Hydrofluoroalcohols with improved thermal and chemical stability
Hydrofluoro alcohols of formula (I): A-(R f ) a —CFX—O—R h O—(CFX—(R f ) a* —CFX—O—R h O—) n H in which: R h is a hydrocarbon-based chain; X is F or a C 1 -C 6 (per)fluoroalkyl; a or a* is 0 or 1; R f is a (per)fluoro(poly)oxyalkylene chain or a (per)fluoroalkyl chain; A is selected from the group consisting of —F, —Cl, and —H (possible only when a=1) or is HO—R h —O—CFX—; n is an integer from 0 to 200, with the condition that n=0 when A is selected from the group consisting of —F, —Cl, and —H.
1. A hydrofluoro alcohol of formula:
A-(R f ) a —CFX—O—R h O—(CFX—(R f ) a* —CFX—O—R h O—) n H (I)
wherein:
R h is a divalent C 1 -C 20 hydrocarbon-based residue,
X is F or a C 1 -C 6 (per)fluoroalkyl, which is linear or branched where possible, optionally containing one or more heteroatoms,
a and a* are equal to 1,
R f is a (per)fluoro(poly)oxyalkylene (PFPE) chain comprising one or more of the following units distributed along the chain: —(C 3 F 6 O)—, —(CF 2 O)—, —(CF 2 CF 2 O)—, —(CF 2 CF 2 CF 2 O)—, —(CF 2 CF 2 CF 2 CF 2 O)—, or —(CF(CF 3 )O)—, optionally comprising one or more of the following units: —(CF 2 CF(CFYOR h OH)O)—, —(CF(CFYOR h OH)CF 2 O)—, or —(CF(CFYOR h OH)O)— with Y being F or a C 1 -C 6 (per)fluoroalkyl, which is linear or branched where possible,
A is:
a group of formula: HO—R h —O—CFX— in which R h and X have the same meaning as defined above, or
a group selected from the group consisting of —F, —Cl, and —H;
n is an integer from 0 to 200,
with the condition that n=0 when A is selected from the group consisting of —F, —Cl, and —H.
2. The hydrofluoro alcohol according to claim 1 , wherein R h is selected from the group consisting of:
a C 1 -C 10 alkyl chain, which is linear or branched where possible,
a C 3 -C 10 cyclic ring or a C 4 -C 20 alkyl chain comprising one or more C 3 -C 10 cyclic rings, and
an aromatic ring in which, optionally, one or more carbon atoms of said aromatic ring are substituted with a heteroatom, or a C 6 -C 20 alkyl chain comprising one or more of said aromatic rings,
wherein R h may contain one or more unsaturations; and wherein the cyclic and/or aromatic rings optionally have one or more hydrogen atoms replaced with C 1 -C 10 (fluoro)alkyl chains, which are linear or branched where possible.
3. The hydrofluoro alcohol according to claim 1 , wherein n ranges from 0 to 100.
4. The hydrofluoro alcohol according to claim 1 , wherein R f is a PFPE chain with a number-average molecular weight from about 100 to about 10 000.
5. The hydrofluoro alcohol according to claim 1 , wherein R f is selected from the group consisting of following structures:
—CF 2 O[(CF 2 O) r (CF 2 CF 2 O) s (CF 2 CF 2 CF 2 O) p (CF 2 CF 2 CF 2 CF 2 O) q —(CF 2 CF(CFYOR h OH)O) p′ (CF(CFYOR h OH)O) q′ ]CF 2 — (B)
wherein the indices r, s, p, q, p′ and q′ are integers, including 0, such that the number-average molecular weight is from about 100 to about 10,000;
—CFY″O[(CF 2 O) r (CF 2 CF 2 O) s (CF 2 CF(CF 3 )O) t (CF 2 (CF 3 )O) u —(CF 2 CF(CFYOR h OH)O) p′ (CF(CFYOR h OH)O) q′ ]—CFY′— (C)
wherein the indices r, s, t, u, p′ and q′ are integers, including zero, such that the number-average molecular weight is from about 100 to about 10,000;
wherein Y, Y′ and Y″ are independently selected from the group consisting of F and C 1 -C 6 (per)fluoroalkyl, which is linear or branched where possible.
6. A process for preparing the hydrofluoro alcohol of claim 1 , comprising the following steps:
Step a)
reaction of a difunctional alkylating compound of formula:
B—O—R h —O—B (II)
wherein B is FC(O)—, or R′—SO 2 — in which R′ is an aromatic group, a hydrogenated or (per)fluorinated C 1 -C 10 alkyl, which is linear or branched where possible, and R h is the same as defined in claim 1 ,
with
a carbonyl compound of formula:
A′-(R f ) a —COX (III)
wherein,
in R f , the optional pendent groups —CFYOR h OH are substituted with optional pendent groups —COY, with Y being F or a C 1 -C 6 (per)fluoroalkyl, which is linear or branched where possible,
X, R f and the index a have the same meaning as defined in claim 1 ,
A′ is —COX with X having the same meaning as defined in claim 1 , or a group selected from the group consisting of —F, —Cl, and —H, with the proviso that A′ is a group selected from the group consisting of —F, —Cl, and —H only when a=1,
working with a ratio k:
k
=
equivalents
-
B
of
alkylating
agent
(
II
)
equivalents
-
C
O
X
+
equivalents
-
C
O
Y
of
(
III
)
of between 1 and 100, limits inclusive, with the condition that k is between 1.25 and 100, limits inclusive, when A′ is F, Cl or H,
in the presence of a source of fluoride anions,
to obtain a product of formula:
A″-(R f ) a —CFX—O—R h O—(CFX—(R f ) a* —CFX—O—R h O—) n B (IV)
wherein, in R f , the optional pendent groups —CFYOR h OH are substituted with optional pendent groups —CFYOR h OB,
A″ is equal to —CFXOR h OB when A′ in formula (III) is —COX with X having the same meaning as defined in claim 1 , or A″ is a group selected from the group consisting of —F, —Cl, and —H, when A′ in formula (III) is a group selected from the group consisting of —F, —Cl, and H,
n has the same meaning as defined in claim 1 , and with the condition that n=0 when A″ is selected from the group consisting of —F, —Cl, and —H;
Step b)
hydrolysis or salification of the product of formula (IV) and production of the compounds of formula (I); and
Step c)
recovery of the product of formula (I).
7. The process according to claim 6 , wherein, in the alkylating agent of formula (II), R′ is an aromatic, optionally substituted with C1-C6 alkyl groups, which are linear or branched where possible.
8. The process according to claim 6 , wherein, in step a), k is between 1.05 and 20 when difunctional compounds of formula (III) are used; or k is between 2 and 100 when monofunctional or polyfunctional compounds of formula (III) are used.
9. The process according to claim 6 , wherein the source of fluoride anions is selected from the group consisting of metal fluorides, optionally supported; and organic fluorides.