Radiation imagery chemistry: process – composition – or product th – Dye image from radiation sensitive dye or dye former by dry... – Developing latent image using radiant energy or heat
Reexamination Certificate
2000-07-31
2002-10-08
Seidleck, James J. (Department: 1711)
Radiation imagery chemistry: process, composition, or product th
Dye image from radiation sensitive dye or dye former by dry...
Developing latent image using radiant energy or heat
C430S332000, C430S334000, C430S338000, C428S480000, C524S366000, C524S378000
Reexamination Certificate
active
06461802
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a polyester film carrying in direct contact an adhesive layer and the use of such a film as support for photosensitive materials, e.g. photographic materials.
BACKGROUND OF THE INVENTION
In order to ensure a perfect adhesion of hydrophilic layers such as photographic light-sensitive emulsion layers to dimensionally stable polyester film supports, i.e. polyester films that have been biaxially stretched and heat-setted, it is known for long time to apply several intermediate layers between the support and the light-sensitive emulsion layer(s). In most cases two intermediate layers are needed. A first one, known as the adhesive layer or primer layer or resin subbing layer or latex subbing layer, shows a good adhesion to the polyester film and at the same time possesses good attaching properties in respect to the second layer, known as the subbing layer or gelatin subbing layer or gelatin sublayer, which usually is formed to a great extent of a hydrophilic colloid such as gelatin. For sake of uniformity we will further refer to the first intermediate layer defined above as the adhesive layer.
A preferred polyester film for use as support for imaging elements such as photographic materials is polyethylene terephthalate (PET). This and other polyester film supports are preferably biaxially stretched at an elevated temperature of e.g. 70-120° C., reducing their thickness by about {fraction (1/9)} to {fraction (1/16)} or more and increasing its area 9 to 16 times. The stretching may be accomplished in two stages, longitudinal and then transversal, or simultaneously. The adhesive layer, when present, may be applied by aqueous coating before or after the biaxial stretch or between the longitudinal and transversal stretch, in a thickness of 0.05 to 5 &mgr;m. An essential ingredient of this layer is an adhesion-promoting (co)polymer. In some preferred embodiments, disclosed e.g. in GB 1 234 755, GB 2 068 004 and EP 0 464 906, this (co)polymer contains as one of its structural units a monomer comprising covalently bound chlorine. Examples of said homopolymers or copolymers suitable for use in the adhesive layer are e.g. polyvinyl chloride; polyvinylidene chloride; a copolymer of vinylidene chloride, an acrylic ester and itaconic acid; a copolymer of vinyl chloride and vinylidene chloride; a copolymer of vinyl chloride and vinyl acetate; a copolymer of butylacrylate, vinyl acetate and vinyl chloride or vinylidene chloride; a copolymer of vinyl chloride, vinylidene chloride and itaconic acid; a copolymer of vinyl chloride, vinyl acetate and vinyl alcohol etc. Further patents disclosing such (co)polymers include U.S. Pat. Nos. 2,627,088, 2,698,235, 2,698,240, 2,943,937, 3,143,421, 3,201,249, 3,271,178, 3,443,950 and 3,501,301.
The adhesive layer is preferably coated from an aqueous medium which is ecologically and economically advantageous. Relatively little is published about the surfactants, also called coating aids or wetting agents, used in the coating solution of the adhesive layer. In the examples of GB 1 533 555 and GB 1 571 583 ULTRAVON W is disclosed as surfactant for the coating solution of the adhesive layer. ULTRAVON W, registered trade mark of Ciba-Geigy, is the disodium salt of heptadecylbenzimidazole disulphonic acid.
Depending on the actual composition there is a some cases a tendency to the formation of repellency spots in the coated and dried adhesive layer when ULTRAVON W is used as surfactant. A repellency is a round, or comet-shaped indentation or crater, or a vestige of such a disturbance which has partially healed after formation. Imperfections of this kind are formed during the coating process or shortly thereafter when the coating composition is still fluid and mobile. When subsequent layers such as the gelatin subbing layer and the photosensitive layer are coated on top of the adhesive layer this imperfection can propagate in these other layers and become visible in the final developed image.
So there is a permanent need for new classes of surfactants which overcome or strongly reduce the tendency to the formation of repellencies in the adhesive layer.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a polyester film carrying in immediate contact an adhesive layer showing none or a very limited number of repellency spots.
It is a further object of the invention to provide imaging elements, in particular photosensitive elements, which use such an improved polyester film as support.
SUMMARY OF THE INVENTION
The objects of the present invention are realized by providing a polyester film carrying in direct contact an adhesive layer comprising an alkyl (poly)glycoside surfactant according to following formula (I):
C
n
H
2n+1
—O—(C
6
H
10
O
5
)
x
—H, (I),
wherein C
6
H
10
O
5
represents a monosaccharide unit,
n=5 to 20,
x represents an integer or fractal mean value between 1 and 4.
An imaging element, in particular a radiation-sensitive element such as a photographic element, using a polyester film as defined above also belongs to the scope of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The polyester film supports which can be advantageously employed in this invention are well known and widely used materials. Such film supports are typically prepared from higher molecular weight polyesters derived by condensing dihydric alcohol with a dibasic saturated fatty carboxylic acid or derivative thereof. Suitable dihydric alcohols for use in preparing polyesters are well known in the art to include any glycol wherein the hydroxy groups are on the terminal carbon atom and that contains from 2 to 12 carbon atoms such as, for example, ethylene glycol, propylene glycol, trimethylene glycol, hexamethylene glycol, decamethylene glycol, dodecamethylene glycol, and 1,4-cyclohexane dimethanol. Dibasic acids that can be employed in preparing polyesters include those dibasic acids containing from 1 to 16 carbon atoms. Specific examples of suitable dibasic acids include adipic acid, sebacic acid, isophtalic acid and terephthalic acid. The alkyl esters of the above-enumerated acids can also be used satisfactorily.
Specific preferred examples of polyester resins, which may be used in the form of webs or sheets are polyethylene terephthalate (PET), poly(cyclohexane 1,4-dimethylene terephthalate), and poly(ethylene naphtalate). The most preferred example is PET.
The thickness of the polyester film is not critical and depends on the application. For instance, polyester film of a thickness ranging between 0.05 to about 0.25 mm can be used with satisfactory results.
In a typical process for the manufacture of a polyester photographic film support, the polyester is melt extruded through a slit die, quenched to the amorphous state, oriented by longitudinal and transverse stretching, and heat set under dimensional restraint. In addition to being directionally oriented and heat set, the polyester film can also be subjected to a subsequent heat relax treatment to provide still further improvement in dimensional stability and surface smoothness.
The adhesive layer or latex subbing layer can be coated on top of the finished polyester film before or after the biaxial stretching or between the longitudinal and transverse stretching. It is the essence of the present invention that the coating solution from the adhesive layer contains, apart from the latex (co)polymer an alkyl-(poly)glycoside as surfactant.
The history, the synthesis of alkyl (poly)glycosides (APG's), and their industrial application as surfactants are extensively reviewed by W. von Rybinski and K. Hill in
Angewandte Chemie
(1998) Vol 110, p. 1394-1412.
The first alkyl glucoside was synthesized and identified by E. Fisher more than 100 years ago. In later developments, Fisher's early work which was concerned with the lower hydrophilic alcohols was extended to hydrophobic alcohols with longer alkyl chains, the typical fatty alcohols. In these industrial processes not pure alkyl monoglucosides but a complex mi
Boeykens Jozef
Mertens Patrick
Thillo Etienne Van
Vandaele Filip
Agfa-Gevaert
Guy Joseph T.
Nexsen Pruet Jacobs & Pollard LLC
Ribar Travis B.
Seidleck James J.
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