Abstract: A stacking and interleafing device for rolls of pressure sensitive adhesive tape has an inclined table adapted to hold a row of the rolls carried in a spaced relationship on a mandrel. The table supports a plurality of upright, parallel plates that separate the adjacent rolls. The plates maintain the rolls in a spaced apart relationship as the mandrel is drawn clear of the rolls and as they advance down the incline. An escapement mechanism mounted over the table successively transfers one row of stripped rolls from a storage portion of the table to a feeder portion of the table subtended by a movable drop-off mechanism. Translation of the drop-off mechanism gravity feeds the rolls, one at a time, and without contact between the rolls, to a conveyor system. A reciprocating shuttle plate receives the rolls from the conveyor system and successively carries each roll to a mandrel mounted on a rotatable stack forming arm. As the shuttle returns to receive another roll, the preceding roll drops onto the mandrel.

Abstract: Release agents for pressure-sensitive adhesive tapes comprise poly(amide acids), e.g., poly(N-fatty alkyl amide-acids) of the following recurring formula: ##STR1## wherein A is a divalent organic radical containing from 2 to 15, preferably 2 to 6, carbon atoms, R is a tetravalent organic radical containing at least 4 carbon atoms, R.sub.1 is hydrogen or an alkyl radical containing about 1 to 30 carbon atoms and R.sub.2 is an alkyl radical containing about 12 to 30 carbon atoms. When R.sub.1 is hydrogen, also provided are the corresponding cyclized imide products and mixtures of the polyamides and polyimides. These poly(amide acids) are formed by the reaction of tetracarboxylic acid dianhydrides and fatty diamines.

Abstract: A system for developing a latent electrostatic image pattern formed on a coated photoconductive paper and which utilizes a nonconductive transfer cylinder that encloses a rotating cylindrical magnet. The magnet produces a longitudinally uniform magnetic field at the outer surface of the cylinder that draws a polarized, magnetically attractable, one component toner material over the outer surface of the transfer cylinder from a toner supply means to a deposit zone over the paper. A roller, plate, or other suitable unit under the paper supports the paper with a uniform, preselected minimum spacing between the transfer cylinder and the electrostatic image pattern on the paper. In the deposit zone electrostatic forces and gravitational forces urging the toner material from the transfer cylinder to the paper exceed the magnetic forces holding the toner on the transfer cylinder causing the toner to deposit selectively in the image areas.

Abstract: The tendency of circular draw plates used in disc cartridges containing a magnetic disc memory to warp during fabrication is significantly reduced by a draw plate which includes two warp reducing apertures each spaced at an angle of 90.degree. from the posts along the circumference of said draw plate. An improved post is disclosed. The post includes a coarse knurl which is urged into a post aperture formed in the draw plate.A ring magnet in the bottom cover is also disclosed. The single ring magnet replaces several pot magnets of prior art cartridges and significantly reduces the cost of producing the disc cartridge. A U-shaped magnet cup into which a magnet is positioned concentrates the magnetic lines of force and thereby increases the magnet's magnetic efficiency.

Abstract: A copolymeric material is provided in accordance with this invention which is the reaction product of a di (omega-thio-organo) dimethyl siloxane oligomer having terminal active hydrogen groups and a difunctional organic compound having terminal isocyanate groups. The siloxane-thiourethane copolymer provides good release per se from tacky adhesive masses or when combined with other film formers.

Abstract: Release agents are provided which comprise the polymeric reaction product of a fatty diamine with a diisocyanate and, optionally, a diol. These polyurea and polycarbamate products have the following recurring formula: ##EQU1## WHEREIN A is an alkylene radical containing about 2 to 6 carbon atoms, B is an arylene radical containing about 6 to 16 carbon atoms, D is an aliphatic organic radical containing about 2 to 6 carbon atoms, R is an alkyl radical containing about 12 to 25 carbon atoms, R' is hydrogen or an alkyl radical containing about 1 to 25 carbon atoms, a and b represent the number of recurring units and the ratio of b/a varies from 0 to 2, and c is 0, 1 or 2. Also provided are pressure sensitive adhesive tapes and release liners utilizing these novel release agents.

Abstract: An adhesive composition suitable for application to a paper backing to form an adhesive tape comprising amylose pectin, a medium molecular weight starch, urea, a sugar or sugar alcohol, a neutralized polyacrylate and water. The composition can be applied to one surface of a paper backing to form an adhesive tape suitable to be wound as a roll without premature bonding and without loss of adhesive strength.