Acid anhydrides

Details Acid anhydrides Acid anhydrides

2001-12-21

2003-11-04

Dentz, Bernard (Department: 1625)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

Reexamination Certificate

active

06642393

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to novel polyimides, novel polyamic acids which are intermediates thereof, a process for producing the same and novel acid dianhydrides to be used in the production of these novel polyimides. More particularly, it relates to novel polyimides obtained by introducing a monomer unit derived from acid dianhydrides substituted by a substituent having an alkyl or fluoroalkyl group into the molecule and these acid dianhydrides.
BACKGROUND OF THE INVENTION
Because of being excellent in heat resistance among various organic polymers, polyimides have been widely used in the fields of, for example, cosmology, aeronautics, electronic communication and office automation instruments. In recent years, there have been particularly required polyimides which have not only a high heat resistance but also various functions appropriate for uses.
In general, a polyimide has a relatively high water absorption due to the large polarization between C═O and N in its imide ring. To improve the existing polyimides, it is therefore one of the problems to be solved to reduce the water absorption.
As one of methods for reducing the water absorption of polyimides, JP-A-57-143329, JP-A-61-57620, JP-A-2-225522, JP-A-4-7333 and JP-A-4-100020 disclose a method of introducing alkyl and fluoroalkyl groups (the term “JP-A” as used herein means an “unexamined published Japanese patent application”). In this method, diamines having an alkyl or fluoroalkyl group is used to thereby introduce these substituents into polyimides. However, there has been reported so far no polyimide obtained by introducing an alkyl or fluoroalkyl group into an acid dianhydride and then reacting it with a diamine. This is seemingly because there is known no acid dianhydride having an alkyl or fluoroalkyl group per se.
SUMMARY OF THE INVENTION
As the results of intensive studies, the present inventors have found out acid dianhydrides carrying a substituent having alkyl or fluoroalkyl group introduced thereinto and a process for producing novel polyimides by using the same. The invention has been completed based on these findings.
The polyimide according to the invention is a polyimide containing a structure represented by the following general formula (I):
wherein
X
1
represents a tetravalent organic group having a substituent —R
1
AR
2
(wherein A represents a divalent linkage group; R
1
represents a single bond or a C
1-3
alkylene group; and R
2
represents a C
1-25
alkyl group or a fluoroalkyl group); and
Y represents a divalent organic group.
DETAILED DESCRIPTION OF THE INVENTION
The term “organic group” as used herein means a group which is a part of an organic compound and has linkage site(s) (the number of these linkage sites is expressed as valency). Aromatic groups and aliphatic groups may fall within the category of the organic group. It is preferable that the organic group has at least a part of its linkage sites on aromatic carbon atom(s). Although the organic group is not particularly restricted in bulkiness, it typically carries from 15 to 74, preferably from 19 to 59 and still preferably form 26 to 46, carbon atoms.
The term “linkage group” as used herein means a divalent functional group which consists of, if necessary, hydrogen atom(s), carbon atom(s) and at least one heteroatom selected from among, for example, oxygen, nitrogen and sulfur atoms and has at least one of the linkage sites on the hetero atom.
In one embodiment of the invention, A is an ester bond, an amide bond or a sulfonamide bond. An ester bond is a group formed by dehydrating condensation of an oxo acid with an alcohol. For example, an ester bond of a carboxylic acid ester may be represented by —COO— or —OCO—. The same applies to other oxo acid esters. An amide bond may be represented by —NH—CO— or —CO—NH—. A sulfonamide bond may be represented by —NH—SO
2
— or —SO
2
—NH—.
In one embodiment of the invention, the polyimide is a copolymer having a structure represented by the following general formula (II):
wherein
X
1
represents a tetravalent organic group having a substituent —R
1
AR
2
(wherein A represents a divalent linkage group; R
1
represents a single bond or a C
1-3
alkylene group; and R
2
represents a C
1-25
alkyl group or a fluoroalkyl group);
X
2
is a tetravalent organic group different from X
1
;
Y represents a divalent organic group;
m is an integer of 1 or more;
n is an integer of 0 or more; and
m/m+n is 0.01 or more; and
having an average molecular weight of from 5,000 to 1,000,000.
m and n represent respectively the numbers of imide units contained in the copolymer molecule, while m/m+n represents the ratio of the imide unit having X
1
. m preferably ranges from 1 to 100, n preferably ranges 0 to 99 and m+n preferably ranges from 1 to 100. m/m+n preferably ranges from 0.01 to 1, still preferably form 0.1 to 1 and still preferably from 0.2 to 1.
X
1
, X
2
and Y may each occur in plural types in a polymer molecule.
The term “average molecular weight” as used herein means weight-average molecular weight measured by gel permeation chromatography (GPC). It preferably ranges from 3,000 to 1,000,000, still preferably from 10,000 to 500,000 and still preferably from 20,000 to 300,000.
In one embodiment of the invention, X
1
is represented by the following general formula:
wherein
Z represents a divalent aromatic or aliphatic group having a substituent —R
1
AR
2
(wherein A represents a divalent linkage group; R
1
represents a single bond or a C
1-3
alkylene group; and R
2
represents a C
1-25
alkyl group or a fluoroalkyl group); and
L is —O— or —NH—.
The term “aromatic group” means a group containing at least one aromatic ring (for example, aryl, heteroaryl, arylalkyl). It carries typically from 15 to 74, preferably form 19 to 59 and still preferably from 26 to 46, carbon atoms in total.
The term “aliphatic group” means a group having an aliphatic moiety but being free from aromatic rings. It carries typically from 1 to 60, preferably form 5 to 45 and still preferably from 12 to 32, carbon atoms.
In one embodiment of the invention, Z is represented by one of the following general formulae:
wherein R
2
represents a C
1-25
alkyl group or a fluoroalkyl group; and p is from 1 to 4.
The above general formulae representing Z all indicate that Z can link at any two sites on the aromatic ring. It is preferable that p is from 1 to 3.
In one embodiment of the invention, Z is —CH
2
CH(COOR
2
)CH(COOR
2
)CH
2
—, —CH
2
CH(OCOR
2
)CH(OCOR
2
)CH
2
—, —CH
2
C(CH
2
COOR
2
)
2
CH
2
—, —CH
2
C(CH
2
OCOR
2
)
2
CH
2
—, —CH(CH
2
COOR
2
)CH(CH
2
COOR
2
)—, —CH(CH
2
COOR
2
)CH(CH
2
OCOR
2
)— or —CH
2
CH(CH
2
COOR
2
)—,
wherein R
2
represents a C
1-25
alkyl group or a fluoroalkyl group.
The polyimide composition of the invention is a composition containing one of the polyimides as described above. This composition may contain an arbitrary liquid or powder as a diluting medium wherein the polyimide can be dissolved or uniformly dispersed.
The polyamic acid according to the invention contains a structure represented by the following general formula (III):
wherein
X
1
represents a tetravalent organic group having a substituent —R
1
AR
2
(wherein A represents a divalent linkage group; R
1
represents a single bond or a C
1-3
alkylene group; and R
2
represents a C
1-25
alkyl group or a fluoroalkyl group); and
Y represents a divalent organic group.
In one embodiment of the invention, A is an ester bond, an amide bond or a sulfonamide bond.
In one embodiment of the invention, the polyamic acid is a copolymer having a structure represented by the following general formula (IV) or a structure represented by the following general formula (IV) wherein some of the amic acid moiety has been dehydrated and condensed:
wherein
X
1
represents a tetravalent organic group having a substituent —R
1
AR
2
(wherein A represents a divalent linkage group; R
1
represents a single bond or a C
1-3
alkylene group; and R
2
represents a C
1-25
alkyl group or a fluoroalkyl group);
X
2
is a tetravale

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