JPH01173031A - Reflecting photographic element having excellent glossy feel and its production - Google Patents

Abstract

PURPOSE:To obtain a reflecting element having excellent whiteness and resolving power by incorporating titanium oxide having 0.1-0.5mum average particle size into a white polyester film which has <=20% total visible light transmittance and does not contain particles having >=3mum diameter and coating a photosensitive silver halide emulsion layer on the surface thereof. CONSTITUTION:For example, the anatase-type titanium oxide having 0.35mum average particle size is prepd. into a water slurry of 400g/l concn. and 20pts.wt. such slurry and 80pts.wt. polyethylene terephthalate having 0.80 intrinsic viscosity are put into a unidirectionally rotating type twin-screw kneading extruder, by which the mixture is melted and kneaded, then pelletized. The particles having >=3mum particle size are substantially not included in the polyethylene terephthalate. The pellets are thereafter vacuum-dried for 6hr at 180 deg.C. The pellets are then extruded onto a rapid cooling rotary drum by using an extruder to form an amorphous sheet having 1.4mm film thickness. This sheet is stretched 2.6 times vertically at 95 deg.C and 3.0 times horizontally at 110 deg.C and is subjected to heat setting at 210 deg.C, following which the sheet is cooled. The white opaque film having 18mum thickness is thus obtd.

Description

[Detailed description of the invention]

[INDUSTRIAL APPLICATION FIELD 1] The present invention relates to a reflective photographic element and a method for manufacturing the same. Here, a reflective photographic element is a so-called transmission photographic element in which a photographic image is projected by transmitted light and the projected image is used, but an opaque material such as a support is used and a photographic layer is provided thereon. It refers to a photographic element, usually called a photographic paper, on which a photographic image formed on the photographic layer is directly viewed by reflected light. [Background of the Invention] Conventionally, as a support for reflective photographic elements, polyethylene-coated paper is generally used, which is a base paper made from pulp and a layer of polyethylene kneaded with a white pigment or the like. However, in reflective photographic elements using polyethylene-coated paper as a support, irregularities on the surface of the adjacent base paper support result in a rough, rippled, glossy surface that impairs the brightness, sharpness, and sharpness of the photographic image. Beauty is severely impaired. In addition, although both sides of the base paper of the support are coated with polyethylene F19119, which does not allow water to pass through, the cut surface of the base paper is not coated, so there are disadvantages such as the development processing solution seeps in from there, resulting in coloring. . As a method to overcome the above drawbacks, several methods have been proposed in which only a thermoplastic resin film is used as a support without using base paper.

[There is. JP-A-49-114921 and JP-B-55-5104 disclose a method of filling a borisdylene resin film with a white pigment, but these films are hard and
It has the disadvantage of being brittle. Polyester such as polyethylene terephthalate has excellent physical properties such as mechanical strength of this film, and techniques using this polyester include British Patent No. 1,563,591 and British Patent No. 1.563.
No. 592 discloses a method of adding barium sulfate to polyester and stretching the polyester. However, this method does not provide sufficient whiteness as a support for reflective photographic elements. This is clear from the extensive use of optical brighteners and other pigments in the examples of the same patent. Moreover, as a result of stretching, IIi! 1 When voids are created around FIQ barium particles and a photographic layer is applied 1
The resolution of one image is insufficient. Further, Japanese Patent Publication No. 56-4901 discloses a technique using barium tate and titanium oxide. In Retention 11, it is stated that saturated polyester resins are also suitable in addition to olefin resins, styrene resins, vinyl chloride resins, polyacrylate resins, polycarbonate resins, etc. as thermoplastic resins that can be used. However, it cannot be applied to polyester resins for the following two reasons. The first point is that the refractive index values of barium sulfate and polyester are close, and suitable whiteness cannot be obtained unless stretched.
The patent does not disclose anything about the case where it is added to polyester resin. Secondly, if titanium oxide is directly added to polyester resin and stretched, voids will be created around the particles, making it impossible to obtain suitable whiteness, and as mentioned above, the resolution of photographic images will also be insufficient. It had To improve these drawbacks, Japanese Patent Application Laid-Open No. 1986-11
No. 8746 has an average particle size of 0.1 to 0.5 for polyester.
Reflection photographic elements have been disclosed in which an emulsion is coated on a film with the addition of micrometer surface-treated titanium oxide and whose film thickness and total visible light transmittance are in specified ranges. Although the whiteness and resolving power of reflective photographic elements have been improved by the technique described in 1 above, there are drawbacks such as insufficient smoothness of the surface of the support film, the appearance of protruding defects, and a lack of gloss. Ta. These protruding defects are caused by insufficient dispersibility of titanium oxide, and when ordinary titanium oxide is used and mixed with polynisdel, the cross-wire conditions cannot be made too harsh and sufficient dispersibility cannot be obtained. I can't. The reason for this is that if the cross-wire conditions are made too severe, the polyester will thermally decompose and its molecular weight will decrease, and the melt viscosity required to disperse titanium oxide will be 1! This is because you will no longer be exposed. In order to solve these problems, the inventors of the present invention have made extensive studies and have arrived at the present invention. [Objective of the Invention 1 The first object of the present invention is to improve the whiteness of J3. The object of the present invention is to provide a reflective η true 51! element which has excellent resolution for photographic images, has no protruding defects in the rough edges, and has excellent gloss.The second object is to provide a method for producing the same. [Structure of the Invention] The first and second object of the present invention is to obtain an average particle diameter of 0.1 to 0.
Total visible light transmittance is 20% containing 5 μm titanium oxide
An LC reflective photographic element comprising a support made of the following white polyester film and having a light-sensitive silver halide photographic emulsion layer coated on at least one side thereof, wherein particles having a grain size of 3 μ1 or more are substantially contained in the support. This is achieved by means of a reflective photographic element which is characterized in that it does not contain. The second object of the present invention is to obtain particles having an average particle size of 0.1 to 0.0 μm after substantially removing particles with a particle size of 3 μm or more by wet or dry classification treatment and/or wet pulverization treatment.
5 μm titanium oxide and polyester are kneaded and a 1”J titanium oxide-containing polyester composition is melt-extruded,
This is achieved by a method for producing a reflective photographic element, which is then biaxially stretched and formed and coated with at least one light-sensitive photographic emulsion layer on the Lri-stretched biaxially stretched film. The present invention will be explained in detail below. In the present invention, the term "substantially no particles with a particle diameter of 3 μm or more in the support" means that an electron micrograph of a cross section of the support film is taken at a magnification of 10,000 times for 10 fields of view 11.
i! When the particle size distribution was measured by image processing of the awarded particle images, the number of particles with a particle diameter of 3 μm or more was 0.1% of the total.
Say the following: If particles with a particle size of 3 μm or more are present on or near the film surface, they will cause protruding defects on the film surface, and large particles will remain as defects even after the emulsion layer is coated, and if there are many such defects, a satin-like surface will occur. and lacks luster. Even particles smaller than 3 μm may cause protruding defects if present near the surface, so it is preferable not to contain particles of 2 μm or more, more preferably 1 μm or more. Wet classification processing involves suspending titanium oxide in a liquid that does not dissolve titanium oxide, such as water, and separating and removing particles larger than a certain particle size by utilizing the difference in sedimentation speed depending on the particle size. Depending on the method, it is classified into natural sedimentation method and centrifugal sedimentation method. Although either method can be used in the present invention, the natural sedimentation method is preferably used because of its high accuracy and simple equipment. There is no particular limit to the concentration of the suspension, but it is usually 100 to 70.
It is carried out in the range of 0o/l. Further, a dispersant such as sodium hexametaphosphate can be added to the suspension. Dry classification processing refers to a method of separating and removing particles of a certain particle size or more by utilizing differences in behavior depending on particle size in a gas such as air. Vines used for wind blowers, air separators, cyclones, etc. In the present invention, a wet classification process is preferably used over a dry classification process in terms of accuracy of classification, ease of handling, etc. Wet pulverization refers to an operation in which titanium oxide is pulverized in a liquid such as water that does not dissolve titanium oxide. Usually, a grinder such as a ball mill, vibration mill, or sand mill is used, and the sand mill type is most effective.The media used include glass beads, alumina beads, zirconia beads, and Ottawa sand, and many commercially available There are models. In the case of a sand mill, approximately 3 to 30 minutes is appropriate for the grinding time in the grinder. In the present invention, wet or dry classification treatment and wet pulverization 5111! I! Either one or both may be performed. The titanium oxide having an average particle diameter of 0.1 to 0.5 μm used in the present invention may be of the rutile type, rice oxide, or anatase type, but the anatase type is more preferably used because of its bluish color. The refractive index of titanium oxide used in the present invention (n −2,5
~2.75) is the refractive index of the polyester used in the present invention (for example, the refractive index of polyethylene terephthalate is approximately 1
．． 613), when used in the support of a reflective photographic element, it has excellent light reflection rJ4 ability and the resulting photographic image has a layered resolution. In the present invention, titanium oxide can be surface-treated. This surface treatment is Δffi,co. M(J, -ri, Sb, Si, Sn, Zn, 7
Hydroxides, hydrated oxides, and phosphorus of metals such as r? ! salt,
or inorganic treatment and/or fatty acid metal salt depositing one or more selected from basic la-acids, etc.
This is an organic treatment in which various coupling agents, alcohols, amines, siloxane polymers, various ester compounds, phosphoric acid compounds, etc. are adsorbed onto the surface of titanium oxide. In the present invention, dry or wet classification treatment and/or wet pulverization treatment may be performed before or after the titanium oxide surface treatment step, and the surface treatment may be both an inorganic treatment and an organic treatment. In some cases, it may be carried out between the inorganic treatment and the organic treatment. The polyester used in the present invention is not only a thermoplastic resin consisting only of polynisdel, but also a thermoplastic resin containing other polymers, additives, etc., to the extent that the resin properties of the main component polyester are not practically changed. Also included. The polyesters used in the present invention include aromatic dicarboxylic acids such as terewattaric acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, ethylene glycol, 1.3
- Polymers of condensates of propanediol, 1°4-butanediol, etc. with glycols, such as polyethylene terephthalate, poly1-ethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, etc., or copolymers thereof can be mentioned. As the polyester used in the present invention, polyethylene terephthalate (hereinafter abbreviated as PET) is preferable. PET film does not penetrate water, has excellent smoothness, and has excellent mechanical properties such as tensile strength and tear strength. It has excellent dimensional stability such as heat shrinkage, and also has excellent chemical resistance during development processing. Polynisder used in the present invention has an intrinsic viscosity of 0 when measured at 20°C in a mixed solvent of phenol/1.1.2.2-tetrac00ethane (60/40 weight ratio).
．． 4 to 1.0 is preferable, more preferably 0.5 to 0.
It is 8. In the present invention, the proportion of titanium oxide contained in the polyester is determined from the viewpoint of whiteness, stretchability, etc. of the support film.
0 to 50 parts by weight is preferable, more preferably 15 to 3 parts by weight.
The total visible light transmittance as a support film is 2 at 0 weight part.
Add so that the amount is 0% or less. In the present invention, "Ul'l!" One or more inorganic pigments used as white pigments in the chemical tanning industry, such as zinc oxide, barium sulfate, silica, talc, and calcium carbonate, can be used in combination with titanium chloride. However, the amount of white pigment that can be used in AT must not exceed 101 parts per 10011 parts of the polyester of the present invention. In the present invention, when the titanium oxide is kneaded with polyester, the polyester is kneaded in a molten state. In the present invention, the kneading machine for blending titanium oxide into polyester includes an extruder with a rotor or blades for kneading, a twin-screw kneading extruder that rotates in the same or different directions, and a -shaft type conti extruder. Continuous mixers such as a Nyusu kneader, batch mixers such as a three-roll, pan-bari mixer, Henschel mixer, and kneader are used. Among them, a co-rotating continuous twin-screw fit kneading extruder is preferably used because it allows continuous kneading while applying strong shearing force. In the present invention, the polyester composition obtained by the above-mentioned cross-crossing may be formed into a -H pellet and then subjected to film forming, or may be subjected to film forming in a molten state. Further, in either method, the composition may be molded as it is based on the amount of Ia, or a composition with a high pigment i of 11 degrees, a so-called masterbatch, may be prepared and this may be diluted and molded. The polyester composition obtained by cross-wiring is extruded through a slit die in a molten state onto a film forming tool, and after being grounded on a rapidly cooling surface such as a rotating drum to form an amorphous sheet, the glass transition humidity (T( The film can be stretched sequentially or biaxially simultaneously in one direction in the longitudinal or transverse directions in a temperature range of 130°C or above.At this time, the mechanical strength of the film support, 4 to 16 times the area ratio, more preferably 6
It is preferable that the stretching is performed in a range of 12 to 12 times. After stretching, it is preferable to carry out heat setting and heat relaxation. In addition, when applying a ¥U membrane, it is preferable to filter with an appropriate grade filter. The film thickness of the film support of the present invention determined above is 50
~300μm is preferable, more preferably 75~250μm
It is μl. If it is thinner than 50 μm, it will not be stiff as a support and will wrinkle easily. Moreover, if the thickness exceeds 300 μm, there will be disadvantages such as being too thick and making it inconvenient to handle. The film support of the present invention may contain other commonly used additives, such as optical brighteners, dyes, ultraviolet absorbers, antistatic agents, etc., to the extent that they do not impair the purpose of the present invention. . At least one light-sensitive silver halide photographic emulsion layer is coated onto the formed, opaque, and whitened film support of the present invention as described above. In this case, if necessary, prior to coating the light-sensitive silver halide photographic emulsion layer,
A surface activation treatment such as fi and/or a subbing layer can be applied. As a coating method for the light-sensitive silver halide photographic emulsion layer, extrusion coating and curtain coating, which allow two or more layers to be coated simultaneously, are particularly useful. Further, the coating speed can be arbitrarily selected, but from the viewpoint of productivity, a speed of 50 coats/1 nm or more is preferable. The reflective photographic element of the present invention can be applied to any photographic element that uses a support, for example, there are no limitations such as black and white or color, and even in the photographic constituent layers, a light-sensitive silver halide photographic emulsion layer, an intermediate There are no particular restrictions on the number and order of the layers, protective layer, filter layer, bank coat layer, etc., and the invention can be applied. In the present invention, the light-sensitive silver halide photographic emulsion layer is
It is a usual silver halide emulsion layer, and for example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide emulsion, etc. can be preferably used. Additionally, this layer can contain a coupler for creating a color image, and it is also possible to contain a hydrophilic polymeric substance other than geladine as a binder, such as polyvinyl alcohol, polyvinylpyrrolidone, etc. It is. Furthermore, the silver halide emulsion layer can be sensitized in the photosensitive wavelength range by cyanine dyes, merocyanine dyes, etc., and may also contain various other photographic additives, such as antifoggants, gold, silver, etc. Chemical sensitizers, hardeners, antistatic agents, and the like can be preferably added. Therefore, the present invention is effective whether the reflective photographic element of the present invention is developed in black and white or in color. [Examples] Specific examples of the present invention will be described below, but the present invention is not limited to these embodiments. Anatase type titanium oxide with an average particle size of 0.35 μm is
A water slurry with a J degree of 40 h/l was prepared and classified by a natural sedimentation method. At this time, the particle size to be removed is 1 μII.
Processing was performed by changing the thickness of I, 3 μIn, 5 μm, and 10 μm. 20 parts by weight of the titanium oxide thus obtained and 80 parts by weight of polyethylene terephthalate having an intrinsic viscosity of 0.80 were melted and mixed in a co-rotating twin-screw kneading extrusion II (70M53/60 manufactured by Automatic Co., Ltd.) and then pelletized. . This pellet I was vacuum dried at 180°C for 6 hours, then melted in an extruder and extruded from a slit die onto a rapidly cooling rotary drum to form an amorphous sheet with a film flp of 1.4n+1, and then longitudinally rotated at 95°C. The film was stretched 2.6 times in the transverse direction at 100° C., then 3.0 times in the transverse direction at 100° C., then heat-set at 210° C. and cooled to obtain a white opaque film support with a thickness of 180 μm. The total visible light transmittance of these films was 5.0% in all cases. An electron micrograph of the cross section of the obtained film was taken at 10.00
10 m field of view at 0x magnification, and the obtained image is analyzed using an image analysis device (Japan Avionics TV-IP2000 model)
The image was processed using the following methods, and the particle size distribution was measured. Particle size 3μm
Table 1 shows the ratio of the number of particles to the total number of particles. After coating this film with a subbing layer consisting of a terpolymer of styrene-butane-maleic anhydride, a co-discharge is applied, and on top of this a halogenated terpolymer of styrene-butane-maleic anhydride is applied. Silver photographic emulsion with a dry film thickness of 15 μm
A reflective photographic element was prepared. (Samples No. 1 to 4) The whiteness, resolution, and protrusion defects of these samples were measured as follows, and the measurement results are shown in Table 1. [11Il Standard Method 1 Whiteness...The reflective photographic element sample is developed without being exposed to light, and the spectral luminosity of the white background area that is exposed to 101: I 3
20 type (measured with Hitachi (manufactured by 1) 380-18
Spectral reflectance of 0IIIll according to JIS-Z-8722 (
The whiteness (L value) was calculated according to the method (1982). Resolution: heavy line for measuring resolution on the reflective photographic element sample
After baking and exposing -1-, it was developed in the usual way, and the optical temperature difference of the double line print image was measured with a microdensitometer 1] DM-5 (manufactured by Roku Konishi). , the value expressed by the following formula was taken as the Ml power: Density difference resolution between [)llaX and Dllll of the double line print image of 5 wood/I1m = x
o. (%) QllaX of heavy line print image of 0.1 wood/mm
and [)win density difference protruding defect...reflection photo IN! ! The number of visible surface projections on the raw sample 100c1 was counted and evaluated according to the following criteria. O~5 pieces/100c1y...O flatness is the best. 6 to 30 pieces/100c, y...0 Excellent stability. 31~100111111/1100C'...Δ
Flatness is not very good. 101 or more/100 CI'...×Poor flatness. If the level is 0 or higher, there will be no problem on Okawa, and the reflection with a glossy feel will be the real element. At a level below Δ, the surface looks 1F rough and lacks luster. Table 1 From the results in Table 1, it can be seen that the samples of the present invention have excellent whiteness and resolution, have few protruding defects, and have a glossy appearance. [Effect of the invention 1 As explained above in li'FIIl, the present invention provides t
Compared to reflective photographic elements, reflective photographic elements that use conventional plastic film as a support have a whiter color, better resolution of photographic images, and fewer protruding defects and a more glossy appearance. It will be done.

Claims (2)

[Claims] (1) A light-sensitive silver halide photographic emulsion layer on at least one side of a support made of a white polyester film with a total visible light transmittance of 20% or less and containing titanium oxide with an average particle size of 0.1 to 0.5 μm. 1. A reflective photographic element coated with a reflective photographic element, characterized in that said support does not contain substantially any particles having a particle diameter of 3 μm or more. (2) Polyester is obtained by kneading titanium oxide with an average particle size of 0.1 to 0.5 μm from which particles with a particle size of 3 μm or more have been substantially removed by wet or dry classification treatment and/or wet pulverization treatment and polyester. A reflective photographic element characterized in that a polyester composition containing titanium oxide is melt-extruded and then biaxially stretched, and at least one light-sensitive silver halide photographic emulsion layer is coated on the biaxially stretched film obtained. manufacturing method.