Fuji Photo Film Company, Limited

Yasushi Suga

Kiyoshi Kobayashi

Yoshinobu Katagiri

Kenji Nakajima

Kimiaki Miyamoto

Kazuhiro Oki

Masakazu Yoneyama

Tomokazu Yasuda

Takashi Nawano

Yasuhiko Tokimasa

Hidetomo Itoh

Shouji Nishida

Yoshihisa Noguchi

Toshimitsu Sasahara

Toshimitu Sasahara

In curtain coating for multiple layers consisting of lower most layer, uppermost layer and intermediate layer, using coating liquid having viscosity more than 300 mPas for one layer or more of multiple layers improves amazingly the curtain coating stability against disturbance such as passing spliced portion of running web. The one layer or more layers for which coating liquid having viscosity more than 300 mPas is to be used is selected from intermediate layer. The curtain coating stability is further improved by combining the high viscosity coating liquid for intermediate layer with other technologies such as electrifying web, heating web upstream of coating point and/or keeping web tension higher than some specified value.

Method of curtain coating

Before the start of coating, a deflector receives a curtain of a coating liquid free-falling from a coating hopper in order to prevent a continuously-running web from being coated with the coating liquid. At the start of the coating, the deflector is moved relatively to the coating hopper, so that the coating liquid can start to be applied to the web. A receding part is formed at the end of the deflector.

Curtain coating apparatus and method

A process for preparing a continuous optical compensatory sheet has the continuous steps of: coating a liquid of a resin for forming an orientation layer in a solvent on a surface of a moving continuous transparent film; drying the coated layer to form a transparent resin layer; subjecting the transparent resin layer to rubbing treatment to give an orientation layer; coating a coating liquid of a discotic compound in a solvent on the orientation layer to form a coated layer; drying the coated layer; heating the coated layer to form a discotic nematic phase, whereby a layer of discotic compound is formed; and winding up the transparent film.

Process for the preparation of continuous optical compensatory sheet

A curtain coating method and apparatus using a rotatable or slidable coating plate and in which a coating liquid freely falls in the form of a thin film from a hopper. The thin film collides with a web continuously running and circumferentially turning around a backup roller to coat the web. The coating plate is rotated or slid to retract so that the freely falling coating liquid reaches the web so as to coat the web after the freely falling coating liquid flows along a checking plate which is doglegged in section and provided on a forward end of the coating plate, thereby coating the web with an even thickness at the start of coating operations.

Curtain coating method and apparatus utilizing checking plate for

A coating method that is capable of rapid curtain coating without causing 'sagging' at high flow rates exceeding 4 cm.sup.3 /cm.sec. One or more layers of a coating solution are formed on a sliding surface, and a free falling curtain of the coating solution is allowed to impinge against a continuously running web. The web has a surface roughness of at least 0.3 .mu.m, the tip of the sliding surface forms an angle of 45.degree. to 120.degree. with respect to the horizontal, and the viscosity of the coating solution is adjusted to at least 90 cps for low shear rate, with the average for all layers formed being at least 80 cps.

Curtain coating method for eliminating sagging at high flow rates

A film applying method in which a coating solution is applied by a solution injector having an edge guide onto a support member as a freely falling coating film, includes forming a solution contact surface of the edge guide to have one of a radius greater than 1.0 mm or a width d greater than 0.7 mm when the coating solution has at least one of a viscosity greater than 45 cp and a dynamic surface tension difference greater than 8 dyne/cm. The edge guide solution contacting surface is narrowed to have a radius less than 1.0 mm or a width d less than 0.7 mm when the coating solution has at least one of a viscosity less than 45 cp and a dynamic surface tension difference less than 8. In a second embodiment, the coating solution is prepared to have at least one of a viscosity greater than 45 cp and a dynamic surface tension difference greater than 8 dyne/cm when the solution contacting part of the edge guide has either a radius r greater than 1.0 mm or a width d greater than 0.7 mm. Alternatively, the coating solution is prepared to have at least one of a viscosity less than 45 cp and a dynamic surface tension difference less than 8 dyne/cm when the solution contacting part of the edge guide has either a radius r less than 1.0 mm or a width d less than 0.7 mm.

Curtain coating method with reduced neck-in

A slide-hopper-type coating method in which the viscosity of the coating solution forming a free-falling curtain and the angle .alpha. which the front edge of the lip of the slide hopper forms with respect to the horizontal are selected with respect to the flow rate of the curtain in such a way that the line of contact between the curtain and the web is concave with respect to the direction in which the web travels. In addition, the angle .beta. which the extension of the curtain in the direction of its fall forms with respect to the direction of travel of the web at the point where the curtain is deposited on the web is preferably adjusted so that it is an obtuse angle not larger than 140.degree.. By satisfying these conditions, the coating method of the present invention is capable of extending the upper limit of coating speeds without causing 'sagging' in the range of high flow quantities of coating solution per unit length of curtain coat width.

Coating method

A silver halide photographic material comprising a support having thereon at least one light-sensitive silver halide emulsion layer, wherein the silver halide emulsion layer or another hydrophilic colloid layer contains a compound represented by the following general formula (I): ##STR1## wherein R.sub.1 and R.sub.2 each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, and at least one of R.sub.1 and R.sub.2 represents a substituted or unsubstituted hydrocarbon group, including an alkyl group having not less than 6 carbon atoms; L represents a divalent bonding group; and M represents a hydrogen atom or a cation.

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Kanagawa, Japan

Yasushi Suga