent BE-853,210.

Finally, US Patent 4,464,427 describes bituminous compositions containing a linear block copolymer as well as a radial block copolymer, 5 belonging to the types mentioned above.

It has been observed that block copolymers of the radiai type confer on bituminous compositions in which they are incorporated adhesion, elasticity and creep resistance characteristics, which are generally superior to those obtained with linear block copolymers.

The higher the number of polymer segments in the radial copolymer, the greater this improvement.

It would therefore be desirable to have block copolymers of the radial type comprising a high number of polymer segments linked to the multifunctional coupling agent.

However, in practice, such an embodiment is limited by the technical difficulties and / or the high costs encountered during the preparation of radial block copolymers which have more than four segments linked to the coupling agent.

It has been discovered that it is possible to go beyond the current state of the art and to prepare block copolymers of the radial type, comprising four polymer segments linked to the tetrafunctional coupling agent, characterized in that the polymer segments have a adjusted branching degree.

The radial and branched block copolymers of the present invention are capable of imparting to the bituminous compositions in which they are incorporated mechanical and technical characteristics which are surprisingly improved compared to the corresponding unbranched radial block copolymers.

Another objective of the present invention is to provide polymer compositions containing said radial and branched block copolymers.

The invention also provides a process for the preparation of said radial and branched block copolymers and polymer compositions containing these radial and branched block copolymers.

Another objective of the invention is to provide bituminous compositions containing said radial and branched block copolymers or said 35 polymer compositions.

* i i t 3 Other objectives of the invention will appear on reading the description below.

In particular, according to the present invention, the radial and branched block copolymers have the following structure:

AT

(A - B) - B (B - A) q,, m

A-B - Z - B-A

I I

CA - B) B - CB - A) P j n

AT

5 in which: Z is a radical derived from a tetrafunctional coupling agent; A is a polystyrene block; B is a polybutadiene block; and M. not. p, q are worth either 1 or 0, with the condition that their sum is between 1 and 4.

The polystyrene sequence "A" generally has a molecular weight of between 10,000 and 40,000, preferably between 15,000 and 25,000.

The polybutadiene block "B" generally has a molecular weight of between 20,000 and 70,000, preferably between 40,000 and 50,000.

15 The sum of m.n. p. q is preferably between 1 and 3.

The polymer compositions according to the present invention contain at least 50% by weight, preferably at least 607% by weight of the radial and branched block copolymers described above, the remainder consisting of BA block copolymers, and of homopolymers "A ”," A "and" B "having the same meanings as above.

The process for the preparation of these polymer compositions comprises the following stages, carried out in the order indicated: a) the polymerization of the styrene monomer is carried out, by the technique of living polymers and by working at a temperature of about 35 ° C. at about 25 65 ° C, using catalysts consisting of aliyl-metallic or aryl-metallic compounds, to produce a polystyrene block, having a molecular mass of 10,000 to 40,000, comprising a metal atom linked to the end of I 1 4 the polymer chain: AM (where "M" is the metal of the alkyl-metallic or aryl-metallic catalyst and "A" is the polystyrene block).

b) the polymerization of the 1,3-butadiene monomer is carried out, by the technique of living polymers, in the presence of the polystyrene block in which the metal atom is linked to the end of the polymer chain, resulting from step (a) previous, by working at a temperature of about 60 ° C to 100 * C, to produce a two-block copolymer in which the metal atom is linked to the end of the polystyrene chain: ABM, where “A“ is the polystyrene block, "B" is the polybutadiene block having a molecular weight of 20,000 to 70,000, and "M" is as defined above.

c) the reaction mixture obtained in step (b) is heated to a temperature between more than 100 ° C. and approximately H0 * C, generally between 110 ° C. and 125 ° C., for a time long enough to cause the grafting of the BA block copolymer, and. to obtain grafted structures with metallic components which can be represented by the formula:

A-B

A-B-M

in which A, B, M are as defined above.

D) the metallic component structures from step (c) are coupled, using a tetrafunctional coupling agent; e) recovering the various polymer species From the mixture resulting from the coupling reaction of step (d), and optionally, f) separating the radial and branched block copolymers present among the 25 species of polymers recovered in the step (e).

According to a preferred embodiment of the present invention, the polymerization of styrene (step (a)), and the subsequent copolymerization with butadiene (step (b)), are carried out adiabatically, so that at the end of step (b), a temperature higher than 100 ° C. is reached, up to a maximum of 140 ° C. The fact that the temperature is, at the end of the copolymerization with butadiene, greater than 100 ° C., is essential for obtaining the radial and branched block copolymers according to the present invention.

In fact, if the final temperature of the copolymerization with butadiene is lower than A100 * C, if no heating is carried out which would raise (J t 5 this temperature to the values mentioned above, the grafting reaction of the BA copolymer on the polybutadiene blocks B does not occur, and the end products obtained after coupling are unbranched radial copolymers.

In practice, the polymerization of styrene (step (a)) is carried out under anhydrous conditions, as is necessary for obtaining living polymers, in solution in inert hydrocarbon solvents, such as for example cyclohexane and n-hexane, at an initial temperature of about 50 ° C, with the catalyst as an alkyl-metai or aryl-metal compound, in particular n-butyl-lithium or sec-butyl-lithium, in a ratio styrene / catalyst molar of between 10,000 and 5,000, and preferably between 1,000 and; 5,000. -

The reaction is allowed to proceed for about 60 minutes, until complete or substantially complete conversion of the styrene, and polymer blocks having a molecular weight between 10,000 and 40,000, and preferably between 15,000 and 25,000, are obtained.

1,3-butadiene is added to the solution containing the polystyrene blocks having a metal atom at the end of their polymer chain, this solution being at the temperature of about 60-65 ° C. approximately 40 minutes, linear polymers BA are obtained, in which the block "B" has a molecular mass of between 20,000 and 70,000, and preferably between 40,000 and 50,000.

The solution from the copolymerization with butadiene is left to stand at a temperature above 100 ° C, and preferably between 110 25 and 125‘C, for a period of 10 to 20 minutes.

After this period, a tetrafunctional coupling agent is added to the mixture, which can be chosen from esters of aliphatic and aromatic dicarboxylic acids, chlorinated derivatives of aliphatic or aromatic hydrocarbons, chlorinated derivatives of aliphatic and aromatic silanes, aromatic substituted unsaturated substances such as, for example, divinylbenzene; tetrachlorinated derivatives of tin, silicon, germanium, and preferably S1CI4, in a SiCl 2 / styrene molar ratio equivalent to a stoichiometric, or roughly stoichiometric, ratio. The preferred "Z" radical is therefore a silicon atom.

6

The coupling reaction is carried out at a temperature between 100 and 140 ° C, and preferably between 110 and 125 * C, in a period of 5 to. 15 minutes, and the yield generally reaches a value of around 90%.

To the polymer species contained in the solution, an amount of about 1 to 1.5% by weight of an antioxidant is added, and the various polymer species are recovered from the reaction mixture by removal of the solvent, and drying in a vacuum oven at 60 * C.

The polymer composition thus obtained can be added as it is to the bituminous composition, or according to a variant, the radial and branched copolymers can be separated from the other polymer species,

The polymer composition originating from stage (e) comprises at least 50% by weight, and preferably at least 60% by weight, of radial and branched copolymers, the balance \ 100% consisting of linear styrene-butadiene copolymers and with polybutadiene.

The radial and branched block copolymers according to the present invention are capable of bringing about a considerable improvement in the mechanical and technical properties of the bituminous compositions in which they are incorporated, compared with the corresponding unbranched radial polymers.

It is also possible to obtain bituminous compositions which have the same characteristics as those of the prior art, using the said copolymers, but in proportions lower than those known in the prior art.

The radial and branched copolymers according to the present invention can be used in proportions of 2 to 30 parts by weight per 100 parts of bitumen, and preferably, from 8 to 13 parts by weight per 100 parts of bitumen.

The invention will be better understood with the aid of the examples below, which in no way limit the field of the invention.

Example 1

In a reactor with a capacity of 1 liter, the moisture of which has been removed by means of hot nitrogen, and which is provided with an agitator, a thermometer and a cooling enclosure, 400 ml of anhydrous cyclohexane and 15 g (0.144 mole) of styrene distilled over calcium hydride. Cyclohexane contains 0.035 g of THF.

The mixture is stirred at. 50’C and agitation is maintained.

0.047 g (0.73 mm) of sec-butyl lithium is added as the polymerization initiator, and the reaction is allowed to proceed for 60 minutes, the temperature being maintained at 50 ° C., until the complete conversion of the styrene .

7 At the end of this period, 35 g (0.648 mmol) of 1.3-butadiene are added and the polymerization is allowed to proceed for 40 minutes.

The final temperature of the polymerization is 95 ° C. The block copolymer which has formed, a living polymer, is left for one minute at 5,100’C, then 0.028 g (0.165 mmol) of S1Cl4 is introduced into the reactor.

The reaction is allowed to proceed for 15 minutes at 97 ° C., and then the mass of polymer obtained is removed from the reactor, in a glass flask containing 45 g of BHT and Polygard.

The polymer solution is then purified in a vapor stream and dried in a vacuum oven at 60 ° C for 2 hours.

The polymer composition is characterized by gel permeation chromatography, and the results are collated in Table I.

Table I

Mp (AB) 70 x 103

Mp (AB) n 260x 103

Mp / Mn (AB): 1.03

Mp / Mn (AB) n: 1.02

The polymer composition is used for the preparation of a bituminous composition, by mixing 13 parts of the polymer composition with 100 parts of bitumen (SOLEA 180/200).

The characteristics of the bituminous composition are collated in Table II, according to the standards ASTM D5-65 and ASTM D36-66T,

Table II

Viscosity (at 180 * C) = 2100 cps

25 Ball and ring test = 125-130 * C

Penetration = 40 - 45 dmm I * - · ·· 8

Example 2

The same amounts of reagents are used as in Example 1, but the reactions are carried out under adiabatic conditions: the initial temperature of the polymerization of styrene is 60 ° C., and over a period of 20 minutes, the temperature of the reaction reaches 63 ° C., when the transformation of the monomer is complete.

At the end of the copolymerization with 1,3-butadiene, the temperature reaches 120 ° C. due to the heat given off by the exothermic reaction.

At the end of the reaction with butadiene, the polymer solution is left for 13 minutes at 120 ° C., then the process is continued by the addition of silicon tetrachloride, as described in Example 1.

The characteristics of the polymer composition are collated in Table III.

The final polymer composition is used to prepare a bituminous composition, by mixing 10 parts of the polymer composition with 100 parts of bitumen (SOLEA180 / 200).

The characteristics of the bituminous composition thus obtained are collated in Table IV, according to standards ASTM D5-65 and ASTM D36-66T.

Iâblsay.IU

20 Mp (AB) 100 x 103

Mp (AB) n 330 xlO3

Mp / Mn (AB): 1.4

Mp / Mn (AB) ß: 1.4

Table IV

25 Viscosity (at 180’C) = 1700 cps

Ball and ring test = 127 * C

Penetration = 56 dmm

Claims (14)

1. Radial and branched block copolymers, characterized in that they have the following structure: A r (A - B) - b <B: A) q 1 'Λ A' - B - T- - B “AI 1, B (A - B) B - (B - A) P l A in which: 5. is a radical derived from a tetrafunctional coupling agent; A is a polystyrene block having a molecular weight between 15,000 and 40,000; Ë is a polybutadiene block having a molecular weight of between 20,000 and 70,000; and 10 m, n. o, q are worth either 1 or 0, with the condition that their sum is between 1 and 4. 2. Radial and branched block copolymers according to claim 1, characterized in that the sum dem, n. p. etq is between 1 and 3- 3. Radial and branched block copolymers according to claim 1, characterized in that the sequence "A" has a molecular weight between 15,000 and 25,000, and that the sequence "B" has a molecular weight between 40,000 and 50,000. 4. Radial and branched block copolymers according to claim 1, characterized in that the radical “Z” is a silicon esratome. 5. Polymer compositions, characterized in that they contain at least 50% by weight of the radial and branched block copolymers according to one of claims 1 to 4, the complement to 1007 * being constituted by linear bisequence copoiymers BA, and by a homopolymer "B”. 6. Polymer compositions according to claim 5, characterized in that they contain at least 60% by weight of said radial and branched block copolymers. 7. Process for the preparation of the polymer compositions according to claim 5 or 6, and radial and branched block copolymers according to one of claims 1 to 4, characterized in that it comprises the following steps, carried out in the order indicated: 10 * "R ^ * <· * * '" "a) polymerization of the styrene monomer is carried out, by the technique of living polymers and by working at a temperature of approximately 35 ° C. to approximately 65 ° C., using catalysts consisting of alkyl-metallic or aryl-metallic compounds, to produce a polystyrene block having a molecular weight of 10,000 to 40,000, having a metal atom bonded to. the end of the polymer chain: A-M (where “M” is the metal of the alkylmetal or arylmetallic catalyst and “A” is the polystyrene block). b) the polymerization of the 1,3-butadiene monomer is carried out, by the technique of living polymers, in the presence of the polystyrene block in which the metal atom is linked to the end of the polymer chain, to produce a bis-sequenced copolymer in which the metal atom is linked to the end of the polybutadiene chain: "ABM, where" A '' is the polystyrene block, "B" is the polybutadiene block having a molecular weight of 20,000 to 70,000, and "M" is as defined above: c) the reaction mixture obtained in stage (b) is heated to a temperature above 100 ° C. for a time long enough to cause the grafting of the bis-block copolymer BA, and for obtain grafted structures with metallic components which can be represented by the formula: A-B A-i-M wherein "A", "B", "M" are as defined above. d) we couple the structures to. metal component from step (c), using a tetrafunctional coupling agent; E) the different polymer species are recovered from the mixture resulting from the coupling reaction of step (d), and optionally, f) the radial and branched block copolymers present among the polymer species recovered in the step (e). 8. Method according to claim 7, characterized in that in step (a), a polystyrene block having a molecular weight of 15,000 to 25,000 is obtained. 9. Method according to claim 7, characterized in that in step (b), a block copolymer B-A is obtained, in which "A" has a mass,. '* ‘» «. > »Π ψ« «molecular from 15-000 to 25,000 and" B "has a molecular weight from 40,000 to 50,000. 10. Method according to claim 7, characterized in that in step (c). the reaction mass is heated to a temperature between 110 and 125’C. 5 for a period of 10 to 20 minutes. 11. Method according to claim 7, characterized in that in step (d). the tetrafunctional coupling agent is chosen from esters of aliphatic or aromatic dicarboxylic acids; chlorinated derivatives of aliphatic or aromatic hydrocarbons; chlorinated derivatives of aliphatic or aromatic silanes; substituted unsaturated aromatics; tetrachlorinated derivatives of tin, silicon and germanium. 12. Method according to claim 11, characterized in that the tetrafunctional coupling agent is SiCl ^. 13. Bituminous compositions, characterized in that they contain a proportion of 2 to 30 parts by weight of the radial and branched block copolymers according to one of claims 1 to 4, or of the polymer compositions according to claim 5 or 6, per 100 parts by weight of bitumen. 14. Bituminous compositions according to claim 13, characterized in that they contain a proportion of 8 to 13 parts by weight of the radial and branched block copolymers according to one of claims 1 to 4, or of the polymer compositions according to claims 5 or 6, for 100 parts by weight of bitumen.