Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Adhesive outermost layer
Reexamination Certificate
2000-01-21
2002-12-31
Dawson, Robert (Department: 1712)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Adhesive outermost layer
C428S421000, C428S521000, C526S242000, C526S245000, C526S247000, C526S206000
Reexamination Certificate
active
06500537
ABSTRACT:
TECHNICAL FIELD
The present invention relates to non-sticking composite materials for office automation equipment which are produced by applying, to a substrate, a fluorine-containing polymer excellent in non-sticking property, stain-proofing property, abrasion resistance, heat resistance and elasticity and particularly in adhesive property to the substrate.
In the present invention, the office automation equipment means a whole electronic business machine and its peripheral devices intended for enhancing efficiency and quality of office work, and particularly means electronic equipment such as copying machine, printer, facsimile machine, personal computer and multifunctional phone which make the best use of information processing technology.
BACKGROUND ART
Hitherto with respect to so-called office automation equipment (hereinafter simply referred to as “OA equipment”) such as facsimile machine and copying machine, various materials have been used on surfaces of parts of OA equipment, for example, a fuser roller having a function to fix a toner powder electrostatically sticking on a paper by heat and pressure, a charging roller having a function to give a given amount of electrostatic charge to a surface of a photosensitive drum by using a high voltage power source, a transfer roller or transfer belt having a function to give an electrostatic charge to a paper from a high voltage power source and transfer a toner powder electrostatically sticking on a surface of a photosensitive drum to the paper and other parts to enable those parts to fully exhibit their functions.
The above-mentioned charging roller is produced by applying a chloroprene rubber or epichlorohydrin rubber to a urethane rubber substrate and thereon nylon in the form of tube which was subjected to treating with a conductivity imparting agent for adjusting conductivity and resistance from the viewpoint of imparting and regulating conductivity, making resistance uniform and making separation of paper easy. Alternatively the charging roller is used as it is without applying anything to the above-mentioned substrate. However there is a problem that a surface of the obtained roller is poor in abrasion resistance, non-sticking property against toner and paper feeding property.
Also in cases of the above-mentioned fuser roller and pressure roller, from the viewpoint of non-sticking property against toner, separation of a copying paper, elasticity and abrasion resistance, the following application methods can be considered, that is, {circle around (1)} a method of applying, to a metallic substrate, a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA) in the form of tube or coating, {circle around (2)} a method of applying, to a metallic substrate, a silicon rubber, fluorine-containing rubber and silicon rubber in that order and applying a silicon oil or fluorine-containing silicon oil to an outermost layer, and {circle around (3)} a method of applying, to a metallic substrate, a silicon rubber or fluorine-containing rubber or further PFA in the form of tube. Thus a fluorine-containing polymer having excellent characteristics such as abrasion resistance and non-sticking property is applied to surfaces of parts of various OA equipment. However due to its excellent non-sticking property, there are problems that the fluorine-containing polymer is insufficient in adhesion to a substrate such as metal, glass or resin (excluding a fluorine-containing polymer) of the above-mentioned parts of OA equipment and causes poor processability in producing the parts and lower abrasion resistance during use, and further that non-sticking property which a fluorine-containing polymer possesses inherently is not enough against a toner and paper feeding ability is not good. Thus those problems become obstruction against an increase in operation speed of various OA equipment and enhancement of durability required therefor which comply with demands for high quality picture, coloring and increase in information processing speed as performance of OA equipment becomes high in highly developed information-intensive society of these days.
Therefore to compensate for lack of adhesion of a fluorine-containing resin, in case where the fluorine-containing polymer is used in the form of coating, there is a method of adhering a fluorine-containing resin to a substrate by roughening the surface of metal chemically or physically with expecting anchor effect between them. However this method requires much labor in the surface roughening itself, and though initial adhesion is possible, lowering of the anchor effect arises when a temperature change is made repeatedly and in case of use at high temperature.
Also a method for chemically activating a surface of a fluorine-containing resin by treating the surface with a solution prepared by dissolving metallic sodium in liquid ammonia has been proposed. However in that method, not only there is a fear that the solution itself causes environmental pollution but also there is a problem that its handling is attended with danger.
Further though a method for carrying out physical and chemical treatment such as plasma sputtering on a surface of a fluorine-containing resin has been proposed for activation of the resin surface, there is a problem that much labor is required for the treatment and an increase in cost is resulted.
Also in order to improve adhesion of a fluorine-containing resin coating, investigations with respect to addition of various components and formation of a primer layer have been made.
For example, there is a technique of adding an inorganic acid such as chromic acid to a coating composition containing a fluorine-containing resin to form chemical conversion coating film on a surface of metal for enhancing adhesion of the composition (JP-B-63-2675). However since chromic acid contains hexahydric chromium, it cannot be said that such a technique is sufficient in view of safety in food and coating work. Further in case of use of other inorganic acids such as phosphoric acid, there was a problem that safety of a fluorine-containing resin coating composition is damaged.
Use of a coating composition containing a fluorine-containing resin as a primer, in which heat resistant resins such as polyamide imide, polyimide, polyethersulfone and polyether ether ketone and in addition, a metal powder are added instead of the above-mentioned inorganic acid, has been studied (JP-A-6-264000). Inherently there is almost no compatibility between a fluorine-containing resin and a heat resistant resin. Therefore there arises a phase separation in a coating film, thus easily causing intercoat adhesion failure between the primer and the top coat of the fluorine-containing resin. Further film defects such as pin holes and cracks arise easily at the time of processing at high temperature or during use due to a difference in heat shrinkage between the fluorine-containing resin and the heat resistant resin or due to lowering of elongation of the coating film by the addition of the heat resistant resin. Also since those heat resistant resins are colored brown by baking, property for exhibiting clear surface pattern is poor and it is difficult to use them for applications requiring white and vivid colors and transparency. Further when the heat resistant resin is blended, non-sticking property and friction resistance which the fluorine-containing resin inherently possesses are lowered.
Also for adhesion of a fluorine-containing resin coating composition to a glass, etc. requiring transparency, an improvement of the adhesion has been tried by treating the substrate with a silane coupling agent or adding a silicone resin to the fluorine-containing resin coating composition (JP-B-54-42366, JP-A-5-177768). However enhancement of adhesion is insufficient, heat resistance is lowered and separation of a coating film, foaming and coloring arise easily at sintering or in use at high temperature.
On the contrary, fluorine-containing resin coating compositions prepared by copolymerizing a hydrocarbon monomer (containing no fl
Araki Takayuki
Kumegawa Masahiro
Oka Noritoshi
Sanemasa Hisato
Shimizu Tetsuo
Daikin Industries Ltd.
Dawson Robert
Keehan Christopher M.
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