Abstract: In a family of side-chain homopolymers of the polyacrylate type derived from 1-(phenyl)-2-(4-cyanophenyl)-ethane and exhibiting one or a number of mesophases, the polymer in accordance with the invention corresponds to the following general chemicals formula: ##STR1## where x indicates the degree of polymerization and 2.ltoreq.n.ltoreq.15.

Abstract: The invention pertains to a capacitor of a thermostable polymer film type. The polymer used is polyphenylquinoxaline or polyhydantoin. The polymer film may be obtained by casting with organic solutions. The capacitor can also be obtained with supporting films covered with metallizations coated with this thermostable polymer.

Abstract: The invention relates to a group of organic compounds of the substituted 2-hydroxyfluorene ester type, which has a smectic A mesomorphous phase. The invention also relates to the process for producing molecules of this group.The compound according to the invention is in accordance with the general chemical formula ##STR1## whereby n can be between 1 and 15 and X=Br or CN. The invention applies to the field of liquid crystals and to display means using such crystals.

Abstract: The polymer material is made from a first monomer and from a second monomer. The first monomer Ar includes at least one aromatic nucleus and the second monomer is a five links conjugated heterocyclic ring. The polymer material has the following general chemical formula: ##STR1## in which: X represents the group constituted by sulphur and selenium; R.sub.1 and R.sub.2 are chosen from the group constituted by hydrogen, and by the alkyl, alkoxyl, and hydroxyl groups; and n is the degree of polymerization. Such materials can be made conductive by adding a doping agent, and they can then be used for manufacturing electrodes, junctions, Schottky barriers, etc.

Abstract: Multiple shocks of a vertically falling mass against a target member coupled with the earth are prevented by holding the mass and retaining it above the target member after its first bounce. This retention is accomplished by means of deformable elements laterally pressed against the mass body by jack rods actuated in response to a control signal produced by a sensor at the moment of the first impact of the mass.

Abstract: A process wherein certain disc-like liquid crystals, which locally undergo heating and then rapid cooling on either side of the transition temperature between two mesophases permit the liquid crystal to become diffuse with an adequate contrast to be used for display purposes. The following liquid crystals can be utilized, i.e.

Abstract: A family of negative resins, capable of undergoing crosslinking under the effect of more or less energetic photons (gamma radiation, X-rays, ultraviolet or visible light), applicable to the protection of objects against atmospheric agents and to the production of masks of the type used in the production of integrated circuits. The typical compound according to the invention contains at least one substance of which the chemical formula comprises a thiirane ring: ##STR1## such as 2,3-epithiopropyl methacrylate copolymerized with a vinyl monomer, such as methyl methacrylate. Crosslinking is facilitated by photoinitiators, such as aryl diazonium and aryl iodonium salts liberating Lewis acids. By selecting the photoinitiator, it is possible to act on the spectral region where irradiation is effective.

Abstract: Cholesteric liquid crystals of the so-called reentrant mesogenic type obtained by mixing a substance such as a cholesterol ester having molecules of the "chiral" type with a liquid crystal of the so-called reentrant nematic type such as a substance corresponding to the general formula: ##STR1## where R is an alkyl or alkoxy or alkylcarbonate group with:R'=H or CH.sub.3and X is an organic radical such that CH=N, CH=CH, C.tbd.C or COO.The use of a liquid crystal in accordance with the invention serves to obtain a temperature-detecting device in which, in contrast to conventional cholesteric devices, the reflected light changes from blue to red when the temperature rises.

Abstract: The present invention relates to data-carrier intended for the high-density recording of information by the use of an etching radiation beam. The data-carrier comprises a substrate upon which there are deposited a very thin film which is absorbent at the wavelength of the etching beam, and a film which is thermodegradable at a temperature lower than the degradation temperature of the absorbent film, the heat developed in the absorbent film being selectively diffused towards the adjacent thermodegradable film.

Abstract: A family of liquid crystals having a type A smectic mesophase with a positive dielectric anisotropy, which are particularly useful in the case of the thermo-optical effect.The substances of the family are in accordance with the general formula: ##STR1## in which R represents an organic group of the alkyl or alkoxy type containing 1 to 15 carbon atoms and in which X and Y designate either the bromine or the nitrile radical.

Abstract: Optical fiber communication systems require a light source to be coupled to a fiber with good alignment, with low risk of fiber breakage, and with a hermetic seal of around the coupling zone. Elastically deformable clamping and sealing rings around the fiber and within a metal sleeve housing the source are known. The invention employs two soft deformable rings spaced apart by a rigid bushing. The rings have conical surfaces compressed between corresponding conical surfaces in the sleeve. Axial alignment of the fiber is achieved with a minimum of interfaces to obtain a good seal.

Abstract: The dielectric spacer between the conductive electrodes of an electrical capacitor is a biaxially oriented film made from a mixture of less than 80 percent by weight of isotactic polypropylene and more than 20 percent by weight of isotactic polybutene-1.

Abstract: A mixture of liquid crystals having a mesophase of the disc-like with wires-type, where a sensitivity to the electrical field can be observed and application can be made to visual display cells. The mixture comprises two hexasubstituted triphenylene derivatives, to the nucleus of which are fixed six identical radicals in positions 2, 3, 6, 7, 10 and 11, which can be alkyl, alkoxy, alkylcarboxylate, alkylbenzoate, and alkoxybenzoate radicals. The electro-optical devices can either be of the variable birefringence type when the liquid crystal molecules have their optical axes parallel to one another and to the walls of a display cell, or of the type with a variable rotatory power under the action of an electrical field when a helical type arrangement is used, or finally, under the effect of a relatively strong field, of the type with dynamic light diffusion.

Abstract: A family of negative resins, capable of undergoing crosslinking under the effect of more or less energetic photons (gamma radiation, X-rays, ultraviolet or visible light), applicable to the protection of objects against atmospheric agents and to the production of masks of the type used in the production of integrated circuits. The typical compound according to the invention contains at least one substance of which the chemical formula comprises a thiirane ring: ##STR1## such as 2,3-epithiopropyl methacrylate copolymerized with a vinyl monomer, such as methyl methacrylate. Crosslinking is facilitated by photoinitiators, such as aryl diazonium and aryl iodonium salts liberating Lewis acids. By selecting the photoinitiator, it is possible to act on the spectral region where irradiation is effective.

Abstract: A resin crosslinkable by electron or photon irradiation (gamma rays, X-rays or ultraviolet rays), which is (after crosslinking) very stable under the action of ambient light and heat. It contains a substance the chemical formula of which comprises a thietane ring: ##STR1## notably a compound of the methacrylic ester polymer type wherein the monomer has the general formula: ##STR2## wherein n may be zero or equal to an integer from 1 to 10. The process for using such a resin consists of dissolving it in a solvent, then applying a thin layer of the solution on the object to be coated and finally treating the coating by irradiation.

Abstract: Two members, at least one member being permeable to ultraviolet radiation are glued together by means of a photopolymerizable substance deposited in layer form on and exposed to radiation through the permeable member. This substance comprises various vinyl monomers, soluble reactive polymers and a photosensitive catalyst, whereby at least one of the monomers or reactive polymers has a thi-irane cycle as part of its structure.

Abstract: The permanent electric polarization is imparted to the sensitive element by electronic bombardment within an enclosure wherein prevails a rarefied atmosphere and in which said bombardment is followed with a coating of the so-polarized sensitive element with a film of liquid of very low saturating vapor pressure whose dielectric strength is higher than that of the rarefied air of the enclosure and having advantageously lubricating properties.

Abstract: A family of negative resins, capable of undergoing crosslinking under the effect of more or less energetic photons (gamma radiation, X-rays, ultraviolet or visible light), applicable to the protection of objects against atmospheric agents and to the production of masks of the type used in the production of integrated circuits. The typical compound according to the invention contains at least one substance of which the chemical formula comprises a thiirane ring: ##STR1## such as 2,3-epithiopropyl methacrylate copolymerized with a vinyl monomer, such as methyl methacrylate. Crosslinking is facilitated by photoinitiators, such as aryl diazonium and aryl iodonium salts liberating Lewis acids. By selecting the photoinitiator, it is possible to act on the spectral region where irradiation is effective.

Abstract: The invention concerns a substance of diester type, i.e. an organic compound with three benzene nuclei joined by --COO-- groups, exhibiting at least one mesomorphic phase of smectic type.The substance of the invention answers to the formula: ##STR1## where R.sub.1 is an alkyl or alkoxy radical and R.sub.2 an alkyl. In the case where R.sub.1 is an octyl and R.sub.2 a pentyl there is a dielectric isotropy frequency of 30 kHz, i.e. a frequency where the dielectric anistropy changes sign.Application to field-effect display devices with dual-frequency memory.

Abstract: The invention relates to an organic compound having an enantiotropic or monotropic mesomorphous phase.