Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1999-05-18
2000-10-31
Woodward, Ana
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525420, 525432, 525436, C08L 6700, C08L 7700
Patent
active
061404292
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention pertains to a method of producing a polyimide resin composition that can be injection molded and has excellent high-temperature performance, and in further detail, to a new method of producing a polyimide resin composition without producing polyamide acid.
BACKGROUND OF THE INVENTION
Aromatic polyimide is known as a resin with excellent heat resistance and mechanical properties U.S. Pat. No. 3,179,631, U.S. Pat. No. 3,249,588 and U.S. Pat. No. 4,755,555), and it is widely used in jet engines, business equipment, and automobile parts. Nevertheless, there is a tendency toward restriction of its use because many polyimides are difficult to mold. In particular, many polyimides are molded into the desired shape, such as films, etc., before the polyamide acid, which is a precursor to polyimide, changes to polyimide, or are molded from a molded article of polyimide into the desired shape by machine molding.
Therefore, there is a need for an injection-moldable polyimide resin composition. In order to solve this invention, a polyimide polymer mixture is disclosed (U.S. Pat. No. 5,470,922, which is incorporated herein by reference) that is made from at least one polymer that can be melted and molded at a temperature lower than 400.degree. C. and that is selected from polyamide and polyester, preferably polyamide or polyester in the form of a liquid crystal polymer, and polyamide acid. This polyimide polymer mixture has heat resistance and mechanical properties rivaling those of conventional aromatic polyimide and excellent injection molding performance.
Nevertheless, because polyamide acid is used to produce this polymer mixture, a process for producing polyamide acid is needed. Therefore, simplification of the manufacturing process is needed. This invention presents a new method of producing an injection-moldable polyimide resin composition with better mechanical properties by a simpler manufacturing method.
SUMMARY OF THE INVENTION
In order to solve the aforementioned problems, this invention is a method of producing injection moldable polyimide resin composition, which is characterized by the fact that at least one aromatic acid anhydride and at least one aromatic diamine are directly combined with at least one polymer that can be melt molded at a temperature lower than 400.degree. C.
Furthermore, at least one aromatic acid anhydride and at least one aromatic diamine are directly combined with at least one polymer that can be melted and molded at a temperature lower than 400.degree. C. and the product is heat treated.
Moreover, this invention is a method of producing molded articles, which is characterized by the fact that a polyimide resin composition obtained by directly combining at least one aromatic acid anhydride and at least one aromatic diamine with at least one polymer that can be melted and molded at a temperature lower than 400.degree. C. is injection molded and then the molded article is heat treated.
DETAILED DESCRIPTION OF THE INVENTION
The polymer used in this invention is a polymer that can be melt molded at a temperature lower than 400.degree. C. The melt-moldable polymer is a polymer that can be molded by an extrusion device at a specific temperature without any degradation. It is a polyamide, polyester, their mixture, etc. Actual examples of polyamides are nylon 6, nylon 66, nylon 610, nylon 612, etc., and mixtures of one or more polyamides can also be used. Actual examples of the polyester are polybutylene terephthalate, polyethylene terephthalate, etc., and mixtures of two or more polyesters can be used. The polyamide or polyester should be a liquid crystal polymer. A liquid crystal polymer is usually a polyester, but it is not limited to polyester. This includes polyester amide and polyester imide.
Examples of the aromatic acid anhydride used in this invention are pyromellitic anhydride, 3,3',4,4'-biphenyl tetracarboxylic anhydride, etc., and examples of the aromatic diamine are oxydianiline and para-phenylene diamine. Two or more of these arom
REFERENCES:
patent: 3179631 (1965-04-01), Endrey
patent: 3249588 (1966-05-01), Gall
patent: 4481339 (1984-11-01), Bolon
patent: 4755555 (1988-07-01), Manwiller et al.
patent: 5183864 (1993-02-01), Nelb, II et al.
patent: 5470922 (1995-11-01), Kaku et al.
International Search Report, dated Apr. 6, 1998.
E. I. Du Pont de Nemours and Company
Woodward Ana
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