Fluoroelastomers: synthesis, properties and applications

To improve color reproduction areas in a display device having light-emitting elements. A display region has a plurality of picture elements. Each picture element includes: first and second pixels each including a light-emitting element which has a chromaticity whose x-coordinate in a CIE-XY chromaticity diagram is 0.50 or more; third and fourth pixels each including a light-emitting element which has a chromaticity whose y-coordinate in the diagram is 0.55 or more; and fifth and sixth pixels each including a light-emitting element which has a chromaticity whose x-coordinate and y-coordinate in the diagram are 0.20 or less and 0.25 or less, respectively. The light-emitting elements in the first and second pixels have different emission spectrums from each other; the light-emitting elements in the third and fourth pixels have different emission spectrums from each other; and the light-emitting elements in the fifth and sixth pixels have different emission spectrums from each other.

Display device and electronic device

A plasma display device includes: a dielectric layer on which a plurality of through-holes of a dielectric layer is disposed in a matrix shape; upper and lower electrode layers formed at both upper and lower surfaces of the dielectric layer; upper and lower substrates disposed on the outer surface of the upper and lower electrode layers; and a third electrode layer having a plurality of third electrodes which are formed between the upper substrate and the upper electrode layer, or the lower substrate and the lower electrode layer, and are insulated from the upper and lower electrode layers. Accordingly, a plasma display device can be realized which has stability and efficiency of a micro discharge. In addition, each pixel can concurrently carry out a sustain discharge by applying an alternating voltage to upper and lower electrodes forming sustain electrodes.

Plasma Display Panel

Chemistry of fluorocarbon elastomers

Fluoropolymers are well-known for their good properties in terms of chemical, thermal and electrical stabilities, inertness to acids, bases, solvents and oils, and high resistance to ageing and oxidation. Polyvinylidene fluoride (PVDF) is useful as a homopolymer endowed with interesting characteristics. It contains a high crystallinity rate, but is base sensitive. In addition, VDF can be co- or terpolymerized with several fluorinated monomers, rendering them suitable as elastomers and various examples of synthesis of VDF-copolymers are also presented. This review also focusses on binary and tertiary systems containing VDF. Several curing systems for these VDF-containing copolymers have been investigated, especially diamines and their derivatives, aromatic polyhydroxy compounds, peroxides with coagents, such as triallylisocyanurate, radiations, and thiol-ene systems. The best vulcanizate properties are obtained by a two-step process. First, the material is press cured at different times and temperatures, then, it is post cured in air or under nitrogen at higher temperature and time, and under atmospheric pressure. Poly(VDF-co-HFP) copolymers can react with primary, secondary or tertiary monoamines, but they are mainly crosslinked by diamines such as hexamethylene diamine (HMDA), their carbamates (HMDA-C), and derivatives. A mechanism of crosslinking is identified by Infrared and 19F NMR spectroscopies, and was evidenced to proceed in three main steps. First, a VDF unit undergoes a dehydrofluorination in the presence of the diamine, then the Michael addition occurs onto the double bonds to form crosslinking, while HF is eliminated from crosslinks in the presence of HF scavengers. The crosslinking mechanism with bisphenols takes place also in three main steps (dehydrofluorination, then substitution of a fluorine atom by a bisphenol, and elimination of HF). The most efficient crosslinking bisphenol is bisphenol AF . A fluoropolymer crosslinked with peroxide/coagent systems needs to be functionalized or halogenated to insure a free radical attack from peroxide. The peroxide is introduced with a coagent that enhances the crosslinking efficiency, and the most efficient one is triallylisocyanurate (TAIC). The crosslinking mechanism of the peroxide/triallylisocyanurate system proceeds in three main steps. The crosslinking reaction occurs from a macroradical arising from the functional or halogenated polymer which is added onto the three double bonds of the TAIC. A fourth way to crosslink VDF-based fluoropolymers deals with high energy radiation, such as X and γ (60Co or 137Cs)-rays, and charged particles (β-particles and electrons). Three different reactions are possible after irradiation of a PVDF, and the one that leads to crosslinking is the recombination between two macroradicals. The irradiation dose used on the VDF-based copolymer has an influence on the thermal and mechanical properties. Finally, a crosslinking system also used to vulcanizate hydrogenated elastomers concerns a thiol-ene system which requires a mercapto function born by the VDF-based polymer. Crosslinking occurs via a non-conjugated diene. The mechanical properties (tensile strength, elongation at break, hardness, elongation modulus, compression set resistance …) of the three main crosslinking systems of fluoroelastomers are compared. Finally, the main applications of crosslinked VDF-based fluoropolymers are summarized which include tubing in the aircraft building industry, sealing, tube or irregular-profile items of any dimension, films with good adhesion to metallic or rigid surfaces, multilayer insulator systems for electrical conductors, captors, sensors, and detectors, and membranes for electrochemical applications.

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Crosslinking of Vinylidene Fluoride-Containing Fluoropolymers

A flat display panel comprising a flat display panel main body, and a front protective plate which comprises an antireflection layer, a translucent electrically conductive layer, containing a metal having an electromagnetic wave shielding property and a near infrared ray shielding property, a highly rigid transparent substrate made of a tempered glass or a semi-tempered glass and an adhesive layer laminated in this order, bonded to the viewer's side surface of the flat display panel main body by means of the adhesive layer.

Flat display panel with a front protection plate

An effective vulcanization recipe for tetrafluoroethylene-propylene elastomer was searched for and the following results were obtained: (1) The C2F4-C3H6 copolymer is susceptible only to peroxide and is not crosslinked at all by other reagents. (2) The peroxide vulcanization is greatly accelerated by some coagents, and triallyl isocyanurate was found to be the best cure promoter. (3) The vulcanizate obtained by using a combination of α,α′-bis-(t-butyl-peroxy)-p-diisopropylbenzene with triallyl isocyanurate as curative exhibits good mechanical properties together with excellent heat and chemical resistance. (4) The mechanism of the vulcanization reactions seems to involve a chain reaction which greatly increases the efficiency of the vulcanization reaction by the peroxide.

Vulcanization of a Fluoroelastomer Derived from Tetrafluoroethylene and Propylene

A flat display panel (1) comprising a flat display panel main body (2), and a front protective (3) plate which comprises an antireflection layer (6), a translucent electrically conductive layer (5), containing a metal having an electromagnetic wave shielding property and a near infrared ray shielding property, a highly rigid transparent substrate (4) made of a tempered glass or a semi-tempered glass and an adhesive layer (7) laminated in this order, bonded to the viewer's side surface (2a) of the flat display panel main body (2) by means of the adhesive layer (7)

Flat display panel

PROBLEM TO BE SOLVED: To provide a planar display panel the main body of which is prevented from being broken and which has an electromagnetic wave shielding function and a near infrared ray shielding function for reducing an electromagnetic noise and a near infrared ray emitted from the main body. SOLUTION: A front surface protecting plate 3 of high rigidity includes a transparent substrate 4 of high rigidity made of tempered glass or semitempered glass, a light transmissive electrically conductive layer 5 which is provided on one surface side of the transparent substrate of high rigidity and which contains a metal having an electromagnetic wave shielding property and a near infrared ray shielding property, an antireflection layer 6 provided on a surface of the electrically conductive layer and an adhesive layer 7 provided on another surface side of the transparent substrate of high rigidity. The planar display panel 1 of high rigidity is constituted by adhering the front surface protecting plate 3 of high rigidity to a visible side surface 2a of the planar display panel main body 2 via the adhesive layer 7.

Planar display panel of high rigidity

A process for producing an electromagnetic wave shielding filter, which comprises bonding a substrate (A) having an electrically conductive mesh layer on one side and a functional film layer (c) at the mesh layer (a) side by means of an adhesive layer (b), wherein the laminate disposed in the order of (a)/(b)/(c) is subjected to a fluid pressure treatment.

Hiroshi Wachi

Papers

Flat display panel with a front protection plate

Vulcanization of a Fluoroelastomer Derived from Tetrafluoroethylene and Propylene

Flat display panel

Planar display panel of high rigidity

Electromagnetic wave shielding filter and its production process