Abstract: Thermally coalescible acrylic resin plastisol or organosol dispersions of reduced viscosity and thixotropy result when 0.2 to 40% by volume of the total volume of the dispersion of a volatile solvent is incorporated in compositions comprising particles of single-phase, random acrylic polymers or copolymers dispersed in nonvolatile plasticizers. Incorporation of a nonvolatile photopolymerizable component provides photosensitive dispersions useful for making relief and planographic printing plates, photoresists, and the like.

Abstract: Thermally coalescible acrylic resin dispersions comprising particles of single-phase, surfactant-free, random acrylic polymers or copolymers, containing at least 80% by weight of acrylic units, dispersed in a surfactant-free medium that comprises a compatible liquid plasticizer that is nonvolatile at room temperature and is not a monomer of any of the polymeric components. Incorporation of a photopolymerizable, ethylenically unsaturated compound provides photosensitive dispersions useful for making relief and planographic printing plates, photoresists, and the like.

Abstract: Thermally coalescible acrylic resin dispersions comprising particles of single-phase, surfactant-free, random acrylic polymers or copolymers, containing at least 80% by weight of acrylic units, dispersed in a surfactant-free medium that comprises a compatible liquid plasticizer that is nonvolatile at room temperature and is not a monomer of any of the polymeric components. Incorporation of a photopolymerizable, ethylenically unsaturated compound provides photosensitive dispersions useful for making relief and planographic printing plates, photoresists, and the like.

Abstract: Photopolymerizable compositions or layers containing an ethylenically unsaturated compound, a photoinitiator or photoninitiator system, and at least one polymeric binder, at least half of the binder being cellulose acetate butyrate having a composition of 44 to 50 weight percent butyryl, 5.0 to 8.5 weight percent acetyl and 0.5 to 1.0 weight percent hydroxyl. The use of the specific cellulose acetate butyrates in photopolymerizable compositions improves cold flow resistance and processability, i.e., development. The compositions and layers are particularly useful in preparing dry film photoresists and solder masks.

Abstract: Thermally coalescible plastisols and organosols of the invention comprise dispersions of single-phase particles of random polymers or copolymers that comprise organic polyelectrolytes that contain at least 1% by weight of ionizable monomer or comonomer, dispersed in a medium that comprises a nonvolatile liquid that is compatible with the resin. Incorporation of a photopolymerizable, ethylenically unsaturated compound provides photosensitive plastisols and organosols useful for making relief and planographic printing plates, photoresists, and the like.

Abstract: Methyl methacrylate polymer powders especially suitable for making plastisols and organosols are prepared by an improved process comprising stepwise emulsion polymerization in aqueous media in the absence of emulsifiers and surfactants and in such manner that at least most of the monomer added at each step is consumed before the addition of the succeeding portion, followed by isolation of the polymer powder by evaporation of the latex at a temperature that is at least 30.degree. C., preferably 40.degree.-50.degree. C., below the glass transition temperature of the polymer.