Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1999-11-29
2001-07-24
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
C528S125000, C528S126000, C528S128000, C528S172000, C528S173000, C528S176000, C528S179000, C528S183000, C528S188000, C528S220000, C528S229000, C528S350000, C528S351000, C528S352000, C528S353000
Reexamination Certificate
active
06265520
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a solvent soluble polyimide used as the material of the alignment layer of a LCD and a method for making thereof.
BACKGROUND OF THE INVENTION
The commercial material of the alignment layer of the LCD is based on a so-called polyimide (PI), however the conventional polyamide is a material that is nearly insoluble, unmelting, thermal-resistant and chemical-resistant. It is very inconvenient for this polyimide to be processed, and in particular applied in making the alignment layer of the LCD.
Conventional aromatic polyimides have good thermal resistance, and these polyimides are usually obtained from the condensation products of aromatic anhydrides or derivatives and aromatic diamines. First, the polyamidic acid is synthesized. Then, a crosslinked imidization is performed under a high temperature to produce the desired polyimide.
The commercial kit of the alignment layer is usually sold in the form of solution containing the intermediates of the reaction used to synthesize the desired polyamide. First, this solution is coated on a substrate, then the substrate is exposed to a high temperature to allow the polyamidic acid cyclize partially or entirely. The polyamidic acid is not a stable substance, so it will easily decompose into low M.W. substances. Therefore, the product composed of this polyimide is not stable. Accordingly, the usages of the conventional polyimides are limited by their preservation (short retention time and low temperature preservation) and cost.
In addition, the process needs a high-temperature long-term baking; therefore, the conductive layer on the substrate is easily oxidized, resulting in the increase at the operating voltage and power consumption. Moreover, the high-temperature baking makes it hard to fabricate the color filter.
A method for making a polyimide synthesized through the intermediate polyamidic acid polymerized by aliphatic anhydrides and diamines was disclosed by Hitachi Chem. Co. Ltd. (Japan unexamined Patent No. 60-135430). However, this method can not provide useful solvent soluble polyimides.
Similarly, a method for making a solvent soluble polyimide by selecting suitable monomers and assembly thereof was disclosed by Hitachi Chem. Co. Ltd. (Japan unexamined Patent No. 59-179623). Unfortunately, the polyimide film appears dark, which is adverse to optical transparency. Accordingly, the polyamides made according to this method can not be used as the material of the alignment layer of the LCD.
In accordance, it is necessary to develop a solvent soluble polyimide, which can be well preserved and used, to make a product with good electric conductivity and stability, and in particular the material of the alignment layer of the LCD.
SUMMARY OF THE INVENTION
Disclosed is a solvent soluble polyamide and a method for making thereof. This invention is characterized by polymerizing the anhydride selected from one or more member(s) of the group consisting of the compounds with following formula (AD1~AD3):
wherein, R
3
, R
4
, R
5
and R
6
of AD1 are independent hydrogen and methyl; with diamine selected from one or more member(s) of the group consisting of the compounds with following formula (AM1~AM5):
under the condition without or with catalyst (tri-ethyl amine, quinoline, pyridine, phosphoric anhydride, tri-chloro phosphate, phosphorous trichloride, p-methyl benzenesulfonic acid, sulfuric acid, phosphoric acid, high-M.W. acidic catalyst and high-M.W. basic catalyst) to produce a novel solvent soluble polyimide with low electric conductivity and good transparency.
This polymerization is shown in following Scheme I:
As shown in Scheme I, the Polymer (I) is the major product of this polymerization, which can be directly used as a material of the alignment layer of a LCD; the Polymer (II) is the minor product of this polymerization, which can be converted to Polymer (I) through cyclization reaction.
Other feature and advantages of the invention will be apparent from the following detailed description, and from the claims.
DETAILED DESCRIPTION OF THE INVENTION
One feature of the invention discloses a solvent soluble polyamide of formula (I):
wherein, R
1
is:
and R
3
, R
4
, R
5
, R
6
are independently selected from the group consisting of hydrogen and methyl group; and/or
R
1
is
R
2
is
wherein, R
7
and R
6
are independently hydrogen or methyl; and/or R
2
is:
wherein, R
9
is —C(O)— or —CH —; and/or R
2
is:
and n is an integer.
Another feature of the invention discloses a method for making a solvent soluble polyimide, the steps comprising:
a) providing a diamine placed in a reactor;
b) introducing a suitable solvent to the reactor;
c) adding an anhydride to the reactor, and healing at a temperature for a period of time allowing the polymerization of the anhydride and the diamine to produce a polyimide of formula (I):
wherein, R
1
is:
and R
3
, R
4
, R
5
, R
6
are independently selected from the group consisting of hydrogen and methyl group; and/or
R
1
is
R
2
is
wherein, R
7
and R
8
are independently hydrogen or methyl; and/or R
2
is:
wherein, R
9
is —C(O)— or —CH
2
—; and/or R
2
is:
and n is an integer.
As the method described above, the diamine is selected from one or more member(s) of the group consisting of following compounds (AM1~AM5):
The anhydride is selected from one or more member(s) of the group consisting of AD1, AD2 and AD3:
wherein, R
3
, R
4
; R
5
and R
6
of AD1 are independent hydrogen
or methyl.
The solvent is selected from one of the group consisting of butoxyethanol, &ggr;-lactone, N-methyl-&ggr;-lactone, ethylene glycol, di-ethyl-diol, and meta-methyl phenol.
Furthermore, the steps b) further comprises introducing a catalyst, selected from one or more member(s) of the group consisting of tri-ethyl amine, quinoline, pyridine, phosphoric anhydride, tri-chloro phosphate, phosphorous trichloride, p-methyl benzenesulfonic acid, sulfuric acid, phosphoric acid, high-M.W. acidic catalyst and high-M.W. basic catalyst, into the reactor under N
2
with a stirring to dissolve the catalyst.
The ratio of the diamine and the anhydride ranges from 0.8 to 1.2. The amount of the added catalyst is 0.1%~3% of the total weight of the diamine and the anhydride. Moreover, step c) is performed at a temperature ranging from 50° C. to 220° C. for 3 hours to 36 hours, preferably at a temperature ranging from 100° C. to 180° C. for 5 hours to 24 hours.
REFERENCES:
patent: 5229485 (1993-07-01), Kramer et al.
patent: 6013760 (2000-01-01), Choi et al.
patent: 6031067 (2000-02-01), Choi et al.
patent: 6054554 (2000-04-01), Choi et al.
patent: 6100365 (2000-08-01), Matsumoto et al.
patent: 59-179623 (1984-10-01), None
patent: 60-135430A (1985-07-01), None
Kuo Hui-Lung
Lee Chein-Dhau
Liu Yi-Chun
Yang Shih-Chi
Hampton-Hightower P.
Industrial Technology Research Institute
Ladas & Parry
LandOfFree
Solvent soluble polyimide and a method for making thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solvent soluble polyimide and a method for making thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solvent soluble polyimide and a method for making thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2508228