Abstract: In order to manufacture sealing gaskets for receptacles containing aggressive chemical substances, one known technique consists in coating a film of PTFE or other plastic material onto rubber. However, in the past, it has been possible to ensure that the film adheres adequately to the rubber only by making use of an intermediate glue. The present method causes a film of PTFE to adhere directly on a sheet of rubber by treating one of the faces of the PTFE film by the corona effect and then rolling the treated film against the rubber while still raw and vulcanizing the resulting laminated structure.

Abstract: An electret fiber sheet has polarized charges on its surface and preferably has charges in ordered orientation across it. The polarized charges are present in an amount of at least 7.times.10.sup.-11 C/cm.sup.2. Such sheets are formed to have a dust collecting efficiency. Sheets having an amount of polarized charge even as high as this are nevertheless stable when they have a maximum orientation energy of depolarization of at least 0.2 eV.Such an electret sheet can be obtained by a process comprising placing a fiber sheet between a non-contact type voltage-application electrode and an earth electrode confronting each other and supplying electricity (voltage>3 kV; current density>1.times.10.sup.-6 mA/cm.sup.2) between the electrodes, provided that the fiber sheet has a weight less than 80 g/m.sup.2 and a covering factor at least 60%.

Abstract: Inorganic powders are coated with a thin film of an organic polymer formed on the individual particles by plasma polymerization. The film thickness may be not more than 100 .ANG., and the inorganic powders include magnetic ones.

Abstract: A multi-layered article is provided wherein at least one of the layers is made of an inert material that strongly resists adherence of adhesives thereto. The inert substrate of the multi-layered article has a thin plasma deposited film thereon, and an adhesive layer bonds another substrate to this thin plasma deposited film.

Abstract: This invention relates to a process for the treatment of synthetic plastic, hydrophobic, transparent, intraocular lenses to avoid trauma which causes protein adhesion to occur on the surface of the lens thereby causing endothelial cell damage and corneal deterioration. The process includes the first step of cross-linking the surface of the synthetic plastic, hydrophobic, transparent, intraocular lens by treating the lens with a stream of gas containing from about 5-100% by weight hydrogen of a low pressure of about 0.5-5 Torr in the presence of an A.C. electrical discharge. The second step involves treating such cross-linked surface with hydroxyl radicals, thereby to hydrophilize the surface. The hydrogen may be pure or a component of an inert gas mixture, e.g. in helium.

Abstract: The surface of a product molded of polyolefin is washed with a fluorine-containing organic solvent such as CCl.sub.2 F--CCl.sub.2 F or CCl.sub.2 F--CClF.sub.2 and, thereafter, the product surface is treated with a plasma. Since the product surface is washed with an organic solvent containing fluorine, wastewater and process operation can be controlled with relative ease. A painted product pretreated by the process of the invention has a high peel strength and water resistance.

Abstract: A vinyl chloride-based resin is compounded with a filler, e.g. calcium carbonate, having been treated on the surface with an epoxy compound such as 3-glycidyloxypropyl trimethoxy silane in advance and the resin composition is shaped into an article which is then subjected to a low temperature plasma treatment. The thus obtained shaped article is imparted with remarkably improved surface properties such as decrease in the phenomenon of plasticizer bleeding and the effect is very durable even after prolonged outdoor exposure of the article.

Abstract: Disclosed is a method of producing implantable prosthetic devices, e.g., tubular vascular prostheses having a substantially non-thrombogenic inside surface and a biocompatible outside surface. The method involves deposition onto an elongate substrate, e.g., a porous tubular substrate, of a fluorine-containing coating by inducing glow discharge progressively along the length of a tubular reaction vessel. A polymerizable fluorine-containing gas is flowed through the tubular substrate and a portion of the gas migrates radially to traverse the pores of the substrate. An RF field is applied to successive volumes of the gas within the vessel and tube. A substantially non-thrombogenic fluorinated coating with a first fluorine to carbon ratio deposits and bonds to the inside surface of the substrate, and a fluorinated biocompatible cross-linked coating with a lower F/C atomic ratio than the inside coating deposits and bonds to the outside surface of the substrate.

Abstract: A process for producing a plasma polymerized film, which comprises forming a plasma polymerized film on the surface of a substrate placed in a reaction zone by subjecting an organic compound containing gas to plasma polymerization utilizing low temperature plasma formed by pulse discharging, in which the time for non-discharge condition is at least 1 msec. and the voltage rise time for gas breakdown is not longer than 100 msec. The plasma polymerized film obtained has a small coefficient of friction, high lubricity, durability and heat resistance and is useful as a solid lubricating film, etc.

Abstract: A solid sheet of adhesive hydrophilic gel which is a homogeneous aqueous mixture, substantially free of unbound water, monomers and crosslinking agents, consisting essentially of an amount dispersed uniformly in water of from about 4 to 35 wt % of a crosslinked polyethylene oxide, effective to form with the water a tacky surfaced viscoelastic solid which sheet of hydrophilic gel is produced by subjecting a liquid film of an aqueous solution having a viscosity of about 2-2,000.times.10.sup.3 cps of a linear water soluble polyethylene oxide having a weight average molecular weight from about 0.02-6.times.10.sup.6 Daltons to an amount of high energy radiation effective to convert the liquid film to a sheet of the viscoelastic solid having an adhesive face.

Abstract: A pyroelectric and isotropic piezoelectric polymeric film, the film being formed from a blend of polyvinylidene fluoride and at least one polymer miscible therewith at a temperature above the melting point of the polyvinylidene fluoride, and a process for preparing the film comprising forming the film, heating it to a temperature sufficient to render the film substantially amorphous, cooling at a rate and to a temperature sufficient to prevent crystallization, and polarizing the film to render same pyroelectric and isotropically piezoelectric.

Abstract: A porous article is prepared by subjecting a substantially non-porous polymeric shaped article containing from about 1.0-30% of plasticizer to a plasma treatment under conditions such that the plasticizer is volatilized or decomposed into gaseous decomposition products thereby creating an internal pore structure while leaving the surface of the article essentially intact and free from microscopically visible pores.

Abstract: The disclosed method provides an electret filter having a permanent electrostatic charge and formed of polymer fibers having an intrinsic viscosity of 1.5 or less. Fibers of the requisite viscosity are formed into a non-woven fabric and fed, at room temperature, through a gap between a discharge electrode and a ground electrode while being tightly pressed against the ground electrode. The ground electrode preferrably presents a polished metal surface for contact with the web.

Abstract: Methods are disclosed for stabilizing poled piezoelectric and pyroelectric polymer films by exposing the poled film to a glow discharge at a reduced pressure for a sufficient period to thereby remove unwanted and unstable homo- and hetero-charges from the poled film.

Abstract: The invention provides a shaped article of a fluorine-containing synthetic resin having improved surface properties such as increased wettability with water, printability, susceptibility to adhesive bonding and less accumulation of static electricity. The improved shaped article is obtained by subjecting the surface of the article to exposure to low temperature plasma generated in a low pressure atmosphere of a nitrogen-containing gaseous organic compound such as amines, imides and amides.

Abstract: Surfaces of hydrophobic polymers are treated to reduce their friction resistance characteristics when in contact with an aqueous environment by exposing the surfaces to an oxidation treatment, preferably by use of radio frequency glow discharge. This oxidation is followed by exposure to atmospheric air, until there is a substantial reduction in the air-water contact angle of the surfaces. The reduced friction resistance characteristics are important in aqueous applications where there is movement between the surfaces of two polymeric materials, such as in double slideable catheters and similar medical products. This process also provides lower coefficients of friction for general polymeric products in contact with water and aqueous solutions.

Abstract: In plasma-treating the inner surface of a plastic tube, the invention provides a treating method which ensures stable treatment under readily operative conditions. The present invention relates to a method comprising the steps of placing a plastic tube inside an electrically insulating tube wherein the difference between the inner diameter of the insulating tube and the outer diameter of the plastic tube is equal to or less than 2 mm, letting a gas into the plastic tube, keeping the inner pressures of both tubes at a reduced pressure, applying a high voltage across electrodes disposed outside the electrically insulating tube to initiate and sustain discharge only inside the plastic tube and thereby plasma-treating the inner surface of the plastic tube.

Abstract: In organic substrates having a surface coating including a first layer of plasma-polymerized alkane and a top layer of plasma-polymerized polar organic compound exhibit improved wettability and hydrophilicity, and a method for applying such coatings to the surfaces of inorganic substrates to improve their hydrophilicity and wettability characteristics.

Abstract: Polymers having a substantially completely fluorinated surface of low surface energy and substantially free of oxygen and having a thickness up to about 200 Angstroms, the remainder of the polymer comprising a non-fluorinated polymer.

Abstract: Direct electrical current is passed through a chemically precipitated industrial wastewater sludge to enhance the settling rate, filterability, and dewatering of the sludge.

Abstract: A process for forming a photoconductive organic film on a substrate by the plasma polymerization reaction of a mixture of an organic compound vapor and a carrier gas activated in a plasma producing region, comprises carrying out the plasma polymerization reaction in the presence of a halogen compound vapor.

Abstract: A novel method is proposed for improving the surface properties or, in particular, for reducing accumulation of static electricity on the surface of a shaped article of a vinyl chloride-based resin.The inventive method comprises first exposing the surface of the shaped article to low temperature plasma of a gas having no polymerizability in plasma and then bringing the plasma-treated surface into contact with a liquid which is inert to the resin, e.g. water, or an aqueous solution containing a surface active agent. The effect of the inventive method is so strong and durable that the treated surface remains anti-static even after 12 months after the treatment.

Abstract: The invention provides a novel method for preventing bleeding of a plasticizer or other additive ingredients contained in a shaped article of a vinyl chloride-based resin composition on to the surface of the article by the treatment with low temperature plasma. Different from conventional procedures for the plasma treatment, much improved reliability and reproducibility as well as effectiveness are obtained by subjecting the article to intermittent exposure to the plasma atmosphere instead of continuous exposure. In the inventive method, the overall treatment time is an alternate sequence of exposure times, each being of the length of 0.001 second to 1000 seconds, and repose times, each being also of the length of 0.001 second to 1000 seconds. The gas for the plasma atmosphere is desirably an inorganic gas selected from the gases other than oxygenic gases, halogen containing gases and sulfur containing gases.

Abstract: The undesirable phenomenon of bleeding of, for example, a plasticizer contained in a shaped article of a plasticized polyvinyl chloride resin on the surface of the article in a long-run use is effectively prevented by the inventive method and the effectiveness of the method is durable over a long period of time even when the article is used in an outdoor environment or under irradiation with ultraviolet light. The method of the invention comprises the first step of exposing the surface of the article to an atmosphere of low temperature plasma of an inorganic gas and then the second step of contacting the thus plasma-treated surface with a halogen or hydrogen halide, preferably, in gaseous state.

Abstract: Gramophone records made of a vinyl chloride based resin are subjected to a treatment with low temperature plasma of a gas having no polymerizability in the plasma condition. A markedly improved anti-static effect is imparted to the surface of the gramophone record which also becomes highly resistant to wearing so that the signal/noise ratio in playing of the gramophone record is remarkably improved even after many times of repeated playing of the record.

Abstract: A method for preventing bleeding of plasticizers on the surface of shaped articles of plasticized polyvinyl chloride resins. The method comprises the steps of (a) blending a urethane elastomer with the polyvinyl chloride resin together with the plasticizer and other optional additives prior to fabrication of the polyvinyl chloride resin composition into shaped articles, (b) fabricating the resin composition into desired shaped articles, and (c) subjecting the thus shaped article to a treatment with low temperature plasma of a gas. Carbon monoxide is preferred as the gas for the plasma atmosphere.

Abstract: Fluorinated low energy polymer surfaces are provided by fluorinating a hydrocarbon polymer with ions or radicals of fluorinated species in a cold plasma.

Abstract: A novel method is provided for placing a covering layer of a cured organopolysiloxane composition onto the surface of a shaped article of a vinyl chloride resin in order to improve or mask the defective surface properties of articles made of vinyl chloride resins. The method comprises treating the surface of a vinyl chloride resin article with a low temperature plasma of gas, placing a covering layer of a curable organopolysiloxane composition on the so-treated surface of the articles and subjecting the article with the curable organopolysiloxane composition to curing conditions for the organopolysiloxane composition. The adhesive bonding between the vinyl chloride resin article and the layer of the cured organopolysiloxane composition, e.g. cured room temperature-vulcanizable silicone rubbers, is so strong and durable that very long service life of the article is ensured in a variety of application fields.

Abstract: Electrodes are immersed within oil which forms a layer over a quantity of water. When current is passed between the electrodes which are held to a predetermined gap from the interstitial surface between the oil and water, water is caused to undergo electrodecomposition. Gaseous hydrogen is then recovered in the sealed space above the oil-water layers and the oxygen is caused to react with constituents in the oil layer.Consequently, there is produced continuously a quantity of hydrogen which is separately collected and is usable in gaseous form.

Abstract: An ionized gas plasma is established in an electrical field in contact with a non-vapor volume of monomer (liquid and/or solid). The plasma creates active polymerization sites in the monomer volume to initiate propagation of polymerization therein. After initiation, the partially-polymerized monomer volume is postpolymerized in the absence of the ionized gas plasma to yield a very high molecular weight polymer which may be essentially free of cross-linking in desirable forms including commercial quantities of bulk self-supporting polymer or a coating. Suitable monomers include liquid vinyl monomers (e.g., methyl, methacrylate) and solid crystalline monomers (e.g., 1,3,5-trioxane).

Abstract: The surfaces of organic and inorganic substrates, such as polyethylene film and metals, respectively, can be modified by cold plasma deposition of difluorocarbene or trifluoromethyl radical specie generated by subjecting precursor vapor, for example, perfluorocyclobutane or hexafluoroethane, to a radio frequency electrical glow discharge.

Abstract: An improved biological test apparatus has an organoplastic support surface which has been treated to become hydrophilic, said surface supporting an aqueous gel employed for the desired test mechanism. The hydrophilic treatment enables the aqueous gel to be in uniform close adherent contact with the support surface. This prevents the formation of an uneven gel thickness and improves the adherence of the gel to the support surface during storage and subsequent use.

Abstract: Trifluoromethyl-substituted compounds are formed in a corona discharge or glow discharge plasma of trifluoromethyl radicals from an organic trifluoromethyl source. A substrate possessing easily replaceable ligands such as halogen or carbonyl, is initially contacted either in the plasma and within a short distance from a downstream visible edge of the plasma or outside of the visible portion of the plasma and within a short distance from the downstream visible edge, to effect a substitution of the halogen or carbonyl ligand on the substrate with a trifluoromethyl radical without substantial decomposition of the substrate.