Compositions – Liquid crystal compositions
Reexamination Certificate
2000-08-02
2003-09-23
Huff, Mark F. (Department: 1756)
Compositions
Liquid crystal compositions
C428S145000, C200S308000
Reexamination Certificate
active
06623660
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention concerns a decorated key top of beautiful appearance giving a feeling of high quality that can be manufactured at low cost, such as push buttons, used for cellular phones, portable information terminals, remote controls for various home electric appliances, card remote controls and various keyboards.
PRIOR ART
As a method for decorating with metallic gloss or pearl gloss the key top portion as a push button, used for a conventional cellular phone, a portable information terminal, a remote control for various home electric appliances, a card remote control and various keyboards or the like, a molding method by blending resin or rubber composing the key top with metal powder or pearl pigment, a screen printing or spraying method of paint containing metal powder or pearl pigment, a metal film deposition method of aluminum, chrome, or the like by evaporation of metal plating, are known.
Moreover, recently, a key top of beautiful appearance giving a feeling of high quality, having light transparent rainbow-colored gloss is strongly demanded.
However, the molding method by blending resin or rubber composing the key top with metal powder or pearl pigment produces a striped pattern or uneven color tone due to powder segregation, as it is difficult to disperse powder uniformly, can not obtain an uniform gloss of good feel of material, causing problems from aesthetic point of view.
Also, the printing or spraying method of paint containing metal powder or pearl pigment could not obtain a decorated key top having an even rainbow-colored gloss of good feel of material.
Further, a key top wherein aluminum or chrome or other metal film is deposited by evaporation or metal plating presents an even metallic gloss, but is lacking the rainbow-colored gloss.
On the other hand, methods by the Applicant, described in Japanese Patent Laid-Open HEI 10-289633 and Japanese Patent Laid-Open HEI 11-176273, provide a decorated key top reflecting selectively light of a particular frequency and having a rainbow-colored gloss, by laminating, in any film thickness, films of inorganic matter such as titanium oxide, but they were inappropriate for mass production because of batch film deposition operation taking much processing time. Moreover, film deposition requires complicated jigs and provokes other problems. Further, as these methods use inorganic matter, compounding with the key top made of organic polymer material, often required various adulteration treatments, increasing labor and cost.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a decorated key top having a selective reflection wavelength band in the visible light range, presenting a light transmitting rainbow-colored gloss and a beautiful appearance giving a feeling of high quality, that can be produced at low cost, by providing the key top surface and/or back with a cholesteric orientation liquid crystalline organic polymer layer, to solve said problem.
The selection of a liquid crystalline organic polymer layer wherein the reflective wavelength is visible light, violet, blue, green, yellow, red or other color tones can be obtained, and reflected light reinforcing wavelength allows the color tone to be controlled.
Namely, it is a decorated key top, wherein a liquid crystalline organic polymer layer having a selective reflection wavelength band in the visible light is formed on the key top surface and/or back.
Moreover, it is a decorated key top, wherein a liquid crystalline organic polymer layer having a selective reflection wavelength band in the visible light is formed, through a plastic film, on the key top surface and/or back.
Further, it is a decorated key top, wherein the liquid crystalline organic polymer layer is composed of cholesteric orientation liquid crystalline organic polymer. Moreover the invention relates to a manufacturing method of decorated a key top, wherein a liquid crystalline organic polymer layer having a selective reflection wavelength band in the visible light is formed on the surface and/or back of a key top molded by a die, or on the surface of a key top formed by dripping liquid resin on a base of polymer material, reacting and hardening the same, through application of crystalline organic polymer and then cholesteric orientation.
Further, the invention relates to a manufacturing method of a decorated key top, wherein a liquid crystalline organic polymer layer having a selective reflection wavelength band in the visible light is formed on the surface and/or back of a key top molded by a die, or on the surface of a key top formed by dripping liquid resin on a base of the polymer material, reacting and hardening the same, by gluing a plastic film having cholesteric orientated crystalline organic polymer layer.
Further, the invention relates to a manufacturing method of a decorated key top, wherein a liquid crystalline organic polymer layer having a selective reflection wavelength band in the visible light is formed on the surface and/or back of a key top molded by a die, or on the surface of a key top formed by dripping liquid resin on a base of polymer material, reacting and hardening the same, by placing a heat transfer sheet having cholesteric orientated crystalline organic polymer layer, and transferring the same by heat and pressure.
As the liquid crystalline organic polymer of the present invention, all of those that are in a crystal state at and beyond the glass transition point and in a glass state at and below the glass transition point can be used, and for example, backbone type liquid crystalline organic polymers such as polyester, polyamide, polyester amid, polycarbonate, polyester imide, polyether, polythiol or the like, polyacrylate base, polymethaacrylate base, polysiloxane base or polymalonate base side-chain type liquid crystalline organic, polymers, rod form stiff backbone type liquid crystalline organic polymers such as synthetic polypeptide, cellulose derivatives, polyisocyanate or the like, and their composite liquid crystalline organic polymers can be used.
The liquid crystalline organic polymer layer is required to be orientated in order to present a rainbow-colored gloss, and such orientation includes smectic orientation, nematic orientation, cholesteric orientation, discotic orientation, but cholesteric orientation and discotic orientation are preferable, and from the viewpoint of color, gloss, handling, or the like, cholesteric orientation is most preferable.
EMBODIMENT OF THE INVENTION
Now, the present invention will be described more in detail.
The liquid crystalline organic polymer layer of the present invention is preferably a multi-layer structure wherein layers of mono-domain having anisotropy in the molecular orientation are superposed continuously in a helical form. The central wavelength of light selectively reflected by the obtained decorated key top depends on the film thickness of a single layer. The film thickness of a single layer is preferably 50 nm 300 nm, and further, considering the optical selective reflection at the specific wavelength, the number of layers is preferably 5 to 50, and the total thickness is preferably 250 nm to 15000 nm. If the total thickness is less than 250 nm, the rainbow-colored gloss becomes pale, and if it exceeds 15000 nm, the translucency decreases disadvantageously.
In practice, though it is subjected to the nature, refractive index, shape of polymer material used for the key top and to the material, refractive index, color tone or the like of liquid crystal polymer, a total thickness range of 500 nm to 5000 nm presents a high optical selective reflection at tie specific wavelength. A beautiful key top presenting rainbow-colored gloss, mainly in red, yellow, blue or violet, that could not be obtained conventionally, can be obtained.
In addition, in order to recognize characters and symbols printed under the liquid crystalline organic polymer layer, it is undesirable that the total light beam transmittance of the liquid crystalline organic polymer layer is less than 70%, b
Huff Mark F.
McGlew and Tuttle , P.C.
Polymatech Co. Ltd.
Sadula Jennifer R.
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