	US 11,898,006 B2
	Process for the manufacture of polyether polymers
Cristiano Monzani, Trezzo sull'Adda (IT); Marco Galimberti, Bollate (IT); and Vito Tortelli, Milan (IT)
Assigned to SOLVAY SPECIALTY POLYMERS ITALY S.P.A, Bollate (IT)
Appl. No. 17/048,683
Filed by SOLVAY SPECIALTY POLYMERS ITALY S.P.A., Bollate (IT)
PCT Filed Apr. 18, 2019, PCT No. PCT/EP2019/060080 § 371(c)(1), (2) Date Oct. 19, 2020, PCT Pub. No. WO2019/202076, PCT Pub. Date Oct. 24, 2019.
Claims priority of application No. 18168487 (EP), filed on Apr. 20, 2018.
Prior Publication US 2021/0238345 A1, Aug. 5, 2021
Int. Cl. C08G 65/00 (2006.01)

CPC C08G 65/007 (2013.01) [C08G 2650/48 (2013.01); C08G 2650/50 (2013.01); C08G 2650/64 (2013.01)]

14 Claims

1. A method for manufacturing a mixture of polymers [mixture (P^FF_COOH—CF3)], said mixture (P^FF_COOH—CF3) comprising polymers possessing a backbone consisting of a sequence of recurring units of formula —O—CF₂—R_F—CF₂—O—CF₂CF₂—(CR_f¹R_f²)_a—O—R_f—O—(CR_f¹R_f²)_b—CF₂CF₂—,

wherein:

R_fis a C₁-C₁₈perfluorocarbon group, possibly comprising one or more than one ethereal oxygen;

R_Fis a bond or a C₁-C₁₈perfluorocarbon group, possibly comprising one or more than one ethereal oxygen;

each of R_f¹and R_f², equal to or different from each other, is F or a C₁-C₆perfluorocarbon group;

a and b being independently zero or 1 and being collectively zero or 1;

and said polymers having chain ends selected from the group consisting of —COOH and —CX_F¹X_F²F, with X_F¹and X_F²being F or a C₁-C₃perfluoroalkyl group;

said process comprising:

Step (1): a step of reacting:

(1a) at least one perfluoro compound [compound (F)] of formula CF₂═CF—(CR_f¹R_f²) a —O—R_f—O—(CR_f¹R_f²)_b—CF═CF₂,

wherein R_f, R_f¹, R_f², a and b have the meaning defined above; and

(1b) at least one hydrogen-containing compound [compound (H)] of formula: HO—CH₂—R_H—CH₂—OH,

with RH being a bond or a C₁-C₁₈(fluoro)hydrocarbon group, optionally comprising one or more than one ethereal oxygen,

in molar ratio compound (H):compound (F) of exceeding 1:1, so as to generate a mixture (P^FH_OH—OH) comprising a major amount of any di-hydroxy compounds of formula (I):

HO—CH₂—RH—[CH₂—O—CF₂CHF—(CR_f¹R_f²)_a—O—R_f—O—(CR_f¹R_f²)_b—CFHCF₂—O—CH₂—R_H—]_n—CH₂—OH; and optionally comprising a minor amount of any compounds of formula (II):

wherein in formulae (I) and (II) R_H, R_f, R_f¹, R_f², a and b have the meaning defined above, and n is such that the number averaged molecular weight of compounds (I) is of 300 to 50 000;

Step (2): a step of reacting mixture (P^FH_OH—OH) with COF₂, so as to generate a mixture (P^FH_{OC(O)F—OC(O)F}) comprising a major amount of any di-fluoroformate compounds of formula (III):

F—C(O)—O—CH₂—R_H—[CH₂—O—CF₂CHF—(CR_f¹R_f²)_a—O—R_f—O—(CR_f¹R_f²)_b—CFHCF₂—O—CH₂—R_H—]_n′—CH₂—O—C(O)—F; and optionally comprising a minor amount of a compound of formula (II), as above detailed, wherein, in formula (III), R_H, R_f, R_f¹, R_f², a and b have the meaning defined above, and n′ is such that the number averaged molecular weight of compounds (I) is of 300 to 50 000;

Step (3): a step of fluorinating mixture (P^FH_{OC(O)F—OC(O)F}) with a source of molecular fluorine, so as to generate a mixture (P^FF_{OC(O)F—OC(O)F}) comprising a major amount of a perfluorinated di-fluoroformate compound of formula (IV):

F—C(O)—O—CF₂—R_F—[—CF₂—O—CF₂CF₂—(CR_f¹R_f²)_a—O—R_f—O—(CR_f¹R_f²)_b—CF₂CF₂—O—CF₂—R_F—]_n″—CF₂O—C(O)—F, and optionally comprising a minor amount of a compound of formula (V):

wherein in formulae (IV) and (V) R_F, R_f, R_f¹, R_f², a and b have the meaning defined above; and n″ is such that the number averaged molecular weight of compounds (I) is of 300 to 50 000;

Step (4): a step of hydrolysing mixture (P^FF_{OC(O)F—OC(O)F}) in the presence of water, so as to generate a mixture (P^FF_COOH—COOH) comprising a major amount of a perfluorinated di-carboxylic acid compound of formula (VII):

HOOC—R_F—[—CF₂—O—CF₂CF₂—(CR_f¹R_f²)_a—O—R_f—O—(CR_f¹R_f²)_b—CF₂CF₂—O—CF₂—R_F]_n′″—COOH, and optionally comprising a minor amount of a compound of formula (V), as detailed above, wherein in formula (VII) R_F, R_f, R_f¹, R_f², a and b have the meaning defined above, and n′″ is such that the number averaged molecular weight of compounds (I) is of 300 to 50 000;

Step (5): a step of fluorinating mixture (P^FF_COOH—COOH), by contacting with a source of molecular fluorine, wherein the required amount of fluorine to convert the targeted fraction of —COOH end groups to generate the mixture (P^FF_COOH—COOH), as detailed above, is added.