Coating processes – With post-treatment of coating or coating material – Heating or drying
Patent
1988-02-10
1990-05-08
Lusignan, Michael
Coating processes
With post-treatment of coating or coating material
Heating or drying
427387, 4273935, 428339, B05D 302
Patent
active
049237187
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a functional film comprising a base substrate composed of a thermoplastic resin having formed thereon a coating layer to improve heat resistance, fire retardance, elongation resistance, solvent resistance, properties of not absorbing water, etc., and to a process for its production. The term "film" as used herein is a term of wide conception including film analogues of sheets, etc.
BACKGROUND ART
Thermoplastic resin-based flexible films permit a high degree of freedom in designing due to their flexibility and possess some insulating properties. In general, however, their insufficient heat resistance limits their uses. Of conventional non-treated films used as base substrates, films composed of engineering plastics such as polyimide (PI), polyether-ether-ketone (PEEK), polyether sulfone (PES), polyphenylene sulfide (PPS), polyparabanic acid (PPA), polyarylate (PAR), etc., have a comparatively excellent heat resistance. However, these films themselves are expensive and require highly sophisticated working techniques which make them more expensive, thus being difficultly used for general purpose uses. Therefore, in recent years, films using inexpensive thermoplastic resin as base substrate and yet having better heat resistance than non-treated films composed of the base substrate itself have been variously studied and, as a result, various such films have actually been proposed.
For example, among them is a film using as base substrate a composition prepared by mixing polyvinyl chloride resin (PVC), a typical example of inexpensive and easily available thermoplastic resins, with predetermined additives. However, in many cases, the technique of mixing with additives to improve heat resistance of base substrate requires to mix various additives for the purpose of obtaining intended heat resistance properties, thus the technique has been pointed out to involve the problem that transparency and other physical values are seriously changed by the mixing of various additives.
A heat-resistant film prepared by impregnating a sheet of heat-resisting fibers or glass fibers with a heat-resistant resin, and laminating the impregnated sheet on a known film also exists. However, this film has a too much thickness and loses a tendency of flexibility, and hence is not sufficiently adapted for uses requiring particularly thin thickness and good flexibility such as flexible printed circuit base (FPC), insulating tapes, etc.
On the other hand, it may also be considered to form a coating layer on a base substrate composed of a thermoplastic resin for attaining heat resistance properties not obtained by the base substrate per se. Such films have the possibility of providing good heat resistance not obtained by the base substrate per se due to the coating layer without much spoiling the physical properties of the base substrate per se such as transparency. As a process for producing such film, it may be generally considered to bake the coating layer to the substrate under the condition of low temperature under which the base substrate composed of thermoplastic resin does not shrink or wrinkle. However, heat resistance, adhesion, etc., of film having a coating layer correlate with the baking temperature and, when baking is conducted under such low temperature, it is feared that the degree of improvement of heat resistance is comparatively small.
As is described above, even heat-resistant film prepared by forming a coating layer on a base substrate composed of a thermoplastic resin fails to markedly improve heat resistance, and existing heat-resistant films have problems with thickness, flexibility, and cost and, when they are mixed with additives to improve heat resistance, other physical properties of them will be spoiled. Thus, these have been still insufficient as heat-resistant films.
With these in mind, the present invention has been completed, and its object is to provide an inexpensive functional film having good heat resistance, fire retardance, properties of not absorbing water
Iida Kosuke
Kadono Yoji
Yamato Hiroshi
Lusignan Michael
Takiron Co., Ltd.
LandOfFree
Functional film and process for its production does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Functional film and process for its production, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Functional film and process for its production will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2348289