WO2024200922A1 - Ring-opening polymerisation method - Google Patents

Abstract

The present invention relates to a method for preparing linear organopolysiloxanes OL via a ring-opening polymerisation reaction of at least one cyclic organopolysiloxane CO in the presence of a catalytic system AI comprising: at least one catalyst A of formula (I); and at least one initiator I chosen from among alcohols and derivatives thereof, silanols and derivatives thereof, or mixtures thereof. The invention also relates to the use of the linear organopolysiloxanes LO obtained thereby in various silicone formulations that can be used in, inter alia, the field of cosmetics, household cleaning products, motor vehicles and energy.

Description

Title of the invention: Ring-opening polymerization method

Technical field:

The invention relates to a method for preparing linear organopolysiloxanes OL by a ring-opening polymerization reaction from cyclic organopolysiloxanes OC, and using a catalytic system AI. More precisely, the method of the present invention makes it possible to obtain linear organopolysiloxanes OL of controlled molecular mass with a very low residual level of cyclic organopolysiloxanes.

Technological background:

A major challenge for the silicone industry in the coming years is to industrially synthesize organopolysiloxanes with a very low or even zero residual cyclic rate.

To date, the industrial synthesis of organopolysiloxanes by polycondensation or by ring-opening polymerization sees the formation of cyclic organopolysiloxanes such as octamethyltetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) or other unwanted cyclic organopolysiloxanes. In conventional industrial processes, this content of unwanted products can amount to a content of between 10 and 15% relative to the total mass of linear organopolysiloxane obtained during the synthesis, which corresponds to thermodynamic equilibrium. Conventionally, this high content of cyclic products requires energy-intensive process steps such as a high-temperature and/or high-pressure devolatilization step to separate these by-products from the linear organopolysiloxane obtained.

Thus, in the interests of economic and energy profitability, there is a need to develop new solutions to avoid or at least limit these long and costly separation stages.

Furthermore, cyclic silicones or organopolysiloxanes such as octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) are and will be subject to restrictions for their use. In addition to the fact that these cyclic compounds present environmental risks due to their non-biodegradability, they are also suspected of being endocrine disruptors and potentially carcinogenic.

In this sense, in 2018 the European regulation limited the content of D4 and D5 to a content of 0.1% by mass in rinse-off cosmetic products. Soon, this regulations will be adopted for other cosmetic products but also in other areas of application of silicones.

Therefore, there is a need to provide processes for providing linear organopolysiloxanes free of or at least having a low content of cyclic silicones. In particular, there is an interest in providing a new catalytic system for implementing such a process. There is also an interest in being able to reliably control the molecular mass of the products formed. This possibility makes it possible to increase the prospects for use and applications of such polymers obtained.

In the prior art, the use of phosphorus ylides of formula (Me)z C=P(NMc2)3, as well as their precursors as a strong, weakly nucleophilic base, were first described in patent application WO-A-98/54229 in C-alkylation reactions of lactams, succinimides and benzodiazepines.

Subsequently, patent application WO003054058 discloses the use of this same catalyst (Me)2C=P(NMe2)3 in a polymerization process by opening of cyclic organopolysiloxane. This catalyst leads to obtaining satisfactory results with a yield of 85 to 90%. However, this system fails to shift the thermodynamic equilibrium and leads to a residual cyclic organopolysiloxane content of the order of 10 to 15%. There is therefore a real need to develop a catalytic system making it possible to obtain higher yields of linear organopolysiloxane while limiting the formation of cyclic organopolysiloxanes by retroscission reaction.

Summary of the invention:

Surprisingly, the Applicant has developed a catalytic system that meets these expectations. Thus, the present invention relates to a process for preparing linear organopolysiloxanes OL by a ring-opening polymerization reaction of at least one cyclic organopolysiloxane OC, in the presence of a catalytic system AI comprising:

dans laquelle : - at least one catalyst A of formula (I):

in which:

-R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a cycle.

-Ri, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two Ri groups form together with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms, -R2, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R2 groups form together with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms,

-R3, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R3 groups form together with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms, and with the condition that the phosphorus atom has at least one heterocyclic amine as a substituent, and at least one initiator I chosen from alcohols and their derivatives, silanols and their derivatives, or their mixtures.

An objective of the present application is therefore to propose a process for the preparation of linear organopolysiloxanes OL by a ring-opening polymerization reaction of cyclic organopolysiloxanes OC making it possible to control the molecular mass of the final product with a yield of linear organopolysiloxanes greater than 90%, preferably greater than 95%.

Another objective of the present application is to provide an AI catalytic system for implementing this process.

Another objective of the present application is to propose a simple and non-hazardous catalytic system compatible with the implementation of the process.

Still other objectives will become apparent from reading the description of the invention which follows.

Detailed description of the invention:

Silicones, otherwise known as organopolysiloxanes, are polymeric materials comprising alternating silicon and oxygen atoms with various organic radicals bonded to the silicon. In the context of the present invention, silicone, silicone product, silicone polymer or organopolysiloxane means polymers comprising a siloxane skeleton (Si-O-Si) having alternating silicon and oxygen atoms with various organic radicals bonded to the silicon. These silicone polymers can be liquid or solid, depending on the molecular weight and the degree of crosslinking.

For the purposes of the present invention, the term “reaction mixture” means all of the reactive chemical species present. By way of example, mention may be made of the catalyst(s) A, the initiator(s) I, the cyclic organopolysiloxane(s) OC, and/or the chain blocker(s) C.

For the purposes of the present invention, the term “catalytic system AI” means the combination of catalyst A and initiator I which forms an active species capable of catalyzing the process of the present invention. The term “heterocyclic amine” means a chemical compound containing at least one heterocyclic ring, which by definition has atoms of at least two different elements, as well as at least one amine group. The following compounds may be mentioned by way of illustration: piperidine, piperazine, pyrrole, pyrrolidine, 4-methylpiperidine.

All the viscosities discussed in this presentation correspond to a dynamic viscosity quantity at 25°C called “Newtonian”, that is to say the dynamic viscosity which is measured, in a manner known per se, with a Brookfield viscometer at a shear rate gradient sufficiently low so that the measured viscosity is independent of the rate gradient.

dans laquelle, R identique ou différent est un radical représentant un hydrogène, un groupe alkyle de 1 à 6 atomes de carbones, un groupe alcényle de 1 à 6 atomes de carbones, ou un groupe aryle en CÔ-CIS ; et n représente un entier naturel compris entre 1 et 2. For the purposes of the present invention, cyclic organopolysiloxane OC is represented by the following formula (II):

in which, R, identical or different, is a radical representing a hydrogen, an alkyl group of 1 to 6 carbon atoms, an alkenyl group of 1 to 6 carbon atoms, or a C6-C7 aryl group; and n represents a natural integer between 1 and 2.

Examples include commercially available cyclic organopolysiloxanes OC such as hexamethylcyclotrisiloxane (CAS 541-05-9), 2-ethenyl-2',4,4',6,6'-pentamethylcyclotrisiloxane (CAS 18395-32-9), 2,4,6-triethenyl-2,4,6- trimethylcyclotrisiloxane (CAS 3901-77-7) ,5,2,4,6-trioxatrisilinane, 1,3,5-Trimethyl-1,3,5-triphenylcyclotrisiloxane (CAS 546-45-2); 2 4 6-trimethylcyclotrisiloxane (CAS 13269-39- 1), 3,5-trivinyl-l,3,5-trimethylcyclotrisiloxane (CAS 3901-77-7), 2-Ethenyl-2,4,4,6,6- pentamethylcyclotrisiloxane (CAS 18395-32-9), 2,4,6,8-T etramethylcyclotetrasiloxane (CAS 2370-88-9), 2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (CAS 2554-06-5), 2,4,6,8-Tetramethyl-2,4,6,8-tetraphenylcyclotetrasiloxane (CAS 77-63-4), octaphenylcyclotetrasiloxane (CAS 546-56-5).

Advantageously, the cyclic organopolysiloxane OC is hexamethylcyclotrisiloxane (CAS 541-05-9) or octamethylcyclotetrasiloxane (CAS 556-67-2)

According to one embodiment of the invention, the method of the present invention uses at least two organopolysiloxanes chosen from the following compounds: octamethylcyclotetrasiloxane (CAS 556-67-2); hexamethylcyclotrisiloxane (CAS 541-05-9) and 2,4,6-triethenyl-2,4,6-trimethylcyclotrisiloxane (CAS 3901-77-7).

dans laquelle : For the purposes of this application, catalyst A is represented by the formula

in which:

-R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a cycle.

-Ri, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two Ri groups together form with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms,

-R2, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R2 groups together form with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms,

-R3, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R3 groups together form with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms, and with the condition that the phosphorus atom has at least one heterocyclic amine as a substituent.

dans laquelle: According to one embodiment of the invention, catalyst A is represented by the following formula (IV):

in which:

-R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a cycle.

-Ri, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two Ri groups together form with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms,

-R2, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R2 groups together form with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms,

-R3, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and n is a natural integer equal to 1, 2 or 3.

dans laquelle: Preferably, catalyst A is represented by the following formula (V):

in which:

-R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a cycle,

-Ri, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms and n, identical or different, is a natural integer equal to 1, 2 or 3.

dans laquelle: Preferably, catalyst A is represented by the following formula (VI):

in which:

-R, identical or different, represents a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a cycle, and n, identical or different, is a natural integer equal to 1 or 2.

dans laquelle n est un entier naturel égal à 1 ou 2. Even more preferably, catalyst A is represented by the following formula (VII):

in which n is a natural integer equal to 1 or 2.

In one embodiment, the process of the invention is characterized in that the molar ratio of catalyst A relative to the cyclic organopolysiloxane OC is from 0.005% to 2%, preferably from 0.01 to 2%, preferentially from 0.05 to 1%, and even more preferentially from 0.1 to 1%. For the purposes of the present invention, the initiator I is chosen from alcohols and their derivatives, silanols and their derivatives, or their mixtures.

dans laquelle : In the context of the present application, the initiator I is chosen from the compounds of formula (VIII):

in which:

Y represents a carbon atom or a silicon atom;

R is the same or different and represents:

-a hydrogen atom,

-an alkyl group of 1 to 12 carbon atoms,

-a cycloalkyl group of 5 to 8 carbon atoms,

-an alkenyl group of 1 to 12 carbon atoms,

- a Ce-Cis aryl group, preferably phenyl,

-a benzyl group

- a siloxyl group having at least 5 units, preferably at least 10 units of formula R ¹ cSiO(4-c)/2 in which

R ^1, identical or different, represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl; an aryl group comprising from 6 to 10 carbon atoms, preferably phenyl; and c = 0, 1 or 2 and; when said radical R is other than a hydrogen atom, the radical R may be substituted or not by an alkyl or alkenyl chain of 1 to 6 carbon atoms, a cycloalkyl group, an aryl group comprising from 6 to 10 carbon atoms or a heteroatom such as oxygen, sulfur or nitrogen.

dans laquelle : In the context of the present application, the initiator I is chosen from the compounds of formula (IX):

in which:

Y represents a carbon atom or a silicon atom;

R is the same or different and represents:

-a hydrogen atom,

-an alkyl group of 1 to 12 carbon atoms,

-a cycloalkyl group of 5 to 8 carbon atoms,

-an alkenyl group of 1 to 12 carbon atoms,

- a Ce-Cis aryl group, preferably phenyl,

-a benzyl group

- a siloxyl group having at least 5 units, preferably at least 10 units of formula R ¹ cSiO(4-c)/2 in which

R ^1, identical or different, represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl; an aryl group comprising from 6 to 10 carbon atoms, preferably phenyl; and c = 0, 1 or 2.

In one embodiment of the present invention, the initiator I is selected from alcohols or silanols having a pKa of 10 to 16, preferably a pKa of 12 to 16, preferentially a pKa of 14 to 16.

dans laquelle : According to another embodiment of the invention, the initiator I is chosen from the compounds of formula (X):

in which:

Y represents a carbon atom,

R is the same or different and represents:

-a hydrogen atom

-an alkyl group of 1 to 12 carbon atoms,

-a cycloalkyl group of 5 to 8 carbon atoms,

-an alkenyl group of 1 to 12 carbon atoms,

- a benzyl group or a phenyl, when said radical R is other than a hydrogen atom, the radical R may be substituted or not by an alkyl, alkenyl chain of 1 to 6 carbon atoms, a cycloalkyl group, an aryl group or a heteroatom such as oxygen, sulfur or nitrogen.

According to one embodiment, the initiator I is an alcohol selected from primary alcohols or secondary alcohols. Preferably, the initiator I is an alcohol selected from primary alcohols.

According to one embodiment, the initiator I is an alcohol chosen from saturated or unsaturated polyols having 2 to 6 hydroxyl groups. By way of example, the following polyols may be mentioned such as glycerol, pentaerythritol, sorbitol or 1,4 butanediol.

According to one embodiment, the initiator I is an alcohol having a pKa of 10 to 16, preferably a pKa of 12 to 16, preferentially a pKa of 14 to 16.

According to one embodiment, the initiator I is an alcohol selected from: methanol (CAS 67-56-1), ethanol (CAS 64-17-5), propanol (CAS 71-23-8), isopropanol (CAS 67-63-0), butanol (CAS 71-36-3), 2-methylpropan-2-ol (CAS 75-65-0), allyl alcohol (CAS 107-18-6), benzyl alcohol (CAS 100-51-6), 3-buten-1-ol (627-27-0), long-chain alkyl alcohols such as undecanol (CAS 112-42-5) or dodecanol (CAS 27342-88-7).

According to a preferred embodiment, the initiator I is benzyl alcohol (CAS 100-51-6).

Alternatively, in the context of the present application, the initiator I has at least one terminal silanol function.

Preferably, the initiator I having a terminal silanol function has at least one siloxyl unit. Preferably, the initiator I having a terminal silanol chemical function has at least two siloxyl units. Even more preferably, the initiator I having a terminal silanol function has at least three siloxyl units.

A silanol terminal function is a chemical function at the end of the chain formed by the chemical bond between a silicon atom and a hydroxyl group.

dans laquelle, In the process of the invention, the initiator I is represented by the formula (XI):

in which,

R ¹ , identical or different, represents: - a linear or branched alkyl group comprising from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms, optionally substituted by a heteroatom O, N, S or a halide,

-an alkenyl group comprising from 2 to 6 carbon atoms,

- a cycloalkyl group of 5 to 10 carbon atoms, optionally substituted by a heteroatom O, N, S or a halide, - a Ce-Cis aryl group, - a hydroxyl group, or - a hydrogen,

R ² identical or different, represents:

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

-a linear or branched alkyl group comprising from 1 to 12 carbon atoms, preferably from 1 to 5 carbon atoms, optionally substituted by at least one heteroatom O, N, S or a halide such as a fluorine atom, for example 1 to 10 fluorine atoms, for example (Ci-Cs)alkyl-CF3, the alkyl being linear or branched; or -a hydrogen; q is an integer between 0 and 20, preferably between 0 and 10, more preferably between 0 and 5, and with the condition that at least one radical R ² is a hydroxyl group (OH).

dans laquelle, In the process of the invention, the initiator I is represented by the formula (XI):

in which,

R ¹ , identical or different, represents:

- a linear or branched alkyl group comprising from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms, optionally substituted by a heteroatom O, N, S or a halide,

-an alkenyl group comprising from 2 to 6 carbon atoms,

- a cycloalkyl group of 5 to 10 carbon atoms, optionally substituted by a heteroatom O, N, S or a halide, - a Ce-Ci8 aryl group, - a hydroxyl group, or -a hydrogen,

R ² identical represent:

- a hydroxyl group (OH), q is an integer between 0 and 20, preferably between 0 and 10, more preferably between 0 and 5.

In another embodiment, initiator I is represented by formula (XI) in which:

R ¹ , identical, represents CH3,

R ² identical or different, represents:

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

- a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms,

- a Ce-Cis aryl group, optionally substituted, or

-a hydrogen. q is an integer between 0 and 20, preferably between 0 and 10, more preferably between 0 and 5, and with the condition that at least one radical R ² is a hydroxyl group (OH).

In another embodiment, initiator I is represented by formula (XI) in which:

R ¹ , identical, represents CH3,

R ² identical, represent:

- - a hydroxyl group (OH), and q is an integer between 0 and 20, preferably between 0 and 10, more preferably between 0 and 5.

The initiator I may be in a solvent. This is particularly advantageous in order to solubilize it in the reaction mixture. The solvent may in particular be an apolar solvent such as an organic solvent of the alkane or aromatic hydrocarbon type. Preferably, the solvent is chosen from n-hexane, n-heptane, n-decane, n-dodecane, isododecane, EXXSOL D60, xylene, toluene and mixtures thereof.

In one embodiment, the process of the invention is characterized in that the molar ratio of initiator I relative to catalyst A is from 1 to 20, preferably from 3 to 20, and preferentially from 5 to 10. In one embodiment, the method of the invention is characterized in that the molar ratio of initiator I relative to the cyclic organopolysiloxane OC introduced is from 0.02% to 20%, preferably from 0.25% to 15%, preferentially from 0.5% to 5%, and even more preferentially from 0.25% to 2.5%.

In one embodiment of the invention, the ring-opening polymerization reaction of at least one cyclic organopolysiloxane OC takes place in the presence of a catalytic system AI and at least one chain blocker C.

dans laquelle, In the method of the invention, the chain blocker C is represented by the formula (XII): Formula XH

in which,

R ¹ , identical or different, represents CH3 or phenyl, preferably CH3;

R ² identical or different, represents:

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

- a linear or branched alkyl group comprising from 1 to 12 carbon atoms, preferably from 1 to 5 carbon atoms, optionally substituted by at least one heteroatom O, N, S or a halide such as a fluorine atom, for example 1 to 10 fluorine atoms, for example (Ci-C5)alkyl-CF3, the alkyl being linear or branched,

- a C5-C10 cycloalkyl group, optionally substituted,

- a Ce-Cis aryl group, optionally substituted, or

-a hydrogen; and q is an integer between 1 and 50, preferably between 1 and 20, more preferably between 1 and 10.

Particularly preferably, the C chain blocker of the invention is represented by formula (XII), in which:

R ¹ , identical, represents CH3,

R ² identical or different, represents:

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

- a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, - a Ce-Cis aryl group, optionally substituted, or

-a hydrogen. and q is an integer between 1 and 20, preferably between 1 and 10, more preferably between 1 and 5.

Other blockers having a siloxane function according to the invention are described in the book Chemistry and Technology of Silicones, published in 1968 by Académie Press, on page 264. The chain blocker C can be in a solvent. This is particularly advantageous in order to solubilize it in the reaction mixture. The solvent can in particular be an apolar solvent such as an organic solvent of the alkane or aromatic hydrocarbon type. Preferably, the solvent is chosen from n-hexane, n-heptane, n-decane, n-dodecane, isododecane, EXXSOL D60, xylene, toluene and mixtures thereof.

In one embodiment, the process of the invention is characterized in that the molar ratio of chain blocker C relative to catalyst A is from 0 to 30, preferably from 0 to 20, and preferentially from 0 to 10.

According to one embodiment of the invention, linear organopolysiloxane OL may be a compound of formula (XIII):

POTWJI? xin in which,

R, identical or different, represents:

-an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl,

- an aryl group comprising from 6 to 10 carbon atoms, preferably phenyl,

R ¹ , identical or different, represents:

-an alkyl group comprising from 1 to 5 carbon atoms

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

-a hydrogen;

- a Ce-Cis aryl group, preferably phenyl, R ² identical or different, represents:

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

-a linear or branched alkyl group comprising from 1 to 12 carbon atoms, preferably from 1 to 5 carbon atoms, optionally substituted by at least one heteroatom O, N, S or a halide such as a fluorine atom, for example 1 to 10 fluorine atoms, for example (Ci-Cs)alkyl-CF3, the alkyl being linear or branched, -a C5-C10 cycloalkyl group, optionally substituted,

-an optionally substituted C’x-C ix aryl group,

- a hydrogen or

- a group (OR ³ ) with R ³ representing: an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably OCH3 or OC2H5, an alkenyl group comprising from 2 to 15 carbon atoms, preferably from 2 to 10 carbon atoms, a G-C'ix aryl or alkylaryl group such as a benzyl group q is an integer between 0 and 50, preferably between 0 and 20, more preferably between 0 and 10; preferably q = 0 represents an integer between 10 and 1,500, preferably between 10 and 1,000, preferably between 50 and 1,000, more preferably between 100 and 500; m2 represents an integer between 0 and 500, preferably between 0 and 100, more preferably between 0 and 50.

According to a preferred embodiment of the invention, the linear organopolysiloxane OL is a compound of formula (XIII): in which,

R, identical or different, represents CH3 or phenyl, preferably CH3;

R ¹ identical or different, represents:

-an alkyl group comprising from 1 to 5 carbon atoms

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a C’x-C ix aryl group, preferably phenyl,

-a hydrogen;

R ² identical or different, represents:

-an alkyl group comprising from 1 to 6 carbon atoms -an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

-a Ce-Cis aryl group,

-a hydrogen;

- a group (OR ³ ) with R ³ representing: an alkyl group comprising from 1 to 10 carbon atoms, an alkenyl group comprising from

2 to 10 carbon atoms, or a benzyl group q is an integer between 0 and 50, preferably between 0 and 20, more preferably between 0 and 10, preferably q = 0; represents an integer between 10 and 1,500, preferably between 10 and 1,000, preferably between 50 and 1,000, more preferably between 100 and 500; m2 represents an integer between 0 and 500, preferably between 0 and 100, more preferably between 0 and 50.

According to a particularly preferred embodiment of the invention, the linear organopolysiloxane OL of the invention is a compound of formula (XIII) in which,

R, identical or different, represents CH3 or phenyl, preferably CH3,

R ¹ , identical or different, represents CH3, phenyl or vinyl;

R ² identical or different, represents:

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

- a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms,

-a Ce-Cis aryl group, optionally substituted, or

-a hydrogen;

- a group (OR ³ ) with R ³ representing: an alkyl group comprising from 1 to 10 carbon atoms, an alkenyl group comprising from

2 to 10 carbon atoms, or a benzyl group q is equal to 0; n2 represents an integer between 10 and 1,500, preferably between 10 and 1,000, preferably between 50 and 1,000, more preferably between 100 and 500; m2 represents an integer between 0 and 500, preferably between 0 and 100, more preferably between 0 and 50 According to a particularly preferred embodiment of the invention, the linear organopolysiloxane OL of the invention is a compound of formula (XIII) in which, R, identical or different, represents CH3 or phenyl, preferably CH3,

R ¹ , identical or different, represents CH3, phenyl or vinyl;

R ² identical, represent:

- a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms,

-an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl,

-a hydroxyl group (OH),

- a group (OR ³ ) with R ³ representing: an alkyl group comprising from 1 to 10 carbon atoms, an alkenyl group comprising from

2 to 10 carbon atoms, or a benzyl group q is equal to 0; represents an integer between 10 and 1,500, preferably between 10 and 1,000, preferably between 50 and 1,000, more preferably between 100 and 500; mi represents an integer between 0 and 500, preferably between 0 and 100, more preferably between 0 and 50.

For the purposes of the present invention, the mass-average molecular mass and the number-average molecular mass, denoted respectively Mw and _Mn, of the various linear organopolysiloxanes OL can be determined by size exclusion chromatography (SEC) in the presence of polystyrene standards in a solvent such as toluene at 35°C.

According to one embodiment of the process of the invention, the linear organopolysiloxane OL of the invention is characterized in that its degree of polymerization is from 2 to 2000, preferably from 4 to 1000, preferentially from 4 to 500 and even more preferentially from 10 to 100.

According to one embodiment of the process of the invention, the linear organopolysiloxane OL of the invention is characterized in that its mass-average molecular mass Mw can be between 500 and 150,000 g/mol, preferably between 1,000 and 150,000 g/mol, preferentially between 1,000 and 100,000 g/mol, even more preferentially between 5,000 and 30,000 g/mol.

According to one embodiment of the process of the invention, the linear organopolysiloxane OL of the invention is characterized in that its number-average molecular mass M _n is between 500 and 150,000 g/mol, preferably between 1,000 and 100,000 g/mol, preferentially between 1,000 and 70,000 g/mol and even more preferentially between 2,500 and 30,000 g/mol. According to one embodiment of the process of the invention, the linear organopolysiloxane OL of the invention is characterized in that its dynamic viscosity is between 100 and 100,000 mPa.s at 25°C, preferably between 1,000 and 80,000 mPa.s at 25°C, even more preferably between 10,000 and 70,000 mPa.s at 25°C.

In the context of the present application, the mass percentage or the weight percentage of cyclic organopolysiloxanes (such as D4) of the products obtained according to the process of the present invention can be measured via the quantitative spectra of NMR- ²⁹ Si. Alternatively, the mass percentage or the weight percentage of D4 of the products obtained according to the process of the present invention could be measured via the chromatograms resulting from a size exclusion chromatography (SEC) analysis.

Hereinafter, the product resulting from the reaction is the sum of the linear organopolysiloxane OL and the cyclic organopolysiloxane OC resulting from the process of the present invention.

In one embodiment, the method according to the invention is characterized in that the content of cyclic organopolysiloxanes OC is less than 2%, preferably less than or equal to 1%, preferably less than or equal to 0.5% relative to the total mass of product resulting from the reaction.

In one embodiment, the process according to the invention is characterized in that the octamethylcyclotetrasiloxane (D4) content is less than 2%, preferably less than or equal to 1%, preferably less than or equal to 0.5% relative to the total mass of product resulting from the reaction.

In one embodiment, the method according to the invention is implemented in a non-polar solvent. The solvent may in particular be an organic solvent of the alkane or aromatic hydrocarbon type.

Preferably, the solvent is chosen from n-hexane, n-heptane, n-decane, n-dodecane, isododecane, EXXSOL D60, xylene, toluene and mixtures thereof.

In one embodiment, the method of the invention is characterized in that the mass ratio, mass of cyclic organopolysiloxane OC relative to the mass of solvent used is from 1 to 500, preferably from 1 to 100 and preferentially from 5 to 50. Advantageously, and preferably, the reaction is carried out at a temperature between 50°C and 150°C, preferably between 50 and 100°C, more preferably between 60 and 80°C, for example at 80°C.

According to the process of the invention, the reaction time is between 2h and 48h, preferably between 8h and 36h, more preferably between 8h and 18h.

The person skilled in the art will know how to adapt these parameters according to the nature of the reactors and the species used.

The present application also relates to the linear organopolysiloxane OL obtained according to the different embodiments of the process of the present invention described above.

The present application also relates to a composition for implementing the method of the present invention comprising:

- at least one cyclic organopolysiloxane OC,

- an AI catalytic system as defined above, and optionally a C chain blocker.

The present application also relates to the use of the organopolysiloxanes OL obtained according to the process of the present invention as an ingredient which can be directly used in various silicone formulations useful in fields such as cosmetics, household cleaning products, automobiles, energy.

dans laquelle: The present application also relates to catalysts A represented by the following formula (XIV):

in which:

-R represents an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked by a radical to form a cycle,

-Ri, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms and n, identical or different, is a natural number equal to 1, 2 or 3.

dans laquelle n est un entier naturel égal à 1 ou 2. More specifically, the present invention relates to catalysts A represented by the following formula (XV):

in which n is a natural integer equal to 1 or 2.

The present application also concerns the use of the catalysts defined according to the formulas (XIV and XV) as catalysts for ring-opening polymerization or polycondensation.

Examples:

Cyclic organopolysiloxanes used in the examples:

Cyclic organopolysiloxane OCi: hexamethylcyclotri siloxane (CAS 541-05-9)

Cyclic organopolysiloxane OC2: octamethylcyclotetrasiloxane (CAS 556-67-2)

Catalysts A used in the examples:

Catalyseur A2:

Catalyst Ai:

Catalyst A2:

Initiators implemented in the examples:

Initiator Ii: Benzyl alcohol (CAS 100-51-6)

Initiator I2:

Chain blockers implemented in the examples:

Ci chain blockers: divinyltetramethyldisiloxane (CAS 2627-95-4).

In the context of the examples described below, the residual mass percentages of cyclic organopolysiloxanes OC and the mass percentages of linear organopolysiloxane OL obtained according to the method of the present invention are measured by size exclusion chromatography (SEC) in the presence of polystyrene standards in a solvent such as toluene at 35°C. Similarly, the number-average molecular mass denoted M _n of the different linear organopolysiloxanes according to the present invention OL is determined by the same size exclusion chromatography (SEC) method. In the context of the examples described below, the mass percentage of residual cyclic organopolysiloxanes is called the mass percentage of cyclic organopolysiloxane at the end of the process implemented according to the present invention.

Example 1: Synthesis of the catalysts of the present invention Ai and A2:

Synthesis of catalyst A 1 of the present invention:

Synthesis of intermediate compound 1:

To a solution of tris(l-pyrrolidinyl)phosphine (1.00 g, 4.15 mmol) in 30 mL of diethoxymethane (DEM) was added 2-iodopropane (1.06 g, 6.23 mmol) at room temperature. The solution was stirred at 40 °C for 7 days. A white precipitate formed, and after filtration and recrystallization from acetonitrile at room temperature, compound 1 was obtained as a white solid (1.45 g, 85%).

Second step leading to obtaining the catalyst Ai of the present invention:

To a suspension of compound 1 in THF (20mL), KHMDS powder (0.52g, 2.63 mmol) was added at room temperature. The solution was stirred at room temperature for 1h. The solution was then filtered and evaporated using a rotary evaporator.

The product thus formed was extracted twice using pentane (2x15 mL). Evaporation of the pentane under vacuum gives a colorless liquid which is the catalyst Ai of the present invention (0.56 g, 75%).

Synthesis of catalyst A2 of the present invention:

To a solution of tripiperidinophosphine (3.00 g, 10.59 mmol) in 30 mL of diethoxymethane (DEM) was added 2-iodopropane (2.70 g, 15.88 mmol) at room temperature. The solution was stirred at 40 °C for 7 days. A white precipitate formed, and after filtration and recrystallization from acetonitrile at room temperature, compound 2 was

Second step leading to obtaining catalyst A2 of the present invention:

To a suspension of compound 2 in THF (20mL), KH (53mg, 1.32 mmol) was added at room temperature. The solution was stirred at room temperature for 12h. The solution was then filtered and evaporated using a rotary evaporator.

The product thus formed was extracted twice using pentane (2x10 mL). Evaporation of the pentane under vacuum gives a colorless liquid which is the catalyst A2 of the present invention (0.102 g, 47%).

Example 2: General protocol for implementing the method of the present invention:

The AI catalytic system is formed by the association of catalyst A (e.g., Ai and A2) (leq, 0.061 mmol) and n equivalents of initiator I, (e.g., Ii or I2). The tables below indicate the different molar ratios I/A. This freshly formed AI catalytic system comprising an amount of 0.025 mmol (0.5 mol%) of catalyst A is mixed in a solution containing a cyclic organopolysiloxane OCi or OC2 (5.07 mmol), and toluene as solvent.

Optionally, a chain blocker such as Ci is added to the reaction mixture.

The reaction mixture is then heated to 80°C for a period of 18 hours.

Example 3a: Tests with D4:

In this example, the general protocol of example 2 was implemented. In this example, octamethylcyclotetrasiloxane OC2 (CAS 556-67-2) was used. The table below describes the different catalysts used as well as the characteristics of the product obtained OL according to the process of the invention.

It may be noted that in the presence of the catalysts described according to the process of the invention Ai and A2, more than 80% of linear organopolysiloxane OL is obtained. Particularly in the presence of the catalyst Ai where the product OL thus obtained has a cyclic organopolysiloxane content of less than 1%.

Example 3b: Tests with D3

In this example, the general protocol of example 2 was implemented. In this example, hexamethylcyclotrisiloxane OCi (CAS 541-05-9) was used. The table below describes the different catalysts used as well as the characteristics of the product obtained OL according to the process of the invention.

It can be noted that in the presence of the catalysts described according to the process of the invention Ai and A2, more than 95% of linear organopolysiloxane OL is obtained. Particularly in the presence of the catalyst Ai where the product OL is obtained with a level of residual cyclic organopolysiloxanes less than 1%.

Example 4: Tests with D4, influence of molar ratio I/A:

In this example, the general protocol of example 2 was implemented. In this example, octamethylcyclotetrasiloxane OC2 (CAS 556-67-2) was used. The table below describes the different molar ratios used as well as the characteristics of the product obtained OL according to the process of the invention.

It can be observed that the molar ratio I/A has an influence on the number-average molecular mass of the OL product obtained by the process of the present invention. Using the information disclosed in the present invention, the person skilled in the art will be able to adapt these parameters to obtain, using the process of the present invention, an organopolysiloxane OL with the desired number-average molecular mass M _n while controlling the cyclic content.

Example 5a: Tests with D4, C/A ratio influence

In this example, the general protocol of example 2 was implemented. In this example, octamethylcyclotetrasiloxane OC2 (CAS 556-67-2) was used. The table below mentions the molar ratio of the chain blocker used relative to the molar amount of catalyst A used as well as the characteristics of the product obtained OL according to the process of the invention. In this example, the molar ratio I/A is 5.

These different tests demonstrate the control of the number-average molecular mass (Mn) of the organopolysiloxane OL according to the process of the invention. The variation of the quantity of material of the chain blocker C influences the molecular mass of the product obtained according to the process of the present invention. Furthermore, it can be noted that the product obtained according to the process of the invention has a very low mass percentage of cyclic organopolysiloxane (less than 1% by mass relative to the total mass of the organopolysiloxane OL obtained).

Example 5b: Test D4, C/A ratio influence

In this example, the general protocol of example 2 was implemented. In this example, octamethylcyclotetrasiloxane OC2 (CAS 556-67-2) was used. The table below mentions the molar ratio of the chain blocker used relative to the molar quantity of catalyst A used as well as the characteristics of the product obtained OL according to the process of the invention. In this specific example, the quantity of catalyst A used is 1.00 mol% relative to the quantity of OC2 used, unlike the other examples. In this example, the molar ratio I/A is 5.

The same conclusions can be drawn from these results as those obtained previously in example 5a).

Claims

[Claim 1] Method for preparing linear organopolysiloxanes OL by a ring-opening polymerization reaction of at least one cyclic organopolysiloxane OC, in the presence of a catalytic system AI comprising: - at least one catalyst A of formula (I):

in which: -R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a cycle, -Ri, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two Ri groups form together with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms, -R2, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R2 groups form together with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms, -R3, identical or different, represent an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or the two R3 groups form together with the nitrogen atom to which they are linked a heterocyclic amine of 5 to 10 atoms, and with the condition that the phosphorus atom has at least one heterocyclic amine as a substituent, and at least one initiator I chosen from alcohols and their derivatives, silanols and their derivatives, or their mixtures. [Claim 2] A method according to claim 1 wherein the cyclic organopolysiloxane OC is represented by the formula (II):

in which, R, identical or different, is a radical representing a hydrogen, an alkyl group of 1 to 6 carbon atoms, an alkenyl group of 1 to 6 carbon atoms, or an aryl group in GC ix; and n represents a natural integer between 1 and 2. [Claim 3] A method according to claim 1 or 2, wherein catalyst A is represented by the following formula (V):

in which: -R, identical or different, represents a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked by a radical to form a cycle, -Ri, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms and n, identical or different, is a natural integer equal to 1, 2 or 3. [Claim 4] A method according to any preceding claim, wherein catalyst A is represented by the following formula (VI):

-R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked by a radical to form a cycle, and n, identical or different, is a natural integer equal to 1 or 2. [Claim 5] Method according to any one of the preceding claims, in which the molar ratio of catalyst A relative to the cyclic organopolysiloxane OC is from 0.005% to 2%, preferably from 0.01 to 2%, preferentially from 0.05 to 1%, and even more preferentially from 0.1 to 1%. [Claim 6] A method according to any preceding claim, wherein the initiator I is selected from compounds of formula (VIII):

in which: Y represents a carbon atom or a silicon atom; R is the same or different and represents: -a hydrogen atom, -an alkyl group of 1 to 12 carbon atoms, -a cycloalkyl group of 5 to 8 carbon atoms, -an alkenyl group of 1 to 12 carbon atoms, - an aryl group of 6 to 10 carbon atoms, preferably phenyl, - a siloxyl group having at least 5 units, preferably at least 10 units of formula R ¹ cSiO(4-c)/2 in which R ^1, identical or different, represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl; an aryl group comprising from 6 to 10 carbon atoms, preferably phenyl; and c = 0, 1 or 2 and; when said radical R is other than a hydrogen atom, the radical R may be substituted or not by an alkyl or alkenyl chain of 1 to 6 carbon atoms, a cycloalkyl group, an aryl group comprising from 6 to 10 carbon atoms or a heteroatom such as oxygen, sulfur or nitrogen. [Claim 7] A method according to any preceding claim, wherein the initiator I is an alcohol or a silanol having a pKa of 10 to 16, preferably a pKa of 12 to 16, more preferably a pKa of 14 to 16. [Claim 8] Method according to any one of the preceding claims, in which the molar ratio of initiator I relative to catalyst A is from 1 to 20, preferably from 3 to 20, and preferentially from 5 to 10. [Claim 9] Method according to any one of the preceding claims, in which the molar ratio of initiator I relative to the cyclic organopolysiloxane OC is from 0.02% to 20%, preferably from 0.25% to 15%, preferentially from 0.5% to 5%, and even more preferentially from 0.25% to 2.5%. [Claim 10] Method according to any one of claims 1 to 9, in which the ring-opening polymerization reaction of at least one cyclic organopolysiloxane OC takes place in the presence of a catalytic system AI and at least one chain blocker C. [Claim 11] A method according to claim 10, wherein the chain blocker C is represented by formula (XII), wherein:

R ¹ , identical, represents CH3, R ² identical or different, represents: -an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl, - a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, - a Ce-Cis aryl group, optionally substituted, or -a hydrogen. and q is an integer between 1 and 20, preferably between 1 and 10, more preferably between 1 and 5. [Claim 12] A method according to any preceding claim, wherein the linear organopolysiloxane OL is characterized in that its degree of polymerization is from 2 to 2000, preferably from 4 to 1000, preferentially from 4 to 500 and even more preferentially from 10 to 100 [Claim 13] Method according to any one of the preceding claims, in which the linear organopolysiloxane OL is characterized in that its mass average molecular weight Mw is from 500 to 150,000 g/mol, preferably from 1,000 to 150,000 g/mol, preferentially from 1,000 to 100,000 g/mol and even more preferentially from 5,000 to 30,000 g/mol. [Claim 14] Method according to any one of the preceding claims, in which the content of cyclic organopolysiloxanes OC is less than 2%, preferably less than or equal to 1%, preferably less than or equal to 0.5% relative to the total mass of product resulting from the reaction. [Claim 15] Composition for implementing the method defined according to claims 1 to 14 comprising: - at least one cyclic organopolysiloxane OC, - a catalytic system AI as defined according to claim 1, and optionally a chain blocker C. [Claim 16] Use of linear organopolysiloxanes OL obtained according to one of claims 1 to 14 as a compound which can be directly used in various silicone formulations useful in fields such as cosmetics, household cleaning products, automobiles, energy. [Claim 17] Catalysts A represented by the following formula (XIV):

in which: -R, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which can be linked together to form a ring, -Ri, identical or different, represent a hydrogen atom or an alkyl chain of 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms and n, identical or different, is a natural integer equal to 1, 2 or 3. [Claim 18] Catalysts A according to claim 17, represented by the following formula (XV):

in which n is a natural integer equal to 1 or 2. [Claim 19] Use of catalysts A defined according to claims 17 and 18 as catalysts for ring-opening polymerization or polycondensation.