Stock material or miscellaneous articles – Composite – Of silicon containing
Reexamination Certificate
2002-08-02
2004-06-29
Buttner, David J. (Department: 1712)
Stock material or miscellaneous articles
Composite
Of silicon containing
C427S387000, C427S317000
Reexamination Certificate
active
06756126
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an aircraft window of synthetic resin having a hard coated film, such as a cabin window, a cockpit window (mainly a side panel), a canopy or windshield, and a method for producing the same.
2. Description of the Related Art
Synthetic resin such as polycarbonate or polyacrylate resin has been in common usage as aircraft windowpanes in light of the balance of performances such as transparency, strength, specific gravity and durability. Polyacrylate resin has good moldability and easily obtainable optical isotropy in case of producing a large size molding body. Polycarbonate has excellent heat resistance and impact load carrying capacity. These resins have been applied to the windowpane of many kinds of aircrafts, taking advantage of each property above.
Meanwhile, aircraft windowpanes have a lot of occasions to be subject to abrasive damage caused by abrasion with atmospheric ice particles or raindrops, by contact with inorganic particles such as volcanic ash or clouds of sand or by contact with insects sticking to the surface of the windowpanes. The surface is wiped with cleaning cloth or the like when in maintenance and cleaning. Though these resins have no problem with bulk strength, the surface hardness thereof is low so that the surface is apt to become scratched. This is the only difficulty because the aircraft window should have good visibility. A frequent exchange of windowpanes brings about increasing maintenance costs, which is no measure for solving the problem. Hence, recently, an aircraft window mounted with a resin windowpane having a surface protective coating has been desired.
However, conventional methods for applying a protective coating can be roughly categorized by (1) a method for forming a SiO
2
film by coating a compound having Si and baking it or by (2) a method for forming a SiO
2
film by PVD such as ion-plating. The method (1) gives insufficient hardness of the surface so that the protection goal cannot be attained. The method (2) generates peeling or cracks of the film due to poor adhesion and does not give sufficient protection because of difficulty in obtaining a thick film.
SUMMARY OF THE INVENTION
In view of the need to solve the prior problems, it is the object of the present invention to provide an aircraft window of synthetic resin having a hard coating with excellent hardness and durability in an aircraft cabin window having at least a double-pane construction with a hollow interspace therebetween or an aircraft cockpit, canopy, or windshield window having a single pane construction including a monolayer or multilayer pane and to provide a method for producing the same.
An aircraft window of synthetic resin having hard coated film and at least a double-pane construction with a hollow interspace therebetween for an aircraft cabin window according to the present invention comprises an outer synthetic resin molded body having hard coated film on the outside surface of the aircraft and an inner synthetic resin molded body. The bodies face each other to form at least a double-pane construction with a hollow interspace therebetween. The hard coated film comprises siloxane bonds and/or silazane bonds obtained by coating a coating composition containing perhydropolysilazane or its condensation polymer which is substantially soluble in organic solvent on the surface of the synthetic resin molded body and heat-treating the body at approximately ambient temperature to 100° C. in air or humidified air.
An aircraft cabin window should have a heat-insulating property because of the extreme temperature difference between the inside and the outside of the cabin, transparency, and strength as a member constructing a part of the fuselage and to endure the pressure difference between the inside and the outside of the cabin. Furthermore, a fail-safe structure includes measures in case the pane is damaged. Therefore, the aircraft cabin window has at least a double-pane construction with a hollow interspace between facing transparent synthetic resin molded bodies.
According to the present invention, one side (the outside of the cabin) of at least one of the molded bodies has the hard coated film. At least double-pane construction means that, if needed, a multi-pane construction, beyond double-pane construction, is adopted. This improves the insulating function and the failsafe function. In this case, the hard coat is indispensably needed on the molded body inside of the cabin where abrasion rarely occurs.
Thus, for example, one side of a transparent molded body of synthetic resin such as polycarbonate or cast acrylate resin is coated with a solution of substantially organic-solvent-soluble perhydropolysilazane or its condensation polymer in an organic solvent so that the film thickness after heat-treating codes to be from 1 &mgr;m to 100 &mgr;m and the coated body is heat-treated at approximately ambient temperature to 100° C. after drying in air. A hard film having silazane bonds and/or siloxane bonds is coated on the one side of thus obtained transparent molded body of synthetic resin such as polycarbonate or cast acrylate resin. A window part comprises the two bodies bonded together with a spacer inserted at the outer perimeter therebetween. The faces having no hard coating of the two bodies are facing each other so as to be spaced apart from one another. The window part is fixed to an opening of the fuselage for a window through a gasket or a sealing member to form a cabin window. In this case, a gasket or a sealing member may be molded so that the two bodies are spaced apart from one another when the two bodies are fixed through the gasket or the sealing member and a two-pane construction is formed by fixing one, body by one body to the gasket or the sealing member.
The cast acrylate resin is a transparent synthetic resin having a high softening point consisting of a homopolymer or a copolymer obtained by polymerizing a polymerizable monomer consisting mainly of methyl methacrylate. The synthetic resin is cast to a panel-formed molded body by heating to flow to a temperature equal to or higher than the softening point thereof. A windowpane can be made from the panel-formed molded body by cutting to a form of the windowpane. A windowpane can also be made by casting the resin to a form of the windowpane. A method other than these is to pour the monomer into a board-formed mold to cast and polymerize at the same time.
The thickness of the transparent molded body of synthetic resin is variable according to the intended strength of the fuselage or the size of the opening of the fuselage. The spacer may be made from the same material as the transparent molded body of synthetic resin or from more elastic material than that of the body. The gasket or the sealing member is selected from organic materials having appropriate elasticity, strength and durability in order to keep the cabin airtight from the outside, where the temperature difference is great, and to firmly support the windowpanes.
One of the perhydropolysilazane or its condensation polymer which is substantially soluble in organic solvent in the coating composition is a cyclic or linear perhydropolysilazane having a structure of the formula (1) as a repeated unit or a mixture thereof.
Further, another of the perhydropolysilazane or its condensation polymer is an intermolecular dehydrogenation condensation polymer of cyclic or linear perhydropolysilazanes having a structure of the formula (1) as a repeated unit or a mixture of them.
Furthermore, another of the perhydropolysilazane or its condensation polymer is a dehydrogenation condensation polymer having a plurality of the condensation structures of (2) or (3) by condensing the cyclic or linear perhydropolysilazane having a structure of (1) with ammonia or hydrazine or condensing the mixture of the cyclic and linear perhydropolysilazane having a structure of (1) with ammonia or hydrazine.
A hard coated film having siloxane bonds and/or silazane bonds according to the
Oguri Kazuyuki
Sekigawa Takahiro
Buttner David J.
Keehan Christopher
Mitsubishi Heavy Industries Ltd.
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Aircraft window of synthetic resin having hard coated film... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Aircraft window of synthetic resin having hard coated film..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aircraft window of synthetic resin having hard coated film... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3343577