Abstract: Disclosed is a process for producing a titanium dioxide pigment used for a resin-coated paper type photographic support, comprising the following steps:(a) a step of adding at least one alkaline earth metal compound in an amount of 0.01-2.0% by weight in terms of a metal oxide based on the titanium dioxide before calcination step and(b) an acid-washing step of washing the titanium dioxide at acidic state after the calcination step and before a step of surface treatment with a hydrated metal oxide,and wherein particle size of the titanium dioxide pigment is 0.110-0.150 .mu.m shown by number-average diameter obtained by measuring the diameter in a certain direction using an electron microscope.A photographic support which comprises the above titanium dioxide pigment is also disclosed.Occurrence of die lip stain and microgrit are substantially restrained in this photographic support and a photographic material made of it shows improved image sharpness.

Abstract: A pneumatically operated screw driver having a pneumatically operated rotor rotatably supported in an outer frame. The rotor is only rotatable about its axis. A moving unit is slidably disposed within the rotor. The moving unit has an upper piston and is axially movable upon application of pneumatic pressure to the upper piston. The moving unit is also rotatable about its axis because of spline connection with the rotor. A valve is disposed for selectively applying the pneumatic pressure to the piston and to the rotor. Upon application of the pneumatic pressure, the moving unit is moved downwardly, and the pneumatic pressure is then introduced into the rotor for rotating the same. The rotation of the rotor is transmitted to the moving unit. The valve closes a fluid passage directing to the piston and to the rotor when the moving unit has the lowermost position.

Abstract: A combustion gas powered tool includes a member defining a part of cylindrical combustion chamber having an axis. A piston is movable in a direction along the axis of the combustion chamber. The piston defines the combustion chamber in conjunction with the member. A mixture of air and fuel is generated in the combustion chamber. The air-fuel mixture in the combustion chamber is burned to drive the piston. An orifice grille extends in the combustion chamber, and is parallel to the axis of the combustion chamber.

Abstract: A photographic support consisting essentially of a substrate and a resin layer provided on the image forming side of the substrate, said resin layer comprising a specific titanium dioxide pigment and others. This photographic support is excellent in that it has a high brightness and a high apparent whiteness and stability of the apparent whiteness is good; printed image of high sharpness can be formed thereon: and occurrence of die lip stain at production is quite little and thus it has good surface property.

Abstract: A pneumatic fastener driving tool includes a main valve operable to cause compressed air to be alternately introduced into and discharged from the upper piston chamber, a first passage leading the compressed air into the main valve chamber, a repeat valve disposed in the first passage for opening and closing the same, and a second passage extending between the lower piston chamber and a repeat valve chamber in which the repeat valve is reciprocably received. With this construction, the repeat valve is reciprocally movable in response to a change of pressure in the lower piston chamber to cause the main valve to reciprocate, thereby reciprocating the piston repeatedly. Since the reciprocating fastener driving movement of the piston is directly related to the reciprocating movement of the repeat valve, the fastener driving work can be achieved reliably without causing any operational failure such as a non-load striking.

Abstract: A pneumatic fastener driving tool including a start valve adapted to be open for start a fastener driving operation by pneumatically driving a driving rod forwardly, and a vent hole for connecting to start valve to atmospheric air to let compressed air escape to atmosphere when compressed air is accidentally supplied through the start valve after one cycle of fastener driving operation is completed due to bouncing of the piston, for example.

Abstract: A photographic support consisting essentially of a substrate and a resin layer provided on the image forming side of the substrate, said resin layer comprising a specific titanium dioxide pigment and others. This photographic support is excellent in that it has a high brightness and a high apparent whiteness and stability of the apparent whiteness is good; printed image of high sharpness can be formed thereon: and occurrence of die lip stain at production is quite little and thus it has good surface property.

Abstract: A fastener driving tool such as a pneumatic nailing machine drives a fastener into a workpiece under a fluid pressure supplied into an upper chamber in a cylinder and applied to a piston reciprocally movably disposed in the cylinder. When the fastener being driven is stopped in a power stroke of the piston due to a pressure shortage, the fluid flows from the upper chamber into a lower chamber in the cylinder to make the pressure in the lower chamber equal to or higher than the pressure in the upper chamber. No reactive forces are thus applied by the high pressure in the upper chamber to the fastener driving tool, and the fastener driving tool is prevented from being repelled back when the fastener is stopped. The fastener can then be driven home into the workpiece in successive power strokes of the piston.

Abstract: A double-side resin coated photographic support obtained by coating at least one polyolefin resin layer on a photographic emulsion layer side, an outermost polyolefin resin layer having a center line average surface roughness of 1.0 .mu.m or less, and passing the resulting resin coated base sheet between a cooling roll and a back-up roll under a special linear pressure is free from surface defects and excellent in surface smoothness.

Abstract: Disclosed is a photographic resin coated paper which is excellent in surface quality. This photographic resin coated paper comprises a paper or synthetic paper substrate having on at least one surface a layer of resin composition comprising a reisn and a titanium dioxide pigment which is prepared by the external seed method and milled by a fluid energy mill. The titanium dioxide pigment is preferably surface treated with an inorganic surface treating agent such as hydrous aluminum oxide. The resin is preferably a thermoplastic resin such as a polyolefin resin.

Abstract: Disclosed is a photographic material which comprises a synthetic plastic film, a polyolefin layer provided on one surface of the plastic film, an image forming layer provided on said polyolefin layer and layer (A) which contains at least one of carboxy-modified polyethylene, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer and polyolefin and which is provided on another surface of the synthetic plastic film opposite to the image forming layer side, the surface of said polyolefin layer which contacts with the image forming layer being a roughened surface and the surface of the layer (A) being a mirror-like surface.

Abstract: There are disclosed photographic materials which comprise a synthetic plastic film such as a polyester film having on one surface a resin layer comprising a resin composition containing at least 50 parts by weight (based on the total weight of the resin layer) of a polyolefin which has undergone at least one kneading or a resin layer comprising a resin composition containing 50 to 95 parts by weight (based on the total weight of the resin layer) of said polyolefin and 5 to 50 parts by weight (based on the total weight of the resin layer) of a high-density polyethylene.Further disclosed is a photographic material which comprises a synthetic plastic film having on one surface a layer of the above composition and on another surface a resin layer which contains at least one of carboxy-modified polyolefin, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer and polyolefin.

Abstract: A polyolefin resin composition containing 5 to 150 ppm of an antioxidant and a high-concentration (e.g. 40 to 80% by weight) titanium dioxide pigment is diluted with a polyolefin resin to prepare a medium-concentration (e.g. 20 to 60% by weight) titanium dioxide pigment-containing photographic master batch, then this master batch is further diluted with a polyolefin resin to form a low-concentration (e.g. 5 to 20% by weight) titanium dioxide pigment-containing resin composition, and this resin composition is melt extruded and coated on a support made of paper or a synthetic paper to produce photographic resin coated paper. According to this process, both die lip staining and formation of microgrits are prevented.

Abstract: In preparing a polyolefin resin coated paper for photographic use which comprises melt-extruding and coating a polyolefin resin composition containing titanium dioxide onto at least one surface of a paper sheet or a synthetic paper base, a polyolefin resin composition comprising polyolefin resin and titanium dioxide surface-treated with 0.2 to 1.2 wt % (calculated as Al.sub.2 O.sub.3) of hydrous aluminum oxide based on titanium dioxide is employed as the polyolefin resin composition. By the use of such a polyolefin resin composition, problems on operation and quality due to generation of die lip stains could be solved without causing any quality problem such as photodeterioration, or the like.

Abstract: A power driven percussion tool is provided with a rotatable magazine block formed with a plurality of bores about the axis of rotation of the magazine block and is loaded with fasteners such as rivets or nails respectively retained in the bores. When the magazine block is stepwise rotated about its axis the bores are successively brought into alignment with the direction in which the fastener can be driven by a reciprocating hammer. The percussion tool is further provided with safety means for disabling the tool when the tool is not in use or being re-loaded with fasteners.