Abstract: Tape products for diverse end users are obtained by applying to a sheet backing a layer of normally tacky and pressure-sensitive adhesive (PSA) containing and completely surrounding resilient non-tacky hollow thermoplastic polymeric microspheres. When the PSA is permanently bonded to the backing and the exposed surface has an irregular contour, a removable and repositionable product results. When the PSA forms a continuous matrix that is strippably bonded to the backing and is 1 mm or more thick, the resultant product is a foamlike transfer tape or foam tape. Depending on the product, the PSA can contain from about 1/5 to about 2/3% of the microspheres by volume.

Abstract: The receptivity of shaped polymer articles (e.g., self-supporting films of polypropylene) to subsequently applied organic coatings is enhanced by exposure to an electrical discharge in the presence of a chlorocarbon or chlorofluorocarbon gas, thereby providing an extremely thin chlorine-containing surface layer in which the Cl:C ratio is inversely related to the distance from the face of the layer. Preferred embodiments of the invention include tape products in which the primed surface of the backing is coated with a pressure-sensitive adhesive or a low adhesion backsize.

Abstract: The receptivity of shaped polymer articles (e.g., self-supporting films of polypropylene) to subsequently applied organic coatings is enhanced by exposure to an electrical discharge in the presence of a chlorocarbon or chlorofluorocarbon gas, thereby providing an extremely thin chlorine-containing surface layer in which the Cl:C ratio is inversely related to the distance from the face of the layer. Preferred embodiments of the invention include tape products in which the primed surface of the backing is coated with a pressure-sensitive adhesive or a low adhesion backsize.

Abstract: The shrinkage of tape joint compounds, which normally comprise water, filler, and binding resin, is significantly reduced by minimizing the amount of water-absorbing materials such as attapulgite and hydroxyethyl cellulose. Comparable improvements can be made to spachtling compounds.

Abstract: Film-backed pressure-sensitive adhesive tape that resembles conventional creped paper-backed masking tape but can be torn cleanly with the fingers, is prepared by extruding an isotactic polypropylene film, passing it through the nip between a rubber roll and a water-cooled embossed steel roll at a temperature and rate such that predominantly crystalline film is obtained. The embossed roll imparts a ridge-and-valley configuration to one surface of the film, valleys extending crosswise of the tape and having a depth greater than half the total film thickness. When the smooth face of the film is coated with pressure-sensitive adhesive, the resultant tape can be torn readily, using only the fingers, in a straight line crosswise of the tape. When subjected to a stretching force in the machine direction (at right angles to the ridges and valleys), the tape elongates uniformly without "necking down.

Abstract: The invention primarily concerns a pressure-sensitive adhesive tape, the adhesive layer of which is filled with glass microbubbles and has a dark appearance by virtue of (1) the microbubbles are stained glass which preferably is dark, and (2) dispersed throughout the adhesive layer is a pigment or dye which preferably is dark. More broadly, the invention concerns any coherent article filled with stained-glass microbubbles. The glass of the microbubbles preferably has an ultraviolet window, permitting the article to be made by photopolymerizing a matrix filled with the microbubbles.

Abstract: Viscous oligomeric epoxy resins can be quickly cured at temperatures of 100.degree. C. by incorporating a hardener that is a blend of (a) the oligomeric reaction product of bisphenol A and bisphenol A monoglycidyl ether and (b) an imidazole. The cured resins are tough and resistant to both moisture and high temperatures. Prepregs, in which glass, graphite or polymeric organic fiber sheets are saturated with these resins, are particularly useful in the repair of damaged aircraft and aerospace structures.

Abstract: A wobbling water distributor head mounted at the end of an angularly disposed tubular water-transporting arm. The base of the distributor head is mounted loosely between spaced shoulders. The wobbling motion of the head causes the distributor arm to traverse a circular path. The area sprinkled is controlled by varying the distance between the shoulders as the distributor arm rotates.

Abstract: Heat-sealable sheet material for use in the fabrication of lapped-seam membrane. In a presently preferred construction, linear low density polyethylene film is adhered to one lateral border of cured polymerized EPDM composition; preferably the adhesive is protected with a removable liner, e.g., a polyester film until lapped-seam splicing is to be carried out. A transfer tape based on thermoplastic heat-sealable adhesive carried by a strippable liner also constitute part of the invention. The transfer tape is advantageously applied to a sheet of uncured EPDM compound and the resultant assembly subjected to heat and pressure to cure the compound and bond the heat-sealable adhesive firmly thereto.

Abstract: Glass microbubbles having, on a weight basis, a composition consisting essentially of 70-80% SiO.sub.2, 8-15% CaO, 3-8% Na.sub.2 O, and 2-6% B.sub.2 O.sub.3, and about 0.2-1.5% SO.sub.3 and having a CaO:Na.sub.2 O ratio of 1-3.5. These microbubbles, which are made of significantly less expensive raw materials than conventional products, can also be made with a higher percent "floaters" and a lower average density. Certain substitutions can be made for at least a portion of each of the first three oxides.

Abstract: A mulcher-chopper of the type in which a horizontally disposed blade is mounted on a driven vertical shaft within a comminuting chamber. The blade is provided with deep and sharp serrations, thereby increasing the effective blade length and enhancing efficiency. Desirably the blade is oriented at an angle so that rotation provides a downdraft that helps move material into the comminuting chamber. A rigid bar, or anvil, extends diametrically across the comminuting chamber, and the blade is juxtaposed thereto, thus providing a highly effective shearing action.

Abstract: Replacement of all or most of the coarse mineral in a coated abrasive product by a superior (and typically more expensive) mineral improves abrading performance significantly more than would be predicted. In some cases the performance is superior to that of products made with either mineral alone. The mineral is typically applied in two layers, substantially all of the coarse mineral being applied in the second layer. Superiority is defined in terms of a test that measures the comparative ability of different minerals to abrade cold rolled steel.

Abstract: Replacement of all or most of the coarse mineral in a coated abrasive product by a superior (and typically more expensive) mineral improves abrading performance significantly more than would be predicted. In some cases the performance is superior to that of products made with either mineral alone. Typically 5% to 30% of the total mineral weight is made up of the superior mineral.

Abstract: Heat-sealable sheet material for use in the fabrication of lapped-seam membranes. In a presently preferred construction, linear low density polyethylene film is adhered to one lateral border of cured polymerized EPDM composition; preferably the adhesive is protected with a removable liner, e.g., a polyester film until lapped-seam splicing is to be carried out. A transfer tape based on thermoplastic heat-sealable adhesive carried by a strippable liner also constitute part of the invention. The transfer tape is advantageously applied to a sheet of uncured EPDM compound and the resultant assembly subjected to heat and pressure to cure the compound and bond the heat-sealable adhesive firmly thereto.

Abstract: Improved imaging device for applying temporary indicia to substrate of the type having a base covered with a relatively light color, opaque, open cell microvoid-containing layer that is rendered translucent when the microvoids are filled with a liquid having a refractive index similar to that of the layer. The improvement in the imaging device involves insuring that the imaging liquid contains no substance having an evaporation rate less than about one-half of the liquid, thereby permitting the imaging device to be repeatedly applied to the same area of the substrate without leaving ghost images.

Abstract: The invention primarily concerns a pressure-sensitive adhesive tape, the adhesive layer of which is filled with glass microbubbles and has a dark appearance by virtue of (1) the microbubbles are stained glass which preferably is dark, and (2) dispersed throughout the adhesive layer is a pigment or dye which preferably is dark. More broadly, the invention concerns any coherent article filled with stained-glass microbubbles. The glass of the microbubbles preferably has an ultraviolet window, permitting the article to be made by photopolymerizing a matrix filled with the microbubbles.

Abstract: Improved correction fluid for obscuring indicia on sheet material. Such fluid, which normally comprises a solution of pigmented thermoplastic resin, is rendered capable of obscuring typed, xerographically copied, or written ink indicia by using a solvent system having a refractive index of 1.410 or less. A preferred non-flammable system includes 20-40 volume percent 1,1,2-trichlorotrifluoroethane and correspondingly 80-60 volume percent heptane.

Abstract: Pressure-sensitive adhesive capable of functioning as an adhesive for diaper closure tape, comprising a blend of specified portions of styrene:butadiene AB block copolymer, random SBR and/or milled natural rubber, and rosin ester tackifier of the type capable of tackifying butadiene-based rubbers.

Abstract: The pressure-sensitive adhesive layer of the novel tape, like that of Silver U.S. Pat. No. 3,922,464, comprises a copolymer of alkyl acrylate such as isooctyl acrylate and a small amount of emulsifier monomer. The novel tape differs from that of Silver by incorporating tackifier resin, thus better resisting lifting forces at elevated temperatures while also being cleanly removable.

Abstract: Durable, specularly reflective mirrors for solar reflectors or fluorescent lamp fixtures are formed by vapor-depositing silver on a polyester film and protectively covering it with a coating of transparent acrylate polymer containing a silver corrosion inhibitor such as glycol dimercaptoacetate. In a preferred embodiment a pressure-sensitive mounting adhesive is applied to the opposite face of the polyester film. Degradation of the polyester, and consequent bubbling of the adhesive, is reduced or eliminated by incorporating UV absorber in acrylate polymer that is applied as a second protective coating.