Receiver sheet

Carbonless Copy Paper. In carbonless copy paper, also referred to as pressure-sensitive record sheet, an acid-sensitive dye precursor, such as crystal violet lactone or /V-hen2oy11eucomethy1ene blue, is microencapsulated with a high boiling solvent or oil within a cross-linked gelatin (76,83,84) or in synthetic mononuclear microcapsules. Microcapsules that have a starch binder are coated onto the back of the top sheet. This is referred to as a coated-back (CB) sheet. The sheet intended to receive the image is treated on the front (coated-front (CF)) with an acid. When the top sheet is mechanically impacted, the dye capsules mpture and the dye solution is transferred to the receiving sheet where the acid developer activates the dye. 

Color intensity and permanence are improved by metal carboxylate salts, especially 2inc salts (83), which cataly2e the dye development and stabili2e the dye in its colored form. The substituted novolak resin, along with extender and binder, can be apphed to the receiving sheet as a solution or aqueous dispersion. Aqueous dispersions are probably the most widely used they are manufactured by the resin suppher or the user from the base resin. 

The first instant color photography system, introduced by the Polaroid Corp. in 1963 as Polacolor, used the transfer of subtractive dyes to a receiver sheet to produce a positive image. The incorporated dye-developers, containing a hydroquinone moiety, are soluble in the alkaline activator solution, except where silver development occurs, when they are immobilized as the quinone form. 

Termination of the process is effected by the acid polymer layer of the receiving sheet. Acting as an ion exchanger, the acid polymer forms an immobile polymeric salt with the alkah cation and returns water in place of alkah. Capture of alkaUby the polymer molecules prevents deposition of salts on the print surface. The dye developers thus become immobile and inactive as the pH of the system is reduced. 

Fig. 18. Schematic cross sections of Copycolor negative and receiving sheet. During processing dyes are released by reduction in the unexposed areas. Dyes...

Polacolor images, stability of, 19 298 Polacolor Pro film, 29 301-302 Polacolor Pro peel-apart film, 29 299 Polacolor receiving sheet, 29 299-300 Polacolor system, 29 241-242 Polado, 23 38-39 Poland... 

According to the high resolution spectra (Fig. 3), the apparent percentage of the ester species (286.5 eV) appears smaller than that of the carbonyl species (288.6eV) on both DOS-and ATBC-oiled sheets, indicating the contribution of the contamination by adventitious hydrocarbon species. The measured percentage of the carbonyl carbon of as-received sheets is 10.9 % for DOS and 18.0 % for ATBC, those of which roughly correspond to the calculated ratios of DOS (9.2 %) and ATBC (21.0 %), respectively. But the effect of contamination makes it difficult to have further insight into the deviation from the calculated values. 

Without a doubt the best known of the instant colour photographic processes is that invented and developed by the Polaroid Corporation. " The original Polacolor system led to the famous Polaroid SX-70 system in 1972. This is a dye diffusion system involving a dye developer in a tripack negative arrangement, placed on top of a receiver sheet, as shown in Figure 2.30. 

The color bases can also be sublimed image-wise from a transfer ribbon onto an acid-developing receiver sheet. They then form the yellow component in color-transfer prints [5],... 

Someone in Orchem research management had conceived an idea for a better product. The weakness of spirit duplication systems was that the wax sheets inevitably leaked color onto the hands of the people who handled them. Secretaries hated them, as the intense colors in the wax matrix transferred to clothing, causing severe staining. Why not have a leucodye, i.e., a colorless precursor of a dye present in the wax layer, and moisten the receiver sheet with an alcoholic solution of an oxidant For a variety of reasons, the preferred oxidant was chlor-anil (tetrachlorobenzophenone), an inexpensive, colorless, and effective material (Scheme 4.6). Unfortunately, this compound also gave rise to hydrochloric acid... 

U) the receiving sheet and the liquid film which has coated it excess hydrocarbon must be stripped off to prevent its carryout into the environment ... 

The crosslinked image areas are then insoluble in solvents. The soluble noncrosslinked areas can be removed with solvent or chemical action to provide relief patterns or images. Alternatively, the change in thermal properties on exposure can be utilized. The crosslinked areas are less easily thermally softened than are the unexposed areas. Thus the unexposed and thermally softened areas can be transferred by pressure to a receiving sheet to give a positive image. Proper choice of the polymeric binder and the monomeric acrylate or methacrylate permits control over the ultimate physical properties of the exposed and unexposed photo-... 

Both covers were then removed from the exposed microporous samples before the samples were placed on the receiver sheet and developed. Microencapsulated media does not need to be covered during exposure. 

This technology involves the transfer of dye from a coated donor ribbon to a receiver sheet via sublimation and diffusion, separately or in combination. The amount of dye transferred is proportional to the... 

An AA3105 aluminium alloy of 0.5 mm thickness was used as the substrate the alloy composition is given in Table 8.1. Specimens of dimensions 50x100 mm were cut from the as-received sheets. 

After uv exposure through an original transparency the sheet was contacted for 5 sec at 125° with an image-receiving sheet of white paper coated with 0.2 mg/m Ag as Ag behenate, 400 mg/m phthalazinone, and 40 g/m 2,6-di-tert-butyl-4-methylphenol in poly(tert-butyl methylate) binder. A copy having a sharp pos. black image was obtained. App. 4/9/1970. 

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