Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1999-06-09
2001-02-13
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S126000, C528S174000, C528S176000, C568S560000, C568S566000
Reexamination Certificate
active
06187894
ABSTRACT:
The present invention relates to an improved process to obtain with high yields poly- and diacyl-peroxides of (per)-fluoropolyethers starting from the corresponding diacyl- and monoacyl-halides.
Perfluoroether diacylperoxide syntheses have already been described in the art.
H. Sawada in Reviews of Heteroatom Chemistry Vol. 8, pages 205-231 mentions a perfluoro-oxa-alkanoyl peroxides series of formula (R
fa
CO
2
)
2
, wherein R
fa
=C
3
F
7
O[CF(CF
3
)CF
2
O]
m
CF(CF
3
) and m=0, 1, 2, 3, and reports that the behaviour to thermal decomposition and their uses are known. Specifically it is reported that the synthesis takes place in aqueous alkales in the presence of hydrogen peroxide. No indication is given how the reaction is carried out.
WO 97/08142 describes a process to obtain diacylperoxides starting from halogen derivatives of formula R(C═O)X wherein X=halogen and R can be in particular the following perfluoropolyether group:
G(CF
2
)
w1
[CF(CF
3
)CF
2
]
x1
[OCF(CF
3
)CF
2
]
y1
[OCF(CF
3
)]
z1
−
wherein w1, x1, y1, z1 are integers, w1 ranges from 0 to 8, x1 from 0 to 1, y1 from 0 to 7, z1 from 0 to 1, w1+x1+y1+z1≧1, and G is fluorine or a substituted carbon atom. The reaction, which can be carried out in batch or in a continuous way in a stable peroxide dispersion in KOH/H
2
O
2
which contains the acylic halide, occurs in very short times, from few seconds to 30 seconds, under stirring such that the Reynolds number results in the range 1.000-40.000. Fluorinated and non fluorinated organic solvents and surfactants can be added. The examples relate to the synthesis of the perf luoroether diacylperoxide having a low molecular weight from HFPO having the formula [CF
3
CF
2
CF
2
OCF(CF
3
) (C═O)O]
2
(equivalent weight 332), starting from the corresponding acylfluoride. The reactions are generally carried out at 0° C. but also at room temperature. The contact time generally ranges, as said, from 1 to 30 seconds. The patent application reports also the peroxide synthesis starting from the following acylfluoride having the formula
CF
3
CF
2
CF
2
O[CF(CF
3
)CF
2
O]
6,3
CF(CF
3
)(C═O)F
having molecular weight of about 1300. The yield is 62%. Moreover, the process uses solvents having high ODP (e.g. CFCH
3
, CF
2
Cl—CFCl
2
).
An object of the present invention is a process to obtain with improved yields (per)fluoroether acylperoxides having an average equivalent weight (EW) in the range 350-5.000, having formula:
Y′—(CF
2
—CF(CF
3
)O)
m
—(CX′FO)
n
—CF
2
CO—O—O—CO—CF
2
—(OCX′F)
n
—(OCF(CF
3
)—CF2)
m
—Y′ (I)
wherein
Y′=Cl, OR
f
wherein R
f
is a C
1
-C
3
perfluoroalkyl;
m, n are integers such that (I) gives the mentioned EW and m
≧40;
X′=F, CF
3
;
T—CF
2
—O—[(CF
2
CF
2
O)
p
—(CF
2
O)
q
—CF
2
—CO—O—O—CO—CF
2
(OCF
2
)
q
—(OCF
2
CF
2
)
p
]
y
—OCF
2
—COOH (II)
wherein
y is an integer comprised between 1 and 5;
p and q are integers such as to give the above mentioned EW and p/q=0.5-2.0;
T=COOH, F with the proviso that if T=COOH y=1-5, if
T=F then y=1;
starting from perfluoroether acylhalides having an average molecular weight (MW) by number in the range 350-5.000, having, respectively, the formula:
Y′—(CF
2
—CF(CF
3
)O)
m
—(CX′FO)
n
—CF
2
CO—Y″ (I′)
wherein
Y′, X′, m and n have the meaning indicated in
Y″=Cl, F; (I);
Y′″—CF
2
—O—(CF
2
CF
2
O)
p
—(CF
2
O)
q
—CF
2
—CO—Y″ (II′)
wherein
Y″ has the meaning indicated in (I′);
Y′″=CO—Y″, F;
by reaction with H
2
O
2
in basic ambient.
The process is carried out at a temperature comprised between −5° C. and +5° C. in a mixture formed by two immiscible liquid phases having a total volume equal to at most ⅔ of the reactor one, kept under stirring so that no emulsions are formed, said liquid phases being the following:
an organic phase formed by a polyhalogenated solvent having very low ODP, in an higher amount,
an aqueous alkaline solution containing an excess of hydrogen peroxide with respect to the halide which is added;
said process comprising the following steps:
a) addition of a (per)fluoropolyether monoacyl or diacyl-halide by cooling so that the &Dgr;T thermal increase, with reference to a reactor having an internal volume in the range 50-250 ml cooled by a 2 l volume cryogenic bath having a temperature comprised between −40° C. and −80° C., is in the range 6° C.-20° C. and that when the addition is over, the temperature decreases to the initial one in a time comprised between 0.1 and 5 minutes;
b) reacting, at the initial temperature, for the necessary time (t
max
) to obtain the conversion of 75% of the acylhalide (I′), (II′), determined by quantitative FTIR analysis
c) reaction interruption, by stopping stirring and allowing the phases to be separated by maintaining the system at the initial temperature, and recovery of the organic phase containing the perf luoropolyether diacyl-/polyacyl-peroxides.
Preferably in step a) the ratio between the alkali moles and the —CO—Y″ functional groups equivalents is comprised between 1.2 and 1.8 and the ratio between the aqueous phase ml volume and the base grams is comprised between 5 and 10; preferably the organic phase volume is half than that of the reactor.
In order to obtain the thermal increases indicated in a), the reactant addition is carried out in a time depending on the perfluoropolyether acylic halides of formula (I′) and (II′) MW and it ranges from 20 to 30 seconds for the perfluoropolyether acyclic halides having MW in the range 350-800 and it is lower than or equal to 15 seconds for those having a MW in the range 800-5.000.
The polyhalogenated organic solvent is preferably (per)-fluorinated and is preferably selected from C
6
-C
10
linear chain perfluoroalkanes, perfluoropolyethers having perfluoroalkylic end groups, optionally containing at one or both end groups an hydrogen atom, said perfluoropolyethers having a low number average molecular weight, preferably in the range 400-1.000. The preferred solvents are perfluoropolyethers having perfluoroalkylic end groups.
The process object of the present invention is feasible both in batch and in a continuous way, and allows to obtain with high yields poly-acylperoxide or diacylperoxide mixtures with EW in the range 350-5.000. Preferably peroxides of formula (II) with equivalent weights (EW) between 1.000 and 2.000, starting from (per)fluoropolyether halides of formula (II′) with number average molecular weight 1.000-2.000, are obtained. Preferably diacylperoxides of formula (I) having preferably equivalent weight in the range 350-800 starting from halides of formula (I′) with number average molecular weight 350-800, are obtained.
In the reaction product mixtures obtainable starting from (II′) the relative amounts of diacyl peroxides and polyacylproxides are related to the hydrogen peroxide excess and, the conditions being equal, with the compound (II′) molecular weight.
By using halides of formula (II′) with MW in the range 3.000-5.000, diacylperoxides of formula (II) with y=1 are obtained; by using halides of formula (II′) with number average molecular weights in the range 350-3.000, dipolyacylperoxides are obtained and in the formula (II) y=1-5 and T=COOH.
With average equivalent weight of the peroxide according to the present invention it is meant the equivalent weight calculated from the molecular weight of the starting acylhalide, subtracted the halogen atomic weight and added that of the oxygen.
The reaction yield is calculated by determining the titre in peroxides of the organic phase by titration with an aqueous titrated solution of sodium thiosulphate in the presence of a 50% w/v potassium iodide aqueous solution.
The (per)fluoropo
Tortelli Vito
Wlassics Ivan
Arent Fox Kintner Plotkin & Kahn
Ausimont S.p.A.
Hampton-Hightower P.
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