Abstract: Surface properties or, in particular, antistatic performance of a shaped article of a synthetic resin can be remarkably and lastingly improved by the exposure of the surface to low temperature plasma in two steps, in one of which the plasma is generated in an atmosphere containing a nitrogen-containing organic compound, e.g. amine, amide and the like compounds, and in the other of which the plasma is generated in an atmosphere containing a fluorine-containing organic compound, e.g. fluorinated hydrocarbon compounds. Alternatively, the plasma treatment is undertaken in one step with low temperature plasma generated in an atmosphere containing both of the nitrogen- and fluorine-containing organic compounds.

Abstract: A continuous vacuum treating apparatus having a vacuum treating chamber for continuously treating the surface of a plastic molding under a vacuum, and at least one auxiliary vacuum chamber disposed at each of the upstream and downstream sides of the vacuum treating chamber. Each auxiliary vacuum treating chamber includes a pair of seal rolls contacting each other, means for effecting seals between the seal rolls and cases over the entire axial lengths of the rolls, and means for effecting seals between both end surfaces and the cases.

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: An arc-welding method, which comprises: arc-welding objects of welding together along the line of a groove formed between said objects of welding by continuously moving a welding electrode along the line of said groove while reciprocating said welding electrode in the width direction of said groove; characterized by: calculating at prescribed time intervals, for each one reciprocation of said welding electrode in the width direction of said groove, deviations (I-Io) of values (I) of one of arc current and arc voltage from a previously set reference value (Io), for each of left-side deviations (L) and right-side deviations (R) relative to the vertical plane which passes through the center of amplitude of said one reciprocation of said welding electrode and is parallel to the line of said groove; calculating at said time intervals, when said welding electrode moves over the left side of said groove relative to said vertical plane, differences (L-R) between said left-side deviations (L) and the immediately prece

Abstract: A welding method comprises rotating a nozzle (3) provided with a welding electrode (9) eccentrically from the center axial line (a) thereof within a groove (2). The center axial line (a) of the nozzle is aligned with the center of the groove (2) by smoothing values of variation in welding current or welding voltage for each of the left and right half cycles of the nozzle and controllably moving the nozzle horizontally at right angles to the welding direction so that the difference between these values becomes null. The height of the nozzle (3) relative to the groove (2) is maintained at a prescribed distance by smoothing values of variation in welding current or welding voltage and controllably moving vertically the nozzle (3) so that the difference between the thus smoothed value and a set value becomes null.

Abstract: In an automatic arc-welding method, which comprises: continuously moving a carriage along the longitudinal direction of a groove formed between the objects of welding; reciprocally moving in the width direction of the groove a welding electrode directed substantially vertically to said groove through a welding torch fitted to said carriage, following the groove face of said groove; producing an arc between the top of said electrode and said groove; moving said torch vertically up and down so that the value (E.sub.v) of the arc voltage or arc current agrees with a previously set value (E.sub.o); on the other hand, continuously detecting a vertical position of said torch as a value of voltage (e.sub.Y) indicated by a potentiometer; reversing the direction of movement of said torch in the width direction of said groove at the moment when said value of voltage (e.sub.

Abstract: The invention provides a novel means for solving and overcoming the problems in the magnetic recording tapes caused by the accumulation of static electricity during travelling of the tape affecting the quality of the reproduced sounds and picture images by playing the tape. The inventive method comprises providing at least one surface of the plastic-made film base with a layer of a plasma-polymerized gaseous compound of a specific type by exposing the surface of the film base to the atmosphere of low temperature plasma generated in the low pressure atmosphere of the gas or vapor of a compound such as an amine, organosilane, aliphatically unsaturated compound and aromatic compound, preferably, before coating the film base with a magnetic coating composition. The plasma-polymerized layer is effective to decrease the surface resistivity of the film base and to reduce the accumulation of static electricity induced by rubbing.

Abstract: In a rotary arc-welding method which comprises: directing a nozzle substantially vertically toward a weld zone of objects of welding; feeding a consumable welding electrode through said nozzle eccentrically from the center axis of said nozzle toward said weld zone; feeding welding current to said consumable welding electrode to produce an arc between the tip of said consumable welding electrode and said weld zone to weld said objects of welding with each other by means of the arc heat; rotating said nozzle to cause a circular movement of said arc from the tip of said consumable welding electrode corresponding to the eccentricity thereof; and, feeding a shielding gas toward said weld zone to shield said arc and said weld zone from the open air; the improvement characterized in that: the diameter of said consumable welding electrode is limited within the range of from 0.8 to 1.

Abstract: An arc-welding method comprises reciprocally moving a welding electrode substantially vertically toward a groove formed between objects of welding, in the width direction of the groove, following the face of the groove; producing, by a welding torch, an arc between the tip of the electrode and the groove; moving the torch vertically up and down so that one of an arc voltage and arc current of the arc agrees with a previously set value; continuously detecting the vertical position of the torch as a value of voltage indicated by a potentiometer; and reversing the direction of the movement of the torch in the width direction of the groove at the moment when the detected value of voltage agrees with a previously set value of voltage.

Abstract: The invention provides a novel method for modifying the surface properties, e.g. antistatic performance and anti-wearing resistance, of a disc-like shaped article made of a vinyl chloride-based resin such as a gramophone record by treating with low temperature plasma so as that the surface of the record is rendered antistatic and the noise generation in playing of the record is remarkably decreased. Different from conventional methods, a great uniformity of the effect by the plasma treatment is ensured by the inventive method all over the surface of the record since the record is transferred through the space between two parallel arrays of electrodes, preferably, with rotation around its axis during the plasma treatment. The manner of connecting the electrodes to the terminals of the high frequency generator may be in two different ways.

Abstract: The invention provides a novel and efficient method for the improvement of the surface properties of a shaped article of a synthetic resin such as a vinyl chloride-based resin. In particular, the outstanding defective point of the plastic resin articles toward accumulation of static electricity on the surface is greatly reduced by the inventive method, in which the surface of the article is exposed to the low temperature plasma generated in a gaseous atmosphere containing an organic silicon compound followed, preferably, by contacting treatment with a halogen or a halogen compound such as hydrogen halides and halogen-containing organic compounds in a gaseous phase. The organic silicon compound in the gaseous plasma atmosphere is preferably diluted with a diluent gas which may be nitrogen, nitrogen oxides, ammonia or rare gases at a specified partial pressure.

Abstract: The invention provides a novel and efficient method for modifying the surface properties of a shaped article of a synthetic resin such as a polyvinyl chloride resin in which a remarkable anti-static effect is obtained on the surface so that accumulation of static electricity on the surface is greatly reduced. The inventive method comprises exposing the surface of the shaped article to a low temperature plasma generated in a gaseous atmosphere containing a nitrogen-containing organic compound such as an amine, acid amide, diamine and heterocyclic organic compound having at least one nitrogen atom in a molecule as the ring member at a pressure from 0.001 to 10 Torr. The gas or vapor of the above mentioned nitrogen-containing organic compound is preferably diluted with an inorganic gas.

Abstract: An arc welding method in which with a welding electrode being oscillated within the groove in the width direction thereof, the movement of the electrode in the upright or vertical direction is controlled to always maintain the arc length constant. The groove of a predetermined shape is subjected to arc welding with predetermined welding speed and wire feed speed so that when a half cycle of the electrode oscillation is completed, the height direction displacement of the electrode is integrated over the time to obtain a cross-sectional area S.sub.o described by the electrode and also an oscillation stroke X.sub.o made by the electrode is obtained, thus storing the cross-sectional area S.sub.o and the oscillation stroke X.sub.o. When the next half cycle is completed, a cross-sectional area S and an oscillation stroke X are similarly obtained so that the welding speed or the wire feed speed is controlled to vary and thereby to vary the cross-sectional area of metal deposition by an amount .DELTA.

Abstract: The invention provides a novel method for the preparation of a composite shaped article of a vinyl chloride-based resin clad with a coating layer of polyvinyl alcohol without the use of any adhesive agent. The method comprises subjecting the surface of the shaped article to exposure to an atmosphere of low temperature atmosphere, coating the thus plasma-treated surface of the shaped article with an aqueous solution of a polyvinyl alcohol and drying. The coating layer of the polyvinyl alcohol thus formed is so firmly bonded to the surface of the vinyl chloride-based resin shaped article that various advantageous properties are imparted to the shaped article.

Abstract: A novel method is proposed for improving the surface properties or, in particular, for increasing the affinity to water of the surface of a shaped article made of a silicone, e.g. a silicone rubber. The inventive method comprises first exposing the surface of the shaped article of the silicone to low temperature plasma of an inorganic gas and then bringing the plasma-treated surface into contact with a liquid inert to the silicone which is an aqueous solution containing a surface active agent. The treated surface retains sufficient affinity to water even 6 months after the treatment.

Abstract: The invention provides a novel method for obtaining a shaped article of a vinyl chloride-based resin which is markedly insusceptible to the undesirable phenomenon of exudation or bleeding of the plasticizer and other additive ingredients contained therein on to the surface of the article. The method comprises formulating the resin composition for the fabrication of the shaped article with an epoxy compound containing, preferably, at least 2% by weight of the oxirane oxygen in the molecule in an amount of at least 0.05% by weight based on the vinyl chloride-based resin and irradiating the shaped article with ultraviolet light having a substantial energy distribution in the wavelength region of 200 nm or shorter. The shaped article obtained by the inventive method is remarkably insusceptible to the plasticizer bleeding even after prolonged outdoor exposure or irradiation with ultraviolet light having wavelengths longer than 290 nm.

Abstract: A novel method is proposed for improving the surface properties or, in particular, for increasing the affinity to water of and for reducing accumulation of static electricity on the surface of a shaped article made of an acrylic 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 an aqueous solution containing a surface active agent. The effect of the inventive method is so strong and durable that the treated surface remains antistatic even 6 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 invention provides a novel method for modifying surface properties, e.g. liability to surface bleeding of plasticizers and other additives and affinity with water, of shaped articles of polymeric materials such as vinyl chloride-based resins and silicone rubbers by the treatment with low temperature plasma of a gas. The plasma treatment in the inventive method is carried out in two steps with the first step carried out in an atmosphere of oxygen and the second step carried out in a non-oxidizing gas such as argon and carbon monoxide. Different from the conventional methods of plasma treatment which suffer from poor reproducibility and low effectiveness, the inventive method can give good reproducibility and high effectiveness presumably owing to the removal of the surface stain in the first step plasma treatment.

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.