Continuous synthesis method for a modified diene elastomer, facility for implementing same

Patent metadata

Field	Value
Publication number	US-9908949-B2
Application number	US-201414910213-A
Country	US
Kind code	B2
Filing date	Jul 11, 2014
Priority date	Aug 8, 2013
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A continuous method for synthesizing a diene elastomer includes modifying the diene elastomer in a functionalizing device by:
a kinetic model according to which the ratio of the rate constants is greater than 1, and a flow represented by a residence time distribution in the functionalizing device that is expressed according to equations 1 or 3: (i) in a functionalizing device having at least one tubular continuous reactor or having at least one cascade of at least two stirred reactors,

E
1

⁡

(
t
)

=

1
2

⁢

(

P

πθ
1

⁢
t

)

1
2

⁢

e

-

P
⁡

(

θ
1

-
t

)

2

4
⁢

θ
1

⁢
t

Eq
⁢

⁢
1

(ii) in a functionalizing device that is a combination of the device (i) and of a device having at least one continuous stirred reactor, having a residence time distribution characterized by the following equation:

E
2

⁡

(
t
)

=

e

(

-

t

θ
2

)

θ
2

Eq
⁢

⁢
2

the device (ii) having a residence time distribution characterized by the equation 3 below, which is the result of the convolution of equations 1 and 2:

E
12

⁡

(
t
)

=

∫
0
t

⁢

E
1

⁡

(

t
-
T

)

⁢

E
2

⁡

(
T
)

⁢

⁢
d
⁢

⁢
T

⁢

⁢

E
12

⁡

(
t
)

=

∫
0
t

⁢

1
2

⁢

(

P

πθ
1

⁡

(

t
-
T

)

)

1
2

⁢

e

-

P
⁡

(

θ
1

-

(

t
-
T

)

)

2

4
⁢

θ
1

⁡

(

t
-
T

)

⁢

e

(

-

T

θ
2

)

θ
2

⁢
d
⁢

⁢
T

Eq
⁢

⁢
3

First claim

The invention claimed is:

1. A method for the continuous synthesis of a modified diene elastomer, comprising the steps:
of anionic polymerization of at least one conjugated diene monomer in the presence of a polymerization initiator,
of modifying the diene elastomer in a functionalizing device, by bringing the living diene elastomer bearing an active site obtained in the previous step into contact, in a single step, with a non-polymerizable functionalizing agent comprising a trialkoxysilane group, and optionally a function capable of interacting with a reinforcing filler,
the modification comprising three reactions in series

Reactions
Mechanism

R1
PLi + A k 1 fi PA

R2
PLi + PA k 2 fi P 2 A

R3
PLi + P 2 A k 3 fi P 3 A

where
A represents the functionalizing agent,
PLi represents a living elastomer chain,
PA represents the chain-end functionalized elastomer,
P 2 A represents the coupled elastomer,
P 3 A represents the three-arm star-shaped elastomer, and

k i represents the rate constant of the reaction R i , that are carried out according to the following rate law:

Reactions
Rate of reaction

R1
V 1 = k 1 [PLi][A]

R2
V 2 = k 2 [PLi][PA]

R3
V 3 = k 3 [PLi][P 2 A]

where
k 1 , k 2 and k 3 are the rate constants respectively of the reactions R1, R2 and R3 (expressed in (m 3 /mol)·s −1 ),
[PLi] is the concentration of living chains (expressed in mol/m 3 ),
[A] is the concentration of modifying agent A (expressed in mol/m 3 ),
[PA] is the concentration of chain-end functionalized elastomer (expressed in mol/m 3 ),
[P 2 A] is the concentration of coupled elastomer (expressed in mol/m 3 ),
[P 3 A] is the concentration of the three-arm star-shaped elastomer (expressed in mol/m 3 ),

with a ratio of the rate constants, defined as:

K
=

k
1

k
2

=

k
2

k
3

,

 of greater than 1, and
the residence time distribution in a functionalizing device (i) or (ii) is expressed respectively according to equations 1 or 3 below:
(i) in a functionalizing device having at least one tubular continuous reactor or having at least one cascade of at least two stirred reactors,

E
1

⁡

(
t
)

=

1
2

⁢

(

P

πθ
1

⁢
t

)

1
2

⁢

e

-

P
⁡

(

θ
1

-
t

)

2

4
⁢

θ
1

⁢
t

Eq
⁢

⁢
1

in which:
P is the dimensionless parameter of resistance to dispersion,
θ 1 is the residence time defined as the reactor volume/total volume flow rate ratio, equal to at least 0.1 minute and at most to 10 minutes,
t is the variable time of the residence time distribution,
(ii) in a functionalizing device that is a combination of the device (i) and of a device having at least one continuous stirred reactor, having a residence time distribution characterized by the following equation:

E
2

⁡

(

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Dire Charlotte
• Marechal Jean Marc
• Dorato Margarita
• Manceau Mathieu
• Pacheco Nuno

Classifications

• C08F236/10

  with vinyl-aromatic monomers · CPC title

• C08L15/00

  Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence) · CPC title

• C08C19/25 Primary

  Incorporating silicon atoms into the molecule · CPC title

• B01J2219/24

  Stationary reactors without moving elements inside · CPC title

• B01J2219/00033

  Continuous processes · CPC title