Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1995-05-10
2004-12-14
Buttner, David J. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S203000, C525S467000
Reexamination Certificate
active
06831147
ABSTRACT:
The present invention provides a process for the production of aromatic polycarbonates with UV-absorber terminal groups and with average molecular weights {overscore (M)}
w
(weight average, determined by light scattering) of between 1500 and 150000, optionally mixed with known aromatic polycarbonates with {overscore (M)}
w
(weight average, determined by light scattering) of between 1500 and 150000, from diphenols, 0.001 mol to 1 mol, preferably 0.01 mol to 0.5 mol per mol of diphenol of chain terminators, carbonic acid donors and optionally branching agents using the known polycarbonate production methods, the phase interface process, the homogeneous solution process (known as the pyridine process) or the melt transesterification process, which process is characterised in that chain terminators of the formula (I) are used
in which
R
1
means H, C
1
-C
18
, alkyl, C
3
-C
6
cycloalkyl and C
6
-C
10
aryl,
R
2
means H, Cl and C
1
-C
12
alkyl,
X means a single bond, C
1
-C
12
alkylene, C
5
-C
6
cycloalkylene and C
6
-C
10
arylene and
Y means a residue reactive under the reaction conditions of polycarbonate production,
optionally combined with other known chain terminators.
In the case of the phase interface process, Y is OH, Cl, O-(alkali), O-ammonium or O-½(alkaline-earth), i.e. (I) is thus used as carboxylic acid, as carboxylic acid chloride, as carboxylic acid alkali salt, as carbonium-ammonium salt or as carboxylic acid alkaline-earth salt.
In the case of the pyridine process, Y has the same meaning as above for the phase interface process.
In the case of the melt transesterification process, Y also has the same meaning as above for the phase interface process and additionally means —O—C
6
-C
10
aryl and C
1
-C
6
alkyl-substituted —O—C
6
-C
10
aryl.
Furthermore, in the case of the transesterification process, Y may also be a bifunctional arylene-bis-oxy residue, which gives rise to a chain terminator of the formula (II)
in which
R
1
, R
2
and X have the meaning stated for the formula (I) and —Y— is a biphenolate residue of the formula (III)
—O—Ar—O— (III)
in which —Ar— is a C
6
-C
30
arylene, which is monocyclic or polycyclic, preferably dicyclic, wherein in the case of the dicyclic arylene residues, these may be bridged by C
1
-C
8
alkylene, C
2
-C
8
alkylidene, C
5
-C
6
cycloalkylene and C
5
-C
10
cycloalkylidene. Heteroatoms such as —O— or —S— may also act as bridging members.
Preferred biphenolate residues —Y— are residues derived from the diphenols of the polycarbonates to be produced, thus for example (III
a
)-(III
d
)
In the case of chain terminator (II), the reactive, molar quantity of chain terminator is in each case twice as high as in (I), such that when synthesising polycarbonate using chain terminator (II) instead of (I), the molar quantity to be used may be halved.
The present invention thus also provides a variant of the melt transesterification process according to the invention, which is characterised in that, instead of the chain terminator of the formula (I), the chain terminator of the formula (II) is used in half the molar quantity calculated for the chain terminator (I).
The chain terminators of the formulae (I) and (II) are either known from the literature or obtainable using processes known from the literature, for example in accordance with the following reaction scheme:
See in this connection, for example, EP-B-0 057 160, page 7.
Preferred compounds of the formula (I) are, for example:
A preferred compound of the formula (II) is
Other known chain terminators which are also to be used in the process according to the invention are, for example, phenols, carboxylic acid halides, sulphonic acid chlorides or chloroformic acid esters.
Examples of the known chain terminators which are also to be used are phenol, p-tert.-butylphenol, 2,6-dimethyl-phenol, p-isooctylphenol, acetyl chloride and benzoyl chloride.
The present invention moreover provides the aromatic polycarbonates obtainable using the process according to the invention with terminal groups of the formula (Ia)
in which
R
1
, R
2
and X have the meaning stated for formula (I), with {overscore (M)}
w
(weight average, determined by light scattering) of between 1500 and 150000, optionally mixed with known aromatic polycarbonates with {overscore (M)}
w
(weight average, determined by light scattering) of between 1500 and 150000, which result from chain termination with the other, known chain terminators.
Aromatic polycarbonates with average molecular weights {overscore (M)}
w
(weight average determined by light scattering) of between 1500 and 150000 obtainable according to the invention are preferably those of the formula (IV)
in which
—O—Z—O— is a diphenolate residue with 6 to 30 C atoms,
E and E′ are identical or different and wherein at least one of the residues E and E′ corresponds to a residue of the formula (Ia)
in which R
1
, R
2
and X have the meaning stated for formula (I),
and wherein the remaining terminal groups E and E′ result from the reaction with the other known chain terminators, optionally including phosgene and wherein “p” is the degree of polymerisation, which results from the molecular weights {overscore (M)}
w
of 1500 to 150000.
The proportion by weight of the terminal groups of the formula (Ia) in the polycarbonates or polycarbonate mixtures according to the invention is between 40 wt. % and 0.1 wt. %, preferably between 0.2 wt. % and 10 wt. %.
The polycarbonates or polycarbonate mixtures according to the invention have good resistance against the action of UV radiation; they are thus, for example, well suited to the production of lamp covers and in the form of sheet for roofing, in particular for exterior applications, for example for greenhouses.
DE-OS 3 903 487 describes polycarbonates in which special phthalimide-substituted hydroxyphenylbenzotriazoles are used as chain terminators. Unlike the compounds of the present application, the compounds used here as chain terminators do not bear any further functional groups, other than the phenolic hydroxyl group, which may be incorporated. These groups are thus incorporated into the polycarbonate molecule. In contrast, the phenolic hydroxyl group of the chain terminators (I) and (II) of the process according to the invention are not incorporated into the polycarbonate molecule.
According to Japanese published patent 04-05291 of 9.1.1992, benzotriazoles of the following formula
in which
R is H, halogen, low alkyl or alkoxy and one index “n” or “m” is 0 to 16 and the other is 2 to 16,
are condensed into polymers, for example into polyethylene terephthalates. The benzotriazoles are chemically incorporated and cannot be extracted with solvents.
In contrast, the benzotriazoles to be used according to the invention act as chain terminators in polycarbonate synthesis.
EP 51 160 describes inter alia the incorporation of a benzotriazolecarboxylic acid into an alkyd resin: in a polyester system prepared from aliphatic monomer units, such as an alkyd resin, the use of another monofunctional aliphatic unit, such as the benzotriazolecarboxylic acid in practical example IV, pages 27-31 is not unusual. In a system prepared from aromatic diols, such as the bisphenols of the present invention, also using an aliphatic benzotriazolecarboxylic acid is novel and not obvious, as it is known that aromatic OH groups are considerably less readily esterifiable than aliphatic OH groups. Under the more severe reaction conditions to be used in this case, it is surprising that the hydroxyl group on the benzotriazole is not condensed, but the carboxyl group is.
In the case of the phase interface process and the homogeneous solution process, the preferred carbonic acid donor is COCl
2
, in the case of the melt transesterification process it is diphenyl carbonate.
Diphenols of the formula (V) suitable for the production of the polycarbonates according to the invention
HO-Z-OH (V)
preferably with 6 to 30 C atoms are both monocyclic and polycyclic diphenols which may contain heteroatoms a
Bier Peter
Scholl Thomas
Bayer AG
Buttner David J.
Connolly Bove & Lodge & Hutz LLP
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