Solvent imaging

Fig. 7 Chain conformations of a strong PE for varying conditions, a Simulated for f = 1/3, showing the influence of the Bjerrum length and solvent quality on the PE structure, b Bjemim length versus charge fraction in a poor solvent. Image reprinted with permission from Ref. [135]. Copyright Americal chemical society 2003...

Odor is of prime importance because a petroleum solvent is often used in closed rooms moreover, the idea of odor is tied instinctively in the public image to toxicity. Odor is a function of the solvent s composition and volatility. Generally, the paraffin hydrocarbons are less odorous while the aromatics are more so. 

After image transfer, the patterned resist must be readily and completely removable without substrate damage. The pattern often can be stripped from the substrate with a mild organic solvent. Proprietary stripper formulations or plasma oxidation treatments are utilized when the imaging chemistry or image transfer process has iasolubilized the pattern. 

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. 

The right-reading positive image resides on the receptor film after lamination, exposure through a positive, and wash-out of the unexposed areas with a solvent or aqueous developer. The four-color proof is built up by the sequential lamination, exposure, and development steps. 

Manual stencils are made by knife-cutting special film stencil materials. These consist of two plastic layers. The image to be printed is cut through one layer, and this part of the stencil is placed in contact with the underside of the screen. A solvent, which is insoluble in the ink but attaches the cut stencil to the screen, is appHed and then the backing layer is removed. Manual stencils can also be produced by drawing directly on the screens using special materials. 

Boron tribromide [10294-33A], BBr, is used in the manufacture of diborane and in the production of ultra high purity boron (see Boron, ELEMENTAL BoRON COMPOUNDS). Anhydrous aluminum bromide [7727-15-3], AIBr., is used as an acid catalyst in organic syntheses where it is more reactive and more soluble in organic solvents than AlCl. Tballium bromide [7789AOA], TlBr, is claimed as a component in radiographic image conversion panels (39). 

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